CS259628B1 - Sealing silicate composition - Google Patents

Abstract

The substance is intended for sealing and monolithic construction elements, for repairs of mechanically stressed substrates and for creating protective layers on solid lightweight materials. It is formulated on the basis of aqueous colloidal solutions of alkali metal silicates and dry matter lower than 35 %/o wt., with a molar ratio M2O : S1O2 above 1.0 : 3.4, clay minerals or magnesium hydrosilicates, surfactants and fillers. By correcting the molar ratio Μθ2θ : SiOz, a high degree of hydration of silicates is achieved, perfect reaction and resistance of the resulting product to water, mechanical stress and atmospheric influences. The definition of the subject of the invention contains 1 main and three dependent points.

Description

The sealing silicate composition for sealing and monolithing building elements, for repairing mechanically stressed substrates and for forming protective layers on solid, lightweight materials is formulated on the basis of aqueous colloidal alkali metal silicate solutions with a high degree of hydration, clay minerals or magnesium hydrosilicates, surfactants and fillers.

To date, various sealing systems have been used for sealing and monolithing solid and hard materials. Plastic and elastic sealants provide tightness under certain conditions, but are unsuitable for use in service for permanent flexibility. Cements based on reactive synthetic resins (EP, UP, PUR) are environmentally harmful, uneconomical and their use is unrealistic from the technological point of view (they are two-component, flammable, require dry substrates, have a long curing time, possible overflows are difficult to remove). Sealing with embedded profiles is particularly ineffective in vibration and heat treatment of elements (UTB), as are ineffective sealants based on polymer cement or gypsum mixtures, and sealants based on aqueous colloidal alkali silicate solutions (water glass) have proved to be most effective. DE-PS 1092 586 describes the reaction of water glasses and chalk at elevated temperatures, US-PS 4 140 535 discloses the possibility of controlling the water-glass solidification by quaternary conditions. aluminates and borates, U.S. Pat. No. 3,715,224 discloses metal ion complexes, U.S. Pat. No. 4,137,087, ligand-forming complexes (ethylenediaminetetraacetate, N - (hydroxyethyl)) - ethylenediaminetetraacetate, DE-PS 2,460,543, and U.S. Pat. No. 2,729,194 discloses oxides, hydroxides and carbonates of various metals, but at the same time insufficient control of the reaction rate by said methods is reported. Recently, there has been a tendency to regulate the rate of freezing of waterglass while increasing the waterproofness and water resistance of orthophosphates of various metals. According to U.S. Pat. No. 4,216,190, aluminum dihydrogen phosphate may be used, but this must be prepared at high temperatures and in small portions directly before use.

Waterglass as a binder of adhesives and sealants without perfect reacting creates strong, hard and brittle joints, but they eventually break down due to airborne carbonate and moisture. For this reason, its use is quite limited even at very advantageous economic relations.

These drawbacks are overcome by the sealant silicate composition of the present invention in which the binder aqueous solution is a colloidal alkali metal silicate (waterglass). to achieve this ratio of 1: 3.2 to 1: 3.5 at a specific gravity of 1.33 to 1.41 g ^-3 and a concentration of 35 to 40% by weight. in two forms - in the form of ions and in the form of ionic micelles of colloidal S1O2. Both forms of S1O2 are in equilibrium, which is changed by changing the concentration and molar ratio of Me2O: S1O2. Sβ2θ:: SiO2 above 1: 3,5, pH adjustment below 13 and at a maximum concentration of less than 35% by weight the modified binder has eliminated colloidal S1O2 micelles and predominates the S1O2 ions The change in the MezO:: S1O2 molar ratio can be achieved by the addition of meta-silica and / or silica silica (aqueous colloidal silica solution). The sealing silicate composition further comprises inert fillers, granular or fibrous, clay minerals from the group of kaolinite and montmorillonite and / or from the group of magnesium hydrosilicates (talc) and surfactants which modify the rheological properties of the composition and prevent the mixture from segregating. The sealant silicate composition is prepared by thoroughly homogenizing all components in conventional mixers.

Example 1

It is perfectly homogenized in mass parts of 36.4 parts of water glass with a molar ratio of Na2O: SiO2 of 1: 3.3, with a dry matter content of 35% by weight. and pH 14, 5.5 parts by weight of 20% by weight of colloidal silica. and pH 8 to change the molar ratio to 1: 6.3 and reduce the dry weight to 33% w / w. and the pH drops to 11.5, 45.5 parts of quartz sand with a grain size of up to 0.2 mm, 12.5 parts of talc with a grain size of up to 0.1 mm, and 0.1 parts of sodium succinate in the form of sulfosalt. A thixotropic paste-like mixture is formed which is applied as a thin-layer coating to expanded polystyrene or mineral fiber boards. Upon reaction, the composition results in a water-soluble, hard and homogeneous layer with high adhesion to the substrate, non-flammable, hygienically safe and with good resistance to atmospheric agents.

Example 2

It is perfectly homogenized in mass parts of 23.6 parts of waterglass with a molar ratio of MezO: S1O2 of 1: 3.5, and a dry matter content of 34% / mass, 3.1 parts of kaolinite, 70.7 parts of quartz sand of grain size up to 1, 0 mm, 1.2 parts bentonite, 0.5 parts ethoxylated bridge alcohol and 0.9 parts cellulose fibers up to 3 mm in length. After homogenization, a thick, thixotropic, pasty mixture is formed which is formed

259828 by gravel as sealant to seal the joints between prefabricated stair treads and risers and between prefabricated elements and mold. Putty after 30 min. solidification resists vibrations and seals all joints and joints perfectly. If quicker solidification is required, 2 parts of sodium fluorosilicate are admixed to 100 parts of the composition. The composition thus treated solidifies in 10 min. In both cases the sealant forms a rigid and hard joint without joints that resists mechanical stress, water and atmospheric influences.

Claims (5)

SUBJECT A sealing silicate composition for sealing and monolithing building elements, for repairing mechanically stressed substrates and for forming protective layers on solid, lightweight materials, characterized in that it contains in parts by weight 8.0 to 40.0 parts of aqueous colloidal alkali metal silicate solutions of a dry matter of less than 35% by weight, with a molar ratio of MezO: S1O2 of at least 1.0: 3.4, where MežO is an alkali metal oxide, 1.0 to 5.0 parts of clay minerals and / or 5.0 to 20.0 parts of magnesium hydrosilicates, 0.1 to 0.5 parts of surfactants and 40.0 to 80.0 parts of fillers. 2. The sealant composition according to claim 1, wherein the molar ratio MeaO: S1O2 is adjusted by the addition of an acid. Example 1 a d 3 It is perfectly homogenized in mass parts of 8.0 parts of water glass with a molar ratio of MezO: S1O2 of 1: 3.2 and a dry matter content of 36% by weight. 1.5 parts of metasilicic acid, 10.0 parts of water, 74.2 parts of quartz sand up to 2.0 mm in size, 6.0 parts of talc and 0.3 parts of ethoxylated stearic acid. A thixotropic leveling compound is formed which is used for repairing cracks and indentations in concrete. The composition solidifies to a rigid, hard product with resistance to mechanical stress, water and weathering. It is stable in volume even at thicknesses over 5 cm. YNALEZU of a meta-silica and / or colloidal silica solution having a dry weight of 20 to 35 wt. 3. A sealing silicate composition according to claim 1, wherein the clay minerals are from the group of montmorillonite and / or kaolinite. 4. The sealant composition according to claim 1, wherein the fillers are mineral, organic, granular, fibrous, individually or in combination. 5. The sealant composition according to claim 1, wherein the binder solidification rate is controlled by the addition of 0.5 to 5.0% by weight. alkali metal and / or alkaline earth metal oxides, carbonates and fluorosilicates, individually or in combination.