[article]
| Titre : |
Improved durability through reactive dispersant technology |
| Type de document : |
texte imprimé |
| Auteurs : |
Steffen Onclin, Auteur ; Kou Huiguang, Auteur ; Rainer Diehl ; Elena Martinez ; Clemens Auschra ; Andrew Recker ; Anthony Moy |
| Année de publication : |
2018 |
| Article en page(s) : |
p. 22-33 |
| Note générale : |
Bibliogr. |
| Langues : |
Américain (ame) |
| Catégories : |
Agents dispersants (chimie)
Copolymère acrylique mélamine
Copolymères séquencés
Essai de dureté
Essais dynamiques
Granulométrie
Noir de carbone
Pâte pigmentaire
Pigments
Polymères à terminaison hydroxyle
Polyuréthanes
Revêtements -- Additifs:Peinture -- Additifs
Rhéologie
Vernis bi-composant
Vernis en phase aqueuse
Viscosité
|
| Index. décimale : |
667.9 Revêtements et enduits |
| Résumé : |
Even though formulation additives comprise only a minor part of a coating formulation, they can have pronounced effects on the physical properties of the final coating. This is especially true for pigment dispersants, which can enter a coating formulation “under the radar” through, for example, pigment pastes. As dispersants are often polar polymers with a low glass transition temperature, the interface between the pigment and continuous phase forms a weak point, especially in coatings designed for high durability. This article addresses the development of an improved dispersant technology. The dispersants are functionalized such that they become part of the continuous phase of the coating, improving overall film integrity. Application examples, in both waterborne and solventborne formulations, demonstrate the effects of reactive technology on mechanical and barrier properties in comparison to conventional systems. |
| Note de contenu : |
- Effect of dispersants on coatings properties
- Dispersant with new anchoring chemistry
- Reducing negative impact of dispersants on coating properties
- Towards waterborne reactive dispersants
- Fig. 1 : Stabilization mechanisms of dispersants
- Fig. 2 : Effect of exchanging part of grinding resin with dedicated dispersant (internal BM 1) on pigment paste rheology and transparecy in a solventborne MS OEM system. Values in brackets reflect dispersant dosage (active dispersant on pigment)
- Fig. 3 : Pendulum hardness and MEK-rub test results of a solventborne MS-OEM basecoat after the addition of 20% pigment paste. Values in brackets reflect dispersant dosage (active dispersant on pigment). MEK-rubs were performed directly on the basecoat
- Fig. 4 : Mill base viscosities, fresh and after two weeks at 50°C, as a function of dispersant dosage. Pigment pastes are resin-free and contain 13% carbon-black
- Fig. 5 : Average particle size of pigment pastes as function of dispersant dosage. Particle size measurements were performed two days after pigment paste preparation
- Fig. 6 : Schematic representation of working principle of analytical ultra-centrifuge
- Fig. 7 : Dispersant adsorption in a solventborne, resin-free carbon black pigment paste, measured with an anlytical ultra-centrifuge. Effective (measured) dispersant on pigment is plotted againsf formulated dispersant on pigment
- Fig. 8 : Jetness and undertone values in a medium-solids OEM basecoat. Coatings were applied on a glass substrate and measurements wre taker from the backside (through the glass) to reduce surface effects
- Fig. 9 : Jetness and undertone values in a 2KPU topcoat. Coatings were applied on a glass substrate and measurements were taken from the backside (though the glass) to reduce surface effects
- Fig. 10 : Schematic representation of co-reactive dispersant concept. The dispersant becomes part of the continuous resin phase to improve film integrity
- Fig. 11 : Pendulum hardness and MEK-rub resistance of an MS-OEM basecoat. The MEK-rub test was performed directly on the basecoat
- Fig. 12 : Pendulum hardness and chemical resistance of a 2KPU topcoat, containing 20% pigment paste. Chemical resistance after 16h exposure. Chemical resistance rating : 5 = no change, 1 = strong change/damage
- Fig. 13 : Functionalization of block copolymer dispersants with hydroxyl-functional groups
- Fig. 14 : Pigment paste rheology (fresh) of resin-free pigment concentrates containing 18% PBk 7 and a DOP level of 100%. Jetness and undertone in a WB 1K acrylic melamine topcoat, applied on glass, after mixing with 20% pigment paste. Measurements were taken from the backside (though the glass)
- Fig. 15 : Pendulum hardness of WB 1K acrylic melamine topcoat containing 20% of carbon black pigment paste
- Fig. 16 : Chemical resistance of a 1k acrylic melamine topcoat, containing 20% pigment paste. Data after 16h exposure. Chemical resistance rating : 5 = no change, 1 = strong change/damage |
| En ligne : |
https://drive.google.com/file/d/1CDNJI6SBFF_mE-AMpYjliE_s5klSpHDp/view?usp=drive [...] |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=31209 |
in COATINGS TECH > Vol. 15, N° 7 (07/2018) . - p. 22-33
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Improved durability through reactive dispersant technology in COATINGS TECH, Vol. 15, N° 7 (07/2018)
