Poly(carbonate-ether) polyurethane emulsion for printing glue and preparation method thereof

Abstract

The invention discloses a poly(carbonic ester-ether) type polyurethane emulsion for printing paste and a preparation method thereof. The poly(carbonic ester-ether) type polyurethane emulsion for printing paste is prepared from, by weight, 30-40 parts of poly(carbonic ester-ether) diol, 16-30 parts of diisocyanate, 10-20 parts of polyether glycol, 2-5 parts of a nonionic hydrophilic chain extender,0.03-0.05 part of a catalyst, 0.4-4.0 parts of a non-hydrophilic small-molecular chain extender, 1-2.5 parts of an ionic hydrophilic chain extender, 50-55 parts of water and 0.5-1.0 part of a post-chain extender. The poly(carbonic ester-ether) type polyurethane emulsion of the invention has excellent softness, high elasticity and normal / low-temperature bending resistance. The water-based polyurethane emulsion of the invention has the advantages of low raw material cost, excellent hand feeling, high rebound, high elasticity, resistance to humidity and heat, warping strength and good compatibility with pigments and fillers.

Description

technical field [0001] The invention relates to a poly(carbonate-ether) type water-based polyurethane emulsion and a preparation method thereof. Background technique [0002] Screen printing is a production process for printing on textiles instead of dyes. Printing glue is the main raw material for screen printing: in order to reflect the softness and elasticity of knitwear, the main resin in the glue must have the characteristics of softness, dryness, non-stickiness and hardness; in order to facilitate construction and ensure the thickness of screen printing, the resin is required to have a high Contains. Most of the traditional printing resins are water-based acrylate emulsions. Because acrylate resins have poor film-forming elasticity, hot stickiness and brittleness, poor washing fastness, and are easy to block the net when compounded into glue, it has become a difficulty in elasticity, softness and easy construction. Water-based polyurethane can effectively make up for...

AI Technical Summary

Problems solved by technology

It is easy to prepare high-solid emulsions with polyether polyols as raw materials, but the film strength is low and the abrasion resistance is poor

Polyurethane prepolymers prepared from polyester polyols have relatively high viscosity and lower solid content than polyether-based polyurethanes, and polyester-based water-based polyurethanes have the disadvantages of poor storage stability and poor hydrolysis resistance.

Although the water-based polyurethane prepared by polytetrahydrofuran diol and polycarbonate diol has the advantages of high strength, hydrolysis resistance and good weather resistance, the cost of raw materials is high and it is difficult to prepare high solid emulsion by conventional processes.

Take the acetone method as an example: choose a polycarbonate polyol with strong crystallinity, add a large amount of acetone to dilute the prepolymer during the synthesis process, and it can still emulsify smoothly. The high temperature of the heating medium and the long desolvation time will cause the boundary layer bound water between polyurethane particles to volatilize, and the emulsion particles to contact each other, the viscosity of the emulsion will increase, and even become a paste, which will affect the preparation of high solid content emulsion

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