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 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 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:
An aqueous non-melt processible polytetrafluoroethylene dispersion having non-melt processible polytetrafluoroethylene particles in an amount of 30 to 70% by weight and an amount of non-ionic surfactant between 2 and 15% by weight based on the weight of polytetrafluoroethylene solids. The dispersion is free of fluorinated surfactant or contains fluorinated surfactant in amounts of not more than 200 ppm based on the amount of polytetrafluoroethylene solids. At least part of the non-melt processible polytetrafluoroethylene particles comprise an effective amount of ionic end groups in the polytetrafluoroethylene polymer chains.
摘要:
The present invention provides an aqueous coating composition comprising (i) particles of a non-melt processible polymer of tetrafluoroethylene and (ii) a non-fluorinated polymer selected from the group consisting of a polysulfone, a polyamide, a polyimide, a polyamide-imide, a polybismaleimide and mixtures thereof, wherein said particles are core-shell particles whereby the shell comprises a copolymer of tetrafluoroethylene and a partially fluorinated or non-fluorinated comonomer. The aqueous coating composition may be used for providing a primer coating on a substrate such as a metal or glass substrate. Such primer coating may provide good or excellent non-stick coatings combined with good or excellent scratch and wear resistance of the coating. Also, such primer coating may provide for good to excellent PTFE coatings that can resist hot salt water. The aqueous coating composition may also be used to provide other coating layers of a multi-layer coating.
摘要:
The present invention provides a method of making an aqueous dispersion of non-melt processible polytetrafluoroethylene, the method comprising:(a) an aqueous emulsion polymerization of an amount of tetrafluoroethylene to produce a final amount of polytetrafluoroethylene solids and optionally up to 1% by weight based on the amount of tetrafluoroethylene of a perfluorinated comonomer, wherein said aqueous emulsion polymerization is initiated with a free radical initiator and the polymerization is carried out in the presence of a fluorinated surfactant, and wherein before completing the feeding of said amount of tetrafluoroethylene but after feeding at least 80% by weight of said amount of tetrafluoroethylene, free radicals capable of introducing ionic end groups or precursors thereof in the polytetrafluoroethylene polymer are caused to be formed at a rate that without counter measures would cause an increase in the polymerization rate of at least 20%;(b) reducing the amount of fluorinated surfactant in the thus obtained aqueous dispersion to an amount of not more than 200 ppm, preferably not more than 100 ppm and more preferably not more than 50 ppm based on the amount of polytetrafluoroethylene solids. The invention further provides an aqueous dispersion of polytetrafluoroethylene particles and the use thereof in coating a substrate.
摘要:
High purity fluoropolymers are obtained by the emulsion polymerization process, removing essentially all ions and coagulating the polymer essentially without adding ions. These polymers are useful in the field of electronic devices.
摘要:
An aqueous non-melt processible polytetrafluoroethylene dispersion having non-melt processible polytetrafluoroethylene particles in an amount of 30 to 70% by weight and an amount of non-ionic surfactant between 2 and 15% by weight based on the weight of polytetrafluoroethylene solids. The dispersion is free of fluorinated surfactant or contains fluorinated surfactant in amounts of not more than 200 ppm based on the amount of polytetrafluoroethylene solids. At least part of the non-melt processible polytetrafluoroethylene particles comprise an effective amount of ionic end groups in the polytetrafluoroethylene polymer chains.
摘要:
The present invention provides a method of coating a substrate having a surface defined by a layer of fluoropolymer. The method utilizes an aqueous dispersion that includes: particles of melt-processible fluoropolymer in an amount of 30 to 70% by weight; a fluorinated surfactant in an amount of not more than 250 ppm based on fluoropolymer solids of the aqueous dispersion; and a non-ionic surfactant comprising an ethoxylated aliphatic alcohol in an amount of 2 to 15% by weight based on total solids of the aqueous dispersion. The aqueous dispersion is free or substantially free of aromatic group containing non-ionic surfactants. The aqueous dispersion may be optionally diluted and/or modified with additional components to obtain a coating composition. The coating composition may then be applied on at least part of the surface of the substrate to define the fluoropolymer layer.
摘要:
High purity fluoropolymers are obtained by the emulsion polymerization process, removing essentially all ions and coagulating the polymer essentially without adding ions. These polymers are useful in the field of electronic devices.