US4413843A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microcapsules, method for their production and pressure sensitive copying sheet
Assignee: New Oji Paper Co Ltd
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Filing: 1979-12-26
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Granted: 1983-11-08
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Expires: 1999-12-26
Abstract
Abstract The method of making microcapsules comprises performing polycondensation of an aminoaldehyde resin prepolymer in an aqueous dispersion including particles of hydrophobic core material in the presence of anion-modified polyvinyl alcohol to form aminoaldehyde resin microcapsules walls around said particles of hydrophobic core material.
Inventors
- 👤 Hiroshi Iwasaki
- 👤 Shinsuke Irii
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:26
CPC Classifications
B; B41; B41M; B41M5/00; B41M5/124; B41M5/165; B01; B01J; B01J13/00; B01J13/02; B01J13/06; B01J13/14; B01J13/18; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2984; Y10T428/2985; Y10T428/2989
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
86 words
A method of making microcapsules comprising the steps of preparing an aminoaldehyde resin prepolymer of at least one amine and at least one aldehyde, and performing polycondensation of said aminoaldehyde resin prepolymer in an aqueous dispersion including particles of hydrophobic core material in the presence of anion-modified polyvinyl alcohol to form aminoaldehyde resin microcapsule walls around said particles of hydrophobic core material, said anion-modified polyvinyl alcohol being used in an amount between about 0.1 and about 20% by weight of the amount of said aqueous dispersion.
Claim 2
Independent Claim
86 words
A method of making microcapsules comprising the steps of preparing an aminoaldehyde resin prepolymer of at least one amine and at least one aldehyde, and performing polycondensation of said aminoaldehyde resin prepolymer in an aqueous dispersion including particles of hydrophobic core material in the presence of anion-modified polyvinyl alcohol to form aminoaldehyde resin microcapsule walls around said particles of hydrophobic core material, said anion-modified polyvinyl alcohol being used in an amount between about 0.1 and about 20% by weight of the amount of said aqueous dispersion.
Claim 3
Dependent Claim
20 words
A method of making microcapsules according to claim 1 in which said aminoaldehyde resin prepolymer is a melamine-formaldehyde resin prepolymer.
Claim 4
Dependent Claim
29 words
A method of making microcapsules according to claim 1 in which said anion-modified polyvinyl alcohol has anionic radicals at 0.5 to 50 mol. % of its total monomer units.
Claim 5
Dependent Claim
29 words
A method of making microcapsules according to claim 3 in which said anion-modified polyvinyl alcohol has anionic radicals at 1 to 20 mol. % of its total monomer units.
Claim 6
Dependent Claim
29 words
A method of making microcapsules according to claim 1 in which said anion-modified polyvinyl alcohol has hydrophobic radicals at 1 to 30 mol. % of its total monomer units.
Claim 7
Dependent Claim
29 words
A method of making microcapsules according to claim 5 in which said anion-modified polyvinyl alcohol has hydrophobic radicals at 2 to 20 mol. % of its total monomer units.
Claim 8
Dependent Claim
12 words
Microcapsules which are prepared by a method as claimed in claim 1.
Claim 9
Dependent Claim
19 words
Pressure sensitive copying sheet comprising a support having coated thereon a layer of microcapsules as claimed in claim 7.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-11-07 | 1987-05-09 | 1987-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-11-07 | 1991-05-09 | 1991-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-11-07 | 1995-05-09 | 1995-11-08 | $7700.00 | Window Closed / Lapsed |