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Patent US3921622A successfully refreshed from Google Patents.
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US3671646A Expired / Lapsed US ⏱️ 0.0 years remaining

Liquid developers for electrostatic photography

Assignee: Mitsubishi Paper Mills Ltd
•
Filing: 1969-07-24
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Granted: 1972-06-20
•
Expires: 1989-07-24
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Abstract

Abstract A liquid developer for electrostatic photography is prepared by dispersing in a dispersion medium composed essentially of a paraffinic hydrocarbon, an alkylaminoethyl methacrylatecontaining polymer; a carboxyl group-containing copolymer or acrylic or methacrylic acid and an ester thereof; a coloring material; and/or a dihydroabietic ester. Colloidal particles of the developer have favorable electric charging properties, and, after development of a photoconductive material and simultaneously with the drying of the liquid, they firmly adhere to the photo-sensitive layer to give a clear image. Further, the developer, which is a colloidal dispersion system, is stable and does not easily cause precipitation or agglomeration.

Inventors

  • 👤 Takaji Kurita
  • 👤 Masaya Motoki
  • 👤 Kazuhiro Emoto
  • 👤 Katsuo Hojo

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 20:32
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/12; G03G9/135; G03G9/1355; G03G9/13; G03G9/131; Y; Y10; Y10S; Y10S524/00; Y10S524/923

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 17 words
A liquid developer according to claim 1, wherein the polydialkylaminoethyl methacrylates are polydimethylaminoethyl methacrylates or polydiethylaminoethyl methacrylates.
Claim 2
Dependent Claim 48 words
A liquid developer according to claim 1, wherein the alkylaminoethyl methacrylate-containing polymer is one member selected from the group consisting of polydialkylaminoethyl methacrylates, copolymers of 33 percent dialkylaminoethyl methacrylates and 67 percent styrene, and copolymers of 30 percent dialkylaminoethyl methacrylates, 50 percent styrene and 20 percent alkyl methacrylates.
Claim 3
Dependent Claim 64 words
A liquid developer according to claim 1 wherein the carboxyl group - containing copolymer is a copolymer of 6 percent methacrylic acid and 94 percent lauryl methacrylate, a copolymer of 3 percent acrylic acid and 97 percent lauryl methacrylate, a copolymer of 8 percent acrylic acid and 92 percent stearyl acrylate, or a copolymer of 4 percent methacrylic acid and 96 percent ethylhexyl methacrylate.
Claim 4
Dependent Claim 25 words
A liquid developer according to claim 1, wherein the pigment is carbon black or phthalocyanine blue and the dye is oil black or oil blue.
Claim 5
Dependent Claim 19 words
A liquid developer according to claim 1, wherein the dihydroabietic ester is methyl glycerin dihydroabietate, or diethylene glycol dihydroabietate.
Claim 6
Dependent Claim 31 words
A liquid developer according to claim 1, wherein the di- or trivalent metal salt is selected from the group consisting of Ca, Mn, Ba, Zn and Al salts of dihydroabietic acid.
Claim 7
Dependent Claim 29 words
A liquid developer according to claim 1, wherein the ratio of the alkylaminoethyl methacrylate-containing polymer to the carboxyl group - containing copolymer is between 1/10 and 1 : 1.
Claim 8
Dependent Claim 24 words
A liquid developer according to claim 1, wherein the amount of acid in the carboxyl - group containing copolymer is less than 10 percent.

References Cited (Backward Citations)

US2138763A Cited
US3252949A Cited
US3401037A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1975-06-20 1975-12-20 1976-06-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1979-06-20 1979-12-20 1980-06-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1983-06-20 1983-12-20 1984-06-20 $7700.00 Window Closed / Lapsed

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