Polyamide resin composition, molded article, and sliding member

Abstract

To provide a polyamide resin composition having superior sliding properties and mechanical characteristics, and capable of maintaining stable sliding properties without dependence on sliding environments in an injection molding step included as one step in its production process, or in broad industrial applications.SOLUTION: A polyamide resin composition comprises a component (A), which is a polyamide resin, and a component (B), which is a modified polyorganosiloxane-based copolymer having at least a reactive portion on its side chain, wherein the mass of the component (B), relative to 100 pts.mass of the component (A), is in a range of 0.1 to 15 pts.mass, and the component (B) is dispersed in the polyamide resin composition, such that the number-average dispersion diameter of the dispersed component (B) is 5 μm or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyamide resin composition, a molded article, and a sliding member. [Background technology]

[0002] Polyamide resins are excellent in sliding properties, moldability, mechanical properties, chemical resistance, etc. Polyamide resins have been widely used as parts materials for industrial materials, automobiles, electrical and electronic equipment, and other industrial applications.

[0003] In recent years, metal components have been increasingly replaced with resins in the fields of automobiles, electrical and electronics, etc. Recently, in the automobile field, from the viewpoints of weight reduction for improved fuel economy, cost reduction, and streamlining of assembly processes, there is a demand for molding materials that have superior sliding properties and mechanical properties such as toughness and impact resistance.

[0004] A known method for further improving the sliding properties of polyamide resin is to blend and knead a solid lubricant such as a fluorine-based resin, graphite, or molybdenum disulfide with the polyamide resin.

[0005] Patent Documents 2 to 4 disclose polyamide resin compositions in which a fluorine-based resin is blended with a polyamide resin to improve sliding properties, while Patent Document 1 discloses a sliding member for a power transmission guide obtained by dispersing a polyolefin-based resin in a polyamide resin. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-117842 [Patent Document 2] International Publication No. 2013 / 047625 [Patent Document 3] Japanese Patent Application Laid-Open No. 2011-084679 [Patent Document 4] Japanese Patent Application Laid-Open No. 2012-102189 Summary of the Invention [Problem to be solved by the invention]

[0007] As a technique for improving sliding properties, blending a fluororesin into a polyamide resin has been proposed. Examples of the fluororesin to be blended include polytetrafluoroethylene. When polytetrafluoroethylene is used, it is necessary to melt-knead the polytetrafluoroethylene under high shear conditions at a temperature equal to or higher than the melting point of the polytetrafluoroethylene in order to finely disperse the polytetrafluoroethylene. As a result of the melt-kneading, there is a problem that the polyamide resin deteriorates and the mechanical strength decreases.

[0008] Blending polyolefin resins with polyamide resins has also been proposed as a technique for improving sliding properties. However, polyamide resins and polyolefin resins have different melt viscosities and SP values. Furthermore, the melt viscosities of polyamide resins and polyolefin resins vary significantly depending on the shear rate applied during production. As a result of the large difference in melt viscosities between polyamide resins and polyolefin resins, the morphology of the polyolefin resins becomes unstable, which significantly affects the mechanical and sliding properties. Furthermore, it has been impossible to exhibit stable sliding properties due to differences in various conditions, such as sliding parts, test environment, and exposure conditions.

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a polyamide resin composition which has excellent sliding properties and mechanical properties and which exhibits stable sliding properties and excellent mechanical properties even under various conditions such as different sliding parts and / or different test environments and exposure conditions. [Means for solving the problem]

[0010] The present invention includes the following aspects. [1] (A) component: polyamide resin, (B) component: a modified polyorganosiloxane copolymer having at least a reactive moiety in its side chain; A polyamide resin composition comprising: the mass of the component (B) is 0.1 to 15 parts by mass relative to 100 parts by mass of the component (A); the component (B) is dispersed in the polyamide resin composition, A polyamide resin composition, wherein the number average dispersed diameter of the dispersed component (B) is 5 μm or less. [2] The polyamide resin composition according to [1], wherein the reactive moiety is at least one selected from the group consisting of a glycidyl group, an acryloyl group, a methacryloyl group, a carboxylic acid anhydride-derived structural unit, and an amino structural unit. [3] The component (A) has a terminal carboxyl group and a terminal amino group, The polyamide resin composition according to [1] or [2], wherein the difference (CA) between the concentration C (mmol / kg) of the terminal carboxyl groups in the component (A) and the concentration A (mmol / kg) of the terminal amino groups in the component (A) is in the range of 30 to 130 mmol / kg. [4] The polyamide resin composition according to [3], wherein B is the mass part of the component (B) minus the siloxane component, and B and the concentration C satisfy the relationship C×B=50 to 300. [5] The polyamide resin composition according to any one of [1] to [4], wherein the component (B) is a graft copolymer. [6] The polyamide resin composition according to any one of [1] to [5], wherein the number average dispersed diameter is 2 μm or less. [7] The polyamide resin composition according to any one of [1] to [6], wherein the proportion of the siloxane component in the component (B) is 50 to 90%. [8] A molded article of the polyamide resin composition according to any one of [1] to [7]. [9] A sliding member comprising the polyamide resin composition according to any one of [1] to [7].

[10] The sliding member according to [9], which is used in a liquid lubrication environment.

[11] The sliding member according to [9] or

[10] , wherein the material that the sliding member comes into contact with is other than a thermoplastic resin. [Effects of the Invention]

[0011] According to the present invention, a polyamide resin composition can be obtained which has excellent sliding properties and mechanical properties and stable sliding properties that are not dependent on the shear rate applied in the injection molding step during the production process. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, a mode for carrying out the present invention (hereinafter referred to as "the present embodiment") will be described in detail. The following present embodiment is an example for explaining the present invention, and is not intended to limit the present invention to the following content. The present invention can be carried out by appropriately modifying it within the scope of its gist.

[0013] In this specification, the term "polyamide" refers to a polymer having an amide (-NHCO-) ​​group in the main chain.

[0014] Unless otherwise specified, numerical ranges used herein are intended to include the lower and upper limits of the range. For example, "0.1 to 15 parts by mass" means 0.1 to 15 parts by mass.

[0015] <Polyamide resin composition> The polyamide resin composition of the present embodiment is (A) component: polyamide resin, (B) component: a modified polyorganosiloxane copolymer having at least a reactive moiety in its side chain; Contains the mass of the component (B) is 0.1 to 15 parts by mass relative to 100 parts by mass of the component (A); the component (B) is dispersed in the polyamide resin composition, The number average dispersed diameter of the dispersed component (B) is 5 μm or less.

[0016] Hereinafter, each component of the polyamide resin composition of the present embodiment will be described.

[0017] <(A) Polyamide resin> In this embodiment, the polyamide resin (A) may be, but is not limited to, (a-1) a polyamide obtained by ring-opening polymerization of a lactam, (a-2) a polyamide obtained by self-condensation of an ω-aminocarboxylic acid, (a-3) a polyamide obtained by condensation of a diamine and a dicarboxylic acid, or a copolymer thereof.

[0018] As the (A) polyamide resin, only one of the above polyamides may be used alone, or two or more of them may be used as a mixture.

[0019] (a-1) Examples of lactams used in the production of polyamide include, but are not limited to, pyrrolidone, caprolactam, undecalactam, and dodecalactam.

[0020] (a-2) The ω-aminocarboxylic acid used in the production of polyamide is not limited to the following, but examples thereof include ω-amino fatty acids, which are ring-opened compounds of the above lactams with water. Furthermore, two or more kinds of the lactam or ω-aminocarboxylic acid may be used in combination and condensed.

[0021] (a-3) Diamines (monomers) used in the production of polyamides include, but are not limited to, linear aliphatic diamines, branched aliphatic diamines, alicyclic diamines, and aromatic diamines.

[0022] Examples of the linear aliphatic diamine include, but are not limited to, hexamethylenediamine and pentamethylenediamine.

[0023] Examples of branched aliphatic diamines include, but are not limited to, 2-methylpentanediamine and 2-ethylhexamethylenediamine.

[0024] Examples of alicyclic diamines include, but are not limited to, cyclohexanediamine, cyclopentanediamine, and cyclooctanediamine.

[0025] Examples of aromatic diamines include, but are not limited to, p-phenylenediamine and m-phenylenediamine.

[0026] (a-3) Dicarboxylic acids (monomers) used in the production of polyamides include, but are not limited to, aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, aromatic dicarboxylic acids, and the like.

[0027] Examples of the aliphatic dicarboxylic acid include, but are not limited to, adipic acid, pimelic acid, and sebacic acid.

[0028] The alicyclic dicarboxylic acid is not limited to the following, but examples thereof include cyclohexanedicarboxylic acid.

[0029] Examples of aromatic dicarboxylic acids include, but are not limited to, phthalic acid and isophthalic acid.

[0030] The diamines and dicarboxylic acids as the monomers may be condensed either alone or in combination of two or more.

[0031] Examples of the polyamide of component (A) include, but are not limited to, polyamide 4 (poly-α-pyrrolidone), polyamide 6 (polycaproamide), polyamide 11 (polyundecaneamide), polyamide 12 (polydodecanamide), polyamide 46 (polytetramethylene adipamide), polyamide 66 (polyhexamethylene adipamide), polyamide 610 (polyhexamethylene sebacamide), polyamide 612 (polyhexamethylene dodecamide), polyamide 6T (polyhexamethylene Examples of suitable polyamides include polyamide 9T (polynonamethylene terephthalamide), polyamide 6I (polyhexamethylene isophthalamide), polyamide 2Me5T (poly-2-methylpentamethylene terephthalamide (hereinafter, the methyl group may be abbreviated as Me)), polyamide MXD6 (polymetaxylylene adipamide), and polyamide PXD12 (polyparaxylylene dodecamide), as well as copolymer polyamides containing at least one of these as a constituent component.

[0032] (Composition ratio of component (A)) From the viewpoint of improving sliding properties, the polyamide resin (A) of this embodiment is preferably a polyamide resin whose main component is polyamide 66, polyamide 46, polyamide 4T, polyamide 6T, polyamide 9T, polyamide 6, or polyamide 610. Hereinafter, "main component" means that the content of the polyamide resin as the main component relative to the total mass of the polyamide resin (A) is 50 mass% or more.

[0033] Furthermore, from the viewpoint of improving heat resistance, the (A) polyamide resin is preferably a polyamide resin having polyamide 66, polyamide 46, polyamide 4T, polyamide 6T, polyamide 9T, or polyamide PXD12 as a main component, and more preferably a polyamide resin having polyamide 66 as a main component.

[0034] In one embodiment, component (A) has a terminal carboxyl group and a terminal amino group.

[0035] (Terminal amino group concentration) The terminal amino group concentration of the (A) polyamide resin is not particularly limited, but is preferably 20 mmol / kg or more, more preferably 30 mmol / kg or more, even more preferably 40 mmol / kg or more, particularly preferably 60 mmol / kg or more, and most preferably 80 mmol / kg or more. The upper limit of the terminal amino group concentration of the (A) polyamide resin is not particularly limited, but can be, for example, 120 mmol / kg.

[0036] The terminal carboxyl group concentration of the (A) polyamide resin is not particularly limited, but a high terminal carboxyl group concentration can improve compatibility with the (B) component. Therefore, by increasing the terminal carboxyl group concentration, the number average dispersion diameter of the (B) component can be reduced, improving the sliding properties. It is desirable to increase the terminal carboxyl group concentration relative to the terminal amino group concentration of the (A) polyamide resin. The difference between the terminal carboxyl group and terminal amino group concentrations is preferably 80±50 mmol / kg or less, more preferably 80±40 mmol / kg or less, even more preferably 80±30 mmol / kg or less, and most preferably 80±20 mmol / kg or less.

[0037] The terminal group concentration of the (A) polyamide resin can be measured by neutralization titration, nuclear magnetic resonance analysis, etc. Specifically, it can be measured by the method described in the examples below.

[0038] (Relative viscosity of component (A) in sulfuric acid) The relative viscosity in sulfuric acid of the (A) polyamide resin is preferably 2.0 or more, more preferably 2.1 or more, even more preferably 2.3 or more, and most preferably 3.2 or more, and the relative viscosity in sulfuric acid of the (A) polyamide resin is preferably 4.5 or less, more preferably 4.4 or less, and most preferably 4.3 or less.

[0039] When the relative viscosity in sulfuric acid is 2.0 or more, a polyamide resin composition having better mechanical properties tends to be obtained, and when the relative viscosity in sulfuric acid is 4.5 or less, a polyamide resin composition having better flowability and processability tends to be obtained. The sulfuric acid relative viscosity can be measured by the method specified in JIS-K6920, which will be described later in the Examples section.

[0040] As the component (A) in the polyamide resin composition of the present embodiment, known products can be used, and commercially available products may also be used.

[0041] <(B) Modified polyorganosiloxane copolymer having at least a reactive moiety in its side chain> In this embodiment, the modified polyorganosiloxane copolymer (B) having a reactive moiety is not particularly limited as long as it is a modified polyorganosiloxane copolymer having a reactive moiety. As the component (B), the reactive moiety is preferably at least one selected from the group consisting of glycidyl, acrylic, carboxylic anhydride-derived, and amino structural units, and more preferably, the modified polyorganosiloxane copolymer having a reactive moiety is a graft copolymer.

[0042] By including the component (B), the sliding properties of the resulting polyamide resin composition are improved.

[0043] [Method for preparing component (B)] The method for preparing component (B) is not limited to the following. A silane coupling agent is added during polymerization of a cyclic organosiloxane to produce (i) a polyorganosiloxane represented by general formula (1). Subsequently, a modified polyorganosiloxane having a reactive moiety is preferably obtained by emulsion graft polymerization of a mixture of (i) a polyorganosiloxane, (ii) an acrylic acid ester monomer or a methacrylic acid ester monomer, and (iii) a monomer copolymerizable with the polyorganosiloxane and having a reactive moiety containing a carboxyl group, an amide group, and / or a structural unit derived from a hydroxyl group, a glycidyl group, or a carboxylic acid anhydride. Alternatively, the modified polyorganosiloxane can be obtained by emulsion graft polymerization of a mixture of the polyorganosiloxane, (ii) an acrylic acid ester monomer, and (iii) a functional group-containing monomer copolymerizable with the polyorganosiloxane. [ka] (In the formula, R is the same or different, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms; X is the same or different, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms or a hydroxyl group; Y is the same or different, a group represented by X or —[O—Si(X)2]cX, and at least two of X and Y are hydroxyl groups; a is a number from 0 to 1,000; b is a positive number from 100 to 10,000; and c is a positive number from 1 to 1,000.)

[0044] Here, R is, but is not limited to, the same or different, substituted or unsubstituted alkyl group having 1 to 20 carbon atoms or aryl group having 6 to 20 carbon atoms, and specific examples thereof include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, cyclopentyl, cyclohexyl, cycloheptyl, phenyl, tolyl, and naphthyl groups. Examples of substituted alkyl groups include halogen atoms, acryloxy groups, methacryloxy groups, carboxy groups, alkoxy groups, alkenyloxy groups, amino groups, alkyl-, alkoxy-, or (meth)acryloxy-substituted amino groups, carboxyl groups, amide groups, and / or alkyl groups substituted with structural units derived from hydroxyl groups, glycidyl groups, and carboxylic acid anhydrides. R is preferably a methyl group.

[0045] X is, but is not limited to, the same or different, substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, alkoxy groups having 1 to 20 carbon atoms, or hydroxyl groups, and specific examples thereof include, in addition to hydroxyl groups, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, cyclopentyl, cyclohexyl, cycloheptyl, phenyl, tolyl, naphthyl, methoxy, ethoxy, propoxy, butoxy, hexyloxy, heptyloxy, octyloxy, decyloxy, tetradecyloxy groups, etc. Furthermore, examples of the substituted alkyl groups include those similar to those described above.

[0046] Y is X or the same or different groups represented by, but not limited to, for example, —[O—Si(X) 2 ] c X.

[0047] Although not limited to the following, a is a number from 0 to 1,000, preferably 0 to 200, because if it is greater than 1,000, the strength of the resulting film will be insufficient, while if b is less than 100, the film will have poor flexibility, and if it is greater than 10,000, the tear strength will decrease, so a is a positive number from 100 to 10,000, preferably 1,000 to 5,000, and c is a positive number from 1 to 1,000, preferably 1 to 200. From the viewpoint of crosslinkability, it is preferable to use a polymer having at least two, and preferably two to four, hydroxyl groups per molecule, with the groups formed at both ends.

[0048] Component (i) can be obtained, for example but not limited to, by ring-opening polymerization of a cyclic organosiloxane. The cyclic organosiloxanes used as raw materials include hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), 1,1-diethylhexamethylcyclotetrasiloxane, phenylheptamethylcyclotetrasiloxane, 1,1-diphenylhexamethylcyclotetrasiloxane, 1,3,5,7-tetravinyltetramethylcyclotetrasiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, 1,3,5,7-tetracyclohexyltetramethylcyclotetrasiloxane, tris(3,3,3-trifluoropropyl)trimethylcyclotrisiloxane, and 1,3,5,7-tetra(3-methacryloxypropyl)tetramethylcyclotetrasiloxane. Examples of the tetramethylcyclotetrasiloxane include 1,3,5,7-tetra(3-acryloxypropyl)tetramethylcyclotetrasiloxane, 1,3,5,7-tetra(3-carboxypropyl)tetramethylcyclotetrasiloxane, 1,3,5,7-tetra(3-vinyloxypropyl)tetramethylcyclotetrasiloxane, 1,3,5,7-tetra(p-vinylphenyl)tetramethylcyclotetrasiloxane, 1,3,5,7-tetra[3-(p-vinylphenyl)propyl]tetramethylcyclotetrasiloxane, 1,3,5,7-tetra(N-acryloyl-N-methyl-3-aminopropyl)tetramethylcyclotetrasiloxane, and 1,3,5,7-tetra(N,N-bis(lauroyl)-3-aminopropyl)tetramethylcyclotetrasiloxane.

[0049] Furthermore, the cyclic organosiloxane may be copolymerized with a silane coupling agent represented by the following general formula (2): The copolymerization of the silane coupling agent has the effect of assisting bonding of the organosiloxane with the monomer of component (ii) or (iii). R 3 (4-d-e) R 5 e Si(OR 4 ) d (2) (In the formula, R3 represents a monovalent organic group having a polymerizable double bond, particularly an alkyl group having 1 to 6 carbon atoms substituted with an acryloxy group or a methacryloxy group; R4 represents an alkyl group having 1 to 4 carbon atoms; R5 represents an alkyl group having 1 to 4 carbon atoms; d represents an integer of 1 to 3; e represents an integer of 0 to 2; and e+d=1 to 3.)

[0050] Specific examples include 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, etc. These silane coupling agents are preferably used in an amount of 0.01 to 20 parts by mass, more preferably 0.01 to 5 parts by mass, per 100 parts by mass of the cyclic organosiloxane.

[0051] The polymerization catalyst used in the polymerization of cyclic organosiloxane is preferably a strong acid, such as hydrochloric acid, sulfuric acid, dodecylbenzenesulfonic acid, citric acid, lactic acid, or ascorbic acid. Dodecylbenzenesulfonic acid, which has emulsifying properties, is preferred.

[0052] In addition, surfactants for use in polymerizing cyclic organosiloxanes include anionic surfactants such as sodium lauryl sulfate, sodium laureth sulfate, N-acylamino acid salts, N-acyltaurate salts, aliphatic soaps, and alkyl phosphates, among which those that are easily soluble in water and do not have polyethylene oxide chains are preferred.More preferred are N-acylamino acid salts, N-acyltaurate salts, aliphatic soaps, and alkyl phosphates, and particularly preferred are sodium lauroyl methyl taurate and sodium myristoyl methyl taurate.

[0053] The polymerization temperature for the cyclic organosiloxane is preferably 50 to 75° C., and the polymerization time is preferably 10 hours or more, more preferably 15 hours or more. Furthermore, it is particularly preferable to age the product after polymerization at 5 to 30° C. for 10 hours or more.

[0054] The (ii) acrylic acid ester or methacrylic acid ester (hereinafter sometimes referred to as the acrylic component) used in the present invention refers to an acrylic acid ester monomer or methacrylic acid ester monomer that does not have a functional group such as a hydroxy group, an amide group, or a carboxyl group, and is preferably an acrylic acid ester or methacrylic acid ester having an alkyl group having 1 to 10 carbon atoms. Furthermore, a monomer that gives an acrylic component polymer with a glass transition temperature (hereinafter sometimes referred to as Tg) of 40°C or higher, preferably 60°C or higher, is preferred. Examples of such monomers include butyl acrylate, methyl methacrylate, isopropyl methacrylate, ethyl methacrylate, and cyclohexyl methacrylate. The upper limit of Tg is preferably 200°C or lower, more preferably 150°C or lower.

[0055] The glass transition temperature can be measured in accordance with JIS K7121.

[0056] The functional group-containing monomer (iii) copolymerizable with component (ii) is a monomer having an unsaturated bond containing a carboxyl group, an amide group, a hydroxyl group, a vinyl group, an allyl group, or the like. Specific examples include methacrylic acid, acrylic acid, acrylamide, allyl methacrylate, vinyl methacrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate. By copolymerizing these, it is possible to improve compatibility.

[0057] Component (II) of the present invention is prepared by emulsion graft polymerizing (i) the polyorganosiloxane obtained as described above with a mixture of (ii) an acrylic acid ester monomer and (iii) a functional group-containing monomer copolymerizable therewith.

[0058] Examples of the radical initiator used here include persulfates such as potassium persulfate and ammonium persulfate, aqueous hydrogen persulfate, t-butyl hydroperoxide, and hydrogen peroxide. If necessary, a redox system using a reducing agent such as sodium sulfite, Rongalite, L-ascorbic acid, tartaric acid, sugars, or amines can also be used.

[0059] The surfactants already contained in the polyorganosiloxane emulsion are sufficient for graft polymerization, but to improve stability, anionic surfactants such as sodium lauryl sulfate, sodium laureth sulfate, N-acylamino acid salts, N-acyltaurine salts, aliphatic soaps, and alkyl phosphates can be added. Nonionic emulsifiers such as polyoxyethylene lauryl ether and polyoxyethylene tridecyl ether can also be added.

[0060] The graft polymerization temperature for components (ii) and (iii) is preferably 25 to 55° C., more preferably 25 to 40° C. The polymerization time is preferably 2 to 8 hours, more preferably 3 to 6 hours.

[0061] Furthermore, a chain transfer agent can be added to adjust the molecular weight and graft rate of the graft polymer.

[0062] The modified polyorganosiloxane (II) thus obtained is a polymer in which components (ii) and (iii) are randomly grafted. In this case, the solid content of the acrylic-modified polyorganosiloxane is preferably 35 to 50 mass%. The viscosity (25°C) is preferably 500 mPa·s or less, more preferably 50 to 500 mPa·s. The viscosity can be measured using a rotational viscometer. The average particle size is preferably 0.1 (100 nm) to 0.5 μm (500 nm).

[0063] The modified polyorganosiloxane of the present invention is granulated and powdered by the following method. Examples include spray drying and airflow drying, but a spray dryer is preferred from the viewpoint of productivity. Hot drying is preferred for powderization, and treatment is preferably carried out at 80 to 150°C. The smaller the average particle size of the resulting powder particles, the better, and preferably 50 μm or less. It is more preferably 1 to 30 μm. The particle sizes of the emulsion and powder can be measured as the cumulative mass average value D50 using a laser diffraction particle size analyzer.

[0064] The modified polyorganosiloxane (B) of the present invention, when blended with polyamide resin (A), can be widely used as a raw material for sliding parts, including, but not limited to, electrical and electronic components, automotive components, building components, and industrial components. It is used in everyday items such as fasteners, fans, and reducer gears, and in vehicles, gear parts, intake manifolds, radiator tanks, canisters, engine covers, bearing retainers, gears, door checkers, chain guide parts, sliding parts around electric power steering, combined valves inside thermal management modules, actuator gears, and exterior parts such as fender mirrors. It can be used particularly in gears, bearing retainers, and chain guide parts where improved sliding properties and wear resistance are desired.

[0065] (Siloxane component content of component (B)) The component (B) preferably contains at least 50% by mass or more of a siloxane component relative to 100% by mass of the component (B).

[0066] ((B) Composition ratio of component) The proportion of the siloxane component constituting component (B) is preferably 50% by mass or more, and particularly preferably 60 to 90% by mass.

[0067] By satisfying the above ratio, the sliding properties of the resulting polyamide resin composition are improved.

[0068] When the parts by mass of the component (B) minus the siloxane component portion is defined as B, B and the concentration C preferably fall within the range of C×B=10 to 1000. More preferably, X falls within the range of 20 to 500, more preferably 50 to 300, and most preferably 30 to 300. By setting X within the above range, sliding properties can be significantly improved.

[0069] (Average dispersed diameter of component (B)) The number average dispersion diameter of component (B) dispersed in the polyamide resin composition is preferably 5 μm or less, more preferably 3 μm or less, even more preferably 2 μm or less, and most preferably 1 μm or less. By controlling the number average dispersion diameter of component (B) to 5 μm or less, sliding properties can be particularly improved. Furthermore, if the number average dispersion diameter is outside the above-mentioned specified range, sliding properties and mechanical properties will be significantly reduced. The method for measuring the number average dispersion diameter of component (B) is not particularly limited, but it can be determined by observing at least 50 dispersed particles using a scanning electron microscope (SEM). Of the minor and major diameters, the dispersion diameter is defined here as the major diameter.

[0070] (Proportion of component (B)) The content of component (B) in the polyamide resin composition of this embodiment is preferably 0.1 to 15 mass%, more preferably 1 to 12 mass%, and even more preferably 2 to 7 mass%, based on 100 mass% of polyamide resin (A). When the content of component (B) is equal to or greater than the lower limit, the sliding properties of the resulting polyamide resin composition are effectively exhibited. When the content of component (B) is equal to or less than the upper limit, the wear resistance and mechanical properties of the resulting polyamide resin composition are improved.

[0071] As the component (B) in the polyamide resin composition of the present embodiment, any known modified polyorganosiloxane copolymer having a reactive moiety can be used, and commercially available products may also be used.

[0072] (Compatibilizer) The compatibilizer in this embodiment is not limited to the following, but is not particularly limited as long as it is a compound that can improve the compatibility between a compound containing a siloxane component and / or an acrylic component and a polyamide resin from the viewpoint of achieving even better sliding properties, mechanical properties, heat resistance, long-term heat resistance, moldability, processability, etc. Examples of compounds that contain a siloxane component and / or an acrylic component and can improve compatibility with a polyamide resin include, but are not limited to, at least one product selected from compounds having an amide bond, such as a reactive functional group capable of reacting with the terminal group and / or main chain amide group of a polyamide resin, and polyamides and / or copolymers thereof.

[0073] (Compatibilizer ratio) The content of the compatibilizer in the polyamide resin composition of this embodiment is preferably 0.01 to 15 parts by mass, more preferably 0.05 to 15 parts by mass, even more preferably 0.1 to 12 parts by mass, and most preferably 1 to 7 parts by mass, relative to 100 parts by mass of the (A) polyamide resin. When the content is equal to or greater than the lower limit, sliding properties, moldability, processability, etc. are effectively exhibited, and when the content is equal to or less than the upper limit, sliding properties, mechanical properties, heat resistance, long-term heat resistance, moldability, processability, etc. are improved.

[0074] From the viewpoint of improving sliding properties, mechanical properties, heat resistance, long-term heat resistance, moldability, and processability, it is preferable to use a compatibilizer that improves the compatibility between (A) the polyamide resin and (B) the modified polyorganosiloxane copolymer having a reactive moiety.

[0075] (copper compound) Examples of the copper compound used in the present embodiment include, but are not limited to, copper halides, copper acetate, copper propionate, copper benzoate, copper adipate, copper terephthalate, copper isophthalate, copper salicylate, copper nicotinate, copper stearate, and copper complex salts coordinated with a chelating agent such as ethylenediamine or ethylenediaminetetraacetic acid.

[0076] These copper compounds may be used alone or in combination of two or more.

[0077] Among these, copper iodide, copper (I) bromide, copper (II) bromide, copper (I) chloride, and copper acetate are preferred, with copper iodide being more preferred. From the viewpoint of sliding properties, the copper compounds are preferably used in the form of a masterbatch with a halide of a metal selected from the group consisting of alkali metals and alkaline earth metals.

[0078] (Amount of copper compound) The amount of the copper compound added is 0.01 to 5 parts by mass, preferably 0.01 to 4 parts by mass, and more preferably 0.03 to 3 parts by mass, per 100 parts by mass of component (A).

[0079] By adjusting the amount of the copper compound to fall within the above range, it is possible to improve heat aging resistance, inhibit copper deposition and corrosion, and also to reduce the coefficient of friction and wear depth.

[0080] (Halides of metals selected from the group consisting of alkali metals and alkaline earth metals) Examples of the metal halide selected from the group consisting of alkali metals and alkaline earth metals (hereinafter, sometimes abbreviated as "metal halide") used in this embodiment include potassium iodide, sodium iodide, potassium bromide, potassium chloride, sodium chloride, etc. Among these, potassium iodide is preferred.

[0081] These metal halides may be used alone or in combination of two or more.

[0082] (amount of metal halide) The amount of the metal halide to be added is 0.05 to 5 parts by mass, preferably 0.1 to 4 parts by mass, and more preferably 0.2 to 3 parts by mass, per 100 parts by mass of the polyamide resin (A).

[0083] By adjusting the blending amount of the metal halide to the above range, it is possible to improve heat aging resistance, suppress copper deposition and corrosion, and also to exert the effect of reducing the friction coefficient and wear depth.

[0084] (Particle size of copper compounds and metal halides) The maximum particle size of both the copper compound and the metal halide to be added is preferably 50 μm or less, more preferably 20 μm or less, and even more preferably 10 μm or less.

[0085] In the present invention, the particle diameter refers to the biaxial average diameter, i.e., the average value of the minor axis and the major axis. Here, the minor axis and the major axis refer to the short side and the long side, respectively, of the circumscribing rectangle that has the smallest circumscribing area of ​​the particle. The maximum particle diameter of the copper compound and the metal halide can be measured by observing at least 50 particles using a scanning electron microscope (SEM).

[0086] By setting the maximum particle size within the above range, the copper compound and metal halide can be finely dispersed in the polyamide resin (A) even when the moisture content in the polyamide resin (A) is low. As a result, metal deposition and corrosion are suppressed, and the toughness, heat aging resistance, appearance, and color of the resulting polyamide resin composition are further improved. Furthermore, the coefficient of friction and wear depth are reduced.

[0087] (molar ratio of halogen to copper) When the copper compound and metal halide are made into a masterbatch, the molar ratio of halogen to copper (halogen / copper) in the masterbatch is preferably 3-30, more preferably 4-25, and even more preferably 5-23.

[0088] By setting the molar ratio of halogen to copper at or above the lower limit, copper deposition and metal corrosion can be suppressed, while by setting the molar ratio of halogen to copper at or below the upper limit, corrosion of the screw and the like of the molding machine can be suppressed without impairing mechanical properties such as toughness.

[0089] (organic compounds having at least one amide group) In this embodiment, an organic compound having at least one amide group (excluding polyamide) can be present in the masterbatch.

[0090] The inclusion of an organic compound (excluding polyamides) having at least one amide group prevents the copper compound and metal halide from dissolving in the water in component (A) and forming a complex during melt-kneading. Furthermore, the dispersion of the copper compound and metal halide in component (A) is stabilized, preventing precipitation and deterioration, without adversely affecting component (A).

[0091] The organic compound having at least one amide group used in this embodiment is a compound having at least one amide group in the molecular chain, and examples of the organic compound having at least one amide group include, but are not limited to, monoamides, substituted amides, methylol amides, and bisamides.

[0092] Monoamides are represented by the general formula R-CONH2 (where R is a saturated aliphatic, unsaturated aliphatic, or aromatic group having 8 to 30 carbon atoms, or one in which some of the -H groups have been replaced with -OH).

[0093] Examples of monoamides include, but are not limited to, lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxystearic acid amide, oleic acid amide, erucic acid amide, linosyl acid amide, and the like.

[0094] Substituted amides are those of the general formula R 1 -CONH-R 2 (However, R 1 and R 2 are each independently a saturated aliphatic, unsaturated aliphatic, or aromatic group having 8 to 30 carbon atoms, or an alkyl group in which some of the -H groups have been replaced with -OH groups.

[0095] Examples of the substituted amides include, but are not limited to, N-lauryl lauric acid amide, N-paltimyl palmitic acid amide, N-stearyl stearic acid amide, N-oleyl oleic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl erucic acid amide, N-oleyl palmitic acid amide, N-stearyl 12-hydroxystearic acid amide, and N-oleyl 12-hydroxystearic acid amide.

[0096] Methylolamides are represented by the general formula R-CONHCH2OH (wherein R is a saturated aliphatic, unsaturated aliphatic, or aromatic group having 8 to 30 carbon atoms, or one in which some of the -H groups have been replaced with -OH).

[0097] Examples of methylolamides include methylol stearic acid amide and methylol behenic acid amide.

[0098] Bisamides are represented by the general formula (R-CONH)2(CH2)n (where R is a saturated aliphatic, unsaturated aliphatic, or aromatic group having 8 to 30 carbon atoms, or a group in which some of the -H groups have been replaced with -OH, and n is 1 to 8).

[0099] Examples of bisamides include, but are not limited to, methylene bislauric amide, methylene bislauric amide, methylene bishydroxystearic amide, ethylene biscaprylic amide, ethylene bislauric amide, ethylene bisstearic amide, ethylene bisisostearic amide, ethylene bishydroxystearic amide, ethylene bisbehenic amide, hexamethylene bisstearic amide, hexamethylene bisbehenic amide, hexamethylene bishydroxystearic amide, ... Examples of the hydroxystearic acid amide include hydroxystearic acid amide, butylene bishydroxystearic acid amide, N,N'-distearyl adipate amide, N,N'-distearyl sebacate amide, methylene bisoleate amide, ethylene bisoleate amide, ethylene biserucate amide, hexamethylene bisoleate amide, N,N'-dioleyl adipate amide, N,N'-dioleyl sebacate amide, m-xylylene bisstearic acid amide, and N,N'-distearyl isophthalate amide.

[0100] These organic compounds having at least one amide group may be used alone or in combination of two or more.

[0101] Among these, bisamides are preferred.

[0102] (Amount of organic compound having at least one amide group) The amount of the organic compound having at least one amide group added is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5.0 parts by mass, and even more preferably 1.0 to 4.0 parts by mass, per 100 parts by mass of the polyamide resin (A).

[0103] By adjusting the amount of the organic compound having at least one amide group within the above range, the dispersibility of the copper compound and metal halide in component (A) can be improved, further improving heat aging resistance, and as a result, copper deposition and metal corrosion can be suppressed, and the friction coefficient and wear depth can be reduced.

[0104] (Master patch moisture content) The water content of the masterbatch is preferably 0.06 to 1.0 mass %, more preferably 0.10 to 0.75 mass %, and even more preferably 0.15 to 0.75 mass %, relative to the total mass of the masterbatch.

[0105] The moisture in the masterbatch may be present as moisture bound to polyamide molecules, or may be moisture adhering to the surface of the masterbatch, for example, the surface of masterbatch pellets or masterbatch powder.

[0106] By keeping the moisture content within the above range, aggregation of copper compounds and metal halides can be suppressed, resulting in improved mechanical properties such as toughness and heat aging resistance, suppressing copper deposition and metal corrosion, and reducing the coefficient of friction and wear depth.

[0107] The moisture content of the masterbatch can be adjusted by controlling the degree of vacuum in the extruder, the immersion time and immersion length in the strand bath during cooling, or the amount of water sprayed.

[0108] (Water Content of Polyamide Resin Composition) The moisture content of the polyamide resin composition in this embodiment is preferably 0.01 to 1 mass %, more preferably 0.03 to 0.5 mass %, and even more preferably 0.05 to 0.30 mass %, relative to the total mass of the polyamide resin composition.

[0109] The water in the polyamide resin composition may be present as water bound to polyamide molecules, or may be present as water attached to the surface of the polyamide resin composition, for example, the surface of pellets or powder. From the viewpoint of improving the effects of the present invention, it is more preferable that the water be present as water bound to polyamide molecules.

[0110] By controlling the moisture content of the polyamide resin composition within the above range, aggregation of copper compounds and metal halides can be suppressed, resulting in improved mechanical properties such as toughness and heat aging resistance, suppressed copper deposition and metal corrosion, and reduced coefficient of friction and wear depth. The moisture content of the polyamide resin composition can be adjusted by controlling the degree of vacuum in the extruder, the immersion time and immersion length in the strand bath during cooling, or the amount of water sprayed.

[0111] (Hindered phenolic heat stabilizer) It is preferable that a heat stabilizer be further added to the polyamide resin composition.

[0112] The heat stabilizer is not particularly limited, but examples thereof include phenol-based stabilizers such as hindered phenol compounds, phosphite-based stabilizers, hindered amine-based stabilizers, triazine-based stabilizers, and sulfur-based stabilizers.

[0113] Preferably, the stabilizer is a hindered phenol compound, which is a phenol-based stabilizer.

[0114] These heat stabilizers are also effective in reducing the coefficient of friction and the depth of wear.

[0115] The content of the hindered phenol-based heat stabilizer is preferably 0.01 to 5 parts by mass, and more preferably 0.015 to 3 parts by mass, per 100 parts by mass of the component (A).

[0116] (fiber filler) Examples of fibrous fillers include, but are not limited to, carbon fibers, glass fibers, calcium silicate fibers, potassium titanate fibers, aluminum borate fibers, wollastonite, and carbon nanotubes.

[0117] Among these, carbon fiber and glass fiber are preferred, with glass fiber being preferred from the viewpoint of increasing the strength of the polyamide resin composition, and carbon fiber being preferred from the viewpoint of improving the sliding properties.

[0118] As the carbon fiber, for example, either polyacrylonitrile (PAN)-based carbon fiber or pitch-based carbon fiber can be used, with PAN-based carbon fiber being preferred from the viewpoint of mechanical properties.

[0119] The above-mentioned fibrous fillers may be used alone or in combination of two or more.

[0120] From the viewpoint of improving sliding properties, the amount of the fibrous filler is preferably 1 part by mass or more and 30 parts by mass or less, more preferably 3 parts by mass or more and 20 parts by mass or less, and even more preferably 5 parts by mass or more and 10 parts by mass or less, per 100 parts by mass of component (A).

[0121] From the viewpoint of productivity, it is preferable to add short carbon fibers of about 3 mm to 10 mm by melt kneading in an extruder. In this case, it is preferable to add the carbon fibers from a side feeder from the viewpoint of preventing breakage of the carbon fibers.

[0122] From the viewpoint of affinity with polyamide resin, the carbon fiber is preferably coated with a urethane-based sizing agent, a maleic anhydride-based sizing agent, an acrylic-based sizing agent, or a polyamide-based sizing agent.

[0123] From the viewpoint of physical properties and sliding properties, the carbon fiber preferably has a diameter of 5 μm or more and 10 μm or less.

[0124] (Moldability improver) If necessary, a moldability improver may be added to the polyamide resin composition within the range that does not impair the object of the present invention.

[0125] The moldability improver is not particularly limited, but examples thereof include higher fatty acids, higher fatty acid metal salts, higher fatty acid esters, and higher fatty acid amides.

[0126] Examples of higher fatty acids include, but are not limited to, saturated or unsaturated, straight-chain or branched aliphatic monocarboxylic acids having 8 to 40 carbon atoms, such as stearic acid, palmitic acid, behenic acid, erucic acid, oleic acid, lauric acid, and montanic acid. Among these, stearic acid and montanic acid are preferred.

[0127] The higher fatty acid metal salt is a metal salt of the above higher fatty acid.

[0128] As the metal element of the metal salt, elements of Groups 1, 2 and 3 of the periodic table, zinc, aluminum, etc. are preferred, and elements of Groups 1 and 2 such as calcium, sodium, potassium and magnesium, and aluminum, etc. are more preferred.

[0129] Examples of metal salts of higher fatty acids include, but are not limited to, metal salts of stearic acid such as calcium stearate, aluminum stearate, zinc stearate, and magnesium stearate; metal salts of montanic acid such as calcium montanate and sodium montanate; and metal salts of palmitic acid such as calcium palmitate. Among these, metal salts of montanic acid and metal salts of stearic acid are preferred.

[0130] The higher fatty acid ester is an ester of the above higher fatty acid with an alcohol. Esters of aliphatic carboxylic acids having 8 to 40 carbon atoms and aliphatic alcohols having 8 to 40 carbon atoms are preferred.

[0131] Examples of fatty alcohols include, but are not limited to, stearyl alcohol, behenyl alcohol, and lauryl alcohol.

[0132] Examples of higher fatty acid esters include stearyl stearate and behenyl behenate.

[0133] The higher fatty acid amide is an amide compound of the above higher fatty acid.

[0134] Examples of higher fatty acid amides include, but are not limited to, stearic acid amide, oleic acid amide, erucic acid amide, ethylene bisstearylamide, ethylene bisoleylamide, N-stearylstearylamide, and N-stearylerucic acid amide.

[0135] These higher fatty acids, higher fatty acid metal salts, higher fatty acid esters, and higher fatty acid amides may be used singly or in combination of two or more.

[0136] (coloring agent) If necessary, a colorant may be added to the polyamide resin composition within the range that does not impair the object of the present invention. The colorant is not particularly limited, but examples thereof include dyes such as nigrosine, pigments such as titanium oxide and carbon black, metal particles such as aluminum, colored aluminum, nickel, tin, copper, gold, silver, platinum, iron oxide, stainless steel, and titanium, and metallic pigments such as mica pearl pigments and colored graphite.

[0137] (Other resins) If necessary, other resins may be added to the polyamide resin composition within the scope of the present invention.

[0138] Such resins are not particularly limited, but include thermoplastic resins and rubber components, which will be described later.

[0139] Examples of thermoplastic resins include, but are not limited to, polystyrene-based resins such as atactic polystyrene, isotactic polystyrene, syndiotactic polystyrene, AS (acrylonitrile-styrene) resin, and ABS (acrylonitrile-butadiene-styrene) resin; acrylic-based resins such as polyacrylic acid, polyacrylic acid ester, and polymethyl methacrylate; and halogen-containing vinyl compound-based resins such as polyvinyl chloride and polyvinylidene chloride.

[0140] These thermoplastic resins may be used singly or in combination of two or more.

[0141] Examples of rubber components include natural rubber, polybutadiene, polyisoprene, polyisobutylene, neoprene, polysulfide rubber, thiokol rubber, acrylic rubber, urethane rubber, silicone rubber, epichlorohydrin rubber, styrene-butadiene block copolymer (SBR), hydrogenated styrene-butadiene block copolymer (SEB), styrene-butadiene-styrene block copolymer (SBS), hydrogenated styrene-butadiene-styrene block copolymer (SEBS), styrene-isoprene block copolymer (SIR), hydrogenated styrene-isoprene block copolymer (SEP), styrene-isoprene-styrene block copolymer (SIS), hydrogenated styrene-isoprene-styrene block copolymer (SEPS), styrene-butadiene random copolymer, hydrogenated styrene-butadiene random copolymer, styrene-ethylene-propylene random copolymer, Examples of such rubbers include styrene-ethylene-butylene random copolymers, ethylene-propylene copolymers (EPR), ethylene-(1-butene) copolymers, ethylene-(1-hexene) copolymers, ethylene-(1-octene) copolymers, ethylene-propylene-diene copolymers (EPDM), and core-shell types such as butadiene-acrylonitrile-styrene-core-shell rubber (ABS), methyl methacrylate-butadiene-styrene-core-shell rubber (MBS), methyl methacrylate-butyl acrylate-styrene-core-shell rubber (MAS), octyl acrylate-butadiene-styrene-core-shell rubber (MABS), alkyl acrylate-butadiene-acrylonitrile-styrene-core-shell rubber (AABS), butadiene-styrene-core-shell rubber (SBR), and siloxane-containing core-shell rubbers such as methyl methacrylate-butyl acrylate siloxane.

[0142] These rubber components may be used singly or in combination of two or more.

[0143] The polyamide resin composition of the present invention can be used in a wide range of applications, including, but not limited to, applications requiring mechanical properties and sliding properties, such as electrical and electronic parts, automobile parts, building parts, and industrial parts, and examples of sliding parts include bearings, gears, door checkers, and chain guide parts, which are generally injection-molded articles.

[0144] [Method of producing polyamide resin composition] The polyamide resin composition of the present embodiment can be obtained by mixing and kneading (A) a polyamide resin, (B) a modified polyorganosiloxane copolymer having a reactive moiety, and (C) a compatibilizer, a copper compound, a metal halide, and other components, which are blended as needed.

[0145] The copper compound and metal halide are preferably prepared as a masterbatch in advance and then melt-kneaded with component (A) and component (B). Alternatively, the copper compound, metal halide, and component (A) are preferably prepared as a masterbatch in advance and then melt-kneaded with component (B). Furthermore, during the production of the polyamide resin composition, the raw materials for component (C) can be blended when mixing and kneading component (A) with a copper compound and a metal halide, which are blended as needed, and other components, and the composition can be prepared in a twin-screw extruder.

[0146] [Masterbatch preparation process] The masterbatch is prepared by melt-kneading the copper compound and the metal halide. In addition to the copper compound and metal halide, it is preferable to blend the organic compound having at least one amide group (excluding polyamide). In addition to an organic compound having at least one amide group (excluding polyamides), it is preferable to incorporate component (A).

[0147] When an organic compound having at least one amide group (excluding polyamides) is blended with the component (A), the copper compound, the metal halide, and the organic compound having at least one amide group (excluding polyamides) may each be blended individually into component (A). Alternatively, at least two of the three compounds may be premixed and then blended into component (A), or at least two of the three compounds may be premixed and pulverized and then blended into component (A), or at least two of the three compounds may be premixed and pulverized to form tablets and then blended into component (A).

[0148] The compounds can be mixed by any known method, such as a tumbler, a Henschel mixer, a Plosser mixer, a Nauta mixer, or a flow jet mixer.

[0149] The compound can be pulverized by a known method, for example, by using a hammer mill, knife mill, ball mill, jaw crusher, cone crusher, roller mill, jet mill, or mortar.

[0150] A known method can be used to form a tablet from a compound, such as compression granulation, tableting, dry extrusion granulation, or melt extrusion granulation.

[0151] The melt-kneading device is not particularly limited, and known devices can be used. For example, melt-kneading devices such as single-screw or twin-screw extruders, Banbury mixers, and mixing rolls are preferably used. Among these, twin-screw extruders are preferably used. Furthermore, the melt-kneading device may be equipped with a degassing mechanism (vent) and a side feeder.

[0152] The melt-kneading temperature in this embodiment is preferably in the range of from 1°C higher than the melting point or softening point of component (A) as determined by differential scanning calorimetry (DSC) measurement in accordance with JIS K7121 to 310°C, more preferably in the range of from 10°C higher to 300°C, and even more preferably in the range of from 15°C higher to 295°C. In this embodiment, the melt-kneading temperature is the set temperature of the barrel of the extruder. The shear rate in the kneader is 100 (SEC -1 ) or more. The average residence time during kneading is preferably about 1 to 15 minutes.

[0153] (Masterbatch, component (A), component (B) melt-kneading process) The polyamide resin composition of this embodiment can be produced by melt-kneading the masterbatch, component (A), and component (B). When component (A) is blended in the masterbatch, the polyamide resin composition of this embodiment is prepared by melt-kneading component (B) with the masterbatch.

[0154] (Total mass of the copper compound and metal halide) The copper compound and metal halide are preferably mixed in a ratio such that the total mass of the copper compound and metal halide is 0.1 to 100 parts by mass, more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the (A) polyamide resin.

[0155] By setting the total mass of the copper compound and metal halide within the above range, metallic copper deposition and metal corrosion in an extruder or molding machine are suppressed, and stability during processing is improved. As a result, heat aging resistance is further improved, the coefficient of friction and wear depth are further reduced, and changes in appearance color due to water absorption can be further suppressed without deteriorating the mechanical properties of the product.

[0156] The blending ratio of the component (B) relative to 100% by mass of the polyamide resin (A) is as described above.

[0157] The masterbatch, component (A), and component (B) are melt-kneaded together with other components that are blended as needed.

[0158] The melt-kneading step is preferably carried out using various commonly used extruders such as a single-screw or twin-screw extruder. From the viewpoints of productivity, versatility, etc., it is particularly preferable to carry out the step using a twin-screw extruder. In this case, the melt-kneading temperature, which varies depending on the type of component (A), is preferably adjusted to a temperature at which the temperature of the molten resin discharged from the extruder outlet is equal to or higher than the melting points of components (A) and (B).

[0159] By setting the melt-kneading temperature within the above range, poor extrusion kneading is unlikely to occur, and the component (B) can be finely dispersed.

[0160] In the case of a twin-screw extruder, it is preferable that the extruder screw has a kneading zone that combines at least two kneading disks. The kneading zone is a region that applies high shear to the molten resin while suppressing its advance in the extrusion direction so that kneading is carried out effectively.

[0161] In the melt-kneading step, component (A), component (B), and masterbatch (copper compound and metal halide), as well as other components (such as a hindered phenol-based heat stabilizer) are fed from the most upstream feed port of the twin-screw extruder, and melt-kneaded in the first kneading zone to obtain a first melt-kneaded product. Furthermore, a preferred method is to feed a fibrous filler, if necessary, from a side feed port provided downstream of the first kneading zone, and disperse the unmelted fibrous filler in the first melt-kneaded product in the second kneading zone provided downstream of the side feed port.

[0162] It is desirable to set the various conditions of the extruder (barrel temperature, screw rotation speed, discharge rate, etc.) so that the resin temperature of the polyamide resin composition discharged from the extruder outlet after the melt-kneading step is higher than the crystallization temperature of component (A) and is 280°C to 400°C. By setting the temperature of the polyamide resin composition at the discharge outlet to 280°C to 400°C, components (A) and (B) can be more finely dispersed. As a result, a polyamide resin composition with excellent sliding properties and mechanical properties can be obtained.

[0163] The temperature of the polyamide resin composition is preferably measured, for example, by directly contacting the detection part of a commercially available thermocouple thermometer with the molten polyamide resin composition discharged from the outlet of the extruder. The temperature of the extruder for achieving the above temperature of the polyamide resin composition is preferably set to 280°C or higher and 400°C or lower.

[0164] By molding the polyamide resin composition, a molded article of the polyamide resin composition of the present embodiment can be obtained. The method for obtaining the molded body is not particularly limited, and any known molding method can be used. Examples of molding methods include extrusion molding, injection molding, vacuum molding, blow molding, injection compression molding, decorative molding, other material molding, gas-assisted injection molding, foam injection molding, low-pressure molding, ultra-thin-wall injection molding (ultra-high-speed injection molding), and in-mold composite molding (insert molding, outsert molding).

[0165] The temperature set in the molding machine when molding the polyamide resin composition of this embodiment is preferably in the range of from 5°C higher than the melting point of the (A) component used to 340°C, more preferably from 10°C higher to 300°C, and even more preferably from 15°C higher to 295°C.

[0166] By setting the temperature of the molding machine within the above temperature range, the polyamide resin composition can be effectively kneaded during molding, and the component (B) in the polyamide resin composition can be more finely dispersed.

[0167] The polyamide resin composition of the present invention can be used in a wide range of applications, including, but not limited to, applications requiring mechanical properties and sliding properties, such as electrical and electronic parts, automobile parts, building parts, industrial parts, etc. Examples of sliding parts include generally injection-molded products such as bearings, gears, door checkers, and chain guide parts.

[0168] The polyamide resin composition of the present invention is not particularly limited as long as its application requires mechanical properties and sliding properties, and it can exhibit stable sliding properties under a wide range of sliding conditions, such as the presence or absence of a sliding mechanism or a lubricated environment, the influence of the type of mating material, and exposure conditions.

[0169] The lubricating environment is not particularly limited, and any commercially available product that improves lubrication can be used. Examples of lubricants include engine oil, silicone oil, motor oil, anti-rust / penetrating lubricant, and grease. [Example]

[0170] The present invention will be described in detail below with reference to specific examples and comparative examples, but the present invention is not limited to the following examples. The raw materials and measurement methods for physical property tests used in the examples and comparative examples are as follows.

[0171] (Production Example 1) Preparation of Polyamide 66 15,000 g of an equimolar salt of adipic acid and hexamethylenediamine, along with 0.5 mol% excess adipic acid relative to the total equimolar salt components, were dissolved in 15,000 g of distilled water to obtain a 50% by mass aqueous solution of the raw material monomer. The resulting aqueous solution was placed in a 40 L autoclave, and the autoclave was purged with nitrogen. The aqueous solution was stirred at a temperature of 110 to 150°C, and the water vapor was gradually removed to concentrate the solution to a concentration of 70% by mass. The internal temperature was then raised to 220°C. The autoclave was then pressurized to 1.8 MPa. The reaction was continued for 1 hour while gradually removing water vapor to maintain the pressure at 1.8 MPa until the internal temperature reached 270°C. The pressure was then reduced to atmospheric pressure over approximately 1 hour. After atmospheric pressure was reached, the mixture was discharged from the bottom nozzle in the form of strands, water-cooled, and cut to obtain pellets. The resulting pellets were dried in a nitrogen stream at 90°C for 4 hours. The pellets had a relative viscosity of 2.71 in 98% sulfuric acid, a melting point of 265°C, and a crystallization temperature of 220°C.

[0172] ((A) Polyamide resin) (A-1) Polyamide resin (Production Example 1) (A-2) Polyamide resin: "Leona 1500-X31", manufactured by Asahi Kasei Corporation (A-3) Polyamide resin: "Leona 3100-001", manufactured by Asahi Kasei Corporation (A-4) Polyamide resin (Production Example 4) (A-5) Polyamide resin: Stanyl (registered trademark) TW341-J, manufactured by DSM K.K. (A-6) Polyamide resin: Maranyl nylon 66 A125J, manufactured by Unitika Ltd.

[0173] ((B) Modified polyorganosiloxane copolymer having reactive moieties in the side chain) (B-1) Modified polyorganosiloxane copolymer having a reactive moiety (Production Example 5) (Production Example 5) A 2L polyethylene beaker was charged with 499.6g of octamethylcyclotetrasiloxane, 0.4g of 3-methacryloxypropyldimethoxysilane, 5g of sodium lauryl sulfate dissolved in 45g of purified water, and 5g of dodecylbenzenesulfonic acid dissolved in 45g of purified water. The mixture was homogenized using a homomixer, then diluted with 400g of water. The mixture was then passed through a high-pressure homogenizer twice at 300kgf / cm² to obtain a uniform white emulsion. This emulsion was transferred to a 2L glass flask equipped with a stirrer, thermometer, and reflux condenser and polymerized at 50°C for 24 hours. After aging at 10°C for 24 hours, it was neutralized to pH 6.2 with 12g of 10% aqueous sodium carbonate. After drying at 105°C for 3 hours, the nonvolatile content of the emulsion was 45.4%, and the organopolysiloxane in the emulsion was a non-flowable soft gel. In this way, an emulsion containing about 45% of component (i) was obtained. This emulsion was graft-copolymerized with methyl methacrylate, butyl acrylate, and acrylamide in a mass ratio of (89 / 1 / 10) using peroxide and vitamin C at room temperature for 4 hours via a redox reaction, yielding an approximately 45% acrylic silicone resin emulsion (acrylic-modified polyorganosiloxane). This acrylic-modified silicone resin emulsion was randomly graft-polymerized with acrylic monomers. The emulsion was designed with 100 parts of polyorganosiloxane (i), 22.5 parts of (ii) acrylic acid ester, and 2.5 parts of a monomer copolymerizable with (iii). The Tg of the acrylic component (ii) was 102°C. The emulsion viscosity (25°C) was 100 mPa·s, and the average emulsion particle size was 220 nm. This emulsion was spray-dried (100°C) to yield a powder with an average particle size of 30 μm (Production Example 5).

[0174] (B-2) Modified polyorganosiloxane copolymer having a reactive moiety (Production Example 6) (Production Example 6) A 2L polyethylene beaker was charged with 499.6g of octamethylcyclotetrasiloxane, 0.4g of 3-methacryloxypropyldimethoxysilane, 5g of sodium lauryl sulfate dissolved in 45g of purified water, and 5g of dodecylbenzenesulfonic acid dissolved in 45g of purified water. The mixture was homogenized using a homomixer, then diluted with 400g of water. The mixture was then passed through a high-pressure homogenizer twice at 300kgf / cm² to obtain a uniform white emulsion. This emulsion was transferred to a 2L glass flask equipped with a stirrer, thermometer, and reflux condenser and polymerized at 50°C for 24 hours. After aging at 10°C for 24 hours, it was neutralized to pH 6.2 with 12g of 10% aqueous sodium carbonate. After drying at 105°C for 3 hours, the nonvolatile content of the emulsion was 45.4%, and the organopolysiloxane in the emulsion was a non-flowable soft gel. In this way, an emulsion containing about 45% of component (i) was obtained. This was then graft copolymerized with methyl methacrylate, butyl acrylate, and acrylic acid in a ratio of (89 / 1 / 10) using a redox reaction with peroxide and vitamin C for four hours, yielding an approximately 45% acrylic silicone resin emulsion. The emulsion was designed with 100 parts of polyorganosiloxane (i), 22.5 parts of (ii) acrylic acid ester, and 2.5 parts of a copolymerizable monomer (iii). The Tg of the acrylic component (ii) was the same as in Example 1. The emulsion viscosity was 150 mPa·s, and the average emulsion particle size was 210 nm. This was spray-dried to obtain a powder (Production Example 6) with an average particle size of 30 μm.

[0175] (B-3) CHALINE R-200, manufactured by Nissin Chemical Co., Ltd., modified polyorganosiloxane copolymer with reactive moieties

[0176] ((C) Other sliding additives) (C-1) MODIPER-A1100, NOF Corporation, polyethylene-polystyrene graft copolymer (C-2) DOWSIL SH200 FLUID (10,000 cSt), manufactured by Dow Toray Industries, Inc., silicone oil (C-3) FUSABOND N416, manufactured by The Dow Chemical Company, maleic anhydride modified polyolefin polymer

[0177] Copper iodide: Copper(I) iodide, manufactured by Wako Pure Chemical Industries, Ltd. Potassium iodide: Potassium iodide, manufactured by Wako Pure Chemical Industries, Ltd. Hindered phenolic heat stabilizer: BASF, IRGANOX 1098 Spreader: Sanyo Chemical Industries, Ltd., PEG400 Azine dyes: Nigrosine, NUBIAN (registered trademark) BLACK TH-807 manufactured by Orient Chemical Industries Co., Ltd.

[0178] (Production Example 2) Preparation of Masterbatch 1.5 parts by mass of a copper compound and 32.5 parts by mass of a 40% by mass aqueous solution of a metal halide were added to 100 parts by mass of the polyamide resin (A-1) obtained in Production Example 1. The mixture was melt-kneaded using a twin-screw extruder (manufactured by the Plastics Engineering Research Institute, twin co-rotating screws, L / D=60 (D=30φ)) at a screw rotation speed of 100 rpm and a cylinder temperature of 280°C to obtain a masterbatch containing the polyamide resin (A-1), the copper compound, and the metal halide.

[0179] (Production Example 3) Polystyrene-Polyamide Polymer 10% by weight of compatibilizer (C-3-1) was added to polyamide resin (A), and the mixture was melt-kneaded using a twin-screw extruder (manufactured by the Plastics Engineering Research Institute, twin-screw co-rotating type, L / D=60 (D=30φ)) at a screw rotation speed of 300 rpm and a cylinder temperature of 280°C to obtain a polystyrene-polyamide polymer containing polyamide resin (A) and 10% by weight of compatibilizer (C-3-1).

[0180] (Production Example 4) Crystalline semi-aromatic polyamide resin A 50-liter rotary dryer was charged with 15 kg of 4T / 6T salt (39 / 61 mol / mol). The rotary dryer was evacuated to 50 mbar and backfilled with nitrogen, and this process was repeated five times. While the reaction water was draining from the rotary dryer, the mixture was heated to a temperature of 220°C in 5 hours, then to 255°C in 15 hours. A low nitrogen purge was used during the reaction. The mixture was cooled to 235°C in 19 hours, and a mixture of 650 kg of 1,6-hexamethylenediamine, 300 g of 1,4-butanediamine, and 1.0 kg of water was added over 7 hours while maintaining the temperature at 235°C. The mixture was allowed to react at 235°C for an additional 29 hours. The nitrogen flow was then increased, and the material was cooled to room temperature. A white powder was obtained.

[0181] [Forming method] Unless otherwise specified, the polyamide resin composition pellets obtained in the examples and comparative examples were molded using an injection molding machine NEX50IV-5EG (manufactured by Nissei Plastics Co., Ltd., screw diameter 26 mm, injection volume 49 cm 3) and set the injection + pressure holding time to 25 seconds, the cooling time to 15 seconds, the mold temperature to 80°C, and the cylinder temperature to (melting point of polyamide resin + 20)°C, and molded a multipurpose test piece type A in accordance with ISO 3167.

[0182] [Formic acid viscosity VN] Measured in accordance with ISO307 (JIS-K6933).

[0183] [Measurement of carboxyl group terminal concentration of polyamide resin] Measurement was performed by neutralization titration as follows. First, 4.0 g of the obtained polyamide resin was dissolved in 50 mL of benzyl alcohol. Next, the obtained solution was titrated with 0.1 N NaOH to determine the concentration C (mmol / kg). The endpoint was determined from the color change of the phenolphthalein indicator. The terminal concentration was evaluated on a scale of 1 to 6 as follows, and the results are shown in the table. 1:80±20mmol / kg 2: 80±30mmol / kg 3: 80±40mmol / kg 4: 80±50mmol / kg 5: <30 mmol / kg 6: >130 mmol / kg

[0184] [Measurement of terminal amino group concentration in polyamide resin] 3.0 g of the polyamide composition was dissolved in 100 mL of a 90% by mass aqueous phenol solution, and the resulting solution was titrated with 0.025 N hydrochloric acid to determine the amount of amino terminals (μequivalents / g). The endpoint was determined from the indicated value of the pH meter.

[0185] [Evaluation of sliding characteristics] (friction coefficient, wear depth) A reciprocating friction and wear test was conducted using a reciprocating friction and wear tester (Toyo Seimitsu Co., Ltd., Model AFT-15MS) and a SUS304 test piece (5 mm diameter ball) as the counter material at a linear velocity of 50 mm / sec, a reciprocating distance of 20 mm, a temperature of 23°C, and a humidity of 50%. Furthermore, a friction coefficient test was conducted with a load of 4 kg and 10,000 reciprocating cycles. The maximum wear depth of the wear scar on the sample after the sliding test was measured using a surface roughness tester (Toyo Seimitsu Co., Ltd., Model 575A-30).

[0186] The evaluation samples were molded under the conditions of Samples 1 to 4 described below. Multipurpose test specimens of type A were molded in accordance with ISO 3167. Because the injection speeds of Samples 1 to 3 differed significantly, the flow speed (shear rate) of the molten resin also differed significantly, confirming significant changes in the morphology of the polyolefin resin. Sample conditions were developed to evaluate a wide range of shear rates during processing. Furthermore, for Sample 4, the multipurpose test specimen of type A was molded in accordance with ISO 3167, with the specimen remaining in the cylinder of the injection molding machine for 60 minutes. The multipurpose test specimen of type A was then prepared in the same manner as described above under [Molding Method].

[0187] The evaluation samples were molded under the conditions of Samples 5 and 6 described below, and were molded into multipurpose test specimens of type A in accordance with ISO 3167 in the same manner as the above-mentioned [Molding method]. Samples 5 and 6 were then produced, respectively.

[0188] Sample 5: (High temperature exposure test: 150°C x 500 hours) Each multipurpose test piece (Type A) was placed in an oven conforming to ISO 188 and heated at 150°C for 500 hours to conduct a high-temperature exposure test. After 500 hours, each multipurpose test piece (Type A) was removed from the oven and allowed to cool at 23°C for 24 hours.

[0189] Sample 6: (High-temperature oil immersion test: 150°C x 500 hours) A multipurpose test piece of type A was immersed in oil (Magnatec 0W-20 manufactured by Castrol) in an autoclave. The autoclave was then heated to 150°C, and after 500 hours, the test piece was removed from the autoclave and wiped with hexane to degrease it.

[0190] Sample 1: The molding method was the same as described above, except that the injection speed was 5 mm / s. Sample 2: The molding method was the same as described above, except that the injection speed was 30 mm / s. Sample 3: The molding method was the same as described above, except that the injection speed was 100 mm / s. Sample 4: The same molding method as above was carried out except that the sample was retained in the molding machine cylinder for 60 minutes. Sample 5: A sample prepared in the same manner as in the above [Molding method] was subjected to a high temperature exposure test and then removed. Sample 6: A sample prepared in the same manner as in the above [Molding method] was subjected to a high-temperature oil exposure test and then removed.

[0191] [Evaluation of mechanical properties] (Tensile test) The compositions obtained in the examples and comparative examples were molded under the conditions shown in [Molding method] into A-type test pieces, and a tensile test was carried out in accordance with ISO 527 at a test speed of 50 mm / min to measure the tensile strength. The ratio of the displacement of the chuck distance at break to the chuck distance before the test was taken as the tensile elongation (%). Tensile elongation (%) = 100 x breaking point displacement (mm) / initial chuck distance (mm) The tensile strength was divided by the tensile elongation to obtain the tensile modulus. Tensile modulus = tensile strength / tensile elongation

[0192] (Charpy impact strength) The compositions obtained in the examples and comparative examples were molded under the conditions shown in [Molding method] to prepare A-type test pieces of 80 x 10 x 4 mm, and the notched Charpy impact strength (kJ / m 2 ) was measured.

[0193] (Examples 1 to 7, 11) (A) Polyamide resin and (B) modified polyorganosiloxane copolymer were mixed in the amounts shown in Tables 1 and 2 and fed at 25 kg / hr from the most upstream feed port of a twin-screw extruder (manufactured by Coperion Co., Ltd., product name "ZSK26MC18") with a screw diameter of 26 mm. The extruder barrel temperature was then set to (melting point of polyamide resin + 20)°C, and the mixture was extruded while melt-kneading at a screw rotation speed of 300 rpm to obtain pellets of a polyamide resin composition. Using the obtained pellets of the polyamide resin composition, test pieces were prepared by the method described in [Molding method], and the sliding properties and mechanical properties were evaluated.

[0194] Example 8 Pellets of the polyamide resin composition were obtained in the same manner as in Example 1, except that the formulation was changed as shown in Table 2 and the barrel temperature of the extruder and the cylinder temperature of the molding machine were changed to 340°C, and evaluation was carried out.

[0195] Example 9 Pellets of the polyamide resin composition were obtained in the same manner as in Example 1, except that 100 parts by mass of the (A-1) polyamide resin was blended with 30 parts by mass of the (A-4) polyamide resin, the barrel temperature of the extruder was set to 320°C, and the amounts were increased as shown in Table 2 below, and evaluation was carried out.

[0196] Example 10 Pellets of the polyamide resin composition were prepared in the same manner as in Example 3. 10 kg of the obtained pellets were placed in a conical ribbon vacuum dryer (manufactured by Okawara Manufacturing Co., Ltd., product name: Ribocone RM-10V) and the atmosphere was thoroughly purged with nitrogen. The pellets were heated at 190°C for 6 hours while stirring and nitrogen was flowing at a rate of 1 L / min. After that, the temperature was lowered while nitrogen was still flowing, and when the temperature reached approximately 50°C, the pellets were removed from the apparatus as they were. The resulting pellets and test pieces were prepared.

[0197] (Comparative Examples 1, 4 to 7) Pellets of polyamide resin compositions were obtained in the same manner as in Example 1 except that the formulation was changed as shown in Table 3, and evaluation was carried out.

[0198] (Comparative Example 2) Pellets of a polyamide resin composition were obtained and evaluated in the same manner as in Comparative Example 1, except that the screw rotation speed was changed to 120 rpm.

[0199] (Comparative Example 3) Comparative Example 1 was carried out in the same manner as Comparative Example 1 except that the barrel temperature of the extruder was set to 230°C, but the motor torque of the twin-screw extruder reached its upper limit, and pellets of the polyamide resin composition could not be obtained.

[0200] [Table 1]

[0201] [Table 2]

[0202] [Table 3]

[0203] From the results of the Examples, the polyamide resin composition of the present invention was excellent in all of the sliding properties (friction coefficient, wear depth), moldability, long-term heat resistance, and mechanical properties (tensile strength, modulus of elasticity, impact resistance, heat resistance). Among these, as compared with the Comparative Examples in particular, it was clear that by combining both component (A) and component (B), the sliding properties were excellent in all of the results of evaluation samples 1 to 6. From these results, it was determined that a polyamide resin composition was obtained that had excellent sliding properties, regardless of the injection speed (shear rate applied to the molten resin) or residence time, and that remained stable even after heat aging.

[0204] On the other hand, the results of the comparative examples showed that although the polyamide resin compositions obtained were excellent in some properties, they were inferior in the balance of sliding properties, long-term heat resistance, moldability, and mechanical properties. Among these, the sliding properties were significantly inferior compared to the examples, and the sliding properties varied significantly depending on the sample conditions. Furthermore, in Comparative Examples 1 and 2, which did not contain component (C), all properties were inferior. From the standpoint of moldability, leakage of molten resin occurred from the nozzle tip of the injection molding machine during injection molding, making continuous injection molding difficult, resulting in low industrial applicability. Furthermore, in Comparative Examples 5 to 7, which did not contain component (B), the sliding properties were significantly inferior. [Industrial Applicability]

[0205] The polyamide resin composition of the present invention has excellent sliding properties and mechanical properties, and therefore has potential applications in the fields of automobiles, electrical and electronics, machinery and industry, office equipment, aviation and space, etc.

Claims

1. Component (A): a polyamide resin; Component (B): a modified polyorganosiloxane copolymer having at least a reactive moiety in its side chain; A polyamide resin composition comprising: the mass of the component (B) is 0.1 to 15 parts by mass relative to 100 parts by mass of the component (A); the component (B) is dispersed in the polyamide resin composition, A polyamide resin composition, wherein the number average dispersed particle diameter of the dispersed component (B) is 5 μm or less.

2. 2. The polyamide resin composition according to claim 1, wherein the reactive moiety is at least one selected from the group consisting of a glycidyl group, an acryloyl group, a methacryloyl group, a structural unit derived from a carboxylic acid anhydride, and an amino structural unit.

3. The component (A) has a terminal carboxyl group and a terminal amino group, 2. The polyamide resin composition according to claim 1, wherein the difference (C-A) between the concentration C (mmol / kg) of the terminal carboxyl groups in the component (A) and the concentration A (mmol / kg) of the terminal amino groups in the component (A) is in the range of 30 to 130 mmol / kg.

4. 4. The polyamide resin composition according to claim 3, wherein B is the part by mass of the component (B) minus the siloxane component portion, and B and the concentration C satisfy the relationship C×B=50 to 300.

5. The polyamide resin composition according to claim 1, wherein the component (B) is a graft copolymer.

6. The polyamide resin composition according to claim 1, wherein the number average dispersed diameter is 2 μm or less.

7. 2. The polyamide resin composition according to claim 1, wherein the proportion of the siloxane component in component (B) is 50 to 90%.

8. A molded article of the polyamide resin composition according to any one of claims 1 to 7.

9. A sliding member comprising the polyamide resin composition according to any one of claims 1 to 7.

10. The sliding member according to claim 9, which is used in a liquid lubrication environment.

11. The sliding member according to claim 10 , wherein a material that the sliding member comes into contact with is other than a thermoplastic resin.

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