In the coating industry, thickeners, also known as gelling agents, play an indispensable role. Its main function is to improve the viscosity of the coating, to ensure that the coating can maintain a uniform suspension state, milky state, and even the formation of gel. Thickeners play a key role in coating printing, latex paint manufacturing and other fields, and affect the performance and quality of coatings in many ways.

The role and importance of thickeners
In the field of coating printing, the preparation of printing pastes usually includes thickeners, water, adhesives and paint pastes. The shear force produced by the printing machinery will make the viscosity of the printing paste decrease instantly, and the thickener plays a key role in this process, so that the viscosity changes with the shear force. This ensures a clear outline for fabric printing and is an integral part of the printing process.

Common types of thickeners and their applications in coating industry

In the manufacture of latex paint, thickeners have many coordinating effects on the properties of latex paint. It can act as a colloidal protective agent during the polymerization of latex and improve the stability of emulsion. In the dispersion stage of pigments and fillers, thickeners can improve the viscosity of dispersed materials and disperse pigments and fillers better. In addition, the thickener also improves the stability and freeze-thaw resistance of the coating during storage and transportation, preventing the deposition and caking of pigments and fillers. During the construction process, it can adjust the viscosity of the latex paint, show thixotropy, and affect the fluidity of the paint.

How thickeners work
Thickener usually through physical water absorption expansion and chemical reaction two principles to achieve the effect of thickening and viscosity.

This type of thickener is based on the principle of physical water absorption and expansion, and expands through the molecular structure when water absorption, thereby increasing the viscosity of the coating. This kind of expansion agent is widely used in water-based systems, which can change the viscosity of the system with the absorption of water. On the other hand, some thickeners work on the principle of chemical reaction, connecting molecules in a liquid to each other through a specific chemical reaction to form a gel or thickened structure. This type of thickener is usually found in high molecular weight polymers and has a variety of roles, including maintaining viscosity, improving dispersion and increasing fluidity.

Common types of thickeners and their applications in coating industry

Common thickener types
Here are some common types of thickeners:

Cellulose ether and its derivatives: including polyanionic cellulose, hydroxyethyl cellulose, methyl hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, etc. By introducing hydrophobic groups, the hydrophobic modified cellulose achieves the associated thickening effect and improves the viscosity and stability of the coating.

Alkali swelling thickener: including non-association type and association type two categories. Association thickeners are water-soluble polymers with hydrophobic groups that can form association structures in polymer aqueous solutions, thereby increasing viscosity.

Polyurethane thickener: It is a non-ionic association thickener, which forms association through intramolecular structure, improves the viscosity of the coating, and shows strong Newtonian flow characteristics.

Bentonite: It is a common inorganic thickener that works through the principle of physical water absorption and expansion to rapidly absorb water and expand, increase the viscosity of the coating and improve the ability to suspend particles.

Common types of thickeners and their applications in coating industry

Selection and application of thickener
Choosing the right thickener usually depends on the specific requirements of the product, including fluidity, transparency, viscosity, gelling, and the requirements for suspended particles. The amount of thickener, compatibility with the main component, no phase separation and storage stability are also factors to consider. In the coating industry, the selection and use of thickeners directly affect the performance and quality of the final product, and is regarded as a key technology in coating manufacturing, providing solid support for the development of the coating industry. The research and application of thickeners will continue to drive innovation in the coatings industry, providing more options and solutions for all types of coatings.