JP2017136839A - Metal/resin composite structure, method for manufacturing metal/resin composite structure, nickel plated steel member and method for producing nickel plated steel member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal/resin composite structure which is formed by strongly joining and sticking a thermoplastic resin to a steel member and has a steel portion with high rust prevention ability, and a method for producing the same, and a nickel plated steel member to which the thermoplastic resin can be strongly joined and stuck and which is excellent in rust prevention ability, and a method for producing the same.SOLUTION: The metal/resin composite structure 106 of the present invention is a metal/resin composite structure formed by joining a nickel plated steel member 108 on which a nickel plating layer 107 is formed to cover a part or all of a surface 110 of a steel member 103 to a thermoplastic resin member 105 comprised of a thermoplastic resin or a resin composition containing the thermoplastic resin. In the metal/resin composite structure 106, an average value of ten- point average roughness (Rz) of at least a joining surface 104 of the nickel plated steel member 108 to the thermoplastic resin member 105, which is measured according to JIS B0601, exceeds 2 μm.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a metal / resin composite structure, a metal / resin composite structure manufacturing method, a nickel-plated steel member, and a nickel-plated steel member manufacturing method.

  A technique for joining and integrating a steel member and a resin is required in a wide range of industrial fields such as parts manufacturing industries such as automobiles, building structures, home appliances, medical equipment, and industrial equipment.

  In recent years, as a technique for joining a resin member and a metal member, a method of joining the resin member and the metal member by directly injection-molding the resin member to the metal member instead of a technique using an existing adhesive, so-called “injection” A “joining method” has been proposed (for example, Patent Documents 1 and 2).

  In the injection joining method, for example, a resin member and a metal member are joined by injection-molding an engineering plastic having a polar group having an affinity for the metal member on a metal member having fine irregularities formed on the surface. (For example, Patent Documents 1 and 2). However, metal members that exhibit strong bonding strength by the injection bonding method are limited to aluminum-based metal, magnesium-based metal, copper-based metal, and titanium-based metal, and the bonding strength is low for polyolefins that do not have polar groups. It was the actual situation.

Moreover, the technique for joining stainless steel as a steel member, carbon steel, and resin is also disclosed (for example, patent documents 3-7).
Patent Document 3 (International Publication No. 2008/081933 pamphlet) discloses a technique of joining a roughened stainless steel obtained by mechanically processing a base material made of stainless steel and then dipping in a sulfuric acid aqueous solution or the like to a resin. It is disclosed.
In Patent Document 4 (International Publication No. 2009/011398 pamphlet) and Patent Document 5 (Japanese Patent Laid-Open No. 2011-156664), a steel material is mechanically processed, then immersed in an aqueous sulfuric acid solution, and then an aqueous amine solution. A technique for joining a roughened steel material obtained by dipping in a resin and a resin is disclosed.
Patent Document 6 (Japanese Patent Application Laid-Open No. 2011-168017) discloses a joined body of stainless steel and a resin treated by being immersed in a treatment liquid in which an oxidizing compound is dissolved in a ferric chloride aqueous solution.

International Publication No. 2003/064150 Pamphlet International Publication No. 2004/055248 Pamphlet International Publication No. 2008/081933 Pamphlet International Publication No. 2009/011398 Pamphlet JP 2011-156664 A JP 2011-168017 A JP 2001-011662 A

According to the study by the present inventors, it is clear that the bonding strength of the metal / resin composite structure obtained by the methods disclosed in Patent Documents 1 to 7 is still not sufficiently satisfactory. became. In particular, when a thermoplastic resin having a low affinity with a steel member such as a polyolefin-based resin is used as the thermoplastic resin member, it has been revealed that the bonding strength of the metal / resin composite structure is inferior.
For example, Patent Document 7 (Japanese Patent Application Laid-Open No. 2001-011662) discloses a method of roughening a stainless steel surface with an aqueous solution containing sulfuric acid, chlorine ions, cupric ions and thiol compounds. However, according to the follow-up tests and resin bonding experiments by the present inventors, it has been clarified that the metal / resin composite structure having a sufficient bonding strength that can withstand practical use cannot be obtained by the method described in Patent Document 7. Yes.

  Furthermore, in the metal / resin composite structure using a steel member as the metal member, there is a problem in the method for imparting rust prevention power to the metal member. That is, in a steel member / resin composite structure, a general-purpose steel member excluding special steel such as stainless steel has a property of being easily oxidized and easily rusted, or the steel member / resin composite structure is exposed to wind and rain. In view of the high frequency of use in the environment, the exposed metal part of the joined body is required to have a high rust prevention ability.

  In general, a general method for imparting a rust preventive function to a metal part of a steel member / resin composite structure is to apply metal plating or coating only to the metal part after manufacturing the joined body. However, this method requires selective metal plating or coating of only the metal portion of the steel member / resin composite structure, but such a method is not practical because of poor productivity. For example, many steps are required in a method in which only the resin portion is masked by a known method, and the entire composite structure including the resin portion is subjected to metal plating or coating and then demasked. In the method of coating or plating without masking the resin part, the resin part may be altered or decomposed by chemical treatment with strong acid or strong alkali. In order to minimize the influence on the resin portion, there has been a problem that the drying baking temperature is lowered, or plating with low rust prevention power is unavoidable.

  That is, the development of surface roughening technology for steel members that exhibit strong bonding force to thermoplastic resins such as polyolefin resins having low affinity with steel members, and the steel members roughened by the roughening technology There has been a strong demand from the industry for a joined body with a wide variety of resin types and having a strong antirust ability.

  The present invention has been made in view of the above circumstances, and is a metal / resin composite structure in which a thermoplastic resin is firmly bonded and fixed to a steel member, and the steel portion has a high rust prevention ability, and a method for producing the same. And a nickel-plated steel member capable of firmly joining and fixing a thermoplastic resin and having an excellent rust prevention ability, and a method for producing the same.

  The inventors of the present invention have made extensive studies on a steel member that can be joined to a thermoplastic resin and has excellent rust prevention ability. As a result, it is a nickel-plated steel member on which a nickel plating layer is formed, and is measured in accordance with JIS B0601, and is an average value of ten-point average roughness (Rz) of at least the surface of the joint with the thermoplastic resin. It has been found that the above problem can be solved by using a nickel-plated steel member having a thickness exceeding 2 μm. Such a nickel-plated steel member has, for example, a surface roughness that combines a step of treating with an aqueous solution containing acid, cupric ion, and chlorine ion, a step of treating with nitric acid, and a step of nickel plating with a nickel plating solution. It can be obtained by the process, and exhibits excellent rust prevention ability, and its roughened surface can be strongly bonded not only to engineering plastics but also to thermoplastic resins with low affinity with steel members such as polyolefin resins. And reached the present invention.

  That is, according to the present invention, the following metal / resin composite structure, metal / resin composite structure manufacturing method, nickel-plated steel member, and nickel-plated steel member manufacturing method are provided.

[1]
A nickel-plated steel member having a nickel plating layer formed so as to cover part or all of the surface of the steel member, and a thermoplastic resin member made of a thermoplastic resin or a resin composition containing the thermoplastic resin. A bonded metal / resin composite structure,
A metal characterized in that an average value of ten-point average roughness (Rz) of a surface of a joint portion between at least the nickel-plated steel member and the thermoplastic resin member measured in accordance with JIS B0601 exceeds 2 μm. / Resin composite structure.
[2]
The metal / resin composite structure according to [1], wherein the surface of the steel member has a fine uneven shape, and the nickel plating layer is formed to cover at least the fine uneven shape.
[3]
The metal / resin composite structure according to the above [2], wherein the fine concavo-convex shape is a shape in which convex portions having an interval period of 5 nm or more and 500 μm or less stand.
[4]
The metal / resin composite structure according to any one of [1] to [3], wherein an average thickness of the nickel plating layer is 0.1 μm or more and 20 μm or less.
[5]
[1] to [1], wherein the nickel plating layer contains phosphorus (P), and the content of the phosphorus (P) in the nickel plating layer is 0.05 wt% or more and 20 wt% or less. 4] The metal / resin composite structure according to any one of 4).
[6]
The thermoplastic resin is polyolefin resin, polyester resin, polyamide resin, polycarbonate resin, polyether ether ketone resin, polyether ketone resin, polyimide resin, polyether sulfone resin, polystyrene resin, polyacrylonitrile resin, styrene / acrylonitrile. Any one of [1] to [5] above, comprising one or more selected from a copolymer resin, an acrylonitrile / butadiene / styrene copolymer resin, and a polymethyl methacrylate resin The metal / resin composite structure according to 1.
[7]
The metal / resin composite structure according to any one of [1] to [6], wherein the steel member includes rolled mild steel.
[8]
A nickel plating layer was formed so as to cover a part or all of the surface of a steel member used for joining with a thermoplastic resin or a thermoplastic resin member composed of a resin composition containing the thermoplastic resin. A nickel plated steel member,
A nickel-plated steel member having an average value of 10-point average roughness (Rz) of at least the surface of the joint with the thermoplastic resin member measured in accordance with JIS B0601 exceeds 2 μm.
[9]
A method for producing a metal / resin composite structure according to any one of the above [1] to [7],
A nickel-plated steel member that has a nickel plating layer formed so as to cover part or all of the surface and that has at least a fine uneven shape on the surface of the joint with the thermoplastic resin member is placed in a mold for injection molding. Installation process;
A step of injection-molding a thermoplastic resin or a resin composition containing the thermoplastic resin in the mold such that at least a part of the thermoplastic resin member is in contact with the fine uneven shape of the nickel-plated steel member; A process for producing a metal / resin composite structure, comprising:
[10]
Used for joining with a thermoplastic resin or a thermoplastic resin member composed of a resin composition containing the thermoplastic resin, a nickel plating layer is formed so as to cover part or all of the surface of the steel member; and It is a manufacturing method for manufacturing a nickel-plated steel member having a fine uneven shape on the surface of a joint portion with at least a thermoplastic resin member,
A first treatment step of treating at least the joint surface of the steel member with the thermoplastic resin member with an aqueous solution containing an acid, a cupric ion, and a chlorine ion;
A second treatment step of treating at least the joint surface with an inorganic acid;
After the second treatment step, at least the joint surface, a third treatment step of nickel plating with a nickel plating solution,
The manufacturing method of the nickel-plated steel member containing this.
[11]
In the method for producing a nickel-plated steel member according to [10] above,
The manufacturing method of the nickel-plated steel member which performs after the said 2nd process process and before the said 3rd process process, further performing the process process which processes at least the said junction part surface with a copper plating peeling liquid.

  According to the present invention, a thermoplastic resin is firmly bonded and fixed to a steel member, and a metal / resin composite structure excellent in rust-proofing power, a manufacturing method thereof, and a thermoplastic resin It is possible to provide a nickel-plated steel member that can be fixed and is excellent in rust prevention power and a method for producing the same.

It is the external view which showed typically an example of the structure of the metal / resin composite structure which concerns on this embodiment. It is sectional drawing which showed typically the cross section of the junction part of the metal / resin composite structure which concerns on this embodiment. 2 is an element mapping of an electron micrograph of a cross-sectional view of a joint portion of a metal / resin composite structure obtained in Example 1. FIG. Description will be given of measurement points on a total of six straight portions including arbitrary three straight portions in parallel relation on the surface of the nickel-plated steel member according to the present embodiment and arbitrary three straight portions orthogonal to the three straight portions. It is a schematic diagram for. On the surface of the nickel-plated steel member obtained in each of the preparation examples, measurement points of a total of 6 linear parts composed of arbitrary 3 linear parts in parallel relation and arbitrary 3 linear parts orthogonal to the 3 linear parts It is a schematic diagram for demonstrating. It is a figure which shows an example of the surface roughness curve of the surface of the nickel-plated steel member based on Example 3, 4. FIG. It is a figure which shows an example of the surface roughness curve of the surface of the nickel-plated steel member based on Example 5, 6. FIG.

  Embodiments of the present invention will be described below with reference to the drawings. In all the drawings, similar constituent elements are denoted by common reference numerals, and description thereof is omitted as appropriate. In addition, "A-B" which shows the numerical range in a sentence represents A or more and B or less unless there is particular notice.

FIG. 1 is an external view schematically showing an example of the structure of the metal / resin composite structure 106 according to the present embodiment. FIG. 2 is a cross-sectional view schematically showing a cross section of the joint portion of the metal / resin composite structure 106 according to the present embodiment.
The metal / resin composite structure 106 according to this embodiment is a nickel-plated steel member 108 in which a nickel plating layer 107 is formed so as to cover a part or all of the surface of the steel member 103, and conforms to JIS B0601. A nickel-plated steel member 108 having an average value of 10-point average roughness (Rz) of the joint surface 104 of at least the nickel-plated steel member 108 with the thermoplastic resin member 105 of more than 2 μm, A thermoplastic resin member 105 made of a resin composition (R2) containing the plastic resin (R1) or the thermoplastic resin (R1) is joined.
In this embodiment, it is preferable that the surface of the steel member 103 has a fine uneven shape, and the nickel plating layer 107 covers the entire shape thinly along the fine uneven shape without sealing at least the fine uneven shape. It is preferable to be formed. The metal / resin composite structure 106 according to this embodiment is obtained by joining a nickel plated steel member 108 and a thermoplastic resin member 105.
Here, it is preferable that the nickel plating layer 107 is formed so as to cover at least the fine concavo-convex shape of the joint surface 104.

The surface 110 of the nickel-plated steel member 108 is formed with a roughened surface suitable for improving the bonding strength between the nickel-plated steel member 108 and the thermoplastic resin member 105, so that no adhesive is used. It becomes possible to ensure the bondability between the nickel plated steel member 108 and the thermoplastic resin member 105.
Specifically, when the thermoplastic resin member 105 enters the roughened shape of the surface 110 of the nickel-plated steel member 108, the nickel-plated steel member 108 and the thermoplastic resin member 105 are physically separated. Therefore, the steel member 103 and the thermoplastic resin member 105 that are normally difficult to join can be firmly joined.

  The metal / resin composite structure 106 obtained in this way can also prevent moisture and moisture from entering the interface between the steel member 103 and the thermoplastic resin member 105. That is, the air tightness and water tightness at the adhesion interface of the metal / resin composite structure 106 can be improved.

  Hereinafter, the metal / resin composite structure 106 in which the thermoplastic resin member 105 and the nickel-plated steel member 108 are bonded together, a method for manufacturing the metal / resin composite structure 106, and the thermoplastic resin can be strongly bonded / fixed, and have anti-rust performance. A method for manufacturing the nickel-plated steel member 108 excellent in the above will be described.

[Thermoplastic resin member]
Hereinafter, the thermoplastic resin member 105 according to the present embodiment will be described.
The thermoplastic resin member 105 is made of a thermoplastic resin (R1) or a resin composition (R2) containing a thermoplastic resin (R1). The resin composition (R2) includes a thermoplastic resin (R1) as a resin component, for example, a filler (B). Furthermore, the resin composition (R2) contains other compounding agents as necessary. The resin composition (R2) contains the thermoplastic resin (R1) as a main component. In the present embodiment, the “main component” is defined as a component occupying 50% by weight or more. The thermoplastic resin (R1) in the resin composition (R2) is preferably more than 50% by weight, more preferably 60% by weight or more.

(Thermoplastic resin (R1))
The thermoplastic resin (R1) is not particularly limited. For example, a polyolefin resin, a polymethacrylic resin such as a polymethyl methacrylate resin, a polyacrylic resin such as a polymethyl acrylate resin, a polystyrene resin, polyvinyl alcohol-poly Vinyl chloride copolymer resin, polyvinyl acetal resin, polyvinyl butyral resin, polyvinyl formal resin, polymethylpentene resin, maleic anhydride-styrene copolymer resin, polycarbonate resin, polyphenylene ether resin, polyether ether ketone resin, polyether ketone Aromatic polyether ketones such as resins, polyester resins, polyamide resins, polyamideimide resins, polyimide resins, polyetherimide resins, styrene elastomers, polyolefin elastomers Mer, polyurethane elastomer, polyester elastomer, polyamide elastomer, ionomer, aminopolyacrylamide resin, isobutylene maleic anhydride copolymer, ABS, ACS, AES, AS, ASA, MBS, ethylene-vinyl chloride copolymer, ethylene-vinyl acetate copolymer , Ethylene-vinyl acetate-vinyl chloride graft polymer, ethylene-vinyl alcohol copolymer, chlorinated polyvinyl chloride resin, chlorinated polyethylene resin, chlorinated polypropylene resin, carboxyvinyl polymer, ketone resin, amorphous copolyester resin, norbornene resin , Fluoroplastic, polytetrafluoroethylene resin, fluorinated ethylene polypropylene resin, PFA, polychlorofluoroethylene resin, ethylene Lafluoroethylene copolymer, polyvinylidene fluoride resin, polyvinyl fluoride resin, tetrafluoroethylene-perfluoroalkyl vinyl ether resin, polyarylate resin, thermoplastic polyimide resin, polyvinylidene chloride resin, polyvinyl chloride resin, polyvinyl acetate resin, polysulfone Resin, polyparamethylstyrene resin, polyallylamine resin, polyvinyl ether resin, polyphenylene oxide resin, polyphenylene sulfide (PPS) resin, polymethylpentene resin, oligoester acrylate, xylene resin, maleic acid resin, polyhydroxybutyrate resin, polysulfone Resin, polylactic acid resin, polyglutamic acid resin, polycaprolactone resin, polyethersulfone resin, polyacrylonitrile resin, styrene-acrylic resin Examples include rilonitrile copolymer resin and acrylonitrile-butadiene-styrene copolymer resin (ABS resin). These thermoplastic resins may be used individually by 1 type, and may be used in combination of 2 or more types.

  Among these, as the thermoplastic resin (R1), from the viewpoint that the effect of improving the bonding strength between the nickel-plated steel member 108 and the thermoplastic resin member 105 can be obtained more effectively, a polyolefin-based resin and a polyester-based resin. One or two or more thermoplastic resins selected from polyamide resins are preferably used.

As the polyolefin-based resin, a polymer obtained by polymerizing olefin can be used without any particular limitation.
Examples of the olefin constituting the polyolefin-based resin include ethylene, α-olefin, and cyclic olefin.

  Examples of the α-olefin include linear or branched α-olefins having 3 to 30 carbon atoms, preferably 3 to 20 carbon atoms. More specifically, propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-octene, Decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene and the like can be mentioned.

  As said cyclic olefin, a C3-C30 cyclic olefin is mentioned, Preferably it is C3-C20. More specifically, cyclopentene, cycloheptene, norbornene, 5-methyl-2-norbornene, tetracyclododecene, 2-methyl-1,4,5,8-dimethano-1,2,3,4,4a, 5 , 8,8a-octahydronaphthalene and the like.

  As the olefin constituting the polyolefin resin, ethylene, propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1- Examples include pentene. Of these, ethylene, propylene, 1-butene, 1-hexene and 4-methyl-1-pentene are more preferable, and ethylene or propylene is more preferable.

  The polyolefin resin may be obtained by polymerizing the above-mentioned olefin alone, or may be obtained by random copolymerization, block copolymerization, or graft copolymerization in combination of two or more. .

  The polyolefin resin may be a linear resin or a resin having a branched structure.

  Examples of the polyester resin include aliphatic polyesters such as polylactic acid, polyglycolic acid, polycaprolactone, and polyethylene succinate, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate (PBT), and polycyclohexylenedimethylene terephthalate (PCT). ) And the like.

  Examples of the polyamide resins include ring-opening polymerization aliphatic polyamides such as PA6 and PA12; polycondensation polyamides such as PA66, PA46, PA610, PA612, and PA11; MXD6, PA6T, PA9T, PA6T / 66, PA6T / 6. Semi-aromatic polyamides such as amorphous PA; polyaromatic polyamides such as poly (p-phenylene terephthalamide), poly (m-phenylene terephthalamide), poly (m-phenylene isophthalamide), amide elastomers, etc. It is done.

  Moreover, as the thermoplastic resin (R1), a nickel plating layer is formed on the surface, and the joining member surface 104 with the thermoplastic resin member 105 has a fine uneven shape, and the steel member 103 and the thermoplastic resin member 105. One or two or more thermoplastic resins selected from thermoplastic resins having a glass transition temperature of 140 ° C. or higher and amorphous thermoplastic resins are preferably used from the viewpoint of more effectively obtaining the bonding strength improvement effect. Used.

  The thermoplastic resin having a glass transition temperature of 140 ° C. or higher is selected from, for example, polycarbonate resin, polyetheretherketone resin, polyetherketone resin and other aromatic polyetherketone, polyimide resin, and polyethersulfone resin. 1 type or 2 types or more are mentioned.

  Examples of the amorphous thermoplastic resin include polystyrene resin, polyacrylonitrile resin, styrene-acrylonitrile copolymer resin, acrylonitrile-butadiene-styrene copolymer resin (ABS resin), polymethyl methacrylate resin, and polycarbonate resin. 1 type or 2 types or more selected from are mentioned.

  Among these, as the thermoplastic resin (R1), from the viewpoint that the effect of improving the bonding strength between the nickel-plated steel member 108 and the thermoplastic resin member 105 can be obtained more effectively, a polyolefin-based resin and a polyester-based resin. , Polyamide resin, polycarbonate resin, polyether ether ketone resin, polyether ketone resin, polyimide resin, polyether sulfone resin, polystyrene resin, polyacrylonitrile resin, styrene / acrylonitrile copolymer resin, acrylonitrile / butadiene / styrene copolymer One or two or more thermoplastic resins selected from resins and polymethyl methacrylate resins are preferably used.

(Filler (B))
The resin composition (R2) is a filler from the viewpoints of adjusting the difference in coefficient of linear expansion between the steel member 103 and the thermoplastic resin member 105, improving the mechanical strength of the thermoplastic resin member 105, improving heat cycle characteristics, etc. It is preferable to further include (B).

  Examples of the filler (B) include fillers such as a fibrous filler, a granular filler, and a plate-like filler. Examples of the fibrous filler include glass fiber, carbon fiber, and aramid fiber. Specific examples of the glass fiber include chopped strands having an average fiber diameter of 6 to 14 μm. Examples of the granular filler and plate-like filler include calcium carbonate, mica, glass flake, glass balloon, magnesium carbonate, silica, talc, clay, glass fiber, carbon fiber, and aramid fiber pulverized product. . These fillers (B) may be used individually by 1 type, and may be used in combination of 2 or more types.

  The content of the filler (B) in the resin composition (R2) is usually 50% by weight or less, preferably less than 50% by weight, more preferably less than 50% by weight, when the entire resin composition (R2) is 100% by weight. Is less than 40% by weight. Further, the lower limit of the content of the filler (B) is preferably 5% by weight or more, more preferably 10% by weight or more.

  The filler (B) has an effect of controlling the linear expansion coefficient of the thermoplastic resin member 105 in addition to the effect of increasing the rigidity of the thermoplastic resin member 105. In particular, in the case of the composite of the steel member 103 and the thermoplastic resin member 105 according to the present embodiment, the temperature dependence of the shape stability of the steel member 103 and the thermoplastic resin member 105 is often greatly different. When the temperature changes, the composite tends to be distorted. When the thermoplastic resin member 105 contains the filler (B), this distortion can be reduced. Moreover, when content of the said filler (B) exists in the said range, reduction of toughness can be suppressed.

In the present embodiment, the filler (B) is preferably a fibrous filler, more preferably glass fiber or carbon fiber, and particularly preferably glass fiber.
Thereby, since shrinkage | contraction of the thermoplastic resin member 105 after shaping | molding can be suppressed, joining to the steel member 103 and the thermoplastic resin member 105 can be made stronger.

(Other ingredients)
The thermoplastic resin (R1) or the resin composition (R2) containing the thermoplastic resin (R1) may contain other compounding agents for the purpose of imparting individual functions.
Examples of the compounding agents include heat stabilizers, antioxidants, pigments, weathering agents, flame retardants, plasticizers, dispersants, lubricants, mold release agents, antistatic agents, and the like.

(Production method of resin composition (R2))
The manufacturing method of a resin composition (R2) is not specifically limited, Generally, it can manufacture by a well-known method. For example, the following method is mentioned. First, the thermoplastic resin (R1), the filler (B), and, if necessary, the other compounding agents are added to a Banbury mixer, a single screw extruder, a twin screw extruder, a high speed twin screw extruder. The resin composition (R2) is obtained by mixing or melt-mixing using a mixing device such as the above.

[Steel members]
Hereinafter, the nickel plated steel member 108 and the steel member 103 before forming the nickel plating layer according to the present embodiment will be described.
(Plated steel member)
The nickel-plated steel member 108 according to the present embodiment is a steel member 103 on which a nickel plating layer 107 is formed. At least the joint surface 104 with the thermoplastic resin member 105 is roughened, and JIS B0601 is used. The average value of the ten-point average roughness (Rz) of the joint surface 104 measured in accordance with the above exceeds 2 μm. Specifically.
JIS B0601 (corresponding international standard: for a total of 6 straight portions consisting of arbitrary 3 linear portions in parallel relation on the surface 110 of the nickel plated steel member 108 and arbitrary 3 linear portions orthogonal to the 3 linear portions. The 10-point average roughness (Rz) at an evaluation length of 4 mm of all linear portions measured in accordance with ISO 4287) is preferably more than 2 μm, more preferably more than 3 μm, and further more preferably 5 μm or more. preferable.
In addition, JIS B0601 (corresponding international standards) are formed on a total of six straight portions including arbitrary three straight portions in parallel relation on the surface 110 of the nickel plated steel member 108 and arbitrary three straight portions orthogonal to the three straight portions. Standard: The 10-point average roughness (Rz) at an evaluation length of 4 mm of all linear portions measured in accordance with ISO 4287) is preferably 40 μm or less, more preferably 35 μm or less, and even more preferably 30 μm or less.

From the viewpoint of further improving the bonding strength between the nickel plated steel member 108 and the thermoplastic resin member 105, the average value of the ten-point average roughness (Rz) on the surface 110 of the nickel plated steel member 108 is preferably It is more than 2 μm and not more than 40 μm, more preferably more than 3 μm and not more than 35 μm, still more preferably not less than 5 μm and not more than 30 μm, particularly preferably more than 7 μm and not more than 30 μm.
In addition, what averaged the 10-point average roughness (Rz) of the above-mentioned arbitrary 6 linear parts can be employ | adopted for the average value of the said 10-point average roughness (Rz).

From the viewpoint of further improving the bonding strength between the nickel-plated steel member 108 and the thermoplastic resin member 105, the average value of the average length (RSm) of the roughness curve elements on the surface 110 of the nickel-plated steel member 108 Is preferably more than 50 μm and less than 500 μm, more preferably 100 μm or more and 400 μm or less.
In addition, what averaged RSm of the above-mentioned arbitrary 6 linear parts can be employ | adopted for the average value of the average length (RSm) of the said roughness curve element.

FIG. 4 is a diagram for explaining a total of six straight portions including arbitrary three straight portions in parallel relation on the surface 110 of the nickel plated steel member 108 and arbitrary three straight portions orthogonal to the three straight portions. It is a schematic diagram.
For example, the 6 straight portions B1 to B6 as shown in FIG. 4 can be selected as the 6 straight portions. First, a center line B1 passing through the center portion A of the joint surface 104 of the nickel plated steel member 108 is selected as the reference line. Next, straight lines B2 and B3 that are parallel to the center line B1 are selected. Next, a center line B4 orthogonal to the center line B1 is selected, and straight lines B5 and B6 orthogonal to the center line B1 and parallel to the center line B4 are selected. Here, the vertical distances D1 to D4 between the straight lines are, for example, 2 to 5 mm.
In general, the surface roughening treatment is applied not only to the joint surface 104 in the surface 110 of the nickel-plated steel member 108 but also to the entire surface 110 of the nickel-plated steel member 108. As shown in FIG. 5, six straight portions may be selected from locations other than the joint surface 104 on the same surface as the joint surface 104 of the nickel-plated steel member 108.

(Steel member before nickel plating)
Next, the steel member 103 before nickel plating will be described.
The steel member 103 according to the present embodiment has a fine concavo-convex shape at least on the joint surface 104 with the thermoplastic resin member 105. From the viewpoint of bonding the steel member 103 and the thermoplastic resin member 105 more firmly, the fine uneven shape is preferably a shape in which convex portions having an interval period of 5 nm or more and 500 μm or less stand.
The interval period of the fine concavo-convex shape is an average value of the distance from the convex portion to the adjacent convex portion, and can be obtained from a photograph taken with an electron microscope or a laser microscope.
Specifically, the surface 110 of the steel member 103 is photographed with an electron microscope or a laser microscope. From the photograph, 50 arbitrary convex portions are selected, and the distances from those convex portions to adjacent convex portions are measured. An interval period is defined by integrating all the distances from the convex portion to the adjacent convex portion and dividing the sum by 50.

The interval period of the convex portions is preferably 10 nm or more and 300 μm or less, more preferably 20 nm or more and 200 μm or less.
When the interval interval of the convex portions is equal to or more than the lower limit value, the thermoplastic resin member 105 can sufficiently enter the concave portions having the fine uneven shape, and the bonding strength between the steel member 103 and the thermoplastic resin member 105 is further increased. Can be improved. Moreover, when the interval period of the convex portions is equal to or less than the above upper limit value, it is possible to suppress the generation of a gap at the metal-resin interface of the obtained metal / resin composite structure 106. As a result, since impurities such as moisture can be prevented from entering from the gap between the metal-resin interface, it is possible to suppress a decrease in strength when the metal / resin composite structure 106 is used at high temperature and high humidity.

  The fine concavo-convex shape having the above-described interval cycle in the steel member 103 according to the present embodiment is, for example, three processing steps of a later-described first processing step, second processing step, and third processing step for the steel member. Can be formed.

In the steel member 103 according to this embodiment, a nickel plating layer 107 is formed so as to cover part or all of the surface. And it is preferable that the nickel plating layer 107 is formed so as to cover at least the fine uneven shape of the joint surface 104. From the viewpoint of improving the rust prevention function of the metal portion of the metal / resin composite structure 106, the nickel plating layer 107 is more preferably formed so as to cover the entire surface of the steel member 103. .
In addition, in the metal / resin composite structure 106 according to the present embodiment, from the viewpoint of further improving the bonding strength between the steel member 103 and the thermoplastic resin member 105 while further improving the antirust performance of the steel portion, the nickel plating layer The average thickness of 107 is preferably from 0.1 μm to 20 μm, more preferably from 0.5 μm to 10 μm, still more preferably from 0.8 μm to 5 μm, and particularly preferably from 1 μm to 4 μm.

[Manufacturing method of nickel-plated steel member with excellent rust prevention performance]
The manufacturing method of the nickel-plated steel member 108 with excellent rust prevention capability according to the present embodiment includes at least the following three steps of the first treatment step, the second treatment step, and the third treatment step, and An optional treatment step may be further included between the second treatment step and the third treatment step.
(First treatment step) At least the step of treating the surface 104 of the steel member 103 with the thermoplastic resin member 105 with an aqueous solution containing acid, cupric ion and chlorine ion (second treatment step) at least Step of treating the joint surface 104 with an inorganic acid (third treatment step) Step of nickel plating at least the joint surface 104 with a nickel plating solution (optional treatment step) Treating at least the joint surface 104 with a copper plating stripper Process

  First, the steel member of the present embodiment is a component material made of a steel material and assembling a predetermined structure. Here, steel members include ordinary steel (carbon steel) and special steel as a whole, for example, carbon steel such as general structural rolled steel, low temperature steel, nuclear steel plate material, etc. , “SPCC”), hot-rolled steel (hereinafter referred to as “SPHC”), hot-rolled steel sheet for automobile structure (hereinafter referred to as “SAPH”), hot-rolled high-tensile steel sheet for automobile processing. (Hereinafter referred to as “SPFH”). Since many of these can be pressed and cut, the structure and shape can be freely selected when they are used as parts and main bodies. Moreover, the steel material as used in this embodiment is not restricted to the said steel material, For example, all the steel materials standardized by Japanese Industrial Standard (JIS "SS400") etc. are contained. The steel member 103 is preferably made of rolled mild steel.

The shape of the steel member 103 is not particularly limited as long as it can be joined to the thermoplastic resin member 105. For example, the steel member 103 can have a flat plate shape, a curved plate shape, a rod shape, a cylindrical shape, a lump shape, or the like. Moreover, the structure which consists of these combination may be sufficient.
Further, the shape of the joint surface 104 to be joined to the thermoplastic resin member 105 is not particularly limited, and examples thereof include a flat surface and a curved surface.

  The steel member 103 is processed into a predetermined shape as described above by metal removal such as cutting, pressing, etc., plastic processing, punching, cutting, polishing, electric discharge processing, and the like, and then a roughening process described later is performed. Those are preferred. In short, it is preferable to use a material processed into a necessary shape by various processing methods.

  Next, each processing step will be described in detail.

(First processing step)
A 1st process process processes the steel member washed with water after degreasing | defatting with a degreasing agent for steel materials, a neutral detergent, etc. as needed using the aqueous solution containing an acid, a cupric ion, and a chlorine ion. By this first treatment step, an uneven copper layer is formed on the surface 110 of the steel member 103.
As an aqueous solution containing acid, cupric ion and chlorine ion, acid is 15 to 70% by weight, chlorine ion is 0.3 to 9.5% by weight, preferably 1 to 7% by weight and cupric ion is at least An aqueous solution containing 0.01% by weight or more, preferably 0.02 to 6% by weight is preferred. In addition, the aqueous solution may contain a thiol compound as required. When the thiol compound is contained, the thiol compound is contained in an amount of 0.00001 to 1% by weight, preferably 0.00005 to 1% by weight. An aqueous solution is preferred.

Examples of the acid include inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, perchloric acid, and sulfamic acid, and organic acids such as sulfonic acid and carboxylic acid. Examples of the carboxylic acid include formic acid, acetic acid, citric acid, oxalic acid, malic acid and the like. As the acid, sulfuric acid is preferred.
Examples of the chloride ion source compound include sodium chloride, potassium chloride, and ammonium chloride.
Examples of the cupric ion source compound include cupric chloride, cupric nitrate, cupric sulfate, cupric acetate, and cupric hydroxide.
Examples of the thiol compound include thiolic acids such as thioformic acid, thioacetic acid, and thiopropionic acid; thiocarboxylic acids such as thioglycolic acid, thiodiglycolic acid, thiolactic acid, and thiomalic acid; Group thiocarboxylic acids and the like.
The treatment temperature is usually 20 to 50 ° C., and the treatment time is usually 20 seconds to 10 minutes. After the first treatment step, washing and drying are performed as necessary.

(Second processing step)
In the second treatment step, the steel member obtained in the first treatment step is treated with an inorganic acid. Examples of inorganic acids include hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid, nitric acid and the like. Among these, nitric acid is preferably used from the viewpoint of the chemical etching power of iron.
For example, when nitric acid is used as the inorganic acid, the concentration of the inorganic acid is preferably 1 to 40% by weight, more preferably 5 to 30% by weight, and still more preferably 10 to 25% by weight. The treatment temperature is usually 20 to 50 ° C., and the treatment time is usually 20 to 180 seconds. As will be described later in the examples, by performing this second processing step, it is possible to dramatically improve the bonding force with the thermoplastic resin member that could not be obtained only by the first processing step. .

The present inventors presume this reason as follows. That is, by carrying out the second treatment step, the inorganic acid is brought into the steel member surface from the concave portion of the uneven copper layer generated on the steel member surface in the first treatment step, that is, from the portion close to the steel member. A large number of recesses (pits) having an overhang portion are formed on the surface 110 of the steel member by preferentially chemically etching iron that intrudes and has a higher ionization tendency than copper. It is surmised that the concave portion having such an overhang portion contributes to the improvement of the bonding force with the thermoplastic resin member 105 due to the anchor effect.
After the second treatment step, washing and drying are performed as necessary.

  This embodiment also includes an aspect in which the cycle of the first processing step and the second processing step is repeated two or more times. In the examples described later, the first processing step → second processing step → first processing step → second processing step is performed between the degreasing step and the third processing step. In such a treatment method, the ten-point average roughness (Rz) of the surface of the steel member can be increased, so that it is preferably used in applications where a high bonding strength is required.

(Third treatment process)
The third treatment step is a step of performing nickel plating on at least the joint surface 104 of the steel member obtained in the second treatment step.
As the nickel plating treatment, for example, electroless nickel plating treatment is preferably used. As the nickel plating solution used for the electroless nickel plating treatment, for example, a solution containing nickel salt and hypozinc phosphate can be used.
As the electroless nickel plating treatment, a known method can be used without limitation. For example, a method using a nickel plating solution containing nickel sulfate or nickel chloride as a nickel salt, sodium hypophosphite as a reducing agent, and a metal of an iron group element or a platinum group element as a reduction catalyst can be mentioned. . In addition to an acidic bath using sodium hypophosphite as the reducing agent, an alkaline bath using sodium hypophosphite or a borohydride compound as the reducing agent and ammonium chloride or sodium hydroxide as the alkali source, or reduction A method using hydrazine as an agent and a method using dimethylaminoborane can also be used without limitation.

Among these electroless nickel plating methods, an electroless nickel-phosphorus composite plating method using nickel salt and hypophosphite as a reducing agent is preferable. The content of nickel salt and hypophosphite in the plating solution is preferably 80 to 99.95% by weight of Ni, 0.05 to 20% by weight of P, more preferably 85 of Ni as the plating layer composition. -99 wt%, P is 1-15 wt%, more preferably, Ni is 90-96 wt% and P is 4-10 wt%.
When the P content is 20% by weight or less, the preparation of the plating solution is easy. When the P content is 0.05% by weight or more, the metal / metal obtained by joining the steel member 103 and the thermoplastic resin member 105 is obtained. This is preferable because the bonding strength of the resin composite structure 106 may be better.
That is, in the metal / resin composite structure 106 according to the present embodiment, the nickel plating layer 107 preferably contains phosphorus (P), and the content of phosphorus (P) in the nickel plating layer 107 is 0.05% by weight. It is more preferably 20% by weight or less, further preferably 1% by weight or more and 15% by weight or less, and particularly preferably 4% by weight or more and 10% by weight or less.

(Optional processing steps)
Optional processing steps are performed as necessary after the second processing step and before the third processing step.
The optional treatment step is a step of treating at least the joint surface 104 of the steel member 103 with a copper plating stripper to remove a part or all of the copper layer. This arbitrary treatment step can be performed, for example, according to the method described in JP-A-2002-356788. Examples of the treatment liquid used in any treatment step include those containing ammonia copper complex salt. More specifically, it is an alkaline aqueous solution containing a copper (II) ammine complex, and includes a copper plating stripping solution containing an anion of an organic acid as a counter ion. This stripping solution may be prepared according to the description in the above-mentioned publication, or a commercially available stripping solution may be processed according to the prescription recommended by the manufacturer. In Examples described later, Melstrip Cu-3940 manufactured by Meltex Co., Ltd. was used. The treatment temperature in any treatment step is usually 20 to 60 ° C., preferably 30 to 50 ° C., and the treatment time is usually 20 to 120 seconds, preferably 30 to 90 seconds. Washing and drying are performed as necessary after any treatment step. This washing operation is not particularly limited as long as the smut generated in the second and / or optional treatment step can be removed. The treatment time is preferably 0.5 to 20 minutes.

[Method for producing metal / resin composite structure]
Next, a method for manufacturing the metal / resin composite structure 106 will be described.
The method for manufacturing the metal / resin composite structure 106 includes at least the following steps (i) to (ii).
(I) A nickel-plated steel member 108 having a fine unevenness formed on the surface 104 of the joining portion 104 at least with the thermoplastic resin member 105 is injected so as to cover part or all of the surface. Step (ii) in the mold for molding (ii) The thermoplastic resin (R1) in the mold so that at least a part of the thermoplastic resin member 105 is in contact with the fine uneven shape of the nickel-plated steel member 108. Alternatively, the step of injection molding the resin composition (R2) containing the thermoplastic resin (R1) and joining the nickel-plated steel member 108 and the thermoplastic resin member 105, that is, surface roughening and nickel plating treatment by the above method For the nickel-plated steel member 108 (surface roughened nickel-plated steel member) subjected to the above steps in this order, the thermoplastic resin (R1) or The metal / resin composite structure 106 is obtained by bonding the resin composition (R2) while forming the resin composition (R2) into a desired shape of the thermoplastic resin member 105.
This will be specifically described below.

First, step (i) will be described.
The nickel-plated steel member 108 can be obtained in the same manner as the above-described method for manufacturing a nickel-plated steel member excellent in rust prevention ability. The description is omitted here.
Next, a mold is prepared, the mold is opened, and the nickel-plated steel member 108 is installed in the cavity (space).

Next, process (ii) is demonstrated. Hereinafter, a case where injection molding is used as a molding method will be described as an example.
The mold is closed, and at least a part of the thermoplastic resin member 105 is in contact with the fine concavo-convex shape of the nickel-plated steel member 108 in the cavity portion of the mold so that the thermoplastic resin (R1) or the thermoplastic resin ( The resin composition (R2) containing R1) is injected and solidified, and the nickel-plated steel member 108 and the thermoplastic resin member 105 are joined.
Thereafter, the metal / resin composite structure 106 can be obtained by opening the mold and releasing the mold.
As the mold, for example, an injection mold generally used in high-speed heat cycle molding (RHCM, heat & cool molding) can be used.

  In addition, as a method for producing the metal / resin composite structure 106 according to the present embodiment, the injection molding method is preferably applied as described above, but other molding methods are suitably combined with the injection molding method and molded. Alternatively, other molding methods may be applied instead of the injection molding method. Examples of other molding methods include transfer molding, compression molding (compression molding), reaction injection molding, blow molding, thermoforming, and press molding.

[Use of metal / resin composite structure]
Since the metal / resin composite structure 106 according to the present embodiment has high productivity and high degree of freedom in shape control, it can be developed for various applications.
Furthermore, the metal / resin composite structure 106 according to the present embodiment is excellent in adhesive strength between resin and steel members, mechanical properties, heat resistance, friction resistance, slidability, airtightness, watertightness, etc. Since it also has excellent rusting power, for example, when the metal / resin composite structure 106 is used as a structural component, it is possible to enjoy the effect of reducing the weight by reducing the amount of steel used in the structural component. It can be widely used for various applications.

  For example, vehicle structural parts, vehicle-mounted products, electronic equipment housings, home appliance housings, building members, structural parts, mechanical parts, various automotive parts, electronic equipment parts, furniture, kitchenware, etc. Applications for household goods, medical equipment, building material parts, other structural parts and exterior parts.

  More specific application examples include the following applications that are designed so that the metal supports a portion where the strength is insufficient with the resin alone. For vehicles, instrument panels, console boxes, door knobs, door trims, shift levers, pedals, glove boxes, bumpers, bonnets, fenders, trunks, doors, roofs, pillars, seats, radiators, oil pans, steering wheels, An ECU box, an electrical component, etc. are mentioned. Examples of building materials and furniture include glass window frames, handrails, curtain rails, chests, drawers, closets, bookcases, desks, chairs, and the like. Examples of precision electronic components include connectors, relays, and gears. Moreover, a transport container, a suitcase, a trunk, etc. are mentioned as a transport container.

  In addition, the high thermal conductivity of the steel member 103 and the adiabatic property of the thermoplastic resin member 105 can be combined to be used for parts used in equipment that optimally designs heat management, for example, various home appliances. . Specifically, household appliances such as refrigerators, washing machines, vacuum cleaners, microwave ovens, air conditioners, lighting equipment, electric water heaters, televisions, clocks, ventilation fans, projectors, speakers, personal computers, mobile phones, smartphones, digital cameras, tablets Electronic information devices such as type PCs, portable music players, portable game machines, chargers, and batteries.

  About these, since a surface area increases by roughening the surface of the steel member 103, the contact area between the steel member 103 and the thermoplastic resin member 105 increases, and the thermal resistance of a contact interface can be reduced. It comes from what it can do.

  Other applications include toys, sports equipment, shoes, sandals, bags, forks and knives, spoons, dishes such as dishes, ballpoint pens and mechanical pencils, files, binders and other stationery, frying pans and pans, kettles, frying, Examples include a ladle, a hole insulator, a whisk, a cooking tool such as a tongue, a lithium ion secondary battery component, a robot, and the like.

  As mentioned above, although the use of the metal / resin composite structure 106 concerning this embodiment was described, these are illustrations of the use of this invention and can also be used for various uses other than the above.

  As mentioned above, although embodiment of this invention was described, these are illustrations of this invention and various structures other than the above are also employable.

Hereinafter, the present embodiment will be described in detail with reference to examples and comparative examples. In addition, this embodiment is not limited to description of these Examples at all.
First, various measurement methods will be described.

(Measurement of ten-point average roughness (Rz) and average length (RSm) of roughness curve elements on the surface of steel members)
Of the surface roughness measured using the surface roughness measuring device “Surfcom 1400D (manufactured by Tokyo Seimitsu Co., Ltd.)” in accordance with JIS B0601 (corresponding ISO 4287), ten-point average roughness (Rz) and roughness The average length (RSm) of the curve element was measured. The measurement conditions are as follows.
・ Tip tip radius: 5μm
・ Standard length: 0.8mm
・ Evaluation length: 4mm
・ Measurement speed: 0.06mm / sec
The measurement was performed on a total of six straight portions including arbitrary three straight portions in parallel relation on the surface of the steel member and arbitrary three straight portions orthogonal to the straight portions (see FIG. 5). In this example / comparative example, since the entire surface of the steel member 103 is roughened, the ten-point average roughness (Rz) and roughness curve of the joint surface 104 of the metal / resin composite structure 106 are used. It is understood that the same evaluation result as the measurement location shown in FIG. 5 can be obtained even if the average length (RSm) of the element is measured.

(Evaluation method of bonding strength)
Using a tensile tester “Model 1323 (manufactured by Aiko Engineering Co., Ltd.)”, a dedicated jig is attached to the tensile tester, and at room temperature (23 ° C.), the distance between chucks is 60 mm and the tensile speed is 10 mm / min. And measured. The joint strength (MPa) was obtained by dividing the breaking load (N) by the area of the metal / resin joint.

[Example 1]
A commercially available cold-rolled cold rolled mild steel plate SPCC having a thickness of 2 mm was cut into a 18 mm × 45 mm rectangle to prepare a test specimen for treatment. Seven of them were immersed in a 60 ° C. aqueous solution diluted with 5% by weight of a commercially available degreasing agent NE-6 (manufactured by Meltec) for 5 minutes so that the test pieces do not overlap each other (no movement) The water washing for 5 seconds (under shaking) was repeated three times.

(First processing step)
Next, the first treatment step was performed. That is, seven test pieces after degreasing were mixed with 50 wt%, 3 wt%, 3 wt%, and 0.0001 wt% of sulfuric acid, cupric sulfate pentahydrate, potassium chloride, and thiosalicylic acid, respectively. The test pieces were immersed in the aqueous solution containing 30 ° C. for 2 minutes (under no peristalsis) so that the test pieces did not contact each other. Next, the first treatment step was completed by repeating the water washing (under peristaltic) for 30 seconds under ultrasonic irradiation three times.

(Second processing step)
Seven test pieces obtained in the first treatment step were immersed in a 20 wt% nitric acid aqueous solution for 120 seconds (under no swinging) so as not to contact each other. The temperature of the aqueous solution at that time was maintained at 40 ° C. Thereafter, washing with water for 20 seconds (under peristalsis) is repeated three times, washing with water for 1 minute under ultrasonic irradiation, and then drying for 15 minutes in a dryer set at 80 ° C. finished. After the second treatment step, the average weight reduction rate of the test piece was 4.9% by weight. Hereinafter, the test piece implemented to the 2nd process process is called the steel member 1. FIG.

(Optional processing steps)
Immerse the seven test pieces that have been processed up to the second treatment step in a copper plating stripper (Meltex CU-3940) at 40 ° C. for 1 minute so that they do not contact each other (under no-motion) I let you. Thereafter, washing with water for 20 seconds (under peristalsis) was repeated three times under ultrasonic irradiation. The optional treatment step was then terminated by drying for 15 minutes in a dryer set at 80 ° C. The average weight loss rate (ΔW) of the test piece after the completion of any treatment step was 3.1% by weight. Hereinafter, the test piece implemented to this arbitrary treatment process may be called the steel member 2.

(Third treatment process)
An electroless plating bath was prepared according to the method disclosed in Japanese Patent No. 4185523 and heated to 90 ° C. Subsequently, the seven steel members 2 were immersed in this plating bath for 20 minutes to form a nickel plating layer on the entire surface of the steel members 2. It was 3.5 micrometers as a result of calculating the average thickness of a plating layer about arbitrary 5 points | pieces from a roughening part about a plating layer, arbitrary 5 points | pieces from the part which is not roughened, and a total of 10 points | pieces.
In addition, the ten-point average roughness (Rz) of the six linear portions measured according to the above method is 6.3 μm, 10.7 μm, 7.4 μm, 9.2 μm, 11.5 μm, and 5.9 μm. The average value was 8.5 μm. Moreover, the average value of the average length (RSm) of the roughness curve element was 172 μm. Hereinafter, the test piece implemented to the 3rd process process may be called the steel member 3. FIG.

(Injection process)
A small dumbbell metal insert mold was attached to J85AD110H manufactured by Nippon Steel Works, and a steel member 3 was installed in the mold. Next, a commercially available glass fiber-containing propylene polymer (manufactured by Prime Polymer Co., Ltd., Prime Polypro V7100, density 1030 kg / m ³ , glass fiber (GF) 20% by weight, propylene-based heavy polymer contained in the mold as a thermoplastic resin. Combined MFR: 18 g / 10 min (hereinafter abbreviated as GF-PP) under the conditions of a cylinder temperature of 250 ° C., a mold temperature of 120 ° C., an injection speed of 25 mm / sec, a holding pressure of 80 MPa, and a holding time of 10 seconds. Injection molding was performed to obtain a metal / resin composite structure. The same injection molding was performed on the other two steel members 3.

(Evaluation of bonding strength)
The average value of the bonding strength measured by the above method for three test samples was 16 MPa. When the fracture surface (metal side surface) was simply observed with a digital microscope, it was confirmed that the resin residue was present. Moreover, the result of having processed the cross section of the junction part at normal temperature using ion milling, and observing element distribution using the electron microscope and the energy dispersive X-ray spectrometer is shown in FIG. It turns out that the antirust layer (electroless nickel plating layer) is provided along the surface roughening shape of the steel member. The results of surface roughening shape parameters and bonding strength are also shown in Table 1.

[Example 2]
A commercially available glass fiber-containing polyamide resin (Amilan 1011G30, containing 30% by weight of GF) (hereinafter abbreviated as GF-PA) (hereinafter abbreviated as GF-PA) was used as the thermoplastic resin, the cylinder temperature as the injection molding condition was 280 ° C., and the mold A metal / resin composite structure was produced in the same manner as in Example 1 except that the temperature was 160 ° C., and the bonding strength was measured.
The average value of the bonding strength of the three samples was 31 MPa. When the fracture surface (metal side surface) was simply observed with a digital microscope, it was confirmed that the resin residue was present. The results of surface roughening shape parameters and bonding strength are also shown in Table 1.

Example 3
In the same manner as in the method described in Example 1, the first processing step, the second processing step, and the arbitrary processing steps described in Example 1 were performed again for the tests performed up to the arbitrary processing steps. . The average value of the average weight reduction rate of the test piece at this time was 5.1% by weight. The third treatment step shown below was performed on this test piece.

  Ion-exchanged water 847 ml / L, SF-762-0N (electroless nickel plating solution manufactured by Nippon Kanisen Co., Ltd.) 100 ml / L, SF-762-1 (electroless nickel plating solution manufactured by Nippon Kanisen Co., Ltd.) 50 ml / L, SF-762-S (electroless nickel plating solution manufactured by Nippon Kanisen Co., Ltd.) 3 ml / L was placed in this order to prepare a plating bath and heated to 85 ° C. Subsequently, the nickel plating layer was formed in the whole surface of the steel member by immersing the seven steel members obtained by the said method in this plating bath for 20 minutes. The average thickness of the plating layer was 3.8 μm. In addition, the ten-point average roughness (Rz) for the six linear portions measured according to the above method is 8.7 μm, 11.0 μm, 6.7 μm, 13.4 μm, 11.5 μm, and 11.8 μm. The average value was 10.5 μm. The average value of the average length (RSm) of the roughness curve elements was 222 μm.

  In the same manner as the injection process described in Example 1, GF-PP injection molding was performed on the steel member to obtain a metal / resin composite structure. The average value of the bonding strength of the three samples was 20 MPa. When the fracture surface (metal side surface) was simply observed with a digital microscope, it was confirmed that the resin residue was present. The results of surface roughening shape parameters and bonding strength are also shown in Table 1. The surface roughness curve is shown in FIG.

Example 4
A metal / resin composite structure was prepared in the same manner as in Example 3 except that GF-PA was used as the thermoplastic resin, the cylinder temperature as the injection molding condition was 280 ° C., and the mold temperature was 160 ° C. The strength was measured.
The average value of the bonding strength of the three samples was 40 MPa. When the fracture surface (metal side surface) was simply observed with a digital microscope, it was confirmed that the resin residue was present. The results of surface roughening shape parameters and bonding strength are also shown in Table 1.

Example 5
In Example 3, a nickel plating layer was formed on the entire surface of the steel member in the same manner as in Example 3 except that the immersion time in the third treatment step was changed from 20 minutes to 40 minutes. The average thickness of the plating layer was 4.1 μm. In addition, the ten-point average roughness (Rz) for the six linear portions measured according to the above method is 5.0 μm, 4.1 μm, 7.9 μm, 7.7 μm, 9.2 μm, and 6.5 μm. The average value was 6.7 μm. The average value of the average length (RSm) of the roughness curve elements was 169 μm. Moreover, injection molding of GF-PP was performed under the same injection conditions as in Example 3 to obtain a metal / resin composite structure. The average value of the bonding strength of the three samples was 5 MPa. When the fracture surface (metal side surface) was simply observed with a digital microscope, it was confirmed that a small amount of resin residue was present. The results of surface roughening shape parameters and bonding strength are also shown in Table 1. The surface roughness curve is shown in FIG.

Example 6
A metal / resin composite structure was prepared and joined in the same manner as in Example 5 except that GF-PA was used as the thermoplastic resin, the cylinder temperature as the injection molding condition was 280 ° C., and the mold temperature was 160 ° C. The strength was measured.
The average value of the bonding strength of the three samples was 15 MPa. When the fracture surface (metal side surface) was simply observed with a digital microscope, it was confirmed that a small amount of resin residue was present. The results of surface roughening shape parameters and bonding strength are also shown in Table 1.

[Comparative Example 1]
Seven cold-rolled mild steel plate SPCC test pieces used in Example 1 were surface-treated in accordance with the method described in Experimental Example 8 of JP 2011-156664 A. Specifically, first, the seven test pieces were immersed in a 7.5 wt% aqueous solution (60 ° C.) of a degreasing agent “NE-6” for aluminum alloy for 5 minutes and washed with water. Next, after being immersed in a 1.5% by weight aqueous sodium hydroxide solution (40 ° C.) for 1 minute and washed with water, then immersed in an aqueous solution containing 10% 98% by weight sulfuric acid (50 ° C.) for 6 minutes and thoroughly washed with ion-exchanged water. . Subsequently, it was immersed in 1% concentration aqueous ammonia (25 ° C.) for 1 minute and washed with water. Then, it was immersed in an aqueous solution (45 ° C.) containing 2 wt% potassium permanganate, 1 wt% acetic acid, and 0.5 wt% hydrated sodium acetate for 1 minute and thoroughly washed with water. Finally, it was dried for 15 minutes in a hot air dryer set at 90 ° C. The average weight loss rate (ΔW) of the obtained test piece was 0.4% by weight.

  The surface-roughened SPCC test piece obtained in this manner was formed in the same manner as in the third treatment step of Example 3 to form a nickel plating layer on the entire surface of the steel member. The average thickness of the plating layer was 3.8 μm. Moreover, the ten-point average roughness (Rz) for the six straight line portions measured according to the above method is 1.8 μm, 1.6 μm, 1.6 μm, 1.9 μm, 0.7 μm, and 1.1 μm. The average value was 1.5 μm. Moreover, the average value of the average length (RSm) of the roughness curve element was 116 μm.

  In the same manner as the injection process described in Example 1, GF-PP injection molding was performed on the steel member to obtain a metal / resin composite structure. The average value of the bonding strength of the three samples was 3 MPa. When the fracture surface (metal side surface) was simply observed with a digital microscope, it was confirmed that no resin residue was present. The results of surface roughening shape parameters and bonding strength are also shown in Table 1.

[Comparative Example 2]
A metal / resin composite structure was prepared and joined in the same manner as in Comparative Example 1 except that GF-PA was used as the thermoplastic resin, the cylinder temperature as the injection molding condition was 280 ° C., and the mold temperature was 160 ° C. The strength was measured.
The average value of the bonding strength of the three samples was 5 MPa. When the fracture surface (metal side surface) was simply observed with a digital microscope, it was confirmed that there was no resin residue. The results of surface roughening shape parameters and bonding strength are also shown in Table 1.

Hereinafter, examples of the reference form will be added.
<Appendix>
(Appendix 1)
A metal / resin composite structure in which a steel member and a thermoplastic resin member composed of a thermoplastic resin or a resin composition containing the thermoplastic resin are joined,
A nickel plating layer is formed so as to cover part or all of the surface of the steel member,
At least the joint surface of the steel member with the thermoplastic resin member has a fine uneven shape,
The metal / resin composite structure, wherein the nickel plating layer is formed so as to cover at least the fine irregularities on the surface of the joint.
(Appendix 2)
The metal / resin composite structure according to appendix 1, wherein an average thickness of the nickel plating layer is 0.1 μm or more and 20 μm or less.
(Appendix 3)
The supplementary note 1 or 2, wherein the nickel plating layer contains phosphorus (P), and the content of the phosphorus (P) in the nickel plating layer is 0.05 wt% or more and 20 wt% or less. Metal / resin composite structure.
(Appendix 4)
4. The metal / resin composite structure according to any one of appendices 1 to 3, wherein the fine concavo-convex shape is a shape in which convex portions having an interval period of 5 nm or more and 500 μm or less stand.
(Appendix 5)
The thermoplastic resin is polyolefin resin, polyester resin, polyamide resin, polycarbonate resin, polyether ether ketone resin, polyether ketone resin, polyimide resin, polyether sulfone resin, polystyrene resin, polyacrylonitrile resin, styrene / acrylonitrile. The metal according to any one of appendices 1 to 4, comprising one or more selected from a copolymer resin, an acrylonitrile / butadiene / styrene copolymer resin, and a polymethyl methacrylate resin / Resin composite structure.
(Appendix 6)
The metal / resin composite structure according to any one of appendices 1 to 5, wherein the steel member includes rolled mild steel.
(Appendix 7)
A method for producing a metal / resin composite structure according to any one of appendices 1 to 6,
A step in which a nickel plating layer is formed so as to cover part or all of the surface, and at least a steel member having a fine irregular shape on the surface of a joint portion with a thermoplastic resin member is placed in a mold for injection molding When,
Injection molding a thermoplastic resin or a resin composition containing the thermoplastic resin in the mold so that at least a part of the thermoplastic resin member is in contact with the nickel plating layer on the fine irregularities of the steel member. A process for producing a metal / resin composite structure.
(Appendix 8)
Used for joining with a thermoplastic resin or a thermoplastic resin member composed of a resin composition containing the thermoplastic resin, a nickel plating layer is formed so as to cover part or all of the surface, and at least thermoplastic It is a manufacturing method for manufacturing a steel member having a fine uneven shape on the surface of a joint with a resin member,
A first treatment step of treating at least the joint surface of the steel member with the thermoplastic resin member with an aqueous solution containing an acid, a cupric ion, and a chlorine ion;
A second treatment step of treating at least the joint surface with nitric acid;
After the second treatment step, at least the joint surface, a third treatment step of nickel plating with a nickel plating solution,
The manufacturing method of the steel member containing this.
(Appendix 9)
In the method for manufacturing a steel member according to attachment 8,
A method for producing a steel member, further comprising a treatment step of treating at least the surface of the joint portion with a copper plating stripper after the second treatment step and before the third treatment step.

DESCRIPTION OF SYMBOLS 103 Steel member 104 Joint surface 105 Thermoplastic resin member 106 Metal / resin composite structure 107 Nickel plating layer 108 Nickel plated steel member 110 Surface

Claims (11)

A nickel-plated steel member having a nickel plating layer formed so as to cover part or all of the surface of the steel member, and a thermoplastic resin member made of a thermoplastic resin or a resin composition containing the thermoplastic resin. A bonded metal / resin composite structure,
A metal characterized in that an average value of ten-point average roughness (Rz) of a surface of a joint portion between at least the nickel-plated steel member and the thermoplastic resin member measured in accordance with JIS B0601 exceeds 2 μm. / Resin composite structure.   2. The metal / resin composite structure according to claim 1, wherein a surface of the steel member has a fine uneven shape, and the nickel plating layer is formed to cover at least the fine uneven shape.   3. The metal / resin composite structure according to claim 2, wherein the fine concavo-convex shape is a shape in which convex portions having an interval period of 5 nm to 500 μm stand.   The metal / resin composite structure according to any one of claims 1 to 3, wherein the nickel plating layer has an average thickness of 0.1 µm or more and 20 µm or less.   The nickel plating layer contains phosphorus (P), and the content of the phosphorus (P) in the nickel plating layer is 0.05 wt% or more and 20 wt% or less. The metal / resin composite structure according to any one of the above.   The thermoplastic resin is polyolefin resin, polyester resin, polyamide resin, polycarbonate resin, polyether ether ketone resin, polyether ketone resin, polyimide resin, polyether sulfone resin, polystyrene resin, polyacrylonitrile resin, styrene / acrylonitrile. It contains 1 type, or 2 or more types selected from copolymer resin, acrylonitrile / butadiene / styrene copolymer resin, and polymethyl methacrylate resin as described in any one of Claim 1 thru | or 5 characterized by the above-mentioned. Metal / resin composite structure.   The metal / resin composite structure according to any one of claims 1 to 6, wherein the steel member includes rolled mild steel. Used for joining with a thermoplastic resin or a thermoplastic resin member composed of a resin composition containing the thermoplastic resin, a nickel plating layer was formed so as to cover part or all of the surface of the steel member A nickel plated steel member,
A nickel-plated steel member having an average value of 10-point average roughness (Rz) of at least the surface of the joint portion with the thermoplastic resin member measured in accordance with JIS B0601 exceeds 2 μm. A method for producing a metal / resin composite structure according to any one of claims 1 to 7,
A nickel-plated steel member that has a nickel plating layer formed so as to cover part or all of the surface and that has at least a fine uneven shape on the surface of the joint with the thermoplastic resin member is placed in a mold for injection molding. Installation process;
Injection-molding a thermoplastic resin or a resin composition containing the thermoplastic resin in the mold such that at least a part of the thermoplastic resin member is in contact with the fine uneven shape of the nickel-plated steel member; A process for producing a metal / resin composite structure, comprising: Used for joining with a thermoplastic resin or a thermoplastic resin member comprising a resin composition containing the thermoplastic resin, a nickel plating layer is formed so as to cover part or all of the surface of the steel member; and It is a manufacturing method for manufacturing a nickel-plated steel member having a fine uneven shape on the surface of a joint portion with at least a thermoplastic resin member,
A first treatment step of treating at least the joint surface of the steel member with the thermoplastic resin member with an aqueous solution containing acid, cupric ion, and chlorine ion;
A second treatment step of treating at least the joint surface with an inorganic acid;
After the second treatment step, at least the surface of the joint portion is nickel-plated with a nickel plating solution, and a third treatment step;
The manufacturing method of the nickel-plated steel member containing this. In the manufacturing method of the nickel-plated steel member according to claim 10,
The manufacturing method of the nickel-plated steel member which further performs the process process of processing at least the said junction part surface with a copper plating peeling liquid after said 2nd process process and before said 3rd process process.

Images