150 years
The Role of Thickeners in OptimisingCoating FormulationsSCAA Conference, Sept. 10.-11. 2015
150 years
ED, Confidential 4
PPG Innovation Days 150 Jahre
1 I Rheology of waterborne coatings
2 I Interaction of rheology modifiers with latex binders
3 I Interior paints: comparison of different rheology modifiers
4 I Rheology modifiers: new developments
5 I Summary & Outlook
ED, Confidential 5
PPG Innovation Days 150 Jahre
1 I Rheology of waterborne coatings
2 I Interaction of rheology modifiers with latex binders
3 I Interior paints: comparison of different rheology modifiers
4 I Rheology modifiers: new developments
5 I Summary & Outlook
150 years
6
Formulation effects Economics Anti-settling, -sagging Stability
Performance effects Gloss Weatherability Hiding power
Application effects Sag control Layer thickness Spraying Brushing Rolling Levelling Spattering
Rheology modifiers
150 years
Importance of rheology on paint application
shear rate [s-1]10 102 103 1041
storage
sag, levelling
stirring
105
104
103
102
painting
visc
osity
[mPa
s]
0.10.01
10
1
ICIStormerBrookfield
Controlled Stress Rheometer
150 years
High PVC paint: typical composition
Water
FillersTiO2Binder
~35%
~18%~10%
Formulation Additives:
paint rheology is influenced by many components: main influence by: rheology modifier, latex, pigments & their interactions
150 yearsRheology modifiers Three different classes studied
Hydrophilic backbone
Hydrophobes
Alkali-soluble backboneCO2H CO2H CO2HCO2H
Associative
HASE HEUR
emulsion: pH <5
pH > 7
COO- COO- COO-
formulation:Non-Associative
ASE
150 yearsRheology Modifiers Benchmark low shear rheology modifiers used
RheologyModifier Chemistry Product form pH Solids Viscosity
(mPas)
HASEassociative anionic polyacrylate
(hydrophobically modified alkali swellableemulsion copolymer)
aqueousemulsion ~3.5 35% ~5
HEURassociative nonionic polyurethane
(hydrophobically modified polyethylene oxideurethane copolymer)
aqueoussolution ~7 30% ~2700
ASE anionic polyacrylate(alkali swellable emulsion copolymer)
aqueousemulsion ~3.5 30% ~40
150 yearsPolymer Binders –Benchmark polymer dispersions
Binder Region Chemistry Solids Particle Size (DLS) MFFT Remark
Acronal ECO 338 ap SA-1 Asia styrene / acrylate 50% 158 nm ~16°C excellent water resistance& hydrolytic stability
SA-2 Asia styrene / acrylate 48% 148 nm ~24°C excellent scrub resistance
AC-3 NAFTA all acrylic 50% 126 nm ~10 °C suitable for zero VOC paintsexcellent cleanability
AC-4 Europe all acrylic 50% 198 nm ~2°C suitable for low VOC paintsbroad formulation latitude
ED, Confidential 12
PPG Innovation Days 150 Jahre
1 I Rheology of waterborne coatings
2 I Interaction of rheology modifiers with latex binders
3 I Interior paints: comparison of different rheology modifiers
4 I Rheology modifiers: new developments
5 I Summary & Outlook
150 years
0
100
200
300
Visc
osity
[mPa
s]
Shear rate [1/s]
binder SA-2 binder AC-4 binder AC-3 binder SA-1
Binder Chemistry Particle sizePseudoplasticity
Indexη(0.1 s-1) / η(1000 s-1)
SA-2 styrene / acrylate 148 nm 12.4
AC-4 all acrylic 198 nm 4.2
AC-3 all acrylic 126 nm 2.6
SA-1 styrene / acrylate 158 nm 2.8
Rheology of pure binders pure Latex @ 40% solids, pH = 8.5
No simple correlation to latex monomer chemistry or particle size
Latex SA-2 with higher hydrodynamic effective volume fraction: Φeff
150 yearsBinary systems Latex (40%) + rheology modifier (0.28%)
1
10
100
1000
10000
Thic
keni
ng E
ffici
ency
@ 0
.1 s
-1
Latex + HASELatex + HEURLatex + ASE
SA-1 SA-2 AC-3 AC4
Different response depending on latex type
HASE shows strongest response
Thickening Efficiency :
TE =(Latex + Rheology Modifier)
(pure Latex)
150 years
Binary systems Latex (40%) + rheology modifier (0.28%)
SA-2
SA-2SA-2
SA-2
AC-4
SA-1
SA-1
SA-1
SA-1
AC-3
AC-3
AC-3
AC-3
AC-4
AC-4
AC-4
HASE most efficient
HEUR more balanced
ASE more pseudoplastic
Impact on low shear andhigh shear viscosity
150 years
Associative rheology modifiers Thickening mechanism of HEUR
Micelle
Surfactants
Latex particle
Mixed Micelle
How to study the interaction between colloid particles and the rheology modifier?
150 years
Interactions between latex and rheology modifier Electrophoretic mobility
-4
-3
-2
-1
0
1
0.0% 0.1% 1.0% 10.0% 100.0%
Elec
troph
oret
ic M
obilit
y [(
µm/s
)/(V/
cm)]
HEUR versus latex
Mob
ility
low
high
Latex AC-4 shows weaker
interactions with HEUR
150 years
SA-2
SA-2
SA-1
SA-1
AC-3
AC-3
AC-4
AC-4
Binary systems Latex (40%) + rheology modifier (0.28%)
Latex AC-4 shows relative lowthickening with HEUR
Good response with all otherbinders
Thickening response of different binders with HEUR
ED, Confidential 19
PPG Innovation Days 150 Jahre
1 I Rheology of waterborne coatings
2 I Interaction of rheology modifiers with latex binders
3 I Interior paints: comparison of different rheology modifiers
4 I Rheology modifiers: new developments
5 I Summary & Outlook
150 years
White base paints used for rheology modifier evaluation
Paint Ainterior mattPVC = 68%
Paint Binterior mattPVC = 80%
Paint Cgloss paintPVC = 18%
Paint Dinterior mattPVC = 68%
from region Asia Asia NAFTA Europe
main binder SA-1 SA-2 AC-3 AC-4
rheology modifier in base paint no cellulosic HEC no cellulosic
HEC
preferred rheology modifier HEUR HEUR HEUR-1 (KU)HEUR-2 (ICI) /
150 years
Base paints + rheology modifiers (0.175% active) Comparison: low shear thickening efficiency
0
5
10
15
20
Thic
keni
ng E
ffici
ency
@ 0
.1 s
-1
Paint A Paint B Paint C Paint D
paint + HASEpaint + HEURpaint + ASE Thickening Efficiency :
TE =η(Paint + Rheology Modifier)
η(pure Base Paint)
HASE: most efficient HEUR: balanced efficiency Paint D with lowest response
150 years
Base paints + rheology modifiers (0.175% active) Comparison: overall thickening response
paint B
paint A
paint D
paint C
different response byeach base paint
Paint D with lowest response
150 years
Rheology of paints Comparison of paint A versus paint B
All paints adjusted to 100 KU Low shear thickening: HASE > ASE > HEUR HEUR: more Newtonian, more balanced
10
100
1000
10000
100000
1000000
Visc
osity
[mPa
s]
Shear rate [1/s]
HASE HEUR ASE base paint A w/o RM
10
100
1000
10000
100000
1000000
Visc
osity
[mPa
s]
Shear rate [1/s]
HASE HEUR ASE base paint B w/o RM
paint A paint B
150 years
Levelling TestSagging Test
Rheology of PaintsPaint B: application properties versus rheology
Rheology Modifier
low shearthickening efficiency
@ 0.1 s-1
Pseudoplasticity index
η(0.1s-1) / η(1000s-1)
Sagging Test Levelling Test
HASE 4202 54661 no sagging poor
HEUR 824 13602 no sagging good levelling
ASE 2977 33116 no sagging poor
base paint B base paint B+ HEUR + HEUR
150 years
Dynamic mechanical analysis Paint B: strain sweep @ 10 rad/s
0.1
1
10
100
1000
0.001 0.01 0.1 1
G' a
nd G
"
[Pa
]
Strain Amplitude
base paint
HEUR ASE HASE
Crossover points correlate to levelling performance
ED, Confidential 26
PPG Innovation Days 150 Jahre
1 I Rheology of waterborne coatings
2 I Interaction of rheology modifiers with latex binders
3 I Interior paints: comparison of different rheology modifiers
4 I Rheology modifiers: new developments
5 I Summary & Outlook
150 years
Development of new nonionic rheology modifiersBranched and hyperbranched polymer structures
Hydrophilic backbone
Hydrophobes
HEUR New concepts
New hydrophobe structures with optimum interaction to latex surface
Branched polymer architectures: backbone a/o hydrophobes
150 years
0.25% thickener actives in a pure acrylic dispersion
New nonionic rheology modifiers Comparison of linear versus hyperbranched HEUR
Hyperbranched end groups + high molecular weightlead to significant improved thickening response
150 years
Properties HEUR 2 Hyper-branched, high molecular weight
Hyper-branched, low molecular weight
Viscosity [mPa*s] 1770 2100 1750
Active [%] 1.48 0.95 0.99
Flow & Levelling 1.0 1.0 1.0
Sag [mm] 200 200 200
Target viscosity: 1700 mPa·s [Brookfield viscosity]Flow & leveling: 0.25 = excellent, >4.0mm = badSag: 300 µm = excellent, 75 µm = bad
New hyperbranched HEURTesting in high PVC pure acrylic paint
significant improved thickening efficiency no compromise in levelling & sag behavior
ED, Confidential 30
PPG Innovation Days 150 Jahre
1 I Rheology of waterborne coatings
2 I Interaction of rheology modifiers with latex binders
3 I Interior paints: comparison of different rheology modifiers
4 I Rheology modifiers: new developments
5 I Summary & Outlook
150 years
31
SummaryRheology modifier types and applications
Applications Latexplasters Interior paints (flat) Façade paints
Dispersion lacquers
semi matt semi gloss highgloss
PVC 80 - 90 % 65% 80% 35 - 65% 65 - 35% ca. 20%
Dispersion Type Styrene acrylic VAc-CopolymersStyrene acrylic
AcrylicStyrene acrylic
Acrylic
AcrylicPVAc.-copol. Styrene acrylic PUR-Acrylic
Acrylic Acrylic - Acrylic-Alkyd
Cellulose ether xxx o xxx o
Cellulose ether / HASE xxx xxx o xx o
Cellulose ether /HEUR
xx xx
HASE o o o o
HASE / HEUR o o xx xxx xxx xx
HEUR o o xx xx xxx xxx
xxx excellent xx very good opossible
150 years
Summary & Outlook
Binary model systems:► Interaction between latex and rheology modifiers was studied
by rheology and correlated to electrophoretic mobility► Optimum thickener response results with “good fit” of hydrophobe
chemistry to latex surface
Paints:► Fully formulated paints show similar trends concerning
different classes of rheology modifiers
New rheology modifiers:► Results from model studies help to design new associative
thickeners with optimum response towards next generationlatex binders
► New hyperbranched HEUR with high efficiency
150 years
Acknowledgements
Clemens Auschra#), Iván García Romero#), Immanuel Willerich#), Robert Reichardt#), Cindy Muenzenberg, Elena Martinez#), Hunter He*)
#) BASF SE, Ludwigshafen, Germany*) BASF Company Ltd., Shanghai, China
150 years
SafetyWhen handling the mentioned products, please comply with the advice and information given in the safety data sheets and observe protective and workplace hygiene measures adequate for handling chemicals.
NoteThe data contained in this publication are based on our current knowledge and experience. In view of the many factors that may affect processing and application of our products, these data do not relieve processors from carrying out their own investigations and tests; neither do these data imply any guarantee of certain properties, nor the suitability of the product for a specific purpose. Any descriptions, drawings, photographs, data, proportions, weights, etc. given herein may change without prior information and do not constitute the agreed contractual quality of the product. The agreed contractual quality of the product results exclusively from the statements made in the product specification. It is the responsibility of the recipient of our product to ensure that any proprietary rights and existing laws and legislation are observed.
Disclaimer
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