Composite modified starch for paper making

Abstract

The invention provides composite modified starch for paper making. The composite modified starch is prepared with a method as follows: 1) edible tapioca starch is taken as a raw material, a sodium chloride solution is added, and the mixture is mixed; 2) pneumatic drying and dewatering are performed; 3) hydrogen peroxide serving as an oxidant is added to the dewatered starch and has a crosslinking reaction with the tapioca starch for 3-5 min; 4) epichlorohydrin is added to serve as a crosslinking agent, the mixture has a crosslinking reaction for 3-5 min, and tapioca crosslinked and oxidized composite modified starch is prepared; 5) a hydrochloric acid solution is added for a reaction, and the pH (potential of hydrogen) is adjusted to range from 6 to 7; 6) air cooling is performed; 7) pneumatic drying and dewatering are performed, and a finished product is prepared. Each of the use quantity of the oxidant and the use quantity of the crosslinking agent is 0.1%-0.5% of the weight of the tapioca starch. Through oxidization and crosslinking, negative and positive charges are balanced, and the composite modified starch for paper making can be used together with respective additives such as a fluorescent brightener, negative ion disperse rosin size and the like and can be adapted to paper-making production of all kinds of paper pulp.

Description

technical field [0001] The invention relates to a composite modified starch for papermaking and belongs to the technical field of papermaking. Background technique [0002] Modified starch refers to the introduction of new functional groups on starch molecules or changing the size and The properties of starch granules, thereby changing the natural characteristics of starch (such as: gelatinization temperature, thermal viscosity and its stability, freeze-thaw stability, gel strength, film-forming property, transparency, etc.), making it more suitable for certain applications Require. This kind of starch that has undergone secondary processing and changed its properties is collectively referred to as modified starch. [0003] The purpose of denaturation of modified starch: one is to meet the requirements of various industrial applications. For example: high-temperature technology (canning sterilization) requires starch to have good high-temperature viscosity stability, froz...

AI Technical Summary

Problems solved by technology

The existing modified starch for papermaking has the following disadvantages: 1) The self-charge of the modified starch affects the potential of the pulp, and there will be a positive charge phenomenon, thereby affecting the use effect; 2) The fibers and fillers have negative charges, and negative and positive charges They are attracted to each other by electrostatic attraction, resulting in flocculation, which affects the evenness and strength of the paper; 3) It cannot be used with anionic additives (such as fluorescent whitening agents, anion-dispersed rosin gum, anions, etc.) at the same time; 4) Some grass Pulp, waste paper pulp, ground wood pulp, there are many heteroanionic chemical substances, which will interfere with the application effect of cationic starch