Polyurethane coating defoaming agent: an essential agent for improving coating quality and technology

Polyurethane is a high molecular polymer with excellent wear resistance, chemical resistance and weather resistance. Polyurethane coatings are commonly used in industrial coatings, automotive coatings, architectural coatings and other fields, and can provide good protection and decorative effects. Polyurethane coating defoamer is a special additive added to the coating. Its function is to control and eliminate foam generated in the coating.

The main reasons why polyurethane coatings produce a large amount of foam during the preparation process are as follows:

1. Improper stirring: During the preparation process, if the stirring is insufficient, the speed is too fast, or the time is too long, air will be stirred into the paint, resulting in foam.

2. The solvent evaporates too quickly: When the solvent evaporates too quickly, the rapid solidification of the paint surface prevents the volatile solvent from escaping smoothly, resulting in foam.

3. The water content is too high: If the water content in the raw materials is too high, or the solvent added during the preparation process contains water, it is easy to cause bubbles in the paint.

A high-quality coating requires a flat surface and good adhesion, and foam can hinder these requirements. Polyurethane coating defoaming agents break the surface tension of liquids and quickly collapse bubbles in the coating, thereby reducing the formation and persistence of foam.

Polyurethane coating defoaming agents are mainly used for the following reasons:

1. Control foam: Defoaming agents can effectively reduce the number and size of foam in paint. Foam has a negative impact on the quality and appearance of the paint, causing the surface of the paint film to be uneven and affecting the adhesion and gloss of the paint.

2. Improve paint fluidity: Excessive foam will increase the viscosity of the paint and reduce its fluidity. Defoaming agents help reduce the surface tension of paint, making it easier to flow and apply, improving painting efficiency.

3. Improve paint stability: Foam not only affects the quality of the paint, but may also cause problems during storage and transportation of the paint. Defoaming agents can adjust the stability of coatings and prevent excessive foaming during long-term storage or transportation.