How Do Coalescing Agents Improve Paint Performance?

It goes without saying that paints are the gateway to creating atmosphere, setting moods, and redefining spaces. Along with protecting surfaces from environmental factors, they can improve the appearance of buildings and other projects. However, paints are subject to wear and tear over time, meaning they need the addition of additives to prevent defects and improve their application and storage.

Coalescing agents are chemicals that play a crucial role in paint formulation. In this blog, we take you to the realm of coalescing agents, detailing their basics, production process, and types. Also, we shed light on the pivotal role these chemicals play during the manufacturing of paints. Continue reading!

What are Coalescing Agents?

Coalescing agents are chemicals that function as a temporary plasticizer for polymer particles. They enable the development of polymeric films at the required temperature of film application. Also, the allow film formation for polymers that demonstrate a minimum film forming temperature (MFFT) above ambient temperature.

Coalescing agents help improve the performance and durability of paints by reducing the glass transition temperature of polymers. Also, they can soften latex particles and improve film formation and drying properties. Coalescing agents are used in a variety of paints and coatings, including water-based paints such as latex, vinyl acrylic, and oil-based paints.

Types of Coalescing Agents

Coalescing agents are classified into various types based on their polymer dispersion system’s distribution. Below, we’ve given an overview of some of the most common coalescing agent types:

Hydrophobic Coalescing Agents

This coalescing agent type comes with hydrocarbon solvents and is usually concentrated in the dispersed polymeric particle. These products usually exhibit low efficiency as coalescing agents. The use of these agents leads to poor shelf stability and increased paint viscosity. It’s hard to incorporate hydrophobic coalescing agents into paint formulations. Their use may result in flocculation, leading to reduced gloss, opacity, and film transparency. A key benefit of this coalescing agent type is its cost-effectiveness.

Hydrophilic Coalescing Agents

These coalescing agents include glycols such as dipropylene glycol butyl ether and propylene glycol butyl ether. They have low to medium volatility and partially dissolve the bio-based polymer after water evaporation. Also, they provide greater control over water evaporation.

Partially Water-Soluble Coalescing Agents

Partially water-soluble coalescing agents are known for having the highest efficiency. Also, they exhibit the most desirable characteristics as a coalescing agent. The water solubility of these coalescing agents is low in the range of 0.5 to 5%. Also, their hydrophobic balance means they can concentrate on the polymeric particle’s surface area. The exact amount of these coalescing agents is based on formulation and application characteristics, such as the polymer’s Tg and the final paint’s application temperature conditions.

Properties of Coalescing Agents

The properties of coalescing agents are given below:

Ease of Addition: Coalescing agents are added to paints during the let-down process of paint manufacturing. The addition of these agents prevents the coagulation of the polymer binder.

Evaporation Rate: The evaporation rate of coalescing agents is low as compared to water. However, it tends to be high enough to ensure that the film forms properly under a wide range of temperature conditions.

VOC: To meet legislative requirements, coalescing agents shouldn’t affect the paint’s VOC. While there’s no global uniformity in paint’s VOC definition, the key definition says that the threshold for VOC is more than 250 degrees Celsius.

Water Solubility: Low water solubility enables the particle to concentrate on the polymeric particle. In addition, it reduces the risk of losing the coalescing agent. As such, lower water is preferred over high water solubility.

Color: Coalescing agents are usually preferred to be colorless to prevent the discoloration of the paint. The dosage of these agents can go up to 3% of the final system.

Hydrolytic Stability: Coalescing agents are mainly used in dispersion paints to get a weakly alkaline pH. As ester-based agents may lose efficiency in storage, a high degree of resistance to hydrolysis is expected.

Latest Market Developments

Arkema Group, BASF SE, Eastman Chemical Company, Dow Inc., Evonik Industries AG, Croda International Plc, Solvay S.A., Elementis Plc, and Ashland Global Holdings Inc. are among the prominent players in the coalescing agents market. The market is highly competitive, with several industry participants trying to improve their presence through strategic partnerships, mergers and acquisitions, and collaborations. Here are some of the latest developments in the market:

• In May 2024, global specialty materials and chemical company Celanese announced the inauguration of two new units in India. The two facilities, which include a Shared Service Center in Hyderabad and the India Technical Center in Silvassa, will provide support to both local and global customers by offering advanced testing and development capabilities.
• In March 2024, Clariant launched Clarity Prime, a digital service that provides AI-powered optimization for catalyst performance. The new edition provides machine learning-based catalyst performance and health alerting. Also, it provides advanced technical support production facilities.

Enhancing Paint Performance

Coalescing agents play an important role in improving the performance and properties of paints, coatings, and other formulations. They help improve the paint forming process and improve the overall paint quality by ensuring better adhesion and durability. As industries continue to evolve and the demand for more sophisticated solutions increases, the top companies are anticipated to introduce advanced coalescing agents in the market.