Flame retardant fillers prepared from bridged polysilsesquioxanes
US9255185B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 13, 2012 |
| Grant date | Feb 9, 2016 |
| Priority date | — |
| Expiry date | Jul 24, 2034 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/1352
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A bridged polysilsesquioxane-based flame retardant filler imparts flame retardancy to manufactured articles such as printed circuit boards (PCBs), connectors, and other articles of manufacture that employ thermosetting plastics or thermoplastics. In an exemplary synthetic method, a bridged polysilsesquioxane-based flame retardant filler is prepared by sol-gel polymerization of a monomer having two or more trialkoxysilyl groups attached to an organic bridging group that contains a fire retardant group (e.g., a halogen atom, a phosphinate, a phosphonate, a phosphate ester, and combinations thereof). Bridged polysilsesquioxane particles formed by sol-gel polymerization of (((2,5-dibromo-1,4-phenylene)bis(oxy))bis(ethane-2,1-diyl))bis(trimethoxysilane), for example, and follow-on sol-gel processing may serve both as a filler for rheology control (viscosity, flow, etc.) and a flame retardant. In an exemplary application, a PCB laminate stack-up includes conductive planes separated from each other by a dielectric material that includes a bridged polysilsesquioxane-based flame retardant filler.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.