Single-component polyurea coating and preparation method thereof

Abstract

The invention discloses a single-component polyurea coating. Cyclobutanone is used as a cosolvent and a closing agent at the same time; terminating amino of amino-terminated polyoxypropylene ether is subjected to chemical closing; an intermediate (ketoimine) obtained after closure and a component containing -NCO cannot generate a chemical reaction in a condition of air (moisture) isolation, and can coexist in the same system; the mixture of the intermediate (ketoimine) is subjected to closure relief under the action of moisture once being in contact with air; the terminating amino is released; amino-NH2 quickly generates a reaction with the -NCO, so as to form a urea bond. The single-component polyurea coating has excellent physicochemical properties of higher mechanical properties, wear resistance, wet skid prevention, corrosion prevention and the like, is less influenced by solvents (acetone, ethylene glycol and the like), and can adapt to an environment of which the content of an organic solvent is high or the concentration of engine oil is higher. The single-component polyurea coating provided by the invention has the advantage that a preparation method is simple, and is suitable for industrialized production.

Description

technical field [0001] The invention relates to a polyurea coating, in particular to a single-component polyurea coating and a preparation method thereof. Background technique [0002] Buildings exposed to sulfate, chloride, CO 2 Under the action of corrosive media in the air such as gas, it will cause rust and corrosion of steel bars, and cracks will occur when concrete absorbs water and expands, thereby reducing the service life of buildings. Spray Polyurea Elastomer technology (SPUA technology for short) is a kind of thick coating construction technology that can be rapidly formed on the surface of objects. layer, and has good wear resistance and impact resistance and marine weather aging resistance, which can better reduce the corrosion rate of buildings under the influence of severe weather. Polyurea elastomer is composed of terminal isocyanate prepolymer (—NCO) and amino compound (—NH 2 ) The high-molecular polymer with urea bonds generated by the reaction of the cu...

AI Technical Summary

Problems solved by technology

Due to the fast reaction speed and very short time, it also brings problems to the normal use of the coating. The film-forming substance is too fast, which will produce some fatal surface defects, which makes the bonding force between the coating and the substrate relatively poor. There may even be discontinuous coatings; at the same time, there are problems such as poor protective effect of polyurea coatings and low tensile strength

The solid content of the one-component polyurea type polyurethane coating that is currently used in this field is generally below 70%, and the coating hardness, tensile strength and elongation are low relative to the two-component coating, especially in some specific occasions (such as Acetone, ethylene glycol, environments with high oil content or environments above 100°C), lower tensile strength and elongation, and are greatly restricted during use

The single-component polyurea polyurethane coating disclosed in Chinese patent CN102101967A is made of blocked isocyanate and blocked polyetheramine. Although the tensile strength and elongation of the coating are improved to a certain extent, the method is complicated. It consumes raw materials and energy, and it is difficult to realize industrialization. At the same time, the one-component polyurea made of end-capped polyetheramine and isocyanate prepolymer has poor storage stability, and is not suitable for environments with high engine oil content.

Images