Titre : |
Waterbased epoxy technologies for metal coating applications |
Type de document : |
texte imprimé |
Auteurs : |
Daniel Suckley, Auteur |
Année de publication : |
2020 |
Article en page(s) : |
p. 78-86 |
Note générale : |
Bibliogr. |
Langues : |
Anglais (eng) |
Catégories : |
Anticorrosifs Anticorrosion Epoxydes Essais de brouillard salin Formulation (Génie chimique) Métaux -- Revêtements protecteurs Revêtements en phase aqueuse
|
Index. décimale : |
667.9 Revêtements et enduits |
Résumé : |
Epoxy resins are well known as high performance materials in various construction and metal coating applications, providing the combined properties of chemical resistance, adhesion, corrosion resistance and mechanical strength. They are one of the best materials available when comparing performance against relative cost and this has in turn led to epoxies being the substance of choice for use as flooring materials and for the corrosion protection of metal. They are often supplied as a two component system comprising a resin and a curing agent. Increasing environmental concems worldwide has led industries to experience a graduai shift towards water-based technologies as limits on emissions, VOC content and safety rulings become more prevalent across the world. Epoxy resins by their very nature are fundamentally incompatible with water and careful design of the molecule be it a curing agent or epoxy resin is crucial to deliver the products in aqueous media but when fully cured give the same high performance as conventional epoxy based materials. This careful design often leads to performance that exceeds that of conventional technologies which this paper intends to describe in detail. High molecular weight resins can be supplied at low easy-to-use viscosities giving performance advantages in the coating such as fast drying times and long pot )ives. Curing agents were designed with low amine contents through careful adjustments to their chemical structure giving a perfect balance between water miscibility and full compatibility with epoxy resins. The Combined waterbased resin and hardener system is further formulated in a 2 -pack corrosion protection coating that give high performance even when applied at relatively low dry film thickness, and is comparable to that ach ieved with conventional solvent-based coatings. |
Note de contenu : |
- Waterbased epoxy coating development
- Performance testing
- Fig. 1 : The chemical structure of a bisphenol A diglycidyl ether epoxy resin (BADGE)
- Fig. 2 : Reactive sites on a standard epoxy resin
- Fig. 3 : Film-forming mechanism of liquid-applied coatings
- Fig. 4 : The basic composition of a high performance waterbased epoxy resin
- Fig. 5 : Plot showing the viscosity rise profile of a waterbaset type epoxy emulsion (WB epoxy) and a liquid epoxy resin (YD 128) cured with the same curing agent
- Fig. 6 : Plot Showing the drying times of A waterbased type 1 epoxy emulsion (WB EPDXY) and a liquid epoxy resin (YD 128) cured with the same curing agent
- Fig. 7 : The generic chemical structure of a waterbased curing agent
- Fig. 8 : Viscosity profiles and coalescing behaviour of the base system (resin and curing agent)
- Fig. 9 : Adhesion properties of the formulated coating throughout it pot life
- Fig. 10 : Appearance of coated panels after 2000 hours of salt spray exposure (ASTM B117)
- Fig. 11 : Test data and coating appearance after salt water immersion
- Fig. 12 : The appearance of a waterbased coated panel and a solvent-based coated panel after 2000 hours salt spray exposure (ASTM B117)
- Table 1 : Physical specifications of the waterbased epoxy (Cetepox 484 R) and waterbased curing agent (Epotec THW 4510)
- Table 2 : Panel evaluation after salt-spray exposure
- Appendix A : Formulation for a 2-packWaterbased corrosion protection coating
- Appendix B : A summary of the main coating properties of the formualtion in A
- Appendix C : Formulation for a 2-packSolvent based corrosion protection coating |
En ligne : |
https://drive.google.com/file/d/1e75Op2FUkYv3N3Fd-eyPy5nBSgkLGw5M/view?usp=drive [...] |
Format de la ressource électronique : |
Pdf |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=35203 |
in PAINTINDIA > Vol. LXX, N° 12 (12/2020) . - p. 78-86