WO2025094869A1 - Polyamide resin composition - Google Patents

Abstract

Provided is a polyamide resin composition which is shiny and has good mechanical properties such as tensile strength and impact resistance.　The polyamide resin composition according to the present invention comprises, in 100% by mass of the polyamide resin composition, 35%-90% by mass of a polyamide resin (A1) having a constituent unit derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid, 0%-5% by mass of polyamide 6 (A2), and 5%-60% by mass of a reinforcing filler (B) coated with a sizing agent including a polyurethane resin.

Description

Polyamide resin composition

The present invention relates to a polyamide resin composition.

Polyamide resin has excellent properties as an engineering plastic and is widely used in various industrial fields such as automobiles, machinery, and electrical/electronics.

　Conventional polyamide resins were made from fossil fuels. With the recent growing interest in environmental issues, there is a demand for environmentally friendly resins. Pentamethylenediamine can be obtained from biomass raw materials. Polyamide resin compositions containing polyamide 5X, which uses pentamethylenediamine, have been developed (see, for example, Patent Documents 1 to 4). Patent Document 1 describes a polyamide resin composition that contains glass fibers and has excellent mechanical properties.

JP 2004-269634 A JP 2022-69966 A JP 2011-225630 A JP 2023-59853 A

However, in the polyamide resin compositions of Patent Documents 1 to 4, the mechanical properties have not yet been sufficiently examined.
On the other hand, molded articles of polyamide resin compositions are often used in places where they are visible to the public, and therefore, are required to have good design.
Therefore, an object of the present invention is to provide a polyamide resin composition which is glossy and has good mechanical properties such as tensile strength and impact resistance.

The present invention relates to, for example, the following [1] to [7].
[1] A polyamide resin composition comprising, based on 100% by mass of the polyamide resin composition, 35 to 90% by mass of a polyamide resin (A1) having a structural unit derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid, 0 to 5% by mass of polyamide 6 (A2), and 5 to 60% by mass of a reinforcing filler (B) coated with a sizing agent containing a polyurethane resin.
[2] The polyamide resin composition according to [1], comprising, based on 100% by mass of the polyamide resin composition, 35 to 85% by mass of the polyamide resin (A1), 0.05 to 5% by mass of the polyamide 6 (A2), and 5 to 60% by mass of the reinforcing filler (B).
[3] The polyamide resin composition according to [1] or [2], containing 0.005 to 0.50 mass% of a colorant (C) based on 100 mass% of the polyamide resin composition.
[4] The polyamide resin composition according to any one of [1] to [3], wherein the polyamide resin (A1) is at least one selected from the group consisting of polyamide 56, polyamide 59, polyamide 510 and polyamide 513.
[5] The polyamide resin composition according to any one of [1] to [4], wherein the reinforcing filler is a fibrous reinforcing filler.
[6] The polyamide resin composition according to any one of [1] to [5], comprising 0.001 to 0.05 mass% of a lubricant (D) based on 100 mass% of the polyamide resin composition.
[7] A molded article made of the polyamide resin composition according to any one of [1] to [6].

The polyamide resin composition of the present invention is glossy and has good mechanical properties such as tensile strength and impact resistance.

The present invention relates to a polyamide resin composition that contains, based on 100% by mass of the polyamide resin composition, 35 to 90% by mass of polyamide resin (A1) having structural units derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid, 0 to 5% by mass of polyamide 6 (A2), and 5 to 60% by mass of reinforcing filler (B) coated with a binder containing a polyurethane resin.

<Polyamide Resin (A1) Having Structural Units Derived from the Reaction Product of Pentamethylenediamine and Aliphatic Dicarboxylic Acid>
The polyamide resin composition contains a polyamide resin (A1) (hereinafter also referred to as "polyamide resin (A1)") having structural units derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid.
The polyamide resin (A1) is an aliphatic homopolyamide resin having a structural unit of a condensation product of pentamethylenediamine and an aliphatic dicarboxylic acid, and is preferably an aliphatic homopolyamide resin based on a structural unit of a condensation product of pentamethylenediamine and an aliphatic dicarboxylic acid.
The diamine used in this polycondensation reaction contains pentamethylenediamine as an essential component, but may contain other diamines within a range that does not impair the effects of the present invention. Preferably, no other diamines are contained.

It is more preferable that 50% by mass or more of the 100% by mass of pentamethylenediamine in polyamide resin (A1) is derived from a biomass raw material. Polyamide resin (A1) using pentamethylenediamine from a biomass raw material is an environmentally friendly material because the raw material is plant-derived.

Examples of the aliphatic dicarboxylic acid include non-alicyclic aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, octadecanedioic acid, and eicosanedioic acid; and alicyclic dicarboxylic acids such as 1,3-/1,4-cyclohexanedicarboxylic acid, dicyclohexanemethane-4,4'-dicarboxylic acid, and norbornanedicarboxylic acid.
Among these, aliphatic dicarboxylic acids other than alicyclic ones are preferred, one selected from the group consisting of adipic acid, azelaic acid, sebacic acid and tridecanedioic acid is more preferred, and adipic acid or sebacic acid is even more preferred.

The polyamide resin (A1) is preferably at least one selected from the group consisting of polyamide 56, polyamide 59, polyamide 510, and polyamide 513, more preferably at least one selected from the group consisting of polyamide 56 and polyamide 510, and even more preferably at least one selected from the group consisting of polyamide 56 and polyamide 510.

The relative viscosity of polyamide resin (A1) is preferably 1.5 to 5.0, more preferably 2.0 to 4.1, and even more preferably 2.4 to 3.1. Being in the above range will result in good moldability. The relative viscosity is measured in accordance with JIS K6920-2 by dissolving 1 g of polyamide resin in 100 ml of 96% concentrated sulfuric acid at 25°C.

The terminal amino group concentration of polyamide resin (A1), as determined by dissolving the resin in a mixed solvent of phenol and methanol and performing neutralization titration, is preferably 30 μmol/g or more, more preferably 30 to 110 μmol/g, and even more preferably 30 to 70 μmol/g. By being in the above range, the interaction with the reinforcing filler is improved, and the mechanical properties are improved.

The upper limit of the amount of polyamide resin (A1) in 100% by mass of the polyamide resin composition is 90% by mass, preferably 85% by mass, and more preferably 80% by mass. The lower limit of the amount of polyamide resin (A1) in 100% by mass of the polyamide resin composition is 35% by mass, and preferably 40% by mass.
The specific range of the blending amount of the polyamide resin (A1) is 35 to 90 mass%, preferably 35 to 85 mass%, and more preferably 40 to 80 mass%, based on 100 mass% of the polyamide resin composition. When the blending amount of the polyamide resin (A1) is within the above range, the mechanical properties are improved and the moldability is good.

<Polyamide 6 (A2)>
The polyamide resin composition is preferably optionally blended with polyamide 6 (A2), which is preferable from the viewpoint of dispersibility of various additives.
The polyamide 6 (A2) may be a ring-opening polymer of ε-caprolactam.

The relative viscosity of polyamide 6 (A2) is preferably 1.5 to 5.0, more preferably 1.9 to 3.9, and even more preferably 2.2 to 2.8. Being in the above range will result in good moldability. The relative viscosity is measured in accordance with JIS K6920-2 by dissolving 1 g of polyamide resin in 100 ml of 96% concentrated sulfuric acid at 25°C.

The terminal amino group concentration of polyamide 6 (A2), as determined by dissolving it in a mixed solvent of phenol and methanol and performing neutralization titration, is preferably 30 μmol/g or more, more preferably 30 to 110 μmol/g, and even more preferably 30 to 70 μmol/g. By being in the above range, the interaction with the reinforcing filler is improved, and the mechanical properties are improved.

The amount of polyamide 6 (A2) is 0 to 5 mass% of 100 mass% of the polyamide resin composition, preferably 0.05 to 5 mass%, and more preferably 0.1 to 3 mass%. When the amount of polyamide 6 (A2) is within the above range, the functions and properties of polyamide resin (A1) are not impaired.

<Reinforcing filler (B) coated with a binder containing polyurethane resin>
The polyamide resin composition contains a reinforcing filler (B) coated with a sizing agent containing a polyurethane resin (hereinafter, also referred to as "reinforcing filler (B) coated with a sizing agent"). The reinforcing filler (B) coated with a sizing agent containing a polyurethane resin is a component that imparts excellent sliding properties and mechanical properties to the polyamide resin composition.

[Reinforcing filler]
Examples of reinforcing fillers include fibrous reinforcing fillers such as glass fibers, carbon fibers, graphite fibers, metal fibers, gypsum fibers, silica fibers, silica-alumina fibers, zirconia fibers, boron nitride fibers, silicon nitride fibers, slag fibers, and boron fibers, potassium titanate whiskers, aluminum borate whiskers, magnesium whiskers, and silicon whiskers, silicates such as wollastonite, sepiolite, zonolite, elestadite, sericite, kaolin, mica, clay, bentonite, asbestos, talc, and alumina silicate, swellable layered silicates such as montmorillonite and synthetic mica, metal compounds such as alumina, silicon oxide, magnesium oxide, zirconium oxide, titanium oxide, and iron oxide, carbonates such as calcium carbonate, magnesium carbonate, and dolomite, sulfates such as calcium sulfate and barium sulfate, glass flakes, glass beads, ceramic beads, boron nitride, silicon carbide, calcium phosphate, and silica. These may be used alone or in combination of two or more.

Among the reinforcing fillers, fibrous reinforcing fillers are preferred. Fiber refers to a shape with an aspect ratio (ratio of long diameter/short diameter) of 10 or more. The reinforcing filler (B) may break when melt-kneaded with other components. Therefore, the preferred embodiment of the fibrous reinforcing filler in the polyamide resin composition includes those that are broken during melt-kneading and no longer meet the definition of "fiber" in this specification, as long as they meet the definition of "fiber" in this specification when blended.
The cross-sectional shape of the fibrous reinforcing filler is not particularly limited, and examples thereof include a perfect circle, a cocoon, an oval, a rectangle, or shapes similar thereto.

The average fiber diameter of the fibrous reinforcing filler is preferably 5.0 μm to 15.0 μm. When the average fiber diameter of the fibrous reinforcing filler is within the above range, the dispersion of the reinforcing fibers in the resin is improved, and mechanical strength can be ensured. The average fiber diameter of the fibrous reinforcing filler is a value measured by an optical microscope, and may be a catalog value when a commercially available product is used. The average fiber diameter of the fibrous reinforcing filler (B) coated with a preferred embodiment of a bundling agent is also preferably within the same range.

When the cross section of the fibrous reinforcing filler is rectangular or a similar shape, the length of one side of the cross section is preferably 0.5 μm to 50 μm, more preferably 1 to 40 μm. The number average fiber length of the fibrous reinforcing filler at the time of blending is preferably 2000 μm to 4000 μm, more preferably 2500 μm to 3500 μm.
Since the polyamide resin composition is produced by melt kneading, the dimensions change due to the breakage of the fibrous reinforcing filler during the process. Therefore, the number average fiber length of the fibrous reinforcing filler in the polyamide resin composition is preferably 100 μm to 450 μm, more preferably 200 μm to 350 μm. The weight average fiber length of the fibrous reinforcing filler in the polyamide resin composition is preferably 150 μm to 550 μm, more preferably 250 μm to 450 μm. The number average fiber length and weight average fiber length of the fibrous reinforcing filler can be determined using image analysis software from an image taken using a transmission microscope. For the fibrous reinforcing filler in the polyamide resin composition, the aspect ratio obtained by dividing the number average fiber length by the average fiber diameter is preferably 10 or more, more preferably 15 to 100, and particularly preferably 30 to 70, from the viewpoints of rigidity, mechanical strength, and fluidity. The number average fiber length and weight average fiber length of the fibrous reinforcing filler coated with a bundling agent are also preferably in the same range as above. The term "fibrous reinforcing filler coated with a sizing agent in a polyamide resin composition" refers to fibrous reinforcing filler coated with a sizing agent in a polyamide resin composition obtained by melt-kneading each component.

Among the fibrous reinforcing fillers, glass fiber, carbon fiber, and graphite fiber are preferred, and glass fiber is more preferred.
Examples of the glass constituting the glass fiber include those having compositions such as A glass, AR glass, C glass, D glass, E glass, H glass, S glass, T glass, M glass, and NE glass.

The shape of the glass fiber is not particularly limited, and examples include flat fiber and chopped strands.

[Polyurethane resin]
The polyurethane resin is a resin obtained by subjecting a polyol component and a polyisocyanate component to a urethane reaction.

<Polyol component>
Examples of the polyol component include polyester polyols (condensation polyester polyols, lactone polyester polyols), polycarbonate polyols, and polyether polyols.

Condensation polyester polyols include those obtained by reacting dicarboxylic acids or their lower alkyl esters with aliphatic diols. Here, examples of dicarboxylic acids or their lower alkyl esters include adipic acid, succinic acid, azelaic acid, pimelic acid, sebacic acid, phthalic acid, etc., or their lower alkyl esters. Examples of aliphatic diols include aliphatic diols without side chains, such as ethylene glycol, 1,4-butanediol, 1,6-hexanediol, and 1,10-decamethylene glycol, and aliphatic diols with side chains, such as 1,2-propylene glycol, 1,3-butanediol, 2,5-dimethyl-2,5-hexanediol, 2,2-diethyl-1,3-propanediol, and neopentyl glycol.

Examples of lactone-based polyester polyols include those obtained by reacting lactone compounds such as β-propiolactone, pivalolactone, δ-valerolactone, ε-caprolactone, methyl-ε-caprolactone, dimethyl-ε-caprolactone, and trimethyl-ε-caprolactone with hydroxy compounds such as short-chain polyols.

Polycarbonate polyols are those obtained by transesterification of hydroxy compounds such as short-chain polyols with diallyl carbonate, dialkyl carbonate, or ethylene carbonate. For example, poly-1,6-hexamethylene carbonate and poly-2,2'-bis(4-hydroxyhexyl)propane carbonate are industrially produced and are easy to obtain. Another method for obtaining polycarbonate polyols is the so-called phosgene method (or solvent method).

Polyether polyols include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyoxypropylene glycol, and glycerin-based polyalkylene ether glycol.

<Polyisocyanate component>
Examples of the polyisocyanate include aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatic polyisocyanates.

Examples of aliphatic polyisocyanates include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethyl caproate, bis(2-isocyanatoethyl) fumarate, bis(2-isocyanatoethyl) carbonate, and 2-isocyanatoethyl-2,6-diisocyanatohexanoate.

Examples of alicyclic polyisocyanates include isophorone diisocyanate (IPDI), 4,4'-dicyclohexylmethane diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis(2-isocyanatoethyl)-4-cyclohexene-1,2-dicarboxylate, 2,5-norbornane diisocyanate, and 2,6-norbornane diisocyanate.

Aromatic polyisocyanates include, for example, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate (TDI), 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), 2,4-diphenylmethane diisocyanate, 4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanato Diphenylmethane, 1,5-naphthylene diisocyanate, 4,4',4''-triphenylmethane triisocyanate, m-isocyanatophenylsulfonyl isocyanate, p-isocyanatophenylsulfonyl isocyanate, 1-methyl-2,6-phenylene diisocyanate, 1-methyl-2,5-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate, 1-methyl-3,5-phenylene diisocyanate, 1-ethyl-2,4-phenyl Diisocyanate, 1-isopropyl-2,4-phenylene diisocyanate, 1,3-dimethyl-2,4-phenylene diisocyanate, 1,3-dimethyl-4,6-phenylene diisocyanate, 1,4-dimethyl-2,5-phenylene diisocyanate, diethylbenzene diisocyanate, diisopropylbenzene diisocyanate, 1-methyl-3,5-diethylbenzene diisocyanate, 3-methyl-1,5-diethylbenzene-2,4-diisocyanate , 1,3,5-triethylbenzene-2,4-diisocyanate, naphthalene-1,4-diisocyanate, 1-methyl-naphthalene-1,5-diisocyanate, naphthalene-2,6-diisocyanate, naphthalene-2,7-diisocyanate, 1,1-dinaphthyl-2,2'-diisocyanate, biphenyl-2,4'-diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, 2,2'-diphenylmethane diisocyanate, etc.

The polyisocyanate is preferably a diisocyanate having two isocyanato groups per molecule.

In the urethane reaction, chain extenders such as polyhydric alcohols and polyhydric amines can also be used.

[Other optional components of sizing agent]
The sizing agent may contain further components other than the polyurethane resin, such as a copolymer having an acidic group, a coupling agent, a lubricant, a nonionic surfactant, an antistatic agent, water, an organic solvent, etc.

Examples of the copolymer having an acidic group include a copolymer of a monomer having an acidic group, and a copolymer of a monomer having an acidic group and a monomer not having an acidic group.
In this specification, the term "acidic group" refers to a group that liberates a proton, and examples of such groups include a carboxyl group, a sulfonic acid group, a phosphoric acid group, and a phenolic hydroxyl group, but does not include a hydroxyl group (excluding a phenolic hydroxyl group).

　Monomers having an acidic group include unsaturated carboxylic acids and carboxylic anhydrides. Examples of unsaturated carboxylic acids include acrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, mesaconic acid, citraconic acid, crotonic acid, isocrotonic acid, and endo-cis-bicyclo[2,2,1]hept-5-ene-2,3-dicarboxylic acid. Examples of carboxylic acid anhydrides include dicarboxylic acid anhydrides such as maleic anhydride, itaconic anhydride, succinic anhydride, phthalic anhydride, glutaric anhydride, dodecenylsuccinic anhydride, chlorendic anhydride, and citraconic anhydride. The carboxylic acid anhydride is preferably maleic anhydride, since it has little steric hindrance during copolymerization and has a small polarity of the compound. The monomer having an acidic group may also be a monomer having a functional group having the same function as the acidic group. Examples of such functional groups include acid halides, amides, imides, anhydrides, and esters of the unsaturated carboxylic acids. Examples of monomers having a functional group having the same function as the acidic group include malenyl chloride, maleimide, monomethyl maleate, dimethyl maleate, glycidyl maleate, and the above-mentioned carboxylic acid anhydrides. These may be used alone or in combination of two or more.

Monomers that do not have acidic groups include styrene, ethylene, acetylene, etc.

The copolymer having an acidic group is preferably a copolymer of an unsaturated dicarboxylic acid and/or a carboxylic acid anhydride with methyl acrylate and methyl methacrylate.

The copolymerization ratio of the unsaturated dicarboxylic acid and/or carboxylic anhydride in the copolymer of the unsaturated dicarboxylic acid and/or carboxylic anhydride with methyl acrylate and methyl methacrylate is preferably 20 to 60 mass%, and more preferably 25 to 55 mass%, from the viewpoints of reactivity and mechanical properties when producing the copolymer. The copolymerization ratio of methyl acrylate is preferably 20 to 75 mass%, and more preferably 30 to 65 mass%, from the viewpoints of reactivity and mechanical properties when producing the copolymer. The copolymerization ratio of methyl methacrylate is preferably 5 to 20 mass%, and more preferably 7 to 17 mass%, from the viewpoints of reactivity and mechanical properties when producing the copolymer. The copolymerization ratio of the monomer not having an acidic group is preferably 10 mass% or less, and more preferably 1 mass% or less.

From the viewpoints of reactivity during production of the copolymer and mechanical properties, the weight average molecular weight of the copolymer is preferably 10,000 to 60,000, and particularly preferably 20,000 to 50,000. The weight average molecular weight of the copolymer is a molecular weight measured by gel permeation chromatography (GPC).
The lubricant may include fatty acid amides, quaternary ammonium salts, and the like.
Examples of the nonionic surfactant include synthetic alcohol-based surfactants, natural alcohol-based surfactants, and fatty acid ester-based surfactants.
The water and organic solvent are components that dissolve the lubricant, the nonionic surfactant, the antistatic agent, etc. The organic solvent may, for example, be ethanol.

The content of each component in the binder can be set appropriately depending on the properties of the resulting reinforcing filler.

[Coating]
The reinforcing filler is coated with a sizing agent containing a polyurethane resin. The reinforcing filler is surface-treated by being coated with the sizing agent. "Coated" means that the sizing agent is attached to at least a part of the surface of the reinforcing filler. The reinforcing filler may be subjected to a bundling treatment using the bundling agent to bundle two or more reinforcing filler strands into one. The bundling treatment may also be performed by applying the bundling agent to a plurality of reinforcing filler monofilaments formed by drawing molten glass from a plurality of nozzles, bundling them into one reinforcing filler strand, and then winding them into a cake.

The reinforcing filler (B) coated with the binder may be surface-treated with a further component. Such components include the further component contained in the binder.

The reinforcing filler (B) coated with a binder containing a polyurethane resin may contain, in addition to the above, components described in JP 2014-231452 A.
The reinforcing filler (B) coated with a sizing agent comprising a polyurethane resin may be one component or a combination of two or more components.

From the viewpoint of exerting strength improving performance, the ignition loss when the volatile substances are completely evaporated from the binder is preferably 0.1 to 1.5 mass%, and more preferably 0.4 to 1.2 mass%. The ignition loss of the binder is a value measured in accordance with JIS R 3420 (2006) 7.3.2.

The upper limit of the amount of the reinforcing filler (B) coated with a sizing agent is 60 mass%, preferably 55 mass%, and more preferably 50 mass% in 100 mass% of the polyamide resin composition. The lower limit of the amount of the polyamide resin (A1) is 5 mass%, preferably 10 mass%, and more preferably 20 mass% in 100 mass% of the polyamide resin composition.
The specific range of the blending amount of the reinforcing filler (B) coated with a sizing agent is 5 to 60 mass %, preferably 10 to 55 mass %, and more preferably 20 to 50 mass %, based on 100 mass % of the polyamide resin composition. When the blending amount of the reinforcing filler (B) is within the above range, it is preferable from the viewpoint of mechanical properties and moldability.

<Colorant (C)>
The polyamide resin composition preferably contains a colorant (C) as an optional component.
The colorant (C) is a component that mainly functions to color the polyamide resin composition. Examples of the colorant (C) include carbon black, nigrosine, titanium oxide, iron oxide, etc. These may be used alone or in combination of two or more.

The upper limit of the amount of the colorant (C) in the polyamide resin composition is preferably 0.50% by mass, more preferably 0.40% by mass, and even more preferably 0.30% by mass. The lower limit of the amount of the colorant (C) in the polyamide resin composition is preferably 0.005% by mass, more preferably 0.05% by mass, and even more preferably 0.10% by mass.
The specific range of the blending amount of the colorant (C) is preferably 0.005 to 0.50 mass%, more preferably 0.05 to 0.40 mass%, and even more preferably 0.10 to 0.30 mass%, based on 100 mass% of the polyamide resin composition. When the blending amount of the colorant (C) is within the above range, it is preferable from the viewpoint of preventing bleeding out onto the surface of the molded article.

<Lubricant (D)>
The polyamide resin composition preferably contains a lubricant (D) as an optional component.
The lubricant is a material that contributes to improving the releasability from a mold when molding a resin composition.

Lubricants include compounds such as terminal modified polyalkylene glycols, phosphates or phosphites, higher fatty acid monoesters, higher fatty acids or their metal salts, carboxylic acid amides, ethylene bisamide compounds, low molecular weight polyethylene, magnesium silicate, and substituted benzylidene sorbitols. These may be used alone or in combination of two or more. Of these, higher fatty acids or their metal salts are preferred.

Examples of the terminal-modified polyalkylene glycol include terminal-modified polyethylene glycol and terminal-modified polypropylene glycol.
More specific examples of the phosphate ester and the phosphite ester include aliphatic phosphate esters and aliphatic phosphite esters such as di(2-ethylhexyl)phosphate, tridecyl phosphite, tris(tridecyl)phosphite, and tristearyl phosphite, and aromatic phosphite esters such as triphenyl phosphite and diphenyl monodecyl phosphite.

Examples of higher fatty acid monoesters include myristyl myristate, stearyl stearate, behenyl behenate, oleyl oleate, and hexyldecyl myristate.
Examples of higher fatty acids include myristic acid, palmitic acid, behenic acid, oleic acid, and arachidic acid.
Examples of metal salts of higher fatty acids include zinc stearate, lithium stearate, calcium stearate, aluminum palmitate, and metal salts of the above-mentioned examples of higher fatty acids.

Carboxylic acid amides include aliphatic monocarboxylic acid amides such as lauric acid amide, palmitic acid amide, oleic acid amide, stearic acid amide, erucic acid amide, behenic acid amide, ricinoleic acid amide, and 12-hydroxystearic acid amide, N-lauryl lauric acid amide, N-palmityl palmitic acid amide, N-oleyl palmitic acid amide, N-oleyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-stearyl erucic acid amide, N-stearyl-12-hydroxystearic acid amide, N-oleyl-12-hydroxystearic acid amide, methylol stearic acid amide, methylol behenic acid amide, and 12-hydroxystearic acid amide. N-substituted aliphatic monocarboxylic acid amides such as 2-hydroxystearic acid monoethanolamide, methylene bisstearic acid amide, methylene bislauric acid amide, methylene bis-12-hydroxystearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisoleic acid amide, ethylene bisstearic acid amide, ethylene biserucic acid amide, ethylene bisbehenic acid amide, ethylene bisisostearic acid amide, ethylene bis-12-hydroxystearic acid amide, butylene bisstearic acid amide, hexamethylene bisoleic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid amide, hexamethylene bis-12-hydroxystearic acid amide, Aliphatic carboxylic acid bisamides such as cystearic acid amide, N,N'-dioleyl sebacic acid amide, N,N'-dioleyl adipic acid amide, N,N'-distearyl adipic acid amide, and N,N'-distearyl sebacic acid amide; N,N'-dicyclohexanecarbonyl-1,4-diaminocyclohexane, 1,4-cyclohexanedicarboxamide, 1,4-cyclohexanedicarboxylic acid diaminocyclohexane, 1,2,3,4-butanetetracarboxylic acid tetracyclohexylamide, N,N'-bis(3-hydroxypropyl)-1,4-cubanedicarboxamide, N,N'-(1,4-cyclohexanediyl)bis(acetamide), and tris(methylcyclohexyl)propanetricarboxamide; Examples of such alicyclic carboxylic acid amides include 1,4-cyclohexanedicarboxylic acid dianilide, 1,4-cyclohexanedicarboxylic acid dibenzylamide, trimesic acid tris(t-butylamide), trimesic acid tricyclohexylamide, trimesic acid tri(2-methylcyclohexylamide), trimesic acid tri(4-cyclohexylamide), 2,6-naphthalene dicarboxylic acid dicyclohexylamide, N,N'-dibenzylcyclohexane-1,4-dicarboxamide, N,N'-distearyl isophthalic acid amide, N,N'-distearyl terephthalic acid amide, m-xylylene bisstearic acid amide, and m-xylylene bis-12-hydroxystearic acid amide.

Examples of the ethylene bisamide compound include ethylene bis stearyl amide and ethylene bis palmityl amide.
Low molecular weight polyethylene includes those having a molecular weight in the range of 500-5,000.
The magnesium silicate may have an average particle size of 1 to 10 μm.

The substituted benzylidene sorbitols include those synthesized by dehydration condensation of sorbitol and a substituted benzaldehyde in the presence of an acid catalyst.
These may be used alone or in combination of two or more.

The amount of lubricant (D) in 100% by mass of the polyamide resin composition is preferably 0.001 to 0.05% by mass, more preferably 0.005 to 0.04% by mass, and even more preferably 0.01 to 0.03% by mass. When the amount of lubricant (D) is within the above range, moldability is good and it is preferable from the viewpoint that the lubricant does not bleed out onto the surface of the molded product.

<Other optional ingredients>
The polyamide resin composition may contain any optional components other than the above-mentioned components, as long as the effects of the present invention are not impaired.
The optional components include resins other than the components (A1) and (A2), and functionality-imparting agents other than the components (B), (C), and (D).

Examples of resins other than components (A1) and (A2) include aliphatic polyamide resins other than components (A1) and (A2), aromatic polyamide resins, polyolefin resins such as low-, medium-, and high-density polyethylene, polypropylene, and polybutene, modified polyolefin resins, polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyester-based elastomers, vinyl aromatic resins such as polystyrene, ABS resin, and AS resin, polyether resins, polyurethane resins, acrylic resins, polyimide resins, polycarbonate resins, polyacetal, polyvinyl alcohol, and rosin resins.

When resins other than the (A1) and (A2) components are blended, the amount is preferably 0.01 to 2.0 mass%, more preferably 0.05 to 1.5 mass%, and even more preferably 0.1 to 1.0 mass%, based on 100 mass% of the polyamide resin composition, from the viewpoint of not impairing the functions and properties of the polyamide resin composition.

The functionality-imparting agent may be any of the various additives that are typically incorporated into polyamide resin compositions. Specific examples of functionality-imparting agents include plasticizers, heat resistance agents, foaming agents, weather resistance agents, crystal nucleating agents, antioxidants, crystallization accelerators, release agents, antistatic agents, dispersants, flame retardants, flame retardant assistants, and spreading agents.

Here, when the functionality-imparting agent is a heat-resistant agent, organic or inorganic heat-resistant agents can be used depending on the purpose, and these may be used alone or in combination of two or more. Heat-resistant agents refer to components that suppress thermal oxidation and thermal deterioration of polyamide resins, and for that purpose also include those known as antioxidants.

Examples of the organic heat-resistant agent include phenol-based compounds, phosphorus-based compounds, sulfur-based compounds, nitrogen-based compounds, etc. These may be used alone or in combination of two or more.
Preferred examples of the phenolic compound include hindered phenolic organic compounds. In this specification, the term "hindered phenol" refers to a compound having a substituent at the ortho position of the phenolic hydroxyl group.
Preferred examples of the phosphorus-based compound include hindered phenol phosphite compounds and hindered phenol hypophosphite compounds.

The heat resistance agent is preferably an inorganic compound or a combination of an inorganic compound and a nitrogen-containing compound.
The inorganic compounds include metal halides and inorganic compounds other than metal halides.

Metal halides are compounds of halogens and metals. Examples of halogens include fluorine, chlorine, bromine, and iodine. Examples of metals include Group 1 elements (alkali metals), Group 2 elements (alkaline earth metals), and Group 3 to Group 12 elements (e.g., transition metals). The metal in the metal halide is preferably a Group 1 element (alkali metal) or Group 11 element (copper group). Examples of metal halides when the metal is a Group 1 element (alkali metal) include potassium iodide, potassium bromide, potassium chloride, sodium iodide, and sodium chloride. Examples of metal halides when the metal is a Group 11 element (copper group) include cuprous chloride, cupric chloride, cuprous bromide, cupric bromide, cuprous iodide, and cupric iodide. The metal halide is more preferably potassium iodide and/or cuprous iodide, and even more preferably a mixture of potassium iodide and cuprous iodide.

Inorganic compounds other than metal halides include metals, metal oxides, metal hydroxides, metal nitrides, metal phosphates, metal phosphites, metal carbonates, metal silicates, metal titanates, metal borates, metal sulfates, metal nitrates, etc.

Nitrogen-containing compounds include melamine, benguanamine, dimethylol urea, and cyanuric acid.

When a heat resistant agent is added, the amount of the heat resistant agent is preferably 0.01 to 2.00 mass%, more preferably 0.05 to 1.00 mass%, and even more preferably 0.10 to 0.50 mass%, based on 100 mass% of the polyamide resin composition.

Examples of functionality-imparting agents other than those mentioned above include the components described in JP-A-2002-370551.
Each of the optional components may be one component or a combination of two or more components.

<Method of producing polyamide resin composition>
The method for producing the polyamide resin composition is not particularly limited as long as it is a method that can knead each component, and examples thereof include a production method using a twin-screw kneader, a twin-screw extruder, a single-screw extruder, a multi-screw extruder, etc. For example, any method may be used, such as a method in which all raw materials are blended using a twin-screw extruder and then melt-kneaded, a method in which a portion of the raw materials are blended and then melt-kneaded, and the remaining raw materials are further blended and melt-kneaded, or a method in which a portion of the raw materials are blended and then the remaining raw materials are mixed using a side feeder during melt-kneading.

[Uses of polyamide resin compositions, etc.]
The polyamide resin composition is not particularly limited, and can be used to manufacture molded articles using known methods such as injection molding, extrusion molding, blow molding, rotational molding, vacuum molding, and compressed air molding. In addition, molded articles containing the polyamide resin composition can be used for parts that require sliding properties. Examples of parts that require sliding properties include gears, cams, pulleys, bearings, bearing retainers, door checks, timing chain guides, cable/hose support/guiding device products, and other dynamic applications. There is no problem with using the composition for other components that require similar functions.

The present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

<<Measurement method and evaluation>>
A check mark was marked as a pass and a check mark was marked as a fail.
(1) Average gloss: Type D2 test pieces were prepared in accordance with ISO 294-3, and the gloss was measured using a glossmeter (BYK Corporation, micro-TRI-gloss μ 4435) at an incident angle of 60° as specified in JIS Z 8741. The gloss was calculated as the average value of a total of five points, including the center of one test piece and four points 20 mm apart from the center in all directions.
◯: Average glossiness is more than 45%, and glossiness is excellent.
×: Average glossiness is 45% or less, and glossiness is poor.

(2) Tensile strength Type A test pieces were prepared based on ISO 294-1, and tensile tests were carried out in an atmosphere at 23° C. based on ISO 527-1 and 2.
Good: The tensile strength is 150 MPa or more, and is excellent in tensile strength.
×: The tensile strength is less than 150 MPa, and the tensile strength is poor.

(3) Charpy impact strength Type B test pieces were prepared based on ISO 294-1, and V-notched based on ISO 179/1eA in post-processing, and a Charpy impact test was carried out in an atmosphere at 23°C.
◯: Charpy impact strength is 6 kJ/ ^m2 or more, and impact resistance is excellent.
×: Charpy impact strength is less than 6 kJ/ ^m2 , and impact resistance is poor.

The components used in the examples and comparative examples are as follows.
PA56: Polyamide 56, relative viscosity 2.78, terminal amino group concentration 49.7 μmol/g, manufactured by Cathay PA66: Polyamide 66, relative viscosity 2.65, terminal amino group concentration 52.9 μmol/g, manufactured by Asahi Kasei Corporation PA6: Polyamide 6, relative viscosity 2.47, terminal amino group concentration 44.5 μmol/g, manufactured by UBE Corporation Sizing agent-coated glass fiber T-249H: Round chop ECS03T-249H Φ10.5 microns (manufactured by Nippon Electric Glass Co., Ltd. Average fiber diameter 10.5 μm, glass fiber is coated with a sizing agent containing polyurethane resin.)
Sizing agent-coated glass fiber T-275H: Round chop ECS03T-275H Φ10.5 microns (manufactured by Nippon Electric Glass Co., Ltd. Average fiber diameter 10.5 μm, glass fiber is coated with a sizing agent containing polyurethane resin.)
Heat resistant agent: Cuprous iodide/potassium iodide = 1/6 (mass ratio) (mixture)
Colorant: carbon black Lubricant: calcium stearate The relative viscosities of polyamide 56, polyamide 66 and polyamide 6 were measured at 25° C. in accordance with JIS K6920-2 by dissolving 1 g of polyamide resin in 100 ml of 96% concentrated sulfuric acid.
The terminal amino group concentrations of polyamide 56, polyamide 66 and polyamide 6 were determined by dissolving the polyamide resin in a mixed solvent of phenol and methanol and subjecting it to neutralization titration.
The average fiber diameter of the glass fibers is a catalog value.

[Examples 1 to 6, Comparative Examples 1 to 4]
The components shown in Table 1 were melt-kneaded in a TEX34αIII twin-screw kneader manufactured by Japan Steel Works, Ltd. to prepare the desired polyamide resin composition pellets. Unless otherwise specified in the evaluation method, the obtained pellets were injection molded at a cylinder temperature of 290° C. and a mold temperature of 80° C. to prepare various test pieces, and various physical properties were evaluated.
In Table 1, the content of each component is the value relative to the polyamide resin composition as 100 mass %.

Examples 1 to 6 are all good in average gloss, tensile strength and Charpy impact strength.
Comparisons between Example 1 and Comparative Example 1, Example 2 and Comparative Example 2, Example 3 and Comparative Example 3, and Example 4 and Comparative Example 4, which are all the same except for the presence or absence of polyamide resin (A1) having a structural unit derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid, show that, under the same conditions, the Examples have a superior average gloss to the Comparative Examples.

The polyamide resin composition of the present invention is suitable for use in molded products that require gloss.

Claims (7)

A polyamide resin composition that contains, in 100% by mass of the polyamide resin composition, 35 to 90% by mass of polyamide resin (A1) having structural units derived from the reaction product of pentamethylenediamine and aliphatic dicarboxylic acid, 0 to 5% by mass of polyamide 6 (A2), and 5 to 60% by mass of reinforcing filler (B) coated with a binder containing a polyurethane resin. The polyamide resin composition according to claim 1, which contains 35 to 85 mass% of the polyamide resin (A1), 0.05 to 5 mass% of the polyamide 6 (A2), and 5 to 60 mass% of the reinforcing filler (B) in 100 mass% of the polyamide resin composition. The polyamide resin composition according to claim 1, which contains 0.005 to 0.50 mass% of colorant (C) per 100 mass% of the polyamide resin composition. The polyamide resin composition according to claim 1, wherein the polyamide resin (A1) is at least one selected from the group consisting of polyamide 56, polyamide 59, polyamide 510 and polyamide 513. The polyamide resin composition according to claim 1, wherein the reinforcing filler is a fibrous reinforcing filler. The polyamide resin composition according to claim 1, which contains 0.001 to 0.05 mass% of a lubricant (D) based on 100 mass% of the polyamide resin composition. A molded article made from the polyamide resin composition according to any one of claims 1 to 6.