US4681831A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chargeable resins for liquid electrostatic developers comprising partial ester of 3-hydroxypropanesulfonic acid
Assignee: EIDP Inc
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Filing: 1986-06-30
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Granted: 1987-07-21
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Expires: 2006-06-30
Abstract
Abstract A liquid electrostatic developer containing negatively chargeable resin particles with improved charging characteristics, said developer consisting essentially of (A) nonpolar liquid having a Kauri-butanol value of less than 30, present in a major amount, (B) nonpolar liquid soluble ionic or zwitterionic charge director compound, and (C) resin particles of a polymer containing at least one acidic constituent having a pKa less than 4.5, preferably 3.0, at 25° C. in water and an acid number due to said acidic constituent of at least one. The average resin particle size by area is less than 10 μm. Optionally a colorant and other additives or adjuvants are present. The liquid electrostatic developer is useful in copying making proofs including digital color proofs, lithographic printing plates, and resists.
Inventors
- 👤 James R. Larson
- 👤 Torence J. Trout
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:38
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/12; G03G9/13; G03G9/131
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
98 words
A liquid electrostatic developer containing negatively chargeable resin particles with improved charging characteristics, said developer consisting essentially of (A) nonpolar liquid having a Kauri-butanol value of less than 30, present in a major amount, (B) nonpolar liquid soluble ionic or zwitterionic charge director compound, and (C) resin particles of a polymer containing at least one acidic constituent having a pKa of less than 4.5 measured at 25° C. in water and an acid number due to said acidic constituent of at least one, the resin particles having an average by area particle size of less than 10 μm.
Claim 2
Dependent Claim
98 words
A liquid electrostatic developer containing negatively chargeable resin particles with improved charging characteristics, said developer consisting essentially of (A) nonpolar liquid having a Kauri-butanol value of less than 30, present in a major amount, (B) nonpolar liquid soluble ionic or zwitterionic charge director compound, and (C) resin particles of a polymer containing at least one acidic constituent having a pKa of less than 4.5 measured at 25° C. in water and an acid number due to said acidic constituent of at least one, the resin particles having an average by area particle size of less than 10 μm.
Claim 3
Dependent Claim
24 words
A liquid electrostatic developer according to claim 1 wherein the resin particles are substantially insoluble in nonpolar liquid (A) at temperatures below 40° C.
Claim 4
Dependent Claim
21 words
A liquid electrostatic developer according to claim 2 wherein the pKa of at least one acidic constituent is less than 3.0.
Claim 5
Dependent Claim
114 words
A liquid electrostatic developer containing negatively chargeable resin particles with improved charging characteristics, said developer consisting essentially of (A) nonpolar liquid having a Kauri-butanol value of less than 30, present in a major amount, (B) nonpolar liquid soluble ionic or zwitterionic charge director compound, and (C) resin particles of a partial ester of 3-hydroxypropanesulfonic acid and a copolymer of ethylene and an α,β-ethylenically unsaturated acid selected from the class consisting of acrylic acid and methacrylic acid having a pKa of less than 4.5 measured at 25° C. in water and an acid number of 7±3 based on 3-hydroxypropanesulfonic acid, the resin particles having an average by area particle size of less than 10 μm.
Claim 6
Dependent Claim
114 words
A liquid electrostatic developer containing negatively chargeable resin particles with improved charging characteristics, said developer consisting essentially of (A) nonpolar liquid having a Kauri-butanol value of less than 30, present in a major amount, (B) nonpolar liquid soluble ionic or zwitterionic charge director compound, and (C) resin particles of a partial ester of 3-hydroxypropanesulfonic acid and a copolymer of ethylene and an α,β-ethylenically unsaturated acid selected from the class consisting of acrylic acid and methacrylic acid having a pKa of less than 4.5 measured at 25° C. in water and an acid number of 7±3 based on 3-hydroxypropanesulfonic acid, the resin particles having an average by area particle size of less than 10 μm.
Claim 7
Dependent Claim
40 words
A liquid electrostatic developer according to claim 4 wherein the resin particles are a partial ester of 3-hydroxypropanesulfonic acid and a copolymer of ethylene (89% by weight)/methacrylic acid (11% by weight) having a melt index of 100 at 190° C.
Claim 8
Dependent Claim
99 words
A liquid electrostatic developer containing negatively chargeable resin particles with improved charging characteristics, said developer consisting essentially of (A) nonpolar liquid having a Kauri-butanol value of less than 30, present in a major amount, (B) nonpolar liquid soluble ionic or zwitterionic charge director compound, and (C) resin particles of a poly(styrene/2-acrylamido-2-methyl-1-propane sulfonic acid) (95% by weight/5% by weight) having a pKa of less than 4.5 measured at 25° C. in water and an acid number due to said acidic constituent of at least one, the resin particles having an average by area particle size of less than 10 μm.
Claim 9
Dependent Claim
99 words
A liquid electrostatic developer containing negatively chargeable resin particles with improved charging characteristics, said developer consisting essentially of (A) nonpolar liquid having a Kauri-butanol value of less than 30, present in a major amount, (B) nonpolar liquid soluble ionic or zwitterionic charge director compound, and (C) resin particles of a poly(styrene/2-acrylamido-2-methyl-1-propane sulfonic acid) (95% by weight/5% by weight) having a pKa of less than 4.5 measured at 25° C. in water and an acid number due to said acidic constituent of at least one, the resin particles having an average by area particle size of less than 10 μm.
Claim 10
Dependent Claim
52 words
A liquid electrostatic developer according to claim 1 wherein component (A) is present in 85.0 to 99.9% by weight, component (C) is present in 0.1 to 15.0% by weight, based on the total weight of the developer, and component (B) is present in an amount of 1 to 1000 mg/g developer solids.
Claim 11
Dependent Claim
25 words
A liquid electrostatic developer according to claim 1 containing up to about 60% by weight of a colorant based on the weight of developer solids.
Claim 12
Dependent Claim
25 words
A liquid electrostatic developer according to claim 7 containing up to about 60% by weight of a colorant based on the weight of developer solids.
Claim 13
Dependent Claim
14 words
A liquid electrostatic developer according to claim 8 wherein the colorant is a pigment.
Claim 14
Dependent Claim
28 words
A liquid electrostatic developer according to claim 10 wherein the percent pigment in the resin is 0.1% to 30% by weight based on the weight of developer solids.
Claim 15
Dependent Claim
14 words
A liquid electrostatic developer according to claim 8 wherein the colorant is a dye.
Claim 16
Dependent Claim
23 words
A liquid electrostatic developer according to claim 1 wherein the particles have an average by area particle size of less than 5 μm.
Claim 17
Dependent Claim
15 words
A liquid electrostatic developer according to claim 1 wherein component (B) is Basic Barium Petronate.
Claim 18
Dependent Claim
13 words
A liquid electrostatic developer according to claim 1 wherein component (B) is lecithin.
Claim 19
Dependent Claim
107 words
A liquid electrostatic developer containing negatively chargeable resin particles with improved charging characteristics, said developer consisting essentially of (A) nonpolar liquid having a Kauri-butanol value of less than 30, present in a major amount, (B) nonpolar liquid soluble ionic or zwitterionic charge director compound, and (C) resin particles of a polymer having a plurality of fibers extending therefrom, said polymer containing at least one acidic constituent having a pKa of less than 4.5 measured at 25° C. in water and an acid number due to said acidic constituent of at least one, the resin particles having an average by area particle size of less than 10 μm.
Claim 20
Dependent Claim
107 words
A liquid electrostatic developer containing negatively chargeable resin particles with improved charging characteristics, said developer consisting essentially of (A) nonpolar liquid having a Kauri-butanol value of less than 30, present in a major amount, (B) nonpolar liquid soluble ionic or zwitterionic charge director compound, and (C) resin particles of a polymer having a plurality of fibers extending therefrom, said polymer containing at least one acidic constituent having a pKa of less than 4.5 measured at 25° C. in water and an acid number due to said acidic constituent of at least one, the resin particles having an average by area particle size of less than 10 μm.
Claim 21
Dependent Claim
14 words
A liquid electrostatic developer according to claim 1 wherein the resin particles are nonfibrous.
Claim 22
Dependent Claim
106 words
A liquid electrostatic developer containing negatively chargeable resin particles with improved charging characteristics, said developer consisting essentially of (A) nonpolar liquid having a Kauri-butanol value of less than 30, present in a major amount, (B) nonpolar liquid soluble ionic or zwitterionic charge director compound, and (C) nonfibrous resin particles of a poly(styrene/2-acrylamido-2-methyl-1-propane sulfonic acid) (95% by weight/5% by weight) containing at least one acidic constituent having a pKa of less than 4.5 measured at 25° C. in water and an acid number due to said acidic constituent of at least one, the resin particles having an average by area particle size of less than 10 μm.
Claim 23
Dependent Claim
106 words
A liquid electrostatic developer containing negatively chargeable resin particles with improved charging characteristics, said developer consisting essentially of (A) nonpolar liquid having a Kauri-butanol value of less than 30, present in a major amount, (B) nonpolar liquid soluble ionic or zwitterionic charge director compound, and (C) nonfibrous resin particles of a poly(styrene/2-acrylamido-2-methyl-1-propane sulfonic acid) (95% by weight/5% by weight) containing at least one acidic constituent having a pKa of less than 4.5 measured at 25° C. in water and an acid number due to said acidic constituent of at least one, the resin particles having an average by area particle size of less than 10 μm.
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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) | 1990-07-20 | 1991-01-19 | 1991-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-20 | 1995-01-19 | 1995-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-20 | 1999-01-19 | 1999-07-21 | $7700.00 | Window Closed / Lapsed |