DE2703342B2 - Mortar for coating thermal insulation panels - Google Patents

Description

The invention relates to a mortar for coating thermal insulation panels, which is particularly beneficial in can be applied in a single operation.

Insulation boards, e.g. B. those based on foamed js Polystyrene or polyurethane foams are coated with grid-reinforced filler or plaster mortar, whereupon a final coat is applied if necessary. To apply such mortar to the insulation boards, several work steps are required because a plastic-modified mortar is first applied, then applies a mesh fabric and this fabric then only after drying with a required Can provide primer. The primer is then topcoated with a plastic-bound dispersion plaster or paint applied.

DE-OS 18 03 381 discloses mixtures for insulating mortars and insulating plaster known. Such mixtures contain besides lime and / or cement with volcanic Tufa encased foamed styrene polymer particles and small amounts of soap. Insulating mortar and insulating plaster themselves serve as thermal insulation material, but are not suitable for coating thermal insulation panels.

In DE-AS 19 17 733 a hydraulic plaster for construction areas where cement and / or lime, such as aggregates, plasticizers and Film formers are used as well as certain carbonyl compounds. Such plaster is very rigid and for insulation boards with regard to its hydraulic setting and the associated too large Ε module unsuitable.

The object of the invention is to provide a mortar for coating thermal insulation panels according to the generic term of claim I to show that can be applied in one operation and good Thermal insulation board adheres.

This object is achieved by the mortar characterized in the claims. This contains mineral aggregates, hydraulic binders, cellulose or its derivatives as well as an alkali-resistant synthetic resin that contains a surfactant protective colloid, the surface-active effect of which is essentially neutralized ^{when exposed to Ca 2+} or Mg ^{2+ ions.}

Stone, marble or other granulates or Sands with a grain size of 0.01 to about 5 mm are used, the largest grain thickness being the Can determine the structure of the surface. A preferred size range for the surcharges is 0.5 to 3 mm.

Portland cement, the given lime, is preferably used as the hydraulic binding agent or hydrated lime can be added.

The mortar also contains cellulose or derivatives thereof due to its water retention capacity can contribute to the setting of the hydraulic binding agent. As cellulose derivatives, for example Mcthylcellulose or Hydroxyäthylcellulosc in question.

As the synthetic resin, there can in principle be used those which are alkali-resistant, a low one Have a tendency to absorb water and are hydrophobic. The hydrophobization of the plastic can be partly steer through the groups introduced here. Here you will be given a Plastic by increasing the branching of the polymer chain, for example by steric hindrance Can prevent the ingress of water. This water-blocking effect of the synthetic resin can be supplemented are due to the water-repellent effect of Ca and Mg ions from the surfactant protective colloid precipitated, water-insoluble layer or the precipitate. Although usually on the Coating of hot plates used synthetic resins are less suitable because their hydrophobic Nature in itself is still inadequate, it can be used with a particularly suitable surfactant Protective colloid system in the mortar according to the invention should nevertheless still be taken into account when the Ca- or Mg-containing »barrier layer« formed in the aforementioned system is relatively tight. As such, usually Materials used can be named, for example, copolymers based on butadiene and styrene, polyvinyl acetate, styrene-acrylic copolymers, polyacrylates or polyvinyl propionate.

In particular, alkali-resistant ones are within the scope of the invention Copolymers of vinyl acetate and carboxylic acid vinyl esters are preferred. Among these connections are in turn particularly advantageous those in the carboxylic acid group that are advantageous represents a monocarboxylic acid group, are highly branched.

The synthetic resins obtained in the form of dispersions or those made from powdered synthetic resins with mixing water resulting dispersions or suspensions are usually due to the content of protective colloids more or less strongly hydrophilized. This sets the hydrophobic nature of the synthetic resin initially "Covered". When choosing a protective colloid that has a surface-active effect under the influence of immigrants Losing calcium and / or magnesium ions from the constituents of the mortar can make it hydrophobic The blocking effect of the synthetic resin is fully utilized

will. The loss of the surface-active nature of such protective colloids can be caused, for example, by complexation of the material used, through the formation of insoluble precipitates or through the immigrants Calcium ions, usually from the hydraulic and / or mineral binders originate. This is how the "blocking" effect of the alkali-resistant synthetic resin comes into play Protection of the embedded fiberglass mesh fully for wear. ι ο

In the investigations on which the invention is based, it has been found to be particularly favorable to design the synthetic resin by special selection of the constituents forming it so that it, if necessary occurring moisture already opposes a steric hindrance. With that according to an embodiment of the invention preferred copolymer of vinyl acetate and the vinyl ester of a branched long chain monocarboxylic acid has z. B. a rise in long-term water resistance Use of an even more branched carboxylic acid component can be achieved.

These effects acting on an interaction hydraulic Binder and emulsifying or surfactant occurring as a protective colloid, can through the addition of metal fatty acid salt, tie for example Sodium stearate or zinc stearate, in some cases, can be fortified.

Particularly preferred is a copolymer of the Versatic acid vinyl ester (under m the designation "Versatic acid" are generally synthetic fatty acids v - stood, but in particular mixtures of predominantly tertiary carboxylic acids with strong branching) r ^; t vinyl acetate, which contains, among other things, polyvinyl alcohol y as a protective colloid. In the case of the resin mentioned, the water-barrier properties appear relatively quickly when combined with the hydraulic binder in the mortar according to the invention.

As surfactant protective colloid for example, soaps, particularly alkali metal soaps such as Na, Ka-salts of low molecular weight fatty acids of abietic acid, carboxymethyl cellulose, hydroxy carboxylic acid,. B. ricinol fatty acid and / or pelroleum sulfonates in question. The surfactant system can bring about its advantageous effect in particular in the case of synthetic resins which have the greatest possible branching and thus steric hindrance. It is necessary that the synthetic resins not only have a low water absorption, but also after "collapse" of the> o surfactant-protective colloid system, which advantageously has emulsifying properties, e.g. B. by the provoked by the migration of calcium and / or magnesium ions precipitation of a barrier layer of at least partially insoluble, calcium-containing precipitate have a hydrophobizing effect. Both the nature of the synthetic resin and the selected surfactant system contribute to this. With the optional addition of perlite, the mortar stays open longer due to the low water evaporation speed, so that it is possible to work even in very warm weather. The "open time" allows the plaster to be worked on with a scratching tool, so that a scratched plaster surface with the same appearance and structure as with mineral high-quality scratch plaster is created. Of course, it is also possible to work on the surface with structure tools in order to achieve any other desired structure, such as trowel or patch plaster. Although the use of expanded perlite is preferred, other expandable materials, such as vermiculite, can also be used according to the invention.

The proportions of the main components of the mortar according to the invention as well as those to be added if necessary further components can be varied within wide ranges. A particularly preferred one Composition contains 40-80% mineral aggregates, 15-40% hydraulic binding agent and possibly Lime (hydrate), 0.1 to 5% cellulose (derivative) and 1-20% alkali-resistant synthetic resin, based on the dry weight of the mixture.

For example, 0.2 to 10% by weight perlite can be added to this composition. Pearl accessories, which exceed 10% by weight of the dry matter are not preferred because the coating weight is too high sinks.

In some embodiments of the invention it may also be desirable, by adding synthetic resin fibers, z. B. polyacrylonitrile, polyester, polyethylene, polyvinyl chloride or polyacrylate fibers of a length from 0.8 to 2 mm, for example, to improve the elastic properties of the mortar. Further advantages are an increase in the flexural strength and good thixotropic properties of the mass. If synthetic fibers are used, their use in an amount of about 0.1 to 5% by weight is preferred.

It can also sometimes be useful to additionally use air-entraining agents in an amount of about 0.01 to 0.05% by weight to be used, e.g. B. Sodium Lauryl Sulphate. A combination can be particularly advantageous here from sodium lauryl sulfate with zinc stearate act.

Finally, pigments or plastic color dispersions can also be added to the mortar. It can also be useful to prevent blooming alkali or alkaline earth metal carbonates, e.g. B. Sodium carbonate and highly condensed phosphates as rust inhibitors.

A number of advantages are achieved by using the mortar according to the invention. These consist mainly in that the wall plaster consists of a single, essentially homogeneous layer can be trained. In contrast to multilayered, temperature stresses can be inhomogeneous Layers no longer have a detrimental effect. Due to the single layer of the plaster, there is a considerable amount Saving in working time achieved.

The production of the mortar according to the invention is extremely simple. This can be done, for example, by that the dry portions are presented and mixed well and then mixed with mixing water will. It is useful here to introduce the fillers and to introduce them in small amounts Distribute ingredients homogeneously. If the chosen plastic-surfactant system is out of shape a dispersion, rather than a powder, it is advisable to add the mixing water to the Let the mixture mature for some time, e.g. 10 minutes, and then mix it again shortly before use.

The mortar according to the invention can be applied either by spraying or by spatula will. The working time saved brings a noticeable reduction in execution prices.

The invention is further illustrated below in examples. All parts are parts by weight.

example 1

350 parts of sand, gravel or granules in a sieve of 1-2.5 mm, 255.9 parts of quartz sand 0.5-1 mm, 100 parts of quartz sand 0.2-0.5 mm, 200 parts of white Portland cement, 60 parts of white lime hydrate ,
10 parts perlite 0-1 mm,
1 part methyl cellulose powder, 2.5 parts sodium or zinc stearate, 03 parts polyacrylonitrile fibers 2 mm = 6.7 dtex, 03 parts polyethylene fibers 0.8 mm = 0.7-1.5 dtex, 20 parts titanium dioxide or colored pigments 1000 parts

This dry mix becomes 80-100 parts of a Plastic dispersion made from vinyl versatate with a branched long-chain monocarboxylic acid or 40-50 Parts of powder of the aforementioned type and the corresponding amount of water are added.

Parts

Parts

in 160 Parts 80 Parts 5 Parts 1 part 2 Parts 15 0.05 Parts 60 Parts 30th Parts

Example 2

Sand, gravel or granules in the Ahsii -

exercise of 2-5 mm,

Quartz sand 0.5-2 mm, or

Stone sand 0.2-0.5 mm.

White portland cement,

Weißkaik,

Perlite 0-1 mm,

Hydroxyethyl cellulose,

Silicone powder,

Sodium lauryl sulfate,

Dispersion or

Powder of a copolymer from Versa-

tic acid vinyl ester and vinyl acetate with

a content of polyvinyl alcohol.

Claims (4)

Patent claims: 1. Mortar for coating thermal insulation boards based on mineral aggregates, s hydraulic binders, cellulose or its derivatives and an alkali-resistant synthetic resin, characterized in that the synthetic resin contains a surfactant protective colloid whose surface-active effect when exposed to Ca ²⁺ or Mg ²⁺ ions are reduced or eliminated. 2. Mortar according to claim 1, characterized in that the alkali-resistant synthetic resin Copolymer of vinyl acetate and a vinyl ester of a highly branched long-chain carboxylic acid, which is preferably a monocarboxylic acid. 3. Mortar according to one of the preceding claims, characterized in that the protective colloid forms insoluble precipitates in Ca ions in the presence 4. Mortar according to one of the preceding claims, characterized in that the protective colloid contains polyvinyl alcohol. 2s