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    2.
    发明专利
    未知

    公开(公告)号：DE1679830A1

    公开(公告)日：1971-03-25

    申请号：DE1679830

    申请日：1965-12-30

    Applicant: HOECHST AG

    Inventor： HARTWIMMER ROBERT DR

    IPC: C08J3/12 ,  B29B1/02

    Abstract: 1,173,000. Treating polytetrafluoroethylene. FARBWERKE HOECHST A.G. 30 Dec., 1966 [30 Dec., 1965], No. 58328/66. Heading C3P. Polytetrafluoroethylene granular powder is manufactured by stirring a polytetrafluoroethylene powder at a temperature in the range of from 20‹ to 300‹ C. in the presence of a dispersing agent consisting of an alkane carrying at least two hydroxy and/or amino groups and/or a compound which can be derived from these alkanes by combining them by means of the hydroxy and/or amino groups or mixtures of these compounds. Polytetrafluoroethylenes: (1) an unsintered polytetrafluoroethylene obtained by polymerization of tetrafluoroethylene in an aqueous dispersion and pulverizing the polymerization product, and (2) the product obtained by polymerization of tetrafluoroethylene in the presence of a small quantity of another perfluoro-olefine, e.g. 0.05 to 0.1% of perfluoropropene. Dispersing agents ethylene glycol, propane - diol - (1.2), propane - diol - (1.3), butane-diol-(1.3), butane-diol-(1.4), a pentane diol or triol, glycerol, di-ethylene glycol, triethylene glycol, ethanolamine, propanolamine, diethanolamine, ethylenediamine and propylenediamine. The proportion between the polytetrafluoroethylene and the dispersing agent is in the range of from 1:1 to 1:10. The polytetrafluoroethylene is preferably degassed by vacuum prior to the addition of the dispersing agent. The stirring may be carried out in the presence of a liquid which is inert under the reaction conditions, viz., alcohols, esters, nitriles, ketones, aromatic or aliphatic hydrocarbons, or water containing specified wetting agents. According to an example, a four-necked flask having a capacity of 4 litres, provided with a stirrer, a cooler and a sump theremometer, was filled with 2 litres of ethylene glycol. 150 ml. of a 20% aqueous dispersion of polytetrafluoroethylene were first added and then 360 g. of screened polytetrafluoroethylene - suspension polymer powder while stirring moderately. The number of rotations was then increased to 300-400 r.p.m. and the mixture was slowly heated. After a short time and at a temperature slightly above 30‹ C., an agglomeration of the particles was observed. At the same time, the dispersion disintegrated and its solid portions also precipitated on the suspended polytetrafluoroethylene particles, favouring agglomeration. The mixture was heated to a temperature in the range of from 40‹ to 50‹ C. for 1 hour, then cooled. The polytetrafluoroethylene granules obtained were separated, washed and dried.

    6.
    发明专利
    未知

    公开(公告)号：DE1720801A1

    公开(公告)日：1972-07-27

    申请号：DE1720801

    申请日：1968-03-12

    Applicant: HOECHST AG

    Inventor： HARTWIMMER ROBERT DR

    IPC: C08F14/18 ,  C08F3/20

    Abstract: 1,229,531. Fluoro-olefine polymers. FARBWERKE HOECHST A.G. 12 March, 1969 [12 March, 1968], No. 13012/69. Heading C3P. A fluorine-containing homo- or copolymer is prepared by polymerizing one or more fluorinecontaining olefines in an aqueous medium in the presence of, as catalyst, an acid derived from a metal of sub-group V B , VI B or VII B of the Mendeleeff Periodic Table, a salt thereof, a compound which forms such an acid or salt under the conditions of polymerization or a mixture of two or more such compounds. In the examples tetrafluoroethylene, trifluorochloroethylene, and hexafluoropropylene are polymerized in the presence of ammonium chloride, desalted water, potassium permanganate and sodium dihydrogen phosphate.

    Solutions of fluorine-containing polymers
    9.
    发明专利
    Solutions of fluorine-containing polymers 未知

    公开(公告)号：DE3843813A1

    公开(公告)日：1990-07-05

    申请号：DE3843813

    申请日：1988-12-24

    Applicant: HOECHST AG

    Inventor： HARTWIMMER ROBERT DR ,  HINTZER KLAUS DR ,  MILLAUER HANS DR ,  SCHWERTFEGER WERNER DR

    IPC: C08J3/09 ,  C08J5/18 ,  C08J5/22

    Abstract: In mixtures of aprotic solvents, such as dimethylformamide and anhydrous carboxylic acids, fluorine-containing polymers containing -COOH groups dissolve without degradation if these groups are first converted into -COON(R)4 groups by reaction with tetraalkylammonium compounds. Such solutions can be used to produce cast films which, after reconversion into the -COOH form, are used as cation exchanger membranes. Films or coatings made from such solutions can also be used on greenhouse covers, where their hydrophilic surface allows condensation to run off more easily. Other applications relate to ion exchangers on supports and catalysts for chemical reactions.

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