US4904562A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing encapsulated toner
Assignee: Canon Inc
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Filing: 1987-09-23
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Granted: 1990-02-27
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Expires: 2007-09-23
Abstract
Abstract An encapsulated toner for electrophotography is produced through a process, comprising: preparing a solution of a shell material resin set to an acidic (or basic) pH region; dispersing solid core particles in the solution to form a dispersion; changing the pH of the dispersion to a pH region, which is preferably a basic (or acidic) pH region, where the shell material resin is precipitated from the dispersion; and coating the solid core particles with the precipitated shell material resin. The shell material is preferably a proton-attracting basic (or dissociative acidic) vinyl-type copolymer and is dissolved in a pH-adjusted aqueous medium comprising water and a polar solvent, such as a lower alcohol. Thus, an encapsulated toner with excellent triboelectric chargeability and environmental characteristic is prepared without coalescence of capsules or formation of free shells.
Inventors
- 👤 Hiroshi Yusa
- 👤 Takaaki Kohtaki
- 👤 Masuo Yamazaki
- 👤 Yasutaka Akashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:56
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/093; G03G9/09392; B; B01; B01J; B01J13/00; B01J13/02; B01J13/06; B01J13/08; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991
Claims Analysis
Total Claims: 59
Claim 1
Independent Claim
109 words
A process for producing an encapsulated toner, comprising: preparing a solution of a shell material resin set to an acidic pH region or a basic pH region wherein the shell material resin comprises a vinyl copolymer having a number-average molecular weight of 5,000 to 40,000, said shell material resin being dissolved in an aqueous medium containing an organic solvent having a solubility parameter of at least 11.0, dispersing solid core particles in the solution to form a dispersion, changing the pH of the dispersion to a pH region where the shell material resin is precipitated from the dispersion, and coating the core particles with the precipitated shell material resin.
Claim 2
Dependent Claim
109 words
A process for producing an encapsulated toner, comprising: preparing a solution of a shell material resin set to an acidic pH region or a basic pH region wherein the shell material resin comprises a vinyl copolymer having a number-average molecular weight of 5,000 to 40,000, said shell material resin being dissolved in an aqueous medium containing an organic solvent having a solubility parameter of at least 11.0, dispersing solid core particles in the solution to form a dispersion, changing the pH of the dispersion to a pH region where the shell material resin is precipitated from the dispersion, and coating the core particles with the precipitated shell material resin.
Claim 3
Dependent Claim
49 words
A process according to claim 1, wherein the solution of the shell material resin is set to an acidic pH region, the solid core particles are dispersed in the solution, and the pH of the dispersion is changed to a basic pH region to precipitate the shell material resin.
Claim 4
Dependent Claim
14 words
A process according to claim 2, wherein the core particles have a pressure fixability.
Claim 5
Dependent Claim
14 words
A process according to claim 1, wherein said organic solvent is a lower alcohol.
Claim 6
Dependent Claim
18 words
A process according to claim 4, wherein said organic solvent is a lower alcohol having 1-5 carbon atoms.
Claim 7
Dependent Claim
69 words
A process according to claim 2, wherein said shell material resin comprises a resin formed from a monomer (A) providing a film-formability (A), a monomer (B1) providing a proton-attracting function (B1) of forming a proton-added product under the action of an acidifying agent in an aqueous medium, and a monomer (C) providing mainly a solubility-promoting function (C) of providing the proton-added product with a solubility in the aqueous medium.
Claim 8
Dependent Claim
53 words
A process according to claim 6, wherein said monomer (A) is styrene (St); said monomer (B1) is N,N-dimethylaminoethyl methacrylate (DM) or N,N-diethylaminoethyl methacrylate (DE); and said monomer (C) is a monomer selected from the group consisting of methyl methacrylate (MMA), 2-ethylhexyl methacrylate (2EHA), n-butyl methacrylate (BMA), butadiene (BD), isoprene (IP) and acrylonitrile (AN).
Claim 9
Dependent Claim
38 words
A process according to claim 6, wherein said shell material resin is a vinyl copolymer selected from the group consisting of St-MMA-DM copolymer St-MAA-DE copolymer, St-2EHA-DM copolymer, St-MMA-2EHA-DM copolymer, St-MMA-MBA-DM copolymer, St-MMA-BD-DM copolymer, St-MMA-IP-DM copolymer and St-AN-MMA-DM copolymer.
Claim 10
Dependent Claim
20 words
A process according to claim 1, wherein said shell material resin has a number-average molecular weight of 10,000 to 30,000.
Claim 11
Dependent Claim
35 words
A process according to claim 1, wherein said shell material resin has a ratio of weight-average molecular weight/number-average molecular weight in the range of 1.5-4.5, and a glass transition temperature of 40° C. or higher.
Claim 12
Dependent Claim
19 words
A process according to claim 10, wherein said shell material resin has a glass transition temperature of 60°-120° C.
Claim 13
Dependent Claim
39 words
A process according to claim 6, wherein said shell material resin is a vinyl copolymer formed from 30-90 mol % of the monomer (A), 5-65 mol % of the monomer (B1), and 5-30 mol % of the monomer (C).
Claim 14
Dependent Claim
28 words
A process according to claim 1, wherein said shell material resin is contained in a proportion of 0.5-20 wt. parts per 100 wt. parts of the aqueous medium.
Claim 15
Dependent Claim
28 words
A process according to claim 13, wherein said shell material resin is contained in a proportion of 1.0-10 wt. parts per 100 wt. parts of the aqueous medium.
Claim 16
Dependent Claim
22 words
A process according to claim 2, wherein said solution of the shell material resin is set to a pH value of 5±1.5.
Claim 17
Dependent Claim
33 words
A process according to claim 15, wherein said shell material resin is dissolved in the aqueous medium with the aid of an acidifying agent to provide said solution of the shell material resin.
Claim 18
Dependent Claim
24 words
A process according to claim 1, wherein the precipitation of the shell material resin is effected at a temperature of -10° to +30° C.
Claim 19
Dependent Claim
24 words
A process according to claim 1, wherein the precipitation of the shell material resin is effected at a temperature of -10° to +5° C.
Claim 20
Dependent Claim
22 words
A process according to claim 2, wherein the pH of the dispersion is changed by adding a basifying agent to the dispersion.
Claim 21
Dependent Claim
52 words
A process according to claim 19, wherein said basifying agent is added to the dispersion at a rate H (ml/min) satisfying the following condition: (H/F×G)=0.005 to 20, wherein F denotes the concentration of the shell material resin in the aqueous medium (g/l), and G denotes the amount of the aqueous medium (l).
Claim 22
Dependent Claim
37 words
A process according to claim 19, wherein said basifying agent is a basic substance selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonia gas, ethylenediamine, diethylene triamine, triethylene-diamine and aqueous solutions of these.
Claim 23
Dependent Claim
13 words
A process according to claim 21, wherein the basifying agent is ammonia water.
Claim 24
Dependent Claim
33 words
A process according to claim 1, wherein the solid core particles are dispersed in the solution in a proportion of 10-50 wt. parts per 100 parts of the aqueous medium constituting the solution.
Claim 25
Dependent Claim
90 words
A process according to claim 3, wherein said solid core particles comprise at least two of the following resins or waxes (a)-(c); (a) a resin or wax with a hardness-imparting function having a Vickers hardness of 2-8 kg/mm 2 as measured under a weight of 10 g applied for 15 sec; (b) a resin or wax with a releasability-imparting function having a critical surface tension of 15-40 dyne/cm at 20° C.; and (c) a resin or wax with a fixability-imparting function having a compression modulus of 0.1-50 kg/mm 2 .
Claim 26
Dependent Claim
36 words
A process according to claim 24, wherein said solid core particles comprise a binder resin obtained by heating said at least two of the resins or waxes (a)-(c) in the presence of a radical generating agent.
Claim 27
Dependent Claim
28 words
A process according to claim 1, wherein said solid core particles comprise 15-180 wt. parts of a magnetic substance per 100 wt. parts of the resinous component therein.
Claim 28
Dependent Claim
28 words
A process according to claim 26, wherein said solid core particles comprise 50-150 wt. parts of the magnetic substance per 100 wt. parts of the resinous component therein.
Claim 29
Dependent Claim
27 words
A process according to claim 1, wherein said solid core particles comprise 0.1-20 wt. parts of a colorant per 100 wt. parts of the resin component therein.
Claim 30
Dependent Claim
22 words
A process according to claim 2, wherein said solid core particles are coated with a 0.01-2.0 μm-thick shell having a triboelectric chargeability.
Claim 31
Dependent Claim
49 words
A process according to claim 1, wherein the solution of the shell material resin is set to a basic pH region, the solid core particles are dispersed in the solution, and the pH of the dispersion is changed to an acidic pH region to precipitate the shell material resin.
Claim 32
Dependent Claim
13 words
A process according to claim 30, wherein the core particles have a pressure-fixability.
Claim 33
Dependent Claim
31 words
A process according to claim 30, wherein said shell material resin is dissolved in an aqueous medium comprising water and an organic solvent having a solubility parameter of 11.0 or higher.
Claim 34
Dependent Claim
14 words
A process according to claim 32, wherein said organic solvent is a lower alcohol.
Claim 35
Dependent Claim
18 words
A process according to claim 33, wherein said organic solvent is a lower alcohol having 1-5 carbon atoms.
Claim 36
Dependent Claim
69 words
A process according to claim 30, wherein said shell material resin comprises a resin formed from a monomer (A) providing a film-formability (A), a monomer (B2) providing a dissociative function (B2) of forming a dissociated product under the action of a basifying agent in an aqueous medium, and a monomer (C) providing mainly a solubility-promoting function (C) of providing the dissociated product with a solubility in the aqueous medium.
Claim 37
Dependent Claim
18 words
A process according to claim 35, wherein the monmer (B2) also has a function of the monomer (C).
Claim 38
Dependent Claim
19 words
A process according to claim 36, wherein the monomer (B2) is a maleic acid mono-alkyl ester or methacrylic acid.
Claim 39
Dependent Claim
20 words
A process according to claim 35, wherein said shell material resin has a number-average molecular weight of 5,000 to 40,000.
Claim 40
Dependent Claim
20 words
A process according to claim 35, wherein said shell material resin has a number-average molecular weight of 10,000 to 30,000.
Claim 41
Dependent Claim
35 words
A process according to claim 35, wherein said shell material resin has a ratio of weight-average molecular weight/number-average molecular weight in the range of 1.5-4.5, and a glass transition temperature of 40° C. or higher.
Claim 42
Dependent Claim
19 words
A process according to claim 40, wherein said shell material resin has a glass transition temperature of 60°-120° C.
Claim 43
Dependent Claim
28 words
A process according to claim 32, wherein said shell material resin is contained in a proportion of 0.5-20 wt. parts per 100 wt. parts of the aqueous medium.
Claim 44
Dependent Claim
28 words
A process according to claim 42, wherein said shell material resin is contained in a proportion of 1.0-10 wt. parts per 100 wt. parts of the aqueous medium.
Claim 45
Dependent Claim
22 words
A process according to claim 30, wherein said solution of the shell material resin is set to a pH value of 8-10.
Claim 46
Dependent Claim
33 words
A process according to claim 44, wherein said shell material resin is dissolved in the aqueous medium with the aid of a basifying agent to provide said solution of the shell material resin.
Claim 47
Dependent Claim
24 words
A process according to claim 30, wherein the precipitation of the shell material resin is effected at a temperature of -10° to +30° C.
Claim 48
Dependent Claim
24 words
A process according to claim 46, wherein the precipitation of the shell material resin is effected at a temperature of -10° to +5° C.
Claim 49
Dependent Claim
22 words
A process according to claim 30, wherein the pH of the dispersion is changed by adding an acidifying agent to the dispersion.
Claim 50
Dependent Claim
52 words
A process according to claim 48, wherein said acidifying agent is added to the dispersion at a rate H (ml/min) satisfying the following condition: (H/F×G)=0.005 to 20, wherein F denotes the concentration of the shell material resin in the aqueous medium (g/l), and G denotes the amount of the aqueous medium (l).
Claim 51
Dependent Claim
30 words
A process according to claim 48, wherein said acidifying agent is selected from the group consisting of hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid and succinic acid.
Claim 52
Dependent Claim
13 words
A process according to claim 50, wherein said acidifying agent is acetic acid.
Claim 53
Dependent Claim
33 words
A process according to claim 30, wherein the solid core particles are dispersed in the solution in a proportion of 10-50 wt. parts per 100 parts of the aqueous medium constituting the solution.
Claim 54
Dependent Claim
90 words
A process according to claim 31, wherein said solid core particles comprise at least two of the following resins or waxes (a)-(c): (a) a resin or wax with a hardness-imparting function having a Vickers hardness of 2-8 kg/mm 2 as measured under a weight of 10 g applied for 15 sec; (b) a resin or was with a releasability-imparting function having a critical surface tension of 15-40 dyen/cm at 20° C.; and (c) a resin or wax with a fixability-imparting function having a compression modulus of 0.1-50 kg/mm 2 .
Claim 55
Dependent Claim
36 words
A process according to claim 53, wherein said solid core particles comprise a binder resin obtained by heating said at least two of the resins or waxes (a)-(c) in the presence of a radical generating agent.
Claim 56
Dependent Claim
28 words
A process according to claim 53, wherein said solid core particles comprise 15-180 wt. parts of a magnetic substance per 100 wt. parts of the resinous component therein.
Claim 57
Dependent Claim
28 words
A process according to claim 55, wherein said solid core particles comprise 50-150 wt. parts of the magnetic substance per 100 wt. parts of the resinous component therein.
Claim 58
Dependent Claim
27 words
A process according to claim 53, wherein said solid core particles comprise 0.1-20 wt. parts of a colorant per 100 wt. parts of the resin component therein.
Claim 59
Dependent Claim
22 words
A process according to claim 30, wherein said solid core particles are coated with a 0.01-2.0 μm-thick shell having a triboelectric chargeability.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1993-02-26 | 1993-08-28 | 1994-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-02-26 | 1997-08-28 | 1998-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-02-26 | 2001-08-28 | 2002-02-27 | $7700.00 | Window Closed / Lapsed |