US4738898A
Expired / Lapsed
US
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Microencapsulation by interfacial polyaddition
Assignee: Rhone Poulenc Specialites Chimiques
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Filing: 1986-12-10
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Granted: 1988-04-19
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Expires: 2006-12-10
Abstract
Abstract A variety of materials, e.g., colorants, agricultural chemicals, pharmaceuticals, etc., are conveniently microencapsulated within polyurea skin membranes by interfacial polyaddition, by emulsifying a polyisocyanato hydrophobic liquid in an essentially aqueous medium, said polyisocyanato hydrophobic liquid comprising dissolved material to be microencapsulated, an aliphatic diisocyanate (i) and an isocyanurate ring trimer (ii) of an aliphatic diisocyanate, the ratio by weight of said diisocyanate (i) to said trimer (ii) ranging from 0.05/1 to 0.70/1, and then interfacially reacting a polyamine therewith. The resulting suspension of microcapsules is well adapted, e.g., for the production of carbonless papers.
Inventors
- 👤 Gilbert Vivant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:06
CPC Classifications
B; B01; B01J; B01J2/00; C; C08; C08G; C08G18/00; C08G18/06; C08G18/70; C08G18/72; C08G18/721; C08G18/725; B01J13/00; B01J13/02; B01J13/06; B01J13/14; B01J13/16; B41; B41M; B41M5/00; B41M5/124; B41M5/165; C08G18/08; C08G18/0838; C08G18/0842; C08G18/0861; C08G18/0866; C08G18/28; C08G18/30; C08G18/32; C08G18/3225; Y; Y10; Y10S; Y10S428/00; Y10S428/914; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2984; Y10T428/2985
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
68 words
A process for the preparation of a suspension of microcapsules by interfacial polyaddition, which comprises emulsifying a polyisocyanato hydrophobic liquid in an essentially aqueous medium, said polyisocyanato hydrophobic liquid comprising (i) an aliphatic diisocyanate and (ii) the isocyanurate ring trimer of an aliphatic diisocyanate, the ratio by weight of said diisocyanate (i) to said trimer (ii) ranging from 0.05/1 to 0.70/1, and then interfacially reacting a polyamine therewith.
Claim 2
Dependent Claim
68 words
A process for the preparation of a suspension of microcapsules by interfacial polyaddition, which comprises emulsifying a polyisocyanato hydrophobic liquid in an essentially aqueous medium, said polyisocyanato hydrophobic liquid comprising (i) an aliphatic diisocyanate and (ii) the isocyanurate ring trimer of an aliphatic diisocyanate, the ratio by weight of said diisocyanate (i) to said trimer (ii) ranging from 0.05/1 to 0.70/1, and then interfacially reacting a polyamine therewith.
Claim 3
Dependent Claim
76 words
A process for microencapsulating an organic material within a polyurea skin membrane by interfacial polyaddition, which comprises emulsifying a polyisocyanato nydrophobic liquid in an essentially aqueous medium, said polyisocyanato hydrophobic liquid comprising dissolved organic material to be microencapsulated, an aliphatic diisocyanate (i), and the isocyanurate ring trimer (ii) of an aliphatic diisocyanate, the ratio by weight of said diisocyanate (i) to said trimer (ii) ranging from 0.05/1 to 0.70/1, and then interfacially reacting a polyamine therewith.
Claim 4
Dependent Claim
76 words
A process for microencapsulating an organic material within a polyurea skin membrane by interfacial polyaddition, which comprises emulsifying a polyisocyanato nydrophobic liquid in an essentially aqueous medium, said polyisocyanato hydrophobic liquid comprising dissolved organic material to be microencapsulated, an aliphatic diisocyanate (i), and the isocyanurate ring trimer (ii) of an aliphatic diisocyanate, the ratio by weight of said diisocyanate (i) to said trimer (ii) ranging from 0.05/1 to 0.70/1, and then interfacially reacting a polyamine therewith.
Claim 5
Dependent Claim
36 words
The microencapsulation process as defined by claim 2, said aliphatic diisocyanate (i) comprising 1,6-diisocyanatohexane, 1,5-diisocyanato-2-methylpentane, 1,5-diisocyanato-3-methylpentane, 1,4-diisocyanato-2,3-dimethylbutane, 2-ethyl-1,4-diisocyanatobutane, 1,5-diisocyanatopentane, 1,4-diisocyanatobutane, 1,3-diisocyanatopropane, 1,10-diisocyanatodecane, 1,2-diisocyanatocyclohexane, 1,4-diisocyanatocyclohexane, 1,2-bis(isocyanatomethyl)cyclobutane, bis(4-isocyanatocyclohexyl)methane or 3,3,5-trimethyl-5-isocyanatomethyl-1-isocyanatocyclohexane, and said trimer (ii) comprising an isocyanurate thereof.
Claim 6
Dependent Claim
24 words
The microencapsulation process as defined by claim 2, wherein the weight ratio of aliphatic diisocyanate (i) to trimer (ii) ranges from 0.10/1 to 0.45/1.
Claim 7
Dependent Claim
17 words
The microencapsulation process as defined by claim 2, said polyisocyanato hydrophobic liquid comprising 1,6-diisocyanatohexane and 1,3,5-tris(6-isocyanatohexyl) isocyanurate.
Claim 8
Dependent Claim
25 words
The microencapsulation process as defined by claim 2, said polyamine being water soluble or dispersible, and comprising at least two primary or secondary amine groups.
Claim 9
Dependent Claim
26 words
The microencapsulation process as defined by claim 6, said polyamine comprising at least one of 1,2-ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane, hydrazine, 1,4-diaminocyclohexane, 1,4-diamino-1-methylpropane, diethylenetriamine, triethylenetetramine and bis(2-methylaminoethyl)methylamine.
Claim 10
Dependent Claim
25 words
The microencapsulation process as defined by claim 2, said hydrophobic liquid being essentially water-immiscible, and both the polyisocyanate and the organic material being soluble therein.
Claim 11
Dependent Claim
34 words
The microencapsulation process as defined by claim 8, said hydrophobic liquid comprising an aliphatic hydrocarbon, a chlorinated aliphatic hydrocarbon, an alicyclic hydrocarbon, a chlorinated alicyclic hydrocarbon, an aromatic hydrocarbon or a chlorinated aromatic hydrocarbon.
Claim 12
Dependent Claim
20 words
The microencapsulation process as defined by claim 2, said hydrophobic liquid essentially consisting of the organic material to be encapsulated.
Claim 13
Dependent Claim
17 words
The microencapsulation process as defined by claim 2, said organic material to be encapsulated comprising a colorant.
Claim 14
Dependent Claim
23 words
The microencapsulation process as defined by claim 2, said hydrophobic liquid comprising an alkylbiphenyl, an at least partially hydrogenated terphenyl or an alkylnaphthalene.
Claim 15
Dependent Claim
52 words
The microencapsulation process as defined by claim 2, said emulsifying being carried out at a temperature of from 15° C. to 30° C. and said polyamine reaction being first carried out at a temperature of from 15° C. to 30° C. and then at a temperature of from 50° to 80° C.
Claim 16
Dependent Claim
35 words
The microencapsulation process as defined by claim 2, wherein the respective amounts of polyisocyanato reactants and polyamine are such that 101% to 150% of amine groups are present in stoichiometric relation to the isocyanate groups.
Claim 17
Dependent Claim
16 words
An aqueous suspension of microcapsules comprising the product of the process as defined by claim 2.
Claim 18
Dependent Claim
15 words
The aqueous suspension as defined by claim 15, said encapsulated organic material comprising a colorant.
Claim 19
Dependent Claim
22 words
The aqueous suspension as defined by claim 16, the microcapsules of which having a mean diameter of from 3 to 20 microns.
Claim 20
Dependent Claim
20 words
The aqueous suspension as defined by claim 16, having a concentration in microcapsules of at least 25% by weight thereof.
Claim 21
Dependent Claim
20 words
The aqueous suspension as defined by claim 16, having a concentration in microcapsules of at least 30% by weight thereof.
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) | 1991-04-19 | 1991-10-19 | 1992-04-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-19 | 1995-10-19 | 1996-04-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-19 | 1999-10-19 | 2000-04-19 | $7700.00 | Window Closed / Lapsed |