Application of defoaming agents in environmentally friendly water-based inks
In recent years, with the need to build an environmentally friendly society and the improvement of people’s living standards, the use of various packaging materials has increased significantly and become increasingly exquisite. The demand for water-based coatings has increased significantly, especially the application of water-based inks has increased year by year. For example, food packaging, gift packaging, internal and external packaging of liquid milk, etc. all use environmentally friendly water-based printing inks such as rosin resin, acrylic resin, and water-based polyurethane.
The rapid development of water-based coatings and inks has led to the development and growth of water-based coating additives and ink additives. Defoaming agent is an indispensable and important additive for water-based ink. It plays the role of eliminating foam and inhibiting the generation of foam during the grinding, ink preparation and use of water-based ink. The development of water-based inks has driven the increase in the amount of defoaming agents, and at the same time put forward higher requirements for the performance of defoaming agents, mainly including:
1.Rapid defoaming ability;
2.Long-lasting anti-foaming ability;
3.Resistant to shear and abrasion;
4.It has good compatibility with the ink system and does not cause surface defects such as shrinkage, orange peel, and blooming in the coating film.
The main defoaming agents used in water-based inks are:
(1) Traditional defoamer: mineral oil wax, metal soap, etc. This type of defoaming agent is rarely used in the market due to poor compatibility with emulsion, poor leveling performance, and poor defoaming effect.
(2) Polyether block defoamer: This type of defoamer has excellent compatibility, fewer surface defects in the paint film, does not affect gloss and haze, and is suitable for ink with high surface requirements.
(3) Silicone defoaming agents: mainly include emulsion polysiloxane and polyether modified silicone defoaming agents. This type of defoaming agent has excellent foam suppression ability and thermal stability, and is commonly used in water-based inks.
(4) Composite defoamer: mineral oil/wax/organic silicone, mineral oil/hydrophobic particles/organic silicon, organic silicon/hydrophobic particles, etc. This type of defoamer has excellent versatility and compatibility, and has fewer surface defects in the paint film.
