METHOD FOR PREPARING TECHNICAL CARBOXYMETHYLSTARCH SODIUM SALT Russian patent published in 2008 - IPC C08B31/10 

FIELD: chemical technology.

SUBSTANCE: invention relates to technology for synthesis of starch ethers. Invention describes a method for synthesis of technical carboxymethylstarch sodium salt. Method involves mixing in reactor-mixer starch, a carboxymethylating agent chosen from the following group: sodium monochloroacetate or monochloroacetic acid, sodium hydroxide and liquid followed by heating and keeping the reaction mass at temperature 60-90°C. The process for synthesis of the end substance is carried out in a paddle mixer at the linear stirring rate 0.10-0.80 m/s wherein a carboxymethylating agent is fed immediately after feeding starch, sodium hydroxide and liquid in the amount 0.28-0.35 kg of liquid per 1 kg of product. Then the prepared mixture is heated and kept at increased temperature for 0.10-0.49 h. Ethyl or isopropyl alcohol is used a liquid with the water content 10-16 wt.-%. Method provides enhancing effectiveness of process for synthesis of technical carboxymethylstarch sodium salt, simplifying equipments used, and decreasing consumptions for removal of liquid excess from the reaction mixture.

EFFECT: improved method of synthesis.

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