JP3345313B2 - Polyester coated heavy duty corrosion resistant steel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for burying steel pipes requiring an anticorrosion coating on the outer surface, or for protecting outer surfaces such as steel pipe piles, steel pipe sheet piles, steel sheet piles, etc. TECHNICAL FIELD The present invention relates to an outer heavy corrosion protection coated steel material excellent in the impact resistance and durability of the anticorrosion coating against impacts generated at the time of casting of a steel structure to be or after being cast, by discarded stones, and other floating matters including ships.

[0002]

2. Description of the Related Art Steel pipes, steel pipe piles,
When a steel pipe sheet pile, steel sheet pile, or the like is coated with a factory that requires long-term durability of several decades, a heavy duty coating material using a resin such as polyethylene or polyurethane, which is an inexpensive resin having excellent corrosion resistance, is used. Anticorrosion coated steel products are manufactured. Such a heavy duty anti-corrosion coating makes use of various resin properties such as polyethylene, polyurethane resin's cost, electrical insulation, chemical resistance, etc.
Those with durability are used. In particular, in order to secure long-term corrosion resistance and impact resistance over several decades, a coating laminated to a thickness of about several mm is generally used. Heavy corrosion protection coated steel using such a coating material is extremely excellent in the anticorrosion of the coating, but the strength of the resin used is low, so it is natural that simply increasing the thickness of the resin to improve the impact resistance is a natural limitation There has been a problem that the coating is damaged due to collision or friction during handling during transportation, storage and construction. In particular, steel pipe piles, steel pipe sheet piles, steel sheet piles, etc. may be used in combination with cathodic protection, which presupposes the occurrence of coating flaws, and there is a problem that periodic anode replacement after construction is required. .

As a method for imparting impact resistance to a heavy corrosion-resistant coated steel material, there is a method of improving abrasion resistance and impact resistance by providing a metal layer on a surface layer as disclosed in Japanese Patent Application Laid-Open No. 8-300559.

Further, as proposed in Japanese Patent Publication No. 7-006595, in heavy corrosion protection coating on a propulsion steel pipe, polyester or glass fiber or metal fiber mixed with glass fiber or metal fiber is used without changing the corrosion protection coating made of polyethylene or polyurethane resin. Methods have been proposed in which a contaminated epoxy acrylate layer is used as its protective coating. On the other hand, as an anticorrosion paint for plated steel sheets,
As shown in 5938, there is an example in which an unsaturated polyester resin containing glass fiber is used as an overcoating and anticorrosion paint to impart scratch resistance.

[0005]

In order to impart impact resistance to a heavy-duty anticorrosion coating, it is effective to form a scratch-resistant coating layer having excellent strength and hardness on its surface layer.
The method of applying a metal coating layer to the surface layer as shown in 559 is effective. However, the metal coating is vulnerable to corrosion, and in the coating process, a mechanical fixing method such as caulking and a working or bending process such as welding are required, and the production efficiency is poor.
Further, there is a method of selecting an alloy such as titanium as a metal coating material resistant to corrosion. However, there is a problem that not only the material cost is high but also it is difficult to process a complicated curved surface such as a steel pipe sheet pile or a steel sheet pile.

On the other hand, in the conventional method of applying an organic coating having excellent impact resistance to the upper layer of the anticorrosion coating layer, Japanese Patent Publication No.
No. 06595, a polyester or glass fiber-containing polyester or glass fiber or metal fiber-containing epoxy acrylate layer is used as a protective coating on the anticorrosion coating layer made of polyethylene or polyurethane resin. A method of forming an organic resin protective coating having hardness is effective. However, in order to laminate different kinds of resins on the anticorrosion coating to have impact resistance, the adhesion becomes a problem. On the other hand, for example, when a polyethylene coating is used for an anticorrosion coating, Japanese Patent Laid-Open No.
As shown in 146271, a method has been proposed in which a protective layer can be covered by embossing a polyethylene surface layer to give physical irregularities. As shown in Japanese Patent Application Laid-Open No. 6-122173, there has been proposed a method of securing impact resistance by interposing a flocked material at the interface, as shown in JP-A-6-122173. However, in each case, a new process is required for strengthening the physical adhesion, and there are problems in quality control and cost. Further, since the anticorrosion layer and the protective layer are not chemically bonded to each other, there is also a problem in long-term durability such as peeling of the coating when the coating is damaged by impact.

Further, as disclosed in JP-A-63-5938, when an unsaturated polyester resin containing glass fiber is used only as an overcoating anticorrosion paint, the performance such as impact resistance, adhesion and anticorrosion required for heavy corrosion protection is obtained. Cannot be satisfied.

Accordingly, the present invention has no problems in durability and workability such as metal coating, and no problem in the adhesive interface between the anticorrosive coating and the protective coating, and does not involve complicated manufacturing steps, thereby improving production efficiency. To provide a polyester-coated heavy-duty corrosion-resistant steel material with excellent impact resistance and corrosion resistance.

[0009]

Means for Solving the Problems As means for solving the above problems, the present inventors have provided a primer layer containing an inorganic pigment on the surface of a steel material which has been subjected to a base treatment, and a 5 mm long layer on the primer layer. The above glass fibers are contained in the range of 5 to 40 vol%, and the total added amount of the glass fibers is 50 vol.
% Of a polyester-cured resin containing a pigment in the range of 1% or less by sequentially laminating an anticorrosion coating layer having a thickness of 1 to 10 mm, it is found that a polyester-coated steel material excellent in impact resistance, scratch resistance and corrosion resistance can be obtained. The present invention has been reached.

That is, the present invention, as shown in FIG.
A primer layer 2 containing an inorganic pigment and a glass fiber having a length of 5 mm or more
A pigment-containing polyester cured resin containing pigment in a range of 0 vol% and a combined total amount of the pigment in a range of 50 vol% or less is 1 to 10 mm in thickness.
2, a polyester-coated steel material characterized by sequentially laminating a colored anticorrosion coating layer 3 or a primer layer 2 containing an inorganic pigment on a surface of a steel material 1 subjected to an undercoat treatment as shown in FIG. 5-40v glass fiber of 5mm or more
1% to 10 mm of an anticorrosive coating layer made of a cured polyester resin containing a pigment in a range of not more than 50 vol%, and a total amount of the combined addition of not more than 50 vol%. The present invention relates to a polyester-coated steel material characterized in that a colored protective layer 5 having a single layer or a reverse layer and having a thickness of 10 to 100 μm is sequentially laminated with a paint.

Hereinafter, the present invention will be described in detail.

The steel material used in the present invention is a steel structure used in the ocean or river, such as a steel pipe or a steel pipe pile, a steel sheet pile, a steel sheet pile, and the like, and is a carbon steel, a stainless steel, a titanium alloy steel, or the like. Use alloy steel and its clad steel.
Its surface is plated with zinc, aluminum, nickel, copper, etc., alloy plating such as zinc-iron, zinc-aluminum, zinc-nickel, zinc-nickel-cobalt, or silica, titanium oxide, etc. And a dispersion-plated steel material in which fine particles of an inorganic material are dispersed.

As a base treatment for a steel material, first, a blast treatment is performed using a sand, a grid, a shot, or the like to remove surface deposits. However, a method other than blasting may be used as long as it has a function of removing surface oil and scale to impart roughness to 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 a chemical agent are used, excellent peeling resistance and the like are obtained. The amount of chromium applied was 50
Coating is performed so as to be in a range of １０００1000 mg / m ² .

On the surface of the steel material subjected to the undercoating treatment, a primer treatment agent obtained by adding an inorganic pigment to a thermosetting resin is applied and cured. The thickness of the primer-treated layer is 10 to 1
50 μm is desirable. If the film thickness is 10 μm or less, the steel material surface coverage by the primer decreases. On the other hand, when the thickness is 150 μm or more, the adhesion decreases due to an increase in the internal stress of the primer and a decrease in the defoaming property. The thermosetting resin of the primer treatment agent only needs to have excellent adhesiveness between the steel material and the polyester resin of the upper layer. Particularly, when an epoxy resin or a urethane resin is used, the adhesiveness to the steel material and the corrosion resistance are excellent. 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, a polyfunctional epoxy resin such as a phenol novolak epoxy resin or a cresol novolak epoxy resin having high heat resistance may be added. As the epoxy resin curing agent, an alicyclic amine, an aliphatic amine, dicyandiamide, a modified imidazole, a phenol novolak curing agent, or the like is used alone or in combination. Any urethane resin may be used as long as it is a compound comprising a polyol and an isocyanate, and is used as a two-component reaction-curable or moisture-curable prepolymer.
A vinyl ester resin having a bisphenol skeleton in the molecule can also be used as a primer resin,
A general vinyl ester resin has a large curing shrinkage and is inferior in adhesion to a steel material. For this reason, when a vinyl ester resin is used as a primer, a resin having a small curing shrinkage is selected.
Use the one adjusted below. The inorganic pigment used for the primer treatment agent is not particularly limited as long as it is an inorganic fine powder insoluble in neutral water, but silicon oxide, alumina, titanium oxide, magnesium silicate, calcium carbonate, a chromic acid compound, Phosphoric acid compounds, boric acid compounds or mixtures thereof can be used. However, even a water-soluble inorganic filler may be added if it is compatible with the resin and does not involve elution after the formation of the film, such as fumed silica.

5 to 40 vol% of glass fiber having a length of 5 mm or more is applied to the surface of the steel material which has been subjected to the base treatment and the primer treatment.
And the total amount of the combined additives is 50
A polyester cured resin layer containing a pigment in a range of not more than vol% is formed with a thickness of 1 to 10 mm. For coating the polyester resin layer, a method such as a hand lay-up method, a spray-up method, a cold press method, a filament winding method, or an injection molding using a mold is used. The 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 can also be used. A solution of these polyester resins dissolved in a polymerizable monomer such as a styrene monomer is treated with a peroxide catalyst such as ketone peroxide or hydroperoxide and a promoter such as cobalt, vanadium, manganese or amine. Use a thermosetting resin that cures.

The polyester resin anticorrosion layer is filled with a glass fiber having a length of 5 mm or more. When the length is 5 mm or less, the effect of improving the strength by the glass fiber cannot be obtained. In the case of using the filament winding method or glass cloth, there is no particular upper limit to the length. However, in the case of using short glass fibers in the spray-up method or the like, if the glass fibers are long, the defoaming property of the paint is reduced. A range of 50 mm is desirable. Further, the addition amount is in the range of 5 to 40 vol%. When the addition amount is less than 5 vol%, the adhesive strength with the primer decreases. In addition, the addition amount is 40 vo
If it exceeds 1%, the anticorrosion property decreases. As the additive fiber, glass fiber is used because it is excellent in price, resin reinforcing effect, and anticorrosion performance. In the case of carbon fiber or metal fiber as a fiber other than glass, the corrosion resistance of the film is reduced due to conductivity.
On the other hand, organic fibers have high shrinkage, and when added alone, the physical properties of the film are reduced.However, since organic fibers have little effect on lowering the corrosion resistance due to conductivity, they are added when used in combination with the glass fiber of the present invention. May be. In addition, inorganic filler pigments can be used in combination with glass fibers. The inorganic filler pigment may be any inorganic fine powder that is insoluble in neutral water and has no conductivity, and may be silicon oxide, alumina, titanium oxide, magnesium silicate, calcium carbonate, a chromate compound, a phosphate compound, and boric acid. Compounds or mixtures thereof can be used. Further, the polyester resin layer is colored by adding a coloring pigment for imparting design and weather resistance. Examples of the coloring pigment used include, for example, cadmium yellow, iron oxide, polyazo yellow, quinophthalone yellow, isoindolinone yellow, quinacridone yellow, vengara red, polyazo brown, azo lake yellow, perylene red, phthalocyanine blue, and phthalocyanine green. , Bengala yellow, cobalt aluminate, aniline black, carbon black, titanium oxide, ultramarine blue, aluminum fine powder and the like. Since the surface layer portion of the unsaturated polyester deteriorates due to exposure, when used in steel pipe piles, steel pipe sheet piles, steel sheet piles and outdoor steel structures, adding 0.5% or more of a coloring pigment improves weather resistance and corrosion resistance. If the total amount of these pigments combined with the fibers exceeds 50 vol%, the anticorrosion property is reduced. In order to provide the polyester resin layer having the above composition with anticorrosion properties and a function as a protective layer, a film of 1 to 10 mm is formed. If the thickness is less than 1 mm, impact resistance, corrosion resistance, durability and the like will be reduced.
On the other hand, when the thickness exceeds 10 mm, the economy and the adhesive strength are reduced.

When a long-term design property is required for the polyester-coated heavy-corrosion-resistant steel material of the present invention, a single layer or a reverse layer having a thickness of 10 to 100 μm is further coated with acrylic urethane, acrylic silicon, or a fluorine-based paint. The colored protective layer is sequentially laminated as the outermost layer. In particular, when used as piles or sheet piles in harbors and rivers, it is economical to provide the polyester-coated heavy-corrosion-resistant steel material 6 of the present invention with the colored protective layer 5 only above the water surface 7 as shown in FIG. .

In FIG. 3, reference numeral 3 denotes a colored anticorrosion coating layer made of a cured polyester resin containing glass fibers.
8 indicates a seabed, a lakebed or a riverbed.

It has been found that by successively laminating the above coatings as shown in the sectional view of FIG. 1 or 2, a polyester-coated steel material excellent in impact resistance, scratch resistance and corrosion resistance can be obtained. .

[0020]

【Example】

EXAMPLES AND COMPARATIVE EXAMPLES 1 After performing grid blasting on the outer surface of a steel pipe having an outer diameter of 200 A x length of 5500 mm x wall thickness of 5.8 mm to remove scale and the like to impart roughness to the surface, chromium-silica chromate The treating agent was applied and dried so that the total amount of chromium adhered became 50 mg / m ^2, and then a base treatment was performed. Next, an epoxy primer using an amine-based curing agent to which 10% by weight of titanium oxide was added was spray-coated so as to have a thickness of 30 to 60 μm, and the steel material was heated to cure the primer. Thereafter, a glass roving having a silane-based surface treatment of 2.3 kg / km was cut by changing the fiber length by a spray-up method to adjust the amount of addition, and 0.7 vol% of a coloring pigment and Spray-coating is performed simultaneously while spray-mixing the unsaturated polyester resin added with the calcium carbonate-filled pigment at a different amount and the peroxide catalyst-containing curing agent, and then the acrylic urethane paint or the fluorine paint is applied to the film thickness. Spray coating was performed to 30 μm to form a colored protective layer. Thereby, Comparative Example 1-1 which does not add glass fiber, Examples 1-1 to 1-5 and Comparative Examples 1-2 to 3 in which the fiber length was cut to 3 to 70 mm with the glass fiber addition amount being 12 vol%, and Cut glass fiber length to 12.5mm and add 12vol%
Or 30.5 vol%, and the filled pigment is 17 to 49 vol.
Examples 1-6 to 11 and Comparative Example 1 added in the range of 1%
-4-9 polyester-coated steel products were produced. The coated steel pipe was cut and the penetration energy of the coating was measured by a falling weight impact test specified in ASTM G14. In addition, as an evaluation method of the anticorrosion property, an adhesion evaluation test after immersion in warm water and a cathode peeling test were performed. Warm water immersion test is 60 ° C
After immersion in warm water for 1000 hours, a cut was made in the polyester anticorrosion layer up to the steel surface, a jig for measuring vertical adhesion was adhered via an adhesive, and the vertical adhesion was evaluated by pull-off measurement. In the cathode peeling test, the electrolytic solution was 3% -NaC
The test was performed at a temperature of 60 ° C. for 40 days by applying a voltage of 1.5 V using a copper sulfate standard electrode. Thereafter, the average peel distance at four points from the initial through-hole (diameter: 9 mm) of the coating was measured and evaluated.

Table 1 shows the results of evaluation of the effect of the glass fiber length and the effect of the total amount of glass fiber and pigment to be added in the spray-up method. The glass fiber length shows excellent performance only at the fiber length of 5 mm or more, which is the range of the present invention. In the case of the spray-up method, the corrosion resistance is slightly reduced at 70 mm due to the problem of defoaming as described above. On the other hand, the total amount of fibers and fillers is 50 v
If it exceeds ol%, both impact resistance and corrosion resistance will be reduced.

[0022]

[Table 1] Example and Comparative Example 2 After performing a grid blasting process on the outer surface of a steel pipe having an outer diameter of 200 A x length of 5500 mm x wall thickness of 5.8 mm to remove scale and the like to impart roughness to the surface, chromium-silica based chromate Apply and dry the treating agent and apply 100
A base treatment was performed so as to be 0 mg / m ² . Next, a vinyl ester primer to which 30% by weight of alumina and 20% by weight of talc were added was applied so as to have a dry film thickness of 30 to 60 μm, and was cured by curing. Thereafter, a silane-based surface treatment was performed by a spray-up method at 2.3 kg /.
A glass roving having a length of 5 km was cut into a length of 5 mm, the amount of which was changed, and an iso-unsaturated polyester resin to which 0.7 vol% of a coloring pigment was added and a peroxide catalyst-containing curing agent were spray-mixed. At the same time, spray coating was performed to form an ortho-unsaturated polyester anticorrosion layer having a thickness of 3 mm. Thereby, the glass fiber addition amount is 0-6.
Examples 2-1 to 2-5 added in a range of 3.4 vol%
And the polyester coating steel material of Comparative Examples 2-1 to 4 was produced. This coated steel pipe was cut and subjected to a falling weight impact test, a cathode peeling test, and an adhesion evaluation test after immersion in hot water under the same conditions as in Example 1.

Table 2 shows the results of evaluating the effect of the amount of glass fiber added. The amount of glass fiber added is within the scope of the present invention.
Excellent performance is shown at ４０40 vol%. When the amount of the fiber added to the polyester resin is less than 5 vol%, various properties are reduced due to a decrease in the adhesive strength with the primer and the strength of the resin. Further, even if the added amount exceeds 40 vol%, the anticorrosion property is reduced.

[0024]

[Table 2] Example and Comparative Example 3 After performing grid blasting on the outer surface of a steel pipe having an outer diameter of 200A x length of 5500 mm x wall thickness of 5.8 mm to remove surface scale and impart roughness to the surface, 2 wt% of strontium chromate And a urethane-based primer mixed with 14% by weight of pulverized silica was applied and cured by curing. Thereafter, a 3.5 kg / km glass roving having a silane surface treatment applied by a spray-up method was applied to a 25 mm glass roving.
A long cut one adjusted to have an addition amount of 12 vol%, a bisphenol-based unsaturated polyester resin containing 0.7 vol% of a coloring pigment and 15 vol% of talc as a filling pigment, and a peroxide catalyst-containing curing. The spray coating was carried out simultaneously while the agents were being mixed by spraying, and the coating thickness was changed to form an unsaturated polyester anticorrosion layer.

Thus, polyester-coated steel materials of Examples 3-1 to 5 and Comparative examples 3-1 and 2 having an unsaturated polyester anticorrosion layer in the range of 0.5 to 15 mm were produced.
This coated steel pipe was cut and subjected to a falling weight impact test, a cathode peeling test, and an adhesion evaluation test after immersion in hot water under the same conditions as in Example 1.

The results of evaluating the effect of the thickness of the unsaturated polyester anticorrosion layer are shown in Table 3. From the results in Table 3, it can be seen that the polyester layer exhibits a function as an anticorrosion layer when the thickness exceeds 1 mm. Also, the higher the thickness, the higher the impact resistance, but if the thickness exceeds 10 mm, the adhesiveness tends to decrease.

[0027]

[Table 3] Example and Comparative Example 4 After performing a grid blast treatment on the outer surface of a steel pipe having an outer diameter of 200 A x length of 5500 mm x wall thickness of 5.8 mm to remove scale and the like to give the surface a roughness, a chromium-silica chromate The treating agent was applied and dried so that the total amount of chromium adhered became 50 mg / m ^2, and then a base treatment was performed. Next, an epoxy primer using an amine-based curing agent to which 10% by weight of titanium oxide was added was spray-coated so as to have a thickness of 30 to 60 μm, and the steel material was heated to cure the primer. A glass roving of 2.3 kg / km, which has been subjected to a silane-based surface treatment by a spray-up method, is cut into a fiber length of 12.5 mm to adjust the addition amount to 12 vol%, and a calcium carbonate-filled pigment is 30 vol%. Was added simultaneously with spray mixing of the ortho-unsaturated polyester resin and the peroxide catalyst-containing curing agent, thereby forming an unsaturated polyester anticorrosive layer having a thickness of 3 mm. Then, simultaneously with the coated steel pipe of Example 1-8, an acrylic urethane paint or a fluorine paint was applied to a thickness of 30.
By forming a colored protective layer by spray coating to a thickness of μm, Examples 1-8-1-2, Examples 4-1 and 2,
Polyester anticorrosion coated steel materials of Comparative Examples 4-1 and 2 were produced. This coated steel pipe was cut and subjected to a falling weight impact test, a cathode peeling test, and an adhesion evaluation test after immersion in hot water under the same conditions as in Example 1. Further, this coated steel pipe was exposed to the vicinity of the shore in a vertical state for 8 years, and visual observation of crack generation, color difference change, blister generation, and the like was performed. The results are shown in Table 4.

[0028]

[Table 4] Comparative Examples 5 and 6 The outer surface of a steel pipe having an outer diameter of 200 A, a length of 5,500 mm and a wall thickness of 5.8 mm was subjected to grid blast treatment to remove scale and the like to impart roughness to the surface, and then a chromium-silica chromate treatment was performed. The agent was applied and dried so that the total amount of chromium becomes 50 mg / m ^2, and then a base treatment was performed. Next, an epoxy primer using an amine-based curing agent to which 10% by weight of titanium oxide was added was spray-coated so as to have a thickness of 30 to 60 μm, and the steel material was heated to cure the primer. Next, the steel pipe was rotated and conveyed, and the surface thereof was covered with a two-layer monolayer of low-density polyethylene containing 2% of maleic anhydride-modified polyethylene adhesive and carbon black from a T-die, and the polyethylene adhesive layer was 200 μm thick.
And a polyethylene layer having a thickness of 2.5 mm were laminated, and Comparative Example 5
Was manufactured.
Furthermore, on the surface, Japanese Patent Publication No. 7-6595 and Japanese Unexamined Patent Publication
Embossing of the shape shown in 46271 was performed. The dimensions of the embossed portion were 5 mm square and the depth was 0.3 mm. On the outer surface of this polyethylene-coated steel pipe, Examples 1-8
Under the same conditions as above, an unsaturated polyester coating having a thickness of 3 mm was applied by a spray-up method, and a heavy duty anticorrosion coated steel pipe of Comparative Example 6 in which a polyester protective layer was laminated on a conventional polyethylene anticorrosive layer was produced. This coated steel pipe was cut and processed.
Under the same conditions as described above, a falling weight impact test, a cathode peeling test, and an adhesion evaluation test after immersion in warm water were performed. Further, this coated steel pipe was exposed to the vicinity of the shore in a vertical state for 8 years, and visual observation of crack generation, color difference change, blister generation, and the like was performed. The results are shown in Table 4.

As is clear from the results in Table 4, polyethylene and polyester are not bonded. Therefore, Examples of the present invention having the same thickness of the polyester protective layer as Comparative Example 6 show superior impact resistance. However,
As for the anticorrosion property, since polyethylene has an anticorrosion function, the anticorrosion property against cathodic peeling and the occurrence of blisters after exposure are good. Also, for the color difference change,
Since the polyester layer is the same, there is no difference between Comparative Example 6 and Examples 1-8 of the present invention. On the other hand, in Comparative Example 4-1 in which no coloring pigment was added to the polyester layer, the color difference change was large. On the other hand, Examples 1-8-1 and 1-8-2 and Examples 4-1 and 4 of the present invention in which a colored protective layer was formed on the surface layer.
-2 shows excellent weather resistance as compared with the conventional polyester alone.

[0030]

As is clear from the examples, the polyester-coated heavy-corrosion-proof steel material of the present invention has significantly improved impact resistance as compared with conventional heavy-corrosion-coated steel pipes, steel pipe piles and steel sheet piles.
In addition, unlike the conventional case where the protective layer is overlaid on the protective layer by physical bonding by the anchor effect, the vertical adhesion with the steel material is obtained, so its long-term durability is obtained along with high impact resistance . In addition, it shows anti-corrosion property due to adhesion and barrier effect of coating, and weather resistance. From these effects, by applying a polyester-coated steel material having high impact resistance and corrosion resistance as a heavy-duty coating, it is possible to prevent the construction of the heavy-duty coating steel material, collision of ships, etc., and damage due to discarded stones. . Further, since the material cost of the coating and the manufacturing process are small, the product can be provided more easily.

[Brief description of the drawings]

FIG. 1 is a diagram showing a partial cross section of a heavy duty anticorrosion steel material coated with polyester of the present invention.

FIG. 2 is a view showing a partial cross section of a heavy duty anticorrosion steel material coated with polyester of the present invention.

FIG. 3 shows a method of providing a colored protective layer only on a portion above the water surface when the polyester-coated heavy-corrosion-resistant steel material of the present invention is used as a pile or a sheet pile, particularly in a harbor or a river, and both landscape and economy are required. It is a figure showing an example of.

[Explanation of symbols]

DESCRIPTION OF REFERENCE NUMERALS 1 Base material-treated steel material 2 Primer layer containing inorganic pigment 3 Corrosion-resistant coating layer made of polyester cured resin containing glass fiber 4 Corrosion protection coating layer made of polyester cured resin containing glass fiber 5 Acrylic urethane, acrylic silicon, fluorine Protective layer colored with a paint based on polyester 6 Heavy-corrosion-resistant steel material coated with polyester of the present invention 7 Water surface 8 Sea bottom, lake bottom, or river bottom

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-5938 (JP, A) JP-A-62-82471 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 1/00-35/00 B05D 7/00-7/26

Claims (2)

(57) [Claims] 1. A steel material which has been subjected to a base treatment, has a primer layer containing an inorganic pigment on the surface thereof, and has a length of 5 m
m or more of glass fibers in the range of 5 to 40 vol%, and the combined total amount of the pigments is in the range of 50 vol% or less. Polyester-coated heavy duty corrosion-resistant steel material characterized by being laminated. 2. A steel material which has been subjected to a base treatment, has a primer layer containing an inorganic pigment on the surface thereof, and has a length of 5 mm
Containing the above glass fibers in the range of 5 to 40 vol%,
And a total thickness of the polyester cured resin containing the pigment in a total addition amount of not more than 50 vol%.
A corrosion protection coating layer of 10 mm to 10 mm, and a further layer of a colored protective layer having a thickness of 10 to 100 μm in a single layer or a reverse layer of acrylic urethane, acrylic silicon, or a fluorine-based paint as an outermost layer is further laminated thereon. Polyester-coated heavy duty corrosion-resistant steel.