Polyamide resin composition and metal resin conjugate

Abstract

To provide a polyamide resin composition which is a polyamide resin composition for joining to metal members, can heighten air tightness between a metal member and a resin member and releasability from a mold, and a metal resin conjugate using the same.SOLUTION: A polyamide resin composition for joining to metal members comprises two different types of semi-aromatic polyamide resins (A1) and (A2), where both of the semi-aromatic polyamide resins (A1) and (A2) comprise a repeating unit represented by the following formula (1), a repeating unit containing component units derived from a dicarboxylic acid, and component units derived from a diamine. The component units derived from the diamine in the semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2) have the same number of carbon atoms but differ in structure, and the mass ratio ((A1) / ((A1)+(A2))) is 0.40 or higher and 0.60 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyamide resin composition and a metal-resin bonded body. [Background technology]

[0002] Polyamide resin compositions have been known as molding materials. Polyamide resin compositions are widely used as materials for various parts, such as automobile parts and electric / electronic parts, and are known to produce molded articles with excellent mechanical strength.

[0003] The polyamide resin composition can be used to form a metal-resin joined body in which a resin member molded from the polyamide resin composition is joined to a metal member. When the polyamide resin composition is used for metal-resin joining, it is required to firmly join the resin member and the metal member.

[0004] For example, Patent Document 1 discloses a metal resin composite having a metal member having an uneven surface and a resin member bonded to the uneven surface of the metal member, wherein the resin member is made of a polyamide resin composition for metal bonding containing a polyamide resin, a reinforcing filler, and a specific amount of talc. Patent Document 1 states that the metal resin composite has an increased bonding strength between the metal member and the resin member. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-177867 Summary of the Invention [Problem to be solved by the invention]

[0006] Depending on the application of the joined body of a polyamide resin composition and a metal member, airtightness between the polyamide resin composition and the metal member is required. For example, when the joined body is used as a conductive part such as a bus bar for electrically connecting a motor placed in a motor case filled with cooling oil to an inverter placed outside the motor case, high airtightness is required to prevent oil leakage outside the motor case.

[0007] However, according to the investigations of the present inventors, the polyamide resin composition used in Patent Document 1 was unable to sufficiently improve the airtightness between the metal member and the resin member.

[0008] Furthermore, the metal-resin bonded body can be produced by insert molding, in which a polyamide resin composition is injection-molded in a state in which a metal member is placed in a mold. From the viewpoint of facilitating the removal of the produced metal-resin bonded body from the mold, it is desirable to use a polyamide resin composition with improved mold releasability.

[0009] An object of the present invention is to provide a polyamide resin composition for bonding to a metal member, which can improve the airtightness between the metal member and the resin member and the releasability from a mold, and a metal-resin bonded body using the polyamide resin composition. [Means for solving the problem]

[0010] In order to solve the above problems, one aspect of the present invention relates to the following polyamide resin compositions for insert molding [1] to [6]. [1] A polyamide resin composition for bonding to a metal member, A semi-aromatic polyamide resin (A1) having a melting point of 280°C or higher as measured by a differential scanning calorimeter (DSC); and a semi-aromatic polyamide resin (A2) having a melting point of 280°C or higher as measured by a differential scanning calorimeter (DSC), The semi-aromatic polyamide resin (A1) comprises a repeating unit (A1-1) represented by the following formula (1) and a repeating unit (A1-2) including a component unit (x1) derived from a dicarboxylic acid and a component unit (y1) derived from a diamine: The semi-aromatic polyamide resin (A2) comprises a repeating unit (A2-1) represented by the following formula (1) and a repeating unit (A2-2) comprising a component unit (x2) derived from a dicarboxylic acid and a component unit (y2) derived from a diamine, the repeating unit (A1-2) is the repeating unit contained in the semi-aromatic polyamide resin (A1) in the greatest amount among the repeating units excluding the repeating unit (A1-1), the repeating unit (A2-2) is the repeating unit contained in the semi-aromatic polyamide resin (A2) in the greatest amount among the repeating units excluding the repeating unit (A2-1), the diamine-derived component unit (y1) and the diamine-derived component unit (y2) have the same number of carbon atoms but different molecular structures, the ratio of the content of the semi-aromatic polyamide resin (A1) to the total mass of the semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2) is 0.40 or more and 0.60 or less; Polyamide resin composition. [ka] [2] The polyamide resin composition according to [1], wherein the semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2) each have a melting point measured by differential scanning calorimetry (DSC) of 290°C or higher and 340°C or lower. [3] The polyamide resin composition according to [1] or [2], further comprising a polyolefin resin (B). [4] The polyamide resin composition according to any one of [1] to [3], further comprising a reinforcing material whose content relative to the total mass of the polyamide resin composition is 45 mass % or less. [5] The diamine-derived component unit (y1) and the diamine-derived component unit (y2) are both component units derived from an aliphatic diamine having from 4 to 15 carbon atoms. The polyamide resin composition according to any one of [1] to [4]. [6] The diamine-derived unit (y1) is a 1,6-diaminohexane-derived unit, The diamine-derived component unit (y2) is a component unit derived from 2-methyl-1,5-diaminopentane. The polyamide resin composition according to any one of [1] to [4].

[0011] Another aspect of the present invention for solving the above problems relates to the metal-resin composite described below in [7]. [7] A metal member; and a resin member comprising the polyamide resin composition for insert molding according to any one of [1] to [6], which is composited with the metal member. metal resin composite [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a polyamide resin composition for bonding to a metal member, which can improve the airtightness between the metal member and the resin member and the mold releasability, and a metal-resin bonded body using the polyamide resin composition. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic diagram showing an exemplary embodiment of a metal-resin bonded body as a busbar unit. [Figure 2] FIG. 2 is a configuration diagram showing an exemplary configuration of a moving body (vehicle) having a busbar unit. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments.

[0015] 1. Polyamide resin composition The polyamide resin composition according to the present embodiment is a polyamide resin composition for bonding to metal members (hereinafter simply referred to as the "polyamide resin composition"), and comprises a semi-aromatic polyamide resin (A1) having a melting point of 280°C or higher as measured by a differential scanning calorimeter (DSC), and a semi-aromatic polyamide resin (A2) having a melting point of 280°C or higher as measured by a differential scanning calorimeter (DSC). The semi-aromatic polyamide resin (A1) comprises a repeating unit (A1-1) represented by the following formula (1) and a repeating unit (A1-2) comprising a component unit (x1) derived from a dicarboxylic acid and a component unit (y1) derived from a diamine. The semi-aromatic polyamide resin (A2) comprises a repeating unit (A2-1) represented by the following formula (1) and a repeating unit (A2-2) comprising a component unit (x2) derived from a dicarboxylic acid and a component unit (y2) derived from a diamine. The diamine-derived component unit (y1) and the diamine-derived component unit (y2) have the same number of carbon atoms but different molecular structures, and the ratio of the content of the semi-aromatic polyamide resin (A1) to the total mass of the semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2) is 0.40 or more and 0.60 or less. [ka]

[0016] The present inventors have found that by using the polyamide resin composition for joining metal members (metal-resin joining), it is possible to improve the airtightness and releasability between the metal member and the resin member.

[0017] The semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2) can form crystals in the polyamide resin composition during molding. When these semi-aromatic polyamide resins (A1) and (A2) contain repeating units with the same structure (repeating units represented by the above formula (1)), these semi-aromatic polyamide resins become more compatible with each other. Furthermore, when the diamine-derived component unit (y1) in the repeating unit (A1-2) contained in the semi-aromatic polyamide resin (A1) and the diamine-derived component unit (y2) in the repeating unit (A1-2) contained in the semi-aromatic polyamide resin (A2) have the same number of carbon atoms, these semi-aromatic polyamide resins become more compatible with each other. This allows the semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2) to exist in a state where their molecules are intertwined with each other. When these resins crystallize, the molecules change from a state in which they are intertwined to an arrangement of the crystalline portions of the individual molecules, which allows the crystallization rate of the polyamide resin composition to be significantly slower than when a single type of polyamide resin is used.

[0018] This allows the solidification rate of the polyamide resin composition to be sufficiently slowed down during metal-resin bonding, allowing the polyamide resin composition to fully penetrate into the minute concave portions of the surface of the metal member, thereby improving the adhesion between the metal member and the resin member in the produced metal-resin bonded body, and thereby improving the airtightness between them.

[0019] As a result of investigations by the present inventors, it was found that the above-mentioned effect is achieved when the ratio of the content of the semi-aromatic polyamide resin (A1) to the total mass of the semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2) is 0.4 or more and 0.6 or less.

[0020] Furthermore, the diamine-derived component unit (y1) in the repeating unit (A1-2) contained in the semi-aromatic polyamide resin (A1) and the diamine-derived component unit (y2) in the repeating unit (A2-2) contained in the semi-aromatic polyamide resin (A2) have different molecular structures, which prevents excessive compatibility between these semi-aromatic polyamide resins. If the semi-aromatic polyamide resins are too compatible with each other, it is thought that the alignment of the crystallization sites of the molecules becomes difficult, making it difficult for the resins to crystallize. Therefore, by preventing this excessive compatibility, the semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2) can be appropriately crystallized. This improves the mold releasability of the resin part from the mold.

[0021] Based on the above findings, the configuration of the polyamide resin composition according to the present embodiment will be described below.

[0022] 1-1. Semi-aromatic polyamide resin (A1) The semi-aromatic polyamide resin (A1) contains a repeating unit (A1-1) represented by the following formula (1) and a repeating unit (A1-2) different from the repeating unit (A1-1). The semi-aromatic polyamide resin (A1) may be a biomass-derived polyamide resin obtained by polymerizing raw materials including biomass-derived raw materials. When the polyamide resin composition contains three or more semi-aromatic polyamide resins, the semi-aromatic polyamide resin that maximizes the value obtained by multiplying the difference between the melting point (Tm) and the crystallization temperature (Tc) of the semi-aromatic polyamide resin by the mass fraction (w) of the semi-aromatic polyamide resin relative to the total mass of the semi-aromatic polyamide resin is defined as the semi-aromatic polyamide resin (A1).

[0023] [ka]

[0024] <Repeating unit (A1-1)> As represented by the above formula (1), the repeating unit (A1-1) is a repeating unit composed of a component unit derived from terephthalic acid and a component unit derived from 1,6-diaminohexane.

[0025] The content of the repeating unit (A1-1) is preferably 20 mol% or more and 95 mol% or less, and more preferably 45 mol% or more and 90 mol% or less, based on the repeating units and the total number of moles of repeating units contained in the semi-aromatic polyamide resin (A1). A content of 20 mol% or more can increase the melting point of the semi-aromatic polyamide resin (A1) and improve its heat resistance. Furthermore, the crystallinity of the semi-aromatic polyamide resin can be improved and its mold releasability can be further enhanced. A content of 95 mol% or less can contain a sufficient amount of the repeating unit (A1-2) to adjust the compatibility with the semi-aromatic polyamide resin (A2), thereby improving the airtightness between a metal member and a resin member and the mold releasability of the resin member from a mold. The content of the repeating unit (A1-1) can be calculated from the charge ratio of the raw materials used in the synthesis of the semi-aromatic polyamide resin (A1) or determined using NMR.

[0026] 1 In the case of H-NMR measurement, for example, a nuclear magnetic resonance apparatus (ECX400 model manufactured by JEOL Ltd.) is used, the solvent is deuterated orthodichlorobenzene, the sample concentration is 20 mg / 0.6 mL, the measurement temperature is 120 °C, and the observation nucleus is 1 The conditions are H (400 MHz), sequence is single pulse, pulse width is 5.12 μsec (45° pulse), repetition time is 7.0 sec, and the number of accumulations is 500 or more. The reference chemical shift is set to 0 ppm for hydrogen in tetramethylsilane, but similar results can also be obtained by setting the peak derived from residual hydrogen in deuterated orthodichlorobenzene at 7.10 ppm as the reference value for the chemical shift. 1 Peaks such as H can be assigned by conventional methods.

[0027] 13In the case of C-NMR measurement, for example, a nuclear magnetic resonance spectrometer (ECP500 model manufactured by JEOL Ltd.) is used as the measurement device, a mixed solvent of ortho-dichlorobenzene / heavy benzene (80 / 20% by volume) is used as the solvent, the measurement temperature is 120°C, and the observation nucleus is 13 The conditions were: C (125 MHz), single pulse proton decoupling, 45° pulse, repetition time 5.5 seconds, accumulation number 10,000 or more, and chemical shift reference value 27.50 ppm. Assignment of various signals was performed based on the standard method, and quantification could be performed based on the accumulated value of signal intensity.

[0028] In addition, in the repeating units, the component units derived from terephthalic acid may include component units derived from biomass-derived terephthalic acid, and the component units derived from 1,6-diaminohexane may include component units derived from biomass-derived 1,6-diaminohexane.

[0029] <Repeating unit (A1-2)> The repeating unit (A1-2) contained in the semi-aromatic polyamide resin (A1) contains a component unit (x1) derived from a dicarboxylic acid and a component unit (y1) derived from a diamine. The repeating unit (A1-2) is the repeating unit contained in the semi-aromatic polyamide resin (A1) in the greatest amount, excluding the repeating unit (A1-1).

[0030] (Dicarboxylic acid-derived component unit (x1)) Examples of dicarboxylic acids include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, etc. Among these, the dicarboxylic acids are preferably aromatic dicarboxylic acids and aliphatic dicarboxylic acids, and more preferably aromatic dicarboxylic acids.

[0031] Examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, etc. Among these, terephthalic acid and isophthalic acid are preferred as aromatic dicarboxylic acids.

[0032] Examples of aliphatic dicarboxylic acids include aliphatic dicarboxylic acids having 4 to 20 carbon atoms. The number of carbon atoms is preferably 6 to 12. Examples of such aliphatic dicarboxylic acids include adipic acid, azelaic acid, and sebacic acid. Among these, adipic acid and sebacic acid are preferred, and adipic acid is more preferred.

[0033] Examples of alicyclic dicarboxylic acids include cyclohexanedicarboxylic acid and its esters.

[0034] (Diamine-derived component unit (y1)) Examples of diamines include aliphatic diamines having 4 to 15 carbon atoms, alicyclic diamines having 4 to 20 carbon atoms, and aromatic diamines. Of these, the diamine is preferably an aliphatic diamine having 4 to 15 carbon atoms.

[0035] The number of carbon atoms in the aliphatic diamine is preferably 4 or more and 12 or less, and more preferably 6 or more and 12 or less. Examples of the aliphatic diamine include linear alkylenediamines and branched alkylenediamines.

[0036] Examples of the linear alkylenediamine include 1,4-diaminobutane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, and 1,12-diaminododecane. Among these, 1,6-diaminohexane, 1,9-nonanediamine, and 1,10-diaminodecane are preferred, and 1,6-diaminohexane is more preferred. The linear alkylenediamine may be contained alone or in combination of two or more.

[0037] Examples of the branched alkylenediamine include 2-methyl-1,3-diaminopropane, 2,2-dimethyldiaminopropane, 1,1-dimethyl-1,4-diaminobutane, 1-ethyl-1,4-diaminobutane, 1,2-dimethyl-1,4-diaminobutane, 1,3-dimethyl-1,4-diaminobutane, 1,4-dimethyl-1,4-diaminobutane, 2,3-dimethyl-1,4-diaminobutane, 2-methyl-1,5-diaminopentane, 2,5-dimethyl-1, 6-Diaminohexane, 2,4-dimethyl-1,6-diaminohexane, 3,3-dimethyl-1,6-diaminohexane, 2,2-dimethyl-1,6-diaminohexane, 2,2,4-trimethyl-1,6-diaminohexane, 2,4,4-trimethyl-1,6-diaminohexane, 2,4-diethyl-1,6-diaminohexane, 2,3-dimethyl-1,7-diaminoheptane, 2,4-dimethyl-1,7-diaminoheptane, 2,5-dimethyl-1,7-diamino Heptane, 2,2-dimethyl-1,7-diaminoheptane, 2-methyl-4-ethyl-1,7-diaminoheptane, 2-ethyl-4-methyl-1,7-diaminoheptane, 2,2,5,5-tetramethyl-1,7-diaminoheptane, 3-isopropyl-1,7-diaminoheptane, 3-isooctyl-1,7-diaminoheptane, 2-methyl-1,8-diaminooctane, 1,3-dimethyl-1,8-diaminooctane, 1,4-dimethyl-1,8-diaminooctane 2,4-dimethyl-1,8-diaminooctane, 3,4-dimethyl-1,8-diaminooctane, 4,5-dimethyl-1,8-diaminooctane, 2,2-dimethyl-1,8-diaminooctane, 3,3-dimethyl-1,8-diaminooctane, 4,4-dimethyl-1,8-diaminooctane, 3,3,5-trimethyl-1,8-diaminooctane, 2,4-diethyl-1,8-diaminooctane, and 5-methyl-1,9-diaminononane. Among these, 2-methyl-1,5-diaminopentane and 2-methyl-1,8-diaminooctane are preferred, and 2-methyl-1,5-diaminopentane is more preferred.

[0038] Examples of the alicyclic diamine having 4 to 20 carbon atoms include 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 1,3-bis(aminomethyl)cyclohexane, 2,5-bisaminomethylnorbornane, and 2,6-bisaminomethylnorbornane. Examples of the aromatic diamine include metaxylylenediamine.

[0039] The content of the repeating unit (A1-2) in the semi-aromatic polyamide resin (A1) is preferably 5 mol% or more and 80 mol% or less, and more preferably 10 mol% or more and 55 mol% or less, based on the total number of moles of the repeating unit (A1-1) and the repeating unit (A1-2). A content of 5 mol% or more sufficiently enhances the compatibility between the semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2), thereby further improving the airtightness between the resin member and the metal member. A content of 80 mol% or less ensures that the repeating unit (A1-1) is sufficiently contained. The content of the repeating unit (A1-2) can be calculated from the charging ratio of the raw materials used in the synthesis of the semi-aromatic polyamide resin (A1) or determined using NMR.

[0040] The dicarboxylic acid-derived component unit (x1) of the repeating unit (A1-2) may include a biomass-derived dicarboxylic acid-derived component unit, and the diamine-derived component unit (y1) may include a biomass-derived diamine-derived component unit.

[0041] <Other> The semi-aromatic polyamide resin (A1) may contain a repeating unit (A1-3) different from the repeating units (A1-1) and (A1-2). The type of the repeating unit (A1-3) is not particularly limited, and it may be, for example, a repeating unit containing a component unit derived from a dicarboxylic acid and a component unit derived from a diamine.

[0042] Examples of the types of component units derived from the dicarboxylic acid and the diamine can be the same as those described above for the repeating units.

[0043] The content of the third repeating unit (A1-3) is preferably 0 mol % or more and 5 mol % or less, more preferably 0 mol % or more and 1 mol % or less, and even more preferably 0 mol % or more and 0.1 mol % or less, based on the total number of moles of the repeating unit (A1-1) and the repeating unit (A1-2).

[0044] The semi-aromatic polyamide resin (A1) can be produced by the same method as that for known polyamide resins, for example, by polycondensing a dicarboxylic acid and a diamine in a homogeneous solution. Specifically, as described in WO 03 / 085029, the semi-aromatic polyamide resin (A1) can be produced by heating a dicarboxylic acid and a diamine in the presence of a catalyst to obtain a low-order condensate, and then applying shear stress to a melt of the low-order condensate to polycondense it.

[0045] 1-2. Semi-aromatic polyamide resin (A2) The semi-aromatic polyamide resin (A2) contains a repeating unit (A2-1) represented by the following formula (1) and a repeating unit (A2-2) different from the repeating unit (A2-1). The semi-aromatic polyamide resin (A2) may be a biomass-derived polyamide resin obtained by polymerizing raw materials including biomass-derived raw materials.

[0046] [ka]

[0047] <Repeating unit (A2-1)> The repeating unit (A2-1) is a repeating unit composed of a component unit derived from terephthalic acid and a component unit derived from 1,6-diaminohexane, as represented by the above formula (1). Note that, in the repeating unit, the component unit derived from terephthalic acid may include a component unit derived from biomass-derived terephthalic acid, and the component unit derived from 1,6-diaminohexane may include a component unit derived from biomass-derived 1,6-diaminohexane.

[0048] The content of the repeating unit (A2-1) can be the same as that described for the semi-aromatic polyamide resin (A1).

[0049] The content of the repeating unit (A2-1) can be measured by the same method as described for the semi-aromatic polyamide resin (A1).

[0050] <Repeating unit (A2-2)> The repeating unit (A2-2) contained in the semi-aromatic polyamide resin (A2) contains a component unit (x2) derived from a dicarboxylic acid and a component unit (y2) derived from a diamine. The repeating unit (A2-2) is the repeating unit contained in the semi-aromatic polyamide resin (A2) in the greatest amount, excluding the repeating unit (A2-1).

[0051] (Dicarboxylic acid-derived component unit (x2)) The type of dicarboxylic acid-derived component unit (x2) can be the same as that described for the dicarboxylic acid-derived component unit (x1) of the semi-aromatic polyamide resin (A1). The dicarboxylic acid-derived component unit (x1) and the dicarboxylic acid-derived component unit (x2) may be the same or different, but are preferably different. Furthermore, the dicarboxylic acid-derived component unit (x1) and the dicarboxylic acid-derived component unit (x2) are preferably derived from dicarboxylic acids having the same number of carbon atoms but different structures, more preferably from aromatic dicarboxylic acids having the same number of carbon atoms but different structures, with one derived from terephthalic acid and the other derived from isophthalic acid being particularly preferred. This can further suppress excessive compatibility between the semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2). As a result, the semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2) can be more appropriately crystallized, thereby improving the mold releasability of the resin part from a mold.

[0052] (Diamine-derived component unit (y2)) The type of diamine-derived component unit (y2) can be the same as that described for the diamine-derived component unit (y1) of the semi-aromatic polyamide resin (A2), except that the diamine-derived component unit (y1) contained in the repeating unit (A1-2) of the semi-aromatic polyamide resin (A1) and the diamine-derived component unit (y2) contained in the repeating unit (A2-2) of the semi-aromatic polyamide resin (A2) have the same number of carbon atoms but different molecular structures.

[0053] In this specification, "having different molecular structures" refers to a case where one has a linear structure and the other has a branched chain structure, a case where both have branched chain structures but the positions of the branched chains in the molecular structures are different, or a case where one has a cyclic structure and the other does not have a cyclic structure.

[0054] The diamine-derived component unit (y1) and the diamine-derived component unit (y2) are both preferably component units derived from aliphatic diamines having from 4 to 15 carbon atoms. Examples of combinations of the diamine-derived component unit (y1) and the diamine-derived component unit (y2) include 1,4-diaminobutane and 2-methyl-1,3-dimethylpropane, 1,6-diaminohexane and 2-methyl-1,5-diaminopentane, 1,9-nonanediamine and 2-methyl-1,8-diaminooctane, and 1,10-diaminodecane and 5-methyl-1,9-diaminononane. Of these, the combination of 1,6-diaminohexane and 2-methyl-1,5-diaminopentane is preferred.

[0055] The content of the repeating unit (A2-2) in the semi-aromatic polyamide resin (A2) can be the same as that in the semi-aromatic polyamide resin (A1).

[0056] The dicarboxylic acid-derived component unit (x2) of the repeating unit (A2-2) may include a biomass-derived dicarboxylic acid-derived component unit, and the diamine-derived component unit (y2) may include a biomass-derived diamine-derived component unit.

[0057] <Other> The semi-aromatic polyamide resin (A2) may contain a repeating unit (A2-3) different from the repeating units (A2-1) and (A2-2). The type and content of the repeating unit (A2-3) may be the same as those of the semi-aromatic polyamide resin (A1). However, when the semi-aromatic polyamide resin (A1) contains the repeating unit (A1-3), it is preferable that the diamine-derived component unit of the repeating unit (A1-3) and the diamine-derived component unit contained in the repeating unit (A2-3) of the semi-aromatic polyamide resin (A2) have the same number of carbon atoms but different molecular structures.

[0058] The semi-aromatic polyamide resin (A2) can be produced by the same method as that for known polyamide resins, for example, by polycondensing a dicarboxylic acid and a diamine in a homogeneous solution. Specifically, as described in WO 03 / 085029, the semi-aromatic polyamide resin (A2) can be produced by heating a dicarboxylic acid and a diamine in the presence of a catalyst to obtain a low-order condensate, and then applying shear stress to a melt of the low-order condensate to polycondense it.

[0059] 1-3. Physical properties of semi-aromatic polyamide resin (A1) and semi-aromatic polyamide resin (A2) The melting points of the semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2) are preferably 290°C or higher and 340°C or lower, and more preferably 300°C or higher and 340°C or lower. A melting point of 290°C or higher can further increase the crystallinity of the polyamide resin and further improve the mold releasability. Furthermore, a melting point of 340°C or lower can be molded without increasing the melting temperature during molding too much.

[0060] The melting points of the semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2) can be adjusted to the above range by adjusting the composition of these resins. For example, the melting point can be increased by increasing the content of component units derived from terephthalic acid.

[0061] Furthermore, the semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2) preferably have a glass transition temperature (Tg) measured by differential scanning calorimetry (DSC) of 70°C or higher and 145°C or lower, more preferably 75°C or higher and 125°C or lower, and even more preferably 80°C or higher and 100°C or lower. A glass transition temperature (Tg) of 70°C or higher increases the temperature at which molecular mobility becomes active in high-temperature environments, thereby suppressing molecular mobility and further improving the heat resistance of the polyamide resin composition and molded article. A glass transition temperature (Tg) of 145°C or lower makes it easier to maintain the fluidity of the resin composition without excessively increasing the mold temperature during molding, thereby improving molding processability.

[0062] The heat of fusion (ΔH) of the semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2) measured by differential scanning calorimetry (DSC) is preferably greater than 5 J / g. The heat of fusion is an indicator of the crystallinity of a resin, and a larger heat of fusion indicates higher crystallinity. When the heat of fusion (ΔH) of the polyamide resin (A) exceeds 5 J / g, the crystallinity is increased, thereby enabling the mechanical strength (such as bending strength) of the resulting molded article to be increased.

[0063] The melting points and heats of fusion (ΔH) of the semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2) can be measured using a differential scanning calorimeter (DSC220C model, manufactured by Seiko Instruments Inc.).

[0064] Specifically, approximately 5 mg of the semi-aromatic polyamide resin to be measured is sealed in a measurement 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 350°C at 10°C / min. The endothermic peak temperatures (°C) during this second heating are taken as the melting points (Tm) of the semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2), and the inflection point corresponding to the glass transition is taken as the glass transition temperature (Tg). The heat of fusion (ΔH) is calculated from the area of the endothermic peak during the first heating process, in accordance with JIS K7122.

[0065] The semi-aromatic polyamide resins (A1) and (A2) preferably have an intrinsic viscosity [η] of 0.9 dL / g to 1.2 dL / g, more preferably 1.0 dL / g to 1.2 dL / g, and particularly preferably 1.0 dL / g to 1.1 dL / g, as measured in 96.5% sulfuric acid at 25°C. When the semi-aromatic polyamide resin (A) has an intrinsic viscosity [η] of 0.9 dL / g or higher, the mechanical strength (e.g., bending strength) of the molded product is easily increased. When the intrinsic viscosity [η] is 1.2 dL / g or lower, the fluidity of the resin composition during molding is less likely to be impaired. The intrinsic viscosity [η] can be adjusted by adjusting the molar ratio of the dicarboxylic acid-derived component units and the diamine-derived component units in each semi-aromatic polyamide resin. Specifically, the closer the molar ratio of the carboxylic acid-derived component units (Aa) to the diamine-derived component units is to 1:1, the higher the intrinsic viscosity can be. It can also be adjusted by the amount of end-capping of the semi-aromatic polyamide resin.

[0066] The intrinsic viscosity [η] of the semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2) can be measured as follows. 0.5 g of the semi-aromatic polyamide resin to be measured is dissolved in 50 ml of 96.5% sulfuric acid solution to prepare a sample solution. The flow time of the obtained solution at 25°C ± 0.05°C is measured using an Ubbelohde viscometer, and calculated based on the following formula: [η]=ηSP / (C*(1+0.205ηSP)) [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) ηSP=(t-t0) / t0

[0067] Examples of the combination of the semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2) include polyamide 6T6I and polyamide 6TDT, polyamide 6T66 and polyamide 6TDT, and the like.

[0068] The ratio of the content of the semi-aromatic polyamide resin (A1) to the total mass of the semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2) is 0.40 or more and 0.60 or less, preferably 0.45 or more and 0.55 or less.

[0069] The total mass of the semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2) is preferably 30% by mass or more and 70% by mass or less, and more preferably 40% by mass or more and 60% by mass or less, based on the total mass of the polyamide resin composition. When the content is 30% by mass or more, the mechanical strength (such as tensile strength) of the polyamide resin composition can be further increased. When the content is 70% by mass or less, the polyamide resin composition can sufficiently contain other components, as described below.

[0070] 1-4. Polyolefin resin (B) In the present embodiment, the polyamide resin composition may further contain a polyolefin resin (B). When the polyamide resin composition contains the polyolefin resin (B), the crystallization rate of the polyamide resin composition is reduced and flexibility is imparted to the resin part after molding.

[0071] Examples of polyolefin resins include ethylene polymers, propylene polymers, butene polymers, and copolymers of these olefins (e.g., ethylene-α-olefin copolymers), etc. Among these, ethylene polymers are preferred.

[0072] Examples of the α-olefin other than ethylene in the ethylene-α-olefin copolymer include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, etc. Among these, propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene are preferred.

[0073] The polyolefin resin preferably includes a modified polyolefin resin. Specifically, the polyolefin resin preferably includes a modified polyolefin resin having a polyolefin unit and a functional group structural unit. The modified polyolefin resin can be obtained by modifying a polyolefin resin before modification with a compound containing a functional group structural unit.

[0074] Examples of the functional group structural unit include functional groups containing heteroatoms. Examples of functional groups containing heteroatoms include carboxylic acid groups (including carboxylic acid anhydride groups), ester groups, ether groups, aldehyde groups, and ketone groups. Among these, carboxylic acid groups (including carboxylic acid anhydride groups) are preferred. That is, the modified polyolefin resin is preferably modified with an unsaturated carboxylic acid or its derivatives.

[0075] Examples of compounds containing a carboxylic acid group include α,β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, and phthalic acid. Examples of compounds containing a carboxylic acid anhydride group include dicarboxylic acid anhydrides having an α,β-unsaturated bond such as maleic anhydride, itaconic anhydride, and phthalic anhydride. Of these, maleic anhydride is preferred.

[0076] The content of the functional group structural unit (modification amount) of the modified polyolefin resin is preferably 0.1% by mass or more and 5.0% by mass or less, more preferably 0.2% by mass or more and 3.0% by mass or less, and even more preferably 0.5% by mass or more and 1.5% by mass or less. When the content of the functional group structural unit is within the above range, the impact resistance and elongation of the resin composition tend to be improved.

[0077] The content (modification amount) of the functional group structural unit of the modified polyolefin resin can be calculated from the charge ratio when preparing the modified polyolefin resin, or can be measured by the NMR method. For the NMR method, the same method as described for the polyamide resin (A) can be used.

[0078] The modified polyolefin resin is obtained by graft-modifying an unmodified polyolefin resin with a compound containing a functional group structural unit.

[0079] Graft modification can be carried out by various conventionally known methods. For example, it may be carried out by a melt modification method in which the polyolefin resin before modification is melted using an extruder and a graft monomer is added to carry out graft copolymerization, or it may be carried out by a solution modification method in which the polyolefin resin before modification is dissolved in a solvent and a graft monomer is added to carry out graft copolymerization. In either case, it is preferable to carry out the reaction in the presence of a radical initiator in order to efficiently graft copolymerize the graft monomer.

[0080] The content of the polyolefin resin is preferably 2% by mass or more and 10% by mass or less, more preferably 3% by mass or more and 8% by mass or less, and even more preferably 3% by mass or more and 6% by mass or less, relative to the total mass of the polyamide resin composition.

[0081] 1-5.Other ingredients The polyamide resin composition may contain other known components.

[0082] Examples of other components include reinforcing materials, nucleating agents, lubricants, flame retardants, flame retardant aids, styrene-based thermoplastic elastomers, anti-drip agents, halogen scavengers, colorants, heat stabilizers, corrosion resistance improvers, anti-drip agents, ion scavengers, elastomers (rubbers), antistatic agents, mold release agents, antioxidants (phenols, amines, sulfurs, phosphorus compounds, etc.), heat stabilizers other than those mentioned above (lactone compounds, vitamin E compounds, hydroquinones, etc.), light stabilizers (benzotriazoles, triazines, benzophenones, benzoates, hindered amines, oxanilides, etc.), and the like.

[0083] (nucleating agent) The nucleating agent can promote the crystallization of the semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2), thereby further increasing the tensile strength and elastic modulus of the molded article.

[0084] Examples of nucleating agents include metal salt compounds such as sodium 2,2-methylenebis(4,6-di-t-butylphenyl)phosphate, aluminum tris(pt-butylbenzoate), and stearates; sorbitol compounds such as bis(p-methylbenzylidene)sorbitol and bis(4-ethylbenzylidene)sorbitol; and inorganic substances such as talc, calcium carbonate, and hydrotalcite. Among these, talc is preferred from the viewpoint of further increasing the crystallinity of the resin member. These nucleating agents may be used alone or in combination.

[0085] Talc generally contains hydrous magnesium silicate (SiO2: 58-64%, MgO: 28-32%, Al2O3: 0.5-5%, Fe2O3: 0.3-5%) as its main component. The average particle size of the talc is not particularly limited, but is preferably 1-15 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 1-7.5 μm. The average particle size of the talc can be measured by a laser diffraction method, for example, using a Shimadzu particle size distribution analyzer (SALD-2000A) manufactured by Shimadzu Corporation.

[0086] The content of the nucleating agent is preferably 0.10% by mass or more and 5.00% by mass or less, and more preferably 0.10% by mass or more and 3.00% by mass or less, based on the total mass of the polyamide resin composition. When the content of the nucleating agent is within the above range, the crystallinity of the resin member is easily increased sufficiently, and sufficient mechanical strength is easily obtained.

[0087] (lubricant) The lubricant improves the injection flowability of the polyamide resin composition and improves the appearance of the resulting resin part. The lubricant can be a metal salt of a fatty acid, such as a metal salt of an oxycarboxylic acid or a metal salt of a higher fatty acid.

[0088] The hydroxycarboxylic acid constituting the hydroxycarboxylic acid metal salt may be an aliphatic hydroxycarboxylic acid or an aromatic hydroxycarboxylic acid. Examples of the aliphatic hydroxycarboxylic acid include aliphatic hydroxycarboxylic acids having 10 to 30 carbon atoms, such as α-hydroxymyristic acid, α-hydroxypalmitic acid, α-hydroxystearic acid, α-hydroxyeicosanoic acid, α-hydroxydocosanoic acid, α-hydroxytetraeicosanoic acid, α-hydroxyhexaeicosanoic acid, α-hydroxyoctaeicosanoic acid, α-hydroxytriacontanoic acid, β-hydroxymyristic acid, 10-hydroxydecanoic acid, 15-hydroxypentadecanoic acid, 16-hydroxyhexadecanoic acid, 12-hydroxystearic acid, and ricinoleic acid. Examples of the aromatic hydroxycarboxylic acid include salicylic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, gallic acid, mandelic acid, and trovic acid.

[0089] Examples of the metal constituting the metal oxycarboxylic acid salt include alkali metals such as lithium, and alkaline earth metals such as magnesium, calcium, and barium.

[0090] Of these, the metal oxycarboxylic acid salt is preferably a metal salt of 12-hydroxystearic acid, and more preferably magnesium 12-hydroxystearate and calcium 12-hydroxystearate.

[0091] Examples of the higher fatty acids that constitute the higher fatty acid metal salts include higher fatty acids having 15 to 30 carbon atoms, such as stearic acid, oleic acid, behenic acid, behenic acid, and montanic acid.

[0092] Examples of metals constituting the above higher fatty acid metal salts include calcium, magnesium, barium, lithium, aluminum, zinc, sodium, and potassium.

[0093] Of these, the higher fatty acid metal salts are preferably calcium stearate, magnesium stearate, barium stearate, calcium behenate, sodium montanate, and calcium montanate.

[0094] The content of the lubricant is preferably 0.01% by mass or more and 1.30% by mass or less relative to the total mass of the polyamide resin composition. When the content of the lubricant is 0.01% by mass or more, the fluidity during molding tends to be improved, and the appearance of the obtained molded product tends to be improved. When the content of the lubricant is 1.30% by mass or less, gas due to decomposition of the lubricant is unlikely to be generated during molding, and the appearance of the product tends to be good.

[0095] (Reinforcement material) The reinforcing material may be an inorganic filler. Examples of reinforcing materials include fibrous reinforcing materials such as glass fiber, wollastonite, potassium titanate whiskers, calcium carbonate whiskers, aluminum borate whiskers, magnesium sulfate whiskers, zinc oxide whiskers, milled fiber, and cut fiber, as well as granular reinforcing materials. One of these may be used alone, or two or more may be used in combination. Among these, wollastonite, glass fiber, and potassium titanate whiskers are preferred, as they can easily increase the mechanical strength of the resin member, and wollastonite and glass fiber are more preferred.

[0096] The average fiber length of the fibrous reinforcing material is preferably 1 μm or more and 20 mm or less, more preferably 5 μm or more and 10 mm or less, from the viewpoints of moldability of the polyamide resin composition and the mechanical strength and heat resistance of the resulting resin part.

[0097] The cross-sectional shape of the fibrous reinforcing material may be circular or non-circular, but is preferably circular from the viewpoint of increasing the tensile strength of the molded article. When the molded article has a thick portion, the fibers tend to be oriented in the thickness direction of the thick portion, so a circular shape can exert a stronger reinforcing effect (the effect of increasing the tensile strength of the molded article) against cracks that occur inside the thick portion. The above cross-sectional shape can be confirmed by observation with an optical microscope.

[0098] The average fiber length and average fiber diameter of the fibrous reinforcing material can be measured by the following method. 1) The polyamide resin composition is dissolved in a hexafluoroisopropanol / chloroform solution (0.1 / 0.9% by volume), and then filtered to obtain a filtrate. 2) Disperse the filtered material obtained in 1) above in water, and measure the fiber length (Li) and fiber diameter (di) of each of 300 randomly selected fibers using an optical microscope (magnification: 50x). The number of fibers with fiber length Li is taken as qi, and the weight-average length (Lw) is calculated using the following formula, which is the average fiber length of the fibrous reinforcement. Weight average length (Lw) = (Σqi × Li 2 ) / (Σqi×Li) Similarly, the number of fibers with 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 reinforcing material. Weight average diameter (Dw)=(Σri×Di 2 ) / (Σri×Di)

[0099] The content of the reinforcing material is preferably 45% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less, based on the total mass of the polyamide resin composition. A content of 45% by mass or less can increase the fluidity of the polyamide resin composition during molding, making it easier for the polyamide resin composition to penetrate into minute recesses on the surface of the metal member. This can further increase the airtightness between the resin member and the metal member in the metal-resin bonded body. The lower limit of the reinforcing material content is not particularly limited, but is, for example, 15% by mass.

[0100] (coloring agent) The colorant imparts a desired color tone to the molded article. The colorant is not particularly limited, but may be a pigment. Examples of the pigment include inorganic pigments such as carbon black, alumina, titanium oxide, chromium oxide, iron oxide, zinc oxide, and barium sulfate, and organic pigments such as azo pigments, phthalocyanine pigments, quinacridone pigments, perylene pigments, anthraquinone pigments, thioindigo pigments, and indanthrene pigments.

[0101] The content of the colorant is preferably 0.01% by mass or more and 5.00% by mass or less, and more preferably 0.10% by mass or more and 2.00% by mass or less, based on the total mass of the polyamide resin composition.

[0102] 1-6. Method for producing polyamide resin composition The polyamide resin composition can be produced by a known resin kneading method, such as mixing the semi-aromatic polyamide resin (A1), semi-aromatic polyamide resin (A2), and other components as necessary, using a Henschel mixer, V-blender, ribbon blender, or tumbler blender, or by mixing and then melt-kneading the mixture using a single-screw extruder, multi-screw extruder, kneader, or Banbury mixer, followed by granulation or pulverization. The melting temperature during melt-kneading is preferably at least 10°C above the melting point (Tm) of the semi-aromatic polyamide resin (A1) and semi-aromatic polyamide resin (A2) but not more than 20°C above the melting point (Tm).

[0103] 2.Metal-resin joint The metal-resin bonded body according to this embodiment includes a metal member and a resin member that contains the polyamide resin composition described above and is bonded to the surface of the metal member.

[0104] 2-1.Resin parts The resin member contains the polyamide resin composition described above. The proportion of the polyamide resin composition relative to the total mass of the resin member is preferably 50.00 mass% or more, more preferably 60.00 mass% or more, and even more preferably 70.00 mass% or more. The upper limit of the proportion of the polyamide resin composition relative to the total mass of the resin member is not particularly limited, but may be 100.00 mass% or less, or may be 90.00 mass% or less, or may be 80.00 mass% or less.

[0105] 2-2.Metallic parts The metal member may be made of any metal, and the material and shape thereof are not particularly limited. For example, the metal member may be made of iron, copper, nickel, gold, silver, platinum, cobalt, zinc, lead, tin, titanium, chromium, aluminum, magnesium, manganese, or an alloy such as stainless steel, brass, or phosphor bronze.

[0106] These materials can be selected depending on the application of the metal-resin bonded body. For example, when thermal conductivity is required, aluminum, aluminum alloys, magnesium, magnesium alloys, copper, and copper alloys are preferred, with copper and copper alloys being more preferred. Furthermore, when weight reduction and strength are required, aluminum, aluminum alloys, magnesium, and magnesium alloys are preferred.

[0107] The metal member preferably has a surface roughened by any method, as long as the surface is roughened by a chemical treatment such as immersion in a treatment solution containing a base or acid or etching, or by a physical treatment such as laser or blasting.

[0108] The surface of the roughened metal member preferably has a center-to-center distance (pitch) of 5 nm to 500 μm. When the center-to-center distance of the multiple protrusions is 5 nm or more, the recesses between the protrusions are appropriately large, allowing the resin member to easily penetrate into the recesses during bonding, thereby further improving the bonding strength between the metal member and the resin member. Furthermore, when the center-to-center distance of the multiple protrusions is 500 μm or less, the recesses are not too large, further preventing gaps from forming at the metal-resin interface of the metal-resin bonded body, thereby further improving airtightness. From the same perspective, the center-to-center distance of the multiple protrusions is more preferably 5 μm to 250 μm. The center-to-center distance of the multiple protrusions is the average value of the distances between the centers of one protrusion and its adjacent protrusion.

[0109] The center-to-center distance of the multiple convex portions can be measured by removing the resin member from the metal-resin bonded body by mechanical peeling, solvent washing, or the like, and observing the surface of the exposed metal member with an electron microscope or laser microscope, or by using a surface roughness measuring device.

[0110] Specifically, when the center-to-center distance between the multiple protrusions is less than 0.5 μm, they can be observed using an electron microscope, and when the center-to-center distance between the multiple protrusions is 0.5 μm or more, they can be observed using a laser microscope or surface roughness measuring device. For example, in a photograph of the surface of a metal part taken with an electron microscope or laser microscope, 50 random protrusions are selected and the center-to-center distance between each of these protrusions is measured. All of the measured center-to-center distances between the protrusions are then added up and divided by 50 (average) to determine the "center-to-center distance between the multiple protrusions."

[0111] The average value of the ten-point average roughness (Rz) of the roughened surface of the metal member 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.

[0112] The average value of the ten-point mean roughness (Rz) can be measured in accordance with JIS B0601 (ISO 4287). Specifically, the ten-point mean roughness (Rz) is measured on a total of six straight line sections, including three arbitrary parallel straight line sections and three arbitrary perpendicular straight line sections, and the average of these is taken as the average Rz value.

[0113] The mean length of the roughness curve element (RSm) of the roughened surface of the metal member is preferably 0.5 μm or more and 500 μm or less. In particular, from the viewpoint of further increasing the 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 μm or more and 500 μm or less. The mean length of the roughness curve element can also be measured according to JIS B0601 (ISO 4287) as described above.

[0114] 3.Method for manufacturing metal-resin bonded body A third embodiment of the present invention relates to a method for producing the above-mentioned metal-resin bonded body. The method for producing the metal-resin bonded body is not particularly limited, but may include, for example, the steps of (1) preparing a metal member, (2) placing the metal member in a mold and injecting a molten polyamide resin composition into the mold, and (3) cooling the polyamide resin composition. The step (1) of preparing a metal member may include a step of roughening the surface of the metal member.

[0115] 3-1.Preparing metal parts First, the above-described metal member is prepared. At this time, at least a part of the surface of the metal member may be roughened, or a metal member having an uneven structure on at least a part of the surface may be prepared.

[0116] The method for roughening the surface of a metal member is not particularly limited. For example, a method using laser processing, a method of immersing a metal member in an aqueous solution of an inorganic base such as NaOH or an aqueous solution of an inorganic acid such as HCl or HNO3, a method of treating a metal member by anodization, a substitution crystallization method of etching with an acid-based etching agent (preferably an acid-based etching agent aqueous solution containing an inorganic acid, ferric ions, cupric ions, and if necessary, manganese ions, aluminum chloride hexahydrate, sodium chloride, etc.), a method of immersing a metal member in an aqueous solution of hydrazine hydrate, ammonia, a water-soluble amine compound, etc., and a hot water treatment method can be used.

[0117] 3-2.Insert molding Next, a metal member is placed in a mold, and the molten polyamide resin composition is injected into the mold to fill the interior of the mold, thereby bonding the softened or molten polyamide resin composition to the prepared metal member.

[0118] Specifically, the prepared metal member is first placed in a cavity (space) within an injection mold. Then, the polyamide resin composition is injected and filled into the cavity of the mold so that at least a portion of the polyamide resin composition contacts the metal member. This allows the injected molten polyamide resin composition to come into contact with the surface of the metal member. The temperature of the injection mold at this time 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 can be, for example, 100 to 350°C.

[0119] 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.

[0120] 3-3. Cooling Thereafter, the polyamide resin composition in contact with the surface of the metal member is cooled and solidified, thereby obtaining a metal-resin bonded body in which a resin member containing the polyamide resin composition is bonded to the surface of the metal member.

[0121] 4.Applications The above-described metal-resin bonded body can be suitably used in various applications where a metal-resin bonded body is currently being used or where the application of a metal-resin bonded body is being considered.

[0122] Examples of such applications include vehicle structural parts, vehicle mounted items, housings for electronic devices, housings for home appliances, structural parts, machine parts, various automobile parts, electronic device parts, household goods applications such as furniture and kitchen utensils, medical equipment, building material parts, other structural parts, and exterior parts.

[0123] More specifically, examples of the above applications include, in the case of vehicles, instrument panels, console boxes, door handles, door trim, shift levers, pedals, glove boxes, bumpers, hoods, fenders, trunks, doors, roofs, pillars, seats, steering wheels, bus bars, terminals, motors, power conversion devices (inverters, converters), ECU boxes, electrical components, engine peripheral parts, drivetrain and gear peripheral parts, intake and exhaust system parts, and cooling system parts, etc. Precision electronic components also include connectors, relays, gears, etc.

[0124] Furthermore, the metal-resin bonded body can be used in various home appliances, such as refrigerators, washing machines, vacuum cleaners, microwave ovens, air conditioners, lighting equipment, electric water heaters, televisions, clocks, ventilation fans, projectors, speakers, and other home appliances, 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, by combining the high thermal conductivity of the copper member with the insulating properties of the resin member.

[0125] Other application examples include components for lithium-ion secondary batteries and robots.

[0126] For example, the metal-resin bonded body can be used in a bus bar unit of a mobile body (vehicle) such as an automobile.

[0127] 1 is a schematic diagram showing an exemplary embodiment of the metal-resin joined body as a busbar unit. The busbar unit 100 includes a busbar 110, which is a conductive metal member (e.g., a copper metal member) and serves as a conductor for supplying current to each member, and a holding member 120, which is the resin member described above and serves as a protective member for protecting the busbar 110.

[0128] Of the surfaces of busbar 110, which is a metal member, the surface that comes into contact with holding member 120 is roughened, and holding member 120, which is a resin member (a resin member including a molded body of a polyamide resin composition), is joined to the roughened surface.

[0129] The bus bar unit 100 can be used to electrically connect, via the bus bar 110, a motor of a moving object and an inverter that controls the power supplied to the motor.

[0130] 2 is a diagram showing an exemplary configuration of a moving body (vehicle) having the busbar unit 100. The moving body 200 has a body 210, a power supply 220 such as a secondary battery that supplies power to drive the body 210, and a drive unit 230 that drives the body 210 with the power supplied from the power supply 220.

[0131] Drive unit 230 has inverter 232 that controls power (current) from power supply 220, motor 234 that rotates by receiving the power controlled by inverter 232, and bus bar unit 100 that has bus bar 110 that connects inverter 232 and motor 234. Motor 234 is housed in motor case 236 together with reducer 235 that converts the rotational speed obtained by motor 234 into a rotational speed for driving machine body 210. Bus bar unit 100 is attached to motor case 236, and bus bar 110 communicates from the inside to the outside of motor case 236 via bus bar unit 100.

[0132] A coolant (coolant oil) for cooling the motor 234 is stored inside the motor case 236. The connection between the bus bar unit 100 and the motor case 236 is sealed with a sealing member such as an O-ring, thereby preventing oil from leaking from the inside of the motor case 236 to the outside.

[0133] In conventional busbar units, oil can leak from between the busbar and the protective member due to poor airtightness between the busbar and the protective member. In contrast, in this embodiment, holding member 120, which is made of a resin member containing the above-mentioned molded article of the polyamide resin composition, is joined with high airtightness to busbar 110, which is a conductive metal member (e.g., a copper metal member), thereby preventing oil leakage.

[0134] 2 shows an example in which the moving body 200 is a vehicle such as an automobile, but the moving body 200 is not particularly limited as long as it has a body and a drive unit and is capable of moving. For example, the moving body 200 may be a train, a ship, an airplane, a drone, a robot, or the like, in addition to vehicles such as an automobile, a motorcycle, and an electric bicycle. [Example]

[0135] The present invention will be described below with reference to examples, which should not be construed as limiting the scope of the present invention.

[0136] 1. Synthesis / preparation of materials 1-1. Synthesis of semi-aromatic polyamide resin (A1) and semi-aromatic polyamide resin (A2) <Polyamide resin (A1) (6T6I)> 2800 g (24.1 mol) of 1,6-diaminohexane, 2774 g (16.7 mol) of terephthalic acid, 1196 g (7.2 mol) of isophthalic acid, 5.7 g of sodium hypophosphite monohydrate as a catalyst, 36.6 g (0.30 mol) of benzoic acid as a molecular weight modifier, 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 3.03 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 intrinsic viscosity [η] of the resulting low-order condensation product was 0.15 dL / g.

[0137] Next, this low-order condensate was placed in a tray-type solid-state polymerization reactor, and after purging with nitrogen, the temperature was raised to 180°C over approximately 1 hour and 30 minutes. After that, the reaction was continued for 1 hour and 30 minutes, and the temperature was lowered to room temperature. The intrinsic viscosity [η] of the resulting prepolymer was 0.20 dL / g.

[0138] The obtained prepolymer was then melt-polymerized in a twin-screw extruder with a screw diameter of 30 mm and L / D=36 at a barrel set temperature of 330°C, a screw rotation speed of 200 rpm, and a resin feed rate of 6 kg / h to obtain polyamide resin (A1).

[0139] The resulting polyamide resin (A1) had an intrinsic viscosity [η] of 1.0 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. The resulting polyamide resin (A1) had a composition in which the content of component units derived from terephthalic acid among component units derived from dicarboxylic acid was 70 mol%, the content of component units derived from isophthalic acid was 30 mol%, and the content of component units derived from 1,6-diaminohexane among component units derived from diamine was 100 mol%.

[0140] <Polyamide resin (A2) (6TDT)> 1,6-diaminohexane 1312 g (11.3 mol), 2-methyl-1,5-pentanediamine 1312 g (11.3 mol), terephthalic acid 3655 g (22.0 mol), sodium hypophosphite 5.5 g as a catalyst, and ion-exchanged water 640 ml were charged into a 1-liter reactor, and after purging with nitrogen, the mixture was heated at 250°C and 35 kg / cm 2 After 1 hour had passed, the reaction product produced in the reactor was transferred to a reactor connected to the reactor and heated to 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 a polyamide resin (A2).

[0141] The resulting polyamide resin (A2) had an intrinsic viscosity [η] of 0.9 dl / g, a melting point (Tm) of 300°C, a glass transition temperature (Tg) of 140°C, and a heat of fusion (ΔH) of 45 J / g. The composition of the resulting polyamide resin (A2) was such that the content of component units derived from terephthalic acid among component units derived from dicarboxylic acid was 100 mol%, and the content of component units derived from 1,6-diaminohexane among component units derived from diamine was 50 mol%, and the content of component units derived from 2-methyl-1,5-pentanediamine was 50 mol%.

[0142] 1-2.Other ingredients 1-2-1. Polyolefin resin A catalyst solution was prepared by adding 0.63 mg of bis(1,3-dimethylcyclopentadienyl)zirconium dichloride to a glass flask thoroughly purged with nitrogen, followed by 1.57 ml of a toluene solution of methylaluminoxane (Al; 0.13 mmol / L) and 2.43 ml of toluene. Next, 912 ml of hexane and 320 ml of 1-butene were introduced into a 2 L stainless steel autoclave thoroughly purged with nitrogen, and the temperature of the system was raised to 80 °C. Subsequently, 0.9 mmol of triisobutylaluminum and 2.0 ml of the catalyst solution prepared above (0.0005 mmol as Zr) were pressurized into the system with ethylene to initiate the polymerization reaction. The total pressure was maintained at 8.0 kg / cm2-G by continuously supplying ethylene, and the polymerization was carried out at 80 °C for 30 minutes. A small amount of ethanol was added to the system to terminate the polymerization, and the unreacted ethylene was then purged. The resulting solution was poured into a large excess of methanol to precipitate a white solid, which was collected by filtration and dried overnight under reduced pressure to obtain a white solid (ethylene-1-butene copolymer).

[0143] The ethylene content of the ethylene-1-butene copolymer was 81 mol %. The density was 0.860 g / cm 3 The MFR (ASTM D 1238, 190°C, 2.16 kg load) was 0.5 g / 10 min, and the melting point was 35°C.

[0144] 100 parts by mass of the obtained ethylene-1-butene copolymer was mixed with 1.0 part by mass of maleic anhydride and 0.04 part by mass of peroxide (Perhexyne 25B, trademark, manufactured by NOF Corporation). The resulting mixture was melt-graft-modified in a twin-screw extruder set at 230°C to obtain a modified polyolefin resin (B).

[0145] The amount of maleic anhydride grafted in the modified polyolefin resin (B) was 0.8% by mass, and the density was 0.866 g / cm 3 The MFR (ASTM D 1238, 190°C, 2.16 kg load) was 0.27 g / 10 min, and the melting point (Tm) was 35°C.

[0146] 1-2-2. Coloring agents A pigmented masterbatch was used as the colorant.

[0147] 1-2-3. Lubricants Sodium montanate was used.

[0148] 1-2-4. Nucleating agent Talc (average particle size 6 μm) was used.

[0149] 1-2-5. Reinforcement material Glass fiber (Owens Corning, FT2A) was used.

[0150] 2. Measurement The physical properties of each of the above resins were measured by the following methods.

[0151] <Melting point (Tm), glass transition temperature (Tg),> The melting point (Tm) and glass transition temperature (Tg) of polyamide resin (A) were measured using a differential scanning calorimeter (DSC220C, manufactured by Seiko Instruments Inc.). Specifically, approximately 5 mg of polyamide resin was sealed in an aluminum pan for measurement and set 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 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 was heated a second time to 350°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).

[0152] <Heat of fusion (ΔH)> The heat of fusion (ΔH) of the polyamide resin was calculated from the area of the exothermic peak of crystallization during the first heating process in accordance with JIS K 7122 (2012).

[0153] <Intrinsic viscosity [η]> The intrinsic viscosity [η] of the polyamide resin was calculated by dissolving 0.5 g of the polyamide resin in 50 ml of a 96.5% sulfuric acid solution, measuring the flow time of the resulting solution at 25°C ± 0.05°C using an Ubbelohde viscometer, and then calculating the intrinsic viscosity [η] based on the formula: [η] = ηSP / (C(1 + 0.205ηSP)). [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) ηSP=(t-t0) / t0

[0154] 3. Preparation of polyamide resin composition The above materials were mixed in a tumbler blender in the composition ratios (unit: parts by mass) shown in Table 1, and melt-kneaded using a 30 mmφ vented twin-screw extruder at a cylinder temperature of 300 to 335°C. The kneaded mixture was then extruded into strands and cooled in a water bath. The strands were then taken up in a pelletizer and cut to obtain pellet-shaped polyamide resin compositions 1 to 4.

[0155] 4. Preparation of Metal-Resin Joint <Production of surface-roughened copper members> A copper alloy plate (2 mm thick) of alloy number C1100 specified in JIS H3100 (2012) was cut to a length of 45 mm and a width of 18 mm to prepare a copper member. The copper member was immersed in a 2.6 mass% sodium hydroxide aqueous solution (55°C) containing 0.16 mass% sodium gluconate for 5 minutes while being subjected to ultrasonic cleaning, and then washed with water (20 seconds x 3 times) to carry out a degreasing process.

[0156] Next, the copper member was immersed for 20 seconds in a 0.002 mass% aqueous sodium hydroxide solution (35°C) containing 0.1 mass% benzotriazole and 0.3 mass% 2-isopropoxyethanol, and then washed with water (20 seconds x 3 times) to remove the coating from the surface of the metal material.

[0157] An etching solution was prepared by dissolving 9.5% by weight of sulfuric acid, 2% by weight of hydrogen peroxide, 1.1% by weight of benzotriazole, 0.024% by weight of glycine, and 0.00225% by weight of sodium chloride in water. A copper component was immersed in the etching solution (40°C) for 3 minutes and then rinsed with water (20 seconds x 3 times) to form a microstructure on the surface of the copper component. The pH of the etching solution at 25°C was measured using a Horiba, Ltd. pH meter "D-71" and found to be 0.3.

[0158] The metal material was immersed in water (room temperature) for 3 minutes while undergoing ultrasonic cleaning to remove smut. The metal material was then dried at 80°C for 20 minutes. Through these steps, a surface-roughened copper member was produced.

[0159] <Production of metal-resin bonded body> The roughened copper member was placed in a small dumbbell metal insert mold attached to an injection molding machine (J55-AD, manufactured by The Japan Steel Works, Ltd.). Next, each polyamide resin composition was injected into the mold under the following conditions: cylinder temperature 335°C, mold temperature 170°C, primary injection pressure 90 MPa, holding pressure 80 MPa, and injection speed 25 mm / sec, filling the mold. This produced a test piece in which a resin member made of polyamide resin was bonded to the surface of the copper member. The bonding area between the copper member and the resin member of this test piece was 50 mm 2 It was.

[0160] 4. Evaluation <Airtightness> The helium leak resistance of the prepared test specimen was evaluated according to a method compliant with ISO 19095. Specifically, the test specimen was set in a dedicated jig that could be sealed, and He gas was applied to the sealed space at a pressure of 0.1 MPa. The He gas that passed through the test specimen was measured by the sniffer method using a He gas detector (HELEN M-222LD, manufactured by Canon Anelva Corporation). The airtightness was evaluated according to the following criteria based on the detected He gas flow rate (leakage amount) 5 minutes after the start of detection. ○ Detected He gas flow rate is 1.0 x 10 -6 Pa·m 3 / s or less × Detected He gas flow rate is 1.0×10 -6 Pa·m 3 More than / s

[0161] <Mold releasability> In the above-mentioned airtightness evaluation, when a test piece for measurement was molded, the mold releasability was evaluated according to the following criteria. ○: Even when the cooling time was extended to 90 seconds or more, the mold release was good. ×: When the cooling time was extended to 90 seconds or more, the test piece could not be released from the mold.

[0162] The composition and evaluation results of each polyamide resin composition are shown in Table 1. The composition values in Table 1 represent parts by mass.

[0163] [Table 1]

[0164] From the results of polyamide resin composition 1, it was found that when the ratio of the content of semi-aromatic polyamide resin (A1) to the total mass of semi-aromatic polyamide resin (A1) and semi-aromatic polyamide resin (A2) is 0.4 or more and 0.6 or less, it is possible to improve the airtightness and the releasability at the same time. [Industrial Applicability]

[0165] The polyamide resin composition of the present invention is useful, for example, for insert-molded articles (for example, automobile parts). [Explanation of symbols]

[0166] 100 Busbar Unit 110 Busbar 120 Retaining member

Claims

1. A polyamide resin composition for bonding to a metal member, A semi-aromatic polyamide resin (A1) having a melting point of 280°C or higher as measured by a differential scanning calorimeter (DSC); and a semi-aromatic polyamide resin (A2) having a melting point of 280°C or higher as measured by a differential scanning calorimeter (DSC), The semi-aromatic polyamide resin (A1) comprises a repeating unit (A1-1) represented by the following formula (1) and a repeating unit (A1-2) including a component unit (x1) derived from a dicarboxylic acid and a component unit (y1) derived from a diamine: The semi-aromatic polyamide resin (A2) comprises a repeating unit (A2-1) represented by the following formula (1) and a repeating unit (A2-2) comprising a component unit (x2) derived from a dicarboxylic acid and a component unit (y2) derived from a diamine, the repeating unit (A1-2) is a repeating unit that is contained in the semi-aromatic polyamide resin (A1) in the greatest amount among all the repeating units contained in the semi-aromatic polyamide resin (A1), excluding the repeating unit (A1-1); the repeating unit (A2-2) is a repeating unit that is contained in the semi-aromatic polyamide resin (A2) in the greatest amount among all the repeating units contained therein, excluding the repeating unit (A2-1), the diamine-derived component unit (y1) and the diamine-derived component unit (y2) have the same number of carbon atoms but different molecular structures, the ratio of the content of the semi-aromatic polyamide resin (A1) to the total mass of the semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2) is 0.40 or more and 0.60 or less; Polyamide resin composition. 【Chemical 1】

2. The polyamide resin composition according to claim 1, wherein the semi-aromatic polyamide resin (A1) and the semi-aromatic polyamide resin (A2) each have a melting point measured by a differential scanning calorimeter (DSC) of 290°C or higher and 340°C or lower.

3. The polyamide resin composition according to claim 1, further comprising a polyolefin resin (B).

4. The polyamide resin composition according to claim 1, further comprising a reinforcing material whose content relative to the total mass of the polyamide resin composition is 45 mass% or less.

5. the diamine-derived component unit (y1) and the diamine-derived component unit (y2) are both component units derived from an aliphatic diamine having from 4 to 15 carbon atoms; The polyamide resin composition according to claim 1.

6. the diamine-derived component unit (y1) is a component unit derived from 1,6-diaminohexane, The diamine-derived component unit (y2) is a component unit derived from 2-methyl-1,5-diaminopentane. The polyamide resin composition according to claim 1.

7. A metal member; A resin member comprising the polyamide resin composition according to any one of claims 1 to 6, bonded to the surface of the metal member. Metal-resin joint.

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