The Answer to Why We Use Paints and Coatings

Why Do We Use Paint?

The Turkish equivalent of the word "coating" is "kaplama" (coating). According to the Turkish Language Association, the definition of the word kaplama is: a layer of another material applied to the outside of something to improve appearance, cover, conceal or protect it. Whether it is a notebook cover, the interior and exterior walls of the buildings where we live or work, our furniture or the surface of the cars we use, the main reason we treat surfaces with coating materials is to protect the surface, extend its life and increase its durability. Paint, which we encounter daily, is an extremely important protective coating material. According to German standard DIN 55945, paint is a substance or mixture of substances that exhibits a viscosity ranging from fluid to putty consistency, is applied to a surface by brushing, spraying, dipping, etc., hardens physically and/or chemically, and forms a paint film on the surface. Today, paint and other coating materials are still viewed as an aesthetic element. However, the primary function of paint is protection, and its secondary function is aesthetics. Rapidly developing industry and technology have made corrosion a matter of significant concern. Unfortunately, because the primary function of paint is not well understood, uninformed and unconscious assessments, choices and applications invite corrosion.

Corrosion is the technical expression of rusting and decay phenomena that we frequently encounter in daily life. According to DIN 50900, corrosion is the decomposition of materials and their environment through chemical or electrochemical reaction.

Although corrosion typically brings to mind the deformation of metal surfaces, corrosion affects wood, stone, concrete and plastic materials as much as it does metals. The crumbling and collapse of concrete is concrete corrosion. While corrosive effects alter the structure of wood, microorganisms cause wood to rot. Numerous protection methods are employed against corrosion. However, there is no anticorrosive system that can be effective indefinitely. Corrosion can be largely prevented through well-selected paint, coating and cathodic protection systems, but most importantly through conscious application. In order for paint applied to a surface to protect it against corrosion, the formulation must be suitable for this purpose, production quality must be high and application must be done correctly. As is known, paint consists of four groups: binder-pigment, fillers, solvent (carrier) and additives. The selection of binder determines the paint's fundamental properties such as surface adhesion, optical and mechanical behavior, and resistance to atmospheric and chemical corrosion. Pigments and fillers are selected in accordance with the structure of the binder used. Thus, the paint's color tone, opacity, and resistance to sunlight are determined. Although fillers are primarily used to reduce raw material costs, they also have beneficial and improving effects on the paint's functions. Solvents primarily enable solid and/or high-viscosity components to be used during paint manufacturing, application to surfaces and the formation of a new film on the surface. In addition to these components that form the foundation of paint, there is another group that directs the paint's character:

Additives

Additives are diverse substances with different functions. Additives are added to paint in much smaller quantities than the main components of binder-pigment, fillers and solvent, and are indispensable components that carry very important responsibilities during paint production, storage, application and in the stages of improving and developing paint film characteristics. Additives have very serious duties and responsibilities in enabling paint to perform its primary function. Of course, their role is not limited to improving the paint's technical properties; their capabilities in reducing costs during production, facilitating manufacturing, and increasing production and pigment efficiency are undeniable. Despite being such a serious functional group, the quantity of additives used in a paint recipe does not exceed 5 percent by weight of the total recipe. While additive addition has a minimal impact on the total raw material cost of paint, it has maximum impact on improving paint quality. Additives exhibit activity in several ways, and this is necessary. At the same time, they interact with one another. Wetting agents improve the wetting of pigment, help the paint adhere better to the surface and increase spreading. The most important step in producing quality paint is preventing foam formation during production and eliminating any foam that forms. In addition to foam control, to benefit from the true efficiency of every raw material you use and to achieve economy in production, an appropriate defoamer must be used.

Using a defoamer in quality paint production is just as important as determining the defoamer suitable for the system and its quantity. The wetting agents and dispersants used in production interact with defoamers. This interaction affects the paint's surface tension, just as it positively or negatively affects dispersion quality and stability.

The compatibility between defoamers and binder is also extremely important. The type of binder and the quantity used primarily affect the paint's surface tension, and are also the primary source of large amounts of stable foam formation in the final stages of paint production. This system, which is the building block of the paint's protective properties against corrosion, will collapse if the foam that forms cannot be prevented, because the air present in the environment will create a surface susceptible to all types of corrosion. In summary, when defoamer selection is incorrect, dispersion becomes insufficient, paint rheology and wet and dry film surface are impaired, and paint quality deteriorates. To protect and strengthen paint against chemical degradation that will occur during paint production and atmospheric and other degradation that will occur during and after surface application, it is necessary to include additives such as light stabilizers, corrosion inhibitors and biocides in the recipe. However, additive selection, as briefly mentioned above, is very important for the final result. The properties to be considered in additive selection should be, in order of priority: functionality, compatibility, availability, price/quality improvement. In the end, if we need an outer garment to protect us from harsh winter rain and cold, on the raincoat we prepare: • There should be no holes, • It should be uniform in thickness throughout and impermeable to cold and water, • It should be resistant to cutting edges and impacts – not easily torn, • Its color should have an energy-boosting effect on our daily life, • Its size should protect all of us from rainwater and cold but not restrict our movement, • It should be very easy to clean, • It should dry quickly and not stain. Is that not right?  

Neslihan Yılmazer / General Manager - Qunes Additives