JP2019099621A - Resin composition for metal joint, metal resin composite, and manufacturing method therefor - Google Patents

Abstract

To provide a resin composition for metal joint capable of a metal resin composite having strong joint strength, a metal resin composite and a manufacturing method therefor.SOLUTION: There are provided a resin composition for metal joint containing a polycarbonate resin (A), and having flow length (2 mmt bar flow) of the resin composition of 350 mm or more, a metal resin composite by jointing the resin composition to a surface of a metal having with unevenness.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a resin composition for metal bonding, a metal resin composite, and a method for producing the composite thereof, a resin composition for metal bonding excellent in bonding property between a metal member and a resin member, and a resin composite obtained by bonding the same to a metal. It relates to the body and its method of manufacture.

  In recent years, in automobile parts and consumer parts, from the viewpoint of weight reduction and recycling, plasticization of parts using metal and miniaturization of resin products are progressing. On the other hand, polycarbonate resins are widely used in various device parts because they are excellent in impact resistance, dimensional accuracy, and flame retardancy.

In recent years, metal-resin composites in which a resin member and a metal member such as aluminum or iron are combined are often used in electric / electronic equipment parts, automobile parts and the like. The compounding of the resin member with the metal member is advantageous also from the viewpoints of electrostatic prevention, thermal conductivity, and electromagnetic wave shielding, in addition to the improvement of the strength of the resin member.
As a method for producing such a metal-resin composite, there is a method called metal insert molding in which a metal and a resin are integrated by inserting a metal member into a mold and injection molding a resin into the mold. is there.

However, joining a polycarbonate resin to a metal is not easy as it is conventionally said, and in metal insert molding, there is a problem that it is difficult to obtain sufficient joining strength between metal and polycarbonate resin. In order to solve this problem, for example, Patent Document 1 proposes a method in which a polycarbonate resin to which a low melting point polyolefin resin such as graft polyethylene is added is insert-molded into a metal member in which a polycarbonate resin is inserted in a mold.
Further, Patent Document 2 proposes a method of blending a specific amount of a polycarbonate oligomer with a specific amount to a polycarbonate resin. However, in these methods, in order to obtain sufficient bonding strength, it is necessary to set the mold temperature close to the glass transition temperature of polycarbonate resin, and it is necessary to take a long cooling time during molding, or Sometimes there is a problem that the resin part is easily deformed.

  Patent Document 3 proposes a method in which a polycarbonate resin to which rubber or triazine thiol is added is insert-molded on a metal member whose surface is subjected to triazine thiol treatment. However, as in the example, the chemical pretreatment of the metal with the chemical solution similar to the additive of the resin is required, and there is a problem that the process becomes complicated.

Japanese Patent Publication No. 2015-512804 Unexamined-Japanese-Patent No. 2017-19165 Japanese Patent Application Laid-Open No. 8-25409

  An object of the present invention is to solve the above-mentioned problems (problems), and a resin composition for metal bonding capable of a metal-resin composite having strong bonding strength, a metal-resin composite, and a method for producing the same Intended to provide.

Based on the above problems, as a result of investigations by the present inventor, it is preferable that <2> to <4>, <6> to <7>, and 9> found that the above problem could be solved.
<1> A resin composition containing a polycarbonate resin (A), wherein a flow length (2 mm t bar flow) of the resin composition is 350 mm or more.
<2> The resin composition is 30 parts by mass or more of resin (B) other than polycarbonate resin (A) and 24 parts by mass or more of phosphorus plasticizer (C) with respect to 100 parts by mass of polycarbonate resin (A) The resin composition for metal joining as described in <1> containing.
The resin composition for metal joining as described in <1> or <2> whose viscosity average molecular weight of <3> polycarbonate resin (A) is 22000 or less.
The resin composition for metal joining in any one of <1> thru | or <3> whose flow length (2 mm t bar flow) of <4> resin composition is 380 mm or more.

The metal resin complex which joined the resin composition in any one of <5><1> thru | or <4> to the surface of the metal which has an unevenness | corrugation.
The metal resin composite as described in <5> whose unevenness | corrugation on a <6> metal surface is 0.01-1000 micrometers in opening diameter, and 0.05-1000 micrometers in depth.
The metal resin complex as described in <5> or <6> in which the unevenness | corrugation of <7> metal surface is formed by laser processing.
The manufacturing method of the metal resin composite characterized by joining the resin composition in any one of <8><1> thru | or <4> to the surface which has the unevenness | corrugation of the metal which has an uneven surface.
<9> The production of the metal-resin composite according to <8>, wherein at least a part of the region where the metal and the resin are joined is heated before the resin composition is joined to the surface having irregularities of the metal. Method.

  The resin composition for metal bonding of the present invention solves the problem of bonding polycarbonate resin, which is a conventional problem, to metal and can achieve strong bonding strength with metal, and metal polycarbonate resin bonded to metal The composite has a high bonding strength and is excellent in the airtightness of the bonding surface. In addition, according to the method for producing a metal-resin composite of the present invention, molding can be performed with a cooling time similar to that of general injection molding, and there is no concern of deformation of the resin part at the time of mold release. Strong bonding is possible without any pretreatment.

It is the schematic of the metal resin complex produced in the Example. Figure (a) is a view from above the composite, and Figure (b) is a view from the side. In an Example, it is a figure which shows the shape of the metal resin composite used when evaluating the airtightness of a metal resin composite.

  Hereinafter, the contents of the present invention will be described in detail. In addition, in this specification, "-" is used in the meaning which includes the numerical value described before and after that as a lower limit and an upper limit.

  The resin composition for metal bonding of the present invention is a resin composition containing a polycarbonate resin (A), and is characterized in that the flow length (2 mm t bar flow) of the resin composition is 350 mm or more. By having such a flow length, strong joint strength between polycarbonate resin and metal can be achieved. The flow length (2 mm t bar flow) of the resin composition is preferably 380 mm or more. The flow length of the resin composition is a bar flow flow length of 2 mm thickness, and the details of the specific method of the measurement are as described in the examples.

[Polycarbonate resin (A)]
The polycarbonate resin (A) contained in the resin composition for metal bonding of the present invention includes an aromatic polycarbonate resin, an aliphatic polycarbonate resin, and an aromatic-aliphatic polycarbonate resin, preferably an aromatic polycarbonate resin. Specifically, thermoplastic aromatic polycarbonate polymers or copolymers obtained by reacting an aromatic dihydroxy compound with phosgene or a diester of carbonic acid are used.

  As the aromatic dihydroxy compound, 2,2-bis (4-hydroxyphenyl) propane (ie, bisphenol A), tetramethylbisphenol A, α, α'-bis (4-hydroxyphenyl) -p-diisopropylbenzene, hydroquinone , Resorcinol, 4,4'-dihydroxydiphenyl and the like. Also, for the purpose of improving the flame retardancy, a compound in which one or more of the above-described aromatic dihydroxy compounds is bonded with tetraalkylphosphonium sulfonate, a polymer having both terminal phenolic OH groups having a siloxane structure, or an oligomer thereof It is also good.

  Preferred examples of the polycarbonate resin (A) include the combined use of 2,2-bis (4-hydroxyphenyl) propane as a dihydroxy compound, or 2,2-bis (4-hydroxyphenyl) propane and another aromatic dihydroxy compound. Polycarbonate resin.

The polycarbonate resin (A) may be a homopolymer consisting of one kind of repeating unit, or may be a copolymer having two or more kinds of repeating units. At this time, as the copolymer, various copolymer forms such as a random copolymer and a block copolymer can be selected.
The polycarbonate resin (A) may be a mixture of a plurality of polycarbonate resins.

The viscosity average molecular weight (Mv) of the polycarbonate resin (A) is preferably 22000 or less. By setting the viscosity average molecular weight to 22000 or less, the flowability and moldability of the obtained resin composition can be improved, and the resin composition can enter into the unevenness of the metal surface to further improve the bonding strength. The Mv of the polycarbonate resin (A) is more preferably 21500 or less, preferably 12000 or more, more preferably 14000 or more, and still more preferably 15000 or more. When the viscosity average molecular weight is lower than 10000, the resulting bonding member tends to be low in mechanical strength.
As described above, the polycarbonate resin (A) may be a mixture of a plurality of polycarbonate resins, or two or more polycarbonate resins having different Mv may be mixed and used. In this case, You may mix polycarbonate resin whose Mv is out of said preferable range. The above preferred Mv of the polycarbonate resin (A) means, in the case of a polycarbonate resin mixture, an Mv measured from the mixture.

In the present invention, the viscosity average molecular weight (Mv) of the polycarbonate resin is obtained by measuring the viscosity of a methylene chloride solution of the polycarbonate resin at a temperature of 20 ° C. using an Ubbelohde viscometer to determine the limiting viscosity ([η]). The value is calculated from the following Schnell's viscosity equation.
[Η] = 1.23 × 10 ⁻⁴ Mv ^0.83

  The method for producing the polycarbonate resin is not particularly limited, and polycarbonate resins produced by any of the phosgene method (interfacial polymerization method) and the melting method (ester exchange method) can also be used. Moreover, the polycarbonate resin which gave the post-process which adjusts the amount of OH groups of the terminal to the polycarbonate resin manufactured by the melting method is also preferable.

  Moreover, polycarbonate resin (A) may contain the polycarbonate oligomer. The Mv of this polycarbonate oligomer is usually 1,500 or more, preferably 2,000 or more, and usually 9,500 or less, preferably 9000 or less. Furthermore, the content of the polycarbonate oligomer is preferably 30% by mass or less, more preferably 20% by mass or less, and particularly preferably 10% by mass or less of the polycarbonate resin (A) (including polycarbonate oligomer).

[Other resins (B) other than polycarbonate resin (A)]
The resin composition for metal bonding of the present invention preferably contains another resin (B) other than the polycarbonate resin (A), and the content thereof is 30 parts by mass or more with respect to 100 parts by mass of the polycarbonate resin (A) Is preferred. By containing other resin (B), it becomes easy to make the flow length of a resin composition 350 mm or more. The upper limit of the content of the other resin (B) is preferably 80 parts by mass or less, more preferably 70 parts by mass or less, particularly preferably 60 parts by mass or less based on 100 parts by mass of the polycarbonate resin (A). .
As resin (B) other than polycarbonate resin (A), a styrene resin or a thermoplastic polyester resin is preferable.

<Styrene-based resin (B1)>
When the resin composition for metal bonding of the present invention contains the styrene resin (B1), it becomes easy to make the flow length of the resin composition 350 mm or more.
Here, as the styrene resin (B1), the aromatic vinyl monomer (b1) alone, or other vinyl monomers (b2,) copolymerizable with the aromatic vinyl monomer (b1) according to need It is preferable that it is resin obtained by polymerizing 1 or more types chosen from b4) and a rubbery polymer (b3).

Examples of the aromatic vinyl monomer (b1) used for the styrene resin (B1) include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, vinylxylene, ethylstyrene, dimethylstyrene, p-tert Styrene derivatives such as -butylstyrene, vinylnaphthalene, methoxystyrene, monobromostyrene, dibromostyrene, fluorostyrene, tribromostyrene and the like, and styrene is particularly preferable.
One of these may be used alone, or two or more may be mixed and used.

  As other vinyl monomers copolymerizable with these aromatic vinyl monomers (b1), vinyl cyanide monomers (b2) are preferable, and examples thereof include acrylonitrile and methacrylonitrile.

Further, as another monomer (b4) other than the copolymerizable vinyl cyanide monomer (b2), aryl esters of acrylic acid such as phenyl acrylate and benzyl acrylate; methyl acrylate, ethyl acrylate, propyl acrylate Alkyl acrylates of acrylic acid such as butyl acrylate, amyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, cyclohexyl acrylate and dodecyl acrylate; aryl methacrylates such as phenyl methacrylate and benzyl methacrylate; methyl methacrylate, ethyl methacrylate, propyl Methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate Alkyl methacrylates such as octyl methacrylate, cyclohexyl methacrylate and dodecyl methacrylate; epoxy group-containing methacrylates such as glycidyl methacrylate; maleimide monomers such as maleimide, N-methyl maleimide and N-phenyl maleimide; acrylic acid, Examples thereof include α, β-unsaturated carboxylic acids such as methacrylic acid, maleic acid, maleic anhydride, phthalic acid and itaconic acid and anhydrides thereof. Preferred are acrylic acid alkyl ester and methacrylic acid alkyl ester.
As these other monomers (b4), one type may be used alone, or two or more types may be mixed and used.

Further, as the rubbery polymer (b3) copolymerizable with the aromatic vinyl monomer (b1), a rubber having a glass transition temperature of 10 ° C. or less is preferable. Specific examples of such rubbery polymers include diene rubbers, acrylic rubbers, ethylene / propylene rubbers, silicone rubbers, mutual bonds such that polyorganosiloxane rubber components and polyalkyl (meth) acrylate rubber components can not be separated. Composite rubber (IPN type rubber) having an entangled structure, and the like can be mentioned, with preference given to diene rubber, acrylic rubber and the like.
In the present specification, “(meth) acrylate” refers to one or both of “acrylate” and “methacrylate”, and the same applies to “(meth) acryl” and “(meth) acrylo”.

Examples of diene rubbers include polybutadiene, styrene-butadiene random copolymer and block copolymer, acrylonitrile-butadiene copolymer, polyisoprene, butadiene-isoprene copolymer, ethylene-propylene-hexadiene copolymer, etc. Copolymers of ethylene, propylene and nonconjugated diene, lower alkyl ester copolymers of butadiene- (meth) acrylic acid, lower alkyl esters of butadiene-styrene- (meth) acrylic acid, and the like can be mentioned.
Examples of the above lower alkyl ester of (meth) acrylic acid include methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate and the like.
The ratio of the lower alkyl ester of (meth) acrylic acid in the lower alkyl ester copolymer of butadiene / (meth) acrylic acid or the lower alkyl ester copolymer of butadiene / styrene / (meth) acrylic acid is the same as that of the rubbery polymer It is preferable that it is 30 mass% or less of the amount.

  The acrylic rubber includes, for example, acrylic acid alkyl ester rubber, and the carbon number of the alkyl group is preferably 1 to 8 here. Specific examples of the acrylic acid alkyl ester include ethyl acrylate, butyl acrylate and hexyl acrylate. Ethylenically unsaturated monomers may optionally be used for the acrylic acid alkyl ester rubber. Specific examples of such compounds include di (meth) acrylate, divinylbenzene, trivinylbenzene, triallyl cyanurate, allyl (meth) acrylate, butadiene, isoprene and the like. The acrylic rubber further includes a core-shell polymer having a crosslinked diene rubber as a core.

  Also about these rubbery polymers (b3), 1 type may be used independently and 2 or more types may be mixed and used.

  The styrenic resin (B1) comprises 50 to 100% by mass of the above-mentioned aromatic vinyl monomer component (b1), 0 to 30% by mass of the vinyl cyanide monomer component (b2), and a rubbery polymer component (b3) It is preferable that it consists of 0-30 mass% and other monomer components (b4) 0-30 mass%, aromatic vinyl monomer component (b1) 50-80 mass%, vinyl cyanide monomer component ( b2) It is more preferable that it consists of 10-30 mass%, rubbery polymer component (b3) 5-25 mass%, and other monomer components (b4) 0-20 mass%, and an aromatic vinyl monomer component (B1) 55 to 70% by mass, vinyl cyanide monomer component (b2) 15 to 25% by mass, rubbery polymer component (b3) 10 to 25% by mass, other monomer components (b4) to 0 More preferably, it consists of 5% by mass.

Specific examples of the styrene resin (B1) used in the present invention include, for example, homopolymers of styrene, copolymers of styrene and (meth) acrylonitrile, and copolymers of styrene and alkyl (meth) acrylates. Copolymers, copolymers of styrene and (meth) acrylonitrile and other copolymerizable monomers, graft copolymers obtained by polymerizing styrene in the presence of rubber, and styrene and (meth) in the presence of rubber Preferred examples include graft copolymers obtained by graft polymerization of acrylonitrile and the like.
More specifically, polystyrene, high impact polystyrene (HIPS), acrylonitrile-styrene copolymer (AS resin), styrene-maleic anhydride copolymer (SMA resin), acrylonitrile-butadiene-styrene copolymer Polymer (ABS resin), acrylonitrile-styrene-acrylic rubber copolymer (ASA resin), styrene-butadiene-styrene copolymer (SBS resin), hydrogenated styrene-butadiene-styrene copolymer (hydrogenated) SBS), hydrogenated styrene-isoprene-styrene copolymer (SEPS), acrylonitrile-acrylic rubber-styrene copolymer (AAS resin), acrylonitrile-ethylene propylene rubber-styrene copolymer (AES resin) and Resin such as styrene-IPN type rubber copolymer or Mixtures of al and the like. Furthermore, it may have stereoregularity such as syndiotactic polystyrene. Moreover, it can replace with said styrene and can use an aromatic vinyl-type monomer widely.

  Among these, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-styrene-acrylic rubber copolymer (ASA resin), acrylonitrile-ethylene propylene resin Rubber-styrene-based copolymer (AES resin) is preferable, among which acrylonitrile-butadiene-styrene-based copolymer (ABS resin) and acrylonitrile-styrene-based copolymer (AS resin) are preferable, and in particular, acrylonitrile-butadiene-styrene A copolymer (ABS resin) is preferred.

  Examples of the method for producing these styrene resins (B1) include known methods such as emulsion polymerization, solution polymerization, suspension polymerization and bulk polymerization, but any method may be used.

  Moreover, a styrene resin (B1) may be used individually by 1 type, and may mix and use 2 or more types.

  The content of the styrene resin (B1) is preferably 30 parts by mass or more, preferably 80 parts by mass or less, more preferably 70 parts by mass or less, per 100 parts by mass of the polycarbonate resin (A). More preferably, it is 60 parts by mass or less. When the content of the styrene-based resin body (B1) exceeds 80 parts by mass, the strength tends to be unsatisfactory, and when it is less than 30 parts by mass, the flowability improving effect tends to be insufficient.

[Thermoplastic polyester resin (B2)]
In the resin composition for metal bonding of the present invention, it becomes easy to make the flow length of the resin composition 350 mm or more even by containing the thermoplastic polyester resin (B2).
As the thermoplastic polyester resin (B2), a polymer or copolymer obtained by a condensation reaction comprising a dicarboxylic acid component consisting of a dicarboxylic acid or its reactive derivative and a diol component consisting of a diol or its ester derivative as main components Although it is united, preferably, a thermoplastic polyester resin obtained by polycondensation reaction of an aromatic dicarboxylic acid as a main acid component with an alcohol mainly composed of an aliphatic diol is used.

  As aromatic dicarboxylic acid, terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 4,4'-biphenylether dicarboxylic acid 4,4′-biphenylmethanedicarboxylic acid, 4,4′-biphenylsulfonedicarboxylic acid, 4,4′-biphenylisopropylidenedicarboxylic acid, 1,2-bis (phenoxy) ethane-4,4′-dicarboxylic acid 2,5-anthracene dicarboxylic acid, 2,6-anthracene dicarboxylic acid, 4,4'-p-ter-phenylene dicarboxylic acid, 2,5-pyridine dicarboxylic acid etc. Alkyl-substituted products such as methyl isophthalic acid) and reactive derivatives (eg, terephthalic acid dimer) Le, alkyl ester derivatives such as diethyl terephthalate) and the like can also be used.

  Among these, terephthalic acid, 2,6-naphthalenedicarboxylic acid and their alkyl ester derivatives are more preferable, and terephthalic acid and its alkyl ester derivatives are particularly preferable. These aromatic dicarboxylic acids may be used alone or in combination of two or more, and together with the aromatic dicarboxylic acid, an aliphatic dicarboxylic acid such as adipic acid, azelaic acid, sebacic acid or dodecanedioic acid, It is also possible to use one or more kinds of alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid in combination.

  As diols, ethylene glycol, diethylene glycol, 1,2-propylene glycol, 1,3-propanediol, triethylene glycol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6- Aliphatic diols such as hexanediol, decamethylene glycol and 2,2-dimethyl-1,3-propanediol; 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, cyclohexanediol, trans- or cis- Alicyclic diols such as 2,2,4,4-tetramethyl-1,3-cyclobutanediol; p-xylenediol, bisphenol A, tetrabromobisphenol A, tetrabromobisphenol A-bis (2-hydroxyethyl ether) Etc) It can be mentioned aromatic diol, and the like, can also be used these substituents.

  Among these, from the viewpoint of heat resistance, dimensional stability, etc., aliphatic diols are preferable, ethylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol are more preferable, and ethylene glycol is particularly preferable.

  The diols may be used alone or in combination of two or more. In addition, as a diol component, one or more long-chain diols having a molecular weight of 400 to 6,000, that is, polyethylene glycol, poly-1,3-propylene glycol, polytetramethylene glycol and the like may be used in combination with the diols. It may be copolymerized.

  In addition, the thermoplastic polyester resin (B2) can be copolymerized with hydroxycarboxylic acids such as parahydroxybenzoic acid, other carboxylic acids, and alcohols other than the above-mentioned diols, and in the present invention, such copolymer resins Can also be used. However, such a copolymerization component is preferably a small amount, and 80% by mass or more, and further 90% by mass or more of the thermoplastic polyester resin (B2) is a component from the aromatic dicarboxylic acid and the aliphatic diol Is preferred. In addition, it is preferable that 80 mol% or more, further 90 mol% or more of the aromatic dicarboxylic acid and the aliphatic diol be occupied by one kind of compound.

  Preferred specific examples of such thermoplastic polyester resin (B2) include polybutylene terephthalate, polybutylene naphthalate, polycyclohexanedimethanol terephthalate, polyethylene terephthalate, polyethylene naphthalate and the like. These may contain copolymerization components. In the present invention, among these, it is preferable to use polyethylene terephthalate (PET) or polybutylene terephthalate (PBT), and it is also preferable to use both in combination. In addition, as for the ratio, when using together, PET: PBT = 1: 1-1: 8 (mass ratio) are preferable. As the thermoplastic polyester resin (B2), polybutylene terephthalate is particularly preferred.

  The molecular weight of the thermoplastic polyester resin (B2) is such that the intrinsic viscosity (IV) measured at 30 ° C. in a mixed solvent of phenol and tetrachloroethane (mass ratio = 50/50) is 0.4 to 2.0. Is preferred. When one having an intrinsic viscosity of less than 0.4 is used, the mechanical strength of the resin composition is inferior, and on the other hand, when it exceeds 2.0, the moldability tends to be reduced. The preferred intrinsic viscosity of the thermoplastic polyester resin (B2) is 0.6 to 1.2.

  The content in the case of containing a thermoplastic polyester resin (B2) is preferably 30 parts by mass or more, preferably 80 parts by mass or less, more preferably 70 parts by mass or less based on 100 parts by mass of the polycarbonate resin (A) More preferably, it is 60 parts by mass or less. When the content of the thermoplastic polyester resin (B2) exceeds 80 parts by mass, the strength tends to be unsatisfactory, and when it is less than 30 parts by mass, the flowability improving effect tends to be insufficient.

  When the resin other than the styrene resin or the thermoplastic polyester resin is further used as the resin (B) other than the polycarbonate resin (A), the content thereof is polycarbonate resin The amount is preferably less than 30 parts by mass, more preferably less than 20 parts by mass, and particularly preferably less than 10 parts by mass with respect to 100 parts by mass of (A).

[Phosphorus plasticizer (C)]
Moreover, it is preferable that the resin composition for metal joining of this invention contains a phosphorus plasticizer (C), and, as for the content, 24 mass parts or more are preferable with respect to 100 mass parts of polycarbonate resin (A). By containing the phosphorus plasticizer (C) in such an amount, it becomes easy to make the flow length of the resin composition 350 mm or more.

  As a phosphorus plasticizer (C), a condensation phosphoric acid ester and a phosphazene type compound can be mentioned preferably.

As condensed phosphoric acid esters, phenyl resorcinol polyphosphate, cresyl resorcinol polyphosphate, phenyl cresyl resorcinol polyphosphate, xylyl resorcinol polyphosphate, phenyl-p-tert-butylphenyl resorcinol polyphosphate Preferred examples thereof include phenyl isopropylphenyl resorcin polyphosphate, cresyl xylyl resorcin polyphosphate, phenyl isopropylphenyl diisopropylphenyl resorcin polyphosphate and the like.
In addition, phenyl bisphenol polyphosphate, cresyl bisphenol polyphosphate, phenyl cresyl bisphenol polyphosphate, xylyl bisphenol polyphosphate, phenyl-p-tert-butylphenyl bisphenol polyphosphate, phenyl isopropyl phenyl Bisphenol polyphosphate, cresyl xylyl bisphenol polyphosphate, phenyl isopropylphenyl diisopropylphenyl bisphenol polyphosphate and the like are mentioned as preferred examples.

  As a phosphazene compound, a cyclic phenoxy phosphazene compound, a chain | strand-shaped phenoxy phosphazene compound, and a bridge | crosslinking phenoxy phosphazene compound is mentioned, for example.

  The content of the phosphorus-based plasticizer (C) is preferably 24 parts by mass or more, preferably 60 parts by mass or less, more preferably 50 parts by mass or less, more preferably 100 parts by mass of the polycarbonate resin (A). It is 40 parts by mass or less. If the content of the phosphorus-based plasticizer (C) is less than 24 parts by mass, the flowability improving effect tends to be insufficient, and if it exceeds 60 parts by mass, the strength tends to be unsatisfactory.

[Other additives]
The resin composition for metal bonding of the present invention includes other additives other than those described above, for example, a mold release agent, a stabilizer, an antioxidant, an ultraviolet light absorber, a brightening agent, a pigment, a dye, a flame retardant, and resistance to Additives such as impact modifiers (including elastomers), reinforcing fillers, antistatic agents, compatibilizers, etc. can be included. These additives may be used alone or in combination of two or more.

As a method for producing the resin composition for metal bonding of the present invention, it can be carried out according to a conventional method for preparation of a resin composition. Usually, the components and optionally added various additives are combined and intimately mixed, and then melt-kneaded in a single-screw or twin-screw extruder. Moreover, it is also possible to prepare a resin composition of the present invention by mixing only a part thereof in advance without mixing each component in advance, supplying it to an extruder using a feeder and melt kneading it.
In addition, when using fibrous reinforcement fillers, such as glass fiber, it is also preferable to supply from the side feeder in the middle of the cylinder of an extruder.

  The heating temperature at the time of melt-kneading can be suitably selected from the range of normally 230-280 degreeC. If the temperature is too high, decomposition gas is likely to be generated. Therefore, it is desirable to select a screw configuration considering shear heat generation and the like.

[Metal resin composite]
The metal-resin composite of the present invention is characterized in that the above-mentioned resin composition is joined to a metal member having irregularities on the surface on the surface side having the irregularities of the metal member.

In the metal resin composite of the present invention, it is preferable that a member (resin member) made of a resin composition is in contact with the metal member on the surface side having the above-mentioned asperities. However, as described later, when the fine particles and the like are fixed by the surface roughening treatment of the metal member, or when the primer layer is provided on the surface of the metal member, the resin member is provided on the surface after such treatment Also, it is included in the aspect which is in contact with the metal member and the surface side having the unevenness having the unevenness.
Further, in the present invention, it is not necessary that the resin member is in contact with all the surface side of the metal member having the unevenness, and it is needless to say that the resin member may be in contact with a part of the surface having the unevenness.

As a metal which comprises a metallic member, various metals, such as aluminum, iron, copper, magnesium, tin, nickel, zinc, and the alloy containing these metals are mentioned. Among these, the metal member preferably contains at least one of aluminum, iron, copper and magnesium, and more preferably contains aluminum. Aluminum includes pure Al and various Al alloys. Examples of iron include iron such as iron, steel, stainless steel, and various iron alloys. Magnesium includes pure magnesium and magnesium alloys.
Moreover, the metal member is a member plated with a metal, such as nickel, chromium, zinc, gold or the like, in addition to the one in which the whole is made of metal, the surface on the uneven side of the member made of a part other than metal. It may be.

The shape of the metal member is not particularly limited, but flat plate, curved plate, plate, rod, cylinder, block, sheet, film and the like, or those manufactured in a desired specific shape are preferable. . The shape of the surface of the raw metal member surface before the roughening treatment is not particularly limited, and is not limited to a single flat surface or a curved surface, and may have various shapes such as stepped portions, concave portions, and convex portions.
The thickness of the metal member is not particularly limited, but is preferably in the range of 0.05 to 100 mm, more preferably 0.1 to 50 mm, and still more preferably 0.12 to 10 mm. . In particular, in the case of an aluminum plate and an iron plate, the thickness is preferably 0.1 to 50 mm, and more preferably 0.2 to 40 mm. The thickness means the thickness when the metal member is flat, and when the metal member is other than flat, among the metal members, among the metal portions which are in contact with the resin member on the side having the unevenness. The thinnest thickness is preferably in the above range.

The metal member has irregularities at least on the surface in contact with the resin member (resin composition). The unevenness can be formed by applying an unevenness treatment (also referred to as roughening treatment) to a metal member. By such a concavo-convex treatment, the metal member can have a fine concavo-convex surface.
The unevenness forming process for forming fine unevenness on the surface of the metal member is not particularly limited, and various known methods can be adopted. For example, chemical conversion treatment or chemical liquid treatment (chemical etching or chemical etching) , Laser processing (laser etching), blast etching and the like. By this treatment, fine irregularities are formed on the surface of the metal member, and the resin composition described above intrudes into the recesses of the fine asperity structure, penetrates the depth of the recess wall, and solidifies as it is. It is thought that strong joint strength can be expressed by fixing without fixing the recess.

  In addition to the etching method, the surface of the metal member is not only an etching method, but fine particles of metal oxide, ceramics, etc., for example, titanium oxide, silicon oxide fine particles or powders dispersed in various solvents. And may be made uneven by physically forming a convex portion. 10 nm-1 mm are preferable, as for the number weight average particle diameter (D50) of microparticles | fine-particles, 20 nm-500 micrometers are more preferable, and 30 nm-200 micrometers are further more preferable.

With regard to chemical conversion treatment and chemical etching, various methods are known depending on the type of metal, and known methods can be used.
When the metal member is aluminum or an aluminum alloy, etching is performed with an acidic aqueous solution and / or a basic aqueous solution, or an oxide film is formed on the surface, then the oxide film is removed, and then ammonia, hydrazine, water-soluble amine compound, etc. The method of processing etc. are mentioned preferably. In addition, according to alumite treatment which is a general surface treatment method applied to aluminum, it is possible to form a concavo-convex structure by electrolyzing aluminum with an acid using an acid.

Irregularization by a laser is formed by irradiating the surface of the metal member with a laser beam and processing the metal surface under the conditions of grooving, melting and resolidification. For example, it is formed by repeating laser scanning in the same scanning direction or cross direction a plurality of times after performing laser scanning processing in a certain scanning direction.
The conditions for laser scanning include output, scan speed, scan frequency, number of scans, hatching width (processing pitch), patterning shape, etc. With these combinations, a fine uneven surface is formed from the desired recesses and protrusions be able to.

  Further, the type of laser used for processing may be appropriately selected from solid laser, fiber laser, semiconductor laser, gas laser, and various wavelengths of liquid laser, and the oscillation form is also a concavo-convex shape that expects continuous wave or pulse wave. It can be selected together. Moreover, when a continuous wave is used, it is possible to set it as a more complicated uneven structure.

  In the present invention, in particular, the roughening by laser processing is most desirable. Compared to the case of chemical etching, the laser treatment is characterized in that the opening diameter and the depth of the unevenness can be easily increased. In this bonding method, it is important that the polycarbonate resin sufficiently infiltrates and solidifies in the inside of the asperities, and therefore it is not limited by the difference in fluidity of the resin, but the opening diameter and / or the depth are large. It is desirable.

As the blast etching, there are shot blasting treatment for projecting a blasting material by utilizing centrifugal force of an impeller (impeller), and air blasting treatment for projecting a blasting material by compressed air using an air compressor. It is possible to provide an uneven shape on the surface. As a blasting material, materials such as silica sand, alumina, aluminum cut wire, steel grid, steel shot and the like can be mentioned.
In addition, wet blast etching is performed by causing water mixed with abrasive particles such as resin particles and metal particles to be directed to the surface of the metal member together with processing air at a high pressure of several tens m / s to about 300 m / s and etching processing The law is also possible.

  As another method, metal plating (for example, zinc plating) and heating to a temperature higher than the melting point of the plated metal (zinc) to evaporate part or most of the metal (zinc) in the plated layer It is also possible to obtain a metal member having a roughened surface.

  The roughening treatment (roughening treatment) exemplified above is used singly or in combination of two or more. Depending on the combination method, effects such as optimization of the uneven structure and cost reduction may be found.

The unevenness on the surface of the metal member preferably has an opening diameter of 0.01 μm or more and 1000 μm or less, more preferably 0.05 μm or more, still more preferably 0.1 μm or more, and more preferably 500 μm or less, still more preferably It is 300 μm or less, particularly preferably 200 μm or less. The depth is preferably 0.05 μm or more and 1000 μm or less, more preferably 0.1 μm or more, still more preferably 0.5 μm or more, and more preferably 500 μm or less, still more preferably 300 μm or less. If it is larger than this, the amount of resin flowing into the concavo-convex portion is too large, and it takes time to solidify, and it tends to be difficult to be joined. Moreover, if it is less than this, even if it uses the resin composition of this invention, it exists in the tendency for it to become difficult to infiltrate in an unevenness | corrugation.
The distance between the opening and the opening is preferably 0.01 μm to 1000 μm, more preferably 0.05 μm or more and 500 μm or less, and still more preferably 0.1 μm or more and 200 μm or less. The distance between the opening and the opening is related to the number of anchors of resin per unit area, and it is difficult to obtain a sufficient anchor effect more or less than this, and the bonding strength tends to be low.

  As for the asperity shape, the opening diameter and / or the depth and the distance between the opening and the opening are important. Although not shown, if there is a recess, there is a protrusion, and in addition to the macro uneven portion, there may be microscopic unevenness.

It is also useful to surface-treat the metal member which has an unevenness | corrugation in the above-mentioned surface by a silane coupling agent.
Although it does not specifically limit as a silane coupling agent, For example, the compound which has a methoxy group, an ethoxy group, a silanol group etc. is mentioned, As a silane coupling agent, vinyl trimethoxysilane, chloropropyl trimethoxysilane, 3-gly Cidoxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-aminoethyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3- ( Preferred examples include N-styrylmethyl-2-aminoethylamino) propyltrimethoxysilane hydrochloride and ureidoaminopropylethoxysilane. In particular, the aluminum base, the iron base and the silane coupling agent form a bond of Al-O-Si or Fe-O-Si to form a strong bond, and the organic functional group of the resin composition and the silane coupling agent React to form a tight bond, and a stronger bond can be achieved.

  In addition, although not essential, by forming a film of the triazine thiol derivative on the surface of the roughened metal surface by a wet method using a solution containing the triazine thiol derivative, further improvement in bonding strength by chemical bonding is achieved. it can.

In bonding the metal member and the resin member, it is also preferable to form a chemical bond by effectively acting a polar group as well as the anchor effect by the unevenness. For example, in order to provide a CO group, a COO group, an NH ₂ group, etc. as an acidic or basic functional group, ozone treatment, plasma treatment, flame treatment, corona discharge treatment, chemical liquid chemical treatment is applied to a metal surface which has been roughened. It is also useful to apply processing and the like.

  Furthermore, it is also preferable to provide a primer layer on the metal member. As a material to be used for the primer layer, it is preferable to use an acrylic material, an epoxy material, a urethane material, a polyamide material, or the like. As a commercial item of the material used for a primer layer, "Aron melt PPET" etc. by Toagosei Co., Ltd. are preferably illustrated, for example.

  The metal resin composite of the present invention can preferably have a tensile strength of 1000 N or more measured under the conditions of a tensile speed of 5 mm / minute and a distance between chucks of 80 mm using a tensile jig in accordance with ISO19095. In this strength, in many cases, a phenomenon is observed in which the resin member breaks the base material and the resin remains at 70% or more in the metal asperities (5 mm × 10 mm area). Although the method of calculating | requiring this residual amount is not limited, it is possible to image | photograph an applicable area | region and to calculate by methods, such as binarization. Moreover, the metal resin composite of this invention can also achieve the high tensile strength which a base material breaks by tension | tensile_strength when the said tension test is done.

[Method of producing metal resin composite]
In order to produce a metal-resin composite, it can be produced by bonding the above-described resin composition to a surface having irregularities of a metal having an asperity surface.
Bonding of the resin composition to the metal member is possible by various molding methods. The molding machine to be used is not particularly limited as long as it can form a metal resin composite of a metal member and a resin composition, and, for example, an injection molding machine, an extrusion molding machine, a heating press molding machine, a compression molding machine, a transfer molding machine Although various molding machines such as cast molding machines can be used, among these, injection molding machines are particularly preferable.

In the case of the injection molding method, specifically, it is preferable to manufacture by an insert molding method in which a metal member is inserted into a cavity portion of an injection mold and the resin composition is injected into the mold. Specifically, a mold for molding is prepared, the mold is opened, and a metal member is installed (inserted) on a part of the mold, and then the mold is closed, and at least a part of the resin composition is a metal member The resin composition is injected into the mold and solidified so as to be in contact with the surface on which the uneven shape is formed. Thereafter, the metal resin composite can be obtained by opening the mold and releasing the mold.
The size of the metal member to be inserted may be determined appropriately depending on the size, structure, etc. of the target metal-resin complex. The metal member to be inserted does not have to extend over the entire metal-resin composite to be obtained, and may be a part of the metal-resin composite.

In order to improve the bonding strength, it is preferable to make the temperature of the molten resin composition and the temperature of the metal member as close as possible at the time of insert molding. Although the method is not particularly limited, it is desirable to heat the metal member in advance. Although the heating method is not particularly limited, for example, a method of inserting one heated by induction heating, infrared heating, a hot plate, a heating furnace, a laser, etc. before insert molding a metal member, a metal member after insertion into a mold A method of heating from the outside with a halogen lamp, a dryer or the like from the outside, a method of heating with a cartridge heater or the like disposed inside the mold, etc. may be mentioned. In particular, it is useful to heat only the bonding region with the resin composition locally. Note that “locally heating” includes that heating is performed to the periphery including the bonding area depending on the heating means, but heating is not performed to a portion farther than the bonding area of the metal member.
The heating temperature is preferably as high as possible, but is usually 100 to 350 ° C, preferably 120 to 250 ° C, and more preferably 130 to 200 ° C.
By setting the heating temperature to 100 ° C. or higher, the difference from the mold temperature can be increased, the effect of heating can be more effectively exhibited, and by setting the heating temperature to 350 ° C. or lower, the temperature rising time can be shortened. Tends to improve, and retention of the resin is less likely to occur, which is preferable in terms of molding.

  As a method of obtaining a metal-resin composite, in addition to the above, a composite is formed by heating a metal member or a resin member (resin composition) such as a laser welding method, a vibration welding method, an ultrasonic welding method or the like. It is also possible to choose the method. An optimal method may be selected according to the shape, cost and the like of the complex. In particular, the laser welding method is preferable because it can weld a local region and can also serve as local heating.

  The size, shape, thickness and the like of the metal-resin composite of the present invention obtained in this manner are not particularly limited, and may be plate-like (disc, polygon, etc.), columnar, box-like, wedge-like, Any shape such as a tray may be used. Moreover, it is not necessary that all parts of the composite have a uniform thickness, and the composite may be provided with a reinforcing rib or the like.

  In the metal-resin composite of the present invention, the metal member and the resin member are firmly joined, and the mechanical strength is excellent. Therefore, general household appliances, office automation equipment (copiers, printers, facsimiles, etc.) and various portable terminals Electrical and electronic components (housings, etc.) (PCs etc.) (housings, cases, covers etc.), automotive parts such as automobiles (structural parts for vehicles or brake pedals etc.), mechanical parts, bicycles and other parts materials It is preferably used.

  Hereinafter, the present invention will be more specifically described with reference to examples. However, the present invention is not limited to the following examples, and can be arbitrarily changed and implemented without departing from the scope of the present invention.

Each component used for the following example and comparative example is as Table 1 below.

(Examples 1 to 15, Comparative Examples 1 to 4)
[Roughening treatment of aluminum plate]
<Laser treatment>
Irregularization was performed on an aluminum (JIS A1050) plate having a thickness of 1.5 mm using a fiber laser with a wavelength of 1062 nm (“MX-Z2000H” manufactured by OMRON Corporation). The output was laser scanning at intervals of 130 μm in the lateral direction, longitudinal direction, and oblique direction, respectively, in the range of 20 W, and then laser scanning at 65 μm intervals in the lateral direction and longitudinal direction. The surface of the obtained aluminum plate was observed with a 10 × objective lens of a laser microscope (“KEYENCE VK-X100”), and the surface roughness was measured. The ten-point average roughness Rz was 134 μm. In addition, the cross section of the surface of the obtained aluminum plate is observed at 100 times using a scanning electron microscope ("S-4800" manufactured by Hitachi High-Technologies Corporation), and ten uneven portions are measured and averaged. When the opening diameter and the depth were measured, the opening diameter was 130 μm and the depth was 100 μm.
<Chemical processing>
After degreasing, an aluminum plate (JIS A1050) having a thickness of 1.5 mm is treated with a chemical solution (chemical etching) using an aqueous solution (aluminium etching solution manufactured by Kanto Chemical Co., Ltd., made of Kanto Chemical Co., Ltd.). After the cleaning step, an aluminum plate having an uneven surface was obtained. The surface of the obtained aluminum plate was observed with a 10 × objective lens of a laser microscope (“KEYENCE VK-X100”), and the surface roughness was measured. The ten-point average roughness Rz was 62 μm.

[Resin pellet production]
Each component other than the C1 component described in the above Table 1 is blended at a ratio (mass ratio) described below in Table 2 below, mixed in a tumbler for 20 minutes, and manufactured by Nippon Steel Works Co., Ltd. Feed into a shaft extruder ("TEX30α") from an upstream feeder, and while feeding C1 component from the middle of the barrel, knead at 250 rpm, discharge amount 40 kg / hour, barrel temperature 260 ° C, strand shape The extruded molten resin was quenched in a water bath and pelletized using a pelletizer to obtain pellets of the resin composition.

[Measurement of flow length (bar flow flow length)]
The pellets obtained by the above-mentioned production method are dried at 80 ° C. for 5 hours, and then the resin flow part is helical and the injection molding machine (“NEX 80 III”, clamping force 80 T) manufactured by Nisshin Plastics Co., Ltd. Using a mold with a thickness of 2 mm and a width of 20 mm, injection molding under the conditions of a cylinder temperature of 240 ° C., a mold temperature of 40 ° C. and an injection pressure of 100 MPa, and its flow length (bar flow flow length, unit: mm) It was measured.

[Production of test piece]
The pellets obtained by the above-mentioned production method are dried at 80 ° C. for 5 hours, and then a cylinder temperature of 240 ° C., a mold, using an injection molding machine (“NEX 80 III”, clamping force 80 T) manufactured by Nissei Resin Industry Co., Ltd. It injection-molded on the conditions of temperature 40 degreeC, and shape | molded the ISO multi-purpose test piece (4 mm thickness).

[Heat resistance evaluation (DTUL)]
As heat resistance evaluation, load deflection temperature (DTUL, unit: ° C.) was measured under the condition of load 1.8 MPa according to ISO 75-1 using ISO multi-purpose test piece (4 mm thickness) obtained by the above-mentioned method .

The aluminum plate (laser-treated or chemically-etched product) obtained above in accordance with ISO 19095 was cut into a size of 45 mm long × 12 mm wide × 1.5 mm thick and mounted in a mold cavity.
Using the pellet of the resin composition obtained above dried at 120 ° C. for 4 hours on the uneven surface side of the mounted aluminum plate, as shown in FIG. 1, the bonding area of the aluminum plate and the resin composition is long A metal in which an aluminum plate (metal member) 1 and a resin composition (resin member) 2 as shown in FIG. 1 are insert-molded (length 45 mm × width 10 mm × thickness 3 mm) to be 5 mm × 10 mm wide. The resin complex was molded.
Insert molding uses “FANUC α-100” manufactured by FANUC as an injection molding machine, cylinder temperature 270 ° C., mold temperature 60 ° C., injection speed 30 mm / sec, filling time 0.58 seconds, holding pressure 110 MPa, holding pressure The conditions were 6 seconds in time and 40 seconds in cooling time.
In Table 2, for the localized heating "with", the bonding area of the metal surface is heated for 120 seconds with a cartridge heater (120 V, 350 W) previously arranged in the mold before injection of the resin, and the bonding area of the metal surface After the temperature of the mixture reached 90.degree. C., it was injection molded to obtain a metal resin composite.

[Joint strength evaluation]
The bonding property was evaluated using the obtained metal resin composite in accordance with ISO19095.
The measurement is carried out using a tensile tester (Instron Co., Ltd. “type 5544”), sandwiching the integrated aluminum plate 1 and the resin composition portion 2 in a jig conforming to ISO 19095, and The bonding strength was evaluated by clamping both ends in the long axis direction with a clamp and pulling at a tensile speed of 5 mm / min and a distance between chucks of 80 mm.
Evaluation criteria are as follows.
A: The resin member broke the base material. The resin remained 100% in the metal asperities.
B: A part of the resin member was broken, but the resin remained at 70% or more and less than 100% in the metal surface asperities.
C: The resin did not remain on the metal surface asperities, and peeled off at the interface.
Of the above A, B and C, A and B can be judged to have no problem in practical use.

[Evaluation of air tightness]
The airtightness of the joint surface was evaluated as follows.
As shown in FIG. 2 (the upper view is a top view, the lower view is a cross-sectional view), the central portion of a disc made of aluminum (JIS A1050) with an outer diameter of 55 mm and a thickness of 2 mm. The same insert molding as above is performed on the upper surface of the inner peripheral side of a doughnut-shaped aluminum disc provided with a hole having an inner diameter of 20 mm, and the resin composition is joined with an overlapping width of 2 mm. A piece was made.
Using a “bottle pressure resistance tester” manufactured by Toyo Seiki Co., Ltd., it was set in a dedicated jig, and after the inside of the jig tank was first filled with water, it was immersed in water at 25 ° C. Next, water supply is started into the jig tank, the pressure inside the weldment is increased in 196 kPa steps, and the point of pressure release from the weld (point of pressure drop) is the maximum breaking pressure (pressure resistance, unit: MPa). did. As an apparatus, a “bottle pressure tester” manufactured by Toyo Seiki Co., Ltd. was used. In addition, the measurement limit of the compressive strength of this apparatus is 2.0 MPa.
Evaluation criteria are as follows.
A: Withstanding strength is 2.0 MPa or more B: Withstanding strength is 1.0 MPa or more and less than 2.0 MPa C: Withstanding strength is less than 1.0 MPa

The results are shown in Table 2 below.

As is clear from the above results, the metal resin composite molded using the resin composition of the present invention is excellent in the bondability of the resin composition (resin member) and the aluminum member (metal member), and the airtightness of the bonding surface Is also excellent (Examples 1 to 15). In particular, by setting the flow length (2 mm t bar flow) of the resin composition to 380 mm or more and further performing local heating, the bonding strength was further improved (Examples 1 to 7). Further, even in the case where local heating was not performed, by setting the flow length (2 mm t bar flow) to 380 mm or more, a bonding strength evaluation (B) judged to be sufficient in practice was obtained.
On the other hand, in Comparative Examples (Comparative Examples 1 to 4) in which the polycarbonate resin does not satisfy the flow length of 350 mm, the bonding strength is poor, and sufficient bonding strength can not be obtained even when locally heated (Comparative Examples 1 to 3).

  The metal resin composite of the present invention is suitable as a material of parts such as general household appliances, office automation equipment, electric and electronic products, parts for vehicles such as automobiles, and mechanical parts because polycarbonate resin members and metal members are firmly joined. Used for

1: Aluminum member 2: Resin composition member

Claims (9)

  It is a resin composition containing polycarbonate resin (A), Comprising: The flow length (2 mm t bar flow) of a resin composition is 350 mm or more, The resin composition for metal joining characterized by the above-mentioned.   The resin composition contains 30 parts by mass or more of another resin (B) other than the polycarbonate resin (A) and 24 parts by mass or more of the phosphorus-based plasticizer (C) with respect to 100 parts by mass of the polycarbonate resin (A) The resin composition for metal joining of Claim 1.   The resin composition for metal joining according to claim 1 or 2, wherein the viscosity average molecular weight of the polycarbonate resin (A) is 22000 or less.   The resin composition for metal bonding according to any one of claims 1 to 3, wherein a flow length (2 mm t bar flow) of the resin composition is 380 mm or more.   The metal resin composite which joined the resin composition of any one of Claim 1 to 4 to the surface of the metal which has an unevenness | corrugation.   The metal-resin composite according to claim 5, wherein the unevenness of the metal surface has an opening diameter of 0.01 to 1000 m and a depth of 0.05 to 1000 m.   The metal-resin composite according to claim 5 or 6, wherein the unevenness of the metal surface is formed by laser processing.   A method for producing a metal resin composite, comprising bonding the resin composition according to any one of claims 1 to 4 to a surface having irregularities of a metal having an irregular surface.   9. The method for producing a metal-resin composite according to claim 8, wherein at least a part of the region where the metal and the resin are joined is heated before the resin composition is joined to the surface having irregularities of the metal.