Polyurethane binder

Abstract

Polyurethane adhesive consists of polyurethane performed polymer 70-90wt% and anchoring agent 10-30wt% which contains hydroxyl group or epoxy group and is prepared by polymerizing at least two unsaturated monomers from free radical. At lest one monomer is polymerized unsaturated monomer containing hydroxyl group or epoxy group with hydroxyl group value:15.5-55, functionality:2-6; epoxy equivalent:1420-7000 and functionality:2-6. It achieves good viscidity and thermal stability, and better heat resistance. It can be used for composite plate, foam polypropylene and polyester plastic.

Description

technical field [0001] The invention relates to a polyurethane adhesive. Background technique [0002] U.S. Patent US586656 The patent invented by Huang uses reactive polyacrylate or other polymers synthesized from unsaturated monomers as raw materials to produce reactive moisture-curing hot-melt products. The isocyanate group of this hot-melt product The content is 1-3%. In order to stabilize the final product, the invention points out that the hydroxyl value of the polymerized product of unsaturated monomers is between 5-15, not more than 15%. Otherwise, cross-linking will occur during the production process and lose its use value. If the hydrogen oxygen value is too low, the heat resistance effect will not be achieved. At the same time, the patent pointed out that the amount of this hydroxyl group-containing high polymer must be between 30-90% to achieve its performance. The patent pointed out that the ideal polymer molecule should be around 12000. But in fact, when ...

AI Technical Summary

Problems solved by technology

But in fact, when the hydrogen oxygen value reaches 15, the viscosity increase value of the product has exceeded 20% per hour at 120 ° C, which is difficult to control in the actual production process, because it generally takes one to four hours or more from the completion of the reaction to the discharge. For a longer period of time, even if the screw discharge device is used, the viscosity of the reactant in the large packaging barrel still increases with time, not to mention that in the actual use process, the glue is often heated in the hot drum or container for more than one or two hours. Instability determines its practical infeasibility

In fact, the patent US586656 has never seen practical application