Part 4 - mypma.org.my...Polyacrylate Dispersants such as Alcosperse 679/Dispex A40, Orotan 681 ETC out perform Sodium Polyacrylate Dispersants such as Orotan N4045 when used in tinting

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MPMA One Day Seminar

Water Based Paints An Overview :Part 4:

WATER BASED DISPERSIONTHEORY,TYPES AND LEVELS

September 15 2015


INTRODUCTION 1-WHY WETTING ANDDISPERSING ADDITIVES ARE REQUIRED

• IF THE PIGMENTS, EXTENDERS ARENOT OPTIMALLY DISPERSED IN THEWATER THEN ONE OR MORE OF THEFOLLOWING CAN OCCUR

• FLOCCULATION• LOW OPACITY• LOW SHEEN• WRONG COLOUR OR HUE


INTRODUCTION 2-WHY WETTING ANDDISPERSING ADDITIVES ARE REQUIRED

CONTINUED• POOR TINTER ACCEPTANCE OR

DEVELOPMENT• FLOODING/FLOATING• SETTLING• POOR SAG RESISTANCE• POOR FLOW


Agglomerate

Flocculate

ideal dispersion

Solid/liquid interface


Additives


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Pigment Stabilization

Electrostatic Repulsion:the higherthe polarity,the greater the effect


ELECTROSTATICSTABILIZATION

• IS THE MOST COMMON PIGMENT, EXTENDERSTABILIZATION SYSTEM USED IN WATER BASEDPAINTS

• EXAMPLES ARE SODIUM POLYACRYLATE ANDACRYLATE COPOLYMER DISPERSANTS:

E.G. DISPEX N 40 OROTAN N4045/ALCOSPERSE149(40%)HIDIS45N , OROTAN 731/ALCOPSPERSE700, OROTAN 681/ALCOSPERSE 679 AND OROTAN165ALL THESE DISPERSANTS NEED TO BE IONISED(pH ABOVE 7.5 TO WORK )


ELECTROSTATICSTABILIZATION 2

• Some people believe that AmmoniumPolyacrylate Dispersants such as Alcosperse679/Dispex A40, Orotan 681 ETC out performSodium Polyacrylate Dispersants such asOrotan N4045 when used in tinting systems thismight have been the case for the earlier SodiumPolyacrylate dispersants such as Alcosperse149 but from a lot lab work and field trials it isnot the case with modern Sodium Polyacrylateswhich work well in Tint bases


Pigment Stabilization

Steric Stabilization:the lower the polaritythe greater the effect


STERIC STABILIZATION• ALTHOUGH THIS STABILIZATION ROUTE IS USED IN

WATER BASED PRODUCTS IT IS USED FAR MOREIN SOLUTION POLYMERS THAN WITH LATEX(DISPERSION) POLYMERS

• THE MOSTLY COMMONLY USED STERIC STABILZERIN WATER BASED PAINTS IN RSA ARE

APEOS-ALKYL PHENOL ETHOXYLATESEG NP 6, NP 9, NP 10 AND NP 11-NP 9 IS THEMOSTLY WIDELY USED APEOS IN RSA MOSTLY ASA PIGMENT, SURFACE WETTING AID WITH TINTERDEVELOPMENT IMPROVING PROPERTIES


APEOS

• SINCE 1995 IN THE EU ANY PAINT ORLATEX UTILISING AN APEO NEEDS TOCARRY A WARNING LABEL –THEREFORE SUCH FORMULATIONS ARE NOLONGER SOLD IN THE DECORATIVEMARKET IN THE EU

• IN RSA THE CHANGEOVER IS SLOWERBUT IS STARTING TO OCCUR ASAPEOS BEGIN TO INCREASE IN PRICE


ADVANTEX/FALAMINE/AMP 95MULTIPURPOSE ADDITIVE 1

• CAN REPLACE AMMONIA FOR pHCONTROL AND DISPERSANTIONIZATION

• TOTALLY REPLACES APEOS ASPIGMENT AND SUBSTRATE WETTINGAGENTS

• CAN PARTIALLY REPLACEPOLYACRYLATE DISPERSANTS


ADVANTEX/FALAMINE/AMP 95MULTIPURPOSE ADDITIVE 2

• ADVANTEX ACTS AS A MICROCOALESCENT SO IT CAN BE USED TOPARTIALLY REPLACE NX795/TEXANOL

• ADVANTEX ACTS A SYNERGIST FORBIOCIDES AND DEFOAMERS

• ADVANTEX AIDS ASSOCIATIVETHICKENER INTERACTION

• ADVANTEX REDUCES THE CHANCEOF FLASH RUSTING


DISPERSANT LEVELS

• ARE DEPENDENT ON THE HARDNESSOF THE WATER TO BE USED IN THEPROCESS

• SOFTER THE WATER LOWER THELEVEL OF POLYACRYLATEDISPERSANT REQUIRED (0.5-1% ONPIGMENT, EXTENDER LOADINGS)


DISPERSANT LEVELS-2

• HARDER WATER HIGHER THE LEVEL(1-2% ON PIGMENT, EXTENDERLOADINGS)

• WB GLOSS/PRIMERS REQUIRE MUCHHIGHER LEVELS OF COPOLYMERDISPERSANTS TO ACHIEVEGLOSS/OTHER PROPERTIES (3-5% ONPIGMENT/EXTENDER LOADING)


DISPERSANT LEVELS-3

• Some people formulate high PVC paintswith very low Dispersant levels to not onlysave cost but also in attempt to improvewater resistance and increase viscosity

• The downside of such a move is big batchto batch variability in opacity and viscosity.

• From experience I found the slight gainsare not worth the pain


DISPERSANT LEVELS-4

• Dolomites which are Calcium MagnesiumCarbonates need much higher Dispersantand Calgon/SHMP levels than thosebased on CaCO3

• Some people who produce very high PVCPaints feel that they only require Calgon,SHMP as sole Dispersant poor storagestability normally results


TINTER ACCEPTANCEIMPROVERS

• ARE SPECIFICALLY ADDED TO IMPROVETHE EASE OF TINTER ACCEPTANCE ANDOR DEVELOPMENT OF TINTER

• THEY ARE VERY SYSTEM ANDFORMULATION DEPENDENT

• EXAMPLES ARE BYK 181, 187, NUOSPERSE115, SURFYNOL 104E/P, HYDROPALAT 7003,DISPERSOL 7003, RHODIFAC RS610


TINTER ACCEPTANCEIMPROVERS- 2

• LEVELS ARE NORMALLY 0.1-1%• POST ADDING DOES NOT NORMALLY

WORK BETTER IN THE MILLBASE• NORMALLY WORK BETTER TO CURE

DARKER RUBS• IF BASE RUBS LIGHTER THEN TIO2

FLOCCULATION IS OCCURRING SOLOOK AT DISPERSANT LEVEL


THICKENER/DISPERSANTS

• POLYACRYLATES WORK WELL WITHHASES

• ACRYLATE CO POLYMERS WORKWELL WITH HEURS

• WRONG DISPERSANT WITH WRONGTHICKENER CAN GIVE PROBLEMSLIKE POOR STABILITY, SYNERSIS LOWSHEEN AND POOR TINTERDEVELOPMENT


CONCLUSIONS

• DISPERSION, DISPERSANTS AREVERY IMPORTANT IN ORDER TO GETTHE BEST OUT OF PIGMENTS OREXTENDERS

• OFTEN PEOPLE EITHER USE TOLITTLE OR TOO MUCH- BOTH CANCAUSE BIG PROBLEMS

Part 4 - mypma.org.my...Polyacrylate Dispersants such as Alcosperse 679/Dispex A40, Orotan 681 ETC out perform Sodium Polyacrylate Dispersants such as Orotan N4045 when used in tinting

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