JP3214344B2 - Laminated steel sheet with excellent press formability - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated steel sheet having a zinc-based plating layer, in which a polymer resin layer is sandwiched between two upper and lower steel sheets, which has corrosion resistance and press formability. It relates to an excellent laminated steel sheet.

[0002]

2. Description of the Related Art A laminated steel sheet has a polymer resin layer sandwiched between two upper and lower steel sheets (skin steel sheets), and imparts properties such as light weight and vibration damping properties of the polymer resin to the steel sheet. Things. In recent years, damping steel sheets provided with damping properties have been actively used, particularly for the purpose of noise reduction of automobiles and quietness of building materials.

[0003] In order to use a laminated steel sheet in the above-mentioned applications, for example, in applications such as rustproof steel plates for automobiles,
In addition to corrosion resistance, it is necessary for the performance required in the vehicle body manufacturing process to be appropriately excellent in press formability, adhesiveness with an adhesive, and the like.

In order to impart corrosion resistance to a laminated steel sheet, a laminated steel sheet using a zinc-based plated steel sheet as a skin steel sheet sandwiching a polymer resin layer is disclosed in Japanese Patent Publication No. 2-27145,
No. 94928 (hereinafter referred to as prior art 1).

[0005]

However, zinc-coated steel sheets generally have a drawback that press formability is inferior to cold-rolled steel sheets. This is because when a zinc-based plated steel sheet is press-formed, the sliding resistance between the zinc-based plated steel sheet and the press die is larger than that of a cold-rolled steel sheet.
This is because the steel sheet is less likely to flow into the mold during the press forming, particularly in a portion where the sliding resistance between the zinc-based plating layer and the press mold is large, and the steel sheet is likely to break.

[0006] Various adhesives are applied for the purpose of preventing rust of vehicle bodies and joining parts, but it has become clear in recent years that the adhesiveness of galvanized steel sheets is inferior to that of cold rolled steel sheets. It has become.

The performance of a laminated steel sheet often depends on the performance of the skin steel sheet. In the case of the laminated steel sheet described in the prior art 1 using a zinc-based plated steel sheet as the skin steel sheet, the zinc-based plating The properties of the steel sheet are directly expressed as the performance of the laminated steel sheet, and although the corrosion resistance is improved, the press formability and the adhesiveness are inferior.

As a method of improving the press formability, which is a drawback of a galvanized steel sheet, Japanese Patent Application Laid-Open No. 4-88196 discloses that a surface of a galvanized steel sheet contains 50 to 60 g / l of sodium phosphate. By immersing the plated steel sheet in an aqueous solution having a pH of 2 to 6, electrolytic treatment, or spraying the aqueous solution, an oxide film mainly composed of P oxide is formed,
A technique for improving press formability is disclosed (hereinafter referred to as Prior Art 2).

[0009] Japanese Patent Application Laid-Open No. Hei 3-91093 discloses that the surface of a zinc-based steel sheet is electrolytically treated, dipped, coated and oxidized, or heated to generate Ni oxide, thereby improving press formability. The technology is disclosed (hereinafter referred to as prior art 3).

However, in the techniques disclosed in Prior Art 2 and Prior Art 3, the press formability is improved, but the adhesiveness is inferior. Therefore, when this galvanized steel sheet is used as the skin steel sheet of the laminated steel sheet, in the laminated steel sheet,
The press formability is improved, but the adhesion is not improved.

[0011] Therefore, there is no laminated steel sheet having a zinc-based plating layer having corrosion resistance and excellent press formability and, if necessary, excellent adhesion.

In order to solve the above-mentioned problems, the present invention is based on the premise that corrosion resistance and press formability are excellent, and if necessary, provides a laminated steel sheet having a zinc-based plating layer excellent in adhesion. The purpose is to do.

[0013]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have intensively studied various characteristics as a laminated steel sheet.

First, the concept of the present invention on the assumption that both corrosion resistance and press formability are compatible will be described below. (1) Since the corrosion resistance is affected by the corrosion resistance of the skin steel sheet itself, it was assumed that a steel sheet having a zinc-based plating layer was used as the skin steel sheet.

(2) In the case of press forming, there is a forming problem that leads to press cracking of the laminated steel sheet, and a forming peculiar to the laminated steel sheet that causes separation between the sandwiched polymer resin layer and the skin steel sheet. There is a problem above.

The former greatly depends on the characteristics of the laminated steel sheet, and it is effective to reduce the sliding resistance between the surface layer of the laminated steel sheet, that is, the skin steel sheet and the press die.

In the latter, when the laminated steel sheet passes through the bead of the press die or the die shoulder R, a shift occurs between the two skin steel sheets, and the shift causes a gap between the polymer resin layer and the skin steel sheet. It causes peeling. When this peeling occurs, a fatigue crack may occur in the skin steel sheet of the press-formed laminated steel sheet in use, or the performance as the laminated steel sheet, for example, excellent vibration damping property may not be sufficiently exhibited. By increasing the adhesive strength between the sandwiched polymer resin layer and the skin steel plate, the occurrence of this peeling can be improved.

(3) Further, since various adhesives are applied for the purpose of preventing rust of the vehicle body and joining parts, in addition to the above-described corrosion resistance and press moldability, it is necessary to appropriately provide adhesiveness according to the application. Become. Since this adhesion depends on the properties of the skin steel sheet,
It is desirable that the skin steel plate also has adhesiveness.

Further, the improvement in the adhesiveness also leads to the improvement in the peeling (processing peeling resistance) between the polymer resin layer and the skin steel sheet described in the above (2).

In the present specification, the formability closely related to press cracking, such as the former observed in cold-rolled steel sheets and galvanized steel sheets, is called press formability. Formability related to peeling between the polymer resin layer of the laminated steel sheet and the skin steel sheet, which is a problem, is called work-resistant peeling property or adhesiveness, and the two are distinguished.

Based on the above concept, attention is paid to the skin steel sheet to be used, and it is considered important to optimize this. A laminated steel sheet which imparts corrosion resistance by a plating layer and has excellent press formability and adhesion is also considered. As a result of study for the purpose of providing, the present inventors have found the present invention.

Based on the above concept, the inventors of the present invention provide corrosion resistance by a zinc-based plating layer on a skin steel sheet constituting a laminated steel sheet, and form an appropriate Fe-Ni-O-based film on the surface thereof. As a result, it has been found that press formability and adhesiveness can be further improved.

That is, a laminated steel sheet using a galvanized steel sheet as a conventional skin steel sheet is inferior in press formability as compared with a case using a cold-rolled steel sheet. This is because, due to the large sliding resistance between the zinc-plated steel sheet, which is a skin steel sheet, and the press mold, the low-melting-point zinc and the mold cause an adhesion phenomenon under a high surface pressure. In order to prevent this, it is effective to form a film having a higher melting point than the zinc or zinc alloy plating layer on the surface of the zinc-based plated steel sheet.
The film formed on the zinc-based plating layer in the present invention includes at least Ni and Fe metals, and Ni
Is a mixed film containing iron and Fe oxides (hereinafter referred to as Fe-Ni-O-based film), which is hard and has a high melting point, which lowers the sliding resistance between the plating layer surface and the press mold during press forming. , The laminated steel sheet slips easily into the press mold,
Press formability is improved.

In addition, the conventional laminated steel sheet having a zinc-based plating layer has a higher adhesiveness to a sandwiched polymer resin layer and an adhesive used in a component assembling process than a cold-rolled steel sheet. Was known to be inferior, but the cause was not clear.

The present inventors have investigated the cause and found that the adhesiveness is controlled by the composition of the oxide film on the surface. That is, in the case of the cold-rolled steel sheet, the oxide film on the surface is mainly composed of Fe oxide, whereas in the case of the zinc-based plated steel sheet, the zinc oxide is mainly composed. Adhesion differs depending on the composition of this oxide, and Zn
The oxide was inferior in adhesiveness to the Fe oxide. Therefore, by forming a film containing Fe oxide on the surface layer of the skin steel sheet as in the present invention, it is possible to improve the adhesiveness.

The present invention has been made based on the above findings. Hereinafter, the means of the present invention will be described.

According to a first aspect of the present invention, there is provided a laminated steel sheet having a polymer resin layer sandwiched between two upper and lower steel sheets, wherein at least one of the steel sheets has a surface which is not in contact with the polymer resin layer. A zinc-based plating layer, and a Fe-Ni-O-based film formed on the zinc-based plating layer, and the adhesion amount of the Fe-Ni-O-based film is 10 to 1500 mg / located m ² within the following ranges, and the oxygen content of the Fe-Ni-O based film is a laminated steel sheet in the range of less than 0.5 and less than 30 wt%.

According to a second aspect of the present invention, there is provided a laminated steel sheet having a polymer resin layer sandwiched between two upper and lower steel sheets, wherein the one steel sheet has a zinc-based plating layer on both sides thereof and the zinc-based plating layer. The other steel sheet has a zinc-based plating layer and a zinc-based plating layer formed on the zinc-based plating layer at least on the surface in contact with the polymer resin layer. Fe-Ni-O-based coating, and each of the above Fe-Ni-O
System deposition amount of the coating is within the range of a total of 10 or more 1500 mg / m ² or less in terms of metal, the oxygen content of the Fe-Ni-O based film is 0.
5 or more and less than 30 wt%, and the Fe-Ni-O
A laminated steel sheet wherein the ratio of the Fe content (wt%) to the sum of the Fe content (wt%) and the Ni content (wt%) in the system coating is in the range of 0.05 or more and less than 1.0.

According to a third aspect, in the first aspect or the second aspect, the polymer resin has a loss tangent based on a glass transition.
When the maximum value of (tanδ) is 0.3 or more, the temperature at which this maximum value
The laminated steel sheet has a maximum value of the loss coefficient (η) of 0.1 or more as a laminated steel sheet in a range of -40 to 80 ° C and a temperature at which the maximum value is in a range of 0 to 120 ° C.

Hereinafter, the reasons for the limitation of the present invention will be described. <Adhesion amount of Fe-Ni-O-based film> By forming the Fe-Ni-O-based film, press formability and adhesiveness are improved. But Fe
Adhesion amount of -ni-O based film is, if less than 10 mg / m ² with a film in terms of metal, the press formability can not be obtained the effect of improving the adhesiveness. When the amount of adhesion exceeds 1500 mg / m ² , the above-described effects are saturated. Therefore, the amount of Fe-Ni-O-based coating
It is necessary to be 10 mg / m ² or more and 1500 mg / m ² or less.

<Oxygen content of Fe-Ni-O-based coating> By containing an appropriate amount of oxygen in the Fe-Ni-O-based coating, press formability and adhesiveness are improved. However, when the oxygen content in the Fe-Ni-O-based coating is less than 0.5 wt%, the metallic properties of the coating become strong, so that the effect of improving the press formability is not exhibited. Large, poor wettability and poor adhesion. On the other hand, if this amount exceeds 30% by weight, the film is entirely composed of oxide, and there is no metal simple substance, which does not satisfy the requirements of the present invention, so that the effects of the present invention cannot be exhibited. Therefore, the oxygen content of the Fe-Ni-O film is
It must be 0.5 or more and less than 30 wt%.

<Ratio of the Fe content (wt%) to the sum of the Fe content (wt%) and the Ni content (wt%) in the Fe-Ni-O-based coating>
The ratio of the Fe content (wt%) to the sum of the Fe content (wt%) and the Ni content (wt%) in the Ni-O-based coating (hereinafter, Fe / Fe in the coating)
By specifying (+ Ni), the adhesiveness can be improved in addition to the press formability. If the ratio is less than 0.05, the effect of improving the adhesiveness cannot be obtained. When this ratio is 1.0, Ni is not present in the film, and the composition requirements of the present invention are not satisfied. When Ni is not present, oil retention is poor and press formability is poor. Therefore, in order to obtain excellent adhesiveness in addition to excellent press formability,
Fe / Fe + Ni needs to be 0.05 or more and less than 1.0.

The polymer resin used for the laminated steel sheet has a maximum loss tangent (tan δ) based on the glass transition of 0.3 or more, and the temperature at which the maximum value is in the range of -40 to 80 ° C. Thus, this polymer resin is sandwiched between steel sheets to form a laminated steel sheet, the maximum value of the loss coefficient (η) of the laminated steel sheet is 0.1 or more, and the temperature at which this maximum value is shown is 0 to 120 ° C.
In this case, in addition to the performance described above, excellent vibration damping properties can be imparted to the laminated steel sheet.

The effects of the present invention are as follows. The first invention is excellent in press formability.

The second invention is excellent in press moldability, adhesiveness with an adhesive, and adhesiveness with a polymer resin layer.

The third aspect of the invention has further excellent vibration damping properties in addition to the effects of the first and second aspects of the invention.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, it is preferable to manufacture a laminated steel sheet using a zinc-based plated steel sheet in which a zinc-based plated layer and an Fe-Ni-O-based film are previously formed as a skin steel sheet. is there. However, if possible, a zinc-based plating layer or a Fe-Ni-O-based film may be formed after forming a laminated steel sheet.

Hereinafter, embodiments of the present invention in the case of using a galvanized steel sheet as the skin steel sheet will be described.

Here, the zinc-based plated steel sheet refers to a zinc-based plated layer formed on a base steel sheet by one or more methods such as hot-dip plating, electroplating, and vapor phase plating. Steel plate.

The chemical composition of the zinc-based plating layer is, in addition to pure zinc, Fe, Ni, Co, Mn, Cr, Mo, Al, Ti, Sn, W, Si, P
Any metal or oxide such as b, Nb and Ta, or a single layer or a plurality of plating layers containing a predetermined amount of one or more of organic substances may be used. Further, the plating layer may contain fine particles such as SiO ₂ and Al ₂ O _3, or the constituent elements of the plating layer are the same as the constituent elements of the plating layer, and the constituent elements of the plating layer are the same as a plurality of layers having different compositions. And a functionally graded plating layer whose composition is continuously changed in the thickness direction.

The above-mentioned zinc-based plating layer is made of Fe-N
It is formed on the surface of the steel sheet which is the lower layer of the iO-based film, but may be formed on the surface of the steel sheet where the above-mentioned film is not appropriately formed, depending on the use condition of the laminated steel sheet.

On the zinc-based plating layer, the first
Fe of the predetermined configuration as described in the invention of the second or second invention
-Form a Ni-O coating. The Fe-Ni-O-based coating is not limited by its forming method, and may be formed by a displacement plating method, a method of immersion in an oxidizing agent-containing aqueous solution, or a cathode in an oxidizing agent-containing aqueous solution. Electrolytic treatment and anodic electrolytic treatment, spraying method of predetermined solution, roll coating method, various CVD
, A vapor deposition method such as a vacuum deposition method and a sputter deposition method can be adopted.

In the Fe—Ni—O coating of the present invention, Zn, Co, Mn, Mo, Al, and Zn contained in the underlying zinc plating layer are included.
The above-described effects can be obtained even when an oxide, a hydroxide, or a metal element containing elements such as Ti, Sn, W, Si, Pb, and Ta is included.

The above-mentioned Fe—Ni—O-based coating is formed on at least one zinc-based plating layer of at least one of the steel sheets used as the skin steel sheet of the laminated steel sheet. For the film-forming surface, for example, one-sided or both-sided film formation can be appropriately selected according to the necessity in the component manufacturing process.

Further, a chromate treatment, a resin film, or the like may be provided on the surface of the skin steel sheet on the side in contact with the resin in order to improve adhesiveness, as long as the effects of the present invention are not impaired.

A Fe-Ni-O-based film having a predetermined composition is formed on the zinc-based plated layer obtained above, and the zinc-based plated steel sheet is placed between at least one of the upper and lower steel sheets used as at least one skin steel sheet. The laminated steel sheet of the present invention can be obtained by sandwiching the molecular resin layer by an ordinary method.

As the above-mentioned method of sandwiching, a method of laminating a polymer resin film on one steel plate and then thermocompression bonding the other steel plate, or a method of applying a liquid polymer resin to one steel plate and then applying the other steel plate Can be exemplified, and the method is not limited to this method.

Examples of the polymer resin include thermoplastic resins such as modified polyethylene, modified polypropylene, vinyl acetate, and polyester, and acrylic and epoxy resins.
Thermosetting resins such as urethane-based, polyester-based, and polymers of these with rubbers such as styrene-butadiene rubber or polymer alloys can be used. Further, the end face corrosion resistance, the processing peeling resistance, and the adhesive property of the bonded surface may be improved by improving the properties of the resin based on these resins or by combining them.

The thickness of the polymer resin layer sandwiched between the two skin steel plates is not particularly limited, and may be a commonly used thickness.
In general, the thickness is generally about 30 to 100 μm, which is easy to manufacture, but is not limited to this thickness.

[0050] The adhesive strength of a laminated steel sheets in terms of resistance to processing peelability (shear adhesion) is normal temperature at 90 kgf / cm ² or more, more preferably 110 kgf / cm ² or more, as measured by a viscoelastic spectrometer The dynamic modulus at 0.5 Hz is 1 × 10 ⁷ dyne / cm ²
It is desirable that this is the case.

The surface (flat portion) of the skin steel sheet Even if the corrosion resistance is excellent, depending on the environment in which the laminated steel sheet is used, the plating composition itself can easily be eluted at the end face on the polymer resin layer side of the skin steel sheet, A part of the plating composition of the alloy plating may be preferentially eluted preferentially, and as a result, peeling may occur between the polymer resin layer and the skin steel sheet, and the corrosion resistance may decrease. In this case, the occurrence of peeling is suppressed by a known method for improving end surface corrosion resistance or adhesion, such as by using a crosslinked polymer resin (thermosetting resin) or the like as necessary to improve adhesion. Can be.

When the molding conditions are severe and good resistance to processing and peeling is required, the elastic modulus is increased, if necessary, while considering the balance between the elastic modulus and the elongation of the polymer resin. The processing and peeling resistance can be further improved by suppressing the amount of displacement between the two skin steel plates when passing through the bead or the die shoulder R, improving the elongation characteristics, increasing the adhesive strength, and the like.

When the laminated steel sheet is required to have a vibration damping property, a loss tangent (tan) based on the glass transition of the polymer resin is required.
δ) has a maximum value of 0.3 or more, and the temperature at which the maximum value is -40.
The maximum value of the loss coefficient (η) of the laminated steel sheet may be 0.1 or more, and the temperature at which this maximum value is present may be in the range of 0 to 120 ° C.

A zinc-based plating layer of a skin steel sheet and Fe-N
The treatment of the surface on which the iO-based film is not formed is not particularly limited. It can be appropriately selected according to the use state of the laminated steel sheet. It may be a single or composite film such as a zinc-based plating, a non-zinc-based plating, a chemical conversion treatment film, an organic resin film formation, or an untreated bare steel sheet without a special treatment film formation.

Further, as the steel plate used above, a steel plate such as a cold-rolled steel plate manufactured by an ordinary method can be used. The thickness is generally about 0.2 to 1.0 mm. But,
The thickness is not limited to this, and the thickness can be appropriately selected according to the application. In the case of severe press working, a known method of improving formability such as increasing the r-value of the steel sheet and increasing the crack limit drawing ratio can be used.

[0056]

【Example】

<Example 1> An Fe-Ni-O-based film was formed on the surface of various plated steel sheets, and a laminated steel sheet was produced using the Fe-Ni-O-based film. Next, the press formability, adhesiveness, and vibration damping properties of the laminated steel sheet were evaluated. Manufacturing conditions and test conditions are shown below.

(1) Coated steel sheet GA used: Galvannealed steel sheet (10 wt% Fe, balance Zn)
Coating weight is 60 g / m ² on both sides, the plate thickness 0.4 mm. GI: In hot-dip galvanized steel sheet, coating weight 90 g / m ² on both sides,
0.4mm thick. EG: Electrogalvanized steel sheet, 40g / m ^{2 on} both sides,
0.4mm thick. Zn-Fe: Electrical Zn-Fe alloy plated steel sheet (15 wt% Fe), coating weight 40 g / m ² on both sides, the plate thickness 0.4 mm. Zn-Ni: Electric Zn-Ni alloy plated steel sheet (12wt% Ni), adhesion amount 30g / m ^{2 on} both sides, 0.4mm thickness. Zn-Cr: electric Zn-Cr alloy plated steel sheet (4 wt% Cr), coating weight 20 g / m ² on both sides, the plate thickness 0.4 mm. Zn-Al: molten Zn-Al alloy coated steel sheet (5 wt% Al), coating weight 60 g / m ² on both sides, the plate thickness 0.4 mm.

(2) Method of forming Fe-Ni-O-based coating A Fe-Ni-O-based coating was formed on the surface of the above-mentioned plated steel sheet by any of the following three methods.

<Formation Method A> A predetermined Fe-Ni-O-based film is formed on the surface of the original plate by subjecting the original plate to cathodic electrolysis in a mixed solution of iron sulfate and nickel sulfate containing an oxidizing agent. Was. Here, the nickel sulfate concentration is fixed at 100 g / l,
The iron sulfate concentration was changed to various predetermined values, and the pH was 2.5
The bath temperature was constant at 50 ° C., and the oxygen content of the coating was adjusted by changing the concentration to various predetermined values using hydrogen peroxide as an oxidizing agent.

<Formation Method B> An aqueous solution containing nickel chloride concentration of 120 g / l and various predetermined concentrations of iron chloride was sprayed on the original plate, and the oxygen of the Fe-Ni-O-based film was mixed in a mixed atmosphere of air and ozone. By drying while adjusting the content, a predetermined Fe-Ni-O-based film was formed on the surface of the original plate.

<Formation Method C> The original plate was immersed in an aqueous solution containing 120 g / l of nickel chloride and various predetermined concentrations of iron chloride, having a pH of 2.5 to 3.5 and a bath temperature of 50 ° C. By adjusting the immersion time, the amount of the Fe-Ni-O-based film deposited was changed to various predetermined values. Further, the oxygen content of the Fe—Ni—O-based film was changed to various predetermined values by adjusting the pH. Also, in order to adjust the oxygen content, a predetermined oxidizing agent is appropriately added to the aqueous solution, and a predetermined Fe-Ni- An O-based film was formed.

(3) Measuring method of adhesion amount, oxygen content and Fe / Fe + Ni of Fe—Ni—O based coating <Amount of adhesion and Fe / Fe + Ni> The plating type is GI, EG, Zn-Cr, Zn-
For Al, the film was dissolved and peeled off with dilute hydrochloric acid together with the lower plating surface layer, and Fe, Ni and metal were quantitatively analyzed by ICP method and measured.

Next, when the plating type is GA, Zn-Fe, or Zn-Ni, since the lower plating layer contains the component elements in the Fe-Ni-O-based film, the upper Fe layer in the ICP method is used. It is difficult to completely separate the component elements in the -Ni-O-based film from the component elements in the underlying plating layer. Therefore, Fe-Ni-
Of the elements in the O-based film, only the elements not contained in the lower plating layer were quantitatively analyzed. Furthermore, after Ar ion sputtering, the composition distribution of each component element in the depth direction of the plating layer was measured by repeating the measurement of each component element in the Fe-Ni-O-based film from the surface by the XPS method. In this measurement method, Fe not contained in the underlying plating layer
The depth from the surface at which the element of the -Ni-O-based film shows the maximum concentration (x), the depth from the surface at which the element is no longer detectable (y), and the depth from the surface at the maximum concentration Depth (x + (y−x) / 2) from the surface obtained by adding の of the difference (y−x) from the depth (x), that is, depth (x) from the surface showing the maximum concentration And the depth from the surface at which the element is no longer detectable (y), the average depth from the surface ((x +
y) / 2) was defined as the thickness of the Fe-Ni-O-based film. Then, based on the results of the ICP method and the XPS method, the amount and composition of the Fe-Ni-O-based film were determined. Next, Fe / Fe +
Ni was calculated.

<Oxygen Content> The oxygen content was determined from the results of depth analysis by Auger electron spectroscopy (AES).

(4) Polymer resin used: AC: rubber having a maximum value of loss tangent (tan δ) of 0.7, a temperature at which this maximum value is 5 ° C., and a dynamic elastic modulus of 2 × 10 ⁷ dyne / cm ² . Modified acrylic ester (thermosetting resin) PP: Acrylic acid modified with a maximum loss tangent (tanδ) of 0.3, a temperature at which this maximum is 50 ° C, and a dynamic elastic modulus of 5 × 10 ⁹ dyne / cm ² Polypropylene (thermoplastic resin) PE: Acrylic acid-modified polyethylene (heat tangent (tan δ) with a maximum value of 0.2, a temperature at which this maximum value is 20 ° C., and a dynamic elastic modulus of 6 × 10 ⁸ dyne / cm ² ) Plastic resin)

The loss tangent (tan δ) of the polymer resin is
50 with a viscoelastic spectrometer (VES-F3) manufactured by Iwamoto Seisakusho
Measured in Hz.

(5) Method of Manufacturing Laminated Steel Sheet For comparison, a plated steel sheet having no Fe-Ni-O-based film was added to the various types of plated steel sheets having the Fe-Ni-O-based film formed thereon for comparison. Then, as the upper and lower skin steel sheets, galvanized steel sheets having the same plating type and the same Fe-Ni-O-based coating (hereinafter, referred to as the same type) were used, and laminated steel sheets were prepared by the following method.

For rubber-modified acrylic ester (AC), a gel-like resin is applied to the surface of a steel plate by a knife-shaped coater, and then the other steel plate is coated with a pair of resin lining rolls at 10 to 20 / cm ^2. Were laminated by applying the surface pressure described above, and were heated and cured at a temperature of 170 ° C. for 5 minutes to produce a laminated steel sheet having a polymer resin layer having a thickness of 50 μm.

For acrylic acid-modified polypropylene (PP) and acrylic acid-modified polyethylene (PE), a resin film was bonded to the surface of a steel sheet preheated to 120 ° C. using a laminating roll, and then 180 ° C. (not less than the melting point of the resin). ), And the steel sheet on which this film is bonded and the other steel sheet separately heated to 180 ° C. are laminated by applying a surface pressure of 10 to ²⁰ kgf / cm ² with a pair of resin lining rolls. A laminated steel sheet having a polymer resin layer thickness of 50 μm was prepared.

(6) Evaluation Test Method <Press Formability> Press formability was evaluated by sliding resistance. In order to evaluate the sliding resistance, the friction coefficient was measured by the friction coefficient measuring device shown in FIG. For measurement, fix the sample 1 on the sample table 2 set on the horizontally movable slide table 3, press the bead 6 at a predetermined load (N), and pull out the slide resistance (F) to load cell. 8
And the coefficient of friction (μ) was calculated from the equation μ = F / N.

FIG. 2 shows the shape and dimensions of the used bead 6 (referred to as type A).
It has a plane of 10 mm and a length of 3 mm. In addition, Knocklast manufactured by Nippon Parkerizing Co., Ltd. was used as a lubricant in the test.
550HN was applied to the sample and used. The pressing load (N) was 400 kgf, and the drawing speed was 1 m / min.

<Adhesion Test> First, the adhesive strength between the laminated steel sheet and the polymer resin was evaluated by the shear adhesion (τ). The measurement is based on JIS K 6850, using a 25 × 150 mm test piece,
Make a slit so that the wrap dimension is 25 x 12.5 mm,
The test was performed at a pulling speed of 5 mm / min.

On the other hand, the adhesive strength between the surface layer of the laminated steel sheet and the adhesive was evaluated by T-type peel adhesion (TP). The test pieces were made by bonding two skin steel sheets of the same type of 200 × 300 mm laminated steel sheets to a thickness of 150 μm with a vinyl chloride-based hemming adhesive, and then held at 150 ° C. for 10 minutes. Produced. The measurement was performed in accordance with JIS K 6854 by cutting into a 25 × 150 mm test piece at a tensile speed of 50 mm / min.

<Vibration Suppression Property> The vibration suppression property of the laminated steel sheet is 25 × 220 mm
A 25 × 280 mm test piece was subjected to central vibration, and a loss coefficient at 1000 Hz was measured and evaluated by a half width method from a resonance response curve.

Tables 1 to 3 show the contents and test results of the test materials based on Example 1.

[0076]

[Table 1]

[0077]

[Table 2]

[0078]

[Table 3]

From Tables 1 and 2, the following can be said. Fe-Ni-
O-based range coating weight of the oxygen content is less than 0.5 or more 30 wt% at 10 or more 1500 mg / m ² or less of the film (hereinafter, coating conditions of the present invention 1
Inventive Example 1 satisfying the above) has a small friction coefficient,
Excellent press formability.

The amount of the Fe—Ni—O-based film deposited is 10 or more and 1500 mg / m
² or less, oxygen content 0.5 to less than 30 wt%, Fe / Fe in the film
+ Ni is in the range of 0.05 or more and less than 1.0 (hereinafter, the coating conditions of the present invention)
Inventive Example 2 satisfying the formula (2) has a small coefficient of friction,
Moreover, the adhesive strength (TP) with the adhesive and the adhesive strength with the polymer resin layer
(τ) is good, and excellent in press formability and adhesiveness.

Fe in Fe—Ni—O coating formed on skin steel sheet
Table 2 where the ratio Fe / Fe + Ni is below the range of the coating condition 2 of the present invention
In No. 46, the adhesive force (TP) with the adhesive and the adhesive force (τ) with the polymer resin layer were inferior to those of Invention Example 2 described above, and the adhesiveness was not improved.

No. 18 to No. 24 and Table 2 in Table 1 where no Fe—Ni—O coating was formed on the polymer resin layer side of the skin steel sheet
In Nos. 47 to 52, the adhesive force (τ) with the polymer resin layer was lower than that of Inventive Example 2, and the adhesiveness with the polymer resin layer was inferior.

Next, the following can be said from Table 3. Fe-Ni
No. 1 to No. 7 in Table 3 where no -O-based film was formed, regardless of the type of plating, all of the above-mentioned invention examples 1 and invention examples
The coefficient of friction is larger than that of
P), the adhesive strength (τ) to the polymer resin layer is low, and the press formability and adhesiveness are poor.

No. 8 to No. 10 in Table 3 in which the amount of the Fe—Ni—O-based film adhered was below the range of the film conditions 1 and 2 of the present invention.
, No.12, No.13, No.15 are all shown in Table 1,
Inventive Example 1 and Inventive Example 2 described in Table 2, the coefficient of friction is large, the adhesive force (τ) with the polymer resin layer, the adhesive force with the adhesive (TP) is low, press moldability, Poor adhesion.

No. 11 and N in Table 3 where the oxygen content of the Fe—Ni—O-based film was lower than the range of the film condition 1 and the film condition 2 of the present invention.
o.14 has a higher coefficient of friction and a lower adhesive force (TP) with the adhesive than the invention examples 1 and 2, and has press moldability,
Poor adhesion.

Further, from Tables 1 to 3, from the viewpoint of the vibration damping property,
The following can be said. The maximum value of the loss tangent (tan δ) based on the glass transition of the polymer resin is 0.3 or more, and the temperature at which this maximum value satisfies the range of -40 to 80 ° C (hereinafter referred to as the polymer resin condition of the present invention). Table showing the production of laminated steel sheets using rubber-modified acrylic ester (AC), a polymer resin
No. 1 of No. 1 and No. 29 of Table 2 in which laminated steel sheets are manufactured using acrylic acid-modified polypropylene (PP), all have a maximum value of loss coefficient (η) of 0.1 or more as a laminated steel sheet. ,
The temperature at which the maximum value is obtained is in the range of 0 to 120 ° C., and furthermore excellent vibration damping properties in addition to the above-mentioned press formability or press formability.

On the other hand, the laminated steel sheet No. 6 in Table 3 in which a laminated steel sheet is manufactured using acrylic acid-modified polyethylene (PE), which is a polymer resin out of the polymer resin conditions of the present invention,
The maximum value of the loss coefficient (η) of the laminated steel sheet is less than 0.1, and the vibration damping property is poor.

Example 2 The test conditions were the same as in Example 1, but the press formability was evaluated by adding the following test method.

As compared with Example 1, the amount and composition of the Fe—Ni—O-based film were changed to investigate the detailed effects of these, and the press formability was evaluated under more severe conditions. The effect of reducing the coefficient of friction under severe conditions, that is, the effect of improving press formability, was further clarified.

The test conditions were based on Example 1, but the press formability was evaluated by adding the following test method.

<Press Formability> In the friction coefficient measurement test described above, as shown in FIG.
A test using a bead (type B) having a flat surface of 0 mm and a length of 60 mm was added.

Tables 4 to 7 show the contents and test results of the test materials based on Example 2.

[0093]

[Table 4]

[0094]

[Table 5]

[0095]

[Table 6]

[0096]

[Table 7]

From Tables 4 to 7, the following can be said. Fe
With respect to the effect of the amount of the -Ni-O-based film attached, if it is within the range of the present invention, it can be seen that the amount of the film attached increases, the friction coefficient decreases, and the press formability improves.

Inventive Example 1 which satisfies Film condition 1 of the present invention
Are excellent in press formability. Inventive Example 2, which satisfies Film Condition 2 of the present invention, is excellent in press moldability and adhesiveness.

On the other hand, when the amount of the film adhered is less than
1, Comparative example No. 1001 to N of Table 4 below the range of coating condition 2
o.1003 has a high coefficient of friction and an adhesive force (T
P), the adhesive strength (τ) to the polymer resin layer is low, and the press formability and adhesiveness are poor.

Comparative Example No. 1018 of Table 5 in which Fe / Fe + Ni in the film was lower than the range of the film condition 1 and the film condition 2 of the present invention, the adhesive force (TP) to the adhesive and the polymer resin layer Has low adhesion (τ) and poor adhesion.

Comparative Example No. 1034 of Table 5 in which Fe / Fe + Ni in the film exceeds the range of the film conditions 1 and 2 of the present invention has a large coefficient of friction and poor press formability.

When the oxygen content in the film is less than the film condition 1 of the present invention.
No.1035, No.1036
Has a large coefficient of friction, a low adhesive force (TP) with an adhesive, and a low adhesive force (τ) with a polymer resin layer, and is inferior in press moldability and adhesiveness.

Further, Comparative Examples No. 1052 and No. 1061 in Table 7 having no formation of the Fe—Ni—O coating film had a large coefficient of friction, an adhesive force (TP) with an adhesive, and a high polymer resin layer. Has low adhesive strength (τ), and is inferior in press formability and adhesiveness.

[0104]

As described above, according to the present invention, a laminated steel sheet having corrosion resistance and excellent press formability or press formability and adhesion can be obtained. It is possible to achieve an improvement in the quality of a steel sheet member, and it is expected that the use of the steel sheet member will be expanded.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a friction coefficient measuring device.

FIG. 2 is a schematic diagram showing the shape and dimensions of a bead used for measuring a coefficient of friction.

FIG. 3 is a schematic diagram showing the shape and dimensions of another bead used for measuring the coefficient of friction.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 sample 2 sample table 3 slide table 4 roller 5 slide table support 6 bead 7 load cell for measuring pressing force 8 load cell for measuring sliding resistance 9 rail

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-75056 (JP, A) JP-A-5-177762 (JP, A) JP-A-63-74634 (JP, A) JP-A-1- 176098 (JP, A) Japanese Utility Model 63-192023 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 15/00-15/20

Claims (3)

(57) [Claims] 1. A laminated steel sheet having a polymer resin layer sandwiched between two upper and lower steel sheets, wherein at least one of the steel sheets has a zinc-based plating on the surface not in contact with the polymer resin layer. Layer and Fe-N formed on the zinc-based plating layer
has iO based film is in the range adhesion amount of total 10 or more 1500 mg / m ² or less in terms of metal of the Fe-Ni-O based film and the oxygen of the Fe-Ni-O based film Content 0.5 or more 3
Laminated steel sheet with excellent press formability within the range of less than 0 wt%. 2. A laminated steel sheet having a polymer resin layer sandwiched between two upper and lower steel sheets, wherein said one steel sheet has a zinc-based plating layer on both surfaces thereof and a zinc-based plating layer formed on the zinc-based plating layer. The other steel sheet has a zinc-based plating layer and a Fe-Ni-based layer formed on the zinc-based plating layer, at least on the surface in contact with the polymer resin layer. has a -O based film, the adhesion amount of Fe-Ni-O based film of the each is within the range of a total of 10 or more 1500 mg / m ² or less in terms of metal, of the Fe-Ni-O based film Oxygen content is more than 0.5 and 30wt%
Less than and in the Fe-Ni-O-based coating
A laminated steel sheet excellent in press formability and adhesiveness, wherein the ratio of the Fe content (wt%) to the sum of the content (wt%) and the Ni content (wt%) is in the range of 0.05 to less than 1.0. 3. The polymer resin has a maximum value of a loss tangent (tan δ) based on glass transition of 0.3 or more, a temperature at which this maximum value is in a range of -40 to 80 ° C., and a loss as a laminated steel sheet. The press formability and vibration damping property according to any one of claims 1 to 3, wherein the maximum value of the coefficient (η) is 0.1 or more, and the temperature at which the maximum value is in the range of 0 to 120 ° C. Excellent laminated steel sheet.