US4631244A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparation of liquid toners for electrostatic imaging using polar additive
Assignee: EIDP Inc
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Filing: 1986-02-18
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Granted: 1986-12-23
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Expires: 2006-02-18
Abstract
Abstract Process for preparation of toner particles for electrostatic imaging comprising A. dispersing at an elevated temperature in a vessel a thermoplastic resin, a dispersant nonpolar liquid having a Kauri-butanol value of less than 30 and optionally a colorant, the temperature being maintained to plasticize and liquify the resin and below that at which the nonpolar liquid degrades and any component decomposes; B. cooling the dispersion, either (1) with or without stirring to form a gel or solid mass, the shredding and grinding the mass by means of particulate media in the presence of additional liquid; (2) with stirring to form a viscous mixture and grinding by means of particulate media in the presence of additional liquid; or (3) while grinding the particulate media thereby preventing formation of a gel or solid mass in the presence of additional liquid, and C. separating the dispersion of toner particles, average by area particle size less than 10 μm, from particulate media, the improvement whereby there is present, at least during the grinding in step B, 0.5 to 99% by weight of a polar additive having a Kauri-butanol value of at least 30, the percentage based on the total weight of liquid. The dispersion having a concentration of toner particles is useful for the preparation of copies and proofs of various colors.
Inventors
- 👤 Robert D. Mitchell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:31
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/12; G03G9/125
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
217 words
A process for preparing toner particles for electrostatic imaging comprising A. dispersing at an elevated temperature in a vessel a thermoplastic resin, a dispersant nonpolar liquid having a Kauri-butanol value of less than 30, and optionally a colorant, while maintaining the temperature in the vessel at a temperature sufficient to plasticize and liquify the resin and below that at which the dispersant nonpolar liquid degrades and the resin and/or colorant decomposes; B. cooling the dispersion, either (1) without stirring to form a gel or solid mass, followed by shredding the gel or solid mass and grinding by means of particulate media in the presence of additional liquid; (2) with stirring to form a viscous mixture and grinding by means of particulate media in the presence of additional liquid; or (3) while grinding by means of particulate media to prevent the formation of a gel or solid mass in the presence of additional liquid; and C. separating the dispersion of toner particles having an average by area particle size of less than 10 μm from the particulate media, the improvement whereby there is present, at least during the grinding in step B, 0.5 to 99% by weight of a polar additive having a Kauri-butanol value of at least 30, the percentage based on the total weight of liquid.
Claim 2
Dependent Claim
217 words
A process for preparing toner particles for electrostatic imaging comprising A. dispersing at an elevated temperature in a vessel a thermoplastic resin, a dispersant nonpolar liquid having a Kauri-butanol value of less than 30, and optionally a colorant, while maintaining the temperature in the vessel at a temperature sufficient to plasticize and liquify the resin and below that at which the dispersant nonpolar liquid degrades and the resin and/or colorant decomposes; B. cooling the dispersion, either (1) without stirring to form a gel or solid mass, followed by shredding the gel or solid mass and grinding by means of particulate media in the presence of additional liquid; (2) with stirring to form a viscous mixture and grinding by means of particulate media in the presence of additional liquid; or (3) while grinding by means of particulate media to prevent the formation of a gel or solid mass in the presence of additional liquid; and C. separating the dispersion of toner particles having an average by area particle size of less than 10 μm from the particulate media, the improvement whereby there is present, at least during the grinding in step B, 0.5 to 99% by weight of a polar additive having a Kauri-butanol value of at least 30, the percentage based on the total weight of liquid.
Claim 3
Dependent Claim
27 words
A process according to claim 1 wherein the 0.5 to 99% of the polar liquid based on the total weight of liquid is present during step A.
Claim 4
Dependent Claim
36 words
A process according to claim 1 wherein the polar liquid is taken from the group consisting of aromatic hydrocarbons of at least 6 carbon atoms, monohydric, dihydric and trihydric alcohols of 1 to 12 carbon atoms.
Claim 5
Dependent Claim
25 words
A process according to claim 1 wherein the particulate media are taken from the class consisting of stainless steel, ceramic, alumina, zirconium, silica, and sillimanite.
Claim 6
Dependent Claim
21 words
A process according to claim 4 wherein the particulate media are spherical having an average diameter of 0.04 to 0.5 inch.
Claim 7
Dependent Claim
31 words
A process according to claim 1 wherein the thermoplastic resin is a copolymer of ethylene and an α-β-ethylenically unsaturated acid selected from the class consisting of acrylic acid and methacrylic acid.
Claim 8
Dependent Claim
16 words
A process according to claim 1 wherein the thermoplastic resin is an ethylene vinyl acetate copolymer.
Claim 9
Dependent Claim
14 words
A process according to claim 1 wherein a colorant is present comprising carbon black.
Claim 10
Dependent Claim
41 words
A process according to claim 1 wherein the thermoplastic resin is a copolymer of ethylene (80 to 99.9%)/acrylic or methacrylic acid (20 to 0%)/alkyl ester of acrylic or methacrylic acid wherein alkyl is 1 to 5 carbon atoms (0 to 20%).
Claim 11
Dependent Claim
28 words
A process according to claim 6 wherein the thermoplastic resin is a copolymer of ethylene (89%) methacrylic acid (11%) having a melt index at 190° C. of 100.
Claim 12
Dependent Claim
15 words
A process according to claim 1 wherein a colorant is present comprising a colored material.
Claim 13
Dependent Claim
20 words
A process according to claim 1 wherein a colorant is present which is a pigment comprising finely divided ferromagnetic material.
Claim 14
Dependent Claim
14 words
A process according to claim 1 wherein a fine particle size oxide is present.
Claim 15
Dependent Claim
30 words
A process according to claim 1 wherein after step C a charge director is added to the dispersion to impart an electrostatic charge of predetermined polarity to the toner particles.
Claim 16
Dependent Claim
19 words
A process according to claim 1 wherein a plurality of thermoplastic resins are employed in the dispersing step A.
Claim 17
Dependent Claim
39 words
A process according to claim 1 wherein the additional dispersant nonpolar liquid, polar liquid or combinations thereof is present to reduce the concentration of toner particles to between 0.1 to 10 percent by weight with respect to the liquid.
Claim 18
Dependent Claim
22 words
A process according to claim 1 wherein the toner particles have an average by area particle size of less than 5 μm.
Claim 19
Dependent Claim
35 words
A process according to claim 1 wherein cooling the dispersion is accomplished while grinding by means of particulate media to prevent the formation of a gel or solid mass in the presence of additional liquid.
Claim 20
Dependent Claim
42 words
A process according to claim 1 wherein cooling the dispersion is accomplished without stirring to form a gel or solid mass, followed by shredding the gel or solid mass and grinding by means of particulate media in the presence of additional liquid.
Claim 21
Dependent Claim
32 words
A process according to claim 1 wherein cooling the dispersion is accomplished with stirring to form a viscous mixture and grinding by means of particulate media in the presence of additional liquid.
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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) | 1989-12-22 | 1990-06-23 | 1990-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-22 | 1994-06-23 | 1994-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-22 | 1998-06-23 | 1998-12-23 | $7700.00 | Window Closed / Lapsed |