DK160139B - COATED FACADE OR ROOF INSULATION PLATE OF MINERAL FIBER, AND PROCEDURE FOR PREPARING THE PLATE - Google Patents

Abstract

1. A coated facing panel or roof insulation panel of plastic-bonded mineral fibres, in particular rock wool, the coating of which is formed on the basis of an inorganic silicate-type binder and particulate inorganic additives, characterized in that the inorganic binder is colloidal silica (silica sol), that the coating (3) is composed of an impregnation layer (3a), which has been formed by pressing the coating composition into the resin-bonded mineral fibre panel with breakage of fibres in the superficial region of the mineral fibre panel and which has a thickness of one or more millimetres, and of a surface layer (3b) formed from the coating composition itself, and that the inorganic additives are at least largely free of electrolytes and of swellable layer silicates such as, especially, natural clays or clays, which are swellable as the result of activation, from the montmorillonite group.

Description

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The invention relates to a coated facade or roof of so 1 is an artificial resin bonded mineral fiber, especially stone wool, and a particularly suitable method for making the plate.

5 Such facade roofs or roofs in floor 1 are provided with a coating known from DE Patent Specification No. 24 55 691 and in practice have functioned satisfactorily. These boards could for the first time meet a number of requirements due to the coating of minor fiber fibers, and also meet a whole range of additional requirements due to the function of these insulating boards. These requirements cannot be met by known coatings designed only to increase the heat resistance or to improve the burnt in the backing properties of mineral fiber boards.

Thus, such facade or roofs in the sun shall be non-flammable, as is also the case with other mineral fiber boards, non-combustible, and in addition fulfill the desired mechanical properties, such as wear resistance and the like. Furthermore, the coating material must be able to be manufactured at a price acceptable for the manufacture of large 20 series, and be easy to work and easy to apply in the manufacture, which already ignores many known and possibly technically promising proposals, even if realized under laboratory conditions. seems conceivable.

In particular, when used as roof insulating boards, there is a further requirement that the coating must not be permeable to 1 bit for bitumen, and that the roof insulation plate must at least be able to withstand the infrequency of the plate.

When used as a facade insulating plate, the coating must be suitable as a carrier for plaster, and thus have a sufficient adhesive ability to the normally hydrophobic mineral fiber plate as well as to mineral or resin bonded forms of plaster. The latter requirement means that the coating e.g. must allow some diffusion in order for the coating on the coating side to dispense water and thus, upon obtaining a staple bond, dry. However, despite the sufficient diffusion openness of the coating, it must form a coherent crack-free film.

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The essential requirements described above, which are further elucidated with regard to further details in DE patent no. 24 55 691, are so complex that since the coating mentioned in DE patent no. 24 55 691 is not disclosed. further promising suggestions.

In the insulation plate according to DE-patent no. 24 55 691, the coating composition consists of water glass as the bonding phase and additions of fine-grained clay mineral substances, such as e.g. oxides or carbonates of alkaline earth or of zinc, oxides or of hydroxides of aluminum and / or barium sulphate as hardener.

By adding water glass as a film-forming binder in combination with curing agents, a large crack-free and relatively thin layer can be obtained in the mineral fiber plate to be coated with good adhesion and abrasion resistance, which also meets all other stated requirements in the best possible way so far, and which in practice has worked well to a large extent. However, in order to meet one of the most important requirements, namely the waterproofing or water resistance, this water-glass coating must, after its application to the mineral fiber board and drying, undergo yet another thermal curing to actually achieve the desired properties. This post-cure must be carried out at relatively high temperatures. However, since the organic binder in the mineral surface, usually phenolic resin, is thermally degraded over approx. 250 ° C, the mineral fiber sheet behind the coating would thereby lose its internal cohesion. Admittedly, the post-curing of the water-glass coating can also be carried out satisfactorily at temperatures up to 200 ° C, but then, in addition to the necessary high energy supply, requires an extremely long time, which ultimately leads to a not insignificant costing of product. Quite apart from the fact that the production line at the end is significantly extended due to the necessary drying zone.

SUMMARY OF THE INVENTION It is an object of the invention to provide a facade or roof in a soldering plate of the one in the preamble of claim 1.

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given species with a coating which makes the sheet suitable for use on roofs and facades, and so that the sheet with coating has the same properties as sheets of water-cured hardened with heat, and which without a costly thermal curing 5 ensures the required waterproofing for the coating and can be made economically satisfactory in large series.

This object is achieved by the feature specified in the characterizing part of claim 1.

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According to the invention, firstly, colloidal silicic acid, ie silica sol, is used instead of water glass. Since the alkali proportion of silica sol compared to water glass is so small that it can be neglected, no compatibility problems arise with the minor fibers. Also, the water resistance is not reduced due to the presence of a substantial alkali content, so that a post-cure to produce the desired water resistance can be avoided.

20 However, it is doubtful whether in the present context a closed film will be formed, as is an indispensable requirement, since dried colloidal silicic acid is present as powder or dust, so that, when used only by silica sol, no In this way, a layer or film formation which is merely approximately the requirements can be counted. However, one cannot do without the formation of a closed, crack-free film of the coating. To enable such film formation, it is known to mix silica sol with painted α 1 aluminum sieve in cat fibers, where the fiber content becomes very significant and can exceed the proportion of silica sol. Such a silica-based coating mass having a fiber content of approx. Due to the high fiber content, 50% by weight is very expensive, compared to a water glass based coating composition, approx. a 10 factor more expensive. For this reason, the use of silicon-sol with aluminum silicate fibers as coating is hardly considered in connection with the production of large series.

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Furthermore, in spite of this, orientation experiments have shown that the adhesiveness of such a coating on the mineral fiber surface is not sufficient. Namely, the high content of aluminum Si 1 ikat fibers in the coating mass prevents a t in 1 - 5 extensible penetration of silicon sol into the mineral fiber surface to form a local anchorage. In this connection, it should be borne in mind that when used as a facade in soldering plates, the forces that will be exerted by the plaster to be applied, especially displacement forces, are quite significant.

However, the solution of the two problems, namely the excessive costs for a mass-advance 1-level as well as the adhesion of the coating to plate surfaces satisfactorily for the intended use, can surprisingly be achieved by an artificial grip according to the additional features as claimed in claim 1. 1, according to which the coating is, in any case, to a great extent not produced on the surface of the mineral fiber plate, but in the fiber layers just below the surface of the mineral fiber plate. Functionally, then, the mineral mineral surface fibers in the mineral fiber plate replace the otherwise required film-forming aluminum in 1 in catf ibre, so that the cost of these can be saved. By connecting the fibers still in the coating with the other fiber structure of the mineral fiber plate, the best possible anchoring of the coating is achieved. By using inorganic granular fillers such as are used in a similar prior art as in silica sol coatings to replace a portion of the fibers required for the formation of a closed layer, the described effect of the mineral fibers may be supported in this direction. in that granular fillers embedded between the mineral fibers further close the holes still present between adjacent mineral fibers. In a preferred embodiment, the coating composition may be further -especially at a low bulk weight of the mineral fiber pad - painted mineral fibers penetrating into the holes of the relatively porous mineral fiber surface and helping to close these holes. Such embedded painted mineral fibers contribute more strongly than large-grained fillers to the formation of films.

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The amount of mineral fibers added can - especially at high bulk sheets and thus from the beginning with tightly packed mineral fibers - be very low and the nature of the fibers can correspond to the fibers in the mineral fiber plate, so that no significant additional costs are incurred. In addition, in an equally advantageous embodiment of the invention, some of the near-surface mineral fibers in the mineral fiber board may be broken, e.g. by applying the coating to a roll, such that the fibers are closer to each other there and can form a denser mesh.

Thereby, it becomes possible to form a cohesive dense layer in the region near the surface of the mineral fiber plate, which meets all the requirements and does not need any post-treatment except drying. This not only avoids the actual cost of the post-cure, but also simplifies the control, as incomplete drying is completely uncritical as opposed to a non-absolute straight-cure, since the plate adjacent to the production 20 in the air has sufficient opportunity for a post-drying so as to ensure the necessary water resistance.

However, colloidal silicas require the addition of a stabilizer to be stable in the solar phase, usually in the form of sodium oxide. While in the case of water glasses, sodium oxide is present in a proportion of e.g. 25% to 30% by weight, when added as a stabilizing agent to aqueous colloidal silicic acid, an amount of well below 1%, e.g.

0.2% by weight. In order for silica sol to dry upon forming a closed layer 30 on the stored fibers and fillers, its conversion from sun to gel is necessary. However, this sol-gel conversion must not occur prior to application of the coating, as the silicon sol with this conversion precipitates in the gel state and, upon gel formation, can no longer exert its binding effect. The stabilizer, which, even in the case of the use of sodium oxide due to the extremely low amount, can not reduce the water resistance and no compatibility problems 6

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with the mineral fibers, however, are responsive to electrolytes, such as sodium sulfate, calcium sulfate, sodium chloride, etc., contained in the coating composition. When electrolyte-containing substances, that is, substances containing or decomposing water-soluble substances which can react with the colloidal silica stabilizer, occur in the mass, premature sol-gel conversion and precipitation of silica sol, thus that the crack-free film formation required by the invention is no longer achieved to the required extent.

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Furthermore, the fillers must be required to be chemically inactive against the silicon stabilizer and at least to a large extent free of electrolytes which can react with silicon stabilizers.

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It is well known from US Patent No. 34,906,05 that impregnating mineral fiber sheets with a silica solvents in a few mm thick layer near the surface to improve the resistance of such sheets in the event of fire.

To this end, a binder consisting of from 5 to 95% by weight of silicon sol and from 95 to 5% by weight of bentonite is used, the silicon sol and the bentonite together forming the bonding phase together with two granular inorganic fillers having a melting point below and above approx. 1,100 ° C and where as the highest melted filler 25 e.g. For example, a hydrated aluminum silicate such as refractory clay (Ballton) can be used, and to the lower melting point a sodium, potassium, calcium, magnesium, and barium aluminosilicate, e.g. Feldspar. In the case of fire, the lower melting point filler forms an additional stiffening ceramic bond which is intended to maintain the physical integrity of the porous impregnation layer forming a support frame even when the mineral fibers are burnt away. The total solids content of the impregnating agent is between 2 and 25 wt.

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the side of the plate facing the coating. The solids content of the impregnating agent again consists of from 1 to 20% by weight of silicon sol (solids), 1 to 15% by weight of bentonite, both as a binder phase, the remainder of the two inorganic fillers 5 with different melting points in a mutual ratio of about 5%.

1: 9 and 9: 1.

In this way, in fine synthetic resin bonded mineral fiber board with improved fire properties with a few mm thick impregnated surface layer, a slurry of solids in the surface is brought to the desired depth and thus the plate is dried at 200 ° C for 1 hour.

In the case of US Pat. No. 34,906,05, these are acoustic cover plates or the like for interior ceilings, where the special problems of roof insulation or facade insulation panels, especially the problem of waterproofing, are not mentioned. They are also not suitable for roofing sheets, since it does not form a closed 20 layer here, and for this the diaphragm proportion, which can decrease to a value of only 1% by weight, is too low. In this writing, the silicon sol is also highlighted not only because of its sol-gel conversion to layer formation, but as a bonding phase in the form of a mixture of silicon sol and bentonite. Bentonite is a clay species named after 25 the first find site at Fort Benton, Wyoming, USA, and distinguished by a high swelling and absorption ability, and is therefore also referred to in German as Quellton. Bentonite consists essentially of clays of the Montmorillonite group, and in a broader sense also of layer silicates, whose swelling ability is due to the fact that 30 water penetrates into their layers and can burst them.

Such naturally or artificially influenced swellable clays serve as binders for producing a so-called "GrUnfestigkeit" for the mineral fiber board in the coated area 35 by its handling, storage, etc. In the event of fire, this "GrUnfestigkeit" becomes a ceramic bond, such as it is sought in accordance with the specification of US Patent No. 34 90 065 to improve the fire properties of the mineral fiber board.

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The invention does not provide a swellable clay in the bonding phase consisting solely of silicon sol, since such clay, due to its high swellability, reduces the coating's water resistance in goodness. The presence of such adhesives on a facade insulating plate would, in the absence of water resistance, not ensure the adhesion of the plaster. Further, as described in U.S. Patent No. 34,906,05, montmori 11only clay, which may have either swellability due to its natural high content dependent on the storage site, especially sodium montmorillonite or by activation as a filler, should also be added as a filler. due to interaction with alkali constituents from other substances in the pulp. Also, in the event that a swell is not necessary for such montmorrilonite clays contained in the fillers of the kind disclosed in U.S. Patent No. 34,906,055 or for local bentonite in the bonding phase, but where swellability is permissible without difficulty, The present invention also makes a choice with respect to the fillers for a coating of facade insulating boards on the basis of the considerations set forth above within the scope of the present invention which exclude swellable layer silicates, such as, in particular, sodium montmorillonite containing or reducing substances. a harmless negligible amount.

In accordance with the invention, inorganic substances can be used as fillers provided they are not water-soluble, such as e.g. alumina or hydroxide, s in 1 icium dioxide, non-swellable burnt or unburned clay minerals, talc, mullite, chalk, zirconia, zinc oxide as well as mixtures of these substances.

Further, as an inorganic filler, pigments may be added as needed to produce a desired color effect, e.g. Fe203, FeOOH, TiO2 »C ^ Oo. When used as a facade insulating plate, it is of great advantage that, besides fine-grained fractions, coarse-grained fillers 35 having a grain size of 0.3 to 1.5 mm, which remain immediately at the surface of the mineral fiber plate, can also be bonded together with the superficial fibers, and at 9

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this way increase the roughness to improve the adhesive ability of the plaster.

The colloidal silicic acid according to the invention can be used in the coating composition with a solids content of between approx. 10 and 50 wt.%, Preferably 30 to 40 wt. Variations in the solids content can be used to adjust the viscosity or generally the flow properties of the coating mass, and of course, further dilution with water is also possible to obtain a desired consistency.

In the case of the use of coarse-grained fillers, it is necessary to add thixotropic agents to the coating mass, to prevent a sediment in the large fractions which makes the coating mass workable in a large production. As a thixotropic agent, inorganic water-binding substances, e.g. pyrogenkiselsyre.

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As a thickening and thixotropic agent, bentonite would in principle also be suitable. Since bentonite greatly decreases the water resistance of the coating in the depicted manner, such additions to the coating mass of a fiber insulation board according to the invention are unsuitable in large quantities, and not in smaller quantities, as well.

Further, in order to adjust the viscosity, thickeners such as methylsiluose, starch products 30, etc. can be used in the coating composition. Furthermore, it is useful in a large-scale technical processing of the coating mass to add known substances to suppress the foam of the mass. Finally, a small amount of known wetting agents for the pulp must be added to ensure better adhesion of the coating to the 35 hydrophobic mineral fibers in the insulating plate.

The process of the invention for making such a coated mineral fiber board is characterized in that

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10, the pulp is pressed into the surface of the mineral fiber board in a desired consistency and under considerable pressure, thereby producing broken mineral fibers in the area just below the mineral fiber surface. The impression may advantageously occur at a depth greater than that corresponding to the thickness of the coating or impregnation, such that a large portion of the mineral fibers near the surface are broken and compressed again, and at the same time a homogeneous distribution of the coating mass occurs in the partially fractured and sealing mineral fibers near the surface. In addition, the mineral fibers, where applicable, may, in addition to the additional coating material added, mineral fibers and fillers act as network formers for the silicon sol, which, conversely, bind these substances during their sol-gel conversion which has occurred during the drying. In this way, a closed crack-free surface coating is produced.

Example 1

A mineral fiber pad having a weight of 70 20 kg / m3 is prepared with 8 wt.% Phenolic resin as the binder and 0.2 wt.% Of a hydrophobic agent on a silicon basis in the usual manner, whereby as mineral fibers e.g. Can be used Basalt fibers.

A coating composition having the following composition is obtained: 25% by weight of silica sol (40% by weight solids content of SiO2) 20% by weight of ground Basalt fibers 29.1% by weight kaolin 0.2% by weight of methylene oxide 30 0.1% by weight of silicone antifoam 0 5 wt% pyrogenic silicic acid 0.1 wt% al kylaryl sulphonate (wetting agent)

The painted Basalt fibers are provided with lengths of between -35 limbs 20 and 300 µm and diameters between 1 and 10 µm.

This coating was pressed into the surface of the mineral fiber plate by means of an application roller under a pressure of 11

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15 N / cm 2. upon application the plate surface was pressed approx. 8 mm down from the application roller, and thus the coating mass was pressed into an area near the surface of the Basalt Customs in an amount of 700 g / m2. Behind the sprung roller, the surface of the mineral fiber sheet was sprung back with a somewhat smaller dimension relative to the depth of application of the application roller and contained the coating mass with a penetration depth of 3 mm. After drying at just under 200 ° C for a few minutes, the mineral fiber board showed a closed crack-free coating with a rough surface and good abrasion resistance.

Eksempel_2

Again, a minor 1 basalt fiber fiber board was prepared in the usual manner, however, with a bulk weight of 150 kg / m 2 and 3 wt% phenolic resin as binder as well as 0.3 wt% hydrophobic agent on silicone basis.

As the coating composition, the following composition was selected: 20 65 wt% silica sol (40 wt% solids content SiO 2) 8 wt% ground Basalt fibers (dimensioned as in Example 1) 16.2 wt% kaolin 25 10.4 wt% aluminum hydroxide having a particle size of over 10 µm 0.2 wt% methylcellulose 0.1 wt% silicone antifoam 0.1 wt% alkylaryl sulfonate as wetting agent.

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This coating mass was also rolled with a coating roll see at a pressure of 50 N / cm 2 on the plate, whereby the application roller here pressed 5 mm into the plate surface. The amount of application thus amounted to 400 g / m2. After ten liters of backing 35 of the coating-filled surface of the mineral fiber plate behind the applicator roller, the coating mass with penetration depth of 2 mm appeared.

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Following a similar treatment as in Example 1, a closed crack-free coating of the surface was also shown, showing a feasibility for use as a roof insulation plate.

5

In both examples, the painted Basalt fibers penetrated into the rough surface of the mineral fiber plate, whereas in practice, however, in the lower region of the impregnation there were in practice exclusively fibers from the mineral fiber plate. A portion of the painted Basalt fibers of Example 1 and Example 2 as well as a substantial portion of the aluminum hydroxide of Example 2 lay on the upper side of the mineral fiber board embedded between the then broken Basalt fibers from the plate and formed a surface which the plaster could sit on stuck on. In doing so, the kaolin, like the silicon sol in the 15, substantially uniformly overlies the entire core region of the coating, and thus also penetrated well into the surface of the mineral fiber plate, filling the voids and forming a connection with the fiber structure of the mineral fiber plate.

The invention will now be explained in more detail with reference to the drawing, in which 1 shows a section through an insulating plate according to the invention and FIG. 2 is a schematic simplified representation of the application of the coating to the insulating plate of FIG. First

The FIG. 1, insulation plate 1 may be a facade insulation plate of synthetic resin bonded mineral fibers 2, e.g. of Basalt fibers bonded with phenolic resin and having a coating 3.

As shown in FIG. 2, a coating mass 5 according to arrow Z is applied to an applicator roll 7 and 35 in a feed hopper 6 in a manner known per se of the application roll 7 in the still uncoated surface 8 of the insulating plate 1. The application roll 7 penetrates the surface 8 of the insulating plate. 13

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the plate 1 at a depth T, thereby pushing, while simultaneously crushing the mineral fibers lying on the surface, the coating mass 5 into the mineral fibers of the insulating plate 1. Behind the application roll 7, the mineral fibers expand again (after they have been pressed together under the roller), thereby absorbing the coating mass 5 penetrating between the mineral fibers via a kind of pumping action. The coating mass is then above an effective penetration depth to the surface layer of the insulating plate 1, which is obviously less than the penetration depth T of the application roller 7. The penetration depth t comprises only the effective core area of the coating, while there may be a softening down below. of the deeper mineral fibers with the coating mass, but no longer an almost closed layer. Such additional wetting is desirable to obtain a good bonding of the coating 3 to the synthetic resin bonded mineral fibers and to increase the adhesive strength of the coating 3, not least in view of the substantially broken fracture near the original surface 8 of the insulating plate 1. 1, as in FIG. 1 is shown as 2a.

In FIG. 1, fine-grained fillers 4 are indicated as kaolin with a particle size of no more than approx. 5 µm, often far less, which, together with the silicon sol of the coating composition, can penetrate well into the surface 8 of the insulating plate 1. Large-grained fillers 10 having a particle size of more than approx. 10 μη », even up to approx. 1 mm is also shown and is added in relatively small amount to the coating mass 5 and remains predominantly on the surface or in close proximity to the surface area of the insulating plate 1 as they are filtered off at the surface by the Basalt fibers. Ground mineral fibers such as Basalt fibers 11 having a length of from 20 µm to 30 µm and a diameter of from 1 µm to 10 µm, preferably between Preferably, 3 µm and 6 µm, like the Basalt fibers 2 in the insulating plate 1, remain in the immediate surface area of the insulating plate 1 as they only, under favorable conditions, penetrate deeper between the mineral fibers 2 or the fractured mineral fibers 2a for the insulating material.

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ring plate 1. In the longer-lying areas of the coating, the broken Basalt fibers 2a of the insulating plate 1 increasingly take over the function of the coated Basalt fibers added to the coating mass 5 and serve as network formers for the bond through the silicon sol together with the fine-grained fillers 4, such as e.g. . kaolin.

In this way, a layer 3 is formed of an impregnating layer 3a having a thickness of one or more mm and a thin 10 superficially closed film 3b, which can also be made in a larger thickness, but where a very small thickness is sufficient. and which can no longer be measured for the rough surface of the insulating plate 1. In the present example, with the added proportion of large-grained fillers 10 and ground basalt fibers 4, a thickness of the film 3b obtained, as indicated in FIG. 1, completely covers the top broken mineral fibers 2a of the insulating plate 1, so that they can under no circumstances appear on the surface. Such or even greater thickness of the film 3b capable of forming a suitable layer is particularly suitable for use of the insulating plate 1 as a roof insulating plate, to obtain a securely closed coating which is closed to penetration of Bitumen and has a corresponding walkability. . However, the large-grained fillers 10 can also be completely omitted. When used as a facade insulation plate, the solid-grained fillers and an accumulation of fibers in the area near the surface, whether broken mineral fibers from the insulating plate 1 or applied to the coating mass 5, painted mineral fibers 11 produce a closed crack-free outer surface of the coating 3, which nevertheless has some roughness, as indicated by the surface irregularities 12. In this connection, large-grained fillers 10 may also be contained in a small proportion embedded in holes between broken mineral fibers 2a in the upper side of the insulating plate 1 and only slightly protrude above these, while otherwise broken mineral fibers 2a 35 or ground mineral fibers 11 are present immediately on the surface of layer 3, thus providing some roughness.

Claims (8)

1. Coated facade or roof in soldering plate (1) of synthetic resin bonded mineral fibers, in particular stone wool, with a coating (3) formed on the basis of an inorganic silicate binder as well as particles of inorganic additives, characterized by that the inorganic binder is colloidal silicic acid, that the coating (3) is at least substantially located in the region of the mineral fiber plate adjacent to the mineral fiber surface (impregnation layer 3a), and that the inorganic additives are at least largely free of electrolytes and free of swellable silicate layers, such as especially natural or activated swellable clays of the Montmori 11 on IT group. 5 Facade or roof insulation board according to claim 1, characterized in that mineral fibers with a length between approx. 20 µm and 300 µm and a diameter between 1 µηι and 10 µιη, preferably between 3 µιπ and 6 µιη, and preferably in an amount of less than 30% by weight of the dried coating composition. Facade or roof insulation board according to claim 1 or 2, characterized in that the coating (3) includes 15 coarse-grained additives with a particle size of more than 10 μιη, in particular more than 100 μηι, preferably in an amount of less than 25% by weight of it. dried coating compound. A facade or roof insulation board according to claim 3, characterized in that a thixotropic agent is added to the coating composition. 5. The facade or roof insulation board according to one or more of claims 1-4, characterized in that additives which are fine-grained with a particle size of less than 5 μπι are added, preferably below 3 μιη, and in particular below 1 μη ». A facade or roof insulation board according to claim 5, characterized in that the fine-grained additive is kaolin. Facade or roof insulation board according to one or more of claims 1-6, characterized in that the additives, in so far as they are in a form other than in the form of mineral fibers, are present in the dried coating composition in a 17 DK 160139 B amount which may not exceed the amount of solids in the silicon sol. Process for producing a facade or roof insulation board according to one or more of claims 1-7, characterized in that the coating mass is pressed into the surface of the minor fiberboard in a desired consistency and under a considerable pressure, and thereby producing broken mineral fibers in the area just below the surface of the mineral fiber. 10 15 20 25 1 35