Azeotrope-like compositions comprising dichloromethane, 1h,1h,2h-heptafluorocyclopentane, and a hydrofluorocarbon and use of the compositions as flash spinning agents
Azeotrope-like compositions of dichloromethane, 1H,1H,2H-heptafluorocyclopentane, and hydrofluorocarbons address high GWP and recovery issues in flash spinning, enabling efficient and cost-effective production of plexifilamentary fibrils.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- DUPONT SAFETY & CONSTRUCTION INC
- Filing Date
- 2025-11-18
- Publication Date
- 2026-06-18
AI Technical Summary
Existing flash spinning processes using solvent mixtures for polymers face challenges with high global warming potential (GWP), complex recovery processes due to liquid phase separation, and unsuitable cloud point pressures, especially when using dichloromethane (DCM) with hydrofluorocarbons like 1H,6H-perfluorohexane or 1H-perfluorohexane.
Development of azeotrope-like compositions comprising dichloromethane, 1H,1H,2H-heptafluorocyclopentane, and hydrofluorocarbons with 4 to 6 carbon atoms, such as 1H,1H,3H,3H-pentafluorobutane (HFC-365mfc) or 1H,4H-octafluorobutane (HFC-338pcc), which form homogeneous phases and provide suitable cloud point pressures for flash spinning a broad range of polymers.
The azeotrope-like compositions simplify spin agent recovery, reduce GWP, and enable flash spinning at lower temperatures, enhancing process efficiency and reducing equipment costs.
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