White acrylic topcoat for airmix spray - formula

This formulation is designed for a white acrylic topcoat suitable for application using an airmix spray. It includes various components to ensure proper pigment dispersion, film preservation, foam control, and appropriate rheology for a smooth application.

Components and Their Functions:

1. Water
   • Function: Vehicle, dissolving and carrying other components.
2. Sodium Polyacrylate (Dispex CX 4240)*
   • Function: Dispersing agent, aiding in the even distribution of pigments and fillers.
3. Biocide (Nuosept BM11)*
   • Function: In-can preservative, preventing microbial growth and extending shelf life.
4. Blend of Silicone and Surfactants (Drewplus™ S-4374)
   • Function: Foam control agent, reducing foam formation during application.
5. Titanium Dioxide (Kronos 2190)*
   • Function: Pigment, providing opacity and whiteness.
6. Calcium Carbonate (Omyacarb 2GU)*
   • Function: Extender, improving the mechanical properties and reducing cost.
7. Ester Alcohol (Texanol)*
   • Function: Coalescing agent, aiding in the film formation process by promoting the merging of polymer particles.
8. Self-Cross-Linking Acrylic Copolymer (Neocryl XK-237)*
   • Function: Binder, providing adhesion and forming a durable film upon drying.
9. 2-(2-Butoxyethoxy)ethanol (Butyldiglycol)
   • Function: Coalescing agent, enhancing film formation.
10. Biocide (Fungitrol L30 DPG)*
    • Function: Dry film preservative, preventing fungal growth on the dried film.
11. Blend of Silicone & Paraffinic Oils (DrewPlus™ S-4480)
    • Function: Foam control agent, further reducing foam during application.
12. Nonionic Synthetic Associative Thickener (NSAT) (Aquaflow™ XLS-525E)
    • Function: Rheology modifier, adjusting the viscosity and flow properties.
13. Nonionic Synthetic Associative Thickener (NSAT) (Aquaflow™ XLS-550)
    • Function: Additional rheology modifier, further fine-tuning viscosity and flow properties.
14. Alkaline (pHLEX™ 400)
    • Function: Neutralizing agent, adjusting the pH to the desired level.
15. Water
    • Function: Additional vehicle, ensuring the right consistency and viscosity.

Properties:

• Total Weight: 100%
• Viscosities:
  • Brookfield (5/100): 2245 mPa·s
• Pigment Volume Concentration (PVC): 21%
• Solid Content:
  • By Mass: 47%
  • By Volume: 35%
• Density: 1.21 g/cm³
• Gloss (60°): 25 GU
• Leveling (Leneta): 9 (1-10; 10=Best)
• Sag Resistance: 500 microns

Preparation Procedure:

1. Initial Mixing:
   • Add water to a mixing container.
   • Gradually add sodium polyacrylate and biocide, stirring to ensure proper dispersion.
   • Incorporate the blend of silicone and surfactants, titanium dioxide, and calcium carbonate, dispersing at high speed until Hegmann < 10 µm is achieved.
2. Additives:
   • Add ester alcohol and mix thoroughly.
3. Let Down:
   • Gradually add the self-cross-linking acrylic copolymer (Neocryl* XK-237) and additional water, mixing to achieve a uniform consistency.
   • Incorporate 2-(2-butoxyethoxy)ethanol, biocide (Fungitrol* L30 DPG), blend of silicone & paraffinic oils, and rheology modifiers (Aquaflow™ XLS-525E and XLS-550).
   • Adjust pH with alkaline (pHLEX™ 400) and add the remaining water, stirring until homogeneous.

This formulation is optimized to provide a white acrylic topcoat with excellent opacity, durability, and smooth application properties suitable for airmix spray application.