WO2013073785A1

WO2013073785A1 - Copper alloy for fish-farming net

Info

Publication number: WO2013073785A1
Application number: PCT/KR2012/009028
Authority: WO
Inventors: 윤의한; 곽범수; 양나래
Original assignee: 주식회사 대창
Priority date: 2011-11-16
Filing date: 2012-10-31
Publication date: 2013-05-23
Also published as: KR20130054022A

Abstract

The copper alloy for a fish-farming net according to the present invention comprises between 60.0wt% and 65.0wt% of copper (Cu), between 0.5wt% and 1.0wt% of tin (Sn), between 0.02wt% and 0.50wt% of phosphorus (P), no more than 0.2wt% of lead (Pb), and a balance of zinc (Zn).

Description

Copper Alloy for Aquaculture Fishing Nets

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copper alloy for aquaculture fish nets, which is excellent in surface properties by inhibiting biofouling in water, and improves corrosion resistance and is environmentally friendly, and relates to a copper alloy material for aquaculture fish nets with increased service life.

In recent years, there is a growing interest in reducing the environmental pollution of marine aquaculture to achieve a sustainable future and improving the productivity of aquaculture.

The biggest problem in the offshore aquaculture industry is subsea pollution as well as coastal sea level pollution. Recently, the government has reached the stage of reviewing and implementing the coastal rest year, which clearly shows the actual condition of environmental pollution. Currently, fishermen are using antifouling agents or chemicals to remove biofouling that clings to fishing nets every three months. In addition, there is a problem that the current flow is interrupted between the fishing net by the adherent organism, the oxygen supply is reduced, the mortality of the cultured fish species is increased, causing a decrease in productivity. The biggest cause of this problem is that the fishing net material uses a material that adheres well such as polyethylene, polypropylene and nylon.

Conventionally, polyethylene (PE), polypropylene (PP), nylon, polyester fiber, and the like have been adopted as a material for aquaculture fish nets.

Polyethylene is a thermoplastic that accounts for over 80% of fishing nets. These nets are divided into knotted nets and no knotted nets, but most fishermen use knotted nets without knotted nets. However, the adherent organisms adhere well to the surface of the fishing net of polyethylene material, and the life of the fishing net is short, and food waste, antifouling agents and chemicals accumulate on the sea floor and contaminate the farm environment.

Polypropylene is a thermoplastic plastic, which is similar to polyethylene but has high strength, light weight, and easy molding, and is widely used for wire coating and synthetic fibers. However, polypropylene has a problem in that the corrosion rate is 20 to 30% higher than that of polyethylene.

Nylon has a problem of poor durability and strength than polyethylene or polypropylene. Nylon nets are mostly applied to drift grill nets.

In addition, fishing nets made of polyester fibers are 10 times higher in strength than ordinary plastics, and do not wrinkle well, but have a problem of high price. Fishing nets made of polyester fibers have not solved the problem of adherent organisms. Recently, a material coated with stainless steel wire has been tried, but this material also does not solve the problem of adherent organisms.

Accordingly, the necessity of using copper alloy as a material for aquaculture fishing nets is used for brass and high technology in human life and industry as a material for fishing nets.

An object of the present invention is to solve the above problems, to prevent the adhesion of organisms to the surface of the fishing net, to prolong the life of the fishing net, to reduce the seabed pollution by avoiding the use of antifouling agents and chemicals To provide a copper alloy material for aquaculture fish nets with improved properties.

Copper alloy for aquaculture fish nets according to an embodiment of the present invention, to achieve the above object, 60.0wt% to 65.0wt% of copper (Cu), 0.5wt% to 1.0wt% of tin (Sn), 0.02wt of phosphorus (P) % To 0.50wt%, lead (Pb) 0.2wt% or less, the remainder is characterized by consisting of zinc (Zn).

Copper alloy for aquaculture fish net according to another embodiment of the present invention, to achieve the above object, 60.0wt% to 65.0wt% of copper (Cu), 0.5wt% to 1.0wt% of tin (Sn), 0.02wt of arsenic (As) % To 0.35wt%, antimony (Sb) 0.02wt% to 0.50wt%, lead (Pb) 0.2wt% or less, and the rest is characterized by consisting of zinc (Zn).

Copper alloy for aquaculture fish nets according to another embodiment of the present invention, to achieve the above object, 60.0wt% to 65.0wt% of copper (Cu), 0.5wt% to 1.0wt% of tin (Sn), 0.02% phosphorus (P) wt% to 0.50wt%, antimony (Sb) 0.02wt% to 0.50wt%, lead (Pb) 0.2wt% or less, and the rest is characterized by consisting of zinc (Zn).

The copper alloy for aquaculture fish nets according to the present invention suppresses de-zinc corrosion even when installed in the ocean, thereby improving corrosion resistance and preventing attachment of deposits on the surface of the fish nets, thereby extending the life of the fish nets and preventing subsea pollution. It is effective to provide a copper alloy material.

1 is a component table of the copper alloy for aquaculture fish nets according to the present invention.

2 is a chemical component analysis result of the copper alloy according to the preferred embodiments of the present invention.

3 is a test result comparing the corrosion resistance of the conventional brass alloy and the copper alloy shown in FIG.

4 is a test result showing the mechanical properties of the copper alloy according to the present invention.

5 is a photograph of a state after five months have elapsed after installing a fishing net prototype made of a copper alloy according to the present invention and a steel fishing net coated with a conventional plastic in a marine farm.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a component table of the copper alloy for aquaculture fish nets according to the present invention. 2 is a chemical component analysis result of the copper alloy according to the preferred embodiments of the present invention. 3 is a test result comparing the corrosion resistance of the conventional brass alloy and the copper alloy shown in FIG. 4 is a test result showing the mechanical properties of the copper alloy according to the present invention. 5 is a photograph of a state after five months have elapsed after installing a fishing net prototype made of a copper alloy according to the present invention and a steel fishing net coated with a conventional plastic in a marine farm.

Referring to Figure 1, three alloy sets are shown as copper alloys for aquaculture fish nets according to the present invention.

Several recent experimental studies have shown that on dry copper and copper alloy surfaces at room temperature, various bacteria known as human pathogens are sterilized. In other words, the number of living bacteria is eliminated in one to two hours. In contrast, the number of bacteria living on stainless steel surfaces does not decrease after hours or days. Aluminum or plastics with painted or plated surfaces, silver ion coatings for antimicrobial or antimicrobial surface treatments, as well as stainless steel, have no bactericidal effect. These results indicate that copper alloys are suitable for exposed surfaces to which humans come in contact as a substance that can reduce bacterial contamination. Copper alloys also have antibacterial effects against Listeria, Salmonella and Influenza A (algae flu). Recently, with the spread of H1N1 influenza A virus (H1N1), the antimicrobial activity of copper has become a major issue. In particular, as a major industry of food supply, marine aquaculture is attracting attention these days, and it is anticipated to use copper alloy having antimicrobial activity as a fish farming net material that can prevent biofouling, which is the biggest problem in aquaculture business.

Each copper alloy for aquaculture nets will be described in detail.

First, the copper alloy for aquaculture fish nets according to the first embodiment is 60.0 wt% to 65.0 wt% of copper (Cu), 0.5 wt% to 1.0 wt% of tin (Sn), 0.02 wt% to 0.50 wt% of phosphorus (P), and lead (Pb) 0.2 wt% or less and the remainder is characterized by consisting of zinc (Zn). The corrosion resistance of Cu in brass alloys increases corrosion when zinc (Zn) is more than 35wt%. Therefore, the content of copper (Cu) in the copper alloy for aquaculture fish nets according to the present invention was limited to less than 65.0wt%. In addition, when the content of copper (Cu) exceeds 65.0 wt%, there is a problem in that corrosion resistance is improved while cutting processability is lowered. On the other hand, when the content of copper (Cu) is less than 60 wt%, it has a structure having an α + β phase. As a result, the β-phase content cannot be reduced even if other additive elements or production processes are changed, which results in poor corrosion resistance. Therefore, the copper (Cu) content in the range of 60.0 wt% to 65.0 wt% can be improved without lowering the machinability.

Tin (Sn) is an element that improves the corrosion resistance of brass and is a β-phase stabilizing element. Tin (Sn) is effective in general corrosion, but less effective in suppressing de-zinc corrosion. If the content of tin (Sn) is less than 0.5wt%, the effect of improving the corrosion resistance is small. If the content of tin (Sn) exceeds 1.0wt%, the weak phase of the γ phase appears, so the content of tin (Sn) should be adjusted.

In addition, phosphorus (P) is included 0.02wt% to 0.50wt%. Phosphorus (P) is similar to arsenic (As) and antimony (Sb) in the copper alloy, and its action is to suppress the zinc corrosion of α-brass. However, it is known that phosphorus (P) does not exhibit de zinc corrosion inhibiting action on the β phase of the industrially important (α + β) brass alloy. This is because phosphorus (P) selectively collects in the α phase and does not protect the β phase grains. That is, phosphorus (P) acts as a stabilizing element of the α phase. If the content of phosphorus (P) is less than 0.02 wt%, there is a problem that the stabilizing effect of the α phase is insignificant. On the other hand, when the content of phosphorus (P) exceeds 0.50 wt%, the excess phosphorus (P) is segregated at the phase boundary between the α phase and the β phase, which causes grain boundary corrosion.

Lead (Pb) is an element that inevitably flows into the impurity level, it is more preferable that lead (Pb) is not included in the copper alloy for aquaculture fish net according to the present invention, but lead (Pb) does not significantly affect the physical properties It was understood that.

The remaining elements contain zinc (Zn) to form a brass alloy whose main components are copper (Cu) and zinc (Zn).

Copper alloy for aquaculture fish nets according to a second embodiment of the present invention, 60.0wt% to 65.0wt% of copper (Cu), 0.5wt% to 1.0wt% of tin (Sn), 0.02wt% to 0.35wt% of arsenic (As) , Antimony (Sb) 0.02wt% to 0.50wt%, lead (Pb) 0.2wt% or less, and the rest is characterized in that made of zinc (Zn).

In the copper alloy of the second embodiment, arsenic (As) and antimony (Sb), which are elements that suppress de-zinc corrosion, are added together. Arsenic (As) and antimony (Sb) added in the second embodiment, as described in the first embodiment, have a function of inhibiting de-zinc corrosion in copper alloy similarly to the effect of phosphorus (Pb). In the second embodiment, when the content of arsenic (As) is less than 0.02 wt%, the stabilizing effect of the α phase is insignificant. On the other hand, when the content of arsenic (As) exceeds 0.35 wt%, the excess arsenic (As) is segregated at the phase boundary between the α phase and the β phase to cause grain boundary corrosion. On the other hand, in the second embodiment, when the content of antimony (Sb) is less than 0.02 wt%, there is a problem that the stabilization effect of the α phase is insignificant. On the other hand, when the content of antimony (Sb) exceeds 0.50 wt%, the excess antimony (Sb) is segregated at the phase boundary between the α phase and the β phase, which causes grain boundary corrosion. In addition, when the content of antimony (Sb) exceeds 0.50 wt%, there is a problem that the hot workability of the copper alloy is deteriorated.

Copper alloy for aquaculture fish nets according to a third embodiment of the present invention, copper (Cu) 60.0wt% to 65.0wt%, tin (Sn) 0.5wt% to 1.0wt%, phosphorus (P) 0.02wt% to 0.50wt% , Antimony (Sb) 0.02wt% to 0.50wt%, lead (Pb) 0.2wt% or less, and the rest is characterized in that made of zinc (Zn).

In the copper alloy of the third embodiment, phosphorus (P) and antimony (Sb), which are elements that suppress de-zinc corrosion, are added together. The amounts of phosphorus (P) and antimony (Sb) added are the same as in the first embodiment and the second embodiment. In the copper alloy according to the second embodiment, phosphorus (P) and antimony (Sb) may be expected to express both a de zinc corrosion inhibitory effect.

The components of the three examples of the copper alloy for aquaculture fish nets according to the present invention have been described above.

Hereinafter, the copper alloy for aquaculture fish nets according to the present invention will be evaluated to evaluate the degree of improved corrosion resistance compared to the conventional copper alloy and to evaluate the mechanical properties to see whether it is suitable for use as a culture fish material.

Figure 2 is a data analysis of the chemical composition of the copper alloy prepared according to the preferred embodiments of the present invention. The result of comparing the copper alloy shown in FIG. 2 with a conventional corrosion resistance test and corrosion resistance test is shown in FIG. 3. The test result shown in FIG. 3 is a test result of applying the corrosion resistance test standard AS2345-2006. The conventional corrosion resistant brass to be compared is a Cu-Zn-Pb-based brass alloy containing 57.9 wt% copper (Cu), 35.5 wt% zinc (Zn), 3.30 wt% lead (Pb), and 0.28 wt% tin (Sn). . Referring to Figure 3 it can be seen that the maximum corrosion depth and average corrosion depth of the copper alloy according to the preferred embodiments of the present invention is significantly improved compared to the conventional brass alloy. In general, the requirements for corrosion resistance for use in aquaculture fish nets are the average corrosion depth of 300 µm or less as a result of the above-mentioned standard test of corrosion resistance. In view of this, the copper alloy according to the present invention satisfies this criterion. Therefore, it can be evaluated that the copper alloy according to the present invention has corrosion resistance enough to be used for fishing nets.

Referring to Figure 4 it can be seen the mechanical properties of the copper alloy for aquaculture fish net according to the present invention. Figure 4 shows the physical properties of the wire for fishing nets made of a copper alloy for cultured fishing nets according to the present invention. Referring to FIG. 4, the result of measuring tensile strength, elongation and hardness of a sample having a diameter of φ3.2, φ4.0, and φ19 of a wire made of a copper alloy according to the first embodiment of the present invention is the property of conventional copper alloys. It can be seen that it is comparable or superior to. These properties were identified as mechanical properties that are not lacking for use in aquaculture fishing nets.

In addition, Figure 5 is a photograph of a state after five months after the fishing net made of copper alloy prototype according to the present invention and the conventional plastic-coated steel fishing net installed in the marine farm. Referring to Figure 5 it can be seen that the adhesion attached to the surface of the fishing net made of a copper alloy according to the present invention is significantly less than the conventional fishing net.

Fishing nets made of the copper alloy for cultured fishing nets according to the present invention inhibits biofouling, and the resulting clean fishing nets improve the flow and circulation of the currents. It also helps maintain high levels of oxygen, which inhibits parasites and pathogens from well-growing or decaying fish. By minimizing the cleaning or replacement of fishing nets, the extreme stress of fish during the replacement process can be reduced. In addition, the fishing nets made of the copper alloy for cultured fishing nets according to the present invention maintains a good environment, the mortality of the fry is lowered, and the growth rate of the fish is increased. That is, by reducing the growth cycle, there is an effect to reduce the feed consumption. Healthy fish have more weight on sale, which in turn increases their selling price. Of course, the high density of fish in the fishing grounds can reduce the cost per m ^{3 of} fishing nets. In addition, the fishing nets made of the copper alloy for cultured fishing nets according to the present invention does not need to remove or clean the deposits attached to the nets, unlike traditional fishing nets. This lowers the overall cost of maintenance and divers' risk allowances. In addition, as the dissolved oxygen increases, the growth environment is improved, and the feed efficiency (FCR) is also improved, resulting in a lower feed value per kg of fish sold. Feed costs can be reduced by about 15%. Of course, the cost of using antibiotics and drugs is also reduced. In addition, the fishing nets made of the copper alloy for cultured fishing nets according to the present invention has high strength and corrosion resistance is suitable for the marine aquaculture industry and is expected to give a quick satisfaction among the existing aquaculture industry. Fishing nets made of the copper alloy for cultured fishing nets according to the present invention can maintain the shape of the fishing nets intact against strong waves and currents, and even such offshore, because of the high mechanical strength and processing easy essential for offshore structures. In addition, the fishing net made of copper alloy according to the present invention can be used for up to 5 years or up to 10 years depending on the condition of the application facility. Copper alloy fishing nets lose very little over time in the ocean and are fully 100% reusable. In view of the strength, if the net diameter is reduced by about 15%, it can be discarded, thereby clarifying the life. Meanwhile, in 2008, marine aquaculture industry has had a 170,000m ³ of waste in landfills. Many of these are attached organisms removed from fishing nets, and methane is produced when these adherents break down. Methane is an environmental substance with a greenhouse effect 62 times greater than CO ₂ . At present, methane accounts for 15% of the global greenhouse effect, and the fishing net made of the copper alloy according to the present invention prevents adherent organisms, thereby suppressing the greenhouse effect.

In addition, the copper alloy for cultured fishing nets according to the present invention has a strong antimicrobial effect as compared to the conventional synthetic resin as mentioned at the beginning of the present invention, there is also an effect of protecting aquatic plants grown by pathogens in aquaculture farms from pests.

As described above, the copper alloy for cultured fishing nets according to the present invention suppresses de-zinc corrosion even when installed in the ocean, thereby improving corrosion resistance and preventing attachment of deposits on the surface of the fishing net, thereby prolonging the life of fishing nets and preventing subsea pollution. It is effective to provide copper alloy material for aquaculture fishing nets.

Claims

60.0 wt% to 65.0 wt% of copper, 0.5 wt% to 1.0 wt% of tin (Sn), 0.02 wt% to 0.50 wt% of phosphorus (P), and 0.2 wt% or less of lead (Pb). Copper alloy for aquaculture fish nets, characterized in that consisting of (Zn).
60.0 wt% to 65.0 wt% of copper, 0.5 wt% to 1.0 wt% of tin (Sn), 0.02 wt% to 0.35 wt% of arsenic (As), 0.02 wt% to 0.50 wt% of antimony (Sb), and lead ( Pb) 0.2 wt% or less and the remainder is made of zinc (Zn) copper alloy for fish farms, characterized in that.
60.0 wt% to 65.0 wt% of copper, 0.5 wt% to 1.0 wt% of tin (Sn), 0.02 wt% to 0.50 wt% of phosphorus (P), 0.02 wt% to 0.50 wt% of antimony (Sb), and lead ( Pb) 0.2 wt% or less and the remainder is made of zinc (Zn) copper alloy for fish farms, characterized in that.