DE275882C - - Google Patents

Description

IMPERIAL

PATENT OFFICE.

PATENT LETTERING

- Jig 275882 CLASS 29 h. GROUP

Patented in the German Empire on April 27, 1912.

The belief has taken root in science and technology that different types of pulp only through the action of a relatively small number of certain reagents can be brought into solution in order to get from it by coagulation various plastic-gelatinous Get crowds. Solutions of the neutral salts are used here: Zinc chloride alone or with hydrochloric acid mixed; It has also been proposed to add alkaline earth metal chlorides to the zinc chloride ,admit. These salts have been added to the zinc chloride solution in order to obtain the To weaken the degradation of the cellulose molecule, which is what Schwalbe, "The Chemistry of Cellulose" 1911, page 154, is clearly expressed.

Later it was used by Dubosc as a solvent

for pulp solutions of rhodanammonium and potassium in proposal, however the solubility of the pulp in such a reagent is contested by Croß and Bevan.

In general, the specialist literature (Dr. C. Schwalbe, "Die Chemie der Cellulose",

J. G. Beltzer and Jules Persoz, "Les matieres cellulosiques", Paris et Liege 1911, and Dr. Walter Vi-eweg, "New Pulp Research", Chemics. Time. 31, 85, 1907) with perfect It can be seen clearly that besides Croß and Bevan also other experts the solubility of the pulp in solutions of neutral salts have not considered probable. Man even has (Vieweg, op. cit., p. 86) to explain the solubility of cellulose in rhodanide solutions resorted to an analogy with the viscose process, which is why it is absolutely unlikely dissociation of ammonium thiocyanate solution

CS ₂ +2 NH ₃ = NH ₁ CNS + H ₂ S,

thought possible.

What the solutions of acidic salts or acidic salt solutions (aqueous acid and salt solutions) As far as is concerned, Schwalbe already thought it possible (op. cit., p. 78) that acid salts Dissolve pulp, while Deming (Chemisches Zentralblatt 1911, 2, 1435) has shown that acidic salt solutions (a salt solution in an aqueous solution of hydrochloric acid and formic acid) introduce new solvents for pulp, and that the effect of zinc chloride, solutions on the action of hydrochloric acid, which are contained in the solutions as a result of hydrolysis is to be traced back.

As is well known, antimony trichloride and tin tetrachloride cannot exist in water: they disintegrate into hydrochloric acid and into colloidal antimony or stannic acid and partly into oxychloride of antimony and tin.

A solution of tin chloride is oxidized on boiling and is decomposed by water, and such a boiled solution can be obtained by evaporation and concentration not recovering the neutral salt or its crystalline hydrate.

H. G, Deming endeavored to dissolve the pulp by adding acids to the solution added or by choosing such connections

fertilize which easily separate free acids in such a way that the process is not reversed can be. Due to the vigorous action of the acids, Deming the hydrolysis of the pulp easily continued until the formation of glycose.

The pulp swells before the transition to the state of a colloidal solution, no matter how much which of the solvents mentioned is used to form a plastic jelly. Regarding the swellability of the pulp in solutions of neutral salts (apart from zinc chloride) is only available from Huebner and Pope (see p. Swallow, a. a. 0., p. 83) to find an indication that such swelling of the pulp also with concentrated potassium iodide and potassium or barium mercury iodide solutions takes place. However, this note has never been used technically either.

In contrast, the essence of the present invention consists in the establishment of the fact that also the neutral salts in their entirety make up the cellulose (e.g. cotton wool, paper) both in a gelatinous-plastic state and in the state of a colloidal one Be able to bring about a solution if one takes care that the working conditions (concentration, Pressure, temperature, duration of exposure) to the properties of the respective th salt used.

The more soluble the salt is (this property is closely related to hydration), d. H. the further the concentration of the solution can be driven, the easier The pulp is soluble in this solution. From this it follows that one must above all strive the solubility artificially, e.g. B. possibly simultaneous by increasing the pressure Increase in pressure and temperature, etc.

to increase.

Because the pulp before transitioning into the state of a colloidal solution is different assumes plastic or gelatinous intermediate states, one can adjust the

4-5 solution process in any stage always get the desired state.

The practical implementation of the procedure is very simple. One fills z. B. a vessel with water, then bring the pulp,

z. B. in the form of cotton wool, in an amount of about 3 g for every 100 ecm of water and uses a salt (e.g. strontium iodide, barium rhodanide and the like) with heating of the vessel contents. With sufficient concentration and at the appropriate temperature, the wadding begins to transform into a gelatinous, plastic state. This overpass works possibly faster if you mix the contents of the vessel.

If you want to keep the pulp in a certain state, you interrupt at the appropriate time heating and adding salt, cooling down, waiting for formation of a precipitate, pour the solution from the precipitate and wash the latter with it Water, alcohol or any other liquid that is suitable for the absorbed Remove salt. The washout liquids and the withdrawn solution are all over again used for the process after increasing the concentration or evaporating the salt Has. Instead of waiting for a precipitate to form, the solution can be for example by means of water, dilute and remove the gelatinous substance from the diluted Separate the solution by filtration.

If, on the other hand, a colloidal solution is to be obtained, then heating and continue adding salt until the dissolution process is complete. ,

From this colloidal solution one can produce pulp in the most varied gelatinous form Recovering states of states by very different means, e.g. B. by diluting with? by means of water, alcohol, salt solutions, by pouring the cellulose solution into this liquid etc.

For certain salts, e.g. B. sodium iodide, calcium bromide and iodide, strontium iodide, barium, calcium, strontium, sodium rhodanide and others, can use the method described be carried out at atmospheric pressure, while for other salts, e.g. B. sodium chloride, Potassium chloride, sodium sulfate, etc., an increased pressure is necessary. The pressure increase can here can be achieved by any known method, e.g. B. by using compressed gases, by performing the method in a sealed container etc.

Disturbing side effects occur because in the cleavage temperature of the pulp which is located at 200 ^0, the solubility is preferably achieved by increasing the pressure with only moderate increase in temperature. When using sodium chloride as a solvent, the dissolution process of the pulp starts with a concentrated salt solution, for example at 170 ° C. and 8 atm. Work pressure. The working pressure can be kept as low as possible by swelling the pulp in the salt solution at a low or moderately elevated temperature. The longer the swelling in the manner indicated, e.g. B. at room temperature, takes place, the easier and at the more moderate temperature, concentration and pressure, the transition of the pulp takes place in the state of a colloidal solution.

To dissolve the pulp and to convert it into a gelatinous state you can of course also use salt

mix as well as solutions of double salts (e.g. double salts of rhodanides) use.

The inventor's experiments have shown that the pulp transfer or Solution process for all known salts takes place. The inventor has experiments with Haloid salts (sodium chloride, calcium bromide, strontium] odide, calcium] odide), sulfuric acid salts (Sodium, calcium, aluminum sulfate, etc.), nitrates (aluminum, potassium nitrate, etc.), Rhodanides (manganese, strontium rhodanide, etc.), acetic acid salts (e.g. of alkali metals), as well as with salts of oxygen halide acids

(e.g. lead chlorate etc.), and believes that it is justified on the basis of this extensive Attempts to claim that his proposed method of processing Pulp finds general application.

In the case of highly saturated solutions, a solution of the cellulose (e.g. paper, Cotton wool) at their highest boiling temperature and atmospheric pressure, practically speaking, immediately comes about, as the inventor's experiments with solutions of lithium chloride, bromide, iodide, sodium iodide. Calcium bromide, Have shown strontium iodide, calcium rhodanide and many others. All of the above Salts are characterized by a particularly strong ability to hydrate and extremely high solubility (Solvability).

The solutions of cellulose in salt solutions solidify when they cool down at around ι percent pulp content, such as gelatin or agar, to be clear or semi-clear Jellies which are extraordinarily elastic.

The plastically gelatinous masses obtained by the above process can, for example in a known way for the production of rayon, photographic film, etc. be used. Impregnated with salts, the jellies are used for the production of galvanic Dry elements and moistened with liquid fuels (alcohol, naphtha, etc.), make a convenient fuel. Mixed with coal dust and the like, the Jellies are formed into briquettes and the like.

Claims (1)

Patent claim: Process for converting pulps of all kinds into the state of different ones plastic or gelatinous masses or a colloidal solution, characterized in that that the pulp with aqueous solutions of neutral salts, with solutions of the zinc salts and the rhodanides of ammonium and potassium, potassium iodide and potassium barium mercury iodide excluded are, with a suitable concentration, temperature, pressure and duration of action depending on the nature of the salt is processed.