High performance Acrylic Dispersions for Masonry and Wood Coatings

Transcription

1 High performance Acrylic Dispersions for Masonry and Wood Coatings Harald Petri, Ulrich Désor, Dr. Matthias Junk Celanese ASEFAPI, 5 th November 2015

2 Agenda Polymer Dispersions Basic Knowledge Homogeneous Acrylic Dispersions Advanced Polymerization Technologies Core/Shell -Technology New Gradual Composition (GC) Technology from Celanese Application Test Results Summary 2

3 What is a Polymer Emulsion? ( in fact : Polymer Dispersion ) Water Homogeneous Medium Synonym Polymer-Dispersion Polymer Colloid Polymer Particle Heterogeneous Medium Latex Polymer-Emulsion A polymer dispersion consists of very small polymer particles distributed in the homogeneous phase water 3

4 Structure of a polymer particle Polymer Properties - chemical composition - glass transition temperature (Tg) - degree of crosslinking - molecular weight Colloidal Properties - emulsifier, type, amount - number of sphere charges - number of charges in serum A polymer particle is composed of a polymer core and a colloidal shell which has a strong impact on workability 4

5 Film formation Phase I Evaporation of water Phase II Phase III Deformation of particles Coalescence Proper film formation only occurs if ambient temperature is above MFFT! Phase IV Interdiffusion of polymer chains Proper film formation needed to obtain a robust polymer film 5

6 Film formation Minimum Film Formation Temperature ( MFTT ) 0 C Temperature Gradient 20 C MFFT 0 C 18 C >20 C MFFT Bench The Minimum Film Formation Temperature ( MFFT ) is the lowest temperature required to obtain a polymer film without any defects. MFFT can vary from 0 C ( freezing water ) to 100 C ( boiling water )! 6

7 Polymer hardness Glass Transition Temperature ( Tg ) Tg of Polymer Film 100 o C 25 o C -100 o C stiff and briddle leather-like tacky Plastic Coatings Masonry Coatings EWC ( Pure Acrylic ; Tg = 98 C ) ( Pure Acrylic ; Tg = 23 C ) ( Pure Acrylic ; Tg = -30 C ) Fibre Cement Coatings Masonry Coatings ( Pure Acrylic ; Tg = 48 C ) - low emission - ( Pure Acrylic; Tg = 6 C ) below Tg : Polymer chains like uncooked Spaghetti ( rigid ) above Tg : Polymer chains like cooked Spaghetti ( flexible ) 7

8 MFFT ( C) Correlation between MFFT and Tg Tg = MFFT Styrene-Acrylic VAE T g ( C) MFFT correlates with Tg in many cases, but is not the same. Tg MFFT for hydrophobic polymers ( e.g. Styrene/Acrylic ). MFFT can be lowered by adding suitable solvents and/or coalescing agents. For hydrophilic polymers ( e.g. VAE ) water can act as coalescing agent ( Hydroplastification ). Heterogeneous dispersions could have more than one Tg whereas every dispersions has only one MFFT. 8

9 Film Forming Process of homogenous Polymer Dispersions ( soft vs. hard ) Lowering of MFFT by adding suitable coalescent agents MFFT /Tg [ C ] hard Dispersion Production Addition of coalescent agents Evaporation of coalescent agents Hard Polymer Film 10 soft Dispersion Storage Application Drying typical ambient temperature 0 Soft Polymer Film time 9

10 Combining opposing properties Film forming without any addition of coalescent agents requires a soft polymer dispersion and thereby a relative soft polymer film hardness. Low Glass Transition Temperature (Tg)? To achieve a better polymer hardness ( low blocking ) especially at high temperatures hard polymer dispersions are required. High Glass Transition Temperature (Tg) Advanced Polymerization Technologies Best of both worlds Optimizing the balance between Soft Polymer Phase ( low Tg ) and Hard Polymer Phase ( high Tg ). Soft phase enables the film forming at lower temperatures and reduced demand of coalescing agents whereas the high Tg phase improves film hardness and block resistance. Celanese High performance Acrylic Dispersions 10

11 Further optimization of the polymer film properties Cross-Cut Test Improvement of durability e.g. chemical resistance, stain resistance Improvement of adhesion on critical substrates e.g. old alkyd paints Cross-linking Wet adhesion Celanese High performance Acrylic Dispersions 11

12 Summary : Optimization tools Low MFFT / Tg - required to achieve a proper film forming at low temperatures without adding suitable coalescent agents. High Tg - for applications where a hard, no blocking polymer film is required. Monomer Composition Cross-Linking - improvement of mechanical and chemical durability. Wet adhesion - optimized adhesion properties on critical substrates. Functionality Advanced Polymer Dispersions - high performance dispersion with optimized balance between film formation ( MFFT ) and polymer hardness. Polymer Morphology 12

13 Mowilith Homogeneous Acrylic Dispersions Product guide Masonry Coatings Solids [ % ] Nano 9420 ph-value 7,5 8,5 8,5 8,5 6,0 8,5 Viscosity [ mpas ] MFFT [ C ] ca. 13 ca. 1 ca. 15 ca. 0 ca. 0 ca. 6 Tg [ C ] ca. 30 ca. 6 ca. 21 ca. 10 ca ca. 18 Functionality? no no yes yes yes no Suggested Applications Exterior Paints Plasters Textured Coatings Exterior Paints Plasters Textured Coatings Masonry Coatings House Paints Concrete Coatings Masonry Coatings House Paints Elast Wall Coatings ( EWC ) Nano Hybrid Paints Binders based on homogeneous polymerization 13

14 Mowilith Homogeneous Acrylic Dispersions Product guide Wood Coatings & Gloss Paints Solids [ % ] ph-value 8,5 8,5 8,9 8,5 Viscosity [ mpas ] MFFT [ C ] ca. 15 ca. 0 ca. 10 ca. 15 Tg [ C ] ca. 21 ca. 10 ca. 23 ca. 25 Functionality? yes yes yes yes Suggested Applications Weather protection wood paints Wood Stains Weather protection wood paints Wood Stains Gloss / Trim Paints Wood Stains Gloss / Trim Paints Binders based on homogeneous polymerization 14

15 Advanced Polymerization Technologies Heterogeneous Polymerization Core-Shell Particle Particle with GC- Technology Celanese new Gradual Composition ( GC) - Technology How to combine opposed mechanical properties in one binder 15

16 Heat flow (mw) Heat flow (mw) Advanced Polymerization Technologies Core-Shell vs. GC Technology Core-Shell Particle Particle with GC Technology Defined phases of hard and soft parts Abrupt phase boundaries (breaking point) Gradual change from hard to soft polymer fraction Two defined Tg broad Tg-range Temperature ( C) Temperature ( C) 16

17 Blocking [ g/6.5 cm 2 ] Elongation at break [ % ] Advanced Polymerization Technologies Impact of morphology % MMA : 50 % BuA Tg =22 C phase 1: 20% MMA : 80 % BuA phase 2: 80 % MMA : 20% BuA phase 1 : phase 2 = 1 : Tg 1 = -18 C Tg 2 = 80 C Homogeneous emulsion Heterogeneous emulsion ( Core-Shell ) 0 Blocking and Elongation of homogeneous and heterogeneous dispersion with same total monomer ratio ( 50% MMA / 50% BuA ) 17

18 Elongation at break (%) Advanced Polymerization Technologies New Gradual Composition (GC) - Technology Excellent balance between blocking resistance and elongation at break/elasticity Dispersions with GC-Technology 60 Equipped with a broad property profile to meet market needs in gloss paints, lacquers and trim paints area Blocking (50 C) Core-Shell Dispersions Linear relation between blocking resistance and elongation at break with different Core- Shell-Grades Either good blocking resistance or good elongation at break Mowilith 7510 is providing a unique balance between hardness and elasticity enabled through the new GC-Technology 18

19 Advanced Polymerization Technologies New Gradual Composition (GC) - Technology Key advantages High gloss MFFT=0 C Styrene-free Excellent elasticity and at the same time highly block resistant Excellent chemical and solvent resistance with great wet adhesion (self crosslinking) Good outdoor durability so far results are in line with expectations Mowilith 7510 : Unification of most important properties for application in gloss paints, lacquers and trim paints 19

20 Gloss units Application test results Gloss after 7 days of drying ( pigmented gloss paint white ) Haze sf = solvent-free formulation sc = solvent-containing formulation 20

21 Application test results Blocking after 1 day of drying at RT (in white pigmented gloss paint) Elongation at break after 28 days of drying (in white pigmented gloss paint) Drying: 1d at room temperature Loading: 1 hour at 50 C with 2kg/6,25 cm² Mowilith 7510 : Excellent elongation at break / elasticity and at the same time highly block resistant 21

22 Application test results Dry film resistance ( pigmented gloss paint white ) Dispersion Recipe Scratch Alcohol Coffee 1d 7d 1d 7d 1d 7d 5 min 30 min 5 min 30 min 7510 sf L6045 FI core/shell 1 sf L6045 FI core/shell 2 sf L6045 FI core/shell 3 sc L6003 FAI homogeneous sc L6003 FAI sf = solvent-free formulation sc = solvent-containing formulation Rating: 1: good 6: worse Mowilith 7510 : Convincing dry film resistance performance, even in solvent-free formulations 22

23 Mowilith heterogeneous Acrylic Dispersions Product guide Wood Coatings & Gloss Paints Polymer Morphology Core Shell Core Shell Core Shell Core Shell Gradual Composition Solids [ % ] ph-value 8,5 8,5 8,5 7,5 8,5 Viscosity [ mpas ] MFFT [ C ] ca. 1 ca. 0 ca. 8 ca. 24 ca. 0 Tg [ C ] ca. -10 / 50 ca. -3 / 85 ca. 13 / 65 ca. 28 / Functionality? yes yes yes yes yes Suggested Applications Wood Stains Gloss/Trim Paints Corrosion Protection Wood Stains Joinery Coatings Gloss/Trim Paints Wood Stains Furniture & Parguet Coatings Gloss/Trim Paints ( low VOC ) 23

24 Summary Acrylic Dispersions are perfect alternatives to solvent-based binders to reduce the VOC content of coatings while remaining the desired properties and application performance. Acrylic Dispersions have a strong reputation regarding versatility, UV-resistance and durability on various substrates including mineral, wood and metal. Mowilith Acrylic Dispersions with homogeneous particle morphology enables the formulation of high performance coatings with long term durability. Through the further optimization of wet adhesion properties the coatings properties improved as well, especially on wood. Mowilith Acrylic Dispersions based on Core-Shell Technology offer excellent block resistance in high gloss formulations at low pvc. Furthermore they provide excellent properties in wood stain applications. ( e.g. early block resistance ) Mowilith 7510 based on the new Gradual Composition (GC) - Technology represents the next generation of Acrylic Dispersion with optimized and excellent balance between high block resistance and elasticity. It s the perfect binder for low emission gloss paints and coatings applications in the professional and DIY segment. 24

25 Disclaimer 2015 Celanese or its affiliates. All rights reserved. This publication was printed based on Celanese s present state of knowledge, and Celanese undertakes no obligation to update it. Because conditions of product use are outside Celanese s control, Celanese makes no warranties, express or implied, and assumes no liability in connection with any use of this information. Nothing herein is intended as a license to operate under or a recommendation to infringe any patents. Celanese, registered C-ball design and all other trademarks herein with, TM, SM, unless otherwise noted, are trademarks of Celanese or its affiliates. Contact Information Europe Celanese Industriepark Höchst Frankfurt am Main, Germany Mowilith.info@celanese.com celanese.com/emulsion-polymers 25

26 Thank you for your attention