Composite active filter material
US4619948A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 7, 1985 |
| Grant date | Oct 28, 1986 |
| Priority date | — |
| Expiry date | Jan 7, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S425/816
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A reticulated hydrophilic foam substrate and bonded active surface particle powder composite filter material is generated by foam polymerization of a prepolymer phase with an aqueous phase. The reticulated hydrophilic foam substrate is characterized by relatively low pressure drop and low resistance to flow through the foam substrate. The prepolymer phase is a hydrophilic polyurethane prepolymer receptive to the aqueous phase for foam polymerization upon mixing with the aqueous phase. The aqueous phase in turn is a pourable and flowable slurry mixture of water, active surface particle powder, and surfactant wetting agent. The aqueous phase includes sufficient water or other evaporable liquid to provide a protective liquid layer or coating over the active surfaces of the powder particles. Upon polymerization of the mixture the active surface powder particles are distributed over and bonded to the webs of the reticulated hydrophilic foam and the major portion of the active surfaces are free from obstruction and available for active filter functioning. The aqueous phase and prepolymer phase upon mixing may be poured, flowed, or injected into a suitable respirator or mask mold to provi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.