Pigment inert

Paint Pigment, inert filler, viscosity control... 

Semigloss lacquer la-kor. Lacquers having the appearance of having been frictionally rubbed. Usually arrived at through the introduction of a pigment (inert). A type of satin finish. 

This occurs naturally as a white solid in various crystalline forms, in all of which six oxygen atoms surround each titanium atom. Titanium dioxide is important as a white pigment, because it is nontoxic. chemically inert and highly opaque, and can be finely ground for paint purposes it is often prepared pure by dissolving the natural form in sulphuric acid, hydrolysing to the hydrated dioxide and heating the latter to make the anhydrous form. 

Available Forms. Phthalocyanines are available as powders, in paste, or Hquid forms. They can be dispersed in various media suitable for aqueous, nonaqueous, or multipurpose systems, eg, polyethylene, polyamide, or nitrocellulose. Inert materials like clay, barium sulfate, calcium carbonates, or aluminum hydrate are the most common soHd extenders. Predispersed concentrates of the pigments, like flushes, are interesting for manufacturers of paints and inks (156), who do not own grinding or dispersing equipment. Pigment—water pastes, ie, presscakes, containing 50—75% weight of water, are also available. 

Titanium whites resist various atmospheric contaminants such as sulfur dioxide, carbon dioxide, and hydrogen sulfide. Under normal conditions they are not readily reduced, oxidi2ed, or attacked by weak inorganic and organic acids. Titanium dioxide dissolves slightly in bases, hydrofluoric acid, and hot sulfuric acid. Owing to its chemical inertness, titanium dioxide is a nontoxic, environmentally preferred white pigment. 

The synthetic pigment is produced by one of several related procedures. The best quahty product is made by reaction of an aqueous solution of CdSO or CdCl with a solution of an alkaline metal sulfide or H2S. Zn, Se, or Hg may be added to the CdS to produce shade vatiations. After precipitation, the color is filtered, washed, and calcined in an inert atmosphere at 500—600°C. 

Color Additives. The FDA has created a unique classification and strict limitations on color additives (see also CoLORANTS FOR FOOD, DRUGS, COSMETICS, AND MEDICAL DEVICES). Certified color additives are synthetic organic dyes that ate described in an approved color additive petition. Each manufactured lot of a certified dye must be analyzed and certified by the EDA prior to usage. Color lakes are pigments (qv) that consist of an insoluble metallic salt of a certified color additive deposited on an inert substrate. Lakes are subject to the color additive regulations of the EDA and must be certified by EDA prior to use. Noncertifted color additives requite an approved color additive petition, but individual batches need not be EDA certified prior to use. 

Extenders are chemically inert, naturally occurring or synthetic, inorganic compounds which are included to confer specific properties to the paint. Such properties include suspending the pigment to prevent the formation of hard settlement, improvement of build , and the provision of tooth or key to improve intercoat adhesion. 

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