US4927727A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermally assisted transfer of small electrostatographic toner particles
Assignee: Eastman Kodak Co
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Filing: 1988-08-09
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Granted: 1990-05-22
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Expires: 2008-08-09
Abstract
Abstract Disclosed is an improved method of making a hard copy in a process where a latent electrostatic image on an image-bearing substrate is developed by applying to the image a dry thermoplastic toner which comprises a binder polymer, and the developed image is transferred to the surface of a receiver by contacting the developed image on the substrate with the surface, then removing the surface from the substrate. The improvement comprises developing the latent electrostatic image with a toner having a particle size less than 8 micrometers, heating the surface before it contacts the developed image to a temperature such that the surface heats the toner particles when it contacts the developed image to a temperature between 10° C. above the T g of the toner binder and 20° C. below the T g of the toner binder, where the temperature is sufficient to fuse discrete toner particles that form the image to each other at points of contact between the particles, but insufficient to cause the contacting particles to flow into a single mass, non-electrostatically transferring the developed image to the surface, where the roughness average of the surface is less than the radius of the particles, and heating the developed image after it has been removed from the substrate to a temperature sufficient to fix it.
Inventors
- 👤 Donald S. Rimai
- 👤 Chandra Sreekumar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 07:24
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/0819; G03G13/00; G03G13/14; G03G13/16; G03G13/22; G03G9/087; G03G9/08784; G03G9/08797
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
221 words
In method of making a hard copy wherein a latent electrostatic image on an image-bearing substrate is developed by applying to said image dry thermoplastic charged toner particles comprising a toner binder, and said developed image is transferred to the surface of a receiver by contacting said developed image on said substrate with said surface, then removing said surface from said substrate, the improvement which comprises (A) developing said latent electrostatic image with a toner having a particle size of less than 8 micrometers; (B) heating said surface before it contacts said developed image, to a temperature such that said surface heats said toner particles when it contacts said developed image to a temperature between 10° C. above the T g of said toner binder and 20° C. below the T g of said toner binder, where said temperature is sufficient to fuse discrete toner particles that form said image to each other at points of contact between said particles, but insufficient to cause said contacting particles to flow into a single mass; (C) non-electrostatically transferring said developed image to said surface, where said surface has a roughness average less than the radius of said toner particles; and (D) heating said developed image after it has been removed from said substrate to a temperature sufficient to fuse it to said surface.
Claim 2
Dependent Claim
221 words
In method of making a hard copy wherein a latent electrostatic image on an image-bearing substrate is developed by applying to said image dry thermoplastic charged toner particles comprising a toner binder, and said developed image is transferred to the surface of a receiver by contacting said developed image on said substrate with said surface, then removing said surface from said substrate, the improvement which comprises (A) developing said latent electrostatic image with a toner having a particle size of less than 8 micrometers; (B) heating said surface before it contacts said developed image, to a temperature such that said surface heats said toner particles when it contacts said developed image to a temperature between 10° C. above the T g of said toner binder and 20° C. below the T g of said toner binder, where said temperature is sufficient to fuse discrete toner particles that form said image to each other at points of contact between said particles, but insufficient to cause said contacting particles to flow into a single mass; (C) non-electrostatically transferring said developed image to said surface, where said surface has a roughness average less than the radius of said toner particles; and (D) heating said developed image after it has been removed from said substrate to a temperature sufficient to fuse it to said surface.
Claim 3
Dependent Claim
25 words
A method according to claim 1 wherein during transferring said surface contacts said developed image at a pressure of about 135 to about 1000 kPa.
Claim 4
Dependent Claim
18 words
A method according to claim 2 wherein said pressure is applied by means of an unheated backup roller.
Claim 5
Dependent Claim
11 words
A method according to claim 1 wherein said substrate is photoconductive.
Claim 6
Dependent Claim
13 words
A method according to claim 4 wherein said substrate comprises an organic photoconductor.
Claim 7
Dependent Claim
11 words
A method according to claim 1 wherein said substrate is reusable.
Claim 8
Dependent Claim
16 words
A method according to claim 1 wherein said substrate is in the form of a drum.
Claim 9
Dependent Claim
14 words
A method according to claim 1 wherein said particles are smaller than 5 micrometers.
Claim 10
Dependent Claim
19 words
A method according to claim 1 wherein said toner binder has a T g between 40° and 100° C.
Claim 11
Dependent Claim
19 words
A method according to claim 9 wherein said toner binder has a T g between 45° and 65° C.
Claim 12
Dependent Claim
22 words
A method according to claim 1 wherein said toner comprises a copolymer of styrene or a derivative of styrene and an acrylate.
Claim 13
Dependent Claim
12 words
A method according to claim 1 wherein said toner comprises a polyester.
Claim 14
Dependent Claim
36 words
A method according to claim 1 wherein said receiver is coated with a thermoplastic polymer that has a T g below said temperature and less than 10° C. above the T g of said toner binder.
Claim 15
Dependent Claim
24 words
A method according to claim 13 wherein said receiver is coated with a release agent which has a lower surface energy than said substrate.
Claim 16
Dependent Claim
11 words
A method according to claim 1 wherein said receiver is paper.
Claim 17
Dependent Claim
27 words
A method according to claim 1 wherein said receiver is a sheet having two surfaces and only the surface that contacts said toner particles is directly heated.
Claim 18
Dependent Claim
40 words
A method according to claim 1 wherein more than one developed image is formed on said substrate in succession, each in a different color, and steps (A), (B), and (C) are performed after at least one developed image is formed.
Claim 19
Dependent Claim
25 words
A method according to claim 17 wherein at least three developed images are formed on said substrate, selected from the three primary colors and black.
Claim 20
Dependent Claim
11 words
A method according to claim 1 wherein said receiver is transparent.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-05-21 | 1993-11-20 | 1994-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-21 | 1997-11-20 | 1998-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-21 | 2001-11-20 | 2002-05-22 | $7700.00 | Window Closed / Lapsed |