Patent US5294490A successfully refreshed from Google Patents.
US5294490A
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Encapsulated toner for heat-and-pressure fixing
Assignee: Kao Corp
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Filing: 1992-05-20
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Granted: 1994-03-15
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Expires: 2012-05-20
Abstract
Abstract An encapsulated toner for heat-and-pressure fixing having excellent offset resistance and blocking resistance, being fixed at a low fixing temperature and being regulated with the charging properties thereof from the inside of the encapsulated toner to stably and repeatedly form a scum-free, clear image many times, comprised of a heat-fusible core containing at least a coloring material, a binder and an electric charge control agent selected from the group consisting of a positive electric charge control agent, a negative electric charge control agent and a mixture thereof at a weight ratio of one to the other ranging from 1:0 (exclusive) to 1:0.5, and a shell formed so as to cover the surface of the core, wherein the main component of the shell is a resin prepared by reacting (A) an iso(thio)cyanate compound comprising (1) 0 to 30 mole % of monovalent isocyanate and/or isothiocyanate compounds, and (2) 100 to 70 mole % of at least divalent isocyanate and/or isothiocyanate compounds, with (B) an active hydrogen compound comprising (3) 0 to 30 mole % of a compound having one active hydrogen atom reactive with isocyanate and/or isothiocyanate groups, and (4) 100 to 70 mole % of a compound having at least two active hydrogen atoms reactive with isocyanate and/or isothiocyanate groups, at a molar ratio of component (A) to component (B) of between 1:1 and 1:20, and wherein at least 30% of all of the linkages in which an isocyanate and/or isothiocyanate group participates are thermally dissociable linkages.
Inventors
- 👤 Mitsuhiro Sasaki
- 👤 Kuniyasu Kawabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:01
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/093; G03G9/09307; G03G9/09314; G03G9/09328; G03G9/0935; G03G9/09378; Y; Y10; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249994; Y10T428/249995; Y10T428/249997; Y10T428/29; Y10T428/2982; Y10T428/2984; Y10T428/2985; Y10T428/2987; Y10T428/31504; Y10T428/31547
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
235 words
An encapsulated toner for heat-and-pressure fixing which comprises a heat-fusible core containing a coloring material, a thermoplastic resin binder having a glass transition point between 10° and 50° C. and 0.1% to 8.0% by weight of an electric charge control agent selected from the group consisting of a positive electric charge control agent, a negative electric charge control agent and a mixture thereof at a weight ratio of one to the other ranging from 1:0 to 1:0.5, and a shell formed so as to cover the surface of said core, wherein a main component of said shell is a resin prepared by reacting (A) an iso(thio) cyanate compound comprising (1) 0 to 30 mole % monovalent isocyanate and/or isothiocyanate compounds, and (2) 100 to 70 mole % of at least divalent isocyanate and/or isothiocyanate compounds, with (B) an active hydrogen compound comprising (3) 0 to 30 mole % of a compound having one active hydrogen atom reactive with isocyanate and/or isothiocyanate groups, and (4) 100 to 70 mole % of a compound having at least two active hydrogen atoms reactive with isocyanate and/or isothiocyanate groups, at a molar ratio of component (A) to component (B) of between 1:1 and 1:20, and wherein at least 30% of all of the linkages in which an isocyanate and/or isothiocyanate group participates are thermally dissociable linkages said encapsulated toner having a softening point between 80° C. and 150° C.
Claim 2
Dependent Claim
235 words
An encapsulated toner for heat-and-pressure fixing which comprises a heat-fusible core containing a coloring material, a thermoplastic resin binder having a glass transition point between 10° and 50° C. and 0.1% to 8.0% by weight of an electric charge control agent selected from the group consisting of a positive electric charge control agent, a negative electric charge control agent and a mixture thereof at a weight ratio of one to the other ranging from 1:0 to 1:0.5, and a shell formed so as to cover the surface of said core, wherein a main component of said shell is a resin prepared by reacting (A) an iso(thio) cyanate compound comprising (1) 0 to 30 mole % monovalent isocyanate and/or isothiocyanate compounds, and (2) 100 to 70 mole % of at least divalent isocyanate and/or isothiocyanate compounds, with (B) an active hydrogen compound comprising (3) 0 to 30 mole % of a compound having one active hydrogen atom reactive with isocyanate and/or isothiocyanate groups, and (4) 100 to 70 mole % of a compound having at least two active hydrogen atoms reactive with isocyanate and/or isothiocyanate groups, at a molar ratio of component (A) to component (B) of between 1:1 and 1:20, and wherein at least 30% of all of the linkages in which an isocyanate and/or isothiocyanate group participates are thermally dissociable linkages said encapsulated toner having a softening point between 80° C. and 150° C.
Claim 3
Dependent Claim
33 words
The encapsulated toner for heat-and-pressure fixing according to claim 1, wherein said thermally dissociable linkage is formed by the reaction of a phenolic hydroxyl or thiol group with an isocyanate or isothiocyanate group.
Claim 4
Dependent Claim
258 words
The encapsulated toner for heat-and-pressure fixing according to claim 2, wherein said compound having a phenolic hydroxyl group is at least one compound selected from the group represented by the following formulae (I), (II) and (III): ##STR5## wherein R 1 , R 2 , R 3 , R 4 and R 5 each independently represent a hydrogen atom, an alkyl group having 1 to 9 carbon atoms, an alkenyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, an alkanoyl group having 1 to 9 carbon atoms, a carboalkoxy group having 2 to 9 carbon atoms, an aryl group having 6 to 9 carbon atoms or a halogen atom; ##STR6## wherein R 6 , R 7 , R 8 and R 9 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkanoyl group having 1 to 6 carbon atoms, a carboalkoxy group having 2 to 6 carbon atoms, an aryl group having 6 carbon atoms or a halogen atom; and ##STR7## wherein R 10 , R 11 , R 12 and R 13 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 1 to 6 carbon atoms, an alkanoyl group having 1 to 6 carbon atoms, a carboalkoxy group having 2 to 6 carbon atoms, an aryl group having 6 carbon atoms or a halogen atom.
Claim 5
Dependent Claim
19 words
The encapsulated toner for heat-and-pressure fixing according to claim 1, wherein said thermoplastic resin binder comprises a vinyl resin.
Claim 6
Dependent Claim
29 words
The encapsulated toner for heat-and-pressure fixing according to claim 2, wherein the isocyanate group to be reacted with the phenolic hydroxyl group is directly bonded to an aromatic ring.
Claim 7
Dependent Claim
26 words
A toner composition for heat-and-pressure fixing, comprising an encapsulated toner as set forth in claim 1 and a fine powder of a hydrophobic silica coated thereon.
References Cited (Backward Citations)
GB2097947A
Cited
US4977052A
Cited
GB2107892A
Cited
US4803144A
Cited
EP0088566A2
Cited
EP0225476A1
Cited
EP0416897A2
Cited
US5043240A
Cited
EP0453857A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-03-14 | 1997-09-13 | 1998-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-03-14 | 2001-09-13 | 2002-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-03-14 | 2005-09-13 | 2006-03-15 | $7700.00 | Window Closed / Lapsed |