Лако-красочные материалы — производство

Opacity of a pigment is its ability to impart hiding power to the coating film in which it has been incorporated. Pigments render opacity to the coating mainly by two mechanisms: • Scattering of light • Absorption of light Except for black and some saturated deep-blue pigments that absorb most incident light, all other pigments […]

Visual method: The most basic method for evaluating color of a pigment is to visually examine the mass tone and tint color ofthe pigment under specific illumination and to compare it with a standard physical sample. This method has the limitation that color perception may vary from person to person or under different con­ditions, such […]

Mass tone (mass color): According to ASTM, when viewed by reflected light, the color of a pigment-vehicle mixture of a thickness that com­pletely obscures the background is known as mass tone or mass color. Tint color (reduced color): The color produced by mixing a predo­minant amount of a white pigment (generally titanium dioxide) with a […]

Chemical purity: The selective absorption of visible light by a pigment is predominantly decided by its chemical structure; therefore, chemical purity is one of the important factors that produces consistent color. Particle size: In general, below a certain optimum particle size, pigment particles are optically active through their entire mass, and absorption is no longer […]

Most pigments that are part of any paint formulation are intended to provide visual effects — predominantly, color and opacity. 3.1.1.2 Color Color can be described as a visual sensation that is produced from the stimulation of the retina of the human eye by light in the visible region of the electromagnetic spectrum. The cones […]

Not all colored insoluble products synthesized are commercial pig­ments. To qualify as a pigment, a product needs to demonstrate various characteristics that are not covered in the definition alone, but are important from an application standpoint. Some important properties and characteristics of pigments are briefly discussed below.

Here, pigments are classified based on their chemical composition as follows: • Inorganic pigments — Oxides: titanium dioxide, iron oxide red, nickel titanate yellow — Sulfides: zinc sulfide, cadmium sulfide — Chromates: chrome yellow, chrome orange, zinc chromate — Molybdates: molybdate orange, zinc molybdate — Phosphates: zinc phosphates, aluminum phosphate — Elements — Metallic: aluminum, […]

Pigments may be classified on different bases, such as color, chemi­cal nature (inorganic or organic) and process of manufacture (syn­thetic or natural). A few of such classifications are explained below. 3.1.1.1 Classification based on color Based on color, pigments can be classified in the following categories: • Achromatic pigments — White pigments: titanium dioxide, zinc […]

In modern scientific and techno-commercial publications, pigments are frequently discussed using a universally accepted standard coding system known as the Colour Index, which was jointly deve­loped by the Society of Dyers and Colourists in the United Kingdom and the Association of Textile Chemists and Colorists in the United States. The Colour Index identifies each colorant […]

Pigments may also influence rheological properties, which play a vital role in storage and application of coatings. In addition, some pigments have specific functions such as mold resistance, antifou­ling properties, infrared light absorption or reflection, phosphore­scence, conductivity, thermochromism or fire retardancy, which are important for certain coatings.