Cosco has introduced a new hardener that allows water-based polyurethane coatings to dry quickly

Solvent-based polyurethane (PU) systems dominate the world market for wood coatings. Due to the slow drying of water-based polyurethane coatings currently produced, it is difficult for wood and furniture manufacturers to switch to systems with lower levels of volatile organic compounds (VOCs) because they take longer to further process their products.
water-based polyurethane coatings made from Covestro's new hardener BayhydurQuix306-70 have similar properties for solvent-based coatings: fast drying, performance and appearance
China
. But they release a small amount of organic solvents.
, however, Covestro has now overcome the barriers to switching technology: from March 19 to 21, the company will present the Bhydur Quix 306-70 at the 2019 European Coatings Show in Nuremberg, Germany. This new hardener makes it possible to prepare a high-quality, water-based two-part wood coating with drying properties similar to solvent-based systems, but with less VOC emissions.
Eva Tejada, an expert in
Covestro's wood coatings, adhesives and specialty products division, said: "Water-based wood coatings based on new hardeners and specific polyol components can reach dry sand in 35 minutes, so there is no need for long dust protection. In less than two hours, the T4 drying time is reached, which means that the film is completely dry. This
60% less drying time than standard water-based polyurethane systems. The service life is not affected by this and, depending on the formulation, the coating can be processed for more than 7 hours after mixing with the ingredients.
Tejada will present the detailed properties of the new hardener, as well as the product description, at the ECS meeting.
water-based wood coating based on Bayhydurquix306-70 has chemical resistance similar to solvent-based systems in the same quality category and has been proven through extensive comparative testing. In terms of appearance, there is no compromise: water-based transparent coatings using new curing agents are as much as mainstream solvent-based PU wood coatings.
from a chemical point of view, the new hardener is an anion-modified isocyanate, including aromatic and adipose parts. Despite its aromatic ingredients, the Bhydur Quix 306-70-based white wood coating does not turn yellow faster than standard solvent-based systems when exposed to ultraviolet light or heat.
overall, bayhydur Quix 306-70 enables paint manufacturers to prepare two-part wood coatings with VOC content below 100 g/L, which are as efficient and efficient as equivalent solvent-based systems.