US 6,294,606 B1 · Nonionic surfactant-free emulsion polymerization process

Abstract

A latex used for the preparation of toner particles by emulsion aggregation is prepared, using a controlled addition of anionic surfactants, without the use of a nonionic surfactant. Such a process comprises preparing an aqueous phase using a limited amount of anionic surfactant; preparing an emulsion of monomers in water with additional anionic surfactant and without a nonionic surfactant; adding a portion of the emulsion to the aqueous phase to initiate seed polymerization, in the presence of an initiator, to form seed polymer; and adding the remaining monomer emulsion to the composition to complete polymerization to form a latex polymer.

Claims24

Dependent claims

A process for preparing a latex polymer, comprising:

(i) preparing an aqueous phase containing anionic surfactant in an amount less than 20% by weight of the total amount of anionic surfactant used in forming the latex polymer;
(ii) preparing an emulsion of monomers in water with anionic surfactant;
(iii) adding a portion of said monomer emulsion to said aqueous phase to initiate seed polymerization to form seed polymer, said portion containing less than 25% by weight of the total amount of monomer used in forming the latex polymer, said aqueous phase further containing a free radical initiator during the formation of the seed polymer;
and
(iv) adding an additional amount of said monomer emulsion to the composition formed in (iii) to complete emulsion polymerization thus forming a latex polymer.

2 more elements

Dependencies are inferred from the claim text.

Nonionic surfactant-free emulsion polymerization process

Life of this patent

Nonionic surfactant-free emulsion polymerization process

Life of this patent

Abstract

Claims24