Toner formulation using wax encapsulated with a styrene acrylate latex formulation and method of preparing the same
View Patent ↗The present disclosure relates to a chemically prepared toner composition including a toner particle having a core including a first polymer binder, an styrene acrylate encapsulated wax latex, a pigment, and a shell formed around the core including a second polymer binder and method to make the same. The disclosed method of preparing the toner results in a change in the distribution of the components of the toner particle wherein the lower molecular weight resins, the pigment, and the wax are located away from the surface of the toner particle and the pigment is clinging to the edge of the wax domain.
1. A method of producing toner comprising:
preparing a latex to encapsulate a wax, the preparing of the latex including the steps of:
(a) preparing a wax dispersion;
(b) preparing a monomer solution;
(c) seeding the wax dispersion with a portion of the monomer solution;
(d) preparing an initiator solution; and
(e) adding the initiator solution and a remaining portion of the monomer solution to the seeded wax dispersion and polymerizing the monomer, wherein a polymer encapsulated wax latex is formed;
preparing a first polymer emulsion;
preparing a second polymer emulsion;
preparing a pigment dispersion;
combining and agglomerating the first polymer emulsion with the pigment dispersion and the polymer encapsulated wax latex to form toner cores;
combining and agglomerating the second polymer emulsion with the toner cores to form toner shells around the toner cores; and
fusing the aggregated toner cores and toner shells to form toner particles and to form aggregated polymer encapsulated wax domains within the toner particles, wherein the pigment is located around the edges of the aggregated polymer encapsulated wax domains and the pigment and wax domains are located away from the surface of the toner particle, and
wherein the monomer solution includes a hydrophilic monomer having one of a carboxyl (—COOH) functional group and a hydroxy (—OH) functional group and hydrophobic styrene and acrylate monomers.
2. The method of claim 1 , wherein the hydrophobic acrylate monomer is an alkyl acrylate.
3. The method of claim 2 , wherein the alkyl acrylate monomer is butyl acrylate.
4. The method of claim 2 , wherein the alkyl acrylate monomer is lauryl acrylate.
5. The method of claim 1 , wherein the hydrophilic monomer having one of a carboxyl (—COOH) functional group and a hydroxy (—OH) functional group is at least one of hydroxyethyl methacrylate and beta-carboxyethyl acrylate.
6. The method of claim 1 , wherein the glass transition temperature (Tg) of the latex is between 20° C. and 60° C.
7. The method of claim 1 , wherein the first polymer emulsion and the second polymer emulsion each include a polyester resin.
8. The method of claim 1 , further comprising the step of adding a borax coupling agent to the surface of the formed toner cores and then performing the step of combining and agglomerating the second polymer emulsion with the formed toner cores having the borax coupling agent on its surface to form toner shells around the toner cores.
9. A method of producing toner comprising:
preparing a latex to encapsulate a wax, the preparing of the latex including the steps of:
(a)preparing a wax dispersion;
(b)preparing a monomer solution;
(c)seeding the wax dispersion with a portion of the monomer solution;
(d)preparing an initiator solution; and
(e)adding the initiator solution and a remaining portion of the monomer solution to the seeded wax dispersion and polymerizing the monomer, wherein a polymer encapsulated wax is formed;
preparing a first polymer emulsion;
preparing a second polymer emulsion;
preparing a pigment dispersion;
combining the first polymer emulsion with the pigment dispersion and the polymer encapsulated wax latex to form toner cores;
adjusting the pH of the combination of the first polymer emulsion with the pigment dispersion and the polymer encapsulated wax latex to promote agglomeration of the toner cores;
combining and agglomerating the second polymer emulsion with the toner cores to form toner shells around the toner cores;
once a toner particle size is reached, adjusting the pH of the mixture of the aggregated toner cores and toner shells to prevent additional particle growth; and
fusing the aggregated toner cores and toner shells to form toner particles and to form aggregated polymer encapsulated wax domains within the toner particles, wherein the pigment is located around the edges of the aggregated polymer encapsulated wax domains and the pigment and wax domains are located away from the surface of the toner particle, and
wherein the monomer solution includes a hydrophilic monomer having one of a carboxyl (—COOH) functional group and a hydroxy (—OH) functional group and hydrophobic styrene and acrylate monomers.
10. The method of claim 9 , wherein the hydrophobic acrylate monomer is an alkyl acrylate.
11. The method of claim 10 , wherein the alkyl acrylate monomer is butyl acrylate.
12. The method of claim 10 , wherein the alkyl acrylate monomer is lauryl acrylate.
13. The method of claim 9 , wherein the hydrophilic monomer having one of a carboxyl (—COOH) functional group and a hydroxy (—OH) functional group is at least one of hydroxyethyl methacrylate and beta-carboxyethyl acrylate.
14. The method of claim 9 , wherein the first polymer emulsion and the second polymer emulsion each include a polyester resin.
15. The method of claim 9 , further comprising the step of adding a borax coupling agent to the surface of the formed toner cores and then performing the step of combining and agglomerating the second polymer emulsion with the formed toner cores having the borax coupling agent on its surface to form toner shells around the toner cores.