The choice of raw materials plays an important role in the environmental impact, quality and safety of the products. The most significant impacts on the environment result from the production of raw materials, for instance titanium dioxide and fillers, and the release of solvents during the application of solvent-borne paints.
Binders keep the film of paint intact and form an adhesion between the film of paint and the surface. The binder and the amount used are selected based on the desired properties of the dry film of paint, such as weather and wear resistance and cleanability. The choice of binder also affects the suitability of the paint for different surfaces. The most common types of binder are polymer dispersions and oils/alkyds. Polymer dispersions are typically based on polyacrylate or polyvinyl acetate; oils and alkyds are completely or partially vegetable oil-based.
Pigments and fillers
Pigments are substances insoluble in water and solvents, which are added to paint mainly to provide the desired color and coverage and to protect the surface from ultraviolet radiation from the sun. In addition, some pigments improve the anticorrosive properties of the paint.
The most common pigments include white titanium dioxide and yellow, brown, red and black iron oxides. Synthetic organic pigments are used in particular in pure blue, green, red, yellow, and orange colors. Today's pigments are not based on heavy metals.
Pigments which do not cover or tint are called fillers. Fillers are insoluble fine granular powders, which are used to give paint, among other things, its required opacity. Fillers contain powdered minerals, for example limestone, whiting or dolomite.
Pigments and fillers are manufactured from non-renewable raw materials. Most of them are obtained by quarrying (titanium dioxide and iron oxides) or from oil products. Iron oxides are generally manufactured from recycled scrap iron.
Nowadays, titanium dioxide is the most common white pigment. It is very durable and has good covering properties. Titanium dioxide is inert in terms of both health and environment (does not react chemically with other substances) and used, for example, in toothpastes and other cosmetics. Environmental impacts of the production of titanium dioxide may vary considerably, depending on the quarrying and processing method of ore.
Water and solvents
Water and/or organic solvents give paint the required viscosity for application. The most common thinner and solvent used in paints produced by Tikkurila is water. In addition to this, a film-forming agent, which improves the properties of the paint film, is used in water-borne paints. The most commonly used film-forming agent is propylene glycol.
A host of additives is also added to paint. They constitute a very small portion of the production formula but significantly improve, for example, the flow of paint-making process, paint preservation and application properties.