rheology modifiers

AG-0706AG-0706

Rheology Modifiers

Advanced sheen Paint Training Part 5

AG-0706AG-0706

Shear Rate .

Viscosit

y

Shear Rate .

Viscosit

y

Time

Viscosit

y

Shearing at constant shear

Viscosity recovery at rest

NEWTONIANFLOW

•Increased shear does not impact viscosity.

PSEUDOPLASTICITYSHEAR THINNING FLOW

(case with Yield Value)

THIXOTROPY

•Flow starts at a given shear (yield)•Increased shear rate induces lower viscosity•Multiple viscosity measurements required to have rheology profile

Yield Value

•At constant shear, viscosity drops•When shear is stopped, viscosity recovers

Rheology Basics

TYPES OF RHEOLOGICAL BEHAVIOUR

AG-0706AG-0706

• Polyvinyl alcohol• Polyacrylamide• Alkali Soluble Emulsion

-Acrylic• Polyacrylic acids

• Cellulose ethers- CMC- MC, HEC, EHEC, etc..• Other polysaccharides

• HASE• HEUR

• HM-HEC

SYNTHETIC NATURAL DERIVATIVES

CO

NV

EN

TIO

NA

LA

SS

OC

IAT

IVE

• Clays (Bentonite, Laponite)• Titanium chelates• Attapigalite Clays (Min-u-gel)

THIXOTROPY:

Water borne Rheological additives: Thickener Types

AG-0706AG-0706

O

OH

OH

CH2OH

O

O

O

CH2OR'

OH

OR"

O

O

OH

OH

CH2OH

OCOOH ammonia

amine

hard baseCOO -

COO-

COO-

COO -

COO-

pH ~ 3.0 pH ~ 8.0

COOH ammoniaamine

hard baseCOO -COO -

COO-

COO-

COO-

COO-

COO -COO -

COO-

COO-

pH ~ 3.0 pH ~ 8.0

ACRYLIC THICKENERS (ASE)(Alkali Soluble Emulsion)

CELLULOSIC THICKENERS(Cellulose Ether)

LIQUID PHASE THICKENING

•EFFICIENT VISCOSITY BUILDERS•FLOCCULATE MANY LATEX BINDERS AND PIGMENTS•RESTRICTING GLOSS DEVELOPMENT AND LEVELLING•MICROBIAL DEGRADATION

•EASY TO FORMULATE WITH•RESTRICTING GLOSS DEVELOPMENT AND LEVELLING

Water borne Rheological additives: Conventional Thickeners

AG-0706AG-0706

THICKENING MECHANISM


AG-0706AG-0706

H

H O

H

H O

H

H O

H

H O

HH

O

HH

O

• Large hydrodynamic volume due to hydrogen bonding of the water molecules to the polymer• Viscosity strongly dependent upon the polymer Molecular Weight• Polymer chain entanglement and cross-linking (ASE)



AG-0706AG-0706

VOLUME RESTRICTION FLOCCULATION


Water

AG-0706AG-0706

Water


VOLUME RESTRICTION FLOCCULATION

AG-0706AG-0706

• HEUR : Hydrophobically modified Ethylene oxide URethane

• HASE : Hydrophobically modified Alkali Soluble Emulsion

Nonflocculating - excellent gloss and levelling

Easy to manipulate high and low shear rheology

Good roller spatter resistance

Very formulation dependent - complex interactions

Water borne Rheological additives: Associative Thickeners

AG-0706AG-0706

ASSOCIATIVE THICKENER CONCEPT

Non-ionic Surfactant

hydrophobehydrophilic tail

Associative Thickener

hydrophobeshydrophilic Polymer


AG-0706AG-0706


in water in a latex polymer

“flower” micelle

latex particle


AG-0706AG-0706

CONVENTIONAL versus ASSOCIATIVE THICKENERIN A LATEX

Conventional thickener Associative thickener

Water borne Rheological additives

AG-0706AG-0706

Shear rate

0.01

0.001 0.01 0.1 1 10 100 1000 10 000

Viscosit

y

0.1

1

10

100

1000

Rheology of paints

RHEOLOGY PROFILE

AG-0706AG-0706

APPLICATION versus RHEOLOGY PROFILE

Shear rate

0.01

0.001 0.01 0.1 1 10 100 1000 10 000

Viscosit

y

0.1

1

10

100

1000

Rheology of paints

AG-0706AG-0706

Shear rate

0.01

0.001 0.01 0.1 1 10 100 1000 10 000

Viscosit

y

0.1

1

10

100

1000

RollingBrush, Loading

Spreading, SpatteringSagging,Levelling

Settling

Rheology of paints

Brush drag,

APPLICATION versus RHEOLOGY PROFILE

AG-0706AG-0706

• Package stability

• Application Feel / Drag• Sag• Brush marks Levelling Flow • Spattering• Pattern• Spreading• Water sensitivity

Rheology Modifiers can control:

Rheology of paints

AG-0706AG-0706

Conventional thickeners

• ASE : Alkali Soluble Emulsion

Associative thickeners

• HEUR : Hydrophobically modified Ethylene oxide URethane

• HASE : Hydrophobically modified Alkali Soluble Emulsion

ROHM and HAAS Rheology Modifiers

Technologies

AG-0706AG-0706

ACRYSOLTM Product Line

RM 2020 RM-5000 RM-6000

RM-8W

RM-12W

SCT-275

HEUR•Non ionic

•Highly associative•Sensitive to colorants

RM-5 TT-935 ER TT-615

RM-935

HASE•Alkali soluble/associative

•Economic

DR-72 DR-73 ER DR-300

DR•Technology similar to HASE

•Reduced colorant viscosity drop•HEC replacement

ASE 60 ERASE

•Purely Alkali soluble


AG-0706AG-0706

0.01

0.001 0.01 0.1 1 10 100 1000 10 000

Viscosit

y

0.1

1

10

100

1000



Settling

Brush drag,



AG-0706AG-0706

0.01

0.001 0.01 0.1 1 10 100 1000 10 000

Viscosit

y

0.1

1

10

100

1000



Settling

Brush drag,

TT-615

ASE-60 ER

DR-72

TT-935 ERRM-935

DR-73 ER

RM-5


DR-300


AG-0706AG-0706

0.01

0.001 0.01 0.1 1 10 100 1000 10 000

Viscosit

y

0.1

1

10

100

1000



Settling

Brush drag,

RM-12W SCT-275

RM-2020 RM-5000

RM-6000



AG-0706AG-0706

ACRYSOLTM ASE-60 ER

(Log) Shear Rate, s-1

(Log) V

iscosity, P

a

ASE-60 ER

250 MBR

• Acrylic thickener (30% solids)

• Specifically designed to develop a high level of structure (high molecular weight, crosslinked)

• Generally used as a co-thickener

• Recommended for: - structured paints - settling & sag resistance

Conventional Thickeners


AG-0706AG-0706

Linear

TelechelicTelechelic

Branched RandomRandom

urethane linkage Hydrophobe

poly (EO)

HEUR Thickeners

(Hydrophobically modified Ethylene oxide URethane)


AG-0706AG-0706

Branched Polymers

SCT-27517.5%

Water/Butyl Carbitol

AcrysolTM HEUR Family

High shear Medium Shear Low shear

Linear Polymers

RM-835%

Water/PG

RM-202020% Water

RM-12 W19 % Water

RM-8W21.5% Water

RM-500018,5% Water

RM-600017,5% Water


AG-0706AG-0706

Hydrophobe

RM-2020 small

RM-8/825/8W medium

SCT-275 medium

RM-12W large

New technology

RM-5000 small

RM-6000 medium

(Log)

Viscosity

Rate of Shear

Acrysol RM-2020RM-5000RM-6000

RM-8/825/8WSCT-275RM-12W


AcrysolTM HEUR Family

AG-0706AG-0706

COO

COO

Acid copolymer backbone

poly (EO) spacer

ester or urethane linkage

Hydrophobe


HASE Thickeners

(Hydrophobically modified Alkali Soluble Emulsion)

AG-0706AG-0706

Newtonian Medium shear Low shear

RM 5 TT 935 ER TT 615Flow,levelling KU Efficient Structure, sag resistance

Low spatter

Low Mw HEC High Mw HECDR-73 ER DR-72Natrosol Plus like rheology Rheology like high Mw HECLow formulated cost Low formulated costAll liquid productivity gains All liquid productivity gainsLess viscosity drop than HASE Less viscosity drop than HASE

DR-300 Improved water resistance

High Shear Medium Shear Low shear

AcrysolTM HASE and DR Family


AG-0706AG-0706

Hydrophobe size

Molecu

lar w

eight

RM-55

TT-935 ER

TT-615

(Log)

Viscosity

Rate of Shear

RM-55

TT-615

TT-935 ER

DR-73 ER DR-72DR-72/DR-300

DR-73 ER

DR-300



AG-0706AG-0706

High Shear Viscosity

Lo

w S

hear

Visco

sity

High Mw HEC

Medium Mw HEC

Low Mw HECHMHEC

Acrysol™ DR-72Acrysol™ DR-72

Acrysol™ DR-73Acrysol™ DR-73

Acrysol™ DR-72 +Acrysol™ DR-72 +Acrysol™ DR-73Acrysol™ DR-73

•powders cause long preparation time and low plant productivity• Difficult to adjust viscosity after production• High formulated cost• Poor flow and roller spatter• Sensitive to microbial attack


Acrysol™™ DR : Technology to replace dry thickeners


AG-0706AG-0706

MASONRY WHITE PAINT MASONRY WHITE PAINT 48% PVC / 30% VS – ACRYLIC BINDER48% PVC / 30% VS – ACRYLIC BINDER

0.72% MHEC (high Mw)

1.5% Acrysol™ DR-72 (30%solids)

2.9% Acrysol™-DR300 (20%solids)

VISCOSITIES AFTER EQUILIBRIUMICI Cone & plate (Poise) 0.9 0.7 0.7KU 110 113 110Brookfield Sp. 4/6 rpm (cPs) 29 300 25 000 29 800

VISCOSITIES AFTER COLORANT ADDITIONICI Cone & plate (Poise) 0.9 0.8 0.9KU 116 130 126Brookfield Sp. 4/6 rpm (cPs) 29 700 39 000 38 200

VISCOSITIES AFTER HEAT AGEING 5 DAYS AT 60°CICI Cone & plate (Poise) 0.8 0.7 0.7KU 108 120 108Brookfield Sp. 4/6 rpm (cPs) 23 000 30 000 25 000




AG-0706AG-0706

1000

1100

1200

1300

1400

1500

1600

1700

1800

1900

2000

MHEC, high Mw Acrysol™ DR-72 Acrysol™ DR-300

We

t-s

cru

b c

yc

les

Acrysol™ DR-300 with superior water resistance




AG-0706AG-0706

0

1

2

3

4

5

MHEC, high Mw Acrysol™ DR-72 Acrysol™ DR-300

SPATTER RESISTANCE *SPATTER RESISTANCE *

*Spatter resist. during roller application. Rated from 1-5; 5=excellent




AG-0706AG-0706

Lo

w S

hear

Lo

w S

hear

Visco

sityV

iscosity

High Shear ViscosityHigh Shear Viscosity

DR-73 ERRM-55

TT-935 ER

RM-2020

RM-8W/825

SCT-275

TT-615RM-12W

ASE-60 ERDR-72

DR-300

RM-5000RM-5000

HASE

ASE

HEUR

Rheology profile at constant mid shear viscosity

New

RM-6000RM-6000



AG-0706AG-0706

KEY INTERACTIONS OF ASSOCIATIVE THICKENERS

WITH PAINT INGREDIENTS

• Effect of latex particle size

• Effect of latex stabilization

• Interaction with pigments

• Interaction with dispersants

• Interaction with surfactants

• Interaction with solvents

AG-0706AG-0706

Handling and Formulating Guidelines

Mixing conditionsEnsure sufficient agitation at the moment of RM addition

Addition orderBoth HASE and HEUR can be added in the grind or the letdownFor HASE thickeners : - grind : adjust pH before addition- letdown : adjust pH and pre-diluted RM with 50% waterHASE are easily incorporated when diluted and preneutralized (pH= 8 to 9)

Dispersant choiceLook at the interactions between dispersant type and RM

RM efficiency depends on- Concentration, molecular weight and associativity of the RM- PVC and VS of the formulation- Binder hydrophobicity- Viscosity suppressants (surfactants, cosolvents)

rheology modifiers

Documents