Paint pigment

Dry methylene chloride does not react with the common metals under normal conditions however, a reaction with aluminum can be initiated, sometimes explosively, by the addition of small amounts of other halogenated solvents or an aromatic solvent (7). Iron catalyzes the reaction, and this can be significant in the handling and storage of methylene chloride and in the formulation of products, eg, in aluminum aerosol containers of pigmented paints, where the conditions necessary for the reaction are commonly found. A typical reaction in this process is shown in equation 2. 

Painting with aluminium-pigmented paint is considered in Chapter 14 because its properties are essentially those of a paint and not of a metallic coating in this respect aluminium paint differs from zinc-rich paint which can be formulated to provide galvanic properties similar to those of metallic zinc. 

Etch primers are widely used. They are mostly based on polyvinyl butyral and contain chromates and phosphoric acid. They are said to act both as primers and as etching solutions because it is believed that the chromates and phosphoric acid form an inorganic him, which provides adhesion, while oxidised polyvinyl butyral provides an organic him. For direct application to new galvanised steel, the best known primers are based on calcium orthoplumbate pigment and metallic lead, but these are now less used for environmental reasons. Zinc-dust paints and zinc-phosphate pigmented paints are also used, but the trend is to use pretreatments to assure good adhesion. 

Figure 6. Isocyanate decrease during curing of an un-pigmented paint at 752 R.H. (24 C). a uncatalyzed b DABCO ci DBTDL...

Figure 4. Total weight loss dependence of anatase pigmented paint films on wavelength and on p.v.c. (1)...

B - standard highly zlno pigmented paint modified by a conductive substitution of 1 % of zinc by carbon black. 

C - standard highly zinc pigmented paint modified b substitution of 3 % of zinc b y zinc phosphate. ... 

Since aggregation is also an important phenomenon in other areas (pigments, paints, powder handUng, etc.) numerous studies deal with the interaction of particles [20]. When two bodies enter into contact they are attracted to each other. The strength of adhesion between the particles is determined by their size and surface energy [21,22], i.e. ... 

Paints. The particles in pigmented paints are often large enough to settle even when peptised therefore, it is desirable that they should be aggregated to a certain extent to facilitate redispersion. 

For unperforated board, intumescent paints still produce optimum fire and flame resistance. However, because the painted surface is continuous, the simpler less flame resistant borax-boric acid pigmented paint produces satisfactory results. 

Pigments, Paints, Polymer Coatings, Lacquers, and Printing Inks... 

From a practical point of view, the attainment of the specified dry film thickness is important. In many cases, a minimum thickness must be achieved or protection will fail in a short period. This aspect demands skill in application and close inspection and control. For metallic zinc paints, the thickness would normally be of the order of 60-100/im, for anticorrosive pigmented paints, together with top coats, 100-200 //m, and for inert barrier types 150-300/im. For special environments or projects, these thicknesses may be varied but it should not be presumed that protection will always be improved or be more effective over a longer period of time by increasing the film thickness. 

SnC>2 is used in white pigmented paint coatings [105]. Stucki and coworkers have noted that it is an efficient photo catalyst for the oxidation of a wide range of organics [106]. It has a band gap of approximately... 

The undercoats are pigmented paints that are applied to primed surfaces prior to the application of finished coats. The undercoats are high pigment paints with a matte finish and a color to complement that of the ultimate finishing coats. 

The photochemical properties of titania surfaces are of interest for several reasons. They determine the stability of pigmented paint systems [76], the rate at which pollutants can be degraded in systems designed to purify air and water [77], and are the root cause of poorly understood phenomena such as water photolysis [78] and super hydrophilicity [79]. Using thin rutile epilayers with five low index orientations, it has been shown that the relative rates of photochemical reactions catalyzed by titania depend on the surface orientation [80]. In this chapter, experiments used to map the complete orientation dependence of the relative photochemical reactivity of TiO are described [81-83]. In this case, the relevant reactions are carried out at room temperature and this gives us the opportunity to fix both the surface morphological structure and stoichiometry. For the reactions described here, all of the surfaces were... 

Amorphous forms of carbon have many uses. These include the black color in inks, pigments (paints), rubber tires, and dry cells. 

Use Medicine, yellow pigment, painting on glass or porcelain. 

If the stirrer consists of a flat toothed disk, as e.g. the ZAR design [526] (Fig. 1.8), the liquid is accelerated radially in a small ring away from the disk and then rapidly decelerated. This produces high shear forces even in the absence of a stator ring and baffles. These two stirrer types are particularly suitable for emulsification and dispersion in a wide range of viscosities (e.g. in the production of pigment paints). 

Most biological materials obey Eq. 4, while coarse granular solids such as sand, minerals, pigments, paint, etc., obey Eq. 5. 

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