JPH0732564B2 - Metal-resin composite and method for producing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a composite of metal and resin and a method for producing the same, and more particularly to improvement of sealing property between contact surfaces of a metal member and a resin structure. For example, in a composite of a bracket and a brush holder used in a rotating electric machine such as a starter motor (hereinafter referred to as a bracket unit), the brush holder is integrally resin-molded in a part of the bracket. It is related to effective technology for things.

[Conventional technology]

As a bracket unit used for a starter motor, there has been proposed one in which a brush holder is integrally molded using a resin in a bracket formed in a thin plate shape (see, for example, Japanese Utility Model Publication No. 61-58843). ).

[Problems to be solved by the invention]

In such a brush holder, when an iron-based material is used for the bracket and a nylon resin is used for the brush holder, when an environmental test such as a thermal shock test is performed, the heat between the bracket and the brush holder is Since the expansion coefficients are different, a relative shift occurs between the contact surfaces of the two, and as a result, the airtightness and the liquidtightness of the housing of the starter motor in which the bracket unit is assembled are deteriorated. Revealed by

An object of the present invention is to provide a technique capable of preventing a decrease in sealability due to relative displacement between contact surfaces of a metal member and a resin structure.

[Means for solving problems]

In the metal-resin composite according to the present invention, the seal film interposed between the contact surfaces of the metal member and the resin structure is compatible with both the metal member forming material and the resin structure forming material. Of a methacrylic acid alkyl ester / acrylic acid alkyl ester copolymer as a main component is used to form the seal film. It is characterized in that it is in a state of being in close contact with each of the contact surfaces with an object and in a state of maintaining flexibility.

Further, the method for producing a composite of metal and resin according to the present invention,
Dispersion containing a methacrylic acid alkyl ester / acrylic acid alkyl ester copolymer as a main component, which has a good affinity for both the metal member forming material and the resin structure forming material on the contact surface of the metal member with the resin structure. And a step of drying the dispersion mainly composed of the methacrylic acid alkyl ester / acrylic acid alkyl ester copolymer coated on the metal member, and the methacrylic acid alkyl ester / acrylic acid alkyl ester copolymer A metal member, in which a dispersion containing a polymer as a main component is dried, is mounted on a molding die to mold a resin structure, and an alkyl methacrylate ester is formed between the contact surfaces of the metal member and the resin structure.・ By dispersion containing acrylic acid alkyl ester copolymer as the main component Sealing film formed Te is characterized in that it comprises a step to be interposed.

[Action]

According to the above-mentioned means, since the seal film is adhered or adhered to both the metal member and the resin structure, the sealed state is constituted by blocking the gap.

In addition, since the seal film has flexibility, if a relative displacement (displacement) occurs between the contact surfaces of the metal member and the resin structure due to the difference in thermal expansion coefficient, the displacement is By following the flexible deformation, the sealed state can be maintained.

〔Example〕

FIG. 1 is a partially cutaway enlarged side view showing a bracket unit which is an embodiment of the present invention, FIG. 2 is a longitudinal sectional view showing a starter motor in which it is used, and FIG. 3 is a II of FIG.
FIG. 4 is an enlarged partial sectional view showing the terminal portion, FIG. 5 is an exploded perspective view of the starter motor, and FIG. 6 is a longitudinal sectional view showing a manufacturing process, FIG. FIG. 8 is an enlarged partial sectional view for explaining the action, and FIG. 9 is a schematic view for explaining the experimental method.

In this embodiment, this motor is configured to be used as a starter motor, and includes a stator 1, a rotor 2, and a bracket unit 3 as a composite of metal and resin according to the present invention.

The stator 1 is provided with a yoke 4 which is integrally formed of a magnetic material by an appropriate means such as drawing press working.
The yoke 4 is formed in a substantially cylindrical shape with one end surface (hereinafter referred to as the front side) being open and the other end surface (hereinafter, referred to as the rear side) being closed. At the outer edge of the opening 5 of the yoke 4, a flange portion 6 is provided so as to project in the radial direction, and a pair of bolt insertion holes 7 and a pair of screw insertion holes 8 are arranged vertically in the flange portion 6, respectively. Have been drilled. At the inner edge of the opening 5 of the yoke 4, a pair of anti-rotation protrusions 9 are provided.
Are placed on the left and right and are projected. A bearing member accommodating portion 10 is formed in a cylindrical shape on the closed wall of the rear surface of the yoke 4, and a bearing member 11 is fitted inside the accommodating portion 10. A plurality of magnets 12 are fixed to the inner peripheral surface of the yoke 4 at equal intervals in the circumferential direction so as to form a magnetic field.

The rotor 2 is provided with a shaft 13 longer than the length of the yoke 4, and a commutator 14 and an armature 15 are fixedly mounted on the outer periphery of the intermediate portion of the shaft 13 in the front and rear directions. A pinion 16 is engraved on the front end of the shaft 13, and the pinion 16 meshes with the driven gear 17 of the starter in the assembled state. Journal portions 18 and 19 are formed at the rear position and the rear end portion of the pinion 16 on the outer periphery of the shaft 13, respectively.
Is journaled rotatably in the inside of the yoke 4 by supporting both journal portions 18 and 19 by a bearing member 58, which will be described later, and the bearing member 11 arranged on the yoke 4.

The bracket unit 3 as a metal-resin composite according to the present invention includes a brush holder 20 as a resin structure integrally molded in a substantially disk shape with nylon resin, and the brush holder 20 is a bracket as a metal member. twenty one
Is integrally molded into. Further, a terminal member 33 is planted at a predetermined position of the brush holder 20 so as to penetrate the bracket 21 in an insulated state, as shown in FIG.

Here, a method of manufacturing the bracket unit according to the embodiment of the present invention and its configuration will be described.

The bracket 21 is formed by punching and pressing a plate material having conductivity such as an iron plate to form the flange portion 6 of the yoke 4.
5 is formed in a flat plate shape as shown in FIG. A pair of bolt insertion holes 22 and a screw hole 23 for screw screwing are arranged and opened in the upper and lower portions of the bracket 21. A window hole 24 is formed substantially in the center of the bracket 21 so as to have an inner diameter slightly larger than the outer diameter of the commutator 14, and a plurality of small holes 25 are circumferentially arranged around the window hole 24. Has been established. Window hole
A bearing member accommodating portion 57 is integrally connected to the 24 in a circular bowl shape. Further, an insertion hole 34 larger than the width and thickness of the terminal member 33 is opened at a position of the upper left corner of the bracket 21 at approximately 45 degrees.

When the brush holder 20 is molded on the bracket 21, the bracket 21 is set so as to be sandwiched by the molding die 70, as shown in FIG. Although detailed description is omitted, the molding die 70 includes an upper die 71 and a lower die 72, and a cavity 73 having a gate 74 opened on its mating surface,
It is submerged in a shape capable of molding a brush holder 20 having a configuration described later. The bracket 21 is set such that a portion for molding the brush holder 20 is inserted into the cavity 73 and sandwiched between the upper mold 71 and the lower mold 72.

At the same time, the terminal member 33 is inserted into the insertion hole 34 of the bracket 21.
Are inserted so as not to come into contact with each other, penetrate through the cavity 73, and are positioned and held by the upper mold 71 and the lower mold 72.

Here, before the bracket 21 is set in the molding die 70,
On the surface of the portion of the bracket 21 where the brush holder 20 is molded, a dispersion containing a methacrylic acid alkyl ester / acrylic acid alkyl ester copolymer as a main component is provided with an appropriate thickness by a suitable means such as a brush or a spray. The coating film 75 is formed by uniformly coating the coating film. Also, this coating 75 has a cavity 73
It is similarly formed on the surface of the insert-molded portion of the terminal member 33 as another metal member which is inserted into the resin and formed into a resin.

The dispersion containing a methacrylic acid alkyl ester / acrylic acid alkyl ester copolymer as a main component is a fluid of a resin having a good affinity for metals and resins.

Incidentally, in this example, in consideration of the fact that the starter motor is used even in a severe cold region, the glass transition point of the methacrylic acid alkyl ester / acrylic acid alkyl ester copolymer is about −30 ° C. or lower. The one that has been adjusted is used. Moreover, a material that can withstand the molding temperature of the resin (about 280 ° C.) is used.

The thickness of the coating film 75 varies depending on the concentration and viscosity of the dispersion, but is preferably 1 to 50 μm, and more preferably about 10 μm. That is, when the thickness is 1 μm or less, flexibility is difficult to be exhibited, and when the thickness is 50 μm, the rate of increase in the effect is reduced and the cost relative to the ratio of the amount used is increased.

The coating film 75 is naturally or forcibly dried to evaporate water as a dispersion medium liquid.
The coating film 75 has a rubber elastic property or flexibility and adheres or sticks to the metal surface. After the coating film 75 is dried, the bracket 21 and the terminal member 33 as metal members are, as described above,
It is set in the mold 70.

In this way, when the bracket 21 and the terminal member 33 are appropriately set in the molding die 70, the cavity 73 is filled with nylon resin as a molding material from the gate 74 while being heated and melted at about 280 ° C., The bracket 21 has a brush holder as a resin structure made of nylon resin.
20 is integrally molded, and a terminal member 33 is implanted and molded in the brush holder 20.

That is, the bracket 21 is arranged so as to be substantially orthogonal to the axial center when the brush holder 20 is molded, and is molded by implantation, so that the portion from the inner edge of the window hole 24 to the outside of the small hole 25 is the front wall of the brush holder 20. It is integrated with the brush holder 20 while being sandwiched between the portion 26 and the rear wall portion 27. In this state, a part of the nylon resin forming the brush holder 20 fills the small holes 25 of the bracket 21 and is a solid cylindrical portion.
28 are formed respectively, and the bracket 21 and the brush holder 20 are integrated by being completely stopped by these columnar portions 28. Also brush holder
When 20 is resin-molded, the terminal member 33 is fixedly held by the holding portion 35 having a substantially rectangular parallelepiped shape in which the insertion hole 34 is filled with resin.

In the front and rear surfaces of the bracket 21 and the front and rear wall portions 26, 27 of the brush holder 20, and in the inner periphery of the small hole 25 and the outer periphery of the columnar portion 28, flexibility is provided between the contact surfaces of the bracket 21 and the brush holder 20. The sealing film 76 having is formed by a coating film 75 containing a methacrylic acid alkyl ester / acrylic acid alkyl ester copolymer as a main component and is interposed, and the methacrylic acid alkyl ester / acrylic acid alkyl ester copolymer is a metal. Further, because of its high affinity with resin, the sealing film 76 is strongly adhered or adhered to the surfaces of the bracket 21 and the brush holder 20, or is physically or chemically bonded to be integrated. Further, a seal film 76 is similarly interposed between the contact surfaces of the brush holder 20 and the terminal member 33 inserted through the brush holder 20.

A hole is formed at a position of approximately 45 degrees in the lower left corner of the front wall portion 26 of the brush holder 20 so that the background of the bracket 21 is exposed. A rear hole portion 31 is similarly formed at a position corresponding to the front hole portion in the rear wall portion 27 of the brush holder 20, and the exposed surface portion of the bracket 21 at the bottom portion of the rear hole portion 31 is for connecting a pigtail. Pigtail connection 32
Is formed. A second lead wire connecting portion 36 is formed by the portion of the terminal member 33 that protrudes forward from the holding portion 55, and a second pigtail connecting portion 37 is formed by the portion that protrudes rearward.

The outer diameter of the rear wall portion 27 of the brush holder 20 is set to be substantially equal to the inner diameter of the opening 5 of the yoke 4 and the axes thereof are aligned with each other. The inner circumference of the opening 5 and the male cage joint 38 are
The female cage connector 39 is substantially configured. A pair of rising walls 40 are erected at right and left positions on the outer edge of the rear surface of the rear wall portion 27 in a direction substantially parallel to the axis, and anti-rotation recesses 41 are provided on the outward surfaces of both rising walls 40. It is submerged in a shape that connects a circle to the apex of a triangle. In the combined state of the male and female cage cages 38, 39, the anti-rotation recesses 41 protruding from the inner edge of the opening 5 of the yoke 4 are fitted in the anti-rotation recesses 41, respectively. ing.

A pair of brush accommodating chambers 42 are disposed at the upper and lower positions on the back surface of the rear wall portion 27 so as to face each other, and the accommodating chambers 42 are provided in parallel with each other so as to project from each other. Due to 43, it is formed into a hollow rectangular parallelepiped shape in which both ends in the radial direction and the back surface are open on three sides. Pins 44 for forming a caulked portion 44A are respectively provided on the back surface of each guide wall 43 so as to project, and one of the inside positions of the rising wall 40 is for positioning a captive prevention plate described later. The pin 45 is projected. The opening on the back side of the brush accommodating chamber 42 is closed by a fall prevention plate 46 fixed by each pin in a state of being in contact with the back surface of each guide wall 43.

A pair of brushes 51A and 51B are arranged inwardly in both housing chambers 42 and are slidably inserted in the radial direction, respectively, and the pigtails 52A and 52B planted in the brushes 51A and 51B fall out. It is slidably inserted in insertion holes 49 formed at the top and bottom of the prevention plate 46, respectively. Brushes 51 arranged on the upper side
The terminal of the pigtail 52A of A is welded to the pigtail connecting portion 37 of the terminal member 33, and the terminal of the pigtail 52B of the brush 51B disposed on the lower side is welded to the pigtail connecting portion 32 of the bracket 21, respectively.
It is electrically connected to 21.

Outside the brushes 51A and 51B of the storage chamber 42, a pair of springs 53 are respectively inserted and stored from the outward openings of the storage chamber 42, and the springs 53 are fixed to the outward openings of the storage chamber 42. The cap 54 is pressed against the commutator 14 of the rotor 2 by applying a reaction force to the cap 54 to urge the brush inward.

A substantially cylindrical bearing member accommodating portion 57 is formed at a position corresponding to the window hole 24 of the bracket 21 so as to project forward, and in this accommodating portion 57, a bearing member 58 such as a ball bearing is accurately formed. It is fitted with the shaft center aligned with. The axis of the accommodating portion 57 is set to coincide with the axis of the male cage connecting portion 38 formed by the outer circumference of the rear end portion 27 of the brush holder 20, and therefore the axis of the accommodating portion 57 is set. The shaft center of the bearing member 58 accommodated together is aligned with the shaft center of the male cage connector 38.

In a state where the bracket unit 3 configured as described above is assembled to the stator 1 and the rotor 2, the brush holder 20 is inserted into the opening 5 of the yoke 4 so that the male and female seals on the outer peripheral surface and the inner peripheral surface of the brush holder 20 are formed. The joint portions 38 and 39 are joined together in a cage to align the axes. In this state, the bearing member
Since the shaft center of 58 is aligned with the male cage connector 38 of the brush holder 20, it is also aligned with the shaft center of the yoke 4. Therefore, the bearing member 58 and the bearing member 11 at the rear end portion of the yoke 4 support the journals 18 and 19 of the rotor 2.
The shaft 13 is accurately aligned with the stator 1 and is rotatably supported.

When the opening 5 of the yoke 4 and the brush holder 20 are joined together in the cage, the anti-rotation protrusion 9 and the recess 41 are aligned and fitted to each other. When both 9 and 41 are fitted together, the bolt insertion hole 7 and the screw insertion hole 8 in the flange portion 6 of the yoke 4
And the bolt insertion hole 22 of the bracket 21 and the screw hole 23 for screw screwing are aligned with each other. When the screw 59 is inserted into the insertion hole 8 of the flange portion 6 of the yoke 4 and screwed into the screw hole 23, the bracket 21 and the yoke 4 are connected to each other, so that the stator 1, the stator 2 and the bracket unit 3 have the axial center. And the positions are matched and integrated at a time. Although detailed description is omitted, the bearing member accommodating portion 57 is fitted to the boss portion 61 of the engine case 60 in the three-body integrated state. Boss part of engine case 60
When the shaft centers of the bearing member housing portion 57 and the bearing member housing portion 57 are set to coincide with each other, the shaft 13 supported by the bearing member 58 of the bearing member housing portion 57 is aligned with the boss portion 61. become. Therefore, the pinion 16 engraved on the shaft 13 accurately meshes with the driven gear 17.

Next, the operation will be described.

As described above, since the starter motor is connected to the engine case, it is expected that the starter motor will be exposed to the temperature environment from the extremely cold atmospheric temperature to the engine overheat temperature. Therefore, for the starter motor, an environmental test including a thermal shock test is performed several tens of times in the range of about -20 ° C to 150 ° C.

By the way, when a bracket unit with no seal film provided between the contact surface between the bracket and the brush holder is used in the starter motor, when the thermal shock test is performed, the difference in the coefficient of thermal expansion between metal and resin As a result, as shown in FIG. 7, a relative displacement 77 occurs between the contact surfaces of the bracket 21 'and the brush holder 20', so that in the subsequent airtightness test, the airtightness of the motor housing deteriorates. It was made clear by the present inventor.
This is because a minute gap 77 is generated due to the relative displacement between the contact surfaces of the bracket 21 'and the brush holder 20'.
This is considered to be because an unexpected ventilation path that cannot be controlled due to this gap is formed as shown by an arrow in FIG. If such relative displacement occurs on both the contact surfaces of the bracket and brush holder, external rainwater, condensed water, etc. will enter the inner surface of the motor housing from between these contact surfaces, causing a loss of motor performance. Becomes

However, in this embodiment, since the seal film 76 is provided between the contact surfaces of the bracket 21 and the brush holder 20, the airtightness of the motor housing is not maintained even after the thermal shock test is performed. It will be maintained as planned. Therefore, it is possible to prevent outside rainwater, condensed water, or the like from entering the inside of the housing from between the contact surfaces of the bracket 21 and the brush holder 20.

That is, in the thermal shock test, the bracket 21 and the brush holder are different due to the difference in thermal expansion coefficient between metal and resin.
Even if a relative displacement occurs between the contact surface with 20 and the seal film 76, since it has an excellent affinity for both metal and resin, as shown in FIG. It will adhere or stick to any of the brush holders 20. In addition, since the seal film 76 has excellent flexibility, the displacement between the bracket 21 and the brush holder 20 due to the difference in coefficient of thermal expansion between the bracket 21 and the brush holder 20 is flexibly deformed, and the integrity of the seal film 76 itself is maintained. Will be maintained. Therefore, even if a relative displacement occurs between the contact surface between the bracket 21 and the brush holder 20, both
Since a seal film 76 prevents a gap or an air passage from being formed between the motor housing and the motor 20, the motor housing can maintain the desired airtightness even after the thermal shock test.

Table 1 carried at the end of this specification shows the results of experiments on this airtightness and was carried out as follows.

First, the experimental sample in which the bracket unit is assembled to the yoke is repeatedly cooled and heated 10 times or more from -20 ° C to 150 ° C at intervals of about 2 hours.

As shown in FIG. 9, in the experimental sample 78 which was subjected to this thermal shock test, the compressor 79 was placed in the airtight chamber formed inside by the bracket unit and the yoke and the fluid was passed through the hose 80 etc. Being combined,
A pressure gauge 81 is attached so that the internal pressure of the airtight chamber can be measured.

In this set state, the experimental sample 78 is immersed in the water in the water tank 82, and air is pressure-fed by the compressor 79 into the airtight chamber. Then, the bracket 21 in the bracket unit
The pressure gauge 81 measures the internal pressure value of the airtight chamber when a bubble 83 is generated from between the contact surfaces between the brush holder 20 and the brush holder 20.
This measured value is the pressure value in Table 1, and its unit is
It is kg / cm ² . By the way, the water immersion phenomenon from the contact surface between the bracket and the brush holder was 0.3 kg / cm ²
If it is above, it can fully endure practical use.

In Table 1, the first sample shows the case where a bracket unit in which the seal film is not provided between the bracket and the brush holder is used, and the second sample and the following samples have the seal film as shown in Table 2. Each of the dispersions listed in 1. is applied and formed as follows. That is, the liquid material is applied to the surface of the bracket three times with a brush to form a film having a thickness of about 10 to 20 μm, and dried for several hours to form a coating film. afterwards,
The brush holder 20 is formed using nylon resin so as to surround the coating film, and the seal film 76 is provided between the bracket 21 and the brush holder 20.

The present invention is not limited to the above embodiment,
It goes without saying that various modifications can be made without departing from the spirit of the invention.

For example, in the above embodiment, a bracket made of an iron plate,
Although a composite with a brush holder made of nylon resin and a composite of a terminal member made of a copper plate and a brush holder made of nylon resin has been described, the present invention is not limited to this, and a resin structure is provided on the metal member. It can be applied to all integrally molded composites. In particular, when applied to a product that requires air tightness or liquid tightness, excellent effects can be obtained.

〔The invention's effect〕

As described above, according to the present invention, the main component is a methacrylic acid alkyl ester / acrylic acid allylic ester copolymer having good affinity for the metal and the resin between the contact surfaces of the metal member and the resin structure. It is possible to maintain a sealed state even when there is a relative displacement between the contact surfaces of the metal member and the resin structure by providing a flexible seal film formed from the dispersion. it can. Further, since the seal film formed by the dispersion containing the methacrylic acid alkyl ester / acrylic acid alkyl ester copolymer as the main component is formed only by evaporating water, no harmful gas is generated, and
Since it can be formed in a short time, the safety and efficiency of work can be improved.

[Brief description of drawings]

FIG. 1 is a partially cutaway enlarged side view showing a bracket unit which is an embodiment of the present invention, FIG. 2 is a longitudinal sectional view showing a starter motor in which it is used, and FIG. 3 is a II of FIG.
A sectional view taken along the line I-III, FIG. 4 is an enlarged partial sectional view showing a terminal portion, FIG. 5 is an exploded perspective view thereof, FIG. 6 is a sectional surface view showing a manufacturing process, FIG. 7 and FIG. FIG. 9 is an enlarged partial sectional view for explaining the action, and FIG. 9 is a schematic view for explaining the experimental method. 1 ... Stator, 2 ... Rotor, 3 ... Bracket unit, 4 ... Yoke, 5 ... Opening part, 6 ... Flange part,
7 ... Bolt insertion hole, 8 ... Screw insertion hole, 9 ... Rotating protrusion, 10 ... Bearing member accommodating portion, 11 ... Bearing member, 12 ...
… Magnet, 13 …… Shaft, 14 …… Commutator, 15 …… Armature, 16 …… Pinion, 17 …… Driven gear, 18,19 …… Journal part, 20 …… Brush holder, 21 …… Bracket, 22 …… Bolt insertion hole, 23 ... Screw hole for screwing, 24 ... Window hole, 25 ... Small hole, 26 ... Front wall part, 27 ... Wall part, 28 ... Cylindrical part, 31 ... Rear hole Part, 32 ...
… Pigtail connection part, 33 …… Terminal member, 34 …… Terminal member insertion hole, 35 …… Terminal member holding part, 36
...... Lead wire connection part, 37 …… Pigtail connection part, 38 ……
Male-ink cage coupling part, 39 ... Female-ink cage coupling part, 40 ... Standing wall, 41 ... Rotation preventing recess, 42 ... Brush accommodating chamber, 43 ...
Guide chamber, 44 …… pin, 44A …… locking part, 45 …… positioning pin, 46 …… falling prevention plate, 47 …… covering part, 48 …… connecting part, 49 …… pigtail insertion hole, 50… ... Small holes, 51A, 51B
...... Brush, 52A, 52B ...... Pigtail, 53 ...... Spring, 54 ...... Cap, 55, 56 ...... Engagement convex part, 57 ...... Bearing member accommodating part, 58 ...... Bearing member, 59 ...... Screw, 60 …… Engine case, 61 …… Boss part, 62 …… Bolt screwing screw hole, 63 …… Bolt, 70 …… Molding die, 71 …… Upper die, 72 ……
Lower mold, 73 …… cavity, 74 …… gate, 75 …… coating film, 76 …… seal film, 77 …… clearance, 78 …… experimental sample, 79
...... Compressor, 80 …… Hose, 81 …… Pressure gauge, 82…
… Aquarium, 83 …… Bubbles.

Claims (4)

[Claims] 1. A resin structure is integrally molded over a front surface and a back surface of a metal member, and at least a part of the front surface of the metal member of the resin structure and at least one of the back surface of the metal member of the resin structure. A part of the metal member is sandwiched between the metal member and the metal member, or the metal member is integrally formed over the front and back surfaces of the resin structure. A dispersion containing, as a main component, a methacrylic acid alkyl ester / acrylic acid alkyl ester copolymer having a good affinity for both the metal member forming material and the resin structure forming material between the contact surfaces with the resin structure. A sealing film formed by using the above is interposed, and in the state where the sealing film is interposed, the contact surface with the metal member and the resin Together in the state to both the close contact respective contact surface with the structure, composite of a metal and a resin, characterized in that it is flexible while maintaining the. 2. The composite of metal and resin according to claim 1, wherein the metal member is made of an iron-based material and the resin structure is made of nylon resin. . 3. A resin structure is integrally molded over the front and back surfaces of a metal member, and at least a part of the front and back surfaces of the metal member of the resin structure and at least one of the back and back surfaces of the metal member of the resin structure. In the method for producing a composite of a metal and a resin, in which the part and a part of the metal member are sandwiched, or the metal member is integrally formed over the front and back surfaces of the resin structure, A disperser containing a methacrylic acid alkyl ester / acrylic acid alkyl ester copolymer as a main component, which has good affinity for both the metal member forming material and the resin structure forming material, on the contact surface of the metal member with the resin structure. The step of applying John, and the methacrylic acid alkyl ester / acrylic acid alkyl ester copolymer coated on the metal member. A step of drying the dispersion as a component, a metal member obtained by drying a dispersion containing a methacrylic acid alkyl ester / acrylic acid alkyl ester copolymer as a main component is mounted on a molding die, and the resin structure is Along with being molded, a seal film formed by a dispersion containing the methacrylic acid alkyl ester / acrylic acid alkyl ester copolymer as a main component is interposed between the contact surfaces of the metal member and the resin structure. And the sealing film is formed in close contact with both the contact surface with the metal member and the contact surface with the resin structure in the state where the seal film is interposed. A method for producing a composite of a metal and a resin, characterized in that the composite is formed so as to maintain flexibility. 4. A patent characterized in that a dispersion containing a methacrylic acid alkyl ester / acrylic acid alkyl ester copolymer as a main component is applied to the surface of a metal member by a brush to a thickness of about 1 to 20 μm. A method for producing a composite of a metal and a resin according to claim 3.