Pigment Brown 33 51 - applications

Pigment Brown 45 (MnWTi). As it has become apparent that antimony is not bio-available from doped rutiles, the trend for such substitutions with respect to food contact applications has strongly diminished. A more scientific survey on colored titanium MMO pigments is given by Maloney [3.93]. 

Almost 100% of the pigment black applications in the printing ink industry involve the dyeing of black inks. Pigment blacks are also used to tint gray and colored inks (brown, oUve, etc.), but this amount is relatively small compared with the entire consumption. 

Pigment Brown 23 and 41 are mainly used in interior and exterior PVC applications (for example in window frames). 

Algae are classified according to their colors (1) Chlorophyceae (green), (2) Rhodophyceae (red), (3) Cyanophyceae (bine-green), and (4) Pheophyceae (brown). The major pigments inclnde chlorophylls a, b, and c, P-carotene, phycocyanin, xanthophylls, and phycoerythrin. All these pigments have great potential for applications in foods, pharmacenticals, and cosmetics. 

Good overall fastness and considerable tinctorial strength broaden the scope of P.Y.83 application. The list includes office articles, artists colors, and solvent-based wood stains, in which the pigment is frequently combined with red pigments and carbon black to produce shades of brown. 

In the print field the pigment is almost exclusively used in air drying systems. P.R.4 is very likely to bloom in stoving enamels. At only 120°C, the concentration limit for blooming is as low as 2.5%, and at 140°C the limit is at 5%, which makes it necessary to carry out test experiments. Application is consequently restricted to baking enamels targeted for low temperature purposes. In epoxy resins, the pigment turns brown, as does P.O.5, and is therefore unsuitable for use in these media. 

P.R.146 is a suitable candidate for a variety of special applications. The list includes wood stains, in which it is frequently blended with yellow pigments, especially with P.Y.83, and also with black to afford shades of brown. The products are fast to overcoating and stable to nitro and acid catalyzed and polyester varnishes. Intense shades match step 5 on the Blue Scale for lightfastness. Other areas of application include office articles and artists colors, cleaning agents, paper mass coloration, laundry markers, etc. In connection with cosmetics, the pigment frequently lends color to soaps. 

P.O.38 is broad in scope. The list of applications includes special media, such as wax crayons, artists colors, and wood stains, including those that are solvent based. The products are very lightfast (step 7 on the Blue Scale) and fast to overcoating. Blends of P.O.38 with yellow pigments, such as P.Y.83 or P.Y.120, or with carbon black produce useful shades of brown. 

Apart from these areas of application, P.V.32 is also used in solvent-based wood stains. The lightfastness of the products equals step 6 on the Blue Scale, which is very good. These systems may safely be overcoated. Pigment blends with yellow pigments, such as with P.Y.83, and blends with black provide interesting shades of brown. 

P.Br.23 confers reddish shades of brown on its application media. In a large number of areas, this pigment is in direct competition with the coloristically similar, somewhat redder and more transparent P.Br.25. 

This disazo condensation pigment, is a recent product. It affords very yellowish shades of brown, covering the range of the displaced benzimidazolone pigment P.Br.32. In terms of fastness and application properties, P.Br.41 largely resembles other representatives of its class. 

Contact of solutions of ethylene oxide with the skin of human volunteers caused characteristic burns after a latent period of 1-5 hours, effects were edema and erythema and progression to vesiculation, with a tendency to coalescence into blebs, and desquamation. Complete healing without treatment usually occurred within 21 days with, in some cases, residual brown pigmentation. Application of the liquid to the skin caused frostbite three of the eight volunteers were said to have become sensitized to ethylene oxide solutions. The undiluted liquid or solutions may cause severe eye irritation or damage. 

As with most nonpolar hydrocarbon-intense polymers, bitumens exhibit good resistance to attack by inorganic salts and weak acids. They are dark, generally brown to black, and their color is difficult to mask with pigments. They are thermoplastic materials with a narrow service temperature range unless modified with fibrous fillers and/or synthetic resins. They are abundant materials that are relatively inexpensive, thus their use in many bulk applications. 

A further important application of these pigments is in paints. The natural red iron oxides are also used in primers for steel structures and cars, for marine coatings and for anti-fouling paints. In the USA, the metallic browns are used for these purposes. The level of soluble salts in the latter pigments is low and this reduces corrosion problems. The metallic browns are also used in heat resistant enamels. 

Metal complexes of tetradentate azomethines, e.g. (199), are reported136 to have very high light-fastness but to be tinctorially weak and dull in hue. Despite this they are of technical interest as very fast yellow to brown pigments. They find no application as dyestuffs, however, because of these deficiencies for example, the chromium complex of (200) gives dull, tinctorially weak dyeings on wool possessing poor wet-fastness properties. 

In addition to jetness, plastics pigmented with carbon blacks typically exhibit color undertones. Undertone in black plastics appears as a distinct blue or brown-to-orange undertone, depending on the particle size of the carbon black used. In general, in full-shade, black molded applications, fine-particle-size carbon blacks impart a bluer tone. This behavior reverses itself in tints. Large-particle-size carbon blacks impart bluer undertone. Note that the effects of fillers, polymers, and dispersion can alter the typical behavior described above. Tint strength is the relative ability of the carbon black to darken a resin colored with chromatic pigments. 

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