E.i. Dupont De Nemours and Company

Ira B Dicker

Walter R Hertler

Sheau-Hwa Ma

Richard C Ebersole

Fritz P Boettcher

William Brown Farnham

Harry J Spinelli

Dotsevi Y Sogah

Patrick H Fitzgerald

Thomas W Del Pesco

Clyde Spencer Hutchins

Evan D Laganis

Luke V Schneider

Aqueous dispersions having improved stability and which are particularly well suited for use as aqueous ink jet ink compositions comprise an aqueous carrier medium which comprises water or a mixture of water and at least one organic component; a particulate solid, preferably a pigment; and an ABC triblock polymer comprising an A block which is a hydrophilic polymer, a B block which is a polymer capable of binding to the particulate solid, a C block, different from the A and B block, which is a hydrophobic or hydrophilic polymer; and wherein the A and C blocks are end blocks.

Aqueous dispersions containing ABC triblock polymer dispersants

This application discloses linear methacrylic ABC triblock polymers in which the composition of each of the three blocks is different and wherein at least one of the blocks is hydrophobic and at least one of the blocks is hydrophilic.

ABC triblock methacrylate polymers

This invention relates to a polymerization process initiated by selected organo-silicon, -germanium and -tin compounds, and to 'living' polymers therefrom.

Initiator for group transfer polymerization

Group Transfer Polymerization (GTP) process for preparing a 'living' polymer, the process comprising contacting under polymerizing conditions in a polymerization medium, at least one acrylic or maleimide monomer with an initiator which is a tetracoordinate organosilicon, organotin or organogermanium compound having at least one GTP initiating site and a catalyst which is or is a source of an anion selected from the group consisting of bifluoride, fluoride, cyanide, azide or a selected oxyanion, or a selected Lewis acid or Lewis base, the process further characterized in that the initiator or the anion or Lewis acid catalyst is chemically attached (grafted) to a solid support that is insoluble in the polymerization medium.

Group transfer living polymer grafted to an initiator support

Process for preparing a silyl ketene acetal adduct, the process comprising contacting and reacting a silyl ketene acetal and an .alpha.,.beta.-unsaturated compound in the presence of a mercury- or Lewis acid-containing catalyst, for example, HgI.sub.2.

Initiators for group transfer polymerization

Group Transfer Polymerization process employing supported initiators

Group Transfer Polymerization wherein the catalyst consists essentially of:

Catalyst for group transfer polymerization

Silylated oxyanion catalysts, such as trimethyl silyl 3-chlorobenzoate, provide increased livingness of group transfer polymerization, thereby permitting higher molecular weights and polymerization efficiencies.

Enhanced livingness of polymerization using silylated oxyanions

Mercury compounds which are useful as co-catalysts in group transfer polymerization are disclosed.

Group transfer polymerization catalyzed by mercury compounds

The duration of 'livingness' in group transfer polymerization with oxyanion catalysts is enhanced by the presence of agents such as acetonitrile or silylated acetonitrile, resulting in higher molecular weight and/or lower polydispersity in the resulting polymers.

Polymer life enhancement in oxyanion-catalyzed polymerization

This invention resides in a polymerization process which is catalyzed by an oxyanion which can form a conjugate acid having a pKa (DMSO) of about 5 to about 24.

Growing community of inventors

Wilmington, DE, United States of America

Ira B Dicker