TECHNICAL INFORMATION
ADDITIVES FOR PIGMENT CONCENTRATESL-TI 1

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Additives for pigment concentrates

Contents
03 Pigment concentrates
04 Definition of terms
07 Advantages and challenges of pigment concentrates
08 Selection of raw materials
17 Formulating guideline
20 Preparation of pigment concentrates in lab scale
21 Testing of pigment concentrates

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Pigment concentrates
Pigment concentrates are widely used as intermediates to tint paints orplastics. When producing and utilizing pigment concentrates, multiple
requirements must be fulfilled to achieve optimum performance:• Producability/controllability during production• Reproducibility/stability of quality• Storage stability of the pigment concentrates• Compatibility in different systems• Optimum performance in final application• No negative impact on other parameters and properties
This brochure provides to give an overview of the raw materials for pigment
concentrates, including how to formulate and test them, and how additives
by BYK can help you to get the best performance in the designatedapplications.

Note
To ensure the best appearance
and full functionality, please
open in Adobe Acrobat.

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Additives for pigment concentrates

Definition of terms

Tinting pastes are pigment
concentrates used to adjust thecolor/shade of an alreadycompleted paint formulation. As
usually small amounts are being
used, the possible impact on thequality of the final paint is relatively
minor.

Universal colorants aremainly used in architectural
coatings to tint solvent- andwater-based systems byusing a single colorant series.

A full mixing system is based on
pigment concentrates suitable for
producing complete paints by mixing witheither clear or pigmented (mostly white or
yellow) base paint. Higher amounts ofpigment concentrates need to be added
to the base paint, e.g. compared totinting pastes. Therefore, the impact of
those pigment concentrates on the final
paint properties can be fairly significant.

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Additives for pigment concentrates / Definition of terms

Overview of pigment concentrates used in architectural coatings

Architectural coatings

Tinting system/in-plant tinting

Solvent-borne
systems

Resin-containing

Water-based
systems

Resin-free

POS (point of sale)

Universal
colorants

Resin-free

Solvent-borne
systems

Resin-containing

Water-based
systems

Resin-free

Universal
colorants

Resin-free

G. 01

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Additives for pigment concentrates / Definition of terms

Overview of pigment concentrates used in industrial coatings

Industrial coatings

Tinting system/in-plant tinting

Full mixing systems

Solvent-borne systems

Water-based systems

Solvent-borne systems

Water-based systems

Resin-containing

Resin-containing

Resin-containing

Resin-containing

Resin-free

Resin-free

Resin-free

Resin-free

G. 02

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Additives for pigment concentrates

Advantages and challenges ofpigment concentrates
Highly reliable and versatile coatings can be formulated byusing pigment concentrates, and a variety of differently
colored paints can be produced quickly, flexibly, and efficiently
in short amounts of time and in small batch sizes.

Achieving optimal
pigment concentration of(high-quality) pigments

However, to ensure the optimum performance, meaning
the perfect balance between color variation and durability,
it is vital that the pigment particles in the concentrate are
deflocculated and well stabilized.

Storage stability

Reproducible color in hue
and color strength

The use of wetting and dispersing
additives, rheology additives, anddefoamers by BYK ensures:S uitable rheological flow
behavior (pourable andflowable without settlingand syneresis)

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Additives for pigment concentrates

Selection of raw materials
All raw materials used in the production of pigment
concentrates have to:
Meet the requirement of the highest quality
paint system
Negative influence on durability in highly durable paintsystems will not be accepted; therefore, the selection of the
raw materials needs special attention. For example, if thecross linking in a 2-pack PU system is reduced, the hardness
and durability is influenced.

Be compatible with all let-down systems

Meet regulatory requirements

What is important is the compatibility between:-W etting and dispersing additives and grinding resin;-W etting and dispersing additives and let-down systems(all let-down systems);-G rinding resin and let-down systems (all let-downsystems);- Solvents and grinding resin;- S olvents and let-down systems (all let-down systems)

Compatibility
Grinding resins

Let-down systems

Solvents

Wetting and dispersing additives

Pigments(check recommended usage)
G. 03

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Additives for pigment concentrates / Selection of raw materials

Solvent (or water)

Grinding resin

The optimal solvent or solvent composition is related tothe systems used and the solubility of the grinding resin.
It should balance the compatibility with all systems andviscosity reduction in the pigment concentrate.

For solvent-borne pigment concentrates, grinding resins
based on acrylates, aldehydes, ketones, polyesters, andalkyds are commonly used. Special attention is required interms of the possible negative impact of the grinding resin
on film properties of the final coating.

Example:In a solvent-borne 2-pack PU system, alcohols will havean influence on the crosslinking, while white spirit is notcompatible. The use of esters, ketones, and aromaticsolvents would be possible.

Grinding resins in water-based systems show a stronger
limitation if compared to solvent-borne systems. One notefor the water-based grinding resins: It is of the utmost
importance that only shear stable resins are used.

Optimum grinding resin level:
The optimum resin amount is a balance between
pigmentation, rheology, and influence on the final paintproperties. Generally, the amount of resin in solvent-borne
pigment concentrates has an effect on viscosity, assumingthat pigments are deflocculated and stabilized by wetting
and dispersing additives.

Influence of grinding resin amount in solvent-borne pigment concentrates

Grinding resin amount
Pigment load

Low

High

Viscosity

Increased

Decreased

Paint properties (durability, etc.)

High impact

Low impact

Thixotropic effect with organic pigments

Reduced thixotropic flow behavior

Increased thixotropic flow behavior

Correct balance will lead to a good flow behavior and stabilization of the pigment in the concentrates

G. 04

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Additives for pigment concentrates / Selection of raw materials

Pre-test 1: Grinding resin and let-down systems
In order to evaluate the compatibility, 10 % of the grinding
resin as delivered should be added to the various nonpigmented let-down systems. There should be no turbidity,
gelation (strong increase in viscosity) or precipitation visible
right after incorporation as well as after 24-hours storage
time at room temperature.
Also of importance is the compatibility of resins with the
deflocculating wetting and dispersing additive, therefore
a compatibility test should also be performed.

Pre-test 1: Examples for incompatibility
Precipitation

Separation

Viscosity increase

G. 05

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Additives for pigment concentrates / Selection of raw materials

Pigment
The pigments have to cover the complete color range ofthe product portfolio to allow the mixing of all colors
needed. They have to meet the requirements of the highest
quality system in the range of let-down systems being used.
Also of importance is the stability of the pigment in the media
used (e.g. solvents, let-down systems, etc). If the pigmentshows limited solvent stability (solvent fastness) the usage
should be checked. Only if the pigment is stable in thesolvents used in the pigment concentrates and let-downsystems is it safe to use. Otherwise there could be
problems regarding color stability or viscosity. Besides
solvent stability (solvent fastness), the pH stability is also
important, especially for water-based systems.

Pre-test 2a: Solvent fastness of two organic yellow pigments
in two different solvents
Mineral spirit

Test procedure:• Mix 5 g of pigment and
75 g of solvent (blend)• Store for at least two weeks
at room temperature

XyleneInformation such as solvent fastness, light fastness, andarea of usage normally can be found in the technical data
sheets of the pigment. If solvent fastness is not mentioned,
a simple test can help.
Pre-test 2a: Solvent fastness
The pigment PY 74 can be used in systems which containmineral spirit (white spirit) as solvent, but cannot be usedin systems where aromatic solvents are used (for example:
2-pack PU or baking systems). The pigment PY 155 would
be stable in both solvents. As such, it is the better choicefor pigment concentrates.

PY 74

PY 155

PY 74 No or slight coloration of liquid shows bleeding stability: pigment is stable and safe to use Strong coloration of liquid shows bleeding: pigment is unstable and inappropriate to use

PY 155G. 06

12Additives for pigment concentrates / Selection of raw materials

Pre-test 2b: Solvent fastness of different pigments in one solvent

Suitable   Not suitable

No coloration (or slightcoloration due to small
particles) of the liquid abovemeans no bleeding: it is safe
to use this pigment.

Strong coloration of theliquid above shows bleeding:
do not use this pigment inthat solvent.
G. 07

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Additives for pigment concentrates / Selection of raw materials

Wetting and dispersing additives

Comparison of stabilization mechanisms

BYK’s portfolio includes controlled flocculating anddeflocculating wetting and dispersing additives. What are
the differences and where is the area of usage?

Controlled flocculation
Focus on protection of substrates

Deflocculation
Focus on optical appearance

Mainly for highfilm-build systems:• Gloss reduction possible• Pseudoplasticity, thixotropy• Anti-settling, anti-sagging

Mainly for top coats andpigment concentrates:• High gloss, low haze• Low viscosity,
Newtonian flow behavior• Enhances flow/levelingBest optical properties for top coats including pigment
concentrates will be achieved by deflocculating wetting
and dispersing additives.

G. 08

Comparison of different stabilization mechanisms with regard to viscosity, settling, and syneresis
Settling tendency without anti-settling additive

Viscosity

Shear rate
Flocculation   Controlled flocculation   

Deflocculation

G. 09

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Additives for pigment concentrates / Selection of raw materials

Importance of deflocculation
Primary particles (deflocculation) will show the originalnature of the pigments:• Increased gloss and reduced haze
• Reduced viscosity• Prevention of seeding• Selected color/hue•	Hiding power in case of opaque pigments ortransparency, if nature of pigment is transparent

The selection of a deflocculating wetting and dispersing
additive for pigment concentrates depends on:• The polarity of the grinding resin• The polarity of the let-down systems- Solvent-borne- Water-based- Universal usage• Chemical nature of the pigment

Pre-test 3: Compatibility of wetting and dispersing
additives in grinding resin and let-down systems
In order to evaluate the compatibility, 5 % active substanceof deflocculating wetting and dispersing additive should
be added to the grinding resin and also to the various
non-pigmented let-down systems. There should be no
turbidity, gelation (strong viscosity increase), or precipitation
visible immediately after incorporation as well as after
24-hours storage time at room temperature.

Example: Deflocculated pigment red 101 (red iron oxide)
OpaqueTransparent

G. 10

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Additives for pigment concentrates / Selection of raw materials

Rheology additives
One requirement of a pigment concentrate is long-term
storage stability. This is where rheology additives have asignificant impact. They can be used as an anti-settling
agent or to adjust the final viscosity. Especially deflocculated
high-density (inorganic) pigments or fillers will create astrong tendency to settle. Rheology additives to prevent
settling need to be formulated.

Rheology additives for pigment concentrates

Note:
Resin-free water-based pigment concentrates, even witha high pigmentation, often show low viscosity. Wheretinting systems are concerned, this will be problematic iflight colors have to be tinted. If lower pigmentation isrequired, a rheology additive will help to adjust the viscosity.

LAPONITE
Synthetic phyllosilicates

Rheology additives, e.g. based on polyurea (product codes:
RHEOBYK-D 4xx or RHEOBYK-74xx) or on phyllosilicates,
help to adjust the viscosity in various systems.
Particularly for universal colorants including thickeners, it isof upmost importance to evaluate the interdependency onwater-based as well as on solvent-borne systems.

Solvent

Water

Universal

GARAMITE
Organophillic phyllosilicates
RHEOBYK-D 4xx and RHEOBYK-74xx
Polyurea

OPTIGEL
Modified phyllosilicates
BYK-AQUAGEL
Modified phyllosilicates
T. 01

Influence of rheology additives on colorant acceptance
Negative influence

No influence

G. 11

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Additives for pigment concentrates / Selection of raw materials

DefoamerIf the defoamer, which is used in
the pigment concentrate, is too
incompatible, it might affect thegloss, haze, or disturb the leveling(e.g. tendency to crater).

Foam formation during the grinding process influences thegrinding efficiency. Therefore, especially water-based
pigment concentrates need a defoamer with a good balance
between efficiency and compatibility. During the complete
grinding process, the additive should de-aerate and defoam
the pigment concentrate. During the final application, thedefoamer should not influence the paint performance andpaint quality. If the defoamer, which is used in the pigment
concentrate, is too incompatible, it might affect the gloss,
haze, or disturb the leveling (e.g. tendency to crater).
In solvent-borne pigment concentrates, foam tendency is
not that strong, so defoamers are rarely used.
Water-based pigment concentrates (either only for waterbased systems or as universal colorants) need a defoamer
during the grinding phase. In the coating industry, the trend
towards environmentally-friendly systems pushes theformulator to use mineral-oil-free defoamers such as silicone
or polymeric defoamers.
For some formulations with a special purpose, the additionof a defoamer after the milling process is required. It is notnecessarily important to use the same defoamer as usedduring milling.

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Additives for pigment concentrates

Formulating guideline
The correct combination of pigment binder ratio andadditive dosage will provide a good balance between
pigmentation, viscosity, stabilization, and storage stability.

The following pages show some examples with different
grinding resins and different usage areas.

Architectural coatings (1/2)

Example: Solvent-borne pigment concentrates based on high solid alkyd resin

Example: Solvent-borne pigment concentrates based on alkyd resin

Pigment : binder ratio(solids : solids)

Additive dosage in %(solids on pigment)

Titanium dioxide

2.0 – 2.5 : 1

2–3

Organic yellow

0.4 – 0.5 : 1

Inorganic yellow

Pigment : binder ratio(solids : solids)

Additive dosage in %(solids on pigment)

Titanium dioxide

4.0 – 5.0 : 1

2–3

15 – 25

Organic yellow

3.0 – 3.5 : 1

15 – 25

0.8 – 1.0 : 1

7–9

Inorganic yellow

4.0 – 5.0 : 1

7–9

Organic orange

1.0 – 1.2 : 1

18 – 25

Organic orange

1.0 – 1.5 : 1

18 – 25

Organic red

0.4 – 1.0 : 1

18 – 23

Organic red

1.5 – 2.0 : 1

18 – 23

Inorganic red

2.5 – 2.8 : 1

8 – 12Inorganic red

4.5 – 5.0 : 1

8 – 12

Organic red violet (magenta)

0.2 – 0.4 : 1

25 – 35

Organic red violet (magenta)

1.0 – 1.5 : 1

25 – 35

Organic violet

0.2 – 0.4 : 1

30 – 40

Organic violet

1.0 – 1.5 : 1

30 – 40

Phthalo blue

0.2 – 0.3 : 1

20 – 30

Phthalo blue

0.9 – 1.3 : 1

20 – 30

Phthalo green

0.2 – 0.3 : 1

25 – 35

Phthalo green

0.9 – 1.3 : 1

25 – 35

Coarser carbon black (e.g. Lamp black 101)

0.3 – 0.4 : 1

25 – 40

Coarser carbon black (e.g. Lamp black 101)

0.7 – 1.0 : 1

25 – 40

Carbon black (e.g. Special black 4)

0.3 – 0.4 : 1

30 – 50

Carbon black (e.g. Special black 4)

0.7 – 1.0 : 1

30 – 50

T. 02

T. 03

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Additives for pigment concentrates / Formulating guideline

Architectural coatings (2/2)

Example: Water-based, resin-free pigment concentrates

Example: Water-based, resin-free universal colorants(solvent- and water-based applications)
Additive dosage in %(solids on pigment)

Additive dosage in %(solids on pigment)

Titanium dioxide

1–3

Titanium dioxide

2–5

Organic yellow

15 – 25

Organic yellow

10 – 15

Inorganic yellow

7–9

Inorganic yellow

6–7

Inorganic yellow transparent

20 – 25

Organic orange

15 – 20

Organic orange

15 – 20

Organic red

15 – 20

Organic red

17 – 20

Inorganic red

5–7

Inorganic red

5–7

Organic red violet (magenta)

25 – 30

Inorganic red transparent

25 – 28

Organic violet

35 – 40

Organic red violet (magenta)

30 – 35

Phthalo blue

25 – 35

Organic violet

30 – 35

Phthalo green

15 – 25

Phthalo blue

20 – 30

Coarse carbon black (e.g. Lamp black 101)

35 – 40

Phthalo green

25 – 30

Medium carbon black (e.g. Special black 4)

30 – 40

Coarse carbon black (e.g. Lamp black 101)

35 – 45

Medium carbon black (e.g. Special black 4)

40 – 50

T. 05

T. 04

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Additives for pigment concentrates / Formulating guideline

Industrial coatings

Example: Solvent-borne pigment concentrates based on aldehyde resin

Example: Water-based pigment concentrates (resin-free or resin-containing)

Pigment : binder ratio(solids : solids)

Additive dosage in %(solids on pigment)

Titanium dioxide

4.5 – 5.0 : 1

2–4

Titanium dioxide

3–5

Titanium dioxide, transparent

1.0 – 2.0 : 1

15 – 20

Titanium dioxide, transparent

20 – 25

Organic yellow

3.0 – 3.5 : 1

15 – 20

Organic yellow

15 – 20

Inorganic yellow

4.0 – 5.0 : 1

7 – 10Inorganic yellow

7 – 10Inorganic yellow, transparent

1.0 – 2.0 : 1

15 – 20

Inorganic yellow, transparent

20 – 25

Organic orange

1.0 – 2.5 : 1

15 – 35

Organic orange

15 – 30

Organic red

1.0 – 2.5 : 1

20 – 30

Organic red

15 – 30

Inorganic red

4.0 – 5.0 : 1

8 – 12Inorganic red

7 – 12Inorganic red, transparent

1.0 – 2.0 : 1

15 – 20

Inorganic red, transparent

20 – 25

Organic red violet (magenta)

1.0 – 1.2 : 1

15 – 45

Organic red violet (magenta)

25 – 35

Organic violet

1.0 – 1.2 : 1

25 – 40

Organic violet

25 – 35

Phthalo blue

0.9 – 1.3 : 1

20 – 40

Phthalo blue

20 – 40

Phthalo green

0.9 – 1.3 : 1

20 – 35

Phthalo green

25 – 35

Coarser carbon black (e.g. Lamp black 101)

0.5 – 1.0 : 1

15 – 30

Coarse carbon black (e.g. Lamp black 101)

30 – 40

Carbon black (e.g. Special black 4)

0.5 – 1.0 : 1

30 – 50

Medium carbon black (e.g. Special black 4)

50 – 70

Fine carbon black (e.g. FW 200, Raven 5000 Ultra)

0.3 – 0.5 : 1

50  –  90

Fine carbon black (e.g. FW 200, Raven 5000 Ultra)

60 – 90

T. 06

Additive dosage in %(solids on pigment)

Note: Resin-containing water-based concentrates include around 5–15 % solid resin

T. 07

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Additives for pigment concentrates

Preparation of pigment
concentrates in lab scale
1. Premix grinding resin (solution), solvent/water andwetting and dispersing additive
2. Add rheological modifier/anti-settling additive, if needed
3. Add pigment, pre disperse for 10–15 minutes
4. Perform grindinga. Inorganic pigments: high-speed mixer, bead,pearl, or sand millb. Organic pigments: bead, pearl, or sand millVortex effect(doughnut effect)

It is important for grinding that the mill base shows
the so-called vortex effect (doughnut effect) during thecomplete grinding process.
BYK starting formulations are tested on our lab scale
grinding equipment. Various grinding equipment is available
on the market for lab scale or production. Therefore, theformulations must be adapted to the specific grinding
equipment and let-down system.

An animation of
the vortex effectcan be found online.

Important
A uniform flow of the mill basewhich will be ground should
be ensured during the entire
dispersing process.

G. 12

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Additives for pigment concentrates

Testing of pigment
concentrates
The success of a sufficient dispersion can be checked via
grinding gauges (Hegman gauges), as this test indicates thepresence or absence of oversized agglomerates and thus
improper dispersion. However, this test method does notindicate whether the pigments are properly deflocculated
and stabilized against re-agglomeration, as the primaryparticles of organic pigments or inorganic pigments such asiron oxide red are way below 1 µm and cannot be seen in atest with a grinding gauge. There are several test methods
that indicate sufficient dispersion and stabilization of apigment concentrate by testing them within a coating
system and measuring various properties.
Possible tests are:
• Viscosity measurement• Color/hue evaluation- Color strength- Determination of color shift/visual assessment, page 22- Rub-out test for color stability(flooding and floating), page 23- Colorant acceptance, page 25

Physical properties:• Gloss• Haze• Seeding• Durability test
• Weather resistance• Substrate adhesion or intercoat adhesion• etc.
• Particle size, page 26• Storage stability, page 27

22Additives for pigment concentrates / Testing of pigment concentrates

Determination of color shift/visual assessment
In full shades, where a pigment concentrate is incorporated
into a clear coat formulation, a visual assessment can be
performed to indicate if the pigments are properly dispersedand stabilized.
For transparent pigments, their state of deflocculation isindicated by the transparency of the coating. When thepigments are flocculated, they scatter the transmitted lightwhich results in a visible turbidity.

Additionally, the color shift visible in the comparison of
two samples can indicate whether or not the pigments arestabilized. If pigments are flocculated, the light is reflectedwith a slightly different wavelength compared todeflocculated pigments. This leads to a color shift/shift inhue between the samples. To determine the stabilization,a color diagram can be used.

It is read in the following way: green pigments appear morebluish when they are deflocculated and more yellowish if
they are flocculated, red pigments appear more blueish
when flocculated and more yellowish when deflocculated.

Color shift of different pigments caused by flocculation/deflocculation
OpaqueTransparent

Deflocculated

Flocculated

Deflocculation

Deflocculation of a red pigment shows a color shift in the
direction of yellow.

In transparency, deflocculation of a green pigment shows a color shift
towards blue, in addition to an improvement in transparency.

G. 13

Flocculation

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Additives for pigment concentrates / Testing of pigment concentrates

Rub-out test
The basic principle behind the rub-out test is to check
whether or not the pigment is properly stabilized. The
pigment concentrate is not tested directly, but incorporated
into a let-down system to obtain either a full-shade system(one single pigment) or a color blend system (containing
the pigment concentrate to be tested and a stable second
pigment, such as titanium dioxide). The paint is appliedand allowed to dry. During drying, the improperly stabilized

pigments agglomerate, which leads to a change in hue.
Before the paint dries completely, the surface is rubbed
with a finger, either from side to side or in a circle, which
redisperses the pigments with the shear force of the rubbing(see G. 14). This can lead to a significant change in color
compared to the unrubbed area, and indicates thereagglomeration of the pigment.

The correct time to perform the test is when the paint isalmost dry but still tacky. If your finger leaves marks on thepaint surface, it is an indication that this is the rightmoment to conduct the rub-out test.

Full shade of opaque PR 101 with rub-out test
Flocculated

Deflocculated

ΔE of rub-out = 6.90

ΔE of rub-out = 0.18

Unrubbed area

Rub-out simulates thedispersion process –pigments are re-dispersed

Rubbed area

Iron oxide is the only
known pigment whichshows flooding andfloating in a full shade(pure tone) when arub-out test is performed.

Remark ΔE measurement:
Due to the uneven surface at the rubbed area, it is recommended to use color measurement equipment with sphere geometry (d8°).

G. 14

24

Additives for pigment concentrates / Testing of pigment concentrates

Rub-out test in color blends
If all full shades in every let-down system show good
performance, a color blend should be tested. As a firststep, one color blend with white is recommended foreach system.

Example:•	Let-down system 1+ T itanium dioxide
concentrate+ Iron oxide redconcentrate• Let-down system 1+ T itanium dioxide
concentrate+ Phthalo green
concentrate• Let-down system 1+ Titanium dioxide
concentrate+ … concentrate• Let-down system 2+ Titanium dioxide
concentrate+ Iron oxide redconcentrate• Let-down system 2
	+ Titanium dioxide
concentrate+ … concentrate• Let-down system 3 + ...
and so on.

For all these mixtures (white reduction or white mixtures),a rub-out test after the application should be performed.
Only if there is no color difference (ΔE depends onrequirements), an additional test, such as a storage test,
should be performed. If one or more system/concentrateshows a strong color difference, an improvement in results
is needed and a cross-check in every system/color must be
carried out.
Therefore, it is recommended to start only with titanium
dioxide concentrate and three additional colored pigment
concentrates (e.g. iron oxide red, organic pigment, andcarbon black).

White reduction
PR 101 pigment concentrate in one let-down system
White reduction 1

PW 6: Insufficiently stabilized
PR 101: Insufficiently stabilized

White reduction 2

PW 6: Insufficiently stabilized
PR 101: Stabilized

PW 6: Stabilized
PR 101: Insufficiently stabilized

PW 6: Stabilized
PR 101: Stabilized

G. 15

25

Additives for pigment concentrates / Testing of pigment concentrates

Colorant acceptance
The stabilization of pigments and the compatibility of
the colorant in the base paint can be determined by thecolorant acceptance test.
In this test, two samples are compared with each other.
For the first sample, the colorant is incorporated into thebase paint at low shear forces (e.g. stirring by hand), forthe second sample, it is incorporated at significantly higher
shear forces, e.g. using high-speed dispersion equipment
or a paint shaker.

Both paints are applied onto a suitable substrate, and a
rub-out test is carried out. If the colorant is sufficiently
stabilized and compatible, the rub-out test should show
a good result in both samples. If a difference can be seen
between the high shear force and the low shear force
sample, the colorant should be checked for stability orcompatibility with the base paint.

Incorporation of pigment concentrates into thebase coat with different shear forces

Low shear force

High shear force

versusStirring

orPaint shaker

High-speed dispersing

G. 16

26

Additives for pigment concentrates / Testing of pigment concentrates

Particle size
The state of flocculation/deflocculation and the resulting
particle size can be directly observed using a microscope.
However, this observation cannot be carried out directlywith the pigment concentrate. It needs to be incorporated
into the base paint first, and the base paint then diluted
with two to four parts of the solvent that is used in thepaint system. Depending on the size of the agglomerates,
it can be checked whether the pigment particles areflocculated or deflocculated.

You can findthe particle size
video online.

Evaluation of particle size by microscope

Flocculated

Deflocculated

G. 17

27

Additives for pigment concentrates / Testing of pigment concentrates

Storage stability
Pigment concentrate will not be used up completely after
production, therefore it is important that the concentrates
show good results both before and after storage. It is
recommended to test stored pigment concentrates in thesame way as conducted during the evaluation (full shades:
color drift, gloss haze, seeding, and white reductions/white
mixtures: rub-out, color strength, gloss, haze, and colorantacceptance).

Storage stability tests – Determination of required actions
Results of lab scale

ActionBefore storage

After storage

Good

Bad

• Adjust the pigment concentrate formulation

Good

Good

• Start pilot plant production• Evaluate mixing ratios for required mixing colors
T. 08

04/2023
L-TI 1

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BYK®-SILCLEAN®, BYKANOL®, BYKCARE®, BYKETOL®, BYKJET®, BYKO2BLOCK®, BYKONITE®, BYKOPLAST®, BYKUMEN®, CARBOBYK®, CERACOL®,CERAFAK®, CERAFLOUR®, CERAMAT®, CERATIX®, CLAYTONE®, CLOISITE®, DISPERBYK®, DISPERPLAST®, FULACOLOR®, FULCAT®, GARAMITE®,GELWHITE®, HORDAMER®, LACTIMON®, LAPONITE®, MINERPOL®, NANOBYK®, OPTIBENT®, OPTIFLO®, OPTIGEL®, POLYAD®, PRIEX®, PURABYK®,
PURE THIX®, RECYCLOBLEND®, RECYCLOBYK®, RECYCLOSSORB®, RECYCLOSTAB®, RHEOBYK®, RHEOCIN®, RHEOTIX®, SCONA®, SILBYK®, TIXOGEL®
and VISCOBYK® are registered trademarks of the BYK group.
The information herein is based on our present knowledge and experience. The information merely describes the properties of our products but noguarantee of properties in the legal sense shall be implied. We recommend testing our products as to their suitability for your envisaged purpose prior touse. No warranties of any kind, either express or implied, including warranties of merchantability or fitness for a particular purpose, are made regarding
any products mentioned herein and data or information set forth, or that such products, data or information may be used without infringing intellectual
property rights of third parties. We reserve the right to make any changes according to technological progress or further developments.
This issue replaces all previous versions.