Copolymers of sodium styrene sulfonate and sodium-N-(4-sulfophenyl)-maleimide
AssigneeExxon Research & Engineering Co.
InventorS. Richard Turner
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Abstract
This invention relates to a water soluble alternating copolymer having a 50 mol. % portion of a sodium-N-(4-sulfophenyl)-maleimide monomer and a 50 mol. % portion of a sulfonated styrenic comonomer. The sulfonated styrenic comonomer is characterized by the formula: ##STR1## wherein Y.sup..sym. is a cation selected from the Groups IA, IIA, IB or IIB of the Periodic Table or an amine of the formula .sup..sym.NHR.sub.1 R.sub.2 where R.sub.1, R.sub.2 and R.sub.3 can be aliphatic groups of C.sub.1 to C.sub.12, wherein the alternating water soluble copolymers are useful as thermally stable deflocculating agents in water based drilling muds.
Claims3
A water soluble, solid alternating copolymer of about 50 mol. % sodium-N-(4-sulfophenyl)-maleimide monomer units and a metal or amine neutralized sulfonate monomer units characterized by the formula:
- ##STR11## wherein Y.sup..sym. is a cation selected from Groups IA, IIA, IB or IIB of the Periodic Table or an amine of the formula:
- ##STR12## where R.sub.1, R.sub.2 and R.sub.3 are aliphatic groups of C.sub.1 to C.sub.12 or hydrogen.
Dependencies are inferred from the claim text.