JP4244244B2 - Algae-proof paint and coated product comprising the same - Google Patents

Description

【００８６】
つぎに、前記のようにして培養した各藻類を混合し、塗膜前面に塗布して殺藻性評価用試験片とした。この試験片を、１５００ルクス（蛍光燈）、２５℃、相対湿度９０％以上の条件で塗膜面を上にして放置した。２週間経過後、試験片上の藻類の生残面積を目視にて観察し、以下の評価基準に基づいて評価した。
【００８７】
（評価基準）
○：塗膜面に藻類による生残が認められない。
△：藻類の生残面積が塗膜面の１／３未満である。
×：藻類の生残面積が塗膜面の１／３以上である。
【００８８】
なお、表１中には、無機系バインダーにおけるシリカ／オルガノヒドロキシシランおよびオルガノヒドロキシシランの部分縮合物（重量比）をあわせて示す（表１中、ＳｉＯ₂／ＣＨ₃Ｓｉ（ＯＨ）₃とする）。
【００８９】
【表１】

【００９０】
表１に示された結果から、本発明の防藻塗料を用いて実施例１〜２で得られた塗装品は、塗膜の平滑性が良好で高硬度であり、密着性、耐擦傷性、耐沸騰水性、促進耐候性、耐汚染性および殺藻性（防藻性）のいずれにもすぐれ、また塩水噴霧（実施例１）および屋外曝露に対する耐性にもすぐれ、耐熱温度も高い（実施例１）といった、すぐれた塗膜性能を兼備するものであることがわかる。
【００９１】
これに対して、無機系バインダー中のシリカ／オルガノヒドロキシシランおよびオルガノヒドロキシシランの部分縮合物（重量比）が４０／６０〜７０／３０の範囲外である塗料を用いた比較例１〜２および光触媒酸化チタンが用いられていない塗料の比較例３で得られた塗装品は、いずれも殺藻性（防藻性）に劣るものであり、その他の塗膜性能をすべて兼備するものではないことがわかる。
【００９２】
なお、実施例１〜２のように本発明の防藻塗料がすぐれた殺藻性（防藻性）を示すのは、光触媒酸化チタンの光励起により発生する活性酸素種（Ｏ₂ ^-や・ＯＨ）の酸化還元反応に起因していると考えられる。
【００９３】
【発明の効果】
本発明の防藻塗料は、光触媒酸化チタンを特定の無機系バインダーに分散混合させて得られるものであるので、すぐれた防藻性を有するとともに、藻のみならず、藻と寄生あるいは共生している地衣類や菌類などの発生をも防止することができる。
【００９４】
さらに本発明の防藻塗料は、景観材料用塗料として要求される耐候性、耐水性、耐擦傷性、耐汚染性などの塗膜性能にもすぐれているので、長期にわたって景観材料の美観を維持することができる。また、安全性の高い光触媒酸化チタンを防藻剤として使用しているので、環境保護の点からも有用である。
【００９５】
さらにまた本発明の防藻塗料は、塗装作業性が良好で、かつ種々の基材に適用することができるので、建築内外装材や道路関係資材などの景観材料の防藻塗料としてきわめて有用である。
【００９６】
前記のごとき防藻塗料からなる本発明の塗装品は、防藻性をはじめとする種々の特性にすぐれ、その美観が長期にわたって維持され得るものである。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an anti-algae paint and a coated product comprising the same. More particularly, the present invention relates to an anti-algae paint that is particularly excellent in durability such as anti-algae property over a long period of time and can be applied to landscape materials such as building interior and exterior materials and road-related materials, and a coated product made thereof.
[0002]
[Prior art]
Currently, dirt caused by algae is a problem in landscape materials such as building interior and exterior materials and road-related materials. For example, as described in “Recent Trends of Mold and Anti-Algae Paints” (Tadamitsu Hirata, Painting and Paints, November 1989 (No. 457), pages 50-58) Due to the diversification of building materials and changes in the surrounding environment, the damage of buildings being contaminated with algae is increasing one to two years after construction.
[0003]
However, as described in, for example, “Recent Molds and Anti-Algae Paints” (Naoki Kishi, Painting and Paints, November 1989 (No. 457), pages 35-49) However, the current situation has not been fully examined in Japan.
[0004]
Conventionally proposed anti-algae coatings are generally obtained by adding an anti-algae agent to an organic binder such as an acrylic emulsion. As the algae preventive agent, a safer, less toxic, highly effective and long lasting effect is desired that does not affect the paint and coating film. For example, Japanese Patent Publication No. 1-17244, Organic algae deterrents such as urea compounds and triazine compounds described in Japanese Patent Publication Nos. 4-74104 and 9-241544, and Japanese Patent Publication No. 8-6053, Japanese Patent Laid-Open No. 5-59308 Metal-based and metal salt-based inorganic anti-algae agents described in the publication are used.
[0005]
The organic anti-algae has a problem mainly in weather resistance such as decomposition by ultraviolet rays and long life and safety such as water resistance. In addition, although the weather resistance and the like are considerably improved, the inorganic anti-algae has a problem of influence on the coating film such as dispersibility in the paint, stability of the paint and discoloration.
[0006]
Furthermore, any of the above-mentioned algae-proofing agents are those that elute from the coating film and express their effects, and are discharged into the natural world by rainwater and the like, and the effects on not only human livestock but also useful microorganisms can be measured. Absent. That is, there is a demand for the development of a safer algae for the purpose of protecting the global environment.
[0007]
Next, as described in the above publication, organic binders such as natural vegetable oils, natural resins, semi-synthetic resins, and synthetic resins are used for the binder to which the anti-algae agent is added. These organic resins have problems in weather resistance, heat resistance, scratch resistance, and the like. That is, discoloration of the coating film, loss of gloss, and scratches occur during long-term outdoor use, which causes a loss of the aesthetics of the landscape material and makes it difficult to maintain the algae-proofing property for a long period of time. Furthermore, since algae have a nutrient source such as carbon and grow, the organic resin can be a nutrient source of algae itself.
[0008]
On the other hand, a technique that mainly uses a photocatalyst such as titanium oxide has been proposed for the purpose of preventing the generation of algae in a water tank or the like. For example, JP-A-8-310591 discloses a method of supporting photocatalytic titanium oxide on the inner wall surface of a water storage tank, and JP-A-9-227752 discloses a thin film of photocatalyst particles on the surface of a methacrylic resin plate for a water tank. Each method for forming a thin film containing photocatalytic particles is described.
[0009]
However, when these methods are considered as an algae prevention method for landscape materials, the effect is insufficient. That is, the technique disclosed in JP-A-8-310591 is a technique in which a solution of a titanium oxide precursor such as titanium alkoxide and an acrylic or olefinic organic resin is applied to the inner surface of a glassy water storage tank, In the case of a water tank made of plastic or dried, it is a method in which a titanium oxide precursor or titanium oxide fine powder of 1 μm or less is dispersed or mixed in an organic adhesive and applied to the water tank. However, each method uses an organic resin as a binder, and the formed coating film has drawbacks such as poor weather resistance, discoloration with time, poor scratch resistance, and the like. There is a problem in maintaining algal control and aesthetics.
[0010]
JP-A-9-227752 discloses photocatalyst particles such as titanium oxide, an organic binder such as a fluorine polymer, a silicon polymer, and an acrylic polymer, an inorganic binder such as water glass and colloidal silica, and a solvent. A method of coating and drying a coating composition on a methacrylic resin plate has been proposed, but there are the following problems when coating such a coating composition on a landscape material such as a building interior / exterior material.
[0011]
First, in a coating composition using an organic binder, as described above, the formed coating film has problems such as weather resistance, scratch resistance, and discoloration with time.
[0012]
Next, in the coating composition using an inorganic binder, although the weather resistance of the formed coating film is somewhat improved, the scratch resistance, long-term anti-algal property and anti-staining property are still insufficient. . Furthermore, the coating material using such an inorganic binder has a big problem from an industrial point of view that the coating workability is poor. That is, since the solid content concentration of such an inorganic binder is as low as several tens% and the viscosity of the paint is low, there is a drawback that coating workability such as thick coating is not good. Landscape materials include various materials and shapes, and when these coating compositions are applied, sagging, flares, etc. are likely to occur, and film thickness unevenness is large. In particular, long-term anti-algae properties cannot be expected with a thin film having a thickness of less than 1 μm.
[0013]
As described above, the conventional algae-proof paint has some drawbacks, and the present situation is that no safe algae-proof paint that can maintain the aesthetics of the landscape material for a long period of time and has not yet been provided.
[0014]
[Problems to be solved by the invention]
The present invention has been made in view of the above prior art, and provides an anti-algae paint capable of preventing the generation of algae on the surface of a painted landscape material and maintaining the beauty over a long period of time, and a coated product comprising the same The purpose is to do.
[0015]
[Means for Solving the Problems]
The present invention
(1) A photocatalytic titanium oxide is dispersed and mixed in an inorganic binder mainly composed of a solid content of silica, organohydroxysilane and a partial condensate of organohydroxysilane, and silica / organohydroxysilane and organohydroxysilane are mixed. An algae-proof paint having a partial condensate (weight ratio) of 40/60 to 70/30, and
(2) Painted product in which the base material is coated with the anti-algae paint and a coating film is formed.
About.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
As described above, the anti-algae coating of the present invention is obtained by dispersing and mixing photocatalytic titanium oxide in an inorganic binder mainly composed of solids composed of silica, organohydroxysilane, and a partial condensate of organohydroxysilane. The partial condensate (weight ratio) of silica / organohydroxysilane and organohydroxysilane is 40/60 to 70/30.
[0017]
In the present invention, since photocatalytic titanium oxide is dispersed and mixed in an inorganic binder having a specific composition as described above, the obtained anti-algae coating exhibits particularly excellent durability such as anti-algae properties over a long period of time.
[0018]
For example, colloidal silica is preferably used as the silica. Such colloidal silica is usually used as a dispersion, and as the colloidal silica dispersion, an aqueous colloidal silica dispersion in which silicic anhydride is dispersed in water and a non-aqueous colloidal silica in which an alcohol solvent is dispersed. And dispersion liquid.
[0019]
The average particle diameter of silica in the colloidal silica dispersion is preferably 150 mμm or less, more preferably 30 mμm or less.
[0020]
The content of silica in the colloidal silica dispersion is appropriately adjusted within a range where the dispersion is stable.
[0021]
The pH of the colloidal silica is desirably acidic from the viewpoint of storage stability.
[0022]
The organohydroxysilane and the partial condensate of organohydroxysilane can be obtained by hydrolyzing organoalkoxysilane.
[0023]
Representative examples of the organoalkoxysilane include, for example, the general formula (II):
R¹Si (OR²)_Three             (II)
(Wherein R¹Consists of an alkyl group having 1 to 3 carbon atoms, a vinyl group, a 3,4-epoxycyclohexylethyl group, a γ-glycidoxypropyl group, a γ-methacryloxypropyl group, a γ-mercaptopropyl group, and a γ-chloropropyl group. A group selected from the group, R²Represents a group selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, an alkoxyethyl group having 1 to 4 carbon atoms, and an aryl group.
[0024]
Representative examples of the organohydroxysilane used in the present invention obtained by hydrolyzing the organoalkoxysilane include, for example, the general formula (I):
R¹Si (OH)_Three              (I)
(Wherein R¹Is the same as above).
[0025]
Examples of the partial condensate of organohydroxysilane used in the present invention include oligomers obtained by partial condensation of organohydroxysilane represented by the general formula (I).
[0026]
The blending ratio of silica to organohydroxysilane and partial condensate of organohydroxysilane (silica / organohydroxysilane and partial condensate of organohydroxysilane (weight ratio)) does not reduce the hardness of the coating film to be formed. In order to make it, it is 40/60 or more, preferably 42/58 or more. In order to prevent the formed coating film from becoming brittle, the blending ratio (weight ratio) is 70/30 or less, preferably 60/40 or less.
[0027]
In addition, there is no limitation in particular in the ratio of the said organohydroxysilane and the partial condensate of organohydroxysilane.
[0028]
The inorganic binder used in the present invention is mainly composed of a solid component composed of the silica, organohydroxysilane, and a partial condensate of organohydroxysilane, and the inorganic binder usually contains a solvent. Preferably, a solvent composed of water, alcohol and ethylene glycol monobutyl ether is included.
[0029]
The water usually comprises water in an aqueous colloidal silica dispersion and condensed water of organohydroxysilane.
[0030]
The alcohol is usually an alcohol such as methanol, ethanol, propanol, butanol, methoxyethyl alcohol, ethoxyethyl alcohol, or aryl alcohol, which is generated by hydrolysis of organoalkoxysilane when obtaining organohydroxysilane. For example, monovalent lower alcohols having 1 to 4 carbon atoms such as isopropanol, isobutanol, sec-butanol, and tert-butanol can also be used.
[0031]
The ethylene glycol monobutyl ether can improve the storage stability of the inorganic binder and can improve the coating workability, and considering such action, the content of ethylene glycol monobutyl ether in the solvent is: It is 20% by weight or more, preferably 25% by weight or more. In view of the fact that when the content of ethylene glycol monobutyl ether is too large, the drying time of the coating film becomes longer, the content of ethylene glycol monobutyl ether in the solvent is preferably 50% by weight or less.
[0032]
In addition, although the said inorganic type binder contains organohydroxysilane, Preferably ethylene glycol monobutyl ether etc., in this specification, what contains these organic substances is defined as an inorganic type binder.
[0033]
The solid content of the inorganic binder may be adjusted with, for example, the solvent. In order not to make it difficult to adjust the film thickness of the coating film, it is 10% by weight or more, preferably 15% by weight. It is desirable that the amount be not less than 30% by weight, preferably not more than 25% by weight, so that the storage stability is not lowered.
[0034]
The pH of the inorganic binder may be adjusted as appropriate using, for example, an organic amine such as aqueous ammonia or triethanolamine, but is preferably 3 or more so that the storage stability of the inorganic binder does not decrease. Is preferably 4 or more, and is 6.5 or less, preferably 5 or less.
[0035]
As a method for producing an inorganic binder, for example,
(A) A method in which an organoalkoxysilane is added to a colloidal silica dispersion and hydrolyzed to form an organohydroxysilane and a partial condensate of the organohydroxysilane, and the reaction product is diluted with a solvent.
(B) A method of diluting a colloidal silica dispersion with a solvent and then adding an organoalkoxysilane to the mixture to cause hydrolysis.
Any method may be employed in the present invention.
[0036]
When the organoalkoxysilane is added to the colloidal silica dispersion for hydrolysis, it is preferable that the liquid temperature is kept at 10 to 80 ° C. and the reaction is carried out by stirring under normal pressure for about 1 to 24 hours. In addition, when using the said non-aqueous colloidal silica dispersion, a part may be added after completion | finish of reaction.
[0037]
Further, when hydrolyzing the organoalkoxysilane, a small amount of a hydrolysis catalyst such as an inorganic acid or an organic acid may be added.
[0038]
Next, the photocatalytic titanium oxide used in the present invention is a titanium oxide that expresses a photocatalytic function with low energy light. By dispersing and mixing it with the inorganic binder, the antialgal antibacterial coating excellent in the obtained antialgal coating is obtained. Sex is imparted. Among such photocatalytic titanium oxides, anatase type titanium oxide having higher activity is preferable. The photocatalytic titanium oxide may be fine powder, titania sol dispersed in water or alcohol, alkoxy titanium which is a precursor of titanium oxide, and the like can be used similarly.
[0039]
The amount of the photocatalytic titanium oxide is preferably 30 parts or more with respect to 100 parts by weight (hereinafter referred to as “parts”) of the solid content of the inorganic binder, in order to impart sufficient antialgal properties to the obtained antialgal coating. Is preferably 50 parts or more, and in order to prevent the surface of the coating film formed from the algae-proof paint from becoming rough and preventing the stain resistance from being lowered, the solid content of the inorganic binder is 400 parts per 100 parts. Part or less, preferably 300 parts or less.
[0040]
In the present invention, photocatalysts other than titanium oxide, for example, photocatalytic semiconductors such as zinc oxide, tin oxide, tungsten oxide, and iron oxide can be used in combination with titanium oxide. Further, for the purpose of enhancing the photocatalytic function of titanium oxide, a metal such as palladium or vanadium or a metal compound may be added. In addition to adding antibacterial and antistatic agents to the coating film formed from the anti-algae paint, additives suitable for the application can be added, and other anti-algae agents can be used in combination. It doesn't matter.
[0041]
As a method for obtaining the algae-proof paint of the present invention by dispersing and mixing the photocatalytic titanium oxide in an inorganic binder, a usual method is adopted, and for example, a disperser such as a ball mill or a sand mill can be used. In addition, when dispersing the photocatalytic titanium oxide, a diluent (solvent), a dispersant, an anti-settling agent, a thickener, a pigment, an extender pigment, and the like can be added as necessary.
[0042]
The solid content of the anti-algae coating of the present invention thus obtained is preferably about 30 to 60% by weight in consideration of coating workability and the like.
[0043]
The anti-algae paint of the present invention is excellent in durability such as anti-algae, and can maintain the aesthetics of the paint over a long period of time. Therefore, it is suitable for painting landscape materials such as building interior and exterior materials and road-related materials. Can be used.
[0044]
The coated product of the present invention is a product in which a coating film is formed by coating the base material with the anti-algae paint.
[0045]
Examples of the base material to which the anti-algae paint of the present invention can be applied include metal materials such as aluminum and stainless steel; inorganic materials such as glass, stone, cement material, concrete material, and slate plate; plastic and wood Organic materials, combinations of two or more of these metal materials, inorganic materials and organic materials, and laminates of two or more of metal materials, inorganic materials and organic materials, etc. Paints can be applied to most substrates that are usually used as landscape materials.
[0046]
A method for forming a coating film by applying an anti-algae paint to a substrate and curing it will be described.
[0047]
First, as a coating method, conventionally known ordinary methods such as a spray coating method, a dipping method, a flow coating method, a roll coating method, and an electrostatic coating method can be employed.
[0048]
Next, the base material coated with the anti-algae paint is heated at, for example, about 80 to 200 ° C. for about 10 to 120 minutes to form a coating film having excellent adhesion to the base material. Since the thickness of the coating film varies depending on the type and use of the substrate on which the coating film is formed, it cannot be determined unconditionally, but is usually about 1 to 100 μm, especially about 5 to 50 μm. Preferably it is adjusted.
[0049]
In consideration of the excellent antialgae property exhibited by the algae-proof paint, a coated product having a coating film formed on the outermost surface with the algae-proof paint is preferable.
[0050]
Furthermore, an undercoat layer is provided in the lower layer portion of the coating film formed of the anti-algae paint, and the undercoat layer is an inorganic paint using the inorganic binder used in the present invention for the purpose of coloring makeup, It may be formed of an organic paint using an acrylic resin or an inorganic / organic composite paint using an inorganic binder and an organic resin in combination. When forming such an undercoat layer, it is preferable to use an inorganic coating material from the viewpoint of adhesion and weather resistance. In addition, there is no limitation in particular in the thickness of this undercoat layer, For example, what is necessary is just about 5-50 micrometers.
[0051]
Thus, the coated article of the present invention is excellent in durability such as anti-algae property, and its aesthetics can be maintained for a long time.
[0052]
【Example】
Next, the algae-proof paint of the present invention and a coated product comprising the same will be described in more detail based on examples, but the present invention is not limited only to such examples.
[0053]
Example 1
184 parts of an aqueous colloidal silica dispersion (silica content: 30% by weight, average particle size: 5 to 20 mμm, pH 3.0) and 100 parts of methyltrimethoxysilane are mixed and stirred at 30 ° C. for 5 hours for hydrolysis. Was completed. Next, 125 parts of ethylene glycol monobutyl ether and 113 parts of isopropanol are added to the resulting hydrolyzate (content of ethylene glycol monobutyl ether in the solvent: about 30% by weight), and ammonia water is added to adjust the pH. The inorganic binder (A) was obtained by adjusting to 4.5. The solid content of the inorganic binder (A) was about 20% by weight.
[0054]
Next, 120 parts of photocatalytic titanium oxide (anatase type titanium oxide, manufactured by Ishihara Techno Co., Ltd., ST-21) is added to 300 parts of the inorganic binder (A), and the mixture is dispersed and mixed in a sand mill. . 1 was obtained. This anti-algae paint No. The solids content of 1 was about 43% by weight.
[0055]
The anti-algae paint No. 1 was coated on an aluminum plate by spray coating, and heat-treated at 160 ° C. for 20 minutes to obtain a coated product having a cured film with a thickness of about 20 μm.
[0056]
Comparative Example 1
100 parts of the aqueous colloidal silica dispersion used in Example 1 and 100 parts of methyltrimethoxysilane were mixed and stirred at 30 ° C. for 5 hours to complete the hydrolysis. Next, 100 parts of ethylene glycol monobutyl ether and 90 parts of isopropanol are added to the resulting hydrolyzate, and ammonia water is further added to adjust the pH to 4.5, so that an inorganic system having a solid content of about 20% by weight. A binder (B) was obtained.
[0057]
Next, 120 parts of the photocatalytic titanium oxide used in Example 1 was added to 300 parts of the inorganic binder (B), and the mixture was dispersed and mixed in a sand mill. 2 was obtained. This paint No. The solids content of 2 was about 43% by weight.
[0058]
The paint No. 2 was coated on an aluminum plate by a spray coating method, and heat-treated at 160 ° C. for 20 minutes to obtain a coated product having a cured film having a thickness of about 20 μm.
[0059]
Comparative Example 2
921 parts of the aqueous colloidal silica dispersion used in Example 1 and 100 parts of methyltrimethoxysilane were mixed and stirred at 30 ° C. for 5 hours to complete the hydrolysis. Next, 350 parts of ethylene glycol monobutyl ether and 315 parts of isopropanol are added to the obtained hydrolyzate, and ammonia water is further added to adjust the pH to 4.5, whereby an inorganic system having a solid content of about 20% by weight is added. A binder (C) was obtained.
[0060]
Next, 120 parts of the photocatalytic titanium oxide used in Example 1 was added to 300 parts of the inorganic binder (C), and the mixture was dispersed and mixed in a sand mill. 3 was obtained. This paint No. The solids content of 3 was about 43% by weight.
[0061]
The paint No. 3 was applied to an aluminum plate by a spray coating method, and heat-treated at 160 ° C. for 20 minutes to obtain a coated product having a cured film with a film thickness of about 20 μm.
[0062]
Comparative Example 3
In the same manner as in Example 1 except that rutile titanium oxide (SR-97, manufactured by Ishihara Sangyo Co., Ltd.) was dispersed in the inorganic binder (A) prepared in Example 1 instead of photocatalytic titanium oxide. Paint No. 4 was obtained. This paint No. The solids content of 4 was about 43% by weight.
[0063]
The paint No. 4 was coated on an aluminum plate by a spray coating method, and heat-treated at 160 ° C. for 20 minutes to obtain a coated product having a cured film with a film thickness of about 20 μm.
[0064]
Example 2
Paint No. obtained in Comparative Example 3 4 was applied to a slate plate by a flow coating method and dried at 80 ° C. for 10 minutes to obtain an undercoat layer having a thickness of about 15 μm.
[0065]
Next, the anti-algae paint No. obtained in Example 1 was used. 1 was applied on the undercoat layer by a flow coating method and heat-treated at 160 ° C. for 20 minutes to obtain a coated product having an overcoat cured film having a thickness of about 15 μm.
[0066]
(Coating performance test)
Next, the following coating film performance tests were performed on the coated products obtained in Examples 1-2 and Comparative Examples 1-3. The results are shown in Table 1.
[0067]
(1) Paint appearance
The smoothness of the coating film was visually observed.
[0068]
(2) Coating film adhesion
A cross-cut tape peeling test was performed in accordance with the method specified in JIS D-0202.
[0069]
(3) Pencil hardness of coating film
It measured based on the method prescribed | regulated to JISK-5400.
[0070]
(4) Scratch resistance test
After the coating surface was reciprocated 200 times with a nylon scrubber, the surface state of the coating film was visually observed and evaluated based on the following evaluation criteria.
[0071]
(Evaluation criteria)
○: No change.
Δ: Some scratches are observed.
X: Significant scratches are observed.
[0072]
(5) Boiling water resistance test
After the coated product test piece (7 cm × 15 cm) was immersed in boiling water for 10 hours, the surface state of the coating film was visually observed and evaluated based on the following evaluation criteria.
[0073]
(Evaluation criteria)
○: No change.
(Triangle | delta): Some cracks have arisen in the coating film.
X: The coating film is peeled or cracked.
[0074]
(6) Salt spray test
After conducting a 1000 hour test in accordance with the method defined in JIS K-5400, the appearance of the coating film was visually observed and evaluated based on the following evaluation criteria.
[0075]
(Evaluation criteria)
○: No change.
Δ: Some rust is observed.
X: The peeling of a coating film is recognized.
[0076]
(7) Accelerated weather resistance test
A 5000 hour test was conducted in accordance with the method defined in JIS K-5400, and after 5000 hours, the degree of discoloration of the coating film was determined with a color difference meter and evaluated based on the following evaluation criteria.
[0077]
(Evaluation criteria)
○: No discoloration (ΔE: less than 0.5).
Δ: Slightly discolored (ΔE: 0.5 or more and less than 1)
X: Remarkably discolored (ΔE: 1 or more).
[0078]
(8) Outdoor exposure test
In accordance with the method specified in JIS K-5400, a coated product test board (30 cm x 30 cm) is mounted outdoors on a weathering test bench, and the degree of discoloration of the paint film after 1 year (including discoloration due to contamination) Was determined with a color difference meter and evaluated based on the following evaluation criteria.
[0079]
(Evaluation criteria)
○: No discoloration (ΔE: less than 0.5).
Δ: slightly discolored (ΔE: less than 0.5 to 1)
X: Remarkably discolored (ΔE: 1 or more).
[0080]
In addition, ΔE in the tests (7) and (8) indicates a color difference between the coating film before the test and the coating film after the test.
[0081]
(9) Heat resistance test
A coated product specimen (7 cm × 15 cm) is left in an atmosphere of 100 ° C., 200 ° C. and 300 ° C., and after 24 hours, the change in the appearance of the coating film is examined. did.
[0082]
(10) Contamination resistance test
After applying 5% carbon black water suspension to a coated product test piece (7 cm × 15 cm) and holding it at 50 ° C. for 5 hours, wipe the surface of the test piece with a cloth and visually observe the removal of dirt. Evaluation was made based on the following evaluation criteria.
[0083]
(Evaluation criteria)
○: No dirt.
(Triangle | delta): There exists some dirt.
X: There is remarkable dirt.
[0084]
(11) Algicidal (algaeproofing) test
Chlorella pyrenoidosa from the outer wall of the building (Chlorella pyrenoidosa), Protococcus viridis (Protococcus viridis), Chlorococcum species (Chlorococcum sp.) and holmidium species (Hormidiumsp.) was cultured on Bold's Basal agar for 2 weeks. The Bold's Basal agar medium was prepared by adding 10 ml of a solution composed of the following components 1 to 6 shown below to 1 ml of each of 7 to 10 and 15 g of agar in 936 ml of distilled water and heating to dissolve.
[0085]

[0086]
Next, each algae cultured as described above was mixed and applied to the front surface of the coating film to obtain a test piece for evaluating algicidal properties. The test piece was left standing with the coating surface facing up under conditions of 1500 lux (fluorescent light), 25 ° C., and relative humidity of 90% or more. After two weeks, the survival area of the algae on the test piece was visually observed and evaluated based on the following evaluation criteria.
[0087]
(Evaluation criteria)
○: Survival due to algae is not observed on the coating surface.
(Triangle | delta): The survival area of algae is less than 1/3 of a coating-film surface.
X: The survival area of algae is 1/3 or more of the coating film surface.
[0088]
In Table 1, the partial condensates (weight ratio) of silica / organohydroxysilane and organohydroxysilane in the inorganic binder are also shown (in Table 1, SiO 2₂/ CH_ThreeSi (OH)_ThreeAnd).
[0089]
[Table 1]

[0090]
From the results shown in Table 1, the coated products obtained in Examples 1 and 2 using the anti-algae paint of the present invention have good coating film smoothness and high hardness, and adhesion and scratch resistance. Excellent boiling water resistance, accelerated weathering resistance, contamination resistance, and algicidal (algae-proofing) properties, excellent resistance to salt spray (Example 1) and outdoor exposure, and high heat resistance (implemented) It can be seen that the film has excellent coating performance such as Example 1).
[0091]
On the other hand, Comparative Examples 1-2 using a coating material in which the partial condensate (weight ratio) of silica / organohydroxysilane and organohydroxysilane in the inorganic binder is outside the range of 40/60 to 70/30 and The coated product obtained in Comparative Example 3 of the paint not using photocatalytic titanium oxide is inferior in algicidal (algaeproofing) property and does not have all other coating film performances. I understand.
[0092]
In addition, the active oxygen species generated by photoexcitation of photocatalytic titanium oxide (O₂ ^-This is probably due to the redox reaction of .OH.
[0093]
【The invention's effect】
Since the anti-algae coating of the present invention is obtained by dispersing and mixing photocatalytic titanium oxide in a specific inorganic binder, it has excellent anti-algae properties and is parasitic or symbiotic with algae as well as algae. The occurrence of lichens and fungi that are present can also be prevented.
[0094]
Furthermore, the algae-proof paint of the present invention has excellent coating performance such as weather resistance, water resistance, scratch resistance, and stain resistance required as a paint for landscape materials, so that the aesthetics of landscape materials can be maintained over a long period of time. can do. In addition, since highly safe photocatalytic titanium oxide is used as an algae inhibitor, it is also useful from the viewpoint of environmental protection.
[0095]
Furthermore, the anti-algae paint of the present invention has excellent paint workability and can be applied to various base materials, so it is extremely useful as an anti-algae paint for landscape materials such as building interior and exterior materials and road-related materials. is there.
[0096]
The coated product of the present invention comprising the above-described anti-algae coating is excellent in various properties including anti-algae properties, and its aesthetics can be maintained over a long period of time.

Claims (13)

Silica / organohydroxysilane and organohydroxysilane partially condensed by dispersing and mixing photocatalytic titanium oxide in an inorganic binder whose main component is a solid consisting of silica, organohydroxysilane and organohydroxysilane partial condensate. An anti-algae paint having an object (weight ratio) of 40/60 to 70/30. The anti-algae paint according to claim 1, wherein the inorganic binder comprises a solid content and a solvent composed of water, alcohol and ethylene glycol monobutyl ether. The algae-proof paint according to claim 2, wherein the content of ethylene glycol monobutyl ether in the solvent is 20% by weight or more. The algae-proof paint according to claim 1, wherein the inorganic binder has a solid content of 10 to 30% by weight. The algae-proof paint according to claim 1, wherein the pH of the inorganic binder is 3 to 6.5. 2. The anti-algae paint according to claim 1, wherein the silica is colloidal silica. Organohydroxysilane is represented by the general formula (I):
R ¹ Si (OH) ₃ (I)
(Wherein R ¹ represents an alkyl group having 1 to 3 primes, a vinyl group, 3,4-epoxycyclohexylethyl group, γ-glycidoxypropyl group, γ-methacryloxypropyl group, γ-mercaptopropyl group, and The anti-algae paint according to claim 1, which is a compound represented by the following formula: a group selected from the group consisting of γ-chloropropyl groups. The anti-algae paint according to claim 1, wherein the photocatalytic titanium oxide is anatase titanium oxide. The anti-algae paint according to claim 1, wherein the amount of the photocatalytic titanium oxide is 30 to 400 parts by weight with respect to 100 parts by weight of the solid content of the inorganic binder.   A coated product obtained by coating a base material with the anti-algae paint according to claim 1, 2, 3, 4, 5, 6, 7, 8, or 9. The base material is a metal material, an inorganic material or an organic material, or a combination of two or more of a metal material, an inorganic material and an organic material, or a laminate of two or more of a metal material, an inorganic material and an organic material The coated product according to claim 10. The coated product according to claim 10, wherein a coating film is formed on the outermost surface with an anti-algae paint. 11. An undercoat layer is provided in a lower layer portion of a coating film formed of an anti-algae paint, and the undercoat layer is formed of an inorganic paint, an organic paint, or an inorganic / organic composite paint. Painted products.