Thermally resistant polyamide resin composition and methods to enhance the thermal resistance properties of polyamide resin.

Abstract

Page 1 of 1 Summary of the invention. A polyamide resin component with heat-resistant properties that can... It can withstand high temperature environments for over 1000 hours at 200°C and is a component... A polyamide resin compound consisting of polyamide resin (A) and polyamide resin (B) with a ratio Lower oxygen permeability of polyamide resin (A) and mass ratio (A) / (B) of polyamide resin. (A) and polyamide resin (B) are 98 / 2-60 / 40 and contain metal cyanide salts of the compositional formula. Typical composition (Ax[M(CN)y]) 0.5-20 parts mass to total of polyamide resin (A) with polyamide. Resin (B) 100 parts by mass

Description

Heat-resistant aging polyamide resin composition and method for improving heat-resistant aging of polyamide resin The present invention relates to a polyamide resin composition having excellent heat-resistant aging properties. Prior art Polyamide resins have excellent properties such as mechanical properties, chemical resistance, and moldability, and have been widely used in various parts such as automotive parts, electrical and electronic parts, and industrial machinery parts. Polyamide resins are a type of resin with relatively excellent heat-resistant aging properties, but deterioration due to the action of heat and light is inevitable. As a method for improving heat-resistant aging properties, methods of adding copper halides, potassium halides, oxazole compounds, etc. as heat stabilizers have been known for a long time (for example, Patent Document 1). By these technologies, polyamide resins are used in parts for applications exposed to high-temperature environments of about 140 ° C in the fields of automotive parts, electrical, and electronic parts. However, for example, regarding the engine room of an automobile, in recent years, with the increase in engine output and the high density of parts, the environmental temperature in the engine room has become higher, and heat-resistant aging properties that have never been required are now demanded. On the other hand, methods of blending fine elemental iron into polyamide (Patent Document 2), methods of blending fine-dispersed metal powder into polyamide (Patent Document 3), methods of blending copper compounds and iron oxide into a mixture of two types of polyamides with different melting points (Patent Document 4), methods of blending heat stabilizers such as copper iodide and potassium iodide and composite oxides such as iron sesquioxide (including iron (II) oxide) (Patent Document 5), etc. have been proposed, and it is said that they have excellent heat-resistant aging properties even in high-temperature environments of about 200 ° C. However, in the methods of Patent Documents 2 and 3, there is a risk of ignition during the production of the composition, and the production is not easy. In the method of Patent Document 4, there is a drawback that the effect is exhibited only with a very limited composition. In the method of Patent Document 5, the heat-resistant aging properties, the stability of mechanical strength, and the reproducibility may be inferior, and there is room for improvement in each case. Japanese Patent Publication No. 7-47690, Japanese Patent Publication No. 2006-528260, Japanese Patent Publication No. 2008-527127, Japanese Patent Publication No. 2008-527129, Japanese Unexamined Patent Application Publication No. 2010-270318 To provide a method for improving heat aging resistance that can simply and stably impart heat aging resistance to a polyamide resin to withstand a high-temperature environment for a long time exceeding 1000 hours at 200°C, and further to provide a polyamide resin composition having excellent heat aging resistance and excellent mechanical properties obtained thereby. In order to solve the above problems, the present inventors have found that the blending of a metal cyanide salt can exhibit heat aging resistance. Furthermore, as a result of intensive research, it has been found that there is a high possibility that the metal cyanide salt improves the gas barrier property of the polyamide resin. Then, recalling that the gas barrier property should be further enhanced, the present invention has been achieved by searching for a polyamide resin that can be additionally blended with the base polyamide resin to enhance the gas barrier property. That is, the present invention is as follows. [1] A polyamide resin composition comprising a polyamide resin (A) and a polyamide resin (B) having a lower oxygen permeability than the polyamide resin (A), wherein the mass ratio (A) / (B) of the polyamide resin (A) to the polyamide resin (B) is 98 / 2 to 60 / 40, and 0.5 to 20 parts by mass of a metal cyanide salt of the following general composition formula (1) is contained with respect to a total of 100 parts by mass of the polyamide resin (A) and the polyamide resin (B). General composition formula (1) ··· A ｘ [M(CN) ｙ (In the general composition formula (1), M is at least one of transition metal elements of Groups 5 to 10 and Periods 4 to 6 of the periodic table, A is at least one of an alkali metal and an alkaline earth metal, y is an integer of 3 to 6, and x is a number obtained by (y - m) / a. Here, m is the valence of M and a is the valence of A.) [2] The polyamide resin composition according to [1], wherein M in the general composition formula (1) is iron. [3] The polyamide resin composition according to [1], wherein the metal cyanide salt of the general composition formula (1) is at least one selected from an alkali metal hexacyanoferrate (II) salt and an alkali metal hexacyanoferrate (III) salt. [4] The polyamide resin composition according to any one of [1] to [3], wherein the copper compound is contained in an amount of 0.0001 to 1 part by mass as copper based on 100 parts by mass in total of the polyamide resin (A) and the polyamide resin (B). [5] The polyamide resin composition according to any one of [1] to [4], wherein the polyamide resin (A) is polyhexamethylene adipamide. [6] A method for improving the heat aging resistance of a polyamide resin, which comprises a polyamide resin (A) and a polyamide resin (B) having a lower oxygen permeability than the polyamide resin (A), and the mass ratio (A) / (B) of the polyamide resin (A) to the polyamide resin (B) is 98 / 2 to 60 / 40, and 0.5 to 20 parts by mass of a metal cyanide salt represented by the following general composition formula (1) is contained based on 100 parts by mass in total of the polyamide resin (A) and the polyamide resin (B). General composition formula (1) ··· A ｘ [M(CN) ｙ (In the general composition formula (1), M is at least one of transition metal elements of Groups 5 to 10 and Periods 4 to 6 of the periodic table, A is at least one of an alkali metal and an alkaline earth metal, y is an integer of 3 to 6, and x is a number obtained by (y - m) / a. Here, m is the valence of M and a is the valence of A.) According to the present invention, a polyamide resin composition excellent in heat aging resistance, which can maintain high strength even for more than 1000 hours in a high temperature environment of 200°C, can be provided. The present invention will be specifically described below. ​The polyamide resin that can be used in the present invention is not particularly limited. For example, ring-opening polymers of cyclic lactams, polycondensates of aminocarboxylic acids, polycondensates of dibasic acids and diamines, and copolymers thereof can be mentioned. Specifically, aliphatic polyamides such as polycaproamide (polyamide 6), polyhexamethylene adipamide (polyamide 66), polytetramethylene adipamide (polyamide 46), polyhexamethylene sebacamide (polyamide 610), polyhexamethylene dodecamide (polyamide 612), polydecamethylene sebacamide (polyamide 1010), poly-lauryl lactam (polyamide 12), poly-11-aminoundecanoic acid (polyamide 11), aliphatic-aromatic polyamides such as polymetaxylylene adipamide (polyamide MXD6), polyhexamethylene terephthalamide (polyamide 6T), polydecamethylene terephthalamide (polyamide 10T), polyhexamethylene isophthalamide (polyamide 6I), polynonamethylene terephthalamide (polyamide 9T), polytetramethylene isophthalamide (polyamide 4I), and copolymers and mixtures thereof can be mentioned. Particularly preferred polyamides for the present invention include polyamide 6, polyamide 66, polyamide 6 / 66 copolymer, polyamide 66 / 6T copolymer, polyamide 6T / 12 copolymer, polyamide 6T / 11 copolymer, polyamide 10T / 11 copolymer, polyamide 6T / 6I copolymer, polyamide 6T / 6I / 12 copolymer, polyamide 6T / 610 copolymer, polyamide 6T / 6I / 6 copolymer. The polyamide resin in the present invention includes a polyamide resin (A) and a polyamide resin (B) having an oxygen permeability lower than that of the polyamide resin (A), and the mass ratio (A) / (B) of the polyamide resin (A) to the polyamide resin (B) needs to be 98 / 2 to 60 / 40. The polyamide resin (A) is not particularly limited, and for example, the polyamides exemplified above can be used. Among them, polycaproamide (polyamide 6), polyhexamethylene adipamide (polyamide 66), polyhexamethylene sebacamide (polyamide 610), polydecamethylene sebacamide (polyamide 1010), polyamide 6T / 11 copolymer, and polyamide 10T / 11 copolymer are preferred. Polycaproamide (polyamide 6) and polyhexamethylene adipamide (polyamide 66) are more preferred, and polyhexamethylene adipamide (polyamide 66) is particularly preferred. As an example of the combination, when the polyamide resin (A) is polyhexamethylene adipamide (polyamide 66), examples of the polyamide resin (B) include aliphatic polyamides such as polycaproamide (polyamide 6), polymetaxylylene adipamide (polyamide MXD6), polyparaxylylene adipamide (polyamide PXD6), polyhexamethylene isophthalamide (polyamide 6I), polytetramethylene terephthalamide (polyamide 4T), polypentamethylene terephthalamide (polyamide 5T), poly-2-methylpentamethylene terephthalamide (polyamide M-5T), polyhexamethylene terephthalamide (polyamide 6T), polynonamethylene terephthalamide (polyamide 9T), polyundecamethylene terephthalamide (polyamide 11T), polydodecamethylene terephthalamide (polyamide 12T), polyamide 6T / 12 copolymer, polyamide 6T / 11 copolymer, polyamide 6T / 6I copolymer, polyamide 6T / 6I / 12 copolymer, polyamide 6T / 610 copolymer, polyamide 6T / 6I / 6 copolymer and other semi-aromatic polyamides, polyhexamethylene hexahydroterephthalamide (polyamide 6T(H)), polybis(3-methyl-4-aminohexyl)methane terephthalamide (polyamide PACMT), polybis(3-methyl-4-aminohexyl)methane isophthalamide (polyamide PACMI), polybis(3-methyl-4-aminohexyl)methane dodecamide (polyamide PACM12), polybis(3-methyl-4-aminohexyl)methane tetradecamide (polyamide PACM14) and other amorphous polyamides. As the polyamide resin (B), it is preferably selected from polycaproamide (polyamide 6), polymetaxylylene adipamide (polyamide MXD6), and polyamide 6T / 6I copolymer in view of availability and effectiveness. The oxygen permeability of the polyamide resin can be determined based on the gas permeability data described in "Edited by Osamu Fukumoto, Polyamide Resin Handbook, Nikkan Kogyo Shimbun, p. 113, 1988", and the permacol values taught in "Written by M. Salame, Prediction of gas barrier properties of high polymers, 1986", "Polymer Engineering and Science, Vol. 26, No. 22, p. 1543-1546", "Written by J. Y. Park, D. R. Poul, Correlation and prediction of gas permeability in glassy polymer membrane materials via a modified free volume based group contribution method, 1997", "Journal of Membrane Science, Vol. 125, p. 23-39", etc. In addition, the oxygen permeability of the polyamide resin can be measured by the method described in the Examples section. The mass ratio (A) / (B) of polyamide resin (A) and polyamide resin (B) is 98 / 2 to 60 / 40, preferably 95 / 5 to 70 / 30, and more preferably 90 / 10 to 75 / 25. If the amount of polyamide resin (B) is less than 2 parts by mass, the compounding effect of polyamide resin (B) is difficult to exhibit, and if it exceeds 40 parts by mass, the original properties of polyamide resin (A) will be impaired. The polyamide resin composition of the present invention may contain other polyamide resins as long as polyamide resin (A) and polyamide resin (B) satisfy the above relationship and do not impair the effects of the present invention. The molecular weight of such a polyamide resin is not particularly limited, but it is preferable to use a polyamide resin having a relative viscosity of 1.7 to 4.5 measured at a concentration of 1% by mass and 25 °C in 98% (98% by mass) sulfuric acid. The relative viscosity of the polyamide resin is more preferably 2.0 to 4.0, and even more preferably 2.0 to 3.5. The metal cyanide salt in the present invention is represented by the following general composition formula (1). General composition formula (1) ··· A ｘ [M(CN) ｙ (In general composition formula (1), M is at least one of the transition metal elements of Groups 5 to 10 and Periods 4 to 6 of the periodic table, A is at least one of an alkali metal and an alkaline earth metal, y is an integer from 3 to 6, and x is a number determined by (y - m) / a. Here, m is the valence of M and a is the valence of A.) The metal cyanide salt may be a hydrate. In the above general composition formula (1), M is at least one of the transition metal elements of Groups 5 to 10 and Periods 4 to 6 of the periodic table. Preferred metal elements include Fe, Co, Cr, Mn, Ir, Rh, Ru, V, and Ni. Considering the valence of the metal element, Fe(II), Fe(III), Co(III), Cr(III), Mn(II), Mn(III), Ir(III), Rh(III), Ru(II), V(IV), V(V), Co(II), Ni(II), and Cr(II) are preferred, more preferably Co(II), Co(III), Fe(II), Fe(III), Cr(III), Ir(III), and Ni(II), and particularly preferably Fe(II) and Fe(III). Two or more metals may be present in the metal cyanide salt (for example, potassium hexacyanocobaltate(II) ferrate(II)). A is at least one of an alkali metal (for example, Li, Na, K) and an alkaline earth metal (for example, Ca, Ba). y is an integer from 3 to 6, and x is selected so that the metal cyanide salt is electrically neutral as a whole. That is, x is a number determined by (y - m) / a (here, m is the valence of M and a is the valence of A). In particular, y corresponds to the coordination number of M, 4 to 6 is preferred, and 6 is particularly preferred.) ​Examples of metal cyanide salts that can be used in the present invention include, but are not limited to, potassium hexacyanoferrate (II), potassium hexacyanoferrate (III), sodium hexacyanoferrate (II), sodium hexacyanoferrate (III), potassium hexacyanocobaltate (III), sodium hexacyanocobaltate (III), potassium hexacyanonickelate (II), calcium hexacyanocobaltate (III), potassium tetracyanonickelate (II), potassium hexacyanochromate (III), potassium hexacyanoiridate (III), calcium hexacyanoferrate (II), potassium hexacyanocobaltate (II), and lithium hexacyanocobaltate (III). More preferably, in terms of handleability and safety, potassium hexacyanoferrate (II), potassium hexacyanoferrate (III), sodium hexacyanoferrate (II), and sodium hexacyanoferrate (III) are used. In the present invention, the blending amount (content) of the metal cyanide salt is 0.5 to 20 parts by mass with respect to a total of 100 parts by mass of polyamide resin (A) and polyamide resin (B). Regarding the blending amount of the metal cyanide salt, the lower limit is preferably 1 part by mass, more preferably 1.5 parts by mass, and still more preferably 2 parts by mass. Regarding the blending amount of the metal cyanide salt, the upper limit is preferably 15 parts by mass, more preferably 13 parts by mass, and still more preferably 12 parts by mass. If it is less than 0.5 part by mass, there is almost no effect on the expression of heat aging resistance. Even if it exceeds 20 parts by mass, the effect of expressing heat aging resistance does not increase further. If the metal cyanide salt is 20 parts by mass or less, unlike metal particles or metal oxide particles, it has little adverse effect on mechanical properties, and particularly in a glass fiber reinforced composition, it can suppress the breakage of glass fibers, so it hardly reduces the mechanical properties. When the metal cyanide salt is a hydrate, this blending amount is considered as the mass of the compound including the water of hydration. In the present invention, in addition to the above-mentioned metal cyanide salt, a known heat stabilizer can also be used. In the description of the content of each of the following components, "a total of 100 parts by mass of polyamide resin (A) and polyamide resin (B)" is abbreviated as "100 parts by mass of polyamide resin". Examples of the copper compound that can be used in the present invention include copper acetate, copper iodide, copper bromide, copper chloride, copper fluoride, copper laurate, copper stearate, and the like. These copper compounds may be used alone or in combination. Copper acetate, copper iodide, copper bromide, and copper chloride are preferred, and cupric bromide is particularly preferably used. The content of the copper compound is 0.0001 to 1 part by mass as copper in the copper compound with respect to 100 parts by mass of the polyamide resin. If it is less than 0.0001 part by mass, the discoloration prevention effect in a more severe environment under a high-temperature atmosphere and ultraviolet irradiation is insufficient. If it is more than 1 part by mass, the discoloration prevention effect in the above-mentioned severe environment reaches a plateau, and there is also a concern that problems such as corrosion of the mold, the screw and cylinder of the extruder or molding machine may occur. A more preferable content is 0.0005 to 1 part by mass, and a further more preferable content is 0.0005 to 0.2 part by mass. When adding a copper compound, it is preferable to use an alkali metal halide compound such as potassium iodide and potassium bromide in combination. By using them in combination, precipitation of copper can be prevented. As a method of adding the copper compound, it may be added at any stage of the production of the polyamide resin, and the addition method is not limited. For example, it may be any method such as a method of adding it to the raw material salt aqueous solution of polyamide, a method of injecting and adding it into the molten polyamide during melt polymerization, or a method of melt-kneading using an extruder or molding machine after blending the granulated polyamide pellets obtained after completion of polymerization and the powder or masterbatch of the copper compound. Furthermore, in the present invention, auxiliary stabilizers such as antioxidants such as hindered phenol antioxidants, phosphorus antioxidants, sulfur antioxidants, amine antioxidants, and light stabilizers can be blended. As the hindered phenol antioxidant, known compounds can be used. These compounds can be used alone or in combination. Among such hindered phenol antioxidants, bifunctional or higher phenols are preferred, and semi-hindered types such as triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate] (IRGANOX 245) are preferred in terms of less discoloration. When blending the hindered phenol antioxidant, the blending amount (content) is preferably 0.05 to 3 parts by mass, more preferably 0.1 to 2 parts by mass, based on 100 parts by mass of the polyamide resin. If it is less than 0.05 parts by mass, the effect of preventing thermal discoloration is insufficient. On the other hand, if it exceeds 3 parts by mass, the effect may reach saturation or blooming on the surface of the molded product may occur. The phosphorus-based antioxidant is at least one selected from inorganic and organic phosphorus-based antioxidants. Examples of the inorganic phosphorus-based antioxidant include hypophosphites such as sodium hypophosphite and phosphites. As the organic phosphorus-based antioxidant, commercially available organic phosphorus-based antioxidants of the phosphite type can be used, but organic phosphorus-containing compounds that do not generate phosphoric acid by thermal decomposition are preferred. As such organic phosphorus-containing compounds, known compounds can be used. When blending the phosphorus-based antioxidant, the blending amount (content) is preferably 0.05 to 3 parts by mass, more preferably 0.1 to 2 parts by mass, based on 100 parts by mass of the polyamide resin. If it is less than 0.05 parts by mass, the effect of preventing thermal discoloration is insufficient. On the other hand, if it exceeds 3 parts by mass, flash may occur in the molded product. In the present invention, it is preferable to use inorganic and organic phosphorus-based antioxidants in combination because the blending amount of the antioxidant can be reduced. As the amine-based antioxidant that can be used in the present invention, known compounds can be used. Also, secondary arylamines can be cited as amine-based antioxidants. A secondary arylamine means an amine compound containing two carbon radicals chemically bonded to a nitrogen atom, and at least one, preferably both, of the carbon radicals are aromatic. When blending an amine-based antioxidant, the blending amount (content) is preferably 0.05 to 3 parts by mass, more preferably 0.1 to 2 parts by mass, based on 100 parts by mass of the polyamide resin. If it is less than 0.05 part by mass, the effect of preventing thermal discoloration is insufficient. On the other hand, if it exceeds 3 parts by mass, the effect may reach saturation or blooming on the surface of the molded product may occur. As the sulfur-based antioxidant that can be used in the present invention, known compounds can be used. When blending a sulfur-based antioxidant, the blending amount (content) is preferably 0.05 to 3 parts by mass, more preferably 0.1 to 2 parts by mass, based on 100 parts by mass of the polyamide resin. If it is less than 0.05 part by mass, the effect of preventing thermal discoloration is insufficient. On the other hand, if it exceeds 3 parts by mass, the effect may reach saturation or blooming on the surface of the molded product may occur. The light stabilizer that can be used in the present invention is preferably one or more hindered amine type light stabilizers (HALS). Preferably, HALS is a compound derived from a substituted piperidine compound, particularly an alkyl-substituted piperidyl, piperidinyl or piperazinone compound, and a compound derived from a substituted alkoxypiperidinyl compound. As such compounds, known compounds can be used. In the present invention, a mixture of a secondary arylamine and a HALS can be used. A preferred embodiment includes at least two types of auxiliary stabilizers, at least one of which is selected from secondary arylamines and at least one of which is selected from the group of HALS. When formulating an auxiliary stabilizer mixture, the total formulation amount (total content) is preferably 0.5 to 10 parts by mass, more preferably 0.5 to 3 parts by mass, based on 100 parts by mass of the polyamide resin. If it is less than 0.5 part by mass, the effect of improving heat aging resistance is insufficient. On the other hand, if it exceeds 10 parts by mass, the effect may saturate or blooming may occur on the surface of the molded product. In the present invention, furthermore, by adding a filler, the strength, rigidity, heat resistance, etc. can be significantly improved. Examples of such fillers include glass fiber, carbon fiber, metal fiber, aramid fiber, asbestos, potassium titanate whisker, wollastonite, glass flake, glass bead, talc, mica, clay, calcium carbonate, barium sulfate, titanium oxide, and aluminum oxide. Among them, chopped strand type glass fiber is preferably used. When these are formulated, the formulation amount (content) is preferably 5 to 140 parts by mass, particularly preferably 5 to 100 parts by mass, based on 100 parts by mass of the polyamide resin. Also, for the polyamide resin composition of the present invention, within a range not impairing the object of the present invention, one or more ordinary additives such as an ultraviolet absorber (for example, resorcinol, salicylate, benzotriazole, benzophenone, etc.), a lubricant and a mold release agent, a nucleating agent, a plasticizer, an antistatic agent, and a colorant containing a dye or a pigment can be added up to about 5 parts by mass based on 100 parts by mass of the polyamide resin. The polyamide resin composition of the present invention can contain each component described above. However, in the composition excluding the above filler, it preferably occupies 90% by mass or more, more preferably 95% by mass or more, in total of the polyamide resin (A), the polyamide resin (B), and the metal cyanide salt. The method of incorporating the metal cyanide salt and other additives in the polyamide resin in the present invention is not particularly limited and can be carried out by any method. For example, after premixing all the components, a method of kneading in an extruder or a kneader, or a method of further kneading and blending other components into pellets obtained by previously kneading any number of components in an extruder or a kneader, etc. can be mentioned. The polyamide resin composition of the present invention has extremely excellent heat aging resistance such that the tensile strength retention rate is 50% or more even after heat treatment at 200 °C for 2000 hours in the heat aging test described in the Examples section below. The polyamide resin composition of the present invention can be made into a molded article by injection molding, extrusion molding, thermoforming, compression molding, or a so-called hollow process typified by blow molding, die slide molding, etc. Further, these molded articles can also be made into molded articles by secondary processing, such as welding processes including vibration welding, hot plate welding, ultrasonic welding, etc. Preferably, it is an injection molded or blow molded article, and a molded article obtained by its secondary processing. Examples of the uses of the molded article of the polyamide resin composition of the present invention in the automotive and vehicle fields include, for example, cylinder head covers, engine covers, housings for intercoolers, valves, end caps, casters, trolley parts, etc., and further, intake pipes (air ducts), particularly intake system parts such as intake manifolds, connectors, gears, fan wheels, coolant storage containers, housings or housing members for heat exchangers, radiators, thermostats, coolant and water pumps, heaters, fastening elements, oil pans, exhaust systems such as mufflers and housings for catalytic converters, timing chain belt front covers, gearboxes, bearing retainers, gasoline caps, seat parts, headrests, door handles, wiper parts, etc. In the field of electrical / electronic equipment, examples include components of circuit boards, housings, films, conductors, switches, terminal strips, relays, resistors, capacitors, coils, lamps, diodes, LEDs, transistors, connectors, controllers, memories, bolts, coil bobbins, plugs, plug components, mechatronics components, cooking equipment, home appliance components such as washing machines, refrigerators, air conditioners, and sensors. In the fields related to daily life and furniture / building materials, examples include components for wheelchairs, baby stroller parts, chair legs, armrests, handrails, window frames, doorknobs, and the like. The present invention will be specifically described below using examples, but the present invention is not limited thereto. The measured values described in the examples were obtained by the following methods. (1) Raw materials used - Polyamide 66: Relative viscosity RV = 2.7, Stabamid 27AE1K manufactured by Rhodia, (Oxygen permeability 80 cm ３ - mm / m ２ - day·atm) - Polyamide 6: Relative viscosity RV = 2.5, TP-4208 manufactured by Jisheng Co., Ltd., (Oxygen permeability 40 cm ３ - mm / m ２ - day·atm) - Polyamide MXD6: Relative viscosity RV = 2.1, T-600 manufactured by Toyobo Co., Ltd., (Oxygen permeability 0.1 cm ３ - mm / m ２ - day·atm) - Polyamide 6T / 6I: Relative viscosity RV = 2.1, Glycolon G21 manufactured by EMS, (Oxygen permeability 30 cm ３ - mm / m ２ - day·atm) - Polyamide 1010: Relative viscosity RV = 2.5, Hiprolon 200NN manufactured by Arkema, (Oxygen permeability 530 cm ３ - mm / m ２ - day·atm) - Potassium ferrocyanide trihydrate (Potassium hexacyanoferrate (II) trihydrate): Purity 99% manufactured by Wako Pure Chemical Industries, Ltd. ・ Potassium ferricyanide (potassium hexacyanoferrate(III)): manufactured by Wako Pure Chemical Industries, Ltd., purity 99% ・ Sodium ferrocyanide decahydrate (sodium hexacyanoferrate(II) decahydrate): manufactured by Wako Pure Chemical Industries, Ltd., purity 99% ・ Iron(II) oxide: manufactured by Wako Pure Chemical Industries, Ltd. ・ Phenolic antioxidant: Irganox 245 manufactured by BASF ・ Cupric bromide: manufactured by Wako Pure Chemical Industries, Ltd., purity 99.9% ・ Glass fiber: T-275H manufactured by Nippon Electric Glass Co., Ltd. (2) Test method ・ Tensile strength and elongation at break: Using Toshiba Machine Co., Ltd. IS-100, the cylinder was set at 280 °C, and after obtaining a molded product under the condition of a mold temperature of 90 °C, the measurement was carried out in accordance with ISO 527-1, 2. ・ Oxygen transmission rate: Using a differential pressure type gas / vapor transmission rate measuring device (device: GTR-30XAD2, G2700T・F manufactured by GTR Tech. Yanaco Technical Science Co., Ltd., detector: gas chromatograph [thermal conductivity detector]) conforming to JIS K7126-1:2006 (differential pressure method), temperature condition: 23 °C ± 2 °C, atmospheric pressure: 1 atm, gas: oxygen gas (dry state), transmission area: 15.2×10 －４ m ２ (φ4.4×10 －２ m), the test was carried out. The measurement sample was prepared as follows. Using Toshiba Machine Co., Ltd. IS-100, the cylinder was set at 280 °C, and a molded product with a size of 100 mm × 100 mm × 2 mm thickness was obtained under the condition of a mold temperature of 90 °C. The sample was pressed at a temperature condition of 280 °C for 1 minute using a hydraulic heat press machine (model WIC manufactured by Kando Metal Industry Co., Ltd.) to produce a film with a thickness of 150 μm to 400 μm. Further, after obtaining a test piece by punching the film, it was used for oxygen transmission rate measurement. - Thermal aging test: The test specimens were heat-treated in a recirculating air oven (hot air circulation dryer NH-401S manufactured by Nagano Scientific Machinery Co., Ltd.) according to the procedure detailed in ISO 2578. The test specimens were taken out of the oven at a predetermined test time (1000 hours, 2000 hours) in an environment of 200 °C, cooled to room temperature, and sealed in an aluminum-lined bag until the test was ready. Subsequently, the tensile strength and elongation at break were measured according to ISO 527-1, 2. The average values obtained from three test specimens were adopted. The retention rates of the tensile strength and elongation at break are the retention rates after heat treatment for 1000 hours and 2000 hours when the initial value without heat treatment is taken as 100%. The resin compositions described as Examples and Comparative Examples were prepared by blending the above raw materials in the ratios (mass ratios) described in Tables 1 and 2 using a twin-screw extruder (STS35 manufactured by Coperion), and melt-kneaded to obtain pellets (diameter approximately 2.5 mm × length approximately 2.5 mm). The obtained pellets were dried at 100 °C for 4 hours or more in a hot air circulation dryer before use. The evaluation results are shown in Tables 1 and 2. Examples 1 to 11 are systems in which polyamide with a lower oxygen permeability than polyamide 66 is blended with polyamide 66. All of them have high initial (before heat treatment) tensile strength and elongation at break, and also show high values for the tensile strength retention rate and elongation at break retention rate after heat treatment at 200 °C for 1000 hours and 2000 hours. Examples 12 and 13 are systems in which polyamide with a lower oxygen permeability than polyamide 6 is blended with polyamide 6. All of them have high initial (before heat treatment) tensile strength and elongation at break, and also show high values for the tensile strength retention rate and elongation at break retention rate after heat treatment at 200 °C for 1000 hours and 2000 hours. Comparative Example 1 is a system of only polyamide 66. Although the tensile strength retention rate and elongation at break retention rate after treatment at 200 °C for 1000 hours show high values, the tensile strength retention rate and elongation at break retention rate after treatment at 200 °C for 2000 hours tend to decrease. Comparative Examples 2 and 3 are systems in which a polyamide having an oxygen permeability higher than that of polyamide 66 is blended with polyamide 66. Although the tensile strength retention rate and the tensile elongation at break retention rate after treatment at 200 °C for 1000 hours show high values, the tensile strength retention rate and the tensile elongation at break retention rate after treatment at 200 °C for 2000 hours tend to decrease. Comparative Example 4 is a system in which a polyamide having an oxygen permeability higher than that of polyamide 6 is blended with polyamide 6. Although the tensile strength retention rate and the tensile elongation at break retention rate after treatment at 200 °C for 1000 hours show high values, the tensile strength retention rate and the tensile elongation at break retention rate after treatment at 200 °C for 2000 hours tend to decrease. Comparative Example 5 is an example in which iron(II) oxide is added without adding a metal cyanide salt. However, the initial tensile strength and the tensile elongation at break are lower compared to the Examples, and the tensile strength retention rate and the tensile elongation at break retention rate after treatment at 200 °C for 2000 hours are significantly decreased. Comparative Example 6 is an example in which no metal cyanide salt is added. However, the tensile strength retention rate and the tensile elongation at break retention rate after treatment at 200 °C for 1000 hours are significantly decreased. According to the present invention, since the heat aging resistance of the polyamide resin in a high temperature environment of about 200 °C can be easily and stably improved, the polyamide resin composition obtained by the present invention can be used for parts of automobiles and electric / electronic products that may be exposed to an environment of 200 °C.

Claims

------11 / 07 / 2018------(OCR)Page 1 of 2 pages, Section 1. The polyamide resin composition is characterized as a polyamide resin composition consisting of polyamide resin (A) and polyamide resin (B) with a lower oxygen permeation rate than polyamide resin (A) and a mass ratio (A) / (B) of polyamide resin (A) and polyamide resin (B) of 98 / 2-60 / 40 and containing the following metal cyanide salts of general composition formula (1): 0.5-20 parts by mass of polyamide resin (A) and polyamide resin (B) 100 parts by mass of general composition formula (1)...Ax[M(CN)y](within the general element formula(1), M is at least one of the transition metals of groups 5-10 and periods 4-6 of the periodic table, A is at least one of the alkali and alkaline earth metals, y is an integer 3-6, X is a number that can be determined by (ym) / a here as the valence of M, a is the valence of A)2 The polyamide resin element specified in Reputation 1 in which M of the general element formula(1) is iron3 The polyamide resin element specified in Reputation 1 in which the metal cyanide salt of the general element formula(1) is one of the chosen types of alkali hexacyanoferrate(II) and alkali hexacyanoferrate(III) salts4 The polyamide resin element specified in Reputation 1-3 in which one of the compounds is copper0.0001-1 Mass part as copper compound of polyamide resin (A) with polyamide resin (B) 100 mass parts 5 Polyamide resin composition specified in any of the claims 1-4 in which polyamide resin (A) is polyhexamethylene adipamide 6 A process to enhance the thermal aging resistance properties of a polyamide resin composition which is a polyamide resin composition consisting of polyamide resin (A) and polyamide resin (B) with a lower oxygen permeation rate than polyamide resin (A) and It is a process to enhance the thermal degradation properties of polyamide resin components in which the mass ratio (A) / (B) of polyamide resin (A) to polyamide resin (B) is 98 / 2-60 / 40 and contains 0.5-20 parts mass of the following general composition formula (1) metal cyanide salts of polyamide resin (A) and 100 parts mass of polyamide resin (B) of polyamide resin (B).Ax[M(CN)y] (within the general element formula(1),M is at least one of the transition metals of groups 5-10 and periods 4-6 of the periodic table,A is at least one of the alkali and alkaline earth metals,y is an integer of 3-6,X is a number that can be found with (ym) / a here as the valence of M, a is the valence of A)------------Page 1 of Page 2 of Claim 1 The characteristic polyamide resin composition is that it consists of polyamide resin (A) and polyamide resin (B) with a lower oxygen permeation rate than polyamide resin (A), and the mass ratio (A) / (B) of polyamide resin (A) to polyamide resin (B) is 98 / 2-60 / 40, and contains 0.5-20 parts mass of the following general composition formula (1) metal cyanide salts to the total mass of polyamide resin (A) and polyamide resin (B) 100 parts mass of general composition formula (1)...Ax[M(CN)y](within general composition formula(1),M is at least one of the transition metals of groups 5-10 and periods 4-6 of the periodic table,A is at least one of the alkali and alkaline earth metals,y is an integer 3-6,X is a number obtainable by (ym) / a, where m is the valence of M, a is the valence of A)2. The polyamide resin composition specified in Reputation 1 in which M of general composition formula(1) is iron.

3. The polyamide resin composition specified in Reputation 1 in which the metal cyanide salt of general composition formula(1) is one or more of the chosen alkali hexacyanoferrate(II) and alkali hexacyanoferrate(III) metal salts.

4. Any of the polyamide resin compositions specified in Reputations 1-3 contain a copper compound.0.0001-1 Mass part as copper to the total mass of polyamide resin (A) with polyamide resin (B) 100 mass parts 5 Polyamide resin composition specified in any of the claims 1-4 in which polyamide resin (A) is polyhexamethylenedipamide 6 A process to enhance the thermal aging resistance of a specific polyamide resin composition is made of polyamide resin (A) and polyamide resin (B) with a lower oxygen permeation rate than polyamide resin (A) and a mass ratio (A) / (B) of polyamide resin (A) to polyamide resin (B) of 98 / 2-60 / 40 and contains a metal cyanide salt of the following general composition formula (1) 0.5-20 mass parts to the total mass of polyamide resin (A) with polyamide resin (B) 100 mass parts General composition formula (1) ... / ^[IVKCNOy](within the general element formula(1),M is at least one of the transition metals of groups 5-10 and periods 4-6 of the periodic table,A is at least one of the alkali and alkaline earth metals,y is the integer 3-6,X is the number that can be found with (y-ta) / l here,ta is the valence of M, a is the valence of A);.