JPH1029267A - Lubricating resin covered metal plate excellent in deep-drawability and coating film adherence - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain excellent deep-drawability and coating film adherence by a method wherein the diameter of each, the projecting height of each the number, the projecting specific area and the like of the projections to be formed by solid lubricant particles in a resin covering are set to the specified values. SOLUTION: For the solid lubricant particles included in a lubricating resin covering, NB/NA>=0.95 is satisfied, in which NA is the number of projections satisfying D70 /D0 >=0.35 and NB is the number of projections satisfying 0.85>=D70 /D0 >=0.35, where D0 is the diameter of the figure projected to arbitrary direction A-A0 -A' of an arbitrary projection formed on the surface of the covering and D70 is the diameter of the figure projected to the direction D-D', which is obtained by rotating the perpendicular A0 -A1 drawn through the point A0 to the line A-A' by 70 deg.. The total sum ΣS of the projected areas of the projections to the whole projected area A is set to satisfy 0.08<ΣS/A<=0.4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating resin-coated metal sheet which is useful as a plate material for automobiles and home electric appliances, a building material, and the like, and which is excellent in deep drawing workability and coating film adhesion. In the following description, the description will be made mainly of the most versatile steel plate as the metal plate to be coated with the resin, but the present invention is not limited to the steel plate as a matter of course, and the same applies to all other metal plates. Can be applied to

[0002]

2. Description of the Related Art Surface-treated metal sheets such as resin-coated steel sheets are widely used in the fields of automobiles, household electric appliances and construction in order to improve aesthetics and corrosion resistance. In addition, most of these resin-coated steel sheets are used after being subjected to forming processing such as bending or press forming in use, and conventionally, degreasing is performed after applying press oil and performing processing, Further, if necessary, a pre-coating treatment is performed, and then a finish coating is performed.

However, in recent years, users have
Paint can be applied without pre-treatment such as press oil application or degreasing to save labor and reduce pollution by avoiding scattering of oil during press working and generation of chlorofluorocarbon and alkaline degreasing waste liquid used in the degreasing process. There is a demand for such a steel sheet, and research and commercialization of a lubricating resin-coated steel sheet capable of responding to such a demand have been promoted. Furthermore, in addition to the omission of the above steps, a surface-treated metal sheet typified by a pre-coated steel sheet, which can be omitted up to the pretreatment and painting steps, has also been developed.

[0004] As a means for enabling bending or pressing without using a processing oil, a method of improving the slip of the surface to be processed by including solid lubricant particles such as wax in a coating resin of a resin-coated steel plate. In order to achieve better workability by further reducing the coefficient of friction of the surface to be processed,
A method has been proposed in which substantially spherical solid lubricant particles having an average particle diameter larger than the film thickness of the resin coating are used, and the particles are projected on the coating surface to form irregularities on the surface.

For example, Japanese Patent Publication No. 5-86916 discloses that a resin coating having a resin adhesion amount of 0.3 to 3 g / m ² has an average particle diameter of 1 to 7 μm and a diameter larger than the dry film thickness of the resin. A lubricating resin-coated steel sheet having improved workability by containing 20 parts by weight or less of the polyolefin-based wax particles with respect to 100 parts by weight of the resin is disclosed.

In Japanese Patent Publication No. 6-59455, the coating amount is 0.2 to 4.0 g / m ² , and the coating has a melting point of 120 ° C. or more and a primary dispersed particle diameter of 20 μm or more. Lubricant is contained in an amount of 10% by weight or more, and the particle size is 3 to 10.
0 μm of a crystalline solid lubricant is added to 0.1 part by weight of the resin.
There is disclosed a lubricating thin film resin-coated steel sheet having improved workability by containing from 02 to 0.4 parts by weight.

However, in these lubricating resin-coated steel sheets, the height of projection of the solid lubricant particles contained in the coating to improve the workability on the resin coating surface and the occupied area ratio of the projection are unstable. When deep drawing is performed, defects such as scratches and galling may occur, and stable workability may not be obtained. In addition, when the coated steel sheet is continuously processed, a phenomenon that the surface of the processed product is discolored black (hereinafter, referred to as “black discoloration”) and the appearance is significantly deteriorated is also experienced. One of the causes of such blackening is that the solid lubricant particles protruding from the coating surface are separated from the coating by the sliding with the mold processing surface and fall off, and this is gradually accumulated on the mold processing surface. It is conceivable that the accumulated particles adhere to the surface of the resin-coated steel sheet which is subsequently processed. Further, when the coating is performed as the final finish, sometimes a problem arises that the adhesion between the coating film and the coating deteriorates.

[0008]

Therefore, in order to effectively and stably exhibit the properties of a lubricating resin-coated metal plate having improved lubricity by incorporating solid lubricant particles in a resin coating, for example, a solid lubricant is required. Quantifies the protrusion of protrusions formed on the resin coating surface by the lubricant particles and contributing to the improvement of lubricity, and exhibits stable workability without blackening and other obstacles caused by falling off from the coating, and processing It is desired to develop a lubricating resin-coated metal plate that does not impair the later finish coating properties.

The present invention has been made in view of such circumstances, and it is an object of the present invention to prevent blackening or the like even when deep drawing is continuously performed, and to provide a coating after processing. An object of the present invention is to provide a lubricating resin-coated metal plate capable of stably exhibiting excellent deep drawing workability without impairing the lubricity.

[0010]

The lubricating resin-coated metal plate excellent in deep drawing workability and coating film adhesion according to the present invention, which can solve the above-mentioned problems, is a lubricated metal plate having projections formed on the surface. Direction (A-A ₀ -A ′ direction) in a projected figure appearing in the field of view of a scanning electron microscope when an arbitrary projection is observed from a direction perpendicular to the surface of the coated metal plate, : Where A ₀ is the diameter of the center point of the projected figure (D ₀ ), and the perpendicular line A ₀ -A drawn from the above A ₀ point
₁ and a plane P including a virtual line drawn in the AA ₀ -A ′ direction.
In the direction (A) in which the perpendicular A ₀ -A ₁ is rotated by 70 °
₀ -A ₂ diameter D in a direction of being cut from a direction) to a scanning electron microscopic field when observing the same projection and said by the plane P of the appearing projected figure (D-D 'direction) ₇₀
And the number of projections satisfying the relationship of the following equation (1) is N
_A, when _{D 70 / D 0 ≧ 0.35 ...} (1) the formula (1) and the following equation, the number of protrusions satisfy both relationships (2) and the _{N B, 0.85 ≧ D 70 /} D ₀ ≧ 0.35 (2) The above N _A and N _B satisfy the relationship of the following expression (3), and N _B / N _A ≧ 0.95 (3) and perpendicular to the surface of the coated metal plate. Direction (A ₁ -A
₍₀ direction) observed by a scanning electron microscope and the sum ΣS of the areas appearing in the projected figure of the projection satisfying the relationship of the above equation (2) is expressed by the following formula with respect to the total surface area A of the projected figure observed by the same method. The point is to satisfy the relationship of Expression (4). 0.08 <ΣS / A ≦ 0.4 (4)

In the above configuration of the present invention, among the projections satisfying the relationship of the above equation (2), the diameter D ₀ is equal to 0.
0.1 the number of protrusions is 1μm or more N _C, the diameter D ₀
When the number of projections is 20μm was N _D, N _D and N
The ratio of _C satisfies the relationship of the following formula (5), and N _D / N _C ≧ 0.95 (5) Further, the ratio of _C is cut by an arbitrary straight line having a length of 300 μm on the surface of the coated metal plate, and the formula (2) ) And the number of protrusions having the diameter D ₀ of 0.1 to 20 μm and ₁ to 300 exhibits more stable performance in deep drawing workability and coating film adhesion.

The above-mentioned projections may be formed by any method, but the most common one is
Formed due to solid lubricant particles mixed as a lubricity improving component in the resin coating, and the particles directly protrude from the coating surface, or protrude when the surface is thinly covered with resin. Is included.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present inventors have conducted various studies aiming at solving the problems pointed out in the prior art as described above. First, even if the particle size of the solid lubricant particles contained in the lubricating resin coating is increased to increase the degree of protrusion of the projections formed on the coating surface, or even if the content is increased, it is not always satisfactory. We experienced that deep drawing workability, such as poor scratching and mold galling characteristics, was not always improved. Also, even if the average particle diameter of the solid lubricant particles is reduced to be smaller than the coating thickness, the solid lubricant particles alone do not necessarily prevent the solid lubricant particles from falling off from the surface of the coating during processing. It was confirmed that blackening sometimes occurred.

Based on these findings, in order to improve the deep drawing processability including blackening resistance and the coating film adhesion, it is only necessary to adjust the particle size and film thickness of the solid lubricant particles contained in the lubricating coating. Rather, it is thought that the projection state, number of projections, and area ratio of projections on the lubricating coating surface (for example, projections caused by solid lubricant particles) may have a large effect, and research is conducted along that line. As a result, the present invention has been made.

That is, the object of the present invention is as follows. First of any protrusions formed on the coating surface due to solid lubricant particles contained in the lubricating resin coating,
The ratio of the diameter in an arbitrary direction observed from a direction perpendicular to the coating surface to the diameter observed in an oblique direction (a direction at 70 ° to the vertical direction) defines the number of projections falling within a certain range. Then, the occupied area ratio of the projections within the predetermined range to the entire surface of the coating is defined. Further, among the projections whose diameter ratios are within a certain range, the number of projections whose diameter observed from a direction perpendicular to the coating surface is within a certain range is controlled, and any constant of the coating surface is controlled. By controlling the number of protrusions cut by a straight line of length, by defining these requirements, it has excellent deep drawing workability without causing scratches and mold galling etc. and excellent coating adhesion By preventing the solid lubricant particles from falling off the coating during deep drawing, the problem of black discoloration occurring during processing is reduced, and a lubricating resin-coated metal sheet of excellent quality (hereinafter, referred to as (Represented by a steel plate).

In the following, in the present invention, the reason for defining the projection state and the number of projections formed from the resin-coated surface, for example, due to the solid lubricating particles, and further, the projection area ratio, etc. will be described in detail.

First, in a lubricating resin-coated steel sheet having projections formed on the resin-coated surface due to solid lubricant particles contained in the resin coating, for example, as shown in FIG. Scanning electron microscope (hereinafter, referred to as
SEM), an arbitrary direction (A-A ₀ -A ′) in a projected figure (projected figure 1) of an arbitrary projection observed by
Direction: However, the diameter of A ₀ is the center point of the projected figure 1) is D _0, and the perpendicular A ₀ -A ₁ drawn from the above A ₀ point and the above A
In the plane P including the imaginary line drawn in the -A ₀ -A 'direction, the same projections as above were observed from the direction (A ₀ -A ₂ direction) in which the perpendicular A ₀ -A ₁ was rotated by 70 °. The diameter in the direction (DD ′ direction) cut by the plane P in the projected figure 2 appearing in the field of view of the scanning electron microscope at this time is D ₇₀ ,
The number of protrusions whose ratio of ₇₀ to D ₀ (D ₇₀ / D ₀ ) satisfies the relationship of the above formula (1) is N _A , and the number of protrusions that simultaneously satisfies the relationship of the above formula (1) and the above formula (2) is Assuming that the number is N _B , that N _A and N _B satisfy the relationship of the above formula (3).
This is one of the essential requirements for achieving the object of the present invention.
The specific reasons for defining these requirements will be clarified later.

In addition to the above requirements, for example, as shown in FIG. 2, as in the case of the projection FIG. 1, observation is made by a scanning electron microscope from a direction perpendicular to the surface of the coated metal plate, and the relationship of the above equation (2) is satisfied. The sum わ れ る S of the areas S ₁ , S ₂ , S ₃ ... Appearing in the projected figure 1 of the projection that satisfies the relationship of the above equation (4) with respect to the total surface area A of the projected figure 1 observed by the same method. That is, satisfying the requirement of “0.08 <ΣS / A ≦ 0.4” is also an essential requirement.

Next, according to claim 2, the relation of the expression (2) is satisfied.
Of the projections satisfying the diameter D₀Is 0.1 μm or more
The number of certain protrusions is N_C , Diameter D₀ Is 0.1 to 20 μm
N_D And N_D And N_C Before
The relation of the expression (5), that is, “N _D / N_C ≧ 0.95 ”
Satisfies the requirements and has a length of 300μ on the coated steel sheet surface
m and cut by any straight line of m
And the diameter D₀Of protrusions having a diameter of 0.1 to 20 μm
A resin coating with a number of 1 to 300 is formed
Shows good coating adhesion in addition to excellent deep drawing processability
It becomes something.

The SE is determined by changing the angle, which is defined by the above equation (2).
The ratio D ₇₀ / D ₀ of the diameter of the projected figure of the projection observed by M
If the ratio is less than 0.35, the effect of improving the deep drawability such as flaws and mold galling characteristics provided by the projections is not sufficiently exhibited, and if the ratio exceeds 0.85, the projections are excessively removed from the coating surface. This is because the solid lubricant particles are liable to peel and fall off due to the sliding force received during processing, and the blackening resistance is deteriorated. However, if the ratio D ₇₀ / D ₀ falls within the range of 0.35 to 0.85, more preferably 0.45 to 0.75,
It has excellent workability and blackening resistance.

When the ratio of N _B / N _A is less than 0.95, the number of protrusions excessively protruding from the coating surface becomes relatively large. Due to the movement, the solid lubricant particles are remarkably peeled and dropped, and the problem of blackening is liable to occur particularly when continuous processing is performed. For these reasons, in the present invention, the above formula (3)
In the ratio of N _B / N _A so as to define 0.95 or more, and more preferably should be less than 0.98.

In the present invention, the ratio of D ₇₀ / D ₀ and N
_The reason why the black discoloration can be reduced and the workability such as scratch resistance and mold galling characteristics can be improved by defining the _B / N _A ratio as described above is considered as follows.

That is, as shown in FIG. 3, assuming that the protrusions on the resin-coated surface are formed by spherical solid lubricant particles embedded in the resin coating and a part of which protrudes from the surface, When the radius r and the protruding height h from the coating surface are obtained from the diameters D ₀ and D ₇₀ , they are as shown in the following equations (6) to (9).

[0024] _{r = {D 70 - (D} 0/2) × sin20 ° -cos20 ° × (D 70 2 -D 0 × D 70 × sin20 °) 1/2} / sin 2 20 ° ... (6) h = {2 × D ₇₀ -D ₀ × sin 20 ° + 2 × (D ₇₀ ² -D ₀ × D ₇₀ × sin 20 °) ^1/2 } / {2 × (1 + cos20 °)}… (7) _{, sin20 ° <D 70 / D} 0 ≦ (1 + sin20 °) / 2) r = D 0/2 ............ (8) h = D 70 × cos20 ° + (D 0/2) × (1- _{cos20 °) - (D 0 ×} D 70 -D 70 2) 1/2 × sin20 ° ... (9) ( where, (1 + sin20 °) from these _{/ 2 <D 70 / D 0} <1), spherical particles H / r which is a measure of the protrusion of is expressed by the following equations (10) and (11), and h / r and D ₇₀ / D ₀
Is as shown in FIG. h / r = 1-1 / cos20 ° + (1 / cos20 °) × sin ² 20 ° × (2 × D ₇₀ / D ₀ -sin 20 °) / [2 × D ₇₀ / D ₀ -sin 20 ° -2 × cos20 ° × {(D ₇₀ / D ₀ ) ^2- (D ₇₀ / D ₀ ) × sin 20 °} ^1/2 ]… (10) (However, sin 20 ° <D ₇₀ / D ₀ ≤ (1 + sin 20 °) / 2) h / r = 1- cos20 ° + (2 × D ₇₀ / D ₀ ) × cos20 °-2 × {D ₇₀ / D _0- (D ₇₀ / D ₀ ) ² } ^1/2 × sin20 °… (11) (However, (1 + sin20 °) / 2 <D ₇₀ / D ₀ <1) As is apparent from FIG. 4, when D ₇₀ / D ₀ is less than 0.35, the protrusion height with respect to the spherical particles is small. It is considered that the workability, such as flaws and mold galling characteristics, becomes insufficient due to the insufficient hardness.

To further supplement, as shown in FIG. 5, when the occupation area ratio (d / l) of the projections on the coating surface is the same, even if the projection height (h = h ₁ ) is the same, small spherical particles [ In the case of a spherical particle [FIG. 5 (a): D = D ₁ ] larger than that of FIG. 5 (b): D = D ₂ ], the probability that the mold cannot be received by the projection due to the protrusion of the particle. It is considered that the height of the protrusion must be increased [FIG. 5C: h = h ₂ ].

On the other hand, when D ₇₀ / D ₀ exceeds 0.85,
Since the contact area between the spherical particles and the resin coating is too small, the particles are easily peeled off by sliding during processing. Therefore, in order to prevent blackening during processing due to peeling of particles and their deposition, the ratio of the number of protrusions of 0.85 or less to the total number of protrusions with D ₇₀ / D ₀ of 0.35 or more is set to 0. It is 95 or more (the upper limit is naturally 1.0), and it is necessary to suppress the separation of particles during processing.

The sum を 満 た す S and the total surface area A of the area S of the projected figure 1 of the projection in FIG.
If the ratio (ΔS / A) is too small, the amount of protrusions projecting to the coating surface itself becomes insufficient, and the effect of improving the deep drawability such as flaws and mold galling characteristics cannot be exhibited effectively. , The lower limit of which must be greater than 0.08. However, if the ΔS / A ratio is too large, the effective area of adhesion between the resin coating and the coating film exposed on the coating surface is reduced, and the adhesion with the coating film is reduced. There is a gap between the film and the film, and when immersed in boiling water, water may enter the space and cause peeling of the film. Requires that the ΔS / A ratio be 0.4 or less.

FIG. 1 shows the projections satisfying the relationship of the above equation (2).
Diameter D ₀ in the projected figure 1 in at least 0.1 [mu] m or more, more preferably should be above 0.3 [mu] m, than of less than 0.1 [mu] m, the absolute projecting height of protrusions protruding from the coated surface Insufficient scratch resistance and mold galling characteristics as intended in the present invention cannot be obtained. Further, the number of projections in the projected figure 1 whose diameter D ₀ is 0.1 μm or more is defined as N _C ,
Them when the number of protrusions in the range of 0.1~20μm was N _D, the ratio of their number (N _D / N _C) is coating adhesion to ensure the adhesion effective area of the resin to be exposed to the coated surface It is an important requirement to increase the value, and it is recommended that the ratio be at least 0.95 or more, more preferably 0.98 or more. When the ratio is less than 0.95, satisfactory coating film adhesion is obtained for the same reason as described above. Can not be obtained.

On the coating surface, the number of projections cut by an arbitrary straight line having a length of 300 μm and satisfying the relationship of the above formula (2) and having the diameter D ₀ of 0.1 to 20 μm is 1 to 300 μm. Is preferably in the range of
If the number is less than 1, the effect of improving the scratch resistance and mold galling property by the projections is not exhibited, and if the number is more than 300, the exposed area of the resin on the coating surface decreases (that is, the adhesion area between the coating film and the coating decreases). Reduction), and in some cases, gaps are generated, and satisfactory coating film adhesion cannot be obtained.

As is clear from the above description, the solid particles to be mixed into the resin coating in order to effectively exhibit the features of the present invention should be those having lubricity itself. Thus, solid particles having lubricating properties are mixed with the coating resin and a part thereof is projected on the coating surface, or the projections caused by the particles are thinly covered with the resin. This is because the coefficient of friction of the coating can be effectively reduced by forming on the coating surface and removing the thin resin on the surface of the particles during processing so that the particles are exposed to the surface. .

The solid lubricating particles are preferably dispersed in the coating in a substantially spherical state in order to form the above-mentioned projections uniformly on the coating surface. However, in some cases, coating is performed by baking the resin coating on the surface of the metal plate at a temperature equal to or higher than the softening point of the solid lubricant to soften the solid lubricant particles and forming the coating with improved dispersibility in the resin. It is also possible to secure the adhesion between the solid lubricant and the solid lubricant and to form the projections satisfying the above-mentioned requirements by floating the solid lubricant particles in a hill shape on the surface side.

Preferred specific examples of the solid lubricant dispersed in the resin coating include polyolefin wax such as polyethylene and polypropylene, and fluororesin wax such as ethylene tetrafluoride. The most preferable is polyethylene wax in consideration of the total cost and cost. Commercial products of such solid lubricants include, for example, "Dijet E-
17 ”,“ KUE-1 ”,“ KUE ”manufactured by Sanyo Chemical Industries, Ltd.
-5 "," KUE-8 "and the like," Kemipearl W-100, 200, 300, 400, 5 "manufactured by Mitsui Petrochemical Industries, Ltd.
00, 640, 700 "and" ELEPON E-20 "manufactured by Nichika Chemical Co., Ltd.

As other solid lubricants, for example, molybdenum disulfide, graphite, metallic soap, boron nitride,
By using melamine cyanuric acid or the like, or oxide particles such as silica, etc., mixing them into the resin, and further engraving the organic resin coating itself with a roll during the baking process, etc. Protrusion of the resulting protrusions on the coating surface is also effective from the viewpoint of improving the deep drawing workability such as scratch resistance and galling characteristics when compared with the organic resin coating as it is.

The type of the resin serving as the vehicle component of the lubricating resin coating is not particularly limited.
Epoxy-based, urethane-based, acrylic-based, polyester-based, and polyolefin-based resins are exemplified.If necessary, a melamine-based, epoxy-based, isocyanate-based, or aziridine-based crosslinking agent is used in combination to increase the coating strength, Further, it is of course possible to add colloidal compounds such as silica and alumina; chromium-based and lead-based rust preventive pigments; and coloring pigments such as titanium oxide and red iron oxide.

A mixture containing the above-described solid lubricant and a resin or other additives is dissolved or dispersed in water or a solvent to form an emulsion, which is applied to the surface of the metal plate to be treated by any method. The lubricating resin coating is formed by drying and, if necessary, baking. The preferred amount of the coating is not particularly limited, but is preferably in the range of 0.1 to 3 g / m ² in order to effectively and economically exert the above-mentioned effects as a lubricating coating. In addition to the structure, if necessary, a multi-layer structure such as a two-layer structure of undercoat-overcoat or a three-layer structure of undercoat-intermediate-overcoat is also possible.

In forming a lubricating resin coating using the coating liquid containing the resin and the solid lubricant particles as described above, the requirements for the appropriate height, total area, and number of the resin coating surface as described above are required. The protrusions to be filled can be obtained by properly adjusting the particle size of the solid lubricant particles to be used, the content in the coating, the coating thickness, and the like. Preferred conditions therefor are as follows.

It is preferable to use solid lubricant particles having an average particle size of 0.1 to 15 μm, more preferably 0.5 to 7 μm, and further preferably a small particle size distribution. As the solid lubricant particles, those having an average particle size of about 0.5 to 3 times the coating thickness of the resin coating are selected and used, and projections caused by the solid lubricant particles are formed on the resin coating surface at an appropriate height. To be formed. Select and use solid lubricant particles having a specific gravity equal to or slightly smaller than the average specific gravity in the state of the coating liquid, and promote the formation of projections by floating the solid lubricant particles on the surface side during coating formation. In connection with the above, when evaporating water or a solvent by baking, if the baking time is insufficient or excessive, the floating of the particles will be insufficient, or the specific gravity of the liquid will increase and the particles will eventually increase. It is preferable that the baking time be controlled in an appropriate range by controlling the air volume of the dryer or the like, since the baking time will be excessively raised. Since the solid lubricant may agglomerate, when mixing the particles into the resin liquid, it is preferable to remove large solids and uniformly disperse the solid lubricant in the resin liquid. In the case of a multi-layer coating, only the coating constituting the uppermost layer may contain a proper amount of solid lubricant particles.

The type of the metal sheet to be treated on which the above-mentioned lubricating resin coating is formed is not particularly limited. Examples include non-ferrous metal plates such as alloy-plated steel plates such as Zn-Ni and Zn-Fe, stainless steel plates, and aluminum plates, and surface-treated metal plates obtained by subjecting these to various chemical conversion treatments. Examples of the plating method include, but are not limited to, electroplating, hot-dip plating, and vapor deposition plating, and examples of the chemical conversion treatment include, but are not limited to, reactive, coating, and electrolytic chromate treatments and phosphate treatments.

[0039]

EXAMPLES Next, the structure and operation and effect of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples, but conforms to the spirit of the preceding and following examples. Of course, the present invention can be implemented with modifications as far as possible, and all of them are included in the technical scope of the present invention.

Example An electrogalvanized steel sheet (thickness: 0.8 mm, zinc adhesion: 20 g / m ² , chromium adhesion: 20 mg / m ² ) subjected to chromate treatment was used as an original plate. As the resin liquid for forming the coating, an aqueous urethane resin (trade name “Superflex” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) may be used.
Spherical polyethylene wax particles (particle size: 0.5 to 5μ)
m, softening point: 110-140 °) and silica particles (trade name “Snowtex O” manufactured by Nissan Chemical Industries, Ltd.) were used.

After applying the above resin solution to the original plate and squeezing it with Ringer roll, drying or baking is performed under the condition that the ultimate temperature of the original plate is 80 to 150 ° C., and the adhesion amount of the organic resin coating is 0.7 to 1 A test material of 0.5 g / m ² was prepared. The coating amount at this time is adjusted by changing the solid content concentration of the resin solution and the rolling amount of the ringer roll, and is also shown in Table 1 below by changing the particle size, the added amount, and the baking temperature of the polyethylene wax used. As described above, the ratio of the diameter of the projections (D ₇₀ / D ₀ ), the diameter of the projections (D ₀ ), and the ratio of the number of projections (N _B / N _A and N _D / N _C ), area ratio (ΣS
/ A) and lubricating resin coatings having different numbers of protrusions cut by a straight line of 300 μm were formed, and a performance evaluation test was performed by the following method.

[Evaluation of Performance] (1) Surface Observation After depositing 1 mg / m ² to 1 g / m ² of gold on the surface of the test material, a scanning electron microscope “S-27” manufactured by Hitachi, Ltd. was used.
"00" at an acceleration voltage of 15 kV. (2) Measurement of dynamic friction coefficient It was determined from the load caused by sliding at a pressing force of 150 kg using a sliding test device.

(3) Evaluation of Deep Drawing Workability Using a 80-ton crank press tester, single-shot press forming was performed, and the rubbing surface of the molded product after forming was in a scorched state, a scratched state and a black state. Observe the abnormal state visually,
The deep drawability was evaluated according to the following criteria. ：: Galling, scratches and blackening are scarcely observed. Δ: Slight galling, scratches and blackening are observed. ×: Clear galling, scratches and blackening are observed.

(4) Evaluation of Coating Film Adhesion An aminoalkyd resin paint [trade name “Amirac 1000” manufactured by Kansai Paint Co., Ltd.] was applied to the surface of each test material on which the lubricity coating was formed. And baked at 130 ° C. for 20 minutes to form a coating film having a thickness of 20 μm. Next, 100 cuts of 1 mm ² were formed by making cuts in the coating film surface, extruded by 10 mm with an Erichsen tester, and subjected to a primary adhesion test by a tape peeling test. Further, each coated steel sheet was immersed in boiling water for 1 hour and then taken out. Immediately in the same manner as above, a tape peeling test was performed to evaluate the secondary adhesion. The evaluation criteria are as follows. ：: Almost no peeling of the coating film was observed. Δ: Slight peeling of the coating film was observed. ×: Clear peeling of the coating film was observed. The results are shown in Table 1.

[0045]

[Table 1]

From Table 1, the following can be considered. First, in Examples 1 to 8 which satisfy all the requirements of the present invention, good results are obtained in both deep drawing workability and coating film adhesion. In contrast, Comparative Examples lacking any of the requirements specified in the present invention cannot satisfy either processability or coating film adhesion as described below.

In Comparative Example 1, the diameter of the projection in projected figure 1 was
Ratio (D₇₀/ D₀ ) Is out of the specified requirements.
Among the properties, the scratching and the galling characteristics were poor.₇₀
/ D ₀ 0.8 for the number of protrusions satisfying ≧ 0.35
5 ≧ D₇₀/ D₀ The ratio of the number of protrusions satisfying ≧ 0.35 (N
_B / N_A ) Is out of the specified range.
Poor denaturation.

In Comparative Examples 3 and 4, 0.8
The total area ratio of the projected figure of the projection satisfying 5 ≧ D ₇₀ / D ₀ ≧ 0.35 is out of the range of 0.08 ≦ ΔS / A ≦ 0.4, and in Comparative Example 3 below the lower limit, In Comparative Example 4 exceeding the upper limit value, the coating film adhesion was poor because of poor scratch resistance and galling characteristics.

[0049] Comparative Example 5, since the ratio of the number of projections satisfying 20μm ≧ D ₀ ≧ 0.1μm for projection number that satisfies _{D 0 ≧ 0.1μm (N D /} N C) is insufficient, a satisfactory coating film Adhesion is not obtained. Comparative Examples 6 and 7 were cut by an arbitrary straight line having a length of 300 μm on the surface of the coated metal plate, and satisfied the relationship of 0.85 ≧ D ₇₀ / D ₀ ≧ 0.35 and had a diameter D ₀ of 0.1. This is a comparative example in which the number of protrusions of up to 20 μm is out of the specified range. Poor film adhesion.

[0050]

The present invention is configured as described above, and provides an excellent deep drawing by defining the diameter, projection height, number, projection area ratio, etc. of the projections formed on the surface of the lubricating coating. It has become possible to stably and reliably provide a resin-coated metal plate having both processability and coating film adhesion.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing a scanning electron microscope view of a projection formed on a surface of a resin-coated metal plate.

FIG. 2 is a schematic diagram showing a distribution state of protrusions on a coating surface.

FIG. 3 is an explanatory view schematically showing a state in which projections are formed by solid lubricant particles contained in a resin coating.

FIG. 4 shows the ratio of the diameter of protrusions (D ₇₀ / D ₀ ) appearing in the scanning electron microscope field of view to the (surface protrusion height) / (the particle radius) of solid lubricant particles contained in the coating. It is a graph which shows a relationship.

FIG. 5 is an explanatory diagram schematically showing the effect of (surface protrusion height) / (particle radius) of solid lubricant particles on workability such as scratch resistance and galling resistance.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroaki Tsubino 1 Kanazawacho, Kakogawa-shi, Hyogo Kobe Steel, Ltd. Inside the Kakogawa Works

Claims (3)

[Claims] 1. A lubricating resin-coated metal plate having projections on its surface, wherein the projections appear in the field of view of a scanning electron microscope when an arbitrary projection is observed from a direction perpendicular to the surface of the coated metal plate. Arbitrary direction (A-A ₀ -A 'direction: A ₀
Is the center point of the projected figure) D ₀ , the perpendicular A ₀ -A ₁ emanating from the A ₀ point and the A-A _0-
In the plane P including the virtual line drawn in the A 'direction, the perpendicular A ₀
Direction of cut by the plane P in appearing projected figure scanning electron microscopic field when the -A ₁ was observed above the same projection from the 70 ° rotation and the (A ₀ -A ₂ direction) (D- The diameter of the projection (D ′ direction) is D _70, and the number of projections satisfying the relationship of the following expression (1) is N _A , D ₇₀ / D ₀ ≧ 0.35 (1) The above expression (1) and the following expression (1) when the number of protrusions satisfy both relationships of 2) was _{N B, 0.85 ≧ D 70 /} D 0 ≧ 0.35 ... (2) above N _a, is N _B a relationship represented by the following formula (3) N _B / N _A ≧ 0.95 (3) and a direction perpendicular to the surface of the coated metal plate (A ₁ -A
₀ ), the sum of the areas ΣS appearing in the projected figure of the projections that satisfies the relationship of the above formula (2), which is observed from the scanning electron microscope, is given by A lubricating resin-coated metal sheet excellent in deep drawing workability and coating film adhesion, which satisfies the relationship of Expression (4). 0.08 <ΣS / A ≦ 0.4 (4) 2. Among the projections satisfying the relationship of the expression (2), the number of projections having the diameter D ₀ of 0.1 μm or more is represented by N
_C, the diameter D ₀ is the number of projections is 0.1 to 20 [mu] m N _D
When the ratio of N _D and N _C satisfies the relationship of the following formula (5), N _D / N _C ≧ 0.95 (5) In addition, an arbitrary straight line having a length of 300 μm on the surface of the coated metal plate. 2. The lubricating resin-coated metal plate according to claim 1, wherein the number of protrusions that are cut and satisfy the relationship of the expression (2) and have the diameter D ₀ of 0.1 to 20 μm is 1 to 300. 3. 3. The projection according to claim 1, wherein the projection is formed by solid lubricant particles mixed in the resin coating.
Or a lubricating resin-coated metal plate according to item 2.