JPS5935856B2 - Curing composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cured composition containing silica sol as a main raw material and suitable as a coating material, adhesive, or filler.

Conventionally, organic emulsions have been mainly used as coating materials.

However, recently, inorganic materials have been desired from the viewpoint of pollution prevention, and in response to this demand, materials using silica sol have been proposed.

As an example, lead is added to soluble silica compounds such as silica sol.
Inorganic emulsion coating materials are known, which are made by mixing metal compounds such as zinc, chromium, and nickel, and extenders such as mica, but these also contain harmful heavy metals such as lead and chromium, so they end up being a problem in preventing pollution. It is insufficient.

The present invention provides an inorganic curing composition that does not contain harmful heavy metals such as lead and chromium and has a high curing strength, and its composition is composed of silica sol as a main component and aarkanite powder mixed therein. It is characterized by being

The present invention will be explained in detail below along with examples.

The cured composition of the present invention has silica sol as its main component, and is made by mixing amaranthite powder therein.

Here, silica sol is a colloidal solution in which fine SiO2 particles are suspended in water, for example, S with a particle size of 10 to 20 mμ.
It refers to a solution containing 2.0 to 0.05% alkali (20 to Na20+) in which iO□ particles are suspended in water.

In general, Cataloid (trade name), Colloidal Silica (trade name), etc. can be used.

Alcanite is a basic sulfate mineral of Al and K or Na, and its chemical components are NaAl 3 (SO4) 2 (OH) a and KAI a (SO4) 2 (OH) cs or anhydrides thereof. This includes:

Next, the blending ratio of the silica sol and Akpanite powder is determined based on the application.
Although it varies depending on the type of silica sol and the particle size of the alumite, generally, in the case of a normal 7-lika sol, the amount of alumite powder is 0.5 to 85% of the silica content in the silica sol.
When used as a coating material or filler, the alumite powder is preferably used in an amount of 0.5 to 200 weight %, more preferably 5 to 100 weight %.

Also, when using it as an adhesive, use alumite powder of 300~
It is preferable to use 850% by weight, and more preferably 500 to 800% by weight.

Similarly, the optimum range of the particle size of the acanthrite powder differs depending on the use of the curing composition.

Furthermore, the stability of the suspension of silica sol and Alarkite powder depends on the fineness of Alarkite.

For example, a suspension of an appropriate amount of alumite crushed to a size of 10 μm or less is stable for about one day.

As described above, the optimum particle size of Alpanite varies depending on various conditions, but generally it is sufficient that it is 50 μm or less.

In the above-mentioned cured composition, the silica sol and the light starch powder do not react with each other in the presence of sufficient water, but the evaporation of water promotes these reactions, resulting in a glass-like, strong and stable cured product.

Therefore, when a suspension of this cured composition is applied to the surface of a porous material, the cured composition penetrates into the fine pores on the surface, and as a result of water evaporation and absorption, the above reaction progresses. A strong cured film is formed.

The coating is stronger than silica sol alone and has stable properties with excellent weather resistance and chemical resistance.

Furthermore, since the silica sol has a low soluble alkali content, it does not cause alkali pollution.

When the cured composition of the present invention is applied to cement materials such as mortar and concrete, and materials mainly composed of Ca such as Ceracola, an even stronger film can be obtained.

The capillary gaps and surfaces of the above cementitious materials and Ca-based materials are covered with slaked lime and calcium sulfate, and when the hardening composition of the present invention penetrates into these gaps, the slaked lime, calcium sulfate and the silica sol in the hardening composition, It reacts effectively with Akpanite powder to form a strong and stable coating.

As described above, when the cured composition of the present invention is used in the above materials, it is not only the reaction between the silica sol and the alarkite (
Since the reaction between slaked lime, calcium sulfate and silica sol, or the reaction between slaked lime, calcium sulfate and alumite proceeds as a secondary reaction, it has the advantage of forming a stronger and more stable coating.

Because the cured composition of the present invention has such properties, it can be used in porous materials such as Oya stone and lightweight cellular concrete, cement materials such as mortar and concrete, and calcium carbonate materials such as Ceracola.
Coating materials, adhesives,
Used as a filler or repair material.

The curing composition of the present invention is used in a state in which the silica sol is suspended with the aarkanite powder, but if water is present, the silica sol and the aarkanite do not react, so even if the aarkanite powder precipitates, it will be reused. This can be stirred to form a suspension,
Easy to use.

When using, stir the liquid thoroughly to make it into a suspended state.
It is best to thoroughly blend the acanthrite powder and silica sol.

Furthermore, in order to stably suspend the silica sol and the acanthite powder, a surfactant with excellent dispersibility such as an alkylaryl sulfonate may be added.

When the cured composition of the present invention is used as a coating material, it is also possible to add a small amount of a compound such as nickel nitrate, iron nitrate, potassium dichromate, potassium chromate, etc. for coloring, if necessary.

In addition, when the cured composition of the present invention is used as a filler for a porous body, if a surfactant with excellent permeability such as sulfosuccinic acid dioctyl ester (trade name: Aerasoi OT) is used in combination, the porous body can be filled. Penetration becomes even better.

Next, examples of the present invention will be shown.

Example 1 A suspension of a cured composition according to the present invention was prepared by mixing a silica sol with a 5i02 concentration of 30% by weight with an acanthrite powder crushed to a size of 40 μm or less.

Here, the properties of the silica sol and the acanthrite powder are shown in Table 1, and their blending ratios are shown in Table 2.

20 parts by weight of the suspension of the above cured composition was mixed with 100 parts by weight of dried Toyoura standard sand, and 3CrLφX3cr
Fill the rLh mold with these mixtures at a pressure of 5 to 9/c4, then immediately remove the mold, place it on a wire mesh shelf, and dry at room temperature. Its unconfined compressive strength was measured.

The results are shown in Table 2. As is clear from Table 2, all the compositions using the cured composition of the present invention containing Akpanite powder have significantly higher compressive strength than those using simple silica sol.

Example 2 Using the same silica sol and Akpanite powder as in Example 1, 5 parts by weight of Akpanite powder was mixed and suspended in 100 parts by weight of silica sol, placed in a 50 ml beaker to a height of 30 mm, and heated at 20°C. When the suspension was left at a temperature for 10 days, the suspension of the cured composition according to the present invention was cured into a translucent glass-like form up to a thickness of 25 mm from the surface due to water evaporation and scattering.

On the other hand, for comparison, when a single silica sol was left for 10 days under the same conditions, it cured more slowly than the suspension of the curing composition of the present invention (and it became glassy only 2 mm below the surface). It was about.

Next, when powder X-ray diffraction was performed on the suspension of the silica sol and alarkite of the present invention, a translucent glass-like substance obtained by hardening the silica sol alone, the maximum value of 5. A diffraction pattern with a wide Q normal distribution pattern of 54 to 2.64 people was obtained, and in the case of the suspension of Shiki's invention, 3.1
A wide normally distributed diffractogram of 5.54λ to 2,30 individuals with a maximum value in 9 individuals was obtained.

As a result, in the case of silicasol alone, the substance obtained by drying is mostly silica gel, whereas in the case of the suspension of the present invention, the substance obtained by drying has a different peak position, and it is found that the substance obtained by drying the suspension of the present invention has different peak positions. Since no diffraction pattern was observed, it is presumed that the silica sol and the Akpanite powder reacted through evaporation and scattering of water.

Example 3 A suspension of 10 parts by weight of silica sol with a SiO2 content of 30% by weight and 10 parts by weight of Akpanite powder with a potash content of 70% by weight, which has been ground to 40μ or less, is sufficiently stirred and suspended. This solution was applied to the surface of a commercially available lightweight aerated concrete board using a brush three times at 10-minute intervals, so that the surface and coating film were applied thinly (uniformly) to such an extent that they could not be seen with the naked eye.

This coated surface became glossy over time, formed a strong and uniform coated surface, and had hydrophobic properties.

On the other hand, when applying only a silica sol solution with a 5i02 content of 30% by weight using the same method, the above case did not have any gloss, and the painted surface was scratched when lightly scratched with a fingernail even after 10 days. Ta.

Example 4 1:5 of sand with a coarse grain ratio of 3.0 to ordinary Portland cement
A mortar of 4X4X16cfrL was prepared by mixing the mixture in a weight ratio of 4X4X16cfrL under conditions of a water/cement ratio of 90%.

This mortar was cured in a humid air box at a temperature of 20°C and humidity of 90% for one day, then removed from the mold, and dried and cured for three days at a humidity of 40% at 20°C. , 20 to silica sol with 25% iO2 content.
Alumite containing 6.0% is crushed to 40μ or less.
．． Table 3 shows the results of measuring the bending strength and -axial compressive strength of each sample after immersing it in a mixed suspension of 055 parts by weight for 1 day and curing it for another 7 days at a temperature of 20°C and a humidity of 90%. I got the result.

As is clear from Table 3, the specimen O using the cured composition of the present invention showed larger values in both bending strength and compressive strength than the other specimens ■@.

Example 5 A leaky rooftop concrete slab with a radial crack of approximately 0.5 to 1 mrn in width was treated with SiO□ content of 3
0% by weight of silica sol and 5.8% of Akpanite powder crushed to 30μ or less, 1% by weight per silica sol.
A suspension of 5% by weight was injected and cured for 7 days.

At this time, when it rained, a sheet was covered over the injection site to prevent rainwater from entering.

On the other hand, for comparison, silica sol alone was injected in the same manner.

When we observed leakage during rain for about one month after curing, we found that the areas where the suspension of silica sol and Akpanite of the present invention were injected were completely prevented from leaking, but when the silica sol alone Some rain leakage was observed at the injection point.

According to JIS R5201, mortar of ordinary Portland cement: Toyoura standard sand: water - 1:2:0.65 (weight ratio) was kneaded to make a mortar specimen of 4 x 4 x 16 CrfL, and this was heated at 20°C for 28 days. After curing in water, the specimens were cut in half using a Miberris bending tester.

After drying the cut specimen for one day at a temperature of 30°C and a humidity of 65%, ■ Silica sol 040μ with a 5i02 content of 30% by weight was applied.
A mixed suspension of 200 parts by weight of pulverized alumite powder with a content of 9.8% by weight and 100 parts by weight of silica sol with a SiO2 content of 30% by weight, O epoxy adhesive (
Product name: BOND QUICK YANDER) was applied to each cut surface and adhered tightly.

After 1 hour of adhesion, both ends of the specimen were bent by hand, and ■
The specimen coated with
It was not possible to break the specimen coated with it by hand.

Therefore, after leaving the specimen coated with @ or O indoors for one day, the bending strength of the specimen coated with @ was measured using a Michaelis bending tester.The bending strength of the specimen coated with @ was 30.7 kg/
The bending strength of the specimen coated with crti, O is 32.1
9/ca, indicating that the cured composition of the present invention exhibits almost the same adhesive properties as commercially available epoxy adhesives as adhesives.

As explained above in detail together with Examples, the cured composition of the present invention can provide an exceptionally strong and stable cured product, and furthermore, since it does not contain harmful compositions, it does not cause any pollution. It has the advantages of

Claims (1)

[Claims] 1. A hardening composition comprising silica sol as a main component and mixed with Akpanite powder.