Water-based polyurethane floor paint

Water-based polyurethane floor paint​

Based on the development trend of the construction industry in recent years, higher requirements have been put forward for the performance, construction efficiency and environmental protection of floor paint. The new two-component water-based polyurethane technology fully meets the needs of market development. Floor paints developed based on these technologies are widely used in commercial and industrial floors and have excellent wear resistance, scratch resistance and chemical resistance.

Overview

Epoxy paint is currently the mainstream technology in floor paint. As the market’s performance requirements for floor paints increase, polyurethane floor paints based on new technologies are also used in the field of high-performance floor paints. Two-component polyurethane floor paints are known for their excellent weather resistance, chemical resistance, The combination of rigidity and softness, wear resistance and scratch resistance has become the benchmark technology for high-performance floor paint. However, although traditional solvent-based polyurethane coatings have excellent performance, their larger odor, higher volatile organic compound content, and flammable and explosive characteristics limit the use of this technology, especially for indoor applications. At the same time, the increase in environmental protection requirements has also provided impetus for the innovation of water-based technology. Therefore, the innovative two-component water-based polyurethane technology conforms to the market development trend, namely: high performance, environmental protection and high efficiency.

Cement-based self-leveling has developed rapidly in recent years, and surface protection is essential to ensure that contaminants will not penetrate into the cement self-leveling and leave permanent stains. The original solution is to first apply a single-component sealing agent and then wax it. The advantage of this solution is that after the surface is contaminated, the contaminants can be removed with wax water and then waxed and renovated. The disadvantage is that it requires regular maintenance, and if it is soaked in open water for a long time, water will penetrate into the self-leveling surface, causing pollution that is difficult to eliminate. The new two-component water-based polyurethane floor paint is very suitable for use on cement-based self-leveling finishes. It not only provides long-lasting, high-quality protection, but also maintains the original cement-based self-leveling color

This article mainly introduces the basic principles and properties of two-component water-based polyurethane, and introduces some application cases in cement self-leveling to share with you.

Mixing and film formation of two-component water-based polyurethane

Different from the homogeneous system of solvent-based polyurethane coatings, during the mixing process of two-component water-based polyurethane, the polyisocyanate component and the polyol component will form a three-phase system, namely water (continuous phase), hydroxyl resin dispersed phase (including Part of the polyisocyanate has entered the hydroxyl resin dispersed phase) and the polyisocyanate dispersed phase under the action of shear force. As mentioned earlier, a very small amount of NCO on the surface of the small droplets of the polyisocyanate dispersed phase will react with water to form a polyurea film. This polyurea film plays a protective role, so the NCO inside the droplets will not be here. The phase reacts with water, thus ensuring that the paint has sufficient operability time.

The paint film formed through chemical cross-linking reaction has properties comparable to traditional solvent-based polyurethane coatings: such as excellent chemical resistance, scratch resistance, abrasion resistance and weather resistance, while its volatility The content of organic compounds is greatly reduced.

Performance of two-component water-based polyurethane floor paint

Aliphatic system → Weather-resistant and UV-resistant

Low viscosity hydrophilic modified polyisocyanate → easy to mix by hand

Medium hydrophilic coating → excellent stain resistance and easy cleaning

Cross-linked → easy cleaning, chemical and abrasion resistance

Medium cross-linking density → balances film breathability

High cross-linking density → heat resistant tire marks

Co-solvent-free water-based system → low VOC, low odor

Polyurethane structure → Flexible (even at low temperatures)

Strong and soft → Excellent scratch resistance

Comparison of two-component water-based polyurethane and water-based epoxy

Two-component water-based epoxy is also widely used in floor paint and other fields. Compared with two-component water-based polyurethane, it has better weather resistance, acid resistance, and scratch resistance, and is especially suitable as a surface. Paint is used, while water-based epoxy is more suitable for use in some less demanding situations, and can also be used as a primer in conjunction with water-based polyurethane.

Based on the above analysis, it can be seen that two-component water-based polyurethane floor paint has great advantages compared with traditional floor paint. However, because the cost of polyurethane is much higher than traditional floor paint, this greatly limits It has been promoted on a large scale and is mainly used in some high-end occasions, such as commercial underground parking lots. Cultural center, exhibition hall, etc. How to reduce the cost of polyurethane floor paint while maintaining the same performance is what we will introduce in future articles.