JP2006240215A - Laminated metal plate and hydrophilic coated metallic plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a painted metal plate capable of maintaining coated surface in a hydrophilic state without water repellency components remaining on a hydrophilic coating when a protective film is peeled and removed. <P>SOLUTION: The laminated metal plate comprises a hydrophilic coating film layer formed of coating containing a hydrophilizing agent, and the protective film laminated on it, which has an adhesive layer formed by blending a surface active agent in the adhesive. The protective film of the laminated metallic plate is peeled so as to obtain a hydrophilic painted metal plate having hydrophilic groups on the surface of the coated layer. Partial hydrolytic condensation product of tetramethoxysilane is preferably used for the hydrophilic agent. Preferably, the surface active agent has water soluble or water dispersible property. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention has a laminated metal plate obtained by laminating a special protective film on a hydrophilic coating layer, and has a hydrophilic function on the surface of the coating layer even after peeling off the protective film when used mainly outdoors. Related to painted metal plate.

  In order to impart corrosion resistance, weather resistance, designability, and the like to metal plates such as building materials and equipment outer plates used outdoors, painted metal plates are used. In recent years, as the air pollution caused by automobile exhaust gas, smoke from the factory, etc. has become severe, the conventional painted metal plate is not enough to prevent the adhesion of dirt, due to carbon-based pollutants contained in the contaminated air, etc. Dirt becomes noticeable in a relatively short period of time.

Thus, as a paint for reducing the adhesion of dirt outdoors, a paint in which an organic silicate condensate is blended with an organic paint composition has been proposed (Patent Documents 1 to 3). In this type of paint, hydrophilicity is imparted to the coating film surface by the blended organosilicate condensate. When the surface of the coating film becomes hydrophilic, the lipophilic carbon-based pollutant, which is a main cause of air pollution, is washed away with rainwater and the like, resulting in a surface on which the pollutant is difficult to settle.
WO94 / 6870 JP 7-331136 A Japanese Patent Laid-Open No. 8-12921

  When using a coated metal plate with a hydrophilic coating surface as a building material or an instrument outer plate, a protective film may be applied in advance for the purpose of preventing wrinkles and dirt during molding and construction. When a protective film is applied, the protective film is peeled off and removed after molding and construction, but if the water-repellent component contained in the adhesive layer of the protective film remains on the coating film surface, There was a problem that the water-repellent state was not achieved, and sufficient antifouling effect was not exhibited.

  The present invention has been devised to solve such problems, and is a pressure-sensitive adhesive in which a surfactant is added to a pressure-sensitive adhesive on a hydrophilic coating layer formed by a paint containing a hydrophilic agent. An object of the present invention is to provide a laminated metal plate laminated with a protective film having a layer, and a hydrophilic coated metal plate having a hydrophilic group on the surface of the coating layer even after the protective film is peeled off from the laminated metal plate.

  In order to achieve the purpose of the protective film used in the present invention, a hydrophilic or water-dispersible surfactant is blended in the pressure-sensitive adhesive layer provided on the base film. A surfactant was added to the pressure-sensitive adhesive to prevent wrinkling during molding and construction of a coated metal sheet with a hydrophilic coating applied to a partially hydrolyzed condensate of tetramethoxysilane. By attaching a protective film having an adhesive layer, even if the protective film is peeled off and removed, no water-repellent component remains in the hydrophilic coating film, and the coating film surface can be kept in a hydrophilic state.

  According to the present invention, in order to prevent wrinkling at the time of molding and construction of a coated metal plate, a protective film having a pressure-sensitive adhesive layer in which a surfactant is blended with a pressure-sensitive adhesive is used. After peeling and removing, no water-repellent component remains on the hydrophilic coating film, and the coating film surface can be kept in a hydrophilic state. As a result, the original stain prevention effect of the hydrophilic coating film can be obtained.

  The hydrophilic coating film of the present invention is formed by applying and baking a coating material obtained by adding a hydrophilic compound to an overcoat organic resin coating material. The base material on which the hydrophilic coating film is provided is not particularly limited. Cold-rolled steel sheet, hot-dip galvanized steel sheet, electrogalvanized steel sheet, molten 5% Al-Zn plated steel sheet, molten 55% Al-Zn plated steel sheet, molten A Zn-Al-Mg alloy-plated steel sheet, a hot-dip aluminum-plated steel sheet, a stainless steel sheet, an aluminum plate, a copper plate, or the like can be used. In order to improve coating film adhesion and corrosion resistance prior to application of the paint on the substrate, pre-coating treatment such as degreasing, surface conditioning treatment, chromate treatment, phosphate treatment, epoxy resin, polyester, etc. Undercoat such as resin is applied.

There are no particular limitations on the organic resin coating of the top coat, and examples include polyester resin, silicon polyester resin, acrylic resin, urethane resin, polyvinylidene fluoride resin, solvent-soluble fluororesin, and vinyl chloride resin. it can. The hydrophilic compound to be added to the organic resin coating is typically an organosilicate compound, and examples thereof include tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, and partial hydrolysis condensates thereof. The surface of the coating film formed from the organic resin paint to which the organosilicate compound is added has hydrophilic groups such as Si—OH, Si—OR (R: C _n H _{n + 1} ) due to the orientation of the organosilicate compound, Shows hydrophilicity. Si-OR itself does not exhibit hydrophilicity, but it is easily hydrolyzed by moisture in the air, rainwater, or the like to change to Si-OH, and thus acts as a hydrophilic group when used outdoors.

  A protective film is produced by apply | coating the adhesive which mix | blended surfactant with the base film. The base film is not particularly limited, and polyethylene, polypropylene, ethylene / propylene copolymer, polyvinyl chloride, polyester and the like are used. As the main component of the adhesive, butyl rubber, polyisobutylene, polybutene, styrene / butadiene copolymer, styrene / isoprene copolymer, acrylic polymer, and the like are used. The pressure-sensitive adhesive is blended with a tackifier resin such as petroleum resin, terpene resin, rosin resin, coumarone / indene resin, ultraviolet absorber, light stabilizer and the like as necessary.

As the surfactant to be blended in the pressure-sensitive adhesive, it is preferable to select a surfactant exhibiting water solubility or water dispersibility. In the case of an oil-soluble surfactant, if it remains on the surface of the hydrophilic coating film, it may be difficult to be washed away by rainwater, so that a sufficient effect may not be obtained. From the balance between hydrophilic groups and lipophilic groups,
H. L. A material having B (Hydrophile Lyophile Balance) of 5 or more is suitable. Further, it is preferable to select a surfactant that is not too compatible with the pressure-sensitive adhesive. If a surfactant having high compatibility with the pressure-sensitive adhesive is used, adsorption of the surfactant to the surface of the hydrophilic coating film hardly occurs, and a sufficient effect may not be obtained.

  Specifically, the surfactant is, for example, an ether type such as polyoxyethylene alkyl ether or polyoxyethylene alkyl phenyl ether, polyoxyethylene glycerin fatty acid ester, polyoxyethylene sorbitan acid ester or the like as a nonionic surfactant. Examples include ether ester types, ester types such as polyethylene glycol fatty acid esters and polyglycerin fatty acid esters, and nitrogen-containing types such as fatty acid alkanolamides and polyoxyethylene alkylamines.

  Examples of the anionic surfactant include alkyl ether carboxylate, alkylbenzene sulfonate, alkyl ether phosphate ester salt and the like. Examples of the cationic surfactant include aliphatic amine salts and aliphatic quaternary ammonium salts. It is effective that the surfactant is blended at a ratio of 1 to 10% by mass with respect to the solid content of the pressure-sensitive adhesive.

  The laminated metal plate thus obtained is subjected to processing such as molding to form a hydrophilic coated metal plate having a hydrophilic group on the surface of the coating layer from which the protective film has been peeled off and removed, and then the interface on the coating layer. Even if the activator is adhered, the hydrophilic property of the hydrophilic coating film is not hindered because the surfactant itself is hydrophilic. Further, the surfactant remaining on the hydrophilic coating film is washed away with rainwater during outdoor use, and thus returns to the surface of the original hydrophilic coating film in a short time.

Preparation of polyester-based hydrophilic coating: After 55% Al-Zn-plated steel sheet is subjected to alkaline degreasing and coating-type chromate treatment, and after coating and baking an epoxy resin-based paint so that the film thickness becomes 5 μm, a primer is provided. A coating film having a film thickness of 15 μm is obtained by adding 10% by mass of a partially hydrolyzed condensate of tetramethoxysilane as a hydrophilizing agent to a colored coating of a regular polyester resin based on melamine resin as a cross-linking agent. The polyester-based hydrophilic coating film was prepared by painting and baking so that

Preparation of fluorine-based hydrophilic coating film: After 55% Al-Zn plated steel sheet is subjected to alkali degreasing and coating-type chromate treatment, an epoxy paint is applied and baked to a film thickness of 5 μm, and a primer is provided. An overcoating material obtained by adding 10% by mass of a partial hydrolysis-condensation product of tetramethoxysilane as a hydrophilizing agent to a fluororesin-based colored coating material composed of polyvinylidene fluoride and an acrylic resin, based on the solid content of the coating, has a film thickness of 25 μm. It was painted and baked to make a fluororesin-based hydrophilic coating film.

Production of protective film: A pressure-sensitive adhesive in which 5% by mass of polyoxyethylene alkyl ether as a surfactant is added to a pressure-sensitive adhesive mainly composed of butyl rubber and a terpene resin tackifier based on the solid content of the pressure-sensitive adhesive. It is applied to a substrate film and dried, and then Example No. The protective film used for 1-2 was produced. Similarly, those obtained by using alkyl ether carboxylate as the surfactant were those of the present invention example No. It was set as the protective film used for 3-4. Further, Comparative Example No. with no surfactant added. It was set as the protective film used for 7-8.

Evaluation of hydrophilicity and antifouling adhesion of hydrophilic coating film : A protective film is applied on the hydrophilic coating film with a laminator, stored at room temperature for 1 week, and then the protective film is peeled off and removed. A test piece for evaluating the hydrophilicity of the membrane and the stain resistance was used. Moreover, the hydrophilic coating film which does not affix a protective film is compared with comparative example No.1. Prepared as 5-6. The hydrophilicity of the coating film was evaluated by the contact angle with water. For soil resistance, Chiba prefecture has an outdoor exposure test in which rainwater flows down onto a hydrophilic coating film from a PVC corrugated sheet mounted vertically on an outdoor exposure test stand. It was conducted in Ichikawa City for 3 months, and the change in lightness (L value) at the site where rainwater flowed was measured as an index of dirt. When the brightness before exposure is L1 and the brightness after exposure is L2, the smaller the ΔL (L2−L1), the lower the brightness, that is, the greater the dirt. Judgment of stain resistance adhesion was marked with ○ when ΔL was 4 or less, and x when ΔL exceeded 4. The evaluation results are shown in Table 1.

  When the protective film which does not mix | blend surfactant with the conventional adhesive is used, comparative example No. which did not affix a protective film. Compared with 5-6, the water contact angle was high and the hydrophilicity was lowered, the ΔL after the outdoor exposure test was greatly reduced, and dirt was noticeable. On the other hand, this invention example No. which mix | blended surfactant with the adhesive was carried out. 1-4 are comparative example No. which did not affix a protective film. Similar to 5-6, the contact angle with water was low and no decrease in hydrophilicity was observed. In the outdoor exposure test, there was little adhesion of dirt, and good dirt resistance was shown.

A coated metal plate with a hydrophilic coating film surface used for exterior building material applications or the like is preliminarily pasted with a protective film assuming a molding process. According to the method of the present invention, even if the protective film is peeled off after processing, the adhesive does not remain on the surface of the coating film, and the hydrophilic group remains, so that a sufficient antifouling effect is exhibited, such as wrinkles on the hydrophilic coating film. Can be prevented.

Claims (4)

  A laminated metal plate, wherein a protective film having a pressure-sensitive adhesive layer in which a surfactant is added to a pressure-sensitive adhesive is laminated on a hydrophilic coating layer formed from a paint in which a hydrophilic agent is added.   A hydrophilic coated metal plate having a hydrophilic group on the surface of the coating layer even after the protective film is peeled off from the laminated metal plate according to claim 1.   The laminated metal sheet according to claim 1, wherein the hydrophilizing agent is a partial hydrolysis condensate of tetramethoxysilane. The laminated metal plate according to claim 1, wherein the surfactant is water-soluble or water-dispersible.