JP2624331B2 - Heavy corrosion protection coated steel excellent in corrosion resistance and hydrogen embrittlement resistance and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention is used for steel sheet piles, steel pipe piles, corrugated pipes, etc. for hot springs, geothermal areas, coastal areas of industrial areas and earth retaining, etc. The present invention relates to a heavy-duty corrosion-resistant coated steel excellent in hydrogen embrittlement resistance and a method for producing the same.

<Prior Art> Generally, a heavy corrosion protection coated steel material is subjected to a chemical conversion treatment and / or a primer treatment, and then coated or lined with an organic and / or inorganic resin in a thickness of 0.5 mm or more.
This method is effective for ordinary coastal areas, rivers, and soils, but is not suitable for environments where acidic and / or hydrogen sulfide is generated such as hot springs, geothermal areas, and industrial areas. Corrosive substances penetrate the coating film within a short period of time, and the corrosion reaction at the interface causes peeling of the coating film.

As a method of improving the anticorrosion property in such a highly corrosive environment, a method of adding a flat pigment such as glass flake or aluminum powder to a resin is known.

<Problems to be Solved by the Invention> However, although the above-described method has an effect of suppressing the transmission of corrosive factors to some extent, it is difficult to completely block the corrosive factors, and it is necessary to maintain the adhesive strength for a long period of time. Is difficult, and a sufficient anticorrosion effect cannot be obtained. The present applicants have previously disclosed an epoch-making invention for solving this problem in Japanese Patent Application No. 62-268197.

<Means for solving the problems> Therefore, this time, after coating the surface of steel with a primer resin paint containing vanadium oxide and copper oxide, heavy anticorrosion coating is performed to prevent hydrogen sulfide from interfering with steel. While maintaining the ability to prevent hydrogen permeation to the steel, it is extremely difficult to prevent the deterioration of the adhesion of the coating film even in a severe corrosive environment where hydrogen sulfide and / or acid is present, and to obtain the long-term corrosion protection of the steel material. As a result, the present invention has been completed.

That is, the present invention provides a vanadium oxide represented by VO _X (1.5 ≦ X ≦ 2.5) and a copper represented by CuyO (1 ≦ y ≦ 2) based on 100 parts by weight of a resin solid content as a primer layer on a steel material surface. Provided is a resin composition layer containing 1 to 500 parts by weight of an oxide, and a heavy corrosion protection coated steel material excellent in corrosion resistance and hydrogen embrittlement resistance, wherein a heavy corrosion protection coating layer is provided thereon. .

Further, the present invention provides a primer layer on the surface of a steel material, which is represented by vanadium oxide represented by VO _X (1.5 ≦ X ≦ 2.5) and CuyO (1 ≦ y ≦ 2) based on 100 parts by weight of resin solid content. A method for producing a heavy corrosion resistant coated steel material excellent in corrosion resistance and hydrogen embrittlement resistance, characterized by providing a resin composition layer containing 1 to 500 parts by weight of copper oxide, and applying a heavy corrosion protection coating layer thereon. provide.

 Hereinafter, the present invention will be described in detail.

The heavy corrosion-resistant coated steel material of the present invention is obtained by providing a resin composition layer as a primer layer on the surface of the steel material, and applying a heavy corrosion protection coating thereon.

In particular, the present invention relates to a resin composition layer in which VO _X (1.5 ≦ X ≦ 2.5) as vanadium oxide and C as copper oxide
Contains uyO (1 ≦ y ≦ 2). Vanadium oxide is
Due to its non-stoichiometric properties, it has a high ability to adsorb hydrogen sulfide, hydrogen and hydroxyl ions, and copper oxide has a high ability to temporarily adsorb corrosion factors such as hydrogen sulfide on its surface. , And a synergistic effect of the two can suppress a corrosion reaction on the surface of the steel material and maintain the adhesive strength for a long period of time.

When expressed as VO _X as a vanadium oxide, x is 1.5
A lower oxide in the range of ≦ x ≦ 2.5 is used. Such an oxide is called a nonstoichiometric compound and its composition cannot be specified by a chemical formula. However, as a stable or metastable oxide, VO ₂ (x = 2) and V ₄ O ₉ (x = 2.25) , V ₂ O ₅ (x
= 2.5).

Further, the copper oxide may be of any type in which the oxidation number of copper is monovalent or divalent, and generally Cu ₂ O and / or
Alternatively, a compound represented by CuO is included. Specific examples of these copper oxides include natural copper oxides such as copper oxide ore and copper sulfide ore: electrolytic oxidation of copper or a water-soluble copper salt in an alkaline salt solution, or dry oxidation of a precipitate from the solution. Obtained copper oxide: a copper oxide obtained by oxidizing metallic copper at a high temperature, or a mixture thereof. The copper oxide may contain other metal oxides such as chromium oxide, zinc oxide, and manganese dioxide.For example, copper oxide powder is dissolved in an aqueous solution of chromium trioxide, and zinc oxide is added to the solution. And a mixture obtained by kneading and drying.

Also, the VO _X and oxides range of x and y is outside the range in CuyO has no stability, and because also varies greatly crystal lattice, which is unsuitable for use.

The above-mentioned vanadium oxide and copper oxide desirably have the same particle size as the pigment usually used in paints.If the particle size is too large, the surface area becomes small, and hydrogen sulfide and hydrogen In addition to the expectation of the adsorption effect, the physical properties of the coating film tend to deteriorate. Therefore, it is preferable to use one having a particle size of about 0.1 to 50 μm.

The above-mentioned compounding of the vanadium oxide and the copper oxide into the resin composition can be easily carried out by using any known dispersing apparatus and dispersing step. The mixing ratio of the above-described vanadium oxide and copper oxide is 1 to 500 parts by weight, preferably 3 to 500 parts by weight, based on 100 parts by weight of the resin solid content.
It is in the range of 150 parts by weight, more preferably 5 to 50 parts by weight. When the amount is less than 1 part by weight, the object of the present invention is:
In the environment where acidic and / or hydrogen sulfide is present, the corrosion prevention effect of the steel material cannot be sufficiently obtained. On the other hand, when it exceeds 500 parts by weight, the coating film performance tends to deteriorate.

In the resin composition containing the vanadium oxide and the copper oxide used to form the primer layer in the present invention, the resin component used as a binder is a resin generally used in paints, and a heavy corrosion protection layer. Is not particularly limited as long as it has good adhesiveness, for example, epoxy resin, tar epoxy resin, acryl-modified epoxy resin, polyurethane resin, epoxy urethane resin,
Polyester resin, phenol resin, chlorine rubber resin,
Natural or synthetic resins such as silicone resins and fluororesins; and polymerized oils such as boiling oil.

Among these resins, a resin suitable for the resin composition of the primer used in the present invention is an epoxy resin, a phenol resin, which is excellent in chemical resistance, solvent resistance, and adhesion.
It is a polyurethane resin, a silicone resin, or the like, and more preferably, a resin composition capable of forming a cured film by crosslinking and three-dimensionalizing at room temperature or under heating.

Specifically, for example, a combination of a bisphenol-type diepoxy resin with a crosslinking agent such as a polyamine or an amino-polyamide resin; a combination of a novolak-type polyfunctional epoxy resin with a polyamine or a bifunctional phenolic resin crosslinking agent; Examples of the resin composition include a combination of a resin and a resol-type phenol resin crosslinking agent; a combination of a polyurethane resin and a polyol crosslinking agent.

Commercially available products include, for example, "Retan GP Primer" (polyurethane resin paint), "Eposeal", and "Epomarin" (all epoxy resin paint) manufactured by Kansai Paint Co., Ltd. However, it is not limited to these.

In the present invention, the coating material for forming a heavy-duty anticorrosion coating layer formed on the primer layer made of the above resin composition is a conventional one such as epoxy resin, polyurethane resin, polyethylene resin, polypropylene resin, vinyl chloride resin, and fluororesin. In general, all resins used as heavy anticorrosion coating materials are applied. These heavy anticorrosion coating layers may be provided via an adhesive layer as necessary. In the present invention, the heavy-duty anticorrosion coating layer means a layer obtained by applying these resins to a film thickness of 500 μm or more.

The resin composition used for the primer layer and the heavy-duty anticorrosion coating layer is usually formed into a coating using an organic solvent, but may be an aqueous dispersion. Examples of the organic solvent used for coating include ketone solvents such as methyl isobutyl ketone and methyl ethyl ketone; ester glycol solvents such as cellosolve and cellosolve acetate; alcohol solvents such as ethyl alcohol and n-butyl alcohol. No.

In accordance with the method of the present invention, the steel materials to be subjected to heavy corrosion protection coating include structural steel materials such as SS, SM, SD, SB, SPC, and alloy steels. Specific examples include a steel pipe pile, a steel pipe sheet pile, a corrugated pipe, and a shape steel.

Further, the resin composition may be blended with an inorganic or organic pigment or additive usually used for a paint. Specific examples of the additive include a pigment dispersant, a filler, a thickener, a sagging agent, a plasticizer, a drying agent, a curing agent, a surfactant and the like.

The heavy-corrosion-coated steel material of the present invention is obtained by sequentially applying a primer layer and a heavy-corrosion-resistant coating layer on the above-mentioned steel material.

In the present invention, the coating means is not particularly limited, and any ordinary method can be used, and examples thereof include spray coating, roll coating, brush coating, ironing, dip coating, and powder coating.

The coating amount of the primer layer is 5 to 300 μm, preferably 10 to 100 μm. If it is less than 5 μm, the effects of the present invention cannot be obtained, and if it is more than 300 μm, sagging occurs, which is not preferable.

Further, the coating amount of the heavy corrosion protection coating layer as the upper layer is preferably 0.5 mm or more. If it is less than 0.5 mm, a long-term anticorrosion effect cannot be obtained. Although the upper limit of the coating is not particularly defined, it is appropriate to set the upper limit to about 5 mm or less from the viewpoint of economy and the like.

<Example> Hereinafter, the present invention will be described more specifically with reference to examples.

(Example 1) After pre-kneading the compounding amount composition shown in Table 1 below, using a pebble mill
The dispersion was performed for 16-18 hours. Particle size after dispersion is 40μ
m or less.

Next, 23.0 parts by weight of 70% Epon 1001 resin varnish and 3.5 parts by weight of cellosolve acetate were added to the dispersion, and the pebble mill was further operated for 30 minutes to obtain a solid content of 75% by weight and a viscosity of 82 ± 10 KU.
(Value at 25 ° C. by a Stormer viscometer) was obtained. An epoxy resin paint for a primer layer was obtained by adding the composition shown in Table 2 below to 100 parts by weight of the paint base material thus obtained.

On the other hand, "ZEBURON" manufactured by Kansai Paint Co., Ltd. was used as a heavy duty anticorrosion paint.

(Examples 2 to 7) Table 3 below shows the results. Using each paint made by Kansai Paint Co., Ltd.
Vanadium oxide and copper oxide are roll-milled to a particle size of 40.
It was dispersed to a thickness of μm to obtain a coating composition for a primer layer.

(Comparative Examples 1 to 5) Based on the specifications shown in Table 3 below, a primer coating composition was prepared in the same manner as in the above Examples, and heavy anticorrosion coating was applied.

The primer paint prepared in the above Examples and Comparative Examples was applied to a SS41 steel plate blasted with an alumina # 46 abrasive at a thickness of 20 μm under predetermined curing conditions, and then a heavy corrosion protection coating material having a thickness of 1.5 mm was applied. A sample was obtained by coating with a thickness, and an anticorrosion test was performed and evaluated in the following manner.

(Anti-corrosion test) 100mm x 100% x 100% with sodium chloride 3%, acetic acid 0.5%, saturated aqueous solution of hydrogen sulfide (pH = 3) at 50 ° C for 100 days
A 100 mm square test material was subjected to an immersion test to determine the peel width from the end face and the adhesive strength at the center.

 Table 4 shows the results.

(Residual adhesive strength) (Urethane) As shown in FIG. 1, a jig 1 for a vertical tensile test was adhered to the center of the sample and bonded to a heavy duty anticorrosive polyurethane coating layer 3 formed on the surface of a steel material 2 with a primer layer 5 interposed therebetween. It was attached via an agent and pulled at a speed of 1 cm / min using an Instron tensile tester to obtain adhesive strength. The adhesive strength after the anticorrosion test was divided by that before the test to obtain the adhesive strength residual rate.

(Polyethylene-based) As shown in FIG. 2, a heavy corrosion-resistant polyethylene coating layer 4 formed on the surface of a steel material 2 with a primer layer 5 interposed therebetween, and a slit 6 reaching the steel material with a width of 2 cm in the center thereof was formed. Part is peeled off.

The base material was fixed, and the polyethylene film was pulled at a rate of 1 cm / min as in the case of the urethane-based film to obtain a tensile adhesive strength, and the residual adhesive strength was determined from the adhesive strength before and after the anticorrosion test.

As is clear from the results in Table 4, when the resin composition for the heavy corrosion protection primer layer of the present invention was used, when the resin coating containing only vanadium oxide or copper oxide was used, or when it was completely contained. Compared to the case where no steel is present, even in an environment in which acidic and / or hydrogen sulfide is present, longer-term adhesion durability is obtained, and a remarkable anticorrosion effect of the steel material is exhibited.

<Effects of the Invention> According to the present invention, a heavy corrosion-resistant coated steel material exhibiting excellent adhesive durability in an environment where acidic and / or hydrogen sulfide is present and having excellent long-term corrosion resistance can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a test method for obtaining a residual adhesive strength when a polyurethane-based heavy anticorrosive paint is used. FIG. 2 is a schematic view showing a test method for obtaining a residual adhesive strength when a polyethylene-based heavy anticorrosive paint is used. DESCRIPTION OF SYMBOLS 1 ... Jig for vertical tensile test, 2 ... Steel, 3 ... Heavy corrosion-resistant polyurethane coating layer, 4 ... Heavy corrosion-proof polyethylene coating layer, 5 ... Primer layer, 6 ... Slit

 ──────────────────────────────────────────────────の Continuing from the front page (72) Takao Kurisu, Inventor 1 Kawasaki-cho, Chiba-shi, Chiba Kawasaki Steel Corporation Research and Development Headquarters (72) Inventor Masami Sugishima 4-171-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa Kansai Inside of Paint Co., Ltd. (72) Inventor Kazuhiko Onishi 4-171-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa Prefecture Inside of Kansai Paint Co., Ltd.

Claims (2)

(57) [Claims] 1. A resin solid content as a primer layer on a steel material surface.
Resin composition containing 1 to 500 parts by weight of a vanadium oxide represented by VO _X (1.5 ≦ X ≦ 2.5) and a copper oxide represented by CuyO (1 ≦ y ≦ 2) based on 100 parts by weight A heavy corrosion protection coated steel material excellent in corrosion resistance and hydrogen embrittlement resistance, comprising a layer provided thereon and a heavy corrosion protection coating layer provided thereon. 2. A resin solid content as a primer layer on a steel material surface.
Resin composition containing 1 to 500 parts by weight of a vanadium oxide represented by VO _X (1.5 ≦ X ≦ 2.5) and a copper oxide represented by CuyO (1 ≦ y ≦ 2) based on 100 parts by weight A method for producing a heavy-duty corrosion-resistant coated steel material having excellent corrosion resistance and hydrogen embrittlement resistance, comprising providing a layer and then applying a heavy-duty corrosion-resistant coating layer thereon.