Sparged toner

Patent metadata

Field	Value
Publication number	US-9798257-B2
Application number	US-201514958838-A
Country	US
Kind code	B2
Filing date	Dec 3, 2015
Priority date	Dec 3, 2015
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

A method for removing volatile organic compounds (VOC's) from toner slurries is described, including the isolated toner particles generated by that method.

First claim

We claim:

1. A method for reducing volatile organic compounds (VOCs) in emulsion aggregation (EA) toner particles, the method comprising:
(a) homogenizing a slurry of one or more resins;
(b) aggregating the slurry to produce growing aggregate particles;
(c) optionally, forming a shell over the growing aggregate particles;
(d) stopping the growth of aggregate particles by increasing the pH of the slurry;
(e) increasing the temperature of the slurry to induce coalescence of the growth-stopped aggregate particles;
(f) during step (e), sparging a gas through the slurry to remove VOCs from the coalescing aggregate particles;
(g) cooling the slurry, wherein the cooled slurry comprises aggregate particles that have coalesced to become EA toner particles; and
(h) separating the EA toner particles from the slurry and drying the separated EA toner particles, wherein the dried EA toner particles are characterized by a total VOC (TVOC) content of less than about 350 ppm.

2. The method of claim 1 , wherein the TVOC content of the dried EA toner particles is less than about 300 ppm.

3. The method of claim 1 , wherein the sparging step (f) takes place when the temperature is in the range of from about 65° C. to about 75° C.

4. The method of claim 3 , wherein the sparging step (f) takes place when the temperature is about 70° C.

5. The method of claim 1 , wherein the gas of the sparging step (f) is air.

6. The method of claim 1 , wherein the gas is sparged at a flow of at least 15 standard cubic feet per minute.

7. The method of claim 1 , wherein the temperature is increased to a value in the range of from about 92° C. to about 96° C.

8. The method of claim 1 , further comprising removing foam generated during the sparging step (f) from a reactor containing the slurry.

9. The method of claim 8 , wherein separating comprises directing the foam to a foam treatment tank.

10. The method of claim 9 , wherein the foam treatment tank comprises an anti-foaming agent.

11. The method of claim 1 , wherein the one or more resins are selected from amorphous resins, crystalline resins and combinations thereof.

12. The method of claim 1 , wherein the VOC's are selected from the group consisting of benzene, toluene, ethylbenzene, m-xylene, o-xylene, isopropylbenzene, n propylbenzene, 2-ethyltoluene, 3-ethyltoluene, 4-ethyltoluene, styrene, n-decane, n undecane, n-dodecane, n-tetradecane, limonene, n-butanol, n-nonanol, n-decanol, trimethylsilanol, n-butyl acetate, hexamethyldisiloxane, acetic acid, hexamethylcyclotrisiloxane, octamethyltrisiloxane, n-butyl ether, cctamethylcyclotetrasiloxane, 1-phenylpropene, n-butyl acrylate, n-butyl propionate, decamethyltetrasiloxane, indane, n-butyl butyrate, decamethylcyclopentasiloxane, benzaldehyde, dodecamethylpentasiloxane, acetophenone, dodecamethylcyclohexasiloxane, tetradecamethylhexasiloxane, tertadecamethylcycloheptasiloxane and combinations thereof.

13. The method of claim 1 , wherein the gas of the sparging step (f) is air and the method further comprises removing foam generated during the sparging step (f) from a reactor containing the slurry.

14. The method of claim 13 , wherein the sparging step (f) takes place when the temperature is in the range of from about 65° C. to about 75° C.

15. The method of claim 14 , wherein the temperature is increased to a value in the range of from about 92° C. to about 96° C.

16. The method of claim 15 , wherein the gas is sparged at a flow of at least 15 standard cubic feet per minute.

17. The method of claim 13 , wherein separating comprises directing the foam to a foam treatment tank comprising an anti-foaming agent.

18. A method for reducing volatile organic compounds (VOCs) in emulsion aggregation (EA) toner particles, the method comprising:
(a) homogenizing a slurry of one or more resins;
(b) aggregating the slurry to produce growing aggregate particles;
(c) optionally, forming a shell over the growing aggregate particles;
(d) stopping the growth of aggregate particles by increasing the pH of the slurry;
(e) increasing the temperature of the slurry to induce coalescence of the growth-stopped aggregate particles;
(f) during step (e), sparging a gas through the slurry to remove VOCs from the coalescing aggregate particles;
(g) cooling the slurry, wherein the cooled slurry comprises aggregate particles that have coalesced to become EA toner particles; and
(f) separating the EA toner particles from the slurry and drying the separated EA toner particles, wherein the dried EA toner particles are characterized by a total VOC (TVOC) content which is at least about 50% lower as compared to the same method having the same steps except for the sparging step (f).

19. The method of claim 18 , wherein the TVOC content is at least about 70% lower.

Assignees

• Xerox Corp

Inventors

• Croteau Matthew W
• Jackson Mark A
• Keeble Roger B B
• Judd Harold R
• Salman Munir
• Marcello Vincenzo G
• Cheng Chieh-Min
• Malachowski Steven M
• Kmiecik-Lawrynowicz Grazyna
• Schriever Linda S

Classifications

• G03G9/0804 Primary

  whereby the components are brought together in a liquid dispersing medium · CPC title

• G03G9/0825

  characterised by their structure; characterised by non-homogenuous distribution of components (microcapsular toners G03G9/093) · CPC title

• G03G9/0815 Primary

  Post-treatment · CPC title

• G03G9/09392

  Preparation thereof · CPC title