AU2015356990A1

AU2015356990A1 - Building material mixture

Info

Publication number: AU2015356990A1
Application number: AU2015356990A
Authority: AU
Inventors: Jens Duewel
Original assignee: Heka Graphit Tech Ug Haftungsbeschraenkt
Current assignee: Heka GraphitTechnology Ug (haftungsbeschrankt)
Priority date: 2014-12-04
Filing date: 2015-12-04
Publication date: 2017-07-27
Also published as: EP3253722B1; EA039443B1; EA201700287A1; WO2016087673A1; EP3253722A1; DE102015121201A1; ES2866648T3

Abstract

The invention relates to a building material mixture, in particular a filler or plaster compound, the dry weight of which has between 30 and 95 wt [%] of graphite, between 4 and 30 wt [%] of a binder and between 0 and 40 wt [%] of a functional additive.

Description

WO 2016/087673 PCT/EP2015/078740 2 "Building Materials Mixture"

This Invention relates to a Building Materials Mixture. A generic Building Materials Mixture is for example used as a plaster, stucco or filler. Notably, such materials can be used to fill surfaces where surface heating has been installed. A surface heating system consists, for example, of a grid of piping, which is laid into a wall, ceiling or floor (for example as floor heating) of a room, and which is then going to be surrounded by the cured Building Materials Mixture. Such surface heaters allow a room to be heated with a lower preheating requirement.

Since in such heating systems, there is no great temperature difference, it would be advantageous to have a filler or plastering compound which has a high thermal conductivity and which also ensures rapid heat transport over the entire surface, even at lower temperature differences, since the thermal energy is often only partially carried into the surface heating by the heating source.

Purpose of the invention is to propose a Building Materials Mixture which in the cured, ready-to-use state forms a material with high thermal conductivity. PCT/EP2015/078740 WO 2016/087673 3

To solve this challenge, the invention proposes a building materials mixture, especially a plaster or filler compound, whose dry weight is composed of between 40 and 95 weight % of graphite, between 4 and 30 weight % binder and between 0 and 40 weight % functional additive. The sum of these three components equals 100 weight %.

This invention not only answers the said challenge in the best possible manner, but, the proposed Building Materials Mixture also has specific properties which help to deflect electromagnetic waves.

Furthermore, the proposed Building Materials Mixture can be used in building technology and can be applied with an airless device, with trowel and as a filler compound.

The Building Materials Mixture as suggested by the invention possesses a certain specific composition. There are be at least two components, preferably three, which are defined by intervals, and these are described by an upper and lower limit.

As such the upper limit of the interval for graphite is 98, 95, 90, 85 or 80 weight [%] . As a lower limit, for example, there are the following values: 20, 25, 30, 35, 40, 45, 50 weight [%] This Patent

Application as disclosed, comprises all such intervals and all possible combinations of the aforementioned upper and lower limits.

Furthermore, the upper limit of the interval for binders in the mixture is 50, 45, 40, 35, 30, 25 or 20 weight [%] . As lower limit, for example, the following values apply: 2, 4, 7, 10, 15, 20, 25, 30, 35 or 40 Weight [%] . This Patent Application as disclosed comprises all such intervals and all possible and compatible combinations of the aforementioned upper and lower limits.

The upper limit of the interval of functional additives in the mixture is 55, 50, 45, 40, 35, 30, 25 or 20 weight [%] . As a lower limit, for example the following values apply: 0, 3, 6, 10, 13, 16, 20, 25 or 30 weight [%] . This Patent Application as disclosed PCT/EP2015/078740 WO 2016/087673 4 comprises all such intervals and all possible and compatible combinations of the aforementioned upper and lower limits.

More particularly, this Patent Application as disclosed comprises a combination of the aforementioned intervals such that the total of the three components shall equal 100 weight [%].

In particular, there had been developed a Building Materials Mixture which, if used as a filler compound, shows a thermal conductivity that is up to 5 times higher than standard filler compounds. Such a filler compound is most adequate for the making of special wall- and ceiling-mounted heating systems. This high thermal conductivity of the new filler compound leads to a good heat distribution between the heating tubes embedded in the filler compound and thus has an isothermal and energetically advantageous thermal radiation of the wall surfaces.

Furthermore, it is highly advantageous in the proposal that various graphite modifications such as expanded graphite flakes, sheet graphite, natural graphite or synthetic graphite may be used as graphite component. The proposal according to the invention can be implemented with a large number of different variants of graphite, which speaks for the versatility of the invention. The list here described is not exhaustive but merely shows examples.

In the preferred case an acrylate (a water soluble substance) compound should be used as binder or glue for the Building Materials Mixture .

Furthermore, the invention foresees the use as a functional additive of at least one of the substances mentioned hereafter in the mixture: trass powder, glass bubbles, aluminium oxide, anti-foaming agent, magnetite, cellulose thickener. The invention is not limited to one functional additive, but can also have at least two functional additives, each having the same or different proportions. Cellulose, for example, forms a network-like or braided type of reinforcing structure which increases the stability of the Building Materials Mixture when it is used to form a layer. The use of PCT/EP2015/078740 WO 2016/087673 5 magnetite, a ferrous oxide, improves the electromagnetic shielding properties of a layer made with the Building Materials Mixture.

The use of trass powder as an additive will result in a firmer, more solid surface forming on top of the layer, or will help to improve the said properties. The use of glass bubbles or micro pearls, with a size in the order of only some μ, will lend to the Building Materials Mixture a paste-like structure. Due to its insulating effect, aluminium oxide has a bad influence on electromagnetic shielding, but improves the thermal conductivity significantly. The use of an anti-foam agent prevents foam from forming during the mixing with water, which can hinder further processing. The use of a thickener means that the ready-to-use building material does not run off the wall, but will stick to it a lot better. Plastic additives allow regulating the adhesion to the base material. Furthermore, the addition of plastic additives allows determining how loose or runny the mixture will be, it can also be used as a thickening agent.

In particular, in another alternative version, the invention proposes that other known filler compounds will not be used in the Building Materials Mixture as elementary contemporary additives such as cement, sand, gypsum, lime or clay. The basic composition, however, will be a new, special compound of materials, consisting of graphite, a binder and a functional additive.

In an advantageous manner of execution it is foreseen that the Building Materials Mixture (processed, for example with water or another liquid or dispersion and cured) and which is set as a layer in a thickness of approximately 1.5 mm, will result in a screen attenuation of more than 10 dB, in particular more than 30, 40 or 50 dB. The property of the Building Materials Mixture or a layer made from the Building Materials Mixture, which has excellent properties as a shield against electromagnetic radiation, is referred to elsewhere in this application. PCT/EP2015/078740 WO 2016/087673 6

It is a particularly smart feature that the substance (processes, e.g. with water, or cured) especially if it is made with a different liquid in dispersion, and the Building Materials Mixture has a thermal conductivity of X>1W/(mK), X>2W/(mK). More particularly, on layers that have been made with a Building Materials Mixture, got a thermal conductivity of X>3W/(mK), X>4W/(mK) X>5W/ (mK) X>6W/ (mK) X>7W/ (mK), X>8W/ (mK) or X>9W/ (mK).

Surprisingly, the proposed invention combines a high electromagnetic shielding with a high thermal conductivity, exactly as needed in residential and industrial building. Already, this double benefit is highly valuable, because with traditional systems it was necessary to use two different elements or systems in combination, which increases costs and space requirements.

However, the invention also encompasses a surface heating system, comprising a support structure and a heating source as well as a covering layer, wherein the covering layer is formed from a Building Materials Mixture as described. As support structure, for example, a wall, a floor, a ceiling, a support plate or the like can be used.In this case, the surface heating can be designed as a mobile module, which is intended for installation, or the surface heating is realized with individual components in the building, piece by piece. The invention covers both variants. As a heating source, for example, a hot water heating system is foreseen which flows through a pipe or pipe grid and thus transports the heating energy. Another variant of the heating source is a resistance heating, which is fed by a corresponding (electrical) current source. The covering layer is usually facing the space to be heated. WO 2016/087673 PCT/EP2015/078740 7

In another preferred manner of execution it is foreseen that the heating source is integrated in the covering layer. Here, too, several variants exist. Firstly, it is possible for the tube grid to be embedded on both sides in the cover layer, that is, surrounded by the building material on the front and rear side. In another variant, the heating source is formed by the graphite share in the Building Materials Mixture, which itself is an electrically effective resistance. This variant has the added advantage that a separate laying of the pipelines is not necessary and, for example, excess current produced from regenerative systems can be used purposefully. Usually, a DC low voltage in the order of protective current is sufficient for the operation of such electrically operated surface heating. Such an arrangement achieves three advantages: on the one hand, an area heating can be realized without complicated wiring (only one current line is required) - this is also suitable, for example, for refurbishment and renovation - and this provides a comfortable temperature level in a room to be heated. At the same time, the heat is distributed on the surface quickly and evenly, and the material used in the Building Materials Mixture ensures a very efficient shielding of electromagnetic radiation .

This invention therefore also encompasses the advantageous use of a Building Materials Mixture, a ready-made building material, respectively, a shielding material made from such, against electromagnetic radiation and/or as a material which distributes warmth. The building material or the Building Materials Mixture, however, realizes both qualities, not wishing to limit the invention to these characteristics. WO 2016/087673 PCT/EP2015/078740 8

As an advantage, already one of the previously described properties is achieved by the Building Materials Mixture.

Furthermore, the invention also comprises a building element, such as e.g. a cladding panel, a facing brick, a thermal storage element which at least in part is made up from a Building Materials Mixture, as described.

The (dry) Building Materials Mixture is a commercially available and used embodiment of the invention, although the described physical properties are only detectable with a layer formed by the described building materials mixture.

Therefore, the invention also broadly encompasses a building material which is made at least partially with a Building Materials Mixture as described above.

In a preferred execution of the proposal, the building material shall contain between 20 and 60 weight [%] water as indicated.

As water component, an interval will be indicated, described by an upper and lower limit. For example, the following values are foreseen for the upper limit: 70%, 65%, 60%, 55%, 50%, 45%, 40%. As lower limit, for example, the following values apply: 10%, 15%, 20%, 25%, 30%, 35%.

This Patent Application as disclosed comprises all such intervals and all possible and compatible combinations of the aforementioned upper and lower limits.

Especially, in an advantageous variant, it is foreseen that the building material, respectively the Building Materials Mixture, contains functional additives which improve the structure-forming properties of the water and, hence, the water component in the preparation can be significantly reduced. PCT/EP2015/078740 WO 2016/087673 9

It is also a positive feature that the Building Material can be premixed and kept in that state prior to use. In this variant, it is foreseen that the building material is maintained with a constant formula, and this uniform composition greatly facilitates the reliable processing of the building material with machines such as, for example, airless application machines.

Therefore, in addition to the dry Building Materials Mixture, to which water has to be added, the wet, pasty building material, which is preferably stored under the exclusion of air, is also commercially available.

Research was done with a first embodiment of the Building Materials Mixture made according to the invention, with respect to its graphite modification and the ability to process the mixture to thin films. Ground sheet graphite with an average particle size of 3,000 pm was used. This sheet graphite is milled from graphite films, which are made from expanded graphite flakes, to the required grain size in a cutting mill.

With such a Building Materials Mixture, layers can be made, but it proved difficult to produce thin layers of sufficiently high quality. Due to the admixture of large graphite particles, the production of surfaces in the Q3 - Q4 quality class cannot be achieved with these mixtures either. Using smaller particles of graphite, however, this required quality class can be achieved in the processing.

To realize this development, series of trial mixtures were made. The Mixture Base was mixed at first largely by hand, then processed in a row or sequence and subsequently examined. PCT/EP2015/078740 WO 2016/087673 10

Depending on the results obtained, the machine-technical tests and the measurement of the thermal conductivity and shielding/attenuation properties were carried out.

In a first Trial Mixture 1 (see Table) there had been used exclusively expanded graphite flakes with an average grain size of approx. 200 pm - 2,000 pm and a binder of Type 5/13 (a powdered binder on the basis of acrylate, with the trade name ACRONAL S 631 P) . The part of graphite flakes in this mixture was roundabout 80 weight % and the part of binder roundabout 20 weight %. The mixing was done by hand in the traditional manner with bucket and trowel. The water value was adjusted such that to 12 kg of dry mixture there had been added roundabout 8 litres of water to obtain a total quantity of 20 kg of mixture for trials. To add this high volume of water was necessary because the expanded graphite flakes absorb a considerable amount of water. For the application of the trials mixture to a plasterboard panel a smoothing trowel had been used. The layer was about 4 mm thick, the drying time was about 72 h.

For the trial mixture 2, there had been chosen a more cohesive binder of type 1/13 (a liquid binder on acrylate basis) which when cured provides a higher mechanical solidity. Furthermore, the expanded graphite flakes had been replaced with ground natural graphite and synthetic graphite. Ground natural graphite has a higher resistance to shearing, and synthetic graphite even considerably more so, than the previously used expanded graphite flakes .

The trial mixture roundabout 15 weight synthetic graphite, particles, the part weight %. 2, then, was distinguished by containing % natural graphite and roundabout 30 weight % In order to ensure a good binding of the of binder had been increased from 20 to 25 WO 2016/087673 PCT/EP2015/078740 11

Furthermore, in this mixture there had been used in addition the light filler substance trass powder (30 weight %). This filler substance improves the plasticity of the filler compound and thereby contributes to the reduction of the dry crack formation. By this composition of the mixture, it was possible to add less water, and to a dry mass of 12 kg 7 litres of water had been added, only.

An anti-foaming agent (Foamstar) was introduced into a third mixture (test mixture 3) in order to avoid foaming and to prevent or minimize the flocculation of the natural graphite. The part of graphite component, as compared to Trial Mix 2, was increased from 45 weight % to 60 weight % and the part of binder reduced from 25 weight % to 6 weight %. Previously conducted trials with test mixtures that had a binder component of 12.5 weight % did not show a significantly better performance in their foaming properties when a power driven mixing device had been used. Besides reducing the binder component to 6 weight %, a thickening agent and small amounts of cellulose were added in the mixture 3 to increase the suppleness of the filler mixture. The trass powder from experimental mixture 2 was replaced by lighter glass bubbles, which have proven to be a valuable processing auxiliary and also have shown to be good light filler in construction chemicals.

As a result of this modified mixing composition, it was found that the experimental mixture 3 was easy to make, both by hand and with machines, and also easy to apply to the surfaces with a commercially available airless apparatus. The surfaces are distinguished by low crack formation during the drying of the mixtures and lead to an improvement in the respective surface quality.

Because this trials mixture 3 is so well suited to the applications both in making and in application, this mixture had been used to perform a series of application-oriented trials. PCT/EP2015/078740 WO 2016/087673 12

The purpose of these investigations was to examine the extent to which this graphite-modified filler compound fulfils important requirements in practice.

In these investigations it was found that the test mixture 3 cures within a period of 24 hours at an application thickness of 3 mm and that it is easy to further process it mechanically. Due to the grinding of the surface, a surface quality in quality grade 3 could be achieved easily and safely.

In further experiments, the behaviour of the mixture was tested as concerns sinking in as a consequence of high layer thicknesses. For this purpose, single-layer plaster layers of 20 mm without supporting fabric were applied on a surface of gypsum cardboard. As a result of these tests, a sufficiently high internal stiffness of this test mixture could be determined.

With a view on possible applications of a graphite modified and airless-capable filler mixture in the rehabilitation of buildings, a series of tests were carried out with the experimental mixture 3 to show their adhesion to frequently occurring building materials.

In general, it could be stated that the adhesion of this putty to the tested substrates was very good in terms of craftsmanship.

The tear-off trial has shown an excellent result. The wallpaper fleece (thickness 2 mm) applied to the filled surface with a standard wall-covering adhesive in this test was split during peeling. This result was obtained, irrespective of whether the fleece was applied to the surface with or without a primer. In this trial, then, it was also shown that the test mixture 3 has a WO 2016/087673 PCT/EP2015/078740 13 sufficiently high cohesive strength to support wallpaper, fleece material and paints.

To determine the heat conducting properties of the test mixture 3, a wall and floor temperature control system was built up in each case. The grooves for the heating elements into which the pipes have been inserted have alternatively been filled with a smoothing trowel as well as with the airless process (airless device of the type Inomat M8) in the wall surface system.

To characterize the experimental mixture 3 with regard to the thermal properties, the produced floor system had been heated and then measured by means of thermo graphic imagery. On the basis of the thermo graphic images, a uniform and homogeneous heating of the surface could be determined in the flooring system.

It is an advantage of the invention that the proposed Building Materials Mixture has a high thermal conductivity. This high thermal conductivity of the filler or plaster compound leads to a reduction in mold formation in buildings. Mold formation in buildings mostly occurs in room corners, where the wall temperature is somewhat lower than that of the adjacent walls. These temperature differences (>3K) are reduced by the high thermal conductivity of the filler or plaster layer, which inevitably also reduces the formation of fungus that we know as mold.

The graphite used in the Building Materials Mixture according to the invention considerably increases the electrical conductivity. This reduces fogging. The fogging effect, also called Black Dust or magic-dust, is a phenomenon where rooms in buildings turn black. WO 2016/087673 PCT/EP2015/078740 14

This effect mostly occurs in heated apartments during wintertime. A spread-out blackish covering forms on the ceiling or on a wall. The layer applied to the wall is electrically grounded and therefore cannot build up an electrostatic charge that would attract particles. Airborne dirt particles, perhaps also polymer plasticiser particles, which bind the dust, are much less likely to be deposited on the wall and pollute the latter when the Building Materials Mixture according to the invention is used.

On the basis of the test mixture, measurements were made with regard to the screening/attenuation properties. To carry out these measurements, the required samples were applied on PMMA boards in the size of 120 mm x 120 mm x 2 mm or on plasterboards in the size of the PMMA plates and in the size of 500 mm x 500 mm x 12.5 mm.

The tests were carried out according to the standards ASTM D 4935-2010 and IEEE-STD 299-2006. The measurements were carried out in a very wide radiation window, that is, in the range of 20 kHz to 18 GHz .

For further orientation during the development of the filler compounds, a glass fibre fabric had been coated with the filler compound.

It was found that the test mixture 3 developed as part of the project has a remarkable shield attenuation of up to 10 dB. This means that with this airless-capable filler compound and a layer thickness of 1 mm at a gypsum board of 12.5 mm thickness, a shielding of 90% can be established in a range 10 of up to 18 GHz against radiation. The proper understanding of this remarkable result with respect to materials science shows that the shielding/attenuation properties of Trial Mix 3 are in this respect much superior to all usual standard filler compounds commercially available, which have next to no screening or attenuating effect. PCT/EP2015/078740 WO 2016/087673 15

In a new Trial Mix 4 the roundabout 30 weight % of glass bubbles had been replaced with roundabout 30 weight % of aluminium oxide powder, to enhance the thermal conductivity. Additives that already had shown their worth in Trial Mix 3, such as the anti-foaming agent (Foamstar), the thickener (Pangeel FF) and the cellulose (Tylose) were also used in this mix. Neither the quantity of such additives had been changed in the new mixture. It is of note in this context that in the preparation of this trial there had been used two different types of cellulose (Tylose 150.000 and Tylose 300). On the basis of these experiments it was found that the use of the Tylose 300 (shorter cellulose fibre of less than 1 mm) leads to a better smoothing behaviour of the applied filler.

No appreciable differences to the mixture 3 could be seen in the manual and machine-technical production as well as in the processing of this new experimental mixture 4. A slight thickening of the substance was observed, while the water content remained the same. When applying the mixture as wall and floor filler compound, however, this slightly higher viscosity was not significant. The mixture 4 was again applied to gypsum cardboard wall surfaces by hand and by means of airless equipment. The spatula application could be ground to a very clean finish after a drying time of 24 h. The surface quality achieved in this case was in the desired quality level 3-4. The trials conducted to apply paints, wallpaper and tiles, where commercially available standard adhesives and tile glues were used, showed that the surface is also very suitable for this purpose. The tensile strength of this test mixture was determined by means of tear-off tests. During these trials and much to the contrary of the previously mentioned results and obtained knowledge, the measured values of tensile strength were too low. WO 2016/087673 PCT/EP2015/078740 16

Also in these measurements it was found that the use of the system-approved epoxy resin adhesive, which was used to glue the adhesive tensile tamp onto the filled surface, resulted in adhesion failure of the adhesive or of the graphite modified filler compound. As a cause, it is to be assumed that the structure of this adhesive, which consists of very large epoxy resin macromolecules, in conjunction with the very rapid chemical cross-linking of this adhesive, is not suitable for penetrating sufficiently deeply and quickly into the surface of the graphite modified filler compound and to produce the molecules and the mechanical linking in order to withstand the required tear force.

In the test mixture 5, in contrast to the experimental mixture 4, the functional additive aluminium oxide was replaced by ground film graphite (grain size 100 pm). In this way, it was the target to find out the extent to which the higher graphite content results in further improvements in the properties of the mixture, and in particular in the thermal conductivity and screening/attenuation of the filling compound. In the composition of the new mixture, the binder used so far was also replaced by a new Binder of the Acronal 734 type. This novel binder in a series of tests has also been found to be very suitable for the development of the desired filler compound. The weights of the various components in the Trial Mix 5 remained the same as in Trial Mix 4 and the proven use of the further functional additives (anti-foaming agent, thickener, cellulose) had been maintained also.

This Trial Mixture 5 was once more a material that, both by hand and by machine, was very easy to make and to process. The respective surfaces could, without any problem, be ground to the required quality categories 3 and 4. WO 2016/087673 PCT/EP2015/078740 17

After expansion of the sheet graphite, respectively, the clay content by contrast to grinding and to reach aluminium oxide down to a content of almost zero (compare the crayon made of graphite without clay share) quality level 4 was considerably easier to achieve .

The application of paints, wallpaper and tiles was also easily carried out on the surfaces coated with Trial Mixture 5.

The tear-off tests carried out to verify these results confirmed the very good overall impression of this Trial Mixture to date. As a result of these tear-off tests, it was found that the surfaces coated with Trial Mixture 5 were so resistant to tear-off that, in the end, usually a structural failure occurred in the middle of the gypsum layer of the plasterboard.

In attempts to remove tiles, it was found that a so high a physical connection is established between a standard tile adhesive and the surface of the trial mixtures 4 and 5, that the removal of the tiles is only possible with great effort and usually ends with the destruction of surface and tiles.

In addition to these tests, in view of a broad application of the new filler compound (coating of masonry made from e.g. bricks), further trials were carried out with the embedding of tissues and glass fibre fleeces as well as mixed fibre tissues (80 weight % glass fibre to 20 weight % carbon fibre) . As a result it can be confirmed that the tissues and fleeces usually employed in construction and which have a surface weight of 120 g/m2 - 220 g/m2 were very easy to embed in both types of filler compound. Both mixtures are therefore eminently suitable to coat and form layers on masonry. PCT/EP2015/078740 WO 2016/087673 18

In order to determine the thermal conductivity of Trial Mixture 4, there had been carried out hot disk experiments, again. The measured results of the thermal conductivity of Trial Mix 4 is on a very high level at λ = 2.289 W/mK and significantly above the value of λ = 0.9654 W/mK that was found with Trial Mixture 3. The cause of the increase in the thermal conductivity between the mixtures 3 and 4 can be explained by the exchange of the glass bubbles with the aluminium oxide powder. With this value in thermal conductivity, the Trial Mixture 4 is also clearly above the thermal conductivity of standard filling compounds, which is approximately λ = 0, 25 W/mK.

The thermal conductivity of the Trial Mixture 5 was determined in conjunction with the thermo graphic examination of a floor heating system which was carried out. The thermo graphic measurements (measuring instrument made by the company Flir) gave an average thermal conductivity for the test mixture 5 of up to λ = 7.82 W/mK.

With these tests, the fast heating of the floor could be demonstrated very impressively, in conjunction with the floor system installed. Compared to the measurements with the Trial Mixture 3, it can be seen that the temperature of the floor with otherwise similar trial conditions after one hour is approx. 6 °C higher. If the temperature of the floor with the Trial Mixture 3 stood at approx. 17 °C after one hour, the latter increased to approx. 23.2 °C during this time span when using Trial Mixture 5.

All in all, it can be concluded that the use of this highly heat-conducting filler compound in building technology allows the temperatures required for living and working to be achieved much faster, accompanied by significant energy savings, a more efficient use of secondary energy sources and a significant increase in residential quality. WO 2016/087673 PCT/EP2015/078740 19

The comparison of the measurement curves clearly shows the increase in the screening attenuation from the Trial Mixture 3 to the Trial Mixture 5.

Taking into account the fact that the filler and plaster compounds currently found on the market show almost no screening or attenuation properties, these properties of the Trial Mixture 3 can be called, as already described, a great success. With average shield attenuation in the range of 20 kHz - 4 GHz of approx. 7 dB, 80% of the electromagnetic radiation is already shielded in this frequency range. In the range of 650 MHz to 18 GHz, the average attenuation of the Trial Mixture 3 is between 3 dB and 10 dB, which results in a shielding of approx. 50% to 90% of the electromagnetic radiation (see Fig. 30). These already very good values are again clearly exceeded by the Trial Mixture 4 and in particular by the Trial Mixture 5.

Thus, the attenuation values of these trial mixtures in the frequency range from 20 kHz to 4 GHz are approx. 13 dB with Trial Mixture 4 and in the case of the Trial Mixture 5 at approx. 32 dB. These high attenuation values represent an impressive shielding of electromagnetic radiation for the building owner and/or user of a building in the order of 95.0% for the Trial Mixture 4 and 99.94% for the Trial Mixture 5. If this observation is extended to the frequency range between 650 MHz and 18 GHz, the screening attenuation according to the measurement in line with IEEE-STD 299-2006 is between 38 dB and 48 dB for the Trial Mixture 4 and between 47 dB and 58 dB for the Trial Mixture 5 (see figure 30). WO 2016/087673 PCT/EP2015/078740 20

Correlating these attenuation values to the screening/attenuation, Trial Mixture 4 in this high frequency range shields between 99.98 % and 99,997 % of the electromagnetic radiation and in case of Trial Mixture 5, between 99,996 % and 99,9997 % of the electromagnetic radiation are shielded. These outstanding attenuation properties of the two fillers are also shown in connection with the use of fabrics and textiles. With these series of measurements, the application of the new filler compound for the airless coating of brick walls, where usually woven fabrics of glass fibres or mixed fibres are inserted into the filler layer, should also be taken into account. The series of measurements seen in figure 31 show again the very high screen attenuation values of the Trial Mixtures 4 and 5.

Hereinafter, a summary with respect to the used Building Materials Mixture and the properties of the mixture according to invention, especially if used as a filler or stucco,

— the development of a graphite modified filler compound with a thermal conductivity of A>lW/mK, more especially A>3W/mK — all standard airless equipment with a nozzle size of 90 till 110 pm and operating pressures 100 bar 250 bar may be used — surface qualities of Ql, Q2, but also Q3 - Q4 are being achieved. — with this newly developed filling compound there had been achieved an excellent screen attenuation of up to 58 dB already with a layer thickness of some 1.5 mm WO 2016/087673 PCT/EP2015/078740 21

In addition, the new filler is very suitable for applying paints, wallpaper and tiles and for the production of surface temperature control systems in building technology. With this new product we are developing new business fields in the areas of temperature control and shielding of buildings. At the moment, the first inquiries from architects on the design of living spaces are in hand in connection with the shielding of electromagnetic radiation ("electro smog") and the contemporary construction of surface temperature control systems .

The inventive concept describes a Building Materials Mixture with high thermal conductivity and screening attenuation, which is achieved without additives such as cement, sand, gypsum, lime and clay.

To achieve high thermal conductivity and shielding/attenuation, functional additives such as — ground natural graphite — expanded graphite — ground sheet graphite — synthetic graphite and — various sorts of soot, — electrically conductive fibres such as e.g. carbon fibres are used as single additives or in combination. The mixing ratio of the individual additive fractions can be adapted to the respective requirements .

The Building Materials Mixture is used in the form of a dry and wet mixture, preferably as a plaster and filling compound for building systems. The processing of the Building Materials Mixture is possible both by hand and by means of airless and plastering systems (the mixture is easy to pump). PCT/EP2015/078740 WO 2016/087673 22

By the use of the additive graphite (expandable to zero) it is possible to make surfaces in the quality category Q3 - Q4. The Building Materials Mixture also permits the making of non-loadbearing building elements such as fagade cladding and facing bricks. With the addition of heat storage substances as phase interchange materials (PCM) (heat storage layer, heat storage bricks) it is equally possible to make the Building Materials Mixture of latent heat storage character.

By virtue of the binder used (glues) in the Building Materials Mixture, this sticks to nearly all surfaces (very positive when it comes to the rehabilitation of buildings).

The hereinafter listed mixtures according to invention in the following table once more show the various trial mixtures of the Building Materials Mixture

Trials Mixture 1 2 3 4 5 Graphite Modification Expanded Graphite Flakes 200 - 2,000 μ 80 Sheet Graphite 100 μ 30 Natural Graphite 5 μ 15 20 20 20 Synthetic Graphite 0-400 μ 30 40 40 40 Binder Binder (5/13) 20 Binder (1/13) 25 6 6 Binder Acronal 734 6 Functional Additives Trass Powder 30 Glass Bubbles, Parover 13-100 μ 30 Aluminium Oxide Martoxid 30 Anti-Foaming Agent Foamstar 1.5 1.5 1.5 Thickening Agent Pangeel FF 2 2 2 Cellulose Tylose 0.5 0.5 0.5 PCT/EP2015/078740 WO 2016/087673 23

The claims now filed with the application and those which are later filed are without prejudice to the attainment of further protection.

Should it become apparent upon closer examination, especially of the state of technology, that some feature of this invention is beneficial for the target but is not of decisive importance, the objective is already now to propose a formulation which in the main claim does not contain such a feature anymore. Even such a sub combination is covered by the publication of this application.

Furthermore, it is necessary to note that in the various types of execution and embodiments as described and in the variants shown in the invention, the features can be combined in any desired manner with each other. Some or multiple features are interchangeable at will. These feature combinations are included in the invention as disclosed.

This also hints to the listed reverse relationships in the dependent claims for the further formulation of the object of the main claim by the features of the related sub claim. However, these are not to be understood as a renunciation of the achievement of independent, objective protection for the characteristics of the reverse-related sub claims .

Features which have been disclosed only in the description, and also individual features from claims which comprise a plurality of features, can at any time be included into the independent claim(s) as material for the invention, in order to distinguish same from the current state of technology, and this, even if such features have WO 2016/087673 PCT/EP2015/078740 24 been mentioned in connection with other characteristics, respectively, are able to achieve especially beneficial results in connection with other materials.

Claims

Patent Claims :

1. A Building Materials Mixture, in particular a filler or plaster compound, the dry weight of which contains between 30 and 95 weight [%] of graphite, between 4 and 30 weight [%] of a binder and between 0 and 40 weight [%] of functional additives.
2. Building Materials Mixture according to claim 1, which distinguishes itself by the fact that various graphite modifications such as expanded graphite flakes, sheet graphite, natural graphite or synthetic graphite may be used as graphite components .
3. Building Materials Mixture according to claim 1 and 2 designated that acrylate, a water-soluble glue or binder is foreseen.
4. Building Materials Mixture according to one of the quoted claims, distinguished by the fact that as functional additives, at least one of the materials hereinafter mentioned is foreseen: trass powder, glass bubbles, aluminium oxide, anti-foaming agent, magnetite, thickener, cellulose, polymer additive.
5. Building Materials Mixture according to one of the preceding claims, characterized in that the Building Materials Mixture is applied as a layer with a layer thickness of approximately 1.5 mm, and which achieves a screen attenuation of more than 10 dB, in particular more than 30, 40 or 50 dB.
6. Building Materials Mixture according to one of the preceding claims, characterized by the fact that the Building Materials Mixture has a thermal conductivity of X>1W /(mK), in particular A>3W /(mK).
7. A surface heating system consisting of a supporting structure, a heating source and a covering layer, the covering layer being formed from a Building Materials Mixture according to one of the preceding claims 1 to 6.
8. Surface heating according to claim 7, characterized by the fact that the heating source is integrated in the covering layer.
9. Use of a Building Materials Mixture according to one of the preceding claims 1 to 6 or a building material produced there from as a shielding material against electromagnetic radiation and/or as a heat energy distributing material, respectively.
10. A Building Material which at least partially consists of a Building Materials Mixture according to one of the preceding claims 1 to 6.
11. Building Material according to claim 10, characterized by the fact that the building material contains between 20 and 60% by weight of water.
12. The Claim is also characterized by the fact that according to claims 10 to 11 the Building Material can be pre-mixed and preserved in this state, ready for use.
13. Structural element, e.g. fagade panel, facing brick, heat storage element, which at least partially is made of a Building Materials Mixture according to one of the preceding claims 1 to 6.