Low molecular weight water soluble phosphinate and phosphonate containing polymers
AssigneeRohm and Haas Company
InventorsKathleen A. Hughes, Graham Swift
Life of this patent
Estimating the term…
Abstract
A process to efficiently utilize the chain transfer agent hypophosphorous acid or salts in the preparation of low moelcular weight polycarboxylate polymers comprising employing in process neutralization of the carboxylic acid monomers. A low molecular weight polycarboxylate polymer containing phosphinate and phosphonate functional groups where less than 20% of the phosphorus is present in inorganic non polymeric compounds.
Claims10
In the process of polymerizing or copolymerizing acrylate monomers to form low molecular weight water-soluble acrylate polymers using a hypophosphorous acid chain transfer agent together with polymerization initiators, water and optional polymerization activators in a heated, agitated aqueous polymerizing mixture containing the monomers, the improvement which comprises concurrently feeding hypophosphorous acid chain transfer agent and an alkaline neutralizer to the polymerizing mixture of monomers such that the alkaline neutralizer is present during at least most, if not all, of the polymerization in an amount sufficient to neutralize at least 20% of the acid groups of the carboxylic monomers present.
Dependencies are inferred from the claim text.