DEVELOPER FOR SELECTIVE PRINTING OF RAISED INFORMATION BY ELECTROGRAPHY

• US 20090291274A1
• Filed: 05/21/2008
• Published: 11/26/2009
• Est. Priority Date: 05/21/2008
• Status: Active Grant

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Tombs, Thomas N., Tyagi, Dinesh, Zaretsky, Mark C., Lambert, Patrick M.
• Granted Patent: US 8,435,712 B2
• Time in Patent Office: Days
• US Class Current: 428/207
• CPC Class Codes: G03G 9/0819 characterised by the dimensions of the particles
• CPC Class Codes: G03G 9/0823 Electric parameters
• CPC Class Codes: G03G 9/08755 Polyesters
• CPC Class Codes: G03G 9/09716 treated with organic compounds
• CPC Class Codes: G03G 9/09725 Silicon-oxides; Silicates
• CPC Class Codes: G03G 9/103 Glass particles
• CPC Class Codes: G03G 9/108 Ferrite carrier, e.g. magnetite
• CPC Class Codes: G09B 21/02 Devices for Braille writing typewriters for Braille B41J3/32
• CPC Class Codes: Y10T 428/24901 including coloring matter

Abstract

The use of electrographic printing to prepare prints which have a desired tactile feel or raised information in a controlled manner by utilizing a developer having toner particle size larger than 50 microns volume average diameter and carrier particles larger than the toner particle size such that the volume average distribution overlap between the toner distribution curve and carrier particle distribution curve is less than 35% and the carrier and toner particles have a volume average diameter size differential equal to or greater than 5 microns or the ratio of carrier-to-toner volume average diameter exceeds 1.25.

Claims

1. A developer for digital printing wherein raised information, with a controllable tactile effect, can be printed by electrographic techniques, the carrier and toner particles comprising:

a) toner particle size larger than 18 microns volume average diameter;

b) carrier particle size larger than the toner particle size with a size between 25 and 60 microns;

c) carrier and toner particle size differential between the volume average diameter for carrier particles and toner particles is greater than 5 microns; and

d) a carrier and toner particle volume average distribution overlap of the toner distribution curve and carrier particle distribution curve that is less than 35%.

2. The developer according to claim 1, wherein the toner particles have an volume average particle size between 20 and 30 microns volume average diameter.

3. The developer according to claim 1, wherein the toner comprises a polymer resin as a polyester binder.

4. The developer according to claim 1, wherein the toner particles have a fineness index of particle size distribution of less than 1.5.

5. Carrier in claim 1, which has a volume average particle size more than 26 microns.

6. The developer according to claim 1, wherein the toner particles comprise hydrophobic particles of silica and/or titania.

7. The developer according to claim 1, wherein the toner particles comprises an optional wax-based release additive.

8. The developer according to claim 1, wherein the carrier particles comprise magnetic particles.

9. The developer according to claim 1, wherein the carrier particles comprise a volume average particle size of greater than 25 microns.

10. The developer according to claim 1, wherein the carrier particles comprise a volume average particle size of less than 50 microns

11. The developer according to claim 1, wherein the carrier particles comprise hard ferrites.

12. The developer according to claim 1, wherein the developer comprises a developer charge between −

5 and −

12 micro coulombs/gram.

13. The developer according to claim 1, wherein the developer comprises dust measurement values of less than 5 grams when toner particles size is at least 20 microns.

14. A electrographic print having a distinct tactile feel, raised information, said print comprising:

A tactile print image formed electrographically on a receiver member utilizing developer comprising the following particles;

a. toner having a particle size larger than 18 microns volume average diameter;

b. carrier having a particle size larger than the toner particle size with a size between 25 and 60 microns such that the carrier and toner particles have a volume average diameter size differential equal to or greater than 5 microns and the volume average distribution overlap between the toner distribution curve and carrier particle distribution curve is less than 35%; and

in an area of the formed print image, where desired tactile feel, raised information is to be formed, selectively forming such tactile feel, raised information by laying down one or more layers of the toner and carrier particles.

15. The print of claim 14, said print exhibiting a tactile feel for raised information providing a desired print image, and marking particle coverage, in areas of said receiver member where tactile feel, raised information is desired of a stack height of at least 20 μ

m in order to yield the desired tactile feel.

16. The print of claim 14 wherein the tactile feel, raised information is in the foreground of such print and represents at least a part of the printed image.

17. The print of claim 14 wherein the tactile feel, raised information is in the background of such print and represents a surface characteristic for the print receiver member.

18. The print of claim 14 wherein the tactile feel, raised information is in the foreground and background of such print.

19. Electrographic printing of distinct tactile feel, raised information, said electrographic printing comprising the steps of:

forming a desired print image, electrographically, on a receiver member utilizing developer comprising the following particles;

a. toner having a particle size larger than 18 microns volume average diameter;

b. carrier having a particle size larger than the toner particle size with a size between 25 and 60 microns such that the carrier and toner particles have a volume average diameter size differential equal to or greater than 5 microns and

c. the volume average distribution overlap between the toner distribution curve and carrier particle distribution curve is less than 35%; and

fixing the toner in an area of the formed print image, where desired tactile feel, raised information is to be formed, selectively forming such tactile feel, raised information by laying down one or more layers of the toner and carrier particles.

20. The method according to claim 19 wherein the coverage by marking particles for a tactile feel, raised information is at least 2 mg/cm².

21. The method according to claim 19 wherein standard size marking particles have a volume average diameter of less than 9 μ

m, and the marking particles for tactile feel, raised information are on the order of a volume average diameter of 12-30 μ

m.

22. The method according to claim 19 wherein the total marking particle stack height is at least 20 μ

m in order to yield the desired tactile feel.

23. The method according to claim 19 wherein one or more electrographic process set-points, control parameters or algorithms, are set to predetermined values when printing tactile feel, raised information, that are different from electrographic process set-points, control parameters or algorithms, used when printing an image without tactile feel, raised information.

24. A developer for digital printing wherein raised information, with a controllable tactile effect, can be printed by electrographic techniques, the carrier and toner particles comprising:

a) toner particle size larger than 18 microns volume average diameter;

b) carrier particle size larger than the toner particle size with a size between 25 and 60 microns;

c) carrier and toner particle size differential between the volume average diameter for carrier particles and toner particles is greater than 5 microns such that a ratio of carrier-to-toner volume average diameter exceeds 1.25.

25. Electrographic printing of distinct tactile feel, raised information, said electrographic printing comprising the steps of:

forming a desired print image, electrographically, on a receiver member utilizing developer comprising the following particles;

a. toner having a particle size larger than 18 microns volume average diameter;

b. carrier having a particle size larger than the toner particle size with a size between 25 and 60 microns such that the carrier and toner particles have a carrier-to-toner volume average diameter exceeds 1.25 such that the volume average distribution overlap between the toner distribution curve and carrier particle distribution curve is less than 35% and

fixing the toner in an area of the formed print image, where desired tactile feel, raised information is to be formed, selectively forming such tactile feel, raised information by laying down one or more layers of the toner and carrier particles.