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公开(公告)号：CA1184728A
公开(公告)日：1985-04-02
申请号：CA410946
申请日：1982-09-08
Applicant: HOECHST AG
Inventor： KUHLS JUERGEN , WEISS EDUARD , BURGSTALLER GOTTFRIED
Abstract: of the disclosure: A process for the continuous agglomeration of granular tetrafluoroethylene polymer powders which cannot be processed from the melt to give molding powders having a high bulk density, an improved powder flow and particle stability and a narrow particle size distribution is described. In this process, the powder to be agglomerated is first introduced uniformly into a pretreatment stage and is dispersed and pre-agglomerated in this stage in the liquid agglomeration medium, composed of water and an organic liquid capable of wetting polytetrafluoroethylene, is then agglomerated to the desired average particle diameter in an agglomeration stage and is finally treated further in an after-treatment stage in order to develop the final shape of the particles. Finally, the powder is separated from the liquid medium and is dried. This makes it possible to obtain, in an economical manner and with excellent processing properties, high-grade agglomerated molding powders of such tetrafluoroethylene polymers, in particular of such polymers which have been modified with small quantities of perfluoro-(alkyl-vinyl) ethers.
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公开(公告)号：FI55347C
公开(公告)日：1979-07-10
申请号：FI206372
申请日：1972-07-20
Applicant: HOECHST AG
Inventor： HARTWIMMER ROBERT , WEISS EDUARD
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公开(公告)号：DE3061298D1
公开(公告)日：1983-01-20
申请号：DE3061298
申请日：1980-02-26
Applicant: HOECHST AG
Inventor： KUHLS JURGEN DR , WEISS EDUARD
IPC: C08J3/02 , C08C1/075 , C08F6/20 , C08F6/24 , C08L3/00 , C08L27/12 , C08L27/18 , C09D127/12 , C08J3/04
Abstract: Aqueous colloidal dispersions of fluorinated polymers can be concentrated, after adding a stabilizing emulsifier, to high solids contents by ultrafiltration over customary semi-permeable membranes if pumps which keep the dispersion free from contact with components which cause frictional forces are used for conveying the dispersion. A considerable proportion of the stabilizing emulsifier added and high proportions of the fluorine-containing emulsifier originally contained in the fluorinated polymer dispersion from the emulsion polymerization can be removed via the aqueous permeate. The fluorine-containing emulsifier can be recovered by a downwstream basic anion exchanger and the stabilizing emulsifier contained in the filtrate flowing out of the anion exchanger can be concentrated in this filtrate by reverse osmosis and optionally recycled into the ultrafiltration process. Fluorinated polymer dispersions which, in addition to having a high solids content, are distinguished by particularly low contents of fluorine-containing emulsifier and of stabilizing emulsifier can be obtained. The process can be applied to all known aqueous, colloidal dispersions of fluorinated homopolymers and copolymers.
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公开(公告)号：CA807637A
公开(公告)日：1969-03-04
申请号：CA807637D
Applicant: HOECHST AG
Inventor： WEISS EDUARD , SCHIMMELSCHMIDT KURT , REHN KARL
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公开(公告)号：DE4040129A1
公开(公告)日：1992-06-17
申请号：DE4040129
申请日：1990-12-15
Applicant: HOECHST AG
Inventor： SCHLIPF MICHAEL DR , WEISS EDUARD
IPC: C08F8/12 , C09D127/12 , C09D131/02
Abstract: A process is described for the preparation of a crosslinkable paint binder by working up a solution of a fluorine-containing copolymer composed of copolymerized units of a perfluoroolefin, a vinyl ester of a short-chain, saponifiable carboxylic acid and a vinyl ester of a strongly branched carboxylic acid which resists saponification. In this process, the bulk of the solvent and the residual monomers are first removed by distillation, the residual highly viscous copolymer is then dissolved in a mixture of alkanol and another solvent which is also capable of dissolving the saponified copolymer to form a homogeneous solution, and the alkaline saponification is subsequently carried out. If desired, the solvent is removed and exchanged for a paint solvent and this solution is finally filtered. A mild saponification is achieved in this manner.
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Patent Agency Ranking
公开(公告)号：CA1165926A
公开(公告)日：1984-04-17
申请号：CA346683
申请日：1980-02-29
Applicant: HOECHST AG
Inventor： KUHLS JUERGEN , WEISS EDUARD
IPC: C08J3/02 , C08C1/075 , C08F6/20 , C08F6/24 , C08L3/00 , C08L27/12 , C08L27/18 , C09D127/12 , B01D13/00 , C08F14/18
Abstract: : Aqueous, colloidal dispersions of fluorinated polymers can be concentrated, after adding a stabilizing emulsifier, to high solids contents by ultrafiltration over customary semi-permeable membranes if pulps which keep the dispersion free from contact with components which cause frictional forces are used for conveying the dispersio A considerable proportion of the stabilizing emulsifier added and high proportions of the fluorine-containing emulsifier originally contained in the fluorinated polymer dispersion from the emulsion polymerization can be removed via the aqueous permeate. The fluorine-containing emulsifier can be recovered by a downstream basic anion exchanger and the stabilizing emulsifier contained in the filtrate flowing out of the anion exchanger can be concentrated in this filtrate by reverse osmosis and optionally recycled into the ultrafiltration process. Fluorinated polymer dispersions which, in addition to having a high solids content, are distinguished by particularly low contents of fluorinecontaining emulsifier and of stabilizing emulsifier can be obtained. The process can be applied to all known aqueous, colloidal dispersions of fluorinated homopolymers and copolymers.
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公开(公告)号：BR8205249A
公开(公告)日：1983-08-16
申请号：BR8205249
申请日：1982-09-08
Applicant: HOECHST AG
Inventor： KUHLS JURGEN , WEISS EDUARD , BURGSTALLER GOTTFRIED
Abstract: A process for the continuous agglomeration of granular tetrafluoroethylene polymer powders which cannot be processed from the melt to give molding powders having a high bulk density, an improved powder flow and particle stability and a narrow particle size distribution is described. In this process, the powder to be agglomerated is first introduced uniformly into a pretreatment stage and is dispersed and pre-agglomerated in this stage in the liquid agglomeration medium, composed of water and an organic liquid capable of wetting polytetrafluoroethylene, is then agglomerated to the desired average particle diameter in an agglomeration stage and is finally treated further in an after-treatment stage in order to develop the final shape of the particles. Finally, the powder is separated from the liquid medium and is dried. This makes it possible to obtain, in an economical manner and with excellent processing properties, high-grade agglomerated molding powders of such tetrafluoroethylene polymers, in particular of such polymers which have been modified with small quantities of perfluoro-(alkyl-vinyl) ethers.
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公开(公告)号：DE3270126D1
公开(公告)日：1986-04-30
申请号：DE3270126
申请日：1982-09-03
Applicant: HOECHST AG
Inventor： KUHLS JURGEN DR , WEISS EDUARD , BURGSTALLER GOTTFRIED
Abstract: A process for the continuous agglomeration of granular tetrafluoroethylene polymer powders which cannot be processed from the melt to give molding powders having a high bulk density, an improved powder flow and particle stability and a narrow particle size distribution is described. In this process, the powder to be agglomerated is first introduced uniformly into a pretreatment stage and is dispersed and pre-agglomerated in this stage in the liquid agglomeration medium, composed of water and an organic liquid capable of wetting polytetrafluoroethylene, is then agglomerated to the desired average particle diameter in an agglomeration stage and is finally treated further in an after-treatment stage in order to develop the final shape of the particles. Finally, the powder is separated from the liquid medium and is dried. This makes it possible to obtain, in an economical manner and with excellent processing properties, high-grade agglomerated molding powders of such tetrafluoroethylene polymers, in particular of such polymers which have been modified with small quantities of perfluoro-(alkyl-vinyl) ethers.
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公开(公告)号：DE59105109D1
公开(公告)日：1995-05-11
申请号：DE59105109
申请日：1991-12-12
Applicant: HOECHST AG
Inventor： SCHLIPF MICHAEL DR , WEISS EDUARD
IPC: C08F8/12 , C09D127/12 , C09D131/02
Abstract: A process is described for the preparation of a crosslinkable paint binder by working up a solution of a fluorine-containing copolymer composed of copolymerized units of a perfluoroolefin, a vinyl ester of a short-chain, saponifiable carboxylic acid and a vinyl ester of a strongly branched carboxylic acid which resists saponification. In this process, the bulk of the solvent and the residual monomers are first removed by distillation, the residual highly viscous copolymer is then dissolved in a mixture of alkanol and another solvent which is also capable of dissolving the saponified copolymer to form a homogeneous solution, and the alkaline saponification is subsequently carried out. If desired, the solvent is removed and exchanged for a paint solvent and this solution is finally filtered. A mild saponification is achieved in this manner.
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公开(公告)号：FI55347B
公开(公告)日：1979-03-30
申请号：FI206372
申请日：1972-07-20
Applicant: HOECHST AG
Inventor： HARTWIMMER ROBERT , WEISS EDUARD
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