the challanges of waterborne coatings nürnberg fair

Nürnberg FairT. PalmRD& I Solutions Manager Wood Coatings EMEA

The Challanges of Waterborne Coatings

Presentation about chemistry needs a lector:

Wood Coatings Europe | RD&I Distribution Finishes 2

•  Thomas Palm•  RD&I Manager •  49 years old•  21 years with Coatings•  Responsible for 60 R&D people•  In 5 countries (Germany/Sweden/

Türkey/ME)That´s

me

And a good assistant who can easily help with any king of experiment like…


Explosions!

Content

Difference between Solvent borne & Waterborne Coatings

Waterborne Binders. Dispersion technology today.

Typical Raw materials used in Waterborne Coatings

Difference between Interior & Exterior Waterborne Coatings


Content






1. Experiment: How to make Gold!


Experiment:

1. Experiment: How to make Gold!

A typical Waterborne Coatings ( 2 Pack Polyurethan Coating) is added to much Isocyanide Hardener)

…. See what happens.


Experiment:

The difference between Waterborne & Solvent borne CoatingDefinition: Solvent Borne Coating

The binder is solved in the Solvent … the lacquer can be diluted further by a solvent which is not water

Waterborne CoatingThe binder is dispersed in the Solvent (Water)The lacquer can be diluted by water (mainly)Note: You are still able to add some solvent


Experiment:Dilution of a binder!

Content





What is color ?


Why a dispersion and why is it so complicate? A natural dispersion/emulsion we all know:

Fat emulsified by lecithin.How tricky can milk be if not treated right (heat, bacteria..)


Acrylic Binders are the backbone of Waterborne CoatingsAcrylic Binders made by emulsion polymerization processThis is done in huge reactors , fully capsulated and with highly process control


Experiment:Disperse A SB Binder

Film Formation of a solvent borne coating

2 K PU Solvent Borne

Film Formation:

1.The Solvent evaporates after application of the coating

2. The hardener (Isocyanide) reacts with the binder molecules

Physical drying

Coalescence and inter-diffusion of polymer chains

Evaporation of water

Particle deformation

Experiment:Film Application

Film formation of a waterborne coating

Atomic Force Microscopy

TOPOGRAPHIC MODE TAPPING MODE100 nm

TOPOGRAPHIC MODE TAPPING MODE100 nm

Before coalescence

After coalescence

Dispersion Gradient Morphology

Film-formation of acrylic dispersions

“Spaghetti Modell”


Experiment:Nuddles

Core-shell: micro phase separationGradient morphology:

gradual change in copolymer composition no phase separation

Combination: hardness and flexibility

Particle morphology

Homogeneous Core-shell Gradient

Effect of particle-morphology on final film-morphology

Phase-separated

Homogeneous

Hard and soft domains

Uniform Tg

In can clarity


Content





What is color ?


Typcial Rawmaterials used in WB Coatings  Thickeners  Pigments/ Colorants  Extenders, Fillers

Waxes, SilicaWetting AgentsDefoamersAcrylic BindersWater


Thickeners

•  Thickeners are used to increase viscosity

•  Created a sprayable or brushable product

•  To create „Sagging Resistance“ or max wet layer thickness for horizontal spraying

•  Typical thickeners are PU thickener or acrylic thickeners

•  Need for correct balance of, thickener level


Acryl Thickener

Pigments

Pigments are used for the color and the hiding power of an opaque coatingTitaniumdioxid is the world widest used white pigmentUsed in coatings but also in tooth pasta, wall paints, road marking, cosmetics…..


Pigments

•  Pigments are used for color•  For the easiness of application for

the end-user but also in production:

•  Pigment colorants are used•  Because:

•  Pigments have to be grinded (Perlmilled) into the lacquer

•  Colorants can be stirred by hand•  Or with a mixer

•  Different to Dyes!. Dyes are solved in the liquid. Pigments are solid!


Colorants

Extenders/Fillers/Waxes/Silica

•  e.g. Talk•  From Natural Sources•  For sanding/adhesion

properties•  A lot more of natural

products•  like Calciumcarbonat (Chalk)•  Mica

•  Waxes/Silica•  As Matting Agents•  Helps blocking•  Antiscratch


Wetting Agents

•  In principal like „dishwashers“•  Help to reduce the surface

tension•  Help to „wet“ the pigments•  But: Create foam

•  During production•  During application

•  Therefore needs a defoamer !


Wetting Of Talk

Defoamer

•  Reduce the foam •  During Production•  During Application

•  Are „borderline“ accepted additives in a waterborne formulation.

•  Too much defoamer•  Can cause craters

This has to be balanced


Defoaming Experiment

Content




Difference between Interior & Exterior Coating Systems

What is color ?


Difference between Interior & ExteriorWood Coatings

Interior•  85% SB, 15 % WB•  2 Pack, e.g. NCO•  Scratch resistant

chemical resistant•  Hard•  Up to mirror like

high gloss (like cars)

Exterior•  > 95% WB•  1 Pack•  UV Resistant

•  Flexible•  Gloss level up to 70

max

Difference between Interior & ExteriorWood Coatings

Interior•  EU: Not regulated•  EU: BPD yes, no use•  Typical

Technologies•  1K/2K WB PU•  1K/2K SB PU•  Acid-Cat•  Nitro, UPE, •  WB UV, 100%UV

Exterior•  EU: VOC regulated•  EU: BPD yes•  Typical Technologies

•  1K WB Acrylic•  1K SB Alkyd•  1K WB Alkyd emulsions•  2K System

Conclusion

WB

• Waterborne Coatings are very complex formulations

• More then 20 raw material can be used in 1 WB Formula

Raw

• High End Technology is used and developed every day to reach ultimate performance

•  Interior and Exterior demands are differing

Systems•  Interior and Exterior demands are differing•  Interior Hard, Exterior Flexibel


If you know feel confused. Time for a brake!

the challanges of waterborne coatings nürnberg fair

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