JPH11291393A - High-strength polyurethane heavy-duty corrosionproof coated steel material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-strength polyurethane heavy-duty corrosion- preventive coated steel material, as a steel material requiring a corrosionproof coating formed on the outer face, which has the high impact properties and the good adhesion of a coating against an impact to be generated, e.g. during driving a sheet pile or a tube pile or by ripraps after driving the sheet pile or the tube pile or other floating objects or the like including vessels. SOLUTION: A steel material primer layer 2 and a polyurethane layer 3 are laminated in 1-6 mm thickness on the surface of a steel material 1 with an applied primary coat. Further, a 2-10 mm thick protecting coated layer 5 of an unsaturated polyester cured resin containing 10-60 wt.% glass fiber, is laminated, through a 0.1-1 mm thick primer layer 4 for polyurethane, on the entire or partial surface layer in the longitudinal direction of the steel material 1, in the order described to obtain the high-strength polyurethane heavy-duty corrosionproof coated steel material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the transport of steel sheet piles and steel pipe sheet piles which require a corrosion-resistant coating on the outer surface thereof, and
Outer surface weight of the anticorrosion coating with excellent impact resistance and durability against impacts caused by the casting of steel structures such as river piers and seawalls, or by impacts caused by discarded stones and other suspended matters including ships The present invention relates to an anticorrosion coated steel material.

[0002]

2. Description of the Related Art For steel sheet piles and steel pipe sheet piles, which are required to have external corrosion protection for several decades, polyurethane heavy-corrosion coated steel materials using a polyurethane resin as a coating material have been manufactured. In such a polyurethane heavy anticorrosion coating, in order to secure long-term anticorrosion and impact resistance, polyurethane is applied to a thickness of about several mm and used. Polyurethane heavy-duty corrosion-resistant coated steel is remarkably excellent in the corrosion resistance of the coating,
Due to the low strength of the resin, the occurrence of coating flaws due to collisions and friction during handling during transportation, storage and construction has become a problem.

On the other hand, in JP-A-6-146271, a steel pipe pile is coated with polyolefin or urethane, then embossed, and a vinyl ester or polyester resin reinforced with a glass cloth or mat is protected on the steel pile. A method of laminating as a coating has been proposed. On the other hand, Japanese Patent Application Laid-Open No. 6-122173 proposes a method of coating a protective coating layer of glass flake-containing vinyl ester, polyester or epoxy on a surface of a polyurethane-coated steel sheet pile through a flocked material.

[0004]

In a method of forming a scratch-resistant coating layer having excellent strength and hardness on the surface layer of a heavy corrosion protection coating, a resin of a different type from that of the corrosion protection coating is laminated. In particular, since steel sheet piles and steel pipe sheet piles have protective coating edges, if a strong impact is applied near the ends, if the vertical adhesion is not sufficient, the protective coating will peel off from the anticorrosion coating and eventually fall off. Occurs.

In Japanese Patent Application Laid-Open No. 6-146271, since a protective coating layer of a vinyl ester or polyester resin reinforced with a glass cloth or mat is laminated, a physical shearing is performed by embossing the polyurethane surface layer to form irregularities. The protective layer can be covered by providing an adhesive force. However, the method of changing the surface shape of the anticorrosion layer cannot be expected to improve the vertical adhesion, so that the embossing method cannot be used for steel sheet piles or steel pipe sheet piles having ends.

On the other hand, as disclosed in Japanese Patent Application Laid-Open No. 6-122173, a method of implanting hair on the surface of polyurethane is effective as a method for strengthening adhesion to steel materials having ends.
However, it is necessary to perform electrostatic flocking or air blowing before the polyurethane resin is cured, and to spray the fibers almost vertically, and the productivity is reduced due to the limitation of the curing speed of the polyurethane. Further, even when the fibers are applied to the uncured polyurethane surface, only a part of the fibers effectively acts, and it is difficult to secure a sufficient adhesive force against peeling of the end portions. Further, the glass flake-containing vinyl ester, polyester or epoxy used as the protective layer has a problem that it is strong against abrasion and the like, but has insufficient impact resistance.

According to the present invention, in a coated steel material having an end portion such as a steel sheet pile or a steel pipe sheet pile, the vertical adhesion between the polyester protective coating and the urethane anticorrosion coating on the surface layer is ensured, so that the impact from the end due to impact can be improved. An object of the present invention is to provide a high-strength polyurethane heavy-corrosion-coated steel material that prevents peeling, has stable impact resistance and excellent corrosion resistance.

[0008]

Means for Solving the Problems As a means for solving the above-mentioned problems, the present inventors painted a primer layer for steel material and a polyurethane layer on the outer surface of a steel sheet pile or a steel pipe sheet pile which had been subjected to a base treatment, thereby preventing corrosion. Make up the coating. Then, after coating a primer layer for polyurethane on all or a part of the surface layer in the length direction, the coloring pigment and glass fiber are coated with 10 to 60.
A high-strength polyurethane heavy-corrosion-coated steel sheet pile, steel sheet pile and steel pipe excellent in shear adhesion, impact resistance, scratch resistance and corrosion resistance by laminating a protective coating layer of an unsaturated polyester cured resin contained in the range of wt%. It has been found that a sheet pile can be obtained, which has led to the present invention.

The gist of the present invention is as follows.

(1) A primer layer for a steel material and a polyurethane layer are sequentially laminated on the surface of the steel material subjected to the base treatment to form an anticorrosion coating, and then a primer layer for a polyurethane is formed on the surface of the primer layer. 10 to 60 wt
%. A high-strength polyurethane heavy-corrosion-coated steel material characterized by sequentially laminating a protective coating layer of an unsaturated polyester cured resin contained in the range of 0.1%.

(2) A high-strength polyurethane heavy-corrosion-coated steel sheet pile according to the above (1), wherein a steel sheet pile is used as a steel material, and a coating is sequentially laminated on the crest or valley surface.

(3) A high-strength polyurethane heavy-corrosion-coated steel pipe sheet pile according to (1), wherein a steel pipe sheet pile is used as a steel material and a coating is sequentially laminated on the outer surface thereof. 1 to 1
The high-strength polyurethane heavy-corrosion-coated steel material according to any one of (1) to (3), wherein a vinyl ester resin layer having a thickness of 1 mm is formed.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

As shown in the sectional view of FIG. 1, one example of the present invention is to laminate a steel material primer layer 2 and a polyurethane layer 3 to a thickness of 1 to 6 mm on the surface of a steel material 1 subjected to a base treatment. 0.1-1 mm on all or some surface layers in the length direction
And a protective coating layer 5 having a thickness of 2 to 10 mm made of an unsaturated polyester cured resin containing glass fiber in the range of 10 to 60 wt% is sequentially laminated via a primer layer 4 for polyurethane having a thickness of 3 mm. Is a high-strength polyurethane heavy-corrosion coated steel material.

As an example of use in a steel sheet pile, as shown in a sectional view from the top of the structure in FIG. 2, a primer layer 2 for steel material and a polyurethane layer 3 is laminated with a thickness in the range of 1 to 6 mm, and then glass fiber is applied to all or a part of the surface layer in the length direction through the primer layer 4 for polyurethane to 10 to 50 w
The protective coating layer 5 having a thickness of 2 to 10 mm made of an unsaturated polyester cured resin contained in the range of t% is sequentially connected and used.

As an example of use in a steel pipe sheet pile, as shown in a sectional view from the upper part of the structure in FIG. 3, a primer layer 2 for steel material and a polyurethane layer 3 is laminated with a thickness in the range of 1 to 6 mm, and then glass fiber is applied to all or a part of the surface layer in the length direction via the polyurethane primer layer 4 for 10 to 60.
The protective coating layer 5 having a thickness of 2 to 10 mm made of an unsaturated polyester cured resin contained in the range of wt% is sequentially connected and used.

The steel material used in the present invention is preferably a steel material used as a marine or river steel structure. The steel products include steel sheet piles, H-section steels, channel steels, and the like as steel pipe sheet piles or other shaped steels. Further, any steel material may be used, and general steel and alloy steel are used.

In the base treatment of the steel material surface, a blast treatment is performed using a sand, a grid, a shot, or the like to remove surface deposits. However, other methods such as degreasing and pickling other than blasting can be used as long as they have a function of removing oil and scale from the surface. Further, as a base treatment, when the use environment of the coated steel material is severe or when cathodic peeling resistance is required, a chromate treatment is performed on the surface after blasting. The chromate treatment agent used for the chromate treatment may be any one containing chromic acid as a component, and one containing partially reduced chromic acid and fumed silica as main components, or phosphoric acid or a compound thereof, silane coupling as the main component. When various additives such as an agent are added, corrosion resistance such as peeling resistance is excellent. The chromate treatment agent is sufficiently dried after being applied by a roller, a brush or the like. The coating amount is such that the total chromium adhesion amount is in the range of 50 to 1000 mg / m ² .

A primer treatment agent for steel material is applied to the surface of the steel material which has been subjected to the base treatment, and is cured. The primer treatment agent is obtained by adding an inorganic pigment to a thermosetting resin.
The primer treatment agent is supplied in the form of a liquid or a powder, applied using roll coating, spray coating, electrostatic powder coating or the like, and cured at room temperature or by heating. The thickness of the primer-treated layer after curing is preferably from 10 to 150 μm.
If the film thickness is 10 μm or less, the steel material surface coverage by the primer decreases. If it is 150 μm or more, the adhesion force decreases due to an increase in the stress of the primer. As the thermosetting resin used for the primer treatment agent, a resin having excellent adhesion to a steel material such as an epoxy resin or a urethane resin is used. The epoxy resin is a diglycidyl ether of bisphenol A or bisphenol F alone or as a mixture. If the paint viscosity does not matter, the use of a polyfunctional epoxy resin such as a phenol novolak type epoxy resin or a cresol novolak type epoxy resin having high heat resistance improves the water resistance. As a curing agent for the epoxy resin, an alicyclic amine, an aliphatic amine, dicyandiamide, a modified imidazole, a phenol novolak curing agent, or the like is used alone or in combination. On the other hand, when a urethane resin is used, a compound consisting of a polyol and an isocyanate may be used.
It is used as a liquid reaction curing type or a moisture curing type using an isocyanate-terminated prepolymer. As the isocyanate-terminated prepolymer, a commercially available product obtained by adding a polyol such as polypropylene glycol and methylene diphenyl isocyanate is used. An inorganic fine powder is mainly added as a pigment to the primer treatment agent. Silicon oxide, alumina, titanium oxide, magnesium silicate, calcium carbonate, chromate compounds, phosphate compounds, borate compounds or mixtures thereof can be used. Further, dry ultrafine silica may be added for controlling the thixotropy of the paint and for improving the anticorrosion property.

A polyurethane resin is coated as an anticorrosion layer on the surface of the steel material which has been subjected to the base treatment and the primer treatment for the steel material. Polyurethane resin, polyol and filled inorganic pigment,
A two-component mixture of a main agent composed of a mixture of color pigments and a curing agent composed of an isocyanate compound is applied. As the polyol, generally available polyols such as polyester polyol, polybutadiene polyol, and polypropylene glycol are used. As the isocyanate, a commercially available isocyanate such as methylene diphenyl diisocyanate is used. As the filled inorganic pigment, silica, titanium oxide, a commercially available inorganic pigment such as kaolin clay is used, and for the coloring pigment, to impart weather resistance to the resin,
Generally, carbon black is used. When another color pigment is used from the viewpoint of design, an ultraviolet absorber is also added. The thickness of the coating is from 1 to 6 mm in consideration of the function as a heavy anticorrosion layer and economy.

A urethane resin or an unsaturated polyester resin is used as a primer for polyurethane used for improving adhesion of polyurethane. The resin used for the primer may be one that adheres to the FRP and urethane coated on the upper layer. As the urethane resin, one-component moisture-curable urethane is used after being diluted with a solvent. The unsaturated polyester resin is obtained by dissolving an unsaturated polyester resin with a polymerizable monomer such as a styrene monomer, and is cured with a peroxide catalyst and a cobalt-based, vanadium-based, manganese-based, amine-based, or other accelerator. In particular, when a vinyl ester having an elongation of 5% or more and having flexibility is used, the adhesiveness is excellent. The polyurethane primer can prevent the stress of curing shrinkage from acting on the adhesive interface as a function thereof, thereby preventing the adhesive force from decreasing. Therefore, even if any unsaturated polyester is used, the adhesive force is improved by using the primer layer as the primer layer. However, the peeling force at the time of impact is dispersed particularly by selecting a material having more elongation than the upper FRP. ,
Further, peeling is suppressed. The film thickness is 100 to 1
Use in the range of 000 μm. When the film thickness is large, the adhesive strength is reduced due to shrinkage of the primer layer itself.

For coating the unsaturated polyester resin layer containing glass fiber as a high-strength protective layer, a method such as a hand lay-up method, a spray-up method, a cold press method, or a casting method using a mold is used. The unsaturated polyester cured resin used in the present invention may be any resin having an ester bond and a double bond in the molecule, and ortho-, iso-, and bisphenol-based unsaturated polyester resins can be used. Although there is a problem of material cost, a vinyl ester which is chemically stable and has a terminal double bond may be used. A solution of these unsaturated polyester resins in which a polymerizable monomer such as a styrene monomer is dissolved at a content of 30 to 60% is prepared by mixing a peroxide catalyst such as ketone peroxide and hydroperoxide with a cobalt-based or vanadium-based catalyst. A thermosetting resin that is cured by an accelerator such as a manganese-based or amine-based accelerator is used.

The polyester resin anticorrosion layer is filled with glass fibers. If the length of the glass fiber is too short, the effect of improving the strength cannot be obtained.
wt% or more is added. When using glass cloth, there is no particular upper limit to the length. However, when using short glass fibers in a spray-up method or the like, the range of 5 to 50 mm is desirable because long glass fibers reduce the defoaming property of the paint. . The upper limit of the addition amount is 60 wt% or less in the spray-up method from the viewpoint of workability. As the additive fiber, glass fiber is used because it is excellent in price, resin reinforcing effect, and anticorrosion performance. Organic fibers, carbon fibers, metal fibers, and the like may be used in combination as fibers other than glass. Further, the polyester resin layer is colored by adding a coloring pigment for imparting design and weather resistance. Since the surface layer portion of the unsaturated polyester deteriorates due to exposure, a coloring pigment is added in the range of 0.5 to 3%. If weather resistance is particularly required, a colored unsaturated polyester cured resin layer containing no glass fiber is formed on the outermost layer with a thickness of 100 to 1000 μm. In order to give the unsaturated polyester cured resin layer having the above composition the function as a protective layer and the adhesion, a film having a thickness of 2 to 10 mm is formed. 2mm thick
Otherwise, the impact resistance is reduced. Also, if the thickness is 10
If it exceeds mm, the heat of curing is large and the shrinkage stress is increased, so that the adhesiveness is reduced.

When the above coatings are sequentially laminated as shown in the cross-sectional view of FIG. 1, since the polyurethane and the surface polyester protective coating have excellent adhesive strength, they do not peel off from the edges, and have stable impact resistance. The present inventors have found that a high-strength polyurethane heavy-duty anticorrosive coating having excellent anticorrosion properties can be obtained, and have reached the present invention.

[0025]

<Example 1> A steel plate having a width of 100 x a length of 300 mm x a thickness of 9 mm was subjected to grid blast treatment to remove scale and the like to give the surface a roughness, and then a chromium-silica-based chromate treatment was performed. 500mg in total chromium deposit
/ M ^2, and then subjected to a base treatment after coating and drying.

1 with isocyanate-terminated prepolymer
A solution obtained by adding 20 wt% of kaolin clay fine powder as a pigment to a liquid moisture-curable urethane resin was spray-coated as a primer coating so as to have a film thickness of 30 to 60 μm and cured. Next, a main component of polybutadiene polyol containing 30 wt% of kaolin clay fine powder on its surface and a curing agent of methylene diphenyl diisocyanate were used.
The liquid-cured urethane elastomer was mixed by a mixer, spray-coated, and conventionally coated with a polyurethane resin.
After that, as a primer for polyurethane on the surface,
NCO by reacting diisocyanate with polyhydric alcohol
A urethane primer whose content was adjusted to 6% was spray-coated and cured at room temperature for 3 hours.

Next, the glass roving was cut to a length of 25 mm at the tip of a gun while spray-mixing an ortho-unsaturated polyester resin containing a styrene monomer and a peroxide catalyst-containing curing agent by a spray-up method. At the same time, spray coating was performed to form a colored protective layer. By the above method, a polyurethane-coated steel material having a high-strength protective coating of Example 1 of the present invention, in which the adhesion was improved by a polyurethane primer, was prepared.

<Embodiment 2> Width 100 x length 300 mm x
Grid blasting is applied to a steel plate having a thickness of 9 mm to remove scale and the like to give the surface a roughness.
g / m ² was applied and dried, and then a base treatment was performed.

1 with isocyanate-terminated prepolymer
A solution obtained by adding 20 wt% of kaolin clay fine powder as a pigment to a liquid moisture-curable urethane resin was spray-coated as a primer coating so as to have a film thickness of 30 to 60 μm and cured. Next, a main component of polybutadiene polyol containing 30 wt% of kaolin clay fine powder on its surface and a curing agent of methylene diphenyl diisocyanate were used.
The liquid-cured urethane elastomer was mixed by a mixer, spray-coated, and conventionally coated with a polyurethane resin.
After that, as a primer for polyurethane on the surface,
Spray coating was performed by mixing various unsaturated polyester resins containing a styrene monomer and a cobalt-based accelerator and a peroxide catalyst to form a primer layer for polyurethane.

Next, the glass roving was cut to a length of 25 mm at the tip of a gun while spray-mixing an iso-unsaturated polyester resin containing a styrene monomer and a curing agent containing a peroxide catalyst by a spray-up method. At the same time, spray coating was performed to form a protective layer. By the above method, a polyurethane-coated steel material having a high-strength protective coating of Examples 2 to 13 of the present invention in which the adhesion was improved by a polyurethane primer was prepared.

COMPARATIVE EXAMPLE 1 A steel plate having a width of 100.times.300 mm and a thickness of 9 mm was spray-coated by the same method as in Example 1, and a conventional polyurethane resin coating was performed.
After that, as a primer for polyurethane on the surface,
Spray painting with epoxy resin using bisphenol A type base agent and amine type curing agent as primer, 8
The composition was cured with warm air at 0 ° C. for 2 hours.

Next, the glass roving was cut to a length of 25 mm at the tip of a gun while spray-mixing an ortho-unsaturated polyester resin containing a styrene monomer and a curing agent containing a peroxide catalyst by a spray-up method. At the same time, spray coating was performed to form a colored protective layer. By the above method, a polyurethane-coated steel material having a high-strength protective coating of Comparative Example 2 using an epoxy resin as a polyurethane primer was prepared.

<Comparative Example 2> width 100 x length 300 mm x
Grid blasting is applied to a steel plate having a thickness of 9 mm to remove scale and the like to give the surface a roughness.
g / m ² was applied and dried, and then a base treatment was performed.

1 with isocyanate-terminated prepolymer
A solution obtained by adding 20 wt% of kaolin clay fine powder as a pigment to a liquid moisture-curable urethane resin was spray-coated as a primer coating so as to have a film thickness of 30 to 60 μm and cured. Next, a main component of polybutadiene polyol containing 30 wt% of kaolin clay fine powder on its surface and a curing agent of methylene diphenyl diisocyanate were used.
The liquid-cured urethane elastomer was mixed by a mixer, spray-coated, and conventionally coated with a polyurethane resin.
2mm as a flocking material on the surface immediately after polyurethane coating
A long nylon fiber was sprayed in an amount of 5 g / m ² .

Next, the protective layer was formed by spray-coating while simultaneously spray-mixing the ortho-unsaturated polyester resin containing a styrene monomer and the peroxide catalyst-containing curing agent by a spray-up method. JP-A-6-12217 with improved adhesion by flocking by the above method
A polyurethane-coated steel material of Comparative Example 3 corresponding to No. 3 was prepared.

As an impact test of the coated steel materials of Comparative Examples 1 to 5 and Examples 1 to 13 prepared by the above method, ASTM
A G14 impact test was performed. According to this, a hemispherical tip having a diameter of 15.9 mm was brought into contact with the coating surface as an evaluation of impact peeling, and a 20 kg weight was imposed from the upper part by 1 m.
Dropped from the height. After that, against the peeling of polyester and urethane generated circumferentially from the impact scar,
The peeling diameter was measured to evaluate the adhesion. Table 1 shows the results
3 are shown.

[0037]

[Table 1]

[0038]

[Table 2]

[0039]

[Table 3] As is clear from the results in Table 1, it is understood that the present invention having an unsaturated polyester coating containing a primer for polyurethane and a glass fiber has high impact strength, small peeling due to impact, and excellent performance. Above all, when a vinyl ester is used as a primer for urethane, excellent impact peeling resistance is obtained.

From the results of Tables 2 and 3, the thickness range of the primer for polyurethane of the present invention is 0.1 to 1 m.
m, it can be seen that the glass fibers contained in the unsaturated polyester protective layer provide excellent performance in the range of 10 to 60%.

[0041]

As is clear from the examples, the high-strength polyurethane heavy-corrosion-coated steel material of the present invention has more stable impact strength and impact strength than the conventional polyurethane heavy-corrosion-coated steel material having a high-strength protective coating. It has high adhesiveness that can prevent peeling of the high-strength protective layer due to As a result, adhesiveness can be ensured even in a coated steel material having a coated end, such as a steel sheet pile or a steel pipe sheet pile, and peeling from the end can be suppressed. Therefore, in the present invention, by applying a high-strength polyurethane heavy-corrosion-coated steel material having impact resistance by the protective layer and corrosion resistance by polyurethane as the steel sheet pile and the steel pipe sheet pile, the protective layer is not peeled off, and the heavy corrosion-resistant coated steel material is not removed. It is possible to prevent damage during construction, collision of ships, etc., and stones.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a high-strength polyurethane heavy-corrosion-coated steel material of the present invention.

FIG. 2 is a cross-sectional view of a part of a high-strength polyurethane heavy-corrosion-coated steel sheet pile according to the present invention, as viewed from above.

FIG. 3 is a cross-sectional view from above of an example of the high-strength polyurethane heavy-corrosion-coated steel pipe sheet pile of the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 base material-treated steel material 2 steel material primer layer 3 polyurethane anticorrosion coating layer 4 polyurethane primer layer 5 unsaturated polyester resin colored protective coating layer containing glass fiber 6 steel sheet pile 7 steel pipe sheet pile

Claims (4)

[Claims] 1. A steel material primer layer and a polyurethane layer are sequentially laminated on a surface of a steel material subjected to an undercoat treatment to form an anticorrosion coating. Then, a polyurethane primer layer is formed on the surface of the primer layer. A high-strength polyurethane heavy-corrosion-coated steel material characterized by sequentially laminating a protective coating layer of an unsaturated polyester cured resin contained in the range of 10 to 60 wt%. 2. A high-strength polyurethane heavy-corrosion-coated steel sheet pile according to claim 1, wherein a steel sheet pile is used as the steel material, and a coating is sequentially laminated on the crest or valley surface. 3. A high-strength polyurethane heavy duty anticorrosion coated steel pipe sheet pile according to claim 1, wherein a steel pipe sheet pile is used as the steel material and a coating is sequentially laminated on the outer surface thereof. 4. A primer for polyurethane, comprising:
The high-strength polyurethane heavy-corrosion-coated steel material according to any one of claims 1 to 3, wherein a vinyl ester resin layer having a thickness of 1 to 1 mm is formed.