Method for preparing organic silicon graft modified polyurethane resin for synthetic leather

Abstract

The invention discloses a method for preparing an organic silicon graft modified polyurethane resin for synthetic leather. The method comprises the following step: polymerizing a chain extender, diisocyanate, a polymer polyhydric alcohol, micromolecule polyhydric alcohol and an organic metal catalyst in an organic solvent at 50-100 DEG C, wherein organic silicon of which one end contains two hydroxide radicals and the other end contains no active hydroxide radical is adopted as the chain extender. In the process that the grafted organic silicon modified resin is filmed, organic silicon chain segments are connected with a polyurethane structure through covalent bonds, the organic silicon chain segments are enriched on the surface of a coating, the water contact angle of the surface of the obtained coating is improved, the surface of the coating is smooth in hand feeling and bright in gloss, the properties of the surface of the coating are long-lasting and are hard to damage by mechanical and washing action, and thus the resin is an excellent and long-lasting synthetic leather surface treatment material.

Description

technical field [0001] The invention relates to the field of new chemical materials, in particular to a preparation method of organosilicon graft-modified polyurethane resin for synthetic leather. Background technique [0002] Silicone has low surface energy, and the adhesion of silicone material to the surface of synthetic leather coating can improve the feel of the coating surface, improve the waterproof and antifouling ability of the coating. However, when the pure silicone material is used as a surface additive, the silicone is only attached to the coating surface through weak physical adsorption, and is easily damaged by mechanical action or washing. As the coating material is used for a long time, the coating surface performance gradually loses . In order to increase the long-term performance of the silicone surface, the silicone structure is usually chemically bonded into the molecular structure of the coating polyurethane resin to obtain a silicone-modified polyuret...

AI Technical Summary

Problems solved by technology

[0011] However, the synthesis of grafted organosilicon-modified polyurethane is extremely difficult. So far, there is no real research and patent of grafted organosilicon-modified polyurethane. Chinese patent CN103483526 discloses a silicone-grafted modified polyester type polyurethane Polymer and its preparation and application. It adopts the reaction of organosilicon with both ends of hydroxyl and trimethylchlorosilane, trying to block one end hydroxyl of the organosilicon with both ends of hydroxyl to obtain single-end hydroxyl organosilicon, and then the single-end hydroxyl organic silicon Silicon introduced into polyurethane as grafted side chains

This patent has serious theoretical flaws. The reaction between 1 mol of organosilicon with hydroxyl groups at both ends and 1 mol of trimethylchlorosilane is completely a probability selective reaction. Hydroxyl chlorosilane reacts to form terminal hydroxyl silicone, this part of the product cannot react with polyurethane prepolymer to connect to the polyurethane structure; 50% of the terminal hydroxyl of silicone with hydroxyl at both ends reacts with trimethylchlorosilane to form a single terminal Hydroxyl silicone, and the reaction of single-end hydroxyl silicone with polyurethane prepolymer can only become the terminal chain of polyurethane structure and cannot become a grafted side chain; Chlorosilane reaction, this part of silicone reacts with polyurethane prepolymer to become the main chain of polyurethane structure