[article]
| Titre : |
An easy, tried-and-true method to ensure quality in coatings |
| Type de document : |
texte imprimé |
| Auteurs : |
Jeffrey B. Carr, Auteur |
| Année de publication : |
2018 |
| Article en page(s) : |
p. 50-54 |
| Note générale : |
Bibliogr. |
| Langues : |
Anglais (eng) |
| Catégories : |
Attapulgite Argile alumino-magnésienne fibreuse.
Charges (matériaux)
Epaississants
Revêtements -- Additifs:Peinture -- Additifs
|
| Index. décimale : |
667.9 Revêtements et enduits |
| Résumé : |
Coatings are complex composites designed to have a stable shelf-life, apply easily to a substrate and provide lasting durability in varied environments. These performance criteria require disparate materials to be finely dispersed and work cohesively, which presents a major challenge as composites can be unstable and ultimately fail at points of inconsistency. To address this, the first thing a new paint chemist learns is that wetting agents are mandatory in allowing mineral fillers to disperse properly. Without them, these inorganic particles generally reject their organic media, agglomerate and settle out. It would be imprudent to forgo wetting agents.
Another well-known, tried-and-true technique to stabilise composites and improve their uniformity is to use high-quality, gel-grade attapulgite mineral products. They have been common in paint applications for several decades as thixotropic thickeners for low-shear flow and levelling, sag resistance and other rheology benefits. However, a seemingly forgotten higher value is their function as excellent stabilisers due to their unique colloidal lathe-shaped particles forming a lattice structure. This keeps liquids and particles more evenly dispersed and suspended, generating important benefits well beyond rheological properties.
This article gives a brief history of attapulgite, a description of its mechanism that sets it apart from other thixotropic thickeners and stabilisers, and discusses its performance benefits in coatings. |
| Note de contenu : |
- Chemistry and morphology
- How attapulgite works
- Particle network and performance
- Features and performance
- Exceptional performance and economies
- Uniform suspensions
- In-can stability
- Fig. 1. Crude attapulgite mined by Active Minerals International LLC
- Fig. 2. Attapulgite lattice network when dispersed in a liquid
- Fig. 3. Comparison of shear stress and viscosity at various shear rates for Min-U-Gel 400 attapulgite and HEC in water. The loading levels of both materials have been exaggerated to produce comparable rheological values. In coatings, where the attapulgite network interacts with particulate solids, the dosage level of Min-U-Gel 400 is similar to HEC. |
| En ligne : |
https://drive.google.com/file/d/10q_Gh8gfTxKb4ZxnFdImNoion6f10QFs/view?usp=drive [...] |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=30049 |
in POLYMERS PAINT COLOUR JOURNAL - PPCJ > Vol. 208, N° 4638 (02/2018) . - p. 50-54
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An easy, tried-and-true method to ensure quality in coatings in POLYMERS PAINT COLOUR JOURNAL - PPCJ, Vol. 208, N° 4638 (02/2018)
