CS260715B1 - Top expanded hydrophobic plaster with high permeability for water vapours - Google Patents

Abstract

This plaster consists of a paste-containing material 0.1 to 10 wt. soluble parts cellulose derivative (carboxymethyl cellulose) or hydroxyethylcellulose), 0.05-0.2 wt. part of ammonia water containing 25 to 40% ammonia, 10 to 35 wt. aqueous parts a styrene acrylate or polyvinyl acetate dispersion polymer or copolymers with 10 to 40% acrylic component and 10 to 80% wt. parts of an inert filler of grain size 0.01 to 3.6 mm and expanded hydrophobised fillers in a 1: 0.5 ratio to 1: 2.5, another possible component is stearate aluminum, calcium or zinc to 5 wt. parts, or silicone hydrophobic a to 2 wt. parts of the fibers in a dispersed form reinforcement. It can be added as a secondary binder calcium or calcium oxide to 50 wt. parts. This plaster creates a structural surface, can be used on unequal and its advantage is that it prevents penetration of rainwater into the surface or to ensure uninterrupted movement water vapor construction.

Description

This plaster consists of a paste-like composition containing 0.1 to 10 wt. 0.05 parts by weight of soluble cellulose derivative (carboxymethylcellulose or hydroxyethylcellulose); % of ammonia water containing 25 to 40% ammonia, 10 to 35 wt. parts by weight of an aqueous dispersion of styrene acrylate or polyvinyl acetate polymer or copolymers with 10 to 40% acrylic component and 10 to 80 wt. parts of an inert filler having a grain size of 0.01 to 3.6 mm and a lightweight hydrophobized filler in a ratio of 1: 0.5 to 1: 2.5 relative to each other. parts, possibly a silicone hydrophobic and up to 2 wt. fiber parts in the form of scattered reinforcement. Cement, hydroxide or calcium oxide up to 50 wt. parts. This plaster creates a structural surface, it can be used on uneven substrates and its advantage is that it prevents the ingress of rainwater into the surface treatment, or ensures the uninterrupted movement of water vapor through the building structure.

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BACKGROUND OF THE INVENTION The present invention relates to a lightweight hydrophobic plaster with a high water vapor permeability, suitable for the exterior surface treatment of building structures, which increases the thermal insulation of the cladding.

The protection of buildings and building structures against atmospheric influences and for the purpose of aesthetic completion is carried out by a number of procedures and materials; Depending on the nature of the substrate, either plaster or paint system is chosen.

The coating and most plaster systems based on high molecular weight substances have the disadvantage that their water vapor permeability is low; this leads to condensation of water pairs and freezing of condensed water in winter. As a result, the integrity and adherence of the surface treatment system, peeling and dropping of paint or plaster are violated.

In contrast, many systems with relatively good water vapor permeability have the disadvantage that they readily absorb water in the liquid phase, thus being hydrophilic.

Consequences are similar to · condensation increases in humidity. Commonly used silicate based plasters are based on cement and / or lime binder; They have good mechanical parameters, but are absorbent and wetted by stresses and other physical influences.

In developed countries, exterior plasters with polymeric binder, often in redispersible powder form, are used. The bulk density of these materials is 1,500 kg. m ' ³ or more; these materials have low porosity and are therefore relatively impermeable to water in both liquid and gaseous phases. Their heat-insulating effects are negligibly low. Thin-layer plasters do not have the ability to compensate for unevenness of the substrate; therefore, they cannot span joint joints, for example on panel objects.

The above-mentioned disadvantages are eliminated by a high-vapor permeability hydrophobic lightweight plaster, which is based on the application of the plaster according to the invention in a thickness of 4 to 20 mm and which contains 0.1 to 1 wt. 0.05 parts by weight of a water-soluble cellulose derivative such as carboxymethylcellulose or hydroxyethylcellulose; % of ammonia water containing 25 to 40 wt. % ammonia, 10 to 35 wt. parts by weight of an aqueous dispersion of styrene acrylate or polyvinyl acetate polymer or copolymer containing 10 to 40% acrylic component, 60 to 80 wt. parts of an inert filler having a grain size of 0.1 to 1.6 mm. The paste consistency is achieved by mixing with a cellular inorganic secondary filler formed by hydrophobizing the expanded perlite with a silicone hydrophobic, the ratio of the paste component to the cellular secondary filler being 1: 0.5 to 1: 2.5. The consistency of the composition to be applied is adjusted by the addition of water and the composition is applied manually or by spraying to the required thickness, preferably from 4 to 20 mimes.

It is preferred to add 0.5 to 3 wt. parts of aluminum, calcium or zinc stearate, or a silicone hydrophobic. It is further preferred, especially at larger thicknesses, that the plaster contains up to 30% by weight. parts of Portland cement and / or calcium hydrate.

In order to reduce the susceptibility to the formation of micro-cracks, it is advantageous to supplement the render with the addition of 0.01 to 2% by weight. Inorganic or organic fiber parts with a thickness of 0,1 to 10 ftm and a length of 2 to 20 mm.

In all applications, it is advantageous to impregnate the surface of the substrate and / or the plaster with a combined hydrophobic before and / or after application of the plaster according to the invention.

An exemplary combination hydrophobic composition is by weight. % by weight of sodium methylsilanolate solution having a dry weight of 15% by weight; % by weight of a 10% by weight solution of sodium hexametaphosphate; parts of a 46% styrene acrylate copolymer dispersion

0.1 wt. of a silicone type defoamer

0.01 wt. part of an organotin-type fungicidal additive

0.1 wt. part of the dye

The plaster according to the invention can be permanently dyed in the mass by adding 1 to 3 wt. parts of light-fast pigment.

The plaster according to the invention can be advantageously used in the construction industry wherever a structural surface is desired, on uneven substrates, and in particular where it is necessary to prevent the ingress of rainwater into the surface treatment and / or to ensure uninterrupted movement of water vapor through the building structure. It is particularly advantageous for the surface treatment of heat insulating materials.

An embodiment of the plaster according to the invention is illustrated in more detail in the following example:

Example 1

The walls and ceilings of the staircase and common areas in the panel apartment building were structurally rendered so that the joints and unevenness of the panels were covered. At the same time, good water vapor permeability during the exploitation of the building was ensured by a suitable composition of the plaster.

The surface was initially impregnated at an average rate of 0.3 kg. nr ² combined hydrophobic. After this layer had dried, a mass of 2 to 5 mm was sprayed in one layer, consisting of a pasty component containing a mass of 2 to 5 mm. parts of carboxymethylcellulose

0.05 wt. % of ammonia water containing 30% NH3 wt. parts by weight of the dispersion of copolymers of PVAc-acrylate having a dry weight of 43 wt. parts of ground limestone with a grain size of 0 to 0.5 mm by weight; parts of titanium white

0.01 wt. parts of an organotin-type fungicidal additive of up to 100 wt. parts of blending water and hydrophobised expanded perlite containing at least 0.005 wt. % of the silicone hydrophobic, the two components being mixed in a ratio of 1: 0.5.

By this method, a structural surface treatment with limited dirtiness, long-term hydrophobicity and high water vapor permeability has been performed.

Example 2

Reinforced concrete panels with a thermal insulation layer on the outside and on the outside were provided with an external plaster with a granular structure so that water vapor transmission through the structure was significantly reduced and that the whole system was long-term resistant to atmospheric influences; this was achieved by the composition of the plaster.

For this purpose, a plaster composition was prepared consisting of 50 parts by weight of a pasty composition of the composition below, 10 parts of cement, 50 parts of hydrophobized expanded perlite and 3 parts of a 40% methylhydrogensiloxane emulsion.

The pasty matter contained

0.3 wt. % of hydroxyethylcellulose

0.1 wt. % ammonia water 30% w / w. % by weight of a dispersion of styrene acrylate copolymers having a dry weight of 40 wt. filler parts having a grain size of 0.1 to 1.6 mm

0.6 wt. of pigment

19.8 wt. water

0.2 wt. 5 to 12 mm by weight of glass fiber. parts of aluminum stearate

The plaster mixture was sprayed onto the panel at a thickness of 10 mm and, after complete drying, was coated with a 5% methylsiloxane resin solution in toluene at a dosage of 1.5 kg. . m ~ ² .

The lightweight hydrophobic plaster according to the invention has the following physical-mechanical properties:

(in parentheses the values of common lime-cement plaster are given for comparison) volume weight 600 - 800 kg. m ~ ³ (1 600 - 1900) thermal conductivity coefficient 0,08 - 0,1 W. mX- ¹ (0,87 - 0,99) adhesion on concrete 0,3 - 0,6 MPa (0,1 to 0 2) bending tensile strength 0.6 - 0.7 MPa (0.5 to 0.7) diffusion coefficient, 5 5 - 7 (11 - 18.5) water absorption hydrophobic, hydrophilic

Claims (3)

SUBJECT 1. A high water vapor permeability lightweight hydrophobic plaster consisting of a pasty mass and a lightweight hydrophobized filler, characterized in that the paste mass contains 0.1-10 wt. 0.05 parts to 0.2 parts by weight of a soluble cellulose derivative such as carboxymethylcellulose or hydroxyethylcellulose; % of ammonia water containing 25 to 40% ammonia, 10 to 35 wt. parts by weight of an aqueous dispersion of styrene acrylate or polyvinyl acetate polymer or copolymers with 10 to 40% acrylic component, 10 to 80 wt. parts of an inert filler with a grain size of 0.01 to 3.6 mm; The ratio of the paste composition to the expanded hydrophobized filler is 1: 0.5 to 1: 2.5. 2. Lightweight plaster according to roll 1, characterized in that it contains up to 5 wt. parts of aluminum, calcium or zinc stearate or silicone hydrophobic and up to 2 wt. fiber parts in the form of scattered reinforcement. 3. Lightweight plaster according to items 1 and 2, characterized in that it contains up to 50 wt. parts of a silicate secondary binder in the form of cement and / or hydroxide or calcium oxide.