JP2679862B2 - Heavy anticorrosion coated steel pipe pile and its manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heavy corrosion protection coated steel pipe pile used for steel structures such as foundation piles used in the ocean, rivers, harbors and the like, and a method for manufacturing the same, and more specifically, A heavy corrosion resistant coated steel pipe pile having a colored coating film having various colors having excellent weather resistance on the outer surface of the heavy corrosion resistant coating and having an excellent appearance, and having excellent water resistance adhesion of the colored coating film and the heavy corrosion resistant coating, and the same. Regarding manufacturing method.

(Prior Art) For coating a conventional polyolefin-coated steel material, for example, a polyolefin-coated steel pipe pile, black polyethylene having excellent corrosion resistance is used. However, due to the recent growing market needs for aesthetic landscapes of steel structures such as cityscapes and rivers, harbors, etc., the development of heavy-duty anti-corrosion coated steel pipe piles that are colored in various colors, are in harmony with the environment, and have excellent weather resistance Is desired. To meet such needs, for example, as shown in FIG. 3, a urethane primer layer 16 and a fluorine-based paint coating having a color are formed on the surface of a polyolefin-coated steel material having a polyolefin coating layer 15 whose outer surface is subjected to flame treatment. 17
There is a heavy anticorrosion coated steel material which is sequentially laminated. In the figure, 1 is a steel pipe pile, 12 is a chromate treatment agent layer, 13 is an epoxy primer layer, and 14 is a modified polyolefin adhesive layer.

(Problems to be solved by the invention) However, in such a conventional heavy anticorrosion coated steel material, between the polyolefin coating layer 15 and the fluorine-based paint coating film 17 which have been subjected to flame treatment in a marine practical use test, The adhesive strength is gradually reduced and blisters are likely to occur in the fluorine-based paint coating film, and it is necessary to further improve the water resistant adhesiveness.

(Means for Solving the Problems) As a result of intensive studies by the present inventors to solve the above-mentioned problems, the outermost layer of the outer surface of the steel pipe contains 0.05 to 5.0% by weight of an antioxidant, and the outer surface is After applying a urethane primer or a modified polyolefin primer to the outer surface of the steel pipe pile coated with polyolefin that has been subjected to flame treatment so that its surface tension is 36 dyn / cm or more, fluorine paint of various colors, acrylic-silicone paint, acrylic The present invention was found to solve the above-mentioned problems by laminating colored paint coating films such as urethane-based paint.

That is, according to the present invention, as shown in FIG. 1, the outermost layer of the outer surface of the steel pipe 1 contains 0.05 to 50% by weight of an antioxidant, and the outer surface is subjected to flame treatment so that the surface tension becomes 36 dyn / cm or more. On the outer surface of the outer polyolefin-coated steel pipe pile having the above-mentioned polyolefin 5, urethane primer or modified polyolefin primer 6, fluorine-based paint of various colors,
A heavy-duty anticorrosion coated steel pipe pile characterized by sequentially laminating a colored paint coating film 7 such as acrylic-silicone paint or acrylic-urethane paint, and an antioxidant on the outermost layer of the outer surface of the steel pipe as shown in FIG. The outer surface of the steel pipe pile 9 having a polyolefin content of 0.05 to 5.0% by weight while being transferred and transported on a roller carriage 8 that rotates while moving the outer surface with a slit burner 10 having a surface tension of 36 dyn / cm or more. Flame treatment, and then apply a urethane primer or a modified polyolefin primer to the outer surface, and then use a fluorine-based paint of various colors, acrylic-
A method for producing a heavy-duty anticorrosion coated steel pipe pile, which is characterized in that a colored paint such as a silicone paint or an acrylic-urethane paint is applied. In the figure, 2 is a chromate treatment agent layer, 3 is an epoxy primer layer, and 4 is a modified polyolefin adhesive layer.

 Hereinafter, the present invention will be described in detail.

The steel pipe used in the present invention is a steel pipe made of alloy steel such as carbon steel and stainless steel. In addition, for the purpose of improving the corrosion resistance of the steel pipe, zinc, aluminum,
Also used is plating of nickel or the like, alloy plating of zinc-iron, zinc-aluminum, zinc-cobalt-nickel or the like, or plating or alloy plating of which dispersion plating in which inorganic fine particles such as silica or titanium oxide are dispersed is applied. You can

As an outer polyolefin coated steel pipe pile, the outer surface of the steel pipe is blasted by grit blasting, sand blasting, etc. to remove rust, then chromate treatment and ground treatment with epoxy primer are performed, then modified polyolefin adhesive modified with maleic anhydride etc. After coating, it is possible to use an outer surface polyolefin-coated steel pipe pile coated with polyolefin, but from the essence of the present invention, it is sufficient if the outermost layer of the coated steel pipe pile has polyolefin, and conventionally known chromate treatment for base treatment. It is also possible to use a steel pipe pile coated with an outer surface polyolefin, which has been treated with an agent, an epoxy primer, a phosphate treatment, a silane coupling treatment or the like alone, or a combination of these base treatments.

As the polyolefin that coats the outermost layer of the steel pipe pile coated with polyolefin on the outer surface, 0.05 to 5.0% by weight of antioxidant is used.
The content of polyethylene, polypropylene, polybutene, or ethylene and propylene, 1-butene,
A copolymer with an α-olefin such as 4-methyl-1-pentene, 1-hexene, 1-octene can be used. The content of antioxidant of polyolefin coating is 0.05
If the content is less than 5% by weight and exceeds 5.0% by weight, the adhesion between the polyolefin coating and the fluorine-based, acrylic-silicone-based, acrylic-urethane-based paint coatings of various colors decreases after the marine practical use test, and the paint coatings Blister occurs in.

Next, the flame treatment applied to the polyolefin-coated outer surface of the outer polyolefin-coated steel pipe pile will be described. As the flame treatment, after the flame treatment, coloring paints of various colors can be applied to the surface of the polyolefin coating without repelling and can be cured to form a coating film.The point is to uniformly flame-treat the outer surface of the polyolefin coating. is necessary. For this purpose, the method using a slit burner shown in FIG. 2 can be used. If the outer surface of the polyolefin coating is not uniformly flame-treated, the adhesion between the polyolefin coating and the colored paint coating of various colors will decrease after the marine practical use test, and blister will occur in the paint coating. . Regarding the degree of flame treatment, for example, in the case of low-density polyethylene, high-density polyethylene, ethylene-propylene block copolymer, "wet test method for polyethylene and polypropylene" specified in JIS K6768, "after flame treatment" It is desirable to perform flame treatment so that the "wetting index (surface tension)" is 36 dyn / cm or more. "Wet index (surface tension)" is 36dy
If it is less than n / cm, the adhesion between the polyolefin coating and the colored paint coatings of various colors decreases after the marine practical use test, and blisters occur in the colored paint coatings.

Next, the urethane primer and the modified polyolefin primer which are laminated on the surface of the flame-treated polyolefin coating will be described. From the viewpoint of water resistance, the urethane primer used in the present invention has a terminal isocyanate group obtained by the reaction of a polyol compound having a molecular weight of 400 to 2000 and having two or more hydroxyl groups in the molecule with a polyisocyanate compound having an isocyanate group in the molecule. Contained urethane prepolymers are desirable. From the viewpoint of water resistance, the modified polyolefin primer is preferably a liquid primer obtained by diluting a modified polyolefin whose main component is a polyolefin modified with an acid anhydride such as ethylene-vinyl acetate copolymer and maleic anhydride with a solvent. As general commercial products, for example, Thermotac E200, Thermotac E300, Thermotac E500, etc., manufactured by China Paint Co., Ltd. can be used.

Next, the colored paint used in the present invention will be described. From the viewpoint of weather resistance as the paint, various colors of NY Porin K manufactured by Shinto Paint Co., Ltd. and V top of various colors manufactured by Dainippon Paint Co., Ltd. #
General commercial acrylic-urethane-based paints such as 100, silica racks of various colors made by China Paint Co., general-purpose acrylic-silicone paints of various colors made by Shinto Paint Co., Ltd., made by Nippon Paint Co., Ltd. It is desirable to use commercially available fluorine-based paints such as Duflon of various colors, Shintoflon of various colors manufactured by Shinto Paint Co., V Freon of various colors manufactured by Dainippon Paint Co., Ltd., and the like.

Next, a method for manufacturing the heavy-duty anticorrosion coated steel pipe pile according to the present invention will be described.

As shown in Fig. 2, an antioxidant is applied to the outermost layer on the outer surface of the steel pipe.
The outer surface of the steel pipe pile 9 containing 0.05 to 5.0% by weight has a surface tension of 36dy while being transported while being rotated on a roller carriage 8 which is rotating and moving.
After subjecting the slit burner 10 to flame treatment to n / cm or more, a urethane primer or modified polyolefin primer is applied to the outer surface, and various colors of fluorine-based paint, acrylic-silcon-based paint, acrylic-urethane-based paint, etc. The colored paint of No. 1 is applied to obtain the heavy anticorrosion coated steel pipe pile according to the present invention. Regarding the degree of flame treatment of the polyolefin-coated surface, for example, in the case of low density polyethylene, high density polyethylene, ethylene-propylene block copolymer, JI
Flame treatment is performed so that the "wetting index (surface tension)" after flame treatment is 36 dyn / cm or more according to the "wetting test method for polyethylene and polypropylene films" specified in SK6768. In Fig. 2, one slit burner is arranged on the side of the steel pipe pile and one slit burner is arranged on the lower face. However, if the flame treatment is difficult to be uniform due to the transport speed of the steel pipe pile, three slit burners are used. With the above arrangement, the "wetting index (surface tension)"
It should be 36 dyn / cm or more. The slit burner is effective in uniformizing the flame treatment.

(Operation of the Invention) As shown in FIG. 1, the heavy anticorrosion coated steel pipe pile of the present invention contains 0.05 to 5.0% by weight of an antioxidant in the outermost layer on the outer surface of the steel pipe pile 1.
A urethane primer or a modified polyolefin primer 6, on the outer surface of an outer surface polyolefin-coated steel pipe pile including the polyolefin 5 whose surface is flame-treated,
A heavy-duty anticorrosion coated steel pipe pile in which colored coating films 7 of various colors such as fluorine-based, acrylic-silicone-based, and acrylic-urethane-based coatings are sequentially laminated. Furthermore, as shown in FIG. 2, the method for producing the heavy corrosion-resistant coated steel pipe pile of the present invention comprises rotating the outer surface polyolefin-coated steel pipe pile 9 having a polyolefin containing 0.05 to 5.0% by weight of an antioxidant in the outermost layer of the outer surface of the steel pipe. The outer surface is subjected to flame treatment so that the surface tension becomes 36 dyn / cm or more while being transferred and transported while being rotated on the roller carriage 8 which is also moving, and then a urethane primer or a modified polyolefin primer is applied to the outer surface. , Various colors of fluorine paint, acrylic-silicone paint, acrylic-
It is manufactured by painting colored paint such as urethane paint.

In the figure, the polyolefin 5 has a thickness of 1 to 10 mm, a urethane primer or a modified polyolefin primer 6
Satisfactorily obtains a film thickness of 5 to 10 μm, and a colored paint coating film such as a fluorine-based, acrylic-silicone, acrylic-urethane-based paint of various colors having a film thickness of 10 to 100 μm.

(Examples) Example-1 A grit blasting treatment is applied to remove rust while a steel pipe having an outer diameter of 200 A, a length of 5500 mm and a thickness of 5.8 mm is spirally swung, and the chromate treatment agent has a total chromium adhesion amount of 350 mg. / m ²
Of the modified polyolefin whose main component is an ethylene-1-butene copolymer modified with maleic anhydride and then spray-coated with an epoxy primer so that the film thickness becomes 50μ and cured. The powder was electrostatically coated to a film thickness of 200 μm, heated and melted, and the surface of the powder was extrusion-coated with a low-density polyethylene in a molten state from a T-die and cooled to manufacture an outer surface polyethylene-coated steel pipe pile.
The content of antioxidant in the low density polyethylene coating is 0.3
In weight%, the low density polyethylene film thickness was 2.5 mm. As shown in FIG. 2, the outer surface polyethylene-coated steel pipe pile manufactured as described above is transferred and transported while being rotated on a roller carriage that is rotating, and one slit burner is provided on the lower surface of the steel pipe pile. After arranging one on each side and subjecting the surface of the polyethylene coating to flame treatment, 5 to 10 µ of the urethane primer (50% by weight of urethane prepolymer, 50% by weight of toluene) of the present invention was applied, and then a fluorine-based paint ( A heavy corrosion-resistant coated steel pipe pile 1 according to the present invention was manufactured by spray-coating Duflon (manufactured by Nippon Paint Co., Ltd., color Marcel value: 10B5 / 10 (blue)) to a film thickness of 30 μ. The "wetting index (surface tension)" of the low-density polyethylene-coated surface after the flame treatment was 54 dyn / cm.

As a comparative material, the outer surface of the outer surface low density polyethylene-coated steel pipe pile obtained as described above was heated with a hand burner for 5 minutes to raise the temperature to 70 to 80 ° C., and a urethane primer was added to the surface for 5 to 10 μm. Fluorine-based paint (Duflon manufactured by Nippon Paint Co., Ltd., Marcel value of color tone: 1
Comparative heavy-duty anticorrosion coated steel pipe pile 1 was manufactured by spray-coating 0B5 / 10 (blue) to a film thickness of 30μ. The "wetting index (surface tension)" of the low-density polyethylene-coated surface after flame treatment with a hand burner was 31 to 54 dyn / cm, and there were large variations depending on the measurement position.

The heavy-duty anticorrosion coated steel pipe pile 1 according to the present invention thus obtained and the comparative heavy-duty anticorrosion coated steel pipe pile 1 were subjected to a three-year marine practical use test, and after the test was completed, the presence or absence of blisters in the fluorine-based paint coating film. And the adhesion test between the fluorine-based paint coating and the low-density polyethylene coating [Cross-cut test: J
According to IS K5400, the adhesive strength is rated from 0 to 10 (maximum 10 points)
Display] was performed. The results are shown in Table 1.

As is clear from the results shown in Table 1, the heavy-corrosion-coated steel pipe pile according to the present invention is
After three years of practical use in the ocean, no blister of the fluorine-based paint coating was observed, and the adhesive strength between the fluorine-based paint coating and the low-density polyethylene coating was sufficiently high. Excellent water resistance adhesion between

Example-2 The content of the antioxidant in the low-density polyethylene coating of the outer surface low-density polyethylene-coated steel pipe pile used in the production of the heavy-corrosion-coated steel pipe pile of the present invention in Example 1 was changed within the range of 0.05 to 5.0% by weight. In the same manner as in Example 1, heavy-duty anticorrosion coated steel pipe piles 2 to 4 according to the present invention were manufactured. As an example, Example 1
Comparative heavy-duty anticorrosion coated steel pipe pile 2 having the content of the antioxidant of 0.01% by weight and comparative heavy-duty anticorrosion coated steel pipe pile 3 having the content of the antioxidant of 6% by weight were manufactured by the same method. The heavy-duty anticorrosion coated steel pipe pile and the comparative heavy-duty anticorrosion coated steel pipe pile obtained as described above were tested in the same marine practical use test as in Example 1, and after the test was completed, the presence or absence of blister formation of the fluorine-based paint coating film was observed. At the same time, an adhesive strength test between the fluorine-based paint coating film and the low-density polyethylene coating [adhesive strength is expressed by a score of 0 to 10 (complete score of 10 according to cross-cut test: JIS K5400)] was performed. The results are shown in Table 1.

As is clear from the results in Table 1, if the content of the antioxidant in the polyolefin coating of the steel pipe pile with heavy corrosion protection according to the present invention is in the range of 0.05 to 5.0% by weight, the results of three years of actual marine use test After that, the blister of the fluorine-based coating film does not occur, and the adhesive force between the fluorine-based coating film and the low density polyethylene coating is sufficiently high. However, when the content of the antioxidant is 0.01% by weight and 6% by weight, blisters are generated in the fluorine-based paint coating film, and between the fluorine-based paint coating film and the low density polyethylene coating. The adhesive strength is also reduced.

Example 3 In the same manner as in Example 1, the degree of flame treatment applied to the outer surface low-density polyethylene coating was changed to 36 to 70 dyn / cm in terms of "wetting index (surface tension)", and the heavy anticorrosion coating according to the present invention was used. Steel pipe piles 5-6 were manufactured. As a comparative example, a comparative heavy anticorrosion coated steel pipe pile 4 was manufactured in the same manner as in Example 1 except that the degree of flame treatment was 34 dyn / cm in terms of “wetting index (surface tension)”. The heavy-duty anticorrosion coated steel pipe pile and the heavy-duty anticorrosion coated steel pipe pile obtained as described above were subjected to the same three-year marine practical use test as in Example 1, and after the test was completed, blister of the fluorine-based paint coating film was generated. In addition to observing the presence or absence, an adhesive strength test between the fluorine-based paint coating and the low-density polyethylene coating [Cross-cut test: in accordance with JIS K5400, an adhesive strength of 0 to 10 (10
Display with a perfect score). The results are shown in Table 1.

As is clear from the results in Table 1, the degree of flame treatment used in the present invention is 36 in terms of "wetting index (surface tension)".
At ~ 70 dyn / cm, after three years of practical use in the ocean, no blister of the fluorine-based coating film is generated, and the adhesive force between the fluorine-based coating film and the low-density polyethylene coating is sufficiently high. However, the "wetting index (surface tension)" was 34 dyn / cm.
In this case, the blister of the fluorine-based paint coating film is generated, and the adhesive force between the fluorine-based paint coating film and the low density polyethylene coating is also reduced.

Example-4 In the same manner as in Example 1, the outer surface low density polyethylene-coated steel pipe pile was changed to an outer surface high-density polyethylene-coated steel pipe pile and an outer surface ethylene-propylene block copolymer-coated steel pipe pile, and a heavy corrosion-resistant coating according to the present invention was used. European steel pipe piles 7 to 8 were manufactured. The heavy-duty anticorrosion coated steel pipe pile and the heavy-duty anticorrosion coated steel pipe pile obtained as described above were subjected to the same 3-year marine practical use test as in Example 1, and after the test was completed, the occurrence of blisters in the fluorine-based paint coating film. In addition to observing, the adhesive strength test between these colored coating films and the low-density polyethylene coating [the adhesive strength is expressed by a score of 0 to 10 (maximum 10 points according to cross-cut test: JIS K5400)] was performed. The results are shown in Table 1. As is clear from the results shown in Table 1, the heavy-corrosion-proof coated steel pipe pile according to the present invention is not affected by the type of polyolefin of the outer surface polyolefin-coated steel pipe pile used for its production, and is also tested for fluorine after three years of actual marine use test. The blister of the paint coating film does not occur, and the adhesive force between the fluoro paint coating and the polyolefin coating is sufficiently high.

Example-5 Acrylic-silicone and acrylic-urethane series fluororesin (Duflon manufactured by Nippon Paint Co., Ltd., Marcel value of color tone: 10B5 / 10 (blue)) is shown in Table 2 in the same manner as in Example 1. The heavy duty anticorrosion coated steel pipe piles 9 to 13 according to the present invention were manufactured in place of the above colored paint. The heavy-duty anticorrosion coated steel pipe pile obtained as described above was subjected to the same three-year marine practical use test as in Example 1, and after the test was completed, the presence or absence of blister formation in the fluorine coating film was observed, and these colored coatings were also used. Table 1 shows the results of an adhesion test between the coating film and the low-density polyethylene coating [cross-cut test: the adhesion is indicated by a score of 0 to 10 (maximum 10 points according to JIS K5400)]. As is clear from the results shown in Table 1, even when the acrylic-silicone or acrylic-urethane type colored paint is used, the blister of the colored paint coating film is generated even after the three-year marine practical use test. In addition, the adhesive force between the fluorine-based paint coating film and the low-density polyethylene coating is sufficiently high.

Example 6 In the same manner as in Example 1, a urethane primer was used as a modified polyolefin primer (“ThermoTac E500”, “ThermoTac E300” or “ThermoTac” manufactured by China Paint Co., Ltd.).
E200 ") instead of the heavy corrosion-resistant coated steel pipe pile 14-16 according to the present invention
Was manufactured. The heavy-duty anticorrosion coated steel pipe pile obtained as described above was subjected to the same three-year marine practical use test as in Example 1, and after the test was completed, the presence or absence of blister formation in the fluorine-based paint coating film was observed. Table 1 shows the results of the adhesion test between the colored paint coating film and the low-density polyethylene coating [cross-cut test: the adhesion is indicated by a score of 0 to 10 (maximum 10 points according to JIS K5400)]. . As is clear from the results in Table 1, even when the modified polyolefin primer was used in place of the urethane primer, no blister of the colored paint coating film was generated after three years of actual marine use test, and The adhesive force between the fluoro paint coating and the low density polyethylene coating is also sufficiently high.

(Effects of the invention) As is clear from the above examples, the outermost layer of the outer surface of the steel pipe contains 0.05 to 5.0% by weight of an antioxidant, and flame treatment is performed so that the surface tension of the surface becomes 36 dyn / cm or more. On the outer surface of the outer surface polyolefin-coated steel pipe pile having the polyolefin, a urethane primer or a modified polyolefin primer, various colors of fluorine paint, acrylic-silicone paint, acrylic-urethane paint, etc. The obtained heavy anticorrosion coated steel pipe pile according to the present invention is different from conventional heavy anticorrosion coated steel pipe piles in various colors of fluorine-based paint, acrylic-silicone paint, acrylic-
A water-resistant adhesive property between a colored coating film such as a urethane-based coating material and a polyolefin coating has a remarkable effect.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a heavy-duty anticorrosion coated steel pipe pile according to the present invention,
FIG. 2 is an explanatory view showing an example of a method for manufacturing a heavy corrosion-resistant coated steel pipe pile according to the present invention, and FIG. 3 is a partial sectional view of a conventional heavy corrosion-resistant coated steel pipe pile. In the figure, 1 is a steel pipe pile, 2 is a chromate treatment layer, 3 is an epoxy primer layer, 4 is a modified polyolefin adhesive layer, 5
Is a polyolefin layer containing 0.05 to 5.0% by weight of an antioxidant and subjected to flame treatment so that the surface tension of the surface is 36 dyn / cm or more, 6 is a urethane primer or modified polyolefin primer layer, 7 is a fluorine-based paint of various colors , Acrylic-silicone-based paint, acrylic-urethane-based paint, and other colored paint coatings, 8 is a roller cart that runs while rotating, and 9 is a polyolefin-coated steel pipe containing 0.05 to 5.0% by weight of an antioxidant before flame treatment. Pile, 10 is a slit burner, 11 is an antioxidant after flame treatment 0.05 ~ 5.0
A polyolefin-coated steel pipe pile containing 10% by weight, 12 is a chromate treatment layer, 13 is an epoxy primer layer, 14 is a modified polyolefin adhesive layer, 15 is a polyolefin layer, 16 is a urethane primer layer, and 17 is a fluorine-based paint coating film.

Front page continuation (72) Inventor Hirotada Kato 1 Kimitsu, Kimitsu-shi, Chiba Shin-Nippon Steel Works Ceremony (2) Inventor Masaaki Uehara 1 Kimitsu, Kimitsu-shi, Chiba Shin-Nihon Steel Ceremony Inside the Kimitsu Works

Claims (2)

(57) [Claims] 1. An antioxidant is added to the outermost layer of the outer surface of the steel pipe in an amount of 0.05 to 5.
On the outer surface of the outer surface polyolefin-coated steel pipe pile containing 0% by weight and having a flame-treated polyolefin so that the surface tension of the outer surface is 36 dyn / cm or more, a urethane primer or a modified polyolefin primer, a fluorine-based paint of various colors A heavy-duty anticorrosion coated steel pipe pile, characterized in that colored paint coatings such as acrylic silicone paint and acrylic urethane paint are sequentially laminated. 2. An antioxidant is added to the outermost layer of the outer surface of the steel pipe in an amount of 0.05 to 5.
An outer surface polyolefin-coated steel pipe pile having a polyolefin content of 0 wt% has a surface tension of the outer surface while being transferred and transported while being rotated on a roller carriage that is rotating.
After flame treatment to 36 dyn / cm or more, apply urethane primer or modified polyolefin primer to the outer surface, and paint with various paints such as fluorine paint, acrylic silicon paint, acrylic urethane paint, etc. A method for manufacturing a heavy-duty anticorrosion coated steel pipe pile, which is characterized by the above.