JP2003221679A - Surface treated steel sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface treated steel sheet which has high performance as a base steel sheet for an organic coated steel sheet, does not contaminate a roll in an organic coating line, and can be easily and inexpensively manufactured. <P>SOLUTION: This surface treated steel sheet has a chromate film on the surface of the zinc-base plated steel sheet, which contains dry SiO<SB>2</SB>and a water- soluble organic resin, and Cr in a coating mass of 10-100 mg/m<SP>2</SP>, and which makes a mass ratio of dry SiO<SB>2</SB>to Cr therein satisfy 2≤[dry SiO<SB>2</SB>]/[Cr]≤6, and a mass ratio of the dry SiO<SB>2</SB>to the water-soluble organic resin therein satisfy 1≤[dry SiO<SB>2</SB>]/[water-soluble organic resin]≤10. <P>COPYRIGHT: (C)2003,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] TECHNICAL FIELD The present invention relates to a coated steel sheet and a vinyl chloride
Require high film adhesion such as minated steel sheet
Surface-treated steel sheet suitable as a base steel sheet for organic coated steel sheets
Related. [0002] 2. Description of the Related Art Conventionally, painted steel sheets and PVC laminated steel sheets have been used.
As a base steel sheet, adhesion and corrosion resistance with organic film are required.
Galvanized steel sheet or zinc-based alloy coated steel sheet to secure
Surface is treated with phosphate or coated chromate
Surface-treated steel sheets have been used. Especially recently,
Coating chromate treatment, which is easier to process than acid salt treatment
The number of cases to do is increasing. [0003] The coating type chromate treatment consists of Cr and SiO.₂
It uses a chromate treatment solution whose main component is
O₂Effect of silanol group on SiO and SiO₂By
Forming fine irregularities on the chromate film.
High adhesion with organic coatings
is there. In particular, dry SiO₂Is the effect of forming fine irregularities
, A particularly excellent adhesion can be obtained. This
For organic coatings where high adhesion is required
Contains dry SiO₂Coating-type chromate treatment using
Commonly used. [0004] However, the conventional coating type
The following films are formed by chromate treatment.
There's a problem. That is, dry SiO 2₂Fine by addition of
Chromate film with irregularities coated with organic film
Despite exhibiting a high degree of adhesion when painted, the coating line
Paint or laminating
When the steel plate surface comes into contact with the roll in the line before
Part of the film is transferred to the roll, and the roll is contaminated.
Problem. As a result, this contaminated
Rolls on the clean steel sheet surface
The kimono is transferred, and finally affects the surface quality after organic coating
It has an impact. To eliminate such problems
The rolls need to be cleaned frequently, but the operability is notable.
Will decrease. [0005] In addition, the contamination of the roll as described above is eliminated.
To achieve this, dry SiO₂To reduce the amount of
It is effective to reduce surface irregularities, but dry Si
O₂Adhesion with organic film decreases when adding less amount
Resulting in. Also, Ni, Co, etc. are applied to the galvanized surface.
After coating, adhere by applying coating chromate
Performance can be improved, but the processing steps are complicated
As a result, productivity is reduced and manufacturing costs are increased. The object of the present invention is therefore to
To solve the problems of the next technology, and as a base steel sheet for organic coated steel sheets
It has excellent performance and low
Simple and low-cost manufacturing without polluting
It is to provide a surface-treated steel sheet that can be used. [0007] [Means for Solving the Problems] The problems as described above are solved.
The surface-treated steel sheet of the present invention is a zinc-coated steel sheet.
Dry SiO on the surface₂And a water-soluble organic resin,
Cr adhesion amount of 10 to 100 mg / m², Dry SiO₂When
When the mass ratio of Cr is 2 ≦ [dry SiO 2₂] / [Cr] ≦ 6,
Dry SiO₂And the mass ratio of water-soluble organic resin is 1 ≦ [dry S
iO₂] / [Water soluble organic resin] ≦ 10
It is a surface-treated steel sheet having a coating. [0008] BEST MODE FOR CARRYING OUT THE INVENTION The details of the present invention and the reasons for limitation will be described below.
explain. The surface-treated steel sheet of the present invention is a galvanized steel sheet.
Dry SiO on the surface of₂And water-soluble organic resin
Chromium in which the proportions of these components and Cr are regulated within specified ranges
Has a coating film. Here, the zinc-based plated steel sheet is zinc-coated steel sheet.
It is possible to use galvanized steel sheets and zinc-based alloy-coated steel sheets.
For example, electro-galvanized steel sheet, hot-dip galvanized steel
Sheet, galvannealed steel sheet, 5% Al-Zn alloy
Steel plate, 55% Al-Zn alloy plated steel plate, Ni, F
e, one or more of Cr, Mn, Co, Al, Mg, etc. and Zn
And the like. [0010] Cr in the chromate film causes the plating surface to
Passivation to improve corrosion resistance and SiO₂of
It is a component that functions as a binder. C for Cr
r^{6 +}With Cr³⁺Must be included
Therefore, both should be included at the stage of the processing solution.
Is preferred. The ratio is 30 as a Cr reduction rate.
７０70% can be used.
The use of mineral acids such as phosphoric acid to
It is not preferable because the adhesion is reduced. Therefore, C
The r reduction ratio is 40 to 5 which can be reduced without using a mineral acid.
It is desirable to set it to 0%. The amount of Cr in the chromate film is determined by organic coating
It greatly affects the later properties and is 10 mg / m²Less than corrosion resistant
Properties and adhesion are reduced. On the other hand, 100 mg / m²Over
Increases the soluble components, resulting in a film with poor water adhesion.
Will be done. For this reason, the Cr adhesion amount is 10 to 100 m.
g / m², Preferably 20 to 60 mg / m²And The chromate film contains SiO₂As an ingredient
Dry SiO₂Is added. Dry SiO₂Is tetrachloride
Silicon (SiCl₄) At high temperature (above 1000 ° C)
Understand (2H₂+ O₂+ SiCl₄→ SiO₂+ 4HC
l) Silica produced by the above method. SiO₂Is organic
It is effective for improving the adhesion to the film and the corrosion resistance. Especially dry
Formula SiO₂The greater the effect, the greater the amount
The adhesion is improved. However, dry SiO₂Many additions
When the steel sheet surface touches the roll of the production line
Is easily transferred to a roll. In chromate film
SiO₂When only fumed silica is added as
Dry SiO inside₂And the mass ratio of Cr and [Dry SiO ₂] /
When [Cr] <2, transfer to a roll is difficult, but organic
A film with poor adhesion and corrosion resistance to the film is formed.
On the other hand, [dry SiO₂] / [Cr] ≧ 2, organic skin
Transfer to a roll, although it has excellent adhesion to the film and corrosion resistance
An easily formed film is formed. Therefore, the adhesion and the corrosion resistance with the organic film are improved.
Additives and their amounts for achieving both roll transfer resistance
As a result of examining the
In order to obtain a high degree of roll transfer resistance,
That water-soluble organic resin is particularly effective
I understood. This is because the water-soluble organic resin is dry SiO₂Compared to
Fine irregularities to improve the adhesion to the organic film
Has little effect, but has many functional groups such as hydroxyl groups.
Because SiO₂Coagulation of film by functioning as a binder for
Strength and chemical adhesion to organic film
Roll transfer resistance without lowering adhesion
It is thought that this is because it can be improved. The water-soluble organic resin is dry SiO₂Mass ratio with
And 1 ≦ [dry SiO₂] / [Water-soluble organic resin] ≦ 10
It is necessary to add in a range that satisfies. [Dry Si
O₂] / [Water-soluble organic resin] <1, adhesion with organic film
Poor sex. On the other hand, [Dry SiO₂] / [Water-soluble organic tree
Grease> 10, the roll transfer resistance is poor. In addition, both
A more preferable mass ratio is 2 ≦ [SiO₂] / [Water-soluble organic tree
Fat] ≦ 5. Also, as a water-soluble organic resin, for example,
Novolak tie made by modifying novolak resin
A water-soluble polyol resin can be used. Also, dry SiO 2₂And the mass ratio of Cr to 2
≤ [dry SiO₂] / [Cr] ≦ 6. [Dry Si
O₂] / [Cr] <2, the adhesion to the organic film is poor,
On the other hand, [Dry SiO₂] / [Cr]> 6, the film is thick
Therefore, a film having particularly poor workability is obtained. And both of them
A more preferable mass ratio is 2 ≦ [SiO₂] / [Cr] ≦ 4
is there. Dry SiO₂Particle size is large for adhesion to organic film
And the average particle size is 9 to 14 nm is the most excellent.
Have been. In addition, the above-mentioned chrome
As a method of forming a coating film, Cr⁶⁺Part of
Chromic acid and dry SiO₂And water-soluble organic resin
The added processing solution can be used. Of these additional components
Above all, dry SiO₂Has low dispersibility and its concentration
Therefore, the processing liquid may have a high viscosity and the coating property may be reduced.
There is sufficient mechanical agitation for the processing solution
In addition, it is preferable to adjust the concentration to be easily applied.
Apply the above treatment liquid to the surface of the plated steel sheet using a roll coater or the like.
After applying uniformly, heat and dry without washing
No. In the heat drying, for example, 120 ° C. using induction heating or the like.
Heat above. [0017] [Example 1] Galvanized steel sheet (sheet thickness 0.5 m)
m, plating amount Z27) according to the coating composition shown in Table 1.
Coating solution with a roll coater and wash it with water.
The specimen was heated and dried at a sheet temperature of 120 ° C. processing
The Cr reduction rate of the liquid is 40% and does not contain mineral acids such as phosphoric acid
A processing solution was used. In addition, dry SiO₂Japan Airlines
"Aerosil 200" (trade name) manufactured by Le Co., Ltd., organic tree
Nonionic novolak type water-soluble polyol for fat
(Having 160 hydroxyl groups) was used. The evaluation of the roll transfer resistance was performed using the test materials 500
After passing 0 m through the rubber roll, the material adhering to the roll is
Sample of the tape using fluorescent X-rays.
Measure the output strength and transfer the film to the roll according to the following evaluation criteria
The degree to which it was done was evaluated. ：: Cr detection intensity less than 50 cps ：: Cr detection intensity of 50 cps or more and less than 200 cps Δ: Cr detection strength 200 cps or more, 1000 cps not yet
Full ×: Cr detection intensity 1000 cps or more The adhesion was evaluated by using an acrylic-based
After applying the adhesive to a thickness of 3 μm,
JIS No.5 is obtained by thermocompression bonding a rubber sheet at a plate temperature of 200 ° C.
After processing into a test piece and stretching it by 20%,
Perform 4T bending with the notch in place.
The film peel width was measured and evaluated according to the following criteria. ：: No peeling from notch, or peeling width from notch
0.5mm or less ：: Peeling width from notch part 0.6 mm or more, 1 mm or less B: peeling width from notch portion of 1.1 mm or more and 2 mm or less X: Peeling width from notch 2.1 mm or more Table 1 shows the results of the above performance evaluation tests.
No. 1 to No. 3 did not add a water-soluble organic resin
Example: [Dry SiO₂] / [Cr] is 2 or more
And roll transfer resistance is reduced, and if it is less than 2, the skin is poor in adhesion.
It becomes a film. No. 4 is [Dry SiO₂] / [Water soluble
Is less than the range of the present invention, and the adhesion is poor.
I have. No. 7 is [Dry SiO₂] / [Water-soluble organic tree
Fat) exceeds the scope of the present invention, and furthermore, dry SiO 2₂] /
[Cr] is also an example beyond the scope of the present invention,
Both properties and adhesion are inferior. No. 10 is dry S
iO₂This is an example in which no roll was added.
Excellent but poor adhesion. No. 11 with Cr
When the amount of coating is less than the range of the present invention, 13 has a Cr adhesion amount
This is an example that exceeds the scope of the present invention, and both have poor adhesion.
I have. On the other hand, No. 1 of the present invention example. 5, no.
6, no. 8, No. 9, No. 12 is an excellent low resistance
Transferability and adhesion are obtained. [0021] [Table 1] [0022] As described above, the surface-treated steel sheet of the present invention
Has high adhesion to organic film and
It is difficult to transfer the film to the rolls in the line.
Surface can be kept clean, which results in excellent surface quality.
It is possible to manufacture continuously organic coated steel sheets
You.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C23C 28/00 C23C 28/00 C (72) Inventor Keiji Yoshida 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nippon Kokan Co., Ltd. (72) Inventor Masaaki Yamashita 1-2-1 Marunouchi, Chiyoda-ku, Tokyo F-term in Nihon Kokan Co., Ltd. (reference) 4J038 DA041 EA011 HA216 HA446 NA03 NA12 PC02 4K026 AA02 AA07 AA12 AA13 AA22 BA06 BB07 CA16 CA19 CA20 CA39 CA41 DA02 DA11 4K044 AA02 AB02 BA10 BA14 BA15 BA21 BB03 BC04 CA11 CA18 CA53 CA62

Claims (1)

Claims 1. A dry SiO 2 coating is applied to the surface of a galvanized steel sheet.
₂ and a water-soluble organic resin, and the Cr adhesion amount is 10 to 1
00 mg / m ² , the mass ratio between dry SiO ₂ and Cr is 2 ≦
[Dry SiO ₂ ] / [Cr] ≦ 6, and has a chromate film in which the mass ratio of dry SiO ₂ and water-soluble organic resin is 1 ≦ [Dry SiO ₂ ] / [water-soluble organic resin] ≦ 10. Surface treated steel sheet.