| Patent Number |
Title Of Patent |
Date Issued |
| 7358296 |
Aqueous dispersions of fluoropolymers |
April 15, 2008 |
| Fluorine-containing emulsifiers can be removed from fluoropolymer dispersions by adding to the dispersion a non ionic emulsifier, removing the fluorine-containing emulsifier by contact with an anion exchanger and separating the dispersion from the anion exchanger. The resulting dispe |
| 7253240 |
Explosion-free process for the production of polytetrafluoroethylene |
August 7, 2007 |
| Use of non-water-soluble organic fluorinated compounds, which are gaseous under the polymerization conditions and act as chain transfer agent in the gas phase, as explosion suppressors in the emulsion polymerization of tetrafluoroethylene. |
| 7252744 |
Treatment of fluorocarbon feedstocks |
August 7, 2007 |
| A method of treating a fluorocarbon feedstock includes generating, in a high temperature zone, an electrical arc between at least one cathode and at least one anode, generating in the high temperature zone and by means of the electrical arc and a plasma gas, an upwardly burning thermal |
| 7094839 |
Process for making a fluoroelastomer |
August 22, 2006 |
| Aqueous microemulsions obtained from a perfluorinated alkane sulphonic or carboxylic acid or salt thereof, a liquid fluorinated monomer comprising a cure-site and optionally an inert liquid and highly fluorinated hydrocarbon compound. The aqueous microemulsion may be formed by mixing |
| 7064170 |
Emulsifier free aqueous emulsion polymerization to produce copolymers of a fluorinated olefin an |
June 20, 2006 |
| Provided is a process for making a copolymer of fluorinated olefin and hydrocarbon olefin selected from ethylene, propylene and mixtures thereof, the process comprising a substantially emulsifier free aqueous emulsion polymerization of said fluorinated olefin and said hydrocarbon ole |
| 6943228 |
Ultraclean fluoroelastomer suitable for use in the manufacturing of electronic components |
September 13, 2005 |
| A curable fluoroelastomer composition for preparing a perfluoroelastomer. The composition includes; (1) a perfluoropolymer having one or more cure-sites selected from a halogen capable of participating in peroxide cure reaction and/or nitrile groups; (2) an organic peroxide and/or a |
| 6884860 |
Fluoroelastomer copolymer based on tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropy |
April 26, 2005 |
| A fluoropolymer suitable for the preparation of a fluoroelastomer. The fluoropolymer generally includes repeating units derived from the monomers tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, chlorotrifluoroethylene and optionally one or more repeating units from flu |
| 6867261 |
Aqueous dispersion of fluoropolymers of different particle size |
March 15, 2005 |
| Aqueous dispersions of fluoropolymers obtained by emulsion polymerization and containing at least one fluoropolymer A) with an average particle size (number-average) of at least 200 nm and at least one fluoropolymer B) with an average particle size (number-average) of not more than 100 n |
| 6833403 |
Aqueous dispersions of fluoropolymers |
December 21, 2004 |
| Fluorine-containing emulsifiers can be removed from fluoropolymer dispersions by adding to the dispersion a nonionic emulsifier, removing the fluorine-containing emulsifier by contact with an anion exchanger and separating the dispersion from the anion exchanger. The resulting disper |
| 6825300 |
Process for making a fluoropolymer having nitrile end groups |
November 30, 2004 |
| The present invention discloses a process for making a fluoropolymer having nitrile endgroups. The process comprises a free radical polymerization of one or more fluorinated monomers in the presence of a nitrile group containing salt or a nitrile group containing pseudohalogen compound. |
| 6825250 |
Process for reducing the amount of fluorinated surfactant in aqueous fluoropolymer dispersions |
November 30, 2004 |
| The present invention provides a process of reducing the amount of fluorinated emulsifier in an aqueous fluoropolymer dispersion by contacting the aqueous fluoropolymer dispersion with an anion exchange resin in a non-fixed resin bed, the process comprising: (a) mixing the aqueous flu |
| 6812310 |
Process for producing fluoropolymers having a reduced amount of polar end groups |
November 2, 2004 |
| A fluoropolymer having a reduced amount of polar end groups. The fluoropolymer is produced by free radical polymerization of fluorinated monomers and the initiation of the polymerization is carried out in the presence of a chloride salt. Polar end groups include hydroxy groups and io |
| 6794550 |
Method of making an aqueous dispersion of fluoropolymers |
September 21, 2004 |
| The invention provides a process for removing steam-volatile fluorinated emulsifiers in their free acid form, from aqueous fluoropolymer dispersions. The process comprises adding a nonionic emulsifier, to the aqueous fluoropolymer dispersion and, at a pH-value of the aqueous fluoropo |
| 6713141 |
Mixtures of thermoplastic fluoropolymers |
March 30, 2004 |
| A low-molecular-weight copolymer of tetrafluoroethylene with units of perfluoro alkyl vinyl ethers having a melt index of .gtoreq.30 suitable as a mixing component with a higher-molecular-weight copolymer of the same monomers for producing moldings in injection molding or by extrusion. |
| 6706193 |
Method for recovering fluorinated emulsifiers from aqueous phases |
March 16, 2004 |
| Fluorinated emulsifiers can be recovered from an aqueous phase containing small amounts of fluoropolymer particles by treating the aqueous phase with a small amount of a nonionic surface-active agent, bringing the aqueous phase adjusted in this way into contact with an anionic exchanger |
| 6696526 |
Mixtures of thermoplastic fluoropolymers |
February 24, 2004 |
| A low-molecular-weight copolymer of tetrafluoroethylene with units of perfluoro alkyl vinyl ethers having a melt index of .gtoreq.30 suitable as a mixing component with a higher-molecular-weight copolymer of the same monomers for producing moldings in injection molding or by extrusion. |
| 6677414 |
Aqueous emulsion polymerization process for the manufacturing of fluoropolymers |
January 13, 2004 |
| Emulsion polymerization of liquid fluorinated monomers which have a boiling point above 50.degree. C. and low water-solubility is markedly more efficient if the monomer is pre-emulsified with a nontelogenic fluorinated emulsifier in water. |
| 6642415 |
Method for recovering fluorinated emulsifiers |
November 4, 2003 |
| Fluorinated emulsifiers, in particular, perfluorooctanoic acid are bound to anionic exchange resins for the purification of aqueous effluent from the production of fluoropolymers. Said emulsifiers may be quantitatively eluted from the exchanger with a water-miscible organic solvent, |
| 6610807 |
Fluoropolymers with improved characteristics |
August 26, 2003 |
| A fluoropolymer composition is provided. The polymer comprises interpolymerized units derived from (i) tetrafluoroethylene, (ii) vinylidene fluoride, (iii) at least one ethylenically unsaturated monomer of the formula CF.sub.2.dbd.CFR.sub.f where R.sub.f is a perfluoroalkyl or a perf |
| 6593416 |
Fluoropolymers |
July 15, 2003 |
| Curable fluoroelastomer compositions having improved compression set after curing are provided, as well as compositions that are of relatively high purity. These compositions include a hydrogen-containing fluoroelastomer having interpolymerized units derived from a cure-site monomer, a c |
| 6566452 |
Aqueous dispersion of fluoropolymers of varying particle size |
May 20, 2003 |
| Aqueous dispersions of fluoropolymers obtained by emulsion polymerization and containing at least one fluoropolymer A) with an average particle size (number-average) of at least 200 nm and at least one fluoropolymer B) with an average particle size (number-average) of not more than 100 n |
| 6489420 |
Fluoropolymers with improved characteristics |
December 3, 2002 |
| A fluoropolymer composition is provided. The polymer comprises interpolymerized units derived from (i) tetrafluoroethylene, (ii) vinylidene fluoride, (iii) at least one ethylenically unsaturated monomer of the formula CF.sub.2.dbd.CFR.sub.f where R.sub.f is a perfluoroalkyl or a perf |
| 6489419 |
Non-free flowable molding powders of modified polytetrafluoroethylenes |
December 3, 2002 |
| Non-free flowable, non-dusting molding powders with a bulk density of more than 450 g/l are obtained when a suspension polymer of tetrafluoroethylene with a content of 0.01 to 1% by weight of units of at least one perfluoro(alkyl-vinyl) ether is ground to a particle diameter of 10 to 50 |
| 6436244 |
Process for the elution of fluorinated emulsifiers |
August 20, 2002 |
| Fluorinated emulsifier acids bound to an anion exchanger resin can be eluted using a mixture of water, a compound of the formula M--X, in which M is an alkali metal or an alkylammonium ion, and X is hydroxyl, fluoride or chloride, and at least one organic solvent which completely dissolv |
| 6099774 |
Process for non-free flowable molding powders of modified polytetrafluoroethylenes |
August 8, 2000 |
| Non-free flowable, non-dusting molding powders with a bulk density of more than 450 g/l are obtained when a suspension polymer of tetrafluoroethylene with a content of 0.01 to 1% by weight of units of at least one perfluoro(alkyl-vinyl) ether is ground to a particle diameter of 10 to 50 |
| 5861464 |
Process for the after-treatment of thermoplastic fluoropolymers |
January 19, 1999 |
| Labile end groups in fluorinated thermoplastics, in particular carboxyl and acid fluoride groups, are converted into carboxamide groups when the polymer is treated with an aqueous, ammonia-containing solution. The after-treated products have a pale color, do not cause corrosion during |
| 5589558 |
Process for the preparation of modified polytetrafluoroethylene and its use |
December 31, 1996 |
| If the employment of polymerization auxiliaries in ammonium form is avoided in the preparation of a polytetrafluoroethylene having a content of 0.02 to 1% by weight of units of a perfluoro-(alkyl vinyl) ether by the suspension process, a polymer which does not tend to discoloration on |
| 5576402 |
Process for the preparation of a modified polytetrafluoroethylene and its use |
November 19, 1996 |
| If the employment of polymerization auxiliaries in ammonium form is avoided in the preparation of a polytetrafluoroethylene having a content of 0.02 to 1% by weight of units of a perfluoro-(alkyl vinyl) ether by the suspension process, a polymer which does not tend to discoloration on |
| 5576381 |
Aqueous dispersion of fluoropolymers, its preparation and use for coatings |
November 19, 1996 |
| Aqueous dispersions of fluoropolymers which are obtained by emulsion polymerization, are not processsable from the melt and form a film on sintering, which comprise a fluoropolymer A) having an average particle size (number average) of from 180 to 400 nm and a fluoropolymer B) having |
| 5530078 |
Preparation of a modified polytetrafluoroethylene and use thereof |
June 25, 1996 |
| Polymerizing tetrafluoroethylene with modifying amounts of a perfluoro(alkyl vinyl ether) at temperatures below 60.degree. C. using permanganate or similar initiators by the suspension process and milling the raw polymer to an average particle size of from 10 to 50 .mu.m gives moldin |
| 5312935 |
Purification of fluorinated carboxylic acids |
May 17, 1994 |
| Fluorinated carboxylic acids which do not have the required purity for use as emulsifier in the polymerization of fluorinated monomers can, if necessary after prior de-watering, be treated with oxidants, whereupon the isolation of the pure product is carried out by crystallisation or, |
| 5276261 |
Process for the preparation of tetrafluoroethylene polymers |
January 4, 1994 |
| 1,1,1,2-Tetrafluoroethane is a good chain-transfer agent for the preparation of polymers of tetrafluoroethylene in aqueous colloidal dispersion. |
| 5153285 |
Process for the preparation of tetrafluoroethylene polymer in aqueous suspension |
October 6, 1992 |
| In the suspension polymerization of tetrafluoroethylene a mixture of tetrafluoroethylene and an inert gas is charged under pressure before starting the polymerization, the total pressure being 5 to 50 bar and the concentration of tetrafluoroethylene in this mixture being 30 to 70 mol %. |
| 4933388 |
Solutions of copolymers of the tetrafluoroethylene/ethylene type |
June 12, 1990 |
| Solutions of copolymers of the tetrafluoroethylene/ethylene typeCopolymer solutions comprising tetrafluoroethylene, ethylene and, as appropriate, further .alpha.-olefinic monomers in low-molecular-weight polymers of chlorotrifluoroethylene are described. They can be used for coatings, im |
| 4859755 |
Crosslinkable, fluorine-containing copolymers as binders for highly weather-resistant surface co |
August 22, 1989 |
| Crosslinkable, fluorine-containing copolymers, comprising:(a) 15 to 70 mol % of copolymerized units of a vinyl ester of the formula ##STR1## in which R.sup.1, R.sup.2 and R.sup.3 are branched or straight-chain alkyl radicals or cycloalkyl radicals, at most one of these radicals is h |
| 4808651 |
Solutions of fluoropolymers, and their use |
February 28, 1989 |
| The invention relates to solutions of fluoropolymers which preferably contain carbonate groups, in solvents of the general formula (I) ##STR1## These solutions are suitable, in particular, for the production of membranes for liquid permeation processes, such as electrolysis. |
| 4584343 |
Crosslinkable fluorine-containing copolymers, surface-coatings based on these copolymers, and th |
April 22, 1986 |
| Crosslinkable fluorine-containing copolymers comprising copolymerized units of(a) a vinyl ester of a heavily branched carboxylic acid,(b) a vinyl ester of a short-chain carboxylic acid and(c) of a fluoroolefin, the vinyl ester groups of component (b) having been converted into OH groups by s |
| 4395500 |
Protective colloid-free plastics dispersion having a bimodal particle size distribution |
July 26, 1983 |
| A protective colloid-free plastics dispersion yielding after drying a polymer film which under the influence of moisture has no or little tendency to whitening contains polymer particles having a bimodal size distribution, that is, on the one hand relatively coarse particles and on t |
