CS253648B1 - Means to increase the waterproofness of building materials - Google Patents

Abstract

The agent for increasing the waterproofing of building materials is intended for waterproofing purposes and is applied to the substrates by painting or gritting in a liquid or pasty consistency. After reacting, it creates a joint-free, dust-free, monolithic coating that is impermeable to liquids at normal and elevated pressure and in a wide range of temperatures. The agent and the coating are non-toxic, non-flammable and hygienically harmless. It is formulated on the basis of a hydraulically reactive binder, mineral fillers, additives facilitating processing, /aqueous dispersion of a synthetic polymer containing carboxyl groups, integrally hydrophobic additives, or a hydrosol of silicon dioxide and water.

Description

BACKGROUND OF THE INVENTION The present invention relates to a composition for increasing the watertightness of building materials based on combined hydraulic binders with organic macromolecular binders, with integrally hydrophobic substances, fillers and modifying additives. The waterproofing agent is applied to the treated substrates in a plastic state by coating or graveling. The deposition creates a continuous, impermeable, non-dusty and resistant to mechanical stress.

Until now, the waterproofing of building materials has been predominantly ensured by asphalt and tar materials, combining coatings with liners of impregnated cardboard or porous fabrics. These materials meet most of the requirements for waterproofing, but are toxic, hygienic and environmentally harmful. Moreover, they are primary energy raw materials and work with them is not productive and demanding. Consequently, it is gradually transferred to foil insulations of thermoplastic materials (PIB, PVC). These require even more demanding technological processing, are economically disadvantageous and have a limited service life. Defect of both measured mass groups is flammability and negative impact on the environment.

Consequently, efforts have been made to apply environmentally and hygienically sound materials to increase the waterproofness of building materials, and the main solutions focus on surface treatment by coating, spraying or gravel. Various bentonite-containing systems are applied here (U.S. Pat. No. 2,277,286,

DE-PS 1 609 408). The systems are very sensitive to water and require secondary protection. Various materials based on aqueous dispersions of synthetic polymers, possibly also in combination with conventional binders (DE-PS 1 75.9 252, DE-PS 2 814 317, DE-PS 2 343 457) achieve the greatest development,

FR-PS 1,502,675, GB-PS 1,065,053, JP-PS 4215-69, CH-PS 570 945, etc.).

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The disadvantage of all these processes is the necessity to create multilayer systems for the possibility of hydrolysis of the organic component especially in alkaline environment and for gradual and gradual penetration of moisture into the mass. This is eliminated by the addition of powdered metal soaps and various organosilicon compounds, which, however, only prolong the life of the Building Material Surfaces.

The above drawbacks are overcome by a waterproofing agent for building materials which includes a hydraulic binder, mineral fillers, aqueous dispersions of carboxyl-containing synthetic polymers, and substances with an integrally hydrophobic effect. The composition further comprises modification aids to facilitate processing and / or hydrosol of the silica. The effect of the composition according to the invention lies in the reaction of carboxyl groups with alkaline earth ions in a hydraulic binder or in substrates. This creates a chemical bond between the inorganic and organic binders, which is not subject to hydrolysis, is resistant to weathering, has good resistance to many aggressive substances in gaseous, liquid and solid states. The integrally hydrophobizing component is homogeneous throughout the mass and increases the waterproofness of the substrate. The possible addition of silica hydrosol increases the mechanical resistance of the whole system, significantly affects the abrasion and abrasion resistance and inertises the entire surface of the treated building material. The usual hydraulic binder is Portland cement or slag-portland cement. The processing aids are selected from the group of lignosulfonic acid, such as partially demethoxylated and decarbonated lignosulfonates, polydisperse alkylphenolic and / or methoxylated adducts with ether bonds or phenolic bonds, abietic acid, oligomeric melamine formaldehyde or phenol formaldehyde resins and the like.

Integrally hydrophobizing additives are selected from the group of fatty acids, paraffinic compounds, chloro paraffins, butyl stearate and the like. The silica hydrosol should have a content of greater than 25% by weight, an alkaline salt content of less than 0.5% by weight. and a S1O2 particle size in the range of 5 to 20 nm. The organic active binder is an aqueous dispersion of a synthetic polymer containing 5-21% by weight, based on the copolymer, of unsaturated monocarboxylic acid units, preferably acrylic or methacrylic acid, in addition to vinyl monomer units and acrylic or methacrylic acid esters in the chain. The filler is ground inorganic materials, especially quartz sands, limestone, talc, subcalcated kaolin, feldspar pegmatites, aluminosilicates and the like.

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The waterproofing agent of building materials can be prepared by homogenizing the individual components, or alternatively, a dry mixture can be prepared from solid components, i.e., hydraulic binder, fillers and processing aids. The liquid component then consists of an organic dispersion binder, a liquid internally hydrophobizing substance, or a hydrosol of silica. The final product is then prepared by homogenizing the liquid and solid components with optional dilution with water according to the purpose of use and processing.

Homogenization of the individual components results in a liquid to pasty thixotropic composition which can be applied to substrates by coating, roller or gravel. Once reacted, the coating forms a continuous, dust-free, flexible and resilient coating resistant to weathering, water, aggressive substances, even at higher pressure media and over a wide temperature range. The coating formed is dust-free, has good abrasion and abrasion resistance, both dry and wet, and is impervious to liquid substances. E.g. concrete with hydraulic permeability Kw = 10 cms ^ ^_ '''when applying the layer of thickness 1.6 mm-12 increased permeability -1 la Kw to 3,2.10 cms.

The composition according to the invention is non-flammable, non-toxic, environmentally friendly and no special safety or hygiene regulations are required during processing. The material is suitable for increasing the watertightness of building materials, depending on the thickness. 3e suitable for insulating layers of substrates exposed to liquids, for protection of facades, roof elements, water management structures, etc.

Examples

1. 5.0 parts by weight of an aqueous dispersion of vinyl chloride-ethyl acrylate-methacrylic acid copolymer having a dry weight of 45% by weight are homogenized by weight. and a methacrylic acid content of 20 wt. % on a dry basis of a copolymer with 2.0 parts of chloroparaffin having a carbon number of up to a chlorine content of 62 wt. drawn to chloroparaffin and 12.9 parts of water. 0.1 parts of a partially demethoxylated and decarbonated sulphile liquor, 40.0 parts of Portland PC 400 cement, 35.0 parts of ground quartz sand with a grain size of up to 0.6 mm and 5.0 parts of talc are added to the resulting emulsion liquid while stirring. It arises

4,253,648 a viscous liquid composition which is suitable for application by coating. The mixture is spread on a porous concrete in a 1 mm thick dries over 2 ha vyreagovaná for 12 h. The modified concrete having the waterproof 1.3 MPa (CSN 73 1321), diffusion 0.24 m, waterproof 0 lm ^-2 (CSN 73 2578) , wet abrasion 60 min, frost resistance and resistance to sudden temperature changes over 25 cycles. Comparative 2 untreated concrete has 0.2 MPa, 0.56 m, 1.8 lm, 12 min, 8 cycles.

2. Separately prepare a dry blend by homogenizing 35.0 parts of SPC 325 slag-portland cement, 64.0 parts of ground quartz sand up to 0.2 mm, and 1.0 parts of partially decarbonated and demethoxylated calcium lignosulfonate. This mixture is introduced with stirring into an aqueous emulsion consisting of a 6-part aqueous dispersion of styrene-2-ethylhexylhexyl acrylate-acrylic acid having a dry weight of 50% by weight. % and an acrylic acid content of 5 wt. %, based on the polymer content, of 3 parts of chloroparaffin having a carbon number of 0 to 0 and 43 wt. chlorine and 21 parts water, all in mass parts. After homogenization, the mixture has a viscous liquid consistency and is suitable for application to substrates with coarse brushes or trowels. The 3 mm thick coating resists 1.6 MPa water pressure against 0.1 MPa for the untreated surface.

3. Perfectly homogenize in parts by weight 20.0 parts of SPC 250 cement, 60.0 parts of ground limestone up to 0.5 mm, 1.5 parts of 8 to 10 units of phenol-formaldehyde olinomer, 2.5 parts of styrene aqueous dispersion -butyl acrylate-acrylic acid having a dry matter content of 50% and an acrylic acid content of 3% based on the dry weight of the polymer, 0.5 parts of chloroparaffin having a carbon number of Cg to C1g and a chlorine content of 54% by weight, 1.0 parts of hydrosol of silica with an dry matter content of 25% by weight, an alkali metal content of 0.1% by weight and a particle size of 12-15 nm and 14.5 parts of water. This gives a paste-like composition suitable for gravel application. The 2.5 mm thick layer has a water-tightness rating (CSN 7313 21) of 1.8 MPa.

Claims (4)

Object of the invention 253 648 CLAIMS 1. A composition for improving the watertightness of building materials, comprising 40.0 to 60.0 parts by weight of a hydraulic binder, 40.0 to 180.0 parts of a mineral filler, 0.1 to 5.0 parts of a processing aid, 2.0 to 10.0 parts of an aqueous dispersion of a carboxylic acid-containing synthetic polymer with a dry matter content of 40 to 60% by weight, 0.5 to 5.0 parts of an integrally hydrophobising additive and / or traces of up to 10.0 parts of a silica hydrosol; 0 to 80.0 parts of water. 2. A composition according to claim 1, wherein the aqueous dispersion of the synthetic polymer comprises 3 to 21% by weight of acrylic acid and / or methacrylic acid, based on the polymer content. 3. A composition according to claim 1, wherein the integrally hydrophobizing additive comprises chloroparaffin having a carbon content of C18 to a chlorine content of 35 to 63% by weight. β 4. A composition according to claim 1 to 3, characterized in that the silica sol has an Si0 ₂ content higher than 25 wt.%, The content of alkali metal salts is less than 0.5% by weight. and a SiO ₂ particle size of from 5 to 25 nm.