JPH02274531A - Composite steel panel - Google Patents

Abstract

PURPOSE:To enable metallic plates to be brought into contact with each other through holes in a resin layer under a pressure applied at the time of welding and to be thereby welded to each other by providing the resin layer with a multiplicity of holes. CONSTITUTION:In a composite steel panel having a resin layer intermediately provided between metallic plates and adhered to the metallic plates, the resin layer is provided with holes having a diameter of 20-50mum in a density of 500-1000 holes/cm<2>. Consequently, the metallic plates can be brought into contact with each other under a pressure applied at the time of welding and to be thereby welded to each other.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a composite steel plate, and in particular, a composite steel plate in which a resin layer serving as a core material is sandwiched between metal plates, and the metal plates and the resin are crimped. Regarding composite steel plates.

[Conventional technology]

Composite steel sheets are made by sandwiching a resin (adhesive) containing a filler (conductive particles to enable welding of composite steel sheets) between metal plates. It is formed by thermocompression bonding via a resin layer.

This composite steel plate consists of two types, one of which is a damping steel plate where the thickness of the steel plate is greater than the thickness of the resin layer and has excellent vibration distribution characteristics, and the other is a vibration damping steel plate with a thinner steel plate and a resin layer. This is a laminated steel plate that is lightweight by increasing its thickness.

As a method for manufacturing such a composite steel plate, there is a conventional example described in Japanese Patent Application Laid-Open No. 62-501.35, for example.

This conventional example involves sandwiching a resin film containing a filler between steel plates and thermally press-bonding them with a heated warm roll (film method).

In addition, room-temperature resins that have damping properties at room temperature (e.g., polyester, whose glass transition temperature is between room temperature and 50°C) are soft at room temperature and difficult to form into a film, so the solvent method is used to There are conventional examples of manufacturing divided steel plates.

This solvent method involves dissolving the adhesive (resin) in a solvent, applying this liquid resin to the surface of the steel plate, then transporting it to a drying oven to volatilize the solvent from the resin layer and heat it with other steel plates. It is crimped.

[Problem to be solved by the invention]

However, when creating a resin film by mixing a filler into a viscous resin, it is difficult to uniformly disperse the filler in the film. If the filler is unevenly distributed, the amount of resin will decrease in areas where the filler is highly dispersed, reducing the adhesion between the resin and the steel plate.
In areas where the filler is less dispersed, conductivity decreases and weldability decreases.

The solvent method also has the same problem as the film method because it is difficult to uniformly disperse the filler in the resin applied to the steel plate.

In addition, the production of filler-containing resin films has low yields because film formation is difficult, and fillers are also expensive.

Therefore, the purpose of this invention is to provide a composite steel plate that has excellent weldability even if the resin layer between the metal plates does not contain filler.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a composite steel plate in which a resin layer is sandwiched between metal plates, and the metal plate and the resin are bonded together, in which the resin layer has holes with a diameter of 20 to 50 μm. 5
It is characterized by being formed at a rate of 00 to 1000 pieces/cry.

[Effect]

According to the present invention, since a large number of holes are formed in the resin layer even if the resin layer does not contain filler,
The pressure applied during welding causes the metal plates to come into contact with each other at the holes, allowing welding.

Here, the diameter of the hole is 20 to 50 μm. If the thickness is less than 20 μm, when the resin layer and the metal plate are bonded together by thermocompression, the resin melts due to the heat applied and closes the holes, making welding difficult. On the other hand, if it exceeds 50 μm, the amount of resin becomes relatively small, the adhesiveness between the metal plate and the resin layer decreases, and the resin layer and metal plate peel off during molding.
This is because damping properties of vibration damping steel plates deteriorate.

Further, the number (density) of the holes formed in the resin layer is 5
00 to 1000 pieces/C. If it is less than 500 pieces/cn1, weldability is insufficient, and 1000 pieces/cff
If it exceeds 1, the amount of resin becomes relatively small, which deteriorates adhesive properties and damping characteristics in the case of a damping steel plate.

[Example] A damping steel plate was created using the film method under the following conditions.

Low-density polyethylene was formed into a film by the T-die method (film thickness: 100 μm).

This film was punched with a perforation roll, then sandwiched between 0.5 mm cold-rolled steel plates, the steel plate and the resin film were thermocompressed using a warm roll heated to 200°C, and then cooled. The steel plate and resin were cooled by rolls.

The gap between the warm rolls was 1.0 mM, and the pressing force was 10 kgf/cm.

The drilling process in the resin film is as follows.

After dulling the iron roll by shot blasting and then applying adhesive to the roll surface, it has a predetermined diameter.
A roll for drilling was created by uniformly pasting a predetermined amount of protrusions such as metal particles.

Then, pair these rolls and adjust the gap to be equal to or slightly smaller than the resin film thickness,
The resin film was lightly rolled down within a pressure range of 5 to 10 kgf/cm. Therefore, by lightly rolling down the film with this roll, holes corresponding to the protrusions attached to the roll surface are transferred to the resin film.

Under these conditions, the amount of metal particles attached to the roll and the size of the diameter of the metal particles are varied to adjust the size and density of the holes formed in the resin film. Composite steel plates as shown in Table 1 were manufactured.

For each of these composite steel plates, the T-peel strength and damping loss coefficient were measured, and the weldability was evaluated.

T-peel strength was measured based on JIS'6854.

The allocation loss coefficient was measured by heating the resulting composite steel plate to 80°C and using a mechanical impedance method.

Weldability was evaluated by performing spont welding and applying a current of 9 KA for 0.2 seconds at a pressure of 170 kgf. Under these welding conditions, welding that can form a nugget even if the welding position is varied is rated as ○. When the welding position was changed, a case where there was a nugget or a defective part was judged as "poor".

These results are shown in Table 1 below.

(Hereinafter, blank space) As can be seen from Table 1 above, the example steel plate 1゜2 has a large T-peel strength and damping loss coefficient because the hole diameter and the number of holes are within the range of the present invention. , has good adhesion and vibration damping properties, as well as good weldability.

On the other hand, in Comparative Example Steel Plate 1, the hole diameter is as small as 15 μm, so the hole is blocked by heat input during thermocompression bonding, resulting in poor weldability.

In Comparative Example Steel Plate 2, the density of holes is within the range of the present invention, but the weldability is good because the hole diameter is large;
The T-peel strength and damping loss number are low, and the adhesion and damping properties are poor.

Comparative steel plate 3 has a hole diameter that exceeds the range of the present invention, and therefore, like comparative steel plate 1 and plate 2, adhesion and vibration damping properties are degraded. On the other hand, since the density of the four holes is smaller than the range of the present invention, weldability is also poor.

Comparative Example Steel Plate 4 has 8 hole diameters within the range of the present invention, but the density of holes is smaller than the range of the present invention, resulting in poor weldability.

Comparative Example Steel Plate 5 has poor weldability because both the hole diameter and the hole density are smaller than the range of the present invention.

Comparative example steel plates 6 and 7 have hole diameters within the range of the present invention, but
Since the density of holes is smaller than the range of the present invention, weldability is poor.

Comparative Example Steel Plate 8 has a hole diameter that exceeds the range of the present invention, and therefore has poor adhesion and vibration damping properties.

Comparative example steel Fi9 has a hole diameter smaller than the range of the present invention, so
Weldability becomes poor.

Next, a damping steel plate was created using the solvent method. The resin used is polyester (polyethylteI/phthalate), which is a room-temperature resin and is difficult to form into a film by itself, and is dissolved in a solvent (toluene, xylene, benzene, etc.). After coating the surface of the steel plate with subl/-, the solvent was heated and dried at 60°C for 1 hour to form a 100 μm thick resin layer on the steel plate, holes were drilled in this resin layer, and then it was crimped with other steel plates. A composite steel plate was manufactured.

Holes were punched into the resin layer by lightly rolling down the resin-coated steel plate from the resin side using a punching roll similar to that used in the film method described above.

Then, the T-peel strength, damping loss coefficient, and weldability were tested under the same conditions as in Table 1 above, varying the hole diameter and hole density. The results are shown in Table 2 below.

(Hereafter, margin) As can be seen from Table 2 above, Example steel FJ, 3.

In No. 4, both the hole diameter and the hole density are within the range of the present invention, so the adhesion, vibration damping properties, and weldability are all good. This shows that the present invention can be applied even when manufacturing a composite steel plate by a solution method.

In addition, as shown in Comparative Example mFiIO~1, at least one of the hole diameter and the hole density is outside the scope of the present invention, so that at least one of adhesiveness, vibration damping property, and weldability is It becomes defective.

In the above example, an example using a cold-rolled steel sheet was explained, but it is not limited to cold-rolled steel sheets, but various surface treatments such as chromate-treated steel sheets, zinc-treated steel sheets, phosphate-treated steel sheets, stainless steel sheets, organic coated steel sheets, etc. steel plate can be used,
Other metal plates can also be used.

When using a resin that is difficult to form into a film, a composite steel plate is manufactured by a solvent method, but it is also possible to form a resin that is difficult to form into a film into a film by a casting method and then perform drilling.

Hole processing is not limited to the above-mentioned methods, but also methods of pressing the resin film with a mold with protrusions, the roll itself that has been subjected to dull processing (discharge dull, sirot dull, laser dull), or the roll itself with unevenness formed on the surface. It can also be done using a roll.

Further, the resin used is a thermoplastic resin such as polypropylene, polyethylene, or thermoplastic phase polyester vinyl monochloride. Or epoxy, polyurethane,
Thermosetting resin such as acrylic or thermosetting polyester. Further, copolymers and modified products thereof may also be used.

These resins can be used alone or by mixing a thermoplastic resin and a thermosetting resin to form a mixed resin that provides stable hardness over a wider temperature range than when using each resin alone. When using a mixed resin, by adjusting the mixing ratio of the thermosetting resin added to the above thermoplastic resin as a base, optimal vibration damping can be achieved depending on the usage environment such as room temperature, medium temperature, and high temperature. Characteristics can be given.

Furthermore, although the above embodiments have been explained regarding the manufacture of damping steel plates, it goes without saying that the present invention can also be applied to laminated steel sheets.

Furthermore, the numerical values of the hole diameter and the number of holes listed in the examples are all examples, and it is also possible to select other numerical values within the range described in the claims without being limited to these. .

〔Effect of the invention〕

As explained above, according to the composite steel sheet according to the present invention, many holes are formed in the resin layer even if the resin layer does not contain filler, so that the holes are formed by the pressurizing force during welding. Welding is possible because the metal plates come into contact with each other at these points.

Claims (1)

[Claims] (1) In a composite steel plate formed by sandwiching a resin layer between metal plates and bonding the metal plate and resin, the resin layer has a
A composite steel plate characterized in that holes with a diameter of 50 μm are formed at a rate of 500 to 1000 holes/cm^2.