JPH08239726A - Material with antibacterial characteristics and marine life resistance - Google Patents

Abstract

PURPOSE: To produce a material stably and continuously having antibacterial characteristics in the field related to living and marine life resistance in the industrial field and also being industrially valuable in respect of mechanical properties, workability, corrosion resistance, and price by specifying the composition of a copper-iron-aluminum alloy. CONSTITUTION: An alloy has a composition consisting of, by weight ratio, 10-80% iron, 1-10% aluminum, and the balance copper with inevitable impurities. It is preferable that 1-15% of one element among chromium, nickel, manganese, and silver is further added according to uses. This alloy can be worked, an a solid material, in this state into a plate or wire and used and also can be thermally sprayed onto the surface of a material having no antibacterial characteristic to provide antibacterial characteristic. At this time, a wire for thermal spraying material can be produced by ordinary wire drawing and a powder can be produced by gas atomizing, water atomizing, etc. Moreover, this alloy is applicable also to the ornamental field because it can change its color, according to its composition, from gold to reddish brown, yellow, etc.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an inorganic antibacterial material for antibacterial and marine resistant organisms.

[0002]

2. Description of the Related Art Silver and copper have been conventionally known as metals having antibacterial properties, that is, substances that mainly suppress the growth or kill of pathogenic bacteria.

However, although any of the metals has an antibacterial property at the beginning, an oxide film is formed on the surface, the effect thereof is reduced, and the appearance is faded, so that it is not widely applied. In addition, although various organic antibacterial materials are commercially available, many of them have not yet been established in terms of safety. Further, although iron-based materials are mainly used in offshore structures, marine organisms such as barnacles and blue mussels adhere to the structure, leading to increased clogging and running resistance in running pipes such as power plants. For this reason, alloys containing 70 to 90% of copper such as cupola nickel are also used, but these alloys are very expensive and lack strength as compared with iron structures.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a material having stable antibacterial properties and marine organism resistance, good processability, and proper corrosion resistance, which is highly useful as an industrial product. The purpose is to do.

[0005]

The gist of the present invention is as follows. That is, by weight ratio, iron 10 to 80%, aluminum 1 to 10
%, Antibacterial and marine-resistant material with the balance copper and inevitable impurities. Further, the above antibacterial containing 1 to 15% by weight of any one of chromium, nickel, manganese, and silver,
Marine biomaterial.

The present invention will be described in detail below. In order for the antibacterial material to become widespread, it is desired that not only it has a single function as an antibacterial material but also mechanical properties such as strength and elongation are comparable to those of conventional materials. Conventional antibacterial materials are
There are many materials that cannot be formed into various shapes because they have high functions but are expensive, lack strength, and have poor workability. The present inventors have investigated an antibacterial material that has good workability, strength, and is inexpensive.

Copper, which is the most popular antibacterial metal, was selected as the base material. Although copper has antibacterial properties, it has no strength and is not suitable for structures. The present inventors added iron to this to improve the strength and aimed to be widely applicable as a general material. However, since iron and copper do not have a solid solubility with each other to form a two-phase alloy and may break from the phase boundary during processing, it is one of the alloy systems that is difficult to use. In particular, the hot workability is very poor, and RA (breakage reduction rate) is found in the hot working test.
Is only about 20%. That is, there is a problem in that each shape such as a plate, a foil, and a line cannot be formed. In addition, this alloy easily rusts, and red rust occurs in a high humidity atmosphere. That is, it cannot be used in an environment where antibacterial properties are required because rust occurs. In order to overcome these drawbacks, the present inventors have conducted various studies, and as a result, completed the present invention.

First, it has been found that aluminum is most suitable for improving hot workability. RA (breakage reduction rate) improved to 80% by adding aluminum,
It has become possible to process foils up to 0 μm, and line processing to around 10 μm. Furthermore, regarding strength, A
The addition of l also increases the strength, and the cast material has a tensile strength of 70
kg / mm ² there, after the cold working 120 kg / mm ²
Becomes The growth rate is 25% for the former and 5% for the latter.
The workability also reached a level without problems.

The ranges of the components will be described below. The antibacterial mechanism is that metal having an antibacterial effect acts as an ion and dissolves in the environment to act on bacteria and algae. That is, to show antibacterial properties, it is necessary to design an alloy capable of dissolving a minimum amount of metal ions. An alloy such as SUS that forms a very dense and stable film does not show antibacterial properties even if it contains copper. However, on the contrary, an alloy having a too high melting rate is severely deteriorated and cannot be an industrial product. The inventors of the present invention determined the component range by carrying out development while examining this optimum value. Hereinafter, unless otherwise specified, it is shown by weight%.

Iron is 10 to 80%. Iron and copper do not form a solid solution with each other and form a two-phase structure. The matrix is copper, and iron crystallizes in dendrite form. It seems that when the amount of iron is large, the proportion of copper is small and the antibacterial property is reduced, but the elution rate of copper is increased and there is little change. The iron concentration can be selected according to the intended use and cost. That is, a high iron component alloy is desirable for a structural member that is inexpensive and requires high strength. Further, the lower the iron concentration, the better the workability. Therefore, when workability is required, it is desirable to keep the iron concentration low. Iron concentration of 50% or more is desirable in fields requiring strength such as offshore structures, and 30% or less of iron is desirable in applications such as kitchen sinks and filtration nets.

As aluminum is added, hot workability and corrosion resistance increase, but antibacterial property decreases. It is considered that this is because aluminum becomes aluminum oxide on the surface to form a dense film, and the higher the aluminum concentration, the more easily the film is formed and the ions of copper and iron are less likely to be eluted. If it is added in an amount of 10% or more, a brittle β phase is formed in the copper phase and the thermal fatigue strength deteriorates.

Chromium, nickel and manganese also have an antibacterial effect,
It has marine resistance. However, these metals should be added depending on the purpose. Chromium forms an oxide film on the surface like aluminum and reduces antibacterial properties and marine organism resistance, but when coexisting with aluminum, it forms a dense oxide film, so it is suitable for fields requiring long life. it can.

Nickel has a similar effect to that of chromium, but nickel allergy has recently become a problem and should be avoided in the field of direct skin contact. However, when nickel is added, the copper phase is strengthened, the iron phase becomes an austenite structure, high-temperature strength can be secured, and the structure becomes finer, resulting in a smooth surface. However, the cost will be increased, and the effect will be combined. Above 15%,
It forms a nickel-aluminum intermetallic compound and becomes brittle.

Manganese increases the dissolution rate of the alloy of the present invention and increases the antibacterial property. Therefore, it is suitable for fields where antibacterial properties are extremely required.

The effects begin to appear when the added concentrations of chromium, nickel and manganese are all 1%, but the higher the concentration, the higher the effect. However, if it is added in an amount of 15% or more, the workability is poor, the value as an industrial product is reduced, and it becomes expensive. Also, any one of these metals is effective, but the use of a plurality of alloys other than antibacterial properties such as strength and elongation does not limit the scope of the present invention.

The alloy of the present invention can be used as a plate or wire as it is as a solid material, or it can be sprayed onto another material having no antibacterial property to impart antibacterial property.

The shape of the thermal spray material is wire or powder. The wire can be produced by a normal wire drawing process, and the cost is low. On the other hand, powder can be produced by a gas atomizing method, a water atomizing method or the like, but it is expensive. The alloy of the present invention can easily be formed into either shape and can be sufficiently used for flame spraying and arc spraying.

The alloy of the present invention can be controlled in color depending on its component such as gold to reddish brown or yellow, and the component can be changed according to design preference, and is applicable to the field of decoration.

[0019]

EXAMPLES The present invention will be further described below with reference to examples. Examples 1 to 4 As shown in Table 1, by weight, four levels of 80% copper, 1%, 4%, 7% and 10% aluminum and the balance iron plate were prepared. It was created. Next, on the agar medium solidified by passing a Dezokishikoreto agar medium 20 ml (lower layer) in a sterile Petri dish (diameter 9cm), 10 E. coli at 45 ° C. ⁴ pieces inoculated Dezokishikoreto agar (upper layer) was overlaid 4ml Each of the above metal samples was placed on the agar medium prepared as described above and kept at 37 ° C. for 48 hours.

After holding, the metal sample was removed and the size of the sterile part of the site was investigated. The results are shown in Table 1. For the size, the diameter of the sterile part was measured. The aseptic part was a part with no colony visually. As a comparative example, SUS304
Used a plate.

[0021]

[Table 1]

From the results shown in Table 1, it was confirmed that all of Examples 1 to 4 had antibacterial properties, and that the lower the aluminum concentration was, the stronger the antibacterial properties were. The inorganic copper had a large sterile area, but the surface was discolored.

Example 5 80% by weight of copper, 2% of aluminum, 5% of chromium,
A remaining iron plate was prepared, and a 10 mm square sample was prepared therefrom. The culture was performed in the same manner as in Example 1, and the size of the aseptic part of the site was examined.

Example 6 70% copper, 2% aluminum, 15 nickel by weight
%, The remaining iron plate was prepared, and from this, a 10 mm square sample was prepared. The sample was placed on an agar medium prepared by mixing Escherichia coli or Staphylococcus aureus and kept in a 37 ° C. thermostat for 24 hours. The sample was removed and the size of the sterile part of the site was investigated. The aseptic part was a part with no colony visually.

Example 7 70% copper, 2% aluminum, 5 manganese by weight
%, The remaining iron plate was prepared, and from this, a 10 mm square sample was prepared. The sample was placed on an agar medium prepared by mixing Escherichia coli or Staphylococcus aureus and kept in a 37 ° C. thermostat for 24 hours. The sample was removed and the size of the sterile part of the site was investigated.

Table 2 shows the measurement results of Examples 5 to 7.
From the results shown in Table 2, it was confirmed that all of Examples 5 to 7 have antibacterial properties. The oxygen-free copper of the comparative example had a wide aseptic area, but the surface was discolored.

[0027]

[Table 2]

Example 8 A pipe having a composition of 10% copper, 8% aluminum, 8% chromium and the balance iron was prepared and built in the sea. ST as a comparative example
PG standard pipes were built in parallel. These were left for 30 days, and the attached organisms were investigated. The attached organisms were mainly barnacles and blue mussels. In the examples, although some attachment was observed near the sea surface, the metal surface was sufficiently exposed. On the other hand, in the STPG tube, a large amount was attached near the sea surface, and no metal surface was visible.

Example 9 A powder having a composition of 50% copper, 3% aluminum, 8% manganese and the balance iron was prepared by an atomizing method, and this powder was sprayed on the surface of a SUS plate. Thickness is 150 μm
Met. The same test as in Example 1 was performed on this sample. As a result, a sterile part having a diameter of 19 mm was recognized.

Example 10 A powder having a composition of 50% copper, 3% aluminum, 8% manganese, and the balance iron was prepared by an atomizing method, and this powder was sprayed on the surface of a SUS plate. The thickness was 150 μm. The same test as in Example 1 was performed on this sample.
As a result, a sterile part having a diameter of 19 mm was recognized.

[0031]

As described in detail above, the present invention makes it possible to provide a material which has antibacterial properties and marine organism resistance and has good mechanical properties.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenji Fukumoto 1618 Ida, Nakahara-ku, Kawasaki City Nippon Steel Corp. Advanced Technology Research Laboratories

Claims (2)

[Claims] 1. An antibacterial and marine organism-resistant material, characterized by comprising iron in an amount of 10 to 80%, aluminum in an amount of 1 to 10%, and the balance being copper and inevitable impurities. 2. The antibacterial and marine organism-resistant material according to claim 1, further comprising 1 to 15% by weight of any one of chromium, nickel, manganese, and silver.