Use of Novel PolyetheralkanolamineComb Polymers as Pigment Dispersants

for Aqueous Coating Systems

Duy T. Nguyen, Ph.DHuntsman Performance Products

Outline

Fundamental Structure-Property Relationship of Polyetheralkanolamine Copolymers

Optimization of PolyetheralkanolaminesStabilization mechanisms: steric and charge

Comparison with other conventional dispersants

Resin-containing pigment concentratesResin-free pigment concentrates

Conclusions

Why use dispersants?

Good Dispersants

Flexibility Production capacity Quality

-VOC-free - Reduced milling time - Better dispersion stability-APE-free - Decreased dispersion viscosity - Increased color development-Compatible with binder to allow higher pigment loading - Maximun color acceptancetypes of all bases

Polyetheralkanolamine Comb Polymers

P ERFANCE S PECIALTIES T ECHNOLOGY

Soluble chain

Anchoring group

Adsorption of a comb polymer at the pigment surface

Pigment

An effective dispersant should have:1) Anchoring groups2) Soluble chains3) Linkers

HydrophobicBackbone

HydrophilicChains

HydrophobicBackbone

HydrophilicChains

HydrophobicBackbone

HydrophilicChains

HydrophobicBackbone

HydrophilicChains

Polyetheralkanolamine Comb Polymers (Patents Pending)

R O N OOH OH

O

O

x

y

R is aromatic or aliphatic

Hydrophilic teeth

2-3

CH3Nomenclature:P7E : x = 3 and y = 7P19E : x = 3 and y = 19P41E : x = 3 and y = 41P58E : x = 8 and y = 58

Pigment Adsorption Studies

1) Fill the sample holder (made of aluminum and has small holes in bottom) with pigment

2) Compact with piston

3) Suspend the holder from the balance just above the surface of a liquid

4) The liquid is raised until it touches the bottom of the porous sample

5) Mass vs. time is then collected as the liquid penetrates into the solid

Kruss K12 Surface Tensiometer

Particle Size and Zeta Potential Analysis

1) No dilution required (0.1- 50% by volume )

2) Wide particle size range ( 5nm – 1000 microns)

3) Small sample volume (20-110 ml)

4) Use of ultrasound technologies

DT-1200 Acoustic Spectrometer

Outline

Fundamental Structure-Property Relationship of Polyetheralkanolamine Copolymers

Optimization of PolyetheralkanolaminesStabilization mechanisms: steric and charge

Effect of EO on Surface Tension

40

42

44

46

48

50

0 20 40 60 80

Moles of EO

4% solution

Surf

ace

tens

ion,

dyn

e/cm

P7E

P19EP41E

P58E

Increasing water solubility

Effect of EO on Interfacial Tension

89

101112131415

0 20 40 60 80Moles of Ethylene Oxide

1% solution

Dispersed phase: Mineral OilFlow rate: 1ml/hr

Inte

rfac

ial T

ensi

on, d

yne/

cm

P19E

P41E

P58E

Increasing water solubility

Effect of EO on Wetting Effectiveness for 4% Polymer Solutions on Carbon Black

200

400

600

800

1000

1200

0 20 40 60 80Moles EO

Wet

ting

Effe

ctiv

enes

s,

mg

Wetting effectiveness = max amount of liquid gained into the carbon black column

P7E

P19EP41E P58E

Effect of EO on Wetting Rate for 4% Polymer Solutions on Carbon Black

1

2

3

4

5

0 20 40 60 80Moles of EO

Wet

ting

rate

, mg/

s

Wetting rate = (weight of liquid gain at half saturation) / (time required for half saturation)

P7E P19E

P41E P58E

Effect of Ethylene Oxide on Carbon Black Dispersion Viscosity

10

100

1000

10000

0 20 40 60 80

Moles of EO

Visc

osity

@ 0

.8/s

, cP

P7E

P19E

P41E

P58E

(Highest wetting rate: dynamic)

37% Carbon Black ; 15% Dispersant on Carbon Black

STERIC STABILIZATION:Adsorption Layer Thickness and Effective Volume Fraction

Eq. (1)

δ

δ = adsorption layer thickness (5-10 nm)

δ

3/2

3/5

s

nl=δ R

• Where n is the number of EO units, l is the EO length (0.369 nm), and s is the average distance between the grafting points (1.6 nm)

• The adsorbed polymer layer can increase the particle radius and add to the volume fraction of the solid particles, φ, to yield an effective volume fraction, φeff

3 effective /R) (1 δφφ += Eq. (3)

Reffective = R +δ Eq.(2) Reff

Rδ

Where δ is the adsorption layer thickness and R is the radius of the carbon black particles (24nm)

Calculation of steric thickness and effective volume fraction

• Adsorbed layer thickness of 5-10 nm is usually considered sufficientto screen the attractive Van der Waals forces

EO content δ (nm) φ φ µ, cpeff

7 (P7E) 1.39 0.29 0.24

19 (P19E) 3.05 0.35 0.24

41 (P41E) 6.11 0.48 0.24 100

58 (P58E) 9.16 0.65 0.24 2,000

NP 40 * 2.3

Note: Length of each EO unit is about 0.35 nm. For 41 EO’s, the length is 14.35 nm, comparedto 6.11 nm. It is concluded that the EO chain may loosely coil at the solid/liquid interfacerather than extend straight into the water

∗ C. Ma, Colloids Surfaces, Vol 66, pg 215, 1992

Zeta

Pot

entia

l, m

V

IEP

IEP

-6-4-202468

10

0 2 4 6 8 10 12 14pH

UntreatedWith P41E (15% onpigment)

IEPIEP

Zeta Potential of 5% Carbon Black as a Function of pH

CHARGE STABILIZATION

Particle Size Distribution

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

PSD

, wei

ght b

asis

10-1 100 101 102

Diameter [um]

5% carbon black (untreated)Bimodal:

Size 1 0.523 micron

Standard deviation 1 0.12

Size 2 16.9 micron

Standard deviation 2 0.12

Fitting error % 18.2

Cumulative

10% 0.3637 micron

16% 0.3936 micron

50% 0.5971 micron

84% 16.5313 micron

90% 18.5258 micron

0.0

0.4

0.8

1.2

1.6

2.0

PSD

, wei

ght b

asis

10-2 10-1 100

Diameter [um]

5% carbon black with 20% active P41E on pigment

UnimodalMedian 0.0924 micronStandard deviation 0.187Fitting error % 5.8Cumulative

10% 0.0551 micron16% 0.0621 micron50% 0.0924 micron84% 0.1392 micron90% 0.1549 micron

Particle Size Distribution

y = 0.9167xR2 = 0.9975

0

50

100

150

200

250

0 50 100 150 200 250 300

Total Concentration, ppm

Ads

orbe

d C

once

ntra

tion,

ppm

Total Concentration vs. Adsorbed Concentration For P41E on Carbon Black

Outline

Comparison with other conventional dispersants

Resin-containing pigment concentratesModified SMA : a styrene maleic anhydride modified with polyethersAcetylenic Diol surfactantP41E : Polyetheralkanolamine comb polymer

Receding Contact Angle of Carbon Black Treated with Dispersants

30

40

60

70

80

90

Untreated Modified SMA P41E

Con

tact

Ang

le, D

egre

es

50

05000

1000015000200002500030000

0 20 40 60 80

Acetylenic DiolP41EModified SMAPolyethermonoamine

P.B 15:3 Dispersion Viscosities 37% Pigment, 5.3% Dispersant on Pigment; P:B =4.7

Visc

osity

, cps

Brookfield RPM

PY 14 Dispersion Viscosities36% Pigment, 5.2% Dispersant on Pigment, P:B =4.7

100

1000

10000

100000

0 20 40 60 80Brookfield RPM

Visc

osity

, cps

Acetylenic DiolP41EPolyethermonoamine

100

1100

2100

3100

4100

5100

6100

0 10 20 30 40 50 60 70

Visc

osity

, cps

P41E

Modified SMA

Carbon Black Dispersion Viscosities38% Pigment, 5.3% Dispersant on Pigment; P:B =4.7

Brookfield RPM

PR 57:1 Dispersion Viscosities36% Pigment Loading, P:B = 4.7

100300500700900

110013001500170019002100

0 10 20 30 40 50 60 70

RPM

Visc

osity

, cps

P41E (2.78% on pigment)

Acetylenic Diol (2.78% on pigment)

Yellow dispersion viscosities- aged three weeks

1

10

100

1000

10000

100000

P41E Acetylenic Diol

InitialAged

Visc

osity

, cps

at 1

2 rp

m

unmeasurable

Tint Strength: Blue Pigment (PB 15:3) in Interior Latex Extra White (1:99 TiO2 White Reduction)

100101102103104105106107108

Col

or S

tren

gth

P41E Acetylenic Diol MSMA

MSMA is reference (100%)

Tint Strength : Carbon Black in Interior Latex Extra White (1:99 TiO2 White Reduction)

100

102

104

106

108

110

112

Col

or S

tren

gth

P41E MSMA Acetylenic Diol

Acetylenic Diol is reference (100%)

Outline

Comparison with other conventional dispersants

Resin-free pigment concentratesModified SMA : a styrene maleic anhydride modified with polyethersP41E : Polyetheralkanolamine comb polymerStyrene Acrylate copolymer

Note: Dispersion with a modified SMA was too thick to mill

Resin-free lithol rubine initial dispersion viscosity45% pigment loading, 10% P41 E on pigment

0

10

20

30

40

50

60

0 100 200 300 400 500 600 700

Shear rate, 1/s

Visc

osity

, cP

Viscosity of Resin-Free Pigment Concentrate45% PB 15:3; 20% dispersant on pigment

02000400060008000

1000012000

0 20 40 60 80

RPM

Visc

osity

(cP) P41E

Styrene Acrylate

0100200300400500600700800

Fresh One week at 50C

Visc

osity

@ 1

1/s,

cP

Styrene acrylateP41E

Viscosity of 30% carbon black resin-free dispersion: 20% dispersant on pigment

Color Strength of Carbon Black in High Gloss Latex Acrylate Paint

102.8

113

100100

102

104

106

108

110

112

114

MSMA P41E Styrene acrylate

40% active oncarbon black

Col

or S

tren

gth

Resin-Free Carbon Black Concentrate: 30 % carbon black, 40% active dispersant on pigment

Color Strength of Carbon Black in Semi Gloss Latex Acrylate Paint

100

115.6

56.6

0

20

40

60

80

100

120

MSMA P41E Untreated

30% active on carbon black

Resin-Free Carbon Black Concentrate: 30 % carbon black, 30% active dispersant on pigment

Col

or S

tren

gth,

%

Color Strength of Carbon Black in Alkyd Resin Paint

100

128

91.2

0

20

40

60

80

100

120

140

Styrene acrylate P41E Untreated

40% active on carbon black

Col

or S

tren

gth

Resin-Free Carbon Black Concentrate: 30 % carbon black,40% active dispersant on pigment

Gloss 60oAngle of Carbon Black in Alkyd Resin Paint

59

74.2

16.4

46.3

01020304050607080

MSMA P41E Styreneacrylate

Untreated

40% active on carbon black

Resin-Free Carbon Black Concentrate: 30 % carbon black, 40% active dispersant on pigment

Glo

ss

Compatibility of P41E in Different Binder Systems

Binder system Compatibility

2 Pack Epoxy Good

Polyester resins Good

Alkyd resins Good

PU dispersions Good

Acrylic dispersions Good

Melamine resins Good

Properties of lithol rubine containing various dispersants in semi gloss latex paint

Dispersant Dosage on ∆E Color Water lithol rubine strength resistance

P41E 10% 0.49 111.09 Good

MSMA 20% 2.20 110.59 Good

Styrene acrylate

20% 0.67 100 Good

P41E is two times more effective than other dispersants!

Properties of lithol rubine containing various dispersants in high gloss paint

Dispersant Dosage ∆E Gloss Color Wateron blue strength resistance

P41E 10% 0.15 33.83 100.55 Good

MSMA 20% 0.27 30.2 101.48 Good

Styrene acrylate

20% 0.20 30.03 100 Good

P41E is two times more effective than other dispersants!

Properties of lithol rubine containing various dispersants in alkyd resin semi gloss paint

P41E 10% 1.00 28.93 263.98 Excellent

MSMA 20% 5.07 26.2 100.00 Excellent

Styrene acrylate

20% 0.87 10.6 180.01 Excellent

Dispersant Dosage ∆E Gloss Color Wateron blue strength resistance

P41E is two times more effective than other dispersants!

Properties of phthalo blue containing various dispersants in flat latex paint

Dispersant Dosage on ∆E Color Waterblue pigment strength resistance

P41E 20% 0.09 104.90 Good

Styrene acrylate

20% 0.47 100 Blisters

MSMA 20% 0.16 102.9 Good

CONCLUSIONS

PolyetheralkanolamineP41E

Flexibility Production capacity Quality

-VOC-free - Reduced milling time - Better dispersion stability-APE-free - Decreased dispersion viscosity - Increased color development-Compatible with binder to allow higher pigment loading - Maximun color acceptancetypes of all bases

Special Thanks To:

Judy PerezLisa Fine

Thank you for your kind attention!www.huntsman.com/cprEmail:duy_t_nguyen@huntsman.com