JP2953654B2 - Surface treated metal plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface-treated metal sheet excellent in deep drawability, scratch resistance and water resistance, and has a problem in appearance change when water droplets adhere to the surface due to condensation or the like. The present invention relates to a surface-treated metal plate suitable for deep drawing products such as components of household electric appliances, for example, audio chassis, computer cases, video cases, motor cases, pulleys and the like.

[0002]

2. Description of the Related Art Materials used for parts of household electrical appliances include Zn-coated steel sheets such as electro-galvanized steel sheets and hot-dip galvanized steel sheets, and even more corrosion resistance and adhesion of paint films when paints are applied. (Hereinafter referred to as "paintability")
For the purpose of improving the surface treatment, a metal-based surface-treated steel sheet obtained by subjecting the Zn-plated steel sheet to a chemical conversion treatment such as a chromate treatment or a phosphate treatment is often used.

[0003] These metal-based surface-treated steel sheets are shipped as products in the form of a coil material or a sheet material by a steel sheet manufacturer, and are subjected to various processes by a user. However,
These surface-treated steel sheets have a hard metallic film formed on the surface, so they come into contact with the transfer table or rub against the metal mold during bending, causing scratches on the steel sheet surface. May occur. Scratches on the steel sheet surface impair the appearance and film performance of the product and degrade its commercial value.

Therefore, a surface-treated steel sheet in which an organic resin film is formed on the surface of a surface-treated steel sheet which has been subjected to a chromate treatment (JP-A-58-153785, JP-A-58-17)
No. 7476) has been proposed. In the case of a surface-treated steel sheet on which a resin film is formed, an effect is recognized on scratch resistance. However, in the case of parts that are subjected to deep drawing, such as motor cases, intense sliding friction occurs with the mold, causing the resin film on the sliding surface to peel and blacken. This causes a problem that the appearance of the product is remarkably impaired, and that the blackened matter adheres to other equipments to cause another problem.

[0005]

In order to solve the problems of the surface-treated steel sheet having such a resin film formed thereon, a resin based on a resin and an inorganic polymer compound and further containing a solid lubricant is used. A surface-treated steel sheet formed (JP-A-6-57442) and a surface-treated steel sheet further formed with a coating containing an aqueous resin (JP-A-6-57441) have been proposed. The surface-treated steel sheet on which the coating based on the inorganic polymer and the resin is formed has an effect of improving the scratch resistance and the occurrence of black matter in the coating during deep drawing. However, since the water resistance of the film is insufficient, when the film comes into contact with water due to dew condensation or the like, some of the film components may be eluted in the water. In such a case, not only the appearance of the film is impaired, but also the corrosion resistance of the steel sheet itself is deteriorated, black spot-like rust and white rust are easily generated, and the effect of improving the paintability by forming the film becomes insufficient. Has disadvantages.

The present invention has been made in view of such circumstances, and an object of the present invention is to form a film based on an inorganic polymer and a resin so as to have excellent scratch resistance and deep drawability. It is an object of the present invention to provide a surface-treated metal plate which is excellent in corrosion resistance, water resistance and coating properties.

[0007]

That is, the surface-treated metal plate of the present invention has a SiO ₂ / Li ₂ O ratio (molar ratio) of 18 to 18.
A treatment liquid comprising an aqueous solution of lithium silicate containing an organic resin, a silane coupling agent, and a solid lubricant is applied to the surface of a metal plate and dried.

[0008] The content of the organic resin in the treatment liquid is as follows:
It is preferably from 8 to 33% by weight based on the total solid content in the treatment liquid. The silane coupling agent is preferably at least one selected from the group consisting of silane coupling agents represented by the following formulas (1) to (4).

[0009]

Embedded image

(Wherein, R ₁ and R ₅ each represent a lower alkyl group, and R ₂ , R ₃ and R ₄ each represent a lower alkoxy group.)

[0011]

Embedded image

(Wherein R _g represents a glycidoxy group;
₂ , R ₃ and R ₄ each represent a lower alkoxy group, R ₅ represents a lower alkyl group, and R ₆ represents a lower alkylene group. )

[0013] The content of the silane coupling agent in the treatment liquid is 0.8 to 0.8 with respect to the total solid content in the treatment liquid.
It is preferably 17.0% by weight. Further, the content of the solid lubricant in the treatment liquid is 0.2 to 2.8% by weight based on the total amount of solids in the treatment liquid, and the particle size of the solid lubricant is 0.1 to 2.8%. It is preferably 1.0 μm. The treatment liquid is 0.020 to 0.6 g / Si equivalent.
It is preferable that the amount of m ² is applied.

Further, the surface-treated metal plate of the present invention is preferably made of SiO 2
A film containing a polymer in which a lithium silicate component having a ₂ / Li ₂ O ratio (molar ratio) of 18 to 33 and an organic resin are silane-coupled, and a solid lubricant are formed on the metal plate surface. It is preferable that the total content of Na and / or K contained as impurities in the film is 1.0% by weight or less.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a treatment liquid used for producing a surface-treated metal plate of the present invention will be described. The processing liquid used in the present invention is SiO ₂ / Li ₂ O
An organic resin, a silane coupling agent, and a solid lubricant are contained in an aqueous solution of lithium silicate having a ratio (molar ratio) of 18 to 33.

The aqueous solution of lithium silicate is SiO ₂ / L
An aqueous solution containing a lithium silicate component such that the i ₂ O ratio (molar ratio) is 18 to 33, and may be a solution in which lithium silicate alone is dispersed in water, or lithium silicate may be used. It may be a solution in which a mixture of and silica colloid is dispersed in water. When a mixture is used, the amount of SiO ₂ / Li can be easily adjusted by adjusting the amount of silicate colloid.
_The treatment liquid can be prepared so that the 2O ratio (molar ratio) is 18 to 33, which is preferable. In short, SiO ₂
It is sufficient that the / Li ₂ O ratio satisfies 18 to 33, preferably 22 or more, more preferably 26 or more, preferably 30 or less, more preferably 28 or less.

If the SiO ₂ / Li ₂ O ratio is less than 18, the film components (particularly, the Li component) are easily eluted, and the water resistance of the film is reduced. On the other hand, SiO ₂ / Li ₂ O
When the ratio exceeds 33, the ease of forming a film of the treatment liquid applied to the metal plate (hereinafter referred to as “film-forming property”) decreases, and the wettability with the metal plate decreases. This is because the treatment liquid applied to the metal plate is easily repelled, and the adhesion of the formed film to the metal plate is reduced. In addition, the formed film is easily cracked, the corrosion resistance is deteriorated, and the film is easily damaged.

As lithium silicate, commercially available lithium silicate can be used. As the silicate colloid, commercially available colloidal silica or silica sol can be used. However, commercially available silicate colloids generally contain sodium silicate or potassium silicate as impurities, and sodium silicate or potassium silicate deteriorates the wettability between the treatment liquid and the metal plate and is formed. Defects are apt to occur in the film, which causes deterioration of corrosion resistance and paintability. Therefore, it is desirable to adjust the total content of Na and / or K (Na content + K content) contained as impurities in the film to 1.0% by weight or less.

The organic resin is added for the purpose of improving the water resistance and corrosion resistance of the film. Examples of the organic resin used in the present invention include urethane resins, acrylic resins, polyethylene resins, polystyrene resins, polyester resins, and modified resins thereof. Of these, urethane-based resins, acrylic-based resins, and modified resins based on them are preferably used.

The content of the organic resin is preferably 8% by weight or more, more preferably 1% by weight, based on the total solid content in the processing solution.
It is at least 0.0% by weight, particularly preferably at least 15% by weight. The upper limit of the content is preferably 33% by weight or less, more preferably 30.0% by weight or less, and particularly preferably 25% by weight or less.
% By weight or less. This is because when the content of the organic resin is less than 8% by weight, the effect of improving the film forming property and water resistance by adding the organic resin is not sufficient. On the other hand, when the content of the organic resin is more than 33% by weight, the blackening phenomenon in which the resin on the sliding surface is peeled off and blackened by deep drawing is likely to occur, and the appearance after the processing is reduced. This is because it deteriorates.

The silane coupling agent is added for the purpose of improving the water resistance of the film. Here, the silane coupling agent refers to an organic silane compound in which an organic group and a hydrolyzable alkoxy group are bonded to a Si atom. The alkoxy group reacts with an inorganic substance, and the organic group bonds to an organic resin. Can be. Therefore, the processing liquid containing the silane coupling agent is combined with the organic resin during the storage of the processing liquid and further applied to the metal plate and dried, including the lithium silicate, the metal plate and the like. Can be combined with inorganic components. In addition, when the treatment liquid contains a silicate colloid, the silicate colloids can be combined with each other or the silicate colloid and lithium silicate. For this reason, the bond between the components in the formed film becomes stronger, and the film components,
In particular, elution of the lithium component can be prevented. As a result, it is considered that the water resistance is improved.

The silane coupling agent used in the present invention is not particularly limited, but one or more selected from the group consisting of the silane coupling agents represented by the following formulas (1) to (4) are preferably used.

[0023]

Embedded image

(Wherein, R ₁ and R ₅ each represent a lower alkyl group, and R ₂ , R ₃ and R ₄ each represent a lower alkoxy group.)

[0025]

Embedded image

(Wherein R _g represents a glycidoxy group;
₂ , R ₃ and R ₄ each represent a lower alkoxy group, R ₅ represents a lower alkyl group, and R ₆ represents a lower alkylene group. )

When such a silane coupling agent is hydrolyzed to generate a silanol group, an alcohol is also generated. Since alcohol has an adverse effect on the film-forming properties, it is preferable that the alcohol be volatilized before the film is formed. Therefore, the alkoxy group in the silane coupling agent is preferably a methoxy group that produces methanol, which is a lower alcohol having the lowest boiling point.
Further, from the viewpoints of dispersibility and compatibility in an aqueous solution, it is preferable to use a silane coupling agent having a glycidoxy group at a terminal as shown in the following formula (3) or (4). Therefore, specifically, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, β- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, etc. are preferably used as the silane coupling agent. Can be

The content of the silane coupling agent is preferably 0.8 to 17.0% by weight based on the total solid content in the processing solution. If it is less than 0.8% by weight, a sufficient effect of improving water resistance cannot be obtained. On the other hand, if it exceeds 17.0% by weight, the silane coupling reaction proceeds too much and the stability of the processing solution is reduced. In severe cases, the processing solution gels and the coating of the processing solution becomes impossible. is there.

The solid lubricant is added for the purpose of preventing the film from being scratched by improving the lubricity of the film and reducing the damage of the film during processing. Examples of the solid lubricant that can be used in the present invention include polyethylene wax, polyethylene oxide wax, polypropylene oxide wax, carnauba wax, paraffin wax, montan wax, rice wax, Teflon wax, molybdenum disulfide, carbon disulfide, and graphite. For example, one or more of these solid lubricants may be arbitrarily selected. Considering the dispersion state and lubrication performance in the processing solution, it is recommended to use a wax-type lubricant, especially polyethylene wax or polyethylene oxide wax, and add it to the aqueous solution of lithium silicate in the form of a water-dispersed wax. You.

The addition amount of the solid lubricant is preferably 0.20% by weight or more, particularly 0.25% by weight or more and 2.8% by weight or less, particularly preferably 1.5% by weight or less. 0.
If the content is less than 20% by weight, the effect of improving lubricity cannot be sufficiently obtained. On the other hand, when the content exceeds 2.8% by weight, the coating property is reduced and the film-forming property is also reduced, so that the corrosion resistance and water resistance of the resulting film are deteriorated.

The solid lubricant used in the present invention is:
It is preferable that the particle size is 0.1 to 1.0 μm.
If the particle size of the solid lubricant is less than 0.1 μm, the lubricant is buried in the film and satisfactory performance cannot be obtained. On the other hand, if it exceeds 1.0 μm, the uniform dispersibility of the solid lubricant in the processing liquid In addition, the liquid stability deteriorates, and it becomes impossible to apply the solution uniformly to the metal plate.

The surface-treated metal sheet of the present invention is produced by applying a treatment liquid having the above composition to the surface of the metal sheet and drying the applied solution. Therefore, a vitreous film made of a strong dry gel of fine silica particles is formed on the surface of the metal plate. Specifically, the vitreous film is a film in which a lithium silicate component and an organic resin contained in the treatment liquid are silane-coupled, and further contain a solid lubricant. The drying may be performed at room temperature, or may be performed by heating depending on the type of the organic resin.

The coating amount of the processing liquid is 0.0% by weight of Si.
The amount is ²⁰ to 0.6 g / m ² . 0.025g /
If it is less than m ² , a tough and hard glassy film cannot be obtained, and sufficient corrosion resistance and deep drawability cannot be obtained. On the other hand, if the Si weight exceeds 0.5 g / m ² , the grounding property and coating property of the coating deteriorate.

The metal plate (metal plate to which the treatment liquid is applied) used in the present invention is not particularly limited, and a metal plate such as an aluminum plate, an aluminum alloy plate, a stainless steel plate, or a titanium plate may be used in addition to a steel plate. Good. However, in consideration of the adhesion of the film, those obtained by subjecting Zn or Zn alloy plated steel sheet to a chemical conversion treatment such as a chromate treatment or a phosphate treatment are preferably used, and from the viewpoint of corrosion resistance, a chromate treatment is performed. Most preferred is a Zn or Zn alloy plated steel sheet. The amount of the chromate film attached is preferably 10 mg / m ² or more as the amount of Cr attached from the viewpoint of corrosion resistance, and is preferably 100 mg / m ² or less from the viewpoint of adhesion to the film. As a method of performing the chromate treatment, there are methods such as a washing type (reaction type) chromate treatment, a coating type chromate treatment, and an electrolytic chromate treatment. However, the method is not particularly limited, and any method may be used.

The coating method of the treatment liquid is not limited, and may be arbitrarily selected from known coating methods such as a roll coater method, a knife coater method, and a spray method. The surface-treated metal sheet formed in this way has not only scratch resistance and deep drawability due to the coating composition, but also corrosion resistance,
Excellent water resistance and paintability.

[0036]

【Example】

[Test method] The test method used in the following examples is as follows. Corrosion resistance A salt spray test was conducted in accordance with JIS Z2371.
The corrosion resistance was evaluated based on the area of white rust generated after 00 hours.
The evaluation criteria are shown below. ：: no white rust ○: less than 5% white rust Δ: 5% or more and less than 10% ×: 10% or more white rust

Water resistance 0.5 ml of ion-exchanged water was applied to the surface of the obtained surface-treated steel sheet.
Was dropped, and a separately prepared surface-treated steel sheet was superimposed on the surface of the surface-treated steel sheet on which water was dropped. That is, water was sandwiched between two surface-treated steel sheets. Then
A 1 kg load was applied to the surface-treated steel sheet, and the appearance of the water-dropped portion after storage for one week was evaluated by observation. The evaluation criteria are shown below. ◎: No change ：: Slight discoloration is observed △: Water dripping part is slightly changed ×: Appearance change is remarkable

Scratch resistance The obtained surface-treated steel sheets were set on a surface test apparatus (manufactured by HEIDON) in a state where two sheets of the surface-treated steel sheets were stacked (the size of the upper surface-treated steel sheet was 10 mm × 10 mm). With a load of 1 kg applied to the set surface-treated steel sheet, a scratch is generated by sliding between the two surface-treated steel sheets,
Flaws were visually evaluated (評 価: extremely good, ：: good, Δ: bad, ×: extremely bad).

Wetability The prepared treatment liquid was applied to the surface of a metal plate with a squeeze roll, and the degree of repellency of the treatment liquid on the surface immediately after application was visually observed and evaluated (（: extremely good, ○: good, Δ). : Bad, ×: extremely bad).

Deep drawing workability Using the obtained surface-treated steel sheet, a press-formed product is produced with an 80-ton crank press, and the sliding surface of the formed product is subjected to mold galling and blackening (blackening resistance). Were visually observed and evaluated (◎: extremely good, ○: good, Δ: bad,
X: extremely bad).

Coatability A melamine-based paint was applied to the obtained coated steel sheet to a thickness of 20 μm.
And sprayed at 150 ° C. for 30 minutes to form a melamine-based coating film. The formed coating film was cut into 100 square grids of 1 mm square with a cutter knife, and a tape peeling test was performed on the square grid to check the number of remaining squares of the coating film. The greater the number of meshes remaining in the coating film, the better the paintability.

Grounding property The surface resistance of the surface-treated steel sheet was measured with a tester and evaluated as follows. ◎: less than 50Ω ○: 50Ω or more and less than 100Ω △: 100Ω or more and less than 200Ω ×: 200Ω or more

[Examples] In the following examples, as a metal plate, an electrolytic Zn-plated steel sheet (Zn
The amount of adhesion was 20 g / m ² , the amount of Cr adhesion was 20 mg / m ² , and the plate thickness was 0.8 mm.

Example 1 First, SiO ₂ / Li in the treatment liquid
_The influence of the 2O ratio on corrosion resistance, water resistance, scratch resistance, and wettability was examined. Lithium silicate and silicate colloid are dispersed in water, and further, 25% by weight of urethane resin,
A treatment liquid was prepared by adding 10% by weight of γ-glycidoxypropyltrimethoxysilane as a silane coupling agent and 1.5% by weight of water-dispersible polyethylene wax particles having a particle diameter of 0.6 μm. In addition, urethane resin, silane coupling agent, the content of polyethylene wax particles,
It is the ratio to the total amount of solids in the treatment liquid finally prepared.

Next, the prepared treatment liquid was applied to S
i was applied to the surface of the metal plate with a squeeze roll so as to have a weight of 0.1 g / m ² and dried at a plate temperature of 80 ° C. to form a vitreous film. Was obtained. In addition, Nos. 1 to 9 were adjusted so that the SiO ₂ / Li ₂ O ratio was 10 to 40 by adjusting the mixing ratio of lithium silicate and silicate colloid in the treatment liquid. No. 1 to 9 surface-treated steel sheets
Tests for corrosion resistance, water resistance, scratch resistance, and wettability were performed. Table 1 shows the results.

[0046]

[Table 1]

The inventive examples Nos. 1 to 5 satisfying the SiO ₂ / Li ₂ O ratio of 18 to 33 are excellent in all of corrosion resistance, water resistance, scratch resistance and wettability. Especially SiO ₂ / L
The present invention Examples of i ₂ O ratio 26 to 28 Nos. 3 and 4, the corrosion resistance, water resistance,耐疵with resistance, and wettability was extremely excellent. On the other hand, Comparative Example N in which the SiO ₂ / Li ₂ O ratio was too small
In Comparative Examples Nos. 8 and 9 in which the water resistance was poor in Nos. 6 and 7, and the SiO ₂ / Li ₂ O ratio was too large, all of the corrosion resistance, water resistance, scratch resistance, and wettability were inferior.

Example 2 Next, the relationship between the content of the organic resin in the treatment liquid and the properties of the obtained surface-treated steel sheet was examined.
Lithium silicate and silicate colloid mixture in water, Si
A treatment liquid was prepared in the same manner as in Example 1 except that the O ₂ / Li ₂ O ratio was dispersed so as to be 25, and the content of the urethane resin was changed to 0 to 40% by weight. In the same manner as in Example 1 using the liquid, surface-treated steel sheets Nos. 10 to 18 were obtained. These surface-treated steel sheets were tested for corrosion resistance, water resistance, wettability and deep drawability. Table 2 shows the results.

[0049]

[Table 2]

The inventive examples Nos. 10 to 14 in which the content of the organic resin is 0.8 to 33% by weight are excellent in all of corrosion resistance, water resistance, wettability and deep drawability. On the other hand, Comparative Examples Nos. 15 and 16 in which the content of the organic resin was too low were inferior in corrosion resistance, water resistance and wettability, and Comparative Examples Nos. 17 and 18 in which the content of the organic resin was too high were deep drawn. Blackening occurred during processing.

Example 3 Next, the relationship between the content or particle size of the solid lubricant in the treatment liquid and the properties of the obtained surface-treated steel sheet was examined. The ratio of SiO ₂ / Li ₂ O in the mixture of lithium silicate and colloidal silicate is 25, and the content of water-dispersible polyethylene wax particles having different particle diameters is 0 to 10.
A treatment liquid was prepared in the same manner as in Example 1 except that the amount was changed to% by weight. Using the prepared treatment liquid, surface-treated steel sheets Nos. 19 to 33 were obtained in the same manner as in Example 1. These surface-treated steel sheets were tested for corrosion resistance, water resistance, paintability, and deep drawability. Table 3 shows the results.

[0052]

[Table 3]

When the content of the solid lubricant in the treatment liquid is 0.2 to
Inventive Examples Nos. 19 to 25 having 2.8% by weight and a particle size of 0.1 to 1.0 µm were excellent in all of corrosion resistance, water resistance, coating property and deep drawing workability. On the other hand, Comparative Examples Nos. 26 and 27 in which the content of the solid lubricant is too low have poor deep drawability, and Comparative Examples Nos. 28 to 30 in which the content of the solid lubricant is too high have corrosion resistance, water resistance, and paint. Poor sex. Comparative Example No. in which the particle size of the solid lubricant was too small.
Comparative Example No. 31 is poor in deep drawability and the particle size of the solid lubricant is too large. Comparative Example No. 32 is inferior in corrosion resistance, paintability and deep drawability (blackening resistance), and the particle size of the solid lubricant is 3 0.0 μm
In Comparative Example No. 33, the solid lubricant could not be dispersed in the solution.

Example 4 Next, the relationship between the type or content of the silane coupling agent in the treatment liquid and the properties of the surface-treated steel sheet was examined. Treatment liquid in the same manner as in Example 1 except that the SiO ₂ / Li ₂ O ratio in the mixture of lithium silicate and colloidal silicate was 25, and the type or content of the silane coupling agent was changed as shown in Table 4. Was prepared, and surface-treated steel sheets Nos. 34 to 46 were produced in the same manner as in Example 1 using the prepared treatment liquid. These surface-treated steel sheets were tested for corrosion resistance, water resistance, and deep drawability. Table 4 shows the results.

[0055]

[Table 4]

The silane coupling agent is used in an amount of 0.8 to 17.0.
Inventive Examples Nos. 34 to 41 contained in the range of wt%
Excellent in corrosion resistance, water resistance and deep drawability. On the other hand, Comparative Examples Nos. 42 and 43 in which the content of the silane coupling agent is too low have poor water resistance, and Comparative Examples Nos. 44 and 45 in which the content of the silane coupling agent is too high have water resistance, Galling has occurred. Comparative Example No. 4 in which the content of the silane coupling agent was 30%
In No. 6, the treatment liquid gelled. No. 36, 39-4
From the comparison of 1, as the silane coupling agent, γ-glycidoxypropyltrimethoxysilane in which the alkoxy group is a methoxy group and the organic group has a glycidoxy group,
It turns out that corrosion resistance and water resistance were the most excellent.

Example 5 Next, the relationship between the total content of Na and / or K in the treatment liquid (Na content + K content) and the properties of the obtained surface-treated steel sheet was examined. In a treatment liquid prepared in the same manner as in Example 1 using a mixed solution having a SiO ₂ / Li ₂ O ratio of 25 in a mixture of lithium silicate and colloidal silicate, the total content of Na and / or K was 0.1%.
Treatment liquids adjusted in the range of 1 to 3.0% by weight were prepared, and these were used to obtain surface-treated steel sheets of Nos. 47 to 53 in the same manner as in Example 1. About these surface-treated steel sheets,
Tests for corrosion resistance, water resistance, wettability, and deep drawability were performed. Table 5 shows the results.

[0058]

[Table 5]

The inventive examples Nos. 47 to 50 in which the total content of Na and / or K is 1.0% by weight or less are excellent in all of corrosion resistance, water resistance, wettability and deep drawability. On the other hand, Comparative Examples Nos. 51 to 53 in which the total content of Na and / or K exceeds 1.0% by weight are inferior in corrosion resistance, water resistance and wettability.

Example 6 Next, the relationship between the amount of treatment liquid applied and the properties of the resulting surface-treated steel sheet was examined. SiO ₂ / Li in a mixture of lithium silicate and silicic acid colloids
0 ₂ O ratio processing solution prepared in the same manner as in Example 1 using a mixed solution of 25 at Si weight after coating and drying.
In the same manner as in Example 1, surface-treated steel sheets of Nos. 54 to 62 were obtained so as to obtain 015 to 2.0 g / m ² . These surface-treated steel sheets were tested for corrosion resistance, deep drawing workability, and earthing property. Table 6 shows the results.

[0061]

[Table 6]

Examples 54 to 58 of the present invention, in which the Si content is 0.02 to 0.6 g / m ² , are excellent in all of the corrosion resistance, the deep drawability and the earthing property. On the other hand, Comparative Example No. 59, in which the Si adhesion amount was too small, was poor in corrosion resistance and deep drawing workability, and Comparative Examples Nos. 60-62, in which the Si adhesion amount was too large, were inferior in grounding properties.

[0063]

The surface-treated steel sheet of the present invention has a SiO ₂ / L
Since a film in which the i ₂ O ratio is 18-33 and which is a vitreous material and an inorganic material such as a lithium silicate component and an organic resin are silane-coupled is formed on the metal surface,
Excellent water resistance, corrosion resistance, paintability, scratch resistance and deep drawability.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Atsushi Kihara 1 Kanazawacho, Kakogawa-shi, Hyogo Kobe Steel, Ltd. Inside the Kakogawa Works (72) Inventor Takefumi Watase 1, Kanazawacho, Kakogawa-shi, Hyogo Kobe Steel, Ltd. Kakogawa Works (56) References JP-A-4-285179 (JP, A) JP-A-5-125555 (JP, A) JP-A-9-99517 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B32B 15/08 B05D 7/14 B05D 7/24 303 C23C 22/00

Claims (8)

(57) [Claims] 1. An SiO ₂ / Li ₂ O ratio (molar ratio) of 18
A surface obtained by applying a treatment liquid containing an organic resin, a silane coupling agent, and a solid lubricant to a lithium silicate aqueous solution of ~ 33 to the surface of a metal plate and then drying. Processing metal plate. 2. The surface-treated metal sheet according to claim 1, wherein the content of the organic resin in the treatment liquid is 8 to 33% by weight based on the total solid content in the treatment liquid. 3. The silane coupling agent according to the following (1):
The surface-treated metal sheet according to claim 1, wherein the metal sheet is at least one selected from the group consisting of silane coupling agents represented by formulas (4) to (4). Embedded image (Wherein R ₁ and R ₅ each represent a lower alkyl group;
₂ , R ₃ and R ₄ each represent a lower alkoxy group. ) (Wherein R _g represents a glycidoxy group, and R ₂ , R ₃ , R
₄ represents a lower alkoxy group, R ₅ represents a lower alkyl group, and R ₆ represents a lower alkylene group. ) 4. The content of the silane coupling agent in the processing solution is 0.8 to the total solid content in the processing solution.
The surface-treated metal plate according to any one of claims 1 to 3, wherein the content is from 1 to 17.0% by weight. 5. The content of the solid lubricant in the treatment liquid is 0.2 to 2.8% by weight based on the total solid content in the treatment liquid, and the particle size of the solid lubricant is 0%. .1 to 1.0
The surface-treated metal plate according to any one of claims 1 to 4, which has a thickness of µm. 6. The processing liquid is 0.020 to 0.020 in terms of Si.
An amount of 0.6 g / m ² is applied.
6. The surface-treated metal plate according to any one of items 1 to 5. 7. An SiO ₂ / Li ₂ O ratio (molar ratio) of 18
33. A surface-treated metal plate, wherein a film containing a solid lubricant and a polymer in which a lithium silicate component and an organic resin are silane-coupled to each other are formed on the surface of the metal plate. 8. The surface-treated metal sheet according to claim 7, wherein the total amount of Na and / or K contained as impurities in the film is 1.0% by weight or less.