JPH07148883A - Damping metal plate of excellent electric-resistance weldability - Google Patents

Abstract

PURPOSE:To obtain a damping metal plate which keeps a damping property and is excellent also in electric-resistance weldability by a method wherein macromolecular resin pinched between metal plates is composed of a center layer having a damping property and an outside layer having an adhesive property to the metal plate, and each layer contains conductive metallic powder of each different specific physical properties. CONSTITUTION:A damping metal plate 1 pinches macromolecular resin between two metal plates 2. The macromolecular resin is composed of a center layer 3 having a damping property and an outside layer 4 having an adhesive property to the metal plate 2 on its both faces. The center layer 3 contains 3-20wt.% of conductive metallic powder 5 wherein an average grain size D1 before being pinched between the metal plates is T0<=D1<=2T0 for a thickness T0 of a macromolecular resin layer, Vickers hardness is 180Hv or under, and a melting point is at least equal to the metal plate in temperature. Besides, the outside layer 4 contains 3-5wt.% of conductive metallic powder 6 wherein an average grain size D2 before being pinched between the metal plates is 0.6 T2<=D22T2 for a thickness T2 of the outside layer, and a melting point is at least equal to the metal plate in temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a vibration damping device having excellent electric resistance welding properties such as spot welding, seam welding, and series welding, and having the adhesion and vibration damping properties required for automobiles, electric machines, machines, and building materials. It relates to a metal plate.

[0002]

2. Description of the Related Art A vibration-damping steel plate sandwiching a polymer resin between two thin steel plates has excellent vibration-damping properties, and is used for automobiles, home appliances, and building materials for the purpose of noise prevention and vibration prevention. Many are used. However, the polymer resin used for these damping steel plates originally has a small adhesion force with the steel plate, and the deformation resistance is extremely small. There was a problem in processing such as peeling. Further, the polymer resin has an extremely high electric insulating property, and as it is, electric resistance welding by direct energization cannot be performed. The following methods have been proposed to solve these problems. First,
In order to improve workability, a method of improving the adhesive strength to a metal plate by using a multilayer resin sheet in which a resin having a strong adhesive property to a metal is applied to the surface of a thermoplastic resin (Japanese Patent Laid-Open No. 58-72445) Japanese Patent Laid-Open No. 60-82349), a polyolefin resin having an adhesive strength of 8 kgf / cm ² or more is provided on the inner and outer surfaces of the thermoplastic resin film (Japanese Patent Laid-Open No. 60-82349). Further, as a method for imparting electric resistance weldability, a method of adding a conductive metal powder to a polymer resin (Japanese Patent Laid-Open No. Sho 61-206)
50-79920, Japanese Patent Publication No. 60-912, JP 62-
87341, JP 57-146649, JP 61-29
261). Generally, even in the case of multilayer resin,
Similarly, a method of adding a metal powder to the resin or dispersing it on the multilayer resin sheet is used. In addition, there is also a method of using a multilayer film in which metal powder is added only to the central layer in order to prevent deterioration of vibration damping property due to addition of metal powder (Japanese Patent Publication No. 55310/1993).

[0003]

DISCLOSURE OF THE INVENTION In the prior art,
By using a multilayer film as the polymer resin, it is possible to achieve both vibration damping and adhesion. Furthermore, it is also possible to impart electric resistance weldability by adding a metal powder into the multilayer film by a conventional technique.

However, although the weldability can be imparted, since the metal powder having a specific shape is added over the entire film, there is a problem that the vibration damping property is deteriorated. In addition, in order to prevent deterioration of vibration damping property, metal powder is added only to the center layer,
In the method of imparting weldability by allowing the outer layer to flow out at the time of laminating the vibration-damping steel sheets to reduce the thickness of the outer layer and ensure the contact between the metal powder and the steel sheet, the resin is applied to the interface between the metal powder and the steel sheet. Remains, and the degree of outflow of the outer layer causes a problem that the weldability is deteriorated.

The present invention has been made to solve the above-mentioned problems, and effectively utilizes the outer layer in a vibration-damping metal plate using a multilayer resin film having both vibration-damping properties and adhesion. To prevent the deterioration of vibration damping,
The purpose of the present invention is to obtain a vibration-damping metal plate having excellent electric resistance weldability.

[0006]

Means for Solving the Problems The present inventors can effectively impart vibration damping property, adhesion force and rigidity by applying a multilayer film to a vibration damping metal plate sandwiching a polymer resin, In addition, by basically adding metal powder to the multilayer film, we believe that it is possible to impart electrical resistance weldability to this multilayer film, and we believe that stable electrical resistance weldability can be achieved without reducing vibration damping. In order to impart the above, the present inventors have earnestly studied the conditions for adding metal powder and the weldability. As a result, since it is a multilayer film, by effectively utilizing its outer layer,
The present invention has been completed.

That is, the vibration-damping metal plate of the present invention having excellent electric resistance weldability is obtained by sandwiching a polymer resin between two upper and lower metal plates, and the polymer resin forms a center layer having a vibration-damping property. It has at least a three-layer structure composed of outer layers having adhesiveness to a metal plate on both sides thereof, and the average particle diameter D ₁ before being crushed and sandwiched between the metal plates is within the center layer. For the layer thickness T ₀ , T ₀ ≦ D ₁ ≦ 2T ₀
And the Vickers hardness is 180 Hv or less and the melting point is equal to or higher than that of the two metal plates, and the conductive metal powder is added in an amount of 3 to 20% by weight based on the total weight of the center layer resin and the conductive metal powder. In the outer layer, the average particle diameter D ₂ before being held by the metal plate is 0.6T ₂ ≦ D ₂ ≦ 2T ₂ with respect to the thickness T _{2 of the} outer layer. The conductive metal powder having a melting point equal to or higher than that of the two metal plates is added in an amount of 3 to 5% by weight based on the total amount of the outer resin and the conductive metal powder.
Further, the conductive metal powder, in the state of being sandwiched between the crushed metal plates, has a metal content within the range of 2T ₀ ≦ D _{1W in} the central layer with respect to the thickness T ₀ of the polymer resin layer. 70% or less of the total number of metal powders in the central layer, 30% or more of metal powders in the range of T ₀ ≦ D _1W , and the thickness T of the outer layer in the outer layer. ₂ , the metal powder in the range of 2T ₂ ≦ D _2W is 70% or less of the total number of metal powders in the outer layer, and the metal powder in the range of T ₂ ≦ D _2W is the total number of metal powders in the outer layer. Is 30% or more. However, D _1W is the width direction diameter of the metal powder in the center layer after being sandwiched between the crushed metal plates,
D _2W is the widthwise diameter of the metal powder in the outer layer after being crushed and held between the metal plates.

From the viewpoint of vibration damping, the polymer resin forming the central layer has a loss tangent (ta) based on the glass transition.
nδ) has a maximum value of 0.3 or more, the temperature at which the maximum value is n is in the range of -40 to 100 ° C, and the maximum value of the loss coefficient of the damping metal plate to which the metal powder is added is 0.1. Above, it is preferable that the temperature at which this maximum value is present is in the range of 0 to 120 ° C.

Further, as a multilayer film, from the viewpoint of film moldability, the polymer resin is used for both the center layer and the outer layer.
It is desirable that the thermoplastic resin is mainly a polyolefin resin.

[0010]

The operation of the present invention will be described based on the results of the examination. First, the spot welding mechanism will be described. The role of metal powder in spot welding is 1 in total
At the initial stage of welding (within about 3 cycles) in spot welding consisting of about 0 cycles, an electric current is applied between welding electrodes sandwiching a damping metal plate such as a damping steel plate. That is, when the vibration-damping metal plate and the material to be welded are sandwiched while being pressed by the welding electrode and an electric current is applied between the electrodes, an electric current flows through the metal powder immediately below the electrode and in the periphery thereof. The energization causes resistance heat generation in the skin metal plate and the metal powder immediately below and around the electrode, and the heat causes the polymer resin to melt or thermally decompose. The polymer resin immediately below the electrode, which has been gasified by melting or thermal decomposition, is removed around the electrode by the pressure applied to the electrode, the skin metal plates come into contact with each other, and spot welding is usually performed as in the case of the metal plate.

Here, when the number of metal powders is small or the amount of metal powders is large and the contact state with the metal plate is insufficient, the current density to the metal powders in contact increases, The metal powder instantly generates resistance heat and the skin metal plate in contact with the metal powder is rapidly heated and melted and scattered to cause pinhole-like defects. When a galvanized steel sheet is used as the skin metal plate, zinc has a lower melting point than iron, and therefore the galvanized layer in contact with the metal powder may be instantaneously melted, scattered or evaporated due to resistance heating. So
It is desirable to increase the addition amount of the metal powder and reduce the current density as compared with the case of using a cold rolled steel sheet.

The present invention has been made on the basis of the above findings, and as a result of further study on the relationship between the conditions for adding metal powder to the multilayer film and the weldability, the following conclusions were obtained. The polymer resin has at least a three-layer structure including a center layer having a vibration damping property and outer layers having adhesiveness to the metal plate on both surfaces thereof. That is, it is difficult for a single film to impart the adhesion force and film rigidity required for the vibration damping property and the processability as described above, and it is desirable to separate the functions of the layers. In terms of the layer steel structure of the multilayer film, the thickness ratio of outer layer / center layer / outer layer is preferably 1: 4: 1 to 1: 8: 1, and more preferably 1: 6, from the viewpoint of damping property. : 1 to 1: 8: 1. When the thickness ratio of the central layer is small, the vibration damping property is deteriorated, and when the thickness ratio of the outer layer is too small, the adhesion is poor. Further, the thickness of the central layer is preferably about 20 to 100 μm in consideration of the vibration damping property, and the thickness of the outer layer is preferably about 3 to 10 μm in consideration of the adhesiveness.

Metal powder having a predetermined particle size is added to each of the central layer and the outer layer. Specifically, in the central layer, the average particle diameter D ₁ before being crushed and held between the metal plates is T ₀ ≦ D ₁ ≦ 2T ₀ with respect to the total thickness T ₀ of the polymer resin layer. Use the one in the range. The reason is that by crushing to the thickness of the polymer resin layer when laminating, a smooth surface is created, metal powder can be effectively contacted with the upper and lower metal plates, and weldability can be imparted with a small addition amount. Because it will be. 2T
_{When 0} <D ₁ , it becomes difficult to crush the metal powder, and as a result, air bubbles are mixed in the interface between the polymer resin layer and the skin metal plate, and the adhesion is lowered. Further, if T ₀ > D ₁ , sufficient contact cannot be obtained and the weldability deteriorates. It is desirable that the metal powder has a substantially spherical shape before being crushed. The reason is that the grain size distribution can be accurately grasped, and the area of the contact portion between the skin metal plate and the metal powder when crushed can be easily obtained, and welding defects such as pinhole defects do not occur. This is because it is possible to accurately and accurately determine the addition amount of the metal powder to the minimum. In the crushed metal powder, the metal powder in the range of 2T ₀ ≦ D _1W is 70% or less of the total number of metal powders in the center layer with respect to the thickness T ₀ of the polymer resin layer,
Further, the metal powder content in the range of T ₀ ≦ D _1W is 30% or more. Two
If the number of particles in the range of T ₀ ≦ D _1W exceeds 70%, it becomes difficult to crush the metal powder, and the number of particles in the range of T ₀ ≦ D _1W becomes 30.
If it is less than%, a sufficient contact state and a smooth surface cannot be obtained, and the weldability deteriorates. The amount of addition is 3 to 20% by weight with respect to the center layer resin. The reason why the lower limit is set to 3% by weight is that it is necessary to secure a sufficient contact area between the metal powder and the skin metal plate in order to perform welding, as can be seen from the mechanism of spot welding described above.
For that purpose, at least 3% by weight or more is necessary, and further 10% by weight in the case of a plated metal plate such as a plated steel plate.
The above amount added is desirable. In the case of a plated steel sheet, it is desirable to increase the addition amount so that the melting point of the plating layer is 40
Since it is about 0 to 500 ° C, the plating layer in contact with the metal powder generates resistance heat and does not immediately melt and scatter in the initial stage of welding.
To prevent this, increase the amount of metal powder added to reduce the current density to the metal powder.
This is to prevent resistance heating of the plating layer in contact with this. The reason for setting the upper limit to 20% by weight is that if it is 20% by weight or more, it becomes difficult to crush during lamination, and the inclusion of air bubbles causes a decrease in adhesion force and a decrease in spot weldability. Weakness is unavoidable, and
The damping performance will be degraded. Plated steel plate (plated metal plate)
In the case of, the composition of the plating layer is Zn, Ni, Sn, Cr,
Various plated steel sheets such as Cu, Fe-Zn type, Ni-Zn type and Zn-Al type can be used.

Further, the outer layer, the thickness T ₂ of the average particle diameter D ₂ before being clamped to the metal plate is the outer layer, 0.
6T ₂ ≦ D ₂ ≦ 2T ₂ is used. The reason for adding such a small-diameter metal powder to the outer layer is that the above-mentioned metal powder added to the central layer alone may cause the resin to remain at the contact interface between the metal plate and the metal powder, resulting in unstable weldability. Because
This is because by contacting the metal powder in the center layer with the metal plate via the metal powder added to the adhesive layer, the upper and lower metal plates can be short-circuited with low resistance, and the weldability is improved. Further, as a result, the amount of metal powder added to the central layer can be reduced, and at the same time, it is possible to prevent deterioration of the vibration damping property. 2T
_{When 2} <D ₂ , the smoothness of the film surface before being held on the metal plate was inferior, air bubbles were mixed in after being held on the metal plate, and the outside of the number of metal powder added to the center layer Since the number of metal powders added to the layer is small, the probability that the metal powder in the central layer and the metal plate will contact via the metal powder in the outer layer is low, and the weldability is not stable. On the other hand, 0.
When 6T ₂ > D ₂ , sufficient contact with the metal plate cannot be obtained, resulting in poor weldability. In the crushed metal powder, the thickness T of the outer layer is
₂ , the metal powder in the range of 2T ₂ ≦ D _2W is 70% or less of the total number of metal powders in the outer layer, and the metal powder in the range of T ₂ ≦ D _2W is the total number of metal powders in the outer layer. Of 30% or more.
This is because if the metal powder in the range of 2T ₂ ≦ D _2W exceeds 70%, air bubbles are mixed after being held by the metal plate, and if the metal powder in the range of T ₂ ≦ D _2W is less than 30%, the weldability is poor. . Also,
The addition amount is 3 to 5% by weight. The reason is that, as described above, since the thickness of the outer layer is smaller than the thickness of the central layer, even if the amount added is 3 to 5% by weight, it is 10 to 100 relative to the number of metal powder in the central layer. This is because the double number is present, so that it can be interposed between the metal powder and the metal plate in the above-mentioned center layer, and the effect on the weldability is sufficient. If it is less than 3% by weight, the weldability is poor. If it exceeds 5% by weight, the adhesion to the metal plate is weakened and the film formability is deteriorated.

Here, it is important that the predetermined metal powder added to the outer layer improves the weldability, but does not affect the reduction of the vibration damping property, and if the addition amount is optimized, the adhesion is reduced. Therefore, it was found that the effective balance of the performance can be improved by effectively using the outer layer.

Further, as the metal powder, it is more preferable that the Vickers hardness of 180 Hv or less is added to the central layer. The reason is that the metal powder can be easily crushed to the thickness of the polymer resin when laminating, a sufficient contact area with the skin metal plate can be secured, and the polymer resin layer and the skin metal plate This is because good adhesion can be obtained without bubbles entering the interface. For example, the Vickers hardness of a cold-rolled steel sheet is about 100 to 130 Hv, the Vickers hardness of an alloyed galvanized steel sheet is about 300 Hv, and the hardness range of a skin steel sheet is about 100 to 300 Hv. On the other hand, it has been found that if the hardness of the metal powder is 1.8 times or less the hardness of the skin steel sheet, it can be crushed by the rolling force of the pressure-bonding roll during lamination. That is, the Vickers hardness of the metal powder is preferably 180 Hv or less. Further, if the hardness is equal to or lower than the hardness of a metal plate such as a skin steel plate, it is more preferable because it can be easily crushed. If metal powder having a hardness 1.8 times or more that of the skin metal plate is used, the metal powder cannot easily bite into the skin metal plate even if the rolling force at the time of stacking is increased, and it is attempted to further crush it. When the rolling force is increased, the skin metal plate is rather deformed, resulting in point contact between the metal powder and the skin metal plate, resulting in insufficient contact.
Spot weldability deteriorates. Further, since the metal powder is not crushed, air bubbles are mixed in the joint surface with the polymer resin layer, which causes a problem of a decrease in adhesion. As described above, by using the metal powder having a Vickers hardness of 180 Hv or less, not only good weldability can be obtained, but also good adhesion can be obtained even if any kind of skin metal plate is used. be able to. Furthermore, since the minimum amount of metal powder added is sufficient, the vibration damping performance is less likely to deteriorate, and good vibration damping performance can also be obtained. In order to bring the hardness of the metal powder to a predetermined hardness, there is a quenching or work hardening method when making it hard, and an annealing method when making it soft, and these are techniques that can be appropriately performed by those skilled in the art.

Next, it is desirable that the melting points of the metal powders are equal to or higher than the melting points of the two skin metal plates together with the metal powders added to both layers. The reason is that the spot welding is performed by melting the skin metal plate, and therefore the metal powder needs to serve as a short-circuit point between the upper and lower metal plates until the skin metal plate melts. During welding, the electric current flows through the metal powder,
Since the metal powder itself also causes resistance heating, there is a high possibility that it will melt and disappear depending on the temperature rise. Therefore, it is desirable that the temperature is at least the melting point of the skin metal plate or higher. Examples of the metal powder that satisfies this condition include nickel powder, iron powder, stainless steel powder, copper powder, and mixed powders thereof.
Of these, nickel powder is particularly preferable.

As the polymer resin, those constituting the central layer are thermoplastic resins such as modified polyethylene, modified polypropylene, vinyl acetate, polyester and the like, acrylic resins, epoxy resins, urethane resins, polyester resins and the like. A thermosetting resin such as a polymer with rubber such as SBR or a polymer alloy can be used, and a thermoplastic resin such as adhesive polyethylene or adhesive polypropylene is used as the outer layer resin in terms of easy film moldability. it can. From the viewpoint of film formability, a thermoplastic resin based on polyolefin such as modified polyethylene or modified polypropylene is desirable for both the center layer and the outer layer.

As the resin for the center layer, the maximum value of the loss tangent (tan δ) based on the glass transition is 0.
It is 3 or more, and the temperature showing this maximum value is -40 to 100
It is desirable to use a polymer resin in the range of ℃,
The maximum value of the loss factor of the vibration-damped metal plate containing the metal powder is set to 0.
The temperature may be 1 or more, and the temperature at which this maximum value is obtained may be in the range of 0 to 120 ° C. Since the increase of the addition amount of the metal powder causes the reduction of the vibration damping property, it is possible to prevent the reduction of the loss coefficient by controlling the addition amounts of the central layer and the adhesive layer.

As a method for producing a multilayer film, there are a dry lamination method, a hot melt lamination method, an extrusion lamination method, a coextrusion method (a feed block method, a multi-manifold method), a multilayer inflation method and the like. May be. However, the coextrusion method is effective from the viewpoint of easy film formation. In order to set the tan δ to 0.3 or more and the maximum value of the loss coefficient to 0.1 or more by these methods, the raw materials and the production conditions may be controlled according to a conventional method. For example, tan δ0.
In order to obtain 3 or more, it is possible to copolymerize polyolefin such as polyethylene and polypropylene with acrylic ester and the like, and in order to obtain the loss coefficient of 0.1 or more, the thickness is 0.2 to 1 It is possible by laminating a film having a thickness of 40 μm or more with a metal powder addition amount of 20% by weight or less on a 6 mm skin steel plate by thermocompression bonding using a pair of pinch rolls without inclusion of bubbles. It is possible to make these appropriate.

As the skin metal plate, cold-rolled steel plate, stainless steel plate, various plated steel plates of zinc, nickel, tin, chromium, copper, etc., and iron-zinc system, nickel-zinc system zinc-aluminum system, etc. are melted. Alternatively, an electroalloyed steel plate, a metal plate such as a copper plate, or the like can be used. Its thickness is about 0.2 to 3.2 mm. In addition, for the purpose of improving corrosion resistance and the like, the surface of the steel sheet may be subjected to chromate treatment or an organic coating.

[0022]

EXAMPLES Examples of the present invention will be described. Figure 1
(A), FIG.1 (b) is sectional drawing which shows the embodiment of this invention,
FIG. 2 is a front view showing a spot welding procedure. In the drawings, 1 and 1'indicate damping steel plates, and damping steel plates 1 and 1 '
Has a polymer resin layer sandwiched between the skin steel plates 2 and 2 ',
The polymer resin layer includes center layers 3 and 3'and outer layers 4 and 4'arranged on both sides thereof, and the outer layers 4 and 4'are in contact with the damping steel plates 1 and 1 '. Metal powders 5, 5'are dispersedly contained in the central layers 3, 3 ', and metal powders 6, 6'are dispersedly contained in the outer layers. In FIG. 1 (b), 7'is a plated layer, 8 is an electrode in FIG. 2, and 9 is a single steel plate (material to be welded).

The damping steel plate 1 (1 ') shown in FIG. 2 and the single steel plate 9 were spot-welded. Table 1 shows various conditions of the vibration-damping steel sheet of the present invention, and Table 2 shows the results of spot welding, vibration-damping property measurement, and adhesion force measurement. Further, for comparison, the same spot welding was performed on the vibration-damping steel plate having the conditions shown in Table 3 and outside the scope of the present invention. Table 4 shows the experimental results.

Below, skin steel plate, polymer resin, metal powder,
Lamination conditions, spot welding conditions, and vibration damping measurement conditions are shown.
In Table 3, those outside the scope of the present invention are marked with *, and in Table 4 those with poor results are marked with *. Also, Table 2
Among them, the mark * is also attached to a portion outside the preferable range although it is within the scope of the present invention. (1) Skin steel sheet 1. Cold rolled steel plate (aluminum killed steel plate), plate thickness 0.8 mm
^t , Vickers hardness 100 Hv 2. Zinc-nickel alloyed electroplated steel plate (material is 1. above), plate thickness 0.8 mm ^t (2) Polymer resin 1. Center layer: acrylic modified polypropylene resin (a), (b), thickness 0.04 mm ^t 2. Outer layer; adhesive polypropylene resin, thickness 0.0
05mm ^t 3 layer film, layer composition ratio 1: 8: 1, total thickness 0.05m
m ^t (3) Method for producing resin film A three-layer film was produced by a coextrusion method using a multi-manifold method. In some cases, metal powder was added to each layer. (4) Metal powder (addition of central layer) 1. Nickel powder ・ Average particle size; 120 μm (distribution 90 to 150), 68 μ
m (63 to 74), 48 μm (44 to 53) ・ Hardness; Vickers hardness of 90 Hv, 180 Hv, 28
0Hv-Amount of addition; addition in the range of 2 to 30% by weight 1. Stainless steel powder ・ Average particle size; 58 μm (distribution 53 to 63) ・ Hardness; Vickers hardness of 180 Hv ・ Addition amount: 3 to 20% by weight (addition of outer layer) 1. Nickel powder ・ Average particle size; 2 μm (distribution 1-6), 5 μm (3-1)
0), 15 μm (10 to 25) ・ Hardness; Vickers hardness of 90 Hv, 180 Hv, 2
80Hv-Amount to be added; added in the range of 1 to 10% by weight (5) Laminating conditions In each case, a pair of pinch rolls lined with resin was used to coat a three-layer film containing metal powder on a skin steel sheet heated to 130 ° C. lamination, in a state of being melted by heating to 180 ° C. resin, and other skin steel plates were heated separately 180 ° C., by a pair of pinch rolls and the resin ^{lining, 10kgf / cm 2 ~80kgf / cm} 2 Within the range of the surface pressure of the above, selected and laminated according to the addition amount of the metal powder, and air-cooled to obtain a damping steel sheet. (6) Spot welding conditions 1. Electrode: dome type, copper-chromium electrode (tip system 6 mm
φ) 2. Applied pressure: 200 kgf 3. Current: 10 kA 4. Energization time: 12 cycles (60 Hz) 5. Control method: constant current control (0.5 cycle control) 6. Test piece combination: A 30 × 100 mm damping steel plate and a 1.6 mm thick single steel plate were overlapped and welded.

7. Evaluation of weldability: 500 spot weldings were carried out at one place per laminated steel sheet, and the number of defects was determined. Further, the resistance during welding at 0.5 cycle was determined from the current / voltage waveform during welding.

It is to be noted that the resistance during welding differs in the range suitable for the type of the surface steel sheet, and is preferably less than 400 μΩ for the cold rolled steel sheet and less than 300 μΩ for the zinc-nickel alloy electroplated steel sheet, and exceeds this range. And weldability deteriorates. (7) Measurement of vibration damping performance A 25 × 220 mm and 25 × 280 mm test piece was used to measure the loss coefficient by the half-width method from the resonance response curve.
The maximum value of the loss coefficient at 1000 Hz is arranged.

As is clear from Table 2, Example No. 1 within the scope of the present invention. 1-No. In No. 10, the resistance during welding was within the suitable range, and the weldability was good. In addition, No. 5, N
o. Other than 7, the adhesion and vibration damping properties were good.

On the other hand, from Table 4, Comparative Example No. 1
Since no metal powder was added to the outer layer, the welding resistance and weldability were poor. Comparative Example No. 2 and No. In No. 9, since the amount of metal powder added to the outer layer exceeded 5%, the adhesion was poor.

Comparative Example No. In No. 3, the particle size of the metal powder in the outer layer was 2T ₂ <D ₂ (the number of particles in the range of 2T ₂ ≦ D _2W was 85% of the number of the metal powder in the outer layer), and thus the adhesion was poor. Comparative Example No. 4 is 3% metal powder added to the central layer
Since it was less than 1, the welding resistance and weldability were poor.

Comparative Example No. In No. 5, since the amount of metal powder added to the central layer was 20% or more, the vibration damping property and the adhesive force were poor. Comparative Example No. In No. 6, the particle size of the metal powder in the central layer is T _0.
Since> D ₁ (the number in the range of T ₀ ≦ D _1W is 20% of the number of the metal powder in the central layer), the resistance during welding and the weldability were poor.

Comparative Example No. In _No. 7, since the particle diameter of the metal powder in the central layer is 2T ₀ <D ₁ (the number in the range of 2T ₀ ≦ D _1W is 90% of the number of the metallic powder in the central layer), the welding resistance and the adhesive force are It was bad.

Comparative Example No. 8 is a single layer film,
The adhesion was poor. Comparative Example No. In No. 10, since the particle size of the metal powder in the outer layer is 0.6T ₂ > D ₂ (the number in the range of 2T ₂ ≦ D _2W is 5% of the number of the metal powder in the outer layer), resistance during welding and weldability Was bad. Comparative Example No. 11
In the case of, since the amount of metal powder added to the outer layer was less than 3%, the resistance during welding and the weldability were poor.

[0033]

As described above, according to the present invention, it is possible to surely obtain a damping steel plate excellent in electric resistance weldability without lowering the adhesive force and the damping property.
In the past, such as electrical machinery, machinery, building materials, etc., it is possible to apply to applications that were difficult to apply due to the problem of balance of adhesion, vibration damping, weldability, or unstable weldability, Industrially useful effects are provided.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

[Table 3]

[0037]

[Table 4]

[Brief description of drawings]

FIG. 1 is a schematic view of a vibration-damping steel plate of the present invention, in which (a) shows one embodiment and (b) shows another embodiment.

FIG. 2 is an explanatory view when spot-welding the damping steel sheet according to the present invention.

[Explanation of symbols]

1, 1 '... damping steel plate, 2, 2' ... skin steel plate, 3, 3 '...
Center layer, 4, 4 '... Outer layer, 5, 5' ... Metal powder, 6,
6 '... metal powder, 7' ... plating layer, 8 ... electrode, 9 ... single steel plate

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] January 12, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 6

[Correction method] Change

[Correction content]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasunori Matsuda 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Steel Pipe Co., Ltd.

Claims (6)

[Claims] 1. A vibration-damping metal plate in which a polymer resin is sandwiched between metal plates, wherein the polymer resin comprises a center layer having vibration-damping properties and outer layers having adhesiveness to the metal plates on both sides thereof. It has at least a three-layer structure, and in the central layer, an average particle diameter D ₁ before being crushed and held between metal plates.
With respect to the thickness T ₀ of the polymer resin layer, T ₀ ≦ D ₁
Within the range of ≦ 2T ₀ , a conductive metal powder having a melting point equal to or higher than those of the two metal plates is added in an amount of 3 to 20% by weight based on the total weight of the center layer resin and the conductive metal powder, and , The average particle diameter D ₂ before being held by the metal plate in the outer layer
Is 0.6T ₂ ≦ D ₂ ≦ with respect to the thickness T _{2 of the} outer layer.
The conductive metal powder having a melting point of 2T ₂ and a melting point equal to or higher than those of the two metal plates is 3 to 3 with respect to the total amount of the outer resin and the conductive metal powder.
A vibration-damping metal plate with excellent electric resistance weldability, which is characterized by containing 5% by weight. 2. A vibration-damping metal plate in which a polymer resin is sandwiched between metal plates, wherein the polymer resin comprises a center layer having vibration damping properties and outer layers having adhesive properties with the metal plates on both sides thereof. The core layer has at least a three-layer structure, and 2T ₀ ≦ D with respect to the thickness T ₀ of the polymer resin layer in the central layer.
Metal powder in the range of _1W is 70% of the total number of metal powder in the central layer
The conductive metal powder having a melting point of 30% or more in the range of T ₀ ≦ D _1W and having a melting point equal to or higher than those of the two metal plates is relative to the total of the center layer resin and the conductive metal powder. 3 to 2
0% by weight is added, and in the outer layer, the metal powder in the range of 2T ₂ ≦ D _2W with respect to the thickness T ₂ of the outer layer is 70% of the total number of metal powders in the outer layer. % Or less and T
The metal powder in the range of ₂ ≤ D _2W is 3 of the total number of metal powders in the outer layer.
Electrically characterized in that conductive metal powder having a melting point of 0% or more and having a melting point equal to or higher than those of the two metal plates is added in an amount of 3 to 5% by weight based on the total amount of the outer layer resin and the conductive metal powder. Damped metal plate with excellent resistance weldability. However, D _1W is the width direction diameter of the metal powder in the center layer after being held between the crushed metal plates, and D _2W is the metal powder in the outer layer after being crushed and held between the metal plates. Is the diameter in the width direction. 3. The polymer resin forming the central layer has a maximum value of loss tangent (tan δ) based on glass transition of 0.3 or more, and a temperature showing this maximum value is in the range of −40 to 100 ° C. , The maximum value of the loss coefficient of the damping metal plate to which the metal powder is added is 0.1 or more, and the temperature showing this maximum value is 0.
The vibration-damping metal plate having excellent electric resistance weldability according to claim 1 or 2, which is in the range of 120 ° C. 4. The thermoplastic resin containing a polyolefin resin as a main component, wherein the polymer resin is a thermoplastic resin.
The vibration-damping metal plate having excellent electric resistance weldability described in 1. 5. The vibration-damping metal plate excellent in electric resistance weldability according to claim 1, wherein the metal powder added to the central layer has a Vickers hardness of 180 Hv or less. 6. The vibration-damping metal plate having excellent electric resistance weldability according to claim 1, wherein the metal powder added to the central layer has a hardness not higher than a metal plate hardness.