JPH05138811A - Manufacture of laminated metal sheet excellent in spot-weldability - Google Patents

Abstract

PURPOSE:To provide the method for manufacturing laminated metal sheet, in the resin layer of which electrically conductive metal powder is dispersed easily, uniformly and stably. CONSTITUTION:Electrically conductive metal powder, the hardness of which is more than or equal to that of metal sheets 4 and 7 is kneaded in advance with an extruder 1 and a die 2 in viscoelastic resin so as to produce resin layer, in which the particle diameter D of the electrically conductive powder in the resin is set to be D<=2.0T to the coating thickness T of the resin, which contains 3-30wt.% of the electrically conductive metal powder with particle diameter satisfying the relationship of 1.0T<=D<=2.0T among the electrically conductive metal powder to the total amount of the resin is applied onto one side of the metal sheet. Next, with pressure rollers 8 and 9, the coated metal sheet and the other metal sheet are bonded together so as to obtain laminated sheet in order to produce tire laminated metal sheet excellent in spot-weldability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a laminated metal sheet having excellent spot weldability.

[0002]

2. Description of the Related Art A laminated metal plate in which a polymer resin is sandwiched between two metal plates has excellent vibration damping properties and light weight properties, and is intended for noise prevention, vibration prevention, weight reduction, etc.
It is widely used in home appliances and building materials. However, since the polymer resin, which is the core material of the laminated metal plate, is an insulating material, it has no electrical conductivity, and as it is, spot welding cannot be performed by direct energization. Therefore, a method of filling a metal powder in a polymer resin (Japanese Patent Laid-Open No. 2-48942)
JP-A-2-86432, JP-A-1-280544,
Japanese Unexamined Patent Publication (Kokai) No. 62-234917), graphite filling method (Japanese Patent Publication No. 61-49112), spiral electric conductor filling method (Japanese Patent Publication No. 61-29261), and metal fibers dispersed by a grooved magnetic roll. Method (JP-A-63
No. 72548), a method of forming a deformed pattern on a metal plate (JP-A-59-145142), and a method of making the surface of the metal plate rougher than the resin layer (JP-A-62-22774).
No. 1) and other publications ensure electrical conductivity between metal plates,
Various methods have been proposed that enable spot welding by direct energization.

[0003]

However, in the above-mentioned conventional proposal method, a method of spraying a metal powder on a resin by utilizing a natural drop (Japanese Patent Laid-Open No. 2-48942) and a conductive filler by a jet nozzle are used. A method of laminating the mixed liquid resin on the surface of the metal plate (Japanese Patent Laid-Open No. 234917/1987).
In the publications such as a method of spraying metal fibers with a grooved magnetic roll (Japanese Patent Laid-Open No. 63-72547) and a method of filling a spiral conductor (Japanese Patent Publication No. 61-29261), metal powder or metal fibers are used. It is difficult to uniformly disperse the conductor in the resin over the width and the longitudinal direction, and it is impossible to secure stable spot weldability such that the conductivity is deteriorated depending on the site of the obtained laminated metal plate.

When graphite is filled (Japanese Patent Publication No. 61-49112), the graphite is crushed by the pressure applied when the lower metal plate and the upper metal plate are bonded together,
Sufficient conductivity cannot be obtained. Further, in a method of forming a deformed pattern on a metal plate (Japanese Patent Laid-Open No. 59-145142),
It is necessary to process the steel plate before manufacturing, and a pattern appears on the surface of the laminated steel plate that is the product. Moreover, it is difficult to make the contact state between the upper and lower metal plates uniform in the width direction and the longitudinal direction, and the conductivity deteriorates depending on the site of the obtained laminated steel plate.

Also, in the method of making the surface of the metal plate rougher than the resin layer (Japanese Patent Laid-Open No. 62-227741), the contact state between the upper and lower metal plates is made uniform in the width and longitudinal directions. It is difficult to do so, and it is impossible to secure stable spot weldability such as deterioration of conductivity due to the site of the obtained laminated metal plate. The object of the present invention is to
It is intended to provide a method for manufacturing a laminated metal plate by uniformly and stably dispersing conductive metal powder in a resin layer, and the laminated metal plate.

[0006]

Means for Solving the Problems The inventors of the present invention have made various studies to solve the above problems, and as a result, have completed the following invention. That is, the present invention is a method for producing a laminated metal plate in which a viscoelastic resin is sandwiched between two metal plates, in which a conductive metal powder is previously kneaded into the viscoelastic resin by an extruder, and then the extruded product is extruded. The kneaded viscoelastic resin is coated on one side of a metal plate with a die attached to the machine tip, and then the coated metal plate and the other metal plate are pressure-bonded with a pressure roll, heat-treated and laminated. A method for producing a laminated metal plate having excellent spot weldability, which is characterized by using a metal plate, wherein the particle diameter (D) of the conductive metal powder mixed in the viscoelastic resin is equal to the coating resin thickness (T). On the other hand, D ≦ 2.0T
And 1.0T ≦ D ≦ 2.
The conductive metal powder having a particle size of 0T is 3% in the total amount of the resin.
The hardness of the conductive metal powder particles is equal to or less than that of the metal plate.

[0007]

As a result of various studies, the inventors of the present invention knead the conductive metal powder in the viscoelastic resin in advance with an extruder and then apply the mixture to easily, uniformly and stably obtain a desired amount. It becomes possible to disperse the conductive metal powder in the resin layer,
It has been found that a laminated metal plate having a resin layer in which a conductive metal powder is uniformly dispersed can be obtained by using such a method.

According to the present invention, as described above, the viscoelastic resin is used when the conductive metal powder having a hardness equal to or less than the hardness of the metal plate is kneaded in the viscoelastic resin in advance by using an extruder to uniformly coat the viscoelastic resin. The particle diameter (D) of the conductive metal powder inside is the resin thickness (T) after pressure bonding
On the other hand, the conductive metal powder having a particle diameter of D ≦ 2.0T and 1.0T ≦ D ≦ 2.0T of the conductive metal powder is 3 to 30 weight% in the total amount of the viscoelastic resin. % Of the resin, using a die attached to the end of the extruder, a predetermined amount of the kneaded viscoelastic resin is continuously applied to the lower metal plate, and when the upper metal plate is pressure-bonded, this resin Between the upper and lower metal plates,
The spot weldability is characterized in that the resin is pressed down using a pressure-bonding roll so that the resin thickness becomes uniform in the width direction, crushed to the resin thickness (T), a desired contact area is obtained, and then heated. It is an excellent method for producing a laminated metal plate.

As the manufacturing apparatus used in the present invention, an extruding device capable of surely kneading the viscoelastic resin and the conductive metal powder and sending the resin forward, and a kneaded viscoelastic resin A die attached to the tip of an extrusion device for coating a metal plate (the shape of the strand, die, etc. is not particularly limited), and another metal plate is pressure-bonded to the upper part of the coating resin provided on the metal plate, and It comprises a pressure bonding device for uniformly spreading the coating resin in the width direction, and a heating device for heating the pressure-bonded laminated steel sheets. Here, first, an extruder used for previously kneading a conductive metal powder having a hardness equal to or less than the hardness of a metal plate into a viscoelastic resin is surely kneaded, and the resin can be sent forward. This is preferable because it is possible.

Further, the particle size range of the conductive metal powder is D ≦
The reason for limiting to 2.0T is based on the knowledge obtained in the examples described later. First, when D ≦ 1.0T, the conductive metal powder is buried in the resin layer, and sufficient conductivity cannot be obtained. .. Also, if D ≧ 2.0T, sufficient conductivity can be obtained, but the vibration damping performance and adhesion required as a laminated metal plate are reduced. From this, as described above, the content of the conductive metal powder of 1.0T ≦ D ≦ 2.0T is limited. That is, if the amount is less than 3% by weight, the effect is insufficient, and if it exceeds 30% by weight, the weldability is good, but the adhesive force is reduced, and the cost of the added conductive metal powder becomes excessive. Conductive metal powder with the above particle size is 3 ~
It is necessary to contain 30% by weight.

The hardness of the conductive metal powder in this case is
Use one that is softer than the hardness of the metal plate. This is because when the hardness of the conductive metal powder is higher than the hardness of the metal plate, when the two metal plates are pressure-bonded, the surface of the metal plate is pressed and scratched.
This is because the appearance deteriorates. In the present invention, examples of the metal plate include cold-rolled steel plates, hot-dip galvanized steel plates, electrogalvanized steel plates, two-layer plated steel plates, stainless steel plates, aluminum plates, titanium plates, and most other metal plates. The plate thickness is not particularly limited. Also,
In the present invention, as the conductive metal powder having a hardness equal to or less than the hardness of the metal plate, Ni powder is preferable, but metal particles such as iron, copper and titanium can also be mentioned. When the metal plate is a steel plate, the Ni powder has a melting temperature and a boiling temperature almost equal to those of the steel plate, and the hardness of the Ni powder can be equal to or less than that of the steel plate (80 to 180 in Hv) by heat treatment. Ni powder is very preferable as the conductive metal powder.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic view of an example of one embodiment of a laminated metal plate manufacturing apparatus according to the present invention. In the figure, 1
Is an extruder {kneader / ruder manufactured by Kasamatsu Kako Co., Ltd., capacity (kneader / case capacity 50 L)}, 2 is an extruder 1
Dies (strand dies) attached to the tip of the, 3 is a resin in which conductive metal powder is kneaded, 4 is a lower metal plate, 5 is a coating resin layer, 6 is a film thickness meter, 7 is an upper metal plate, 8 Reference numerals 9 and 9 are pressure-bonded rolls, 10 is a laminated metal plate, 11 and 12 are heating furnaces (hot air circulation furnace), and 13 is conductive metal powder (Ni powder).

First, prior to coating, an extruder (kneader, ruder) 1 was used to coat a desired amount of the thermosetting acrylic viscoelastic resin. The conductive metal powder 13 having a particle size is sufficiently dispersed and filled in the resin in advance. In this case, the viscoelastic resin 3 has a viscosity of 100 poise at 30 ° C. and a shear rate of 10 ³ sec ^−1.
Use the above. The hardness of the conductive metal powder 13 is softer than the hardness of the metal plates 4 and 7. In this embodiment, the hardness (Hv) is as follows: conductive metal powder 13 ... Hv90, metal plates 4 and 7 ... Hv1
It is 10.

Next, a viscoelastic resin 3 obtained by kneading the conductive metal powder 13 is fixed on the lower metal plate 4 by a die (strand die) 2 attached to the tip of the kneader ruder 1. The resin thickness (T) is continuously applied uniformly in the width direction. In this way, the coating resin layer 5 having uniform conductivity is provided on the lower metal plate 4. The coating thickness of the resin layer in the width direction of the coating resin layer 5 is measured by the film thickness meter 6, and the coating thickness is controlled to be a desired coating thickness which is constant in the width direction. Next, another upper metal plate 7 is pressure-bonded.
The upper metal plate 7 to be pressure-bonded on the resin layer 5 is sent to the pressure rolls 8 and 9 together with the lower metal plate 4 provided with the resin layer 5 and pressure-bonded to form a laminated metal plate 10 as shown in FIG. ..

FIG. 2 is a schematic cross-sectional view of a laminated metal plate manufactured by the method of the present invention. As shown in the drawing, the conductive metal powder 13 is just projected from the coating resin layer 5 and the conductivity is reduced. It becomes possible to reduce the metal powder 13
Crush to the coating thickness (T) with pressure rolls 8 and 9,
A desired contact area can be obtained. Crimping roll at this time
It is necessary that the pressing force of the rollers 8 and 9 has a force to uniformly spread the coated resin in the width direction and to crush the conductive metal powder 13 mixed in the resin to the coating thickness. Also,
The material of the crimping rolls 8 and 9 is not particularly limited as long as the required crimping force can be uniformly obtained in the width direction. The laminated metal plate 10 thus formed is sent to the heating furnaces 11 and 12 and heated until the coating resin layer 5 is sufficiently crosslinked, and becomes a laminated metal plate product capable of spot welding.

In this embodiment, cold-rolled steel plates are used as the upper and lower metal plates 4 and 7 in this case, but other hot-dip galvanized steel plates, electrogalvanized steel plates, two-layer plated steel plates, stainless steel plates, aluminum plates, Most metal plates such as titanium plate can be used, and the thickness thereof is not particularly limited. Further, as the conductive metal powder having a hardness equal to or less than the hardness of the metal plate, Ni powder is preferable, but metal particles such as iron, copper and titanium can also be mentioned. When the metal plate is a steel plate, N
The i powder has a melting temperature and a boiling temperature almost equal to those of the steel sheet, and the hardness of the i powder can be less than or equal to that of the steel sheet (80 to 180 in Hv) by heat treatment. Is preferred.

Examples of the present invention will be specifically described below. Thermosetting acrylic resin (30 ℃, shear rate 10 ³
In sec ^-1 , 500 to 800 poise) is filled with various kinds of particle size and the amount of conductive metal powder 13 added, and the apparatus shown in FIG.
A lower steel plate 4 having a thickness of 0.4 mm was coated on a cold-rolled steel plate, and the upper metal plate 7 was pressure-bonded to obtain a laminated steel plate. Table 1 shows the experimental conditions and results of the examples in the method of the present invention. Table 2 shows the experimental conditions and results of the comparative material.

[0018]

[Table 1]

[0019]

[Table 2]

The welding test was conducted with a sample size of 30 mm × 10.
0 mm, pressure 200 kgf, current 10.5 kA, energizing time 12 cycles, squeeze time 35 cycles, electrode tip D type, original diameter
16 mm, tip diameter 6 mm. Fifty pieces of laminated steel plates and veneers (same material and thickness as laminated steel plates) were combined and welded normally, and the weldability was evaluated by the percentage of those that could be welded normally. As is clear from Table 1 and Table 2, in the case of the examples of the present invention, the particle diameter of the conductive metal powder is D, and the resin thickness is T.
Then, it can be seen that 1.0T ≦ D ≦ 2.0T, and that the amount of the conductive metal powder added is 3 to 30% by weight, stable welding can be performed, and that good adhesion is obtained. ..

[0021]

EFFECTS OF THE INVENTION According to the present invention, in a method for producing a laminated metal plate capable of spot welding, it becomes possible to uniformly disperse conductive metal powder in a resin layer by using an extruder and a die. It became possible to manufacture a stable plate. Further, a conductive metal powder having a hardness equal to or less than the hardness of the metal plate is previously kneaded in the resin using an extruder and a die, and uniformly filled, and the particle size of the conductive metal powder in the resin is applied to the coating resin. Disperse the conductive metal powder in the resin layer easily, uniformly and stably by specifying the thickness (T) and specifying the amount of the conductive metal powder and press-bonding using the press-roll. A method of manufacturing a laminated metal plate is obtained.

[Brief description of drawings]

FIG. 1 is a schematic view of an apparatus for manufacturing a laminated metal plate according to the present invention,

FIG. 2 is a schematic cross-sectional view of a laminated metal plate manufactured by the method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Extruder (kneader, ruder), 2 dies (strand dies), 3 resin mixed with conductive metal powder, 4 metal plate, 5 coating resin layer 6 film thickness meter 7 metal plate , 8 crimp rolls, 9 crimp rolls, 10 laminated metal plates, 11 heating furnaces, 12 heating furnaces, 13 conductive metal powders.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location B32B 31/06 7141-4F

Claims (3)

[Claims] 1. A method for producing a laminated metal plate comprising a viscoelastic resin sandwiched between two metal plates, wherein conductive metal powder is previously kneaded into the viscoelastic resin by an extruder and then the extruder is used. With the die attached to the tip,
A spot characterized in that the kneaded viscoelastic resin is applied to one side of a metal plate, and then the coated metal plate and the other metal plate are pressure bonded by a pressure roll to form a laminated metal plate. A method for manufacturing a laminated metal sheet having excellent weldability. 2. The particle diameter (D) of the conductive metal powder mixed in the viscoelastic resin is D ≦ 2.0T with respect to the coating resin thickness (T).
And 1.0T ≦ D ≦ 2.
The conductive metal powder having a particle size of 0T is 3% in the total amount of the resin.
The method for producing a laminated metal sheet having excellent spot weldability according to claim 1, wherein the content is from about 30% by weight. 3. The method for producing a laminated metal plate having excellent spot weldability according to claim 1, wherein the hardness of the conductive metal powder particles is equal to or lower than that of the metal plate.