Two-component polyurethane coating with low emission of volatile organic compounds (VOC), and preparation method of polyurethane coating

Abstract

The invention relates to a two-component polyurethane coating with low emission of volatile organic compounds (VOC). The polyurethane coating is prepared from a component A, a component B and a component C, wherein the weight ratio of the component A to the component B to the component C is equal to 1 to (2 to 3) to (0.5 to 1); the component A is prepared from 10-30 parts of a diisocyanate prepolymer and 70-90 parts of diphenylmethane diisocyanate; the component B is prepared from 50-80 parts of short-oil alkyd resin, 5-25 parts of an organic solvent, 0-0.5 part of a dispersing agent, 0-5 parts of extinction powder, 0-1.0 part of wax powder, 0-15 parts of talcum powder, 0-3.0 parts of an anti-settling agent, 0-0.5 part of a leveling agent, 0.1-0.5 part of a defoaming agent and 0.1-0.3 partof a drying catalyst; the component C is prepared from 70-90 parts of butyl acetate and 10-30 parts of propylene glycol methyl ether acetate. The two-component polyurethane coating provided by the invention is prepared from the high solid content raw materials, so that the consumption of the solvent is effectively reduced; the VOC emission of the polyurethane coating is about 400g / L, so that thepolyurethane coating is especially suitable for being applied and popularized to finishing and painting of wood furniture.

Description

technical field [0001] The invention relates to the field of coatings, in particular to a two-component low-VOC polyurethane coating and a preparation method thereof. Background technique [0002] Since the synthesis of hexamethylene diisocyanate and phenylene diisocyanate by German Bayer company in the 1950s, polyurethane (PU) coatings have developed rapidly. Because polyurethane coatings have excellent hardness, adhesion, chemical resistance, decoration and wear resistance, they are widely used in wood furniture paints, automotive paints, anti-corrosion coatings and special coatings. [0003] At present, the market share of solvent-based polyurethane coatings for furniture coatings is about 80%. The construction viscosity required for furniture coating is relatively low, and the coating contains more organic solvents. These solvents will eventually evaporate into the atmosphere and cause serious pollution. As the country's environmental protection requirements are gettin...

AI Technical Summary

Problems solved by technology

As far as coatings are concerned, there are currently three methods: one is water-based coatings, which are still immature, and the bottlenecks such as construction and hardness have not yet been broken through, so they still cannot completely replace oil-based coatings.

The market volume is less than 1% of solvent-based wood lacquers; the second is UV-curable coatings, which are limited by construction conditions and application fields, and there are also pollution problems; the third is the self-development of solvent-based polyurethane coatings, and its main direction is Reduce VOC

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