AKD (alkyl ketene dimer) starch and preparation method thereof

Abstract

The invention relates to an AKD (alkyl ketene dimer) starch and a preparation method thereof. The method is implemented by selecting native corn starch as a raw material of starch through the following steps of: (1) adding the native corn starch into a reactor; (2) mixing an oxidant, a synergistic agent and water so as to obtain a solution; (3) injecting the solution obtained in the step (2) into the reactor in the step (1); and (4) carrying out standing, heating, heat preservation, cooling and sieving on a reactant obtained in the step (3) so as to obtain a finished product. The pH value of the AKD starch prepared by using the method disclosed by the invention is 6.5-8.5; and the viscosity of paste (6%) of the AKD starch at the temperature of 60 DEG C is less than or equal to 30mPa.s. The method is environmental-friendly, energy-saving, mild in reaction conditions, and easy to operate.

Description

technical field [0001] The invention relates to a starch for surface sizing agent for paper, cardboard and other papers, in particular to an AKD starch and a preparation method thereof. Background technique [0002] my country is a big country in the production and consumption of paper, and its output and consumption both rank second in the world. Sizing is an important process in papermaking. Its purpose is to make paper or paperboard resistant to the diffusion and penetration of liquids (especially water and aqueous solutions). According to the classification method of sizing, sizing agents can be divided into internal sizing agents and surface sizing agents. Because acidic papermaking is inferior to medium-alkaline papermaking in terms of strength and durability, and there are difficult problems in equipment corrosion and wastewater treatment, papermaking enterprises have gradually changed from the original acid sizing in the international scope. The biggest advantage o...

AI Technical Summary

Problems solved by technology

[0015] Niu Gaofeng applied raw corn starch to the preparation of cultural paper, which can achieve a good sizing effect by using a viscosity reducer in conjunction with corn starch, but this method is a wet method, which does not solve the environmental pollution problem of wet method

[0016] To sum up, in the prior art, AKD starch is mostly cassava flour, and the source of raw materials is unstable, which affects product quality

Although there have been studies on the use of cornstarch for papermaking, the methods used are complicated to operate and the raw materials used are relatively expensive, and have not solved the problems faced by the large-scale application of cornstarch to the papermaking industry.

At the same time, the existing AKD starch production process is mostly wet preparation, which consumes a lot of water and energy. Generally, each ton of modified starch needs to consume 25 tons of water and 0.9 tons of steam; the environmental pollution is serious, and the centrifuged wastewater is milky. , COD is generally 4000-5000, and the generated sewage contains chloride ions, which is difficult to treat, and it is difficult to reduce its COD and BOD values ​​by general biological treatment