KR20200138239A - Clad metal plate and joiner having same - Google Patents

Abstract

An object of the present invention is to provide a coated metal plate capable of maintaining non-adhesion to a caulking material even after leaving it outdoors. The coated metal plate of the present invention has a metal plate and a coating layer containing a resin disposed on the surface thereof. The volume resistivity of the coating layer measured according to JIS C 2139:2008 is 1.0×10 ¹⁷ Ω·cm or less, and the surface free energy calculated based on the contact angle measured according to JIS R 3257:1999 is 36.6 mJ/ m ² or less.

Description

Clad metal plate and joiner having same

The present invention relates to a coated metal plate and a joiner having the same.

Joiners are used in the joint between the exterior boards in the exterior of the building. The joiner has the function of maintaining the external board at regular intervals.

The joints between the external boards are filled with a caulking material to ensure waterproof and airtightness. At this time, if the caulking material is bonded to the side end faces of the two exterior boards and the joiner on three sides, the exterior board expands and contracts according to changes in the external environment (especially temperature changes). It cannot be followed, and the stress caused by the expansion and contraction of the exterior board concentrates on the caulking material, and the caulking material is liable to break.

In order to eliminate this problem, the caulking material adheres to the side cross-sections of two adjacent exterior boards, but does not adhere to the joiner, that is, two-sided bonding.

As a method of performing double-sided adhesion, a method of forming a coating film having low adhesion to the caulking material on a surface (receiving portion of the caulking material) in contact with the caulking material of the joiner has been studied. For example, a joiner having a coating film containing a specific fluororesin (refer to Patent Document 1) on a surface in contact with a caulking material, and a joiner having a coating film containing low-density polyethylene or polypropylene (refer to Patent Document 2) are disclosed.

Japanese Patent Laid-Open No. 2009-62707 Japanese Patent Laid-Open Publication No. 2004-68464

However, after being brought into the construction site, the joiner is sometimes left outdoors until the exterior of the building is constructed. In the meantime, there is a problem that the surface of the joiner in contact with the caulking material becomes easy to adhere to the caulking material, and three-sided bonding occurs when the exterior of the building is constructed. The same problem also existed in the joiner disclosed in Patent Documents 1 and 2.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a coated metal plate capable of maintaining low adhesion to a caulking material even after being left outdoors, and a joiner having the same.

The present invention relates to a coated metal plate having the following configuration and a joiner using the same.

[1] having a metal plate and a coating layer containing a resin disposed on the surface of the metal plate, the volume resistivity of the coating layer as measured in accordance with JIS C 2139:2008 is 1.0×10 ¹⁷ Ω·cm or less, and JIS A coated metal plate having a surface free energy of 36.6 mJ/m ² or less calculated by the Kaelble-Uy equation based on the contact angle measured in accordance with R 3257:1999.

[2] In [1],

The resin is an ethylene-vinyl acetate copolymer or a silicone rubber, the coated metal plate.

[3] In [2],

The resin is an ethylene-vinyl acetate copolymer, and the content ratio of the structural unit derived from vinyl acetate in the ethylene-vinyl acetate copolymer is 5% by mass or more with respect to the total structural units constituting the ethylene-vinyl acetate copolymer. A coated metal plate which is less than mass%.

[4] In any one of [1] to [3],

The thickness of the coating layer is 3 ~ 120μm, the coated metal plate.

[5] In any one of [1] to [4],

The metal plate has a chemical conversion treatment film disposed on a surface on which the coating layer is disposed.

[6] A joiner having the coated metal plate according to any one of [1] to [5], for being disposed at the joints of adjacent exterior materials.

[7] In [6],

The joiner has a protrusion and a substrate portion connected to a base end of the protrusion, and the covering layer is disposed on at least a surface of the protrusion for supporting the caulking material.

According to the present invention, it is possible to provide a coated metal plate capable of maintaining non-adhesion to a caulking material even after leaving it outdoors, and a joiner having the same.

1 is a cross-sectional view showing a configuration example of a coated metal plate according to the present embodiment.
2 is a partial perspective view showing an example of a state in which a joiner is used.
3A and 3B are cross-sectional views of a joiner.

The present inventors analyzed and examined the reason why the conventional joiner disclosed in Patent Documents 1 or 2 is easily adhered to the caulking material after being left outdoors. Although the details are not clear, the following phenomenon occurs. I guessed it might be.

That is, it is thought that while the joiner is left outdoors, contaminants such as dust and dirt adhere to the coating film on the surface of the joiner, and the contaminants are fixed by outdoor light, moisture, heat, or the like. In addition, it is considered that the adhered contaminants become the starting point, and the caulking material becomes easy to adhere.

In other words, in order to maintain the non-adhesion to the caulking material, it is effective to maintain a surface state in which contaminants are difficult to adhere to. For this purpose, 1) lowering the chargeability of the coating film surface, and 2) It is considered effective to lower the surface energy. Further, the inventors of the present invention have examined various materials, and specifically, 1) the volume resistivity measured in accordance with JIS C 2139: 2008 is 1.0×10 ¹⁷ Ω·cm or less, and 2) Kaelble based on the contact angle When the surface free energy calculated by the -Uy equation was 36.6 mJ/m ² or less, it was found that contaminants were difficult to adhere to and thus non-adhesion to the caulking material could be maintained.

In addition, among materials that satisfy these physical properties, ethylene-vinyl acetate copolymer is a material that is generally used for sealing or bonding purposes, but when left outdoors, contaminants are particularly difficult to adhere to the surface of the coating film. It has been found that it is possible to maintain good non-adhesion with ash. The present invention has been made based on these findings.

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

1. Clad metal plate

1 is a cross-sectional view showing the configuration of a coated metal plate according to the present embodiment.

As shown in Fig. 1, the coated metal plate 10 of the present embodiment includes a metal plate 11 and a coating layer 13 disposed on the surface thereof.

<Metal plate (11)>

The metal plate 11 used as the coating original plate can be appropriately selected according to the application of the coated metal plate. Examples of the metal plate 11 include plated steel sheets such as galvanized steel sheets, Zn-Al alloy plated steel sheets, Zn-Al-Mg alloy plated steel sheets, and aluminum plated steel sheets; Steel sheets such as cold-rolled steel sheets and stainless steel sheets (including austenitic, martensitic, ferritic, and ferrite-martensite two-phase systems); Aluminum plate; Aluminum alloy plate; And copper plates. Among them, from the viewpoint of enhancing corrosion resistance, the metal plate 11 is preferably a plated steel plate, and more preferably a hot-dip plated steel plate. The plating amount of the plated steel sheet is not particularly limited, but may be, for example, 30 to 500 g/m ² .

The metal plate 11 may be subjected to chemical conversion treatment on its surface from the viewpoint of improving the corrosion resistance and coating film adhesion of the coated steel sheet. The type of chemical conversion treatment is not particularly limited, but may be, for example, chromate treatment, chromium free treatment, or phosphate treatment.

The thickness of the metal plate 11 may be set in accordance with the use and workability, and is not particularly limited, but is preferably 0.3 to 0.6 mm from the viewpoint of obtaining the workability and mechanical strength necessary for forming a joiner, for example.

Chemical conversion treatment can be carried out by a known method. For example, a chemical conversion treatment liquid may be applied to the surface of a steel sheet by a method such as a roll coating method, a spin coating method, or a spray method, and then dried without washing with water. The drying temperature and drying time are not particularly limited as long as moisture can be evaporated. From the viewpoint of productivity, the drying temperature is preferably within the range of 60 to 150°C as the reached substrate temperature, and the drying time is preferably within the range of 2 to 10 seconds. The adhesion amount of the chemical conversion coating film is not particularly limited as long as it is within a range effective for improving corrosion resistance and coating film adhesion. For example, in the case of a chromate film, the amount of adhesion may be adjusted so that the total amount of adhesion in terms of Cr is 5 to 100 mg/m ² . In the case of a chromium-free film, the amount of adhesion is set in the range of 10 to 500 mg/m ^{2 in the} Ti-Mo composite film and in the range of 3 to 100 mg/m ² in terms of fluorine or total metal elements in the fluorine acid-based film. Good to adjust. In addition, in the case of a phosphate coating, the amount of adhesion may be adjusted to be 5 to 500 mg/m ² .

<Coating layer (13)>

The coating layer 13 is a layer containing a resin (resin layer) disposed on at least a part of the surface of the metal plate 11. The covering layer 13 becomes the outermost layer of the covering metal plate 10. The coating layer 13 has a volume resistivity of 1.0×10 ¹⁷ Ω·cm or less, and a surface free energy of 36.6 mJ/m ² or less from the viewpoint of maintaining non-adhesion with the caulking material.

If the volume resistivity of the coating layer 13 is 1.0×10 ¹⁷ Ω·cm or less, it is difficult to generate static electricity or the like because the coating layer 13 is difficult to charge, and contaminants, etc., can hardly adhere while exposed to the outdoors. have. The volume resistivity of the coating layer 13 is more preferably 4.0×10 ¹⁶ Ω·cm or less.

The volume resistivity of the coating layer 13 can be measured in conformity with JIS C 2139:2008 "solid electrical insulating material-measuring method of volume resistivity and surface resistivity" (IEC 60093: 1980). Specifically, it can measure under the following conditions.

(Exam conditions)

Test device: Digital ultra-high resistance/micro ammeter 8340A type (made by ADshi)

Electrode size: Main electrode 50 mmφ, guard electrode inner diameter 60 mmφ, outer diameter 80 mmφ

Applied voltage: 100V, 500V (DC)

Application time: 60 sec

Test environment: temperature 23±2℃, humidity 50±5% RH

Specimen dimensions: 100 mm×100 mm

If the surface free energy of the covering layer 13 is 36.6 mJ/m ² or less, the reactivity of the surface of the covering layer 13 is low, so even if contaminants adhere to the covering layer 13 while being exposed to the outdoors, the surface reactivity is low. Therefore, it can be made difficult to fix the contaminants. It is more preferable that the surface free energy of the coating layer 13 is 34.2 mJ/m ² or less.

The surface free energy of the coating layer 13 can be calculated based on a contact angle measured in accordance with JIS R 3257:1999 (IEC 62073). Specifically, it can measure in the following procedure.

1) The contact angle of pure water and methylene iodide is measured in accordance with JIS R 3257:1999 "Test Method for Wetability of Substrate Glass Surface". As a measuring device, a portable contact angle meter PCA-1 (manufactured by Kyowa Interface Science Co., Ltd.) can be used.

2) Using the obtained contact angle value, calculate the surface free energy using the Kaelble-Uy equation (γs=γs ^d +γs ^p , γs ^d : dispersion component of surface free energy, γs ^p : polar component of surface free energy).

The volume resistivity and surface free energy of the coating layer 13 can be adjusted depending on the composition of the coating layer 13, particularly the type of resin.

The resin constituting the coating layer 13 may be one having volume resistivity and surface free energy satisfying the above ranges, and is not particularly limited, but may be an ethylene-vinyl acetate copolymer, silicone rubber, or the like.

[Ethylene-vinyl acetate copolymer]

The ethylene-vinyl acetate copolymer contains a structural unit derived from ethylene and a structural unit derived from vinyl acetate.

The content ratio of the structural unit derived from vinyl acetate should be such that it does not exhibit adhesiveness and can obtain low chargeability, and is not less than 5% by mass and 20% by mass with respect to all structural units constituting the ethylene-vinyl acetate copolymer. It is preferably less than. If the content ratio of the structural unit derived from vinyl acetate is 5% by mass or more, it is easy to obtain a low volume resistivity and thus low chargeability is easily obtained, and contaminants can hardly adhere to the surface of the coating layer 13. When the content ratio of the structural unit derived from vinyl acetate is 20% by mass or less, adhesion is difficult to be expressed, and contaminants may be difficult to adhere to the surface of the coating layer 13. It is more preferable that the content ratio of the structural unit derived from vinyl acetate is 5 to 17 mass% with respect to all structural units constituting the ethylene-vinyl acetate copolymer.

The ethylene-vinyl acetate copolymer may further contain structural units derived from monomers other than ethylene and vinyl acetate. Examples of other monomers include 3 to 20 carbon atoms such as propylene, 1-butene, 3-methyl-1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, and 1-decene. α-olefin, (meth)acrylic acid, (meth)acrylic acid ester, and styrene are included. The content ratio of the structural units derived from other monomers is preferably 10% by mass or less, and more preferably 0% by mass with respect to all structural units constituting the ethylene-vinyl acetate copolymer.

The melt flow rate of the ethylene-vinyl acetate copolymer (JIS K 7210-1999, 190° C., 2160 g load) is preferably 1 to 20 g/10 minutes. When the MFR of the ethylene-vinyl acetate copolymer is within the above range, it is easy to maintain sheet formability. The MFR of the ethylene-vinyl acetate copolymer is more preferably 5 to 15 g/10 min.

〔Silicone rubber〕

The silicone rubber is not particularly limited, and may be a cured product of an addition reaction curable or condensation curable silicone rubber composition.

The cured product of the addition reaction curable silicone rubber composition is cured (additionally cured) a silicone rubber composition containing an organopolysiloxane having two or more alkenyl groups (preferably vinyl groups) in one molecule as a crosslinkable reactive group and a curing agent. Can be obtained.

As the crosslinkable reactive group, the organopolysiloxane having two or more alkenyl groups (preferably vinyl groups) in one molecule is preferably an organopolysiloxane represented by the following formula (1).

RnSiO _(4-n)/2 ···(1)

In formula (1), R is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 12 carbon atoms, respectively. However, at least two of a plurality of R are alkenyl groups (preferably vinyl groups). Examples of the monovalent hydrocarbon group include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an aryl group, an aralkyl group, and those in which at least part of the hydrogen atoms of these groups are substituted with a halogen atom, etc., A methyl group, a vinyl group, a phenyl group, or a trifluoropropyl group is preferable, and a methyl group is more preferable. A plurality of R may be the same or different from each other. N is a positive number from 1.95 to 2.05.

The curing agent (crosslinking agent) may be an addition reaction curing agent. The addition reaction curing agent may be a silane compound such as organohydrogenpolysiloxane.

The silicone rubber composition may further contain a reaction catalyst, silicone oil, or the like, if necessary. The reaction catalyst includes platinum-based catalysts such as platinum metal particles, chlorinated platinum, and chloroplatinic acid. The silicone oil is a liquid silicone oil having an organopolysiloxane as its main skeleton, and examples thereof include dimethyl silicone oil having only a methyl group as an organo group; Modified silicone oils in which a part of the methyl group is substituted with a phenyl group, a vinyl group, an alkyl group, an aralkyl group, an amino group, a carboxyl group, an epoxy group, a hydroxyl group, a polyoxyalkylene group, and the like are included. The total amount of these components can be 10% by mass or less with respect to the total solid content of the silicone rubber composition.

The cured product of the condensation curable silicone rubber composition comprises a silicone rubber composition comprising a diorganopolysiloxane having two or more silicon atoms bound by a hydroxyl group, a silane compound having three or more condensation functional groups in one molecule, and a condensation catalyst. It can be obtained by hardening (condensation hardening).

Diorganopolysiloxane having two or more silicon atoms bonded to a hydroxyl group in one molecule includes an organic group bonded to a Si atom, for example, an alkyl group such as a methyl group or an ethyl group; Aryl groups such as a phenyl group and a tril group; Diorganopolysiloxane which is a cycloalkyl group, such as a cyclohexyl group, is contained.

The silane compound is a polyfunctional silane compound having a hydrolyzable group, and is preferably a silane compound represented by the following general formula (2).

(R ₁ ) mSiXn ···(2)

(In the formula, R ₁ represents a methyl group, a vinyl group, or a phenyl group. X represents an alkoxy group having 1 to 5 carbon atoms, a methyl ethyl ketooxime group, a propenyloxy group, or an acetoxy group. M represents 0 or 1. N represents 3 or 4. However, when m is 0, n is 4, and when m is 1, n is 3.) It is preferable that it is a silane compound represented by.

Examples of the condensation catalyst include titanium compounds such as tetraisopropoxytitanium and tetra-n-butoxytitanium.

Examples of the silicone rubber composition include S coat 57 manufactured by Shin-Etsu Chemical Corporation.

Among these, it is preferable that the resin constituting the coating layer 13 is an ethylene-vinyl acetate copolymer from the viewpoint of being easy to obtain non-adhesion to the caulking material.

In addition, the composition of the coating layer 13 is not limited to these. For example, even if the volume resistivity is a resin (for example, polyethylene or polypropylene) that does not satisfy the above range, by combining it with a conductive material such as carbon black, the volume resistivity and surface free energy as a whole of the covering layer 13 are reduced. You may make it satisfy the above range.

[Other ingredients]

The coating layer 13 may further contain components other than the resin described above, within a range that does not impair the effects of the present invention. Examples of other components include color pigments, extender pigments, and aggregates.

Examples of the colored pigment include inorganic pigments such as titanium oxide, calcium carbonate, carbon black, iron black, titanium yellow, bengala, royal blue, cobalt blue, cerulean blue, ultramarine, cobalt green, and molybdenum red; Complex oxide firing pigments containing metal components such as CoAl, CoCrAl, CoCrZnMgAl, CoNiZnTi, CoCrZnTi, NiSbTi, CrSbTi, FeCrZnNi, MnSbTi, FeCr, FeCrNi, FeNi, FeCrNiMn, CoCr, Mn, Co, SnZnTi, etc.; Metallic pigments such as Al, resin coated Al, and Ni; And, Litole Red B, Brilliant Scarlet G, Pigment Scarlet 3B, Brilliant Carmine 6B, Lake Red C, Lake Red D, Permanent Red 4R, Bordeaux 10B, First Yellow G, First Yellow 10G, Para Red, Watching Red, Benzidine Yellow , Benzidine Orange, Bon Maroon L, Bon Maroon M, Brilliant First Scarlet, Vermilion Red, Phthalocyanine Blue, Phthalocyanine Green, First Sky Blue, and aniline black. Examples of extender pigments include barium sulfate, titanium oxide, silica, and calcium carbonate. Examples of the aggregate include resin particles; Inorganic particles made of inorganic compounds such as glass, silicon carbide, boron nitride, zirconium oxide, alumina, and silica are included. In addition, when the covering layer 13 contains silicone rubber, silicone oil or the like may be included as another component. The total amount of these other components may be 10% by mass or less with respect to the coating layer 13.

The thickness of the coating layer 13 may be such that the non-adhesion to the caulking material can be maintained when used as a joiner, and although it is not particularly limited, it is preferably 3 to 120 μm. When the thickness of the coating layer 13 is 3 μm or more, it is easy to maintain good non-adhesion to the caulking material when used as a joiner, and when it is 120 μm or less, for example, when coating and forming the coating layer 13, drying of the paint It is easy to suppress the appearance defect of the coated metal plate 10 due to the occurrence of agglomeration at the time. The thickness of the coating layer 13 is more preferably 5 to 100 μm from the above viewpoint.

<other floor>

The coated metal plate 10 of the present invention may further have another layer (no drawing mark) such as an undercoat film or an adhesive layer between the metal plate 11 and the coating layer 13, if necessary.

〔Paint coating〕

The undercoat film may be disposed on the surface of the metal plate or the chemical conversion film. The undercoat film can increase the adhesion of the coating layer and the corrosion resistance of the coated metal plate.

The kind of resin (base resin) constituting the undercoat film is not particularly limited. Examples of the resin constituting the undercoat film include an epoxy resin, an acrylic resin, and a polyester resin. The undercoat may further contain an aggregate, a rust inhibitor, or the like, if necessary. Such an undercoat film can be formed by applying an undercoat paint on a metal plate and then heat treatment at 200 to 250°C for 30 to 120 seconds.

〔Adhesive layer〕

The adhesive layer is not particularly limited, but may be a cured product of a thermosetting adhesive such as a melamine adhesive or an epoxy adhesive, or various elastomer adhesives.

2. Manufacturing method of coated metal plate

The coated metal plate of the present invention can be produced by any method. The coated metal plate 10 of the present invention may be obtained, for example, by laminating a film as a resin composition for a coating layer on the metal plate 11, followed by thermocompression bonding (thermal lamination) to form the coating layer 13 (heat Compression method); The film may be laminated on the metal plate 11 via an adhesive to form the coating layer 13 (adhesion method); It may be obtained by flow casting a melt of the resin composition for a coating layer on the metal plate 11 and then cooling to form the coating layer 13 (extrusion flow casting method); After coating the resin composition for a coating layer on the metal plate 11, it may be dried or heated to form the coating layer 13 (coating method).

For example, the coating layer 13 containing an ethylene-vinyl acetate copolymer is thermocompression bonding a film containing an ethylene-vinyl acetate copolymer on a metal plate 11 (thermocompression bonding method), or an ethylene-vinyl acetate copolymer After melt flow-casting the resin composition for a coating layer including, it can be formed by cooling (extrusion flow casting method). The thermocompression bonding conditions in the thermocompression bonding method are not particularly limited, but may be, for example, 100 to 200°C.

Further, the coating layer 13 containing silicone rubber can be formed by applying the resin composition for coating layers containing the silicone-based coating composition described above on the metal plate 11, followed by drying or heat curing at room temperature. The coating method of the resin composition for a coating layer is not particularly limited, but may be, for example, a roll coating method, a flow coating method, a curtain flow method, or a spray method. The heat curing conditions may be such that the reaction curable silicone rubber in the resin composition for a coating layer is sufficiently cured, and may be, for example, 25 to 300°C.

The covering layer 13 may be disposed on the entire surface of the metal plate 11, or when made of a joiner 20 to be described later, it is disposed only at a portion serving as a receiving portion of the caulking material (the surface 21A of the protrusion 21 to be described later). May be. Such a coated metal plate can be preferably used, for example, as a coated metal plate for joiners.

3. Joiner

The joiner of the present invention is a joiner (joint) to be disposed at the joints of the exterior materials adjacent to each other, and has the coated metal plate of the present invention.

2 is a partial perspective view showing an example of a state in which the joiner 20 is used. 3A and 3B are cross-sectional views illustrating a configuration example of the joiner 20.

As shown in Fig. 2, the joiner 20 has a hat-type covered metal plate 10 having a cross-sectional shape. This joiner 20 is also called a double-edged joiner. The joiner 20 has a protrusion 21 and two substrate portions 23 connected to the base end of the protrusion 21. The protrusion 21 may be disposed on the joint 30 of the exterior of the building to support the caulking material 40 (it may be a receiving portion of the caulking material 40). The two substrate portions 23 may maintain a distance (the width of the joint portion 30) between the ends of the two outer casings 50 adjacent to each other at regular intervals.

The covering layer 13 may be disposed on at least the surface (surface) 21A of the protrusion 21 in contact with the caulking material among the surfaces of the joiner 20. That is, the covering layer 13 may be disposed over the entire surface of the joiner 20 (see Fig. 3A), or may be disposed only on the surface (surface) 21A supporting the caulking material of the protrusion 21 Good (see Fig. 3(B)).

The joiner 20 can be manufactured by any method. For example, the joiner 20 may be obtained by molding the coated metal plate 10 having the metal plate 11 and the coating layer 13 described above by press working or the like; After molding the metal plate 11 by press working or the like, it may be obtained by forming the covering layer 13 on the surface 21A of the protruding portion 21.

<Example>

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited by these Examples.

1. Preparation of material for coating layer

(Film 1~7)

Pellets of an ethylene-vinyl acetate copolymer having a vinyl acetate content shown in Table 1 were placed between a press machine, and molded under pressure while heating the melting temperature of the ethylene-vinyl acetate copolymer to +30°C to obtain an ethylene-vinyl acetate copolymer. Films 1 to 7 having a thickness of 50 μm were obtained.

The composition of the films 1-7 is shown in Table 1.

Among these, the melt flow rate of Film 3 (JIS K 7210-1999, 190°C, 2160 g load) was 9.0 g/10 min.

(Film 8~13)

Film 8: Polystyrene film (PS) (manufactured by Asahi Kasei Chemicals, OPS (registered trademark) film, thickness 50 μm)

Film 9: High-density polyethylene film (HDPE) (manufactured by Nitto L Material, Polyethylene Masker, thickness 10 μm)

Film 10: polyvinylidene chloride film (PVdC) (manufactured by Asahi Kasei, Saran (registered trademark) UB, thickness 25 μm)

Film 11: Polypropylene film (PP) (manufactured by Toray Film Processing Co., Ltd., Torepan (registered trademark) NO, thickness 50 μm)

Film 12: Polymethyl methacrylate film (PMMA) (manufactured by Mitsubishi Chemical, Acriprene TM, thickness 50 μm)

Film 13: Polycarbonate 　 Film (PC) (made by Teijin, Pure Ace (registered trademark), thickness of 100 μm)

(Paint 1~3)

Paint 1: Silicone-based paint (Shin-Etsu Chemical Co., Ltd., silicone rubber S coat 57)

Paint 2: Silicone-based paint (Shin-Etsu Chemical Co., Ltd., silicone resin KR-300)

Paint 3: Epoxy resin-based paint (Nippe Powerbind manufactured by Nippon Paint Industrial Coatings, Inc.)

2. Fabrication and evaluation of coated metal plate

(Preparation of chemical conversion treatment metal plate)

As a coating original plate (metal plate), a molten 55% Al-45% Zn alloy plated steel plate with a thickness of 0.35 μm (adhered amount on both sides 150 g/m ² ) was prepared.

This plated steel sheet was subjected to alkali degreasing. Subsequently, a coating-type chromate treatment liquid (Surfcoat NRC300, manufactured by Nippon Paint) was applied to the surface of the obtained plated steel sheet as a pre-coating treatment, heated to a reached temperature of 100°C, and converted to a total chromium-based adhesion amount of 40 mg/m ² A film was formed to obtain a chemical conversion treatment metal plate.

(Manufacture of coated metal plates 1 to 4 and 8 to 10)

The film shown in Table 2 was disposed on the chemical conversion-treated film of the obtained chemical conversion-treated metal plate, and the ethylene-vinyl acetate copolymer was temporarily bonded at a glass transition temperature (Tg) + 40°C by a thermal lamination method, and then again glass with an oven. It heated at the transition temperature (Tg) + 80 degreeC for 60 seconds, and the coating layer of 50 micrometers in thickness was formed, and the coating metals 1-4 and 8-10 were obtained.

(Manufacture of coated metal plate 5)

After applying the paint shown in Table 2 on the chemical conversion treatment film of the obtained chemical conversion treatment metal plate, it was dried at room temperature for one week to form a coating layer having a thickness of 100 μm to obtain a coated metal plate 5.

(Manufacture of covered metal plate 11)

The coating material shown in Table 2 was applied on the chemical conversion-treated film of the obtained chemical conversion-treated metal plate, and then heated at 300° C. to form a 5 μm-thick coating layer to obtain a coated metal plate 11.

(Manufacturing of coated metal plates 6, 12, 14)

Except having changed the ethylene-vinyl acetate copolymer film 1 to the film shown in Table 2, it carried out similarly to the covering metal plate 1, and obtained the covering metal plates 6, 12, and 14. In addition, thermal lamination (temporary adhesion) was performed at the glass transition temperature (Tg) + 40°C of the resin, and heating in the oven was performed at the glass transition temperature (Tg) +80°C of the resin.

(Manufacturing of coated metal plates 7, 13, 15)

Films 9, 11, or 13 were attached to the chemical conversion treatment film of the obtained chemical conversion treatment metal sheet through an adhesive to obtain a coated metal plate 7, 13 or 15.

(Manufacturing of coated metal plate 16)

The coating material shown in Table 2 was applied onto the chemical conversion-treated film of the obtained chemical conversion-treated metal plate, and then heated at 200° C. to form a coating layer having a thickness of 5 μm to obtain a coated metal plate 16.

For the obtained coated metal plates 1 to 16, the volume resistivity and surface free energy of the coating layer were measured by the following method.

(Volume resistivity)

The volume resistivity of the coating layer was measured in accordance with JIS C 2139:2008 "solid electrical insulating material-measuring method of volume resistivity and surface resistivity". Measurement was performed under the following conditions.

(Exam conditions)

Test device: Digital ultra-high resistance/micro ammeter 8340A type (made by ADshi)

Electrode size: Main electrode 50 mmφ, guard electrode inner diameter 60 mmφ, outer diameter 80 mmφ

Applied voltage: 100V, 500V (DC)

Application time: 60 sec

Test environment: temperature 23±2℃, humidity 50±5% RH

Specimen dimensions: 100 mm×100 mm

Number of trials: n=3

(Surface free energy)

According to JIS R 3257:1999 "Surface wettability test method of substrate glass", the contact angle of pure water and methylene iodide was measured. The measurement was performed using a portable contact angle meter PCA-1 (manufactured by Kyowa Interface Science Corporation). The surface free energy was calculated using the obtained contact angle value and the Kaelble-Uy equation.

In addition, the non-adhesion of the coated metal plates 1 to 16 after exposure to the caulking material was measured by the following method.

(Non-adhesion to caulking material)

The obtained coated metal plate was exposed to the outdoors for 2 weeks in conformity with JIS Z 2381, with an exposure angle of 35 degrees and an installation direction of south. To the coated metal plate after outdoor exposure, a primer for caulking material was applied with a brush and dried at room temperature for 30 minutes. Then, a caulking material was applied to the surface of the primer and dried at room temperature for one week.

The dried caulking material was pulled off by hand from the coated metal plate, and those that were easily peeled were evaluated as "○", and those that were not peeled were evaluated as "x".

In addition, as a caulking material, a one-pack modified silicone caulking material (SR Seal S70; Sunrise MSI Co., Ltd.) or a urethane caulking material (FC700; Nichiha Corporation) was used. In addition, the primer is applied, taking into account that the primer is often unintentionally applied even to the surface that serves as the receiving part of the caulking material during actual construction, so that the condition is close to the actual construction conditions.

Table 2 shows the evaluation results of the coated metal plates 1 to 16.

As shown in Table 2, the coated metal plates 1 to 5 having a coating layer having a volume resistivity of 1.0×10 ¹⁷ Ω·cm or less, and a surface free energy of 36.6 mJ/m ² or less are also applicable to any of the urethane-based caulking material and the silicone-based caulking material. It can be seen that the non-adhesiveness after exposure is good.

On the other hand, it can be seen that the coating metal plates 6 to 16 having a coating layer in which at least one of the volume resistivity and surface free energy is outside the range of the present application have low non-adhesion after exposure to any of the urethane-based caulking material and the silicone-based caulking material.

This application claims priority based on Japanese Patent Application No. 2018-065011 for which it applied on March 29, 2018. All of the contents described in the application specification and drawings are incorporated in the specification of the present application.

<Industrial availability>

According to the present invention, it is possible to provide a coated metal plate that maintains non-adhesion to a caulking material even after leaving it outdoors. Such a coated metal plate can maintain good non-adhesion to a caulking material, and is very suitable as a joiner capable of suppressing three-sided adhesion.

10 clad metal plate
11 metal plate
13 cladding layer
20 joiner
21 protrusion
21A surface
23 Substrate
30 joints
40 caulking material
50 exterior materials

Claims (7)

Metal plate,
It has a coating layer containing a resin disposed on the surface of the metal plate,
The volume resistivity of the coating layer measured in accordance with JIS C 2139:2008 is 1.0×10 ¹⁷ Ω·cm or less, and the surface calculated by the Kaelble-Uy equation based on the contact angle measured in accordance with JIS R 3257:1999 Clad metal plate with a free energy of 36.6 mJ/m ² or less. The method of claim 1,
The resin is an ethylene-vinyl acetate copolymer or a silicone rubber, the coated metal plate. The method of claim 2,
The resin is an ethylene-vinyl acetate copolymer,
The coated metal sheet, wherein the content ratio of the structural unit derived from vinyl acetate in the ethylene-vinyl acetate copolymer is 5% by mass or more and less than 20% by mass with respect to all structural units constituting the ethylene-vinyl acetate copolymer. The method according to any one of claims 1 to 3,
The thickness of the coating layer is 3 ~ 120μm, the coated metal plate. The method according to any one of claims 1 to 4,
The metal plate has a chemical conversion treatment film disposed on a surface on which the coating layer is disposed. A joiner having the clad metal plate according to any one of claims 1 to 5 and disposed at the joints of adjacent exterior materials. The method of claim 6,
The joiner has a protrusion and a substrate portion connected to a base end of the protrusion,
A joiner, wherein the covering layer is disposed on at least a surface of the protrusion for supporting the caulking material.

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