KR19990080536A - Emulsion type waterproofing material mainly containing bentonite - Google Patents

Abstract

The present invention relates to a bentonite-based waterproofing material, which is used in corners of pipes, gaps between pipes and structures, gaps between piles and structures, and connections between waterproof materials, and so on, to fill minute gaps with water. It is a specially manufactured waterproofing material that prevents other liquids from seeping or leaking and maintains the required viscosity until it is put into the covering material immediately after use.

Description

Emulsion type waterproofing material mainly containing bentonite

An object of the present invention is to provide a bentonite that exhibits excellent expandability and excellent water resistance, which can be used for cracks in structures, seams of pipes, construction joints, expansion joints, reinforcing bars or pipes, gaps in structure penetrations of piles, and other fine parts. An object of the present invention is to provide an emulsion type waterproofing material which is a main component.

Bentonite is a highly plastic mineral with swelling properties. Therefore, various end products made by processing bentonite are widely used as waterproofing materials for external structures such as mines, dams, artificial lakes, stone structures, oil wells, water expansion joints, and building foundations.

However, a number of known bentonite-containing compositions are used in a solid state, and thus have difficulty in using them in a plane having fine cracks or irregularities.

As a result, silicon, rubber, coating waterproofing materials, etc., which are not bentonite-containing compositions, are conventional waterproofing materials used for fine cracks, flat surfaces with high unevenness, and the like. These conventional waterproofing materials may leak when water is leaked when gaps occur in materials and structures after filling gaps, and there is always a great risk of leakage when gaps occur due to climate change or impact.

Therefore, the present invention focuses on the fact that it is difficult to expect a satisfactory waterproofing effect even when the conventional silicone, rubber, coating waterproofing material, etc. are used in a plane having fine gaps or irregularities, and to provide an emulsion type bentonite-based waterproofing material as an alternative thereto .

That is, the present invention has the flexibility and viscosity to easily fill even minute gaps, and when water comes into contact, it automatically expands by 10 to 15 times the volume and has a self-healing capacity to fill gaps, as well as dry or prolonged exposure. It is intended to overcome the shortcomings of conventional silicone, rubber, waterproofing film, etc. by maintaining the applied circular shape without the loss of external forces.

Bentonite is a clay mineral composed of montmorilloite-based expandable three-layered plates (Si-Al-Si), and is formed of Al 2 Si 4 (OH), a pyrophyllite (leadite) chemical structural formula. Among them, in the Gibbsite layer, which is an intermediate layer of aluminum oxide, + trivalent aluminum is replaced by magnesium (Mg), which is + divalent, and the amount of insufficient charge is reduced to sodium (Na). The satisfied form is sodium bentonite.

0.33Na (1.67Al 0.33Mg) Si4O (OH) 2

In this case, aluminum in the zip-site layer may be replaced with iron in addition to magnesium, and thus, insufficient charge may be satisfied with calcium. Bentonite is distinguished according to a component that satisfies the insufficient charge.

In other words, bentonite has exchangeable ions on the surface due to aluminum in the zipite layer substituted by magnesium or iron, and sodium-based montmorillonite is formed when sodium is adsorbed on the exchangeable ions, and calcium-based montmorillonite when calcium is adsorbed. Is formed. Of course, when other components are adsorbed, they are classified as montmorillonite. Among various montmorillonites, sodium montmorillonite has the best swelling properties.

As a result of the unbalance of charge generated in the zipite layer, which is an interlayer of bentonite, the corners of each bentonite layer are positive and the surface is negative. This water molecule again attracts more and more water molecules. Thus, water molecules are continuously adsorbed into the space between bentonite layers to continue swelling, and the swelling stops when the water is depleted or the external pressure coincides with the internal swelling pressure. The minimum external pressure that can prevent free swelling of bentonite is known to reach approximately 146 kg / m ² (30 pounds per square foot).

In other words, in the case of drying and wetting, it is not found in other clays with swelling of more than three times the thickness of the plate crystal layer. In fact, bentonite reacts with water in the purified state to 5 times its weight, 13 ~ It is characterized by swelling up to 16 times and changing to a thixotropic gel-like substance.

The present invention is an emulsion type waterproofing material prepared from a mixture of bentonite and a non-aqueous medium as a raw material.

In the waterproof material according to the present invention, bentonite is preferably used in an amount of 60 to 80% by weight of the total composition. If the content of bentonite is 60% by weight or less, the added non-aqueous medium becomes excessive, thereby decreasing the contact between bentonite and water and the hydration expandability. In addition, when the amount is 80% by weight or more, a small amount of non-aqueous medium is present in the final composition, thereby decreasing the binding strength with bentonite. Therefore, the amount of bentonite used is preferably within the above range.

In the bentonite-containing composition as described above, the non-aqueous medium is used in an amount of 60% by weight or less based on the total weight of the composition, such as oil, glycerin or alcohol. In particular, glycerin is most preferred as a waterproofing material of the present invention because glycerin in the non-aqueous medium is superior to the other bentonite as compared to other media.

Example 1

2 ml of glycerin was added to 8 g of bentonite and sufficiently stirred to prepare a waterproof material having high viscosity. Various physical properties were tested for this product, and the results are shown in Table 1 below.

Test result Test Items unit Result Test Methods Hydraulic test bar 2.9 ASTM D-751 (M-A) (30days, 100ft Head Pressure) Tear load kgf 9.3 Volume expansion rate % 895 Self test standard (room temperature, distilled water, 250 hours)

Example 2

4 g of glycerin was added to 6 g of bentonite, followed by stirring sufficiently to prepare a low viscosity emulsion type waterproofing material. Various physical properties were tested for this product, and the results are shown in Table 2 below.

Test result Test Items unit Result Test Methods Hydraulic test bar 2.6 ASTM D-751 (M-A) (30days, 100ft Head Pressure) Tear load kgf 8.8 Volume expansion rate % 886 Self test standard (room temperature, distilled water, 250 hours)

As can be seen from the above tables, the composition based on bentonite according to the present invention has excellent volume expansion capacity, tear strength, and can be used in structures with high unevenness on the surface, or water expansion joints.

Claims (2)

Waterproofing material prepared using the composition consisting of 40 to 20% by weight of non-aqueous medium and 60 to 80% by weight of sodium bentonite. The waterproofing material of claim 1 wherein the non-aqueous medium is glycerin.