A kind of method for preparing cationic starch size

Abstract

The invention discloses a method for preparing cationic starch slurry. The method comprises the following steps: adding water and native starch into a reactor, preparing starch milk of which the mass percentage concentration of the native starch is 10-15%, adding 2,3-epoxypropyltrimethyl ammonium chloride which accounts for 1-10% of the mass of the starch relatively and sodium hydroxide which accounts for 1-2% of the mass of the starch relatively under stirring conditions, performing high-temperature reaction at the temperature which is 30-50 DEG C higher than the gelatinization temperature of the native starch, and adjusting a pH value to be 6.5-7.5 by using diluted hydrochloric acid or sulfuric acid after reaction ends to obtain the cationic starch slurry. The slurry disclosed by the invention can be directly used for warp sizing, ensures that a process for specifically producing cationic starch in a starch factory or a slurry factory can be removed, and ensures that the production cost can be greatly saved, production procedures can be simplified, and the pollution to the environment caused by wastewater discharged in a cationic starch production process can be reduced.

Description

technical field [0001] The invention relates to a method for preparing starch derivatives, in particular to a method for preparing cationic starch slurry. Background technique [0002] At present, the cationic starch size in the textile industry usually directly purchases the cationic starch produced by the starch factory, adds water to prepare a certain concentration of starch milk, and after heating and gelatinizing, the cationic starch size that can be used in the sizing process is obtained. The common method used by starch factories to produce cationic starch is the wet process. In the reactor, the original starch and sodium sulfate or sodium chloride that account for 5%-25% of the original starch quality are added with water to prepare 20-23Be (mass percentage concentration) About 39%-41%) starch milk, stir evenly; under stirring adjustment, add sodium hydroxide solution to adjust the pH to 11-12.5, alkalinize for 1-3h, add 1%-8% of the original starch quality For quat...

AI Technical Summary

Problems solved by technology

In this reaction, as the reaction proceeds, the generated cationic starch will expand, making it difficult to carry out post-treatment. In order to inhibit the expansion of starch, it is necessary to add a large amount of starch expansion inhibitor sodium sulfate or sodium chloride, which increases The difficulty of post-processing increases the production cost, and also seriously affects the purity of the product and the performance of the product

In addition, due to the reaction below the starch gelatinization temperature, the starch is in a granular state, which will hinder the diffusion of the cationic etherifying agent into the interior of the starch granules, seriously affecting the reaction efficiency of the cationic etherifying agent and the degree of substitution of the cationic starch.