Organosilicon-modified cationic aqueous polyurethane paper wet strength agent and preparation method

Abstract

The invention relates to the technical field of chemistry, and in particular to an organosilicon-modified cationic aqueous polyurethane paper wet strength agent and a preparation method. The organosilicon-modified cationic aqueous polyurethane paper wet strength agent consists of the following materials: polyether diol, tertiary amino polyether diol, polyether triol, dibutyltin dilaurate, isocyanate, cationic hydrophilic chain extender, end-capping agent, glacial acetic acid, acetone, organosilicon modifier and water. The invention introduces tertiary amino groups into both a soft segment structure and a hard segment structure, quaternary ammonium cations are generated after acid neutralization, consequently, the cationic degree is increased, and the organosilicon-modified cationic aqueous polyurethane paper wet strength agent can be better adsorbed on paper fibers with negative charges, and can be quickly and completely retained; by organosilicon modification, crosslinking density is increased, a chemical network structure is formed, and the organosilicon-modified cationic aqueous polyurethane paper wet strength agent which has a high cationic degree and high wet strength can be formed when used on paper; with water as dispersant, the organosilicon-modified cationic aqueous polyurethane paper wet strength agent is nontoxic, pollution-free and highly compatible, and the existence of free formaldehyde and organic halide in conventional wet strength agents are prevented, so the organosilicon-modified cationic aqueous polyurethane paper wet strength agent is environment-friendly and safe.

Description

technical field [0001] The invention relates to the technical field of chemistry, in particular to an organosilicon-modified cationic water-based polyurethane paper wet strength agent and a preparation method thereof. Background technique [0002] Water-based polyurethane (WPU) uses water as a solvent, has the characteristics of non-toxic, non-polluting, safe, reliable, good compatibility, and easy to modify, and has good applications in the fields of coatings, adhesives, textiles, and papermaking. The precipitation of free formaldehyde and the presence of organic chlorine in traditional paper wetting strength agents will cause certain harm to the environment and human body. Therefore, water-based polyurethane has become a hot spot in the research of wet strength agents in the paper industry in recent years. Blocked cationic water-based polyurethane can generate electrostatic attraction with hydroxyl groups in paper fibers, form physical crosslinking, increase paper strength...

AI Technical Summary

Problems solved by technology

This method has limitations in improving the degree of cationicity. The amount of tertiary amino chain extender directly affects the physical crosslinking of hydrogen bonds between polyurethane hard segments. Excessive use will lead to serious phase separation, thereby destroying the mechanical properties of the material.

[0004] Silicone resin has the advantages of low surface energy, water resistance, high and low temperature resistance, and flame retardancy. In the existing preparation methods, linear polysiloxane-modified waterborne polyurethane containing active groups is the main method, and the water resistance has been improved. However, severe phase separation makes the storage stability of the emulsion and the mechanical properties of the coating film poor.

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