Polyurathane-based Powder Coatings
Features:
Great adhesion and mechanical properties;
High gloss, great leveling and fullness;
Chemical and weather resistance
Polyurethane-Based Powder Coatings: Technical Overview
Category
Speci...
Category：Paint chemicals
Introduction
Features:
Great adhesion and mechanical properties;
High gloss, great leveling and fullness;
Chemical and weather resistance
Polyurethane-Based Powder Coatings: Technical Overview
| Category | Specifications |
|---|---|
| Definition | Thermosetting coatings utilizing polyurethane resins cured with blocked isocyanates |
| Resin Chemistry | Hydroxyl-functional polyester/polyether + blocked isocyanate (e.g., IPDI, HDI) |
| Curing Mechanism | Deblocking at 160-200°C, forming urethane linkages |
Performance Characteristics
| Property | Value/Rating | Test Method |
|---|---|---|
| Gloss Retention | >90% after 3000h QUV | ASTM G154 |
| Chemical Resistance | 5/5 (alkali, acid, solvents) | ISO 2812 |
| Flexibility | 2mm conical mandrel pass | ASTM D522 |
| Impact Resistance | 160 in-lb direct | ASTM D2794 |
| Adhesion | 5B (cross-cut) | ASTM D3359 |
Comparison with Other Systems
| Parameter | Polyurethane | Epoxy | Polyester |
|---|---|---|---|
| UV Resistance | ★★★★★ | ★★ | ★★★★ |
| Chemical Resist. | ★★★★★ | ★★★★★ | ★★★ |
| Decorative Finish | ★★★★ | ★★ | ★★★★★ |
| Curing Window | 160-200°C | 140-180°C | 180-220°C |
| Cost Index | $$ | $ | $$ |
Formulation Guidelines
| Component | Function | Content (%) |
|---|---|---|
| Hydroxy polyester | Base resin | 50-70 |
| Blocked isocyanate | Crosslinker | 15-25 |
| Flow modifiers | Surface control | 1-3 |
| UV absorbers | Weatherability | 2-5 |
| Catalysts | Cure acceleration | 0.5-1.5 |
Application Parameters
| Process Factor | Requirements |
|---|---|
| Substrate Temp. | 180°C (metal), 160°C (heat-sensitive) |
| Film Thickness | 50-120μm |
| Transfer Efficiency | 60-80% (electrostatic spray) |
| Reclaim Ratio | ≤50% without property loss |
Market Applications
| Industry | Typical Uses |
|---|---|
| Automotive | Alloy wheels, bumper guards |
| Agriculture | Heavy equipment coatings |
| Architecture | Aluminum cladding |
| Consumer Goods | Appliance housings |
Environmental & Safety
| Aspect | Status |
|---|---|
| VOC Emissions | 0 g/L |
| REACH Compliance | Fully compliant (non-SVHC) |
| Worker Protection | Requires isocyanate handling precautions |
Key advantages highlighted:
Superior balance of chemical/UV resistance
Excellent mechanical properties
Broad curing window flexibility
Premium decorative finishes
Inquiry
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