JPH10279830A - Wall coating material and wall coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To impart antibacterial action, antifouling action, and long-term durability to coated walls, ceilings, etc., by using a coating material contg. a coated aggregate prepd. by coating the surface of an inorg. aggregate with anatase titanium dioxide by using an inorg. adhesive. SOLUTION: A typical natural aggregate used is natural sand, crushed stone, pumice, kansui-seki, perlite, silica sand, glass beads, etc., and has a particle size of 0.1-10 mm. The anatase titanium dioxide used pref. has a particle size of 7-50 nm and is compounded in an amt. of 2-20 wt.% of the aggregate. The inorg. adhesive used as a binder is aluminum oxide, silicon dioxide, zirconium oxide, lithium silicate, cement, etc. For instance, the coating process comprises the step of charging the aggregate into a high-speed flowing mixer; the step of charging the adhesive to cause it to adhere to the surface of the aggregate; and the step of dispersing titanium oxide to adhere it to the surface followed by drying.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wall coating finishing material suitable for trowel coating which exhibits an antibacterial action and an antifouling action on a dry finished surface such as a wall surface or a ceiling surface, and a method of using the same.

[0002]

2. Description of the Related Art As a wall coating finishing material, an inorganic powder such as calcium carbonate, clay, talc, and mica is applied to the surface of an inorganic aggregate such as natural sand, crushed stone, and cold water stone.
It is known to include a coated aggregate coated with a binder such as C, methylcellulose, or a synthetic resin emulsion. (For example, Japanese Patent Publication No. 47-29178
Nos. 57-30829, 62-5915, JP-A-4-285045, and JP-B-6-33354.

[0003] Titanium dioxide is classified into two types, a rutile type and an anatase type, according to the difference in crystal structure, and those widely known as white pigments belong to the rutile type. It is already known to use anatase-type titanium dioxide as a photocatalyst to purify air contaminated by bacteria, volatile substances, suspended substances and the like. (For example, Japanese Patent Application Laid-Open No. 6-81
No. 1092)

On the other hand, in order to suppress the occurrence of bacteria such as mold on the painted wall finishing surface, organic copper compounds, organic tin compounds, organic zinc compounds, phenolic compounds, pyridine compounds, antibiotics, etc. Attempts have also been made to incorporate surfactants and the like. However,
These substances have problems such as poor sustainability and ineffectiveness against a wide range of bacteria, and there is a concern that they may have an adverse effect on the human body. Therefore, they have been difficult to put to practical use.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an anatase-type titanium dioxide in a wall coating finishing material to exhibit an antibacterial action and an antifouling action on a dry-finished surface such as a painted wall or ceiling. It was done.

As described above, this type of wall coating finish material is obtained by coating the surface of an inorganic aggregate with a binder such as a CMC, methylcellulose, or synthetic resin emulsion as a binder, and kneading with an organic adhesive. Painted. However, a wall finishing material in which an anatase-type titanium dioxide is coated on the surface of an inorganic aggregate using an organic adhesive such as CMC, methylcellulose, or a synthetic resin emulsion can be used only a few months after painting. Due to the oxidizing action of titanium, the organic binder is gradually oxidized and decomposed, and the coating film on the wall surface is peeled off.

[0007]

In view of such circumstances, the present inventors have developed an environment in which anatase-type titanium dioxide acts as a photocatalyst upon receiving light energy, and an anatase-type titanium dioxide as a photocatalyst. The research objective was to select a binder that stably adheres to the surface over a long period of time.As a result of repeated tests, the intended purpose was achieved by coating the surface of the inorganic aggregate with anatase-type titanium dioxide using an inorganic adhesive They have found what can be done and have completed the present invention.

[0008] The present invention is characterized in that it comprises a coated aggregate obtained by coating an anatase type titanium dioxide on the surface of an inorganic aggregate with an inorganic adhesive. Coated aggregate obtained by coating titanium with an inorganic adhesive, and cement as an essential component, characterized in that the cement is blended in a ratio of 5 to 50 parts by weight with respect to 100 parts by weight of the coated aggregate. In the construction, the wall coating material is kneaded with water and applied to the wall surface, and the uncured cement on the surface of the coating film is removed to expose the coated aggregate.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Typical examples of the inorganic aggregate used in the present invention are natural sand, crushed stone, pumice, cold water stone, pearlite, silica sand, glass beads, and a fired body mainly composed of glass. Those having a particle size in the range of 0.1 to 10 mm are suitable. If the particle size of the aggregate is larger than the above range, workability such as iron elongation and iron separation is deteriorated, and If it is smaller than the range, the aggregate is buried in an inorganic adhesive such as cement, and it is not possible to produce a beautifully finished wall surface.

[0010] The anatase type titanium dioxide is a commercially available powdery one having a particle size in the range of 7 to 50 nm, which is suitable for use. The blending amount of anatase type titanium dioxide with respect to the inorganic aggregate is preferably 2 to 20 parts by weight of titanium dioxide with respect to 100 parts by weight of the aggregate, and if the amount is small, the inorganic aggregate cannot be sufficiently concealed. The aesthetics of the surface deteriorates, and the cost of raw materials increases if more than necessary. Representative inorganic adhesives used as a binder of inorganic aggregate and anatase type titanium dioxide are aluminum oxide, silicon dioxide,
Zirconium oxide, lithium silicate, cement and the like can be mentioned.

As a method of coating the surface of the inorganic aggregate with anatase type titanium dioxide, for example, using a high-speed fluid mixer, first, an inorganic aggregate is charged, and then an inorganic adhesive is charged, and then the surface of the aggregate is charged. An inorganic adhesive is adhered to the whole, and finally, titanium oxide is dispersed and adhered and dried.
In this case, while the inorganic adhesive is heated to a temperature of 100 to 120 ° C., mixing and stirring should be normally performed at a peripheral speed of 1 to 10 m per second for about 60 minutes. By attaching titanium oxide to the outermost surface of the inorganic aggregate, it becomes possible to exhibit an oxidizing effect by receiving light energy. It may cause oxidative effects.

The surface-treated coated aggregate can be mixed with cement as an inorganic adhesive for water kneading in advance, whereby a uniformly mixed wall coating material can be obtained. Time work can be simplified. In this case, 5 to 50 parts by weight of cement should be mixed with 100 parts by weight of the surface-treated coated aggregate. If the mixing ratio of cement to the coated aggregate is less than the above range, sufficient adhesive strength cannot be obtained when the coating film on the wall is dried, and if it exceeds the above range, the cement is coated on the wall surface. Thus, the photocatalytic action of titanium dioxide is significantly inhibited.

In the present invention, when cement is mixed with a coated aggregate obtained by coating an anatase-type titanium dioxide on the surface of an inorganic aggregate with an inorganic adhesive, and the mixture is kneaded with water and applied to a wall surface, the surface of the coating film is not removed. The hardened cement should be removed to reveal the coated aggregate and enhance the photocatalytic action of anatase titanium dioxide. As a means for removing the uncured cement on the coating film surface, washing can be performed, but the cement on the wall surface can be easily removed by brushing with a plaster brush or the like.

In carrying out the present invention, the surface of the inorganic aggregate is coated with calcium carbonate, clay, talc, mica, clay, colored clay, silica powder, silica powder, bentonite, sepiolite, rutile type titanium dioxide, colored titanium mica, etc. Coloring with inorganic fillers or inorganic extenders, or by using these inorganic fillers or inorganic extenders together with anatase-type titanium dioxide that coats the inorganic aggregate, changes the color tone of the painted surface be able to.

[0015]

【Example】

Example 1 Natural sand 10 having a particle size in the range of 2-3 mm
0 parts by weight and 5 parts by weight of a lithium silicate (Li ₂ O.nSiO ₂ ) -based adhesive [manufactured by Nippon Chemical Industry Co., Ltd.] are put into a high-speed fluid mixer, and heated to a temperature of 100 to 120 ° C. Mix and stir at a peripheral speed of 5 m / sec for 2 minutes, then add 3 parts by weight of anatase type titanium dioxide having a particle size of 50 nm or less (manufactured by Ishihara Sangyo Co., Ltd.), and further stir and mix for 60 minutes to obtain natural sand. A coated aggregate whose surface was coated with titanium dioxide was obtained.

10 parts by weight of white cement was mixed with 100 parts by weight of the above-mentioned coated aggregate, 80 parts by weight of water was added thereto, and the mixture was kneaded. The coated aggregate was iron-coated on the base of the plaster board at a rate of 4 kg per 1 m ² . . After that, when the water on the painted surface was drained, the painted surface was brushed with a plaster brush to remove the cement on the surface, and the wall surface was naturally dried. As a result, a finished surface having a wash-like uneven pattern was formed. The wall-finished surface thus obtained was then left for 6 months in a place exposed to direct sunlight, but no peeling of the coating and no discoloration of the coating were observed.

Immediately after being troweled and dried, a part of the painted surface is cut out, placed in a 9-liter transparent glass container having a size of 90 cm ^{2 and} an acetaldehyde concentration adjusted to 100 ppm, and irradiated with ultraviolet light. 5mW /
was irradiated for 2 hours in an amount of cm ^2, the concentration of acetaldehyde in the glass vessel was reduced to 50 ppm. In addition,
For the purpose of comparison, in the above-described embodiment, the coated aggregate was applied to the base of the plaster board, the painted surface was not brushed, the cement was left on the surface and the air-dried plaster board was 90 cm ² in size, and the acetaldehyde concentration was 100 pp.
m, and the same ultraviolet treatment was performed. No decrease in the concentration of acetaldehyde in the container was observed.

Example 2 In the same manner as in Example 1, a coated aggregate was prepared by coating the surface of natural sand with anatase-type titanium dioxide, and 10 parts by weight of white cement was uniformly mixed with 100 parts by weight of the coated aggregate. To prepare a wall coating material. Put this product in a polyethylene bag, temperature 50 ℃, humidity 6
It was stored for 6 months under the condition of 0%, after which 80 parts by weight of water was added and kneaded, and as in Example 1, the coated aggregate was iron-coated on the base of the plaster board at a rate of 4 kg per 1 m ² , After that, when the painted surface was drained,
When the painted surface was brushed with a plaster brush and the cement on the surface was removed, and the wall surface was air-dried, a finished surface having a washed-out uneven pattern was formed. A part of the painted surface was cut out, placed in a 9 liter transparent glass container having a size of 90 cm ^{2 and} an acetaldehyde concentration adjusted to 100 ppm, and irradiated with ultraviolet rays at an amount of 0.5 mW / cm ² for 2 hours. However, the acetaldehyde concentration in the glass container was 50 ppm. The wall finish obtained in this way is then placed in direct sunlight.
After leaving for a month, no peeling of the coating film and no discoloration of the coating film were observed.

Comparative Example 1 100 parts by weight of the same natural sand and anatase-type titanium dioxide 3
Parts by weight into a high-speed fluid mixer, 10 parts by weight of an aqueous solution containing 0.5 parts by weight of methylcellulose was added thereto, and mixed and stirred for 1 minute. Obtained. The coated bone 1.5 parts by weight per aggregate 100 parts by weight of CMC in material, ethylene vinyl acetate resin with 10 parts by weight per aggregate 100 parts by kneading water, the plasterboard underlayer, the coating aggregate 1 m ²
Iron was applied at a rate of 1.5 kg per unit. When the wall surface thus coated was allowed to stand for 6 months in a place exposed to direct sunlight, spots due to discoloration occurred in the coating film, and peeling was locally observed.

[0020]

According to the present invention, an aesthetically pleasing finished surface having a washed-out unevenness pattern can be obtained by troweling the wall or ceiling surface and brushing the painted surface, and the painted surface is an anatase type dioxide. The photocatalytic effect of titanium provides an antibacterial effect and an antifouling effect, and can maintain a beautiful wall surface for a long time.

Claims (3)

[Claims] 1. A wall coating material comprising a coated aggregate obtained by coating an anatase type titanium dioxide on the surface of an inorganic aggregate with an inorganic adhesive. 2. A coated aggregate comprising, as essential components, a coated aggregate obtained by coating an anatase type titanium dioxide on the surface of an inorganic aggregate with an inorganic adhesive and cement.
A wall coating material, wherein cement is blended in an amount of 5 to 50 parts by weight with respect to 0 parts by weight. 3. A coated aggregate comprising, as essential components, a coated aggregate obtained by coating an anatase type titanium dioxide on the surface of an inorganic aggregate with an inorganic adhesive and cement.
A wall coating material obtained by mixing 5 to 50 parts by weight of cement with respect to 0 parts by weight is kneaded with water and applied to the wall surface. A wall painting method characterized by being exposed.