Zinc Pigments

Zinc dust is produced from primary or secondary zinc metal by evaporation. The generated zinc vapor is condensed under controlled conditions under exclusion of air followed by sieving processes in order to obtain different particle size fractions [5.105]. The particle sizes of zinc dust are normally in the range 2 to 8 pm [5.105]. A product classed as fine quality shows a typical particle size of 3 pm whereas standard quality has particle size 8 pm [5.105]. [Pg.226]

While the correct loading level of zinc dust in primers is still a matter of debate, these primers normally have a zinc dust content of more than 80% in the dry paint film [5.53, 5.105]. The requirements of test methods for zinc dust pigments suitable for use in protective coatings are specified in ISO 3549 - Zinc dust pigments for paints - Specifications and test methods [5.106]. [Pg.226]

Zinc dust coatings are utilized in large quantities for the protection of structural steel, also including underwater steel construction and ship building [5.56]. Zinc dust is used in organic and inorganic binder systems (alkali silicates, ethyl silicates) [5.56, 5.105]. [Pg.226]

Zinc as a pigment for application in protective coatings is also available in the form of zinc flakes with a lamellar particle shape. Zinc flakes are mainly used in so-called [Pg.226]

Another question is the proper technique for the evaluation of protective properties of zinc pigmented coatings. IMtll now, the most popular one is the test in a salt chamber (12.141. This technique does not allow a complete understanding of the complex phenomena oo-ouring in the coating. It seems that the impedance technique selected in this work provides more adequate and useful data. [Pg.230]

It was decided to carry out modifications of the highly zinc pigmented psdnt using the impedance technique to test the protective properties. Steel electrodes with the following coatings were tested ... [Pg.230]

SZAUER AND MlSZCZYK Performance of Zinc-Pigmented Coatings... [Pg.231]

C - standard highly zinc pigmented paint modified b substitution of 3 % of zinc b y zinc phosphate. ... [Pg.231]

In the case of electrode B the oonductlve carbon black was used with the purpose to Influence the cathodic protection period. The modification C was made with zinc phosphate to Influence the second step In protective action of zinc pigmented coatings. [Pg.231]

Flmre 1. Electrode potential vs. Immersion time In 3 jb NaCl solution and Impedance diagrams for steel electrodes with unmodified zinc pigmented coatings. [Pg.231]

It has been found that protective properties of zinc pigmented coatings can be enhanced b using zinc phosphate as an additive Influencing the performance of the coatings In the second stags of their protective action. [Pg.233]

Negative results have been obtained with oarbon black as an additive Intended to Improve protection properties of zinc pigmented coatings b Influencing the first stage of their protective action. [Pg.233]

Flake zinc pigments have a barrier effect and also act by a cathodic anticorrosive mechanism. Compared with zinc dust coatings, flake zinc pigments are formulated with lower pigment volume concentrations [5.178]. [Pg.209]

Flake Zinc Pigments. Flake zinc pigments are used mainly as high-quality anticorrosive pigments in powder or paste form. Owing to their platelet structure they have a considerably higher surface area than spherical zinc dust particles. They can... [Pg.230]

The flake zinc pigments give a considerably brighter, better metallic effect than zinc dust. Their appearance can be further improved by combining them with aluminum pigments or by applying a topcoat based on aluminum pigment. [Pg.231]

Another widespread application for flake zinc pigments is the coating of small articles with complex shapes (e.g., screws, steel springs, bolts, rivets) and for special anticorrosive paints (Section 5.2.11.1). [Pg.231]

These coatings give the most effective corrosion protection. They contain high volumes of zinc pigment and are exclusively used as primers. The steel is protected... [Pg.92]

The presence of strongly electronegative zinc-pigmented coating short circuits all local cell activity on steel. The steel becomes totally cathodic to the anodic zinc coating. The zinc corrodes, but the steel will not corrode even at bare spots, it is mandatory that the zinc coating be in electrical contact with the steel surface therefore, the steel must be stropped of all contamination. [Pg.92]

Zinc sulfide Min. Yrbk., Lead and Zinc Pigments Tappi 12-49 24A... [Pg.87]

Zinc oxide pigments Zinc pigments zinc yellow and zinc sulfide... [Pg.447]

Nickel oxide-zinc batteries Flaked zinc pigment Electroplating Alloys... [Pg.70]

VDA 621-415 Wet/dry and humidify cycling. High time of wetness, poor correlation for zinc pigments and galvanized steel. Also used for testing heavy in structure paints... [Pg.571]

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