Ceskoslovenska Akademie Ved

Josef Babka

Miloslav Kolinsky

Lubomir Lochmann

Vaclava Jisova

Theodor Kremlicka

The invention relates to a method and to a reactor for the single-step polymerization of vinyl monomers by a heterogeneous polymerization in bulk by means of organometalic catalysts. A method according to the invention consists in charging a vertical reactor, which is provided with at least two planetary stirrers situated outside the reactor axis, each stirrer formed from a planar centrally-symmetrical two-blade paddle, with a vinyl monomer, the subsequent introduction of an organometalic catalyst in a solution under stirring and in partial doses amounting to 10.sup.-5 to 10.sup.-3 mole up to the final amount of 5.times.10.sup.-4 to 5.times.10.sup.-2 mole of catalyst per mole of monomer, stirring of the batch, cutting and disintegration of the formed compact mass with the planetary stirrers and its parallel wiping from the surface of reactor with wiping blades until the batch acquires a powdery form and the resulting product is discharged.

Method for the single-step production of vinyl polymers

The invention relates to a mixture for activation of polytetrafluoroethylene and other fluoroplastics for bonding by means of adhesives. The mixture contains an organometallic compound of an alkali metal stabilized against effects of atmospheric oxygen and humidity and is particularly suitable for the surface activation in a lot or continuous production or for spaceous articles, where the simple use without protective atmosphere is advantageous. It consists of 1-60 wt. % of an organic polymer (mol. wt. above 4000) obtained by polymerization of ethylene, C.sub.1 -C.sub.3 alkyl, phenyl, or C.sub.1 -C.sub.10 alkoxy substituted theylene, ethylene oxide or propylene oxide or a mixture of these polymers, 1 mol of Li, Na or K metal, 0.4-2 mol of a hydrocarbon containing 2-4 bonded, condensed or aneled aromatic nuclei, 500-5000 ml of a solvent from a group comprising aliphatic and cycloaliphatic ethers or polyethers, and, if it is required, up to 50 vol. % of an aromatic, aliphatic or cycloaliphatic hydrocarbon and/or up to 1 mol of the crown ether of the general formula ##STR1## where m + n = 2 to 10. The surfaces treated with this mixture give virtually the same strength of bonding as after treatment with known organometallic agents, but under much more convenient condition of handling and application.

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Prague, Czechia

Josef Babka