JPH1029266A - Resin covered metal plate excellent in press molding property and corrosion resistance and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve and stabilize press molding properties, corrosion resistance after working, coating film adherence and the like by a method wherein solid lubricants are fixed to the resin film covering the surface of a stock metal plate under the condition that the height of the solid lubricant, its specific area and its diameter and their number in the certain segment of a line are controlled. SOLUTION: Solid lubricants 3 are protrusively fixed to the surface of a resin film 2. The projecting height of the lubricant is set to be 0.01-1.5μm and its specific area in plane view is set to be 15-80%. Under the condition that the number of the solid lubricate 3 having its major axis D1 of 0.1μm or longer is NA and that having D1 satisfying 0.1μm<=D1 <=50μm is NB, NA and NB are controlled to satisfy 0.90<=(NB/NA)<=1.0. In addition, the number of the major axis D1 on an arbitrary line having the length of 200μm on the surface of the resin film 2 is controlled to be 1-100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-coated metal plate used as a material for automobiles, household electric appliances, building materials and the like, and a method for producing the same. By fixing the lubricant,
A resin-coated metal plate capable of exhibiting excellent effects in both press formability and corrosion resistance by satisfying predetermined requirements of a solid lubricant fixing form as required, and such a resin-coated metal plate. It relates to a useful method for manufacturing.

[0002]

2. Description of the Related Art Generally, surface treated steel sheets such as organic resin coated steel sheets are widely used as materials for automobiles, household electric appliances, building materials and the like. In most cases, this surface-treated steel sheet is used after being subjected to processing such as bending and press forming. Conventionally, press oil is applied and processed, followed by degreasing, and further, if necessary, phosphate. It has been pre-treated such as treatment and painted for use.

[0003] In recent years, however, the press oil application and degreasing steps have been omitted on the user side, thereby preventing the generation of chlorofluorocarbons and the generation of alkaline waste liquid during the scattering and degreasing of press oil, and the pretreatment. There is a need for pollution-free and labor-saving processes that enable painting without coating. Therefore, from the viewpoint of responding to such a situation, an organic resin-coated steel sheet which can be processed without press oil and can be coated without performing a pretreatment such as a phosphate treatment has been developed.

In order to enable processing without press oil, a lubricant such as a solid lubricant is mixed into a resin film of an organic resin-coated steel sheet so as to ensure lubricity required during press processing. ing. From the viewpoint of realizing better workability by reducing the friction coefficient of the surface, a spherical wax resin having an average particle size larger than the resin coating thickness is used as the solid lubricant. It has also been practiced to make the solid lubricant protrude from the surface of the resin film by being contained in the film to form irregularities on the surface.

As such a technique, for example, Japanese Patent Publication No. 5-8
No. 6916 discloses that a polyolefin wax having a resin adhesion amount of 0.3 to 3 g / m ² and an average particle size of 1 to 7 μm and a dry film thickness of the resin is larger than that of the resin 1.
A lubricated resin-treated steel sheet containing 20 parts by weight or less with respect to 00 parts by weight is disclosed.

In Japanese Patent Publication No. 6-59455, the coating amount is 0.2 to 4.0 g / m ² , the melting point of the coating is 120 ° C. or more, and the primary dispersion particle diameter is 20 μm.
Particle size containing 10% by weight or more of
0 μm of solid lubricant was added to 0.02
A lubricating thin-film resin steel sheet containing up to 0.4 parts by weight has been proposed.

[0007]

In the prior art, the adoption of the above-mentioned structure has provided a certain effect as far as lubricity is concerned. However, these techniques have the following problems.

That is, during continuous processing or transport, there is a problem that the solid lubricant present in the coating or protrudes or elutes due to sliding with a heated mold or press machine. . When such a situation occurs, recesses and defects are formed in the film, which significantly reduces the corrosion resistance of the product, and the desorbed particles accumulate in the mold, reattaching to the product and impairing the commercial value of the product. (Hereinafter, such a phenomenon is referred to as “black change”). In addition, the protrusion height of the solid lubricant and the occupied area ratio of the protrusion on the surface vary, and there is a problem that workability such as flaws and galling characteristics during deep drawing and performance such as coating film adhesion are not stable. .

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a resin-coated metal plate which can be press-formed without press oil and has good corrosion resistance of a product after the molding. It is an object of the present invention to provide a useful method for producing such a resin-coated metal sheet.

[0010]

Means for Solving the Problems The resin-coated metal plate of the present invention which can solve the above-mentioned problems is that a surface of a base metal plate is coated with a resin film and a solid lubricant is coated on the film. The point is that it is fixed.

In the above resin-coated metal plate, (1) the area ratio of the solid lubricant in plan view is 15 to 8;
It is preferable to satisfy requirements such as 0%, and (2) the protrusion height of the solid lubricant from the resin film surface is 0.01 to 1.5 μm.

In the resin-coated metal sheet of the present invention, the solid lubricant having a major axis D ₁ of 0.1 μm or more is N _A
Included number, when the number of the solid lubricant which satisfies these following formula (1) was N _B, these N _A and N _B
Satisfies the relationship of the following formula (2) and the following (1) on an arbitrary line having a length of 200 μm on the surface of the resin film.
When the number of solid lubricants satisfying the formula is 1 to 100, the effect of the present invention is maximized. _{0.1μm ≦ D 1 ≦ 50μm ... (} 1) 0.90 ≦ (N B / N A) ≦ 1.0 ... (2)

In producing the resin-coated metal plate of the present invention, a resin coating solution containing a solid lubricant is applied to the surface of the base metal plate, and then dried at a temperature higher than the softening point of the solid lubricant. The solid lubricant may be fixed to the surface of the resin film.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is constituted as described above. In short, it has been found that the above-mentioned object can be achieved satisfactorily if a solid lubricant is fixed to the surface of a resin film. The invention has been completed. The reason why the above-mentioned effects were obtained by the present invention could not be completely clarified, but could be considered as follows.

FIG. 1 is a diagram schematically showing a surface portion of a resin-coated metal plate of the present invention. In FIG. 1, 1 indicates a base metal plate, 2 indicates a resin film, and 3 indicates a solid lubricant. That is, as shown in FIG. 1, in the resin-coated metal plate of the present invention, since the solid lubricant 3 is present in a protruding state on the surface of the resin film, the solid lubricant 3 is formed between the resin film and the mold during continuous pressing. It is believed that it acts as a lubricant between them and improves press formability. Also, this solid lubricant suppresses scratches and the like due to impact and sliding between the resin-coated metal plate and the mold, so that the appearance of the product becomes beautiful and the resin film remains sound, so that the molded product It is considered that corrosion resistance is also improved.

With respect to such a resin-coated metal plate of the present invention,
In a conventional resin-coated steel sheet, as shown in FIG.
Since the solid lubricant 3 having a particle size larger than the thickness of the film is present therein, the solid lubricant 3 is peeled off by sliding with a mold during continuous pressing, and countless concave portions are formed in the film. However, it is considered that the corrosion resistance after molding is lowered, and the desorbed one is reattached to the mold to impair the appearance of the product. Alternatively, even when the particle size of the solid lubricant is smaller than the film thickness, the solid lubricant dissolves or squirts due to sliding with a heated mold during continuous pressing to generate a number of fine defects in the film. Therefore, it is considered that the corrosion resistance of the molded article is reduced.

Hereinafter, preferred requirements of the present invention will be described. In the present invention, as shown in FIG. 1, the solid lubricant 3 is projected and fixed to the surface of the resin film 2, and the solid lubricant observed by a scanning electron microscope (SEM) is removed from the surface of the resin film 2. Has a protrusion height of 0.01 to 1.
By satisfying the requirements of 5 μm, the area ratio of the solid lubricant in plan view of 15 to 80%, etc., the press moldability (including blackening) of the product is improved. In addition, the corrosion resistance of the molded product is dramatically improved.

In the present invention, the protrusion height of the solid lubricant is preferably at least 0.01 μm. If the protrusion height is less than 0.01 μm, the lubricating action on the surface is not sufficient, and the surface of the resin film is scratched, and the corrosion resistance of the scratched portion is reduced. On the other hand, if the protruding height of the solid lubricant exceeds 1.5 μm, the lubricant is scraped off due to sliding with the mold during press molding, and the blackening resistance is rather deteriorated. Gaps easily occur between the layers, and the adhesion of the coating film becomes unstable. A more preferable range of the protrusion height of the solid lubricant has a lower limit of 0.02 μm and an upper limit of 1.0 μm.

The area ratio of the solid lubricant in plan view is preferably 15 to 80%. This area ratio is 1
If it is less than 5%, the effect of improving workability such as scratch resistance at the time of press forming, particularly at the time of deep drawing is not sufficient, and 80%
If it exceeds 300, the adhesion of the coating film after coating is reduced. The preferred lower limit of this area ratio is 20%, and the preferred upper limit is 70%.
%, The effect of the present invention is maximized by setting the ratio in such a range.

Incidentally, the SEM observation in the present invention shows that the resin-coated metal
1 mg / m of gold (Au) on the surface of the plate ^Two ~ 1g / m^Two Evaporation
After that, the scanning microscope “S-2700” [trade name:
Using Hitachi, Ltd.] at an accelerating voltage of 15 kV.
EM observation.

On the other hand, the major axis D ₁ of the solid lubricant is 0.1 μm.
m or more. The major axis D ₁ is 0.1μ
If it is less than m, the lubricity and the scratch resistance are reduced, and the effect of improving the workability is not recognized, and the corrosion resistance of the flaw portion is reduced. Incidentally long diameter D ₁ is more preferably 0.3μm or more.

[0022] When the long diameter D ₁ is the number of individuals lubricant is 0.1μm and N _A, the number of individuals lubricant The diameter D ₁ is and 50μm or less at 0.1μm was N _B, the the number ratio of (N _B / N _a) is 0.90 or more 1.
The value is preferably 0 or less [formula (2)], and more preferably 0.95 or more. The above ratio is 0.9
If it is less than 0, the contact area between the coating film and the resin film decreases, and in some cases, a gap is generated, and the adhesion of the coating film becomes unstable.

Further, a length of 200 on the surface of the resin film
It is preferable that the number of solid lubricants satisfying the expression (1) on an arbitrary line of μm is 1 to 100. If the number is less than 1, the effect of improving the scratch resistance and the corrosion resistance of the molded product will not be sufficient. When the number exceeds 100, the contact area ratio between the coating film and the solid lubricant increases,
In some cases, a gap is formed between the film and the coating film, and the adhesion of the coating film is reduced.

Next, the manufacturing method of the present invention will be described. According to the method of the present invention, the solid lubricant is fixed to the surface of the resin film by applying a resin coating solution containing the solid lubricant and then drying the applied liquid at a temperature equal to or higher than the softening point of the solid lubricant. At this time, by drying the solid lubricant at a temperature equal to or higher than the softening point, the fluidized lubricant may have a specific gravity difference or a surface free energy difference between the solid lubricant and air and between the resin liquid (or resin film) and air. After drying, the solid lubricant adheres to the surface of the resin film as shown in FIG.

The type of the solid lubricant used in the present invention is not particularly limited, but typical examples thereof include polyolefin wax-based solid lubricants such as polyethylene and polyolefin, and fluororesins such as tetrafluoroethylene. Solid lubricants, carnauba wax and the like. Among them, it is most preferable to use a polyolefin wax-based solid lubricant. Specific examples of such solid lubricants include, for example, DIJET E-17 (trade name: manufactured by Ryo Kagaku Co., Ltd.), KUE-1, KUE-5, and KUE-8.
[All brand names: manufactured by Sanyo Chemical Industry Co., Ltd.], Chemipearl W-100, W-200, W-300, W-400,
W-500, W-640, W-700 (all trade names: manufactured by Mitsui Petrochemical Industries, Ltd.), Elepon E-20
[Product name: Nika Chemical Co., Ltd.], Dispalon SE21
0-15T, SE1020-7TN, SE478-
10T, SE470-10T, SE-480-10
T, SR510-10X, SE470-10X, SE
1020-7X [All trade names: manufactured by Kusumoto Kasei Co., Ltd.]
And other commercially available products can be used.

Next, the present invention relates to the resin-coated metal plate of the present invention.
A base metal plate (and a plating method), a chemical conversion treatment method, a resin film, a coating method, and the like will be described. However, the present invention is not limited thereto, and any material that satisfies the requirements of the present invention can be used.

First, the base metal sheet (base sheet to be treated) used in the present invention includes cold-pressed steel sheets, galvanized steel sheets, aluminum-plated steel sheets, Zn-Al alloy-plated steel sheets, Zn-Ni alloy-plated steel sheets, stainless steel sheets, aluminum sheets and the like. Can be mentioned. Examples of the plating method include an electroplating method, a hot-dip plating method, and a vapor deposition plating method.

For example, a resin-coated steel sheet is generally subjected to a chemical conversion treatment between the above-mentioned original plate and the resin film. Examples of the chemical conversion treatment include a phosphate treatment and a chromate treatment. As a form of the chromate treatment method, any of a reaction type, a coating type and an electrolytic type can be adopted.

As the resin used as the resin film,
Epoxy-based, urethane-based, acrylic-based, polyester-based, polyethylene-based, and melamine-based resins can be mentioned, and it is recommended to add the above-mentioned solid lubricant to a liquid (resin coating liquid) of these resins. . Further, these resins may be mixed with a melamine-based, epoxy-based, isocyanate-based, aziridine-based, or carbodiimide-based cross-linking agent to cross-link the resins. Furthermore, in the resin coating solution, the workability, corrosion resistance,
As long as the coating adhesion is not impaired, the above resin, solid lubricant and crosslinking agent, colloidal compound, pigment, diluting solvent, surfactant, defoamer, penetrant, thickener, thickener,
Various additives such as bones may be added.

The resin-coated metal plate of the present invention can be produced by applying the above-mentioned resin coating solution to the surface of an original plate by an optional method and drying it. The coating is not limited, and for example, it can be applied to the surface of a zinc-based plated steel sheet whose surface has been cleaned or subjected to chromate treatment by employing a roll coater method, a spray method, a curtain flow coater method, or the like. Considering the treatment of uniformity of the film thickness, the treatment cost, the coating efficiency and the like comprehensively, the most practically preferable method is a method of coating with a roll coater. The resin-coated metal plate of the present invention includes a metal plate having a resin film formed on only one side or both sides.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following Examples do not limit the present invention, and any design changes in the spirit of the present invention will be described. It is included in the range.

[0032]

EXAMPLES Various test materials were prepared by the following procedure. First, an electrogalvanized steel sheet (thickness: 0.8 m) was used as an original sheet on which the resin film forming composition (resin coating liquid) was applied.
m, a plating amount: 20 g / m ² ) and subjected to a chromate treatment (Cr adhesion amount: 20 mg / m ² ). On the other hand, as the resin coating solution, a urethane resin having a shear D hardness of 51 [“Superflex” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.] was added to spherical polyethylene wax particles (softening point:
110 to 140 ° C.) and colloidal silica [“Snowtex O” manufactured by Nissan Chemical Industries, Ltd.] were used.

The above resin coating solution is applied to an original plate and
After squeezing with a tool, the plate temperature reaches 80-180 ° C
Baking under the conditions, the amount of resin film attached is 0.5-2.0g
/ M ^Two The test material was manufactured as follows. At this time, the resin film
The amount of adhesion of the
So adjusted. The form of the solid lubricant shown in Table 1 below
(The ratio of the height of the solid lubricant, the coverage, and the numerical value of the solid lubricant N
_B / N_A , Solid lubricant separated by 200μm line segment
Number), the particle size of the wax to be added,
Control by changing the amount and baking temperature
Was. For the obtained resin-coated metal plate, the following items
The performance was evaluated. The results are summarized in Table 1 below.
Shown. The evaluation method for each item of performance is as follows.
You.

[Evaluation of Performance] Surface Observation Gold (Au) was applied on the surface of the test material in an amount of 1 mg / m ² to 1 g / m.
^{2 After} vapor deposition, using a scanning microscope "S-2700" (trade name: manufactured by Hitachi, Ltd.), acceleration voltage: 15 kV
Was observed by SEM. Measurement of Dynamic Friction Coefficient Sliding was performed at a pressing force of 150 kg using a sliding test apparatus, and the dynamic friction coefficient was determined from the tensile load.

Evaluation of Press Formability Using a single-shot press tester, the test material was subjected to cylindrical deep drawing, and the sliding surface of the molded product was evaluated for flaws and blackening. The evaluation criteria are as follows. (Evaluation criteria for flaws) A: No galling or flaw is recognized. ：: Galling and flaws are hardly recognized. Δ: Slight galling and flaws are observed. ×: Clear galling and flaws are observed. (Evaluation criteria for black change) ：: Black change is not recognized. ：: Black change is hardly observed. Δ: slight black change is observed. X: A clear black change is recognized.

Evaluation of Corrosion Resistance After Forming The test material was cylindrically deep-drawn using a single-shot press tester, and the molded product was subjected to a salt spray test according to the method described in JISZ2371 to investigate corrosion resistance. The measurement results show the time of 1% white rust generation on the sliding surface.

Evaluation of Coating Adhesion A melamine alkyd-based coating “Amirac 1000” (trade name, manufactured by Kansai Paint Co., Ltd.) was applied and the coating was applied at 130 ° C. for 2 hours.
Baking for 0 minutes, the coating thickness: 20 μm. Next, a 1 mm ² grid was cut on the painted surface using a cutter knife.
Draw 00 cells, extrude 6mm with Erichsen tester,
A tape peel test was performed. The evaluation criteria are as follows. (Evaluation criteria for coating film adhesion) A: No peeling of the coating film was observed. ：: Some peeling of the coating film was observed. Δ: Clear peeling of the coating film is observed. ×: Peeling of the coating film was observed before the tape was peeled.

[0038]

[Table 1]

From these results, the following can be considered.
First, the test material No. 1 to 12 are examples satisfying the requirements defined in the present invention, and it can be seen that good results are obtained in any of the press moldability, the corrosion resistance after molding, and the coating film adhesion. On the other hand, the test material No. 1
Samples Nos. 3 to 21 are comparative examples lacking any of the requirements specified in the present invention, and are inferior in any of the performances as shown below.

First, the test material No. In No. 13, the height of the solid lubricant is less than the lower limit specified in the present invention, and press formability and corrosion resistance after forming are reduced. The test material No. In the case of No. 14, the height of the solid lubricant exceeds the upper limit specified in the present invention, and the press formability and black change resistance are reduced. Further, the test material No. having an area ratio of the solid lubricant less than the lower limit specified in the present invention. In the case of No. 15, the press formability and the corrosion resistance after forming were reduced, and the test material N having an area ratio exceeding the upper limit specified in the present invention was used.
o. In the case of No. 16, the blackening resistance and the coating film adhesion were reduced.

The test material No. In the case of _No. 17, the long diameter D1 of the solid lubricant is less than the lower limit specified in the present invention, and the press formability and the corrosion resistance after forming are deteriorated. The test material No. In the case of No. 18, the ratio N _B / N _A is less than the lower limit specified in the present invention, and the coating film adhesion is deteriorated. In addition, when the number of the solid lubricants separated by the 200 μm line segment included in the surface was less than the lower limit specified in the present invention, the sample No. In the case of Sample No. 19, the press formability and the corrosion resistance after forming were reduced, and the number of the test materials No. 19 exceeded the upper limit specified in the present invention. In the case of No. 20, the coating film adhesion was reduced. Further, the test material No. 1 was dried below the softening point of the solid lubricant to form a resin film. In the case of No. 21, the blackening resistance, the corrosion resistance after molding, and the coating film adhesion were reduced.

[0042]

The resin-coated metal plate of the present invention has a solid lubricant fixed on a resin film, and further has a height, area ratio, diameter, and constant line segment of the solid lubricant on the resin film. By appropriately controlling the number of partitions, a resin-coated metal plate having improved and stabilized press formability (including black change resistance), corrosion resistance after processing, coating film adhesion, and the like was realized. As a result, the oiling and degreasing work during press molding and the pretreatment for painting (phosphate treatment) can be omitted, and the working environment is improved, and the productivity and cost can be reduced by saving steps. Is obtained. Further, the resin-coated metal sheet of the present invention is excellent in corrosion resistance after molding, so that it can be used in a wide range of applications, for example, a product can be used without painting.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a state of a solid lubricant present in a resin-coated metal plate of the present invention.

FIG. 2 is a schematic diagram showing a state of a solid lubricant present in a conventional resin-coated metal plate.

[Explanation of symbols]

 1 Base metal plate 2 Resin film 3 Solid lubricant

Claims (5)

[Claims] 1. A resin-coated metal plate excellent in press formability and corrosion resistance, wherein a surface of a base metal plate is coated with a resin film and a solid lubricant is fixed on the film. . 2. The resin-coated metal sheet according to claim 1, wherein an area ratio of the solid lubricant in a plan view is 15 to 80%. 3. The protruding height of the solid lubricant from the resin film surface is 0.01 to 1.5 μm.
The resin-coated metal plate according to the above. Wherein is a solid lubricant diameter D ₁ is 0.1μm or more is included N _A number, when the number of the solid lubricant which satisfies these following formula (1) was N _B, these N _A
And N _B satisfies the following relationship (2), and the number of the solid lubricant that satisfies the following formula (1) in an arbitrary line length 200μm on the resin film surface 1-100
The resin-coated metal sheet according to any one of claims 1 to 3, wherein the number is one. _{0.1μm ≦ D 1 ≦ 50μm ... (} 1) 0.90 ≦ (N B / N A) ≦ 1.0 ... (2) 5. A resin coating solution containing a solid lubricant is applied to the surface of a base metal plate, and then dried at a temperature equal to or higher than the softening point of the solid lubricant, so that the solid lubricant is applied to the surface of the resin film. A method for producing a resin-coated metal sheet excellent in press formability and corrosion resistance, comprising fixing the resin-coated metal sheet according to claim 1.