Preparation method of wet strength agent for papermaking

Abstract

The invention relates to a preparation method of a wet strength agent for papermaking and belongs to the technical field of preparation of wet strength agents. Chitosan is subjected to swelling treatment with anhydrous ethanol firstly and then modified with maleic anhydride and phosphoric acid, and modified chitosan is obtained; modified chitosan reacts with isocyanate, and a chitosan polymer is obtained; hydroxyl and amino in the chitosan polymer can form hydrogen bonds with cellulose in paper and can perform bridging and film formation among cellulose to enhance the wet strength and the tearing strength of paper; then, methyl benzene sulfonic chloride and other substances are utilized to modify hydroxypropyl guar gum, and modified guar gum is obtained; finally, modified guar gum is mixed with a chitosan polymer concentrated solution and other substances for ageing, and the wet strength agent for papermaking is obtained. The wet strength agent solves the problem that a conventional wet strength agent cannot improve the wet strength and the tear resistance of paper, improves the wet strength and the tear resistance of paper greatly, and can realize expanded production.

Description

technical field [0001] The invention relates to a method for preparing a wet strength agent for papermaking, and belongs to the technical field of wet strength agent preparation. Background technique [0002] As a raw material for papermaking, cellulose has the characteristics of being hydrophilic. When the paper is wetted with water, the cellulose will lose its corresponding strength. In the process of industrial papermaking, if a wet strength agent is added, the wet strength of the paper can be significantly improved. tensile strength. Wet strength agent is an important papermaking chemical that can not only improve the quality of paper sheets, but also make irreversible changes in the dry strength of paper sheets in a dry state and the wet strength after soaking. A long time ago, the way people endowed paper with wet strength was to put the paper into sulfuric acid to make it parchmentized. The parchmented paper fibers were denatured and bonded. After the treated paper w...

AI Technical Summary

Problems solved by technology

[0006] The technical problem to be solved by the present invention: Aiming at the problem that the traditional wet strength agent cannot improve the wet strength and tear resistance of paper, and cannot meet the requirements of industrial production, a chitosan modified with maleic anhydride and isocyanate is provided. Wet strength agent, organic amine modified hydroxypropyl guar gum is used as an auxiliary agent to prepare a method for paper wet strength agent. The present invention first utilizes absolute ethanol to swell chitosan, and then utilizes maleic anhydride and phosphoric acid to it. Carry out modification to obtain modified chitosan, and then react it with isocyanate to obtain chitosan polymer. The hydroxyl and amino groups in chitosan polymer can form hydrogen bonds with cellulose in paper, and can form a hydrogen bond in the fiber Bridging between primes and forming a film to enhance the wet strength and tear strength of paper, and then modifying hydroxypropyl guar gum with toluenesulfonyl chloride and other substances to obtain modified guar gum, and finally combining it with shell polymer Sugar polymer concentrate and other substances are mixed and aged to obtain paper-making wet strength agent

The invention solves the problem that traditional wet strength agents cannot improve the wet strength and tear resistance of paper, greatly improves the wet strength and tear resistance of paper, and can expand production