KR20170140735A - Sour resistance resin composition and coating steel pipe using the same - Google Patents

Abstract

Disclosed are a sour-resistant resin composition, and a coating steel pipe using the same. According to an embodiment of the present invention, provided is a sour-resistant resin composition consisting of: 50-70 wt% of a water-dispersed polyurethane resin; 10-30 wt% of a modified acrylic resin; 0.5-1.5wt% of a curing agent; 10-25 wt% of an anti-rust additive; 1-5 wt% of a cross-linking agent; and residual water. Moreover, provided is a coating steel pipe using the same.

Description

TECHNICAL FIELD [0001] The present invention relates to a resin composition for shower-

Resistant resin composition and a coated steel pipe using the same.

Currently, oil / gas is the most commonly used energy source on the earth, about 60%, and is expected to increase steadily despite the development of alternative energy sources.

The most important role in the oil / gas industry is the pipeline. This is because the pipeline is a much more efficient and economical means of transport than other transport methods such as shipping, rail, and land transport.

However, due to resource depletion in recent years, the mining environment has gradually been changed to oil / gas mining. In other words, the extraction of oil / gas with high corrosive sour gas such as hydrogen sulphide (H ₂ S) is increasing, which requires a pipeline to safely carry the hydrogen sulfide contained in transportation of oil / gas .

In order to reduce the cost of loss prevention and corrosion caused by advanced steel companies in Japan and Europe, we have steadily developed steel pipes for sour resistance. It has become necessary to apply the steel pipe for sour during transportation.

When the H ₂ S gas is contained in the oil / gas, it is known that the hydrogen is collected from the surface of the steel pipe into the incompletely weakened portion on the inner surface to generate a step-like crack, which eventually leads to the destruction of the steel pipe.

The fracture by H ₂ S occurs when the steel pipe is placed in the Sour corrosion atmosphere (Hydrogen Induced Cracking (HIC)) and when stress is applied to it (Sulfide Stress Corrosion Cracking (SSCC )). In the case of these two types of cracks, it is difficult to escape from the effect of this breakage in the existing general steel pipe. This is because the failure by sour can occur not only at incomplete defects at the time of manufacturing the steel pipe but also at any time due to potential factors which are very difficult to detect by the nondestructive inspection method.

In addition, despite the improvement of the internal sour characteristics due to the continuous technology of microstructure control and cooling technology by component design and rolling in the material, the residual stress that occurs during molding, welding, heat treatment process, Sour results are completely different from the material state due to inclusions and changes in the microstructure of the heat treatment, and the existing non-sour steel pipe products have been commercialized by techniques such as component design and strength, For steel pipe products, it is a very differentiated steel product that the element technology of the material and the element technology of the steel pipe must be accumulated at the same time to reach commercialization.

Currently, efforts are being made to secure steel makers, especially materials and welded steel pipes, in order to reduce the breakage of steel pipes by sour and to commercialize them. Especially, in order to strengthen the steel pipe industry related to oil / gas, Will continue to grow.

An embodiment of the present invention is to provide a resin composition capable of improving the corrosion resistance, more specifically, the properties of inner shower (sour) characteristics and adhesion.

Further, another embodiment of the present invention is to provide a coated steel pipe having excellent showering property.

One embodiment of the present invention is a composition comprising 50 to 70% by weight of a water-dispersible polyurethane resin; 10 to 30% by weight of a modified acrylic resin; 0.5 to 1.5% by weight of a hardener; 10 to 25% by weight of a rust inhibitive additive; 1 to 5% by weight of a crosslinking agent; And a water remaining portion.

The number-average molecular weight of the water-dispersed polyurethane resin may be 5,000 to 10,000, and the weight-average molecular weight of the water-dispersed polyurethane resin may be 50,000 to 100,000.

The modified acrylic resin may include a vinyl-modified acrylic resin, a silicone-modified acrylic resin, an epoxy-modified acrylic resin, or a combination thereof.

The modified acrylic resin may have a number average molecular weight of 12,000 to 15,000, and the modified acrylic resin may have a weight average molecular weight of 50,000 to 100,000.

The curing agent may be one comprising a carbodiimide compound, a polyaziridine compound, an isocyanate compound, or a combination thereof.

The rust inhibitive additive may include a titanate compound, a zirconium compound, a phosphoric acid compound, or a combination thereof.

The titanate compound includes titanium acetylacetonate, isopropyl ditriethanol aminotitanate, or a combination thereof, and the zirconium compound may include zirconium acetylacetonate, zirconium lactate, or a combination thereof.

Wherein the crosslinking agent is a silane coupling agent of 3-aminopropyltriepoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, or a combination thereof; Metal silicates of lithium polysilicate, sodium polysilicate, potassium polysilicate, or combinations thereof; Or a combination thereof.

The pH of the showerable resin composition may be 9.0 to 10.0.

The specific gravity of the showerable resin composition may be 1.04 to 1.08.

The viscosity of the showerable resin composition may be 15 to 20 seconds upon discharge from the Dean cup (# 4 Din 53211).

The solid content of the showerable resin composition may be 28 to 32% by weight.

Another embodiment of the present invention is a steel pipe comprising: a steel pipe; And a coating layer formed on the surface of the steel pipe and formed of the above-described inner shower resin composition.

The steel tube may comprise an inner shower material, API (American Petroleum Institute) material, or a combination thereof.

The thickness of the coating layer may be 10.0 to 20.0 mu m.

The resin composition according to one embodiment of the present invention can improve the corrosion resistance, more specifically, the properties of the inner sour property and the adhesion property.

In addition, the coated steel pipe according to another embodiment of the present invention has an excellent showering property.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited thereto, and the present invention is only defined by the scope of the following claims.

One embodiment of the present invention is a composition comprising 50 to 70% by weight of a water dispersible polyurethane resin; 10 to 30% by weight of a modified acrylic resin; 0.5 to 1.5% by weight of a hardener; 10 to 25% by weight of a rust inhibitive additive; 1 to 5% by weight of a crosslinking agent; And a water remaining portion.

Specifically, the showerable resin composition according to an embodiment of the present invention comprises 50 to 60% by weight of the water-dispersed polyurethane resin, 10 to 20% by weight of the modified acrylic resin, 0.5 to 1.5% by weight of a curing agent, To 15% by weight of the crosslinking agent, 1.5 to 2.0% by weight of the crosslinking agent, and the balance of water.

The showerable resin composition may be water-soluble because water is used as a solvent. When the water-soluble resin composition is used as described above, it can be eco-friendly in process in comparison with the use of an oily resin composition using an organic solvent, and cost can be reduced.

Further, the resin composition comprising the above-mentioned components is excellent in corrosion resistance and in more detail, shower resistance.

The water-dispersed polyurethane resin is obtained by neutralizing a polyurethane prepolymer prepared by reacting a polyester polyol, a diisocyanate and a crosslinking agent with a neutralizing agent and then dispersing the polyurethane prepolymer in water to react with a diamine as a chain extender to form a cross- have.

The polyester polyol may be at least one of PEAG, PNAG, PBAG, PHAG and PCL, and the diisocyanate may be at least one of TDI, MDI, HDI, H12MDI and IPDI. Here, TDI and MDI of aromatic type are low in cost and weather resistance is weak, and HDI, H12MDI and IPDI of lipid-dense type are high in price and good in weather resistance.

The number average molecular weight of the water-dispersed polyurethane resin may be from 5,000 to 10,000. The weight average molecular weight of the water-dispersed polyurethane resin may be 50,000 to 100,000.

In addition, it is possible to impart good adhesion, workability, and ductility to the steel sheet at an appropriate blending ratio of hard segment and soft segment of the water-dispersed polyurethane resin.

The water-dispersible polyurethane resin may be contained in an amount of 50 to 70% by weight, specifically 50 to 60% by weight based on the total amount of the showerable resin composition. When the polyurethane resin is used in an amount less than the above range, there is a problem in corrosion resistance. When the content exceeds the above range, there is a problem in drying property and the physical properties may be lowered.

The modified acrylic resin is a resin developed to impart elasticity to the rigid properties possessed by acrylic resins and to improve corrosion resistance.

The modified acrylic resin may include a vinyl-modified acrylic resin, a silicone-modified acrylic resin, an epoxy-modified acrylic resin, or a combination thereof. The vinyl-modified acrylic resin and the silicone-modified acrylic resin give excellent elasticity, and the epoxy-modified acrylic resin can impart excellent corrosion resistance.

For example, the modified acrylic resin may be a silicone-modified acrylic resin. Specifically, 15 to 25 parts by weight of water as a solvent is added to an ethylene-acrylate copolymer, and 2 to 5 parts by weight of a neutralizing agent such as N, N-diethanolamine or triethylamine is added thereto, For 3 hours to prepare a water-dispersed acrylic copolymer resin.

Then, a silicon intermediate having a hydrolyzable alkoxysilyl group in an amount of 0.5 to 2.0 parts by weight is gradually added dropwise and subjected to a secondary reaction in which the reaction is carried out for 2 to 3 hours to obtain a silicone-modified acrylic resin having a siloxane bond (-Si-O-Si-O-) Resin can be produced. As the organosilane, at least one compound selected from aminopropyltrimethoxysilane, aminopropyltriethoxysilane, aminoethylaminopropyltrimethoxysilane and aminoethylaminopropyltriepoxysilane can be selected and used.

The modified acrylic resin may have a number average molecular weight of 12,000 to 15,000, and the modified acrylic resin may have a weight average molecular weight of 50,000 to 100,000.

The modified acrylic resin may be contained in an amount of 10 to 30% by weight, specifically 10 to 20% by weight based on the total amount of the showerable resin composition. When the modified acrylic resin is used within the above-mentioned content range, corrosion resistance is excellent, and the resin can be used in a small amount, thereby reducing the cost.

The curing agent may be one comprising a carbodiimide compound, a polyaziridine compound, an isocyanate compound, or a combination thereof. The curing agent binds with the functional group of the resin to have a denser structure, thereby further improving the physical properties of the coating film.

The curing agent may be contained in an amount of 0.5 to 1.5% by weight based on the total amount of the showerable resin composition. When the curing agent is used in an amount less than the above range, corrosion resistance may occur. When the curing agent is used in an amount exceeding the above range, there may arise a problem in solution stability.

The rust-preventive additive is an additive added to further improve physical properties such as basic corrosion resistance of the main resin.

The rust inhibitive additive may include a titanate compound, a zirconium compound, a phosphoric acid compound, or a combination thereof.

Examples of the titanate compound include, but are not limited to, titanium acetylacetonate, isopropyl ditriethanol aminotitanate, and the like.

Examples of the zirconium compound include zirconium acetylacetonate and zirconium lactate, and they may be used alone or in combination with a polymerized phosphoric acid compound.

The rust-inhibitive additive may be included in an amount of 10 to 25% by weight, and more specifically 10 to 15% by weight based on the total amount of the showerable resin composition. When the rust inhibitive additive is used within the above content range, excellent rust inhibitive effect can be obtained and corrosion resistance can be improved.

The cross-linking agent can improve the adhesion between the above-mentioned resins and the rust-preventive additive.

Wherein the crosslinking agent is a silane coupling agent of 3-aminopropyltriepoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, or a combination thereof; Metal silicates of lithium polysilicate, sodium polysilicate, potassium polysilicate, or combinations thereof; Or a combination thereof.

The crosslinking agent may be contained in an amount of 1 to 5% by weight, and more preferably 1.5 to 2.0% by weight based on the total amount of the showerable resin composition. When the cross-linking agent is used within the above-mentioned content range, the adhesion between each resin and the rust-preventive additive described above can be improved.

The water may be included as a remainder with respect to the total amount of the showerable resin composition.

The showerable resin composition may have a pH, a specific gravity, a viscosity and a solid content within a predetermined range in order to obtain various physical property balance.

For example, the pH of the showerable resin composition may be 9.0 to 10.0.

The specific gravity may be 1.04 to 1.08.

The viscosity may also be 15 to 20 seconds under the conditions of the Dean cup (# 4 Din 53211) measurement.

The solid content may be 20 to 35% by weight, and specifically 28 to 32% by weight.

The showerable resin compositions each controlled within the above range are excellent in corrosion resistance and in detail, showerability. Further, it is possible to obtain a balance of physical properties excellent in adhesion.

In another aspect of the present invention, And a coating layer formed on the surface of the steel pipe and formed of the above-described showerable resin composition.

The steel pipe may be made of a material including an inner shower material, an API (American Petroleum Institute) material, or a combination thereof.

The coating layer may be formed using the above-described showerable resin composition. Accordingly, it is possible to realize a coated steel pipe having superior appearance and surface texture as well as excellent corrosion resistance and excellent showering property.

The thickness of the coating layer may be 5.0 to 30.0 mu m, and may be 10 to 20 mu m. When the thickness of the coating layer is within the above range, it is possible to obtain a balance of physical properties excellent in corrosion resistance and in detail, showering property.

Hereinafter, preferred embodiments and comparative examples of the present invention will be described. However, the following examples are only a preferred embodiment of the present invention, and the present invention is not limited to the following examples.

Example

Preparation of shower resistant resin composition

The specifications of the components used in the production of the showerable resin composition are as follows.

As the water-dispersed polyurethane resin, VS-8238, VS-8308A (V100) and VS-8572A manufactured by Victor Chem were mixed and used.

As the modified acrylic resin, VAC-507S and VAC-920R manufactured by Victor Chem were mixed and used.

As the hardening agent, PZ-28 of polyaziridine series manufactured by Hannok Industry and DBTDL of isocyanate series manufactured by Victor Chem were used.

Anticorrosive additive was used as a mixture of Dupont Tyzor TE ^® Inc. and Dupont's Zircore ^®.

As the crosslinking agent, 3-glycidoxypropyltrimethoxysilane of Aldrich was used.

Water was used as a solvent.

Examples 1 to 4

Examples 1 to 4 were prepared by mixing each component in the composition shown in the following [Table 1], and stirring the mixture at a speed of 300 rpm for 30 minutes in an agitator.

Comparative Examples 1 to 3

Comparative Examples 1 to 3 were prepared in the same manner as in Examples 1 to 3 except that the composition containing the urethane resin, the curing agent and the crosslinking agent in a low content (Comparative Example 1) and the case of not containing a curing agent (Comparative Examples 2 and 3) The resin composition was prepared using the same method as the method described above.

Component content (the remainder being water, each value representing weight% with respect to the total amount of the mixture of 100% by weight) Urethane resin Acrylic resin Hardener Cross-linking agent Anti-rust additives Example 1 50 10 0.5 1.5 10 Example 2 60 10 1.0 1.5 10 Example 3 60 20 1.0 2.0 10 Example 4 60 20 1.5 2.0 15 Comparative Example 1 40 10 0.3 1.0 10 Comparative Example 2 50 10 - 1.5 10 Comparative Example 3 50 20 - 2.0 10

Manufacture of coatings for coated steel pipes

The surface of the steel tube was immersed in the resin compositions of Examples 1 to 4 and Comparative Examples 1 to 3, dried at 70 占 폚 in a dry oven, and a coating film having a thickness of 10 占 퐉 was formed.

evaluation

Evaluation for Examples 1 to 4 and Comparative Examples 1 to 4

(1) Corrosion resistance measurement

Coatings formed using the resin compositions of Examples 1 to 4 and Comparative Examples 1 to 3 were continuously exposed to a 5% NaCl and 35 ° C for 120 hours in a Q-FOG salt sprayer in accordance with KS-D-9502, And the results are shown in [Table 2].

(Corrosion resistance evaluation standard)

◎: Satisfies 120 hours of salt water spray (less than 5% of red rust after 120 hours)

○: Satisfied with salt water spray for 96 hours (less than 5% red rust occurrence rate after 96 hours)

×: unsatisfactory 96 hours of saline water formation (more than 20% red rust occurrence rate after 96 hours)

(2) Adhesion (CCT) measurement

Coatings formed using the resin compositions of Examples 1 to 4 and Comparative Examples 1 to 3 were prepared by a cross-hatch cutter at intervals of 1 mm at an interval of 10 cubic by 10 cubic centimeters each. The scotch tape was fully bonded, And the adhesion of the coating film was measured. The results are shown in Table 2.

(Evaluation Criteria of Adhesion)

○: No peeling

△: 1 or more and 5 or less peeling occurred

X: More than 6 delaminations occurred

Results of physical property evaluation Corrosion resistance Adhesiveness
(CCT) Example 1 ○ ○ Example 2 ○ ○ Example 3 ◎ ○ Example 4 ◎ ○ Comparative Example 1 X Δ Comparative Example 2 X Δ Comparative Example 3 X Δ

Through the above Table 2, it can be confirmed that when the showerable resin composition according to one embodiment of the present invention is used, the corrosion resistance, more specifically, the inner shower property and the adhesion property are both excellent.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims. As will be understood by those skilled in the art. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

Claims (15)

50 to 70% by weight of a water-dispersed polyurethane resin;
10 to 30% by weight of a modified acrylic resin;
0.5 to 1.5% by weight of a hardener;
10 to 25% by weight of a rust inhibitive additive;
1 to 5% by weight of a crosslinking agent; And
Water balance
Wherein the showerable resin composition comprises:
The method according to claim 1,
Wherein the water-dispersed polyurethane resin has a number average molecular weight of 5,000 to 10,000, and the water-dispersed polyurethane resin has a weight average molecular weight of 50,000 to 100,000.
The method according to claim 1,
Wherein the modified acrylic resin comprises a vinyl-modified acrylic resin, a silicone-modified acrylic resin, an epoxy-modified acrylic resin, or a combination thereof.
The method of claim 3,
Wherein the modified acrylic resin has a number average molecular weight of 12,000 to 15,000, and the modified acrylic resin has a weight average molecular weight of 50,000 to 100,000.
The method according to claim 1,
Wherein the curing agent comprises a carbodiimide-based compound, a polyaziridine-based compound, an isocyanate-based compound, or a combination thereof.
The method according to claim 1,
Wherein the rust inhibitive additive comprises a titanate compound, a zirconium compound, a phosphoric acid compound, or a combination thereof.
The method according to claim 6,
Wherein the titanate compound comprises titanium acetylacetonate, isopropyl ditriethanol aminotitanate, or a combination thereof, wherein the zirconium compound is selected from the group consisting of zirconium acetylacetonate, zirconium lactate, Composition.
The method according to claim 1,
Wherein the crosslinking agent is a silane coupling agent of 3-aminopropyltriepoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, or a combination thereof; Metal silicates of lithium polysilicate, sodium polysilicate, potassium polysilicate, or combinations thereof; Or a combination thereof.
The method according to claim 1,
Wherein the pH of the showerable resin composition is 9.0 to 10.0.
The method according to claim 1,
Wherein the showerable resin composition has a specific gravity of 1.04 to 1.08.
The method according to claim 1,
Wherein the viscosity of the showerable resin composition is 15 to 20 seconds upon discharge from a Dean cup (# 4 Din 53211).
The method according to claim 1,
Wherein the showerable resin composition has a solid content of 28 to 32% by weight.
Steel pipe; And
A coating layer formed of the showerable resin composition according to any one of claims 1 to 12, which is located on the surface of the steel pipe
Coated steel pipe.
14. The method of claim 13,
Wherein the steel tube comprises a material for showering, an API (American Petroleum Institute) material, or a combination thereof.
14. The method of claim 13,
Wherein the coating layer has a thickness of 10.0 to 20.0 mu m.