Functional material and functional coating composition

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a functional material capable of easily removing pollutants containing oily components indoors and outdoors by rainfall, shower cleaning, etc. in a member to which pollutants containing oily components are likely to adhere. ..

【0002】

[Conventional technology]

In the surface layer of conventional glass and ceramic glazes, the photocatalyst is fixed to the surface layer, and the organic decomposition ability of the photocatalyst naturally decomposes the dirt. A method was taken to make it difficult to adhere.

【0003】

However, when sufficient ultraviolet rays cannot be obtained or when the load of dirt is very large, pollutants containing oily components may not be removed by methods such as rainfall and shower cleaning.

【0004】

[Problems to be Solved by the Invention]

An object of the present invention is to make the contact angle with oil larger than the contact angle with water in a member to which pollutants containing oily components are likely to adhere indoors and outdoors, thereby contaminating with the adhering oily components. The purpose is to provide a functional material that can facilitate the removal of substances.

【0005】

[Means for solving problems]

The present invention has been made to solve the above problems, and has a fine concavo-convex film made of an oxide on the surface, and the surface has a contact angle with oil larger than a contact angle with water. The oxide contains an oxide having a photocatalytic function in which at least one metal selected from Cu, Ag, Zn, V, W, Pt, Nb, and Sb is supported, and the surface roughness Ra of the uneven film is the base material. Provided is a functional material having a surface roughness larger in the range of 6 nm or more and 40 nm or less and having a primary particle size of the raw material of the oxide of 15 nm or less.

【0006】

Further, by forming a fine concavo-convex film of oxide, it is possible to have a function of contact angle of water of 25 degrees or less, charge half-life of 10 seconds or less, or both of them. Further, by using an oxide having a photocatalytic function, this function can be improved and maintained by photoexcitation.

【0007】

The method for forming a fine uneven film has an appropriate uneven interval and uneven height (surface roughness) by changing the immobilization method such as oxide composition or liquid concentration, coating conditions and firing temperature, and firing time. It forms a fine uneven film. For example, SiO₂, Al₂O₃, K₂O, Na₂O, Li₂O, TiO₂Prepare one or two or more coating solutions containing one or two or more oxides such as, and apply this on a temperature-controlled substrate once or many times by a method such as spraying, which is sufficient. A film is formed by heating to a temperature at which film strength is obtained.

【0008】

[Action]

By forming a fine uneven film with appropriate surface roughness, the diffusion resistance of oil on the member surface is increased and the contact angle of oil is not lowered, while water on the uneven film on the member surface is formed. Increases osmotic force and reduces the contact angle of water. For this reason, when cleaning with rain, shower, high-pressure spray, sponge wipe with water, etc. after the pollutant containing oily components adheres to the surface, the contact angle of oil becomes larger than the contact angle of water. , Water easily enters between the oil and the surface of the member, and the removability is improved. If the uneven spacing and surface roughness of the fine uneven film are too large, the oil will soak into the unevenness and it will be difficult to remove it by wiping or washing. It is preferable that the size is larger in the range of 6 nm or more and 40 nm or less.

【0009】

By making the contact angle with water smaller than the contact angle with oil and making the contact angle of water 25 degrees or less, the surface becomes easy to get wet with water. Is easy to get in and the removability is improved. Further, by using an oxide having a photocatalytic function, the contact angle of water can be further lowered by photoexcitation, and the removability is further improved.

【0010】

Further, by setting the charge half-life to 10 seconds or less, it is possible to prevent electrostatically attached dust in the air. Further, by using an oxide having a photocatalytic function, the charge half-life can be further reduced by photoexcitation, and the adhesion prevention effect is enhanced. In addition to the above, the action of decomposing organic substances by the photocatalyst can prevent the growth of sleepiness, mold, and algae, does not generate new stains, and can decompose oily components that adhere to the stains.

【0011】

BEST MODE FOR CARRYING OUT THE INVENTION

Next, an embodiment of the present invention will be described with reference to the drawings. 1, FIG. 2 and FIG. 3 are cross-sectional views showing an outline of a functional material according to an embodiment of the present invention.

【0012】

As shown in FIG. 1, the surface of the functional material of the present invention is covered with an oxide 2 on the surface 1 of the base material to form a fine uneven film. In FIG. 2, the substrate surface 1 forms a fine uneven film in which the oxide 2 and the oxide 3 having a photocatalytic function are microscopically dispersed. In FIG. 3, the substrate surface 1 is covered with an oxide 2, and the oxide 3 having a photocatalytic function is microscopically dispersed on the surface to form a fine uneven film.

【0013】

SiO for base material surface 1 such as tile, glass, ceramics, enamel panel, etc.₂, Al₂O₂, K₂O, Na₂O, Li₂O, TiO₂Oxide 2 is immobilized by applying an oxide, a metal alcoside or titanium alkoxide, an organic titanate or a derivative thereof, etc., which are blended as required, in a uniform layer or a multilayer and then firing.

【0014】

In this case, the surface roughness due to the voids and fine pores between the oxide particles is determined by the liquid composition, liquid concentration, substrate temperature, coating pressure, coating amount, number of coatings, heating temperature, heating time, heating rate, etc. Optimize by adjusting as appropriate. For example, the liquid composition and liquid concentration are preferably 1% or less for oxide sol and 5% or less for metal alkoxide. The substrate temperature is preferably 80 degrees or higher, and the coating pressure, coating amount, and number of coatings are appropriately adjusted so as to be as fine and uniform as possible. Further, it is necessary to select the heating device so that the surface temperature of the base material becomes uniform as quickly as possible while considering the thermal shock property of the base material, and adjust the temperature rise rate appropriately.

【0015】

If the uneven spacing and surface roughness of the fine uneven film are too large, the oil permeates the unevenness and is difficult to remove by wiping or washing. Therefore, it is preferably 500 nm or less, and preferably 400 nm or less. Further, it is more preferable that the surface roughness of the fine uneven film is larger in the range of 6 nm or more and 40 nm or less as compared with the surface roughness of the substrate surface. The surface roughness Ra was measured under the following measurement conditions in accordance with JIS B0601. (Needle speed 0.03 mm / s, cutoff 0.025 mm, measurement length 0.3 mm).

【0016】

In order to prevent the surface roughness from becoming too large, the primary particle size is preferably 15 nm or less, and preferably 10 nm or less as a raw material for the oxide. When a metal alkoxide is used, titanium alkoxide, alkoxysilane and the like can be mentioned, and titanium tetraisopropoxide is preferable. Examples of the organic titanate derivative include titanium chelate, and di-i-propoxy-bis (acetylacetonato) titanium is desirable.

【0017】

Oxides are, for example, SiO₂, Al₂O₃, K₂O, Na₂O, Li₂O, TiO₂A mixed sol containing the above is applied to the surface of the glass or glaze layer, and on top of this, the alkali metal is reduced compared to the mixed sol used for the lower layer, and TiO₂The photocatalytic function and the film strength can be improved by forming a multilayer structure by inclining the composition with respect to the surface layer of the base material, such as by applying a mixed sol in which

【0018】

Generally, for example, the contact angle of water on the surface layer of a glazed tile is 30 degrees, and the contact angle of oil is 20 degrees. Even after cleaning, it is difficult for water to enter the gap between the oil and the surface of the base material, so it is difficult to remove it. Further, the charge half-life of the surface layer portion is 30 to 60 seconds, and it is not possible to sufficiently prevent the charged dust in the air from adhering electrostatically. On the other hand, in the functional material of the present invention, the contact angle with water is smaller than the contact angle with oil by forming a fine uneven film of oxide, the contact angle with water is 15 degrees, and the contact angle with oil is 15 degrees. Was 22 degrees and the charging half-life was 1.1 seconds. In this case, since the contact angle of water is smaller, when cleaning the surface to which dirt substances in the air with a large amount of oil are attached with water, water easily enters the gap between the oil and the surface of the base material, so that it is easy to remove. Further, since it is possible to sufficiently prevent the charged dust in the air from adhering electrostatically, it is possible to easily remove the dirt due to the adhering oily component for a long period of time. The charging half-life was measured in accordance with JIS L1094 (Method A).

【0019】

Oxides having a photocatalytic function can more easily run off oily contaminants during cleaning by photoexcitation. The liquid composition, liquid concentration, coating amount, so that the contact angle of water is preferably 25 degrees or less, preferably 10 degrees or less, and the charging half-life is preferably 10 seconds or less, preferably 5 seconds or less. Adjust the number of applications as appropriate. Further, the oxide having a photocatalytic function preferably contains at least one or more of titanium oxide, zinc oxide and tin oxide.

【0020】

The metal supported on the oxide having a photocatalytic function may be any metal as long as it has an improved photocatalytic function. For example, Cu, Ag, Zn, V, W, Pt, Nb, Sb and the like can be mentioned. In particular, by using either one or a combination of doping and photoreduction as a method of supporting a metal on a photocatalyst, sustainability of function can be obtained.

【0021】

Oxides having a photocatalytic function need to be microscopically arranged as a site for hydrophilization by photoexcitation or a site for decomposing organic substances, and the arrangement interval is preferably 400 nm or less, preferably 200 nm or less. ..

【0022】

By using the above manufacturing method, it can be formed directly on the surface of ceramics, glass, tiles, enamel panels and ceramics.

【0023】

(Reference example 1) 25 g / m of a mixture of silica sol and alumina sol with a solid content ratio of 1: 1 and a total solid content of 0.3% on the surface of glass whose surface temperature has been preheated to 120 ° C.²After spraying the coating amount in two steps, a mixed solution of silica sol and potassium sol with a solid content ratio of 3: 1 and a total solid content of 0.2% is 25 g / m.²The coating amount of the above was sprayed in two parts and heat-treated at 850 ° C. to form a fine uneven film of oxide on the glass. The contact angle of water on this surface was 15 degrees, the contact angle of oil was 25 degrees, and the surface roughness Ra was 20 nm. When a mixture of carbon black and oil was dripped on the surface of this glass and water was dripped from both sides of this line, the liquid floated on the surface of the water and could be easily dropped from the surface of the glass. ..

【0024】

(Reference Example 2) The same procedure was performed except that the spray of Example 1 was not sprayed. The contact angle of water on this surface was 31 degrees, the contact angle of oil was 22 degrees, and the surface roughness Ra was 8 nm, but a mixture of carbon black and oil could not be easily removed from the surface of the glass. It was.

【0025】

(Example 1) A total of 1: 7: 2 solid content ratio of titanium oxide sol, silica sol, and potassium sol with Cu and Ag supported on the surface of a glazed mat tile whose surface temperature has been preheated to 80 ° C. 25 g / m of mixed solution with 0.5% solid content²25 g / m of titanium tetraisopropoxide 5% solution diluted with IPA continuously after spraying once with the amount of²After spraying once with the coating amount of, heat treatment was performed at 700 ° C. to form a fine uneven film of oxide on the glazed tile. The contact angle of water on this surface was 22 degrees, the contact angle of oil was 26 degrees, the surface roughness Ra was 400 nm, and the charging half-life was 1.6 seconds. A mixture of carbon black and oil was hung on the surface of this glazed tile, and when water was dripped from both sides of this line, this liquid floated on the surface of the water, so it could be easily dropped from the surface of the glazed tile. did it.

【0026】

In addition, the glazed tiles were exposed outdoors for a week. The contact angle of water on this surface was 15 degrees, the contact angle of oil was 22 degrees, and the charging half-life was 0.6 seconds. A mixture of carbon black and oil was hung on the surface of this glazed tile, and when water was dripped from both sides of this line, this liquid floated on the surface of the water, so it could be easily dropped from the surface of the glazed tile. did it.

【0027】

(Comparative Example 1) 100 g / m of a mixed solution of titanium oxide sol, silica sol, and alumina sol used in Example 2 having a solid content of 1.5%.²The same procedure as in Example 2 was carried out except that the amount of the coating was once sprayed. The contact angle of water on this surface was 18 degrees, the contact angle of oil was 25 degrees, the surface roughness Ra was 520 nm, and the charging half-life was 1.1 seconds. When a mixture of carbon black and oil was dripped on the surface of this glazed tile and water was dripped from both sides of this line, the liquid was soaked into the surface, so it was easy to do without floating on the surface of the water. I couldn't drop it.

【0028】

In addition, the glazed tiles were exposed outdoors for a week. The contact angle of water on this surface was 14 degrees, the contact angle of oil was 20 degrees, and the charging half-life was 0.6 seconds. When a mixture of carbon black and oil was dripped on the surface of this glazed tile and water was dripped from both sides of this line, the liquid was soaked into the surface, so it was easy to do without floating on the surface of the water. I couldn't drop it.

【0029】

[Effect of the invention]

As described above, according to the present invention, in a member indoors or outdoors to which pollutants containing oily components are likely to adhere, the fine oxides have a larger contact angle with oil than a contact angle with water. By forming a smooth uneven film, it is possible to provide a functional material capable of easily removing contaminants containing an attached oily component. Further, according to the present invention, the amount of detergent used for cleaning can be reduced, and the emission of carbon dioxide can be suppressed at the same time as the energy required for water pollution and purification.

[Simple explanation of drawings]

[Figure 1]

It is sectional drawing which shows the outline of the functional material which concerns on one Embodiment of this invention.

[Figure 2]

It is sectional drawing which shows the outline of the functional material which concerns on one Embodiment of this invention.

[Fig. 3]

It is sectional drawing which shows the outline of the functional material which concerns on one Embodiment of this invention.

[Explanation of symbols]

1 ... substrate surface layer, 2 ... oxide, 3 ... oxide with photocatalytic function.