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Acid etch of automotive clearcoats. II. Comparison of degradation chemistry in laboratory and field testing / P. J. Schmitz in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 72, N° 902 (03/2000)
[article]
Titre : Acid etch of automotive clearcoats. II. Comparison of degradation chemistry in laboratory and field testing Type de document : texte imprimé Auteurs : P. J. Schmitz, Auteur ; Joseph W. Holubka, Auteur ; Li - Feng Xu, Auteur Année de publication : 2000 Article en page(s) : p. 53-61 Note générale : Bibliogr. Langues : Américain (ame) Tags : Matériau revêtement Vernis Automobile Dégradation chimique Exposition intempérie Retombée atmosphérique Pluie acide Essai laboratoire en champ Etude comparative expérimentale Spectrométrie photoélectron Rayon X Index. décimale : 667.9 Revêtements et enduits Résumé : A laboratory test procedure was developed to quantitatively evaluate the acid etch resistance of automotive clearcoats, Here we attempt to verify that the conditions used in the laboratory test reproduce the field degradation chemistry to assure that the test is evaluating realistic performance characteristics. In this study we applied X-ray photoelectron spectroscopy (XPS) as a tool to determine if degradation products are observable which can be used to verify the consistency of the field and laboratory degradation processes for acrylic melamine-based clearcoats. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=5822
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Code-barres Cote Support Localisation Section Disponibilité 001207 - Périodique Bibliothèque principale Documentaires Disponible Acid etch resistance of automotive clearcoats. I : Laboratory test method development / Joseph W. Holubka in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 72, N° 901 (02/2000)
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Titre : Acid etch resistance of automotive clearcoats. I : Laboratory test method development Type de document : texte imprimé Auteurs : Joseph W. Holubka, Auteur ; Li - Feng Xu, Auteur ; P. J. Schmitz, Auteur Année de publication : 2000 Article en page(s) : p. 77-82 Note générale : Bibliogr. Langues : Américain (ame) Tags : Matériau revêtement Vernis Industrie automobile Propriété chimique Feuil Résistance acide Essai laboratoire Gravimétrie Index. décimale : 667.9 Revêtements et enduits Résumé : This paper reports on the development of a laboratory test procedure for the evaluation of the environmental etch resistance of clearcoats. The test evaluates the bulk acid hydrolysis resistance of clearcoats by gravimetrically following material weight loss as a function of exposure time to a sulfuric acid solution, under conditions that simulate outdoor exposure. The bulk hydrolysis resistance of five production clearcoat technologies including acrylic melamine, acrylic melamine-silane, carbamate, acrylic urethane, and epoxy acid were evaluated. Results from the weight loss measurements were consistent with those anticipated based on the coating systems bulk chemistry and inherent hydrolysis resistance, for clearcoat systems processed under nominal processing conditions. The relative rankings from the laboratory test were found to correlate with field etch ratings. The test method is inexpensive, quantitative, and generates repeatable results that are not subject to environmental variations associated with current field etch testing. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=5826
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Code-barres Cote Support Localisation Section Disponibilité 001206 - Périodique Bibliothèque principale Documentaires Disponible Mechanism for environmental etch of acrylic melamine - based automotive clearcoats : identification of degredation / P. J. Schmitz in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 72, N° 904 (05/2000)
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Titre : Mechanism for environmental etch of acrylic melamine - based automotive clearcoats : identification of degredation Type de document : texte imprimé Auteurs : P. J. Schmitz, Auteur ; Joseph W. Holubka, Auteur ; Li - Feng Xu, Auteur Année de publication : 2000 Article en page(s) : p. 39-45 Note générale : Bibliogr. Langues : Américain (ame) Tags : Industrie automobile Matériau revêtement Vernis Mélamine résine Acrylique dérivé polymère Feuil Dégradation chimique Hydrolyse Pluie acide Mécanisme réaction Produit Etude expérimentale Peinture Index. décimale : 667.9 Revêtements et enduits Résumé : This paper focuses on defining the reaction mechanism involved in the environmental etch of acrylic melaminic-based automative clearcoats via an identification of reaction products. This has been accomplished through a comparative study of products formed on acid treatment of neat crosslinkers, and those formed following laboratory acid treatment and field exposure of acrylic melamine clearcoat systems. Bulk elemental, X-ray photoelectron spectroscopy (XPS), and infrared (IR) analyses of sulfuric acid-treated melamine crossllinkers show that acid hydrolysis results primarily in the formation of melamine sulfate. Melamine sulfate formation was also observed following laboratory and field exposure of acrylic melamine clearcoat systems. These results confirm that the primary mode of melamine crosslink decomposition is through hydrolysis of acetal linkages and subsequent formation of melamine sulfate. However, data show that hydrolysis of pendent amino groups on the triazine ring also occurs. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=5805
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Code-barres Cote Support Localisation Section Disponibilité 001209 - Périodique Bibliothèque principale Documentaires Disponible