JPH10156281A - Coated steel plate of superior water-repellent, non-adhesive, antifungus and fungus-resistant properties - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a coated steel plate of superior water-repellent, inadhesive, antifungus and fungus-resistant properties. SOLUTION: A coated steel plate is provided with a film having a composition of tetrafluoroethylene resin of 3-7 pts.wt. with a mixture at 0.5-20wt.% of tetrafluoroethylene resin particles having a silver alloy or a nickel alloy coating layer by the sputtering method and thermoplastic polyether sulfone resin of 7-5 pts.wt. having aromatic hydroxyl group. For coating of the tetrafluoroethylene resin particles, a silver alloy containing Cu and/or Zn of 10-50wt.%, and/or a copper alloy containing Cu and/or Sn of 10-50wt.% is used. Particularly, silver alloy or the nickel alloy demonstrating the amorphous phase is preferred from the viewpoint of keeping a high activity for a long period of time. As the island-shaped coatings (a) of the silver alloy or the copper nickel alloy is formed on the surfaces of resin particles (b) by the arrangement, the coated steel plate having a film surface, on which resin particles are exposed and water repellency and non-adhesiveness demonstrated by tetrafluoroethylene and the antifungus properties and fungus-resistant properties demonstrated by the silver alloy or nickel alloy are provided, can be manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-repellent, non-adhesive coated steel sheet provided with antibacterial and antifungal properties.

[0002]

2. Description of the Related Art For interior materials, exterior materials, furniture furniture, home electric appliances, etc., a water-repellent treatment is applied to prevent stains and impart a clean feeling.
Steel plates with non-stick coating are used. To improve water repellency and non-adhesiveness, ethylene tetrafluoride resin is mainly used as an active ingredient (Japanese Patent Publication No. 55-3091).
No. 0). For example, when a resin paint to which a tetrafluoroethylene resin is added is applied to the surface of a steel plate and baked, a coating film having a two-layer structure of a surface layer in which the tetrafluoroethylene resin is concentrated and a lower layer is formed. The lower layer is mainly composed of a thermoplastic polysulfone resin having an aromatic hydroxyl group or the like, and ensures adhesion of the coating film to the base material. The surface layer expresses water repellency and non-adhesion by concentrating the tetrafluoroethylene resin.

In recent years, when a hygienic environment has been strongly desired, it has been studied to impart an antibacterial and antifungal action to a water-repellent or non-adhesive painted steel sheet surface. Antibacterial and antifungal pigments are roughly classified into organic and inorganic pigments, and can be used depending on the application. Generally, a pigment is dispersed in paint, cement, resin, and the like. Organic pigments have problems in heat resistance, persistence of effects, safety, and the like. In addition, in a state in which the antibacterial and antifungal effects are inactivated, they may become a nutrient source and promote the propagation of various bacteria. The inorganic antibacterial / antifungal pigment utilizes a metal or ion such as Ag, Cu, Zn, Ni, or Sn that exhibits antibacterial / antifungal action. These metals are used by being supported on ceramics such as zeolite by ion exchange.

[0004]

However, in order to improve the antibacterial and antifungal action of a coated steel sheet provided with water repellency and non-adhesiveness by concentrating the surface of an ethylene tetrafluoride resin, a metallic antibacterial and antifungal agent is required. Even if the agent is added to the tetrafluoroethylene resin,
The added antibacterial / antifungal agent is not contained in the outermost fluororesin layer due to the specific gravity and the surface tension, and settles in the lower layer. As a result, the desired antibacterial and antifungal action cannot be imparted to the surface layer. The present invention has been devised to solve such a problem, and by using a coating material containing a tetrafluoroethylene resin coated with a metallic antibacterial and antifungal agent,
An object of the present invention is to provide a coated steel sheet which maintains water repellency, non-adhesion, and has excellent antibacterial and antifungal effects.

[0005]

In order to achieve the object, a coated steel sheet according to the present invention comprises 0.5 to 20% by weight of a tetrafluoroethylene resin particle having a silver alloy or nickel alloy coating layer formed by a sputtering method. %, And a coating film having a composition of 3 to 5 parts by weight of a tetrafluoroethylene resin mixed at a ratio of 7 to 5 parts by weight of a thermoplastic polyether sulfone resin having an aromatic hydroxyl group is formed. I do. As the alloy for coating the tetrafluoroethylene resin particles,
Ag alloys containing 50% by weight of Cu and / or Zn and Ni alloys containing 10 to 50% by weight of Cu and / or Sn are used. Among them, a silver alloy or a nickel alloy exhibiting an amorphous phase is preferable for maintaining high activity for a long period of time.

[0006]

When a resin coating compounded with a thermoplastic polyethersulfone resin (PES) compounded with a tetrafluoroethylene resin (PTFE) is applied to a steel sheet, as shown in FIG.
An upper layer in which PTFE particles are dispersed is formed on a lower layer mainly composed of ES. When this coating film is baked, the PTFE particles float due to specific gravity and surface tension, and a surface layer made of PTFE having excellent water repellency and non-adhesion is formed. This surface layer is in close contact with the base steel sheet via the lower layer made of PES. Even if an antibacterial metal such as Ag, Cu, Zn, Ni, or Sn is added as an antibacterial / antifungal agent to a resin paint that forms a coating film having such a two-layer structure, antibacterial properties are still maintained due to specific gravity and surface tension. The metal settles in the lower layer. Therefore, the antibacterial and antifungal effects originally exhibited by the antibacterial metal cannot be obtained.

Therefore, in the present invention, ethylene tetrafluoride resin particles b having an antibacterial and antifungal metal provided as an island-like coating a on the surface thereof as shown in FIG. The resin particles have a part of the particle surface coated with an antibacterial and antifungal metal, but the remaining surface has the tetrafluoroethylene resin exposed. Further, since the antibacterial and antifungal metal is adhered with a small amount of coating, when the coating film shown in FIG. 1 is formed, it concentrates on the surface layer similarly to the conventional tetrafluoroethylene resin particles. Therefore, the tetrafluoroethylene resin particles effective for water repellency and non-adhesion are exposed on the surface, and the antibacterial and antifungal metal is also exposed on the surface.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As the tetrafluoroethylene resin particles, relatively small particles having a molecular weight of 200,000 to 2,000,000 are effective for improving dispersibility in paint, adhesion when formed into a coating film, workability, and the like. . The particle size is 1/3 to 1 of the thickness of the coating film.
/ 10 is desirable. As a means for forming an antibacterial / antifungal metal island coating on the tetrafluoroethylene resin particles,
A powder sputtering device developed by the present inventors can be used. In this type of powder sputtering apparatus, an apparatus for feeding powder to a rotating drum and sputtering powder particles fluidized by the rotation of the rotating drum (Japanese Patent Laid-Open No. 2-153068) is used. Sputtering equipment (Japanese Patent Laid-Open No. Sho 62)
-250172).

As shown in FIG. 3, the powder sputtering apparatus has a rotary drum 1 supported by two rolls 2 and one of the rolls 2 is rotated by a motor 3 as shown in FIG. Inside the rotating drum 1, two sputtering sources 4 are arranged, and the charged tetrafluoroethylene resin particle raw material 5 is sputtered. Above the rotating drum 1, a decompression processing chamber 7 having a heating coil 6 on its outer periphery is arranged.
The bottom of the decompression processing chamber 7 is connected to the rotary drum 1 via a supply pipe 9 provided with a valve 8. The supply pipe 9 has a double pipe structure in which an Ar gas introduction pipe 10 is inserted inside a portion below the valve 8, and is inserted into the inside of the rotary drum 1 from a side surface, and a tip of the rotary drum 1 is provided. Extends to the bottom. A branch pipe 11 is attached to the supply pipe 9 below the valve 8, and the tip of the branch pipe 11 is connected to the fluid jet mill 12. The outlet side of the fluid jet mill 12 is connected to the upper part of the decompression processing chamber 7 via the circulation pipe 13. Valves 14 and 15 are inserted into the branch pipe 11 and the circulation pipe 13, and a solid-gas separation device 16 is connected to the circulation pipe 13.

The resin particles 5 metal-coated by sputtering in the rotating drum 1 are sent from the branch pipe 11 and the circulation pipe 13 to the decompression processing chamber 7 and subjected to the sputtering process until the coating having a predetermined thickness is formed in an island shape. Served repeatedly. Here, when the amount of the antibacterial / antifungal metal attached to the tetrafluoroethylene resin particles is adjusted to a range of 0.5 to 20% by weight, an island-like coating a partially covering the surface of the resin particles is formed. . When the amount of the antibacterial / antifungal metal adhered is less than 0.5% by weight, the antibacterial / antifungal action of the obtained resin particles b is small. Conversely, if the antibacterial / antifungal metal is coated with an adhesion amount exceeding 20% by weight, the entire surface of the resin particles 5 is covered with the antibacterial / antifungal metal, and the resin particles b are hardly concentrated on the surface layer. Such adjustment of the amount of adhesion can be easily performed by powder sputtering. Resin particles 5 with island-like coating formed
The (resin particles b) are collected by the solid-gas separator 16.

As the antibacterial and antifungal metal which forms the island-shaped coating a, a silver alloy containing 10 to 50% by weight of Cu and / or Zn or a nickel alloy containing 10 to 50% by weight of Cu and / or Sn can be used. used. Ag and Ni exhibit antibacterial properties by themselves, but when Cu, Zn or Sn is alloyed with them, a better antibacterial and antifungal action is exhibited. The content of Cu and / or Zn or Cu and / or Sn is 1
Outside the range of 0 to 50% by weight, the effect of alloying is reduced. Japanese Patent Application No. 7-294739 discloses this type of alloy.
And Japanese Patent Application No. 8-24946 are silver alloys and nickel alloys proposed by the present inventors. Among them, Cu:
10 to 50% by weight, Zn: 10 to 50% by weight, and Ag:
10 to 50% by weight or Cu: 10 to 50% by weight, Sn:
An alloy system having a composition of 10 to 50% by weight and Ni: 10 to 50% by weight exhibits an amorphous phase, and since each component is uniformly eluted and ionized over a long period of time, the antibacterial and antifungal action is maintained. Excellent in nature. The above-mentioned content is necessary for making the alloy coating amorphous.

Since the island-shaped coating a of the antibacterial and antifungal metal is formed by the sputtering method, it has a fine structure due to the quenching effect. Also in this respect, the elution of the antibacterial and antifungal metal elements is constant, and the effect is maintained for a long time. Above all, those that have become amorphous have little change in the elution rate of the constituent elements with time and have good corrosion resistance. The resin particles b provided with the island-shaped coating a of the antibacterial and antifungal metal were mixed with ordinary tetrafluoroethylene resin particles at a ratio of 0.5 to 20% by weight after the resin particles b were mixed in a ratio of 3: 7. ~
It is blended with a thermoplastic polyether sulfone resin having an aromatic hydroxyl group in a weight ratio of 5: 5. As such a thermoplastic polyether sulfone resin, a resin having a small particle size is preferable, and a resin having a particle size of 20 μm or less is practically used. When compounding resin particles with thermoplastic polyether sulfone resin, if only resin particles b provided with island-shaped coating a of antibacterial and antifungal metal are mixed into the coating, the non-adhesiveness when formed into a coating film is inferior. . Therefore, it is necessary to mix the resin particles b with ordinary tetrafluoroethylene resin particles at a ratio of 0.5 to 20% by weight in the paint. If the proportion of the resin particles b is less than 0.5% by weight, the required antibacterial and antifungal action cannot be obtained, but if the proportion exceeds 20% by weight, the non-adhesiveness deteriorates. On the other hand, if the mixing ratio of the thermoplastic polyether sulfonic acid resin: ethylene tetrafluoride resin is less than 3: 7, the adhesion of the coating film is deteriorated, and if it is more than 5: 5, the non-adhesiveness is deteriorated.

[0013]

EXAMPLE In an atmosphere with an Ar partial pressure of 1 × 10 ⁻³ Torr,
Ag alloy of 40% by weight of Ag—30% by weight of Cu—30% by weight of Zn and 40% by weight of Ni—30% by weight of Cu—30% by weight of Sn in tetrafluoroethylene resin having a particle size of 1 to 10 μm
The i-alloy was coated at 5% by weight and 20% by weight by a sputtering method with an output of 500 W. The obtained alloy-coated tetrafluoroethylene resin was added to the uncoated tetrafluoroethylene resin by 0 to 30.
% By weight and mixed with 50% by weight of a polysulfone resin having an aromatic hydroxyl group, were applied to a galvanized steel sheet and baked. FIG. 4 shows the results of investigating the antibacterial and antifungal properties and the water repellency (non-adhesiveness) of the obtained coating film. In the figure, ◎,
Excellent was represented by ○, and no significance was observed or deteriorated was represented by ×. For water repellency (non-adhesive), a mixture of eggs, sugar and soy sauce in a weight ratio of 1: 1: 1 was dropped 10 cc onto a coated steel plate and heated at 250 ° C. for 60 minutes.
Evaluation was made on the state of remaining on the coating film when peeled. From the results of FIG. 4, it can be seen that when the content of the tetrafluoroethylene resin coated with the antibacterial / antifungal alloy is less than 0.5% by weight, the antibacterial / antifungal property is not exhibited, and conversely, it exceeds 20% by weight. It turns out that the water repellency (non-adhesiveness) is inferior.

Ag 40% by weight-Cu 30% by weight-Zn3
A 0 wt% Ag alloy and a Ni alloy of 40 wt% of Ni-30 wt% of Cu-30 wt% of Sn were coated on a tetrafluoroethylene resin by 5 wt% by a sputtering method. 10% by weight of an alloy-coated resin is mixed with an uncoated ethylene tetrafluoride resin, and a mixture of 20% to 60% by weight of a thermoplastic polyether sulfone resin having an aromatic hydroxyl group is applied to a galvanized steel sheet. Baked. The antibacterial and antifungal properties and the water repellency (non-adhesiveness) of the obtained coating film were investigated.
5, the water repellency (non-adhesiveness) does not appear when the mixing amount of the tetrafluoroethylene resin is less than 30% by weight, and when the mixing amount exceeds 50% by weight, the water repellency ( (Non-adhesiveness). 40% by weight of a pigment obtained by mixing various alloys with 5% by weight of tetrafluoroethylene resin and 5% by weight of uncoated tetrafluoroethylene resin, and a thermoplastic polyether sulfone resin 60 having an aromatic hydroxyl group. % By weight and a resin coating was prepared.
The antibacterial and antifungal properties, the water repellency and the non-adhesive property were examined for the case where this resin paint was applied to a galvanized steel sheet.
As can be seen from the results of the investigations in Tables 1 and 2, the alloys coated under the conditions specified in the present invention all exhibited excellent antibacterial and antifungal properties and water repellency (non-adhesiveness).

[0015]

[0016]

Ag 40% by weight-Cu 30% by weight-Zn3
A 5 wt% coating of a 0 wt% Ag alloy and a Ni alloy of 40 wt% of Ni—30 wt% of Cu—30 wt% of Sn on a tetrafluoroethylene resin was mixed with 5 wt% of an uncoated tetrafluoroethylene resin, 40% by weight of a thermoplastic polyether sulfone resin having an aromatic hydroxyl group
A resin coating was prepared by mixing. The steel plate coated with this resin paint is cut into a size of 25 cm ² in area.
It was immersed in 00 cc of boiling water, and the elution amount of constituent metal ions was examined. The investigation results were divided into those with a crystalline structure formed by the sputtering method with an output of 600 W of the antibacterial and antifungal alloy, and those with an amorphous structure formed by indirect cooling at a power of 300 W. As shown in FIG. From FIG. 6, it can be seen that when the structure of the surface coating alloy is amorphous, the rise of the constituent metal is quickly eluted and the elution rate is almost constant. On the other hand, in the case of crystalline, the elution rate fluctuated. From this comparison, it is confirmed that the amorphous structure exhibits an antibacterial and antifungal action that is superior to the crystalline structure in terms of rapidity and durability.

[0018]

As described above, the coated steel sheet of the present invention has a silver alloy or a nickel alloy exhibiting antibacterial and antifungal properties, and has a coating film containing tetrafluoroethylene resin particles as an island coating. Antibacterial and antifungal properties are imparted and water repellent,
A surface layer having excellent non-adhesiveness is formed. Therefore, it is used in a wide range of fields as kitchen equipment, sanitary equipment, exterior materials and interior materials for buildings requiring a sanitary environment.

[Brief description of the drawings]

Fig. 1 Coating film with concentrated surface of ethylene tetrafluoride resin particles

Fig. 2 Tetrafluoroethylene resin particles with island-shaped coating of antibacterial and antifungal metal

Fig. 3 Powder sputtering equipment used to form a coating of antibacterial and antifungal metal

FIG. 4 Ag—Cu—Zn alloy and Ni—Cu—Sn
The amount of the alloy-coated resin and the antibacterial and anti-mildew properties of the coating film formed by applying the resin coating prepared by mixing the alloy-coated tetrafluoroethylene resin with the uncoated ethylene tetrafluoride resin Graph showing the relationship between water repellency and non-adhesiveness

FIG. 5: Ag—Cu—Zn alloy and Ni—Cu—Sn
Formed from resin paint prepared by blending 10% by weight of tetrafluoroethylene resin coated with 5% by weight alloy with 10% by weight of uncoated tetrafluoroethylene resin and mixing with thermoplastic polyethersulfone resin having aromatic hydroxyl groups The graph which shows the relationship between the mixing amount of the tetrafluoroethylene resin with respect to the polyethersulfone resin, the antibacterial property, the antifungal property, and the water repellency (non-adhesiveness) of the coated film.

FIG. 6: Ag—Cu—Zn alloy and Ni—Cu—Sn
For a coating film formed from a resin paint prepared by mixing an alloy-coated tetrafluoroethylene resin with a thermoplastic polyethersulfone resin having an aromatic hydroxyl group,
Graph showing the elution amount of metal ions in boiling water

[Explanation of symbols]

a: island-like coating of antibacterial and antifungal metal b: ethylene tetrafluoride resin particles 1: rotating drum 2: roll 3: motor 4:
Sputtering source 5: Raw material of resin particles 6: Heating coil 7: Decompression processing chamber 8: Valve 9: Supply pipe 10: Ar gas introduction pipe 11: Branch pipe 12: Fluid jet mill 13: Circulation pipe 1
4, 15: valve 16: solid-gas separation device

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiroshige Nakamura 7-1 Takayashinmachi, Ichikawa City, Chiba Prefecture Nisshin Steel Co., Ltd.

Claims (4)

[Claims] 1. A method according to claim 1, wherein 3 to 5 parts by weight of a tetrafluoroethylene resin obtained by mixing 0.5 to 20% by weight of ethylene tetrafluoride resin particles on which a silver alloy or nickel alloy coating layer is formed by sputtering. A coated steel sheet excellent in water repellency, non-adhesion, antibacterial and antifungal properties, on which a coating film having a composition of 7 to 5 parts by weight of a thermoplastic polyether sulfone resin having an aromatic hydroxyl group is formed. 2. A silver alloy comprising 10 to 50% by weight of Cu and / or
Or the alloy containing Zn or the water repellency according to claim 1,
Non-adhesive, antibacterial and mildew-resistant coated steel sheet. 3. The method according to claim 1, wherein the nickel alloy comprises 10 to 50% by weight of Cu.
2. The coated steel sheet according to claim 1, which is an alloy containing Sn and / or Sn. 4. The water-repellent, non-adhesive, water-repellent material according to claim 1, wherein the silver alloy or the nickel alloy exhibits an amorphous phase.
Painted steel sheet with excellent antibacterial and antifungal properties.