Patent US4093556A successfully refreshed from Google Patents.
US4093556A
Expired / Lapsed
US
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Process for microencapsulation of metallocenes
Assignee: Henkel Loctite Corp
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Filing: 1975-07-02
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Granted: 1978-06-06
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Expires: 1995-07-02
Abstract
Abstract A process for producing metallocenes encapsulated by a urea-formaldehyde polymer shell. The presence of a small amount of a cationic surfactant, preferably an alkyl hydroxy amine, is required during the condensation polymerization which forms the shell.
Inventors
- 👤 Stanley Wojciak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:30
CPC Classifications
B; B01; B01J; B01J13/00; B01J13/02; B01J13/06; B01J13/14; B01J13/18; C; C07; C07F; C07F17/00; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2989
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
174 words
A process for microencapsulating a water-insoluble metallocene comprising: (a) providing an aqueous solution of a water-soluble precondensate of urea and formaldehyde wherein the precondensate concentration is about 15 to about 50 percent by weight; (b) adding to said precondensate solution a particulate metallocene in such amount that the weight ratio of metallocene to precondensate is between about 1:1 and about 8:1; (c) adding to said precondensate solution or the mixture of said precondensate solution with said metallocene a cationic surfactant in such amount that the weight ratio of surfactant to metallocene is between about 1:6,000 and about 1:10 said surfactant having the formula t-C 18-22 H 37-45 NHCH 2 CH 2 OH (d) forming a slurry of the metallocene; (e) adjusting the pH of the resultant dispersion to about 1 to about 6.5 by addition of a water-soluble acid, thereby causing polymerization of said precondensate, and (f) continuing said polymerization in the temperature range of about 15° to about 80° C. until said metallocene particles are encapsulated with a shell of water-insoluble urea-formaldehyde polymer.
Claim 2
Dependent Claim
174 words
A process for microencapsulating a water-insoluble metallocene comprising: (a) providing an aqueous solution of a water-soluble precondensate of urea and formaldehyde wherein the precondensate concentration is about 15 to about 50 percent by weight; (b) adding to said precondensate solution a particulate metallocene in such amount that the weight ratio of metallocene to precondensate is between about 1:1 and about 8:1; (c) adding to said precondensate solution or the mixture of said precondensate solution with said metallocene a cationic surfactant in such amount that the weight ratio of surfactant to metallocene is between about 1:6,000 and about 1:10 said surfactant having the formula t-C 18-22 H 37-45 NHCH 2 CH 2 OH (d) forming a slurry of the metallocene; (e) adjusting the pH of the resultant dispersion to about 1 to about 6.5 by addition of a water-soluble acid, thereby causing polymerization of said precondensate, and (f) continuing said polymerization in the temperature range of about 15° to about 80° C. until said metallocene particles are encapsulated with a shell of water-insoluble urea-formaldehyde polymer.
Claim 3
Dependent Claim
26 words
A process of claim 1 wherein the weight ratio of urea to formaldehyde in the precondensate is in the range of about 0.9:1 to about 1.8:1.
Claim 4
Dependent Claim
23 words
A process of claim 2 wherein the concentration of the precondensate in its aqueous solution is about 25 to about 35% by weight.
Claim 5
Dependent Claim
21 words
A process of claim 3 wherein the weight ratio of the metallocene to the precondensate is about 1.1:1 to about 3:1.
Claim 6
Dependent Claim
22 words
A process of claim 4 wherein the weight ratio of the cationic surfactant to the metallocene is about 1:5,000 to about 1:1,000.
Claim 7
Dependent Claim
16 words
A process of claim 5 wherein the pH is adjusted to about 2 to about 3.
Claim 8
Dependent Claim
20 words
A process of claim 6 wherein the polymerization is performed at a temperature of about 20° to about 45° C.
Claim 9
Dependent Claim
18 words
A process of claim 1 wherein the slurry is neutralized prior to recovery of the encapsulated metallocene particles.
Claim 10
Dependent Claim
10 words
A process of claim 1 wherein the metallocene is ferrocene.
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) | 1981-06-05 | 1981-12-05 | 1982-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-05 | 1985-12-05 | 1986-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-05 | 1989-12-05 | 1990-06-06 | $7700.00 | Window Closed / Lapsed |