Automotive Coatings Formulation: Chemistry, Physics und Practices

3.5.3.7 Formulations
Table 3.5.2 shows the composition of a typical OEM primer surfacer 
[93]
.
A combination of a flexibilised saturated polyester, melamine resin, and blocked polyisocyanate 
(ratios by weight: 65:20:15) leads to excellent stonechip resistance. Optimum application behav-
iour is controlled with solvents in a balanced ratio of low boiling non-polar (xylene) and polar (n-
butanol and isobutanol) solvents, medium-boiling non-polar (Aromatic 100) and polar (butyl glycol 
Table 3.5.2: Composition of an OEM primer surfacer
Pos.
Component
Solids wt-%
Formulation wt-‰
01
saturated polyester (65 % in aromatic 100. 
BDGA. isobutanol. xylene = 77 : 11 : 6 : 6)
99.1
152.4
02
barium sulphate
182.9
182.9
03
titanium dioxide, rutil
121.9
121.9
04
carbon black
0.6
0.6
05
thickenner
4.3
7.6
06
dispersing agent, soy lecithine
1.5
1.5
07
methoxy propyl acetate
30.5
08
n-butanol
9.1
grind on required fineness, than add:
09
saturated polyester (65 % in aromatic 100, 
BDGA, isobutanol, xylene = 77 : 11 : 6 : 6)
99.1
152.4
10
blocked polyisocyanate (75 % in ar. 100)
isocyanurate-trimer + methyl ethyl ketoxime
45.8
61.0
11
melamin resin (71 %), butanol-etherified
61.0
85.9
12
poly acrylate (25 % in Xylene)
0.5
2.1
13
butyl diglycol acetate
36.6
14
butyl glycol acetate
30.5
15
pine oil
24.4
16
n-butanol
36.6
17
xylene
64.0
sum
616.7
1000.0
characteristic values
application solids (15‘ 165°C) 61,2 %
viscosity (DIN 4/23°C) 
25 sec
viscosity (ISO cup 23°C) 
38 sec