[article]
Titre : |
Novel bimodal high-solid polymer dispersions for architectural coatings |
Type de document : |
texte imprimé |
Auteurs : |
Michael Krayer, Auteur ; Sean W. Bullis, Auteur |
Année de publication : |
2024 |
Note générale : |
Bibliogr. |
Langues : |
Américain (ame) |
Catégories : |
Epaississants Formulation (Génie chimique) Granulométrie Haut extrait sec Revêtements en bâtiment:Peinture en bâtiment Revêtements en phase aqueuse:Peinture en phase aqueuse Rhéologie
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Index. décimale : |
667.9 Revêtements et enduits |
Résumé : |
Over the past few decades, the performance of water-based architectural paint has consistently improved. However, latex polymer dispersions used in water-based coatings are typically limited to around 50 wt % polymer solids. This is because most polymer dispersions used for architectural coatings have a fairly narrow, single particle-size distribution (monodisperse), and when the monodisperse polymer particles approach their close packing limit, there is a sharp increase in viscosity at solids contents much beyond 50%. On the other hand, polymer dispersions with a bimodal particle-size distribution can achieve a signifi cantly higher solids content due to the increased random close packing limit of polydisperse systems (Figure 1). BASF has extensive experience in developing and producing higher solid polymer dispersions, especially for pressure-sensitive adhesive applications, achieving solids content up to 70%.
Recently, BASF has developed a 60 wt % polymer dispersion with a bimodal particle-size distribution for water-based architectural coating applications. Compared to architectural paints formulated with conventional polymer dispersions, paints formulated with bimodal high-solid dispersions can achieve a higher solids content, resulting in an increased dry fi lm thickness. For instance, in a paint formulation that uses a monodisperse latex binder, increasing the paint solids content beyond 50 wt % (or 40 vol%) causes the formulation to quickly turn into a paste, making it unsuitable as a paint. However, paint formulations that use a bimodal high-solid latex can achieve solids contents of more than 60 wt % (or 50 vol%). |
Note de contenu : |
- Brush vs. Roller application
- Practical approach to optimization rheology of architectural paints
- Base paint formulation
- Applying benchmark paints
- Comparing rheology profiles of benchmark paints and commercial paints and determining desired rheology package
- Application study of high-solid paints vs. commercial paints
- Conclusions and lessons learned
- Table 1 : Initial base paint formulation containing latex polymer dispersions with different particle sizes and particle-size distributions
- Table 2 : Latex polymer surface area calculation based on formulas in Table 1
- Table 3 : Base paint formulation with higher paint solids content containing latex polymer dispersions with different particle sizes and particle-size distributions
- Table 4 : Final base paint formulation
- Table 5 : Commercial paint ranking. Ranking from 1–5 (1: Worst, 5: Best)
- Table 6 : Measured leneta flow and leveling (ASTM D4062) and sag resistance of the two most preferred commercial paints, commercial paints A and B, compared with the two less preferred paints, commercial paints K and L
- Table 7 : Weight percentage (wt %) of rheology modifiers in the base paint formulation
- Table 8 : Solids content of BASF paint formulations with latex A vs. commercial paints
- Table 9 : Average application amounts and corresponding coverage rates
- Table 10 : Summary of common verbatims recorded for each paint by a panel of eight participants |
En ligne : |
https://drive.google.com/file/d/18goTMcxEWKmOG-4uYZB42vZPGQsOcMJ5/view?usp=drive [...] |
Format de la ressource électronique : |
Pdf |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=41450 |
in COATINGS TECH > Vol. 21, N° 4 (07-08/2024)
[article]
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