madder lake and crimson lake), true organic pigments have only been known since the early years of the twentieth century. Although, natural dyes have been precipitated on to inorganic bases (known as lakes) and used in artists' colors since the Middle Ages (e.g. However, modern manufacturing techniques are capable of imparting properties not previously associated with the chemical type: it is now possible to produce high opacity organic pigments. Organic Pigments Organic pigments are traditionally transparent. This means that there are no visible particles and the transparency of the medium is unchanged. In addition, depending on the demands of the particular application, pigments are required to be resistant to light, weathering, heat and chemicals such as acids and alkalis.ĭye is a substance that is applied in order to impart color with some degree of permanence. Polymer Soluble Dyes are soluble in the medium in which they are dispersed. Pigments are thus required to resist dissolving in solvents that they may contact during application, otherwise problems such as 'bleeding' and migration may occur. During the dispersion of the pigment into the polymer, high shear is generally needed to break up these agglomerates (improved tinting strength). During the pigment production process, primary particles generally aggregate and generate agglomerates. The structure and shape of these particles depends on the crystallinity of the pigment. The smallest units are called primary particles. They are distinct particles, which gives the medium their color and opacity. Pigments are organic or inorganic, colored, white or black materials that are practically insoluble in the medium in which they are dispersed. Functional fillers impart a desired property to the coating like corrosion inhibitor and special effect pigments create optical effects like metallic, hammer finish and diverse color perceptions depending on the angle. While organic pigments do not disperse easily and form agglomerates (clumps of pigment particles), inorganic pigments get more easily dispersed in the resin.

Some of the main pigment classes include: They are also used to impart bulk or a desired physical and chemical property to the wet or dry film.

Pigments are finely ground natural or synthetic, insoluble particles used to impart color when added to paints and coatings formulations.

Pigments v2