Subhash Gangal Phones & Addresses
-
134 Colts Neck Way, Hockessin, DE 19707
-
Parkersburg, WV
Publications
Us Patents
Aqueous Polymerization Of Fluorinated Monomer Using Polymerization Agent Comprising Fluoropolyether Acid Or Salt And Short Chain Fluorosurfactant
View pageUS Patent:
7705074, Apr 27, 2010
Filed:
Nov 9, 2007
Appl. No.:
11/937544
Inventors:
Paul Douglas Brothers - Chadds Ford PA, US
Subhash Vishnu Gangal - Hockessin DE, US
Subhash Vishnu Gangal - Hockessin DE, US
Assignee:
E. I. du Pont de Nemours and Company - Wilmington DE
International Classification:
C07F 9/40
US Classification:
524131, 524130, 524157, 524166, 524238, 524239, 524300, 524368, 524544, 524545, 524546, 524805, 526173, 526181, 526182, 526193, 526209, 526214, 526217, 526220, 526222, 526242, 526247, 526249, 526253, 526254, 526255
Abstract:
A process comprising polymerizing at least one fluorinated monomer in an aqueous medium containing initiator and polymerization agent to form an aqueous dispersion of particles of fluoropolymer, the polymerization agent comprising: fluoropolyether acid or salt thereof having a number average molecular weight of at least about 800 g/mol; and fluorosurfactant having the formula:[R—O-L-A Ywherein: Ris a linear or branched partially or fully fluorinated aliphatic group which may contain ether linkages; n is 0 or 1; L is a linear or branched alkylene group which may be nonfluorinated, partially fluorinated or fully fluorinated and which may contain ether linkages; A is an anionic group selected from the group consisting of carboxylate, sulfonate, sulfonamide anion, and phosphonate; and Y is hydrogen, ammonium or alkali metal cation; with the proviso that the chain length of R—O-L- is not greater than 6 atoms.
Aqueous Polymerization Of Fluorinated Monomers Using Polymerization Agent Comprising Fluoropolyether Acid Or Salt And Hydrocarbon Surfactant
View pageUS Patent:
7897682, Mar 1, 2011
Filed:
Nov 9, 2007
Appl. No.:
11/937536
Inventors:
Paul Douglas Brothers - Chadds Ford PA, US
Subhash Vishnu Gangal - Hockessin DE, US
Subhash Vishnu Gangal - Hockessin DE, US
Assignee:
E. I. du Pont de Nemours and Company - Wilmington DE
International Classification:
C08K 5/06
US Classification:
524758, 524759, 524760
Abstract:
A process for polymerizing at least one fluorinated monomer in an aqueous medium in the presence of initiator and polymerization agent to form an aqueous dispersion of particles of fluoropolymer having a fluoropolymers solids content of at least about 10% by weight. The polymerization agent is a combination of fluoropolyether acid or salt thereof and hydrocarbon surfactant. The aqueous medium contains less than about 300 ppm of perfluoroalkane carboxylic acid or salt fluorosurfactants. The process is preferably performed without adding polymer seed prior to polymerization kick-off.
Aqueous Polymerization Of Fluorinated Monomers Using Polymerization Agent Comprising Fluoropolyether Acid Or Salt And Siloxane Surfactant
View pageUS Patent:
7977438, Jul 12, 2011
Filed:
Nov 9, 2007
Appl. No.:
11/937541
Inventors:
Paul Douglas Brothers - Chadds Ford PA, US
Subhash Vishnu Gangal - Hockessin DE, US
Subhash Vishnu Gangal - Hockessin DE, US
Assignee:
E. I. du Pont de Nemours and Company - Wilmington DE
International Classification:
C08F 14/18
US Classification:
526194, 526206, 526209, 526214, 526242
Abstract:
A process for polymerizing at least one fluorinated monomer in an aqueous polymerization medium in the presence of initiator and polymerization agent to form an aqueous dispersion of particles of fluoropolymer having a fluoropolymers solids content of at least about 10% by weight. The polymerization agent is a combination of fluoropolyether acid or salt thereof and siloxane surfactant. The aqueous polymerization medium contains less than about 300 ppm of perfluoroalkane carboxylic acid or salt fluorosurfactants.
Aqueous Polymerization Of Fluorinated Monomer Using Polymerization Agent Comprising Fluoropolyether Acid Or Salt And Short Chain Fluorosurfactant
View pageUS Patent:
8519072, Aug 27, 2013
Filed:
Jun 23, 2011
Appl. No.:
13/167000
Inventors:
Paul Douglas Brothers - Chadds Ford PA, US
Subhash Vishnu Gangal - Hockessin DE, US
Subhash Vishnu Gangal - Hockessin DE, US
Assignee:
E I du Pont de Nemours and Company - Wilmington DE
International Classification:
C08F 14/18
US Classification:
526214, 526225, 526242, 524805
Abstract:
A process comprising polymerizing at least one fluorinated monomer in an aqueous medium containing initiator and polymerization agent to form an aqueous dispersion of particles of fluoropolymer, the polymerization agent comprising:.
Nucleation In Aqueous Polymerization Of Fluoromonomer
View pageUS Patent:
8563670, Oct 22, 2013
Filed:
Nov 9, 2011
Appl. No.:
13/292344
Inventors:
Paul Douglas Brothers - Chadds Ford PA, US
Subhash Vishnu Gangal - Hockessin DE, US
Dipti Dilip Khasnis - Wilmington DE, US
Subhash Vishnu Gangal - Hockessin DE, US
Dipti Dilip Khasnis - Wilmington DE, US
Assignee:
E I du Pont de Nemours and Company - Wilmington DE
International Classification:
C08F 2/16
C08F 114/18
C08F 114/18
US Classification:
526 75, 526242
Abstract:
A process is provided for polymerizing fluoromonomer in an aqueous medium, wherein a dispersion of essentially surfactant-free hydrocarbon-containing oleophilic nucleation sites is first formed in the aqueous medium, and then polymerization is commenced to form a dispersion of fluoropolymer particles at the oleophilic nucleation sites, wherein the nucleation sites can be derived from hydrocarbon-containing compound. The surfactant used to stabilize the fluoropolymer dispersion can also be hydrocarbon-containing.
Aqueous Polymerization Of Fluorinated Monomer Using A Mixture Of Fluoropolyether Acids Or Salts
View pageUS Patent:
20090281241, Nov 12, 2009
Filed:
May 6, 2009
Appl. No.:
12/436280
Inventors:
Paul Douglas Brothers - Chadds Ford PA, US
Subhash Vishnu Gangal - Hockessin DE, US
Gregory Allen Chapman - Washington WV, US
Jon Lee Howell - Bear DE, US
Adam Paul Smith - Vienna WV, US
Subhash Vishnu Gangal - Hockessin DE, US
Gregory Allen Chapman - Washington WV, US
Jon Lee Howell - Bear DE, US
Adam Paul Smith - Vienna WV, US
Assignee:
E. I. DU PONT DE NEMOURS AND COMPANY - Wilmington DE
International Classification:
C08F 2/16
C09K 3/00
C09K 3/00
US Classification:
524758, 25218215
Abstract:
A composition comprising a mixture of fluoropolyether acids or salts having a number average value of about 800 to about 2500 g/mol. The amount of fluoropolyether acids or salt in the mixture having a molecular weight of not more than 500 g/mol is not more than 50 ppm by weight of the total amount of fluoropolyether acids or salts in the mixture. The amount of fluoropolyether acids or salts in the mixture having a molecular weight of 2500 g/mol or greater is not more than 40% by weight of the total amount of fluoropolyether acids or salts in the mixture. Preferably the fluoropolyether acids or salts comprise an anionic group selected from the group consisting of carboxylate, sulfonate, sulfonamide anion and phosphonate. Also disclosed is an aqueous dispersion polymerization process for fluoropolymer manufacture employing polymerization agent comprising the specified mixture of fluoropolyether acids or salts.
Abatement Of Fluoroether Carboxylic Acids Or Salts Employed In Fluoropolymer Resin Manufacture
View pageUS Patent:
20090281261, Nov 12, 2009
Filed:
May 6, 2009
Appl. No.:
12/436273
Inventors:
Paul Douglas Brothers - Chadds Ford PA, US
Lam H. Leung - Bear DE, US
Subhash Vishnu Gangal - Hockessin DE, US
Lam H. Leung - Bear DE, US
Subhash Vishnu Gangal - Hockessin DE, US
Assignee:
E. I. DU PONT DE NEMOURS AND COMPANY - Wilmington DE
International Classification:
C08F 2/04
C08F 14/18
C08F 14/18
US Classification:
526209, 526250
Abstract:
A process for making fluoropolymer resin comprising polymerizing at least one fluorinated monomer in an aqueous medium containing initiator and polymerization agent comprising fluoroether carboxylic acid or salt thereof to form an aqueous dispersion of particles of fluoropolymer. The fluoroether carboxylic acid or salt thereof employed in the process has the formula:wherein Ris a linear, branched or cyclic partially or fully fluorinated aliphatic group which may contain ether linkages; L is a branched partially or fully fluorinated alkylene group which may contain ether linkages; and Y is hydrogen, ammonium or alkali metal cation. Wet fluoropolymer resin is isolated from the aqueous medium. The wet fluoropolymer resin is to produce a dry fluoropolymer resin and to decarboxylate the residual fluoroether carboxylic acid or salt to produce a vapor of fluoroether byproduct. The vapor of fluoroether byproduct is captured.
Aqueous Polymerization Of Fluorinated Monomer Using Polymerization Agent Comprising Fluoropolyether Acid Or Salt And Short Chain Fluorosurfactant
View pageUS Patent:
20100152363, Jun 17, 2010
Filed:
Feb 25, 2010
Appl. No.:
12/712278
Inventors:
Paul Douglas Brothers - Chadds Ford PA, US
Subhash Vishnu Gangal - Hockessin DE, US
Subhash Vishnu Gangal - Hockessin DE, US
Assignee:
E.I. DU PONT DE NEMOURS AND COMPANY - Wilmington DE
International Classification:
C08F 2/16
US Classification:
524545, 524544
Abstract:
A process comprising polymerizing at least one fluorinated monomer in an aqueous medium containing initiator and polymerization agent to form an aqueous dispersion of particles of fluoropolymer, the polymerization agent comprising: