Polyamide resin composition

Abstract

Provided is a polyamide resin composition having suppressed water absorption, good dimensional stability, good tensile strength, and other tensile characteristics sufficient for the utility thereof.　The polyamide resin composition according to the present invention comprises: a polyamide resin (A) that contains two or more polyamide resins (A1) having a constituent unit derived from a reactant of pentamethylenediamine and an aliphatic dicarboxylic acid; and a filler (B). The ratio X of the polyamide resin composition as determined by formula (1) in1H-NMR is 4.74-5.98. Formula (1): [(i) + (ii) + (iii)] / (iii) = X (In formula (1) , (i) is the integrated value of a chemical shift of 1.20-1.90 ppm, (ii) is the integrated value of a chemical shift of 2.05-2.50 ppm, and (iii) is the integrated value of a chemical shift of 3.15-3.50 ppm.

Description

Polyamide resin composition

[0001] The present invention relates to a polyamide resin composition.

[0002] Polyamide resins have excellent properties as engineering plastics and are widely used in various industrial fields such as automobiles, machinery, and electric and electronic industries.

[0003] Conventional polyamide resins were made from fossil fuels. Due to the increasing interest in recent environmental problems, environmentally friendly resins are in demand. Pentamethylenediamine can be obtained from biomass raw materials. Polyamide resin compositions containing polyamide resins having pentamethylenediamine as a constituent have been developed (see, for example, Patent Documents 1 to 4). Patent Document 1 describes a polyamide resin composition excellent in mechanical properties containing glass fibers. Patent Document 5 describes a polyamide resin composition containing a polyamide resin having pentamethylenediamine and an aliphatic dicarboxylic acid having 7 or more carbon atoms as main components.

[0004] JP-A-2004-269634 JP-A-2022-69966 JP-A-2011-225630 JP-A-2023-59853 WO 2010 / 113736

[0005] For polyamide resins having pentamethylenediamine as a constituent, mechanical properties are also required as in the case of other polyamide resins that have been widely used so far. In addition, polyamide resins having pentamethylenediamine as a constituent have a problem of high water absorption. In the polyamide resin compositions of Patent Documents 1 to 4, the examination of mechanical properties has not been sufficient yet. In the polyamide resin of Patent Document 5, the balance between water absorption and mechanical properties was poor. Therefore, an object of the present invention is to provide a polyamide resin composition having suppressed water absorption, good dimensional stability, good tensile strength, and other tensile properties that satisfy practicality.

[0006] The specific means for solving the above problem are as follows: [1] A polyamide resin composition comprising a polyamide resin (A) and a filler (B), wherein the polyamide resin (A) comprises two or more polyamide resins (A1) having constituent units derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid, and the polyamide resin composition was measured at 400 MHz using deuterated hexafluoroisopropanol as a solvent and tetramethylsilane as a reference substance. １ A polyamide resin composition having a ratio X of 4.74 or more and 5.98 or less, as determined by the following formula (1) in 1H-NMR. [(i) + (ii) + (iii)] / (iii) = X ... (1) (In equation (1), (i) is the integral value of a chemical shift of 1.20 to 1.90 ppm, (ii) is the integral value of a chemical shift of 2.05 to 2.50 ppm, and (iii) is the integral value of a chemical shift of 3.15 to 3.50 ppm.) [2] A polyamide resin composition comprising a polyamide resin (A) and a filler (B), wherein the polyamide resin (A) comprises two or more polyamide resins (A1) having constituent units derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid, and the ratio of the number of methylene groups to the number of amide groups in the polyamide resin (A), as determined by the following equation (2), is 4.74 or more and 5.98 or less. (In formula (2), the content ratio of polyamide resin (k) in polyamide resin (A) is the ratio (mass ratio) of polyamide resin (k) when the total polyamide resin (A) is set to 1.) [3] The polyamide resin composition according to [1] or [2], wherein the polyamide resin (A) comprises a polyamide resin (a1) having structural units derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid having 6 to 8 carbon atoms, and a polyamide resin (a2) having structural units derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid having 9 to 16 carbon atoms. [4] The polyamide resin composition according to [3], wherein 100% by mass of the polyamide resin composition contains 10.0 to 50.0% by mass of the polyamide resin (a1) and 20.0 to 55.0% by mass of the polyamide resin (a2). [5] A polyamide resin composition according to any one of [1] to [4], comprising 45.0 to 75.0% by mass of the polyamide resin (A) in 100% by mass of the polyamide resin composition. [6] A polyamide resin composition according to any one of [1] to [5], comprising 20.0 to 50.0% by mass of the filler (B) in 100% by mass of the polyamide resin composition. [7] A polyamide resin composition according to any one of [1] to [6], wherein the filler (B) is coated with a sizing agent. [8] A polyamide resin composition according to any one of [1] to [7], wherein the filler (B) is at least one selected from the group consisting of glass fibers, carbon fibers and graphite fibers. [9] The polyamide resin composition according to [7], wherein the sizing agent comprises a polyurethane resin.

[10] A polyamide resin composition according to any one of [1] to [9], wherein the polyamide resin (A1) having constituent units derived from the reaction product of pentamethylenediamine and aliphatic dicarboxylic acid is selected from the group consisting of polyamide 56, polyamide 59, polyamide 510, polyamide 513 and polyamide 516.

[11] The polyamide resin composition according to [3], wherein the polyamide resin (a1) contains polyamide 56, and the polyamide resin (a2) contains at least one selected from the group consisting of polyamide 59, polyamide 510, polyamide 513 and polyamide 516.

[12] A polyamide resin composition according to any one of [1] to

[11] , wherein the polyamide resin composition contains 0.01 to 0.25% by mass of a colorant (C) in 100% by mass of the polyamide resin composition.

[13] A polyamide resin composition according to any one of [1] to

[12] , wherein the polyamide resin (A) comprises polyamide 6 (A2).

[14] A polyamide resin composition according to any one of [1] to

[13] , wherein the water absorption rate of an ISO 294-3 Type D2 test specimen of the polyamide resin composition is 1.90% or less when the specimen is immersed in water at 23°C for 24 hours.

[15] A molded article containing a polyamide resin composition according to any one of [1] to

[14] .

[16] A polyamide resin composition comprising a polyamide resin (A) and a filler (B), wherein the polyamide resin (A) comprises a polyamide resin (a1) having structural units derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid having 6 to 8 carbon atoms, and a polyamide resin (a2) having structural units derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid having 9 to 16 carbon atoms, wherein the polyamide resin composition contains 10.0 to 50.0% by mass of the polyamide resin (a1) and 20.0 to 55.0% by mass of the polyamide resin (a2) in 100% by mass of the polyamide resin composition.

[0007] The polyamide resin composition of the present invention exhibits suppressed water absorption, good dimensional stability, good tensile strength, and other tensile properties that satisfy practical requirements.

[0008] [First aspect of the present invention] The first aspect of the present invention is a polyamide resin composition comprising a polyamide resin (A) and a filler (B), wherein the polyamide resin (A) comprises two or more polyamide resins (A1) having structural units derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid, and the polyamide resin composition was measured at 400 MHz using deuterated hexafluoroisopropanol as a solvent and tetramethylsilane as a reference substance. １ A polyamide resin composition having a ratio X of 4.74 or more and 5.98 or less, as determined by the following formula (1) in H-NMR: [(i) + (ii) + (iii)] / (iii) = X ... (1) (In formula (1), (i) is the integral value of chemical shifts from 1.20 to 1.90 ppm, (ii) is the integral value of chemical shifts from 2.05 to 2.50 ppm, and (iii) is the integral value of chemical shifts from 3.15 to 3.50 ppm.)

[0009] In this specification, "one type of polyamide resin" or "one type of polyamide resin" refers to polyamide resins in which the types and content of constituent units contained as monomers are the same. In this specification, the numerical values ​​listed in the numerical range are values ​​obtained by rounding the value to the nearest tenth of the stated value.

[0010] [Polyamide resin (A)] Polyamide resin (A) includes polyamide resin (A1) having structural units derived from the reaction product of pentamethylenediamine and aliphatic dicarboxylic acid, but may optionally also include polyamide 6 (A2).

[0011] <Polyamide resin (A1) having structural units derived from the reaction product of pentamethylenediamine and aliphatic dicarboxylic acid> Polyamide resin (A) contains two or more polyamide resins (A1) having structural units derived from the reaction product of pentamethylenediamine and aliphatic dicarboxylic acid. It may also contain three or more polyamide resins (A1). Polyamide resin (A1) is an aliphatic polyamide resin having structural units of a condensate of pentamethylenediamine and aliphatic dicarboxylic acid, and is preferably an aliphatic homopolyamide resin based on structural units of a condensate of pentamethylenediamine and aliphatic dicarboxylic acid. The diamine used in this polycondensation reaction has pentamethylenediamine as an essential component, but may also contain other diamines to the extent that it does not impair the effects of the present invention. Preferably, it does not contain other diamines.

[0012] It is more preferable that 50% or more of the pentamethylenediamine in the polyamide resin (A1) is derived from biomass raw materials. Polyamide resin (A1) using biomass-derived pentamethylenediamine is an environmentally friendly material because the raw material is plant-derived. Therefore, in the embodiment in which biomass-derived pentamethylenediamine is used in the polyamide resin (A1), the polyamide resin composition of the present invention has the effect of suppressing environmental impact.

[0013] The proportion of biomass-derived carbon in the polyamide resin (A) (hereinafter also referred to as "biomass content") is preferably 50-90%, more preferably 55-88%, and even more preferably 60-87%. The biomass content is preferably determined by the following formula (4). When the biomass content is within the above range, the environmental burden is suppressed. The content ratio of polyamide resin (k) in polyamide resin (A) is the ratio (mass ratio) of polyamide resin (k) when the total amount of polyamide resin (A) is considered as 1. The biomass content of polyamide resin (k) can be determined by calculating the percentage of biomass-derived carbon in polyamide resin (k) using radiocarbon (C14) measurement as shown in ASTM D6866-22 Method B (AMS). Catalog values ​​are also acceptable. Polyamide resin (k) refers to each type of polyamide resin in polyamide resin (A).

[0014] Examples of aliphatic dicarboxylic acids 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, undecanedionic acid, dodecanedionic acid, tridecanedionic acid, tetradecanedionic acid, pentadecanedionic acid, hexadecanedionic acid, octadecanedionic acid, and eicosanedionic acid; and alicyclic dicarboxylic acids such as 1,3- / 1,4-cyclohexanedicarboxylic acid, dicyclohexanemethane-4,4'-dicarboxylic acid, and norbornanedicarboxylic acid. Among these, non-alicyclic aliphatic dicarboxylic acids are preferred, one selected from the group consisting of adipic acid, azelaic acid, sebacic acid, and tridecanedionic acid is more preferred, and adipic acid or sebacic acid is even more preferred.

[0015] The polyamide resin (A1) having structural units derived from the reaction product of pentamethylenediamine and aliphatic dicarboxylic acid is preferably selected from the group consisting of polyamide 56, polyamide 59, polyamide 510, polyamide 513, and polyamide 516.

[0016] Preferably, the two or more polyamide resins (A1) include a polyamide resin (a1) having structural units derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid having 6 to 8 carbon atoms, and a polyamide resin (a2) having structural units derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid having 9 to 16 carbon atoms. A copolymerized polyamide resin having both structural units derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid having 6 to 8 carbon atoms and structural units derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid having 9 to 16 carbon atoms is included in polyamide resin (a2). Polyamide resins (a1) and (a2) may be used individually or in combination of two or more types.

[0017] Polyamide 56 is an example of the polyamide resin (a1).

[0018] Examples of polyamide resins (a2) include polyamide 59, polyamide 510, polyamide 513, and polyamide 516, with polyamide 510 being preferred. Polyamide 510 is an environmentally friendly material because it can use pentamethylenediamine derived from biomass raw materials, as well as sebacic acid derived from biomass raw materials, and the biomass-derived components can be 33% by mass or more, preferably 100% by mass.

[0019] The relative viscosity of one type 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 within this range results in good moldability. The relative viscosity was measured in accordance with JIS K6920-2, by dissolving 1 g of polyamide resin in 100 ml of 96% concentrated sulfuric acid and measuring at 25°C.

[0020] The terminal amino group concentration of one type of polyamide resin (A1) is preferably 8 μmol / g or higher, more preferably 10 to 110 μmol / g, and even more preferably 12 to 70 μmol / g, as determined by neutralization titration after dissolving in a mixed solvent of phenol and methanol. Being within this range allows for good interaction with reinforcing fillers and improves mechanical properties.

[0021] The upper limit of the amount of polyamide resin (a1) blended is preferably 50.0% by mass, more preferably 45.0% by mass, even more preferably 40.0% by mass, and particularly preferably 37.0% by mass, based on 100% by mass of the polyamide resin composition. The lower limit of the amount of polyamide resin (a1) blended is preferably 10.0% by mass, more preferably 15.0% by mass, even more preferably 17.0% by mass, and particularly preferably 25.0% by mass, based on 100% by mass of the polyamide resin composition.

[0022] The upper limit of the amount of polyamide resin (a2) blended is preferably 55.0% by mass, more preferably 52.5% by mass, even more preferably 50.0% by mass, and particularly preferably 40.0% by mass, based on 100% by mass of the polyamide resin composition. The lower limit of the amount of polyamide resin (a2) blended is preferably 20.0% by mass, more preferably 25.0% by mass, even more preferably 27.0% by mass, and particularly preferably 30.0% by mass, based on 100% by mass of the polyamide resin composition.

[0023] The polyamide resin composition preferably contains 10.0 to 50.0% by mass of polyamide resin (a1) and 20.0 to 55.0% by mass of polyamide resin (a2) per 100% by mass, more preferably 15.0 to 45.0% by mass of polyamide resin (a1) and 25.0 to 52.5% by mass of polyamide resin (a2), even more preferably 16.0 to 40.0% by mass of polyamide resin (a1) and 27.0 to 52.0% by mass of polyamide resin (a2), and particularly preferably 16.0 to 37.0% by mass of polyamide resin (a1) and 30.0 to 52.0% by mass of polyamide resin (a2). When the amounts of polyamide resin (a1) and polyamide resin (a2) are within the above ranges, mechanical properties are improved, water absorption is suppressed, and moldability and dimensional stability are good.

[0024] The mass ratio of polyamide resin (a1) to polyamide resin (a2) (polyamide resin (a1) / polyamide resin (a2)) is preferably 85 / 15 to 22 / 78, more preferably 80 / 20 to 25 / 75, and even more preferably 75 / 25 to 25 / 75. When the mass ratio of polyamide resin (a1) to polyamide resin (a2) is within the above range, mechanical properties are improved, water absorption is suppressed, and moldability and dimensional stability are good.

[0025] The upper limit of the amount of polyamide resin (A1) is preferably 75.0% by mass, more preferably 72.0% by mass, and even more preferably 70.0% by mass, based on 100% by mass of the polyamide resin composition. The lower limit of the amount of polyamide resin (A) is preferably 45.0% by mass, more preferably 50.0% by mass, and even more preferably 60.0% by mass, based on 100% by mass of the polyamide resin composition. The amount of polyamide resin (A1) is preferably 45.0 to 75.0% by mass, more preferably 50.0 to 72.0% by mass, and even more preferably 60.0 to 70.0% by mass, based on 100% by mass of the polyamide resin composition. When the amount of polyamide resin (A1) is within the above range, excellent mechanical properties and moldability can be achieved simultaneously.

[0026] The polyamide resin (A1) is preferably 80.0 to 100% by mass, more preferably 90.0 to 100% by mass, even more preferably 95.0 to 99.8% by mass, and even more preferably 99.0 to 99.7% by mass, based on 100% by mass of polyamide resin (A).

[0027] <Polyamide 6(A2)> The polyamide resin (A) preferably optionally contains polyamide 6(A2). When polyamide 6(A2) is incorporated into the polyamide resin composition, it is preferable from the viewpoint of the dispersibility of various additives. Examples of polyamide 6(A2) include ring-opened polymers of ε-caprolactam.

[0028] 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 within this range results in good moldability. The relative viscosity was measured in accordance with JIS K6920-2, by dissolving 1 g of polyamide resin in 100 ml of 96% concentrated sulfuric acid and measuring at 25°C.

[0029] The terminal amino group concentration of polyamide 6(A2), as determined by neutralization titration after dissolving in a mixed solvent of phenol and methanol, is preferably 30 μmol / g or higher, more preferably 30 to 110 μmol / g, and even more preferably 30 to 70 μmol / g. Being within this range allows for good interaction with reinforcing fillers and improves mechanical properties.

[0030] The amount of polyamide 6(A2) added is preferably 0 to 5.0% by mass, more preferably 0.05 to 5.0% by mass, and even more preferably 0.1 to 3.0% by mass, based on 100% by mass of the polyamide resin composition. When the amount of polyamide 6(A2) is within the above range, the function and properties of the polyamide resin (A1) are not impaired. As polyamide 6(A2) is added in small amounts, it does not affect the physical properties of the polyamide resin composition.

[0031] The polyamide resin (A) may contain aliphatic polyamide resins and aromatic polyamide resins other than components (A1) and (A2). When the aliphatic polyamide resins and aromatic polyamide resins other than components (A1) and (A2) are blended, their amount is preferably 0.01 to 2.0% by mass, more preferably 0.05 to 1.5% by mass, and more preferably 0.1 to 1.0% by mass, of 100% by mass of the polyamide resin composition, from the viewpoint of not impairing the function and properties of the polyamide resin composition.

[0032] The upper limit of the amount of polyamide resin (A) is 75.0% by mass, preferably 73.0% by mass, and more preferably 70.0% by mass, based on 100% by mass of the polyamide resin composition. The lower limit of the amount of polyamide resin (A) is 45.0% by mass, preferably 50.0% by mass, more preferably 53.0% by mass, and even more preferably 60.0% by mass, based on 100% by mass of the polyamide resin composition. The amount of polyamide resin (A) is preferably 45.0 to 75.0% by mass, more preferably 50.0 to 73.0% by mass, even more preferably 53.0 to 72.0% by mass, and particularly preferably 60.0 to 71.0% by mass, based on 100% by mass of the polyamide resin composition. When the amount of polyamide resin (A) is within the above range, the mechanical properties are improved and the moldability is good.

[0033] <Filler (B)> Filler (B) is added to the polyamide resin composition. Filler (B) is a component that imparts excellent mechanical properties to the polyamide resin composition.

[0034] [Fillers] Examples of fillers include 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, fibrous reinforcing fillers such as potassium titanate whiskers, aluminum borate whiskers, magnesium-based whiskers and silicon-based whiskers, silicates such as warlastenite, 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 can be used individually or in combination of two or more types.

[0035] Among the fillers, fibrous reinforcing fillers are preferred, and at least one selected from the group consisting of glass fibers, carbon fibers, and graphite fibers is more preferred. A fiber is defined as a shape with an aspect ratio (ratio of major axis to minor axis) of 10 or more. Filler (B) may break when melt-mixed with other components. Therefore, the preferred embodiment of fibrous reinforcing filler in the polyamide resin composition includes those that no longer meet the definition of "fiber" as defined herein as a result of breaking during melt-mixing, as long as they meet the definition of "fiber" as defined herein at the time of compounding. The cross-sectional shape of the fibrous reinforcing filler is not particularly limited and may be circular, cocoon-shaped, oval, rectangular, or similar shapes.

[0036] 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 this range, the dispersibility of the reinforcing fibers in the resin improves, thus ensuring mechanical strength. The average fiber diameter of the fibrous reinforcing filler is a value measured by an optical microscope, but if a commercially available product is used, a catalog value may be used. It is also preferable that the average fiber diameter of the fibrous reinforcing filler (B) coated with a preferred embodiment of the sizing agent is within the same range.

[0037] 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 breakage of the fibrous reinforcing filler during that 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 the weight average fiber length of the fibrous reinforcing filler can be determined using image analysis software from an image taken using a transmission microscope. Regarding 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 the weight average fiber length of the fibrous reinforcing filler coated with a sizing agent are also preferably in the same range as described above. Note that the "fibrous reinforcing filler in the polyamide resin composition" refers to the fibrous reinforcing filler in the polyamide resin composition. The polyamide resin composition is obtained by melt-kneading each component.

[0038] Among the fibrous reinforcing fillers, glass fibers, carbon fibers, and graphite fibers are preferred, and glass fibers are more preferred. Examples of the glass constituting the glass fiber include those having a composition such as A glass, AR glass, C glass, D glass, E glass, H glass, S glass, T glass, M glass, and NE glass.

[0039] The shape of the glass fiber is not particularly limited, and examples include flat fibers and chopped strands.

[0040] [Binder] It is preferable that the filler is coated with a binder. A binder refers to a composition that is applied to the surface of a filler for the purpose of organically modifying the filler surface. It contains a resin and may optionally contain other components such as coupling agents, water, and organic solvents described later. By being coated with the binder, the filler is surface-treated. "Coating" means that the binder adheres to at least a part of the surface of at least one filler. Also, the filler may be subjected to a bundling treatment with the binder to bundle two or more fillers into one. The bundling treatment can also be performed by applying the binder to a plurality of filler monofilaments formed by pulling out a molten filler material from a plurality of nozzles, then bundling them into one filler strand, and then winding it up as a cake.

[0041] <Polyurethane resin>It is preferable that the binder contains a polyurethane resin. A polyurethane resin is a resin obtained by subjecting a polyol component and a polyisocyanate component to a urethane reaction.

[0042] ≪Polyol component≫ Examples of the polyol component include polyester polyols (condensation-type polyester polyols, lactone-type polyester polyols), polycarbonate polyols, polyether polyols, etc.

[0043] Examples of the condensation-type polyester polyol include those obtained by reacting a dicarboxylic acid or its lower alkyl ester with an aliphatic diol. Here, examples of the dicarboxylic acid or its lower alkyl esters include adipic acid, succinic acid, azelaic acid, pimelic acid, sebacic acid, phthalic acid or its lower alkyl esters, etc. Examples of the aliphatic diol include aliphatic diols without side chains such as ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,10-decamethylene glycol, etc., 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, neopentyl glycol, etc.

[0044] 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 hydroxyl compounds such as short-chain polyols.

[0045] Polycarbonate polyols are obtained by transesterification reactions 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 readily available. Another method for obtaining polycarbonate polyols is the so-called phosgene method (or solvent method).

[0046] Examples of polyether polyols include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyoxypropylene glycol, and glycerin-based polyalkylene ether glycol.

[0047] <Polyisocyanate components> Examples of polyisocyanates include aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatic polyisocyanates.

[0048] 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.

[0049] 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.

[0050] Examples of aromatic polyisocyanates include 1,3-phenylenediisocyanate, 1,4-phenylenediisocyanate, 2,4-tolylenediisocyanate (TDI), 2,6-tolylenediisocyanate, 4,4'-diphenylmethanediisocyanate (MDI), 2,4-diphenylmethanediisocyanate, 4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl, and 3,3'-dimethyl-4,4'-diisocyanatobiphenyl. Phenylmethane, 1,5-naphthylene diisocyanate, 4,4',4''-triphenylmethane triisocyanate, m-isocyanatophenylsulfonyl isocyanate, p-isocyanatophenylsulfonyl isocyanate, 1-methyl-2,6-phenylenediisocyanate, 1-methyl-2,5-phenylenediisocyanate, 1-methyl-2,6-phenylenediisocyanate, 1-methyl-3,5-phenylenediisocyanate, 1-ethyl-2,4-phenyl Diisocyanates, 1-isopropyl-2,4-phenylenediisocyanate, 1,3-dimethyl-2,4-phenylenediisocyanate, 1,3-dimethyl-4,6-phenylenediisocyanate, 1,4-dimethyl-2,5-phenylenediisocyanate, diethylbenzene diisocyanate, diisopropylbenzene diisocyanate, 1-methyl-3,5-diethylbenzene diisocyanate, 3-methyl-1,5-diethylbenzene-2,4-diisocyanate Examples include 1,3,5-triethylbenzene-2,4-diisocyanate, naphthalene-1,4-diisocyanate, 1-methylnaphthalene-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, and 2,2'-diphenylmethanediisocyanate.

[0051] The polyisocyanate is preferably a diisocyanate having two isocyanate groups per molecule.

[0052] In the urethane reaction, chain extenders such as polyhydric alcohols and polyhydric amines can also be used.

[0053] [Other optional components of the sizing agent] The sizing agent may contain further components. Examples of further components include copolymers having acidic groups, coupling agents, lubricants, nonionic surfactants, antistatic agents, water, organic solvents, etc.

[0054] Examples of copolymers having acidic groups include copolymers of monomers having acidic groups, or copolymers of monomers having acidic groups and monomers not having acidic groups. In this specification, an acidic group refers to a group that releases a proton, and examples include carboxyl groups, sulfonic acid groups, phosphoric acid groups, phenolic hydroxyl groups, etc., and hydroxyl groups (except for phenolic hydroxyl groups) are not included in the definition of acidic groups.

[0055] Examples of monomers having an acidic group include unsaturated carboxylic acids and carboxylic acid 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 endocis-bicyclo[2,2,1]hept-5-ene-2,3-dicarboxylic acid. Examples of carboxylic acid anhydrides include dicarboxylic acids such as maleic anhydride, itaconic anhydride, succinic anhydride, phthalic anhydride, glutaric anhydride, dodecenylsuccinic anhydride, chlorendicic anhydride, and citraconic anhydride. Maleic anhydride is preferred as the carboxylic acid anhydride because it exhibits less steric hindrance during copolymerization and has low compound polarity. Furthermore, the monomer having an acidic group may also be a monomer having a functional group having a function equivalent to that of an 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 a function equivalent to that of an acidic group include malenyl chloride, maleimide, monomethyl maleate, dimethyl maleate, glycidyl maleate, and the above-mentioned carboxylic acid anhydrides. These may be used individually or in combination of two or more.

[0056] Examples of monomers that do not have acidic groups include styrene, ethylene, and acetylene.

[0057] As a copolymer of monomers having an acidic group, it is preferable that the copolymer is obtained by copolymerizing an unsaturated dicarboxylic acid and / or a carboxylic acid anhydride with methyl acrylate and methyl methacrylate.

[0058] In copolymers obtained by copolymerizing unsaturated dicarboxylic acids and / or carboxylic acid anhydrides with methyl acrylate and methyl methacrylate, the copolymerization ratio of unsaturated dicarboxylic acids and / or carboxylic acid anhydrides is preferably 20 to 60% by mass, and particularly preferably 25 to 55% by mass, from the viewpoint of reactivity and mechanical properties when producing the copolymer. The copolymerization ratio of methyl acrylate is preferably 20 to 75% by mass, and particularly preferably 30 to 65% by mass, from the viewpoint of reactivity and mechanical properties when producing the copolymer. Furthermore, the copolymerization ratio of methyl methacrylate is preferably 5 to 20% by mass, and particularly preferably 7 to 17% by mass, from the viewpoint of reactivity and mechanical properties when producing the copolymer.

[0059] The copolymerization ratio of monomers without acidic groups is preferably 10% by mass or less, and particularly preferably 1% by mass or less.

[0060] The weight-average molecular weight of the copolymer is preferably 10,000 to 60,000, and particularly preferably 20,000 to 50,000, from the viewpoint of reactivity and mechanical properties when producing the copolymer. The weight-average molecular weight of the copolymer is the molecular weight measured by gel permeation chromatography (GPC).

[0061] Examples of lubricants include fatty acid amides and quaternary ammonium salts. Examples of nonionic surfactants include synthetic alcohol-based surfactants, natural alcohol-based surfactants, and fatty acid ester-based surfactants. Water and organic solvents are components that dissolve lubricants, nonionic surfactants, and antistatic agents. Examples of organic solvents include ethanol. Examples of coupling agents include silane-based coupling agents, titanium-based coupling agents, aluminum-based coupling agents, and zirconia-based coupling agents.

[0062] The content of each component in the sizing agent can be appropriately set according to the characteristics of the resulting reinforced filler.

[0063] The filler may be surface-treated with further components. Such components include additional components contained in the sizing agent.

[0064] Filler (B) may contain, for example, the components described in Japanese Patent Publication No. 2014-231452. Filler (B) may be one component or a combination of two or more components.

[0065] From the viewpoint of exhibiting strength-enhancing performance, the ignition loss when volatile substances are completely evaporated from the sizing agent is preferably 0.1 to 1.5% by mass, and more preferably 0.4 to 1.2% by mass. The ignition loss of the sizing agent is a value measured in accordance with JIS R 3420 (2006) 7.3.2.

[0066] The upper limit of the amount of filler (B) is preferably 50.0% by mass, more preferably 46.0% by mass, and even more preferably 40.0% by mass, based on 100% by mass of the polyamide resin composition. The lower limit of the amount of filler (B) is preferably 20.0% by mass, more preferably 25.0% by mass, and even more preferably 28.0% by mass, based on 100% by mass of the polyamide resin composition. The amount of filler (B) is preferably 20.0 to 50.0% by mass, more preferably 25.0 to 46.0% by mass, and even more preferably 28.0 to 40.0% by mass, based on 100% by mass of the polyamide resin composition. When the amount of filler (B) is within the above range, it is preferable from the viewpoint of mechanical properties and moldability.

[0067] The upper limit of the total blending amount of polyamide resin (A) and filler (B) is preferably 100.0% by mass, more preferably 99.9% by mass, and even more preferably 99.7% by mass, based on 100% by mass of the polyamide resin composition. The lower limit of the total blending amount of polyamide resin (A) and filler (B) is preferably 80.0% by mass, more preferably 90.0% by mass, and even more preferably 95.0% by mass, based on 100% by mass of the polyamide resin composition. The total blending amount of polyamide resin (A) and filler (B) is preferably 80.0 to 100.0% by mass, more preferably 90.0 to 99.9% by mass, and even more preferably 95.0 to 99.7% by mass, based on 100% by mass of the polyamide resin composition. When the total blending amount of polyamide resin (A) and filler (B) is within the above range, the mechanical properties are good.

[0068] <Coloring Agent (C)> The polyamide resin composition preferably contains a coloring agent (C) as an optional component. The coloring agent (C) is a component whose main function is to color the polyamide resin composition. Examples of coloring agents (C) include carbon black, nigrosine, titanium dioxide, and iron oxide. These may be used individually or in combination of two or more.

[0069] In 100% by mass of the polyamide resin composition, the amount of colorant (C) is preferably 0.01 to 0.25% by mass, more preferably 0.02 to 0.23% by mass, and even more preferably 0.03 to 0.20% by mass. Having the colorant (C) within this range is preferable from the viewpoint of preventing bleed-out on the surface of the molded article.

[0070] <Heat-resistant agent (D)> The polyamide resin composition preferably contains a heat-resistant agent (D) as an optional component. Here, if the functional agent is a heat-resistant agent, organic or inorganic heat-resistant agents can be used as the heat-resistant agent depending on the purpose, and these may be used individually or in combination of two or more types. A heat-resistant agent is a component that suppresses thermal oxidation and thermal degradation of the polyamide resin, and for that purpose, it also includes what is called an antioxidant.

[0071] Examples of organic heat-resistant agents include phenolic compounds, phosphorus compounds, sulfur compounds, and nitrogen compounds. These may be used individually or in combination of two or more. Hindered phenolic organic compounds are preferred as phenolic compounds. In this specification, hindered phenol refers to a compound having a substituent at the ortho position of the hydroxyl group of phenol. Phosphorus ester compounds of hindered phenols and hypophosphorous ester compounds of hindered phenols are preferred as phosphorus compounds.

[0072] The heat-resistant agent is preferably a combination of an inorganic compound and a nitrogen-containing compound, or an inorganic compound. Examples of inorganic compounds include metal halides and inorganic compounds other than metal halides.

[0073] 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). Preferably, the metal in a metal halide is a Group 1 element (alkali metal) or a 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, or 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. It is more preferable that the metal halide is potassium iodide and / or cuprous iodide, and even more preferable that it is a mixture of potassium iodide and cuprous iodide.

[0074] Inorganic compounds other than metal halides include metals, metal oxides, metal hydroxides, metal nitrides, metal phosphate salts, metal phosphite salts, metal carbonate salts, metal silicate salts, metal titanate salts, metal borate salts, metal sulfate salts, and metal nitrate salts.

[0075] Examples of nitrogen-containing compounds include melamine, benguanamine, dimethylolurea, and cyanuric acid.

[0076] When a heat-resistant agent (D) is included, the amount of heat-resistant agent (D) is preferably 0.01 to 2.00% by mass, more preferably 0.05 to 1.00% by mass, and more preferably 0.10 to 0.50% by mass, of 100% by mass of the polyamide resin composition.

[0077] <Other Optional Components> The polyamide resin composition may contain optional components other than those listed above, as long as they do not impair the effects of the present invention. Optional components include resins other than component (A), and functional additives other than components (B), (C), and (D).

[0078] Examples of resins other than component (A) include low-density, medium-density, and high-density polyethylene, polypropylene, polyolefin resins such as polybutene, modified polyolefin resins, polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyester 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.

[0079] (A) When resins other than component (A) are blended, their amount is preferably 0.01 to 2.0% by mass, more preferably 0.05 to 1.5% by mass, and more preferably 0.1 to 1.0% by mass, of 100% by mass of the polyamide resin composition, from the viewpoint of not impairing the function and properties of the polyamide resin composition.

[0080] Functionality imparters include various additives commonly incorporated into polyamide resin compositions. Specific examples of functional imparters include plasticizers, heat resistant agents, lubricants, foaming agents, weathering agents, crystal nucleating agents, antioxidants, crystallization accelerators, mold release agents, antistatic agents, dispersants, flame retardants, flame retardant aids, and spreading agents.

[0081] Other functional additives not mentioned above include, for example, the components described in Japanese Patent Publication No. 2002-370551. Each optional component may be a single component or a combination of two or more components.

[0082] [Polyamide resin composition] The polyamide resin composition was measured at 400 MHz using deuterated hexafluoroisopropanol as the solvent and tetramethylsilane as the reference substance. １By setting the ratio X, determined by the following formula (1) in H-NMR, within the following ranges, it is possible to achieve a balance between the mechanical properties, water absorption rate, moldability, and dimensional stability of the polyamide resin composition or its molded article. The preferred range and method for determining the ratio X determined by the following formula (1) are as follows. In the polyamide resin composition of the present invention, the upper limit of the ratio X determined by the following formula (1) is 5.98, preferably 5.97, more preferably 5.91, and even more preferably 5.59. Also, in the polyamide resin composition, the lower limit of the ratio X determined by the following formula (1) is 4.74, preferably 4.75, more preferably 4.82, and even more preferably 4.91. In the polyamide resin composition of the present invention, the ratio X determined by the following formula (1) is 4.74 or more and 5.98 or less, preferably 4.75 or more and 5.97 or less, more preferably 4.82 or more and 5.91 or less, and even more preferably 4.91 or more and 5.90 or less. [(i) + (ii) + (iii)] / (iii) = X ... (1) (In equation (1), the polyamide resin composition was measured at 400 MHz using deuterated hexafluoroisopropanol as the solvent and tetramethylsilane as the reference substance.) １ In ¹H-NMR, (i) is the integral value for chemical shifts from 1.20 to 1.90 ppm, (ii) is the integral value for chemical shifts from 2.05 to 2.50 ppm, and (iii) is the integral value for chemical shifts from 3.15 to 3.50 ppm.

[0083] In polyamide resin (A), a methylene group (CH) adjacent to a carbonyl group (C=O) ２ The peak appears in the chemical shift of (ii), and is adjacent to the methylene group (CH) adjacent to the amino group (NH). ２ The peak at (iii) appears in the chemical shift of (iii) and is a methylene group (CH) that is not adjacent to a carbonyl group (C=O) or an amino group (NH). ２The peak of (i) is presumed to appear in the chemical shift of (i). The presence of components other than the polyamide resin in the polyamide resin composition of the present invention does not affect the value of X because the peaks of these components do not overlap with the chemical shifts of (i) to (iii), or preferably, even if the peaks overlap, the amount is so small. Therefore, the ratio X obtained by the following formula (1) can be said to represent the properties of the polyamide resin (A).

[0084] In other words, the value X expressed by equation (1) can be said to be the ratio of the number of methylene groups to the number of amide groups in polyamide resin (A), and the two values ​​are approximately the same. The ratio of the number of methylene groups to the number of amide groups in polyamide resin (A) can be expressed by the following equation (2). In equation (2), the content ratio of polyamide resin (k) in polyamide resin (A) is the ratio (mass ratio) of polyamide resin (k) when the total amount of polyamide resin (A) is set to 1. Polyamide resin (k) refers to each individual type of polyamide resin in polyamide resin (A).

[0085] Therefore, the ratio of the number of methylene groups to the number of amide groups is preferably 4.74 or more and 5.98 or less, more preferably 4.75 or more and 5.97 or less, even more preferably 4.82 or more and 5.91 or less, and particularly preferably 4.91 or more and 5.90 or less.

[0086] The polyamide resin composition can be said to have improved mechanical properties, suppress water absorption, and have good moldability and dimensional stability if the ratio X, determined by the following formula (1), is within the above range, that is, if it is the ratio of the number of methylene groups to the number of amide groups in the polyamide resin (A).

[0087] The ratio X obtained by formula (1) above and the ratio of the number of methylene groups to the number of amide groups in polyamide resin (A) can be achieved by adjusting the content of the polyamide resin (a1), polyamide resin (a2), and any other polyamide resins that constitute polyamide resin (A).

[0088] The polyamide resin composition preferably has a water absorption rate of 1.90% or less, more preferably 1.85% or less, and even more preferably 1.80% or less, when an ISO 294-3 Type D2 test specimen of the polyamide resin composition is immersed in water at 23°C for 24 hours, as determined by the following formula (3): Water absorption rate = (Weight of test specimen after immersion - Weight of test specimen before immersion) / Weight of test specimen before immersion * 100 (3)

[0089] The water absorption rate being within the above range improves mechanical properties and provides good dimensional stability. The water absorption rate being within the above range is achieved by setting the value X represented by formula (1) above to a specific range for the polyamide resin (A) in the polyamide resin composition. Specifically, this is the ratio of the number of methylene groups to the number of amide groups in the polyamide resin (A), thereby adjusting the proportion of hydrophilic amide groups in the polyamide resin to a specific range.

[0090] <Method for Manufacturing Polyamide Resin Composition> There are no particular restrictions on the method for manufacturing the polyamide resin composition, as long as it can knead each component. For example, methods using a twin-screw kneader, twin-screw extruder, single-screw extruder, multi-screw extruder, etc. may be used. For example, a method in which all raw materials are mixed and then melt-kneaded using a twin-screw extruder, a method in which some raw materials are mixed, melt-kneaded, and then the remaining raw materials are mixed and melt-kneaded again, or a method in which some raw materials are mixed, and the remaining raw materials are mixed using a side feeder during melt-kneading. Any of these methods may be used.

[0091] [Uses of Polyamide Resin Compositions] Polyamide resin compositions are not particularly limited and can be used in the manufacture of molded articles using known methods such as injection molding, extrusion molding, blow molding, rotational molding, vacuum molding, and pressure molding. Furthermore, molded articles containing polyamide resin compositions can be used in parts requiring strength, heat resistance, and dimensional stability, such as automobile and vehicle parts, railway parts, and agricultural equipment parts. Examples of parts requiring dimensional stability include canisters, radiator tanks, rail insulation devices, and muffler protectors. They can also be used in other components requiring similar functions.

[0092] [Second aspect of the present invention] A second aspect of the present invention is a polyamide resin composition comprising a polyamide resin (A) and a filler (B), wherein the polyamide resin (A) comprises a polyamide resin (a1) having structural units derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid having 6 to 8 carbon atoms, and a polyamide resin (a2) having structural units derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid having 9 to 16 carbon atoms, and the polyamide resin composition comprises 10.0 to 50.0% by mass of the polyamide resin (a1) and 20.0 to 55.0% by mass of the polyamide resin (a2) in 100% by mass of the polyamide resin composition.

[0093] A second aspect of the present invention preferably includes optional components similar to those in the first aspect of the present invention, such as polyamide resin (A2), colorant (C), and heat-resistant agent (D). In the second aspect of the present invention, preferred embodiments of polyamide resin (A), polyamide resin (A1), polyamide resin (a1), polyamide resin (a2), filler (B), and other optional components, as well as their content in the polyamide resin composition, are the same as in the first aspect of the present invention. The second aspect of the present invention satisfies the value of X in formula (1) and the number of amide groups in the polyamide resin (A). The water absorption rate, manufacturing method, and uses of the polyamide resin composition are also the same as in the first aspect of the present invention.

[0094] [Third aspect of the present invention] A third aspect of the present invention is a polyamide resin composition comprising a polyamide resin (A) and a filler (B), wherein the polyamide resin (A) comprises two or more polyamide resins (A1) having constituent units derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid, and the ratio of the number of methylene groups to the number of amide groups in the polyamide resin (A), determined by the following formula (2), is 4.74 or more and 5.98 or less. (In formula (2), the content ratio of polyamide resin (k) in polyamide resin (A) is the ratio (mass ratio) of polyamide resin (k) when the total amount of polyamide resin (A) is set to 1.)

[0095] A third aspect of the present invention preferably includes optional components similar to those in the first aspect of the present invention, such as polyamide resin (A2), colorant (C), and heat-resistant agent (D). In the third aspect of the present invention, preferred embodiments of polyamide resin (A), polyamide resin (A1), polyamide resin (a1), polyamide resin (a2), filler (B), and other optional components, as well as their content in the polyamide resin composition, are the same as in the first aspect of the present invention. The water absorption rate, manufacturing method, and uses of the polyamide resin composition are also the same as in the first aspect of the present invention.

[0096] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0097] <<Measurement Method and Evaluation>> ○ was considered a pass, and × was considered a fail. (1) Biomass content of polyamide resin (A) The biomass content of polyamide resin (A) in the polyamide resin composition was calculated using the following formula. The biomass content of polyamide resin (k) was determined by calculating the percentage of biomass-derived carbon in polyamide resin (k) by radiocarbon (C14) measurement as shown in ASTM D6866-22 Method B (AMS). The content ratio of polyamide resin (k) in polyamide resin (A) is the ratio (mass ratio) of polyamide resin (k) when the total amount of polyamide resin (A) is considered as 1. ○: Biomass content of 60% or more, highly environmentally friendly. ×: Biomass content of less than 60%, less environmentally friendly.

[0098] (2) Water absorption rate A Type D2 test specimen of a polyamide resin composition prepared in accordance with ISO 294-3 was immersed in water at 23°C for 24 hours, and the water absorption rate was determined and evaluated using the following formula (3). Water absorption rate = (Weight of test specimen after immersion - Weight of test specimen before immersion) / Weight of test specimen before immersion * 100 (3) ○: Water absorption rate is 1.90% or less, water absorption is suppressed. ×: Water absorption rate is greater than 1.90%, water absorption is not suppressed.

[0099] (3) Molding shrinkage rate Type D2 test specimens of the polyamide resin composition were prepared in accordance with ISO 294-3, and the molding shrinkage rate was measured in accordance with ISO 294-4 to evaluate dimensional stability. ○: Molding shrinkage rate in the MD direction is 0.30% or less and molding shrinkage rate in the TD direction is 0.80% or less, indicating excellent dimensional stability. ×: Molding shrinkage rate in the MD direction is greater than 0.30% and / or molding shrinkage rate in the TD direction is greater than 0.80%, indicating poor dimensional stability.

[0100] (4) Tensile strength, tensile fracture strain, tensile modulus Type A test specimens of the polyamide resin composition were prepared in accordance with ISO 294-1, and tensile tests were conducted in a 23°C atmosphere in accordance with ISO 527-1,2. Tensile strength was evaluated according to the following criteria: ○: Tensile strength of 175 MPa or more, excellent tensile strength. ×: Tensile strength less than 175 MPa, poor tensile strength.

[0101] 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, biomass content 47%, manufactured by Cathay Corporation PA66: Polyamide 66, relative viscosity 2.65, terminal amino group concentration 52.9 μmol / g, biomass content 0%, manufactured by Asahi Kasei Corporation PA510: Polyamide 510, relative viscosity 2.57, terminal amino group concentration 14.2 μmol / g, biomass content 100%, manufactured by Cathay Corporation PA12: Polyamide 12, relative viscosity 1.68, terminal amino group concentration 14.0 μmol / g, biomass content 0%, manufactured by UBE Corporation PA6: Polyamide 6, relative viscosity 2.47, terminal amino group concentration 44.5 μmol / g, biomass content 0%, manufactured by UBE Corporation Polyurethane resin 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 fibers are coated with a sizing agent containing polyurethane resin.) Polyurethane resin 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 fibers are coated with a sizing agent containing polyurethane resin.) Heat resistant agent: Cuprous iodide / potassium iodide = 1 / 6 (mass ratio) (mixture) Coloring agent: Carbon black Spreading agent: Polyoxyethylene polyhydric alcohol fatty acid ester The relative viscosity of polyamide 56, polyamide 66, polyamide 510, polyamide 12 and polyamide 6 is measured at 25°C after dissolving 1 g of polyamide resin in 100 ml of 96% concentrated sulfuric acid, in accordance with JIS K6920-2. The terminal amino group concentrations of polyamide 56, polyamide 66, polyamide 510, polyamide 12, and polyamide 6 were determined by neutralization titration after dissolving the polyamide resins in a mixed solvent of phenol and methanol. The average fiber diameter of the glass fibers is the catalog value.

[0102] In Table 1, X and the number of methylene groups / amide groups are as follows. The value of X and the value of the number of methylene groups / amide groups are approximately the same. [(i) + (ii) + (iii)] / (iii) = X ... (1) (In (1), the polyamide resin composition was measured at 400 MHz using deuterated hexafluoroisopropanol as the solvent and tetramethylsilane as the reference substance. １ In ¹H-NMR, (i) is the integral value for chemical shifts from 1.20 to 1.90 ppm, (ii) is the integral value for chemical shifts from 2.05 to 2.50 ppm, and (iii) is the integral value for chemical shifts from 3.15 to 3.50 ppm.

[0103] The ratio of methylene groups to amide groups is the ratio of methylene groups to amide groups for polyamide resin (A). In formula (2), the content ratio of polyamide resin (k) in polyamide resin (A) is the ratio (mass ratio) of polyamide resin (k) when the total amount of polyamide resin (A) is set to 1.

[0104] [Examples 1-5, Comparative Examples 1-6] Each component listed in Table 1 was melt-kneaded in a TEX34αIII twin-screw kneader manufactured by Japan Steel Works Ltd. to produce the target 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 produce various test pieces, and various physical properties were evaluated. In Table 1, the content of each component is the value with the polyamide resin composition as 100% by mass.

[0105]

[0106] Examples 1 to 5 exhibit good biomass content, water absorption rate, dimensional stability (represented by molding shrinkage rate), and tensile strength. Other mechanical properties (represented by tensile fracture strain, tensile modulus, flexural strength, flexural modulus, and Charpy impact strength) are also at values ​​sufficient for practical use. Comparative Example 1 contains one type of polyamide resin having constituent units derived from a reaction product of pentamethylenediamine and aliphatic dicarboxylic acid, along with polyamide 12 and a trace amount of polyamide 6. Therefore, the value X in formula (1) can be seen from the value in formula (2) as not satisfying the present invention. It has a low biomass content and is less environmentally conscious, and its tensile strength is lower compared to the examples.

[0107] Comparative Example 2 contains only one type of polyamide resin having structural units derived from the reaction product of pentamethylenediamine and aliphatic dicarboxylic acid, and a trace amount of polyamide 6. Therefore, the value X in formula (1) can be said to not satisfy the present invention from the value in formula (2), resulting in a low biomass content and less consideration for the environment, as well as a higher water absorption rate and a larger molding shrinkage rate compared to the example. Comparative Example 3 does not contain a polyamide resin having structural units derived from the reaction product of pentamethylenediamine and aliphatic dicarboxylic acid, resulting in a low biomass content and no consideration for the environment, as well as a larger molding shrinkage rate compared to the example. Comparative Example 4 has a high proportion of polyamide resin (a2), so the value X in formula (1) can be said to not satisfy the present invention from the value in formula (2), resulting in a larger molding shrinkage rate and a lower tensile strength compared to the example.

[0108] Comparative Example 5 has a high proportion of polyamide resin (a1) and a low proportion of polyamide resin (a2), so the value X in formula (1) from the value in formula (2) does not satisfy the present invention. It has a low biomass content and is less environmentally conscious, as well as a higher water absorption rate and a larger molding shrinkage rate compared to the examples. Comparative Example 6 contains only one type of polyamide resin and a trace amount of polyamide 6, which has constituent units derived from the reaction product of pentamethylenediamine and aliphatic dicarboxylic acid. Therefore, the value X in formula (1) from the value in formula (2) does not satisfy the present invention, and its tensile strength is lower than that of the examples.

[0109] The polyamide resin composition of the present invention is suitably used as a molded product for parts requiring low water absorption and dimensional stability, such as automobile and vehicle parts, railway parts, and agricultural equipment parts.

Claims

1. A polyamide resin composition comprising a polyamide resin (A) and a filler (B), wherein the polyamide resin (A) comprises two or more polyamide resins (A1) having structural units derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid, and the polyamide resin composition was measured at 400 MHz using deuterated hexafluoroisopropanol as a solvent and tetramethylsilane as a reference substance. １ A polyamide resin composition having a ratio X of 4.74 or higher and 5.98 or lower, as determined by the following formula (1) in ¹H-NMR: [(i) + (ii) + (iii)] / (iii) = X ... (1) (In formula (1), (i) is the integral value for chemical shifts of 1.20 to 1.90 ppm, (ii) is the integral value for chemical shifts of 2.05 to 2.50 ppm, and (iii) is the integral value for chemical shifts of 3.15 to 3.50 ppm.) 2. A polyamide resin composition comprising a polyamide resin (A) and a filler (B), wherein the polyamide resin (A) comprises two or more polyamide resins (A1) having constituent units derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid, and the ratio of the number of methylene groups to the number of amide groups in the polyamide resin (A), determined by the following formula (2), is 4.74 or more and 5.98 or less. (In formula (2), the content ratio of polyamide resin (k) in polyamide resin (A) is the ratio (mass ratio) of polyamide resin (k) when the total amount of polyamide resin (A) is set to 1.) 3. The polyamide resin composition according to claim 1 or 2, wherein the polyamide resin (A) comprises a polyamide resin (a1) having structural units derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid having 6 to 8 carbon atoms, and a polyamide resin (a2) having structural units derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid having 9 to 16 carbon atoms.

4. The polyamide resin composition according to claim 3, comprising 10.0 to 50.0% by mass of the polyamide resin (a1) and 20.0 to 55.0% by mass of the polyamide resin (a2) in 100% by mass of the polyamide resin composition.

5. The polyamide resin composition according to claim 1 or 2, wherein the polyamide resin (A) is contained in an amount of 45.0 to 75.0% by mass of 100% by mass of the polyamide resin composition.

6. The polyamide resin composition according to claim 1 or 2, wherein the polyamide resin composition contains 20.0 to 50.0% by mass of the filler (B) in 100% by mass of the polyamide resin composition.

7. The polyamide resin composition according to claim 1 or 2, wherein the filler (B) is coated with a sizing agent.

8. The polyamide resin composition according to claim 1 or 2, wherein the filler (B) is at least one selected from the group consisting of glass fibers, carbon fibers, and graphite fibers.

9. The polyamide resin composition according to claim 7, wherein the sizing agent comprises a polyurethane resin.

10. The polyamide resin composition according to claim 1 or 2, wherein the polyamide resin (A1) having constituent units derived from the reaction product of pentamethylenediamine and aliphatic dicarboxylic acid is selected from the group consisting of polyamide 56, polyamide 59, polyamide 510, polyamide 513 and polyamide 516.

11. The polyamide resin composition according to claim 3, wherein the polyamide resin (a1) comprises polyamide 56, and the polyamide resin (a2) comprises at least one selected from the group consisting of polyamide 59, polyamide 510, polyamide 513, and polyamide 516.

12. The polyamide resin composition according to claim 1 or 2, comprising 0.01 to 0.25% by mass of a coloring agent (C) in 100% by mass of the polyamide resin composition.

13. The polyamide resin composition according to claim 1 or 2, wherein the polyamide resin (A) comprises polyamide 6 (A2).

14. The polyamide resin composition according to claim 1 or 2, wherein the water absorption rate of an ISO 294-3 Type D2 test specimen of the polyamide resin composition is 1.90% or less when the test specimen is immersed in water at 23°C for 24 hours.

15. A molded article comprising the polyamide resin composition according to claim 1 or 2.

16. A polyamide resin composition comprising a polyamide resin (A) and a filler (B), wherein the polyamide resin (A) comprises a polyamide resin (a1) having structural units derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid having 6 to 8 carbon atoms, and a polyamide resin (a2) having structural units derived from a reaction product of pentamethylenediamine and an aliphatic dicarboxylic acid having 9 to 16 carbon atoms, and the polyamide resin composition comprises 10.0 to 50.0% by mass of the polyamide resin (a1) and 20.0 to 55.0% by mass of the polyamide resin (a2) in 100% by mass of the polyamide resin composition.

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