ESACOTE® PU 77 is a low VOC, anionic, waterborne dispersion of an aliphatic polyurethane based on polycarbonate diols. It is produced by Lamberti and has a variety of applications due to its robust properties. Here are the key characteristics and specifications of ESACOTE® PU 77:
Chemical and Physical Properties
- Appearance at 25°C: Opalescent liquid
- pH: 7.00-9.00 (at 25°C, ASTM E 70)
- Viscosity: < 400 cPs (Brookfield RVT @ 25°C, 50 rpm, spindle 2)
- Solid Content: 34-36%
- Solvent Content: < 0.5% (MEK)
- Density at 25°C: ~1.04 g/ml
- Minimal Film Forming Temperature (MFFT): ~35°C
- Koenig Hardness: ~105 seconds
- Film Aspect: Tough, transparent, and glossy
Main Uses
ESACOTE® PU 77 is used as a binder in clear and pigmented coatings, providing several beneficial properties:
- Good hardness development
- High gloss and clarity
- Mechanical and chemical resistance
- Good balance of elasticity and hardness
- Excellent flow and leveling
Applications
ESACOTE® PU 77 can be used across various substrates and applications, including:
- Plastic Films (e.g., PVC): As OPV (overprint varnish) antiscratch varnish.
- Flexo and Rotogravure Lamination Inks: Provides high lamination strength.
- Metal Coatings: For pretreatment on substrates such as galvalume, galvanized iron, aluminum, or cold rolled steel.
- Wood Coatings: For parquet and furniture top coat formulations, both clear and pigmented.
- Architectural Coatings: As top coat for flooring (2K on concrete). Adhesion promoters may be used to improve adherence on porous substrates, and a primer is recommended.
Formulation and Compatibility
- Can be used as a sole binder or in combination with other water-based resins.
- A preliminary check of compatibility is recommended when combining with other resins.
- Small percentages of glycols are suggested for good film formation.
- Ammonia (few drops) can help maintain premix pH over 7 for better compatibility.
- Crosslinkers such as water-dispersible polyisocyanates, melamine resins, polyaziridines, or carbodiimides can be used to enhance properties.
Storage and Handling
- Store between +10°C and +35°C.
- Keep away from frost and direct light.
- Stable for 12 months if stored under recommended conditions.