JP5375008B2 - Adhesive bonding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sticking/joining method and car body structural components produced by suitably using the same to have improved adhering accuracy and strength. <P>SOLUTION: The sticking/joining method, when electrically-conductive members 1, 2 are stuck/joined to each other, comprises a step (a) of forming spots for temporary joint on the adhesion surface 1a of one 1 of the members by using dispensers 6, 7 and a first electrically-conductive adhesive 4 and applying a second thermocurable adhesive 5 for normal adhesion over the whole area of the adhesion area to obtain desired adhesion strength; and a step (b) of sticking both of the members 1, 2 to each other, making an electric current flow from the member 2 to the member 1 to cure the first adhesive 4 and perform temporary joint, and heating both of the members to cure the second adhesive 5 and perform normal adhesion. Consequently, with th simple sticking/joining method, a plurality of spots for temporary joint can be stuck/joined simultaneously to restrain deformation from being caused owing to the shrinkage of the first adhesive 4 for temporary joint and the final adhesion can be performed by the second adhesive 5 to attain high precision and strength. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

The present invention relates to adhesive bonding how.

  Conventionally, welding such as spot welding and laser welding has been used as a method for joining members constituting a vehicle body, but in recent years, in order to cope with diversification of materials, it is also possible to join a wide range of surfaces. Since it is easy to improve rigidity, adhesion by an adhesive is also used. Bonding with the adhesive is generally realized by curing the applied adhesive with heat. For example, at 170 ° C. for 30 minutes.

Among the adhesives, in recent years, as disclosed in Patent Document 1, curing is started by energy applied to a part from the outside, and the heat generated along with the curing is propagated to adjacent sites. A chain-reaction type adhesive that hardens as it is attracting attention. According to this adhesive, even when a place to be applied is set at a position where it is difficult to use a conventional ultraviolet curable adhesive or the like and it is difficult to irradiate ultraviolet rays, the adhesive can be reliably cured inward.
JP-A-11-193322

  However, in the adhesion with the chain reaction type adhesive, the curing time differs depending on the site, and distortion may occur with the curing shrinkage of the adhesive. And when this distortion is large, there exists a problem that joining strength and joining accuracy cannot fully be obtained.

  On the other hand, as a technique for suppressing such distortion caused by adhesion, there is a method of performing temporary bonding after temporarily fixing the sheet. However, even with this temporary fixing, it is difficult to cure the balance of the entire temporary fixing portion, and the distortion generated at the temporary fixing stage remains in the main bonding, resulting in the accuracy and strength of the main bonding. There is a problem that decreases.

An object of the present invention is to suppress the occurrence of distortion due to shrinkage of the adhesive is to provide an adhesive bonding how that can be bonded with high accuracy and strength.

The adhesive bonding method of the present invention is a method in which conductive members are adhesively bonded to each other, and a first adhesive having conductivity is spot-formed between the bonded surfaces of the members, and between the bonded surfaces. A step of forming a second adhesive having a thermosetting property over the entire surface of a predetermined adhesion range other than the portion where the first adhesive is spot-formed, and from one of the members to the other Passing a current to the substrate and curing the first adhesive to perform temporary fixing, and after the temporary fixing, curing the second adhesive by heating to perform main bonding. Features.

  According to the above configuration, in the present invention, at least two kinds of adhesives are used in bonding the conductive members such as metal plates. It should be noted that the first adhesive is used for temporary fixing as having conductivity, and the second adhesive is used for main bonding as having thermosetting properties (non-conductive). Note that a plurality of types of thermosetting adhesives may be properly used as the second adhesive depending on the part and the member interval.

  Then, these adhesives are formed in a predetermined thickness by application or the like on the bonding surface of one member or both members in an arbitrary order, or bonded between two opposing members. Agent is injected. It should also be noted at this time that the first adhesive is spot-formed while the second adhesive is formed over the entire bonding area in order to obtain a desired adhesive strength. Subsequently, an electric current is passed from one of the members to the other, the first adhesive is cured and temporarily fixed, and then the second adhesive is cured by heating to perform main bonding.

  Therefore, since the spot of the 1st adhesive agent which has electroconductivity is used for a temporary fix using the electroconductivity of both members, a some temporary fix location can be adhesively joined substantially simultaneously by electricity supply. In this way, it is possible to suppress the occurrence of distortion caused by the shrinkage of the temporary fixing adhesive by an extremely simple method, and to achieve the final bonding by the main bonding with high accuracy and strength.

  In the adhesive bonding method of the present invention, the main bonding step is a coating film drying step.

  According to said structure, the 2nd adhesive agent can be hardened using the heat | fever for drying a coating film.

  Therefore, the main bonding step can be used in combination with the drying step to shorten the step, and the second adhesive can be uniformly cured.

  Furthermore, in the adhesive bonding method of the present invention, the first adhesive is a chain reaction type adhesive that generates heat as it hardens and propagates to an adjacent site and hardens. It is characterized by being.

  According to said structure, hardening by energization heating of said 1st adhesive agent can be performed more reliably.

  In the adhesive bonding method of the present invention, the spot forming portion of the first adhesive is formed in a recess in the member.

  According to the above configuration, when the first adhesive is cured, the amount of the first adhesive, and hence the amount of generated heat, is formed by forming the spot forming portion of the first adhesive in the recess. The chain curing reaction can be surely performed.

  Furthermore, in the adhesive bonding method of the present invention, at least one of the members has a substantially perpendicular hat-shaped cross section and has a flange extending from the outer periphery of the recess, and the flange portion is adhesively bonded to the other member. The second adhesive is formed on the inner peripheral side of the flange portion, and the spot of the first adhesive is formed on the outer peripheral side.

  According to the above configuration, at least one of the members has a substantially perpendicular hat-shaped cross section and has a flange extending from the outer periphery of the recess, and the flange portion is adhesively bonded to the other member. When both members have a bag-like structure, the second adhesive is formed on the inner peripheral side of the bag and the spot of the first adhesive is formed on the outer peripheral side.

  Therefore, the adhesion strength can be increased by main-bonding the inner peripheral side where force is easily applied and easily peeled off.

Adhesive bonding how the present invention, as described above, when adhesively bonded members to each other having conductivity, the adhesion surface of the member, the first adhesive having conductivity as well as spot formation, the Among the bonding surfaces , a second adhesive having a thermosetting property is formed over the entire surface of the predetermined bonding range in a region other than the portion where the first adhesive is spot-formed , An electric current is passed from one side of the member to the other, the first adhesive is cured and temporarily fixed, and then the second adhesive is cured by heating to perform main bonding.

  Therefore, using the conductivity of both members, the spot of the first adhesive having conductivity is used for temporary fixing, and therefore, a plurality of temporarily fixed portions can be bonded and joined substantially simultaneously by energization. In this way, it is possible to suppress the occurrence of distortion caused by the shrinkage of the temporary fixing adhesive by an extremely simple method, and to achieve the final bonding by the main bonding with high accuracy and strength.

[Embodiment 1]
FIG. 1 is a perspective view for explaining an adhesive bonding method according to an embodiment of the present invention. In the present embodiment, two members 1 and 2 each having a substantially hat-shaped cross section as shown in FIG. 1A are bonded together and processed into a hollow columnar member 3 as shown in FIG. An example will be described. In FIG. 1, the members 1 and 2 have the same shape in order to simplify the drawing and description, but may have different shapes, or one may have a plate shape. The created member 3 can be used as a vehicle body structural component such as a front frame of an automobile, for example.

  It should be noted that in the adhesive bonding method of the present invention, at least two types of adhesives 4 and 5 are used to bond the members 1 and 2 having conductivity such as metal plates to each other. 4 is used for temporary fixing as having conductivity, and the second adhesive 5 is used for main bonding as having thermosetting properties. Note that a plurality of types of thermosetting adhesives may be selectively used as the second adhesive 5 depending on the region and the interval between the members 1 and 2.

  Then, these adhesives 4 and 5 are arranged in an arbitrary order on the adhesive surface 1a of one member or both members (member 1 in the example of FIG. 1) by dispensers (liquid metering discharge devices) 6 and 7. Each is applied and formed to a predetermined thickness. It should also be noted at this time that, as shown in FIG. 1 (a), the second adhesive 5 is formed over the entire bonding range in order to obtain a desired adhesive strength. 4 is that a spot is formed. Subsequently, as shown in FIG. 1B, the bonding surfaces 1a and 2a of both members 1 and 2 are bonded together, and current flows from one of the members (member 2 in FIG. 1) to the other (same member 1). The first adhesive 4 is cured and temporarily fixed, and then the second adhesive 5 is cured by heating to perform the main bonding.

  Specifically, one member 1 is placed on a conductive jig 9 connected to GND (ground) 8 as shown in FIG. The adhesives 4 and 5 are respectively applied, and the state shown in FIG. For example, when the first adhesive 4 has 100 parts by weight of an alicyclic epoxy resin as a main agent, the above-mentioned chain reaction type adhesive is formed by blending 0.6 parts by weight of a cationic polymerization initiator as a curing agent. It is formed by adding 50 parts by weight of carbon black as a conductive fine powder to the agent, and has conductivity as described above.

  Subsequently, as shown in FIG. 1B, another member 2 is overlapped, and is clamped by the clamper 10 with the jig 9 with a desired tightening force as appropriate. The clamper 10 is swingably displaceable from the tip of the support column 10a on a support column 10a standing on a base (not shown), and is held and fixed at the standing position in FIG. 1 (a) and the fall position in FIG. 1 (b). It is configured with a possible arm 10b. In the arm 10b, the contact portion with the member 2 is covered with an insulator 10c. Thereafter, the power source line 12 is connected to the other member 2 by the clamper 11, and the power source line 12 is connected to the power source 14 via the switch 13.

  Therefore, when the switch 13 is turned on, the electric current flows through the first adhesive 4 using the conductivity of both the members 1 and 2, and the first adhesive 4 generates heat and hardens. Temporary fastening locations can be adhesively bonded at the same time. In this way, it is possible to suppress the occurrence of distortion due to the shrinkage of the temporary adhesive 4 by a very simple method, and to achieve the final adhesion with the second adhesive 5 with high accuracy and strength. In addition, the first adhesive 4 is a chain reaction type adhesive that generates heat as it hardens itself, propagates to the adjacent portion, and is cured. Curing of the adhesive 4 by energization heating can be performed more reliably.

  Also, it should be noted that in the adhesive bonding method of the present invention, the members 1 and 2 have flanges 1c and 2c extending from the outer periphery of the recesses 1b and 2b, with the cross section perpendicular to the axis being formed in a substantially hat shape. The flanges 1c and 2c become the bonding surfaces 1a and 2a that are bonded and bonded to the other members 2 and 1, and both the members 1 and 2 are bonded and bonded to form a bag-like structure. In this case, as shown in FIG. 1A, the spot of the second adhesive 5 on the inner peripheral side of the flanges 1c and 2c (bag) and the spot of the first adhesive 4 on the outer peripheral side. Are formed respectively. In this way, the adhesive strength can be increased by main-bonding the inner peripheral side where force is easily applied and easily peeled off.

  On the other hand, as the second adhesive 5 for the main bonding, a conventional thermosetting (non-conductive) adhesive can be used. For example, product names (registered trademark) Betamate 1496V, Betamate 1480, Betamate 1022D manufactured by Dow Chemical Co., Ltd. are available. These are all epoxy-based, and the curing condition thereof is, for example, 170 ° C. for 30 minutes as described above. When such a normal thermosetting (non-conductive) adhesive is used for the main adhesion, particularly in the case of a vehicle body structural component, the second adhesion is performed using the drying heat in the coating film drying process. It is preferable to cure the agent 5. By creating in this way, the main bonding step can be combined with the drying step to shorten the step, and the second adhesive 5 can be uniformly cured. Further, heating can be continued for a time sufficient for curing. According to the experiment results of the present inventors, the adhesive strength is 2 to 6 MPa in the case of the first adhesive 4 under the above conditions, and 20 to 30 MPa in the case of the second adhesive 5 under the above conditions.

  In the above description, the members 1 and 2 are bonded together after the adhesives 4 and 5 are applied to the bonding surface 1a of the member 1, but the adhesive is injected between two opposing members. Good.

[Embodiment 2]
2 and 3 are views for explaining an adhesive bonding method according to another embodiment of the present invention. FIG. 2 is a perspective view of the member 21. FIG. It is sectional drawing which looked at the state which piled up from the cut surface line III-III of FIG. It should be noted that in the present embodiment, when the first adhesive 4 is cured, the spot forming portion of the first adhesive 4 is formed in the recess 21d in the member 21. . As a result, the amount of the first adhesive 4, and hence the heat generation amount, can be increased, and the chain curing reaction can be performed reliably.

It is a perspective view for demonstrating the adhesive bonding method which concerns on one Embodiment of this invention. It is a perspective view for demonstrating the adhesive bonding method which concerns on other forms of implementation of this invention. It is sectional drawing seen from the cut surface line III-III of FIG.

Explanation of symbols

1, 2; 21 Member 1a, 2a Adhesive surface 1b, 2b Recess 1c, 2c Flange 3 Member 4 First adhesive 5 Second adhesive 6, 7 Dispenser 8 GND
9 Jig 10 Clamper 11 Clamper 12 Power supply line 13 Switch 14 Power supply 21d Recess

Claims (5)

In the method of adhesively bonding the members having conductivity,
A first adhesive having conductivity is spot-formed between the bonding surfaces of the member, and a predetermined bonding is performed in a region other than the portion where the first adhesive is spot-formed among the bonding surfaces. Forming a thermosetting second adhesive over the entire surface;
Passing a current from one of the members to the other, curing the first adhesive, and temporarily fixing;
And a step of performing a main bonding by curing the second adhesive by heating after the temporary fixing.   The adhesive bonding method according to claim 1, wherein the main bonding step is a coating film drying step.   The first adhesive is a chain reaction type adhesive that generates heat as it hardens and propagates to an adjacent site to be cured. The adhesive bonding method described.   The adhesive bonding method according to claim 3, wherein in the member, the spot forming portion of the first adhesive is formed in a recess. At least one of the members has a substantially perpendicular hat-shaped cross section, and has a flange extending from the outer periphery of the recess. 5. The adhesive bonding method according to claim 1, wherein the second adhesive is formed on the peripheral side and the spot of the first adhesive is formed on the outer peripheral side . 6.

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