Water soluble polyurethane associative thickener and use thereof

Abstract

The invention discloses a water soluble polyurethane associative thickener and use thereof. In the invention, the water soluble polyurethane associative thickener with a branch structure is obtained by dehydrating polyethylene glycol and a surface-active substance which serves as a capping agent and has a plurality of ethyoxyl structures, and adding diisocyanate and a diisocyanate polycondensate serving as a chain extender in a protective atmosphere of an inert gas to perform a reaction in an organic solvent, and the water soluble polyurethane associative thickener has high thickening capability and can be widely used. In the invention, the surface-active substance with plurality of ethyoxyl structures is used as the capping agent to participate in an reaction, so the molecular weight is high, the reaction is smooth and the industrial production is convenient; the diisocyanate and the chain extender are added at one time, so the uncertainty of the product, which is caused by the waterbrought in during stepwise addition, is avoided; and the efficiency of the reaction of the carbimide group and the hydroxyl in an organic solvent is high, a catalyst is not used, the hydrolysis effect of the catalyst on the product is avoided, and the stability of the product is high.

Description

technical field [0001] The invention relates to a thickener, in particular to a water-soluble polyurethane associative thickener and its application, belonging to the field of materials. Background technique [0002] Polyurethane associative thickener is a kind of thickener developed in the 1980s, which is a water-soluble oligomer containing hydrophobic groups. Traditional polyurethane associative thickener molecules are generally obtained by direct addition of organic monoisocyanate and polyether, or by reacting polyether with a certain molecular weight and excess diisocyanate first, and then blocked by organic amines or alcohols. It is a linear structure with lipophilic end groups at both ends and a long-chain hydrophilic group in the middle. The thickening principle of polyurethane associative thickener is: lipophilic end groups associate to form micelles, and the association of micelles forms a network structure, that is, the coupling of hydrophilic groups and water in ...

AI Technical Summary

Problems solved by technology

[0003] Because the isocyanate group (NCO) of organic monoisocyanate or diisocyanate has reactivity to water and active hydrogen, therefore, in order to avoid the generation of by-products, before carrying out polymerization reaction, usually by vacuum drying dehydration method in the prior art, will The water in the raw material is removed, and the bulk polymerization reaction is carried out. The obtained product is usually a waxy solid, which is very inconvenient in application. It needs to be dissolved with a solvent and a co-solvent before it can be added to the latex paint, etc. in thickened products

In addition, the existing preparation method has many side reaction products, and the obtained polyurethane associative thickener has darker color, high reaction viscosity, difficulty in mass transfer and heat transfer, difficulty in increasing molecular weight and achieving effective thickening branched structure, and the product Production and storage stability is not high