Automotive Coatings Formulation: Chemistry, Physics und Practices

 
topcoat
 
batch, 
comparing the result with the requisite colour, and 
calculating the quantity of pigment pastes needed 
for adjustment. The production process requires 
that pigment pastes be available in adequate 
quantities – in terms both of number to cover all 
possible colours and of quantity to cater for all pos-
sible batch sizes. The pigment pastes must offer 
excellent storage stability and may not change 
their dispersion state or their colour strength. 
Furthermore, it must be remembered that,
 
when 
specific quantities of pigment pastes are added for 
Table 3.6.3: Specific densities of pigments
Pigments
Densities
[g/cm³]
White
titanium dioxide. rutil
4.0 – 4.2
Yellow
yellow iron oxide
3.7 – 4.1
nickel titanium yellow
4.4 – 4.6
chromium titanium yel-
low
4.3 – 4.5
bismuth vanadate
5.5 – 5.6
Ni-Azocomplexes
1.6 – 2.0
anthrapyrimidines
1.5 – 1.6
isoindolinones
1.8 – 2.1
Red
red iron oxide
4.5 – 5.2
naphthol AS-reds
1.4 – 1.5
perylenes
1.5 – 1.7
thioindigos
1.7 – 2.1
chinacridones
1.5 – 1.7
dioxazines
1.5 – 1.9
Blue
cobalt blue
3.8 – 4.3
indanthrene blue
1.4 – 1.6
phthalocyanine blue (Cu)
1.6 – 1.7
phthalocyanine blue
1.4
Green
chromium oxide green
5.0 – 5.2
cobalt green
4.9 – 5.5
phthalocyanine green
1.9 – 2.9
Black
carbon blacks
1.8
Topcoats

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adjustment purposes, the corresponding quantities of let-down components must be adjusted in 
order that a change in of film properties which depend on the optimum composition may be ruled 
out. This can be circumvented by preparing tinting coats. Tinting coats are topcoats containing 
only one pigment, as well as all the other ingredients in the right combinations necessary for 
ensuring topcoat