| Titre : |
Importance of rheological additives in coatings : a review |
| Type de document : |
texte imprimé |
| Auteurs : |
Shailesh Patil, Auteur ; Yogesh Mahajan, Auteur |
| Année de publication : |
2015 |
| Article en page(s) : |
p. 67-74 |
| Note générale : |
Bibliogr. |
| Langues : |
Anglais (eng) |
| Catégories : |
Epaississants
Fluides, Mécanique des
Revêtements -- Additifs:Peinture -- Additifs
Rhéofluidifiants
Rhéologie
Thixotropie
|
| Index. décimale : |
667.9 Revêtements et enduits |
| Résumé : |
Flow behavior is one of the most important methodological properties of a coating system, it determines to a great extent the usability and accessibility of the coating material. Rheology is the science of flow and deformation of matter and rheological additives are used to control and modify this flow behavior. When a coating system is stored pigments and fillers tend to settle and form sediments, which can be quite hard at times and hence difficult to re-disperse. Application of a coating at higher film thickness on a vertical or inclined substrate can show sagging or runs down. Higher viscosities in the lower shear range and vice versa substantially reduce both sedimentation and sagging. This results in a longer shelf life and less setting. However, the rheological properties described above may also have undesirable effects on deaeration / defoaming and surface flow of the coating : air bubbles rise to the coating surface more slowly and the leveling of the surface is impaired. Clearly, the "right' flow behavior is always a compromise determined by the application parameters for each application. To achieve proper leveling and antisagging as well as antisettling property, the rheological agents play an important role in system. |
| Note de contenu : |
- VISCOSITY/RHEOLOGY : New newtonian flow behavior - Shear thinning or pseudoplastic behavior - Effect of temperature - Effect of pressure - Effect of molecular weight and distribution
- RHEOLOGY RELATED DEFECTS : Settling - Orientation
- RHEOLOGICAL ADDITIVES/THICKENER TYPES : Clay thickeners - Cellulose derivatives - Alkali soluble swellable polymers (associative thickeners) - Urethane based thickeners - Hydrophobically modified ethoxylated urethane alkali soluble emulsions - Synthetic silica - Polyamide wax - Sulfonated castor oil - Oxydized polyolefin
- ORGANIC THIXOTROPIC AGENTS
- RHEOLOGICAL ADDITIVES FOR HIGH SOLID COATINGS : Sag control agents SCA - Microgels
- TECHNOLOGICAL TRENDS AND NEW ORGANIC RHEOLOGICAL ADDITIVES |
| En ligne : |
https://drive.google.com/file/d/1ezO7F9FktvLPReGQ9oMQan67I-f6a9ud/view?usp=drive [...] |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=24155 |
in PAINTINDIA > Vol. LXV, N° 4 (04/2015) . - p. 67-74
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Importance of rheological additives in coatings : a review in PAINTINDIA, Vol. LXV, N° 4 (04/2015)
