JP2960892B2 - 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 plate excellent in deep drawability, and more particularly to a component of household electric appliances, such as an audio chassis, a computer case, and the like.
The present invention relates to a surface-treated metal plate suitable for deep drawing products such as a video case, a motor case, and a pulley.

[0002]

2. Description of the Related Art Materials used for parts of household electrical appliances include Zn-based steel sheets such as electro-galvanized steel sheets and hot-dip galvanized steel sheets, and Zn-based steel sheets for the purpose of further improving corrosion resistance and paintability. Inorganic surface-treated steel sheets obtained by subjecting a plated steel sheet to a chemical conversion treatment such as a chromate treatment or a phosphate treatment are widely used.

[0003] These inorganic surface-treated steel sheets are shipped as a coil material or a sheet material from a steel sheet maker as a product, and subjected to various processes by a user. However, since these surface-treated steel sheets are formed of a hard inorganic coating on the surface, 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 resin-coated steel sheet having an organic resin film formed on a surface-treated steel sheet subjected to a chromate treatment (Japanese Patent Application Laid-Open Nos. 58-153785 and 58-17747).
No. 6 publication). In the case of this resin-coated steel sheet, since the surface is covered with the resin film, an effect is recognized on the 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 above-mentioned problems of the resin-coated steel sheet, a lubricating steel sheet in which a film having an inorganic polymer compound and a solid lubricant is formed as a resin film (JP-A-6-57442). Or a lubricated steel sheet on which a film having an aqueous resin is further formed (Japanese Patent Laid-Open No. 6-57441).
Publication). The film-treated steel sheet based on these inorganic polymers has an effect of improving the scratch resistance and the occurrence of black matter in the film during deep drawing.
However, when applying the solution to the steel plate, coating defects such as repelling may occur and the water permeability of the film is high, so black spot-like rust and white rust easily occur, and when coating is performed Had a defect such as poor adhesion of the coating film. That is, although the scratch resistance and the deep drawability were improved, there were problems in terms of corrosion resistance and paintability.

[0006] Further, these surface-treated metal sheets are generally coated after processing. However, with the diversification of applications in recent years, they may be used without coating, and some of them are partially coated. Other parts may be left unpainted. One of the important properties required when used unpainted is stain resistance. The contamination resistance means that, for example, when the surface is contaminated with magic ink or the like due to children's graffiti, the contaminated portion can be easily wiped off using ethanol or the like, and the surface can be returned to a clean surface. Nature. However,
Conventional film-treated steel sheets have poor stain resistance, and once contaminated with oil-based magic, traces of contamination are very noticeable.
There were also problems such as remarkably impairing the appearance. Therefore, there has been a demand for the development of a surface-treated steel sheet which has stain resistance and can be used without painting.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is a resin film-coated metal plate having excellent scratch resistance and deep drawability, and having excellent corrosion resistance and coating properties. Moreover, it is an object of the present invention to provide a surface-treated metal plate having stain resistance and which can be used without painting.

[0008]

According to the present invention, there is provided a film comprising an alkali metal silicate or an alkali metal silicate and a silicate colloid, and further comprising an organic resin and a solid lubricant. Surface treated metal plate,
The alkali metal silicate is lithium silicate, the (Li atom / Si atom) ratio (hereinafter referred to as Li / Si ratio) in the coating is 0.2 to 0.6, and the organic resin is Is a graft polymer having a silicone resin component.

As the graft polymer, a graft polymer composed of a silicone resin component and an acrylic resin component may be used, and the graft polymer is a comb-shaped graft polymer composed of a trunk polymer and a branch polymer;
It is preferable that part or all of the branch polymer is a silicone resin in order to improve the stain resistance. The content of the silicone resin component in the above graft polymer is preferably 5 to 50% by weight, and the content of the graft polymer in the coating is preferably 0.5 to 10.0% by weight.

It is recommended that the content of Na and / or K present as an impurity in the alkali metal silicate is 1.0% by weight or less in total, and the amount of the coating film is 0.025% in terms of Si. It is desirably about 0.5 g / m ² .
Further, a silane coupling agent is added to the film in an amount of 1.0 to 1
By containing 0.0% by weight, it is possible to improve the coating property (secondary adhesion) and the printability.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have developed a metal plate coated with a resin film having excellent deep drawability, and a surface-treated metal plate having excellent overall corrosion resistance, including corrosion resistance after degreasing with an organic solvent, and excellent coatability. We worked diligently to develop it. As a result, lithium silicate is selected as the metal silicate which is the main component of the coating, and the Li / Si ratio in the coating is controlled within a specific range, thereby ensuring excellent deep drawability. It has been found that a film excellent in corrosion resistance and paintability can be formed. Furthermore, if the organic resin is a comb-shaped graft polymer, at least a part of the branch portion of which is a graft polymer composed of a silicone resin component,
The present inventors have found that the stain resistance can be improved, and that the film forming property and lubricity of the film can be improved.

If the Li / Si ratio is too small, the film-forming property of the film is reduced, and the film is easily repelled even when applied to a metal plate, and a film having excellent adhesion cannot be formed. As well as being easily scratched. Therefore, Li / Si
The ratio needs to be 0.2 or more. On the other hand, Li /
If the Si ratio is too large, the adhesion of the coating film when coated is deteriorated. Therefore, the Li / Si ratio needs to be 0.6 or less. As described above, in the present invention, the Li / Si ratio of the aqueous solution of lithium silicate or the Li / Si ratio in the mixture of the aqueous solution of lithium silicate and the colloid of silicate are described.
It is necessary to set the ratio to 0.2 to 0.6,
A range of 0.4 is more preferable.

As described above, the mechanism of improving the film by adding a graft polymer containing silicone as a component has not been elucidated, but is considered as follows. That is,
In a film in which a graft polymer containing a silicone resin as a branch (branch polymer) component is dispersed, the silicone resin is exposed on the surface of the film, and the silicone resin exposed on the surface reduces the contamination resistance. It is presumed that it exerts, and that the lubricity on the film surface is improved and the workability of the film is also improved.

However, when the content of the graft polymer is 0.5
%, The effect of improving the stain resistance and the lubricity of the film is not sufficient. Also, if the content exceeds 10.0%, the resin peels off on the sliding surface during deep drawing, causing a blackening phenomenon,
Deteriorates the appearance after processing. Therefore, it is recommended that the content of the graft polymer be 0.5 to 10.0%.

The silicone resin component content is 5%.
When the content is less than 50%, no improvement effect is observed in the stain resistance and the lubricity of the film, while the content of the silicone resin component is less than 50%.
%, The effect of improving lubricity saturates and paintability deteriorates. Accordingly, the content of the silicone resin component contained in the graft polymer is preferably 5 to 50%, more preferably 20 to 45%.

In the present invention, the resin component which forms the graft polymer by graft polymerization with the silicone resin component is not limited, but the acrylic resin component is typically exemplified.

In the present invention, the solution applied for the purpose of forming a film may be an aqueous solution of lithium silicate alone or a solution of lithium silicate as long as it satisfies the above Li / Si ratio of 0.2 to 0.6. A mixed solution of an aqueous solution and a silicate colloid may be used, and it can be obtained by adding a lubricant-containing resin to this.

Therefore, in producing the surface-treated metal plate according to the present invention, an aqueous solution of lithium silicate or a mixture of an aqueous solution of lithium silicate and colloidal silicate is applied to the surface of the metal plate and dried to obtain fine silica particles. Can be formed on the surface of the metal plate.

As the lithium silicate, a commercially available lithium silicate may be used, and a commercially available colloidal silica or a colloid sol may be used for the silicic acid colloid. Contains sodium and potassium silicate.
Sodium silicate and potassium silicate deteriorate the wettability between the coating solution and the steel sheet during coating, and when dried to form a film, defects are generated in the obtained film, causing corrosion resistance and adhesion to decrease. . Therefore, it is desirable to control the content of Na and / or K contained in the film to 1.0% or less in total.

The amount of the film formed on the surface of the metal plate is preferably in the range of 0.025% to 0.5 g / m ^{2 by} weight of Si. When the coating weight is less than 0.025 g / m ^{2 in} terms of Si, a tough and hard vitreous coating cannot be obtained, and sufficient corrosion resistance and deep drawability cannot be obtained. On the other hand, when the coating amount is more than 0.5 g / m ^{2 in} terms of Si, the grounding property and coating property of the coating deteriorate.

The present invention is not limited by the method of applying the coating liquid, and may be arbitrarily selected from known coating methods such as a roll coater method, a knife coater method, and a spray method.

The material of the base for forming the film according to the present invention is not particularly limited, and a metal plate such as an aluminum plate, an aluminum alloy plate, a stainless steel plate, a titanium plate and the like can be used other than the steel plate. However, in consideration of the adhesiveness to the material at the time of forming the film, a material obtained by subjecting a Zn or Zn alloy plated steel sheet to a chemical conversion treatment such as a chromate treatment or a phosphate treatment is preferably used.

In particular, as the chemical conversion treatment applied to the Zn or Zn alloy plated steel sheet, a Zn or Zn alloy plated steel sheet subjected to chromate treatment is most preferable from the viewpoint of corrosion resistance. Coating weight of the chromate film in that case from the viewpoint of corrosion resistance, it is preferably 10 mg / m ² or more as Cr deposition amount, whereas the upper limit of the Cr adhesion amount, from the viewpoint of adhesion between the film and the 100 mg / m ² Is preferred. still,
As a method of performing chromate treatment, a washing type (reaction type)
There are methods such as chromate treatment, coating type chromate treatment, and electrolytic chromate treatment, but the method is not particularly limited.
Any method can be used.

As described above, according to the present invention, a coated metal plate having excellent scratch resistance and deep drawability, which has excellent corrosion resistance and paintability, and which is resistant to contamination when used without coating. It is possible to provide a surface-treated metal plate exhibiting properties.

Further, in the case of parts such as home electric appliances, characters or figures are generally printed by silk printing or the like in addition to painting. In these applications, characters or lines after printing are blurred. It is required to print clearly without repelling. When printability is required for the surface-treated metal plate as described above, it is recommended to include a silane coupling agent in the film according to the present invention.

Further, by containing a silane coupling agent, not only the adhesion after coating (primary adhesion) but also the
It is also possible to improve coating film adhesion (secondary adhesion) after dipping in boiling water after coating. Although the mechanism of improving the adhesion of the coating film of such a silane coupling agent has not been completely elucidated, alcohol groups and silanol groups are generated by hydrolysis of an alkoxy group bonded to silicon in an aqueous solution. It is presumed that the generated silanol groups strengthen the bonding force with the coating film after coating.

With respect to the alkoxy group bonded to silicon in the silane coupling agent, the effect of improving the coating film adhesion is presumed to be due to the silanol group generated by the hydrolysis of the alkoxy group. It is preferably a lower alkoxy group such as a methoxy group or an ethoxy group. Among these, the alkoxy group is more preferably a methoxy group having a low boiling point of the alcohol generated by hydrolysis, considering that the alcohol generated after hydrolysis has an adverse effect on the film-forming properties of the film. As the silane coupling agent, a general silane coupling agent represented by the following formula (1) or (2) can be used.

[0028]

Embedded image

(R ₁ , R ₅ ; lower alkyl group, R ₂ , R
₍₃ , R ₄ ; lower alkoxy group) As described above, the present invention does not limit the kind of the silane coupling agent to be contained, but from the viewpoint of dispersibility and compatibility in an aqueous solution, the following (3) It is preferable to use a silane coupling agent having a glycidoxy group at the terminal as shown in the formula (4) or (4).

[0030]

Embedded image

(R _g : glycidoxy group, R ₂ , R ₃ , R
₄ ; a lower alkoxy group, R ₅ ; a lower alkyl group, R ₆ ;
Lower alkylene group)

The content of the silane coupling agent is 1.
When the amount is less than 0%, the effect of improving the adhesion of the coating film is insufficient, and a steel sheet having excellent adhesion to the coating film after coating, particularly secondary adhesion and printability cannot be obtained. When it is more than 0%, the effect of improving the coating film adhesion, particularly the secondary adhesion, is saturated, and the formed film becomes brittle, adversely affecting workability. It is recommended that the content be 1.0 to 10.0%.

As described above, the silane coupling agent has a remarkable effect on improving the secondary adhesion and printability of the coated film, but the printability and coatability are sufficient only by adding the silane coupling agent. Is not obtained, lithium silicate is selected as the main alkali metal silicate, the Li / Si ratio in the film is controlled, and the contents of Na and K contained in the alkali metal silicate are selected. By optimizing the surface treatment, it is possible to obtain, for the first time, a surface-treated metal plate excellent in primary adhesion, secondary adhesion and printability after coating.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the following examples do not limit the present invention. It is included in the technical range of.

[0035]

EXAMPLE 1 First, the following experiment was carried out for the purpose of examining the effect of the Li / Si ratio in the treatment liquid on corrosion resistance, scratch resistance, wettability and paintability. As the metal plate, a chromate-treated electric Zn-plated steel plate (Zn adhesion amount 20 g / m2)
² , Cr adhesion amount 20 mg / m ² , plate thickness 0.8 mm).

A comb-shaped graft polymer which is a graft copolymer of an acrylic resin and a silicone resin and has a silicone resin component of 35% is polymerized, and this is mixed with a mixed solution of lithium silicate and colloid of silicate. The treatment liquid containing 0% was applied to the surface of the above-mentioned original plate with a squeezing roll such that the Si weight after application and drying was 0.2 g / m ^2, and dried at a plate temperature of 80 ° C. Was formed to produce a surface-treated steel sheet. The mixed solution was prepared by adjusting the blending amount of lithium silicate and colloidal silicate so that the Li / Si ratio varied in the range of 0 to 1.0. 1
~ 14 test pieces were obtained.

The test pieces were tested for corrosion resistance, scratch resistance, wettability, and paintability as follows. (i) Corrosion resistance test A salt spray test was carried out according to 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

(Ii) Scratch resistance test Using a surface property tester (manufactured by HEIDON), two test materials were stacked, and abrasion due to mutual sliding was generated.
The flaw was visually evaluated. The evaluation criteria are shown below.
In addition, the size of the upper test material was 10 mm × 10 mm, and the load during sliding was 1 kg. ◎: extremely good (no flaws) ○: good (some flaws are seen but no problem) △: bad (flaws are noticeable) ×: extremely bad (flaws are noticeable)

(Iii) Wettability test The coating solution was applied on a steel plate with a squeezing roll, and the repellency of the surface after drying was visually observed and evaluated according to the following criteria. ◎: extremely good (no repelling at all) ：: good (slight repelling at the edge but no problem) △: bad (significant repelling at the edge or partial repelling at the center ×): extremely poor (repelling is remarkable over the entire surface)

(Iv) Paintability test An acrylic paint was applied to the obtained coated steel sheet to a thickness of 20 μm.
After baking at 150 ° C for 30 minutes, 100 square grids of 1 mm square are put with a cutter knife, and a tape peeling test is performed on the square grid. The film adhesion was evaluated. Li / of each mixed solution
Table 1 shows the Si ratio and the test results.

[0041]

[Table 1]

Inventive Example No. satisfying the Li / Si ratio: 0.2 to 0.6. Nos. 1 to 8 are excellent in all of corrosion resistance, scratch resistance, wettability and paintability. On the other hand, Comparative Example No. in which the Li / Si ratio was too small. In Comparative Examples Nos. 9 to 11, the corrosion resistance, scratch resistance and wettability were poor and the Li / Si ratio was too large. Nos. 12 to 14 are inferior in paintability.

Example 2 Next, the effect of the content of the graft polymer in the treatment liquid on the obtained surface-treated steel sheet was examined.

A mixture of an aqueous solution of lithium silicate and a colloid of silicate, in which a Li / Si ratio is 0.4, is a graft copolymer of an acrylic resin and a silicone resin. % In the same manner as in Example 1 except that a coating solution prepared by adjusting the treatment liquid by containing 0 to 15% by weight of a comb-shaped graft polymer which is a No. 15 to 28 surface-treated steel sheets were obtained. For these surface-treated steel sheets, a corrosion resistance test was performed by the above-described method, and a stain resistance test and a deep drawing workability test were performed by the following methods.

(V) Stain resistance test A test piece was painted with an oil-based red magic ink (manufactured by Uchida Yoko Co., Ltd.), allowed to stand for 24 hours, and then wiped off with a gauze soaked with ethanol to leave a mark of the remaining magic ink. Were evaluated visually (◎: extremely good, ○: good,
Δ: bad, ×: extremely bad).

(Vi) Deep drawing workability test A single press test was performed using an 80-ton crank press device, and the sliding surface of the molded product was subjected to mold galling and blackening (blackening resistance). ) Was evaluated visually to determine the deep drawability. The evaluation criteria are shown below. ◎: No mold seizure or blackening phenomenon at all ○: Slightly observed, but no problem level Δ: Mold seizure or blackening phenomenon conspicuous ×: Mold seizure or blackening phenomenon remarkably conspicuous The results are shown in Table 2.

[0047]

[Table 2]

Inventive Example No. Nos. 15 to 22 are excellent in all of corrosion resistance, stain resistance, and deep drawing workability. On the other hand, in the case of No. Nos. 23 and 24 have poor stain resistance, while if too large (Nos. 25 to 28), blackening occurs during drawing.

Example 3 Next, the relationship between the silicone content in the graft polymer and the properties of the resulting surface-treated steel sheet was examined. A mixture of lithium silicate and colloidal silicate, in which the Li / Si ratio is 0.4, has a silicone content of 0-6.
The same procedure as in Example 1 was carried out except that a coating liquid prepared by adding a comb-shaped graft polymer of an acrylic resin and a silicone resin in a range of 0% to prepare a treatment liquid was used.
o. 29 to 40 surface-treated steel sheets were obtained. These surface-treated steel sheets were examined for stain resistance, paintability, and deep drawability by the methods described above. The results are shown in Table 3.

[0050]

[Table 3]

In the inventive example No. 1 having a silicone content of 5.0 to 50.0% in the graft polymer. 29-35
Is excellent in stain resistance, paintability and deep drawability. On the other hand, Comparative Example N having too little silicone content
o. Comparative Examples Nos. 36 to 38 are poor in stain resistance and deep drawability and have too much silicone content. 39,4
0 indicates poor paintability.

Example 4 Next, the relationship between the contents of Na and / or K in the treatment liquid and the properties of the obtained surface-treated steel sheet was examined. In a mixed solution of lithium silicate and colloidal silicate, wherein the Li / Si ratio is 0.4, sodium silicate and / or potassium silicate are mixed with Na and / or K in an amount of 0 to 0.
Except that it was added varying in the range of 3.0% by weight,
In the same manner as in the first embodiment, 41 to 47 surface-treated steel sheets were obtained. For these surface-treated steel sheets,
A corrosion resistance test, a wettability test, and a deep drawing workability test were performed in the same manner as in Example 2. The results are shown in Table 4.

[0053]

[Table 4]

The content of Na and / or K is 1.0% by weight
The present invention example No. 41 to 44 are excellent in all of corrosion resistance, wettability and deep drawing workability. On the other hand, in Comparative Example No. 1 in which the content of Na and / or K exceeds 1.0% by weight. 45
-47 are inferior in corrosion resistance and wettability.

Example 5 Next, the relationship between the amount of coating film and the properties of the resulting surface-treated steel sheet was examined. A coating solution obtained in the same manner as in Example 1 except that a mixture of lithium silicate and colloidal silicate having a Li / Si ratio of 0.4 was used. And dried in the same manner as in Example 1 so as to obtain 0.025 to 1.0 g / m ^2.
o. 48 to 57 surface-treated steel sheets were obtained.

For these surface-treated steel sheets, a corrosion resistance test and a deep drawability test were performed in the same manner as in Examples 1 and 2, and the surface resistance was measured with a tester to evaluate the grounding properties as follows. . ◎: less than 50Ω ○: 50Ω or more and less than 100Ω Δ: 100Ω or more and less than 200Ω ×: 200Ω or more The results are shown in Table 5.

[0057]

[Table 5]

The amount of Si adhesion is 0.025 to 0.5 g / m ²
Of the present invention satisfying the range of the present invention. Nos. 48 to 53 are excellent in all of corrosion resistance, deep drawing workability and earthing property. On the other hand, in Comparative Example No. 1 in which the Si adhesion amount was too small. Comparative Example No. 54 was poor in corrosion resistance and deep drawability and had too much Si adhesion. 55 to 57 are inferior in grounding properties. Examples 6 to 11 described below were conducted for the purpose of examining the characteristics of the surface-treated metal plate when the silane coupling agent was added.

Example 6 A Li / Si ratio of 0 to 1.0 was prepared in the same manner as in Example 1 except that γ-glycidoxypropyltrimethoxysilane was contained at 5.0% by weight as a silane coupling agent. No. in the range of No. 101-114 test pieces were obtained. These specimens were tested for corrosion resistance, scratch resistance, wettability, and paintability (primary adhesion) by the methods described above. In addition, paintability (secondary adhesion) and printability were determined by the following methods. Was examined.

(Vii) Paintability Test (Secondary Adhesion) Each of the coated test pieces was immersed in boiling water for 1 hour, allowed to stand at room temperature for 1 hour, and then subjected to the same method as in the primary adhesion to measure the remaining amount of the coating film. The secondary adhesion was evaluated by the number of stitches.

(Viii) Printability test The obtained steel sheet was 0.2 m thick by silk screen printing.
m, 0.5 mm, and 1.0 mm lines were printed, and the sharpness of each line after printing was visually evaluated. The printing was performed using an epoxy paint and the baking conditions were 40 ° C. × 20 minutes. The evaluation criteria are shown below. ◎: No bleeding or bleeding ○: Slight bleeding is observed but no problem is observed △: Repelling or bleeding is noticeable ×: Repelling or bleeding is remarkable Table 6 shows the Li / Si ratio of each mixed solution and test results. Shown in

[0062]

[Table 6]

In the present invention, the Li / Si ratio is in the range of 0.2 to 0.6. Nos. 101 to 108 are excellent in all of corrosion resistance, scratch resistance, wettability, paintability and printability. On the other hand, in Comparative Example No. where the Li / Si ratio was too small. 109-1
Comparative Example No. 11 is inferior in corrosion resistance, scratch resistance and wettability, and has an excessively large Li / Si ratio. 112
-114 are inferior in paintability and printability.

Example 7 In the same manner as in Example 2 except that 5.0% by weight of γ-glycidoxypropyltrimethoxysilane was added as a silane coupling agent, the content of the organic resin in the treatment solution was reduced. The effect on the surface-treated steel sheet was examined. Table 7 shows the results
Shown in

[0065]

[Table 7]

When the content of the graft polymer is 0.5 to 1
Inventive Example No. Nos. 115 to 122 are excellent in all of corrosion resistance, deep drawing workability, stain resistance, paintability and printability. On the other hand, in Comparative Example No. 1 in which the content of the graft polymer was too small. Nos. 123 and 124 were inferior in corrosion resistance and stain resistance, and also had mold seizure. In Comparative Example No. 1 in which the content of the graft polymer was too large. In the case of 125 to 128, blackening occurred during deep drawing.

Example 8 In the same manner as in Example 2 except that 5.0% by weight of γ-glycidoxypropyltrimethoxysilane was added as a silane coupling agent, the silicone content in the graft polymer was reduced to the surface. The effect on the treated steel sheet was investigated.
The results are shown in Table 8.

[0068]

[Table 8]

Inventive Example No. 129 to 135 have a silicone resin content of 5.0 to 5 in the graft polymer.
0.0%, which is excellent in all of deep drawing workability, stain resistance, paintability and printability. On the other hand, in Comparative Example No. 1 in which the silicone content in the graft polymer was too low. 136-1
Comparative Example No. 38 is inferior in deep drawing workability and stain resistance and has too much silicone content. 139 and 140 are inferior in paintability and printability.

Example 9 In the same manner as in Example 4 except that 5.0% by weight of γ-glycidoxypropyltrimethoxysilane was contained as a silane coupling agent, Na and / or K in the treatment liquid were changed. Was examined for the relationship between the content of Pb and the properties of the resulting surface-treated steel sheet. The results are shown in Table 9.

[0071]

[Table 9]

The content of Na and / or K is 1.0% by weight
The present invention example No. 141 to 144 are excellent in all of corrosion resistance, wettability and deep drawing workability. On the other hand, in Comparative Example No. 1 in which the content of Na and / or K exceeds 1.0% by weight.
145 to 147 are inferior in corrosion resistance and wettability.

Example 10 Next, the relationship between the content of the silane coupling agent in the treatment liquid and the properties of the surface-treated steel sheet was examined. Li / Si ratio of 0.4
The test piece No. was prepared in the same manner as in Example 1 except that the silane coupling agent shown in Table 10 below was contained in an amount of 0 to 20.0% by weight. 148 to 160 were prepared, and the deep drawability and the paintability were examined by the above-described method.

[0074]

[Table 10]

The silane coupling agent is used in an amount of 1.0 to 10.0.
Inventive Example No. contained in the range of% by weight. 148-15
No. 5 is excellent in both deep drawability and paintability. On the other hand, when the silane coupling agent was not added or the content was too small, the comparative example No. 156,1
Comparative Example No. 57 was poor in secondary adhesion and contained too much silane coupling agent. Nos. 158 to 160 caused mold seizure during deep drawing.

Example 11 Except that 5.0% by weight of γ-glycidoxypropyltrimethoxysilane was contained as a silane coupling agent, the same procedure as in Example 5 was carried out to obtain the coating amount of the film and the resulting surface treatment. The relationship with the properties of the steel sheet was investigated. The results are shown in Table 11.

[0077]

[Table 11]

The Si adhesion amount is 0.025 to 0.5 g / m ²
Of the present invention satisfying the range of the present invention. 161 to 166 are excellent in all of corrosion resistance, deep drawing workability and earthing property.
On the other hand, in Comparative Example No. 1 in which the Si adhesion amount was too small. Comparative Example No. 167 is poor in corrosion resistance and deep drawability and has too much Si adhesion. 168 to 170 are inferior in grounding properties.

[0079]

As described above, the present invention is a resin-coated metal sheet having excellent scratch resistance and deep drawability, which is excellent in corrosion resistance and paintability, and has stain resistance. As a result, it has become possible to provide a surface-treated metal plate that can be used without painting. Further, it has become possible to provide a surface-treated metal plate which is excellent in secondary adhesion and printability in addition to the above characteristics.

Continuation of the front page (56) References JP-A-52-76236 (JP, A) JP-A-8-267002 (JP, A) JP-A-6-57441 (JP, A) JP-A-4-285179 (JP) , A) JP-A-1-312082 (JP, A) JP-B-44-19686 (JP, B1) (58) Fields investigated (Int. Cl. ⁶ , DB name) C23C 22/00-22/86

Claims (10)

(57) [Claims] 1. A surface-treated metal plate on which a coating containing an alkali metal silicate or an alkali metal silicate and a silicate colloid and further containing an organic resin is formed, wherein the alkali metal silicate is lithium silicate. And a (Li atom / Si atom) ratio in the coating is 0.2 to 0.6, and the organic resin is a graft polymer and has a silicone resin component. . 2. The surface-treated metal plate according to claim 1, wherein the graft polymer comprises a silicone resin component and an acrylic resin component. 3. The surface-treated steel sheet according to claim 1, wherein the graft polymer is a comb-shaped graft polymer comprising a trunk polymer and a branch polymer, and a part or all of the branch polymer is a silicone resin. 4. The graft polymer according to claim 1, wherein the content of the silicone resin component is 5 to 50% by weight.
4. The surface-treated metal plate according to any one of 3. 5. The surface-treated metal sheet according to claim 1, wherein the content of the graft polymer in the coating is 0.5 to 10.0% by weight. 6. The surface-treated metal sheet according to claim 1, wherein the total content of Na and / or K present as impurities in the alkali metal silicate is 1.0% by weight or less. 7. The coating amount of the coating is 0.025 to 0.025 as Si.
Surface-treated metal sheet according to any one of claims 1 to 6 is 0.5 g / m ^2. 8. The surface-treated steel sheet according to claim 1, wherein the coating contains a silane coupling agent in an amount of 1.0 to 10.0% by weight. 9. The surface-treated metal sheet according to claim 8, wherein the silane coupling agent is at least one selected from the group consisting of silane coupling agents represented by the following formula (1) or (2). . Embedded image (R ₁ , R ₅ ; lower alkyl group, R ₂ , R ₃ , R ₄ ; lower alkoxy group) 10. The surface-treated metal plate according to claim 8, wherein the silane coupling agent is at least one selected from the group consisting of silane coupling agents represented by the following formula (3) or (4). . Embedded image (R _g; glycidoxy _{group, R 2, R 3, R} 4; a lower alkoxy group, R _5; a lower alkyl group, R _6; lower alkylene group)