JPH06122174A - Colored polyolefin coated steel - Google Patents

Abstract

(57) [Summary] [Object] To provide a colored polyolefin-coated steel material having a polyolefin coating of various colors and having an excellent appearance. [Structure] The surface of the steel material 1 that requires aesthetic appearance is subjected to a surface treatment, and a black polyolefin layer 5 containing carbon black and a weathering agent, a coloring pigment, and a different weathering agent are added through a modified polyolefin adhesive layer 4. A colored polyolefin-coated steel material, which is obtained by sequentially laminating the colored polyolefin layer 6 described above.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to steel sheet pile members used in the ocean, rivers, harbors and the like, H-section steels, section steels for wall connection, steel pipe piles, square steel pipe piles, steel pipe sheet piles, steel plate and other steel structure members. More specifically, the present invention relates to a colored polyolefin-coated steel material which is colored in various colors and has excellent weather resistance, which prevents cracking and fading of the colored layer due to light, especially ultraviolet rays, at the same time.

[0002]

2. Description of the Related Art A conventional polyolefin-coated steel material is a polyolefin coating such as black polyethylene having excellent corrosion resistance. However, due to the recent increasing market needs for the beauty of steel structures in cityscapes, rivers, and ports, it has been desired to develop polyolefin-coated steel materials that are colored in various colors, are in harmony with the environment, and have excellent corrosion resistance. There is. To meet such needs, a method of coating a steel material with a polyolefin to which various color pigments are added has been proposed.

[0003]

However, in such a conventional steel material coated with a colored polyolefin, when ultraviolet rays are exposed for a long period of time, cracks are generated from the surface of the colored polyolefin coating to impair the corrosion resistance, and the color is The color fades and the aesthetics are impaired. In order to prevent cracking and discoloration of the surface, there are proposals of various hindered amine weatherproofing agents and UV absorbers, but simply adding these weathering-resistant additives, for example, in an outdoor exposure test for about 5 years, While cracking from the surface of the coating impairs corrosion resistance,
Significant fading occurs and the aesthetics are also impaired. in this way,
It is difficult for the conventional technology to prevent the generation of surface cracks and the fading at the same time.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that carbon black and a specific hindered amine are attached to the surface of a steel material that has been subjected to a base treatment via a modified polyolefin adhesive. The inventors have found that the above-mentioned problems can be solved by sequentially laminating a black polyolefin containing a weathering agent and a colored polyolefin containing a specific hindered amine weathering agent and a coloring pigment, and have reached the present invention.

That is, according to the present invention, as shown in FIGS. 1 to 8, for example, a steel material, steel sheet pile, H-section steel, shaped steel for connecting walls, steel pipe pile, square steel pipe pile, steel pipe sheet pile, etc., needs to be aesthetically pleasing. The surface is removed by blasting or the like to remove scales, the chromate film 2 and the epoxy primer layer 3 are sequentially laminated and subjected to an undercoating treatment, and carbon black is applied to the surface through a modified polyolefin adhesive layer 4 to a thickness of 0.1. ~ 5 wt% and bis (2,
Black polyolefin layer 5 containing 0.5 to 5% by weight of 2,6,6-tetramethyl-4-piperidyl) sebacate
0.1 to 10% by weight of a coloring pigment and poly [{6- (1,
1,3,3-tetramethylbutyl) imino 1,3,5
-Triazine-2,4-diyl} {(2,2,6,6-
Tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}] 0.1 to 2% by weight of a colored polyolefin layer 6 was sequentially laminated. It is a characteristic polyolefin-coated steel material. Hereinafter, the present invention will be described in detail.

The steel materials used in the present invention are steel plates made of alloy steel such as carbon steel and stainless steel, steel sheet piles, H-section steels, section steels for connecting walls, steel pipe piles, square steel pipe piles and steel pipe sheet piles. Also,
For the purpose of improving the corrosion resistance of the steel material, zinc, aluminum, chromium or other plating on the surface, zinc-aluminum, zinc-nickel or other alloy plating, inorganic fine particles such as silica or titanium oxide are dispersed in the plating or alloy plating. It is also possible to use one that has been subjected to dispersion plating.

When the colored polyolefin-coated steel material of the present invention is manufactured, the surface treatment of the steel material is performed by blasting the surface of the steel material with grit blast, sand blast or the like to remove rust, and then chromate treatment and epoxy primer are applied and cured. Then, the base treatment is performed, and then the modified polyolefin adhesive layer 4 obtained by modifying the polyolefin with maleic anhydride or the like is coated, and then the black polyolefin layer 5 and the colored polyolefin layer 6 of the present invention are coated. Then, it suffices that the modified polyolefin adhesive layer and the black polyolefin layer are firmly laminated and coated on the surface of the coated steel material, and as a base treatment, a conventionally known chromate treatment,
Epoxy primer, phosphate treatment, silane coupling treatment alone, or a combination of these primer treatments can be used.

The modified polyolefin adhesive layer 4 of the present invention,
As the polyolefin used for forming the black polyolefin layer 5 and the colored polyolefin layer 6, polyethylene, polypropylene, propylene, 1-butene, 4-
A copolymer of ethylene with an α-olefin such as methyl-1-pentene, 1-hexene or 1-octene is used. As the modified polyolefin adhesive, a modified polyolefin obtained by modifying a polyolefin with an acid anhydride such as maleic anhydride, a modified polyolefin prepared by adding an elastomer such as ethylene-propylene rubber to the polyolefin with an acid anhydride, or a modification thereof Although an adhesive obtained by diluting polyolefin with polyolefin is used, other polyolefin adhesives can be used.

In order to prevent discoloration and cracking of the colored polyolefin layer due to ultraviolet rays at the same time, the black polyolefin layer contains 0.1 to 5% by weight of carbon black and bis (2,2,6,6-tetramethyl-). 0.5 to 5% by weight of 4-piperidyl) sebacate was added, and 0.1 to 10% by weight of a coloring pigment was added to the colored polyolefin layer, and poly [{6- (1,1,3,3-tetramethylbutyl ) Imino 1,3,5-triazine-2,4-diyl}
{(2,2,6,6-tetramethyl-4-piperidyl)
Imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}] 0.1-2% by weight
Need to be added. Among them, black polyolefin is added with carbon black in the range of 0.1 to 5% by weight, and a specific hindered amine weathering agent, that is, bis (2,2,6,6-tetramethyl-4-piperidyl).
When sebacate is added in an amount of 0.5 to 5% by weight, the effect of preventing cracking and fading of the upper colored polyolefin layer is exhibited. The above-mentioned bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate is Sanol LS77 manufactured by Sankyosha.
0 is available. As a color pigment to be added to the colored polyolefin, a preferable color tone is selected from the landscape of the colored polyolefin-coated steel, isoindolinone yellow (yellow), quinacridone red (red), perinone red (red), phthalocyanine blue (blue), phthalocyanine. Organic pigments such as green (green), inorganic pigments such as titanium oxide (white), chromium oxide (green), iron oxide red (red), iron oxide (yellow), titanium yellow (yellow), either alone or in a mixture. Color it. When the addition amount of the above-mentioned coloring pigment is added to the polyolefin in the range of 0.1 to 10% by weight, when the addition amount of the pigment which exhibits the effect of preventing cracking and discoloration of the colored polyolefin layer exceeds 10% by weight, It is not preferable because the impact resistance of the coating deteriorates. Further, in the colored polyolefin of the present invention, it is necessary to add a specific amount of a specific hindered amine-based weatherproofing agent in order to exert an effect of preventing crack generation and discoloration. That is, the colored polyolefin includes poly [{6- (1,1,3,3-tetramethylbutyl) imino 1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetra- Methyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}] is added in an amount of 0.1 to 2% by weight. The above poly [{6- (1,1,3,3-
Tetramethylbutyl) imino 1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,
As 2,6,6-tetramethyl-4-piperidyl) imino}], CHIMASS manufactured by Ciba-Geigy Ltd.
ORB944LD can be used. Further, when the sheet can be used for forming the black polyolefin layer and the colored polyolefin layer, as shown in FIG. 9, the black polyolefin 5 and the colored polyolefin 6 are extruded from the two-layer T die 7 in two layers to form a sheet. An electron beam crosslinked colored / black polyolefin laminated sheet obtained by forming a two-layer sheet 9 by a roll 8 and irradiating an electron beam from the surface to crosslink is used.

Next, the method for producing the colored polyolefin-coated steel material of the present invention will be described by taking a polyolefin-coated steel sheet pile as an example. First, as shown in FIG. 9, the electron beam cross-linked colored / black polyolefin laminated sheet has a lower layer of the black polyolefin layer 5 and an upper layer of the colored polyolefin layer 6.
And a colored / black polyolefin laminated sheet 9 by extruding into a sheet from a two-layer T-die so that
To make. Next, an electron beam is irradiated from the surface of this colored / black polyolefin laminated sheet to produce an electron beam crosslinked colored / black polyolefin laminated sheet. Grit blasting is applied to the crests or troughs of steel sheet pile, and a chromate treatment agent is applied and baked. Next, an epoxy primer is applied to the surface thereof, heated and cured, and the powder of the modified polyolefin adhesive is immediately electrostatically coated and melted. In the coating of the mountain surface, the steel sheet pile coated with the modified polyolefin adhesive layer in a molten state on the mountain surface is moved on the carrier roll 11 and the carrier table 10 as shown in FIG. The electron beam cross-linked colored / black polyolefin laminated sheet 9 is pressure-bonded by the pressure-bonding roll 12 in the web portion, then the auxiliary roll 13, and further the pressure-bonding roll 1 in the flange portion.
After pressure bonding in sequence with Nos. 4 and 15, water cooling is performed to obtain the colored polyolefin-coated steel sheet pile (FIG. 2) of the present invention. Further, in the coating of the valley surface, the steel sheet pile coated with the modified polyolefin adhesive layer in a molten state is moved on a transport roll and a transport table as shown in FIG. The colored / black polyolefin laminated sheet 9 is pressure-bonded by the pressure-bonding roll 16 of the web portion, then sequentially pressed by the auxiliary roll 17, the pressure-bonding rolls 18 and 19 of the flange portion, and further the pressure-bonding roll 20 of the claw portion, and then water-cooled according to the present invention. A colored polyolefin coated steel sheet pile (Fig. 3) is obtained. As the method for applying the chromate treating agent, conventionally known methods such as roll application, brush application, and ironing application with various brushes can be used. The epoxy primer can be applied by a conventionally known method such as spray coating, ironing with a rubber ring or a rubber spatula. A method in which a modified polyolefin adhesive is previously laminated with an electron beam cross-linking colored / black polyolefin laminated sheet and the laminated sheet is coated can also be used.

In the colored polyolefin-coated H-section steel of the present invention shown in FIG. 4, the entire surface of the H-section steel 1 is sandblasted, the chromate treatment agent 2 is applied and baked. Next, the epoxy primer 3 is applied to the surface and heated and cured. Next, the modified polyolefin adhesive powder 4 is sprayed and melted on the surface. Next, after spraying the black polyolefin powder 5 on the surface, the colored polyolefin powder 6 of the present invention is sprayed to obtain the colored polyolefin-coated H-section steel of the present invention.

The colored polyolefin-coated structural steel for connecting walls of the present invention shown in FIG. 5 is obtained by sandblasting the entire surface of the structural steel 1 for connecting walls, applying a chromate treatment agent 2 and baking it. Next, the epoxy primer 3 is applied to the surface and heated and cured. Next, the modified polyolefin adhesive powder 4 is sprayed on the surface, and then the black polyolefin powder 5 is sprayed. The colored polyolefin powder 6 of the present invention is sprayed on the surface of the wall surface, which requires a design property, to obtain the colored polyolefin-coated continuous wall shaped steel according to the present invention.

In the colored polyolefin-coated steel pipe pile according to the present invention shown in FIG. 6, the outer surface of the steel pipe 1 is grit blasted, the chromate treatment agent 2 is applied, and the steel pipe 1 is heated and baked while rotating the steel pipe 1 in a spiral shape. Then, the epoxy primer 3 is spray-coated on the surface and heated and cured. Next, the powder 4 of the modified polyolefin adhesive is electrostatically coated on the surface and melted by the heat of the steel pipe, and then the black polyolefin 5 and the colored polyolefin 6 of the present invention are formed into a sheet by two layers from the two-layer T die. Extrusion coated to obtain a colored polyolefin coated steel pipe pile according to the present invention.

In the colored polyolefin coated square steel pipe pile according to the present invention shown in FIG. 7, the outer surface is grit blasted and the chromate treatment agent 2 is applied and heated and baked while the square steel pipe 1 is transferred and transported by the transport table. Then, the epoxy primer 3 is spray-coated on the surface and heated and cured. Next, the powder 4 of the modified polyolefin adhesive is electrostatically coated on the surface and melted by the heat of the square steel pipe, and then the black polyolefin 5 and the colored polyolefin 6 of the present invention are extrusion-coated from a square die into a square tube shape. A colored polyolefin coated square steel pipe pile according to the present invention is obtained.

In the colored polyolefin-coated steel pipe sheet pile according to the present invention shown in FIG. 8, the outer surface of the steel pipe sheet pile 1 is sandblasted, and the chromate treatment agent 2 is applied and baked. Then, apply epoxy primer 3 on the surface and heat,
Let it harden. After spraying the powder 4 of the modified polyolefin adhesive on the surface, the powder 5 of the black polyolefin is sprayed. Next, the colored polyolefin powder 6 of the present invention is sprayed to obtain the colored polyolefin steel pipe sheet pile according to the present invention.

The colored polyolefin coated steel material of the present invention is
As shown in FIGS. 1 to 8, steel plates, steel sheet piles, H-section steels, wall section steels, steel pipe piles, square steel pipe piles, steel pipe sheet piles, and other surfaces that require aesthetics are scaled by blasting, etc. Is removed, and the chromate film 2 and the epoxy primer layer 3 are sequentially laminated and subjected to an undercoating treatment, and carbon black is added to the surface of the layer 5 through the modified polyolefin adhesive layer 4 in an amount of 0.1 to 5%.
Black polyolefin layer 5 containing 0.5% to 5% by weight of bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate and 0.1 to 10% by weight of a coloring pigment and poly [{ 6- (1,1,3,3-tetramethylbutyl)
Imino 1,3,5-triazine-2,4-diyl}
{(2,2,6,6-tetramethyl-4-piperidyl)
Imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}] 0.1-2% by weight
It is a polyolefin-coated steel material, characterized in that the contained colored polyolefin layers 6 are sequentially laminated. The chromate film 2 has a total chromium adhesion amount of 200 to 1500
Adhesion amount of mg / m ² , epoxy primer coating 3 is 10-1
The modified polyolefin adhesive layer 4 has a film thickness of 50 μm.
0 ~ 600μm thickness, black polyolefin layer 1 ~ 5
Good results are obtained when the thickness of the colored polyolefin layer is 0.5 to 5 mm.

[0017]

EXAMPLES The present invention will be described below based on examples. Example 1 The crest surface of a steel sheet pile (FSPIII type) was grit blasted to remove rust, and a chromate treatment agent was applied to the crest surface so that the total amount of deposited chromium was 600 mg / m ^2, and then 16
It was heated to 0 ° C. and baked. While the chromate-treated steel sheet pile was being conveyed by a table roller, an epoxy primer was spray-coated on the surface so that the film thickness was 50 μm, and heated at 190 ° C. by high frequency induction heating to cure.
Then, a powder of maleic anhydride-modified polyethylene adhesive is electrostatically coated on the surface so that the film thickness becomes 300 μm, and the electron beam cross-linked colored / black polyethylene laminated sheet (of the colored polyethylene layer of the present invention is formed on the surface. Film thickness is 0.5m
m, the thickness of the black polyethylene layer is 1.0 mm),
The colored polyethylene-coated steel sheet pile of the present invention (coated steel material number 1 in Table 1) was produced. 0.1 wt% of phthalocyanine green was added as a coloring pigment to the colored polyolefin of the coated electron beam cross-linked colored / black polyethylene laminated sheet,
As a hindered amine weathering agent, poly [{6- (1,
1,3,3-tetramethylbutyl) imino 1,3,5
-Triazine-2,4-diyl} {(2,2,6,6-
Tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}] CHIM manufactured by Ciba-Geigy Japan
0.1% by weight of ASSORB944LD was added. Also, carbon black is 0.1% by weight in black polyethylene.
And as a hindered amine weathering agent bis (2, 2, 6,
0.5% by weight of 6-tetramethyl-4-piperidyl) sebacate Sanol LS770 manufactured by Sankyo Co. was added. In addition, as a comparative example, a colored polyethylene-coated steel sheet pile (coated steel material number 12 in Table 1) manufactured without laminating black polyethylene on an electron beam cross-linked colored polyethylene sheet was manufactured. These electron beam crosslinked colored polyethylene-coated steel sheet piles were cut into a length of 1 m and subjected to an outdoor exposure test.
After the exposure test for 7 years, the color difference of the coated surface and the presence or absence of cracks on the surface were examined and the results are shown in Tables 3 to 4. Table 3-
From the results of Table 4, the colored polyethylene-coated steel sheet pile of the present invention in which the black polyethylene and the colored polyethylene of the present invention were laminated and coated was compared with the colored polyethylene-coated steel sheet pile of the comparative example in which only the colored polyethylene was coated. It has excellent corrosion resistance and aesthetics without cracks.

[Table 1]

[Table 2]

[Table 3]

[Table 4]

Example 2 Content of carbon black and sanol LS770 added to the black polyethylene of Example 1, phthalocyanine green and CHIMASSOR added to the colored polyethylene.
The addition amount of B944LD was changed as shown in Tables 1 and 2 to manufacture electron beam crosslinked colored polyethylene-coated steel sheet piles (coated steel material numbers 2 to 9 in Table 1) of the present invention. In addition, as a comparative example, carbon black, sanol LS770, phthalocyanine green and CHIMASSORB 944LD were added to the colored polyethylene laminated on the black polyethylene which is outside the scope of the present invention. ~ 16) were produced. Example 1 of these electron beam crosslinked colored polyethylene coated steel sheet piles
Table 3 to Table 4 show the results of the same outdoor exposure test as above. From the results of Tables 3 to 4, all of the electron beam cross-linked polyethylene-coated steel sheet piles in which black polyethylene and colored polyethylene satisfying the constitutional requirements of the present invention are laminated and coated have no color difference change or cracking and have excellent corrosion resistance. Combines aesthetics.

Example 3 A grit blasting treatment was carried out while rotating the outer surface of a steel pipe (SGP outer diameter 200 A × length 5 m) in a spiral shape.
Chromate treatment agent on the surface has a total chromium adhesion of 60
Brush with a brush to obtain 0 mg / m ² 16
It was heated to 0 ° C. and baked, and further, an epoxy primer was spray-coated on the surface so as to have a film thickness of 50 μm and cured to be subjected to a base treatment. Then, on its surface, maleic anhydride-modified polyethylene adhesive, black polyethylene (with 2.5% carbon black addition by SANOL LS
770 2% by weight), colored polyethylene (as a coloring pigment, 1% by weight of phthalocyanine green, 0.5% by weight of titanium yellow and 1% by weight of titanium oxide, and C
0.4% by weight of HIMASSORB 944LD added)
Of the colored polyethylene-coated steel pipe pile according to the present invention (coated steel material No. 1 in Table 2) by extrusion-coating three layers integrally from a three-layer T die so that the respective film thicknesses are 0.25 mm, 1 mm and 2 mm
0) was obtained. Length of this colored polyethylene-coated steel pipe pile is 1
The sample was cut into m and subjected to an outdoor exposure test. After the exposure test for 7 years, the color difference of the coated surface and the presence / absence of the occurrence of cracks on the surface are shown in Table 3. From the results shown in Table 3, the colored polyethylene-coated steel pipe pile has both excellent anticorrosiveness and aesthetics without a color difference change or cracking only when the black polyolefin and the colored polyethylene satisfying the constitutional requirements of the present invention are laminated and coated. Example 4 H-section steel (height 125 mm x side length 125 mm x maximum thickness 9
(mm) surface is sandblasted to remove rust, and the chromate treatment agent on the surface has a total chromium adhesion of 600 mg / m
^It was applied so that it would be ² , and heated at 160 ° C. and baked. An epoxy primer was spray-coated on the surface of the chromate-treated H-section steel so that the film thickness was 50 μm and cured. Then, on its surface, powder of a maleic anhydride-modified ethylene-1-butene copolymer adhesive was applied, and the film thickness was 40.
Thermal spraying to 0μ, then the film thickness of 1mm on the surface
Powder of black ethylene-1-butene copolymer (the addition amount of carbon black is 2.5% by weight and the addition amount of SANOL LS770 is 3% by weight) is sprayed. Then, on the surface thereof, a colored ethylene-1-butene copolymer of the present invention (containing 1% by weight of phthalocyanine blue, 1% by weight of chromium oxide and 1% by weight of titanium oxide as a coloring pigment, and a film thickness of 2 mm, and CHIMASSORB944
LD was added by 0.6% by weight) to spray the colored ethylene-1-butene copolymer coated H-section steel of the present invention (coated steel material number 11 in Table 2). The colored ethylene-1-butene copolymer-coated H-section steel was cut into a length of 1 m and subjected to an outdoor exposure test. After the exposure test for 7 years, the color difference of the coated surface and the presence / absence of the occurrence of cracks on the surface are shown in Table 3. From the results in Table 3, the black polyolefin of the present invention and the colored ethylene-1-butene copolymer were laminated and coated. The colored ethylene-1-butene copolymer-coated H-section steel of the present invention has both excellent corrosion resistance and aesthetic appearance without change in color difference or generation of cracks.

[0020]

According to the present invention, as is clear from the above examples, carbon black and bis (2,2,6, A black polyolefin layer containing 6-tetramethyl-4-piperidyl) sebacate, a coloring pigment and poly [{6- (1,1,3,3-tetramethylbutyl) imino 1,3,5-triazine-2. , 4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}] The colored polyolefin-coated steel material of the present invention in which the polyolefin layer 6 is laminated and coated can prevent cracking and discoloration of the surface of the colored polyolefin coating due to ultraviolet rays in the sunlight at the same time, and thus has never been seen before. Combine corrosion resistance and aesthetics that was.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a steel material of the present invention whose surface is laminated with a black polyolefin and a colored polyolefin.

FIG. 2 is a cross-sectional view showing a steel sheet pile of the present invention in which a black polyolefin and a colored polyolefin are laminated and coated on the mountain surface.

FIG. 3 is a cross-sectional view showing a steel sheet pile of the present invention in which a valley surface is laminated and coated with a black polyolefin and a colored polyolefin.

FIG. 4 is a cross-sectional view showing an H-section steel of the present invention, the surface of which is laminated with black polyolefin and colored polyolefin.

FIG. 5 is a cross-sectional view showing a shaped wall steel for a wall of the present invention in which a black polyolefin and a colored polyolefin are laminated and coated on one surface.

FIG. 6 is a cross-sectional view showing a steel pipe pile of the present invention in which a black polyolefin and a colored polyolefin are laminated and coated on the outer surface.

FIG. 7 is a cross-sectional view showing a square steel pipe pile of the present invention in which a black polyolefin and a colored polyolefin are laminated and coated on the outer surface.

FIG. 8 is a cross-sectional view showing a steel pipe sheet pile of the present invention in which a black polyolefin and a colored polyolefin are laminated and coated on the outer surface.

FIG. 9 is a perspective view showing an example of a method for producing a colored / black polyolefin laminated sheet of the present invention.

FIG. 10 is a perspective view showing an example of a method for applying a laminated coating of the black polyolefin and the colored polyolefin of the present invention on the mountain surface of the steel sheet pile.

FIG. 11 is a perspective view showing an example of a method for laminating and coating a black polyolefin and a colored polyolefin of the present invention on the valley surface of a steel sheet pile.

[Explanation of symbols]

1 Steel materials such as blasted steel plate, steel sheet pile, H-section steel, shaped steel for wall, steel pipe pile, square steel pipe pile, steel pipe sheet pile 2 Chromate film 3 Epoxy primer film or epoxy primer 4 Modified polyolefin adhesive layer 5 Black polyolefin layer 6 Colored polyolefin layer 7 Two-layer T-die 8 Sheet forming roll 9 Two-layer sheet or colored / black polyolefin laminated sheet 10 Conveying table 11 Conveying roll 12 Crimping roll 13 Auxiliary roll 14 Crimping roll 15 Crimping roll 17 Crimping roll 17 Auxiliary Roll 18 Crimping Roll 19 Crimping Roll 20 Crimping Roll

Claims (1)

[Claims] 1. In a coated steel material in which a black polyolefin and a colored polyolefin layer are sequentially laminated on a surface of a steel material subjected to a base treatment via a modified polyolefin adhesive layer, the black polyolefin layer contains 0.1 to 5% by weight of carbon black. And bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate in an amount of 0.5 to 5% by weight, and the colored polyolefin layer contains 0.1 to 10% by weight of a coloring pigment and poly [{6- (1,1,3,3-Tetramethylbutyl) imino 1,3,5-triazine-2,4-diyl}
{(2,2,6,6-tetramethyl-4-piperidyl)
Imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}] 0.1-2% by weight
A colored polyolefin-coated steel material characterized by containing.