DE923091C - Process for preventing or breaking off depolymerization processes in the case of polymeric carbohydrates, their decoctions or derivatives - Google Patents

Description

Process for preventing or stopping depolymerization processes in the case of polymeric carbohydrates, their derivatives or derivatives As is well known, show polymeric carbohydrates and their derivatives, such as cellulose, starch, pectin, alginic acid derivatives, Ethers and esters of cellulose and the like, compared to other polymerization products the property of very highly viscous solutions even in low concentrations form. However, this property is lost in a relatively short time. Of the Degree of viscosity loss depends on external conditions, e.g. B. the temperature and moisture. As can easily be seen, they especially lose low concentrated solutions, e.g. B. the alginate, in water during storage Considerably in viscosity over 1 to 2 weeks.

Assuming that the observed loss of viscosity is due to the bacterial Degradation of the solutions is based, the inventors used this germicidal to stabilize Agent added, e.g. B. Phenol derivatives, benzoates, salicylic acid, but to no avail. The loss of viscosity could not generally be achieved by adding germicides impede.

Thorough experiments have shown that a drop in viscosity does not occur if such sterilizing agents are used at the same time have a reducing effect.

It was further found that the loss of viscosity also by the The addition of small amounts of other reducing substances is to be prevented, for example by adding polyoxybenzenes (such as hydroquinone or pyrogallol), hexoses, Hexobioses (like grape sugar), uronic acids, sulfides or aldehydes.

It follows that the drop in viscosity of the solutions is called polymeric substances not on the action of bacteria, but on a through Oxidation occurring depolymerization of the polymers is due, and that this depolymerization is prevented by the addition of the reducing agent.

It has also been found that the addition of reducing agents not only the depolymerization of freshly prepared solutions, for example des Sodium alginate, but also the further depolymerization of already aged Solutions can limit. So you can z. B. one through for various purposes an intentionally induced depolymerization at a given concentration Alginate solution degraded to a certain degree of viscosity by the addition Stabilize reducing agents over a longer period of time.

Finally, it was found that you can also use the polymers in the dry Reduce the condition by adding small amounts of reducing agent over a longer period of time Can preserve periods of time unchanged.

Working examples I. The same 20% solutions of technical alginate were each mixed with 0.1% of substances with different effects. The viscosity of the solution without additives fell from Soo to I25 CP in 10 days, the solutions with the germicidal additives mentioned in the first column were just as thin, while agents with a reducing effect stabilized the solutions unchanged. Means with germ Germicidal. Killing and reducing Means Means reducing effect Sodium Benzoate Hydroquinone Formaldehyde Mercury iodide pyrogallol benzaldehyde Reduced silver mannuronic acid methyl alcohol Phenol dextrose resorcinol Sodium sulfide 2. A clay mud, as used for deep boreholes, with a content of 0.06% artificially depolymerized alginate and 0.2% phosphate was added 0.1% of each of the following substances and the filter plate value was adjusted Andree, who was over 2000 seconds for the freshly made rinses, measured after 10 days. Without addition .............. 440 seconds with addition of phenol ...... 470 - - - Formaldehyde 1000 - - - Benzaldehyde 900 - - - Hydroquinone Soo - 3. In the same way, a clay rinse to which a sodium cellulose glycolate known under the trade name Tylose could be stabilized for a long time by adding small amounts of reducing substances.

4. A technical alginate in powder form was made by an additive stabilized by 0.25% hydroquinone for months.

Claims (3)

PATENT CLAIMS: I. Methods of Prevention or Cancellation of depolymerization processes in aqueous clay rinses or approaches for those which water-soluble polymeric carbohydrates, their derivatives or derivatives, such as Contain starch, pectin, alginic acid, cellulose and its esters, ethers or the like, characterized in that the polymeric substances, their solutions, suspensions or od. Like. Or approaches for this with reducing agents are added, in particular with polyoxybenzenes, sulfides, hexoses, hexoblose, uronic acids, glucose or Aldehydes. 2. The method according to claim I, characterized in that the aqueous Solution, swelling, suspension or the like 0.1 to 10%, based on the dry polymers, preferably traces up to IO / o, based on the respective solution or od. Like., the reducing agents are added. 3. The method according to claim I and 2, characterized in that the Reducing agent for the polymers mentioned as early as during the extraction or purification process the same are added. Cited publications: USA .-- Patentschmften Nos. 2547 141, 2535 357, 2,535,359, 2,535,360, 2,535,361, 2,535,363; "Seifensieder-Zeitung", 1947, 5. 130, right column, para. 4.