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US5047307A Expired / Lapsed US ⏱️ 0.0 years remaining

Toner for use in compositions for developing latent electrostatic images, method of making the same, and liquid composition using the improved toner

Assignee: HP Indigo BV
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Filing: 1989-08-16
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Granted: 1991-09-10
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Expires: 2009-08-16
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Abstract

Abstract A liquid composition for developing latent electrostatic images comprising toner particles associated with the pigment dispersed in a nonpolar liquid. The salient feature of the invention is that the toner particles are formed with a plurality of fibers or tendrils from a thermoplastic polymer and carry a charge of a polarity opposite to the polarity of the latent electrostatic image. The polymer is insoluble or insolvatable in the dispersant liquid at room temperature. The toner particles are formed by plasticizing the polymer and pigment at elevated temperature and then either permitting a sponge to form and wet-grinding pieces of the sponge or diluting the plasticized polymer-pigment while cooling and constantly stirring to prevent the forming a sponge while cooling. When cool, the diluted composition will have a concentration of toner particles formed with a plurality of fibers.

Inventors

  • 👤 Benzion Landa
  • 👤 Peretz Ben-Auraham
  • 👤 Joseph Hall
  • 👤 George A. Gibson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 20:06
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/12

Claims Analysis

Total Claims: 21
Claim 1
Independent Claim 92 words
A method of producing toner particles adapted for electrophoretic movement through a nonpolar liquid comprising the steps of plasticizing at a temperature in the range of about 65° C. and 100° C. a thermoplastic polymer with a nonpolar liquid having an electrical volume resistivity in excess of about 10 9 ohm centimeters and a dielectric constant below about 3.0 to form a sponge, shredding said sponge into pieces, adding more nonpolar liquid, wet-grinding the pieces into particles, and continuing the grinding step to pull the particles apart to form fibers extending therefrom.
Claim 2
Independent Claim 92 words
A method of producing toner particles adapted for electrophoretic movement through a nonpolar liquid comprising the steps of plasticizing at a temperature in the range of about 65° C. and 100° C. a thermoplastic polymer with a nonpolar liquid having an electrical volume resistivity in excess of about 10 9 ohm centimeters and a dielectric constant below about 3.0 to form a sponge, shredding said sponge into pieces, adding more nonpolar liquid, wet-grinding the pieces into particles, and continuing the grinding step to pull the particles apart to form fibers extending therefrom.
Claim 3
Independent Claim 108 words
A method of producing toner particles adapted for electrophoretic movement through a nonpolar liquid comprising the steps of plasticizing at a temperature in the range of about 65° C. and 100° C. an ethylene copolymer resin and a pigment with a nonpolar liquid having an electrical volume resistivity in excess of about 10 9 ohm centimeters and to form a sponge, cooling said sponge, shredding the sponge into pieces, adding more nonpolar liquid, wet-grinding the pieces into particles, continuing the grinding step to pull the particles apart to form fibers extending therefrom, and adding a charge director to impart a charge of predetermined polarity to the toner particles.
Claim 4
Independent Claim 108 words
A method of producing toner particles adapted for electrophoretic movement through a nonpolar liquid comprising the steps of plasticizing at a temperature in the range of about 65° C. and 100° C. an ethylene copolymer resin and a pigment with a nonpolar liquid having an electrical volume resistivity in excess of about 10 9 ohm centimeters and to form a sponge, cooling said sponge, shredding the sponge into pieces, adding more nonpolar liquid, wet-grinding the pieces into particles, continuing the grinding step to pull the particles apart to form fibers extending therefrom, and adding a charge director to impart a charge of predetermined polarity to the toner particles.
Claim 5
Dependent Claim 23 words
The method according to claim 1 wherein a charge director is added to impart a charge of predetermined polarity to the toner particles.
Claim 6
Dependent Claim 15 words
The method according to claim 1 wherein the particles are less than about 5 microns.
Claim 7
Dependent Claim 33 words
The method according to claim 1 wherein the thermoplastic polymer is selected from the group consisting of ethyl vinyl acetate copolymers, isotactic polypropylene, polybutyl terethalate, ethylene ethyl acrylate, ethylene vinyl acetate, methacrylate resins.
Claim 8
Dependent Claim 26 words
The method according to claim 1 wherein the polymer is an ethylene copolymer having carboxylic acid functionality and an acid number between about 54 and 90.
Claim 9
Dependent Claim 14 words
The method according to claim 1 wherein the polymer is an ethylene copolymer resin.
Claim 10
Dependent Claim 16 words
The method according to claim 1 wherein the sponge has a hardness of at least 120.
Claim 11
Dependent Claim 18 words
The method according to claim 1 wherein the sponge has a hardness of between about 25 and 45.
Claim 12
Dependent Claim 20 words
The method according to claim 1 wherein the step of plasticizing ranges from between about ten minutes and 3 hours.
Claim 13
Dependent Claim 33 words
The method according to claim 2 wherein the thermoplastic polymer is selected from the group consisting of ethyl vinyl acetate copolymers, isotactic polypropylene, polybutyl terethalate, ethylene ethyl acrylate, ethylene vinyl acetate, methacrylate resins.
Claim 14
Dependent Claim 19 words
The method according to claim 2 wherein the ethylene copolymer has an acid number between about 54 and 90.
Claim 15
Dependent Claim 16 words
The method according to claim 2 wherein the sponge has a hardness of at least 120.
Claim 16
Dependent Claim 18 words
The method according to claim 2 wherein the sponge has a hardness of between about 25 and 45.
Claim 17
Dependent Claim 20 words
The method according to claim 2 wherein the step of plasticizing ranges from between about ten minutes and 3 hours.
Claim 18
Dependent Claim 15 words
The method according to claim 2 wherein the particles are less than about 5 microns.
Claim 19
Dependent Claim 15 words
The method according to claim 2 wherein the particles are less than about 10 microns.
Claim 20
Independent Claim 93 words
A method of producing toner particles adapted for electrophoretic movement through a nonpolar liquid comprising the steps of plasticizing at a temperature in the range of about 65° C. and 100° C. an ethylene copolymer resin with a nonpolar liquid having an electrical volume resistivity in excess of about 10 9 ohm centimeters and to form a sponge, shredding the sponge into pieces, wet-grinding the pieces into particles, pulling the particles apart to form fibers extending therefrom, and adding a charge director to impart a charge of predetermined polarity to the toner particles.
Claim 21
Independent Claim 93 words
A method of producing toner particles adapted for electrophoretic movement through a nonpolar liquid comprising the steps of plasticizing at a temperature in the range of about 65° C. and 100° C. an ethylene copolymer resin with a nonpolar liquid having an electrical volume resistivity in excess of about 10 9 ohm centimeters and to form a sponge, shredding the sponge into pieces, wet-grinding the pieces into particles, pulling the particles apart to form fibers extending therefrom, and adding a charge director to impart a charge of predetermined polarity to the toner particles.

References Cited (Backward Citations)

JPS5499636A Cited
JPS59159176A Cited
US4631244A Cited
US4707429A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-09-09 1995-03-11 1995-09-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-09-09 1999-03-11 1999-09-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-09-09 2003-03-11 2003-09-10 $7700.00 Window Closed / Lapsed

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