JPH02265742A - Aluminum-plated steel sheet covered with silicone resin - Google Patents

Abstract

PURPOSE:To give electric conductivity to a film and to make resistance welding possible even to a thick resin film by compounding an organopolysiloxane resin with a specified amt. of aluminum powder and making the thickness of the film into a specified thickness. CONSTITUTION:An aluminum powder used is a flaky non-leafing type and the loading thereof is 5-50 pts.wt. based on 100 pts.wt. organosiloxane resin. The thickness of the resin film is 3-10mum with which the film thickness is easily controlled when coated. To manufacture a silicone resin-covered steel sheet, e.g. a molten Al-plated steel sheet or a molten 4% Al-Zn-plated steel sheet with a sheet thickness of 0.6mm and the amt. of adhesion of 40g/m<2> (on both surfaces) is degreased with an alkali degreasing agent, washed with water and air-dried or forcibly dried by means of hot air. Then, a silicone resin treated by means of a specified adjustment is compounded with an aluminum powder and said steel sheet is coated with this paint by means of a roll coat method and dried at 300 deg.C for 3min or at 350 deg.C for 2min and then cooled with water or air-dried resistance welding can be performed thereby even if the thickness of a resin film is as thick as 3-10mum and manufacturing efficiency and yield can be also improved.

Description

Detailed Description of the Invention (Industrial Application) The present invention is easy to manufacture and can be used in applications that require heat resistance of 250 to 350°C and long-term corrosion resistance, such as ducts for automobiles and fan heaters. The present invention relates to a silicone resin coated aluminum plated steel sheet suitable for

(Prior art) Since the exterior and interior of automatic 77 rollers are exposed to road freezing agents and high-temperature ELF gas, conventionally aluminum-plated steel sheets and aluminum alloy-plated steel sheets with excellent corrosion resistance and heat resistance have been used. There is.

However, since the catalytic converter was incorporated into the automobile exhaust system and the temperature and composition of the 77Fu changed, the internal parts of the 77 Fu began to corrode severely. This is due to the fact that due to traffic congestion, the stop time becomes longer, the temperature of the 77 is lowered, and condensate tends to stay inside the 77, and the installation of a catalytic converter also causes the problem. # This is because the gas components change and corrosive sulfate ions, chloride ions, ammonium ions, etc. are produced in the condensate.

Therefore, the present inventors developed a muffler material that solved this problem by first applying the general formula Ra(CsHs)bsiO to an aluminum-plated steel plate or an aluminum alloy-plated steel plate.
n-a-b-c(Ofl)c (in the formula, R is an unsubstituted or substituted furkyl group or alkenyl group, and a and b are 0.
6≦锜≦1.3.0.35≦b≦0.95, and 1.
A positive number satisfying 4≦a+b≦1.7, C indicates that the proportion of hydroxyl groups bonded to silicon atoms in this compound is 0.0
A silicone resin-coated aluminum plated steel sheet obtained by applying an organoborin loxane resin (having a value of 1 to 3.0% by weight) to a film thickness of 0.5 to 2 μm and drying it. (Japanese Unexamined Patent Publication No. 63-172)
No. 640).

(Problems to be Solved by the Invention) Conventionally, this plated steel sheet was produced using a continuous coating line using a roll coater, but the coating thickness was reduced to 0.5.
Unless it is extremely thin, about 2 μm, resistance welding (spot welding) will not be possible when assembling it to 77 mm. Therefore, Or7 siloxane resin was diluted with +t solvent and coated with a roll coater, but it was difficult to control the resin and film thickness to less than 2μ pupil over the entire length of the steel strip, so conventionally the line speed was slowed down. This reduces manufacturing efficiency or sacrifices product yield.

(Means for Solving the Problems) According to the present invention, 5 to 50 parts by weight of aluminum powder is disposed per 100 parts by weight of organopolysiloxane resin, and the film thickness can be increased to 3 to 10 μm.

(Function) When conductive aluminum powder is blended into a resin, applied, and dried, the formed resin skin wX thickness becomes conductive. Therefore, resistance welding is possible even if the resin and film thickness is as thick as 3 to 10 microns.

What shape and shape is the aluminum powder mixed here?
Although it may be of high quality, it is preferable to use a non-leaching type with septa-like shapes. If a leaving type is used, white rust is likely to occur because aluminum powder is present on the surface of the resin skin II. Corrosion resistance will decrease.

The blending amount of aluminum powder is 0 or nonoxane (
5 to 50 parts by weight per 100 parts by weight of fat. If the weight is less than 5 parts, if the resin and film thickness are 3 to 4 μm, the proportion of welding failures will increase in resistance welding, and if it exceeds 50 parts by weight, there will be no problem in resistance welding. Corrosion resistance decreases because the resin content in the resin film decreases.

The resin and film thickness is 3μ, which makes it easy to control the film thickness during painting.
argue. However, if the thickness exceeds 10μ, it will lead to a significant increase in manufacturing costs, so it should be less than 10μ.

(Example) A fused^1 plated steel plate and a 4%^1-Zn fused plated!1w4 plate, both of which have a thickness of 0.61 and a coating weight of 40 g/m'' (both sides), were treated with a commercially available alkaline degreaser. After degreasing and washing with water, or degreasing and washing with water, phosphate chromate treatment, washing with water, and forced drying with air or hot air.Next, each silicone resin was prepared as follows.
A coating material was prepared by blending a 7-luminium powder paste of the phosphorescent type, which was applied by the roll foot method, dried at 300.degree. C. for 3 minutes or at 350.degree. C. for 2 minutes, and cooled in water or air-dried.

Resin A> PIlzSiCI23 0 mo1%, Ph5iC1
s20 theory o1%, Me2SiC1z 30
A mixture of mo1% mo1 and MeSiCI320 mo1% was dissolved in trichlorethylene and hydrolyzed, then trichlorethylene was distilled off and polymerized to prepare a xylene solution with a nonvolatile content of 50%. The viscosity of this solution (at 25°C) was 50 centistokes, the hydroxyl group content was 1.0% by weight,
Average composition formula: 8 formula % A mixture was prepared in the same manner as resin A, and y14 g of a xylene solution with a nonvolatile content of 5096 was poured. Solution viscosity (25℃) is 130
centistokes, hydroxyl group content 0.5% by weight, average composition formula Neo, sr'ho, tsiO+, zi
s(OH)o, ox.

<Tree@C> Ph2SiClz 30 mo1%, Ph5iCIz
30 mo1%, MezSiClz 20 mo1%
A xylene solution with a non-volatile content of 50% was prepared using a mixture of 20 mo1% of MeSiCls and 20 mo1% of the resin. The solution viscosity (25°C) is 130 centistokes,
Hydroxyl group content 0.5% by weight, average composition formula Meo, 5Ph
o, 1SiO+, zss(OH). ,. .

Met.

<Resin D> Ph2SiClz 1 6 mo1%, Ph5i
Cls 1 6 mo1%, He2SiC1,24m
A xylene solution with a non-volatile content of 50% was prepared using a mixture of 1% o and (/He5iClz 44 mo1%) in the same manner as Resin A.The solution viscosity (25°C) was 150 centistokes, and the hydroxyl group content was 0.3 wt %, average compositional formula Me=, *tPho, 4m5iO+, ts(OH
)*, -x.

Ph5iC1z 40 mo1%, MeSiCls 2
A xylene solution with a non-volatile content of 60% was prepared in the same manner as resin A using a mixture of 0so1% and t4e2sic1.40 mo1%.

The solution viscosity (at 25° C.) was 20 centistokes, the hydroxyl group content was 5.0% by weight, and the average composition formula was 8%.The mixture was prepared in the same manner as FM fat A to prepare a xylene solution with a non-volatile content of 50%. Solution viscosity (25"C) is 50 centistokes, hydroxyl group content 0.7% by weight, average composition formula Men, s++Pho, 5ssiO+, +
It was 5 (011) o, os.

<! H fat G> Ph5iCIs 20 mo1%, He2SiC123
A xylene solution with a non-volatile content of 50% was prepared in the same manner as Resin A using a mixture of 0 mo1% and He5iCl and 50 mo1%.

The solution viscosity (at 25° C.) is 150 centistokes, the hydroxyl group content is 0.5% by weight, and the average composition formula is 8%.
The following tests were conducted.

(1) Corrosion resistance test of heated surface The test was conducted by immersing the test piece in a beaker containing a test solution containing 2,500 ppm of ammonium ions and 500,011 pp of chlorine ions, pH 6, and temperature of 80°C.

(2) Corrosion resistance test after heating As shown in Figure 1, the test piece 1 was placed in an atmospheric circulation type gear opener 2 and heated at 300°C for 200 hours.
After heating, as shown in Figure 2, ammonium ion 2500 pps+, salt 1 ion 5000 ppm%
Place the test piece 1 so that it is half immersed in a beaker 4 containing a test solution 3 with a pH of 6 and a temperature of 80°C, and then
As shown in Figure 3, it was immersed in a constant temperature water bath 5 for 48 hours at 80°C.
The test was carried out by maintaining the temperature at ℃.

(3) 10% Stretching Test An unheated test piece was subjected to 10% stretching, and an immersion test as shown in FIGS. 2 and 3 was conducted in the manner described above.

(4) Spot welding test With the resin surfaces of two test pieces aligned, spot welding was performed under the following conditions: pressurizing force 300 kgf, welding current 8^, energization time 10 cycles, electrode tip diameter 4.2...I I did it.

The results are shown in Table 1 along with the manufacturing conditions.

(Effects) As described above, when aluminum powder is blended with the ORGA/siloxane resin to impart conductivity to the resin film, resistance welding is possible even if the resin film is thickened to 3 to 10 μm. Therefore, manufacturing of aluminum-based plated steel sheets becomes easy, and manufacturing efficiency and product yield can be improved.

[Brief explanation of drawings]

Figures 1 to 3 show the 77-Ra1 corrosion practice test method.
Figure 1 shows the test piece being heated, Figure 2 shows the test piece immersed in the test solution in the beaker after the heating test, and Figure 3 shows the test piece placed in the beaker in a constant temperature bath. It shows the state in which it is held with fi crushed.

Claims (1)

[Claims] General formulas for aluminum-plated steel sheets or aluminum alloy-plated steel sheets▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R is an unsubstituted or substituted alkyl group or alkenyl group, and a and b are 0 .6≦a≦1.3, 0.35≦b
≦0.95 and a positive number satisfying 1.4≦a+b≦1.7, c is a positive number such that the proportion of hydroxyl groups bonded to silicon atoms in this compound is 0.01 to 3.0% by weight. In an aluminum-based plated steel sheet formed by coating and drying an organopolysiloxane resin shown in
5 to 50 parts by weight of aluminum powder is blended per 100 parts by weight of organopolysiloxane resin, and the film thickness is 3 to 10 parts by weight.
A silicone resin coated aluminum plated steel sheet characterized by having a thickness of μm.