| Titre : |
Self-stratifying coatings |
| Type de document : |
texte imprimé |
| Auteurs : |
Vladimir V. Verkholantsev, Auteur |
| Année de publication : |
2000 |
| Article en page(s) : |
p. 24-33 |
| Note générale : |
Bibliogr. |
| Langues : |
Anglais (eng) |
| Catégories : |
Revêtements autostratifiants:Peinture autostratifiante
|
| Index. décimale : |
667.9 Revêtements et enduits |
| Résumé : |
The objective of the project, which was funded by the European Commission and Europwan coatings and resins manufacturers, was the formulation of liquid self-stratifying coatings which after application as thin films spontaneously form two coherent layers, thus providing an undercoat and finishing coat in one operation. As a first step a database was compiled of the relevant physical properties of polymers used in surface coatings. This necessitated extensive new measurements of solubility, surface energies, phase equilibria and other parameters. A theory of stratification was developed for films comprising binary mixtures of polymers in solution and tested for a wide range of polymer mixtures. Group-contribution (UNIFAC) theory was employed to predict phase-separation and surface properties. A preliminary study was also made of the principles of formulating waterborne stratifying coatings from aqueous polymer dispersions. Solution coatings were successfully formulated for steel, plastic and wood substrates. Their performance was then evaluated under industrial spray application conditions. The mechanism of formation of stratified films in the experimental compositions could be described in terms of the solubility relationships of the polymer mixtures, the surface tensions of the separate phases and the kinetic aspects of solvent evaporation from paint films. Principal component and discriminant analysis of the experimental data generated quantitative equations for calculating the probability of stratification from the physical properties of polymers. For medium to high solids application, the coatings were liquid in liquid emulsions rather than homogeneous solutions. The problem of reproducibly locating pigments in the two layers was not fully resolved and would require further study to achieve commercially viable coatings. A fuller description of the research including experimental details is to be found in the accompanying papers from the participating research institutes. |
| Note de contenu : |
- Polymer/polymer heterophase strutures
- Self-stratifying coatings concept
- Phase separation process
- Stratification
- Mechanism of self-stratification processes
- Advantages and application fields |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=11062 |
in EUROPEAN COATINGS JOURNAL (ECJ) > N° 12/00 (12/2000) . - p. 24-33
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Self-stratifying coatings in EUROPEAN COATINGS JOURNAL (ECJ), N° 12/00 (12/2000)
