JP2019209222A - Coated film formation method - Google Patents

Abstract

To provide a coated film formation method that can suppress progress of deterioration such as color change and crack due to an existing coated film and a joint filler while using uneven patterns and multicolor patterns of the existing coated film and hold aesthetic property over a long time.SOLUTION: A coating material with visible light permeability is applied to a surface to be coated in which a plurality of plate-like base materials having existing coating surfaces are provided in parallel and joint fillers are charged into connection parts between the plate-like base materials to form a new coated film after joint processing materials are applied to surfaces of the joint fillers to form processed coated films. The coating materials for use each contains resin components including 20 weight% or more of (meth) acrylic acid alkyl ester (A) having an alkyl group having three or more carbons in resin constituting component and forms a coated film with ultraviolet permeability of 30% or less.SELECTED DRAWING: None

Description

  The present invention relates to a novel film forming method.

  Conventionally, in exteriors of buildings and civil engineering structures, coatings are formed on various base materials with various coating materials for the purpose of protecting the base materials and imparting colors. Such a coated surface may be provided with a concavo-convex pattern or a multicolor pattern from the viewpoint of aesthetics or the like. However, when such a coating surface is exposed outdoors for a long time, it tends to deteriorate due to the influence of sunlight, rainfall, and the like. Specifically, there is a risk of discoloration, cracking, and the like. Therefore, it is necessary to repaint the coating surface (existing coating surface) on which such deterioration has occurred.

  On the other hand, in recent years, there is a movement to repaint the existing coating surface to improve aesthetics and extend the life of the substrate. For example, Patent Document 1 describes a method of restoring the original color tone by polishing a deteriorated portion on the surface of a coating layer of a ceramic industry outer wall material and then applying a transparent coating agent.

JP 2001-227138 A

  By the way, about the thing which has an uneven pattern among the above-mentioned existing coating surfaces, according to uneven shape etc., the way of sunlight, the way of flowing water, the degree of staying, etc. are partially different. Become. Therefore, in a portion where the load due to sunlight or water is large, the deterioration is likely to proceed, and there is a possibility that local discoloration, cracking, or the like is caused. On the coated surface having a multicolor pattern, when there is a difference in durability depending on the color tone, there is a possibility that the same deterioration may occur in a color tone region where the durability is relatively insufficient. Moreover, when the existing coating surface is provided in plate-shaped base materials, such as a ceramics-type exterior material, there exists a possibility that degradation may arise due to the joint material between plate-shaped base materials.

  For such an existing coating surface, even if it is repainted by the method described in the above-mentioned patent document, the progress of the deterioration of the existing coating surface cannot be sufficiently suppressed, and it is caused by the joint material. Then, there is a possibility that the deterioration proceeds, and it may be difficult to obtain the effect of repainting.

  The present invention has been made in view of such problems, and a plurality of plate-like base materials having existing coating surfaces are provided side by side, and a joint surface is formed by filling a joint material between the plate-like base materials. A film forming method is provided. In other words, for such coated surfaces, while taking advantage of the uneven pattern and multicolor pattern of the existing coating, it suppresses the progress of deterioration such as discoloration and cracking caused by the existing coating and joint material, and maintains aesthetics for a long time. It is an object of the present invention to provide a film forming method that can be used.

  In order to solve such a problem, the present inventor, as a result of diligent investigation, applied a specific coating material to the entire coated surface after processing the connecting portion on the coated surface as described above. Thus, the inventors have conceived a film forming method for forming a film, and have completed the present invention.

That is, the present invention has the following characteristics.
1. A plurality of plate-like base materials having an existing coating surface are provided, and a method for forming a coating on a surface to be coated, in which joints between the plate-like base materials are filled with joint material,
After the step of applying a joint treatment material to the surface of the joint material to form a treatment film,
A process of forming a new coating by applying a coating material having visible light permeability to the surface to be coated,
The existing coating surface has a concavo-convex pattern and / or a multicolor pattern,
The covering material is
A resin component containing 20% by weight or more of (meth) acrylic acid alkyl ester (A) having an alkyl group having 3 or more carbon atoms in the resin component is formed, and a film having an ultraviolet transmittance of 30% or less is formed. What is claimed is: 1. A method for forming a film, comprising:
2. A plurality of plate-like base materials having an existing coating surface are provided, and a method for forming a coating on a surface to be coated, in which joints between the plate-like base materials are filled with joint material,
After the step of applying a joint treatment material to the surface of the joint material to form a treatment film,
A step of applying a first coating material having a visible light transmission property and a second coating material having a visible light transmission property to form a new coating on the coated surface,
The existing coating surface has a concavo-convex pattern and / or a multicolor pattern,
The first covering material and the second covering material are respectively
A resin component containing 20% by weight or more of (meth) acrylic acid alkyl ester (A) having an alkyl group having 3 or more carbon atoms in the resin component is formed, and a film having an ultraviolet transmittance of 30% or less is formed. What is claimed is: 1. A method for forming a film, comprising:
3. The first covering material and the second covering material are respectively
The (meth) acrylic acid alkyl ester (A) having an alkyl group having 3 or more carbon atoms includes a (meth) acrylic acid alkyl ester (a1) having an alkyl main chain having 3 or more carbon atoms,
When the weight ratio of the component (a1) in the component (A) is r,
1. r (r ₁ ) in the first covering material is larger than r (r ₂ ) in the second covering material. The film formation method of description.
4). 1. The film thickness of the new coating is 30 μm or more. ~ 3. The film forming method according to any one of the above.

  According to the film forming method of the present invention, while making use of the uneven pattern and multicolor pattern of the existing film, the progress of deterioration such as discoloration and cracking caused by the existing film and joint material is suppressed, and the aesthetics are maintained for a long period of time. be able to.

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

  In the present invention, a plurality of plate-like base materials having an existing coating surface (existing coating surface having a concavo-convex pattern and / or a multicolor pattern) are provided side by side, and a joint material is filled in a connecting portion between the plate-like substrates. This is a film forming method in which a specific coating material is applied to the surface to be coated and then a specific coating material is applied to form a new coating film.

  Even if the surface to be coated is repainted with a conventional transparent coating agent, it is difficult to suppress the progression of discoloration, cracks, etc. at the parts that are inherently deteriorated. There is also a possibility that fine cracks generated on the surface may progress with time. Such cracks easily spread to the coating after repainting, so that the aesthetics and water shielding properties of the new coating are impaired, and it is difficult to obtain a sufficient effect in terms of extending the life of the substrate.

  On the other hand, in the present invention, while making use of the uneven pattern and multicolor pattern on the existing coating surface, the progress of deterioration such as discoloration and cracking caused by the existing coating surface and joint material is suppressed, and aesthetics are maintained over a long period of time. It is possible to extend the life of the base material. Such an effect is considered to be exerted, for example, by sufficiently imparting resistance to sunlight and water by the specific new coating of the present invention.

  In the present invention, a plurality of plate-like substrates having existing coating surfaces are provided side by side, and a coated surface in which joints between the plate-like substrates are filled with a joint material is to be coated. Such coated surfaces include, for example, those formed on the surface of buildings, civil engineering structures, etc., especially on exterior surfaces (outer walls, roofs, etc.) that are easily affected by sunlight, water, etc. Those formed are preferred.

  Examples of the plate-like substrate include cement board, extrusion molded board, slate board, PC board, ALC board, fiber reinforced cement board, metal siding board, ceramic siding board, ceramic board, calcium silicate board, plastic board, Hard wood piece cement board, PVC extrusion siding board, plywood and the like.

  A plurality of such plate-like base materials are provided on the coated surface. And the joint part between plate-shaped base materials is filled with joint materials, such as a sealing material and a dry-type joint material. Among these, as the sealing material, for example, silicone-based sealing material, modified silicone-based sealing material, polysulfide-based sealing material, modified polysulfide-based sealing material, acrylic urethane-based sealing material, polyurethane-based sealing material, SBR-based sealing material, butyl rubber-based A sealing material etc. are mentioned. Examples of the dry joint material include molded articles of synthetic rubber such as chlorinated polyethylene and EPDM (ethylene / propylene / diene rubber). The width of the connecting portion is preferably 3 to 20 mm, more preferably 5 to 15 mm.

  The existing coating surface on the plate-like substrate has a concavo-convex pattern and / or a multicolor pattern. Such an existing film is formed by one or more coating agents. Various coating agents such as colored or non-colored, opaque or transparent can be used as the coating agent. For example, vinyl acetate resin, alkyd resin, epoxy resin, acrylic resin, urethane resin, acrylic silicon resin, silicon resin, fluorine resin And those containing one or more resins selected from the above. The existing coating surface is a coating of one layer or two or more layers, and for example, a colored coating layer, a transparent coating layer or the like may be laminated thereon.

  Examples of uneven patterns include tile-like patterns, brick-like patterns, stone-like patterns, rock-like patterns, wood-tone patterns, geometric patterns, striped patterns, lattice patterns, polka dot patterns, sand wall patterns In addition to Yuzu skin pattern, ripple pattern, etc., there are graphic patterns designed for animals and plants. Specifically, examples of the shape of the convex portion when the concavo-convex pattern is viewed from the front include shapes such as a square, a rectangle, a circle, an ellipse, a triangle, a rhombus, a polygon, and an indefinite shape. Moreover, as a cross-sectional shape of the convex part in a concavo-convex pattern, a trapezoid, a square, a rectangle, a semicircle, a waveform, a staircase shape, a triangle, a mountain shape, an indefinite shape etc. are mentioned, for example. The recesses in the concavo-convex pattern may be flat and form joints. Although the height difference between the concave portion and the convex portion may be constant or different in each portion, it is preferably 20 mm or less, more preferably about 1 to 15 mm. Such a concavo-convex pattern should just be attached | subjected to any one or both of a plate-shaped base material and an existing film.

  A multicolor pattern is a pattern in which at least two or more colors are visible and mixed, for example, a pattern in which spots of two or more colors are mixed, and spots (one color or two or more colors) are scattered on the background color. Patterns to be painted in two or more colors (for example, island patterns, line patterns, tile patterns, brick patterns, stone patterns, rock patterns, wood patterns, geometric patterns, stripes Pattern, lattice pattern, random pattern, etc.). Such a multicolor pattern may be formed by, for example, various printing techniques (inkjet printing or the like), or formed by a decorative coating agent such as a stone finish finishing coating material or a multicolored paint. It may be.

  The present invention can be preferably applied as a repainting method (remodeling method) when the surface to be coated has deteriorated over time. The degree of aging deterioration is not particularly limited, but those used as wall surfaces for about 5 years or more (more preferably 8 years or more) are suitable as the object of the present invention. Prior to the formation of the treatment film or the new coating film, various treatments such as washing and partial repair can be performed on the joints and / or the existing film surface as necessary. The existing joint material may be left as it is for the connecting portion between the plate-like base materials, but a new joint material can be placed before the new coating is formed.

  In the present invention, the treated film is formed by applying the joint treatment material to the above-described connecting portion, that is, the surface of the joint material. Thereby, it is possible to suppress the progress of deterioration such as discoloration and cracks caused by the joint material. As the joint treatment material, those having properties such as adhesion to the joint material and the covering material and elasticity capable of following the displacement of the joint material are preferable. Furthermore, what has the intensity | strength which relaxes the displacement of a joint part, having such a performance is more preferable. Such a joint treatment material is advantageous in terms of suppressing cracks in the new coating. When the joint material contains a plasticizer, the use of a joint treatment material having a plasticizer migration preventing effect is advantageous in suppressing discoloration (for example, discoloration due to contamination, etc.) of the new coating. As the joint treatment material, one or more kinds having such performance can be used.

  The joint treatment material desirably contains a resin component. Examples of the form of such a resin component include water-soluble resins, water-dispersible resins, solvent-soluble resins, solvent-free resins, non-water-dispersed resins, and composites thereof. Among these, the water-dispersible resin can be produced by a one-stage to multi-stage (two-stage or three-stage or more) emulsion polymerization method or the like. These may have cross-linking reactivity, and may be either one-component type or two-component type. Examples of the resin component include acrylic resins, urethane resins, epoxy resins, silicone resins, polyolefins, chlorinated polyolefins, and composites thereof (for example, acrylic urethane resins and acrylic silicone resins). These can be used alone or in combination of two or more. Among these, acrylic resins, silicone resins, acrylic silicone resins, and the like are preferable.

  The joint treatment material may contain various components other than the resin component. Examples of such components include coloring pigments, extender pigments, thickeners, film-forming aids, silane coupling agents, leveling agents, wetting agents, plasticizers, antifreezing agents, pH adjusting agents, preservatives, Examples include glazes, anti-algae agents, antibacterial agents, dispersants, antifoaming agents, adsorbents, fibers, cross-linking agents, curing agents, ultraviolet absorbers, antioxidants, and catalysts. As an example of a suitable joint treatment material, for example, a material containing a coloring pigment, a silane coupling agent and the like in addition to the above resin component can be cited. The color tone of the joint treatment material can be appropriately set depending on the type, combination, mixing amount, and the like of the color pigment.

  In the present invention, a treated film is formed by applying and drying such a joint treatment material on the surface of the joint material. When applying the joint treatment material to the surface of the joint material, for example, a known applicator such as a brush, a roller, or a spray can be used. The joint treatment material can be appropriately diluted as necessary.

The joint treatment material is desirably applied so as to cover at least the surface of the joint material, and may be applied over the vicinity of the joint material. The application width of the joint treatment material is preferably 1 to 5 times the width of the connecting portion filled with the joint material, but may be applied widely over the surface of the plate-like substrate as necessary. The coating amount of the joint treatment material is preferably 0.01 to 0.4 kg / m ² , more preferably 0.05 to 0.3 kg / m ² . When a new sealing material is cast as the joint material, it is desirable to apply the joint treatment material after two or more days have passed since the sealing material was filled.

  Drying after applying the joint treatment material may be performed at room temperature (preferably 0 to 50 ° C., more preferably 5 to 45 ° C.), and heating may be performed as necessary. After the treatment film formed of the joint treatment material is dried, the next step can be performed.

  In the present invention, after the above step, a coating film having visible light permeability is applied to the surface to be coated to form a new coating. Such a coating material is a resin containing 20% by weight or more of (meth) acrylic acid alkyl ester (A) (hereinafter also referred to as “component (A)”) having an alkyl group having 3 or more carbon atoms in the resin component. Contains ingredients. And the film which has visible light transmittance | permeability and whose ultraviolet transmittance is 30% or less is formed.

  The resin component in the coating material acts as a binder, and the component (A) can mainly impart resistance to water. In addition, in this invention, acrylic acid alkylester and methacrylic acid alkylester are collectively described as (meth) acrylic acid alkylester.

  Examples of the form of the alkyl group in component (A) include linear, branched, and cyclic. Examples of the component (A) include n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, N-pentyl (meth) acrylate, isopentyl (meth) acrylate, neopentyl (meth) acrylate, t-pentyl (meth) acrylate, 1-ethylpropyl (meth) acrylate, 2-methylbutyl (meth) acrylate , 3-methylbutyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylbutyl (meth) acrylate, 2-methylpentyl (meth) acrylate, (meth) acrylic acid 4-methylpentyl, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, (meth ) Isooctyl acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, n-decyl (meth) acrylate, n-undecyl (meth) acrylate, n-lauryl (meth) acrylate, etc. Is mentioned. These can be used alone or in combination of two or more. Among these, as (A) component, what has a C4 or more (more preferably 4 or more and 8 or less) alkyl group is suitable.

  The ratio of the component (A) in the resin component is 20% by weight or more, preferably 25 to 99% by weight, more preferably 30 to 98% by weight. If (A) component is the said ratio, the tolerance with respect to water, etc. can be improved, and it becomes possible to acquire effects, such as discoloration, the suppression of deterioration, such as a crack, and aesthetics maintenance. In the present invention, “α to β” has the same meaning as “α to β”.

  In the coating material of the present invention, the (meth) acrylic acid alkyl ester (a1) (hereinafter also referred to as “(a1) component”) having an alkyl main chain having 3 or more carbon atoms is used as the component (A) in the resin component. It is preferable to include. As such (a1) component, the alkyl part is a linear or branched alkyl group (excluding cyclic), and the main chain (longest carbon straight chain) has 3 or more carbon atoms. Some can be used. If the resin component contains the component (a1), in addition to the resistance to water, the crack prevention property can be further enhanced, and it is more preferable in terms of water shielding, aesthetic retention, and longer life of the substrate. .

  The component (a1) has an alkyl main chain having 3 or more carbon atoms in the alkyl portion. The alkyl part of the component (a1) may have various side chains (for example, an alkyl group having fewer carbon atoms than the alkyl main chain) as long as it has such an alkyl main chain. As the component (a1), among the above-described component (A), those satisfying such conditions can be used. For example, n-propyl (meth) acrylate, isobutyl (meth) acrylate, (meth) acrylic acid 1-ethylpropyl, (meth) acrylic acid t-pentyl, (meth) acrylic acid neopentyl, (meth) acrylic acid n-butyl, (meth) acrylic acid 2-methylbutyl, (meth) acrylic acid isopentyl, (meth) acrylic 3-methylbutyl acid, 2-ethylbutyl (meth) acrylate, n-pentyl (meth) acrylate, 2-methylpentyl (meth) acrylate, 4-methylpentyl (meth) acrylate, n- (meth) acrylate Hexyl, 2-ethylhexyl (meth) acrylate, n-heptyl (meth) acrylate, isooctyl (meth) acrylate (Meth) acrylic acid n- octyl, (meth) acrylic acid n- nonyl, (meth) acrylic acid n- decyl, (meth) acrylic acid n- undecyl, and (meth) n- lauryl acrylic acid. These can be used alone or in combination of two or more. Among these, as the component (a1), those having an alkyl main chain having 4 or more (more preferably 4 or more and 8 or less) carbon atoms in the alkyl moiety are suitable.

  Examples of the component (A) other than (a1) (hereinafter also referred to as “component (a2)”) include isopropyl (meth) acrylate, t-butyl (meth) acrylate, cyclohexyl (meth) acrylate, and the like. It is done. These can be used alone or in combination of two or more.

The weight ratio of the component (a1) in the component (A) can be expressed as “r”. This “r” is a value calculated by the following equation.
[Formula] r = {weight of component (a1) in resin component} / {weight of component (A) in resin component}

  As the resin component, other monomers (hereinafter also referred to as “component (B)”) excluding component (A) can be included. Examples of the component (B) include methyl (meth) acrylate, ethyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, a carboxyl group-containing monomer, an amino group-containing monomer, and a pyridine monomer. , Hydroxyl group-containing monomer, nitrile group-containing monomer, amide group-containing monomer, epoxy group-containing monomer, carbonyl group-containing monomer, alkoxysilyl group-containing monomer, fluorine-containing monomer, aromatic monomer, UV-absorbing group-containing monomer, photostable group Examples thereof include monomers. These can be used alone or in combination of two or more. The component ratio of the component (B) is preferably 80% by weight or less (more preferably 1 to 75% by weight, more preferably 2 to 70% by weight) in the resin component. In the present invention, the monomer is a compound having a polymerizable unsaturated double bond.

  In the present invention, an embodiment containing an ultraviolet absorbing group-containing monomer and / or a light-stable group-containing monomer as the component (B) is preferable from the viewpoint of improving the effect of the present invention. The UV-absorbing group-containing monomer is a compound having an UV-absorbing group and a polymerizable unsaturated double bond. Examples of the UV-absorbing group include benzophenone-based UV-absorbing groups, benzotriazole-based UV-absorbing groups, Examples include triazine-based ultraviolet absorbing groups and salicylate-based ultraviolet absorbing groups. The photostable group-containing monomer is a compound having a photostable group and a polymerizable unsaturated double bond, and examples of the photostable group include a piperidyl group.

  Such a resin component can be produced, for example, by polymerizing a monomer group including the component (A) (preferably including the component (a1)) and, if necessary, the component (B). Examples of the form of the resin component include water-soluble resins, water-dispersible resins, solvent-soluble resins, solvent-free resins, non-water-dispersed resins, and composites thereof. Among these, the water-dispersible resin can be produced by a one-stage to multi-stage (two-stage or three-stage or more) emulsion polymerization method or the like. These may have cross-linking reactivity, and may be either one-component type or two-component type.

  The coating material in this invention forms the film which has visible-light transmittance. Thereby, a film having transparency can be formed, and a finish utilizing the color tone (multicolor pattern or the like) of the existing film surface can be obtained. The visible light transmittance may be such that the existing coating surface can be visually recognized, and the coating may be colorless and transparent or colored and transparent. Any of the above may be used. The colored transparent film can be formed by, for example, a coating material containing a color pigment, a dye, or the like. The matte film can be formed by, for example, a covering material containing extender pigments, matting agents, and the like.

  The degree of visible light transmittance can be indicated by visible light transmittance. The visible light transmittance is preferably 30% or more, more preferably 35 to 100%, and still more preferably 40 to 95%. The visible light transmittance is a value obtained by measuring the transmittance of light having a wavelength of 580 nm with a spectrophotometer for a film having a thickness of 30 μm (the film having no film (air) has a transmittance of 100%). is there.

  In order to obtain such visible light transmittance, for example, the color pigment ratio in the coating material may be set low. The color pigment ratio in the coating material is preferably 10% by weight or less, more preferably 5% by weight or less, and still more preferably 0 to 3% by weight. An embodiment in which the coating material does not contain a color pigment is also suitable.

  The coating material in the present invention forms a film having an ultraviolet transmittance of 30% or less, preferably 20% or less, more preferably 0 to 15%. In the present invention, when the ultraviolet transmittance is within the above range, it is possible to increase the resistance to sunlight and the like, and it is possible to obtain effects such as suppression of deterioration such as discoloration and cracking, and maintaining aesthetics. The ultraviolet transmittance is a value obtained by measuring the transmittance of light having a wavelength of 350 nm with a spectrophotometer for a coating having a thickness of 30 μm (the transmittance is 100% in the case of no coating (air)). .

As a means for obtaining such ultraviolet transmittance, for example,
(1) A coating material containing a resin component having an ultraviolet absorbing group is used.
(2) A coating material containing an ultraviolet absorber is used.
(3) A coating material containing ultraviolet shielding powder is used.
Etc. These means may be employed alone or in combination.

  In the above (1), for example, a resin component containing an ultraviolet absorbing group-containing monomer may be used as the component (B). The ratio of the UV-absorbing group-containing monomer in the resin component is preferably 0.05 to 10% by weight, more preferably 0.1 to 5% by weight.

  Examples of the UV absorber (excluding compounds having a polymerizable unsaturated double bond) in (2) above include, for example, benzophenone UV absorbers, benzotriazole UV absorbers, triazine UV absorbers, and salicylate UV absorbers. Agents, cyanoacrylate UV absorbers, benzoate UV absorbers, malonic ester UV absorbers, oxalic anilide UV absorbers and the like. Among these, examples of the benzophenone-based ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, and 2-hydroxy-4-n. -Octoxybenzophenone, 2-hydroxy-4-n-dodecyloxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, bis (5-benzoyl-4-hydroxy-2-methoxyphenyl) methane, 2,2'-dihydroxy -4-methoxybenzophenone, 2,2'-dihydroxy-4,4'dimethoxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 2-hydroxy-4- Methoxy-2'- Carboxymethyl benzophenone, 2-hydroxy-4-stearyloxy benzophenone. Examples of the benzotriazole ultraviolet absorber include 2- (2-hydroxy-5-tert-butylphenyl) -2H-benzotriazole, 3- (2H-benzotriazol-2-yl) -5- (1,1 -Dimethylethyl) -4-hydroxyalkyl ester, 2- (2H-benzotriazol-2-yl) -4,6-bis (1-methyl-1-phenylethyl) phenol, 2- (2H-benzotriazole-2) -Yl) -6- (1-methyl-1-phenylethyl) -4- (1,1,3,3-tetramethylbutyl) phenol, methyl 3- (3- (2H-benzotriazol-2-yl) And a reaction product of -5-tert-butyl-4-hydroxyphenyl) propionate and polyethylene glycol. Examples of triazine-based ultraviolet absorbers include 2- (4,6-bis (2,4-dimethylphenyl) -1,3,5-triazin-2-yl) -5-hydroxyphenyl derivatives, 2- (2 , 4-Dihydroxyphenyl) -4,6-bis- (2,4-dimethylphenyl) -1,3,5-triazine and (2-ethylhexyl) -glycidic acid ester reaction product, 2,4-bis " 2-hydroxy-4-butoxyphenyl] -6- (2,4-dibutoxyphenyl) -1,3-5-triazine, etc. These may be used alone or in combination of two or more. The mixing ratio is preferably 0.05 to 10 parts by weight, more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the resin component.

  As the ultraviolet shielding powder in the above (3), those having the ability to absorb and / or reflect ultraviolet rays can be used. For example, alumina, zirconium oxide, barium sulfate, precipitated barium sulfate, calcium carbonate, magnesium carbonate, Aluminum hydroxide, Magnesium hydroxide, Titanium oxide, Magnesium oxide, Zinc oxide, Boron nitride, Bismuth oxychloride, Zinc phosphate, Mica, Cryolite, Talc, Diatomaceous earth, White clay, Kaolin, Clay, Porcelain clay, Barite powder, Silica sand, Examples thereof include silica powder, white carbon, metal powder, and organic resin powder. These can be used alone or in combination of two or more. The average particle size of the ultraviolet shielding powder is preferably 1 to 200 nm. In the above (3), it is desirable to set the mixing ratio of the ultraviolet shielding powder within a range in which visible light permeability can be secured.

  In addition to the above components, the coating material in the present invention may be a known additive such as an aggregate, a color particle, a coloring pigment, an extender pigment, a dye, a gloss, as long as it does not significantly impair the effects of the present invention. Detergent, thickener, wetting agent, antifreezing agent, film-forming aid, antiseptic, antifungal agent, antialgae, antibacterial agent, dispersant, antifoaming agent, light stabilizer, antioxidant, adhesion It may contain an imparting agent, a low contamination agent, a hydrophilizing agent, a water repellent, a crosslinking agent, a curing accelerator, a catalyst and the like.

  In the present invention, a new coating film is formed by applying (coating) such a coating material. As the coating material, one or two or more coating materials that satisfy the above-described conditions can be used. In the present invention, such a covering material can be applied repeatedly. For example, one type of coating material may be applied several times, or two or more types of coating materials may be applied repeatedly. When coating is performed, an appropriate interval may be provided to dry the coating.

  The film thickness of the new coating formed by such a coating material is preferably 30 μm or more, more preferably 50 μm or more, still more preferably 60 μm or more, particularly preferably more than 65 μm, and most preferably 70 μm or more. When the lower limit of the film thickness is within the above range, the new coating is sufficiently resistant to sunlight and water, and it suppresses deterioration such as discoloration and cracks caused by existing coating surfaces and joint materials, and has a long-term aesthetic appearance. It is suitable in terms of maintaining the property. Although the upper limit of the film thickness of a new coating is not specifically limited, Preferably it is 300 micrometers or less, More preferably, it is 250 micrometers or less, More preferably, it is 200 micrometers or less. If the upper limit of the film thickness is within the above range, it is possible to obtain a finish utilizing the uneven pattern on the existing coating surface. In addition, the film thickness in this invention is a dry film thickness, and when it coats 1 type, or 2 or more types of coating | covering materials, it is the total dry film thickness after coating.

In applying the coating material, a known coating device can be used. For example, a spray, a roller, a brush, or the like can be used as the coating instrument. The coating amount of the covering material, the number of coatings, etc. are desirably set so that the final film thickness is within the above range. The coating amount of the coating material (the total coating amount in the case of repeated coating) is preferably 0.1 to 0.6 kg / m ² , more preferably 0.15 to 0.5 kg / m ² . The number of coatings of the covering material is preferably 1 to 3 times. At the time of painting, the coating material can be appropriately diluted as necessary. Drying after applying the coating material may be performed at room temperature (preferably 0 to 50 ° C., more preferably 5 to 45 ° C.), and heating may be performed as necessary.

  In the present invention, the first coating material and the second coating material can be sequentially applied to the surface to be coated as described above to form a new coating film. In this case, it is desirable to apply the second covering material after applying the first covering material and drying the film. As the first covering material and the second covering material, those satisfying the conditions of the covering material can be used. These may be the same or different. Such a new coating has visible light permeability.

In the present invention, materials having different resin components can be used as the first coating material and the second coating material. In this case, it is desirable that r (hereinafter also referred to as “r ₁ ”) of the resin component in the first coating material is larger than r (hereinafter also referred to as “r ₂ ”) of the resin component in the second coating material. That is, it is desirable to satisfy r ₁ −r ₂ > 0. By using the first coating material and the second coating material containing the resin component in such an aspect, it is possible to sufficiently suppress the progress of deterioration such as discoloration and cracks caused by the existing coating surface and joint material, Adhesion at the existing coating surface and the connecting part is also improved. Furthermore, effects such as maintaining aesthetics and extending the lifetime of the substrate can be enhanced. R ₁ and r ₂ are values calculated by the following formula 1 and the following formula 2, respectively.
[Formula 1] r ₁ = {weight of component (a1) in resin component in first coating material} / {weight of component (A) in resin component in first coating material}
[Formula 2] r ₂ = {weight of component (a1) in resin component in second coating material} / {weight of component (A) in resin component in second coating material}

R ₁ represented by the above formula is preferably 0.1 to 1.0, more preferably 0.2 to 0.9, still more preferably 0.3 to 0.85, and particularly preferably 0.4 to 0. And r ₂ is preferably 0.05 to 0.8, more preferably 0.1 to 0.6, still more preferably 0.15 to 0.55, and particularly preferably 0.2 to 0.5. It is. The difference (r ₁ −r ₂ ) between r ₁ and r ₂ is preferably 0.01 or more, more preferably 0.05 to 0.5, still more preferably 0.08 to 0.4, and particularly preferably 0. .1 to 0.3. In such a case, the above-described effects can be sufficiently obtained.

  The film thickness of the new coating formed by laminating the first coating material and the second coating material is preferably 30 μm or more, more preferably 50 μm or more, further preferably 60 μm or more, particularly preferably more than 65 μm, and most preferably 70 μm or more. It is. The film thickness ratio {(film thickness of the first coating material film) :( film thickness of the second coating material film)} between the first coating material film and the second coating material film is preferably 80:20. -20: 80, more preferably 70: 30-30: 70, still more preferably 65: 35-35: 65. By being such an aspect, it is sufficient in terms of suppressing discoloration, cracking, etc. caused by the existing coating surface and joint material, improving adhesion at the existing coating surface and the connecting portion, maintaining aesthetics over a long period of time, etc. An effect can be obtained.

  Each of the first coating material and the second coating material can be applied a plurality of times. It is also possible to apply two or more types of coating materials corresponding to the first coating material, or to apply two or more types of coating materials corresponding to the second coating material. For example, two or more types having different colors and gloss levels, such as a colorless transparent type, a colored transparent type, a glossy type, and a matte type, can be applied. When coating is performed, an appropriate interval may be provided to dry the coating. In such a case, it is desirable that the film thickness after repeated coating satisfies the above conditions.

In the application of each coating material, a known coating device can be used as described above. The coating amounts of the first coating material and the second coating material are each preferably 0.05 to 0.4 kg / m ² , more preferably 0.08 to 0.3 kg / m ² . The number of coatings of each coating material is preferably 1 to 3 times. At the time of painting, each coating material can be appropriately diluted as necessary. What is necessary is just to perform drying after each coating | covering material application at normal temperature, and can also heat it as needed.

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

  The following materials were prepared as coating materials.

Coating material 1: Water dispersible resin 1 {cyclohexyl methacrylate, 2-ethylhexyl acrylate, methyl methacrylate, UV-absorbing group-containing monomer, photo-stable group-containing monomer, acrylic acid (weight ratio 20: 52: 23: 2: 2 1) emulsion polymer, 72% by weight of component (A) in resin component, r = 0.72}, thickener, film-forming aid, antifoaming agent, and water. Visible light transmittance 61%, ultraviolet light transmittance 5%.

・ Coating material 2: Water dispersible resin 2 {cyclohexyl methacrylate, 2-ethylhexyl acrylate, methyl methacrylate, UV-absorbing group-containing monomer, photo-stable group-containing monomer, acrylic acid (weight ratio 25: 30: 40: 2: 2 1) emulsion polymer, 55% by weight of component (A) in resin component, r = 0.55}, thickener, film-forming aid, antifoaming agent, and water. Visible light transmittance 62%, ultraviolet light transmittance 4%.

・ Coating material 3: water dispersible resin 3 {cyclohexyl methacrylate, 2-ethylhexyl acrylate, methyl methacrylate, UV-absorbing group-containing monomer, photo-stable group-containing monomer, acrylic acid (weight ratio 32: 18: 45: 2: 2 1) emulsion polymer, 50% by weight of component (A) in the resin component, r = 0.36}, thickener, film-forming aid, antifoaming agent, and water. Visible light transmittance 62%, ultraviolet light transmittance 5%.

-Coating material 4: Water dispersible resin 4 {Cyclohexyl methacrylate-2-ethylhexyl acrylate-Methyl methacrylate-UV-absorbing group-containing monomer-Photo-stable group-containing monomer-Acrylic acid (weight ratio 46: 4: 45: 2: 2 1) emulsion polymer, 50% by weight of component (A) in resin component, r = 0.08}, thickener, film-forming aid, antifoaming agent, and water. Visible light transmittance 60%, ultraviolet light transmittance 6%.

-Coating material 5: Water-dispersible resin 5 {cyclohexyl methacrylate-2-ethylhexyl acrylate-methyl methacrylate-light-stable group-containing monomer-acrylic acid (weight ratio 25: 30: 42: 2: 1), polymer and resin Component (A) 55% by weight of component, r = 0.55}, thickener, film-forming aid, antifoaming agent, water, and triazine-based ultraviolet absorber (0.3 parts relative to 100 parts by weight of resin component) Parts by weight). Visible light transmittance 60%, ultraviolet light transmittance 25%.

Coating material 6: Water-dispersible resin 6 {cyclohexyl methacrylate, 2-ethylhexyl acrylate, methyl methacrylate, light-stable group-containing monomer, acrylic polymer (weight ratio: 32: 18: 47: 2: 1), resin Component (A) 50% by weight of component, r = 0.36}, thickener, film-forming aid, antifoaming agent, water, and triazine-based ultraviolet absorber (0.3 parts per 100 parts by weight of resin component) Parts by weight). Visible light transmittance 60%, ultraviolet light transmittance 24%.

Coating material 7: Water dispersible resin 7 {cyclohexyl methacrylate, 2-ethylhexyl acrylate, methyl methacrylate, UV-absorbing group-containing monomer, photostable group-containing monomer, acrylic acid (weight ratio 10: 8: 77: 2: 2 1) emulsion polymer, 18% by weight of component (A) in resin component, r = 0.44}, thickener, film-forming aid, antifoaming agent, and water. Visible light transmittance 60%, ultraviolet light transmittance 5%.

-Coating material 8: Water-dispersible resin 8 {Cyclohexyl methacrylate, 2-ethylhexyl acrylate, methyl methacrylate, acrylic acid (weight ratio 10: 8: 81: 1), 18 weights of component (A) in resin component %, R = 0.44}, a thickener, a film-forming aid, an antifoaming agent, and water. Visible light transmittance 59%, ultraviolet light transmittance 55%.

(Example 1)
Ceramic siding boat deteriorated by outdoor exposure (having a tiled uneven pattern on the surface, black acrylic resin film on the concave part, brown acrylic resin film on the convex part, acrylic silicon resin transparent film on the whole 2), and the inter-board connecting portion (width 10 mm) filled with a modified silicone sealant was used as the coated surface. The joint of the coated surface is brush-coated with an application amount of 0.15 kg / m ² , dried for 2 hours, and then the coated material 1 is dried as the first coating material on the entire coated surface. Spray coating is performed so that the film thickness (shown as “film thickness” in Table 1; the same shall apply hereinafter) is 38 μm, and after drying for 3 hours, the coating material 2 is dried as a second coating material so that the dry film thickness becomes 38 μm. A test specimen was prepared by spray coating and drying and curing for 7 days. In addition, all processes of painting or drying curing were performed under standard conditions (temperature 23 ° C., relative humidity 50%). As the joint treatment material, a mixture of water-dispersible resin (acrylic silicone resin emulsion), coloring pigment, silane coupling agent, and additives (dispersant, thickener, film-forming aid, antifoaming agent, water, etc.) Was used.

[Test I]
About the test body obtained by the said method, adhesiveness was evaluated by the cross-cut tape method according to JISK5600-5-6. Evaluation criteria are “A: defect area is less than 10%”, “B: defect area is 10% or more and less than 30%”, “C: defect area is 30% or more and less than 50%”, “D: defect The partial area was 50% or more. " The test results are shown in Table 1.

[Test II]
About the test body obtained by the above method, an eye super UV tester (manufactured by Iwasaki Electric Co., Ltd.) is used as an accelerated weathering tester, and light irradiation is 6 hours and condensation is 2 hours (8 hours in total) up to 60 cycles. An accelerated test was conducted. At this time, the appearance change (crack state) on the surface of the test specimen at the end of 20 cycles, the end of 40 cycles, and the end of 60 cycles was observed, and the color difference before and after the acceleration was measured. Appearance change was evaluated in four stages (excellent; A>B>C>D; inferior), “A: no change” and “D: cracking progressed”. The color difference was evaluated as “A: less than 1 color difference”, “B: more than 1 and less than 3”, “C: more than 3 and less than 10”, and “D: more than 10 color difference”. The test results are shown in Table 1.

(Example 2)
A test body was prepared in the same manner as in Example 1 except that the covering material 2 was used as the first covering material and the covering material 3 was used as the second covering material, and the same test was performed. The test results are shown in Table 1.

(Example 3)
A test body was prepared in the same manner as in Example 1 except that the covering material 3 was used as the first covering material and the second covering material, respectively, and the same test was performed. The test results are shown in Table 1.

(Example 4)
A test body was prepared in the same manner as in Example 1 except that the covering material 3 was used as the first covering material and the covering material 2 was used as the second covering material, and the same test was performed. The test results are shown in Table 1.

(Example 5)
A test body was prepared in the same manner as in Example 1 except that the covering material 3 was used as the first covering material and the covering material 4 was used as the second covering material, and the same test was performed. The test results are shown in Table 1.

(Example 6)
A test body was prepared in the same manner as in Example 1 except that the covering material 5 was used as the first covering material and the covering material 6 was used as the second covering material, and the same test was performed. The test results are shown in Table 1.

(Example 7)
A test body was produced in the same manner as in Example 1 except that the first coating material and the second coating material were coated so that the dry film thicknesses were 12 μm, respectively, and the same test was performed. The test results are shown in Table 1.

(Comparative Example 1)
A test body was prepared in the same manner as in Example 1 except that the covering material 7 was used as the first covering material and the second covering material, respectively, and the same test was performed. The test results are shown in Table 1.

(Comparative Example 2)
A test body was prepared in the same manner as in Example 1 except that the covering material 8 was used as the first covering material and the second covering material, respectively, and the same test was performed. The test results are shown in Table 1.

(Comparative Example 3)
A test specimen was prepared in the same manner as in Example 1 except that the joint treatment with the joint treatment material was not performed and the coating material 3 was used as the first coating material and the coating material 4 was used as the second coating material. Went. The test results are shown in Table 1.

[Test III]
The test specimens of Examples 1 to 7 and Comparative Example 3 were exposed outdoors for 6 months, and the appearance change due to dirt on the specimen surface was observed. Evaluation was made on a stage (excellent; A>B>C>D; poor). The test results are shown in Table 1.

[Test IV]
About the test body of Examples 1-7 and the comparative example 3, after carrying out the total 20 cycles of the warm-cool repetition test which makes water immersion (23 degreeC) 18 hours->-20 degreeC 3 hours-> 50 degreeC 3 hours 1 cycle, The surface state was observed and evaluated in four stages (excellent; A>B>C>D; inferior), where “A” indicates that no crack was generated and “D” indicates that a crack was apparently generated. The test results are shown in Table 1.

Claims (4)

A plurality of plate-like base materials having an existing coating surface are provided, and a method for forming a coating on a surface to be coated, in which joints between the plate-like base materials are filled with joint material,
After the step of applying a joint treatment material to the surface of the joint material to form a treatment film,
A process of forming a new coating by applying a coating material having visible light permeability to the surface to be coated,
The existing coating surface has a concavo-convex pattern and / or a multicolor pattern,
The covering material is
A resin component containing 20% by weight or more of (meth) acrylic acid alkyl ester (A) having an alkyl group having 3 or more carbon atoms in the resin component is formed, and a film having an ultraviolet transmittance of 30% or less is formed. What is claimed is: 1. A method for forming a film, comprising: A plurality of plate-like base materials having an existing coating surface are provided, and a method for forming a coating on a surface to be coated, in which joints between the plate-like base materials are filled with joint material,
After the step of applying a joint treatment material to the surface of the joint material to form a treatment film,
A step of applying a first coating material having a visible light transmission property and a second coating material having a visible light transmission property to form a new coating on the coated surface,
The existing coating surface has a concavo-convex pattern and / or a multicolor pattern,
The first covering material and the second covering material are respectively
A resin component containing 20% by weight or more of (meth) acrylic acid alkyl ester (A) having an alkyl group having 3 or more carbon atoms in the resin component is formed, and a film having an ultraviolet transmittance of 30% or less is formed. What is claimed is: 1. A method for forming a film, comprising: The first covering material and the second covering material are respectively
The (meth) acrylic acid alkyl ester (A) having an alkyl group having 3 or more carbon atoms includes a (meth) acrylic acid alkyl ester (a1) having an alkyl main chain having 3 or more carbon atoms,
When the weight ratio of the component (a1) in the component (A) is r,
The film forming method according to claim 2, wherein r (r ₁ ) in the first covering material is larger than r (r ₂ ) in the second covering material.   The film forming method according to any one of claims 1 to 3, wherein a thickness of the new coating is 30 µm or more.