JP2012102189A - Polyamide resin composition, its molding, and method for using the same - Google Patents

Abstract

[Problem] To provide a polyamide resin composition having excellent slidability and mechanical properties and having excellent sliding property stability, and a molded product thereof.
A polyamide resin composition comprising 1 to 30 parts by mass of a siloxane compound (B) and 2 to 60 parts by mass of a fluororesin (C) with respect to 100 parts by mass of a polyamide resin (A). .
[Selection] Figure 1

Description

  The present invention relates to a polyamide resin composition, a molded product thereof and a method for using the same, and more specifically, a polyamide resin composition having excellent slidability and mechanical properties and excellent stability of sliding properties and molding thereof. Product and usage.

Polyamide resin is an engineering plastic that has excellent properties such as impact resistance, friction resistance, and wear resistance, heat resistance, and oil resistance. Automotive parts, electronic / electric equipment parts, mechanical parts, OA equipment parts, etc. Also widely used.
In recent years, the use of plastics is increasing as an alternative material in the field where metals are used for the purpose of reducing weight and improving chemical resistance, and polyamide resin is also expected as a metal alternative material.

Then, it has been studied to use a polyamide resin having excellent mechanical properties and wear resistance as a material for sliding parts such as gears, cam bearings, bearing retainers or door check products.
For example, Patent Document 1 contains a polyamide resin composed of terephthalic acid and 1,9-nonanediamine or 2-methyl-1,8-octanediamine, a modified polyolefin resin reactive with polyamide, and a lubricant in a specific quantity ratio. Proposed polyamide resin compositions for sliding members have been proposed. As a material for sliding parts, it is generally necessary that the coefficient of dynamic friction is low, the amount of wear is small, the mechanical properties are excellent, the softening temperature is high, and the molding is easy. However, the material described in Patent Document 1 is not necessarily sufficient from such a viewpoint.
In particular, in the case of a member that requires a high degree of reliability, such as an accelerator pedal rotor for automobiles, in addition to the high slidability and rigidity as described above, the creep resistance is also excellent. It is necessary to ensure these stably.

JP 2002-363403 A

  An object of the present invention is to provide a polyamide resin material having excellent slidability and mechanical properties, and having excellent stability of sliding characteristics.

  As a result of intensive studies to achieve the above object, the present inventors have obtained a polyamide resin material suitable for the above object by blending a specific amount of a siloxane compound and a specific amount of a fluororesin into a polyamide resin. As a result, the present invention has been completed.

  That is, according to 1st invention of this invention, 1-30 mass parts of siloxane compounds (B) and 2-60 mass parts of fluororesin (C) are contained with respect to 100 mass parts of polyamide resins (A). A polyamide resin composition is provided.

  According to the second aspect of the present invention, in the first aspect, the polyamide resin (A) is obtained by a polycondensation reaction between xylylenediamine and an α, ω-linear aliphatic dicarboxylic acid. A polyamide resin composition is provided which is an amine-based polyamide resin.

  According to the third invention of the present invention, there is provided a polyamide resin composition characterized in that, in the first or second invention, the siloxane compound (B) is an organopolysiloxane.

  According to a fourth invention of the present invention, there is provided a polyamide resin composition characterized in that in any one of the first to third inventions, the fluororesin (C) is polytetrafluoroethylene. The

  According to the fifth invention of the present invention, in any one of the first to fourth inventions, the reinforcing filler (D) is further added in an amount of 10 to 250 parts by mass relative to 100 parts by mass of the polyamide resin (A). A polyamide resin composition characterized by containing is provided.

  According to a sixth invention of the present invention, in any one of the first to fifth inventions, a mixture in which a siloxane compound (B) is previously contained in a thermoplastic resin is mixed with a polyamide resin (A) and a fluororesin ( A polyamide resin composition characterized by being contained in C) is provided.

  Moreover, according to the 7th invention of this invention, the molded article formed by shape | molding the polyamide resin composition of the invention in any one of the 1st-6th is provided.

  Furthermore, according to the eighth invention of the present invention, a portion that slides a molded product formed by molding the polyamide resin composition of any one of the first to sixth inventions with a molded product formed by molding the polyamide resin. The use method of the polyamide resin composition characterized by using for the member which has this is provided.

According to the present invention, there is provided a polyamide resin composition having a low dynamic friction coefficient, a small fluctuation of the dynamic friction coefficient, excellent slidability, and excellent reproducibility of the sliding characteristics.
Therefore, the polyamide resin composition of the present invention is used as a material for sliding members in a wide range of fields such as gears, cam bearings, bearing retainers or door check products, and in particular, as an accelerator pedal rotor for automobiles. It can be suitably used for a member that requires a high degree of reliability.

It is the graph which measured the dynamic friction coefficient of the polyamide resin composition of the Example of this invention. It is the graph which measured the dynamic friction coefficient of the polyamide resin composition of the comparative example of this invention. It is the graph which measured the dynamic friction coefficient of the polyamide resin composition of the comparative example of this invention.

Hereinafter, each component used for the polyamide resin composition of this invention and the manufacturing method of the molded article are demonstrated in detail.
(1) Polyamide resin (A)
The polyamide resin (A) used in the resin composition of the present invention is a polymer having a repeating unit of acid amide obtained by ring-opening polymerization of lactam, polycondensation of aminocarboxylic acid, and polycondensation of diamine and dibasic acid. Specifically, polyamide 6, 11, 12, 46, 66, 69, 610, 612, 6I, 6/66, 6T / 6I, 6 / 6T, 6 / 6I, 66 / 6T, 66 / 6I , 66 / 6T / 6I, xylylenediamine polyamide resin (polyamide XD), polytrimethylhexamethylene terephthalamide, polybis (4-aminocyclohexyl) methane dodecamide, polybis (3-methyl-4-aminocyclohexyl) methane dodecamide And polyundecamethylene hexahydroterephthalamide. The above “I” indicates an isophthalic acid-derived component, and “T” indicates a terephthalic acid-derived component.
As the polyamide resin (A) used in the present invention, an appropriate polyamide resin can be selected in consideration of various properties possessed by these polyamide resins and the intended use of the molded product.

Among the polyamide resins described above, polyamide XD having an aromatic ring as a raw material diamine component has high mechanical strength and elastic modulus, excellent oil resistance, low water absorption, and has a molding shrinkage rate in molding. It is preferable because it is small.
Polyamide XD is a polycondensation of diamine structural units containing xylylenediamine (structural units derived from diamines) and dicarboxylic acid structural units containing α, ω-linear aliphatic dicarboxylic acids (structural units derived from dicarboxylic acids). It is a polyamide resin obtained by making it. Preferably 70 mol% or more, more preferably 80 mol% or more in the diamine structural unit is xylylenediamine, preferably 70 mol% or more, more preferably 80 mol% or more of the dicarboxylic acid structural unit is the number of carbon atoms. 4-20 α, ω-linear aliphatic dicarboxylic acids.
If the xylylenediamine is less than 70 mol%, the finally obtained polyamide resin composition has insufficient rigidity, elastic modulus, heat resistance, etc., and an α, ω-linear aliphatic having 4 to 20 carbon atoms. If the dicarboxylic acid is less than 70 mol%, the polyamide resin composition becomes hard and the processability tends to deteriorate.

  As the xylylenediamine used as the raw material diamine component of the polyamide XD, metaxylylenediamine, paraxylylenediamine and a mixture thereof are preferably used, but metaxylenediamine is preferable from the viewpoint of the appearance of the molded product and the sliding property. When metaxylylenediamine and paraxylylenediamine are used in combination, the combination ratio is preferably 15 to 60 mol% for paraxylylenediamine, 85 to 40 mol% for metaxylylenediamine, more preferably paraxylylene. Range amine is 15 to 45 mol%, metaxylylenediamine is 85 to 55 mol%, most preferably paraxylylenediamine is 20 to 40 mol%, and metaxylylenediamine is 80 to 60 mol%. If the amount of paraxylylenediamine is less than 15 mol%, the crystallization rate may decrease and the molding cycle may be prolonged, and sufficient improvement of the melting point may not be easily observed, resulting in insufficient heat resistance. If it exceeds 1, the melting point becomes too high, which may cause inconveniences such as thermal degradation during polymerization and molding, which is not preferable.

In the present invention, a diamine other than xylylenediamine can be used as the diamine component. As diamines other than xylylenediamine, tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2, 2 , 4-trimethyl-hexamethylenediamine, aliphatic diamines such as 2,4,4-trimethylhexamethylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1,3 -Diaminocyclohexane, 1,4-diaminocyclohexane, bis (4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminomethyl) decalin (including structural isomers), bi Alicyclic diamines such as (aminomethyl) tricyclodecane (including structural isomers), bis (4-aminophenyl) ether, paraphenylenediamine, bis (aminomethyl) naphthalene (including structural isomers), etc. The diamine etc. which have the following aromatic ring can be illustrated, and can be used 1 type or in mixture of 2 or more types.
When a diamine other than xylylenediamine is used as the diamine component, it is less than 30 mol% of the diamine acid structural unit, preferably 1 to 25 mol%, particularly preferably 5 to 20 mol%.

  Examples of the α, ω-linear aliphatic dicarboxylic acid used as a raw material dicarboxylic acid component of polyamide XD include, for example, succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, adipic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid. An aliphatic dicarboxylic acid such as an acid can be exemplified, and one or two or more kinds can be mixed and used. Among these, adipic acid or sebacic acid or a mixture thereof is preferable from the viewpoint of flexibility, and adipic acid is particularly preferable. preferable.

  In the present invention, a dicarboxylic acid other than an α, ω-linear aliphatic dicarboxylic acid can be used as the dicarboxylic acid component. Examples of the dicarboxylic acid component other than the α, ω-linear aliphatic dicarboxylic acid include phthalic acid compounds such as isophthalic acid, terephthalic acid and orthophthalic acid, 1,2-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1 , 4-Naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6 -Naphthalenedicarboxylic acid such as naphthalenedicarboxylic acid and 2,7-naphthalenedicarboxylic acid, polyvalent carboxylic acids such as trimellitic acid and pyromellitic acid, and carboxylic acid anhydrides such as trimellitic anhydride and pyromellitic anhydride Etc., and one kind or a mixture of two or more kinds can be used.

  When a dicarboxylic acid other than the α, ω-linear aliphatic dicarboxylic acid is used as the dicarboxylic acid component, it is preferable to use isophthalic acid from the viewpoint of molding processability and barrier properties. The proportion of isophthalic acid is less than 30 mol% of the dicarboxylic acid structural unit, preferably 1 to 25 mol%, particularly preferably 5 to 20 mol%.

  As described above, the polyamide resin (A) preferably includes a polyamide resin obtained by polycondensation of xylylenediamine and adipic acid or sebacic acid, but metaxylylenediamine, adipic acid or sebacic acid and The proportion of the polyamide resin obtained by polycondensation is preferably 60% by mass or more in the polyamide resin (A), more preferably 75% by mass or more, still more preferably 90% by mass or more, and all of the component (A) Particularly preferred is a polyamide resin obtained by polycondensation of xylylenediamine and adipic acid or sebacic acid.

A method for producing a polyamide resin from xylylenediamine and an α, ω-linear aliphatic dicarboxylic acid is not particularly limited, and a conventionally known method such as an atmospheric pressure melt polymerization method or a pressure melt polymerization method, polymerization Manufactured according to conditions.
For example, it is produced by a method in which a polyamide salt composed of xylylenediamine and a dicarboxylic acid such as adipic acid is heated in the presence of water under pressure and polymerized in a molten state while removing added water and condensed water. It can also be produced by a method in which xylylenediamine is directly added to a molten dicarboxylic acid and polycondensed under normal pressure. In this case, in order not to solidify the reaction system, xylylenediamine is continuously added, and the reaction system is heated up so that the reaction temperature is higher than the melting point of the generated oligoamide and polyamide, while the reaction system is heated. Condensation proceeds.

  In addition, the polycondensation reaction system includes lactams such as ε-caprolactam, ω-laurolactam, ω-enantolactam, 6-aminocaproic acid, 7-aminoheptanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, 9 -Amino acids such as aminononanoic acid and paraaminomethylbenzoic acid may be added as long as the performance is not impaired.

Further, it is possible to use a material which has been further heat-treated to increase the melt viscosity.
As a heat treatment method, for example, using a batch-type heating device such as a rotating drum, in an inert gas atmosphere or under reduced pressure, it is heated gently in the presence of water, and crystallized while avoiding fusion. After that, after heating and crystallizing using a grooved stirring and heating method, a method of further heat treatment, using a hopper-shaped heating device, the heat treatment is performed in an inert gas atmosphere. And a method of performing a heat treatment using a batch heating device such as a rotating drum after crystallization using a groove type stirring and heating device.
Among these, a method of performing crystallization and heat treatment using a batch heating apparatus is preferable. As conditions for the crystallization treatment, the temperature is raised to 70 to 120 ° C. in the presence of 1 to 30% by mass of water with respect to the polyamide resin obtained by melt polymerization, and over 0.5 to 4 hours. Crystallized, and then in an inert gas atmosphere or under reduced pressure, at a temperature of [melting point of polyamide resin obtained by melt polymerization−50 ° C.] to [melting point of polyamide resin obtained by melt polymerization−10 ° C.]. Conditions for heat treatment for ˜12 hours are preferred.

The melting point of the polyamide resin (A) is preferably controlled in the range of 150 ° C to 300 ° C, more preferably 160 to 280 ° C, still more preferably 170 to 270 ° C, and particularly preferably 180 to 260 ° C. It is preferable that the melting point be in the above range because processability and heat resistance tend to be improved.
Moreover, it is preferable that the glass transition point of a polyamide resin (A) is the range of 50-130 degreeC. By making the glass transition point in the above range, the barrier property tends to be good, which is preferable.
The melting point and glass transition point of the polyamide resin (A) can be measured by a differential scanning calorimetry (DSC) method. After the sample is heated and melted once, the influence of the thermal history on the crystallinity is eliminated, and then again. It refers to the melting point and glass transition point measured at elevated temperatures. Specifically, for example, the temperature is increased from 30 ° C. to a temperature not lower than the expected melting point at a rate of 10 ° C./min, held for 2 minutes, and then decreased to 50 ° C. at a rate of 20 ° C./min. Next, the temperature is raised to a temperature higher than the melting point at a rate of 10 ° C./min, and the melting point and glass transition point can be determined.

The polyamide resin (A) preferably has a terminal amino group concentration of less than 100 μequivalent / g, more preferably 5 to 75 μequivalent / g, still more preferably 10 to 50 μequivalent / g, and a terminal carboxyl group concentration of preferably 100 μequivalent / g. Those having less than g, more preferably 10 to 90 μeq / g, and still more preferably 10 to 50 μeq / g are preferably used.
The polyamide resin (A) preferably has a relative viscosity of 1.7 to 4 measured in 96% sulfuric acid at a resin concentration of 1 g / 100 cc and a temperature of 25 ° C., more preferably 1.9 to 3.8. preferable. If the relative viscosity is less than 1.7, the mechanical strength tends to decrease, and if it exceeds 4, the moldability may decrease.

  The number average molecular weight of the polyamide resin (A) is preferably 6,000 to 50,000, and more preferably 10,000 to 43,000. If the number average molecular weight is less than 6,000, the mechanical strength tends to decrease, and if it exceeds 50,000, the moldability may decrease.

  The polyamide resin (A) may contain a phosphorus compound in order to increase the processing stability during melt molding or to prevent the polyamide resin from being colored. As the phosphorus compound, a phosphorus compound containing an alkali metal or an alkaline earth metal is preferably used, and examples thereof include phosphates such as sodium, magnesium, and calcium, hypophosphites, and phosphites. Among these, it is preferable to contain a hypophosphite of an alkali metal or an alkaline earth metal because the anti-coloring effect of the polyamide resin is particularly excellent. When using a phosphorus compound, it is contained in the polyamide resin (A) so that the phosphorus atom concentration in the polyamide resin composition (A) is 200 ppm or less, preferably 160 ppm or less, more preferably 100 ppm or less. desirable.

(2) Siloxane compound (B)
The siloxane compound (B) used in the present invention is an organosilicon compound having a siloxane bond as a skeleton and an organic group or the like directly bonded to the silicon. As the organic group directly bonded to silicon, methyl group, ethyl group, phenyl group, vinyl group, trifluoropropyl group, and combinations thereof are known, but known siloxane compounds having these are particularly limited. Can be used without Some organic groups were substituted with substituents having epoxy groups, amino groups, polyether groups, carboxyl groups, mercapto groups, ester groups, chloroalkyl groups, alkyl groups having 3 or more carbon atoms, hydroxyl groups, and the like. Siloxane compounds can also be used. A siloxane compound can be used individually or in combination of 2 or more types.

Siloxane compounds are classified into silicone oils, silicone elastomers, and silicone resins based on the degree of crosslinking. Regarding these siloxane compounds, reference can be made to the description in “Silicone Material Handbook” (issued and edited by Toray Dow Corning Silicone Co., Ltd., published in August 1993).
As the siloxane compound (B), any of the above-mentioned classifications can be used. Among them, silicone resins and silicone oils are preferable from the viewpoints of handling property and coating film adhesion. Specific examples of the silicone oil include dimethyl silicone oil, phenylmethyl silicone oil, alkyl-modified silicone oil, fluorosilicone oil, polyether-modified silicone oil, aliphatic ester-modified silicone oil, amino-modified silicone oil, carboxylic acid-modified silicone oil, Examples include oily silicones such as carbinol-modified silicone oil, epoxy-modified silicone oil, and mercapto-modified silicone oil.
As the kinematic viscosity of the silicone oil, the kinematic viscosity at 25 ° C. is preferably 50,000 cst, 150,000 cSt or more, more preferably 500,000 cSt or more. The upper limit of kinematic viscosity is usually about 10,000,000 cst.

Moreover, in this invention, it is preferable to mix | blend the mixture which made the thermoplastic resin contain the siloxane compound (B) previously with the polyamide resin (A) and the fluororesin (C). Specifically, it is preferable to blend as a master batch in the form of pellets in which a siloxane compound is dispersed in a thermoplastic resin at a high concentration. Moreover, what was masterbatched using the polyamide resin as a thermoplastic resin is preferable.
As a method for producing a masterbatch, a conventionally known method can be adopted, and examples thereof include a ribbon blender, a Henschel mixer, a Banbury mixer, a drum tumbler, a short-shaft or multi-screw extruder, and the like. Among them, a method using a Henschel mixer, a short-shaft or multi-screw extruder is preferable, and a method of melt-kneading and pelletizing using a short-shaft or multi-screw extruder is particularly preferable. Thus, by making it into a master batch and melt-kneading at the time of manufacture, it exists in the tendency for the mechanical characteristics and slidability of a molded article to become more favorable.
As such a siloxane compound masterbatch, a commercially available product can be used. Examples thereof include Toray Dow Corning Silicone Co., Ltd., trade name silicone concentrate BY27 series, and the like.
The preferable content of the siloxane compound in the siloxane compound (B) masterbatch is 10 to 80% by mass, more preferably 20 to 70% by mass, and still more preferably 30 to 60% by mass.

  The content of the siloxane compound (B) is 1 to 30 parts by mass, preferably 3 to 25 parts by mass, more preferably 3 to 20 parts by mass, particularly preferably 100 parts by mass of the polyamide resin (A). Is 3 to 15 parts by mass. If the content is less than 1 part by mass, sufficient wear resistance and slidability cannot be obtained. Moreover, when it exceeds 30 mass parts, in addition to inferior extrudability and molding processability when the resin composition is produced by melt kneading, mechanical properties also deteriorate.

(3) Fluorine resin (C)
The fluororesin (C) used in the present invention is a synthetic polymer containing a fluorine atom (F) in the molecule. For example, polytetrafluoroethylene, polyhexafluoropropylene, tetrafluoroethylene / hexa Fluoropropylene copolymer, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene / ethylene copolymer, hexafluoropropylene / propylene copolymer, polyvinylidene fluoride, vinylidene fluoride / ethylene copolymer, etc. Is mentioned.
Among them, polytetrafluoroethylene, tetrafluoroethylene / barfluoroalkyl vinyl ether copolymer, tetrafluoroethylene / hexafluoropropylene copolymer, tetrafluoroethylene / ethylene copolymer, and polyvinylidene fluoride are particularly preferable. Ethylene is preferred.

The fluororesin (C) preferably has an average particle diameter of 5 to 25 μm, more preferably 10 to 20 μm. When such a particle size is used, it is easy to disperse and hardly agglomerate, and in particular, the effect of improving the wear resistance can be enhanced.
Further, the weight average molecular weight of the fluororesin (C) is preferably 10,000 or more, more preferably 30,000 or more, further preferably 50,000 or more, and particularly preferably 100,000 or more. The upper limit of the weight average molecular weight is not particularly limited, but is usually 10,000,000 or less.

  Content of a fluororesin (C) is the range of 2-60 mass parts with respect to 100 mass parts of polyamide resins (A). When the fluororesin is less than 2 parts by mass, the reproducibility of the slidability of the resulting resin composition is lowered, and when the content is more than 60 parts by mass, the resin composition is produced by melt kneading. In this case, the extrudability and moldability deteriorate, and the mechanical properties also deteriorate. The content is preferably 5 to 50 parts by mass, more preferably 5 to 45 parts by mass, and particularly preferably 5 to 35 parts by mass.

  The total content of the siloxane compound (B) and the fluorine-based resin (C) is preferably 15 to 80 parts by mass, more preferably 20 to 70 parts by mass with respect to 100 parts by mass of the polyamide resin (A). By making the total content within the above range, it is possible to maintain the mechanical strength while ensuring extrudability and molding processability when the resin composition is produced by melt-kneading, and wear resistance of the resulting molded product. It is preferable because it tends to improve the properties.

(4) Reinforcing filler (D)
The resin composition of the present invention preferably contains a reinforcing filler (D). The reinforcing filler (D) may be an organic filler or an inorganic filler. For example, glass fiber, glass flake, glass bead, carbon fiber, silica, silica / alumina fiber, zirconia fiber, boron fiber, boron nitride fiber, nitriding Silicon fiber, potassium titanate fiber, stainless steel fiber, aluminum, titanium, copper, brass, talc, mica, kaolin, wollastonite, calcium carbonate, titanium oxide, zinc oxide, barium sulfate, potassium titanate whisker, aluminum borate whisker Inorganic fibers such as metal fibers, other inorganic fillers, and organic fibers (for example, aromatic polyamide fibers, liquid crystalline aromatic polyester fibers, etc.).
In the present invention, preferred reinforcing filler (D) includes inorganic fibers (for example, glass fibers). The glass fiber of the preferable reinforcing filler is not particularly limited as long as it is usually used for a thermoplastic resin, but chopped strand made from E glass (non-alkali glass) is preferable. The reinforcing filler (D) can be used alone or in combination of two or more.

  When the reinforcing filler (D) is an inorganic or organic fiber, the average fiber diameter is not particularly limited, and is, for example, 1 to 100 μm, preferably 1 to 50 μm, more preferably 3 to 30 μm, still more preferably 1 to 20 μm. The average fiber length is not particularly limited, but is, for example, about 0.1 to 20 mm, preferably about 1 to 10 mm.

The reinforcing filler (D) is a sizing agent or a surface treatment agent (for example, an epoxy compound, an acrylic compound, an isocyanate compound, a silane compound, in order to improve interfacial adhesion with the polyamide resin (A). It is preferable to use those surface-treated with a functional compound such as a titanate compound). The reinforcing filler (D) may be surface-treated in advance with the sizing agent or surface treatment agent, or may be surface-treated by adding a sizing agent or surface treatment agent during the preparation of the polyamide resin composition. .
The content of the reinforcing filler (D) is preferably 10 to 250 parts by weight, more preferably 20 to 200 parts by weight, more preferably 30 to 160 parts by weight, particularly preferably 100 parts by weight of the polyamide resin (A). Is 40 to 150 parts by mass. If the content exceeds 250 parts by mass, the fluidity may be remarkably lowered, the moldability and appearance may be impaired, and if the content is small, the mechanical properties may be reduced, which is not preferable.

(5) Other components In addition, in the polyamide resin composition of the present invention, a crystal nucleating agent, a conductive agent, a lubricant, a plasticizer, a copper halide (for example, Stabilizers such as copper iodide, copper chloride, copper bromide) and / or alkali metal halides (for example, potassium iodide, potassium bromide, etc.) and antioxidants such as hindered phenols and phosphites , Releasability improvers, pigments, dyes, dispersants, antistatic agents, ultraviolet absorbers and other well-known additives can be blended.
Moreover, you may mix | blend other resin other than a polyamide resin (A) in the range which does not impair the effect of this invention. Specific examples of the other resins include polyamide resins other than the polyamide resin (A), polyester resins, polycarbonate resins, polyphenylene ether resins, polyacetal resins, polyimide resins, and the like. A mixture of seeds or more can be used.

(6) Manufacturing method of polyamide resin composition The manufacturing method of the polyamide resin composition of this invention is not specifically limited, A polyamide resin (A), a siloxane compound (B), a fluorine resin (C), and a necessity It can manufacture by mixing and kneading | mixing the other component mix | blended according to according to arbitrary orders. Of these, a melt kneading method using various commonly used extruders such as a single screw or twin screw extruder is preferable, and a method using a twin screw extruder is particularly preferable from the viewpoint of productivity and versatility.
At that time, although the melt kneading temperature depends on the type of the polyamide resin, it is usually preferable to adjust the melting point of the polyamide resin to the melting point or higher, for example, 200 to 300 ° C., and the residence time to 10 minutes or less. It is preferable to have reverse screw elements and / or kneading discs at more than one location, and melt knead while retaining part of the screw elements. By setting the melt-kneading temperature within the above range, it tends to be difficult for extrusion-kneading failure and resin decomposition to occur.

Further, as described above, the siloxane compound (B) is preferably blended as a master batch in the form of pellets in which the siloxane compound is dispersed in a thermoplastic resin at a high concentration, particularly a polyamide resin.
Similarly, in order to improve the dispersibility of each component in the resin composition and the molded product, after obtaining a masterbatch containing a larger amount of each component than the final blending amount, the masterbatch is converted into a pellet shape or powder. The polyamide resin composition of the present invention can also be obtained by melt-kneading the required amount of the polyamide resin (A) in the form of granules and other desired components or the remaining components.

(7) Molded product In the present invention, a molded product can be produced by melt-kneading, extruding, and molding the pelletized polyamide resin composition pellets of the present invention by various molding methods. Further, the resin melt-kneaded by an extruder can be directly formed into an extrusion molded product, a blow molded product, an injection molded product or the like without going through the pellets.
The polyamide resin composition of the present invention can be used as a molding material for various molded products. There is no limitation on the shape, pattern, color, size, etc. of the molded product, and it may be set arbitrarily according to the application. As the applicable molding method, a method applicable to the molding of a thermoplastic resin can be applied as it is, an injection molding method, an extrusion molding method, a hollow molding method, a rotational molding method, a compression molding method, a differential pressure molding method, a transfer molding. Law.

As the use of the obtained molded product, various members that require slidability and / or wear resistance are suitable, and a movable or non-movable member having a sliding portion is preferable. In particular, it is suitable for a member having a sliding part with a molded product formed by molding a polyamide resin. Specifically, for example, as a material for sliding members of electrical / electronic equipment, office equipment, automobiles, industrial equipment, etc., bearings, gears, cams, rollers, accelerator pedal rotors, sliding plates, pulleys, levers As a material for a sliding member such as a guide, it can be suitably used as a component that requires high performance in a wide range of fields.
In particular, it is used for a member having a sliding part with a molded product formed by molding a polyamide resin, for example, an accelerator pedal rotor that contacts an accelerator pedal molded from a polyamide resin and slides when it operates. Is particularly preferred.

Hereinafter, the present invention will be described specifically by way of examples.
[Materials used]
Each component used in the following Examples and Comparative Examples is as follows.

<Polyamide resin (A)>
-Polymetaxylylene adipamide:
Product name “MX Nylon # 6000” manufactured by Mitsubishi Gas Chemical Company, Inc.
Melting point 240 ° C., glass transition point 85 ° C., number average molecular weight 15,000
Relative viscosity 2.17 (96% sulfuric acid, resin concentration 1 g / 100 ml, measured at 25 ° C.)
Terminal amino group concentration 39 μequivalent / g, terminal carboxyl group concentration 84 μequivalent / g
Hereinafter, it is abbreviated as “MXD6”.
Polyamide 66:
Melting point 265 ° C., glass transition point 50 ° C., relative viscosity 3.0 (96% sulfuric acid, resin concentration 1 g / 100 ml, measured at 25 ° C.)

<Siloxane compound (B)>
・ Organopolysiloxane masterbatch:
Product name "BY27-005", manufactured by Toray Dow Corning
Base resin: polyamide 66 (content 50 mass%)
Polydimethylsiloxane content 50% by mass
In the table, “silicone” is abbreviated.
In addition, in Tables 1-2, the quantity of the siloxane compound contained substantially was described. Further, the blending amounts of the polyamide 66 and the polyamide 66 used for the base resin of the organopolysiloxane masterbatch are combined and listed in the “PA66” column.

<Fluorine resin (C)>
Polytetrafluoroethylene:
Product name "Lublon L5F" manufactured by Daikin Industries, Ltd.
Hereinafter, abbreviated as “PTFE”.

<Glass fiber>
Chopped strand manufactured by Nippon Electric Glass Co., Ltd., trade name “T-296GH”
Hereinafter, it is abbreviated as “GF”.
<Talc>
Product name “Micron White 5000A” manufactured by Hayashi Kasei Co., Ltd.

[Examples 1-6 and Comparative Examples 1-8]
After dry blending each component other than PTFE and glass fiber described in Tables 1 and 2 at a ratio described in Tables 1 and 2 below, the obtained dry blend was made into a twin screw extruder (manufactured by Toshiba Machine Co., Ltd.). “TEM26SS”) was charged from the base, PTFE was charged into the base by a separate feed and melted, and then glass fibers were side-fed to produce resin composition pellets.
The temperature setting of the extruder was 280 ° C., and the discharge rate was 30 kg / hr.
The obtained pellets were dried at 80 ° C. for 12 hours, and then injection molding was carried out at a setting of a cylinder temperature of 275 ° C. and a mold temperature of 130 ° C. with an injection molding machine “NEX80” manufactured by Nissei Plastic Industry Co., Ltd. A test piece (test piece 1) having a size of 60 × thickness of 3 mm was prepared and evaluated by the following method.
The results are shown in Tables 1-2.

[Evaluation methods]
(1) Sliding property (1-1) Coefficient of dynamic friction Using a thrust type friction and wear tester manufactured by Orientec Co., Ltd. Measurement was performed using the test piece 2 as a counterpart material.
The test piece 2 of the mating material was made of 30% by mass glass fiber reinforced polyamide 66 (manufactured by Mitsubishi Engineering Plastics, trade name “Novamid 3021G30”). Injection molding was performed at a temperature of 275 ° C. and a mold temperature of 130 ° C., and a cylindrical thrust test piece having an outer diameter of 26 mm, an inner diameter of 23 mm, and a height of 15 mm was formed.
Measurement conditions were as follows: a test piece stored at 23 ° C. and humidity of 50%, kept in an absolutely dry state, with a surface pressure of 3 MPa, an average inner diameter of the rotary motion of 30 mm / second, a test time of 1,000 minutes, and a dynamic friction coefficient. Was measured. The results are shown in Tables 1-2.
The measurement was performed five times by the above method, and the one having the lowest dynamic friction coefficient was evaluated according to the following criteria.
○: The coefficient of dynamic friction is small and is always 0.3 or less.
X: A dynamic friction coefficient is large and exceeds 0.3.
Moreover, the example of the measurement result of the dynamic friction coefficient from the initial stage (0 minutes) to the last stage (1,000 minutes) is shown in FIGS. In the figure, the horizontal axis represents time (minutes) and the vertical axis represents the dynamic friction coefficient. FIG. 1 shows the results corresponding to the example of the present invention, and FIGS. 2 and 3 show the results corresponding to the comparative example.

(1-2) Stability Measurement was performed five times by the above method, and the stability of the measurement was evaluated according to the following criteria.
○: Reproducibility of measurement is good, and all five measurements show a stable result with a low coefficient of dynamic friction and a small fluctuation as shown in FIG.
X: The reproducibility of the measurement is poor, and a result with a large fluctuation of the dynamic friction coefficient as shown in FIG. 2 or 3 is shown in at least one measurement out of five measurements.

(2) Mechanical properties After the resin composition pellets of Example 1 obtained by the method described above were dried at 80 ° C. for 12 hours, an injection molding machine (“α-100iA” manufactured by FANUC) was used, and the cylinder An ISO test piece was molded at a temperature of 275 ° C. and a mold of 130 ° C. Using the obtained test piece, the bending strength and the flexural modulus were measured according to the ISO 178 standard, and the notched and unnotched Charpy impact values were measured according to the ISO 179-1 and 179-2 standards. The results are shown in Table 1.

  The polyamide resin composition of the present invention has excellent slidability and mechanical properties, and is excellent in stability of sliding characteristics, such as bearings, gears, cams, rollers, accelerator pedal rotors, sliding plates, pulleys. As a sliding part material such as lever, guide, etc., it can be suitably used as a part that requires high performance in a wide range of fields such as electrical / electronic equipment, office equipment, automobiles, industrial equipment, etc. Is very expensive.

Claims (8)

  A polyamide resin composition comprising 1 to 30 parts by mass of a siloxane compound (B) and 2 to 60 parts by mass of a fluororesin (C) with respect to 100 parts by mass of a polyamide resin (A).   The polyamide resin according to claim 1, wherein the polyamide resin (A) is a xylylenediamine-based polyamide resin obtained by a polycondensation reaction of xylylenediamine and an α, ω-linear aliphatic dicarboxylic acid. Composition.   The polyamide resin composition according to claim 1 or 2, wherein the siloxane compound (B) is an organopolysiloxane.   The polyamide resin composition according to any one of claims 1 to 3, wherein the fluororesin (C) is polytetrafluoroethylene.   Furthermore, 10-250 mass parts of reinforcement fillers (D) are contained with respect to 100 mass parts of polyamide resin (A), The polyamide resin composition of any one of Claims 1-4 characterized by the above-mentioned. .   The mixture of the thermoplastic resin previously containing the siloxane compound (B) is contained in the polyamide resin (A) and the fluororesin (C), according to any one of claims 1 to 5. Polyamide resin composition.   The molded article formed by shape | molding the polyamide resin composition of any one of Claims 1-6.   A molded article formed by molding the polyamide resin composition according to any one of claims 1 to 6 is used for a member having a portion that slides with a molded article formed by molding a polyamide resin. Use method of a polyamide resin composition.

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