Лако-красочные материалы — производство

In the Sherwin-Williams process, a lead nitrate solution is reacted with a solution of sodium dichromate, ammonium molybdate, and sulfuric acid [3.132]. Instead of ammonium molybdate, the corresponding tungsten salt can be used, giving a pigment based on lead tungstate. The pigment is stabilized by adding sodium silicate (25% SiO2) and aluminum sulfate (Al2(SO4)3 -18 […]

Molybdate red and molybdate orange [12656-85-8], C. I. Pigment Red 104:77605, are mixed-phase pigments with the general formula Pb(Cr, Mo, S)O4 [3.115]. Most com­mercial products show a MoO3 content of 4-6%, a refractive index of 2.3-2.65 and densities of about 5.4-6.3 g cm-3). Their hue depends on the proportion of molybdate, crystal form, and particle […]

Chrome yellow pigments are mainly used for paints, coil coatings, and plastics. They have a low binder demand and good dispersibility, hiding power, tinting strength, gloss and gloss stability. Chrome yellows are used in a wide range of applications, not only for economic reasons but also on account of their valuable pigment properties. They are […]

In large-scale production, lead or lead oxide is reacted with nitric acid to give lead nitrate solutions, which are then mixed with sodium dichromate solution. If the precipitation solutions contain sulfate, lead sulfochromate is formed as a mixed — phase pigment. After stabilization the pigment is filtered off, washed until free of electrolyte, dried, and […]

The chrome yellow pigments [1344-37-2], C. I. Pigment Yellow 34:77600 and 77603, are pure lead chromate or mixed-phase pigments with the general formula Pb(Cr, S)O4 [3.115] (refractive index 2.3-2.65, density ca. 6 g cm-3). Chrome yellow is insoluble in water. Solubility in acids and alkalis and discol­oration by hydrogen sulfide and sulfur dioxide can be […]

The most important chromate pigments include the lead chromate (chrome yellow) and lead molybdate pigments (molybate orange and molybdate red) whose colors range from light lemon yellow to reds with a blue hue. Chrome yellow, molybdate orange, and molybdate red are used in the production of paints, coatings, and plastics, and are characterized by brilliant […]

Bismuth vanadate pigments are not acutely toxic either on inhalative or oral incorpo­ration. Animal trials gave some indication of inhalational toxicity, which was probably due to the vanadium content. The “no effect level” for rats is 0.1 mg m-3 (exposure: 3 months, 6 h/day, 5 days/week) [3.114]. Toxic effects are observable only when the concentration […]

Bismuth vanadate pigments are used in the manufacture of lead-free, weather re­sistant, brilliant yellow colors for automotive OEM and re-finishes, industrial and обо Fig. 3.13 BiVO4 coatedwithSiO2. decorative paints, and partly for powder coatings and coil-coating systems. In combi­nation with additional pigments, B1VO4 can be used as a basis for important yellow, orange, red and […]

Bi(NO3)3 + NaVO3 + 2 NaOH BiVO4 + 3 NaNO3 + H2O Here bismuth vanadate is produced on combining an alkaline sodium or ammo­nium vanadate solution with an acidic bismuth nitrate solution. An amorphous product, of approximately bismuth-vanadium-oxide-hydroxide is formed in strongly acidic mediums (Figure 3.11). By heating the suspension to reflux and controlling pH, […]

Bismuth vanadate can be synthesized either 1. by solid state processing using the appropriate starting materials, e. g. Bi2O3 and V2O5, or 2. by co-precipitation from aqueous solutions. 1. Solid state reaction [3.105, 3.106, 3.108, 3.109] ВІ20з + V2O5 2 BiVO4