JP2017019165A - Metal/resin composite structure and method for manufacturing metal/resin composite structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal/resin composite structure in which a metal member and a resin member can be joined directly to each other, and a balance between productivity and joint strength is excellent.SOLUTION: There is provided a metal/resin composite structure 106 formed by joining a metal member 103 and a resin member 105 formed of a polycarbonate resin composition, where the polycarbonate resin composition contains a polycarbonate resin (A) having a weight average molecular weight (Mw) in a range of 20,000-60,000 and a molecular weight distribution (Mw/Mn) in a range of 1.5-15.0 measured by gel permeation chromatography (GPC), and polycarbonate oligomer (B) having a weight average molecular weight (Mw) in a range of 500-5,000 and a molecular weight distribution (Mw/Mn) in a range of 1.5-5.0 measured by GPC, and a mass ratio ((A)/(B)) of the polycarbonate resin (A) to the polycarbonate oligomer (B) is 90/10 to 99/1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a metal / resin composite structure and a method for producing a metal / resin composite structure.

  In automobile parts and electronic equipment parts, demands such as weight reduction, design improvement, and reduction of assembly man-hours are increasing. Among them, a metal-resin integration technique that can join a metal and a resin without using an adhesive or mechanical fastening has been studied.

  In recent years, as a technology for joining and integrating metal moldings and resin moldings, engineering plastics with polar groups that have affinity with the metal member are joined to the metal member surface with fine irregularities (For example, Patent Documents 1 to 5).

  For example, in Patent Documents 1 to 3, after an aluminum alloy is immersed in a hydrazine aqueous solution to form a recess with a diameter of 30 to 300 nm on the surface, a polybutylene terephthalate resin (hereinafter referred to as “PBT”) is formed on the treated surface ), Or a technique for joining a polyphenylene sulfide resin (hereinafter referred to as “PPS”).

  In Patent Document 4, an aluminum material is anodized in an electrolytic bath of phosphoric acid or sodium hydroxide to form an anodized film having a recess having a diameter of 25 nm or more on the surface of the aluminum material, A technique for joining an engineering plastic to a processing surface is disclosed.

  Further, Patent Document 5 discloses a technique in which fine irregularities or holes are formed in an aluminum alloy with a specific etching agent, and polyamide 6 resin, polyamide 66 resin, and PPS are injected and bonded to the holes.

  On the other hand, the technology for joining amorphous resin and metal is far less than that of crystalline resin, and it is currently difficult to efficiently join amorphous resin to develop high strength. ing. Especially for polycarbonate, from the viewpoints of transparency, moldability, colorability, mechanical properties, and surface glossiness, there is a high demand especially for design parts such as smartphones, especially for joining with metals such as aluminum. It is coming.

JP 2004-216425 A JP 2009-6721 A International Publication No. 2003/064150 Pamphlet International Publication No. 2004/055248 Pamphlet JP 2013-52671 A

  According to the study by the present inventors, in the metal / resin composite structure obtained by the methods disclosed in Patent Documents 1 to 5, when the resin member is an amorphous resin, sufficient bonding is achieved. It has been found that the strength cannot be secured.

Accordingly, the present inventors have found various physical characteristics and molding conditions of a resin member (hereinafter also referred to as a polycarbonate resin member) made of a polycarbonate resin, which is an amorphous resin, and the resulting metal / resin composite structure. The relationship with the bonding strength of the steel was studied. First, the present inventors have found that the bonding strength of the resulting metal / resin composite structure tends to increase even if it is a polycarbonate resin member if the temperature of the mold during molding is increased. However, generally, raising the temperature of the mold during molding improves the bonding strength, but tends to cause a delay in the molding cycle, and may cause a problem in terms of productivity.
In other words, the conventional metal / amorphous resin composite structure has a trade-off relationship between bonding strength and productivity, and the trade-off relationship could not be improved only by changing the molding conditions. .

  The present invention has been made in view of the above circumstances, and by directly controlling the physical properties of the polycarbonate resin member within a specific range, the metal member and the resin member can be directly joined without excessively raising the molding temperature. It is possible to provide a metal / resin composite structure having an excellent balance between productivity and bonding strength.

  In order to stably and efficiently obtain a metal / resin composite structure excellent in bonding strength between a metal member and a polycarbonate resin member, the present inventors have obtained a relationship between various characteristics of the resin member and bonding strength. It was investigated. As a result, by using a polycarbonate resin member that satisfies specific requirements, the above trade-off relationship can be improved, and a metal / resin composite structure having excellent bonding strength can be stably and efficiently produced under a wide range of molding conditions. As a result, the present invention was reached.

  That is, according to the present invention, the following metal / resin composite structure and a method for producing a metal / resin composite structure are provided.

[1]
A metal / resin composite structure formed by bonding a metal member having a fine uneven surface and a resin member composed of a polycarbonate resin composition (C),
The polycarbonate resin composition (C) is
The weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) is in the range of 20,000 to 60,000, and the molecular weight distribution (Mw / Mn) is in the range of 1.5 to 15.0. The weight average molecular weight (Mw) measured by GPC is in the range of 500 to 5,000, and the molecular weight distribution (Mw / Mn) is in the range of 1.0 to 5.0. A polycarbonate oligomer (B)
A metal / resin composite structure having a mass ratio ((A) / (B)) of the polycarbonate resin (A) to the polycarbonate oligomer (B) of 90/10 or more and 99/1 or less.
[2]
The metal / resin composite structure according to the above [1], wherein convex portions having an interval period of 5 nm or more and 500 μm or less stand on the fine uneven surface of the metal member.
[3]
The resin member further includes a filler (D),
The metal / resin composite structure according to [1] or [2], wherein the content of the filler (D) in the resin member is 5% by mass or more and 50% by mass or less.
[4]
The metal / resin composite structure according to the above [3], wherein the filler (D) contains glass fibers.
[5]
The metal / resin composite structure according to any one of [1] to [4], wherein the metal member includes one or more metal materials selected from aluminum and an aluminum alloy.
[6]
Conforms to JIS B0601 (corresponding international standard: ISO4287) for a total of 6 straight line parts consisting of any 3 straight line parts in parallel relation on the surface of the metal member and any 3 straight line parts orthogonal to the 3 straight line parts The metal / resin composite structure according to any one of [1] to [5] above, wherein the measured surface roughness satisfies the following requirements (1) and (2) simultaneously.
(1) Includes one or more straight line portions with a load length ratio (Rmr) of a roughness curve at a cutting level of 20% and an evaluation length of 4 mm of 30% or less. (2) Evaluation length of all straight line portions. Ten point average roughness (Rz) at 4 mm exceeds 2 μm [7]
Conforms to JIS B0601 (corresponding international standard: ISO4287) for a total of 6 straight line parts consisting of any 3 straight line parts in parallel relation on the surface of the metal member and any 3 straight line parts orthogonal to the 3 straight line parts The metal / resin composite structure according to the above [6], wherein the surface roughness measured as described above further satisfies the following requirement (3).
(3) One or more straight line parts having a load length ratio (Rmr) of a roughness curve at a cutting level of 40% and an evaluation length of 4 mm are 60% or less [8]
The above-mentioned ten-point average roughness of all the straight portions of a total of six straight portions composed of any three straight portions in parallel relation on the surface of the metal member and any three straight portions orthogonal to the three straight portions. The metal / resin composite structure according to the above [6] or [7], wherein (Rz) exceeds 5 μm.
[9]
The above-mentioned ten-point average roughness of all the straight portions of a total of six straight portions composed of any three straight portions in parallel relation on the surface of the metal member and any three straight portions orthogonal to the three straight portions. The metal / resin composite structure according to the above [8], wherein (Rz) is 15 μm or more.
[10]
A production method for producing the metal / resin composite structure according to any one of [1] to [9],
Placing the metal member having a fine uneven surface in the cavity of the mold; and
Bonding the metal member and the resin member by injecting the resin member into the cavity portion;
The manufacturing method of the metal / resin composite structure containing this.

  ADVANTAGE OF THE INVENTION According to this invention, a metal member and a resin member can be joined directly, and the metal / resin composite structure excellent in balance of productivity and joining strength can be provided.

It is the external view which showed typically an example of the structure of the metal / resin composite structure of this embodiment. It is the block diagram which showed typically an example of the process which manufactures the metal / resin composite structure of this embodiment. The model for demonstrating the measurement location of a total of 6 linear parts which consist of the arbitrary 3 linear parts in the parallel relationship on the surface of the metal member which concerns on this embodiment, and the arbitrary 3 linear parts orthogonal to the said 3 linear parts. FIG. The model for demonstrating the measurement location of a total of 6 linear parts which consist of the arbitrary 3 linear parts in the parallel relationship on the surface of the metal member which concerns on this embodiment, and the arbitrary 3 linear parts orthogonal to the said 3 linear parts. 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, "-" between the numbers in a sentence represents the following from the above, unless there is particular notice.

[Metal / resin composite structure]
First, the metal / resin composite structure 106 according to the present embodiment will be described.
FIG. 1 is an external view schematically showing an example of the structure of the metal / resin composite structure 106 of the present embodiment. The metal / resin composite structure 106 is obtained by joining a metal member 103 and a resin member 105 to each other, and joining the metal member 103 and the resin member 105.
In the metal / resin composite structure 106 according to the present embodiment, the resin member 105 made of the polycarbonate resin composition (C) enters the fine unevenness formed on the surface 110 of the metal member 103 and the metal and the polycarbonate resin. It is obtained by bonding the composition (C) to form a metal-resin interface.
Here, the polycarbonate resin composition (C) according to this embodiment has a weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) in the range of 20,000 to 60,000, and the molecular weight. The polycarbonate resin (A) having a distribution (Mw / Mn) in the range of 1.5 to 15.0 and the weight average molecular weight (Mw) measured by GPC in the range of 500 to 5,000, the molecular weight And a polycarbonate oligomer (B) having a distribution (Mw / Mn) in the range of 1.0 or more and 5.0 or less. And mass ratio ((A) / (B)) of polycarbonate resin (A) with respect to polycarbonate oligomer (B) is 90/10 or more and 99/1 or less.

Since the surface 110 of the metal member 103 has an uneven shape suitable for improving the bonding strength between the metal member 103 and the resin member 105, the metal member 103 and the resin member 105 can be formed without using an adhesive. It is possible to ensure the bonding property between the two.
Specifically, the physical resistance (anchor effect) is effective between the metal member 103 and the resin member 105 by the resin member 105 entering the fine uneven shape on the surface 110 of the metal member 103. It is possible to firmly bond the metal member 103 and the resin member 105 that are normally expressed and difficult to bond.

  The metal / resin composite structure 106 obtained in this manner can also prevent moisture and moisture from entering the interface between the metal member 103 and the 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.

When the resin member 105 composed of the polycarbonate resin composition (C) according to the present embodiment is used, the present inventors can obtain even if the molding cycle is improved by lowering the mold temperature during molding. The present inventors have newly found that high bonding strength can be maintained for the metal / resin composite structure to be obtained.
That is, according to the present embodiment, by using the resin member 105 composed of the polycarbonate resin composition (C), the metal member 103 and the resin member 105 can be directly bonded, and productivity and bonding strength can be improved. The metal / resin composite structure 106 having an excellent balance can be realized.

  The reason why such a metal / resin composite structure 106 is excellent in the balance between productivity and bonding strength is not necessarily clear, but the resin member 105 made of the polycarbonate resin composition (C) has a mold temperature. Even if it is lowered, it is considered that the metal member 103 is excellent in the balance between the intrusion into the concave portion of the fine concavo-convex shape, the adhesion with the metal member 103, and the mechanical strength after molding.

  Hereinafter, each member constituting the metal / resin composite structure 106 will be described.

<Metal member>
Hereinafter, the metal member 103 according to the present embodiment will be described.
The metal member 103 according to the present embodiment has a fine uneven surface. From the viewpoint of bonding the metal member 103 and the resin member 105 more firmly, the fine concavo-convex surface is preferably such that convex portions having an interval period of 5 nm or more and 500 μm or less stand.
The interval period of the surface of the fine unevenness 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 metal 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 protrusions is equal to or more than the lower limit value, the resin member 105 can sufficiently enter the recesses on the surface of the fine unevenness, and the bonding strength between the metal member 103 and the resin member 105 can be further improved. it can. 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.

As a method of forming a fine uneven surface having the above-mentioned interval cycle, a metal member is treated by an inorganic base aqueous solution such as NaOH and / or a metal member immersed in an inorganic acid aqueous solution such as HCl or HNO _3, or an anodic oxidation method. And a method of immersing a metal member in one or more aqueous solutions selected from hydrated hydrazine, ammonia, and a water-soluble amine compound as disclosed in WO 2009/31632 pamphlet. These methods can be properly used depending on the metal type of the metal member 103 to be used and the uneven shape formed within the interval period.

The metal member 103 according to the present embodiment has a total of six linear portions including arbitrary three linear portions in parallel relation on the surface 110 of the metal member 103 and arbitrary three linear portions orthogonal to the three linear portions. It is preferable that the surface roughness measured according to JIS B0601 (corresponding international standard: ISO4287) satisfies the following requirements (1) and (2) simultaneously.
(1) Includes one or more straight line portions with a load length ratio (Rmr) of a roughness curve at a cutting level of 20% and an evaluation length of 4 mm of 30% or less. (2) Evaluation length of all straight line portions. Ten point average roughness (Rz) at 4 mm exceeds 2 μm

FIG. 3 is a schematic diagram for explaining a total of six linear portions including arbitrary three linear portions in parallel relation on the surface 110 of the metal member 103 and arbitrary three linear portions orthogonal to the three linear portions. is there.
As the six straight line portions, for example, six straight line portions B1 to B6 as shown in FIG. 3 can be selected. First, a center line B1 passing through the center portion A of the joint surface 104 of the metal member 103 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 addition, since the surface roughening process is normally performed not only on the joint surface 104 in the surface 110 of the metal member but also on the entire surface 110 of the metal member, for example, as shown in FIG. The six straight line portions may be selected from locations other than the joint surface 104 on the same plane as the joint surface 104 of 103.

  When the above requirements (1) and (2) are satisfied at the same time, it is not always clear why the metal / resin composite structure 106 having better bonding strength can be obtained. This is probably because the anchor effect between 103 and the resin member 105 can be effectively expressed.

From the viewpoint of further improving the bonding strength between the metal member 103 and the resin member 105, any three straight lines in a parallel relationship on the surface 110 of the metal member 103 and any three straight lines orthogonal to the three straight lines. The surface roughness measured in accordance with JIS B0601 (corresponding international standard: ISO4287) further satisfies one or more of the following requirements (1A) to (1C) for a total of 6 straight line parts composed of parts. It is particularly preferable that the requirement (1C) is satisfied. Part of requirement (1C) is the same as requirement (3) described above.
(1A) A straight line portion with a load length ratio (Rmr) of a roughness curve at a cutting level of 20% and an evaluation length of 4 mm is preferably 30% or less, preferably 2 straight portions or more, more preferably 3 straight portions or more, most preferably (1B) A straight line portion having a load length ratio (Rmr) of a roughness curve at a cutting level of 20% and an evaluation length of 4 mm is preferably 20% or less, preferably 1 straight line portion or more, more preferably 2 straight lines. Part or more, more preferably 3 straight parts or more, most preferably 6 straight parts are included. (1C) Straight line part having a load length ratio (Rmr) of 60% or less of the roughness curve at a cutting level of 40% and an evaluation length of 4 mm Is preferably 1 straight part or more, more preferably 2 straight parts or more, further preferably 3 straight parts or more, and most preferably 6 straight parts

Further, from the viewpoint of further improving the bonding strength between the metal member 103 and the resin member 105, a cutting level of 20% measured on the surface 110 of the metal member 103 in accordance with JIS B0601 (corresponding international standard: ISO 4287). The average value of the load length ratio (Rmr) of the roughness curve at an evaluation length of 4 mm is preferably 0.1% or more and 40% or less, more preferably 0.5% or more and 30% or less, and still more preferably. Is from 1% to 20%, and most preferably from 2% to 15%.
In addition, what averaged the load length rate (Rmr) of the above-mentioned arbitrary 6 linear parts can be employ | adopted for the average value of the said load length rate (Rmr).

Each load length ratio (Rmr) of the surface 110 of the metal member 103 according to the present embodiment can be controlled by appropriately adjusting the conditions of the roughening treatment on the surface of the metal member 103.
In the present embodiment, the type and concentration of the etching agent, the temperature and time of the roughening treatment, the timing of the etching treatment, and the like are particularly cited as factors for controlling the load length ratios (Rmr).

From the viewpoint of further improving the bonding strength between the metal member 103 and the resin member 105, any three straight lines in a parallel relationship on the surface 110 of the metal member 103 and any three straight lines orthogonal to the three straight lines. It is preferable that the surface roughness measured in accordance with JIS B0601 (corresponding international standard: ISO4287) further satisfies the following requirement (2A) for a total of six straight line parts composed of parts.
(2A) The 10-point average roughness (Rz) at an evaluation length of 4 mm of all straight portions is preferably more than 5 μm, more preferably 10 μm or more, and further preferably 15 μm or more.

From the viewpoint of further improving the bonding strength between the metal member 103 and the resin member 105, the average value of the ten-point average roughness (Rz) on the surface 110 of the metal member 103 is preferably more than 2 μm and 50 μm or less, and more The thickness is preferably more than 5 μm and 45 μm or less, more preferably 10 μm or more and 40 μm or less, and particularly preferably 15 μm or more and 30 μm or less.
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 metal member 103 and the resin member 105, any three straight lines in a parallel relationship on the surface 110 of the metal member 103 and any three straight lines orthogonal to the three straight lines. It is preferable that the surface roughness measured in accordance with JIS B0601 (corresponding international standard: ISO4287) further satisfies the following requirement (4) for a total of six straight line parts composed of parts.
(4) The average length (RSm) of the roughness curve elements of all straight portions is more than 10 μm and less than 300 μm, more preferably 20 μm or more and 200 μm or less.

From the viewpoint of further improving the bonding strength between the metal member 103 and the resin member 105, the average value of the average length (RSm) of the roughness curve elements on the surface 110 of the metal member 103 is preferably more than 10 μm and less than 300 μm. More preferably, it is 20 μm or more and 200 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.

The ten-point average roughness (Rz) of the surface 110 of the metal member 103 and the average length (RSm) of the roughness curve element according to the present embodiment appropriately adjust the conditions of the roughening treatment for the surface 110 of the metal member 103. It is possible to control by doing.
In the present embodiment, the temperature and time of the roughening treatment, the etching amount, etc. are particularly cited as factors for controlling the ten-point average roughness (Rz) and the average length (RSm) of the roughness curve elements. .

Although the metal material which comprises the metal member 103 is not specifically limited, For example, iron, stainless steel, aluminum, an aluminum alloy, magnesium, a magnesium alloy, copper, a copper alloy, etc. can be mentioned. These may be used alone or in combination of two or more. Among these, aluminum (aluminum simple substance) and aluminum alloy are preferable from the viewpoint of light weight and high strength, and aluminum alloy is more preferable.
As the aluminum alloy, alloy numbers 1050, 1100, 2014, 2024, 3003, 5052, 6061, 6063, and 7075 defined in JIS H4000 are preferably used.

The shape of the metal member 103 is not particularly limited as long as it can be joined to the resin member 105. For example, the metal 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 resin member 105 is not particularly limited, and examples thereof include a flat surface and a curved surface.

The metal member 103 was processed into a predetermined shape as described above by metal removal such as cutting, pressing, etc., metal processing, punching, cutting, polishing, electric discharge processing, etc., and then the roughening process described later was performed. Those are preferred. In short, it is preferable to use a material processed into a necessary shape by various processing methods.
It is preferable that the metal member 103 processed into a necessary shape is not oxidized or hydroxylated on the surface joined to the resin member 105, and the presence of rust which is an oxide film is apparent on the surface when left standing for a long time. Is preferably removed by polishing, chemical treatment or the like.

Next, a method for preparing the metal member 103 that satisfies the above requirements (1) to (4), (1A) to (1C), (2A) and the like will be described.
Such a metal member 103 can be formed, for example, by roughening using an etching agent.
Here, roughening the surface of the metal member using an etchant itself has been performed in the prior art. However, in this embodiment, factors such as the type and concentration of the etching agent, the temperature and time of the roughening process, the timing of the etching process, and the like are highly controlled. In order to obtain the metal member 103 that satisfies the above requirements (1) to (4), (1A) to (1C), (2A), etc., it is important to control these factors to a high degree.
Hereinafter, an example of the roughening method of the metal member surface for obtaining the metal member 103 which satisfy | fills the said requirements (1)-(4), (1A)-(1C), (2A) etc. is shown. However, the roughening method of the metal member surface which concerns on this embodiment is not limited to the following examples.

(1) Pretreatment process First, it is desirable that the metal member 103 does not have a thick film made of an oxide film, hydroxide, or the like on the surface on the joint side with the resin member 105. In order to remove such a thick film, the surface layer may be polished by mechanical polishing such as sand blasting, shot blasting, grinding, barrel processing, or chemical polishing before the next etching step. Good. Further, when there is significant contamination of machine oil or the like on the surface on the joint side with the resin member 105, it is preferable to perform treatment with an alkaline aqueous solution such as a sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution, or degreasing.

(2) Surface roughening treatment process In this embodiment, as a surface roughening treatment method of a metal member, it is preferable to perform the process by the acid type etching agent mentioned later at a specific timing. Specifically, the treatment with the acid-based etching agent is preferably performed at the final stage of the surface roughening treatment step.

In Patent Document 5 described above, as an etchant used for surface roughening treatment of a metal member made of a metal material containing aluminum, an aspect using an alkaline etchant, an alkaline etchant and an acid etchant are used in combination. An embodiment is disclosed in which an acid-based etching agent is treated and then washed with an alkaline solution.
The alkaline etching agent is preferably used from the viewpoint of workability because the reaction with the metal member is gentle. However, according to the study by the present inventors, since such an alkaline etching agent has a mild reactivity, the degree of roughening treatment on the surface of the metal member is weak and it is difficult to form a deep uneven shape. It became clear that there was. In addition, when an alkaline etchant or an alkaline solution is used in combination after an acid etchant treatment, the deep uneven shape formed by the acid etchant is treated with the subsequent alkaline etchant or alkaline solution. It became clear that the uneven shape was made somewhat smooth.

  Examples of the roughening treatment using the acid-based etching agent include treatment methods such as immersion and spraying. The treatment temperature is preferably 20 to 40 ° C., the treatment time is preferably about 5 to 350 seconds, 20 to 300 seconds are more preferred, and 50 to 300 seconds are particularly preferred from the viewpoint that the surface of the metal member can be more uniformly roughened.

  By the roughening treatment using the acid-based etching agent, the surface of the metal member 103 is roughened into an uneven shape. The etching amount (dissolution amount) in the depth direction of the metal member 103 when using the acid-based etching agent is 0.1 to 500 μm when calculated from the mass, specific gravity and surface area of the dissolved metal member 103. Is more preferable, it is more preferable that it is 5-500 micrometers, and it is still more preferable that it is 5-100 micrometers. When the etching amount is equal to or greater than the lower limit, the bonding strength between the metal member 103 and the resin member 105 can be further improved. Further, if the etching amount is equal to or less than the above upper limit value, the processing cost can be reduced. The etching amount can be adjusted by the processing temperature, processing time, and the like.

  In this embodiment, when the metal member is roughened using the acid-based etching agent, the entire surface of the metal member may be roughened, and only the surface to which the resin member 105 is bonded is partially formed. The roughening treatment may be performed.

(3) Post-treatment step In this embodiment, it is usually preferable to perform washing and drying after the surface roughening treatment step. Although there is no restriction | limiting in particular about the method of water washing, It is preferable to wash | clean for predetermined time with immersion or flowing water.

  Furthermore, as a post-treatment step, it is preferable to perform ultrasonic cleaning in order to remove smut and the like generated by the treatment using the acid-based etching agent. The ultrasonic cleaning conditions are not particularly limited as long as the generated smut and the like can be removed, but the solvent used is preferably water, and the treatment time is preferably 1 to 20 minutes.

(Acid etching agent)
In this embodiment, as an etching agent used for the roughening process of the metal member surface, the specific acid type etching agent mentioned later is preferable. By treating with the specific etching agent, an uneven shape suitable for improving the adhesion between the metal member and the resin member is formed on the surface of the metal member, and the anchor effect between the metal member 103 and the resin member 105 is formed. It is considered that the bonding strength is further improved.

  Hereinafter, the components of the acid-based etching agent that can be used in this embodiment will be described.

  The acid-based etching agent contains at least one of ferric ions and cupric ions and an acid, and may contain manganese ions, various additives, and the like as necessary.

-Ferric ion The said ferric ion is a component which oxidizes a metal member, and this ferric ion can be contained in an acid type etching agent by mix | blending a ferric ion source. Examples of the ferric ion source include ferric nitrate, ferric sulfate, and ferric chloride. Among the ferric ion sources, ferric chloride is preferable because it has excellent solubility and is inexpensive.

  In this embodiment, content of the said ferric ion in an acid type etching agent becomes like this. Preferably it is 0.01-20 mass%, More preferably, it is 0.1-12 mass%, More preferably, it is 0.5-7 % By mass, still more preferably 1-6% by mass, particularly preferably 1-5% by mass. If content of the said ferric ion is more than the said lower limit, the fall of the roughening rate (dissolution rate) of a metal member can be prevented. On the other hand, if the content of the ferric ion is not more than the above upper limit value, the roughening rate can be properly maintained, so that it is more suitable for improving the bonding strength between the metal member 103 and the resin member 105. Roughening becomes possible.

-Cupric ion The said cupric ion is a component which oxidizes a metal member, and can mix | blend this cupric ion in an acid type etching agent by mix | blending a cupric ion source. Examples of the cupric ion source include cupric sulfate, cupric chloride, cupric nitrate, and cupric hydroxide. Of the cupric ion sources, cupric sulfate and cupric chloride are preferred because they are inexpensive.

  In this embodiment, it is preferable that content of the said cupric ion in an acid type etching agent is 0.001-10 mass%, More preferably, it is 0.01-7 mass%, More preferably, it is 0.00. It is 05-1 mass%, More preferably, it is 0.1-0.8 mass%, More preferably, it is 0.15-0.7 mass%, Most preferably, it is 0.15-0.4 mass%. If content of the said cupric ion is more than the said lower limit, the fall of the roughening rate (dissolution rate) of a metal member can be prevented. On the other hand, if the content of the cupric ion is less than or equal to the above upper limit value, the roughening rate can be maintained appropriately, so that it is more suitable for improving the bonding strength between the metal member 103 and the resin member 105. Roughening becomes possible.

  The acid-based etching agent may contain only one of ferric ion and cupric ion, or may contain both, but both ferric ion and cupric ion It is preferable to contain. When the acid-based etching agent contains both ferric ions and cupric ions, a good roughened shape that is more suitable for improving the bonding strength between the metal member 103 and the resin member 105 can be easily obtained.

  When the acid-based etching agent contains both ferric ions and cupric ions, the contents of ferric ions and cupric ions are preferably in the above ranges. The total content of ferric ions and cupric ions in the acid-based etching agent is preferably 0.011 to 20% by mass, more preferably 0.1 to 15% by mass, and even more preferably. Is 0.5 to 10% by mass, particularly preferably 1 to 5% by mass.

Manganese ions The acid-based etching agent may contain manganese ions in order to uniformly roughen the surface of the metal member. Manganese ions can be contained in the acid-based etching agent by blending a manganese ion source. Examples of the manganese ion source include manganese sulfate, manganese chloride, manganese acetate, manganese fluoride, and manganese nitrate. Among the above manganese ion sources, manganese sulfate and manganese chloride are preferable from the viewpoint of being inexpensive.

  In this embodiment, it is preferable that content of the said manganese ion in an acid type etching agent is 0-1 mass%, More preferably, it is 0-0.5 mass%.

-Acid The acid is a component that dissolves a metal oxidized by ferric ions and / or cupric ions. 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. One or more of these acids can be added to the acid-based etching agent. Of the inorganic acids, sulfuric acid is preferred because it has almost no odor and is inexpensive. Among the organic acids, carboxylic acid is preferable from the viewpoint of uniformity of the roughened shape.

  In the present embodiment, the acid content in the acid-based etching agent is preferably 0.1 to 50% by mass, more preferably 0.5 to 50% by mass, and 1 to 50% by mass. It is still more preferable, it is still more preferable that it is 1-30 mass%, it is still more preferable that it is 1-25 mass%, and it is still more preferable that it is 2-18 mass%. If content of the said acid is more than the said lower limit, the fall of the metal roughening rate (dissolution rate) can be prevented. On the other hand, if the content of the acid is not more than the upper limit, it is possible to prevent crystal precipitation of the metal salt when the liquid temperature is lowered, so that workability can be improved.

Other components To the acid-based etching agent that can be used in the present embodiment, a surfactant may be added to prevent unevenness due to surface contaminants such as fingerprints, and other additives may be added as necessary. May be. Other additives include halide ion sources added to form deep irregularities, such as sodium chloride, potassium chloride, sodium bromide, potassium bromide and the like. Alternatively, thio compounds such as thiosulfate ions and thiourea added to increase the roughening treatment speed, azoles such as imidazole, triazole and tetrazole added to obtain a more uniform roughened shape, Examples thereof include a pH adjuster added to control the oxidization reaction. When these other components are added, the total content is preferably about 0.01 to 10% by mass in the acid-based etching agent.

  The acid-based etching agent of this embodiment can be easily prepared by dissolving each of the above components in ion-exchanged water or the like.

<Resin member>
Hereinafter, the resin member 105 according to the present embodiment will be described.
The resin member 105 according to the present embodiment is made of a polycarbonate resin composition (C).
Here, the polycarbonate resin composition (C) according to this embodiment has a weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) in the range of 20,000 to 60,000, and the molecular weight. The polycarbonate resin (A) having a distribution (Mw / Mn) in the range of 1.5 to 15.0 and the weight average molecular weight (Mw) measured by GPC in the range of 500 to 5,000, the molecular weight And a polycarbonate oligomer (B) having a distribution (Mw / Mn) in the range of 1.0 or more and 5.0 or less. And mass ratio ((A) / (B)) of polycarbonate resin (A) with respect to polycarbonate oligomer (B) is 90/10 or more and 99/1 or less.

  The polycarbonate resin composition (C) according to the present embodiment usually comprises a polycarbonate resin (A) and a polycarbonate oligomer (B), which will be described later, in a mass ratio ((A) / (B)) of 90/10 or more 99. / 1 or less, preferably 92/8 or more and 98/2 or less, more preferably 93/7 or more and 98/2 or less.

(Polycarbonate resin (A))
The polycarbonate resin (A) according to this embodiment has a weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) of usually 20,000 to 60,000, preferably 25,000 to 60,000. The molecular weight distribution (Mw / Mn) is usually from 1.5 to 15.0, preferably from 2.0 to 15.0, more preferably from 30,000 to 55,000. It is in the range of 2.1 to 14.0, more preferably 2.3 to 12.5.

The raw material for producing the polycarbonate resin (A) is not particularly limited as long as the above molecular weight characteristics are satisfied. For example, mention may be made of polycarbonate obtained by reacting a dihydroxy compound with phosgene, carbonic diester or halogen formate. Can do.
Examples of the dihydroxy compound include 2,2-bis (4-hydroxyphenyl) propane (hereinafter also referred to as “bisphenol A”), tetramethylbisphenol A, tetrabromobisphenol A, and bis (4-hydroxyphenyl) -p. -Aromatic dihydroxy compounds such as diisopropylbenzene, hydroquinone, resorcinol and 4,4'-dihydroxydiphenyl can be mentioned, and among these, bisphenol A is preferred. Further, the polycarbonate may have a small amount of one or more structural units derived from a trifunctional or higher polyhydroxy compound as required. As such a polycarbonate resin (A), a commercially available product is usually used as it is.

(Polycarbonate oligomer (B))
The polycarbonate oligomer (B) according to this embodiment has a weight average molecular weight (Mw) measured by GPC of 500 or more and 5,000 or less, preferably 1,000 or more and 4,000 or less, more preferably 2,000 or more and 3 , 500 or less, and the molecular weight distribution (Mw / Mn) is 1.0 or more and 5.0 or less, preferably 1.0 or more and 4.0 or less, more preferably 1.2 or more and 3.0 or less. is there.
The raw material for producing the polycarbonate oligomer (B) is not particularly limited as long as the above molecular weight characteristics are satisfied. Usually, dihydroxy compounds such as bisphenol A and compounds such as phosgene, carbonic acid diester or halogen formate are exemplified. be able to.
The polycarbonate oligomer (B) in a specific molecular weight range and molecular weight distribution range can be easily prepared based on a known method using a molecular weight modifier, or by a minor change in formulation (for example, JP-A-6-234842). No., JP-A-7-173277, JP-T-2004-528403, etc.). In the examples described later, a polycarbonate oligomer (B) was prepared based on the examples described in JP-A-7-173277.

  The resin member 105 may be composed only of the polycarbonate resin composition (C), and may contain a filler (D) described later. When the filler (D) is included, the content of the polycarbonate resin composition (C) is usually 50% by mass or more and 95% by mass or less, preferably 50% by mass or more when the entire resin member 105 is 100% by mass. It is 90 mass% or less, More preferably, it is 60 mass% or more and 90 mass% or less.

(Filler (D))
In the present embodiment, the resin member 105 may further include a filler (D) from the viewpoint of adjusting the linear expansion coefficient difference between the metal member 103 and the resin member 105 and improving the mechanical strength of the resin member 105.

  As a filler (D), 1 type, or 2 or more types can be selected from the group which consists of glass fiber, carbon fiber, carbon particle, clay, talc, silica, mineral, and a cellulose fiber, for example. Among these, Preferably, it is 1 type, or 2 or more types selected from glass fiber, carbon fiber, talc, and a mineral, Especially preferably, it is glass fiber.

  The shape of the filler (D) is not particularly limited, and may be any shape such as a fiber shape, a particle shape, or a plate shape.

  In addition, when the resin member 105 contains a filler (D), the content is usually 5% by mass or more and 50% by mass or less, preferably 10% by mass or more and 50% by mass, when the entire resin member 105 is 100% by mass. % Or less, more preferably 10 mass% or more and 40 mass% or less.

  The filler (D) has an effect of controlling the linear expansion coefficient of the resin member 105 in addition to the effect of increasing the rigidity of the resin member 105 made of the polycarbonate resin composition (C). In particular, in the case of the composite of the metal member 103 and the resin member 105 according to the present embodiment, the temperature dependence of the shape stability of the metal member 103 and the resin member 105 is often greatly different, so that a large temperature change occurs. And the composite is easily distorted. This distortion can be reduced when the resin member 105 contains the filler (D). Moreover, when content of the said filler (D) exists in the said range, reduction of toughness can be suppressed.

In the present embodiment, the filler (D) is preferably a fibrous inorganic filler, more preferably glass fiber or carbon fiber, and particularly preferably glass fiber.
As a result, it is possible to lower the glass transition temperature while increasing the rigidity of the resin member 105, and even if the mold temperature during molding is lowered, the mobility of the molecular chain of the resin member 105 is reduced. Can be suppressed. As a result, it is possible to maintain the penetration of the resin member 105 into the concave portion of the fine uneven shape of the metal member 103, and to suppress a decrease in the bonding strength between the metal member 103 and the resin member 105. Furthermore, since the shrinkage | contraction of the resin member 105 after shaping | molding can be suppressed, joining to the metal member 103 and the resin member 105 in the recessed part of the said fine uneven | corrugated shape can be made stronger.

  In this embodiment, when the content of the fibrous inorganic filler in the resin member 105 is 100% by mass of the entire resin member 105 from the viewpoint of improving the bonding strength while maintaining the moldability of the resin member 105, Preferably they are 5 to 50 mass%, More preferably, they are 10 to 50 mass%, Most preferably, they are 10 to 40 mass%.

(Other ingredients)
The resin member 105 may contain other compounding agents for the purpose of imparting individual functions.
Examples of the compounding agents include thermal stabilizers, antioxidants, pigments, weathering agents, flame retardants, plasticizers, dispersants, lubricants, mold release agents, antistatic agents, and other impact resistance modifiers.

(Manufacturing method of the resin member 105)
In the manufacturing method of the resin member 105, it is particularly important to highly control each factor such as the type and content of the polycarbonate resin composition (C) and the filler (D) constituting the resin member 105.
For example, the polycarbonate resin composition (C) described above, further a filler (D), if necessary, the above other compounding agents such as a Banbury mixer, a single screw extruder, a twin screw extruder, a high speed twin screw extruder, etc. The resin member 105 is obtained by mixing or melt-mixing using a mixing apparatus.

[Method for producing metal / resin composite structure]
Next, a method for manufacturing the metal / resin composite structure 106 according to this embodiment will be described.
The manufacturing method of the metal / resin composite structure 106 includes the following steps (i) to (ii).
(I) Step of disposing the metal member 103 having a fine uneven surface in the cavity portion of the mold (ii) Step of joining the metal member 103 and the resin member 105 by injecting the resin member 105 into the cavity portion This will be described in detail.

  First, (i) a mold is prepared, the mold is opened, and the metal member 103 is placed in the cavity (space). (Ii) Thereafter, the mold is closed, and the resin member 105 is injected into the cavity portion of the mold to be solidified so that at least a part of the resin member 105 is in contact with the fine uneven surface of the metal member 103. The member 103 and the resin member 105 are joined. Thereafter, the metal / resin composite structure 106 can be obtained by opening the mold and releasing the mold.

  Here, in the step (ii), the surface temperature of the mold is not particularly limited from the start of injection of the resin member 105 to the completion of pressure holding. As will be apparent from examples described later, when the resin member 105 composed of the polycarbonate resin composition (C) according to this embodiment is used, the glass transition temperature (hereinafter also referred to as Tg) of the resin member 105 is used. ) It is characterized by exhibiting sufficient bonding strength (base metal fracture level) with metal even at the following mold surface temperature. Of course, the present invention does not limit the surface temperature of the mold to be higher than Tg. If the feed energy to the mold and the molding time are sufficiently secured, an attempt is made to obtain higher bonding strength. In such a case, the temperature can be maintained at Tg + (5 or more and 100 or less) ° C.

  In the step (ii), when the surface temperature of the mold is set to a temperature equal to or higher than Tg, a cooling operation after completion of the pressure holding is preferably employed. Thereby, since the molding cycle of the metal / resin composite structure 106 can be shortened, the metal / resin composite structure 106 can be obtained efficiently.

  As described above, according to the manufacturing method of the metal / resin composite structure 106 according to the present embodiment, the metal / resin composite structure 106 having excellent bonding strength between the metal member 103 and the resin member 105 can be stably obtained. It can be manufactured even more efficiently.

  Further, as a molding method to which the manufacturing method of the metal / resin composite structure 106 according to the present embodiment is applied, an injection molding method, a transfer molding method, a compression molding method, a reaction injection molding method, a blow molding method, and a thermoforming method are used. And a press molding method. Among these, the injection molding method is preferable.

[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, since the metal / resin composite structure 106 according to the present embodiment exhibits high airtightness and watertightness, it is preferably used for applications according to these characteristics.

  For example, use for household goods such as structural parts for vehicles, on-vehicle equipment, housing for electronic equipment, housing for home appliances, structural parts, mechanical parts, various automotive parts, electronic equipment parts, furniture, kitchenware, etc. , Medical equipment, building material parts, other structural parts and exterior parts.

  More specifically, the following parts 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 metal member 103 and the adiabatic property of the resin member 105 are combined, so that the metal member 103 can 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 the surface area increases by roughening the surface of the metal member 103, the contact area between the metal member 103 and the resin member 105 increases, and the thermal resistance of the contact interface can be reduced. Derived from.

  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 of this invention was described, these are illustrations of the use of this invention, and it 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.

Note that FIGS. 1, 2 and 4 are used as a common view of each embodiment.
FIG. 1 is an external view schematically showing an example of the structure of a metal / resin composite structure 106 of a metal member 103 and a resin member 105.
FIG. 2 is a configuration diagram schematically showing an example of a process of manufacturing the metal / resin composite structure 106 of the metal member 103 and the resin member 105. Specifically, a metal member 103 that has been processed into a predetermined shape and has a joint surface 104 having a fine concavo-convex surface on the surface is placed in a mold 102, and a resin composition is gated / runnered by an injection molding machine 101. A process of manufacturing a metal / resin composite structure 106 which is injected through 107 and integrated with a metal member 103 having a fine uneven surface is schematically shown.

(Measurement of load length ratio (Rmr), ten-point average roughness (Rz), and average length (RSm) of roughness curve elements on the surface of a metal member)
Of the surface roughness measured according to JIS B0601 (corresponding ISO 4287) using a surface roughness measuring device “Surfcom 1400D (manufactured by Tokyo Seimitsu Co., Ltd.)”, the load length ratio (Rmr) of the roughness curve The ten-point average roughness (Rz) and the average length (RSm) of the roughness curve elements were 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 line portions including arbitrary three straight line portions in parallel relation on the surface of the metal member and arbitrary three straight line portions orthogonal to the straight line portion (see FIG. 4). In this example / comparative example, since the entire surface of the metal member 103 is roughened, the load length ratio (Rmr) of the roughness curve for the joint surface 104 of the metal / resin composite structure 106, It is understood that the same evaluation result as the measurement point shown in FIG. 4 can be obtained even when the ten-point average roughness (Rz) and the average length of the roughness curve element (RSm) are measured.

(Joint strength evaluation method and overall pass / fail judgment)
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. Further, the interface on the metal member side after the fracture was observed, and if the resin remained in 10% or more of the interface area, it was determined that the base material was broken, and otherwise, it was determined that the interface was peeled. However, when the mechanical properties of the resin itself are reduced, the base material may be destroyed even though the bonding strength is low. Therefore, the case where the bonding strength was 20 MPa or more and the base material was broken was determined to be “good”, and the other was determined to be “poor”.

(Method for preparing resin composition)
<Preparation method of polycarbonate oligomer (B)>
8406 g (36.87 mol) of bisphenol A, 316.5 g (2.11 mol) of p-tertiarybutylphenol as a molecular weight regulator, 5.994 g (0.05935 mol) of triethylamine, 4277 g (106.93 mol) of caustic soda, An aqueous mixture having a total weight of 69.94 kg was prepared by dissolving 16.794 g of rhodium hydrosulfite in 57.06 kg of water. This mixture, phosgene and organic solvent were introduced into the first tank reactor at 129.56 g / min, 7.638 g (0.07715 mol) / min and 127.37 g / min, respectively. The reaction mixture is discharged from the tank reactor at 264.57 g / min. The residence time was 20 minutes. The continuously discharged reaction mixture is supplied to a second tank type reactor using piping, polymerized in a residence time of 40 minutes, and further the reaction mixture is supplied to a third tank type reactor and retained. Polymerization was carried out in 40 minutes. The reaction mixture continuously discharged from the third tank reactor was immediately separated and neutralized with hydrochloric acid. The obtained organic phase was washed with pure water until the electrolyte disappeared. This continuous operation was carried out for 9 hours, and the organic solvent was evaporated away from the obtained organic solvent solution containing the aromatic polycarbonate to obtain a solid aromatic polycarbonate. The obtained solid polycarbonate was pulverized with a pulverizer to obtain a polycarbonate oligomer (B1). When the molecular weight of the obtained PC oligomer was measured, Mn = 1,900, Mw = 2800, and Mw / Mn was 1.5.

<Method for Preparing Polycarbonate Resin Composition (C)>
Panlite L1225L (hereinafter referred to as polycarbonate resin (A1)) manufactured by Teijin Limited was used as the polycarbonate resin (A). The number average molecular weight (Mn) in the GPC measurement of the polycarbonate resin (A1) was 16,380, the weight average molecular weight (Mw) was 39,110, and Mw / Mn was 2.4. The polycarbonate oligomer (B1) obtained by the above method is used in the ratio shown in Table 1 with respect to the polycarbonate resin (A1) using a twin screw extruder KZW15TW (screw diameter 15 mm, L / D = 45) manufactured by Technobel. The resin pellets of PC-1 to PC-4, which are polycarbonate resin compositions (C), were obtained by melt-kneading at 300 ° C. and 300 rpm, respectively.

(DSC measurement of resin member)
The DSC measurement of the resin member was performed by the following method using a DSC apparatus (X-DSC7000 manufactured by SII).
A 5 mg sample was cut out from the resin pellet, and DSC measurement was performed under the conditions of a start temperature of 30 ° C., a measurement temperature range of 30 to 200 ° C., a temperature increase rate of 10 ° C./min, a temperature decrease rate of 10 ° C./min, and a nitrogen atmosphere. Here, as the glass transition temperature, a glass transition temperature (Tg) of 2ndRun was employed in the DSC measurement. Table 2 shows the Tg of each resin member.

(GPC measurement)
GPC measurement (molecular weight measurement) for the polycarbonate resin (A) and the polycarbonate oligomer (B) was performed by the following method.
3.0 ml of chloroform was added to a 3.0 mg sample and sufficiently dissolved, followed by filtration with a 0.45 μm hydrophilic PTFE membrane filter cartridge (Millex-LH; Merck Millipore), and the filtrate was used as a measurement sample. The GPC apparatus was composed of a pump, an injector, a column, and a detector. The flow rate of the pump was 1.0 ml / min, the temperature inside the column was 40 ° C., and measurement was performed by injecting a measurement solution from a 10 μl injector. Chloroform was used as the solvent. In addition, two PolyPore 7.5 × 300 mm (manufactured by Polymer Laboratory) were connected in series to the column. As the detector, a 486 UV-visible detector (manufactured by Nippon Waters) was used.
In the analysis of the sample, a calibration curve prepared from a monodisperse polystyrene (hereinafter referred to as PS) standard sample was used. The calibration curve was obtained by plotting the logarithmic value of the molecular weight of PS and the peak detection time (retention time) of PS and regressing to a cubic equation. Monodisperse polystyrene PS-1 (Agilent Technology) was used as a standard PS sample for preparing a calibration curve.

(Surface roughening treatment of metal members)
[Method for preparing metal member]
An aluminum plate (thickness: 2.0 mm) of alloy number 5052 defined in JIS H4000 was cut into a length of 45 mm and a width of 18 mm. This aluminum plate was treated with an acid-based etching agent (sulfuric acid: 8.2% by mass, ferric chloride: 7.8% by mass (Fe ³⁺ : 2.7% by mass), cupric chloride: 0.4% by mass (Cu Etching was performed by immersing in ( ²⁺ : 0.2% by mass) ion-exchanged water: remainder (30 ° C.) for 80 seconds and rocking. Subsequently, ultrasonic cleaning (in water, 1 minute) was performed with running water and dried to obtain a surface-treated metal member.

The interval interval of the obtained metal members was measured with a laser microscope (VK-X100 manufactured by KEYENCE).
Further, the surface roughness of the obtained metal member was measured using a surface roughness measuring device “Surfcom 1400D (manufactured by Tokyo Seimitsu Co., Ltd.)”, and cutting levels of 10%, 20%, and 30% were obtained for the six straight portions. , 40%, 50%, 60%, 70% and 80%, the load length ratio (Rmr), the ten-point average roughness (Rz) and the average length of the roughness curve element (RSm) were determined. Among these, the Rmr (20%) value at a cutting level of 20%, the number of straight portions where the Rmr (20%) value is 30% or less, the Rmr (40%) value at a cutting level of 40%, the Rmr (40%) ) The etching rate was calculated from the number of straight portions where the value was 60% or less, the Rz value of 6 straight portions, the average length (RSm) of the roughness curve elements, and the mass ratio of the metal members before and after the etching treatment.
The obtained results are shown below.

Interval period [μm]: 92
Rmr (20%) value [%] at a cutting level of 20%: 17.5, 10.3, 13.4, 10.6, 3.8, 7.4
Number of straight portions where the Rmr (20%) value is 30% or less: 6
Rmr (40%) value [%] at a cutting level of 40%: 43.6, 26.1, 48.0, 46.7, 33.5, 34.2
Number of straight portions where Rmr (40%) value is 60% or less: 6
Rz value [μm] of 6 linear portions: 17.8, 18.1, 19.6, 17.8, 17.2, 18.0
RSm value [μm] of 6 straight portions: 104.0, 83.0, 85.6, 98.7, 106.6, 103.1
Etching rate [% by mass]: 2.6

[Example 1]
A small dumbbell metal insert mold 102 was attached to an injection molding machine J85AD manufactured by Nippon Steel Works, and a metal member was installed in the mold 102. The surface temperature of the mold 102 was previously heated to a temperature 10 ° C. lower than the Tg of the PC-1 resin pellet.
Next, using the resin pellets of PC-1 in the mold 102, injection molding is performed under the conditions of a cylinder temperature of 300 ° C., an injection speed of 25 mm / sec, a holding pressure of 120 MPa, and a holding time of 10 seconds, and cooling is performed. By performing, the metal / resin composite structure 106 was obtained. Table 2 shows the evaluation results of the bonding strength.

[Example 2, Comparative Examples 1-2]
A metal / resin composite structure 106 was obtained by the method shown in Example 1 except that the resin pellets were PC-2 resin pellets, PC-3 resin pellets, and PC-4 resin pellets, respectively. Table 2 shows the evaluation results of the bonding strength.

As shown in Table 2, in Examples 1 and 2, despite the mold temperature being Tg or less, a very high bonding strength was obtained, and the fracture mode and the strength of the base material fracture level were obtained. Was confirmed. That is, the metal / resin composite structure 106 obtained in the example had high bonding strength even when molded at a lower mold temperature, and was excellent in balance between productivity and bonding strength.
On the other hand, when the metal / resin composite structure 106 obtained in the comparative example was molded at a lower mold temperature, the bonding strength was low, and the balance between productivity and bonding strength was poor.
Further, as apparent from Table 2, the polycarbonate resin (A) is composed of a polycarbonate resin composition (C) in which a polycarbonate oligomer (B) having specific molecular weight characteristics is added in a quantitative ratio defined in the present invention. It was found that the resin member exhibited sufficient bonding strength with the metal member even at a mold temperature equal to or lower than the Tg of the resin member.

DESCRIPTION OF SYMBOLS 101 Injection molding machine 102 Mold 103 Metal member 104 Joint surface 105 Resin member 106 Metal / resin composite structure 107 Gate / runner 110 Surface

Claims (10)

A metal / resin composite structure formed by bonding a metal member having a fine uneven surface and a resin member composed of a polycarbonate resin composition (C),
The polycarbonate resin composition (C) is:
The weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) is in the range of 20,000 to 60,000, and the molecular weight distribution (Mw / Mn) is in the range of 1.5 to 15.0. The weight average molecular weight (Mw) measured by GPC is in the range of 500 to 5,000, and the molecular weight distribution (Mw / Mn) is in the range of 1.0 to 5.0. A polycarbonate oligomer (B)
The metal / resin composite structure whose mass ratio ((A) / (B)) of the said polycarbonate resin (A) with respect to the said polycarbonate oligomer (B) is 90/10 or more and 99/1 or less.   2. The metal / resin composite structure according to claim 1, wherein convex portions having an interval period of 5 nm or more and 500 μm or less stand on the surface of the fine irregularities of the metal member. The resin member further includes a filler (D),
The metal / resin composite structure according to claim 1 or 2, wherein a content of the filler (D) in the resin member is 5 mass% or more and 50 mass% or less.   The metal / resin composite structure according to claim 3, wherein the filler (D) includes glass fibers.   The metal / resin composite structure according to any one of claims 1 to 4, wherein the metal member includes one or more metal materials selected from aluminum and an aluminum alloy. Conforms to JIS B0601 (corresponding international standard: ISO 4287) for a total of 6 straight line parts consisting of any 3 straight line parts in parallel relation on the surface of the metal member and any 3 straight line parts orthogonal to the 3 straight line parts. The metal / resin composite structure according to claim 1, wherein the measured surface roughness satisfies the following requirements (1) and (2) simultaneously.
(1) Includes one or more straight line portions with a load length ratio (Rmr) of a roughness curve at a cutting level of 20% and an evaluation length of 4 mm of 30% or less. (2) Evaluation length of all straight line portions. Ten point average roughness (Rz) at 4 mm exceeds 2 μm Conforms to JIS B0601 (corresponding international standard: ISO 4287) for a total of 6 straight line parts consisting of any 3 straight line parts in parallel relation on the surface of the metal member and any 3 straight line parts orthogonal to the 3 straight line parts. The metal / resin composite structure according to claim 6, wherein the measured surface roughness further satisfies the following requirement (3).
(3) One or more straight line portions having a load length ratio (Rmr) of a roughness curve at a cutting level of 40% and an evaluation length of 4 mm are 60% or less.   The ten-point average roughness of all the straight portions of a total of six straight portions including arbitrary three straight portions in parallel relation on the surface of the metal member and arbitrary three straight portions orthogonal to the three straight portions. The metal / resin composite structure according to claim 6 or 7, wherein (Rz) exceeds 5 µm.   The ten-point average roughness of all the straight portions of a total of six straight portions including arbitrary three straight portions in parallel relation on the surface of the metal member and arbitrary three straight portions orthogonal to the three straight portions. The metal / resin composite structure according to claim 8, wherein (Rz) is 15 μm or more. A manufacturing method for manufacturing the metal / resin composite structure according to any one of claims 1 to 9,
Placing the metal member having a fine uneven surface in the cavity of the mold; and
Bonding the metal member and the resin member by injecting the resin member into the cavity portion;
The manufacturing method of the metal / resin composite structure containing this.

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