The document outlines the properties and applications of various liquid rheology additives, particularly focusing on specific products like BYK-410, BYK-411, BYK-420, BYK-425, BYK-430, and BYK-431. It discusses rheological behavior including viscosity, pseudoplastic and thixotropic flow, as well as compatibility and effectiveness in different systems, such as polar and non-polar environments. Additionally, it highlights techniques for improving compatibility and efficiency in various applications including paints and coatings.

1. Liquid Rheology Additives
Wesel, August 2007, Andreas Freytag

2. Newton’s Two Plate Model
Force (F)
Area (A)
Velocity (v)
Distance (d)
τ (Pa) = shear stress
(force / area)
D(1/s) = shear rate
(velocity / distance)
η= τ / D η = viscosity (Pa·s)
(resistance against flow)
07/03/12, Page 2, Rheology Additives

3. Viscosity Curve
viscosity η
newtonian: η = const.
pseudoplastic flow: η = f (D)
(shear thinning)
shear rate D
07/03/12, Page 3, Rheology Additives

4. Thixotropy Curve
viscosity η is time dependent:
Viscosity η
D = const. D=0 viscosity η
Time t shear rate D
07/03/12, Page 4, Rheology Additives

5. Viscosity Profile
Viscosity (Pa·s)
η
100 Storage Transportation Production
Leveling Stirring Application
10 Sagging
Settling
Rotational viscometer
Brookfield
1 Flow cup 4 mm ICI
cone/plate
0,1
0,001 0,01 0,1 1 10 100 1000 10000
shear rate D (1/s)
07/03/12, Page 5, Rheology Additives

6. Liquid Rheology Additives: Differentiation
Polar systems
BYK-411 BYK-410 BYK-420 BYK-431 BYK-430 BYK-425
Non-polar systems
Thixotropic flow : Pseudoplastic flow :
• Slower structure recovery • Faster structure recovery
after shear after shear
 good for leveling and air release  excellent sag resistance
• Anti-settling • Anti-settling
• Pronounced shear-thinning
07/03/12, Page 6, Rheology Additives

7. BYK-410, BYK-411, BYK-420:
Thixotropy Additives Based on Modified Urea
BYK-410
BYK-411
BYK-420
Urea groups
Modifying groups :
High polarity Medium polarity Low polarity
07/03/12, Page 7, Rheology Additives

8. Mode of Action
Incorporation
under stirring Active substance
precipitates in form
of micro crystals
Structure formation
Network build up via hydrogen bondings
Result: Strong thixotropic flow behavior
07/03/12, Page 8, Rheology Additives

9. Structure Formation Through Hydrogen Bonding
O
C
N
N
H H
O
C
N Hydrogen bonding via urea groups
N
H H
07/03/12, Page 9, Rheology Additives

10. BYK-410: Efficiency Depends on Polarity of System
too non-polar Compatible too polar
White spirits Diacetone alcohol Isopropanol
Xylene Butanol Water
Isobutanol
Butylglycol
Butylacetate
Propylenglycol-
Monomethylether
Suitable solvent mixtures:
Xylene / n-Butanol = 80 / 20
Butyl acetate / Dowanol PM = 75 / 25
07/03/12, Page 10, Rheology Additives

11. BYK-410: Compatibility Adjustment
Compatibility
improvement
1. Addition of BYK-410 to the possible using
non-pigmented formulation solvents with
(homogeneous mixing) suitable
polarity
2. Compatibility test
visual judgement of compatibility Particles /
(particles / seeds) and seeds visible
rheological effect
Compatibility
is acceptable,
No particles / no seeds and
no formulation
rheological effect
changes are
necessary
07/03/12, Page 11, Rheology Additives

12. BYK-411: Rheology Control in Low Polar Resins
• No effect in pure solvents,
requires resin
• Structure formation via hydrogen
bonding and associative
interactions
Control 1 % BYK-411
07/03/12, Page 12, Rheology Additives

13. BYK-411: Compatibility Test
Resin + BYK-411
homogenize
Compatible Incompatibility
+ +
effective no effect
Resin is
Resin is not suitable !
suitable ! Improvement is
not possible !
07/03/12, Page 13, Rheology Additives

14. BYK-420: Rheology Control in Aqueous Systems
Homogenous, rapid incorporation: Inhomogenoues incorporation:
excellent thickening effect no thickening effect
homogenoues, no particles inhomogenoues, particles
07/03/12, Page 14, Rheology Additives

15. BYK-420 in Aqueous Effect Pigment Slurry
1. Water 50,0 – 68,7
2. Co-solvents 5,0 – 10,0
(e.g., glycols and glycol ethers)
• DISPERBYK-190 or
DISPERBYK-192 1,0 – 3,0
• Effect pigment 25,0 – 35,0
5. BYK-420 0,3 – 1,0
(incorporation under stirring)
07/03/12, Page 15, Rheology Additives

16. BYK-420: Effective Thickening of Pure Water
150
BYK-420 1% active loading
Acrylate thickener 1% active loading
Pa s
Synthetic clay 1% active loading
100 Natural clay 2% active loading
Fumed silica 5% active loading
Viscosity
50
0
0,05 0,1 0,2 0,5 1 2 5 10
shear rate D(1/s)
07/03/12, Page 16, Rheology Additives

17. BYK-420: Compatibility Test
Compatibility
improvement
1. Addition of BYK-420 to the possible using
non-pigmented formulation co-solvents and
(homogeneous mixing) wetting/dispersing
additives
2. Compatibility test
visual judgement of compatibility Particles /
(particles / seeds) and seeds visible
rheological effect
Compatibility
is acceptable,
No particles / no seeds and
no formulation
rheological effect
changes are
necessary
07/03/12, Page 17, Rheology Additives

18. Liquid Rheology Additives: Differentiation
Polar systems
BYK-411 BYK-410 BYK-420 BYK-431 BYK-430 BYK-425
Non-polar systems
Thixotropic flow : Pseudoplastic flow :
• Slower structure recovery • Faster structure recovery
after shear after shear
 good for leveling and air release  excellent sag resistance
• Anti-settling • Anti-settling
• Pronounced shear-thinning
07/03/12, Page 18, Rheology Additives

19. BYK-425: Pseudoplastic Flow in Aqueous Systems
Conventional
PU thickener
Urea modification
BYK-425
• Urea modified polyurethane
• dissolved in polypropylene glycol
urea hydrophobic
groups groups
07/03/12, Page 19, Rheology Additives

20. BYK-425:
Association via Hydrophobic Groups and Hydrogen Bonding
Latex
07/03/12, Page 20, Rheology Additives

21. BYK-425: No Effect in Pure Water
BYK-420 Dosage:
2 % active substance
viscosity (Pa*s)
BYK-425
shear rate (1/s)
07/03/12, Page 21, Rheology Additives

22. BYK-425: Strong Effect With Resin
Acrylate emulsion
Johncryl SCX 8280
Additive dosage :
0,2% effective substance
Control
BYK-425
BYK-420
PU thickener
Viscosity (Pa*s)
shear rate (1/s)
07/03/12, Page 22, Rheology Additives

23. BYK-425: Advantages
• Thickener with broad universal compatibility in various aqueous binder systems
• Post addition possible
• Easy to handle
- no pH adjustments necessary
- can be diluted with water
• No negative influence on film properties
• VOC-free, APEO-free
• No higher costs compared to common thickeners
• Dependant on system two to three times more effective
07/03/12, Page 23, Rheology Additives

24. BYK-430 / BYK-431 Chemical Structure
High molecular weight urea modified polyamides
BYK-430
BYK-431
Urea groups
Polyamide
Compatibility enhancing structures (alkyl, polyether)
07/03/12, Page 24, Rheology Additives

25. Conventional Rheology Additives: Pastes or Powders
Organo clays Polyamide paste Polyamide powder
07/03/12, Page 25, Rheology Additives

26. BYK-430 / BYK-431: Easy Incorporation
Efficiency %
BYK-430/BYK-431 (liquid)
100
No seeding
60
40
Polyamide
(powder/paste)
20
Seeding
20 30 40 50 60 70
Incorporation temperature °C
07/03/12, Page 26, Rheology Additives

27. BYK-430 / BYK-431: Application Areas
Non-polar systems Polar systems
BYK-430
BYK-431
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BYK-431: M BYK-430:
- Architectural paints -Recommended for solvent-borne high
- Refinish coatings and primers build systems
- Protective / marine coatings
- Industrial coatings
e.g. : e.g. :
- Alkyds, polyesters - 2-pack epoxy top coat
- Thermoplastic acrylates - 2-pack coal tar epoxy
- Epoxy primers
- 2-pack polyurethanes - 2-pack polyurethanes
07/03/12, Page 27, Rheology Additives

28. BYK-430 / BYK-431: Viscosity Curves
100 BYK-430 / BYK-431
BYK-410
50
Polyamide
20
Castor oil derivative
10
Control
Viscosity [ Pa s ]
5
2 Dosage :
3% BYK-430 (30% solids),
1 1% castor oil (100% solids)
1% polyamide (100% solids)
0.5
0.2
0.1
0.1 1 10 100 1000
Shear rate [ 1/s ]
07/03/12, Page 28, Rheology Additives

29. BYK-430: Best Sag Resistance in 2-pack Epoxy
BYK-430 Polyamide Castor oil derivative Control
50 µm 50 µm
100 µm
150 µm
200 µm
250 µm 250 µm
300 µm 300 µm
350 µm
400 µm
450 µm
500 µm
700 µm
07/03/12, Page 29, Rheology Additives

30. BYK-431: Excellent Sag Resistance in 2-pack Acrylate
Control BYK-431 BYK-410 Polyamide Polyamide
Paste Powder
90 µm
150 µm
180 µm
350 µm 350 µm
Rheology additive dosage 1%
07/03/12, Page 30, Rheology Additives

31. BYK-430 / BYK-431: Advantages
• Handling
- Liquid, easy to handle and processing
- Post addition possible
- No deagglomeration required
- No controlled cool down phase after production required
- Activation temperature below 50°C
- No seeding tendency during storage
• Application
- Excellent sag control
- Ideal anti-settling properties even at higher temperatures
- No intercoat adhesion problems (compared to other polyamides)
07/03/12, Page 31, Rheology Additives

32. ANTI-TERRA®, BYK®, BYK®-DYNWET®, BYK®-SILCLEAN®,
BYKANOL®, BYKETOL®, BYKOPLAST®, BYKUMEN®, DISPERBYK®,
DISPERPLAST®, LACTIMON®, NANOBYK®, SILBYK® and
VISCOBYK® are registered trademarks of BYK-Chemie.
AQUACER®, AQUAFLOUR®, AQUAMAT®, CERACOL®, CERAFAK®,
CERAFLOUR®, CERAMAT®, CERATIX® and MINERPOL® are
registered trademarks of BYK-Cera.
This information is given to the best of our knowledge. Because of the
multitude of formulations, production, and application conditions, all the
above mentioned statements have to be adjusted to the circumstances of
the processor.
No liabilities, including those for patent rights, can be derived from this
fact for individual cases.
07/03/12, Page 32, Rheology Additives