Titre : |
Cure of secondary carbamate groups by melamine-formaldehyde resins |
Type de document : |
texte imprimé |
Auteurs : |
H. P. Higginbottom, Auteur ; G. R. Bowers, Auteur ; Patricia E. Ferrell, Auteur ; Loren W. Hill, Auteur |
Année de publication : |
1999 |
Article en page(s) : |
p. 49-69 |
Note générale : |
Bibliogr. |
Langues : |
Américain (ame) |
Tags : |
'Matériau revêtement' Peinture Thermodurcissable Durcissement 'Groupe fonctionnel' Carbamate Réticulation Réticulant 'Mélamine résine' Formaldéhyde Aminoplaste 'Mécanisme réaction' Feuil 'Propriété dynamomécanique' 'Etude expérimentale' |
Index. décimale : |
667.9 Revêtements et enduits |
Résumé : |
Melamine-formaldehyde (MF) resins have been used as crosslinkers for hydroxyl-functional co-reactants in thermoset coatings for about 60 years. Crosslink densities of films prepared from oligomeric urethane polyols suggested that the methoxymethyl groups of MF resins could react with urethane groups (i.e., secondary carbamate groups) as well as reacting with hydroxyl groups. Co-reactants that contain secondary carbamate groups and no hydroxyl groups have been prepared with several types of backbone structures. Cure of such co-reactants by MF resins has been studied using a gradient oven with determination of impact resistance, solvent resistance, and hardness. Several formulations from these cure profile sets have been selected for crosslink density determinations by dynamic mechanical analysis (DMA). Crosslink densities of cured films are consistent with complete conversion of secondary carbamate groups at temperatures only slightly higher than those used for cure of hydroxyl groups. The -OH groups on certain acrylic polyols were converted to secondary carbamate groups. The original acrylic and the converted acrylic were both cured with MF resins. Acid resistance was much better for films prepared from the acrylic that contained secondary carbamate groups. |
Note de contenu : |
- RESULTS AND DISCUSSION : Synthesis and characterization of secondary carbamate co-reactants - Cure response of model carbamates in a gradient oven test - Dynamic mechanical analysis of films from selected co-reactants - Secondary carbamate groups on the same backbone - Effect of melamine crosslinker structure on cure of secondary carbamates - MF cure of aqueous polyurethane dispersions |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=17912 |
in JOURNAL OF COATINGS TECHNOLOGY (JCT) > Vol. 71, N° 894 (07/1999) . - p. 49-69