1. Specialty Additives for Architectural Coatings
PNWSCT Coatings Fest 2014
Rocky Prior, Charlie Hegedus, Ingrid Meier
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2. Objective
Provide guidance for selection of specialty additives for architectural coatings
Discuss a variety of different additive types
Provide general chemistry descriptions
Describe unique properties and benefits
Provide performance examples and guidelines for additive selection
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3. Multi-Functional Surfactants
Improve substrate and pigment wetting. Increase coating flow and leveling
Can affect other properties such as adhesion, foam, rheology, minimum film formation temperature, etc.
Traditional Surfactants
Low Foam Dynamic Wetting Agents
Superwetting Surfactants
Coalescing Surfactants
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4. Traditional Surfactants Used in Architectural Coatings
Provide surface tension reduction to wet both pigment and substrate; can improve color development and color acceptance
Also can improve other properties such as viscosity stability, freeze-thaw stability, scrub resistance
Tend to stabilize foam, requiring defoamer
Primarily nonionic surfactants that range in HLB
Originally, alkylphenol ethoxylates (APEs) and modified APEs dominated
Non-APE alcohol ethoxylates are replacing APEs
Comparable or improved performance to APE surfactants
Can often be “drop in” replacements
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5. Low Foam Dynamic Wetting Agents
Gemini structures that contain two amphiphilic groups linked with a short “spacer”
Unique molecular structures do not stabilize foam and prevent these surfactants from interacting strongly with other system components
This feature makes these wetting agents ideal for use in Architectural Coatings because they can perform their intended function without adversely affecting other properties
hydrophile
hydrophobe
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6. Low Foam Dynamic Wetting Agent: No Adverse Viscosity Effects in Vinyl Acrylic Wall Paint
White semi-gloss wall and trim vinyl
acrylic interior paint with 0.5% by
weight surfactants. VOC = 35 g/L.
White semi-Gloss Wall and Trim vinyl acrylic interior paint with 0.5% by weight surfactants. VOC = 35 g/L.
Surfynol® 420 surfactant does not affect paint viscosity. Other surfactants such as nonyl phenol ethoxylates (NPE) and octyl phenol ethoxylates (OPE-1 through 4) dramatically reduce viscosity which can cause pigment settling and poor application with defects such as sags.
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7. Superwetting Surfactants
Rapidly wet extremely low surface energy substrates (e.g., wood, old paint, contaminated surfaces, plastics, etc.)
Very low dynamic surface tensions
Extremely fast wetting rates and low contact angles
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8. Superwetting Surfactants
Commercial paint
0.9% Dynol™ 360
0.9% Dynol™ 800
Vinyl acrylic interior paint applied to a contaminated surface crawls and has major film defects. The same paint with 0.9% Dynol™ 360 surfactant and Dynol™ 800 surfactant wets the contaminated surface perfectly.
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9. Coalescing Surfactants
Unique surfactant structures
Enable surface tension reduction at <1 wt.%
Dynol™ 360 and Surfynol® AD01 surfactants provide low foam dynamic wetting
As coalescing surfactants, they also assist in latex coalescence and film formation (very unique property)
Can be used to replace and reduce co-solvent
Reduce MFFT and / or VOC while maintaining other properties (e.g., hardness, scrub resistance, etc.)
NOT A PLASTICIZER – does not reduce hardness
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10. Coalescing Surfactants
Coalescence and film formation of a polyurethane-acrylic latex topcoat. Adding 0.9% Dynol™ 360 surfactant eliminates the need for a solvent based coalescing aid.
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11. Lowering MFFT with Coalescing Surfactant – Dynol™ 360 Surfactant
Minimum Film Formation
Temperature (oC)
Weight Percent Coalescing Surfactant
Acrylic-polyurethane clear wood coating, 40% volume solids, VOC = 95 g/L.
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12. Wetting Agent Selection Guidelines for Architectural Coatings
Moderate dynamic wetting
Minimal foam
Strong dynamic wetting
Superwetting
Carbowet® GA-210
Surfynol 465, 485, PSA336
Surfynol® 104, 420, 440, AD01 (*)
Dynol™ 800, 980
360 (*)
Higher water solubility
No foam
Lower water solubility
Moderate water solubility
(*) Coalescing surfactants
Dry pigment wetting
Strongest Wetting
Stronger wetting, Lower Water Solubility, Greater foam control
Efficient wetting, Higher HLB, Less foam control
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13. Wetting Agent Selection Guidelines
Match coating requirements to wetting agent properties:
Surface tension reduction (type of substrate)
Dynamic surface tension (application process)
Foam generation (or defoaming) performance
Compatibility (solubility and HLB)
Water resistance (HLB)
Minimum film formation temperature (MFFT) - coalescing surfactant
Viscosity effects (e.g., interactions with pigment dispersants, rheology modifiers)
Environment, health, and safety requirements (e.g., low/no VOC, HAPs, APE, etc.)
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14. Dispersants and Surfactants in Pigment Grinds and Dispersions Used in Architectural Coatings
Improve pigment dispersion process, pigment wetting, grinding, color development, dispersion stability, rheology
Dispersants
Low Foam Dynamic Wetting Agents
Grind Aids
Stabilizing Surfactants (Co-Dispersants)
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15. Dispersants in Architectural Coatings
Dispersants are surface active molecules that orient on the pigment surface and prevents agglomeration and flocculation through stabilizing mechanisms
Specially designed polymers (high performance dispersants)
Commodity polymers (acrylic acids, styrene-acrylics, EO/PO block copolymers) – often used to disperse TiO2
Some surfactant chemistries (alkylphenol ethoxylate types, alkyl ethoxylates, alkyl sulfonates, phosphates, etc.)
A variety of chemistries can be combined to create an optimally stabilized dispersion
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16. ZetaSperse 3100 Dispersant
Optimum Dispersant Provides Maximum Color Development and Viscosity Stability
Carbon Black Dispersion
15.0 parts Pigment
31.3 parts Dispersant
1.0 parts Surfynol DF 75
52.7 parts water
Benchmark A
Viscosity: cps
Benchmark B
Viscosity: gel
Benchmark C
Viscosity: 30 cps
ZetaSperse Dispersant
Viscosity: 26cps
15.0 parts Raven 5000 Ultra III, 31.3 parts Dispersant,
1.0 parts Surfynol DF 75, 52.7 parts water 16
Copyright © Air Products and Chemicals, Inc. 2014
Copyright © Air Products and Chemicals, Inc. 2014

17. F.A.Z.T.  Formulator Assisting ZetaSperse Tool
Use F.A.Z.T. or Selector Guide to Choose Optimal Dispersant for Pigments or Fillers
An online tool that provides specific dispersant recommendations and starting point formulations
Accessible from mobile and desktop devices
Based on a database of >1500 global pigments
Formulas calculated from pigment properties, dispersant attributes and our own extensive testing and experience
Copyright © Air Products and Chemicals, Inc. 2014

18. Surfactant Usage in Grinds and Dispersions in Architectural Coatings
Surfactants can enhance dispersion attributes and improve processing in the three dispersion steps:
Wetting Dry Particles
Milling/Grinding to Disperse Particles
Stabilizing Dispersed Particles
A variety of benefits can be achieved
Dry pigment wetting and deaeration
Milling efficiency and color development
Letdown compatibility and resistance to shock and flocculation
Dispersion viscosity and color stability
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19. Dry Pigment Wetting and Deaeration
Dynamic wetting agents enable complete wetting and deaeration of pigments/particles during dispersion
Improves cut-in time
Enables a more efficienct milling process
Reduces microfoam and optimizes milling density
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20. Dry Pigment Wetting and Deaeration
10 g of P.B. 15:3 added to surface of additive solutions
Styrene-Acrylic Polymeric Dispersant Only
Same Polymeric Dispersant + 0.3% Dynamic Wetting Agent
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21. Milling/Grinding of the Pigment
Pigments agglomerate during the drying process, lowering performance
Milling is the process by which pigments are returned to an optimal particle size
milling
process
Requires energy
grinding, shearing, impacting
additives optimize process
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22. Grind Aids Improve Milling Efficiency
Grind aids can improve milling efficiency through optimal wetting and dynamic stabilization
Increased color development, gloss and hiding power
Reduced milling time; improved energy use
Dispersion stability and letdown benefits
Carbowet® GA-series surfactants are designed for these performance improvements
Greater milling efficiency
With Grind Aid
Without Grind Aid
Jumpstart from proper de-aeration
Greater milling effectiveness
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23. Grind Aid Surfactant Can Shorten Milling Time
0.3 wt.% Surfactant in an acrylic interior flat paint, 100 mm thick film
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24. Grind Aid Surfactant Can Enable Replacement of TiO2 with CaCO3
0.3 wt.% Surfactant in an acrylic Interior Flat Paint, 100 mm thick film
Opacity
Ratio of Replaced CaCO3 (%)
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25. Stabilizing Surfactant Dispersants for Resin-Containing Systems (Co-Dispersants)
ZetaSperse® 100-series dispersants are designed to enhance the stabilization and performance properties of ionic dispersants
Enhances letdown compatibility
Improves dispersion viscosity stability
Can lower dispersion viscosity allowing higher loadings
ZetaSperse 170 dispersant
Amine alkoxylate designed for acidic pigments such as some carbon blacks and mineral oxides
ZetaSperse 179 and 182 dispersants
Specialty high-HLB alcohol alkoxylates
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26. Shock and Letdown Compatibility
The dispersant plays a large role in preventing issues when the pigment grind is let down
Surface tension gradients can drive exchange between dispersions prior to equilibrium
This can cause the molecules stabilizing the colorant to leave the pigment surface and migrate into the white base paint and vice versa
Surfactants may “buffer” the system by providing dynamic stabilization similar to benefits seen in milling
Balancing pigment-dispersant differences between the grind and the letdown formulations
Copyright © Air Products and Chemicals, Inc. 2014

27. Dynamic Wetting Agents
Surfactant Selection Guidelines for Pigment Grinds and Dispersions
Dry pigment wetting
Faster milling
Color development
Letdown compatibility
Color stability improvement
Viscosity reduction
Stabilization enhancement
Stronger stabilization characteristics; Higher water solubility
Efficient wetting and surface tension reduction; Lower water solubility
Dynamic Wetting Agents
Dynol™ 360
Surfynol® 420,104, AD01
Grind Aids
Carbowet®
GA100, GA210,
GA211, GA221
Co-Dispersants
ZetaSperse®
170, 179, 182
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28. Surfactant Selection Guidelines for Pigment Grinds and Dispersions
With any dispersion, the stabilizing dispersant is identified first
F.A.Z.T. and ZetaSperse selectors
Other additives are selected to optimize the dispersion properties and process:
Dynamic wetting for incorporation and milling
Dynamic stabilization for milling and letdown compatibility
Equilibrium stabilization for robust dispersion, color, and viscosity stability
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29. Defoamers and Deaerators
Reduce or eliminate foam at surface or in bulk of coating
Can affect other properties such as wetting
Conventional defoamers
Molecular defoamers
Deaeators
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30. Conventional Defoamers
Organic oils or siloxane. May contain hydrophobic particles (silica, wax or polyurea)
Work by an incompatibility mechanism
Wet across bubble wall surface, weaken wall, bubble breaks
More incompatible -> stronger defoaming
More compatible -> weaker defoaming but less chance for craters
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31. Siloxane Defoamer in Exterior Flat Paint: Optimized Defoaming Strength and Compatibility
Silcone A
Defoamer
Silcone B
Airase® 5400
High quality flat white exterior house paint based on Rhoplex 464, Dow formulation W PVC = 45%, VOC = 50 g/L, Vol solids = 36%.
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32. Molecular Defoamers Specific Gemini (twin) surfactant structures
Work by molecular displacement of surfactants stabilizing foam
Eliminate microfoam and macrofoam
“Wetting defoamers” – also providing wetting agent function B B A A
Spacer
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33. Deaerators vs. Defoamers
Air phase
Liquid phase
Defoaming
Deaeration
Defoamers eliminate macrofoam – bubbles present on the surface of the paint
Deaerators eliminate microfoam (tiny air bubbles in bulk coating). Are less prone to diffuse to coating surface and difficult to remove.
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34. Siloxane Deaerator in an Air- Assisted Spray Applied coating
Clear wood coating based on self-crosslinking acrylic (DSM). Viscosity = 60 sec DIN cup 4. Solids content ~ 37% by weight.
VOC ~ 200 g/L.
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35. Defoamer and Deaerator Selection Guidelines
Low viscosity
Letdown
Pigment Grinds
High PVC
Stronger defoaming, less compatible
More compatible, weaker defoaming
Surfynol MD20
Airase 5600, 5700
Airase 4500, 5400, 5500
Surfynol DF-58
Airase® 5100, 5200
Surfynol® DF58
Thin films
Moderate PVC
Moderate shear
High viscosity
High shear
Low PVC
Thick films
Clear coats
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36. Defoamer and Deaerator Selection Guidelines
Match formulation and application requirements to defoamer properties and benefits
What are the paint characteristics:
Binder, PVC, viscosity, thickness, dry time, gloss
What surfactants are being used? Are they stabilizing foam?
Where and how does foam occur (grind, mixing, shaking, application); amount of agitation?
How is the paint produced?
How is the coating applied?
Macrofoam or microfoam?
Are silicones acceptable?
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