Method for preparing amphiprotic starch solution for papermaking

Abstract

The invention provides a method for preparing amphiprotic starch solution for papermaking, which belongs to the field of fine chemicals for papermaking. The amphiprotic starch solution is added at a papermaking wet end, and has a dry strengthening effect on paper. Starch is used as the basic material, water, sodium hydroxide, sodium hypochlorite or potassium persulfate and cationic etherifying agent are added. The amphiprotic starch solution is obtained after the aqueous solution is heated. The preparation method is fulfilled by the heating reaction of aqueous solution. The amphiprotic starchsolution has high concentration, can be diluted by cold water to any concentration and cannot be aged, so the technical problem of starch aging is solved. When in use, the amphiprotic starch solutioncan be added at the wet end without being heated to gelatinize, the amphiprotic starch solution as dry-strengthening agent for papermaking can notably increase the dry strength indexes of paper, suchas burst index and ring crush index, and under the circumstance of the same added amount, the amphiprotic starch solution has a better effect than the like product. The innovation of the invention isthat a simple technique for producing the amphiprotic starch solution is provided, the production time is not longer than 2 hours, the aging and retrograding problems of the amphiprotic starch are solved, and the invented amphiprotic starch solution can be directly added at the papermaking wet end without going through the step of gelatinization by heating.

Description

Technical field:

[0001] The invention relates to a method for preparing an amphoteric starch solution for papermaking, and belongs to the field of papermaking fine chemicals. Background technique:

[0002] Starch, the storage form of carbohydrates in green plants, is an important renewable and biodegradable natural resource with very important practical applications in the paper industry and other industries. Native starch produced from cereal and tuber crops is widely used in many industries. With the development of the paper industry, starch products are increasingly required to have specific functions, such as better film-forming properties, freeze-thaw stability, cold water solubility, shear resistance, aging resistance, salt resistance, etc. Starch molecules have many hydroxyl groups and are highly hydrophilic, but starch granules are insoluble in water. Even after fully gelatinizing, the starch paste solution will quickly undergo aging and retrogradation. This is beca...