JP5292248B2 - Exterior wall coating structure and exterior wall finishing method - Google Patents

Description

  The present invention relates to an outer wall coating structure and a finishing method of a finish coating material for construction.

  2. Description of the Related Art Conventionally, various coating finishes have been applied to a building skin in order to protect a building body, impart design properties, and improve aesthetics. Especially on the south side exposed to direct sunlight and the part facing the main road, the degree of deterioration due to ultraviolet rays and dirt due to exhaust gas and dust discharged from automobiles is large, and it is represented by vivid colors immediately after construction. There was a problem that the aesthetics deteriorated in a short period of time, and the foundation mortar was neutralized by water permeability such as rainwater accompanying the deterioration of the coating material, which promoted deterioration of the outer coating film.

A coating composition comprising a polyisocyanate compound added to a polyol compound having a glass transition temperature of 15 to 100 ° C., and containing a polycaprolactone diol and / or polycaprolactone triol and a low condensation compound of tetraalkoxysilane has high weather resistance. Further, it is disclosed that a cracked coating does not occur over time and a coating having an anti-staining effect is obtained. (Patent Document 1)

  The main component is (A) a synthetic resin emulsion having a reactive silyl group, (B) a polysiloxane compound having a polyoxyalkylene chain, (C) a pigment, and (D) an anionic dispersant having a polyoxyalkylene chain. An aqueous solution containing 0.1 to 8.0 parts by weight of (B), 5 to 600 parts by weight of (C), and 0.1 to 10 parts by weight of (D) with respect to 100 parts by weight of the solid content of (A). It is disclosed that the coating composition is excellent in stain resistance, can form a coating film that does not crack over time, has a glossy coating film with high gloss, and further has excellent storage stability. Yes. (Patent Document 2)

An acrylic resin emulsion synthesized with an unsaturated group-containing polymerizable monomer containing 30 to 60% by weight of a methyl methacrylate monomer and having a glass transition temperature of 10 ° C. or higher and lower than 30 ° C., an aggregate having a hydroxyl group on its surface, a vinyl group A water-based coating composition characterized by comprising a trialkoxysilane, a pigment, a filler, a thickener, and a film-forming aid, having excellent weather resistance and stain resistance, and can be applied even when applied at low temperatures. Cracks due to irregularities based on the design of the material surface do not occur, and the water resistance is stable. (Patent Document 3)
However, unless the water permeability to the base such as mortar is improved, the coating of the outer coating material is deteriorated due to the movement of the base, and further durability cannot be obtained.

JP-A-10-259354 JP 2001-181559 A Japanese Patent Application No. 2009-096684 Japanese Patent No. 2875993 JP-A-9-71418 JP 10-67516 A JP 2000-247638 A JP 2008-222853 A JP 2008-88436 A

  The problem to be solved is the exterior wall finishing method and coating structure that do not require coating / measuring and mixing of coating materials and paints, so that there is no deterioration in water permeability even after outdoor exposure, and the deterioration of the outer coating film is prevented by preventing the deterioration of the base. Provide an outer wall finishing method and a coating structure to prevent.

The invention of claim 1 is an acrylic resin emulsion synthesized with 30 to 70% by weight of methyl methacrylate and having a glass transition temperature of 10 ° C. or higher and lower than 50 ° C. , and a particle size of 30 to 60% by weight in all coating materials. and aggregate having a hydroxyl group at 100μm or more surfaces, outer wall to form a coating material layer finish for buildings containing trialkoxysilane having a vinyl group, to form a further coating having a photocatalytic function having a hydrophilic on its surface layer The finishing method is easy to work, suppresses deterioration of water permeability, and prevents deterioration and contamination of the outer coating film.

Invention of Claim 2 is the outer wall coating-film structure formed by the outer wall finishing method of Claim 1, and suppresses the fall of water permeability, and prevents deterioration and contamination of a skin coating film.

  The present invention provides a coating film structure and a finishing method that can be easily performed, reduce water permeability, suppress deterioration of the base, have a sense of unevenness, and have design properties.

The present invention is a finish coating material for buildings and exterior coatings made of synthetic resin emulsion, and has little decrease in water permeability even after outdoor exposure, delays neutralization of the mortar, etc. Deterioration is suppressed.
The building finish coating material specified in JIS A 6909 is applicable as “This standard is mainly made of cement, synthetic resin and other binders, pigments, aggregates, etc., mainly spraying the inner and outer walls or ceiling of the building, The finish coating material for construction that finishes into a pattern with three-dimensional formability by roller coating, trowel coating, etc. is prescribed. "Among these, synthetic resin emulsions are used for exterior applications. What is used in the present invention is one that is suitable for both thinning and thickening.
Since this exterior synthetic resin emulsion-based finish coating material has irregularities, it is disadvantageous for water permeability and reduction of water permeability becomes a problem. The present invention has improved this problem.

  The exterior synthetic resin emulsion-based finish coating material of the present invention is described in Patent Document 3, and the acrylic resin emulsion includes an acrylic ester copolymer resin, a vinyl acetate / acrylic ester copolymer resin, and a silicon-modified acrylic resin. An aqueous acrylic resin emulsion such as a resin can be used, and its glass transition temperature is 10 ° C. or higher and lower than 50 ° C. In addition, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid and itaconic acid containing 30 to 70% by weight of methyl methacrylate monomer, and monoesters thereof, styrene, α-methylstyrene, vinyltoluene And styrenes such as chlorostyrene, vinyl esters such as vinyl acetate, and unsaturated group-containing polymerizable monomers such as vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, and butyl vinyl ether. As commercial acrylic emulsions, Ultrazole A25 (Gantz Kasei Co., Ltd., trade name, solid content 48%, glass transition temperature 48 ° C., methyl methacrylate monomer 70 wt% blended), Acronal A754 (BASF Japan Ltd., trade name) , Solid content 48%, glass transition temperature 14 ° C., methyl methacrylate monomer 50 wt% or more blended), YJ1070 Daq (solid content 46.5%, glass transition point 41 ° C., methyl methacrylate monomer 40 wt% or more, BASF Japan Ltd. Product name).

  As the aggregate, an aggregate having a hydroxyl group on its surface is used, and the particle size can be arbitrarily selected depending on the design and the feeling of unevenness. In particular, cinnabar is optimal. Generally, Tohoku cinna sand No. 7 (Tohoku cinna sand Co., Ltd., trade name, specific gravity 1.5, average particle size 150 μm) is used. Other than cinnabar, glass, silica, talc, clay, etc. can be used. The aggregate is distinguished from the filler by the particle size, and the particle size is 100 μm or more. The composition of the aggregate is preferably 30 to 60% by weight with respect to the entire coating material, and a design with an unevenness can be easily obtained on the surface of the coating film, and the coating operation and coating film strength can also be obtained.

  As the trialkoxysilane having a vinyl group, 3-methacryloxypropyltrimethoxysilane or 3-acryloxypropyltrimethoxysilane can be used, and KBM-503 (Shin-Etsu Chemical Co., Ltd., trade name, 3- Methacryloxypropyltrimethoxysilane), KBM-5103 (trade name, 3-acryloxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.), and the like. The amount of trialkoxysilane is preferably 0.2 to 2% by weight based on the entire coating material. In this range, cracking of the coating film surface can be suppressed, and storage stability and the like are improved.

  In addition, pigments for concealing and coloring the base, fillers for adjusting the viscosity and coatability, thickeners for water retention and workability, and disappearance to eliminate bubbles caused by entrainment in the coating material. A foaming agent, a dispersing agent for uniformly dispersing a filler, a pigment, and the like, and a film forming aid for adjusting the film forming property of the coating film can be blended.

  In the construction of the finish coating material blended in the above configuration, use a pattern roller, a hammer, a spray gun, etc., select a construction tool so as to be the intended design, and apply the amount suitable for the design. Finish with. The appropriate viscosity of the finish coating material is preferably 300 to 700 Pa · s, and is adjusted by adding water.

  The hydrophilic photocatalyst paint used in the present invention is appropriately added with a layer that suppresses the decomposition of the finish coating material as necessary depending on the configuration of the photocatalyst. The layer withstands adhesion to the finish coating and decomposition of the photocatalyst, and can be inorganic, silicate, fluororesin, silicone resin, acrylic silicone resin, Beloxytitanium, etc., and has good adhesion with the photocatalyst binder. Select one that does not degrade the photocatalytic function. The function of the photocatalyst can be used in the present invention as long as it is a titanium-based photocatalyst paint having a function of decomposing organic substances and hydrophilicity but having a hydrophilic function. It is a photocatalyst paint that forms a film with a continuous coating film on a building finish coating material layer, and is a photocatalyst paint that has a measure not to decompose the organic components of the building finish coating material layer. As an example in which the layer for suppressing the decomposition is unnecessary, a part of the photocatalyst of Patent Document 8 or Patent Document 9 is a structure that suppresses the decomposition of the object to be coated with a fluororesin, calcium phosphate apatite, or the like. As a photocatalyst paint, anatase type titanium oxide is generally developed with efficient photocatalytic function. The beryloxytitanium-based ones of Patent Documents 4-7 can also be used. Patent Documents 8 and 9 can be cited as those that do not require a layer for suppressing the decomposition. Commercially available Sagan Coat (Sakai Corporation, trade name, peroxotitanium series), Pure Coat AN Plus (Pearex Technologies, trade name, fluororesin coating system) NU-COAT AP (Neutral Co., Ltd., trade name, ceramic apatite coating) System) is raised.

The photocatalyst paint is applied using a sponge roller, a wool roller, or a spray gun (cup gun) to form a photocatalyst paint layer having hydrophilicity.
Hereinafter, it will be specifically described in Examples and Comparative Examples.

Finishing material A
28 parts by weight of Achronal A754, 1 part by weight of Texanol CS-12 (Chisso Co., Ltd., trade name), 40 parts by weight of Tohoku Tosuna No. 7, Silaace S-710 (Chisso Co., Ltd., trade name, 3-methacryloxy) 1 part by weight of propyltrimethoxysilane, R-820 (Ishihara Sangyo Co., Ltd., trade name, titanium oxide) 3 parts by weight, Whiten SB (Shiraishi Calcium Co., Ltd., trade name, calcium carbonate, average particle size 2 μm) 5 parts by weight, and the thickener was 0.8 parts by weight of water-soluble cellulose ether hi-Metroise 90SH-4000 to obtain Finishing Coating Material A.

Finishing coating material B
A finish coating material B was obtained in the same manner except that the acronal A754 of the finishing coating material A was changed to Ultrasol A25 and the texanol CS-12 was changed to 3 parts by weight.

Finishing material C
A finishing coating material C was obtained in the same manner except that Acronal A754 of the finishing coating material A was changed to 29 parts by weight of YJ1070Daq and texanol CS-12 was changed to 3 parts by weight.

Finish coating material D
Finishing material A acronal A754 was changed to 25 parts by weight of YJ1555D (solid content 56%, Tg 16 ° C., methyl methacrylate monomer not used, manufactured by BASF Japan Ltd., trade name), and texanol CS-12 was changed to 1 part by weight. Except for this, the finish coating material D was used.

Photocatalytic treatment 1
After drying the finish coating material, apply PTA (Tsubaki Corporation, trade name, base protection layer) with a cup gun by spray application 60 g / m ² , and after drying for 2 hours, TPX (Tsubaki Corporation, trade name, outdoor coating material) It applied by spray application 60g / m < ² > with the cup gun, and left still at 23 degreeC relative humidity 50% for 24 hours.

Photocatalyst treatment 2
After the finish coating material is dried, Pure Coat AN Plus (Pearex Technologies Co., Ltd., trade name) is applied by spray application with a cup gun at 60 g / m ² and dried for 2 hours. , Trade name) was applied by spray application 60 g / m ² with a cup gun and allowed to stand at 23 ° C. and 50% relative humidity for 24 hours.

Photocatalyst treatment 2
After the finish coating material was dried, NU-COAT AP (Neutral Co., Ltd., product name) was applied by spray application at 100 g / m ² with a cup gun and allowed to stand for 24 hours at 23 ° C. and 50% RH.

  The coating material A was used, and Photocatalyst Treatment 1 was performed to obtain Example 1.

  A finishing coating material B was used, and photocatalyst treatment 2 was performed to obtain Example 2.

  A finishing coating material C was used, and photocatalyst treatment 3 was performed to obtain Example 3.

Comparative Example 1
Comparative Example 1 was carried out in the same manner except that the finish coating material A of Example 1 was changed to the finish coating material D.

Comparative Example 2
Comparative Example 2 was carried out in the same manner except that the photocatalytic treatment of Example 1 was not carried out.

Comparative Example 3
Comparative Example 3 was carried out in the same manner except that the photocatalyst treatment of Example 3 was not treated.

Comparative Example 4
Comparative Example 4 was carried out in the same manner except that the photocatalyst treatment of Comparative Example 1 was not treated, and Comparative Example 4 was obtained.

Table 1 shows the evaluation results.

Test specimen preparation method After applying 0.2 kg / m ² of JS-410 (Aika Kogyo Co., Ltd., trade name, solvent-type chlorinated rubber sealer) on the ground and drying for 4 hours, the examples and comparative examples Apply the finish coating material with 0.9 kg / m ² with a hammer and leave it at 23 ° C. and 50% relative humidity for 12 hours. Smooth the same finish with 2.0 kg / m ² with a hammer. And left to stand at 23 ° C. and 50% relative humidity for 14 days. Then, the photocatalyst process described in the table | surface was performed and it was set as the test body.

Evaluation Method 1) Contamination Resistance A flexible board (80 × 265 mm thickness 4 mm) defined in JIS A5430 was used as a base, and a test specimen was prepared in accordance with the test specimen preparation method (with the finish coating material of Examples and Comparative Examples). . This test body was installed in a vertically long shape at an angle of 70 ° with respect to the horizontal plane, and was installed at an angle of 10 ° with respect to the horizontal plane at a position 300 mm in height from the upper part of the coating surface of the test body. Rainwater that has fallen to a wave width of 32 mm and a length of 500 mm falls to the upper part of the coating film of the test specimen and flows down under the coating film of the test specimen under its own weight, and is exposed outdoors for two months. The color difference between the coated film portion and the pre-exposure was measured with a color difference meter (CM-2600d manufactured by Konica Minolta Sensing Co., Ltd.), and this color difference was defined as stain resistance (ΔE). ΔE is less than 3.0, ΔE is 3.0 to less than 5.0, Δ is ΔE is 5.0 or more.

2) Weather resistance A flexible board (70 × 70 mm thickness 8 mm) defined in JIS A5430 was used as a base, and a test specimen was prepared according to the test specimen preparation method. UV irradiation is performed with an eye super UV tester SUV-W151 (Iwasaki Electric Co., Ltd., trade name, condensation-type super-accelerated weathering tester, reference manufacturer's data can reproduce 20 years of outdoor exposure in about 1000 hours). After that, it is assumed that the condensation is performed at 70 ° C. and 90% relative humidity for 24 hours, and the exposure is promoted for a total of 500 hours (equivalent to promotion for 10 years). The color difference was defined as a weather resistance evaluation value, ΔE was less than 0.5, and ΔE was 0.5 or more was evaluated as x.

3) Water permeability B method Using a flexible board (400 x 200 mm, thickness 4 mm) defined in JIS A 5430 as a base, a test body was prepared according to the test body preparation method, and the test body was held horizontally according to JISA 6909. After fixing the test device with a silicone sealant and leaving it to stand for 48 hours or more, put water at 23 ± 2 ° C. up to a height of 250 mm from the surface of the test piece, and the height of the head at that time and the height of the head after 24 hours. Find the difference.
The average value of three tests was taken, and 0.3 ml or less was marked with ◯, greater than 0.3 and less than 0.5 ml was marked with Δ, and 0.5 ml or more was marked with x.

4) Water permeability B method after accelerated exposure Using a flexible board (400 x 200 mm thickness 4 mm) defined in JIS A 5430 as a base, a test body was prepared according to the test body preparation method, and the test body was a U eye super UV tester SUV. -In W151, UV irradiation conditions were 63 ° C and 50% relative humidity for 24 hours, followed by UV irradiation at 70 ° C and 90% relative humidity for 24 hours, for a total of 1500 hours of exposure. The water permeability test B method was tested. The method was the same as the water permeability B method, and the average value of three tests was taken. A value of 0.3 ml or less was evaluated as ◯, a value larger than 0.3 and less than 0.5 ml was evaluated as Δ, and 0.5 ml or more as x.

Claims (2)

Acrylic resin emulsion synthesized with 30 to 70% by weight of methyl methacrylate and having a glass transition temperature of 10 ° C. or more and less than 50 ° C., and a hydroxyl group on the surface of 30 to 60% by weight in the total coating material with a particle size of 100 μm or more. and aggregate having to form a coating material layer finish for buildings containing trialkoxysilane having a vinyl group, further outer wall finishing method for forming a coating film having a photocatalytic function having a hydrophilic on its surface layer. An outer wall coating structure formed by the outer wall finishing method according to claim 1 .