JP3939258B2 - Organic film protective paint - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coating material that protects an organic film from photocatalytic action, and a construction method thereof.
[0002]
[Prior art]
Research and development on the formation of antifouling coatings on building walls using photocatalytic functions has progressed, and Japanese Patent Application Laid-Open No. 7-331120 discloses a paint prepared by mixing a commercially available water-soluble paint and titania fine powder, and a commercially available oil-based paint. A coating material in which fine titania powder is mixed is disclosed. Also, from the applicant of the present invention, according to Japanese Patent Application Laid-Open No. 2001-162217, a fluororesin-based coating material containing an inorganic filler is formed by laminating a primer and a fluororesin-based coating material. And a method for forming an antifouling coating film obtained by further coating a titanium peroxide solution thereon.
[0003]
In the invention disclosed in Japanese Patent Application Laid-Open No. 2001-162217, the base material on which the antifouling coating film is formed is limited to inorganic and metal base materials such as various ceramic building materials, mortar, concrete, cement, and metal. It was.
[0004]
This is because the photocatalytic layer by the titanium peroxide solution that forms the antifouling coating film decomposes organic substances that are pollutants by photocatalytic action, but when the substrate is an organic film made of plastic or various resins, The surface of the organic film is affected at the same time as the pollutant decomposition.
[0005]
When the resin or organic color pigment constituting the surface of the organic film is decomposed, the surface is in a state where powder is blown, and a coating film defect called so-called choking is developed. The expression of choking varies depending on the type of organic film and the condition of light, but it may occur in about one month.
[0006]
[Problems to be solved by the invention]
Therefore, the present invention protects an existing organic film composed of any plastic base material or a continuous coating film of an organic synthetic resin by various water-soluble, oil-based, and emulsions from photocatalytic action, and decomposes contaminants by photocatalytic action. The present inventors have developed an organic film protective coating and its construction method that can self-clean the surface by action.
[0007]
[Means for Solving the Problems]
As a result of diligent research, the present inventor has been able to apply directly onto the existing organic film, and since it is clear, the color, texture, etc. of the existing organic film are not impaired and the upper layer is formed. The above-mentioned problems are solved by a paint that protects an organic film from the action of a photocatalyst paint that is applied in a layered manner and a construction method thereof. Therefore, the gist of the present invention is as follows.
[0008]
A paint that is applied between various existing organic coatings or between an organic resin surface and a photocatalytic coating, and is obtained by reacting 70% by mass or more of a peroxo-modified anatase sol with alcohol in the presence of lithium silicate. An organic film protective paint characterized by being a clear paint that forms an inorganic coating film by drying at room temperature.
This will be described in detail below.
[0009]
The clear paint (referred to as “first invention”) mainly composed of an inorganic polymer will be described. The main component is 70% by mass or more of peroxo modified anatase sol (referred to as “PA sol”), and in the presence of lithium silicate composed of amorphous silica, lithium oxide, and water, alcohol such as methanol, ethanol, isopropanol, etc. It is obtained by reacting 20% by mass. An inorganic coating film is formed by drying at room temperature, but the photocatalyst is inactive and can protect the organic film.
[0010]
A clear paint (referred to as “second invention”) containing a peroxotitanic acid solution will be described. A peroxotitanic acid solution (referred to as “PTA solution”) as a main component is a kind of titanium peroxide solution, and anatase-type titanium oxide dispersed in the solution is crystallized at a temperature of 250 ° C. For this reason, when it is applied and dried at room temperature to form a clear coating film, titanium oxide as a photocatalyst remains inactive. Therefore, there is no possibility that the organic film is attacked by the room temperature dry clear coating film of the PTA solution.
[0011]
Both the protective coatings of the first invention and the second invention can be applied by a conventionally known coating method. That is, there are no restrictions on the painting method, such as brush painting, roller painting, spray painting, and the like. After application, dry at room temperature. This is because when heat drying is performed, photocatalytic activity due to titanium oxide may occur in the protective coating film. The drying conditions vary depending on weather conditions such as the temperature and humidity at the time of application, but when the temperature is around 20 ° C., a drying time of at least 2 hours is required. When a photocatalyst coating is applied on the coating without completely forming a protective clear coating, the titanium oxide component of the photocatalyst may be transferred to the protective coating and the protective effect may be lost.
[0012]
The photocatalyst paint to be applied on the above protective coating is mainly composed of a titanium peroxide solution, particularly PA sol, an inorganic binder such as pure water (or ion exchange water), alcohol, lithium silicate, and dispersed if necessary. Examples thereof include an additive such as an agent, have a photocatalytic activity as a coating film, and exhibit a self-cleaning effect. As a method for forming an antifouling coating film using such a paint, the present applicant discloses in Japanese Patent Application Laid-Open No. 2001-162217.
[0013]
The organic film effective to be protected by the protective coating according to the present invention includes all organic films in which the coating film is affected by the photocatalytic activity when the coating having photocatalytic activity is applied as it is.
[0014]
Various synthetic resin moldings such as alkyd resin, polyurethane resin, vinyl chloride resin, vinylidene chloride resin, vinyl acetate resin, ethylene-vinyl acetate copolymer resin, and other various thermoplastic resins, acrylic resin, epoxy resin, phenol resin An organic film on the surface of a molded product obtained by molding various thermosetting resins such as urea resin and fluororesin by a conventionally known method such as injection molding can be exemplified.
[0015]
Moreover, the coating film by the coating material which uses organic synthetic resin as a binder of various water-soluble, emulsion, oil-based (solvent) can be illustrated. Specifically, acrylic resin, alkyd resin, polyurethane resin, epoxy resin, vinyl chloride resin, vinylidene chloride resin, ethylene-vinyl acetate copolymer resin, phenol resin, urea resin, fluororesin, etc., can be used alone or in combination. It is a membrane.
[0016]
When applying the protective paint according to the present invention on the organic film to be protected, it removes contaminants such as dust and dirt existing on the surface of the organic film to make it clean, and brush painting, roller painting, spray painting It coats by the conventionally well-known painting methods, such as. First invention, be any protective coating of the second invention, the coating amount, 50 g / m ² to 200 g / m ² are suitable. If it is less than 50 g / m ^2, it cannot be sufficiently protected from the photoactive effect of the photocatalyst paint to be laminated, and there is a possibility of causing coating film defects such as choking on the surface of the organic film. Even if it is applied in excess of 200 g / m ² , the protective effect is not proportionally increased, and the cost increases, which is economically disadvantageous.
[0017]
After applying the protective coating of the present invention, it is dried and cured at room temperature until it is dried to form a protective clear coating film. The drying time varies depending on the temperature, humidity, wind speed, weather, etc. in the coating environment, but under an average weather condition around 20 ° C., a curing time of 2 hours is required. It is sufficient to dry and form a clear coating. However, if the photocatalytic coating is applied before the coating is formed, the components of the photocatalytic coating may migrate into the protective coating and attack the organic film. There is. In addition, there is no limitation in particular also about the coating method of the photocatalyst coating apply | coated on a protective clear coating film, Brush coating, roller coating, spray coating, etc. can be used.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
In order to provide an understanding of the present invention, examples are described below. Needless to say, the present invention is not limited to the following examples.
[0019]
[Example 1]
Three parts were selected as the objects to be coated: (1) polyurethane resin molded product, (2) outdoor wall painted with acrylic resin emulsion, and (3) outdoor floor painted with solvent-based epoxy resin. The surface was cleaned, and the protective coating 1 according to the first invention obtained by blending 77% by mass of PA sol, 0.5% by mass of lithium silicate, and 22.5% by mass of ethyl alcohol was applied to each by 50 g / m ² using a roller. did. Curing and drying were performed for 2 hours at 20 ° C. to obtain a clear protective coating film 1. On the clear protective coating film 1, a photocatalyst coating comprising 60% by mass of PA sol, 20% by mass of ion-exchanged water, 10% by mass of methyl alcohol, 8% by mass of lithium silicate, and 2% by mass of additive is applied by a roller at 80 g / m ^2. Applied. Curing drying was carried out at 20 ° C. for 2 hours to obtain a clear coating film 1 having photocatalytic activity.
Leave the objects to be coated (1) to (3) outdoors for 6 months with visible light and rain. After 6 months, check the surface of the organic film on each object to be stained and check for coating defects such as choking. Observed.
[0020]
[Example 2]
The surface of each part was cleaned on the same object to be coated as in Example 1 and obtained by blending 77% by mass of PTA solution, 10% by mass of ion-exchanged water, 3% by mass of lithium silicate, and 10% by mass of ethyl alcohol, respectively. 2 Protective paint 2 according to the invention was applied at 50 g / m ² with a roller. Curing drying was performed at 20 ° C. for 2 hours to obtain a clear protective coating film 2. On the clear protective coating film 2, a photocatalyst paint comprising 60% by mass of PA sol, 20% by mass of ion-exchanged water, 10% by mass of methyl alcohol, 8% by mass of lithium silicate, and 2% by mass of additive is applied by a roller at 80 g / m ^2. Applied. Curing and drying were performed at 20 ° C. for 2 hours to obtain a clear coating film 2 having photocatalytic activity.
The objects to be coated (1) to (3) are allowed to stand outdoors for 6 months with visible light and rain, and after 6 months, the film on the clear film of each object to be coated, the film such as choking on the organic film, etc. The presence or absence of defects was observed.
[0021]
【Test results】
In the protective coatings (1) to (3), both the first and second examples exhibited the antifouling effect by the photocatalyst, and the dirt on the surface was washed away by the rain. In addition, the organic film and the organic coating film of each object were not choking and other coating film defects, and maintained a beautiful state.
[0022]
【The invention's effect】
According to the organic film protective paint and its construction method according to the present invention, conventionally, when a photocatalyst paint having a photocatalytic effect was applied, the effect could erode the original coating film, and thus various coatings were impossible. It is also possible to form a photocatalytic coating film on an organic film made of the above resin or a coating film made of a synthetic resin paint using an organic synthetic resin as a main binder component. The coating that protects the organic film from the photocatalytic action and the coating that exhibits the photocatalytic action are all clear films, so the original organic film to be protected, the primary color, pattern, texture, etc. of the organic coating It is possible to add a self-cleaning effect in a form that makes full use of the above.

Claims (1)

A paint that is applied between various existing organic coatings or between an organic resin surface and a photocatalytic coating, and is obtained by reacting 70% by mass or more of a peroxo-modified anatase sol with alcohol in the presence of lithium silicate. An organic film protective paint characterized by being a clear paint that forms an inorganic coating film by drying at room temperature.