Purchase the 2006 Additives Guide at the Link Below
There are many additives a formulator may choose to solve or alleviate problems that arise, to improve product quality, or to prevent problems from arising during manufacturing. Additives belong to a broad and diffuse category of key components in a coating formulation, and some of them are multipurpose in function. Additives usually comprise only a small percentage of a coating formulation - usually less than 5%.The function of additives is almost always very specific in nature. Their function can vary from being independent of the other ingredients in the "can" and on their performance in the final coating, to those whose function is critical to performance and on which performance of the final coating is vitally dependent. Still other additives may be important to the manufacturing process and important to a coating's performance - that is, they have a dual purpose. For example, a defoamer may be a production aid that is critical to the manufacturing process, but may or may not contribute anything to the application or final coating properties. A flow and leveling aid probably contributes nothing to the manufacturing process and may even have a deleterious effect, but it is necessary to obtain a smooth, glossy final coating that will have the eye appeal necessary for a decorative coating. A bactericide may be important in preventing bacterial contamination of production equipment and stored paint, but will do nothing to protect the cured paint film.
Some additives, such as dispersing agents and defoamers, can be proprietary products with highly specific functions that work well in some systems but cannot be used in others. In addition, because of the proprietary nature of many additives, their chemical composition is not disclosed. This can make general recommendations difficult. In addition, this lack of structural knowledge means that additive substitutions cannot be made on the basis of fundamental structural chemistry. Thus, with such knowledge of the basic nature of a specific raw material unavailable, one cannot ascertain or deduce just how the compound carries out its function in the formulation. Often these areas of function overlap, and a clear definition of category and function is difficult, if not impossible. As an example, AMP-95, depending on the point of addition, the usage level or the type of formula, may act as a dispersant, pH buffer, freeze-thaw stabilizer or flash-rust inhibitor.
Occasionally, the use of one additive will require the use of another to counter some undesirable effect of the first. For instance, the addition of a surfactant to improve colorant compatibility in a tint base could result in foaming, which would require the addition of a defoamer, or loss of viscosity, which would require a thickener.
With a large number of additives available for a particular problem, formulators or laboratory chemists can find themselves in trouble if the wrong additive is selected to alleviate or correct the problem. Selection of an incorrect additive may compound the problem, making selection of another additive necessary. This additive may be negated by the first additive, leaving the problem in its initial state or make it even worse than after the first addition. Correct additive selection is important to success, and such selection is made through vendor assistance or years of experience.
The key to formulation is to understand the function of an additive in terms of its chemical or physical nature and behavior in the presence of other components in the coating formulation. This is not an easy or simple task, and it requires good applied thinking and practical knowledge. Often it means a long period of experience is needed to become truly knowledgeable. The technical service staffs of vendors can be useful in making proper additive selections.
The 2006 Additives Guide is a brief description of the various additives and some generic examples to give one a basic understanding of where additives (as opposed to polymers, pigments/extenders and solvents) fit into the coatings arena. The majority of additive types are represented.
To purchase the 2006 Additives Guide in print or on CD, click on the link below or contact Inside Sales Manager Andrea Kropp at kroppa@pcimag.com, or call 810/688-4847.
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