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Title: Polymerization initiators containing thio bridges
Claims: We claim: 1. A process for the manufacture of a polymer of one or more vinyl compounds by polymerizing the monomeric vinyl compound(s), employing as initiator in an amount of from 0.05 to 5% by weight based on the monomer(s) a compound which forms free radicals, wherein said compound which forms free radicals that is used during the polymerization is selected from organic compounds, containing thio bridges, of the general formula (I) ##STR17## where R.sup.1, R.sup.2 and R.sup.3 may be identical or different and each is --S--alkyl, --S--cycloalkyl or --S--aryl, each substituent R.sup.1, R.sup.2 and R.sup.3 being of up to 14 carbon atoms, and any 2 of the substituents being optionally linked to form a ring, and R.sup.4 is --S--alkyl, --S--cycloalkyl or --S--aryl, each of up to 14 carbon atoms, or is ##STR18## but, where R.sup.4 is ##STR19## R.sup.3 may also be hydrogen or an --Si--(--X).sub.3 group, X being linear alkyl of 1 to 3 carbon atoms. 2. A process as claimed in claim 1, wherein the organic compound containing thio bridges is a tetrakis-(organylthio)-methane. 3. A process as claimed in claim 1, wherein the formula of the organic compound containing thio bridges, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are identical. 4. A process as claimed in claim 1, wherein the organic compound containing thio bridges is tetrakis-(methylthio)-methane, tetrakis-(phenylthio)-methane or tetrakis-(phenylthio)-ethane. 5. A process as claimed in claim 1, wherein the organic compound containing thio bridges is a 1,1,2,2,-tetrakis-(organylthio)-ethane or a hexakis-(organylthio)-ethane. 6. A process as claimed in claim 1, wherein, in the formula of the organic compound containing thio bridges, R.sup.1 and R.sup.2 are identical and R.sup.3 is either hydrogen, an --Si(--X).sub.3 group or identical with R.sup.1 and R.sup.2. 7. A process as claimed in claim 1, wherein the organic compound containing thio bridges is hexakis-(phenylthio)-ethane or a p-methyl, o-methyl, p-tert.-butyl, p-methoxy, fluoro- or chloro-substituted derivative thereof, hexakis-(.beta.-naphthylthio)-ethane, hexakis-(cyclohexylthio)-ethane, hexakis-(methylthio)-ethane, 1,1,2,2-tetrakis-(phenylthio)-1,2-bis-(methylthio)-ethane or its 1,2-bis-(trimethylsilyl) analogue or the compound of the formula (VI) herein. 8. A process as claimed in claim 1, wherein the organic compound containing thio bridges is used to modify a preformed vinyl polymer. 9. A process as claimed in claim 1 wherein a polymer produced by the process of claim 1 is subsequently modified by reacting an additional amount of said organic compound containing thio bridges at a reaction temperature at which there is significant decomposition of said organic compound and groups containing sulfur bridges are introduced into the polymer. 10. A process as claimed in claim 1, wherein the polymerization is carried out as a mass polymerization or as a solution polymerization in the presence of up to 50% by weight of an inert diluent, based on the monomer(s). Other info: Inventors: Pohlemann, Heinz (Limburgerhof, DE, US) Naarmann, Herbert (Wattenheim, DE, US) Seebach, Dieter (Lich, DE, US) Application Number: 792881 Filing Date: 1977-05-02 Publication_date: 1978-10-17 Assignee: BASF Aktiengesellschaft (Ludwigshafen am Rhine, DE) Primary Class(es): 525/342 525/329.1, 525/329.8, 525/330.4, 525/331.4, 525/331.5, 525/333.1, 525/333.2, 525/333.5, 525/333.9, 526/194, 526/204, 526/222, 526/328, 526/346 Other Classes: US Patent Ref:
Other Refs: Other References: Coffen et al., J.A.C.S. 2258-2268 (93) 1971, "Tetrathioethylenes". | |