The Role of Thickeners in Optimising Coating Formulations

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







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







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







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







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







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

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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Date post:	19-Jan-2017
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The Role of Thickeners in Optimising Coating Formulations

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