JP3284733B2 - Method for producing colored cement concrete products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing colored cement concrete products using metal sulphates. More specifically, the present invention is to chemically treat the surface of mortar and / or concrete product such as cement mortar, concrete panel, block, pile, tile, cement concrete building, construction, etc. to promote color development. The present invention relates to a method for easily and efficiently producing a colored cement concrete product which does not peel off a formed colored film (layer) and is excellent in long-term weather resistance and stability.

[0002]

2. Description of the Related Art Cement concrete products are used in large quantities in the fields of construction and civil engineering, but in recent years, in consideration of harmony with nature and increasing interest in landscapes, environmentally friendly colored cement concrete products have been used. Has come to be strongly desired.

[0003] Conventionally, as a method for producing a colored cement concrete product, a method in which a pigment is mixed with a raw material such as cement during the production of the product, or a paint of a predetermined color or an emulsion of the pigment is brushed on the surface of the product. A method of applying by spraying or spraying is known. However, the method of mixing with the above raw materials not only requires a large amount of pigment but also has a drawback that a coloring effect is not obtained unless expensive white cement is used, and it is difficult to produce a natural color. In addition, in the case of a method of applying a paint, there is a problem in handling and safety and hygiene because a large amount of an organic solvent is used, in addition to easy peeling of the coating film, poor weather resistance, and the like. Is difficult to produce natural shades.

In addition to the above method, Japanese Patent Application Laid-Open No.
Japanese Patent Application Laid-Open No. 8-68620 describes a method of applying an aqueous solution of a metal sulfate such as manganese sulfate or iron sulfate to a surface of a cement product to form a color or color. Since this method is a method utilizing a chemical reaction, the difficulty of the method can be improved, but it takes a long time until the color tone changes over time and the color tone becomes stable, In particular, in the case of a cement concrete product which has been manufactured for a long period of time, coloring does not occur, or coloring is insufficient and coloring cannot be performed. This method also has room for improvement.

According to the study of the present inventors, the details of the coloring and coloring mechanism of the method using metal sulfate are not clear, but free Ca generated by the hydration reaction of cement in cement concrete products. (OH) ₂ reacts with the metal sulfate to form fine crystals of metal hydroxide to form a color,
Along with calcium sulfate and other reaction products generated at the same time, it enters the minute gaps of the cement concrete in the surface layer of the cement concrete product, densifies the surface layer, and the surface of the surface of the microcrystalline hydroxide salt is unique. It is presumed that a colored film layer was formed and colored. The reason why it takes a long time for the color tone to stabilize depends on the leaching rate of free Ca (OH) ₂ and the reaction rate of hydroxide formation, which bleed from the cement concrete product to the surface layer. Therefore, this is the cause of the gradual color development, and the leaching of free Ca (OH) ₂ occurs in cement concrete products which have been manufactured for a long time since the surface is neutralized or dried too much. It is presumed that insufficient color formation does not result in color formation or causes poor color formation.

[0006]

DISCLOSURE OF THE INVENTION In view of the foregoing, the inventors of the present invention aimed at developing a method for producing a colored cement concrete product which can improve the above-mentioned difficulties.
Further, intensive studies have been made for the purpose of improving poor coloring and instability of the color tone of the method using a metal sulfate. As a result, if the surface of the cement concrete product or the surface of the colored film (layer) is subjected to an alkali treatment before and / or after the colored film (layer) is formed on the cement concrete product, color development is promoted, The formation of a colored film (layer) with a stable color tone by promoting the formation of a strong colored film (layer) at an early stage. The coloring does not peel off and has excellent long-term weather resistance and stability. The ability to easily and efficiently produce cement concrete products, and good coloring even for cement concrete products that have been produced for a long period of time and have become uncolorable or poorly colored due to neutralization, drying, etc. The present invention has been found that it is possible to prevent the whitening phenomenon of the cement concrete product, and also to achieve the above object.

[0007]

SUMMARY OF THE INVENTION The present invention is directed to an alkali treatment of a cement concrete product before and / or after forming a colored film mainly composed of a metal sulfate and / or a reaction product thereof. And a method for producing a colored cement concrete product. The present invention also relates to a cement concrete product, which comprises a group 1B, 6
Before and / or before impregnation and / or application of an aqueous solution of a metal sulfate selected from the group consisting of group A, group 7A and group 8 to form a colored film mainly containing metal sulfate and / or a reaction product thereof And then subjecting the surface of the cement concrete product to an aqueous alkali solution. Further, the present invention relates to a cement concrete product comprising a 1B group, 6A
And / or coating with an aqueous solution of a metal sulfate selected from the group consisting of Group 7A, Group 7A and Group 8 to form and / or form a colored film based on metal sulfate and / or its reaction product. And then treating the surface of the cement concrete product with an aqueous alkaline solution having a pH of 8 or more.

The type, shape, size and the like of the cement concrete product to which the present invention can be applied are not particularly limited. For example, cement mortar, concrete panel,
Blocks, piles, tiles, joints, cement concrete
The present invention can be applied to any of cement mortar products and cement concrete products such as buildings and structures, and to any places. Further, the production of the colored cement concrete product according to the present invention may be carried out at the site where coloring is performed or at a factory for producing the cement concrete product.

In the present invention, the metal sulphate is preferably a water-soluble metal sulphate, preferably group 1B or 6A of the periodic table.
A water-soluble metal sulphate selected from the group consisting of Groups 7A and 8 is used. Specific examples of metal sulfates include water-soluble metal sulfates such as copper sulfate, chromium sulfate, manganese sulfate, iron sulfate, cobalt sulfate, and nickel sulfate. The metal sulfate may be used alone or in combination of two or more.

The metal sulphate is impregnated and / or applied to the surface of the cement concrete product as a solution, generally as an aqueous solution. Upon impregnation and / or application, color develops and a colored film forms on the surface of the cement concrete product. The method of impregnation and / or application is not particularly limited, but a method such as brushing, spraying, and dipping is usually employed. The operation of impregnation and / or application may be performed once or repeatedly. Further, impregnation and / or coating may be performed by partially changing the type of metal sulfate. Various coloring patterns can be formed by these operations.

The concentration when used as an aqueous solution of metal sulfate varies depending on the impregnation and application amount of the metal sulfate into the cement concrete product, but ranges from 2% by weight (based on anhydride) to a saturated concentration. , Preferably 5 to 30
It is appropriately selected and used in consideration of the color tone from the range of weight%.
Generally, the lower the density, the lighter and the higher the color, the deeper the color. However, if the density is less than 2% by weight, the color is hardly colored. The amount of metal sulfate impregnated and applied to the cement concrete product may vary depending on the surface condition of the cement concrete product, the type of metal sulfate, the concentration of the metal sulfate aqueous solution, and the like. Product surface area 1
^{1 to} 150 g, preferably 20 to 100 g, per m ² is suitable. If the amount of impregnation and application is too small, coloring is not sufficient, and if it is excessively large, there is no particular change in color tone.

Further, in the present invention, cement concrete
The reason why the bleaching phenomenon of the product can also be suppressed is presumed that elution of the alkali component in the product from the inside to the surface is blocked by the densified surface layer and the colored film.

In the present invention, the alkali treatment may be performed before or after the formation of a colored film mainly containing a metal sulfate and / or a reaction product thereof on a cement concrete product. It may be done later. However, if it is performed before the formation of the colored film, the color development is more effectively promoted even for a cement concrete product whose surface is neutralized or too dry, and the color tone is stable and strong. Not only can a colored film be formed at an early stage, but also a cement concrete of an aqueous solution of metal sulfate can be used.
This is preferable because the absorption into the product is small and the amount of impregnation and / or application is small.

[0014] The alkali treatment is a method of impregnating and / or applying an aqueous alkali solution having a pH of 8 or more, preferably 10 or more, on the surface of a cement concrete product before and / or after forming a colored film. Done. When the pH is lower than 8, there is almost no effect of promoting color development, and therefore, it is preferable to use a high pH alkaline aqueous solution. The method of impregnation and / or coating is not particularly limited, but a method such as brushing, spraying, dipping or the like is usually employed. The operation of impregnation and / or application may be performed once or repeatedly.

The amount of impregnation and / or application of the aqueous alkali solution is as follows:
The surface condition of the cement concrete product, the pH of the aqueous alkaline solution, the viscosity, the drying speed, etc., vary, but the amount is preferably 20 to 2000 g, preferably 50 to 500 g, per 1 m ^{2 of the} surface area of the product to be treated. If the impregnation and / or coating amount is too small, the effect cannot be expected, and if it is too large, the metal sulfate component cannot penetrate into the cement concrete product, which is not preferable.

In the case where an alkali treatment is performed before forming a colored film, it is preferable to perform the above-described coloring operation with a metal sulfate while the alkali-treated surface layer is in a wet state from the viewpoint of early color development.

The alkaline substance used in the alkali treatment may be any one which is water-soluble and has a pH of an aqueous solution of 8 or more, preferably 10 or more. In use, the alkaline substance may be completely dissolved in water. It may be a partially dissolved aqueous suspension solution. Specific examples of the alkali substance include hydroxides of alkali metals such as sodium hydroxide and potassium hydroxide, (bi) carbonates of alkali metals such as sodium (bi) carbonate and potassium (bi) carbonate, and sodium metasilicate. Oxidation of alkali metal silicates such as potassium, potassium metasilicate, water glass, hydroxides of alkaline earth metals such as calcium hydroxide, magnesium hydroxide and strontium hydroxide, and alkaline earth metals such as calcium oxide and magnesium oxide Objects and the like. They may also be mixtures. Sludge or sludge water discharged from a cement concrete factory can also be used.
Among the alkaline substances, calcium oxide, calcium hydroxide and the like are particularly preferably used because they are also one of the components of the cement concrete product.

In the present invention, although the mechanism by which color formation is promoted by the alkali treatment and a strong colored film (layer) having a stable color tone can be formed at an early stage is not sufficiently clear, it is not sufficiently clear, but the alkali is used for cement concrete. The surface (layer) of the cement product is activated and promotes the reaction with the metal sulfate, and the alkali more firmly integrates the surface (layer) of the cement concrete product with the metal sulfate and its reaction product. It is presumed that it has the effect of causing.

[0019]

According to the present invention, color formation is promoted without poor color formation, etc., and the formation of a strong colored film layer is promoted at an early stage, whereby a colored film having a stable color tone can be formed. Without this, it is possible to easily and efficiently produce a colored cement concrete product excellent in long-term weather resistance and stability, and also to prevent the whitening phenomenon of the cement concrete product.

[0020]

EXAMPLES In each example, the accelerated weathering test was conducted according to JIS.
A1415 "Accelerated exposure test method for plastic building materials", length 150mm, width 70mm, thickness 20
Using a 0 mm sample, the test was conducted under the conditions of sunshine carbon, a black panel temperature of 63 ± 3 ° C., a humidity of 50% RH, and a rainfall of 12 minutes in 60 minutes of a spray cycle.

Example 1 In a 30 × 30 × 3 cm formwork, ordinary Portland cement: sand = 1: 2 (weight ratio), water cement ratio (W / C) =
A cement mortar of 0.45 (weight ratio) was poured in, and after moist air curing overnight, demolded, further moist air curing overnight, and then 9
Aerial curing was performed for 0 days to produce a cement panel. PH12 aqueous sodium hydroxide solution is added to cement panel.
200 g / m ² was applied, the panel surface is left at room temperature the iron sulfate aqueous solution having a concentration of 15 wt% is impregnated sprayed 80 g / m ² while still wet. The surface of the cement panel developed color simultaneously with drying, and a yellow-brown colored film was formed on the surface in one hour of the impregnation treatment. After the panel was left at room temperature and dried for 1 hour, a colored cement panel having a dark yellow-brown film equivalent to 500 hours of accelerated weathering was obtained. This colored cement panel had a stable dark yellow-brown color tone even after being left outdoors for one year or more, and neither fading nor efflorescence was observed.

Example 2 The same sodium hydroxide solution and iron sulfate solution as in Example 1 were used except that the aerial curing for 90 days in the production of the cement panel in Example 1 was changed to 180 days. To obtain a colored cement panel having a film of The results were excellent as in Example 1.

Comparative Example 1 A colored cement panel was produced in the same manner as in Example 1 except that the aqueous sodium hydroxide solution of Example 1 was not applied. As the sprayed aqueous solution of iron sulfate dried, a thin yellow-brown film was formed on the panel surface.
It did not reach a dark tan color comparable to 00 hours. Thereafter, when left outdoors, the color gradually turned brown, and it changed to dark yellow-brown over a period of six months to one year.

Comparative Example 2 The same procedure as in Example 1 was carried out except that the panel was changed from the air curing for 90 days in the production of the cement panel of Example 1 to 180 days, and the aqueous sodium hydroxide solution of Example 1 was not applied. Production of a colored cement panel was attempted in the same manner as in Example 1.
However, the sprayed aqueous solution of iron sulfate permeated the panel and did not develop color. Then, the spraying operation of an aqueous solution of iron sulfate having a concentration of 15% by weight again at 80 g / m ² was repeated twice, and the panel was slightly changed to yellow.

Example 3 A cement panel in which the aerial curing for 90 days in the production of the cement panel of Example 1 was changed to 180 days, and
100 g of H12 calcium oxide aqueous solution (lime water)
/ M ² and a density of 20 while the panel surface is wet.
A 80% aqueous solution of manganese sulfate was impregnated by spraying at 80 g / m ² and allowed to stand at room temperature. The surface of the cement panel developed color simultaneously with drying, and a brown colored film was formed on the surface one hour after the impregnation. After the panel was left at room temperature and dried for 1 hour, a colored cement panel having a brown film equivalent to 500 hours of accelerated weathering was obtained. This colored cement panel had a stable brown color tone even when left outdoors for one year or more, and neither fading nor efflorescence was observed.

Comparative Example 3 A colored cement panel was produced in the same manner as in Example 3 except that the lime water in Example 3 was not applied. However, the sprayed manganese sulfate aqueous solution permeated the panel and did not develop color. Then, the operation of spraying 80 g / m ^{2 of an} aqueous solution of manganese sulfate having a concentration of 20% by weight again was repeated twice, but no color was formed.

Example 4 Using a cement panel in which the air curing for 90 days in the production of the cement panel of Example 1 was changed to 180 days,
100 g / m ^{2 of} H12 cement sludge water is applied,
While the panel surface was wet, a 12% by weight aqueous solution of chromium sulfate was sprayed at 80 g / m ^{2 to} impregnate the panel. The surface of the cement panel developed color simultaneously with drying, and a blue-green colored film was formed on the surface one hour after the impregnation treatment. After the panel was left at room temperature and dried for 1 hour, a colored cement panel having a bluish green film equivalent to 500 hours of accelerated weather resistance was obtained. This colored cement panel had a stable blue-green color tone even after being left outdoors for one year or more, and neither fading nor efflorescence was observed.

Comparative Example 4 A colored cement panel was produced in the same manner as in Example 4, except that the cement sludge water was not applied. However, the sprayed chromium sulfate aqueous solution permeated the panel and did not develop color. Therefore, the density 12
When the operation of spraying 80 g / m ^{2 of a} chromium sulfate aqueous solution of ² % by weight was repeated twice, the panel turned slightly blue-green.

Example 5 Using a cement panel in which the air curing for 90 days in the production of the cement panel of Example 1 was changed to 180 days,
An aqueous solution of H12 water glass was applied at 100 g / m ^2, and while the panel surface was wet, a 12% by weight aqueous solution of copper sulfate was sprayed and impregnated at 80 g / m ² to stand at room temperature. The surface of the cement panel developed color simultaneously with drying, and a blue-green colored film was formed on the surface one hour after the impregnation treatment. After the panel was left at room temperature and dried for 1 hour, a colored cement panel having a blue film equivalent to 500 hours of accelerated weather resistance was obtained. This colored cement panel had a stable blue color tone even after being left outdoors for one year or more, and neither fading nor efflorescence was observed.

Comparative Example 5 The procedure of Example 5 was repeated except that the aqueous solution of water glass was not applied.
Production of a colored cement panel was attempted in the same manner as in Example 5. However, the sprayed copper sulfate aqueous solution permeated the panel and did not develop color. Then, the operation of spraying 80 g / m ^{2 of an} aqueous solution of copper sulfate having a concentration of 12% by weight again was repeated twice, and the panel turned only slightly blue.

Example 6 A cement panel in which the aerial curing for 90 days in the production of the cement panel of Example 1 was changed to 180 days, and a 20% by weight aqueous solution of manganese sulfate was applied at 160 g / m ² using a cement panel. While the surface was moistened, it was impregnated by spraying 50 g / m ^{2 of an} aqueous sodium hydroxide solution of PH12 and allowed to stand at room temperature. The surface of the cement panel developed color simultaneously with drying, and a brown colored film was formed on the surface one hour after the impregnation. After leaving the panel at room temperature for 1 hour, accelerated weather resistance 5
A colored cement panel having a brown film comparable to 00 hours was obtained. This colored cement panel had a stable brown color tone even when left outdoors for one year or more, and neither fading nor efflorescence was observed.

Comparative Example 6 A colored cement panel was produced in the same manner as in Example 6, except that the aqueous sodium hydroxide solution of Example 6 was not applied. As the sprayed manganese sulfate aqueous solution dried, a thin brown film was formed on the panel surface, but did not reach a brown color equivalent to 500 hours of accelerated weather resistance. Thereafter, when left outdoors, the color gradually turned brown, and it turned brown over a period of six months to one year.

Claims (3)

(57) [Claims] 1. A colored cement characterized in that the surface is subjected to an alkali treatment before and / or after a colored film mainly composed of a metal sulfate and / or a reaction product thereof is formed on a cement concrete product. Manufacturing method of concrete products. 2. The periodic table 1 is used for cement concrete products.
Before impregnating and / or applying an aqueous solution of a metal sulfate selected from the group consisting of Group B, Group 6A, Group 7A and Group 8 to form a colored film mainly composed of a metal sulfate and / or a reaction product thereof; And / or after being produced, cement concrete
A method for producing a colored cement concrete product, characterized in that the surface of the product is treated with an aqueous alkaline solution. 3. The method for producing a colored cement concrete product according to claim 2, wherein the pH of the aqueous alkali solution is 8 or more.