Plaster compound, plaster coating and plaster system

Abstract

The invention relates to a plaster compound for forming a single-layer or multi-layer plaster coating, in particular a reinforcing coating, containing - at least one polymer binder, - fillers, - additives and - water, wherein the fillers are present in an at least trimodal particle size distribution, comprising - at least one coarse filler with an average particle size D50 of 100-500 µm, preferably 140-400 µm, further preferably 160-350 µm, - at least one fine filler with an average particle size D50 of 30-100 µm, preferably 35-90 µm, further preferably 40-75 µm, and - at least one ultrafine filler with an average particle size D50 of 1-30 µm, preferably 2-26 µm, more preferably 2-24 µm, and wherein the at least one fine filler is a lightweight filler with a particle density according to DIN EN 1097-6 of less than 500 kg / m³, preferably less than 400 kg / m³, more preferably less than 300 kg / m³. The invention also relates to a single-layer or multi-layer plaster coating and a plaster system.

Description

[0001] Plaster mass, plaster layer and plaster system

[0002] The invention relates to a plastering compound for forming a single- or multi-layer plaster layer, in particular a reinforcement layer. Furthermore, the invention relates to a single- or multi-layer plaster layer, in particular a reinforcement layer, formed from a plastering compound according to the invention.

[0003] The preferred application of the invention is in thermal insulation composite systems comprising an insulation layer, a reinforcing layer as a base coat, and a top coat. The layers of plaster applied to the insulation layer form a plaster system. The invention therefore further relates to a plaster system with a single- or multi-layer plaster layer formed from a plaster compound according to the invention.

[0004] State of the art

[0005] In prefabricated housing, insulated wall elements are prefabricated in the factory and simply installed on the construction site. In the case of wall elements with an external thermal insulation composite system, this is also applied in the factory, so that application takes place under defined environmental conditions, particularly with regard to temperature and / or humidity. Conditions can also be created in a production hall that promote rapid drying of the applied plaster layers of the external thermal insulation composite system. This allows for faster commencement of the next processing step, intermediate storage, and / or removal, thus reducing the dwell time of the prefabricated wall element in the production hall and achieving high throughput.To further increase throughput, it has already been proposed to accelerate the drying of organically bound reinforcement layers using volatile solvents, such as 1-methoxy-2-propanol, which has an evaporation rate below 80. However, this has resulted in new problems, particularly a strong odor nuisance in the production hall.

[0006] Alternatively, attempts have been made to accelerate the drying of reinforcement layers by increasing the solids content of the plaster. However, this resulted in a deterioration in the application properties, for example, in terms of the open time of the plaster. Furthermore, the plaster's setting properties deteriorated.

[0007] The present invention is concerned with the task of providing a plastering compound for forming a single- or multi-layer plaster layer, in particular a reinforcement layer, that dries quickly and thus enables high throughput in prefabricated house construction. At the same time, the plastering compound should exhibit good processing properties and be as odorless as possible.

[0008] To achieve this objective, the plastering compound having the features of claim 1 is proposed. Advantageous further developments of the invention are set forth in the subclaims. Furthermore, a single- or multi-layer plaster coating and a plastering system are specified.

[0009] Disclosure of the invention

[0010] The proposed plastering compound for forming a single or multi-layer plastering layer, in particular a reinforcing layer, contains at least one polymer binder, fillers, additives and

[0011] Water.

[0012] The fillers are present in an at least trimodal particle size distribution, comprising at least one coarse filler with an average particle size D50 of 100-500 gm, preferably 140-400 gm, further preferably 160-350 gm, at least one fine filler with an average particle size D50 of 30-100 gm, preferably 35-90 gm, further preferably 40-75 gm and at least one ultrafine filler with an average particle size D50 of 1-30 gm, preferably 2-26 gm, further preferably 2-24 gm.

[0013] At least one fine filler is a lightweight filler with a bulk density according to DIN EN 1097-6 of less than 500 kg / m 3 , preferably below 400 kg / m 3 , preferably below 300 kg / m 3 .

[0014] The D50 value, also known as the half-size particle size or median value, indicates the mean particle size of a filler, such that the proportion of particles larger than the D50 value is equal to the proportion of particles smaller than the D50 value. These values ​​are preferably determined according to DIN ISO 9276-1:2004-09 (Presentation of particle size analysis results - Part 1: Graphic representation) and ISO 9276-2:2014-05 (Presentation of particle size analysis results - Part 2: Calculations of mean particle sizes / diameters and moments from particle size distributions). The Mastersizer 3000 from Malvern Instruments Limited can be used as the size determination instrument. However, these values ​​can usually also be easily obtained from a technical data sheet.

[0015] The proposed filler combination with the specified D50 values ​​enables particularly dense packing of the fillers, as the fine fillers settle into the remaining spaces between the coarse fillers, and the ultrafine fillers settle into the remaining spaces between the coarse fillers and the fine fillers. The denser the packing, the less polymer binder and thus water is required, as less space is available to be filled with polymer binder and water. The less water contained in the plaster mix, the less water must evaporate during the drying of a plaster layer made from the plaster mix. As a result, drying can be accelerated.

[0016] To determine the average particle size (D50 value) of the fillers contained with at least a trimodal particle size distribution, the D50 value of the coarse filler fraction can be used as a starting point. This is because the coarse fillers form a kind of basic framework within the packing. Within this basic framework, spaces remain between the coarse fillers, the size of which can be calculated, so that the size of the fine fillers can be determined accordingly. This applies analogously to the spaces remaining between the coarse and fine fillers, which are to be filled with ultrafine fillers.

[0017] When calculating the remaining spaces between the fillers, the particles of a size fraction can be simplified or modeled as spheres of the same size, with the size corresponding to the respective D50 value. In reality, the shape of the particles deviates from spherical. Furthermore, not all fillers of a size fraction are the same size, but also exist in a size distribution. However, all of this can be neglected when calculating the remaining spaces or when determining the average particle size D50 of the individual size fractions.

[0018] In a sphere that is as close as possible to the dense packing, tetrahedral and octahedral interstices form. A smaller sphere with a diameter of d fits into an octahedral interstices between two particles / spheres of a coarse filler with a diameter of D if d lies between 0.155*D and 0.414*D. However, the tetrahedral interstices are more important. A smaller sphere with a diameter of d fits into a tetrahedral interstices between two particles / spheres of a coarse filler with a diameter of D if d lies between 0.225*D and 0.291*D.

[0019] In general, it can be said that the D50 value of the fine filler should be between 0.155 and 0.414, preferably between 0.225 and 0.414, further preferably between 0.225 and 0.291, of the D50 value of the coarse filler in order to obtain the densest possible packing.

[0020] Furthermore, the D50 values ​​of the individual filler fractions, namely ultrafine filler: fine filler: coarse filler, preferably have a size ratio of 1:3-10:15-40. This ensures that the ultrafine filler fills the gaps or spaces remaining between the coarse filler and the fine filler.

[0021] A dense filler pack in a plastering compound normally results in the plastering compound, or a single- or multi-layer plaster layer made from the plastering compound, becoming very "heavy." To prevent this, the plastering compound according to the invention comprises a lightweight filler as a fine filler. The lightweight filler can be, for example, pumice, perlite, especially expanded perlite, expanded glass, expanded clay, expanded slate, expanded mica, especially expanded or foamed vermiculite, and / or hollow glass spheres. Lightweight filler mixtures can also be used. If different fine fillers or types of fine fillers are included, preferably all fine fillers are also lightweight fillers.

[0022] Furthermore, preferably, only the at least one fine filler contains a lightweight filler, meaning that no lightweight filler is contained in the other filler fractions. If the at least one coarse filler contained a lightweight filler, this would impair the strength of the individual particles of the coarse filler and thus the subsequent plaster layer. If the at least one ultrafine filler contained a lightweight filler, this would increase the oil absorption of the filler and thus the binder requirement. As a result, the drying of a plaster layer formed from the plaster mass would be slowed down again.

[0023] The oil absorption according to DIN EN ISO 787-5 of at least one ultrafine filler contained in the plaster should therefore be as low as possible, with a low oil absorption indicating a nodular, compact particle shape. The oil absorption according to DIN EN ISO 787-5 is preferably between 5 and 30, more preferably between 6 and 25, and particularly preferably between 8 and 20.

[0024] Silicate, carbonate, oxide, hydroxide, and / or sulfate fillers, such as quartz, cristobalite, limestone, marble, dolomite, aluminum hydroxide, and / or alkaline earth sulfates, can be used as ultrafine fillers. For all size fractions, not only one filler or filler type can be used, but also a mixture of different fillers.

[0025] Silicate and / or carbonate fillers, such as uranium, cristobalite, limestone, marble, and / or dolomite, can be used as coarse fillers. The Mohs hardness of the coarse filler should be at least 3 to ensure sufficient strength for the plaster layer formed from the plaster mixture.

[0026] Furthermore, it is suggested that the lightweight filler has an average grain strength according to DIN EN 13055-1 of at least 1.2 N / mm 2 , preferably at least 1.6 N7mm 2 , furthermore preferably at least 1.8 N / mm 2 ,. The lightweight filler particles are preferably at least approximately spherical, since the spherical shape increases the compressive strength and thus the fracture strength of the individual particles.

[0027] Since lightweight filler particles are generally porous and therefore do not have a closed particle surface, they exhibit a comparatively high oil absorption. This means that the use of lightweight fillers increases the binder requirement. Since the water content in the plaster mix increases with the binder content, this has a negative impact on the drying behavior of a plaster layer formed from the plaster mix. As a further improvement measure, it is therefore recommended that the lightweight filler contain a hydrophobizing agent to make the surface of the lightweight filler particles hydrophobic. With the help of the hydrophobizing agent, the lightweight filler is made hydrophobic, thus reducing the binder requirement again. Alternatively or additionally, a closed-cell lightweight filler with a closed surface and / or hollow glass spheres can be used.

[0028] A plaster composition according to the invention preferably contains, based on the total weight of the starting materials:

[0029] 50-75% by weight, preferably 50-70% by weight, further preferably 55-70% by weight of the at least one coarse filler,

[0030] 1-10 wt.%, preferably 1-7 wt.%, further preferably 1-5 wt.% of the at least one fine filler

[0031] 5-25 wt.%, preferably 5-20 wt.%, further preferably 6-15 wt.% of the at least one fine filler.

[0032] The specified weight proportions of the individual filler fractions in the proposed plaster mix result in the densest possible filler packing. Ideally, the proportion of ultrafine fillers is selected just high enough that not all gaps and cavities between the coarser filler particles are filled with at least one ultrafine filler. This ensures that a plaster layer formed from the plaster mix remains permeable to water vapor and can "breathe." This means that the binder should not completely fill the gaps and cavities. The binder proportion therefore also plays a role. A relevant parameter in this context is the pigment volume concentration (PVC). The PVC describes the ratio of the volume of the pigments and fillers contained to the total volume of non-volatile components, usually pigments, fillers, and binders.It is therefore a key parameter for characterizing the volume ratio of pigment and filler to binder. The lower the PVC, the higher the binder content.

[0033] To determine the PVC, reference can be made to DIN EN ISO 4618:2015-01. The following formula can be used to calculate the PVC:

[0034] PVK [%] — (^Vpigments + Vfillers / ^Vpigments + ^Vfillers + ^jVbinder) X 100

[0035] Another key parameter is the critical pigment volume concentration (CPVC). In DIN EN ISO 4618:2015, the CPVC is defined as a specific PVC value at which the voids between the contacting solid particles of a coating are just barely filled with binder. Above the CPVC (supercritical range), therefore, not all voids are filled with binder. Below the CPVC (subcritical range), all voids are filled with binder.

[0036] The coarse grain typically found in plastering compounds leads to the formation of unfilled air pockets, so that the PVC of a plaster layer made from a conventional plastering compound is always in the supercritical range. Therefore, information on the PVC is generally unnecessary for plastering compounds or plaster layers. Specifying the PVC only makes sense if the coating contains finely divided pigments and fillers, resulting in a dense packing of the pigments and fillers. This is the case with paints and varnishes, as well as with the plastering compound proposed here. A dense packing of fillers leads to small gaps or cavities, so that the binder requirement to fill the gaps or cavities is inherently low. This means that the CPVC shifts toward a higher value. With a PVC of preferably 75-95%, and more preferably 80-90%, the proposed plastering compound lies in the supercritical range.This means that, according to the definition given above, not all gaps and cavities are filled with binder, or the system is "low-binder." Due to the remaining gaps and cavities, a plaster layer formed from the plaster compound remains permeable to water vapor, despite the dense filler packing.

[0037] Therefore, the solids content of the at least one polymer binder, based on the total weight of the starting materials, is preferably 4-15 wt.%, preferably 4-12 wt.%, further preferably 5-10 wt.%.

[0038] Furthermore, the at least one polymer binder is preferably a polymer binder based on vinyl acetate / ethylene copolymers, copolymers based on vinyl aromatics, in particular styrene, and acrylates and / or homo-, co-, or terpolymers based on pure acrylates, in particular based on styrene-acrylate copolymers, and / or pure acrylates comprising homo- or copolymers of acrylates and / or methacrylates, optionally with acrylic and / or methacrylic acid as a comonomer unit. Particular preference is given to homo- or copolymers based on pure acrylates and / or based on styrene-acrylate copolymers.

[0039] Furthermore, the at least one polymer binder preferably has a minimum film temperature below 15°C, preferably below 12°C, and furthermore preferably below 9°C. The comparatively low minimum film temperature makes it possible to dispense with the addition of a film-forming aid. This applies in particular if, as is common in prefabricated house construction, the plaster compound is applied in a production hall, i.e., at warm temperatures. Film-forming aids often have a low evaporation number, generally below 80, so they evaporate more quickly than water, which has an evaporation number of 80. The evaporation number is a measure of the volatility of liquids, which is important for the evaluation of solvents, thinners, and extenders. The evaporation number of diethyl ether, which is given as 1, serves as the basis.Film-forming agents with an evaporation rate of less than 80 in a plastering compound should therefore accelerate the drying of a plaster layer formed from the plastering compound. Surprisingly, however, it has been shown that the opposite is true. This could be due to the fact that mixing a film-forming agent with water leads to a reduction in vapor pressure and a resulting increase in the boiling point.

[0040] The same applies to co-solvents, so that not only the addition of film-forming agents but also the addition of co-solvents is advantageously eliminated. Eliminating co-solvents also solves the problem of odor nuisance mentioned above, which is due to high VOC levels (i.e., a high proportion of volatile organic compounds).

[0041] Since it cannot be ruled out that small amounts of film-forming aid and / or co-solvent are introduced by other recipe ingredients, it is proposed in a further development of the invention that, based on the total weight of the starting materials, less than 0.5 wt. %, preferably less than 0.3 wt. %, furthermore preferably less than 0.1 wt. %, of film-forming aid and / or less than 0.5 wt. %, preferably less than 0.3 wt. %, furthermore preferably less than 0.1 wt. %, of co-solvent is / are contained. Furthermore, it is proposed that the plaster composition contain an acrylate-based thickener as an additive. By adding the thickener, the rheological properties and thus the processing properties of the plaster composition can be controlled.

[0042] The acrylate-based thickener preferably replaces a cellulose-based thickener, meaning that the active addition of a cellulose-based thickener is omitted. Cellulose-based thickeners have the property of binding water, so they are often used as water-retaining agents in other systems. The addition of a cellulose-based thickener would therefore slow the drying of the plaster or any plaster layer formed from it.

[0043] The proposed plaster composition preferably contains 0.1 - 2.0 wt.% of the acrylate-based thickener based on the total weight of the starting materials.

[0044] Furthermore, the plaster composition preferably contains other additives, for example preservatives, fibers, wetting / dispersing agents, defoamers, and / or water repellents. The proportion of the other additives is preferably 0.1-5.0 wt.% based on the total weight of the starting materials.

[0045] A plaster composition according to the invention therefore preferably contains:

[0046] 4.0-15.0 wt.% of at least one polymer binder (solid) 50.0-75.0 wt.% of at least one coarse filler 1.0-10.0 wt.% of at least one fine filler 5.0-25.0 wt.% of at least one ultra-fine filler 5.0-25.0 wt.% water 0.1-2.0 wt.% thickener 0.1-5.0 wt.% further additives, each based on the total weight of the starting materials.

[0047] A plaster layer formed from the plaster mix is ​​characterized by its rapid drying properties. This makes the plaster mix particularly suitable for use in prefabricated house construction, as it enables higher throughput in the prefabrication of wall elements. This is especially true when using the plaster mix to form a single- or multi-layer reinforcement layer, as this usually needs to dry before the next processing step can take place and / or the wall element can be loaded or transported away.

[0048] Therefore, a single- or multi-layer plaster layer, in particular a reinforcement layer, made of a plastering compound according to the invention is also proposed. Due to the composition of the plastering compound, the single- or multi-layer plaster layer dries very quickly, so that the next processing step and / or removal can be carried out quickly.

[0049] The reinforcement layer and the top coat layer form a plaster system. Furthermore, a plaster system is proposed that comprises a single- or multi-layer plaster layer, in particular a reinforcement layer, formed from a plastering compound according to the invention, as well as at least one further plaster layer, preferably a top coat layer. The plaster system can be used in particular in prefabricated house construction to increase throughput during the prefabrication of wall elements. The plaster system can in particular be applied to an insulation layer, thus forming a thermal insulation composite system.

[0050] The advantages of the invention are demonstrated below using a specific embodiment. This embodiment specifies a plastering compound according to the invention for forming a single- or multi-layer plaster layer, in particular a single- or multi-layer reinforcement layer.

[0051] 7.0 wt.% polymer binder based on pure acrylate (solid)

[0052] 25.0 wt.% quartz sand (coarse filler, grain size 0.1 - 0.2 mm)

[0053] 37.0 wt.% quartz sand (coarse filler, grain size 0.1 - 0.4 mm)

[0054] 2.5 wt.% expanded perlite (fine filler)

[0055] 10.0 wt.% calcium carbonate (fine filler)

[0056] 16.7% wt. water

[0057] 0.0 wt% film-forming agent / co-solvent

[0058] 0.3 wt.% acrylate-based thickener

[0059] 0.0 wt% cellulose-based thickener

[0060] 1.5 wt.% other additives

[0061] 100 wt.% To produce a plaster compound according to the invention, all starting materials were mixed homogeneously. The plaster compound was then applied to a 2.0 mm thick layer of expanded polystyrene and dried to constant weight in a constant-climate chamber at an ambient temperature of 23 °C and a relative humidity of 50%. Drying, or rather, the evaporation of water, was monitored gravimetrically. The plaster compound is considered dry when the 98% value was exceeded before constant weight was reached. The drying time in this case was approximately eight hours. For comparison, additional plaster compounds were prepared from the following recipes as Reference Examples 1 and 2. Reference Example 1

[0062] 7.0 wt.% polymer binder based on pure acrylate (solid)

[0063] 25.0 wt.% quartz sand (coarse filler, grain size 0.1 - 0.2 mm)

[0064] 37.0 wt.% quartz sand (coarse filler, grain size 0.1 - 0.4 mm)

[0065] 0.0 wt.% expanded perlite (fine filler)

[0066] 12.5 wt.% calcium carbonate (fine filler)

[0067] 16.7% wt. water

[0068] 0.0 wt% film-forming agent / co-solvent

[0069] 0.3 wt.% acrylate-based thickener

[0070] 0.0 wt% cellulose-based thickener

[0071] 1.5 wt.% other additives

[0072] 100 wt.%. In contrast to the plaster composition according to the invention, no fine filler, in particular no fine filler in the form of a lightweight filler, was included. Instead, the proportion of ultrafine filler was increased.

[0073] A layer of plaster was formed from the plaster mix in the same way as described above and dried. The drying time was approximately 11.5 hours.

[0074] Reference example 2

[0075] 7.0 wt.% polymer binder based on pure acrylate (solid)

[0076] 25.0 wt.% quartz sand (coarse filler, grain size 0.1 - 0.2 mm)

[0077] 37.0 wt.% quartz sand (coarse filler, grain size 0.1 - 0.4 mm)

[0078] 0.0 wt.% expanded perlite (fine filler)

[0079] 12.5 wt% calcium carbonate (fine filler) 15.2 wt% water

[0080] 1.5 wt% film-forming agent / co-solvent

[0081] 0.0 wt.% acrylate-based thickener

[0082] 0.3 wt.% cellulose-based thickener

[0083] 1.5 wt.% other additives

[0084] 100% by weight

[0085] In contrast to the plaster compound according to the invention, this one also contained no fine filler, especially no fine filler in the form of a lightweight filler. Instead, the proportion of ultrafine filler was increased. Additionally, a film-forming agent / co-solvent and a cellulose-based thickener were added.

[0086] A layer of plaster was formed from this plaster mixture in the same way as described above and dried. The drying time was over 22 hours.

[0087] Further differences between the plaster layer produced from the plaster mix according to the example and the plaster layers produced from the plaster mixes according to the reference examples were observed with regard to the Shore A hardness according to ISO 7619:2012-02. The Shore A hardness at which a plaster layer can be considered reworkable or loadable is > 75. The following timescales were determined for the plaster layers produced until a Shore A hardness of > 75 was reached:

[0088] Plaster layer made from the plaster mass according to the example: 11.5 hours.

[0089] Plaster layer made from the plaster mass according to reference example 1 : 14 hours.

[0090] Plaster layer made from the plaster mixture according to Reference Example 2: 17.5 hours.

[0091] The advantages of the invention are explained below with reference to the single attached

[0092] This figure shows a graph illustrating the different drying times of the plaster compounds according to the working example and the two reference examples.

[0093] Detailed description of the figure

[0094] Three curves can be seen in the figure or graph. Curve A shows the drying process of the plastering compound according to the invention according to the specified embodiment. Curve B shows the drying process of the plastering compound according to Reference Example 1, and Curve C shows the drying process of the plastering compound according to Reference Example 2. Furthermore, the 98% value is indicated by a dashed line. If a curve reaches the 98% value, 98% of the respective plastering compound is dry. This means that the plastering compound is considered dry.

[0095] Drying can be determined gravimetrically, in particular. The procedure is as follows:

[0096] The plaster mix is ​​applied to a tared EPS board in the desired layer thickness. The weight of the EPS board, including the applied plaster mix, is then determined and recorded. The board is then dried under specified conditions until constant mass is reached on a scale with a data logger, with the weight being recorded every 10 minutes. The initial weight of the sample less the weight of the EPS board corresponds to the 0% drying value. The weight at constant mass less the weight of the EPS board corresponds to the 100% drying value. Using these two weights, the 98% drying value can be calculated. The respective drying time is read off at the intersection of the drying curve and the 98% value.

Claims

Patent claims 1. Plastering compound for forming a single or multi-layer plaster layer, in particular a reinforcing layer, containing at least one polymer binder, fillers, Additives and Water, wherein the fillers are present in an at least trimodal particle size distribution, comprising at least one coarse filler with an average particle size D50 of 100-500 pm, preferably 140-400 pm, further preferably 160-350 pm, at least one fine filler with an average particle size D50 of 30-100 pm, preferably 35-90 gm, further preferably 40-75 gm and at least one ultrafine filler with an average particle size D50 of 1-30 pm, preferably 2-26 gm, further preferably 2-24 gm, and wherein the at least one fine filler is a lightweight filler with a bulk density according to DIN EN 1097-6 of less than 500 kg / m 3 , preferably below 400 kg / m 3, preferably below 300 kg / m 3 , is.

2. Plastering compound according to claim 1, characterized in that the lightweight filler has an average grain strength according to DIN EN 13055-1 of at least 1.2 N / mm 2 , preferably at least 1.6 N7mm 2 , furthermore preferably at least 1.8 N / mm 2 , has.

3. Plastering compound according to claim 1 or 2, characterized in that the lightweight filler contains a hydrophobizing agent for hydrophobizing the surface of the lightweight filler particles.

4. Plastering compound according to one of the preceding claims, characterized in that in each case based on the total weight of the starting materials 50-75 wt.%, preferably 50-70 wt.%, further preferably 55-70 wt.% of the at least one coarse filler, 1-10 wt.%, preferably 1-7 wt.%, further preferably 1-5 wt.% of the at least one fine filler 5-25 wt.%, preferably 5-20 wt.%, further preferably 6-15 wt.% of the at least one fine filler are contained.

5. Plastering compound according to one of the preceding claims, characterized in that, based on the total weight of the starting materials, the solids content of the at least one polymer binder is 4-15 wt.%, preferably 4-12 wt.%, further preferably 5-10 wt.%.

6. Plastering compound according to one of the preceding claims, characterized in that the at least one polymer binder has a minimum film temperature below 15°C, preferably below 12°C, further preferably below 9°C.

7. Plastering compound according to one of the preceding claims, characterized in that in each case, based on the total weight of the starting materials, less than 0.5 wt.%, preferably less than 0.3 wt.%, furthermore preferably less than 0.1 wt.%, of film-forming aid and / or less than 0.5 wt.%, preferably less than 0.3 wt.%, furthermore preferably less than 0.1 wt.%, of co-solvent is or are contained.

8. Plastering compound according to one of the preceding claims, characterized in that an acrylate-based thickener is included as an additive, which preferably replaces a cellulose-based thickener, wherein preferably 0.1-2.0 wt.% of the thickener, based on the total weight of the starting materials, is also included.

9. Plastering compound according to claim 8, characterized in that further additives, for example preservatives, fibers, wetting / dispersing agents, defoamers and / or hydrophobicizing agents, are included, wherein preferably 0.1-5.0 wt.% of further additives are included based on the total weight of the starting materials.

10. Plastering compound according to one of the preceding claims, characterized in that in each case based on the total weight of the Starting materials 4.0-15.0 wt.% of at least one polymer binder (solid) 50.0-75.0 wt.% of at least one coarse filler 1.0-10.0 wt.% of at least one fine filler 5.0-25.0 wt.% of at least one fine filler 5.0-25.0 wt% water 0.1-2.0 wt.% thickener 0.1-5.0 wt.% of other additives are included.

11. Single or multi-layer plaster layer, in particular a reinforcing layer, made of a plaster composition according to one of the preceding claims.

12. Plaster system comprising a single or multi-layer plaster layer formed from a plastering compound according to one of claims 1 to 10, in particular Reinforcing layer, as well as at least one further plaster layer, preferably a finishing plaster layer.

13. Plastering system according to claim 12, characterized in that the plastering system is designed to form a Thermal insulation composite system is applied to an insulation layer.

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