JP2016094011A - Painted metal plate and shutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a painted metal plate that is used for making a shutter, and can prevent the occurrence of the noise of the shutter for the long term and a shutter comprising the painted metal plate.SOLUTION: A painted metal plate comprises a metal plate, and a coating that coats the metal plate. The coating has a glass-transition temperature of 40-60°C. The coating comprises heat melting type resin particles with an agglomeration average particle diameter of 3 μm or less.SELECTED DRAWING: None

Description

  The present invention relates to a painted metal plate that can be used for a shutter of a building and the like, and a shutter constituted by the painted metal plate.

  A shutter provided in an opening such as a doorway of a building or a house is configured by connecting a plurality of members called slats made of a metal plate such as steel or aluminum so as to be rotatable with respect to each other. The surface of the metal plate is decorated by baking or spraying a paint.

  By the way, in house window shutters, wind noise due to wind swell and vibration, or squealing and frictional noise generated at the curled part that is the connecting part of the slats when the shutter is opened and closed, rubbing noise between the shutter curtain and the guide rail May be felt as noise or abnormal noise. Various methods for preventing noise from the shutter as described above have been proposed. For example, noise can be prevented by arranging a damping material formed of resin or the like in the rotating part of the shutter slat. Have been proposed (see, for example, Patent Document 1).

JP 2002-357064 A

  However, the conventional shutter has a problem that, even when noise generation is small at the time of new installation, deterioration or damage of the connecting portion or the like occurs over time, and noise is gradually generated to increase noise. In particular, when the temperature of the slats is high at high temperatures in summer, deterioration and damage are promoted, and the noise may be further increased.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a coated metal plate that can be used for manufacturing a shutter and can suppress generation of noise of the shutter for a long period of time, and a manufacturing method thereof. Is.

  The coated metal plate according to the present invention is a coated metal plate provided with a metal plate and a coating film covering the metal plate, wherein the coating film has a glass transition temperature of 40 to 60 ° C., It is characterized by containing hot-melt resin particles having an agglomerated average particle diameter of 3 μm or less.

  The base resin constituting the coating film is preferably a polyester resin.

  Moreover, it is preferable that 0.3-3.0 mass% of said hot-melt type resin particles are contained with respect to the said coating film.

  Moreover, it is preferable that the occupation area rate of the thermomeltable resin particles per unit area is 0.3 to 4.0% on the surface of the coating film.

  The shutter which concerns on this invention is equipped with the slat comprised from the said coating metal plate.

  According to the coated metal plate of the present invention, generation of shutter noise can be suppressed for a long time.

  Hereinafter, modes for carrying out the present invention will be described.

  The coated metal plate of the present invention is formed by coating the surface of a metal plate with a coating film. Although the material in particular is not restrict | limited as this metal plate, The steel plate, aluminum plate, etc. which consist of appropriate steel materials, such as stainless steel, are mentioned. Moreover, it is also preferable that a metal plate is a steel plate by which plating processing was given, such as a hot-dip galvanized steel plate and a hot-dip galvanized steel plate.

  It is also preferable that a chemical conversion treatment layer is formed on the metal plate. The chemical conversion treatment layer is a layer formed by a known chemical conversion treatment. Examples of the treatment agent (chemical conversion treatment agent) for forming the chemical conversion treatment layer include chromium such as a chromate treatment agent, a trivalent chromic acid treatment agent, a chromate treatment agent containing a resin, and a trivalent chromic acid treatment agent. Treatment agents; Phosphate treatment agents such as zinc phosphate treatment agents and iron phosphate treatment agents; Oxide treatment agents containing metal oxides such as cobalt, nickel, tungsten, zirconium alone or in combination; Corrosion Treatment agent containing an inhibitor component for preventing oxidization; treatment agent in which a binder component (organic, inorganic, organic-inorganic composite, etc.) and inhibitor component are combined; treatment agent in which an inhibitor component and metal oxide are combined; binder component and silica And a treatment agent in which a sol such as titania or zirconia is combined; a treatment agent in which the components of the exemplified treatment agents are further combined.

  As an example of a chromium-containing treatment agent, prepared by blending water and water-dispersible acrylic resin, a silane coupling agent having an amino group, and a source of chromium ions such as ammonium chromate and ammonium dichromate Treatment agents to be used. The water-dispersible acrylic resin is obtained, for example, by copolymerizing a carboxyl group-containing monomer such as acrylic acid and a glycidyl group-containing monomer such as glycidyl acrylate. The chemical conversion treatment layer formed from this chemical conversion treatment agent has high water resistance, corrosion resistance, and alkali resistance, and this chemical conversion treatment layer suppresses the occurrence of white rust and black rust on the hot-dip metal plate, thereby improving the corrosion resistance. In order to improve corrosion resistance and prevent coloration of the chemical conversion treatment layer, the chromium content in the chemical conversion treatment layer is preferably in the range of 5 to 50 mg / m2.

  Examples of oxide treating agents containing zirconium oxide include water and water-dispersible polyester urethane resins, water-dispersible acrylic resins, zirconium compounds such as sodium zirconium carbonate, and hindered amines. And a treatment agent prepared in this manner. The water-dispersible polyester-based urethane resin is synthesized, for example, by reacting a polyester polyol with hydrogenated isocyanate and self-emulsifying by copolymerizing dimethylol alkyl acid. Such a water-dispersible polyester-based urethane resin imparts high water resistance to the chemical conversion treatment layer without using an emulsifier, leading to improvement in corrosion resistance and alkali resistance of the hot-dip metal plate.

  Under the chemical conversion treatment layer or instead of the chemical conversion treatment, nickel plating treatment, cobalt plating treatment, or the like may be performed.

  The chemical conversion treatment layer may be formed by a known method such as a roll coating method, a spray method, a dipping method, an electrolytic treatment method, or an air knife method using a chemical conversion treatment agent. After application of the chemical conversion treatment agent, a step such as standing at room temperature or drying or baking with a heating device such as a hot air furnace, an electric furnace, or an induction heating furnace may be added as necessary. A curing method using energy rays such as infrared rays, ultraviolet rays and electron beams may be applied. The temperature and drying time during drying are appropriately determined according to the type of chemical conversion treatment agent used and the required productivity. The chemical conversion treatment layer thus formed becomes a continuous or discontinuous film on the plating layer. The thickness of the chemical conversion treatment layer is appropriately determined according to the type of treatment, required performance, and the like.

  The coating film to be coated on the surface of the metal plate can be formed by applying a paint for a coated metal plate prepared in advance to the metal plate. This paint for a coated metal plate comprises at least a base resin and a wax.

  The base resin is a resin component for forming a coating film into a film shape, and its glass transition temperature is preferably 2 to 60 ° C. If the glass transition temperature of the base resin is in the above range, the glass transition temperature of the coating film can be set in the range of 40 to 60 ° C., and the decrease in the hardness and heat resistance of the coating film can be suppressed. In addition, it becomes easy to prevent peeling, scraping, scratching and the like of the coating film, and the film forming property of the coating film and the workability of the coated metal plate are improved. When the base resin contains a cross-linking agent, even if the glass transition temperature of the base resin is lower than 40 ° C., cross-linking occurs during coating film formation, and the glass transition temperature of the coating film is 40 to 60 ° C. Can be in the range. In addition, the glass transition temperature here shows the value (TMA method) measured with the thermomechanical analyzer.

  For example, polyester resin, acrylic resin, epoxy resin, urethane resin, urethane-acrylic resin, fluorine resin, silicon resin, vinyl chloride resin, vinylidene chloride resin, polystyrene resin, etc. can do. Among these resins, polyester resins are particularly preferable. In this case, the coating film formed by applying the paint for the coated metal plate to the metal plate has good hardness while ensuring flexibility, It will prevent deterioration of workability. The above-exemplified base resins may be used alone or in combination of two or more.

  When the base resin is a polyester resin, the hydroxyl value (OH value) indicating the hydroxyl content of the polyester resin is preferably 20 to 100 mgKOH / g. If the hydroxyl value of the polyester resin is within this range, it is possible to prevent the curability of the paint from becoming too low, and the hardness and solvent resistance of the coating film are difficult to decrease, and stable coating film processability is achieved. It will have.

The polyester resin in the polyester resin-based paint can be produced using a known method such as a direct esterification method, a transesterification method, or a ring-opening polymerization method. As a specific example of the direct esterification method, for example, there is a method of polycondensation of a polyvalent carboxylic acid and a polyhydric alcohol. Examples of the polyvalent carboxylic acid include phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, maleic acid, maleic anhydride, fumaric acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride And tribasic or higher polyvalent carboxylic acids such as trimellitic acid, trimellitic anhydride, pyromellitic acid and pyromellitic anhydride, and anhydrides thereof. Polyhydric alcohols include ethylene glycol, propylene glycol, diethylene glycol, butanediol, neopentyl glycol, diols such as 1,4-hexanediol, 1,6-hexanediol, and cyclohexanedimethanol, glycerin, trimethylolethane, Examples include trihydric or higher polyhydric alcohols such as trimethylolpropane and pentaerythritol. The polyester resin can also be produced by condensation polymerization by transesterification between a lower alkyl ester of a polyvalent carboxylic acid and a polyhydric alcohol. Furthermore, the polyester resin can also be produced by ring-opening polymerization of lactones such as β-propiolactone, δ-valerolactone, and ε-caprolactone. The said polyester resin may be used individually by 1 type, and may be used in combination of 2 or more type.

  The molecular weight of the base resin is preferably a number average molecular weight of 2,000 to 10,000, and if it is within this range, the hardness of the coating film is difficult to decrease, and the processability of the coating film may be impaired. Will also be small. In addition, the base resin preferably has a cross-linked structure to such an extent that the hardness and workability of the coating film are not impaired. In this case, for example, a cross-linking agent such as melamine may be included in the base resin. And by having this crosslinked structure, it becomes easy to adjust the glass transition temperature of a coating film to 40 to 60 degreeC.

  The paint for a coated metal plate used in the present invention contains a wax. When a paint film is formed by applying the paint for a coated metal plate to the metal plate with this wax, the slipperiness of the paint film Will be improved.

  Conventional waxes such as polyethylene wax can be used as the wax, and in particular, it contains polytetrafluoroethylene particles (hereinafter referred to as PTFE particles) and hot-melt resin particles. preferable. This is because PTFE particles and hot-melt resin particles are excellent in dispersibility in the coating film and can impart high slipperiness to the coating film.

  As the PTFE particles, for example, those having an average particle diameter of 3 to 12 μm can be used. If the average particle diameter of the PTFE particles is within this range, the PTFE particles are easily dispersed uniformly in the wax, and the PTFE particles are less likely to fall off from the surface of the coating film even after the coating film is formed. . The average particle size of the PTFE particles is more preferably 3 to 6 μm. The average particle diameter of PTFE particle here is a value measured by a laser diffraction scattering method. The shape of the PTFE particles may be spherical, or may be an irregular shape (a shape in which the sphere is distorted).

  The hot-melt resin particles are resin particles that are melted by heating, and are preferably melted at 100 to 120 ° C. Within this range, the hot-melt resin in the coating film after forming the coating film The dispersibility of the particles is excellent. That is, as will be described later, the agglomerated average particle diameter of the hot-melt resin particles in the coating film can be reduced to 3 μm or less.

  Although it does not specifically limit as said hot-melt type resin particle, For example, a fluorine-type polyethylene particle can be used. Fluorine-based polyethylene particles are made of a copolymer of polyethylene and a resin bonded with fluorine atoms. The resin bonded with fluorine atoms is, for example, one having a structure in which at least one fluorine atom is substituted on the skeleton (or side chain) of polyolefin such as polyethylene or polypropylene, or the main chain or side of acrylic resin or the like. Examples include those having a structure in which at least one fluorine atom is substituted in the chain. The copolymer of polyethylene and a resin having fluorine atoms bonded thereto may be any of a block copolymer, a random copolymer, a graft copolymer, and an alternating copolymer. Specific examples of the fluorine-based polyethylene particles include PTFE-modified polyethylene.

  In addition, it is preferable to prepare a wax dispersion in which the wax is dispersed or dissolved in a dispersion medium in advance so that the wax can be easily blended into the paint for the coated metal sheet.

In preparing a wax dispersion containing PTFE particles and hot melt resin particles, for example, the following can be performed. First, PTFE particles, hot melt resin particles, and a dispersion medium are prepared. As the PTFE particles, for example, powdery particles can be used, and as the hot-melt resin particles, a dispersion or powdery particles can be used. Moreover, the dispersion medium is not particularly limited, but ethanol, isopropanol, butanol, butyl glycol, butyl diglycol, butyl glycol acetate, solvent naphtha, etc. may be used alone or in combination of two or more. Can do.

  Then, PTFE particles and heat-melting resin particles are added to the dispersion medium, and then PTFE particles and heat-melting resin particles are dispersed in the dispersion medium by mechanical treatment. This dispersion is preferably carried out at 20 ° C. to 40 ° C. when the temperature exceeds 60 ° C., the hot-melt particles may melt and the particles may aggregate. Further, the time for dispersion by the mechanical treatment can be, for example, 15 to 30 minutes, although it depends on temperature conditions.

  As the mechanical treatment, for example, a method of adding inorganic beads such as glass, alumina and zirconia to the wax dispersion and stirring with a commercially available stirrer such as a disper is preferable.

  When the wax dispersion is prepared by the method as described above, it becomes easy to suppress aggregation of PTFE particles and hot-melt type resin particles. Therefore, when a coating film is formed, PTFE particles and hot-melt type in the coating film are formed. The dispersibility of the resin particles is excellent.

  The PTFE particles are preferably contained in an amount of 30 to 60 parts by mass with respect to 100 parts by mass of the wax dispersion, and within this range, good slipperiness can be imparted to the coating film. The cost is never too high. On the other hand, the hot-melt resin particles are preferably contained in an amount of 5 to 35 parts by mass with respect to 100 parts by mass of the wax dispersion. Aggregates less easily.

  In the paint for a coated metal plate used in the present invention, the base resin and the wax prepared as described above can be included, but as long as the effect of the present invention is not impaired, a coloring pigment, Other additives such as an ultraviolet absorber and a light stabilizer may be contained.

  Moreover, it does not specifically limit as a solvent in the coating material for coating metal plates, For example, xylene, cyclohexanone, isobutanol, etc. can be used.

  In the paint for a coated metal sheet used in the present invention, the base resin is preferably contained in an amount of 30 to 90% by mass with respect to the total amount of solids (components excluding solvent) of the paint for a coated metal sheet. In this case, peeling of the coating film after formation of the coating film is difficult to occur, and deterioration of coating film processability can be prevented. On the other hand, the wax is preferably contained in an amount of 3 to 5% by mass based on the total solid content of the paint for a coated metal sheet. In this case, good slipperiness can be imparted to the surface coating film after the coating film is formed, and when the paint for the coated metal sheet is prepared, wax adheres to the supply pipe or the like to contaminate the supply pipe, Loss can be suppressed.

  In addition to the above components, various additives such as a viscosity modifier, a dispersion stabilizer, and a deterioration inhibitor may be added to the wax dispersion.

In forming the coating film on the metal plate, for example, a coating for a coated metal plate can be applied by an appropriate method such as spray coating, bar coating, roller curtain coating, curtain flow coating, roll coating, or the like. Thus, after apply | coating the coating material for coating metal plates, it forms into a film by hardening and drying by heating with heating apparatuses (heaters), such as a hot air drying furnace and a dielectric heating apparatus, and a coating film is formed. The temperature at which the coating film is formed is at least equal to or higher than the melting temperature of the hot-melt resin particles, and can be, for example, 210 to 240 ° C. and 30 to 60 seconds. in this case,
The hot-melt resin particles are melted during the film formation, and the aggregation is suppressed, and the aggregate average particle diameter can be easily controlled as described later.

  The coating film thus formed has a glass transition temperature of 40 to 60 ° C. When the glass transition temperature is less than 40 ° C., the hardness and heat resistance of the coating film are lowered, the coating film is easily peeled off, and noise is easily generated when a coated metal plate is used as a shutter. End up. On the other hand, when the glass transition temperature exceeds 60 ° C., the adhesiveness of the coating film is deteriorated, and the coating film is liable to be peeled off, and the coating film processability may be deteriorated. The glass transition temperature of the coating film is particularly preferably 45 to 58 ° C. In addition, the glass transition temperature here shows the value (TMA method) measured with the thermomechanical analyzer.

  In addition, when a coating film is formed by using a wax containing PTFE particles and hot-melt resin particles in a paint for a coated metal plate, PTFE particles having a low surface free energy can be easily disposed on the surface layer of the coating film. (The particle surface may be exposed on the surface layer). Therefore, the slipperiness of the coating film is further increased (that is, the dynamic friction coefficient and the static friction coefficient are small), and the generation of noise can be easily prevented.

  Furthermore, since the hot-melt resin particles are dispersed in the coating film, the hot-melt resin particles are present on the surface layer even if, for example, the surface of the coating film is scraped due to abrasion or the PTFE particles fall off. Therefore, it can prevent that the slipperiness of a coating film falls. That is, even if the coating film surface is scraped due to wear or the like over time, the dynamic friction coefficient and the static friction coefficient are hardly changed.

  In the present invention, the aggregation average particle diameter of the hot-melt resin particles in the coating film is 3 μm or less. Here, the aggregated average particle diameter refers to the diameter when the aggregate of aggregated hot-melt resin particles is converted into one sphere. If the agglomerated average particle diameter of the heat-melting resin particles in the coating film exceeds 3 μm, the heat-melting resin particles are likely to be unevenly distributed in the coating film and are not uniformly dispersed in the coating film. . Therefore, for example, if the surface layer of the coating film has been scraped, the hot melt resin particles may not appear on the surface of the coating film. May not be sufficiently imparted. Particularly preferred agglomerated average particle diameter of the hot-melt resin particles is 2.5 μm or less. In addition, if the agglomerated average particle diameter of the hot-melt resin particles becomes too small, sufficient slipperiness may not be imparted, so the lower limit value of the agglomerated average particle diameter is preferably 1.0 μm.

  The method for measuring the agglomerated average particle diameter is, for example, observing the surface of the coating film with a scanning electron microscope (SEM), and from the obtained observation image, agglomerates (thermal melting) of hot-melt resin particles in the coating film What is necessary is just to measure the diameter equivalent to the circular area of the aggregate | assembly of a type | mold resin particle. In this case, for example, by measuring the diameters of the 10 aggregates in the SEM image and calculating the arithmetic average thereof, the aggregated average particle diameter of the hot-melt resin particles can be obtained. On the other hand, PTFE particles are also included in the coating film, but PTFE particles are not in the form of aggregates like hot-melt resin particles in the first place, so the distinction between PTFE particles and hot-melt resin particle aggregates in SEM images. Is easy. If it is difficult to distinguish between the two, for example, if elemental analysis is performed in advance by energy dispersive X-ray analysis (EDS), PTFE particles are rich in fluorine atoms, and hot-melt resin particles are rich in carbon atoms. Therefore, the two can be distinguished. Therefore, it is also possible to measure the aggregated average particle diameter of the hot-melt resin particles by analyzing in combination with EDS measurement and SEM observation.

  And it is preferable that the maximum diameter of the said diameter per said aggregate contained in a coating film (henceforth the largest aggregate particle diameter) is 4.0 micrometers.

  And in the said SEM image, it is preferable that the occupation area rate of the hot-melt type resin particle per unit area of the coating-film surface is 0.3 to 4.0%. If the occupation area ratio of the heat melting type resin particles in this range is in this range, excellent slipperiness can be imparted to the coating film, and noise can be reduced.

  The hot-melt resin particles contained in the coating film are preferably contained at least 0.3% by mass with respect to the total amount of the coating film. In this case, the coating film exhibits sufficient slipperiness to suppress noise. Can be granted. Further, the upper limit of the content of the heat-melting resin particles in the coating film is 3.0 mass% with respect to the total amount of the coating film because the heat-melting resin particles may easily aggregate when it is too large. It is preferably 0.9% by mass, more preferably 0.6% by mass.

  The film thickness of the surface coating film is not particularly limited, but can be formed with a thickness of 15 to 20 μm, for example, and within this range, the paint for the coated metal plate is applied to the metal plate for the shutter. Thus, when a surface coating film is formed, it is easy to suppress the generation of noise, and the appearance is less likely to be damaged.

  Forming a slat for a shutter using the painted metal plate of the present invention can be performed by a known method. For example, the painted metal plate may be cut or bent.

  As described above, since the coated metal plate of the present invention is excellent in surface slipperiness, it is difficult to generate noise due to friction or the like when used for a shutter or the like, and even if the coating is scraped off due to wear. Since the slipperiness is not easily lowered, the generation of noise can be suppressed in the long term. That is, as described above, in the shutter, the frictional noise generated in the curled portion that is the connecting portion between the slats when the shutter is opened and closed is the cause of the noise. As a result, frictional noise can be reduced. In particular, in an electric shutter, since it is easy to generate noise conventionally, the coated metal plate of the present invention can be suitably used for such an electric shutter.

  Hereinafter, the present invention will be specifically described by way of examples.

(Examples 1-9, Comparative Example 2)
In Examples 1 to 9 and Comparative Example 2, coated metal sheet paints were prepared at the blending ratios shown in Table 1. Preparation of the coated metal plate paint is carried out by first adding PTFE particles and fluorine-based polyethylene particles) to 60 parts by mass of butyl diglycol, adding glass beads to this, and dispersing at 25 ° C. for 20 minutes by a stirring method using a disper. To obtain a wax dispersion. Next, the above-mentioned wax dispersion was added to a solution in which a polyester resin was added to 180 parts by mass of cyclohexanone to obtain a coated metal sheet paint.

  Next, a molten 55% aluminum-galvanized steel sheet (Galbarium steel sheet (registered trademark)) having a thickness of 0.30 mm and a width of 910 mm was prepared as a metal plate, and this metal plate was degreased and then subjected to a coating type chromate treatment. The coated metal plate paint was applied as an undercoat on the metal plate to form a coating film having a thickness of 3 μm, followed by overcoating with the painted metal plate paint to form a coating film having a thickness of 17 μm. The coated metal sheet was applied to the metal with a roll coater, the undercoating temperature was 200 ° C, the baking time was 30 seconds, and the upper coating temperature was 225 ° C, the baking time. The test was performed under the condition of 30 seconds.

(Comparative Examples 1 and 3)
In Comparative Examples 1 and 3, a coated metal sheet paint was prepared at a blending ratio shown in Table 1. In preparing the wax dispersion, a coated metal plate paint was prepared in the same manner as in Examples 1 to 9 and Comparative Example 2 except that glass beads were added and the stirring method using a disper was not performed. did. Moreover, the coating metal plate was performed by the method similar to Examples 1-9 and Comparative Example 2.

(Comparative Examples 4 and 5)
A coated metal sheet paint was prepared in the same manner as in Examples 1 to 9 and Comparative Example 2 except that no wax was used and glass beads were added and the stirring method using a disper was not performed. Moreover, the coating metal plate was performed by the method similar to Examples 1-9 and Comparative Example 2.

  In the above Examples and Comparative Examples, the raw materials shown below were used.

(Substrate resin)
Polyester resin A (IPT-139 number average molecular weight of about 3000 Tg2 ° C., manufactured by Nippon Paint Co., Ltd.)
Polyester resin B (Nippon Paint Co., Ltd. IPT-139 modified average molecular weight about 3000 Tg 23 ° C.)
・ Polyester resin C (IPT139 modified 2 by Nippon Paint Co., Ltd. Number average molecular weight of about 3000, Tg = 60 ° C.)
(wax)
PTFE particles (KTL-8N, KTL-8N average particle size 4 μm)
・ Fluorine-based polyethylene particles (PTFE-modified polyethylene wax CERACOL607 manufactured by Big Chemie Japan Co., Ltd. Aggregation average particle diameter 4 μm, wax melting point 105 ° C.)
The fluorine-based polyethylene particles are equivalent to hot-melt resin particles.

  The evaluation results of the coated metal plates obtained in the examples and comparative examples are shown in Table 2 and Table 3, respectively. In addition, each evaluation method was performed by the method shown below.

(Glass transition temperature of coating film)
The coating film formed on the coated metal plate is peeled off, and TMA (Thermomechanica)
l Analysis) was measured by a needle approach method.

(Dynamic friction coefficient)
Using a Bauden tester, slide on the coating film / SUS spherical surface with a load of 1 kg, measure the friction coefficient after the first sliding and the friction coefficient after 100 times sliding, respectively, and the dynamic friction coefficient of the coating on the coated metal plate It was.

(Static friction coefficient)
The static friction coefficient was measured in terms of slip angle with a load of 200 g using a Haydon testing machine. In this measurement, the temperature of the coated metal plate was set to normal temperature and 60 ° C., respectively, and the static friction coefficient of the coating film on the coated metal plate was used.

(Sliding (load 1kg) steel ball sliding)
Using a rubbing tester, the occurrence of wrinkles on the coating film was observed when a steel ball was slid on the coating film with a load of 1 kg, and the number of wrinkles that reached the substrate was measured.

(Sliding (load 5kg) Erichsen extrusion)
Using an Erichsen tester, a steel plate extruded 5 mm was slid on the same steel plate with a load of 5 kg using a rubbing tester, and the number of times the base film was exposed to the extrusion side was investigated.

(Impact test)
The measurement was performed in accordance with JIS G 3322 13.2.4.

(Shutter noise evaluation)
A shutter made of a painted metal plate, exposed to the outdoors, opened and closed a total of approximately 10,000 times indoors and outdoors, measured the sound during the opening and closing, and the ones with low noise utterances overall A product with good noise generation as a whole was evaluated as defective.

(Adhesion test)
About the coated metal plate of each Example and Comparative Example, after sandwiching one sample material (the same coated metal plate as the evaluation object) and bending it 180 ° with the painted surface outside at room temperature (1T), the cellophane adhesive tape After being applied to the surface of the bent portion and sufficiently rubbing and sticking with fingers, it was immediately peeled off (1TT). And the place which peeled off the cellophane adhesive tape in a bending part was observed visually, and the presence or absence of peeling of a coating film was determined on the following reference | standard: (circle): There was no peeling and it was favorable.
X: Peeling occurred.

(Coating film hardness (pencil hardness))
The hardness of the top coat of the coated metal plate was determined in accordance with JIS G 3322 13.2.3.

(Adhesion (cross cut, cross cut after 2 hr))
The coated metal plate was immersed in boiling ion exchange water at 98 ° C. or higher for 2 hours, dried for 1 hour, and then 10 × 10 = 100 coating film cut grids were made at 1 mm intervals. In this coated metal plate, the cellophane adhesive tape was adhered to the coating film, which was immediately peeled off, and the number of grids remaining without breaking was counted.

(Adhesion (cross-cut, exelin 5mm extrusion))
10 × 10 = 100 coating film cut grids were made at 1 mm intervals on the coated metal plate, and the portions were extruded 5 mm with an Erichsen tester, and then the coated surface was observed to confirm the presence or absence of peeling.

(Agglomerated average particle diameter of hot-melt resin particles)
The surface of the coating film was photographed with an SEM, and in the obtained image, an aggregate of 10 hot-melt resin particles was arbitrarily selected, the diameter corresponding to each circular area was measured, and the arithmetic average was calculated. By calculating, the aggregation average particle diameter of the hot-melt resin particles was measured. Further, among the aggregates of the hot-melt resin particles projected in the SEM image, those having the maximum diameter were also recorded.

(Occupied area ratio of hot-melt resin particles on the coating surface)
The total sum which calculated the circular area of all the hot-melt type resin particles projected on the SEM image was calculated, and the occupation area ratio of the hot-melt type resin particles was calculated by the following formula.
Occupied area ratio of heat-melting resin particles (%) = [(total sum of circular areas of heat-melting resin particles) / (total area of coating film)] × 100

  As is apparent from Table 2, the coated metal plates in Examples 1 to 9 have a stable coefficient of dynamic friction even after sliding, and no significant increase in the coefficient of static friction at normal temperature and 60 ° C. is observed. . For this reason, the noise of the shutter is also suppressed. This is because the coated metal plate in coating examples 1 to 9 has a glass transition temperature of the coating film of 40 to 60 ° C., and the melt-melt resin particles having an average particle diameter of 3 μm or less in the coating film. It is because it contains.

On the other hand, the coated metal plate of Comparative Example 1 had a low glass transition temperature of the coating film and a large agglomerated average particle size of the hot-melt resin particles. Therefore, the noise of the shutter was large. This is thought to be because the slipperiness of the coating film is poor and the coating film is easily peeled off. Further, in Comparative Example 2, although the coefficient of friction is small, the glass transition temperature of the coating film is high, so that the adhesion of the coating film is low and the coating film is easily peeled off. there were. In the coated metal plate of Comparative Example 3, since the aggregation average particle diameter of the hot-melt resin particles was large, sufficient slipperiness was not imparted, and thus the shutter noise was large. Since the coated metal plates of Comparative Examples 4 and 5 did not contain wax, the slipperiness was low and the shutter noise was large.

Claims (5)

  A coated metal plate comprising a metal plate and a coating film covering the metal plate, wherein the coating film has a glass transition temperature of 40 to 60 ° C., and the coating film has an aggregate average particle diameter of 3 μm or less. Painted metal plate containing hot melt resin particles.   The coated metal plate according to claim 1, wherein the base resin constituting the coating film is a polyester resin.   The coated metal plate according to claim 1 or 2, wherein the hot-melt resin particles are contained in an amount of 0.3 to 3.0 mass% with respect to the coating film.   The coated metal plate according to any one of claims 1 to 3, wherein an occupation area ratio of the hot-melt resin particles per unit area is 0.3 to 4.0% on the surface of the coating film. A shutter provided with the slat comprised from the coating metal plate as described in any one of Claims 1 thru | or 4.