JPS63307807A - Germicide used in solution for preparing cement - Google Patents

Abstract

PURPOSE:To obtain a germicide capable of preventing putrefaction and deterioration of the titled solution for a long period simply by pouring thereof into the solution, by blending B2O5 with SiO2, Na2O3, Al2O3 and Ag2O3, melting the obtained blend and forming the resultant silver-containing soluble glass into a granular substance having a specific minor axis. CONSTITUTION:The titled pharmaceutical obtained by blending 40-76wt.% B2O5 with 20-56wt.% SiO2, 3-20wt% Na2O3, 1-5wt.% Al2O3 and 0.2-2.0wt.% Ag2O3, melting the obtained blend and forming the resultant silver-containing soluble glass into a granular substance having 0.5mm-10cm (preferably 1mm-5cm) minor axis. Putrefaction and deterioration of a solution for preparing a cement containing a cement stabilizer, etc., blended therein, can be prevented for a long period and usable period can be prolonged simply by pouring the above-mentioned pharmaceutical into the solution.

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention can be used for a long period of time by simply adding cement admixtures such as cement stabilizers and cement stabilizing water reducers into a cement making solution. The present invention relates to a disinfectant for cement-making solutions that can prevent spoilage and deterioration of the cement-making solutions and extend the expiration date of the cement-making solutions.

"Prior Art" Conventionally, when adding water to cement material to create a cement mixture, cement admixtures such as higher fatty acid compounds, mineral oil compounds, and organic acid derivatives are mixed into the water.
Efforts are being made to provide cement with waterproofing effects, improved releasability, stable water reduction properties, and air entrainment properties. If such a cement admixture was added to the water used each time cement is smelted, it would require more man-hours each time, so it is better to mix the cement admixture into the stored water to be used in advance ( Cement making solution) can be used immediately when making cement mixture.

``Problem to be solved'' By the way, water pre-mixed with the cement admixture (cement preparation solution) contains higher fatty acid compounds, mineral oil compounds, organic acid derivatives, etc., compared to water alone. Because these solute components are mixed in, bacteria are likely to attach to them and cause them to rot or deteriorate. Therefore, there is no problem with the stored cement-making solution if it is quickly consumed, but if it is stored for a long time, it may rot and deteriorate and become unsuitable for use.

A possible solution to this problem is to add a well-known fungicide to the cement preparation solution to prevent spoilage. It is not suitable for practical use because it has problems such as having an adverse effect on the cement mix, giving off an odor to the finished cement mix, and lack of long-lasting effects.

``Means to Solve Problems'' As is well known, copper and silver have long been known to have sterilizing properties. For example, hospitals used copper containers to hold medical equipment, and in the Middle Ages, silver tableware was used to prevent food from spoiling. Although the detailed sterilization effects of copper and silver are not known, it is clear that they are due to the active effects of these ions.

In other words, the presence of 0.1 to 0.3 ppm of copper ions prevents the growth of algae, and the presence of 0.05 to 0.10 ppm of silver ions kills E. coli in the water. Are known.

Therefore, it is possible to provide a bactericidal agent for cement preparation solutions using silver, but metal ions other than silver are usually obtained from metal salts, which are metal compounds. The elution rate is either slow or fast compared to the appropriate range for disinfectants in cement-making solutions, and the rate cannot be controlled.

In response to this problem, the inventors of the present invention have conducted extensive research focusing on the low-speed dissolution of glass, and have come to the following findings. In other words, quartz glass is an ideal glass in terms of physical and chemical stability, but
It is not practical for general use because it will not melt unless it is at a high temperature of .degree. C. or higher. As is well known, glasses that are in practical use contain silicic acid, which is a network-forming oxide, and soda (Na).
Modified oxides such as zO) and lime (CaO) are added to make it easier to melt, and the composition and structure make it easier to mold into various shapes. That is, Na ions,
It has a structure in which the covalent bonds of the irregular network structure formed by the network-forming oxide are partially severed by Ca ions or the like. A typical glass having this structure is called soda-lime-silicate glass, or simply silicate glass, and is used in glass products that are produced in large quantities and is available at low cost. The surface of this silicate glass is damaged by water and moisture, albeit slightly more so than quartz glass. In other words, it has low solubility in water. However, its dissolution rate is quite slow, making it unsuitable for controlling the dissolution of disinfectants.

When a modified oxide is further added to the silicate glass, the covalent bonds caused by the silicic acid are further broken, and the network structure becomes a chain structure. Typical glasses with this structure are
It is called soda silicate glass, and because it dissolves easily in water, it is used in the composition of water glass, which is often used in adhesives and hardening agents. When a modified oxide is further added to this glass, it becomes a covalently bonded silicate ion, resulting in an inverted glass structure with an increased number of ionic bonds. This inverted glass tends to crystallize during the melting process and is difficult to vitrify homogeneously, but by replacing part or all of the silicic acid, which is a network-forming oxide, with boric acid or phosphoric acid, it can be relatively easily vitrified homogeneously. It can be made of glass.

As described above, the dissolution rate of glass in water requires physical and chemical consideration of the process, but it is possible to control the dissolution rate by appropriately selecting the composition of the glass. As mentioned above, such glass is simply called soluble glass or controlled release glass.
sS). This meltable glass can stably contain metal ions such as silver, which are effective active ions, up to about half of its constituent components, and by adjusting the melting rate of this glass, it is possible to It would be possible to elute an appropriate amount of metal ions at a constant rate over a period of one hour to several decades.

For example 1. As shown in Figure 1 (a), (b), and (c), when particles I of soluble glass containing an active element (silver) with a controlled dissolution rate are put into water, the silver in the glass particles I dissolves into the glass. It elutes as ions at a constant concentration. The dissolution rate of the glass and the effect of the silver ions at this time are shown as functions of time as shown in FIGS. 2(a) and 2(b).

Figure (a) is a graph showing changes in dissolution rate of soluble glass in a large volume of water, and Figure (b) is a graph showing changes in elution concentration of silver ions in a predetermined volume of water. Among these figures, particularly figure (b) shows an important meaning. That is, it can be seen from this figure that the concentration of silver ions is always constant until the molten glass is completely melted.

As mentioned above, the melting rate of meltable glass can be controlled because glass is an amorphous and homogeneous material, and there is no need to control the dissolution rate with water-resistant materials such as coatings or capsules. be. Further, meltable glass is capable of bonding with a large amount of metal ions, and typically leaves no residue when melted. Furthermore, since the optimum dissolution rate can be selected, it is possible to prevent the elution of excess metal ions and to achieve the most efficient adjustment while minimizing environmental pollution.

In addition, this meltable glass can be formed into any shape, such as powder, fiber, flake, etc., depending on the purpose of use.
It can also be shaped into bubble glass, tubes, or blocks. Meltable glass has the advantages of being easily produced using conventional glass engineering knowledge, causing low environmental pollution, and having high added value.

Based on the above findings, we investigated the composition and particle size of a silver-containing glass agent that was optimal as a bactericidal agent for cement preparation solutions, and found that the composition was: B, 0. ...40-76 weight% 5iOz...20-56 weight% Nat03"' 3-20 weight% A12tOs...1-5 weight% A9tN Os...0.2-2.0 weight% % is preferable, and the particle size of the particles is such that the short axis is 0.5u to 10c.
m, preferably IIN~5cx.

The present invention has been made based on this knowledge. That is, the bactericidal agent in the cement making solution of the present invention contains 13
tos: 40-76% by weight, SiO2: 2θ-56% by weight, NatO3: 3-20% by weight, AQlo s:
Silver-containing soluble glass obtained by mixing and melting 1 to 5% by weight of Ag2NOs and 0.2 to 2.0% by weight of Ag2NOs is formed into particles with an average minor axis of 0.5zx to Loan. This is a characteristic feature.

Examples of this invention will be shown below.

"Example 1" A g N O 3 ...... 0.5 part A very slowly melting silver-containing soluble glass obtained by mixing and melting the above components was prepared with an average minor axis lam It was molded into granules. 100 g of the obtained granular silver-containing soluble glass (sterilizing agent for cement preparation solution) was put into 5% aqueous solution of cement stabilizer (polyoxyethylene + anion activator) [cement preparation solution] 100012. the result,
The solution did not spoil even after two weeks, when spoilage normally occurs, and no spoilage occurred even after six months.

This is because the bactericidal agent gradually dissolves into the cement-making solution, and the silver component in the dissolved glass exerts a bactericidal effect in the solution, killing bacteria that adhere to solute components in the solution. This is because the eluted silver ions remain relatively stable in the solution and maintain their bactericidal activity over a long period of time.

"Example 2" Silver-containing meltable glass obtained by melting 1 part of Ag No. 3" (average particle size 1.
5cm) 100iJ to cement stabilizing water reducing agent (organic acid derivative) 5% aqueous solution [solution for making cement] 100012
I put it inside. As a result, the solution did not spoil even after two weeks, which would normally occur, and no spoilage occurred even after six months.

As described above, according to the bactericidal agent of the cement making solution of the present invention, the bactericidal action of the silver eluted from the bactericidal agent kills bacteria adhering to the solute components in the cement making solution,
It is possible to prevent the solution from spoiling over a long period of time.

"Effects of the Invention" The disinfectant in the cement making solution of the present invention is 820s:4
0-76% by weight, 5ift: 20-56% by weight, Nat
Os: 3-20% by weight, A (lfios: 1-5
A silver-containing soluble glass obtained by mixing and melting A92N O =: 0.2 to 2.0 wt%, with an average minor axis of 0
．． It is characterized by being formed into granules of 5 cm to 10 cm, and exhibits the following effects. That is, the bactericidal action of silver eluted from the bactericidal agent in the cement-making solution of the present invention kills bacteria adhering to solute components in the cement-making solution, thereby preventing the cement-making solution from spoiling over a long period of time. be able to.

[Brief explanation of the drawing]

Figure 1 (aXb) and (c) are schematic diagrams of the dissolution of the bactericide in the solution for making cement of the present invention in water, and Figures 2 (a) and (b) are the dissolution of the bactericide in the solution for making cement of the present invention. The rate and elution concentration of contained silver ions are shown as a function of time. (a) Figure is a graph showing the change in dissolution rate of a disinfectant (soluble glass) in a large volume of water, (b) Figure is a graph showing the change in dissolution rate of a disinfectant (soluble glass) in a large volume of water. 2 is a graph showing changes in elution concentration of contained silver ions in a predetermined volume of water. 1... Dissolvable glass containing granular silver (sterilizing agent for cement making solution).

Claims (1)

[Claims] B_2O_3: 40~76% by weight, SiO_2: 20~
56% by weight, Na_2O_3: 3-20% by weight, Al_
2O_3: 1 to 5% by weight, Ag_2NO_3: 0.2 to
A bactericidal agent for a solution for making cement, which is obtained by mixing and melting 2.0% by weight of silver-containing soluble glass and forming it into granules with an average minor axis of 0.5 mm to 10 cm.