[article]
Titre : |
Isocyanate free polyurethane technology for wood coating applications : approaches to reducing VOC in clearcoat formulations |
Type de document : |
texte imprimé |
Auteurs : |
Jeffrey Wexler, Auteur ; Rebecca Ortiz, Auteur ; Nahrain Kamber, Auteur ; Nicholas Leonard, Auteur ; Yanxiang Li, Auteur ; Paul Popa, Auteur |
Année de publication : |
2017 |
Article en page(s) : |
p. 42-52 |
Note générale : |
Bibliogr. |
Langues : |
Américain (ame) |
Catégories : |
Bois -- Revêtements Bois -- Vernis Durée de vie en pot Formulation (Génie chimique) Polyuréthanes Réduction des composés organiques volatils Réticulation (polymérisation) Revêtements sans isocyanates Rhéologie Solvants organiques Viscosité
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Index. décimale : |
667.9 Revêtements et enduits |
Résumé : |
Industrial wood surfaces, such as furniture and cabinetry, require coatings to help protect and extend their life. Polyurethane coatings provide enhanced appearance, stain and chemical resistance, as well as exterior durability. When formulated as ambient cure systems, traditional two-component polyurethanes typically must balance cure speed for pot life. This article describes clearcoat formulations using a novel nonisocyanate polyurethane technology based on the reaction of a polycarbamate with polyaldehydes. A major benefit of this system is the ability to decouple pot life and cure speed without adversely affecting fast hardness development and quick dry time. For the end user, this can lead to faster return to service and higher production rates. Additional coating benefits are high clarity, excellent durability and chemical resistance, and fast sandability. Reducing VOC is a major need for the applicator, and different approaches are presented aimed at reducing the VOC of a clear formulation for wood, which can maintain a useful pot life while retaining its fast cure and dry properties. An example is shown where a clear formulation is modified to meet the requirements of the Utah VOC Rule R307-343 Emission Standards for Wood Furniture Manufacturing Operations for acid-cure alkyd amino topcoats (1.0 lb solvent per lb of solid), which was chosen for its relatively higher VOC restriction. This is a traditional solventborne technology, and the current carbamate resin, which is in n-butyl acetate at 67% solids, can be formulated using exempt solvents as low as 450 g/L just meeting this standard. To reach more stringent VOC regulation targets below 450 g/L would require producing the carbamate resin dispersed in a VOC-exempt solvent. |
Note de contenu : |
- BACKGROUND : CHEMISTRY OF THE ISOCYANATE-FREE POLYURETHANE TECHNOLOGY
- MATERIALS AND METHODS : Strategy - Viscosity - Film hardness and flexibility - Film curing/degree of crosslinking
- RESULTS AND DISCUSSION : Survey of VOC-exempt solvents - Adjusting the % solids - Replacing ethanol with butanol - Other primary alcohols (propanol and methanol) |
En ligne : |
https://drive.google.com/file/d/1-DG1wkqHkp6CpjL5zSXdeE8mNNHKyn9K/view?usp=drive [...] |
Format de la ressource électronique : |
Pdf |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=28870 |
in COATINGS TECH > Vol. 14, N° 8 (08/2017) . - p. 42-52
[article]
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