Polymerization of fluoromonomers
AssigneeE. I. Du Pont de Nemours and Company
InventorsRichard Alan Morgan, Clay Woodward Jones, Theodore Treat, Jeffrey A. Hrivnak
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Abstract
Aqueous dispersion polymerization of fluoromonomers is improved by using a combination of fluorosurfactants, one of which is a perfluoropolyether carboxylic acid or sulfonic acid or salt of either.
Claims22
A process comprising polymerizing at least one fluorinated monomer in an aqueous medium containing initiator and dispersing agent to obtain an aqueous dispersion of particles of fluoropolymer, wherein said dispersing agent is a combination of at least two fluorosurfactants, at least one of said fluorosurfactants being perfluoropolyether carboxylic or sulfonic acid or salt thereof, and at least one of said fluorosurfactants being fluoroalkyl carboxylic or sulfonic acid or salt thereof, or fluoroalkoxy aryl sulfonic acid or salt thereof.
A process comprising polymerizing tetrafluoroethylene and optionally at least one other fluorinated monomer in an aqueous medium containing initiator and dispersing agent to obtain an aqueous dispersion of particles of fluoropolymer, wherein said dispersing agent is a combination of at least two fluorosurfactants, at least one of said fluorosurfactants being perfluoropolyether carboxylic or sulfonic acid or salt thereof, and at least one of said fluorosurfactants being fluoroalkyl carboxylic or sulfonic acid or salt thereof, or fluoroalkoxy aryl sulfonic acid or salt thereof, wherein said at least one fluorinated monomer makes less than 0.5 mole % of total monomer polymerized, and wherein some of said particles have length to diameter ratios of greater than 3.
A process comprising polymerizing tetrafluoroethylene and optionally at least one other fluorinated monomer in an aqueous medium containing initiator and dispersing agent to obtain an aqueous dispersion of particles of fluoropolymer, wherein said dispersing agent is a combination of at least two fluorosurfactants, at least one of said fluorosurfactants being perfluoropolyether carboxylic or sulfonic acid or salt thereof, and at least one of said fluorosurfactants being fluoroalkyl carboxylic or sulfonic acid or salt thereof, or fluoroalkoxy aryl sulfonic acid or salt thereof, wherein said at least one fluorinated monomer makes up less than 0.5 mole % of total monomer polymerized, and wherein those of said particles that are spherical or that have a length to diameter ratio of less than 3, average no more than 150 nm in their greatest dimension.
Dependencies are inferred from the claim text.