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Specialty Additives for Architectural Coatings PNWSCT Coatings Fest 2014 Rocky Prior, Charlie Hegedus, Ingrid Meier Copyright © Air Products and Chemicals,

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Presentation on theme: "Specialty Additives for Architectural Coatings PNWSCT Coatings Fest 2014 Rocky Prior, Charlie Hegedus, Ingrid Meier Copyright © Air Products and Chemicals,"— Presentation transcript:

1 Specialty Additives for Architectural Coatings PNWSCT Coatings Fest 2014 Rocky Prior, Charlie Hegedus, Ingrid Meier Copyright © Air Products and Chemicals, Inc. 2014

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 Copyright © Air Products and Chemicals, Inc. 2014

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 Copyright © Air Products and Chemicals, Inc. 2014

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 Copyright © Air Products and Chemicals, Inc. 2014

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 Copyright © Air Products and Chemicals, Inc. 2014

6 Low Foam Dynamic Wetting Agent: No Adverse Viscosity Effects in Vinyl Acrylic Wall Paint 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. Copyright © Air Products and Chemicals, Inc White semi-gloss wall and trim vinyl acrylic interior paint with 0.5% by weight surfactants. VOC = 35 g/L.

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 Copyright © Air Products and Chemicals, Inc. 2014

8 0.9% Dynol™ 360 Commercial paint 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. Superwetting Surfactants Copyright © Air Products and Chemicals, Inc. 2014

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 Copyright © Air Products and Chemicals, Inc. 2014

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. Copyright © Air Products and Chemicals, Inc. 2014

11 Lowering MFFT with Coalescing Surfactant – Dynol™ 360 Surfactant Minimum Film Formation Temperature ( o C) Weight Percent Coalescing Surfactant Copyright © Air Products and Chemicals, Inc Acrylic-polyurethane clear wood coating, 40% volume solids, VOC = 95 g/L.

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, (*) 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 Copyright © Air Products and Chemicals, Inc. 2014

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.) Copyright © Air Products and Chemicals, Inc. 2014

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) Copyright © Air Products and Chemicals, Inc. 2014

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 TiO 2 -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 15 Copyright © Air Products and Chemicals, Inc. 2014

16 ZetaSperse 3100 Dispersant Viscosity: 26cps Benchmark B Viscosity: gel Benchmark A Viscosity: 9350 cps Benchmark C Viscosity: 30 cps Carbon Black Dispersion 16 Copyright © Air Products and Chemicals, Inc Optimum Dispersant Provides Maximum Color Development and Viscosity Stability 15.0 parts Raven 5000 Ultra III, 31.3 parts Dispersant, 1.0 parts Surfynol DF 75, 52.7 parts water 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: 1.Wetting Dry Particles 2.Milling/Grinding to Disperse Particles 3.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 18 Copyright © Air Products and Chemicals, Inc. 2014

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 19 Copyright © Air Products and Chemicals, Inc. 2014

20 Dry Pigment Wetting and Deaeration Styrene-Acrylic Polymeric Dispersant Only Same Polymeric Dispersant + 0.3% Dynamic Wetting Agent 10 g of P.B. 15:3 added to surface of additive solutions 20 Copyright © Air Products and Chemicals, Inc. 2014

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 21 Copyright © Air Products and Chemicals, Inc. 2014

22 Grind Aids Improve Milling Efficiency Greater milling efficiency With Grind Aid Without Grind Aid Jumpstart from proper de- aeration Greater milling effectiveness 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 Copyright © Air Products and Chemicals, Inc. 2014

23 Grind Aid Surfactant Can Shorten Milling Time 0.3 wt.% Surfactant in an acrylic interior flat paint, 100 m thick film Copyright © Air Products and Chemicals, Inc. 2014

24 Grind Aid Surfactant Can Enable Replacement of TiO 2 with CaCO wt.% Surfactant in an acrylic Interior Flat Paint, 100 m thick film Ratio of Replaced CaCO 3 (%) Opacity Copyright © Air Products and Chemicals, Inc. 2014

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 25 Copyright © Air Products and Chemicals, Inc. 2014

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 26 Copyright © Air Products and Chemicals, Inc. 2014

27 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 Surfactant Selection Guidelines for Pigment Grinds and Dispersions Copyright © Air Products and Chemicals, Inc. 2014

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 28 Copyright © Air Products and Chemicals, Inc. 2014

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 Copyright © Air Products and Chemicals, Inc. 2014

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 Copyright © Air Products and Chemicals, Inc. 2014

31 Siloxane Defoamer in Exterior Flat Paint: Optimized Defoaming Strength and Compatibility Silcone A Defoamer Silcone B Defoamer Airase ® 5400 Defoamer Copyright © Air Products and Chemicals, Inc. 2014

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 A A Spacer BB Copyright © Air Products and Chemicals, Inc. 2014

33 Deaerators vs. Defoamers 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. Deaeration Copyright © Air Products and Chemicals, Inc. 2014

34 Siloxane Deaerator in an Air- Assisted Spray Applied coating Copyright © Air Products and Chemicals, Inc. 2014

35 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 Copyright © Air Products and Chemicals, Inc Defoamer and Deaerator Selection Guidelines

36 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? Copyright © Air Products and Chemicals, Inc. 2014

37 Thank you tell me more Copyright © Air Products and Chemicals, Inc. 2014


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