| Titre : |
Novel metal-free catalysts for epoxy carboxy coatings |
| Type de document : |
texte imprimé |
| Auteurs : |
Ravi Ravichandran, Auteur ; Michael Emmet, Auteur ; Matthew Gadman, Auteur ; John Florio, Auteur ; Steven Woltornist, Auteur |
| Année de publication : |
2019 |
| Article en page(s) : |
p. 28-40 |
| Note générale : |
Bibliogr. |
| Langues : |
Américain (ame) |
| Catégories : |
Automobiles -- Vernis
Catalyseurs
Essais accélérés (technologie)
Essais de résilience
Essais dynamiques
Formulation (Génie chimique)
Polyacryliques
Réticulation (polymérisation)
vernis en phase solvant
Viscosité
|
| Index. décimale : |
667.9 Revêtements et enduits |
| Résumé : |
A new class of metal-free catalysts has been developed that promotes the crosslinking reaction of epoxy functional polymers with carboxyl functional compounds and polymers. Particularly effective at much lower cure temperatures, these catalysts provide stable single package formulations and improved resistance properties. In addition, unlike amine-based cmpounds, these catalysts do not yellow during cure or on over-bake. |
| Note de contenu : |
- INTRODUCTION : Epoxy acid automotive clearcoats - Epoxy acid-based powder coatings - Binder, crosslinking chemistry, and catalysis
- EXPERIMENTAL : Experiment I : catalyst studies on NACURE XC-324 in a 1K SP epoxy/carboxy clearcoat (Materials and preparation of 1K SB epoxy/carboxy clearcoat formulation - Film preparation of 1K SB epoxy/carboxy clearcoats - Film properties of catalyzed clearcoats - Viscosity stability of epoxy carboxy liqiud coatings - Gel fraction studies - QUV resistance of catalyzed epoxy carboxy coatings - Humidity exposures of catalyzed epoxy carboxy coatings - Crickmeter abrasion - Overbake resistance) - Experiment II : Catalyst studies on NACURE XC-355 in a 2K SB epoxy/carboxy clearcoat (materials and preparation of 2K SB/epoxy carboxy clearcoat formulation - Film preparation of 2KSB epoxy/carboxy clearcoat - Film preparation of HMMM crosslinked acrylic and epoxy/carboxy clearcoats - Cure response of acrylic OH/HMMM and acrylic COOH/GMA - Environmental etch comparison of acrylic OH/HMMM vs acrylic COOH/GMA
- Fig. 1 : Epoxy carboxy crosslinking reaction
- Fig. 1a : Viscosity stability of epoxy/carboxy SB coatings (60°C storage)
- Fig. 1b : Viscosity stability of epoxy/carboxy SB coatings (50°C storage)
- Fig. 1c : Viscosity stability of epoxy/carboxy SB coatings (ambient storage)
- Fig. 2 : Percent weight retention after 6h of reflux with acetone/metanol (1/1)
- Fig. 3 : Yellowness measurements after QUV exposure
- Fig. 4 : Change in gloss following crockmeter abrasion
- Fig. 5 : Yellowing (b*) and total color (E*) change of clearcoats after overbake
- Fig. 6 : Oscillation curve of complet viscosity and temperature as a function of time
- Fig. 7 : MEK resistance of hardness of epoxy/acid clearcoats-100°C/30 min bake
- Table 1 : Classes of available catalyst technologies
- Table 2 : 1K SB epoxy/carboxy clearcoat
- Table 3a : Film properties of carboxy functional acrylic and GMA epoxy-120°C/30 min
- Table 3b : Film properties of carboxyl functional acrylic and GMA epoxy - 110°C/30 min
- Table 4 : Viscosity stability of epoxy carboxy liquid coatings (60°C/16 h)
- Table 5 : Gel fraction studies after 6h Soxhlet extraction with acetone/methanol (1/1)
- Table 6 : Yellowness measurements after QUV exposure-b*values
- Table 7 : Yellowness measurements after QUV exposure-Δ*values
- Table 8 : Humidity exposures of catalyzed epoxy/carboxy coatings-Blister ratings
- Table 9 : Visual rating for crockmeter tests-0-R rating
- Table 10 : Images with visual rating and change in gloss following crockmeter abrasion
- Table 11 : Change in color values of catalyzed clearcoats after overbake
- Table 12 : 2K solventborne epoxy/carboxy clearcoat
- Table 13a : Pre-experiment steps for oscillation tests
- Table 13b : Protocol for oscillation tests
- Table 14 : Film properties of carboxyl functional acrylic and GMA epoxy-100°C/30 min
- Table 15 : Yellowing resistance follwing 100°C/30 min overbake
- Table 16 : Total color change following 100°C/30 min overbake
- Table 17 : (a) Hydroxyl functional acrylic/HMMM vs (b) acid functional acrylic/GMA epoxy
- Table 18 : MEK resistance of (a) acrylic OH/HMMM vs (b) acrylic COOH/GMA
- Table 19 : Acid etch resistance of (a) acrylic OH/HMMM vs (b) acrylic COOH/GMA |
| En ligne : |
https://drive.google.com/file/d/1hbklMv6qE5mymZKYqIQ2MXKYVZtkH1VA/view?usp=drive [...] |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=32045 |
in COATINGS TECH > Vol. 16, N° 3 (03/2019) . - p. 28-40
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