JP7156009B2 - Manufacturing method of composite of coated metal material and resin material - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method of manufacturing a composite of a coated metal material and a resin material.

In recent years, in the automobile industry, the use of resins has been increasing in response to the demand for weight reduction. In addition to replacing resin materials, composites of metal plates and resin materials are also being applied. Therefore, in manufacturing the composite, it is required to efficiently join the metal plate and the resin material.

An ultrasonic bonding method using ultrasonic vibration is known as a bonding method. An ultrasonic bonding apparatus having a horn and an anvil is used for the ultrasonic bonding method. In the material to be joined in which two members are superimposed, a horn is brought into contact with one member side, and the other member side is supported by an anvil. Then, while the two members are in close contact with each other, ultrasonic vibration is applied to the materials to be bonded through a horn, thereby generating frictional heat at the bonding interface, heating the bonding interface, and bonding the materials to be bonded. be able to.

Regarding the method of joining two members made of dissimilar materials such as a metal material and a resin material, the present applicant uses a coated metal material as the metal material and controls the amplitude of ultrasonic vibration, the pressure holding time, etc. The inventors have proposed a method for producing a composite having good bonding strength (Patent Document 1).

When applying the ultrasonic bonding method to the bonding of metal materials, as shown in FIG. A horn 43 arranged on the side of the upper plate 43 applies pressure 46 to the material to be joined, and ultrasonic vibration is applied to the material. As for the vibration direction of ultrasonic waves, ultrasonic vibration is applied in a horizontal vibration direction 48 that is perpendicular to the longitudinal direction of the horn 43 . The materials to be joined vibrate in the horizontal direction along the joining interface 48 , and friction is generated at the joining interface 48 . A heating area 45 is formed in the vicinity of the bonding interface by the friction, and heat required for bonding is obtained. Patent Literature 1 describes a joining method that applies lateral vibration to join a coated metal material and a resin material and utilizes frictional heat generation in the metal material.

When resin materials are ultrasonically bonded to each other, longitudinal ultrasonic vibration is applied because the transmissibility of lateral vibration in resin materials is low. For example, in FIG. 6 of Patent Document 2, as a method of ultrasonically welding the upper case and the lower case, a protrusion (welding rib) is provided in the upper case, and after contacting the lower case, the horn is attached to the upper case. It is described that the welding ribs are melted by applying longitudinal vibration to weld the upper case and the lower case. In Patent Document 2, vertical vibration causes friction between a projection and a lower case, and heat generated by the friction is used for bonding.

JP 2018-114670 A JP-A-2003-137205

A horn, which is a tool for transmitting ultrasonic vibrations, applies pressure by pressing the tip of the horn against the surfaces of the materials to be bonded in order to reliably transmit the ultrasonic vibrations to the materials to be bonded and perform good bonding. For this reason, it is inevitable that the bonded composite will have impressions of the horn remaining on the surface in contact with the horn.

The impressions of the horn may impair the appearance of the product depending on the application of the material to be joined. Composites of painted metal materials and resin materials may have painted metal steel sheets on the outer surface side, so ultrasonic bonding that can avoid horn impressions so as not to reduce the design of the painted metal steel sheets. A method is needed. Japanese Patent Laid-Open No. 2002-200001 does not describe such a problem regarding the indentation of the horn. Moreover, in Patent Document 2, there is no description suggesting a method of joining the painted metal material and the resin material.

The present invention has been made in view of the above circumstances. It is an object of the present invention to provide a method for producing a composite that avoids the formation and has a good appearance.

As a result of investigations, the inventors have found that by placing a horn on the resin material side and applying ultrasonic vibration in the longitudinal vibration direction to the object to be joined by the horn, the coated metal material and the resin material are in good contact. The present invention has been completed by discovering that it is possible to join to . Specifically, the present invention provides the following.

(1) The present invention provides a composite in which a painted metal material having an organic resin layer on at least one surface of the metal material and a resin material are bonded by an ultrasonic bonding apparatus equipped with a horn and an anvil. wherein the painted metal material and the resin material are laminated so that the surface of the painted metal material provided with the organic resin layer faces the surface of the resin material. holding the object to be joined between the horn and the anvil, placing the horn on the side of the resin material, and placing the anvil on the side of the painted metal stock; The horn is pressed against the surface of the resin material, and ultrasonic vibration in a longitudinal vibration direction is applied to the object to be joined by the horn to join the coated metal material and the resin material. ,
and the horn maintains a distance of 0.3 mm or more and 1.2 mm or less between the tip of the horn and the joint interface with respect to the joint interface between the coated metal material and the resin material. and a method of manufacturing a composite of a coated metal material and a resin material.

(2) The present invention is the method for producing a composite of a coated metal material and a resin material according to (1), wherein the amplitude of the ultrasonic vibration is 30 μm or more and 80 μm or less.

(3) The coated metal element according to (1) or (2), wherein after the ultrasonic vibration is stopped, the state in which the object to be joined is pressed by the horn is maintained for 0.1 s or more. A method for manufacturing a composite of a profile and a resin material.

According to the present invention, it is possible to obtain a composite of a painted metal material and a resin material that does not have horn impressions on the surface of the painted metal material and has a good appearance. Moreover, according to the present invention, since it is not necessary to prepare a structure to be joined such as a protrusion (see Patent Document 2) used in ultrasonic joining of resin materials, workability of joining is improved.

FIG. 2 is a schematic diagram showing a form before applying ultrasonic vibration in the present embodiment. FIG. 4 is a schematic diagram showing a form after starting application of ultrasonic vibrations in the present embodiment. FIG. 4 is a schematic diagram showing a form in which the horn is held with the tip of the horn placed at a certain distance from the bonding interface in the present embodiment. It is a figure which shows the test body used in the Example. It is a figure for demonstrating the tension test apparatus used in the Example. It is a schematic diagram showing an ultrasonic bonding method according to a conventional example.

An embodiment according to the present invention will be described below. The invention is not limited to the following description.

This embodiment manufactures a composite in which a coated metal material having an organic resin layer on at least one surface of the metal material and a resin material are bonded by an ultrasonic bonding apparatus equipped with a horn and an anvil. It is a way to The manufacturing method according to the present embodiment includes the steps of: (1) stacking the painted metal material and the resin material so that the surface of the painted metal material provided with the organic resin layer and the surface of the resin material face each other; (2) holding the body between the horn and the anvil, with the horn on the side of the resin material and the side of the painted metal blank; (3) pressing the horn against the surface of the resin material, and applying ultrasonic vibration to the object to be bonded in the thickness direction of the object to be bonded by the horn; and joining the coated metal preform and the resin material. The composite obtained by this manufacturing method has good appearance without horn impressions on the surface of the coated metal blank, and can be applied to many applications.

(Preparation of object to be bonded)
In the manufacturing method according to the present embodiment, a coated metal material and a resin material are layered to produce an object to be joined in which the surface of the coated metal material provided with the organic resin layer faces the surface of the resin material. do. FIG. 1 shows the state of the materials to be joined before the ultrasonic vibration is started. As shown in FIG. 1 , the coated metal preform 1 has an organic resin layer 3 on at least one surface of the metal preform 1 . The coated metal material 1 and the resin material 4 are bonded via the organic resin layer 3 by ultrasonic bonding treatment, which will be described later. For this reason, it is preferable that the object to be joined 5 to be subjected to the ultrasonic bonding process is in a form in which the surface of the coated metal material 1 and the resin material 4 are stacked so as to face each other.

(Holding by horn and anvil)
The manufacturing method according to the present embodiment uses an ultrasonic bonding apparatus including a horn and an anvil. The horn is a jig for transmitting ultrasonic vibrations generated by a vibration generator (not shown) to the object to be joined, and is used by bringing the tip of the horn into contact with the surface of the object to be joined. . The anvil is a jig for supporting the objects to be joined. As shown in FIG. 1, the article to be joined 5 is held between a horn 21 and an anvil 22 . At that time, the horn 21 is arranged on the resin material 4 side, and the anvil 22 is arranged on the painted metal material 1 side. Since the horn of the ultrasonic bonding apparatus is arranged on the side of the resin material, even if the ultrasonic bonding described later is performed, the surface of the coated metal material 1 is not indented by the horn. Therefore, the appearance of the bonded composite does not deteriorate even when the outer surface of the composite is coated with a metal preform. It is preferable that the horn contacting the surface of the resin material presses the resin material to bring the coated metal material and the resin material into close contact with each other.

(Ultrasonic bonding process)
In the manufacturing method according to the present embodiment, the horn is pressed against the surface of the resin material to apply pressure, and the horn imparts ultrasonic vibration in the longitudinal vibration direction to the resin material, and the object to be bonded is subjected to ultrasonic bonding treatment. be done. Specifically, it is preferable to start applying the ultrasonic vibration when the pressure applied by the horn reaches a predetermined pressure. FIG. 2 shows a form in which ultrasonic bonding progresses after starting vibration. Ultrasonic vibration in a longitudinal vibration direction 24 (also referred to herein as “longitudinal vibration”) that vibrates along the longitudinal direction of the horn 21 is applied to the workpiece 5 .

A region of the resin material 4 in contact with the tip of the horn 21 generates heat due to friction caused by the longitudinal vibration 24, the resin is heated, and a partially softened and melted region 11 is formed. This area is hereinafter referred to as a "softening area". Since the horn 21 presses the resin material downward with a constant pressure 23 , the softened area 11 is formed and the horn 21 quickly starts to descend, and the tip of the horn 21 is buried in the resin material 4 . do. As a result, the horn 21 approaches the joint interface 12 between the resin material 4 and the organic resin layer 3 , and the softened region 11 at the tip of the horn also approaches the joint interface 12 .

When the horn 21 approaches the bonding interface 12 , the bonding interface 12 is heated by the heat of the softened region 11 that has approached, and is heated by the frictional heat generated by the ultrasonic vibration of the horn 21 . As a result, an interface layer is formed in which the resin material 4 and the organic resin layer 3 are locally melted.

After the ultrasonic vibration is applied for a predetermined period of time, the application of vibration is stopped, and the pressure is continued for a predetermined period of time, whereby the bonding layer is solidified to form a bonded portion.

That is, this embodiment proceeds through the following two processes.
(i) A process in which a softened region is formed in the vicinity of the tip of the horn by longitudinal vibration, and the horn is rapidly lowered in the resin material to approach the joint interface. (ii) The tip of the horn is placed at a predetermined distance from the joint interface. The process of heating the joint interface at the position, by heating by the softening zone and by heating by the friction of ultrasonic vibrations

In this embodiment, as shown in FIG. 3, it is preferable that the tip of the horn 21 is held at a predetermined distance 13 from the joint interface 12 between the coated metal material 1 and the resin material 4 . At the bonding interface 12, the organic resin layer 4 of the coated metal material 1 and the resin material 4 are in close contact with each other. At the bonding interface 12 , an interface layer is formed in which the resin material 4 and the organic resin layer 3 are bonded by heating by the softened region 11 and frictional heat due to ultrasonic vibration of the horn 21 . If the tip of the horn is too close to the joint interface, the heat generated by the softened region and the frictional heat generated by the ultrasonic vibration will exert an excessive influence on the resin material and the organic resin layer, possibly causing damage to the coating state of the organic resin layer. On the other hand, if the tip of the horn and the bonding interface are too far apart, the resin material and the organic resin layer cannot be sufficiently heated, so that a good bonding layer cannot be obtained.

From the above point of view, the distance between the bonding interface, the tip of the horn and the bonding interface is preferably 0.3 mm or more and 1.2 mm or less. An appropriate range can be selected for the distance according to the amplitude conditions of the ultrasonic vibration. For example, when the amplitude is 30-40 μm, the distance is preferably 0.3 mm. When the amplitude is 50-80 μm, the distance is preferably 0.6-1.2 mm.

(amplitude of ultrasonic vibration)
If the amplitude of the ultrasonic vibration is too small, the softened area at the tip of the horn will not be sufficiently formed, and a good joint will not be obtained. On the other hand, if the amplitude is too large, even if the joint is once made, there is a risk that the joint will be destroyed due to the application of excessive vibration. Therefore, the amplitude of ultrasonic vibration is preferably in the range of 20 μm or more and 80 μm or less.

When the tip of the horn has a curved shape, the tip of the horn tends to eject the resin and sink when it descends in the resin material, so that the joining interface can be approached in a short period of time.

(Excitation time of ultrasonic vibration)
In the present embodiment, the vibration time for applying ultrasonic vibration can be appropriately selected according to conditions such as the amplitude, applied pressure, and film thickness of the coated steel sheet. If the vibration time is too short, a sufficient softening region and frictional heat cannot be obtained, resulting in a decrease in bonding strength. If the vibration time is too long, even if they are temporarily joined, they will separate due to vibration. Therefore, it is preferable to apply vibration within a suitable range, for example, a range of 0.2 to 0.6 seconds.

(Horn holding time)
In the present embodiment, it is preferable that the state in which the object to be bonded is pressed by the horn is maintained for 0.1 s or longer after the application of the ultrasonic vibration is stopped. If the pressing state is released at the same time as the vibration is stopped, a dense structure cannot be formed during the cooling of the joint, and sufficient joint strength cannot be obtained.

(Pressure of ultrasonic vibration)
At the start of vibration, it is preferable that the horn presses the object to be welded with a certain pressure or more. The pressurization can cause the horn to settle in the resin material in a short period of time to approach the bonding interface. In addition, the coated metal material and the resin material are brought into close contact with each other, contributing to bonding by heating the bonding interface. On the other hand, if the pressure is excessively large, the pressure device will be burdened and the horn impression on the surface of the object to be joined will be large, so excessive pressure is not preferable. A load of 20 to 300 N, for example, can be used as the pressurizing force.

(painted metal material)
The painted metal material used in this embodiment has an organic resin layer on one or both surfaces of the metal material. The type of metal that constitutes the metal material is not particularly limited. For example, the metal may be iron, a metal other than iron, or an alloy. Examples of metal materials include cold rolled steel sheets, galvanized steel sheets, Zn-Al alloy plated steel sheets, Zn-Al-Mg alloy plated steel sheets, aluminum plated steel sheets, stainless steel sheets (austenitic, martensitic, ferritic, (including ferrite and martensite two-phase systems), aluminum plates, aluminum alloy plates, copper plates, and other metal plates, pressed products, aluminum die-casts, zinc die-casts, and other castings and forgings, cutting, powder metallurgy Various metal members etc. molded by etc. are included. If necessary, the metal preform may be subjected to known pre-painting treatments such as degreasing and pickling.

The organic resin layer improves the adhesion between the metal preform and the molded article of the thermoplastic resin composition. As the resin for the organic resin layer, olefin resin such as polypropylene, polyurethane, acrylic resin, acrylic/styrene resin, vinyl acetate, EVA (ethylene-vinyl acetate copolymer), and ester resin can be used.

The film thickness of the organic resin layer is preferably 0.2 μm or more. When the film thickness of the organic resin film is less than 0.2 μm, it may not be possible to uniformly cover the surface of the metal material. As a result, in a composite having an organic resin layer with a film thickness of less than 0.2 μm, minute gaps may occur between the metal preform and the resin material. If minute voids are generated, the sealing performance of the aforementioned composite may be degraded. On the other hand, the upper limit of the film thickness of the organic resin film is not particularly limited, but is preferably 10 μm or less, more preferably 3 μm or less. Even if the film thickness of the organic resin layer exceeds 10 μm, no significant improvement in performance is observed, and it is also disadvantageous from the viewpoint of productivity and cost.

(resin material)
The resin material used in this embodiment is not particularly limited. Resin materials include moldings and members made of resin. Resins that can be used include polyethylene resins, polypropylene resins, polybutylene terephthalate resins, polyamide resins, polyphenylene sulfide resins, acrylonitrile-butadiene-styrene resins, polyvinyl chloride resins, polycarbonate resins, and the like.

(complex)
By the manufacturing method according to the present embodiment, a composite is obtained by bonding the painted metal material and the resin material. Even when the painted metal stock is selected as the outer surface of the composite, no horn impression remains on the surface of the painted metal stock. Therefore, it is suitable for many applications where good appearance is required.

(shear tensile strength)
In this embodiment, the composite preferably has a shear tensile strength of 10 MPa or more per unit area. In this specification, the shear tensile strength (unit: Pa) is obtained by dividing the peak load (unit: N) obtained in the shear tensile test by the area (mm ² ) where the horn contacts the object to be joined. It means a numerical value calculated as shear strength per unit area. In addition, in this specification, the shear tensile strength is sometimes referred to as "joint strength". Composites of painted metal preforms and resin materials having a shear tensile strength of 10 MPa or more are suitable for use in many applications requiring weight reduction.

Examples are described below. The invention is not limited to the following examples.

As shown in FIG. 4, a test was prepared by stacking a painted metal preform 1 having an organic resin layer 2 and a resin material 4 . The test specimen was obtained by facing the surface of the coated metal material 1 provided with the organic resin layer 2 and the surface of the resin material 4 .

Specifically, as a metal material of the painted metal material, in mass%, C: 0.033%, Si: 0.003%, Mn: 0.17%, P: 0.012%, S : 0.02%, Cr: 0.03%, Cu: 0.01%, and the balance Fe. , Nisshin Steel Co., Ltd.) was used.

The coated metal preform 1 has an organic resin layer 3 made of a urethane-based resin and having a thickness of 2 μm on both sides of a substrate 2 having a thickness of 0.6 mm. The painted metal blank 1 was cut to dimensions of 75 mm length and 25 mm width. The resin material 4 is a plate-shaped product having a length of 75 mm, a width of 25 mm, and a thickness of 3 mm. was used. As shown in FIG. 4, the coated metal material 1 and the resin material 4 were stacked so that they overlap each other at a portion of 20 mm in the longitudinal direction, and subjected to a bonding test.

For the ultrasonic bonding of the test piece, a horn was placed on the resin material side of the test piece, and the coated metal material side was supported by an anvil. The horn used had a rectangular cross section of 5 mm×10 mm and a tip shape with a radius of curvature of 5 mm. A horn was placed almost in the center of the specimen. The test piece was pressed between the horn and the anvil, and when a predetermined pressure was reached, ultrasonic vibration in the longitudinal direction was started. When the tip of the horn reached a position at a predetermined distance from the bonding interface position between the resin material and the organic resin layer, it was stopped at that position. After the predetermined vibration time was completed, the pressurization was maintained for a predetermined time. After that, the pressure was released to obtain a joined test piece.

The conditions of the ultrasonic bonding test are as follows. The amplitude of ultrasonic vibration is changed between 20 and 80 μm, the frequency of ultrasonic vibration is 20 kHz, the vibration time of ultrasonic vibration is 0.3 s, the applied pressure at the start of vibration is 50 N, and the horn after vibration is stopped. was set to 0.1 s. The distance between the tip of the horn and the joint interface was changed in the range of 0.3 to 1.5 mm.

(Evaluation of bondability)
The bonded specimens were subjected to a tensile test at a tensile speed of 5 mm/min using a tensile testing apparatus as shown in FIG. 5, and the peak load at which the specimens broke was determined. The fracture position of the specimen was visually observed, and the fracture surface was observed with an SEM.

The specimen was fixed with an upper jig 33 on the coated metal material 1 side and with a lower jig 34 on the resin material 4 side. The painted metal material 1 was fixed so that one end on the side opposite to the joint portion protruded from the upper jig 33 , and the protruding end was gripped by the upper grip portion 31 . The resin material 4 was fixed in its entirety by a lower jig 34 and gripped by a lower grip portion 32 . Thereby, it is possible to prevent the resin material 4 from being crushed by the lower grip portion 32 . When the specimen was attached to the tensile tester, the specimen was gripped so that the center axis of the tensile load and the thickness center axis of the coated steel sheet were substantially aligned.

Since the joint area of the specimen is considered to correspond to the contact area of the horn, the peak load (N) obtained from the tensile test is divided by the contact area of the horn as an indicator of the shear tensile strength of the specimen. was used as the bonding strength (MPa) of the specimen. In this embodiment, since the cross-sectional shape of the horn is a rectangle of 5 mm×10 mm, the contact area of the horn is set to 50 mm ² .

Bondability was evaluated based on bond strength. If the bonding strength is 10 MPa or more, the bondability is determined to be good (○), and if the bonding strength is less than 10 MPa or the bonding itself is impossible, the bondability is poor. It was determined to be (×). Table 1 shows the results.

The composites obtained in the examples were ultrasonically bonded with a horn placed on the resin material side in the bonding of the painted metal preform having the organic resin layer and the resin material. , no horn impression was formed on the surface of the resin material. Then, in the method of manufacturing the composite of the coated metal material and the resin material, as shown in Table 1, by selecting the distance between the tip of the horn and the joint interface in the range of 0.3 to 1.2 mm, , a composite having good bondability with a bonding strength of 10 MPa or more was obtained. It was also confirmed that the amplitude of ultrasonic vibration can be selected from the range of 30 to 80 μm.

1 Painted metal material 2 Metal material 3 Organic resin layer 4 Resin material 5 Object to be bonded 11 Softened area 12 Bonding interface 13 Distance between horn tip and bonding interface 21 Horn 22 Anvil 23 Pressure 24 Vibration direction (longitudinal vibration )
31 upper grip part 32 lower grip part 33 upper jig 34 lower jig 41 upper plate 42 lower plate 43 horn 44 anvil 45 heating area 46 pressure 47 vibration direction (lateral vibration)
48 bonding interface

Claims (3)

A method for manufacturing a composite in which a painted metal material having an organic resin layer on at least one surface of the metal material and a resin material are bonded by an ultrasonic bonding apparatus equipped with a horn and an anvil, ,
Preparing an object to be joined in which the surface of the painted metal material and the resin material are laminated so that the surface of the painted metal material provided with the organic resin layer and the surface of the resin material face each other;
holding the object to be joined between the horn and the anvil, locating the horn on the side of the resin material and locating the anvil on the side of the painted metal stock;
pressing the object to be joined by the horn and applying ultrasonic vibration in a longitudinal vibration direction to the object to be joined by the horn to join the coated metal material and the resin material;
including
The horn maintains a distance of 0.3 mm or more and 1.2 mm or less between the tip of the horn and the bonding interface with respect to the bonding interface between the coated metal material and the resin material.
A method for manufacturing a composite of a coated metal material and a resin material. 2. The method for manufacturing a composite of a coated metal material and a resin material according to claim 1, wherein the amplitude of said ultrasonic vibration is 30 [mu]m or more and 80 [mu]m or less. 3. A composite of a coated metal material and a resin material according to claim 1 or 2, wherein after the ultrasonic vibration is stopped, the state in which the object to be joined is pressed by the horn is maintained for 0.1 s or more. manufacturing method.

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