A kind of high-durability water-based polyurethane outdoor wood paint and preparation method thereof

Abstract

The invention provides a high-durability water-based polyurethane outdoor wood paint: calculated according to mass percentage, its raw materials include 15-20% of polyurethane dispersion A, 60-70% of polyurethane dispersion B, 0.1-0.6% of water-based crosslinking agent; polyurethane dispersion The effective active ingredient of body A includes mercapto-terminated aliphatic water-based polyurethane, and the elongation at break of polyurethane dispersion A is not less than 400%; the effective active ingredient of polyurethane dispersion B includes polyester-type aliphatic water-based polyurethane; The active ingredient of the aqueous crosslinking agent includes polycarbodiimide. The present invention uses polyurethane dispersion A with high elongation at break to compound polyurethane dispersion B, so that the coating film with the polyurethane component as the main film-forming component has both excellent hardness and toughness, greatly reducing the In the process of temperature change, the paint film cracks due to the inconsistency of shrinkage between the paint film and the wood, thus optimizing the protective function of the paint film on the wood surface.

Description

technical field [0001] The invention belongs to the field of chemical coatings, and in particular relates to a high-durability water-based polyurethane outdoor wood varnish and a preparation method thereof. Background technique [0002] In recent years, my country's wood-structured buildings have developed rapidly. From the wooden villas developed by real estate to the market's popularity to the wooden-structured landscapes in tourist attractions and leisure and entertainment clubs, people's pursuit of wooden-structured buildings has never stopped. However, due to the porous and sparse nature of the wood itself, the wood fibers are easily corroded by insects, ants and molds, and the coefficient of thermal expansion and contraction is large, it needs to be protected by coating to prolong the service life and reduce the waste of resources. [0003] The national environmental protection policy further restricts high VOC coatings and strongly supports environmental protection co...

AI Technical Summary

Problems solved by technology

However, outdoor wood products require coatings with very high weather resistance, mildew resistance, crack resistance, water resistance, and flexibility. Mildew, but the heat-viscous and brittle characteristics of the paint film lead to a large difference between the stress shrinkage and the thermal expansion and contraction deformation coefficient of wood. After long-term outdoor exposure and changes in natural conditions of wind, sun, and rain, the paint film is prone to cracking Cause mold to enter the wood through the cracks in the paint film, cause the wood to be corroded and breed insects and ants, causing further damage, requiring renovation and painting in a short period of time, and inconvenient color adjustment during the painting process, etc.

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