Pre-Accelerated UPR (Cobalt, Ready-to-Use)
Key Features
- Pre-dissolved cobalt accelerator — add MEKP and use
- Eliminates separate accelerator weighing and addition
- Reduces operator error in small workshop environments
- Consistent, reproducible gel time batch-to-batch
- Full mechanical properties same as non-accelerated grade
Pre-Accelerated Unsaturated Polyester Resin is a general purpose orthophthalic UPR formulated with cobalt octoate accelerator pre-dissolved into the resin at the factory, simplifying workshop use by requiring only the addition of MEKP catalyst immediately before use. This ready-to-use format eliminates the need for separate accelerator handling, reducing operator error risk and streamlining small-batch fabrication operations.
The cobalt concentration is optimized at 0.3-0.5% (expressed as metal) to give a gel time of 15-25 minutes when 1.5% MEKP is added at 20-25°C. No additional promoter should be added without first reducing the catalyst level to avoid excessively fast gel times. The resin retains full pot life until MEKP is added.
Mechanical properties and processing characteristics are identical to the non-pre-accelerated equivalent: viscosity 300-600 mPa·s, flexural strength 115-125 MPa, tensile strength 60-70 MPa. Suitable for hand lay-up, spray-up, filament winding, and casting applications in workshops where simplicity and consistency of operation are priorities.
Specifications
| Parameter | Value |
|---|---|
| Acid Value | 15-25 mg KOH/g |
| Appearance | Clear to pale yellow, cobalt-blue tinted |
| Density (25°C) | 1.12-1.14 g/cm³ |
| Styrene Content | 35-40% |
| Viscosity (25°C) | 300-600 mPa·s |
| Cobalt Content (as metal) | 0.3-0.5% |
| Gel Time (25°C, 1.5% MEKP) | 15-25 min |
Applications
FAQ
Yes. Gel time is controlled primarily by the MEKP level. Use 1.0% MEKP for a longer pot life (~30-40 min) and 2.0-2.5% MEKP for faster cure (~8-12 min) at 20-25°C. Do NOT add more cobalt octoate to a pre-accelerated resin — the factory level is already optimized. Over-accelerating can cause thermal runaway in thick sections.
Direct Contact
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