DE1057187B - Method and device for the production of mica products - Google Patents

Description

GERMAN

The invention relates to a method for the production of, in particular, multilayer and layered Mica products for electrical insulation purposes with transfer of the individual mica particles into their place in the association of the mica layer with the aid of electrostatic forces according to the main patent application L10658 VIIId / 21c. There electrostatic devices are also proposed in which the mica flakes from a high-voltage electrode fed to an electrode that is advantageously connected to earth peeled off and placed on a substrate to be coated, arranged between the two electrodes to be brought. It is known here to arrange both electrodes against one another in such a way that their lines of force to run tangentially to a base to be coated under the two electrodes. The from Mica particles fed to an electrode lying on the ground are drawn off by a high-voltage electrode and fall before they reach it, on the document to be applied. In the process described, pure dry mica is produced used, and additional facilities are required to put a binder together, advantageously with a solvent, to be applied to the substrate to be coated or the individual mica flakes. Furthermore, mica flakes that adhere particularly tightly to one another are often produced in these processes not fully exfoliated; so individual _. Mica packets get on the base so that this is applied with different thicknesses.

It is also known in the manufacture of mica laminates by machine or by hand work mica flakes, which are provided with a binder coating, on a base to scatter, for which additional facilities and energy expenditure are required.

Finally, it was also known in the machine production of mica products from a mica pulp mixed with binder.

In order to make additional devices for applying the binding agent and solvent superfluous in a method for the production of, in particular, multilayer and layered mica products and in particular to ensure that the mica packets are as much as possible, in the known method described above according to the main patent application, according to the invention, in a solvent and binding agent mixture Mica flakes slurried in a known manner are brought onto a substrate to be coated by means of electrostatic devices known per se, such as those used for spraying paint. Varnishes are expediently used to suspend the mica particles. Binders can also be added in powder method and device
for the manufacture of mica products

Addition to patent application L 10658 VIIId / 21 c

Applicant:

LICENTIA Patent-Verwaltungs-G.m.b.H., Hamburg 36, Hohe Bleichen 22

Dipl.-Ing. Rudolf Flötgen and Dipl.-Phys. Karl Kalb, Kassel,

have been named as inventors

or in the form of granules are applied to the substrate to be coated or the mica flakes.

In the following, a possible embodiment of the arrangement according to the Invention and the method according to the invention described.

_- _; ; The drawing shows a shovel-shaped electrode 1 which is connected to high voltage and whose upwardly directed blade at 2 acts as a spray edge. Opposite this, a flat, ground-lying electrode 3 is arranged in such a way that the lines of force forming between the two electrode edges run tangentially to the substrate 4 to be coated, for example continuously guided in the direction of the arrow. In the shovel-shaped electrode 1 there is a slurry 5 of mica flakes in a solvent and binder. This slurry is continuously topped up from a mixer through a line (not shown) connected to the nozzle 6. In this mixer, the slurry is produced by known means, for example a stirrer, and the mica packets are broken up into their individual flakes. A pumping station can be installed between the mixer and the electrode blade, the delivery rate of which can be conveniently regulated, or the mica slurry can also be from. can be fed to a raised mixer via a control valve of the electrode blade. This slurry is drawn off via the spray edge 2 of the electrode 1 from the electrode 3 which is connected to earth. This suction electrode is located so far away from the spray edge, that the mica flakes and the solvent and binder less outweighed on the electrode itself 510/335

Claims (7)

hit, but fall out of the force field of the electrodes due to their own weight and reach the substrate to be coated. Since the mica particles are positioned parallel to the lines of force of the electrode, they reach the base at a "very acute angle," 5 · practically parallel to the base, and adhere to its advantageously glued surface. This spraying of mica flakes suspended in a solvent and binder shows two main advantages: 1. When preparing the slurry, the individual mica packets are already in a mixer largely peeled and evenly covered with a binding agent skin; 2. the slurried mica flakes are drawn individually over the spray edge of the paddle electrode, and here in the mixer itself, not yet exfoliated mica packets are sucked off in layers and so divided. To remove any excess solvent that may form from the electrode blade can, a controllable via a valve, not shown, return line 7 is provided through which the excess solvent is returned to the mixer. The solvent used to prepare the mica slurry is advantageously selected so that the mica flakes are well wetted and kept in suspension for as long as possible. Particularly Chlorinated hydrocarbons and small additions of wetting agents have proven their worth. Patent claims: 1. Process for the production of, in particular, multilayer and layered mica products for electrical insulation purposes with transferring the individual mica particles to their place in the Association of the mica layer by means of electrostatic forces according to patent application L 10658 VIIId / 21 c, characterized in that with the help of known electrostatic devices, like them are used for spraying paint, mica flakes, which are in a solution and Binder mixture are slurried in a known manner, on a substrate to be coated to be brought. • 2. '. Process according to Claim 1, characterized in that the solvent used is chlorinated hydrocarbons be used. 3. The method according to claim 1 and 2, characterized in that the solvent is wetting agent can be added. 4. The method according to claim 1 to 3, characterized in that a lacquer is used as a binder will. 5. Apparatus for performing the method according to claim 1 to 4, characterized by a shovel-shaped electrode (spray electrode), which is connected to high voltage and which the slurried mica is fed, as well as a suction electrode lying on the ground, which is in a such a position of the blade electrode is arranged opposite that the lines of force of these two Electrodes tangential to the one to be coated guided under or between the two electrodes Underlay run. 6. Apparatus according to claim 5, characterized in that the spray electrode has a Dosing device is connected to a mixer in which the mica slurry is produced will. 7. Apparatus according to claim 5 and 6, characterized by an adjustable return line for excess solvent from the spray electrode to the mixer. Considered publications:
German Patent Nos. 939 461, 915 579;
German patent application L 10658 VIII d / 21 c (published on November 5, 1953); German interpretation document E 5717 VIII d / 21 h (published on September 27, 1956). 1 sheet of drawings © 909 510/335 5.59