Use of hydroperoxides as regulators in polymerizations
AssigneeWacker Polymer Systems GmbH & Co. KG
InventorsPeter Weiler, Ulf Dietrich, Peter Ball
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Abstract
The invention provides for the use of non-copolymerizable hydroperoxides of the formula R—O—O—H as regulators in the free-radically initiated polymerization of ethylenically unsaturated monomers, where R is H, a C1-C18-alkyl radical, a C7-C22-aralkyl radical or a saturated or unsaturated carbocyclic or heterocyclic ring having from 3 to 18 carbon atoms, and may be substituted or unsubstituted.
Claims20
A process for emulsion or suspension polymerization by free radical polymerization of unsaturated monomers in the presence of a free radical polymerization initiator in water, the improvement comprising polymerizing said at least one unsaturated monomer in the presence of an effective molecular weight limiting amount of at least one non-copolymerizable hydroperoxide regulator of the formula
- R—O—O—H
- wherein R is H, or an optionally substituted hydrocarbyl radical selected from the group consisting of C1-18 alkyl, C7-22 aralkyl, C3-18 saturated or unsaturated carbocyclic radical, and C3-18 saturated or unsaturated heterocyclic radical,
- wherein when said hydroperoxide is also employed as said free radical initiator, a reducing agent is also employed, and the mol ratio of said hydroperoxide to said reducing agent is from 1.2:1 to 20:1, and when said hydroperoxide is employed as a regulator with a non-hydroperoxide free radical initiator, the mol ratio of hydroperoxide to free radical initiator is greater than 0.2:1 at the onset of polymerization, said emulsion or suspension polymerization taking place in the presence of at least one surface active agent selected from the group consisting of protective colloids and emulsifiers, said unsaturated monomers comprising no more than about 0.1 to 5 weight percent of water soluble auxiliary monomers.
Dependencies are inferred from the claim text.