JP3217166B2 - Algae and fungicide for cement - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-algal fungicide for cement, which is added to and mixed with cement or concrete produced by using cement to prevent the occurrence of algae and fungi.

[0002]

2. Description of the Related Art Copper ions (Cu ²⁺ ) have been used for various types of anti-algal and antifungal agents since they are effective for anti-algal and anti-fungal activities. For example, copper sulfate (CuSO ₄ ) is used to prevent or eliminate the occurrence of algae in a pool, and a Bordeaux solution (basic copper salt) is used to prevent a disease caused by mold in agriculture. These are all based on the anti-algal and fungicidal action of copper ions. By the way, generation of algae and fungi may be observed on the surface of the cement / concrete structure. In particular, a large amount of contamination by algae and fungi is observed on tile joints in bathrooms and on the north side of buildings, which is unpleasant in appearance and unfavorable in health. Even in such a cement concrete structure, it is known that copper ions are effective in preventing algae and fungi.

[0003]

However, even if the concentration of copper ions is only about 1 ppm, the hardening of cement is inhibited, so that copper ions or copper salts cannot be mixed with cement before use. That is, not only water-soluble compounds such as copper sulfate (CuSO ₄ ), copper chloride (CuCl ₂ ), and copper nitrate (Cu (NO ₃ ) ₂ ), but also basic copper sulfate [CuSO ₄ .Cu (OH) _2], basic copper carbonate _{[CuCO 3 · Cu (OH)} 2], in water of the basic copper chloride _{[CuCl 2 · Cu (OH)} 2] , etc. a compound of poorly soluble, inhibiting the curing of the cement Therefore, it cannot be used by being mixed with cement in advance. on the other hand,
Copper metal (Cu), copper oxide (CuO), cuprous oxide (Cu ₂
O), copper sulfide (CuS) and the like do not inhibit the hardening of the cement, but hardly release copper ions, so that they have no effect as an anti-algal and fungicide and are considered to be impractical. .

[0004] For the above-mentioned reasons, in order to apply algae and fungicide treatment to cement concrete, for example, after the cement concrete is hardened, a method of treating its surface with copper ions is adopted. However, this method requires a lot of time and labor for the treatment, so that the construction efficiency is impaired and the construction cost is increased.

The present invention has been made in view of the above circumstances, and can be added to unhardened cement concrete without inhibiting the hardening reaction of cement, and has excellent anti-algal and anti-fungal properties. It is an object of the present invention to provide an anti-algal fungicide for cement having a small change in color tone.

[0006]

Means for Solving the Problems Claim 1 of the present invention
In the described anti-algal and fungicide for cement, the solution to the above-mentioned problem is to comprise a mixture of a cuprous oxide powder and a titanium oxide powder. The anti-algal fungicide for cement according to claim 2,
The solution of the above-mentioned problem is made of an alkali-treated cuprous oxide powder.

Hereinafter, the present invention will be described in detail. The anti-algal fungicide for cement according to claim 1 of the present invention comprises a mixture of cuprous oxide (Cu ₂ O) powder and titanium oxide (TiO ₂ ) powder. This mixture has anti-algal and anti-fungal properties without substantially inhibiting the hardening reaction of the cement, and has a slight change in color tone given to the cement. Here, the cuprous oxide powder alone hardly inhibits the hardening reaction of the cement, but has a weak effect on the algal and fungicidal properties and further changes the color tone given to the cement, which is not preferable.

[0008] Regarding the particle size of the cuprous oxide powder and the titanium oxide powder, both are preferably fine particles, for example, those having a particle size of about 0.1 to 10 µm are suitable. The mixing ratio of the cuprous oxide powder and the titanium oxide powder is preferably in the range of cuprous oxide: titanium oxide = 1: 10 to 8: 2. If the amount of cuprous oxide is larger than this range, the anti-algal and fungicidal properties will be reduced, and even if the amount is low, the anti-algal and anti-fungal properties will also be reduced. In addition, it is necessary to sufficiently mix the cuprous oxide powder and the titanium oxide powder so as to be uniform, and in order to perform such uniformity, it is necessary to perform the mixing and the pulverization simultaneously using, for example, a ball mill. preferable.

[0009] The anti-algae of the present invention comprising such a mixture
In order to use the antifungal agent for anti-algae and antifungal of cement and concrete, for example, the following three methods can be adopted. The first method is to directly knead the cement concrete. Second, after the cement concrete is cast, before the cement concrete has set,
The mixed powder is applied by a spray method or the like. A third method is to apply the mixed powder to a mold in advance by a spray method or the like, and then to cast cement / concrete into the mold. According to the third method, after hardening, the mixture powder migrates to the cement / concrete side and exerts its effect.

The above three methods are all cement /
This is a treatment in a state where the concrete has not yet set, that is, the anti-algal and anti-fungal agent of the present invention can be used before the hardening of the cement concrete. By the way, since the cuprous oxide powder is reddish brown, the mixture of this and the titanium oxide powder also exhibits reddish brown. This color is almost inconspicuous when the mixture is used for ordinary cement, so there is no particular problem. However, when used for white cement, the cement concrete may become pink or brown.

If such coloration becomes a problem, it is effective to treat the cuprous oxide powder with an alkali, that is, with a basic substance, and the coloration is reduced by such treatment. You. That is, the color of the cuprous oxide powder changes from reddish brown to blue-gray by this treatment, and therefore, the degree of discoloration to the white cement is reduced, and the discoloration becomes less noticeable. In addition, such alkali treatment also activates the cuprous oxide in its anti-algal and anti-fungal properties, whereby the cuprous oxide becomes sufficiently effective as an anti-algal and anti-fungal agent by itself without adding titanium oxide powder.

As the basic substance used in the treatment, sodium hydroxide, potassium hydroxide or calcium hydroxide is preferred. As a treatment method, these compounds are added to water to prepare an aqueous solution or suspension of 1 to 10 mol / l, and a cuprous oxide powder is suspended in the obtained solution, and the color tone of the suboxide powder is changed. Is allowed to stand, and after a change in color tone is recognized, this may be filtered. If the concentration of the basic substance is less than 1 mol / l, it takes a long time to change the color tone, and even if it exceeds 10 mol / l, no further effect can be expected. Is done. Further, it is a matter of course that such an alkali-treated cuprous oxide powder may be used alone or in a mixture with the titanium oxide powder as described above. The anti-algal and anti-fungal agent becomes more effective.

[0013]

[Function] The mixture powder of cuprous oxide and titanium oxide does not inhibit the setting reaction of cement, has an anti-algal and anti-fungal effect, and has a small change in color tone for the following reasons. Conceivable. If a powder mixture of cuprous oxide and titanium oxide is added to or applied to cement concrete before curing, the cuprous oxide does not dissolve in water and does not release copper ions, and therefore does not inhibit the setting of the cement. However, as the cement hardens, calcium hydroxide (Ca (OH) ₂ ) is generated from the cement. The cuprous oxide then reacts slowly with the calcium hydroxide, releasing copper ions. At this time, the titanium oxide plays a catalytic role and promotes the release of copper ions. Also,
It is considered that the change in the color tone is small because the refractive index of titanium oxide is large and the color of cuprous oxide is weakened.

On the other hand, the reason why the coloration of cement concrete caused by cuprous oxide is weakened by the alkali treatment is considered as follows. That is, cuprous oxide reacts with alkali to form copper hydroxide on its surface, but since this copper hydroxide is bluish-gray, its color is less noticeable even when applied to white cement. It should be noted that copper hydroxide inhibits the hardening of the cement, but the amount produced here is considered to be small since the amount is only a trace on the surface. However, since a small amount of copper ions is released, the alkali-treated cuprous oxide powder has anti-algal and anti-fungal properties, and thus functions alone as an anti-algal and anti-fungal agent.

[0015]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples (experimental examples). (Experimental Example 1) Cuprous oxide powder and titanium oxide powder were prepared at the compounding ratios shown in Table 1, and each was mixed by a ball mill to obtain various mixtures (sample numbers 3 to 7). The obtained mixture was added to the cement in an amount of 1% by weight, respectively, to prepare a mortar by the JIS method. The setting time of the resulting mortar and the compressive strength after curing for 28 days were measured. Further, the mortar after curing is 3 mm thick.
To prepare test pieces, and these test pieces were neutralized in a carbon dioxide gas atmosphere so that algae and fungi would grow well.
The test for antifungal properties was based on JIS-Z-2911, and the antialgal properties were determined by naked eyes after outdoor exposure for 3 months.
Table 1 shows the obtained results.

For comparison, a test piece (sample No. 1) to which a mixture of cuprous oxide powder and titanium oxide powder was not added (sample No. 1), and a test piece prepared by adding cuprous oxide powder alone (sample No. 1) 2) A test piece (sample No. 8) prepared by adding titanium oxide powder alone was prepared, and the same tests as those of the above sample Nos. 3 to 7 were performed. The obtained results are also shown in Table 1. . The evaluations of the antifungal property and the antialgal property in Table 1 are as follows. 3: No growth of mold and algae was observed. 2: The growth of mold and algae is 1/3 or less of the sample area. 1: Growth of mold and algae exceeded 1/3 of the sample area.

[Table 1] As shown in Table 1, the test pieces obtained by adding the samples of the present invention having the sample numbers 3 to 7 did not show any growth of molds and algae. -It was confirmed that it had excellent antifungal properties.

Experimental Example 2 100 g of cuprous oxide
/ L of calcium hydroxide suspension and left until the cuprous oxide turns blue. The solid content of this suspension was recovered and subjected to the same test as in Experimental Example 1. The results were a setting time of 3 hours and 30 minutes and a compressive strength of 380 kgf / cm 2, and it was confirmed that the antifungal property and the antialgal property were all 3 and the effect was higher than before the alkali treatment. Furthermore, the color tone was pink before processing,
It turned out to be normal, and it turned out that the problem about coloration was also solved.

[0018]

As described above, in the present invention, the anti-algal and fungicide properties of the cement according to the first aspect of the present invention are based on the fact that the cuprous oxide powder itself does not dissolve in water and thus does not release copper ions, so that Although it does not inhibit the hardening, it reacts with calcium hydroxide generated as the hardening of the cement progresses and gradually releases copper ions, so after the hardening of the cement, its anti-algal and anti-fungal properties Demonstrate the nature. In addition, during the reaction between calcium hydroxide and cuprous oxide, titanium oxide plays a catalytic role to promote the release of copper ions, so that the mixture of the present invention has higher anti-algal and anti-mold properties. . In addition, since the refractive index of titanium oxide is large, and thus the color of cuprous oxide is weakened, the color of the mixture as a whole is also weakened, so that the change in the color tone of cement concrete caused by this mixture can be reduced. As described above, the anti-algal and fungicidal agents of the present invention can be directly used for cement and concrete before curing. Algae and fungicide treatment can be carried out extremely easily, so that construction efficiency can be improved and construction costs can be reduced.

The anti-algal and antifungal agent for cement according to the second aspect of the present invention is obtained by subjecting a cuprous oxide powder to an alkali treatment so that the anti-algal and antifungal effect can be exerted by cuprous oxide alone. Therefore, by using this, it is possible to easily perform the anti-algal and anti-fungal treatment similarly to the anti-algal and anti-fungal agent of the first aspect. The anti-algal and fungicide for cement according to claim 3 is obtained by subjecting a cuprous oxide powder to an alkali treatment.
Copper hydroxide was generated on the surface of the cuprous oxide powder, and the color of the powder itself was changed to blue-gray, so that the color became less noticeable even when applied to white cement,
Therefore, the degree of coloration on cement / concrete can be further reduced.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C04B 22/06

Claims (3)

(57) [Claims] An anti-algal fungicide for cement comprising a mixture of a cuprous oxide powder and a titanium oxide powder. 2. An anti-algal fungicide for cement comprising an alkali-treated cuprous oxide powder. 3. The anti-algal fungicide for cement according to claim 1, wherein the cuprous oxide powder is subjected to an alkali treatment.