JP2007098192A - Coating film layered product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating film layered product which enhances the fouling resistance of the surface of a coating film while retaining the texture of a matte coating film. <P>SOLUTION: A covering layer is provided on the surface of the matte coating film in a state for the matte coating film to be visible. The covering layer uses a resin component and silica sol of which the average primary particle size is 1-200 nm as indispensable ingredients wherein the resin component is a mixture of two or more resins which are substantially incompatible with each other. The covering layer is formed by a covering liquid of which the solid content ratio of the resin component and the silica sol is 100:50-100:500 and the amount of the coating of the covering layer is 0.1-50 g/m<SP>2</SP>as a solid content. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a coating film laminate used as a surface makeup for buildings, civil engineering structures, and the like.

  2. Description of the Related Art Conventionally, various gloss grades have been provided as surface cosmetic paints for buildings and civil engineering structures. Among these, paints capable of forming a matte coating film have been gaining popularity in recent years because they provide a calm and unique texture.

  As the matte paint, paints defined in JIS K5663 “Synthetic resin emulsion paint” are generally used. In addition, architectural finish coating materials specified in JIS A6909, for example, thin finish coating materials such as ricin paint, thick finish coating materials such as stucco paint, other stone finish finish coating materials, sandstone finish finish coating materials, etc. Some of them have a matte appearance, and are widely used as thick film type materials capable of forming an uneven pattern.

  Incidentally, in recent years, in urban areas and the like, oily pollutants and the like are floating in the atmosphere due to exhaust gas from automobiles and the like. Even in the matte paint as described above, these contaminants may be deposited on the surface of the coating film, resulting in a loss of aesthetics.

As an antifouling treatment agent applicable to the coating film surface, Patent Document 1 describes a composition comprising a resin, an oxide sol organic solvent, and water.
However, when the antifouling agent as disclosed in Patent Document 1 is applied to the matte coating film, the finish may be different from the initial glossy state. In addition, a phenomenon that the hue of the coating film changes to black, that is, a so-called wet color may occur. Furthermore, interference unevenness in which a part of the film has a rainbow color may occur. As described above, the antifouling agent as disclosed in Patent Document 1 has a problem that the texture of the original matte coating film is easily impaired. In the first place, such an antifouling agent is designed as a material for a glossy coating film such as a coating film on an automobile outer plate, and it is not assumed that the object is a matte coating film.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to improve the stain resistance of the coating film surface while maintaining the texture of the matte coating film.

WO99 / 54414

  As a result of intensive studies to achieve the above object, the present inventor obtained a coating layered product provided with a specific coating layer mainly composed of a specific resin component and silica on the surface of the matte coating layer. The present invention has been conceived and the present invention has been completed.

That is, the present invention has the following characteristics.
1. In the coating film laminate in which the coating layer is provided on the surface of the matting coating layer in a state where the matting coating layer is visible,
The coating layer includes a resin component and silica sol having an average primary particle size of 1 to 200 nm as essential components,
A mixture of two or more resins in which the resin components are substantially incompatible with each other;
The resin component and the silica sol are formed by a coating liquid having a solid content ratio of 100: 50 to 100: 500,
The coating amount of the coating layer is 0.1 to 50 g / m ² in terms of solid content.
2. The silica sol is a water-dispersible silica sol having a pH of 5.0 or more and less than 8.5. The coating film laminated body of description.

  ADVANTAGE OF THE INVENTION According to this invention, the stain resistance of the coating-film surface can be improved, maintaining the texture of a matt coating film.

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

  The coating film laminate of the present invention has a coating layer provided on the surface of a matte coating film layer, and is mainly exposed to surface cosmetics such as buildings and civil engineering structures, particularly in the rain and sunlight. It can be preferably applied to cosmetics for exterior surfaces.

  Of these, the matte coating layer is formed of a matte paint. Examples of such matte paints include paints defined in JIS K5663 “Synthetic Resin Emulsion Paint”. This type of paint is commonly referred to as a flat paint. Other matte paints include thin finish coating materials such as lysine paints, thick finish paints such as stucco paints, etc. as defined in JIS A6909, other stone finish finishes, sandstone finish finishes, etc. There are various finishing coating materials for buildings. Such a building finish coating material can be used as a thick film type material capable of forming an uneven pattern.

The matte paint film layer can be formed by applying and drying a matte paint on the surface of a base material such as a building or a civil engineering structure. The matte paint film layer may exist in advance as an old paint film on the surface of a base material such as a building or a civil engineering structure.
The degree of “matte” in the matte coating layer can be defined by its specular gloss. The specular gloss (measuring angle 60 degrees) of the matte coating layer is usually 20 or less, preferably 15 or less, more preferably 10 or less.

  The coating film laminate of the present invention has a coating layer provided on the surface of the matte coating layer described above. This coating layer is provided in a state where the matte coating layer is visible. That is, the hue and concavo-convex pattern of the matte coating film hardly change regardless of the presence or absence of the coating layer.

The coating layer in the present invention is formed by a coating solution containing a resin component and silica sol having an average primary particle diameter of 1 to 200 nm as essential components.
Among these, as the resin component, a mixture of two or more kinds of resins that are substantially incompatible with each other is used. In the present invention, by using such a resin mixture of two or more kinds, it is possible to suppress the occurrence of bottom gloss, wet color, interference unevenness, etc., and maintain the texture of the matte coating film.
In the present invention, “two or more types of resins that are substantially incompatible with each other” means that the formed film made of the resin mixture is translucent. As such a semi-transparent film, those having a concealment ratio of 0.08 to 0.90 (preferably 0.08 to 0.80, more preferably 0.10 to 0.60) are suitable. In addition, the concealment rate said here is a value measured according to JIS K5663 5.8 (however, a dry film thickness is 80 micrometers).

  As the resin component in the coating liquid, in particular, two or more kinds of resins having a refractive index difference of 0.01 or more (preferably 0.02 or more, more preferably 0.03 or more, and further preferably 0.05 or more). It is desirable to include. The use of a plurality of resins having different refractive indexes is advantageous in terms of maintaining the texture of the matte coating film. The refractive index in the present invention is a value measured using an Abbe refractometer (light wavelength: 589 nm, measurement temperature: 20 ° C.).

Specifically, the resin component includes cellulose, polyvinyl alcohol, ethylene resin, polyester resin, epoxy resin, polyamine, polyol, polycarbonate, alkyd resin, melamine resin, vinyl chloride resin, vinyl acetate resin, acrylic resin, urethane resin, acrylic resin. Silicon resin, silicon resin, fluororesin, etc., or a composite system thereof can be used. In the present invention, a combination satisfying the above-mentioned conditions is selected from these resins and used. In the present invention, a large number of three or more types of resins can be used, but it is desirable to use a combination of two types of resins in consideration of production efficiency and the like. The mixing ratio of the resin is not particularly limited as long as it satisfies the above-mentioned conditions, but when two kinds of resins are used, the solid content weight ratio is usually 98: 2 to 2:98, preferably 95: 5. ~ 5: 95.
In addition, as the resin component, a resin having crosslinking reactivity may be included. When a resin having crosslinking reactivity is used, the water resistance, weather resistance, chemical resistance, etc. of the coating can be improved. Moreover, as a form of the resin component, a water-soluble resin and / or a water-dispersed resin (resin emulsion) is preferable. These resin components may be a one-component type or a multi-component type in which two or more components are mixed at the time of use, but a one-component type is desirable in terms of coating workability.

The silica sol in the coating liquid is a component that contributes to the improvement of stain resistance by the action of polar groups such as silanol groups.
The average primary particle diameter of the silica sol is usually 1 to 200 nm, preferably 5 to 100 nm. Within this range, a plurality of silica sols having different average primary particle sizes can be used in combination. When the average primary particle diameter of the silica sol is larger than 200 nm, the specific surface area becomes small and silanol groups are reduced, so that the stain resistance is insufficient. When the average primary particle size is smaller than 1 nm, the silica sol itself becomes unstable, so that it is not practical. In addition, the average primary particle diameter said here is a value measured by the light-scattering method.

  As the silica sol, a water-dispersible silica sol having a pH of 5.0 or more and less than 8.5 (preferably 6.0 or more and 8.0 or less) is suitable. The silica sol prepared at such pH can exhibit an excellent antifouling effect due to abundant silanol groups on the particle surface. Moreover, the aqueous coating liquid which hardly contains an organic solvent can be obtained by the combination of water-soluble resin and / or water-dispersible resin, and water-dispersible silica sol.

  Such a neutral type water-dispersible silica sol can be produced using a silicate compound as a raw material. Examples of the silicate compound include tetramethoxysilane, tetraethoxysilane, tetra n-propoxysilane, tetraisopropoxysilane, tetra n-butoxysilane, tetraisobutoxysilane, tetra sec-butoxysilane, tetra t-butoxysilane, tetra Examples thereof include phenoxysilane and the condensates thereof. In addition, alkoxysilane compounds other than the above silicate compounds, alcohols, glycols, glycol ethers, fluorine alcohols, silane coupling agents, polyoxyalkylene group-containing compounds, and the like can also be used. As the medium of the water-dispersible silica sol, water and / or a water-soluble solvent can be used. Examples of the water-soluble solvent include alcohols, glycols, glycol ethers and the like.

  The solid content weight ratio of the resin component and the silica sol in the coating liquid is usually 100: 50 to 100: 500 (preferably 100: 80 to 100: 400, more preferably 100: 100 to 100: 300). Within such a range, excellent antifouling performance can be obtained. When there is too little silica in this solid content ratio, a sufficient effect cannot be obtained in terms of stain resistance. When there is too much silica, the silica of the coating layer may be detached over time, and the anti-staining effect may be impaired. Further, cracks are likely to occur in the coating layer.

Components other than the resin component and silica sol can be appropriately mixed in the coating liquid for forming the coating layer. Such components include, for example, thickeners, leveling agents, wetting agents, plasticizers, film-forming aids, antifreezing agents, pH adjusting agents, preservatives, antifungal agents, antialgae agents, antibacterial agents, dispersions Agents, antifoaming agents, ultraviolet absorbers, antioxidants, catalysts, crosslinking agents and the like.
The solid content concentration of the coating liquid is usually set to 10% by weight or less (preferably 5% by weight or less, more preferably 3% by weight or less). Further, the pH of the coating liquid is desirably set to pH 5.0 or more and less than 8.5 (preferably 6.5 or more and 8.0 or less). If the solid content concentration and pH of the coating liquid are set within such ranges, it is advantageous in terms of the stability of the coating liquid.

When forming the coating layer with the coating liquid, coating means such as spray coating, brush coating, roller coating, etc. can be appropriately employed.
The coating amount of the coating layer is 0.1 to 50 g / m ² (preferably 0.5 to 20 g / m ² ) in terms of solid content. When the coating amount is less than 0.1 g / m ^{2, the} effect of improving the stain resistance is not obtained, and when it is more than 50 g / m ² , the fine unevenness on the matte coating surface is flattened, The texture of the matte paint film is easily damaged. In addition, since the coating layer in the present invention does not cause defects such as uneven gloss even if the coating amount varies slightly within the above range, the efficiency of the coating operation can be improved.

  Examples are given below to clarify the features of the present invention.

(Aqueous coating solution A)
Urethane resin emulsion (solid content 30 wt%, refractive index 1.441) and acrylic resin emulsion (solid content 50 wt%, refractive index 1.492) were mixed so that the solid content weight ratio was 58:42. . The concealment ratio of this resin mixture was 0.11 (dry film thickness 80 μm). Next, this resin mixture and a water-dispersible silica sol (pH 7.6, solid content 20% by weight, average primary particle size 27 nm) are mixed so that the solid content weight ratio is 100: 125, and water is added thereto to form a solid. An aqueous coating solution A having a content of 2% by weight and a pH of 7.1 was prepared.

(Aqueous coating solution B)
Acrylic resin emulsion (solid content 50 wt%, refractive index 1.492) and water-dispersible silica sol (pH 7.6, solid content 20 wt%, average primary particle size 27 nm) so that the solid content weight ratio is 100: 125. And water was added thereto to prepare an aqueous coating solution B having a solid content of 2% by weight and a pH of 7.2. In addition, the concealment rate of the acrylic resin emulsion used for the aqueous coating liquid B was 0.05 (dry film thickness 80 μm).

(Test Example 1)
40 parts by weight of titanium oxide dispersion (solid content 70% by weight), 160 parts by weight of heavy calcium carbonate (average particle size 8 μm), 200 ml by weight of acrylic resin emulsion (solid content 50% by weight) A matte paint was prepared by uniformly mixing 270 parts by weight (diameter 200 μm), 16 parts by weight of a film-forming aid, 5 parts by weight of a thickener, and 5 parts by weight of an antifoaming agent by a conventional method. The matte paint obtained by the above method is applied to a slate plate that has been subjected to a sealer treatment in advance so that the coating amount (solid content) is 800 g / m ^2, and the standard state (temperature 23 ° C., relative humidity) (50%) for 48 hours to form a white matte coating. The specular gloss of this matte coating film was 1.6.
Further, after adding 3% by weight of carbon black dispersion (solid content 20% by weight) to the matte paint, coating was performed in the same manner to form a gray matte coating film. The specular gloss of this matte coating film was 1.9.

Each matte coating film obtained by the above method was spray-coated with the aqueous coating solution A so that the coating amount (solid content) was 3 g / m ² and dried in a standard state for 24 hours. As a result of confirming the finished state of each specimen thus obtained, no difference from the matte coating was observed in the gloss / color state and overall texture.
Next, the white specimen was exposed outdoors at an angle of 45 degrees southward in Ibaraki City, Osaka Prefecture, and the appearance after 3 months was confirmed. As a result, the change in whiteness (ΔL) in the test specimen to which the aqueous coating liquid A was applied was -1.0. In addition, when the same test was done about the test body which formed only the matte coating film, that (DELTA) L was -4.5.

(Test Example 2)
A test specimen was prepared in the same manner as in Test Example 1 except that the aqueous coating liquid B was used instead of the aqueous coating liquid A. When the finished state was confirmed, generation of bottom gloss and wet color was observed. ΔL in the outdoor exposure test was −1.2.

Claims (2)

In the coating film laminate in which the coating layer is provided on the surface of the matting coating layer in a state where the matting coating layer is visible,
The coating layer includes a resin component and silica sol having an average primary particle size of 1 to 200 nm as essential components,
A mixture of two or more resins in which the resin components are substantially incompatible with each other;
The resin component and the silica sol are formed by a coating liquid having a solid content ratio of 100: 50 to 100: 500,
The coating amount of the coating layer is 0.1 to 50 g / m ² in terms of solid content.   The coating film laminate according to claim 1, wherein the silica sol is a water-dispersible silica sol having a pH of 5.0 or more and less than 8.5.