DE875313C - Writing and drawing board - Google Patents

Description

Writing and drawing board The invention relates to a writing and drawing board, in which a carrier, e.g. B. made of cardboard, paper, plywood, sheet metal or the like, is provided with a coating that forms the writing surface. With such It is already known on tablets to use a mixture of gelatine dissolved in water as a coating, To use chlorohydrate, magnesium sulphate and magnesium, fluat; this solution will then added Lithopone. After application and drying, the layer is sanded off.

It has been shown that hydrochloride is the indispensable part of such tables Impaired wipeability. The same is true for magnesium fluate.

In order to avoid this disadvantage, the coating contains according to the invention except gelatin or any other substance that acts as a binding agent, such as crystallized Magnesium sulfate, a colorless nitrocellulose varnish and plaster of paris as well as depending on the use one of the blackboards for writing or drawing with a pencil or pen. Color addition.

The colorless Cellulo.selack gives the writing surface the necessary Hardness without adversely affecting wipeability; the little addition of plaster of paris! also contributes to hardening and, on the other hand, causes rapid drying.

When used for writing or drawing with a stylus, it is used as color @z. B. Black vine with an addition of emery (Naxos-Schrnirge @ l) added; when using the blackboard for writing with pencil, graphite or colored pencils Lithopon white added.

The writing and drawing board according to the invention is expedient one side with a cover for stylus writing, on the other side with a cover for writing with pencils, graphite or colored pencils.

The composition of the coating for a sch "#varze board is, for example the following: 1. 3a parts of Naxos emery (black) to accommodate the stylus lettering; z. 6 parts black vine to color the mass; 3. 3 parts of plaster of paris to drain the water and for hardening; 4 .. 15 parts of waterproof nitrocellulose lacquer for mixing the. Components i: to 3; 5. 4 parts of dissolved gelatin, which binds all components, makes the mass smooth, prevents cracks ° or cracks. and the knowledge guaranteed.

The composition for a white board for rubbing with pencil or colored pencil is the following: 1. 6 parts plaster of paris to drain the water and to harden it the crowd; a. 4. Parts of lithopon white to color the mass; 3. 15 parts more water resistant Nitrocellulose lacquer for mixing, parts i- and a; 4. 12 parts of dissolved gelatin. Instead of gelatin you can. criticized magnesium sulphate may be used.

The whiteboard. after. the invention consists of a cardboard carrier " Paper, plywood or the like. On one side of this carrier is a , vei: ße coating, layer, on the other side a black coating layer. the The first layer consists of a mixture of gelatine, colorless nitrocellulasel @ aok, Plaster of paris and a white color, like lithopon white. This layer is used for drawing or writing in pencil. The other layer contains paint in place of the white an addition. black in color, like vine black and emery. This layer serves for writing or drawing with a stylus.

Claims (1)

PATENT CLAIMS: i. Writing and drawing board with a carrier, e.g. B. of cardboard, paper, plywood, Bleeh od. The like., And one of the writing surface forming, Mixture containing gelatine or crystallized magnesium sulphate and coloring additives, characterized in that the mixture also contains a colorless Nitrocel.luloselack and contains plaster of paris. a. Writing or drawing board according to claim i, characterized in that .that they have a black layer on one side for writing on with pens, on the other side with a white layer for writing with pencils or colored pencils or graphite.