Polyamide resin composition for metal-resin bonding

Abstract

To provide a composite structure of metal and a resin, in which a resin member composed of a polyamide resin composition is firmly bonded and fixed to a metal member.SOLUTION: A metal / resin composite structure has a metal member and a resin member bonded to the metal member. The resin member is composed of a polyamide resin composition containing a polyamide resin (A) and talc (B). The polyamide resin (A) contains a component unit (a1) derived from dicarboxylic acid, containing a component unit derived from terephthalic acid, and a component unit (a2) derived from diamine, containing a component unit derived from linear aliphatic diamine and a component unit derived from branched aliphatic diamine. The content of the talc is 0.1-5 mass% with respect to the polyamide resin composition.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a metal / resin composite structure, a method for manufacturing a metal / resin composite structure, and an engine mount member. [Background technology]

[0002] BACKGROUND ART Techniques for joining resin members and metal members are in demand in a wide range of industrial fields, such as automobiles, communication devices, home appliances, and industrial equipment.

[0003] As a technique for joining a resin member and a metal member, a technique known as "injection joining" has been proposed in which a resin material is injected into a metal member inserted into a mold to join the resin member and the metal member.

[0004] For example, a technique has been disclosed in which a resin member such as polybutylene terephthalate resin (hereinafter referred to as "PBT") or polyphenylene sulfide resin (hereinafter referred to as "PPS") is injection bonded to a surface-roughened metal member (see, for example, Patent Document 1). Also, by further developing the metal surface roughening treatment technique, a method has been disclosed in which polyamide resin such as PA6 or PA66 is injection molded onto a surface-roughened metal member (Patent Documents 2 to 4). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-216425 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-315398 [Patent Document 3] Japanese Patent Application Laid-Open No. 2007-182071 [Patent Document 4] International Publication No. 2008 / 081933 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the bonding strength of the composite structures of the resin member and the metal member obtained by the methods shown in Patent Documents 2 to 4 was still not at a sufficient level.

[0007] For example, when conventional composite structures are applied to powertrain components that require high rigidity at high temperatures, such as engine mount brackets, which are components inside an automobile engine compartment and support the engine, the bonding strength at high temperatures may not yet be sufficient, leaving room for improvement.

[0008] The present invention has been made in view of the above circumstances, and aims to provide a metal / resin composite structure in which a resin member made of a polyamide resin composition is firmly joined and fixed to a metal member, a method for manufacturing the same, and an engine mount member. [Means for solving the problem]

[0009] The present invention relates to the following metal / resin composite structure, a method for manufacturing a metal / resin composite structure, and an engine mount member.

[0010] The metal / resin composite structure of the present invention is a metal / resin composite structure having a metal member having a textured surface and a resin member bonded to the textured surface of the metal member, wherein the resin member is made of a polyamide resin composition containing a polyamide resin (A) and talc (B), the polyamide resin (A) contains component units (a1) derived from a dicarboxylic acid and component units (a2) derived from a diamine, the component units (a1) derived from the dicarboxylic acid contain component units derived from terephthalic acid, the component units (a2) derived from the diamine contain component units derived from a linear aliphatic diamine having 4 to 15 carbon atoms and component units derived from a branched aliphatic diamine having 4 to 18 carbon atoms, and the content of the talc (B) is 0.1 to 5 mass% based on the polyamide resin composition.

[0011] The engine mount member of the present invention includes the metal / resin composite structure of the present invention.

[0012] The method for producing a metal / resin composite structure of the present invention includes the steps of: 1) placing a metal member having a textured structure on its surface in an injection molding die; and 2) injecting the molten polyamide resin composition onto the surface of the metal member having the textured structure, allowing it to solidify, and joining the resin member. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a metal / resin composite structure in which a resin member made of a polyamide resin composition is firmly joined and fixed to a metal member, a method for producing the same, and an engine mount member. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is an external view that schematically shows an example of the structure of the metal / resin composite structure of this embodiment. [Figure 2] FIG. 2 is a schematic diagram showing a method for measuring ten-point roughness. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present inventors have found that a polyamide resin (A) containing a component unit derived from a branched aliphatic diamine has good fluidity during molding. However, a resin composition containing such a polyamide resin does not have sufficient bonding strength to a metal member having a textured structure.

[0016] In response to this, the present inventors have discovered that by combining talc (B) with a polyamide resin (A) containing component units derived from a branched aliphatic diamine, the bonding strength between a metal member and a resin member can be significantly increased while maintaining fluidity during molding.

[0017] The reason for this is not clear, but is presumed to be as follows. That is, since polyamide resin (A) contains component units derived from branched aliphatic diamines, it exhibits good fluidity during molding, but its crystallization rate is slow. Therefore, it hardly crystallizes during injection molding, but tends to crystallize after injection molding. As a result, the amount of cure shrinkage on the metal member after injection molding is large, which tends to cause gaps at the interface between the metal member and the resin member, resulting in low bonding strength. In contrast, by blending a predetermined amount of talc (B) with polyamide resin (A), crystallization can be promoted appropriately even during injection molding. This reduces the amount of cure shrinkage (on the metal component) after injection molding, making it less likely for gaps to form at the interface between the metal component and the resin component, thereby increasing the bonding strength.

[0018] Furthermore, by further adding a polyamide resin (C) having a lower heat of fusion (ΔH) (crystallinity) than the polyamide resin (A), the fluidity and crystallization rate of the resin composition during injection molding can be well balanced, making it even less likely that gaps will form at the interface between the metal member and the resin member, further increasing the bonding strength.

[0019] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0020] 1.Metal / resin composite structure FIG. 1 is an external view schematically showing an example of the structure of a metal / resin composite structure 100 according to this embodiment.

[0021] As shown in FIG. 1, a metal / resin composite structure 100 according to this embodiment includes a metal member 110 having an uneven structure on its surface, and a resin member 120 joined to the metal member 110.

[0022] 1-1. Metallic parts 110 The metal member 110 has a fine uneven structure on at least a part of the surface to be bonded to the resin member 120 .

[0023] (material) The metal material constituting the metal member 110 is not particularly limited, but may be, for example, iron, high-tensile steel, stainless steel, aluminum, aluminum alloy, magnesium, magnesium alloy, copper, copper alloy, titanium, or titanium alloy. These may be used alone or in combination of two or more. Among them, from the viewpoints of light weight and high strength, aluminum (single aluminum) and aluminum alloy are preferred, and aluminum alloy is more preferred. Furthermore, from the viewpoint of high strength, iron and high-tensile steel are preferred. As aluminum alloys, alloy numbers 1050, 1100, 2014, 2024, 3003, 5052, 6061, 6063, and 7075 specified in JIS H4000 are preferably used.

[0024] The shape of the metal member 110 is not particularly limited as long as it can be bonded to the resin member 120, and may be, for example, a flat plate, a curved plate, a rod, a cylinder, a block, etc. Furthermore, the surface 111 to be bonded to the resin member 120 is not particularly limited, and may be a flat surface or a curved surface.

[0025] The metal member 110 is preferably formed into a predetermined shape by plastic processing such as cutting and pressing, punching, machining, polishing, electrical discharge machining, or other thinning processes, and then subjected to a roughening treatment, which will be described later. If the formed metal member 110 has an oxide film (rust) on its surface due to being left in the open air for a long period of time, it is preferable to remove the oxide film (rust) by polishing or chemical treatment.

[0026] (Uneven structure) It is preferable that the metal member 110 has a fine uneven structure including a plurality of protrusions at least on the surface 111 that contacts the resin member 120. This can improve the bonding strength between the metal member 110 and the resin member 120.

[0027] The center-to-center distance (pitch) of the multiple convex portions constituting the fine uneven structure is not particularly limited as long as it satisfies the requirement for satisfactory bonding between the metal member 110 and the resin member 120, but is preferably 5 nm to 500 μm. When the center-to-center distance of the multiple convex portions is 5 nm or more, the recesses between the convex portions are appropriately large, allowing the polyamide resin composition to easily penetrate into the recesses during bonding, thereby further improving the bonding strength between the metal member 110 and the resin member 120. Furthermore, when the center-to-center distance of the multiple convex portions is 500 μm or less, the recesses are not too large, thereby further preventing gaps from forming at the metal-resin interface of the metal / resin composite structure 100. This further prevents moisture and other contaminants from penetrating through the gaps at the metal / resin interface, thereby further preventing a decrease in bonding strength when the metal / resin composite structure is used under high temperature and high humidity conditions. From the same perspective, the center-to-center distance of the multiple convex portions is more preferably 5 μm to 250 μm. The center-to-center distance of the plurality of protrusions is the average value of the distances between the center of one protrusion and the center of the adjacent protrusion.

[0028] The center-to-center distance of the multiple convex portions can be measured by removing the resin member from the metal / resin composite structure by mechanical peeling, solvent cleaning, etc., and observing the surface of the exposed metal member 110 using an electron microscope or laser microscope, or a surface roughness measuring device.

[0029] Specifically, a concave-convex structure in which the center-to-center distance between multiple protrusions is less than 0.5 μm can be observed using an electron microscope, while a concave-convex structure in which the center-to-center distance between multiple protrusions is 0.5 μm or more can be observed using a laser microscope or surface roughness measuring device. For example, in a photograph of the surface of the metal member 110 taken with an electron microscope or a laser microscope, 50 random convex portions are selected and the center-to-center distance between each of these convex portions is measured. All of the measured center-to-center distances between the convex portions are then added up and divided by 50 (average) to determine the "center-to-center distance between multiple convex portions."

[0030] The average value of the ten-point average roughness (Rz) of the surface 111 of the metal member 110 having a fine uneven structure over an evaluation length of 4 mm is not particularly limited, but is preferably greater than 2 μm, more preferably greater than 2 μm and not greater than 50 μm, and even more preferably greater than 2.5 μm and not greater than 45 μm.

[0031] The average value of the ten-point mean roughness (Rz) can be measured in accordance with JIS B0601 (ISO 4287). Specifically, as described below, the ten-point mean roughness (Rz) is measured on three arbitrary parallel straight line sections and three arbitrary perpendicular straight line sections, a total of six straight line sections, and the average of these is taken as the average Rz (see Figure 2 described below).

[0032] The surface 111 of the metal member 110 having a fine uneven structure preferably has a mean length of the roughness curve element (RSm) of 0.5 to 500 μm. In particular, from the viewpoint of bonding strength, it is preferable that the center-to-center distance between multiple convex portions is less than 0.5 μm and the mean length of the roughness curve element (RSm) is 0.5 to 500 μm. The mean length of the roughness curve element can also be measured according to JIS B0601 (ISO 4287) as described above.

[0033] 1-2. Resin member 120 The resin member 120 is a molded product of a polyamide resin composition.

[0034] The polyamide resin composition contains a polyamide resin (A) and talc (B).

[0035] 1-2-1. Polyamide resin (A) The polyamide resin (A) contains a component unit (a1) derived from a dicarboxylic acid and a component unit (a2) derived from a diamine.

[0036] [Component unit (a1) derived from dicarboxylic acid] The component unit (a1) derived from a dicarboxylic acid is not particularly limited, but from the viewpoint of facilitating increased crystallinity, it is preferable that the component unit (a1) contains a component unit derived from terephthalic acid.

[0037] The content of the component units derived from terephthalic acid is not particularly limited, but is preferably 20 to 100 mol% relative to the total number of moles of the component units (a1) derived from dicarboxylic acids. If the content of the component units is 20 mol% or more, the crystallinity and mechanical strength of the polyamide resin (A) are likely to be improved. From the same viewpoint, the content of the component units is more preferably 50 to 100 mol%.

[0038] The dicarboxylic acid-derived component unit (a1) may further contain component units derived from other dicarboxylic acids than those mentioned above, provided that the effects of the present invention are not impaired. Examples of other dicarboxylic acids include aromatic dicarboxylic acids other than terephthalic acid (e.g., naphthalenedicarboxylic acid, isophthalic acid, etc.), alicyclic dicarboxylic acids (e.g., cyclohexanedicarboxylic acid), and aliphatic dicarboxylic acids having 4 to 20 carbon atoms.

[0039] The total content of component units derived from other dicarboxylic acids (total content of component units derived from aromatic dicarboxylic acids other than terephthalic acid, component units derived from alicyclic dicarboxylic acids, and component units derived from aliphatic dicarboxylic acids having 4 to 20 carbon atoms) is preferably 0 to 80 mol %, more preferably 0 to 50 mol %.

[0040] [Diamine-derived component unit (a2)] The diamine-derived component unit (a2) is not particularly limited, but from the viewpoint of increasing the fluidity during injection molding (to the extent that the mechanical strength of the resulting molded article is not impaired), it is preferable that the diamine-derived component unit (a2) contains a linear aliphatic diamine-derived component unit and a branched aliphatic diamine-derived component unit.

[0041] The linear aliphatic diamine is preferably a linear aliphatic diamine having 4 to 15 carbon atoms. Examples of linear aliphatic diamines having 4 to 15 carbon atoms include 1,4-butanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, and 1,10-decanediamine. Of these, 1,6-hexanediamine, 1,9-nonanediamine, and 1,10-decanediamine are preferred, and 1,6-hexanediamine is more preferred. These aliphatic diamines may be used alone or in combination of two or more.

[0042] The content of the component units derived from linear aliphatic diamines is preferably 20 to 80 mol % of the total content of the component units derived from linear aliphatic diamines and the component units derived from branched aliphatic diamines. When the content of the component units is 20 mol % or more, the crystallization rate does not become too slow, making it easy to appropriately increase the crystallinity and mechanical strength of the polyamide resin (A). When the content of the component units is 80 mol % or less, the crystallization rate of the polyamide resin (A) does not become too high, making it difficult to impair fluidity during molding. From the same viewpoint, the content of the component units derived from linear aliphatic diamines is more preferably 30 to 60 mol % of the total content.

[0043] The branched aliphatic diamine is preferably a branched aliphatic diamine having 4 to 18 carbon atoms. Examples of branched aliphatic diamines having 4 to 18 carbon atoms include 2-methyl-1,5-pentanediamine, 2-methyl-1,8-octanediamine, 2-methyl-1,6-hexanediamine, 2-methyl-1,7-heptanediamine, 2-methyl-1,9-nonanediamine, and 2-methyl-1,10-decanediamine. Among these, 2-methyl-1,8-octanediamine and 2-methyl-1,5-pentanediamine are preferred, and 2-methyl-1,5-pentanediamine is more preferred. These aliphatic diamines may be used alone or in combination. For example, the diamine-derived component unit (a2) preferably includes at least one of a component unit derived from 2-methyl-1,8-octanediamine and a component unit derived from 2-methyl-1,5-pentanediamine.

[0044] The content of the component units derived from a branched aliphatic diamine is preferably 20 to 80 mol % of the total content of the component units derived from a linear aliphatic diamine and the component units derived from a branched aliphatic diamine. When the content of the component units is 20 mol % or more, the crystallization rate of the polyamide resin (A) tends to be appropriately slowed, and therefore the fluidity during molding tends to be improved. When the content of the component units is 80 mol % or less, the crystallinity and mechanical strength of the polyamide resin (A) are less likely to be impaired. From the same viewpoint, the content of the component units derived from a branched aliphatic diamine is more preferably 40 to 70 mol % of the total content.

[0045] The total of the component units derived from a linear aliphatic diamine and the component units derived from a branched aliphatic diamine is preferably 60 to 100 mol %, more preferably 70 to 100 mol %, and even more preferably 100 mol %, based on the total number of moles of the component units (a2) derived from diamine.

[0046] The diamine-derived unit (a2) may further contain other diamine-derived unit(s) as long as the effects of the present invention are not impaired. Examples of other diamines include aromatic diamines and alicyclic diamines. The total content of the other diamine-derived unit(s) may be 5 mol % or less based on the total number of moles of the diamine-derived unit (b).

[0047] Examples of such polyamide resins (A) include polyamide resins containing, as the dicarboxylic acid-derived component units (a1), component units derived from terephthalic acid; and, as the diamine-derived component units (a2), component units derived from 1,6-hexanediamine and component units derived from 2-methyl-1,5-pentanediamine or 2-methyl-1,8-octanediamine.

[0048] [Physical Properties] The heat of fusion (ΔH) of the polyamide resin (A) measured by a differential scanning calorimeter (DSC) is preferably higher than that of the polyamide resin (C) described below. Specifically, the heat of fusion (ΔH) of the polyamide resin (A) is preferably higher than 20 J / g. When the heat of fusion (ΔH) of the polyamide resin (A) is higher than 20 J / g, the crystallinity is not too low, and the heat resistance is easily increased. From the same viewpoint, the heat of fusion (ΔH) of the polyamide resin (A) is more preferably 30 to 130 J / g.

[0049] The melting point (Tm) of the polyamide resin (A) measured by a differential scanning calorimeter (DSC) is preferably 280 to 340°C. When the melting point (Tm) of the polyamide resin (A) is 280°C or higher, mold releasability, mechanical strength, heat resistance, etc. are less likely to be impaired, and when it is 340°C or lower, there is no need to increase the molding temperature excessively, making it easier to obtain molding processability. The melting point (Tm) of the polyamide resin (A) is more preferably 290 to 320°C.

[0050] The glass transition temperature (Tg) of the polyamide resin (A) measured by a differential scanning calorimeter (DSC) is preferably 70 to 170° C., more preferably 128 to 155° C. When the glass transition temperature (Tg) of the polyamide resin (A) is within the above range, heat resistance is less likely to be impaired.

[0051] The heat of fusion (ΔH), melting point (Tm) and glass transition temperature (Tg) of the polyamide resin (A) can be measured using a differential scanning calorimeter (DSC220C, manufactured by Seiko Instruments Inc.). Specifically, approximately 5 mg of polyamide resin (A) is sealed in a measuring aluminum pan and heated from room temperature to 350°C at 10°C / min. To completely melt the resin, it is held at 350°C for 3 minutes and then cooled to 30°C at 10°C / min. After leaving it at 30°C for 5 minutes, it is heated a second time to 360°C at 10°C / min. The temperature (°C) of the endothermic peak during this second heating is taken as the melting point (Tm) of polyamide resin (A), and the inflection point corresponding to the glass transition is taken as the glass transition temperature (Tg). The heat of fusion (ΔH) is determined from the area of ​​the exothermic peak of crystallization during the first heating process in accordance with JIS K7122.

[0052] The heat of fusion (ΔH), melting point (Tm) and glass transition temperature (Tg) of the polyamide resin (A) can be adjusted by the composition of the dicarboxylic acid and diamine.

[0053] The polyamide resin (A) preferably has an intrinsic viscosity [η] of 0.5 to 2.0 dL / g, as measured in 96.5% sulfuric acid at 25°C. When the polyamide resin (A) has an intrinsic viscosity [η] of 0.5 dL / g or more, the mechanical strength (toughness, etc.) of the resulting resin part (molded article) is easily increased, while when the intrinsic viscosity [η] is 2.0 dL / g or less, the fluidity during molding is less likely to be impaired. From the same viewpoint, the polyamide resin more preferably has an intrinsic viscosity [η] of 0.80 to 1.15 dL / g. The intrinsic viscosity [η] can be adjusted by, for example, the amount of terminal blocking of the polyamide resin (A).

[0054] The intrinsic viscosity of the polyamide resin (A) can be measured in accordance with JIS K6810-1977. Specifically, 0.5 g of polyamide resin (A) is dissolved in 50 ml of 96.5% sulfuric acid solution to prepare a sample solution. The flow time of this sample solution is measured using an Ubbelohde viscometer at 25±0.05°C, and the obtained value can be applied to the following formula to calculate the viscosity. [η]=ηSP / [C(1+0.205ηSP)]

[0055] In the above formula, each algebra or variable represents: [η]: Intrinsic viscosity (dl / g) ηSP: Specific viscosity C: Sample concentration (g / dl)

[0056] ηSP is calculated by the following formula: ηSP=(t-t0) / t0 t: Number of seconds for sample solution to flow down (seconds) t0: Number of seconds the blank sulfuric acid flows (seconds)

[0057] From the viewpoint of thermal stability during compounding and molding, the polyamide resin (A) may have at least some of its molecular terminal groups blocked with a terminal blocking agent. The terminal blocking agent is preferably a monoamine when the molecular terminal is a carboxyl group, and is preferably a monocarboxylic acid when the molecular terminal is an amino group.

[0058] Examples of monoamines include aliphatic monoamines such as methylamine, ethylamine, propylamine, and butylamine; alicyclic monoamines such as cyclohexylamine and dicyclohexylamine; Examples of monocarboxylic acids include aromatic monoamines such as aniline and toluidine. Examples of monocarboxylic acids include aliphatic monocarboxylic acids having 2 to 30 carbon atoms, such as acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecylic acid, myristic acid, palmitic acid, stearic acid, oleic acid, and linoleic acid; aromatic monocarboxylic acids, such as benzoic acid, toluic acid, naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, and phenylacetic acid; and alicyclic monocarboxylic acids, such as cyclohexanecarboxylic acid. The aromatic monocarboxylic acids and alicyclic monocarboxylic acids may have a substituent on the ring structure.

[0059] The content of polyamide resin (A) is preferably 20 to 99% by mass relative to the polyamide resin composition. When the content of polyamide resin (A) is 20% by mass or more, the properties of polyamide resin (A) are easily obtained. From the same viewpoint, the content of polyamide resin (A) is more preferably 35 to 80% by mass relative to the polyamide resin composition.

[0060] 1-2-2. Talc (B) Talc (B) can appropriately increase the crystallization rate of the polyamide resin (A), thereby increasing the bonding strength between the metal member 110 and the resin member 120.

[0061] Talc (B) generally contains hydrous magnesium silicate (SiO2: 58 to 64%, MgO: 28 to 32%, Al2O3: 0.5 to 5%, Fe2O3: 0.3 to 5%) as its main component.

[0062] The average particle size of the talc (B) is not particularly limited, but is preferably 1 to 15 μm. When the average particle size of the talc is within the above range, the talc can be easily dispersed in the polyamide resin (A) without impairing the fluidity of the polyamide resin composition. From the same viewpoint, the average particle size of the talc is more preferably 1 to 7.5 μm.

[0063] The average particle size of the talc (B) can be measured by a laser diffraction method, for example, using a Shimadzu particle size distribution analyzer SALD-2000A manufactured by Shimadzu Corporation.

[0064] The content of talc (B) is preferably 0.1 to 5% by mass relative to the polyamide resin composition. A talc content of 0.1% by mass or more can moderately crystallize the polyamide resin (A) during injection molding, thereby reducing the amount of cure shrinkage due to crystallization of the polyamide resin (A) after injection molding. This further reduces the likelihood of gaps forming between the surface 111 of the metal member 110 (specifically, between the multiple convex portions constituting the uneven structure) and the resin member 120, further enhancing bonding strength. A talc (B) content of 5% by mass or less prevents excessive crystallization of the polyamide resin (A) during injection molding, thereby preventing loss of fluidity and further suppressing poor conformability of the polyamide resin composition to the fine uneven structure of the surface 111 of the metal member 110 (poor filling between the multiple convex portions constituting the fine uneven structure). From the same perspective, the content of talc (B) is preferably 0.1 to 3.5% by mass relative to the polyamide resin composition.

[0065] The content of talc (B) is preferably 0.02 to 11 parts by mass, and more preferably 0.1 to 7 parts by mass, per 100 parts by mass of the total of polyamide resin (A) and talc (B).

[0066] 1-2-3. Other ingredients The polyamide resin composition may further contain other components in addition to those described above, provided that the effects of the present invention are not impaired. Examples of such other components include a polyamide resin (C) other than the polyamide resin (A), a fibrous inorganic filler (D), a lubricant (E), and other additives (e.g., colorants, antioxidants, heavy metal deactivators (chelating agents), flame retardant aids, ultraviolet absorbers, heat stabilizers, antistatic agents, antibacterial agents, antifogging agents, antiblocking agents, nucleating agents, dispersants, thickeners, foaming agents, pigments, dyes, organic fillers, etc.). Among these, a polyamide resin (C) other than the polyamide resin (A), a fibrous inorganic filler (D), and a lubricant (E) are preferred.

[0067] (Polyamide resin (C)) The heat of fusion (ΔH) of the polyamide resin (C) is preferably lower than the heat of fusion (ΔH) of the polyamide resin (A). Specifically, the heat of fusion (ΔH) of the polyamide resin (C) measured by a differential scanning calorimeter (DSC) is preferably 0 to 5 J / g. When the heat of fusion (ΔH) of the polyamide resin (C) is 5 J / g or less, the crystallinity of the resin composition can be reduced, thereby further reducing the amount of cure shrinkage on the metal member 110 and facilitating further enhancement of the bonding strength with the metal member 110. From the same viewpoint, the heat of fusion (ΔH) of the polyamide resin (C) is more preferably 0 J / g. Furthermore, the polyamide resin (C) is preferably an amorphous resin.

[0068] The difference in the heat of fusion (ΔH) between the polyamide resin (C) and the polyamide resin (A) is not particularly limited, but is preferably 20 J / g or more. When the difference in the heat of fusion (ΔH) is 20 J / g or more, it is easy to adjust the crystallization rate of the polyamide resin composition during injection molding. From the same viewpoint, the difference in the heat of fusion (ΔH) between the polyamide resin (C) and the polyamide resin (A) is more preferably 30 to 130 J / g, and even more preferably 30 to 60 J / g. The heat of fusion (ΔH) of the polyamide resin (C) can be measured by the same method as described above.

[0069] The polyamide resin (C) is not particularly limited as long as the heat of fusion (ΔH) satisfies the above range, but contains component units (c1) derived from a dicarboxylic acid and component units (c2) derived from a diamine.

[0070] [Component unit (c1) derived from dicarboxylic acid] The component unit (c1) derived from a dicarboxylic acid is not particularly limited, but from the viewpoint of adjusting the crystallinity, it is preferable to include a component unit derived from isophthalic acid.

[0071] The content of the component units derived from isophthalic acid is not particularly limited, but is preferably 20 to 100 mol% relative to the total number of moles of the component units (c1) derived from dicarboxylic acid. If the content of the component units is 20 mol% or more, the crystallinity of the polyamide resin (A) is likely to be increased. From the same viewpoint, the content of the component units is more preferably 50 to 100 mol%.

[0072] The dicarboxylic acid-derived component unit (c1) may further contain a component unit derived from a dicarboxylic acid other than those mentioned above. Examples of the other dicarboxylic acid include aromatic dicarboxylic acids other than isophthalic acid (such as terephthalic acid), alicyclic dicarboxylic acids (such as cyclohexanedicarboxylic acid), and aliphatic dicarboxylic acids having 4 to 20 carbon atoms. Among these, terephthalic acid is preferred from the viewpoint of good affinity with the polyamide resin (A).

[0073] The molar ratio of the component units derived from isophthalic acid to the component units derived from terephthalic acid in the component units (c) derived from dicarboxylic acid is preferably component units derived from isophthalic acid / component units derived from terephthalic acid=60 / 40 to 100 / 0. By appropriately lowering the crystallization rate of the polyamide resin (C), it is possible to adjust the balance between the fluidity during molding and the crystallization rate when combined with the polyamide resin (A).

[0074] Furthermore, the content of component units derived from isophthalic acid in the component units (c1) derived from dicarboxylic acids constituting the polyamide resin (C) is preferably greater than the content of component units derived from isophthalic acid in the component units (a1) derived from dicarboxylic acids constituting the polyamide resin (A).

[0075] The total content of component units derived from other dicarboxylic acids is preferably 0 to 80 mol %, more preferably 0 to 50 mol %.

[0076] [Diamine-derived component unit (c2)] The diamine-derived component unit (c2) is not particularly limited, but preferably contains an aliphatic diamine-derived component unit.

[0077] The aliphatic diamine is preferably an aliphatic diamine having 4 to 15 carbon atoms. From the viewpoint of appropriately adjusting the crystallization rate by combining it with the polyamide resin (A), the aliphatic diamine having 4 to 15 carbon atoms is preferably a linear aliphatic diamine. The linear aliphatic diamine is the same as described above, and is preferably 1,6-hexanediamine. Note that the diamine-derived component unit (c2) does not necessarily have to contain a branched aliphatic diamine-derived component unit.

[0078] The content of the component units derived from linear aliphatic diamines is preferably 40 to 100 mol% relative to the total number of moles of component units (c2) derived from diamines. If the content of these component units is 40 mol% or more, the crystallization rate tends to be slowed, and if it is 100 mol% or less, heat resistance tends to be maintained. From the same viewpoint, the content of these component units is more preferably 60 to 100 mol% relative to the total number of moles of component units (c2) derived from diamines.

[0079] [Physical Properties] Since the polyamide resin (C) is an amorphous resin, the melting point (Tm) is not observed.

[0080] The glass transition temperature (Tg) of the polyamide resin (C) is not particularly limited, but is the same as the glass transition temperature (Tg) of the polyamide resin (A), and can be, for example, 90 to 130°C.

[0081] The intrinsic viscosity [η] of the polyamide resin (C) is not particularly limited, but is lower than the intrinsic viscosity [η] of the polyamide resin (A), for example, 0.50 to 1.50 dl / g, preferably 0.50 to 0.90 dl / g.

[0082] The melting point (Tm), glass transition temperature (Tg), and intrinsic viscosity [η] can be measured by the same methods as described above.

[0083] The content of polyamide resin (C) is not particularly limited, but may be 0 to 30% by mass relative to the polyamide resin composition. If the content of polyamide resin (C) is above a certain amount, the crystallization rate is likely to be delayed, and if it is 30% by mass or less, heat resistance is unlikely to be impaired. From the same viewpoint, the content of polyamide resin (C) may be 0 to 20% by mass relative to the polyamide resin composition.

[0084] Furthermore, the content of polyamide resin (C) may be 0 to 60% by mass relative to the total of polyamide resin (C) and polyamide resin (A). When the content of polyamide resin (C) is at least a certain amount, the crystallinity of the resin composition can be further reduced, and the amount of cure shrinkage on metal member 110 during injection molding can also be further reduced. When the content of polyamide resin (C) is 60% by mass or less, the crystallinity of the resulting resin composition is less likely to be impaired, and the mechanical strength and heat resistance of the molded article are less likely to be impaired. From the same perspective, the content of polyamide resin (C) may be more preferably 1 to 40% by mass, and even more preferably 5 to 40% by mass, relative to the total of polyamide resin (C) and polyamide resin (A).

[0085] (Fiber-like inorganic filler (D)) The fibrous inorganic filler (D) can impart high mechanical strength to the resin member 120, which is a molded product of the polyamide resin composition.

[0086] Examples of the fibrous inorganic filler (D) include glass fiber, carbon fiber, wollastonite, potassium titanate whiskers, calcium carbonate whiskers, aluminum borate whiskers, magnesium sulfate whiskers, zinc oxide whiskers, milled fiber, and cut fiber. One of these may be used alone, or two or more may be used in combination. Among these, glass fiber and wollastonite are preferred, and glass fiber is more preferred, as they can easily increase the mechanical strength of the resin member 120.

[0087] The average fiber length of the fibrous inorganic filler (D) may be, for example, 1 μm to 20 mm, preferably 5 μm to 10 mm, from the viewpoints of moldability of the resin composition and the mechanical strength and heat resistance of the resulting molded article. The aspect ratio of the fibrous inorganic filler (D) may be, for example, 5 to 2000, preferably 30 to 600.

[0088] The average fiber length and average fiber diameter of the fibrous inorganic filler (D) can be measured by the following method. 1) The resin composition is dissolved in a hexafluoroisopropanol / chloroform solution (0.1 / 0.9% by volume), and then filtered to obtain a filtrate. 2) The filtered material obtained in 1) is dispersed in water, and the fiber length (Li) and fiber diameter (di) of each of 300 randomly selected fibers are measured using an optical microscope (magnification: 50x). The number of fibers with a fiber length of Li is defined as qi, and the weight-average length (Lw) is calculated based on the following formula, which is the average fiber length of the fibrous filler. Weight average length (Lw) = (Σqi × Li 2 ) / (Σqi×Li) Similarly, the number of fibers having a fiber diameter Di is taken as ri, and the weight average diameter (Dw) is calculated based on the following formula, and this is taken as the average fiber diameter of the fibrous filler. Weight average diameter (Dw)=(Σri×Di 2 ) / (Σri×Di)

[0089] The content of the fibrous inorganic filler (D) is not particularly limited, but is preferably 0 to 75 mass % relative to the polyamide resin composition, more preferably more than 0 mass % and not more than 75 mass %, and even more preferably 15 to 60 mass %.

[0090] (Lubricant (E)) The lubricant (E) can improve the flowability and kneading processability of the polyamide resin composition during molding, and the releasability from a mold.

[0091] The lubricant (E) is not particularly limited, but is a metal salt of a medium-chain fatty acid having 8 to 10 carbon atoms or a long-chain fatty acid having 12 or more carbon atoms.

[0092] Examples of fatty acids include octylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, 12-hydroxystearic acid, behenic acid, montanic acid, sebacic acid, and ricinoleic acid, with montanic acid, 12-hydroxystearic acid, and behenic acid being preferred.

[0093] Examples of metal salts include lithium salts, sodium salts, potassium salts, magnesium salts, calcium salts, barium salts, zinc salts and aluminum salts, with calcium salts, magnesium salts, zinc salts, aluminum salts and lithium salts being preferred.

[0094] Examples of such metal salts of fatty acids include calcium 12-hydroxystearate, zinc 12-hydroxystearate, magnesium 12-hydroxystearate, aluminum 12-hydroxystearate, lithium 12-hydroxystearate, calcium behenate, zinc behenate, magnesium behenate, lithium behenate, calcium montanate, zinc montanate, magnesium montanate, aluminum montanate, and lithium montanate, which can be used alone or in combination of two or more.

[0095] The content of the lubricant (E) is, for example, 0 to 10% by mass, preferably 0.1 to 8% by mass, relative to the polyamide resin composition. When the content of the lubricant (E) is a certain amount or more, the flowability is improved and the kneading and moldability are likely to be improved, while when the content is a certain amount or less, the kneading processability of the resin composition is unlikely to be impaired.

[0096] When two or more lubricants (E) are contained, the content of the metal montanate in the total lubricant (E) is 20 to 100 mass%, preferably 30 to 100 mass%, more preferably 50 to 100 mass%, thereby increasing the bonding strength of the metal / resin composite structure.

[0097] (Physical Properties of Polyamide Resin Composition) The injection flow length (L / t) of the polyamide resin composition varies depending on the composition, but is preferably 18 mm or more, and more preferably 20 to 30 mm. When the flow length (L / t) is at least a certain level, the composition has excellent fluidity, and therefore, when joined to the metal member 110, the polyamide resin composition is easily filled without gaps between the convex portions of the uneven structure on the surface 111 of the metal member 100. The flow length can be measured by injection molding using a bar flow mold.

[0098] The flow length of the polyamide resin composition can be adjusted by the composition and content ratio of polyamide resins (A) and (C), the content of talc (B) and fibrous inorganic filler (D), etc. In order to increase the flow length, it is preferable to increase the content of branched aliphatic diamine in polyamide resin (A) or add polyamide resin (C), for example.

[0099] (Method of producing polyamide resin composition) The polyamide resin composition can be produced by a known resin kneading method, for example, by mixing the above-mentioned components in a Henschel mixer, V blender, ribbon blender, or tumbler blender, or by mixing and then melt-kneading the components in a single-screw extruder, multi-screw extruder, kneader, or Banbury mixer, followed by granulation or pulverization.

[0100] 1-3.Physical properties The metal / resin composite structure 100 of this embodiment has a metal member 110 having a fine uneven structure on its surface, and a resin member 120 made of a polyamide resin composition firmly bonded to the surface having the fine uneven structure.

[0101] Specifically, the tensile shear strength of the joint surface between the metal member 110 and the resin member 120 is preferably 40 MPa or more, more preferably 45 MPa or more, and even more preferably 47 to 70 MPa.

[0102] Furthermore, the fracture surface after measuring the tensile shear strength preferably exhibits a base material fracture morphology, which is defined as a fracture morphology in which residual resin is observed over 80% or more of the area of ​​the interface of the metal / resin joint.

[0103] The bond strength can be measured by a tensile test under the conditions of 23°C, a chuck distance of 60 mm, and a tensile speed of 10 mm / min. Specifically, a special jig is attached to a tensile tester, and the breaking load (N) of the metal / resin composite structure is measured under the above conditions. The breaking load (N) is then divided by the area of ​​the metal / resin bond to calculate the bond strength (tensile shear strength) (MPa).

[0104] The bonding strength can be adjusted by the composition of the polyamide resin composition, particularly the types and contents of polyamide resin (A), talc (B), and polyamide resin (C). To increase the bonding strength, it is preferable to adjust the composition so that the fluidity during injection molding is increased while the appropriate crystallization occurs during injection molding. From the viewpoint of appropriate crystallization during injection molding, it is preferable to appropriately increase the content of talc (B). From the viewpoint of increasing the fluidity, it is preferable to increase the content of branched aliphatic diamine in polyamide resin (A) or add polyamide resin (C).

[0105] 2.Method for manufacturing metal / resin composite structures The manufacturing method of the metal / resin composite structure 100 according to this embodiment is not particularly limited, but may include, for example, 1) a step of placing a metal member 110 having a textured structure on its surface in an injection molding die, and 2) a step of injecting a molten polyamide resin composition onto the surface of the metal member 110 having the textured structure, solidifying it, and joining the resin member 120.

[0106] Regarding step 1) First, a metal member 110 having an uneven structure on at least a portion of its surface is prepared.

[0107] The method for obtaining the metal member 110 having a fine uneven structure is not particularly limited, and examples thereof include a laser processing method as disclosed in Japanese Patent No. 4020957; a method of immersing a metal member in an aqueous solution of an inorganic base such as NaOH and / or an aqueous solution of an inorganic acid such as HCl or HNO; a method of treating a metal member by an anodic oxidation method as disclosed in Japanese Patent No. 4541153; a displacement crystallization method in which etching is performed with an acid-based etching agent, preferably an acid-based etching agent aqueous solution containing an inorganic acid, ferric ions, cupric ions, and optionally manganese ions, aluminum chloride hexahydrate, sodium chloride, etc., as disclosed in International Publication No. 2015-8847; a method of immersing a metal member in an aqueous solution of one or more selected from hydrazine hydrate, ammonia, and a water-soluble amine compound as disclosed in International Publication No. 2009 / 31632 (hereinafter, sometimes referred to as the NMT method); and a hot water treatment method as disclosed in Japanese Patent Laid-Open No. 2008-162115.

[0108] These methods allow the etching method to be selected arbitrarily depending on the type of metal used and the distance between the centers of the multiple convex portions. However, from the viewpoint of the bonding strength between the metal member 110 and the resin member 120, the substitution crystallization method and the NMT method are preferred in this embodiment.

[0109] Then, the mold is opened, and the prepared metal member 110 having the concave-convex structure is placed in the cavity (space) within the mold.

[0110] Regarding step 2) Then, the polyamide resin composition is injected into the cavity of the mold so that at least a portion of the polyamide resin composition comes into contact with the surface having the fine uneven structure of the metal member 110. Thereafter, the polyamide resin composition is cooled and solidified, thereby bonding the metal member 110 and the resin member 120 together.

[0111] The temperature of the injection molding die is not particularly limited as long as it is a temperature at which the polyamide resin composition can be melted to a state suitable for injection molding, and may be, for example, 100 to 250°C.

[0112] After injection and pressure holding, the mold is cooled, then opened, and ejected using an ejector pin if necessary, to obtain the metal / resin composite structure 100.

[0113] As the mold, a known injection molding mold, for example, a mold for high speed heat cycle molding (RHCM, heat & cool molding) or a core back mold for foam molding can be used.

[0114] 3. Applications of metal / resin composite structures The metal / resin composite structure 100 according to this embodiment has high productivity and a high degree of freedom in shape control, and therefore can be applied to a variety of uses.

[0115] Furthermore, the metal / resin composite structure 100 according to this embodiment has high heat resistance, mechanical properties, friction resistance, sliding properties, airtightness, and watertightness, and is therefore suitable for use in applications that suit these properties.

[0116] Examples of such applications include vehicle structural parts, vehicle mounted items, electronic device housings, home appliance housings, structural parts, machine parts, various automotive parts, electronic device parts, household applications such as furniture and kitchenware, medical equipment, building material parts, and other structural and exterior parts.

[0117] Specifically, these include the following parts designed to support areas where resin alone is not strong enough: In the automotive industry, these include instrument panels, console boxes, door handles, door trim, shift levers, pedals, glove boxes, bumpers, hoods, fenders, trunks, doors, roofs, pillars, seats, steering wheels, ECU boxes, electrical components, engine peripherals, drivetrain and gear peripherals, intake and exhaust system components, and cooling system components. In building materials and furniture, these include glass window frames, handrails, curtain rails, dressers, drawers, closets, bookshelves, desks, and chairs. In precision electronic components, these include connectors, relays, and gears. In transportation containers, these include shipping containers, suitcases, and trunks.

[0118] Furthermore, by combining the high thermal conductivity of the metal member 110 with the insulating properties of the resin member 120, the resin member 120 can be used in components for devices that require optimal heat management design, such as various home appliances. Specific examples include home appliances such as refrigerators, washing machines, vacuum cleaners, microwave ovens, air conditioners, lighting equipment, electric water heaters, televisions, clocks, ventilation fans, projectors, and speakers, as well as electronic information devices such as personal computers, mobile phones, smartphones, digital cameras, tablet PCs, portable music players, portable game consoles, chargers, and batteries.

[0119] Other uses include toys, sports equipment, shoes, sandals, bags, tableware such as forks, knives, spoons and plates, stationery such as ballpoint pens, mechanical pencils, files and binders, cooking utensils such as frying pans, pots, kettles, spatulas, ladles, slotted ladles, whisks and tongs, parts for lithium-ion secondary batteries, and robots.

[0120] Furthermore, the metal / resin composite structure 100 according to this embodiment has excellent mechanical properties and abrasion resistance because the resin member 120 contains polyamide, making it extremely useful as a sliding part for dynamic applications such as gears, bushings, and door checker arms.

[0121] Furthermore, the metal / resin composite structure 100 according to this embodiment is useful as a bracket constituting an engine mount member that supports an engine (vibration member) on a support member in a vibration-damping manner. An engine mount member in which a polyamide resin composition is integrally molded into an insert fastener formed on the bracket for fixing to the vibrating member and / or support member, or into a metal reinforcing rib embedded in the bracket body for strength enhancement, is obtained by forming a finely textured surface on the surface of the fastener or the metal reinforcing rib, and then insert-molding the polyamide resin composition. The engine mount member according to this embodiment has a bracket that exhibits high bonding strength and heat resistance, and also has high vibration characteristics, so it can effectively withstand vibrations from an engine, etc. [Example]

[0122] The present invention will be described below with reference to examples, which should not be construed as limiting the scope of the present invention.

[0123] 1. Metallic parts <Preparation of Surface-Treated Metal Member (M-1)> An aluminum plate (thickness: 2.0 mm) of alloy number 6063 specified in JIS H4000 was cut into a length of 45 mm and a width of 18 mm. This aluminum plate was immersed in an alkaline etching agent (15% by mass of sodium hydroxide, 3% by mass of zinc oxide) at 30°C for 3 minutes (hereinafter sometimes abbreviated as "alkaline etching agent treatment"), and then immersed in 30% by mass of nitric acid at 30°C for 1 minute. The alkaline etching agent treatment was then repeated once more. The resulting aluminum alloy plate was then immersed in an acid etching agent (4.1% by mass of sulfuric acid, 3.9% by mass of ferric chloride, 0.2% by mass of cupric chloride) at 30°C for 5 minutes and etched by shaking. It was then ultrasonically cleaned in running water (in water for 1 minute) and dried to obtain a surface-treated metal member (M-1).

[0124] The surface properties of the obtained surface-treated metal member (M-1) were as follows: Center distance between multiple convex parts: 95 μm Average element length Rsm: 104 μm Rz of six straight sections: 19.2μm, 20.8μm, 18.5μm, 18.2μm, 18.4μm, 19.6μm Average Rz value: 19 μm Etching rate: 2.9% by mass

[0125] <Preparation of surface-treated metal member (M-2)> The aluminum plate, in which alloy number A6063 was changed to alloy number A5052, was etched in an acid-based etching solution (sulfuric acid: 8.2 mass%, ferric chloride: 7.8 mass% (Fe 3+ : 2.7 mass%, Cupric chloride: 0.4 mass% (Cu 2+ The metal member was immersed in a solution of 0.2% by mass of aluminum hydroxide, the remainder being ion-exchanged water, for 80 seconds and swung to perform etching. The metal member was then ultrasonically cleaned in running water (in water for 1 minute) and dried to obtain a surface-treated metal member (M-2).

[0126] The surface properties of the obtained surface-treated metal member (M-2) were as follows: Center distance between multiple convex parts: 92 μm Average element length Rsm: 96.8 μm Rz of six straight sections: 17.8μm, 18.1μm, 19.6μm, 17.8μm, 17.2μm, 18.0μm Average Rz value: 18.1 μm Etching rate: 2.6% by mass

[0127] The surface properties (center-to-center distance between a plurality of convex portions and surface roughness) of the surface-treated metal member were measured by the following method.

[0128] (Center-to-center distance of multiple convex parts) The interval period of the surface-treated metal member was measured using a laser microscope (Keyence VK-X100). Specifically, 50 randomly selected convex portions were selected from a photograph of the surface of the metal member, and the center-to-center distance between adjacent convex portions was measured. All the measured center-to-center distances were added up and divided by 50 to obtain the "center-to-center distance of multiple convex portions."

[0129] (surface roughness) The surface roughness of the surface-treated metal parts was measured using a surface roughness measuring device, Surfcom 1400D (Tokyo Seimitsu Co., Ltd.), and the etching rate was calculated from the ten-point mean roughness (Rz) on the six straight lines shown in Figure 2, the mean element length (Rsm), and the mass ratio of the metal parts before and after the etching treatment. The measurement conditions were as follows: ·Stylus tip radius: 5μm Reference length: 0.8 mm Evaluation length: 4mm ·Measurement speed: 0.06mm / sec Measurements were taken on three randomly selected parallel lines on the surface of the metal part, plus three randomly selected perpendicular lines to these lines, for a total of six lines, and the average value was calculated (see Figure 2).

[0130] 2. Constituents of polyamide resin composition (1) Polyamide resin <Polyamide resin (PA-1)> 1,6-hexanediamine 1312g (11.3 mol), 2-methyl-1,5-pentanediamine 1312g (11.3 mol), terephthalic acid 3655g (22.0 mol), sodium hypophosphite 5.5g (5.2 × 10-) as a catalyst 2 mol) and 640 ml of ion-exchanged water were charged into a 1-liter reactor, and after replacing with nitrogen, the mixture was heated at 250°C and 35 kg / cm 2 The reaction was carried out for 1 hour under the conditions of (a) and (b) above. The molar ratio of 1,6-hexanediamine to 2-methyl-1,5-pentanediamine was 50:50. After 1 hour had elapsed, the reaction product produced in the reactor was transferred to a reactor connected to the reactor and maintained at a pressure of about 10 kg / cm. 2 The mixture was extracted into a receiver set at a low temperature to obtain a polyamide precursor having an intrinsic viscosity [η] of 0.15 dL / g. The polyamide precursor was then dried and melt-polymerized using a twin-screw extruder at a cylinder temperature of 330°C to obtain polyamide resin (PA-1).

[0131] The resulting polyamide resin (PA-1) had the following composition: 100 mol% of dicarboxylic acid-derived units were derived from terephthalic acid; 50 mol% of diamine-derived units were derived from 1,6-hexanediamine; and 50 mol% of 2-methyl-1,5-pentanediamine. The polyamide resin (PA-1) had an intrinsic viscosity [η] of 0.9 dl / g, a melting point (Tm) of 300°C, a glass transition temperature of 140°C, and a heat of fusion (ΔH) of 45 J / g.

[0132] <Polyamide resin (PA-2)> 2800 g (24.1 mol) of 1,6-hexanediamine, 1390 g (8.4 mol) of terephthalic acid, 2581 g (15.5 mol) of isophthalic acid, 109.5 g (0.9 mol) of benzoic acid, 5.7 g of sodium hypophosphite monohydrate, and 545 g of distilled water were placed in a 13.6 L autoclave and purged with nitrogen. Stirring was initiated at 190 °C, and the internal temperature was raised to 250 °C over 3 hours. At this time, the internal pressure of the autoclave was increased to 3.02 MPa. After the reaction was continued for 1 hour, the low-order condensation product was discharged into the atmosphere through a spray nozzle installed at the bottom of the autoclave and extracted. The low-order condensation product was then cooled to room temperature, pulverized in a pulverizer to a particle size of 1.5 mm or less, and dried at 110 °C for 24 hours. The obtained low-order condensate had a water content of 3000 ppm and an intrinsic viscosity [η] of 0.14 dL / g. Next, this low-order condensate was melt-polymerized in a twin-screw extruder with a screw diameter of 30 mm and L / D = 36 at a barrel setting temperature of 330°C, a screw rotation speed of 200 rpm, and a resin feed rate of 6 kg / h to obtain a polyamide resin (PA-2).

[0133] The resulting polyamide resin (PA-2) had the following composition: Among the dicarboxylic acid-derived units, the content of terephthalic acid-derived units was 70 mol %, the content of isophthalic acid-derived units was 30 mol %, and the content of 1,6-hexanediamine-derived units among the diamine-derived units was 100 mol %. The polyamide resin (PA-2) also had an intrinsic viscosity [η] of 0.9 dl / g, a melting point (Tm) of 330°C, a glass transition temperature (Tg) of 125°C, and a heat of fusion (ΔH) of 50 J / g.

[0134] <Polyamide resin (PA-3)> 2800 g (24.1 mol) of 1,6-hexanediamine, 2581 g (15.5 mol) of terephthalic acid, 1390 g (8.4 mol) of isophthalic acid, 109.5 g (0.9 mol) of benzoic acid, 5.7 g of sodium hypophosphite monohydrate, and 545 g of distilled water were placed in a 13.6 L autoclave and purged with nitrogen. Stirring was initiated at 190 °C, and the internal temperature was raised to 250 °C over 3 hours. At this time, the internal pressure of the autoclave was increased to 3.02 MPa. After the reaction was continued for 1 hour, the low-order condensation product was discharged into the atmosphere through a spray nozzle installed at the bottom of the autoclave and extracted. The low-order condensation product was then cooled to room temperature, pulverized in a pulverizer to a particle size of 1.5 mm or less, and dried at 110 °C for 24 hours. The resulting low-order condensate had a water content of 3000 ppm and an intrinsic viscosity [η] of 0.14 dl / g. Next, this low-order condensate was melt-polymerized in a twin-screw extruder with a screw diameter of 30 mm and L / D=36 at a barrel setting temperature of 330°C, a screw rotation speed of 200 rpm, and a resin feed rate of 6 kg / h to obtain a polyamide resin (PA-3).

[0135] The resulting polyamide resin (PA-3) had the following composition: Among the dicarboxylic acid-derived units, the content of terephthalic acid-derived units was 30 mol %, the content of isophthalic acid-derived units was 70 mol %, and the content of 1,6-hexanediamine-derived units among the diamine-derived units was 100 mol %. The intrinsic viscosity [η] of the polyamide resin (PA-3) was 0.65 dL / g, no melting point (Tm) was observed, the glass transition temperature (Tg) was 125°C, and the heat of fusion (ΔH) was 0 J / g.

[0136] Table 1 shows the compositions and physical properties of the polyamide resins (PA-1) to (PA-3).

[0137] [Table 1]

[0138] The intrinsic viscosity [η], melting point (Tm), glass transition temperature (Tg) and heat of fusion (ΔH) of the polyamide resin were measured by the following methods.

[0139] [Intrinsic viscosity [η]] According to JIS K6810-1977, 0.5 g of polyamide resin was dissolved in 50 ml of 96.5% sulfuric acid solution to prepare a sample solution. The flow time of the obtained sample solution was measured using an Ubbelohde viscometer at 25±0.05°C. The measurement results were applied to the following formula to calculate the intrinsic viscosity [η] of the polyamide resin. [η]=ηSP / [C(1+0.205ηSP)] ηSP=(t-t0) / t0 [η]: Intrinsic viscosity (dl / g) ηSP: Specific viscosity C: Sample concentration (g / dl) t: Number of seconds for sample solution to flow down (seconds) t0: Number of seconds the blank sulfuric acid flows (seconds)

[0140] [Melting point (Tm), glass transition temperature (Tg), heat of fusion (ΔH)] The melting point (Tm), glass transition temperature (Tg), and heat of fusion (ΔH) of the polyamide resin were measured using a differential scanning calorimeter (DSC220C, manufactured by Seiko Instruments Inc.). Specifically, approximately 5 mg of polyamide resin was sealed in a measurement aluminum pan and placed in the differential scanning calorimeter. The polyamide resin was then heated from room temperature to 350°C at 10°C / min. To completely melt the resin, it was held at 360°C for 3 minutes and then cooled to 30°C at 10°C / min. After leaving the sample at 30°C for 5 minutes, it was heated a second time to 360°C at 10°C / min. The temperature (°C) of the endothermic peak during this second heating was taken as the melting point (Tm) of the polyamide resin, and the inflection point corresponding to the glass transition was taken as the glass transition temperature (Tg). The heat of fusion ΔH was calculated from the area of ​​the exothermic peak of crystallization during the first heating process in accordance with JIS K7122.

[0141] (2) Talc Talc: average particle size 6 μm

[0142] (3) Fibrous inorganic filler Glass fiber: Nippon Electric Glass Co., Ltd. ECS03T-251H (glass fiber with an average fiber diameter of 10.5 μm)

[0143] (4) Lubricant Calcium montanate

[0144] 3. Fabrication and evaluation of metal / resin composite structures [Examples 1 to 5 and Comparative Examples 1 to 7] (Preparation of Pellets of Polyamide Resin Composition) The polyamide resin, talc (B), glass fiber (D), and lubricant (E) shown in Table 2 were kneaded in the proportions shown in Table 2 in a 30 mmφ vented twin-screw extruder with a barrel temperature set to 335°C, and pelletized in a pelletizer to obtain pellets of the composition.

[0145] (injection molding) Next, a small dumbbell metal insert mold was attached to an injection molding machine J55AD manufactured by Japan Steel Works, Ltd. Next, the mold was heated to 160°C, and then a surface-treated metal member shown in Table 2 was placed in the mold.

[0146] The pellets of the polyamide resin composition prepared above were dried for 24 hours under conditions of 110°C and 10 Torr (1330 Pa), and then placed in the hopper of the injection unit of the injection molding machine. Then, injection molding was carried out under conditions of a cylinder temperature of 335°C, a mold temperature of 150°C, an injection speed of 40 mm / sec, a holding pressure of 90 MPa, and an injection holding pressure time of 8 seconds, thereby obtaining a metal / resin composite structure.

[0147] The bonding strength and fluidity of the obtained metal / resin bonded bodies were evaluated by the following methods.

[0148] (Joining strength) Using a tensile testing machine Model 1323 (manufactured by Aiko Engineering Co., Ltd.), a dedicated jig was attached to the tensile testing machine, and the breaking load (N) of the metal / resin composite structure was measured at room temperature (23°C) under the conditions of a chuck distance of 60 mm and a tensile speed of 10 mm / min. The breaking load (N) was then divided by the area of ​​the metal / resin bonded portion to calculate the bond strength (tensile shear strength) (MPa).

[0149] (Flow length test (injection flowability)) A bar flow mold with a width of 10 mm and a thickness of 0.5 mm was used, and injection was carried out under the following conditions, and the flow length (mm) of the resin inside the mold was measured. Injection molding machine: Sodick Plastec Co., Ltd., Tupearl TR40S3A Injection pressure setting: 2000 kg / cm 2 Cylinder set temperature: 335℃ Mold temperature: 150℃

[0150] Table 2 shows the evaluation results of Examples 1 to 5 and Comparative Examples 1 to 7.

[0151] [Table 2]

[0152] As shown in Table 2, the metal / resin composite structures of Examples 1 to 5, which contain polyamide resin (A) and a predetermined amount of talc (B), have high bonding strength. Furthermore, the polyamide resin compositions of Examples 1 to 5 also have good fluidity during injection molding.

[0153] In particular, it is clear that the bonding strength of the metal / resin composite structure is further increased by further including polyamide resin (C) (comparison between Examples 1 and 3).

[0154] In contrast, the metal / resin composite structures of Comparative Examples 1, 2 and 6, which did not contain polyamide resin (A), and the metal / resin composite structures of Comparative Examples 3 and 4, which did not contain talc, all showed low bonding strength. [Industrial Applicability]

[0155] According to the present invention, it is possible to provide a metal / resin composite structure in which a resin member made of a polyamide resin composition is firmly joined and fixed to a metal member, a method for producing the same, and an engine mount member. [Explanation of symbols]

[0156] 100 Metal / resin composite structure 110 Metallic parts 111 Surface (joint surface) 120 Resin parts

Claims

1. A polyamide resin composition for metal-resin bonding, which is bonded to a surface having an uneven structure of a metal member having an uneven structure on the surface, the concave-convex structure has a plurality of convex portions, and the center-to-center distance of the plurality of convex portions is 5 nm to 500 μm; The polyamide resin composition for metal-resin bonding comprises: A composition comprising a polyamide resin (A), talc (B), and a polyamide resin (C), The polyamide resin (A) contains a component unit (a1) derived from a dicarboxylic acid and a component unit (a2) derived from a diamine, The dicarboxylic acid-derived component unit (a1) includes a terephthalic acid-derived component unit, The diamine-derived component unit (a2) comprises a component unit derived from a linear aliphatic diamine having 4 to 15 carbon atoms, a component unit derived from a branched aliphatic diamine having 4 to 18 carbon atoms, and Including, the content of the talc (B) is 0.1 to 5% by mass relative to the polyamide resin composition, The heat of fusion (ΔH) of the polyamide resin (C) measured by a differential scanning calorimeter is lower than that of the polyamide resin (A). Polyamide resin composition for metal-resin bonding.

2. The branched aliphatic diamine-derived component units include at least one of 2-methyl-1,8-octanediamine-derived component units and 2-methyl-1,5-pentanediamine-derived component units. The polyamide resin composition for metal-resin bonding according to claim 1 .

3. The component units derived from the linear aliphatic diamine include component units derived from 1,6-hexanediamine, The branched aliphatic diamine-derived component units include 2-methyl-1,5-pentanediamine-derived component units. The polyamide resin composition for metal-resin bonding according to claim 1 or 2.

4. The heat of fusion (ΔH) of the polyamide resin (C) is 0 to 5 J / g. The polyamide resin composition for metal-resin bonding according to any one of claims 1 to 3.

5. The polyamide resin (C) comprises a component unit (c1) derived from a dicarboxylic acid and a component unit (c2) derived from a diamine, The dicarboxylic acid-derived component unit (c1) includes an isophthalic acid-derived component unit, The diamine-derived component unit (c2) includes a component unit derived from an aliphatic diamine having 4 to 15 carbon atoms. The polyamide resin composition for metal-resin bonding according to any one of claims 1 to 4.

6. The dicarboxylic acid-derived component unit (c1) may further include a terephthalic acid-derived component unit, the molar ratio of the component units derived from isophthalic acid to the component units derived from terephthalic acid is such that the component units derived from isophthalic acid / the component units derived from terephthalic acid is 60 / 40 to 100 / 0; The polyamide resin composition for metal-resin bonding according to claim 5 .

7. The content of the polyamide resin (C) is 1 to 40 mass% based on the total of the polyamide resin (C) and the polyamide resin (A). The polyamide resin composition for metal-resin bonding according to any one of claims 1 to 6.

8. The polyamide resin composition further contains a fibrous inorganic filler. The polyamide resin composition for metal-resin bonding according to any one of claims 1 to 7.

9. The content of the fibrous inorganic filler is more than 0 mass% and 75 mass% or less relative to the polyamide resin composition. The polyamide resin composition for metal-resin bonding according to claim 8.

10. The metal member comprises one or more selected from iron, high-tensile steel, stainless steel, aluminum, aluminum alloy, magnesium, magnesium alloy, copper, copper alloy, titanium, and titanium alloy. The polyamide resin composition for metal-resin bonding according to any one of claims 1 to 9.

11. The content of the talc (B) is 0.1 to 0.35 mass% of the polyamide resin composition for metal-resin bonding. The polyamide resin composition for metal-resin bonding according to any one of claims 1 to 10.

12. The average particle size of the talc (B) is 1 to 15 μm. The polyamide resin composition for metal-resin bonding according to any one of claims 1 to 11.

13. The average particle size of the talc (B) is 6 to 15 μm. The polyamide resin composition for metal-resin bonding according to any one of claims 1 to 11.

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