摘要:
A process of reducing the amount of fluorinated emulsifiers in fluoropolymer dispersions by contacting the fluoropolymer dispersion with an anion exchange resin in the presence of a pH-dependent surfactant, and fluoropolymer dispersion containing the pH-dependent surfactant and uses thereof.
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:
A process of reducing the amount of fluorinated emulsifiers in fluoropolymer dispersions by contacting the fluoropolymer dispersion with an anion exchange resin in the presence of a pH-dependent surfactant, and fluoropolymer dispersions containing the pH-dependent surfactant and uses thereof.
摘要:
The present invention provides an aqueous non-melt processible polytetrafluoroethylene dispersion comprising non-melt processible polytetrafluoroethylene particles in an amount between 30 and 70% by weight based on the total weight of the dispersion and one or more non-ionic surfactants and wherein at least a part of said non-melt processible polytetrafluoroethylene particles comprise polytetrafluoroethylene polymer chains having repeating units comprising ionic groups. The invention further provides a method for obtaining the dispersions.
摘要:
A method of making a fluoropolymer dispersion by first providing a fluoropolymer dispersion comprising fluoropolymer particles and one or more fluorinated surfactants selected from fluorinated carboxylic acids or salts thereof having the general formula: [Rf—O-L-COO−]iXi+ (I) wherein L represents a linear fully fluorinated alkylene group, Rf represents a linear fully fluorinated aliphatic group or a linear fully fluorinated aliphatic group interrupted with one oxygen atom, Xi+ represents a cation having the valence i and i is 1, 2 or 3; then adding one or more non-fluorinated surfactants selected from anionic and non-ionic surfactants followed by reducing the total amount of the one or more fluorinated surfactants to an amount of not more than 500 ppm, for example not more than 250 ppm based on the total weight of the dispersion while maintaining or increasing the amount of solids in the dispersion.
摘要:
The present invention provides a fluoropolymer dispersion comprising fluoropolymer particles having an average particle size of 10 to 400 nm dispersed in water whereby the dispersion is free of fluorinated surfactant having a molecular weight of less than 1000 g/mol or contains the fluorinated surfactant having a molecular weight of less than 1000 g/mol in an amount of not more than 0.025% by weight based on the total weight of solids in the dispersion. The dispersion further comprises a non-ionic surfactant and an anionic surfactant selected from fluorinated anionic surfactants having a molecular weight of at least 1000 g/mol, non-fluorinated anionic surfactants and mixtures thereof.
摘要:
A method of making a fluoropolymer dispersion by first providing a fluoropolymer dispersion comprising fluoropolymer particles and one or more fluorinated surfactants selected from fluorinated carboxylic acids or salts thereof having the general formula: [Rf—O-L-COO−]iXi+ (I) wherein L represents a linear fully fluorinated alkylene group, Rf represents a linear fully fluorinated aliphatic group or a linear fully fluorinated aliphatic group interrupted with one oxygen atom, Xi+ represents a cation having the valence i and i is 1, 2 or 3; then adding one or more non-fluorinated surfactants selected from anionic and non-ionic surfactants followed by reducing the total amount of the one or more fluorinated surfactants to an amount of not more than 500 ppm, for example not more than 250 ppm based on the total weight of the dispersion while maintaining or increasing the amount of solids in the dispersion.
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:
Provided is a method comprising polymerizing at least one fluorinated monomer in an aqueous emulsion polymerization in the presence of a carbosilane surfactant having at least one hydrophobic part, wherein the hydrophobic part has at least one silicon atom, and having at least one hydrophilic part, with the proviso that the carbosilane contains no Si—O bonds.
摘要:
A method of making a fluoropolymer dispersion by first providing a fluoropolymer dispersion comprising fluoropolymer particles and one or more fluorinated surfactants selected from fluorinated carboxylic acids or salts thereof having the general formula: [Rf—O-L-COO−]iXi+ (I) wherein L represents a linear fully fluorinated alkylene group, Rf represents a linear partially or fully fluorinated aliphatic group or a linear partially or fully fluorinated aliphatic group interrupted with one oxygen atom, Xi+ represents a cation having the valence i and i is 1, 2 or 3; then adding one or more non-fluorinated surfactants selected from anionic and non-ionic surfactants followed by reducing the total amount of the one or more fluorinated surfactants to an amount of not more than 500 ppm, for example not more than 250 ppm based on the total weight of the dispersion while maintaining or increasing the amount of solids in the dispersion.
摘要翻译:首先提供含氟聚合物颗粒和一种或多种选自氟化羧酸或其盐的含氟表面活性剂的含氟聚合物分散体的制备方法,所述含氟聚合物分散体具有以下通式:[Rf-OL-COO-] iXi +(I)其中L表示 线性全氟化亚烷基,Rf表示直链部分或完全氟化的脂族基团或被一个氧原子间隔的直链部分或全氟化的脂族基团,X i +表示i为i且i为1,2或3的阳离子; 然后加入一种或多种选自阴离子和非离子表面活性剂的非氟化表面活性剂,然后将一种或多种氟化表面活性剂的总量减少至不超过500ppm,例如不超过250ppm,基于 分散体的总重量,同时保持或增加分散体中固体的量。