Large-particle-size waterborne polyurethane emulsion and preparation method thereof, and application of large-particle-size waterborne polyurethane emulsion in impregnated gloves

Abstract

The invention relates to a large-particle-size waterborne polyurethane emulsion and preparation method thereof, and application of large-particle-size waterborne polyurethane emulsion in impregnated gloves. The raw material formula of the polyurethane emulsion comprises a polyol component, isocyanate, a hydrophilic chain extender, a cross-linking agent, an alcohol chain extender, an amine chain extender, a catalyst, a neutralizer and water, wherein the polyhydric alcohol component comprises polyhydric alcohol with functionality of 3 or more and polyhydric alcohol with functionality of 2 or more; and the cross-linking agent is a cross-linking agent having functionality of 3 or more. According to the invention, a polyurethane structure of a cross-linked network is prepared by optimizing a polyhydric alcohol component and using the cross-linking agent with polyfunctionality, the hydrophilic chain extender, the amine chain extender and other substances, and hydrophilic groups are distributed on a polyurethane molecular chain and are stably dispersed in deionized water, so the waterborne polyurethane emulsion with a particle size of 4000 nm or above is obtained. The emulsion is used for preparing gloves, and glove cores do not need to be pretreated and are directly impregnated, molded and cured.

Description

technical field [0001] The invention belongs to the technical field of polyurethane emulsion, and in particular relates to a large-diameter aqueous polyurethane emulsion, a preparation method and its application in impregnated gloves. Background technique [0002] Water-based polyurethane impregnated gloves have developed rapidly in recent years. In the process of preparing impregnated coated gloves, in order to control the amount of glue applied and speed up the drying speed, acidic or alkaline flocculation aids are needed to treat the glove core. After impregnating the glove core with water-based Polyurethane slurry is often solidified with acidic or alkaline flocculation aids, such as oxalic acid, calcium nitrate, calcium chloride, etc. The use of these flocculation aids greatly saves drying time and material costs, so acid Alkali flocculation treatment has also become an indispensable step in the process of preparing impregnated coated gloves, but the use of a large amou...

AI Technical Summary

Problems solved by technology

[0003] In the existing technology, in the process of preparing waterborne polyurethane, hydrophilic groups are usually introduced into the polyurethane molecular chain, such as: carboxylic acid, sulfonic acid, phosphorus, etc. The existence of these hydrophilic groups makes the macromolecular polyurethane The molecular chain can be uniformly dispersed in the aqueous solution, the more the amount of hydrophilic groups contained, the smaller the particle size of the water-based polyurethane emulsion, the better the stability of dispersion in the aqueous solution, but as the content of the hydrophilic groups increases, it also makes The abrasion resistance and hydrolysis resistance of water-based polyurethane become worse, and it is more difficult to flocculate and solidify when preparing gloves. In order to prevent the penetration of water-based polyurethane slurry and speed up the flocculation speed of water-based polyurethane, it is usually necessary to pre-flocculate the glove core in the process of using it to prepare gloves Treatment, in order to speed up the flocculation speed of water-based polyurethane with the use of acid-base flocculation aids, or usually increase the solid content and cross-linking density of water-based polyurethane and add kaolin, montmorillonite, graphene, heavy calcium and other fillers to modify it, However, these methods also increase the instability of the resin while improving the flocculation speed of water-based polyurethane, which increases the cost of using the resin, and the wearing feeling of the prepared gloves is not good.

[0004] There are also some patents to disclose the preparation of large particle size waterborne polyurethane dispersions, such as a kind of large particle size waterborne polyurethane dispersion and its preparation method disclosed in Chinese patent CN112794978A, although the particle size is larger than ordinary waterborne polyurethane dispersions and good stability, However, its particle size is only about 500nm, which is still not suitable for impregnated gloves without pretreatment

Images