Polyester Resin Intermediates
More than half of powder coating processes utilize a polyester resin in the binder system. Eastman™ provides high-quality polyester resin intermediates that deliver cost effective production and targeted surface finish performance. Browse their solutions portfolio and learn how and why to select their resin intermediate products.
Powder Coatings - Polyester Resin Powders
Powder coating is becoming increasingly more popular due to a variety of benefits over liquid paint processes and higher expectations from consumers for products that last. Powder coating processes improve overall coating performance, reduce the cost during application and can eliminate all VOC (volatile organic compounds), HAPs (hazardous air pollutants), and hazardous waste generated during application.
For thermoset polyester resin powders, there are two basic categories — hydroxyl and carboxyl terminated. Each variety of polyester resin uses different types of cross-linkers in composition of the binder system. A quick table details the combination of polyester resin & cross-linker type:
| Polyester Resin Type | Matching Cross-Linker Type |
|---|---|
Hydroxyl Terminated | Blocked Isocyanates Tetramethoxymethyl glycoluyril (Powderlink™ 1174) |
Carboxyl Terminated | Triglycidylisocyanurate (TGIC) ß-hydroxylakylamide (Primid™ XL552) Epoxy Resins |
The high-quality monomers from Eastman™ Chemical Company allow for optimized polyester resin & powder coating performance.
Eastman™ Resin Intermediate Product Portfolio
| Grade | Physical Form | Molecular Weight | Melting Point (°C) | Assay Weight (%) |
|---|---|---|---|---|
| NPG™ Glycol | Platelets | 104.15 | 127 | 99.5 |
| NPG-90 Glycol | Slurry | 104.15 | 31b | 89 |
| CHDM-D90 | Molten | 144.21 | 50 | 99.5 |
| CHDM-D | Liquid | 144.21 | -30 to 40c | 90 |
| HPHP | Nugget | 204.26 | 46 to 50 | 98.1 |
| 1,4-CHDA | Powder | 172.00 | 164 to 167 | 99.5 |
b Crystallizes below 31°C (88°F)
c CHDM-D90 is a CHDM-D/water mixture exhibiting multiple melting points across this range.
c CHDM-D90 is a CHDM-D/water mixture exhibiting multiple melting points across this range.
- Primary component of most polyester resins for powder coating
- NPG based resins can be made with a glass transition temp (Tg) of 52°-68°C (125.6°-154.4°F)
- Low Initial Color & Good Color Stability
- Good powder Flow & Fluidization Properties
- Good Balance of Hardness & Flexibility
- Good Chemical & Stain Resistance
NPG™ Glycol (Neopentyl Glycol)
- Structural & reactivity properties similar to Eastman NPG™ glycol
- Resin Tg is reduced by approx. 0.2°C for every mole% replacement of NPG glycol in a PTA/NPG Resin
- Excellent Weathering Characteristics - Ideal for Outdoor Applications
- Improved Smoothness & Flexibility in TGIC and ß-hydroxylakylamide systems
- Good Chemical & Stain Resistance
HPHP (Hydroxypivalyl Hydroxypivalate)
- CHDM presents no effect on Tg as it replaces NPG™ glycol in PTA/NPG resin systems
- Tg is raised by approx. 0.2°C for every mole% replacement of NPG glycol in a PIA/NPG resin systems
- Primary alcohol functionality provides good reactivity during synthesis
- Superior detergent resistance for appliance & other applications
CHDM (1,4-Cyclohexanedimethanol)
- CHDA has higher solubility and reduced resin cook time
- Tg is reduced by approx. 0.4°C for every mole% replacement of PTA with CHDA in a PTA/NPG resin system
- Excellent flexibility and hardness
- Better smoothness (less orange peel) as CHDA is more efficient at reducing melt viscosity than PTA
