摘要:
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 dispersions can be concentrated and used for coating applications.
摘要:
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 dispersions can be concentrated and used for coating applications.
摘要:
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, impregnations, cast films and for the production of fibers and filaments by gel spinning.
摘要:
A process for manufacturing fluoroolefins comprising perfluorinating a starting material comprising at least one carbon-bonded hydrogen by electrochemical fluorination, dissociating this separated effluent in a pyrolysis, quenching and separating the effluent to yield tetrafluoroethylene and/or hexafluoropropylene.
摘要:
A process for recovering a fluorinated carboxylic acid or salts thereof from exhaust gas streams. The process includes contacting the exhaust gas stream with a composition capable of at least partially removing the fluorinated carboxylic acid or salt thereof from the exhaust gas stream. The fluorinated carboxylic acid or salt thereof is selected from the group consisting of fluorinated carboxylic acids or salts thereof that correspond to the general formula: [Rf—O-L-COO−]iXi+ (I) wherein L represents a linear partially or fully fluorinated alkylene group or an aliphatic hydrocarbon group, Rf represents a linear partially or fully fluorinated aliphatic group or a linear partially or fully fluorinated aliphatic group interrupted with one or more oxygen atoms, Xi+ represents a cation having the valence i and i is 1, 2 or 3.
摘要:
The invention provides a method for recovery of an anionic fluorinated surfactant from a basic anion exchange resin having quaternary ammonium groups, the method comprising eluting the anion exchange resin with a composition comprising an ammonium salt and a water miscible organic solvent. The method according to the invention may provide one or more of the following advantages. For example, the method can be designed to allow for recovery of substantially all of the fluorinated surfactant from a basic anion exchange resin having quaternary ammonium groups. Also, the liquid used for recovering the surfactant from the anion exchange resin is a simple liquid that can be readily and cost effectively manufactured. Further the process may be carried out in a convenient and easy manner. Furthermore, the method generally does not require large amounts of the eluting composition.
摘要:
A process for manufacturing fluoroolefins comprising perfluorinating a starting material comprising at least one carbon-bonded hydrogen by electrochemical fluorination, dissociating this separated effluent in a pyrolysis, quenching and separating the effluent to yield tetrafluoroethylene and/or hexafluoropropylene.
摘要:
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 fluoropolymer dispersion with an effective amount of a surfactant so as to stabilize the fluoropolymer dispersion while being contacted with the anion exchange resin; (b) contacting the aqueous fluoropolymer dispersion with an anion exchange resin by agitating the aqueous fluoropolymer dispersion with an effective amount of anion exchange resin for a time of less than 4 hours to reduce the amount of fluorinated emulsifier in the aqueous fluoropolymer dispersion to a desired level; and (c) separating the anion exchange resin from the aqueous fluoropolymer dispersion.
摘要:
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 fluoropolymer dispersion with an effective amount of a surfactant so as to stabilize the fluoropolymer dispersion while being contacted with the anion exchange resin; (b) contacting the aqueous fluoropolyrner dispersion with an anion exchange resin by agitating the aqueous fluoropolymer dispersion with an effective amount of anion exchange resin for a time of less than 4 hours to reduce the amount of fluorinated emulsifier in the aqueous fluoropolymer dispersion to a desired level; and (c) separating the anion exchange resin from the aqueous fluoropolymer dispersion.
摘要:
A composition comprising (a) a fluoropolymer having pendant imidate groups, which imidate groups have the formula: —C═NH(OR) wherein R is a C1-C10 aliphatic group which aliphatic group may have F or Cl substituents; and optionally, (b) a perfluorovinyl ether of the general formula: CF2═CFO(R′fO)a(R″fO)bRf wherein R′f and R″f are the same or are different C1-C6 linear or branched perfluoroalkylene groups; a and b are, independently, 0 or an integer from 1 to 10; and Rf is a C1-C8 perfluoroalkyl group or a C1-C15 perfluoroalkoxy group. Also provided are a method of making a fluoropolymer composition and curable and cured articles comprising a fluoropolymer composition.