Pigmento

Pigmento is a substance used to impart color to a material, typically by dispersing microscopic particles that are insoluble in the medium. Unlike dyes, pigments are not soluble and form a dispersion in binders such as oil, polymer, or water-based systems. This property makes pigments more resistant to bleeding, staining, and chemical attack, contributing to durability and opacity in many products.

Pigmentos are broadly categorized as inorganic, organic, natural, and synthetic. Inorganic pigments include iron oxides, titanium dioxide (white), ultramarine, and carbon black. Organic pigments include phthalocyanines (blue‑green), quinacridones (red-violet), and dioxazines. Natural pigments are minerals or organic compounds extracted from nature, whereas synthetic pigments are manufactured for stability, color range, and cost.

Key properties include tinting strength, hiding power (the pigment’s ability to obscure underlying color), color index or shade, lightfastness, heat stability, chemical inertness, and particle size and dispersion. These factors influence performance in different media and conditions.

Applications span paints and coatings, plastics, inks, cosmetics, and printing inks. The choice of pigment depends on color, opacity, stability, regulatory constraints, and compatibility with binder and processing conditions.

Manufacturing and processing involve producing inorganic pigments by precipitation or solid-state synthesis, followed by grinding to the desired particle size; organic pigments are usually synthesized chemically, then milled and dispersed. Pigments are designed for specific end-uses, such as outdoor durability or food-grade compatibility. Safety and environmental considerations include potential toxicity of certain pigments and regulatory controls.

History notes that pigments have been used since prehistoric times, with synthetic pigments expanding color options in the 19th century. Pigment properties such as opacity, tinting strength, and lightfastness determine their suitability for various applications.