| Titre : |
Self-crosslinking surfactant free acrylic dispersions |
| Type de document : |
texte imprimé |
| Auteurs : |
Fred Bückmann, Auteur ; Ad Overbeek, Auteur ; Tijs Nabuurs, Auteur |
| Année de publication : |
2001 |
| Article en page(s) : |
p. 53-60 |
| Note générale : |
Bibliogr. |
| Langues : |
Anglais (eng) |
| Index. décimale : |
667.9 Revêtements et enduits |
| Résumé : |
Surfactant free acrylic dispersions with with a core-shell particle morphology are described, where the shell polymer is a self-crosslinking polymeric dispersant used for the stabilisation of the polymer particle. The phase ratio's and the magnitude in which the Tg's of the polymeric dispersant and the subsequently formed polymer differ were found to be of crucial importance to obtain a very low MFT and hence very good film formation combined with very high hardness and good anti blocking properties. In addition films cas from these dispersions have excellent chemical resistances which make these dispersions very useful as binders for high performance coating systems. |
| Note de contenu : |
- POLYMER ENTANGLEMENT IS CRUCIAL FOR FILM FORMATION
- HYDROPHILIC LOW MOLECULAR WEIGHT POLYMER BACKBONES : Water acts as plasticizing agent - Additional crosslinking to overcome poor water resistance
- SEQUENTIAL POLYMERISATION FOR PHASE SEPARATED PARTICLE MORPHOLOGIES : Low Tg for film formation plus high Tg for durability - Core/shell emulsions usually require surfactant
- CROSSLINKING FOR IMPROVED CHEMICAL RESISTANCE : Reaction between polymer chains or emulsion particles - A variety of crosslinking mechanisms
- THE ROLE OF THE SURFACTANT : Migration is a problem - Copolymerisable surfactants - reactivity is difficult to adjust - Polymeric surfactants with reduced mobility - Stabilisation by anionic initiators - only for low solids
- CONCEPT OF SURFACTANT FREE DISPERSIONS WITH SELF DISPERSING POLYMERS : Creation of core/shell particles through secondary dispersion - More rapid buildup of toughness and resistance
- POLYMERIC SELF-CROSSLINKING SURFACTANT
- PROPERTIES OF POLYMERIC SELF CROSSLINKING SURFACTANT : Surface tension is reduced effectively - Stable dispersion with low particle size - Core/shell geometry verified
- THE EFFECT ON FILM FORMATION : Crosslinks at the particle surface are mos effective - Crosslinking both core and shell polymers - Surfactant does not exude
- INVESTIGATING MODEL DISPERSIONS : Tg affects surface hardness - Acid value influences MFT but not hardness - Very good blocking properties with low Tg material
- APPLICATION IN HIGH PERFORMANCE COATINGS : Translucent industrial wood coatings with excellent wetting - Flexible and anti-blocking coatings for joinery |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=33499 |
in EUROPEAN COATINGS JOURNAL (ECJ) > N° 7-8/01 (07-08/2001) . - p. 53-60
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Self-crosslinking surfactant free acrylic dispersions in EUROPEAN COATINGS JOURNAL (ECJ), N° 7-8/01 (07-08/2001)
