DE1225093C2 - Process for the production of heat-insulating sheets combined with alkali silicates - Google Patents

Description

Because of their good thermal conductivity, metal sheets show unfavorable behavior when exposed to them from heat or fire. They are quickly heated over red heat and therefore make for spread a small obstacle to a fire.

It is known to use metal sheets or structural elements made from sheet metal with insulating paints to provide. With prolonged exposure to heat, however, these coatings become more uneven as a result Thermal expansion cracks, so that their insulating effect is lost.

It is also known for the surface protection of solid metals or for thin metallic ones To apply vapor-deposition layers on these silicate layers from water glass solutions. These layers can also be applied as insulating layers on transformer cores or capacitor foils will. To increase the adhesive strength of these layers on the metal surfaces one gives metal salts, especially heavy metal salts, to the waterglass solutions. The application of this Laying is done by dipping, brushing or spraying. The layers are then increased at Temperatures dried. In this way, it is possible to apply only thin layers in one operation. In order to produce thicker layers, the above-mentioned operations must be repeated several times be repeated. However, these layers are not able to counteract the influence of the underlying metal protect from heat.

There are also known refractory insulation materials made from foam vermiculite, a fibrous reinforcing agent and a binder. The binder consists entirely or for the most part processed fuller's earth in the form of synthetic sodium montmorillonite, in which the calcium the naturally modified fuller's earth is replaced by sodium.

Known materials with high tensile strength contain a mineral binder in addition to glass fibers, cement, plaster of paris, magnesia, anhydrite, lime, etc. come into consideration as binders.

To produce an enamel coating, water glass solutions, containing powdered asbestos, applied and then the layers applied in this way exposed to high temperatures.

According to a proprietary, non-prior art proposal, one can be under the influence Produce heat-insulating properties assuming fire protection panels from elevated temperatures by preferably artificial Embed silicate fibers in a layer of an alkali silicate solution and then through the layer Dehydration solidified to form a dense plate at elevated temperatures. The plates have a Water content of 20 to 70 percent by weight, preferably 40 to 60 percent by weight, as well as one Fiber content of 10 to 40 percent by weight, preferably 15 to 25 percent by weight, based on the anhydrous alkali silicate.

It has been found that heat-insulating, combined with alkali metal sheets in a simple manner Way can be produced if you have a fibrous and water-containing alkali silicate board on one or both sides cover with a sheet metal or a sheet metal on both sides with a fibrous and water-containing alkali silicate board and the plate pack thus obtained at temperatures of 50 to 150 ° C, preferably 80 to 120 ° C, pressed. '

The sheets can be produced discontinuously or continuously in such a way that the sheet metal and the fire protection plate between two heated pairs of rollers running at the same time Pressure can run through.

The sheets produced according to the invention can easily be processed into shaped bodies on the deep-drawing machines customary in metal processing, the processing being carried out at elevated temperatures at which the fire protection panels become plastic but do not yet foam. This is carried out at temperatures of 50 to 150 ⁰ C, preferably from 80 to 120 ° C, the case. A sheet metal combined with a fire protection plate, which, based on anhydrous alkali silicate, has a water content of 50 percent by weight and a fiber content of 17 percent by weight, can be ^{stretched, for example, at a temperature of 100 ° C. up to 60 e} / o of its original length without noticeable cracks appear in the fire protection panel.

The side of the sheet that is not covered with a fire protection plate can be used without difficulty be provided with a conventional stoving enamel. It is advisable to use paints that are at temperatures to be burned in around 100 to 120 ° C, since at higher temperatures the fire protection plate closes foaming begins.

The sheet metal combinations produced according to the invention have excellent heat and flanun-insulating properties also have a significantly reduced droning effect, which they z. B. especially for vehicle construction, e.g. B. for the production of body parts in automotive engineering, makes suitable.

example

On a 40-40 cm sheet of iron with a thickness of 0.4 mm, an equally large 1.2 mm thick fire protection plate containing 17 · / · 5 cm long glass pile silk and 50 · / · water, both based on anhydrous alkali silicate, is placed , applied and 5 minutes at 100 atm and a temperature of

■■ '. ■' ■■ '■'. . ³ ■ ■ '■ - ■' ■ ^: ■■ ⁴

90 ° C pressed in a laboratory press and deformed below and a height of 2.0 cm. On the

Pressure cooled. Metal side is based on a commercially available paint

The sheet metal combination obtained in this way is applied to 90 ° C urea-formaldehyde and alkyd resin.

heated and stoved on an eccentric deep drawing press and baked for 1 hour at 100 ° C. One

clamped cap tool to a ball 5 separation of the metal from the fire protection plate

segment with an upper diameter of 7.5 cm does not occur here.

Claims (1)

Claim: Process for the production of heat-insulating sheets combined with alkali silicates, characterized in that one has a fibrous and water-containing alkali silicate board, the a water content of 20 to 70 percent by weight, preferably 40 to 60 percent by weight, and a fiber content of 10 to 40 percent by weight, preferably 15 to 25 percent by weight, based on the anhydrous alkali silicate, has one or both sides with a sheet or covers a sheet on one or both sides with such a fibrous and water-containing alkali silicate board and the plate pack thus obtained at temperatures of 50 to 150 ° C, preferably 80 to 120 ° C, pressed.