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Effect of additives on color troubles
Overview
It is well known that paint systems consisting of multiple pigments differing in particle size, densityand degree of flocculation are liable to suffer from color troubles such as flooding or floating that
occurs in the films applied by spraying and flow ( dip) coating.
In order to avoid these color troubles, the use of an anti-flooding/floating agent is generally
recommended. An anti-flooding/floating agent is a combination o f a pigment dispersant and a surface
control agent.
This paper discusses the mechanism how to eliminate these color troubles in paint containing two
different types of pigments.

1. Introduction
Pink paint consistingofwhite paint and red paint tends to suffer from color troubles such as flooding
and floating when the coating is applied by spraying or flow ( dip ) coating. Use of a pigment
dispersant would prevent flooding, but would not stop floating. A surface-control agent would be
effective only in preventing floating.
Howeverananti-flooding/floating agent which functionsasadispersantandasurface-control agent at
the same time would prevent both flooding and floating.

2. Examples
2-1. Prevention offloodingandfloating.
Effectivenessoftheanti-flooding/floating agent can be observed in photo No.1.
The sample withnoadditivesshows both flooding and floating ( panel A) .
In the formula containing dispersant Disparlon 2150, floodinghasdisappeared, but floating ( silking )is present ( panel B) .
In the formula with a surface control agent silicone, floatinghasdisappeared, but flooding is present( panel C) .
Anti-flooding/floating agent Disparlon 2200, a combination of dispersant and silicone, has prevented
both flooding and floating ( panel D).
Photo No.1.

panel ( A )Controlled

Prevention of flooding and floating

panel ( B)panel ( C )2150

silicon( Dispersant)( Surfacecontrolagent)panel ( D )2200(Anti-flooding/floatingagent )-22-2. Prevention of Benard Cells.
Influence of theadditives on Benard Cells formation is illustrated in photo No.2.
While the formula without any additives ( spot A) and that with Dispersant Disparlon 2150 ( spotB) allowed the appearance of Benard Cells, use of silicone ( spot C) and anti-flooding/floating
agent Disparlon 2200 ( spot D) effectivelyprevented Benard Cells from appearing.
Crosssectional views of the paint spots under a microscopearegiveninphotoNo.3.
When observed carefully, spot A showed circulatory or vortex flows in the film while it was wet aswell assome flocculation of redpigment.
On the other hand, the anti-flooding/floating agent prevented the occurrence of such circulation
currents and also contributed to the improved pigment dispersion ( spot D).
Photo No.2.

Prevention of Benard Cells.

Spot ( A )Spot ( B)2150

Spot ( C )siliconControlled(Dispersant)(Surfacecontrolagent)

Photo No.3.

Spot ( D )2200( Anti-flooding/floatingagent)

Cross sectional viewsofpaintspots

Controlled

Disparlon2200
Anti-flooding/floating agent

Spot ( A)

Spot ( D)

2-3. Prevention ofSilking.
The effect ofsomeproductsonsilkingisshownin photo No.4 ( E, F, G, H).
As was the case with the Benard Cells experiment, no difference was seen between the-no-additives
formula ( panel E) and the formula with Disparlon 2150 ( panel F ) in terms of silking. However,the use of silicone ( panel G) and Disparlon 2200 ( panel H) effectively prevented silking.
Photo No.4.
Panel E
Controlled

Prevention of silking
Panel F
2150
Dispersant

-3Panel G
silicone
Surface control
agent

Panel H
2200
Anti-flooding/floating agent

3. Conclusion
The wordcolor troubles
is a general term referring to various phenomenon that can occur inapplied films, among which flooding and floating are predominant. Fig.1. represents the simplified
models of these twophenomenon.
Flooding is a term describing the difference in color between the surface of a film and underlying
layers. The color density of the surface changes depending on the shear strength given to the paint( during the sprayingordipping process) .
The main cause of flooding is insufficient dispersion stability of pigmentsused.
Floating is a termdescribing the unevenness of color observedonthefilmsurfacethathasaspottedor molted appearance. The main causeofthisunevennessofcolorisseparation of different pigmentsthat can occur during solvent evaporation, which leads to the formation of Benard Cells.
Fig.1 Schematic illustrationoftwotypesofpigmentseparationrepresentingcolortroubles

Flooding

Floating

Our anti-flooding/floating agent Disparlon 2200 consists of a pigment dispersant Disparlon 2150
based on an aliphatic polycarboxylic acid and a specially prepared silicone that works as a surface
control agent.
Relations between an anti-flooding/floating agent anddifferent color troubles are shown inFig.2.
1. A dispersant can prevent flooding by stabilizing pigment dispersion through modification o f t h eelectrical chargeofpigmentsbutdoesnotwork to prevent floating.
2. A surfacecontrol agent canprevent floating by checking Benard Cell formation, but does notwork toprevent flooding.
3. An anti-flooding/floating agent functioning both as a dispersant and as a surface control agent can
prevent both flooding and floating.
Fig.2

Color troubles and anti-flooding/floating agent

Flooding

Floating

Eliminated by stabilizing
dispersion

Eliminated by preventing
Benard Cell formation

Dispersant

Surface control agent

Anti-flooding/floating agent
Copyright 1999. Kusumoto Chemicals,Ltd. Allright Reserved.