Toner formulation including a softening agent and method of preparing the same
A chemically prepared core shell toner formulation for use in electrophotography having an inventive softening agent consisting of a core shell latex having an encapsulated interpenetrating polymer network microgel in the core of the toner is disclosed. Having this core shell latex with an encapsulated IPN microgel in the core of the toner results in a toner that can simultaneously fuse at a desirable low temperature and survive the temperature extremes associated with shipping and storage.
1. A chemically prepared toner, comprising:
a core including a first polymer binder, a core shell styrene acrylic latex containing an encapsulated interpenetrating polymer network microgel, a pigment, and a wax; and
a shell formed around the core including a second polymer binder, wherein the encapsulated interpenetrating polymer network microgel includes a first acrylate polymer network and a second polymer network having a self-crosslinkable non water soluble silicon oil.
2. The chemically prepared toner of claim 1 , wherein the core shell styrene acrylic latex includes a hydrophilic monomer having carboxyl (—COOH) and hydroxy (—OH) functional groups and a hydrophobic monomer having styrene and acrylate functionality.
3. The chemically prepared toner of claim 2 , wherein the hydrophobic monomer having acrylate functionality is an alkyl acrylate.
4. The chemically prepared toner of claim 3 , wherein the alkyl acrylate monomer is lauryl acrylate.
5. The chemically prepared toner of claim 2 , wherein the hydrophilic monomers having carboxyl (—COOH) and hydroxy (—OH) functional groups are hydroxyethyl methacrylate and beta-carboxyethyl acrylate.
6. The chemically prepared toner of claim 1 , wherein the self-crosslinkable non water soluble silicon oil is selected from the group consisting of monomethoxysilane, dimethoxysilane, trimethoxysilane, octyltrimethoxysilane, octadecyltrimethoxysilane, monoethoxysilane, diethoxysilane, and triethoxysilane and methacryloxypropylmethyldimethoxysilane.
7. The chemically prepared toner of claim 6 , wherein the self-crosslinkable non water soluble silicon oil is octyltrimethoxysilane.
8. The chemically prepared toner of claim 1 , wherein the glass transition temperature (Tg) of the core shell latex is between 20° C. and 60° C.
9. The chemically prepared toner of claim 1 , wherein the first polymer binder and the second polymer binder each include a polyester resin.
10. The chemically prepared toner of claim 9 , wherein the first polymer binder includes a first polyester resin or mixture and the second polymer binder includes a second polyester resin or mixture different from the first polyester resin or mixture.
11. The chemically prepared toner of claim 1 , further comprising a borax coupling agent between the outer surface of the core and the shell.