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US 5,492,788 AGranted
System for replenishing liquid electrostatic developer
AssigneeXerox Corporation
InventorsGary A. Denton, Michael J. Levy
Life of this patent
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AssigneeXerox Corporation
InventorsGary A. Denton, Michael J. Levy
Estimating the term…
System and process for replenishing liquid developer in equipment, such as a printer, whereby the percent of toner solids is maintained at about 0.5 to 4% by weight based on the total weight of liquid developer, the system comprising at least one liquid toner concentrate vessel containing aggregates of thermoplastic resin particles, median particle size (volume weighted) greater than 15 .mu.m, and with 90% of the particles (volume weighted) not less than 30 .mu.m, composed of 50 to 100% by weight of particles and 0 to 50% by weight carrier liquid; a liquid vessel containing carrier liquid, means communicating each of said vessels with a dispersing vessel containing electric field means for breaking apart agglomerates of liquid toner, wherein contents of the liquid toner concentrate vessel and the liquid vessel are supplied thereto and the resin particles are dispersed in the carrier liquid to form particles having a median particle size (volume weighted) of less than 15 .mu.m, and with 90% of the particles (volume weighted) less than 30 .mu.m in an amount of about 0.5 to 20% by weight of resin particles and about 99.5 to 805 by weight carrier liquid the dispersion being supplied and metered into the supply vessel containing original liquid developer to maintain the desired weight of solids. The system is useful in copying, proofing and ets., and the liquid developer is useful for making copied, proofs, lithographic printing plates and resists.
A process for the preparation of liquid developers comprising subjecting a liquid developer concentrate including a resin, a pigment, and a liquid to a pulsed electric field to form a liquid dispersion, said subjecting step comprises applying a voltage ranging from about 1000 V/mm to about 1500 V/mm to produce the electric pulses.
A process which comprises subjecting a liquid developer including a thermoplastic resin, a pigment, and a charge adjuvant dispersed in a liquid to a pulsed of electric fields thereby enabling redispersion of said resin, pigment and charge adjuvant in the liquid, said subjecting step comprises applying a voltage ranging from about 1000 V/mm to about 1500 V/mm to produce the electric pulses.
An apparatus for dispersing a liquid developer including (A) a nonpolar liquid, (B) thermoplastic resin particles, and (C) a charge director compound;
A process which comprises subjecting a liquid developer including a thermoplastic resin, a pigment, and a charge adjuvant dispersed in a liquid to a pulsed of electric fields thereby enabling redispersion of said resin, pigment and charge adjuvant in the liquid and wherein the particles in size subsequent to the electric field pulses being applied thereon from about 1 to about 6 microns average volume diameter.
A process which comprises subjecting a liquid developer including a thermoplastic resin, a pigment, and a charge adjuvant dispersed in a liquid to a pulsed of electric fields thereby enabling redispersion of said resin, pigment and charge adjuvant in the liquid and wherein said subjecting step comprises applying the electric pulses for 8 period of time of from about 0.05 seconds to about 3.0.times.10.sup.-5 seconds.
Dependencies are inferred from the claim text.