JP2016035050A - Polyamide resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyamide resin composition which can exhibit stable thermal aging resistance and mechanical strength even under a high-temperature environment of about 200°C and is easy to produce.SOLUTION: The polyamide resin composition contains 0.1-10 pts.mass of an iron salt of an organic carboxylic acid based on 100 pts.mass of a polyamide resin. The organic carboxylic acid constituting the iron salt of the organic carboxylic acid is preferably at least one selected from 4-30C fatty acids and 4-30C oxycarboxylic acids.SELECTED DRAWING: None

Description

  The present invention relates to a polyamide resin composition, and particularly relates to a polyamide resin composition excellent in heat aging resistance.

  Polyamide resins have excellent properties such as mechanical properties, chemical resistance and molding processability, and thus have been widely used for various parts such as automobile parts, electrical and electronic parts, and industrial machine parts. Polyamide resins are a class of resins that are relatively excellent in heat aging resistance, but deterioration due to the action of heat and light is inevitable. As a method for improving heat aging resistance, copper halide, potassium halide, oxazole compounds, etc. are heated. A method of adding as a stabilizer has been known for a long time (for example, Patent Document 1).

With these techniques, polyamide resins are used for parts that are exposed to a high temperature environment of about 140 ° C. in the field of automobile parts, electrical and electronic parts.
However, for example, in the engine room of an automobile, the environmental temperature in the engine room has increased with the increase in engine output and the density of parts in recent years, and unprecedented heat aging resistance has been demanded. .

In contrast, a method of blending fine elemental iron with polyamide (Patent Document 2), a method of blending finely dispersed metal powder with polyamide (Patent Document 3), and a copper compound and oxidation in two types of polyamide mixtures having different melting points A method of blending iron (Patent Document 4), a method of blending a heat stabilizer such as copper iodide and potassium iodide and a complex oxide such as iron trioxide (including iron (II) oxide) (Patent Document) 5) etc. are proposed, and it is said that it is excellent in heat aging resistance even in a high temperature environment of about 200 ° C.
However, in the methods of Patent Documents 2 and 3, there is a risk of igniting during the production of the composition and the production is not easy, and in the method of Patent Document 4, there is a defect that the effect is manifested only with a very limited composition. In the method of Patent Document 5, the heat aging resistance and the stability of mechanical strength are sometimes inferior, and there is room for improvement in the current situation.

Japanese Patent Publication No. 7-47690 JP-T-2006-528260 Special table 2008-527127 Special table 2008-527129 JP 2010-270318 A

  An object of the present invention is to provide a polyamide resin composition which can exhibit stable heat aging resistance and mechanical strength even under a high temperature environment of about 200 ° C. and can be easily produced.

The inventor of the present invention has reached the present invention as a result of intensive studies to solve the above-mentioned problems.
That is, the present invention
[1] A polyamide resin composition comprising 0.1 to 10 parts by mass of an organic carboxylic acid iron salt with respect to 100 parts by mass of a polyamide resin.
[2] The polyamide according to [1], wherein the organic carboxylic acid constituting the iron salt of the organic carboxylic acid is at least one selected from fatty acids having 4 to 30 carbon atoms and oxycarboxylic acids having 4 to 30 carbon atoms. Resin composition.
[3] The polyamide resin composition according to [1], wherein the organic carboxylic acid constituting the iron salt of the organic carboxylic acid is at least one selected from stearic acid, lauric acid, and gluconic acid.
[4] The polyamide resin composition according to any one of [1] to [3], wherein a molded product obtained from the polyamide resin composition has a tensile strength retention after heat treatment at 200 ° C. for 1000 hours of 70% or more. .

  The polyamide resin composition of the present invention is used for automobiles and electrical / electronic parts that require little deterioration of mechanical properties and high heat aging resistance even when exposed to a high temperature (about 200 ° C.) environment for a long period of time. A possible polyamide resin composition can be provided.

The present invention will be specifically described below.
The polyamide resin in the present invention is not particularly limited. For example, a ring-opening polymerization product of cyclic lactam, a polycondensation product of aminocarboxylic acid, a polycondensation product of dibasic acid and diamine, and a copolymer thereof. Specifically, polycaproamide (polyamide 6), polyhexamethylene adipamide (polyamide 66), polytetramethylene adipamide (polyamide 46), polyhexamethylene sebacamide (polyamide 610) , Polyhexamethylene dodecamide (polyamide 612), poly-lauryl lactam (polyamide 12), poly-11-aminoundecanoic acid (polyamide 11) and other aliphatic polyamides, poly (metaxylene adipamide) (hereinafter MXD-6) ), Poly (hexamethylene terephthalamide) (hereinafter abbreviated as 6T), poly ( Aliphatic-aromatic polyamides such as oxamethylene isophthalamide (hereinafter abbreviated as 6I), poly (nonamethylene terephthalamide) (hereinafter abbreviated as 9T), poly (tetramethylene isophthalamide) (hereinafter abbreviated as 4I), and the like And copolymers and mixtures thereof. Particularly suitable 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 6T / 6I copolymer, polyamide 6T / 6I / 12 copolymer, polyamide 6T / 610 copolymer, and polyamide 6T / 6I / 6 copolymer.

  The molecular weight of such a polyamide resin is not particularly limited, but a polyamide resin having a relative viscosity of 1.7 to 4.5 measured at 25% in a concentration of 1% by mass in 98% (98% by mass) sulfuric acid is used. It is preferable. The relative viscosity of the polyamide resin is more preferably 2.0 to 4.0, still more preferably 2.0 to 3.5.

Although it does not specifically limit as an iron salt of organic carboxylic acid in this invention, The organic carboxylic acid part which comprises a compound is from C4-C30 fatty acids and C4-C30 oxycarboxylic acids. It is preferably at least one selected. 5-26 are more preferable and, as for carbon number of the fatty acids and oxycarboxylic acids which comprise an organic carboxylic acid part, 6-20 are more preferable. A plurality of organic carboxylic acids are bonded to the iron salt of the organic carboxylic acid depending on the valence of iron, and the “carbon number” is the number of carbons per organic carboxylic acid. An oxycarboxylic acid is a compound having a carboxyl group and a hydroxyl group in one molecule.
Examples include iron (II) butyrate, iron (III) butyrate, iron (II) valerate, iron (III) valerate, iron (II) caproate, iron (III) caproate, iron (II) enanthate, Iron (III) enanthate, iron (II) caprylate, iron (III) caprylate, iron (II) pelargonate, iron (III) pelargonate, iron (II) caprate, iron (III) caprate, laurin Iron (II) acid, Iron (III) laurate, Iron (II) myristic acid, Iron (III) myristic acid, Iron (II) palmitate, Iron (III) palmitate, Iron (II) margarate, Margaric acid Examples include iron (III), iron (II) stearate, iron (III) stearate, iron (II) montanate, iron (III) montanate, iron (II) gluconate, iron (III) gluconate, etc. . In addition to these, iron salts in which the organic carboxylic acid moiety is an aromatic carboxylic acid, a dicarboxylic acid, or an unsaturated carboxylic acid can be used. These compounds can be used alone or in combination. Among such iron salts of organic carboxylic acids, an iron salt in which the organic carboxylic acid portion is a fatty acid having 4 to 30 carbon atoms and an oxycarboxylic acid having 4 to 30 carbon atoms is preferable in terms of an effect of improving heat resistance, As for the said C4-C30 fatty acid, a C4-C30 linear saturated fatty acid is more preferable. Furthermore, iron (II) laurate, iron (III) laurate, iron (II) caprylate, iron (III) caprylate, iron (II) stearate, iron (III) stearate, iron montanate (II ), Iron (III) montanate, iron (II) gluconate, and iron (III) gluconate are preferred, particularly iron (II) laurate, iron (III) laurate, iron (II) stearate, stearic acid Iron (III), iron (II) gluconate, and iron (III) gluconate are preferred.

  In this invention, the compounding quantity of the iron salt of organic carboxylic acid is 0.1-10 mass parts with respect to 100 mass parts of polyamide resins. The amount of the organic carboxylic acid iron salt is preferably 0.5 to 8 parts by mass, more preferably 1 to 8 parts by mass, still more preferably 1 to 5 parts by mass, and particularly preferably 1.5 to 5 parts by mass. is there. If the amount is less than 0.1 parts by mass, there is almost no effect of developing heat aging resistance, and if it exceeds 10 parts by mass, the effect of developing heat aging property will not increase any further. If the iron salt of the organic carboxylic acid is 10 parts by mass or less, unlike metal particles or metal oxide particles, there is little adverse effect on mechanical properties, and glass fiber breakage particularly in glass fiber reinforced compositions. Since it can be suppressed, the mechanical properties are hardly deteriorated.

Although it is unclear why the effect of improving the heat aging resistance of the iron salt of the organic carboxylic acid in the present invention is present, the iron salt has an oxygen scavenging effect near the surface of the polyamide resin, and the oxidative deterioration of the polyamide resin. It is thought that it is because it can suppress.
Moreover, the iron salt used by this invention can suppress the fall of the mechanical property of the polyamide resin composition after mix | blending compared with iron compounds like iron oxide which is a heat-resistant aging compound used conventionally. Iron oxide is a metal oxide among minerals and has a very high Mohs hardness of 6, and in a polyamide resin composition containing glass fibers, the mechanical properties are lowered because the glass fibers are broken. On the other hand, since the iron salt of organic carboxylic acid is not a mineral, the polyamide resin composition containing glass fibers is excellent in mechanical properties because the glass fibers are not damaged.

  In the resin composition of the present invention, a known heat stabilizer can be used in combination with the iron salt of the organic carboxylic acid.

  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, and copper stearate. 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 addition amount of a copper compound is 0.0001-1 mass part as copper in a copper compound with respect to 100 mass parts of polyamide resins. If the amount is less than 0.0001 parts by mass, the effect of preventing discoloration in a high temperature atmosphere and a severer environment under ultraviolet irradiation is insufficient, and if the amount is more than 1 part by mass, the effect of preventing discoloration in the severe environment will reach its peak. Furthermore, there is a concern that problems such as corrosion of molds, screws, cylinders, etc. of extruders and molding machines may occur. A more preferable addition amount is 0.0005 to 1 part by mass, a further preferable addition amount is 0.0005 to 0.03 part by mass, and a particularly preferable addition amount is 0.0005 to 0.02 part by mass. is there.

  Moreover, when adding a copper compound, it is preferable to use together alkali metal halide compounds, such as potassium iodide and potassium bromide. By using together, precipitation of copper can be prevented. As a method for 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, a method of adding to a raw material salt aqueous solution of polyamide, a method of injecting and adding to a molten polyamide in the middle of melt polymerization, and after blending a granulated polyamide pellet and the copper compound powder or masterbatch after polymerization Any of a method of melt kneading using an extruder, a molding machine or the like may be used.

Furthermore, in the present invention, an auxiliary stabilizer such as a hindered phenol antioxidant, a phosphorus antioxidant, a sulfur antioxidant, an amine antioxidant, or a light stabilizer is added. Can do.
Examples of the hindered phenol antioxidant include n-octadecyl-3- (4′-hydroxy-3 ′, 5′-di-tert-butylphenyl) propionate, 1,1,3-tris (2-methyl-4 -Hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5, -di-tert-butyl-4-hydroxyphenyl) benzylbenzene, 1,3 5-tris (4-hydroxy-3,5-di-tert-butylbenzyl) -s-triazine-2,4,6- (1H, 3H, 5H) -trione, ethylene glycol-bis [3,3-bis (3′-tert-butyl-4′-hydroxyphenyl) butyrate], tetrakis [methylene-3 (3,5-di-tert-butyl-4-hydroxyphenyl) propylene Nate] methane, 3,9-bis [2- {3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] 2,4,8,10- Tetraoxaspiro [5,5] undecane, 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3 -Tert-butyl-5-methyl-4-hydroxyphenyl) propionate], N, N'-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyl] hydrazine, 2,2 ' -Methylene-bis (4-methyl-6-tert-butylphenol) terephthalate, 1,3,5-tris [(3,5-di-tert-butyl-4 Hydroxyphenyl) propionyloxyethyl] isocyanurate, N, N-hexamethylenebis (3,5-di-tert-butyl-hydroxy-hydrocinnamide), and 2,2-bis [4- {2- (3 5-Di-tert-butyl-4-hydroxyhydrocinnamoyloxy)} ethoxyphenyl] propane.

  These compounds can be used alone or in combination. Among such hindered phenol-based antioxidants, a bifunctional or higher phenol is preferable, and 3,9-bis [2- {3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy } -1,1-dimethylethyl] 2,4,8,10-tetraoxaspiro [5,5] undecane, N, N′-hexamethylenebis (3,5-di-tert-butyl-4-hydroxycin Namamide), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane and n-octadecyl-3- (4′-hydroxy-3 ′, 5′-di-tert) -Butylphenyl) propionate, triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate] Particularly preferred, triethylene glycol - bis preferable [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate] (IRGANOX 245) point of the semi-hindered type discolored difficulty such.

  When the hindered phenol-based antioxidant is blended, the blending amount is preferably 0.05 to 3 parts by mass, more preferably 0.1 to 2 parts by mass with respect to 100 parts by mass of the polyamide resin. is there. If it is less than 0.05 part by mass, the effect of preventing thermal discoloration is insufficient, while 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 antioxidant is at least one selected from inorganic and organic phosphorus antioxidants. Examples of inorganic phosphorus antioxidants include hypophosphites such as sodium hypophosphite and phosphites.
As the organic phosphorus antioxidant, commercially available organic phosphorus antioxidants such as phosphites can be used, but organic phosphorus-containing compounds that do not generate phosphoric acid by thermal decomposition are preferable. Examples of such organic phosphorus-containing compounds include triphenyl phosphite, diphenylisodecyl phosphite, trisnonyl phosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (HCA), 10- (3,5-di-tert-butyl-4-hydroxybenzyl) -9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-decyloxy-9,10-dihydro And -9-oxa-10-phosphaphenanthrene-10-oxide.

When mix | blending phosphorus antioxidant, it is preferable that the compounding quantity is 0.05-3 mass parts with respect to 100 mass parts of polyamide resins, More preferably, it is 0.1-2 mass parts. If the amount is less than 0.05 parts by mass, the effect of preventing thermal discoloration is insufficient. On the other hand, if the amount exceeds 3 parts by mass, flashing may occur in the molded product.
In the present invention, it is preferable to use inorganic and organic phosphorus antioxidants in combination because the amount of the antioxidant can be reduced.

  Examples of amine-based antioxidants that can be used in the present invention include polycondensates with dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine oxalate, poly [[6- (1,1,3,3-tetrabutyl) imino-1,3,5-triazine-2,4-diyl] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) Imyl]], bis (1,2,2,6,6-pentamethyl-4-piperidyl) ester of 2-n-butylmalonic acid, tetrakis (2,2,6,6-tetramethyl-4-piperidyl)- 1,2,3,4-butanetetracarboxylate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, N, N′-bis (2,2,6,6-tetramethyl- 4-piperidyl) hexame Polycondensation product of range amine and 1,2-dibromoethane, poly [(N, N′-bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine)-(4-monophorino- 1,3,5-triazine-2,6-diyl) -bis (3,3,5,5-tetramitylpiperazinone)], tris (2,2,6,6-tetramethyl-4-piperidyl) -Dodecyl-1,2,3,4-butanetetracarboxylate, tris (1,2,2,6,6-pentamethyl-4-piperidyl) -dodecyl-1,2,3,4-butanetetracarboxylate, Bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1,6,11-tris [{4,6-bis (N-butyl-N- (1,2,2,6, 6-pentamethylpiperidin-4-yl) Mino-1,3,5-triazin-2-yl) amino} undecane, 1- [2- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6,6 Tetromethylpiperidine, 8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,3,8-triazaspiro [4,5] undecane-2,4-dione, 4-benzoyloxy-2 , 2,6,6-tetramethylpiperidine, N, N′-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl- 4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate. Secondary arylamines can also be mentioned as amine-based antioxidants. By secondary arylamine is meant an amine compound containing two carbon radicals chemically bonded to a nitrogen atom, wherein at least one, preferably both carbon radicals are aromatic.

  Examples of suitable secondary arylamines include the Uniroyal Chemical Company, Middlebury, Conn. 4,4′-di (α, α-dimethylbenzyl) diphenylamine commercially available as Naugard 445; secondary arylamine condensation product of the reaction of diphenylamine and acetone commercially available as Aminox from Uniroyal Chemical Company; Unichemical Chemical Mention may be made of para- (paratoluenesulfonylamido) diphenylamine which is commercially available from Company as Naugard SA. Other suitable secondary arylamines include N, N'-di- (2-naphthyl) -p-phenylenediamine available from ICI Rubber Chemicals, Calcutta, India. Other suitable secondary arylamines include 4,4'-bis (α, α'-t-octyl) diphenylamine, 4,4'-bis (α-methylbenzhydryl) diphenylamine, and the like.

  When mix | blending an amine type antioxidant, it is preferable that the compounding quantity is 0.05-3 mass parts with respect to 100 mass parts of polyamide resins, More preferably, it is 0.1-2 mass parts. If it is less than 0.05 part by mass, the effect of preventing thermal discoloration is insufficient, while if it exceeds 3 parts by mass, the effect may reach saturation or blooming on the surface of the molded product may occur.

  Examples of the sulfur-based antioxidant that can be used in the present invention include dilauryl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodiuropionate, distearyl-3,3′-thiodipropionate. Acid ester, lauryl stearyl-3,3′-thiodipropionate, dilauryl thiodipropionate, dioctadecyl sulfide, pentaerythritol-tetra (β-lauryl-thiopropionate) ester, dithiocarbamate dimethyl ester Dithiocarbamic acid and its metal salt, diethyldithiocarbamic acid and its metal salt, dibutyldithiocarbamic acid and its metal salt, ethylphenyldithiocarbamic acid and its metal salt, etc., as the metal salt, zinc salt, nickel salt, tellurium salt, etc. Cite It is possible.

  When the sulfur-based antioxidant is blended, the blending amount is preferably 0.05 to 3 parts by mass, more preferably 0.1 to 2 parts by mass with respect to 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, while 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).
HALS is a compound of the following general formula and combinations thereof.

  In these formulas, R1 to R5 are independent substituents. Examples of suitable substituents are hydrogen, ether groups, ester groups, amine groups, amide groups, alkyl groups, alkenyl groups, alkynyl groups, aralkyl groups, cycloalkyl groups and aryl groups, which substituents are functional groups. May be contained. Examples of functional groups are alcohol, ketone, anhydride, imine, siloxane, ether, carboxyl group, aldehyde, ester, amide, imide, amine, nitrile, ether, urethane and any combination thereof. The hindered amine light stabilizer can also form part of a polymer or oligomer.

  Preferably, HALS is a compound derived from a substituted piperidine compound, in particular an alkyl-substituted piperidyl, piperidinyl or piperazinone compound, and a compound derived from a substituted alkoxy piperidinyl compound. Examples of such compounds are 2,2,6,6-tetramethyl-4-piperidone; 2,2,6,6-tetramethyl-4-piperidinol; bis- (1,2,2,6,6-penta Methylpiperidyl)-(3 ′, 5′-di-t-butyl-4′-hydroxybenzyl) butyl malonate; di- (2,2,6,6-tetramethyl-4-piperidyl) sebacate (Tinuvin®) 770, MW 481); oligomers of N- (2-hydroxyethyl) -2,2,6,6-tetramethyl-4-piperidinol and succinic acid (Tinuvin® 622); cyanuric acid and N, N Di (2,2,6,6-tetramethyl-4-piperidyl) -hexamethylenediamine oligomer; bis- (2,2,6,6-tetramethyl-4-piperidinyl) succine Bis- (1-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl) sebacate (Tinuvin® 123); bis- (1,2,2,6,6-pentamethyl- 4-piperidinyl) sebacate (Tinvin® 765); Tinuvin® 144; Tinuvin® XT850; Tetrakis- (2,2,6,6-tetramethyl-4-piperidyl) -1,2 , 3,4-butanetetracarboxylate; N, N′-bis- (2,2,6,6-tetramethyl-4-piperidyl) -hexane-1,6-diamine (Chimasorb® T5); N-butyl-2,2,6,6-tetramethyl-4-piperidinamine; 2,2 ′-[(2,2,6,6-tetramethyl-piperidini ) -Imino] -bis- [ethanol]; poly ((6-morpholine-triazine-2,4-diyl) (2,2,6,6-tetramethyl-4-piperidinyl) -iminohexamethylene- (2, 2,6,6-tetramethyl-4-piperidinyl) -imino) (Cyasorb® UV 3346); 5- (2,2,6,6-tetramethyl-4-piperidinyl) -2-cyclo-undecyl- Oxazole) (Hostavin® N20); 1,1 ′-(1,2-ethane-di-yl) -bis- (3,3 ′, 5,5′-tetramethyl-piperazinone); 8-acetyl -3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro (4,5) decane-2,4-dione; polymethylpropyl-3-oxy- [4 (2,2 , 6, 6-tetramethyl) -piperidinyl] siloxane (Uvasil® 299); 1,2,3,4-butane-tetracarboxylic acid-1,2,3-tris (1,2,2,6,6- Pentamethyl-4-piperidinyl) -4-tridecyl ester; α-methylstyrene-N- (2,2,6,6-tetramethyl-4-piperidinyl) maleimide and N-stearylmaleimide copolymer; 1,2,3 , 4-butanetetracarboxylic acid, β, β, β ′, β′-tetramethyl-2,4,8,10-tetraoxaspiro [5.5] undecane-3,9-diethanol, 1,2,2 , 6,6-Pentamethyl-4-piperidinyl ester (Mark® LA63); 2,4,8,10-tetraoxaspiro [5.5] undecane-3,9-di Β, β, β ′, β′-tetramethyl-polymer with ethanol, 1,2,3,4-butanetetracarboxylic acid, 2,2,6,6-tetramethyl-4-piperidinyl ester (Mark ( Registered trademark LA68); D-glucitol, 1,3: 2,4-bis-O- (2,2,6,6-tetramethyl-4-piperidinylidene)-(HALS7); 7-oxa- 3,20-diazadispiro [5.1.1.12] -heneicosan-21-one-2,2,4,4-tetramethyl-20- (oxiranylmethyl) oligomer (Hostavin® N30); Propandioic acid, [(4-methoxyphenyl) methylene]-, bis (1,2,2,6,6-pentamethyl-4-piperidinyl) ester (Sanduvor® PR31); N, N′-1,6-hexanediylbis [N- (2,2,6,6-tetramethyl-4-piperidinyl (Uvinul® 4050H); 1,3,5-triazine-2 , 4,6-triamine, N, N ′ ″-[1,2-ethanediylbis [[[4,6-bis [butyl (1,2,2,6,6-pentamethyl-4-piperidinyl) amino]- 1,3,5-triazin-2-yl] imino] -3,1-propanediyl]]-bis [N ′, N ″ -dibutyl-N ′, N ″ -bis (1,2,2, 6,6-pentamethyl-4-piperidinyl) (Chimassorb® 119 MW 2286); poly [[6-[(1,1,3,33-tetramethylbutyl) amino] -1,3,5-triazine- 2,4-diyl] [(2,2,6,6 Tetramethyl-4-piperidinyl) -imino] -1,6-hexanediyl [(2,2,6,6-tetramethyl-4-piperidinyl) imino]] (Chimassorb® 944 MW 2000-3000) 1,5-dioxaspiro (5,5) undecane 3,3-dicarboxylic acid, bis (2,2,6,6-tetramethyl-4-peridinyl) ester (Cyasorb® UV-500); 5-dioxaspiro (5,5) undecane 3,3-dicarboxylic acid, bis (1,2,2,6,6-pentamethyl-4-peridinyl) ester (Cyasorb® UV-516); N-2, 2,6,6-tetramethyl-4-piperidinyl-N-amino-oxamide; 4-acryloyloxy-1,2,2,6,6-pentamethy Ru-4-piperidine; 1,5,8,12-tetrakis [2 ′, 4′-bis (1 ″, 2 ″, 2 ″, 6 ″, 6 ″ -pentamethyl-4 ″-) Piperidinyl (butyl) amino) -1 ′, 3 ′, 5′-triazin-6′-yl] -1,5,8,12-tetraazadodecane; HALS PB-41 (Clariant Huningue S .; A. Nylostab® S-EED (Clariant Huningue SA); 3-dodecyl-1- (2,2,6,6-tetramethyl-4-piperidyl) -pyrrolidine-2,5-dione; Uvasorb® HA88; 1,1 ′-(1,2-ethane-di-yl) -bis- (3,3 ′, 5,5′-tetra-methyl-piperazinone) (Good-rite®) ) 3034); 1,1′1 ″-(1,3,5-triazine-2,4,6-triyltris ((cyclohexylimino) -2,1-ethanediyl) tris (3,3,5,5-) Tetramethylpiperazinone) (Good-rite® 3150) and 1,1 ′, 1 ″-(1,3,5-triazine-2,4,6-triyltris ((cyclohex Silymino) -2,1-ethanediyl) tris (3,3,4,5,5-tetramethylpiperazinone) (Good-rite® 3159);

  In the present invention, a mixture of a secondary arylamine and HALS can be used. Preferred embodiments comprise at least two co-stabilizers, at least one selected from secondary arylamines and at least one selected from the group of HALS. When mix | blending an auxiliary stabilizer mixture, it is preferable that the total compounding quantity is 0.5-10 mass parts with respect to 100 mass parts of polyamide resins, More preferably, it is 0.5-3 mass parts. If the amount is less than 0.5 parts by mass, the effect of improving the heat aging resistance is insufficient. On the other hand, if the amount exceeds 10 parts by mass, the effect may be saturated or blooming may occur on the surface of the molded product.

In the present invention, the strength, rigidity, heat resistance and the like can be significantly improved by adding a filler. Such fillers include glass fiber, carbon fiber, metal fiber, aramid fiber, asbestos, potassium titanate whisker, wollastonite, glass flake, glass beads, talc, mica, clay, calcium carbonate, barium sulfate, oxidation Examples thereof include titanium and aluminum oxide. Among them, chopped strand type glass fibers are preferably used.
When mix | blending these, the compounding quantity is 5-140 mass parts with respect to 100 mass parts of polyamide resins, Most preferably, it is 5-100 mass parts.

Further, with respect to the polyamide resin composition of the present invention, ultraviolet absorbers (for example, resorcinol, salicylate, benzotriazole, benzophenone, etc.), lubricants and mold release agents, nucleating agents, plasticizers, and the like within a range not impairing the object of the present invention. One or more conventional additives such as an antistatic agent and a colorant containing a dye / pigment can be added up to about 5 parts by mass with respect to 100 parts by mass of the polyamide resin.
The polyamide resin composition of the present invention can contain each component described above, but in the composition excluding the filler, the total of the polyamide resin and the iron salt of the organic carboxylic acid is 90% by mass. It is preferable to occupy the above, and more preferably 95% by mass or more.

  The method for incorporating the iron salt of organic carboxylic acid and other additives in the present invention into the polyamide resin is not particularly limited, and may be carried out by any method. For example, after all the components are premixed, the method is kneaded in an extruder or kneader, or the other components are kneaded and blended with pellets obtained by kneading any number of components in advance in an extruder or kneader. Is mentioned.

  The tensile strength retention of the molded product obtained from the polyamide resin composition of the present invention after heat treatment at 200 ° C. for 1000 hours can be 70% or more. The molded product is a test piece molded in accordance with the description in the following example section, and the heat treatment is a process performed in the procedure described in the following example section. The tensile strength retention is the retention of the tensile strength after the heat treatment relative to the tensile strength of the test piece before the heat treatment. The tensile strength retention is more preferably 80% or more.

  The polyamide resin composition of the present invention can be formed into a molded body by a so-called hollow method represented by injection molding, extrusion molding, thermoforming, compression molding, blow molding, die slide molding or the like. Moreover, these molded products can be formed into molded products by secondary processing, for example, welding methods including vibration welding, hot plate welding, ultrasonic welding, and the like. Preferably, it is an injection-molded or blow-molded body, and a molded body by secondary processing thereof.

  Examples of uses of the molded article of the polyamide resin composition of the present invention include, in the automobile and vehicle fields, for example, a cylinder head cover, an engine cover, an intercooler housing, a valve, an end cap, a caster, a trolley part, etc. In addition, intake pipes (air ducts), especially intake system parts such as intake manifolds, connectors, gears, fan wheels, coolant storage containers, housings or housing parts for heat exchangers, radiators, thermostats, coolants and water pumps, Heater, fastening element, oil pan, exhaust system such as muffler and catalytic converter housing, timing chain belt front cover, gear box, bearing, gasoline cap, seat parts, headrest, door handle, wiper Such as parts, and the like.

In the electrical / electronic equipment field, for example, circuit board components, housings, films, conductors, switches, terminal strips, relays, resistors, capacitors, coils, lamps, diodes, LEDs, transistors, connectors, controllers, memories, bolts, coil bobbins , Plugs, plug parts, mechatronic parts, cooking equipment, washing machine, refrigerator, air conditioner and other home appliance parts, sensors and the like.
In the fields related to daily life and furniture and building materials, for example, there are parts for wheelchairs, stroller parts, chair legs, armrests, handrails, window frames, door knobs, and the like.

  EXAMPLES The present invention will be specifically described below using examples, but the present invention is not limited to these. In addition, the measured value described in the Example was based on the following method.

(1) Raw materials used: Polyamide 66: Relative viscosity RV = 2.7, Stadamid 27AE1K manufactured by Rhodia
Polyamide 6T / 12: Relative viscosity RV = 2.7 manufactured by Toyobo Co., Ltd. (6T / 12 = 65/35 (molar ratio))
・ Iron (III) laurate: manufactured by Mitsuwa Chemical Co., Ltd. ・ Iron stearate (III): manufactured by Tokyo Chemical Industry Co., Ltd. • Iron stearate (II): manufactured by Strem Chemicals Co., Ltd.—Iron gluconate (II): manufactured by Tokyo Chemical Industry Co., Ltd.・ Iron chloride (II): Wako Pure Chemical Industries, Ltd. ・ Phthalocyanine iron (II): Wako Pure Chemical Industries, Ltd. ・ Iron oxide (II): Wako Pure Chemical Industries, Ltd. ・ Iron oxide (III): Wako Pure Chemical Industries, Ltd. ・ Phenol System antioxidant: Irganox 245 manufactured by BASF, cupric bromide: manufactured by Wako Pure Chemicals, Inc., glass fiber: manufactured by Nippon Electric Glass Co., Ltd. T-275H

(2) Test method, tensile strength, tensile breaking elongation: using Toshiba Machine IS-100, setting the cylinder at 280 ° C. (320 ° C. when using polyamide 6T / 12), mold temperature of 90 ° C. After obtaining a molded product according to ISO527-1,2, the measurement was performed according to ISO527-1,2.

-Thermal aging test: According to the procedure detailed in ISO2578, the test piece was heat-processed in the recirculation air oven (Nagano Scientific Machinery Co., Ltd. hot-air circulation type dryer NH-401S). The specimens were removed from the oven at 200 ° C. environment for a predetermined test time (500 hours, 1000 hours), cooled to room temperature and sealed in an aluminum lined bag until ready for testing. Subsequently, the tensile strength and the tensile elongation at break were measured according to ISO527-1,2. The average value obtained from three test pieces was adopted.

  The retention ratios of tensile strength and tensile elongation at break are the retention ratios after heat treatment for 500 hours and 1000 hours when the initial value without heat treatment is 100%.

The resin compositions described as Examples and Comparative Examples were prepared by blending the above raw materials at the ratios (mass ratios) described in Tables 1 and 2 using a twin-screw extruder (STS35 manufactured by Coperion Co., Ltd.). The mixture was kneaded to obtain pellets (diameter: about 2.5 mm × length: about 2.5 mm). The obtained pellets were used after drying at 100 ° C. for 4 hours or more in a hot air circulation dryer. The evaluation results are shown in Tables 1 and 2.
In Tables 1 and 2, the blending amount of each raw material represents the total of the polyamide resin, the organic carboxylic acid iron salt, and the filler (glass fiber) as 100 parts by mass. It becomes 2.9 mass parts of iron salt of organic carboxylic acid, filler 44.1 mass parts, antioxidant 0.29 mass part, and copper compound 0.03 mass part with respect to 100 mass parts. Looking only at the compounding amount of the organic carboxylic acid iron salt, Examples 1, 3, and 4 were 2.9 parts by mass, Example 2 was 7.7 parts by mass, and Example 5 with respect to 100 parts by mass of the polyamide resin. 7 to 9 is 4.5 parts by mass, Example 6 is 1.4 parts by mass, and Comparative Example 1 is 0.03 parts by mass.

Examples 1 to 9 have high initial tensile strength (before heat treatment) and tensile elongation at break, and the retention of tensile strength and tensile elongation after heat treatment at 200 ° C. for 500 hours and 1000 hours are both 70% or more. Indicates a high value.
Comparative Example 6 is a case where only a phenolic antioxidant and cupric bromide were added, but the tensile strength after 200 hours at 500 ° C. for 500 hours and the retention of tensile elongation at breakage were greatly reduced. ing.
Comparative Example 1 is a case where the amount of iron (III) stearate added is small, but the tensile strength after 200 hours at 500 ° C. for 500 hours and the retention rate for tensile elongation at break are reduced.
Comparative Examples 2, 3, 4, and 5 are cases where iron oxide (II), iron oxide (III), iron chloride (II), and phthalocyanine iron (II) were added, respectively. The tensile strength after time and the retention of tensile elongation at break are greatly reduced.

  According to the present invention, the polyamide resin composition obtained according to the present invention has an environment at 200 ° C. because the heat aging resistance in a high temperature environment of about 200 ° C. can be easily and stably improved. It can be used for parts of automobiles and electrical / electronic products that may be exposed to

Claims (4)

  A polyamide resin composition comprising 0.1 to 10 parts by mass of an organic carboxylic acid iron salt with respect to 100 parts by mass of a polyamide resin.   2. The polyamide resin composition according to claim 1, wherein the organic carboxylic acid constituting the iron salt of the organic carboxylic acid is at least one selected from fatty acids having 4 to 30 carbon atoms and oxycarboxylic acids having 4 to 30 carbon atoms. .   The polyamide resin composition according to claim 1, wherein the organic carboxylic acid constituting the iron salt of the organic carboxylic acid is at least one selected from stearic acid, lauric acid, and gluconic acid.   The polyamide resin composition according to any one of claims 1 to 3, wherein a molded article obtained from the polyamide resin composition has a tensile strength retention after heat treatment at 200 ° C for 1000 hours of 70% or more.