US5160529A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microcapsules and microencapsulation process
Assignee: Imperial Chemical Industries Ltd
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Filing: 1991-02-06
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Granted: 1992-11-03
•
Expires: 2011-02-06
Abstract
Abstract Microcapsules containing a substantially water-insoluble liquid material, such as an anilide herbicide, and optionally also a herbicide antidote, within a porous shell to effect a slow rate of release of said herbicide (and optionally said antidote) through said shell, are produced by a process which comprises (a) providing an organic solution comprising said material and an etherified amino resin prepolymer dissolved therein which from about 50% to about 98% of the methylol groups of said prepolymer have been etherified with a C4-C10 alcohol; (b) creating an emulsion of said organic solution in a continuous phase aqueous solution comprising water and a surface-active agent, wherein said emulsion comprises discrete droplets of said organic solution, there being formed thereby an interface between the discrete droplets of organic solution and the surrounding continuous phase aqueous solution; and (c) causing in situ self-condensation and curing of said amino resin prepolymer in the organic phase of said discrete droplets adjacent to said interface by simultaneously heating said emulsion to a temperature between about 20 DEG C. to about 100 DEG C., and adding to said emulsion an acidifying agent and maintaining said emulsion at a pH of between about 0 to about 4 for a sufficient period of time to allow substantial completion of in situ condensation of said resin prepolymers to convert the liquid droplets of said organic solution to capsules consisting of solid permeable polymer shells enclosing said liquid material. Also disclosed are the microcapsules formed by the above-described process.
Inventors
- 👤 Herbert B. Scher
- 👤 Marius Rodson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:19
CPC Classifications
A; A01; A01N; A01N25/00; A01N25/26; A01N25/28; A01N37/00; A01N37/18; A01N37/22; A01N37/26; B; 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
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
231 words
A microencapsulated herbicidal composition comprising a substantially water-insoluble anilide herbicide within a porous shell, having a slow release of said herbicide through said shell, said composition having been prepared by a process comprising: a) providing an organic solution comprising said herbicide and an etherified amino resin prepolymer dissolved therein in which from about 50% to about 98% of the methylol groups of said prepolymer have been etherified with a C 4 -C10 alcohol; b) creating an emulsion of said organic solution in a continuous phase aqueous solution comprising water and a surface-active agent, wherein said emulsion comprises discrete droplets of said organic solution dispersed in said continuous phase aqueous solution, there being formed thereby an interface between the discrete droplets of organic solution and the surrounding continuous phase aqueous solution; and c) causing in situ self-condensation and curing of said amino resin prepolymer in the organic phase of said discrete droplets adjacent to said interface by simultaneously heating said emulsion to a temperature between about 20° C. to about 100° C., and adding to said emulsion an acidifying agent and maintaining said emulsion at a pH of between about 0 to about 4 for a sufficient period of time to allow substantial completion of in situ condensation of said resin prepolymers to convert the liquid droplets of said organic solution to capsules consisting of solid permeable polymer shells enclosing said herbicide.
Claim 2
Dependent Claim
231 words
A microencapsulated herbicidal composition comprising a substantially water-insoluble anilide herbicide within a porous shell, having a slow release of said herbicide through said shell, said composition having been prepared by a process comprising: a) providing an organic solution comprising said herbicide and an etherified amino resin prepolymer dissolved therein in which from about 50% to about 98% of the methylol groups of said prepolymer have been etherified with a C 4 -C10 alcohol; b) creating an emulsion of said organic solution in a continuous phase aqueous solution comprising water and a surface-active agent, wherein said emulsion comprises discrete droplets of said organic solution dispersed in said continuous phase aqueous solution, there being formed thereby an interface between the discrete droplets of organic solution and the surrounding continuous phase aqueous solution; and c) causing in situ self-condensation and curing of said amino resin prepolymer in the organic phase of said discrete droplets adjacent to said interface by simultaneously heating said emulsion to a temperature between about 20° C. to about 100° C., and adding to said emulsion an acidifying agent and maintaining said emulsion at a pH of between about 0 to about 4 for a sufficient period of time to allow substantial completion of in situ condensation of said resin prepolymers to convert the liquid droplets of said organic solution to capsules consisting of solid permeable polymer shells enclosing said herbicide.
Claim 3
Dependent Claim
14 words
A composition according to claim 1 in which the herbicide is an α-haloacetanilide herbicide.
Claim 4
Dependent Claim
15 words
A composition according to claim 2 wherein the amino resin prepolymer is a urea-formaldehyde prepolymer.
Claim 5
Dependent Claim
15 words
A composition according to claim 2 wherein the amino resin prepolymer is a melamine-formaldehyde prepolymer.
Claim 6
Dependent Claim
64 words
A composition according to claim 1 in which the herbicide has the formula ##STR3## in which X is halogen; R 4 is one or more of C 1 -C 6 alkyl, C 1 -C 6 alkoxy, or halogen; n is 0 or an integer from 1 to 5; and R 5 is C 1 -C 6 alkyl, C 2 -C 8 alkoxyalkyl or pyrazol-1-methyl.
Claim 7
Dependent Claim
36 words
A composition according to claim 5 in which n is 0 or 2; and when n is 2, then R is 2,6-di(C 1 -C 4 alkyl) in which the alkyl groups are the same or different.
Claim 8
Dependent Claim
20 words
A composition according to claim 1 in which the herbicide is metolachlor, butachlor, alachlor, acetochlor, metazochlor, pretilachlor, dimethachlor or propachlor.
Claim 9
Dependent Claim
12 words
A composition according to claim 1 in which the herbicide is acetochlor.
Claim 10
Dependent Claim
15 words
A composition according to claim 8 wherein the amino resin prepolymer is a urea-formaldehyde prepolymer.
Claim 11
Dependent Claim
15 words
A composition according to claim 8 wherein the amino resin prepolymer is a melamine-formaldehyde prepolymer.
Claim 12
Dependent Claim
20 words
A composition according to claim 8 in which the alcohol with which the methylol groups have been etherified is n-butanol.
Claim 13
Dependent Claim
19 words
A composition according to claim 1 which further comprises a herbicide antidote suitable for use with a haloacetanilide herbicide.
Claim 14
Dependent Claim
20 words
A composition according to claim 12 in which the antidote is a dichloroacetamide antidote, a dioxolane antidote or 1,8-naphtalic anhydride.
Claim 15
Dependent Claim
15 words
A composition according to claim 12 wherein the amino resin prepolymer is a urea-formaldehyde prepolymer.
Claim 16
Dependent Claim
20 words
A composition according to claim 14 in which the antidote is a dichloroacetamide antidote, a dioxolane antidote or 1,8-naphthalic anhydride.
Claim 17
Dependent Claim
15 words
A composition according to claim 12 wherein the amino resin prepolymer is a melamine-formaldehyde prepolymer.
Claim 18
Dependent Claim
19 words
A composition according to claim 1 wherein the amino resin prepolymer is a urea-formaldehyde, melamine-formaldehyde, benzoguanamine-formaldehyde or glycoluril-formaldehyde prepolymer.
Claim 19
Dependent Claim
17 words
A composition according to claim 1 wherein the amino resin prepolymer is a urea-formaldehyde or melamine-formaldehyde prepolymer.
Claim 20
Dependent Claim
15 words
A composition according to claim 1 wherein the amino resin prepolymer is a urea-formaldehyde prepolymer.
Claim 21
Dependent Claim
15 words
A composition according to claim 19 in which the wall-modifying agent is pentaerythritol tetrakis (mercaptopropionate).
Claim 22
Dependent Claim
15 words
A composition according to claim 1 wherein the amino resin prepolymer is a melamine-formaldehyde prepolymer.
Claim 23
Dependent Claim
24 words
A composition according to claim 1 in which from about 70% to about 90% of the methylol groups of the prepolymer have been etherified.
Claim 24
Dependent Claim
25 words
A composition according to claim 1 in which the alcohol with which the methylol groups of the prepolymer have been etherified is n-butanol or isobutanol.
Claim 25
Dependent Claim
19 words
A composition according to claim 1 in which the aqueous solution of step (b) further comprises a protective colloid.
Claim 26
Dependent Claim
23 words
A composition according to claim 1 in which the prepolymer comprises from about 1 to about 70 weight percent of the organic solution.
Claim 27
Dependent Claim
41 words
A composition according to claim 1 in which the in situ self-condensation in step (c) is carried out at a pH of between about 1.0 and about 3.0 and at a temperature of between about 40° C. and about 70° C.
Claim 28
Dependent Claim
31 words
A composition according to claim 1 in which the organic solution contains a wall-modifying agent which serves to modify the character of the wall by varying its permeability to the herbicide.
Claim 29
Dependent Claim
227 words
A process for the microencapsulation of a substantially water-insoluble anilide herbicide within a porous shell to effect a slow release of said herbicide through said shell which comprises: a) providing an organic solution comprising said herbicide and an etherified amino resin prepolymer dissolved therein in which from about 50% to about 98% of the methylol groups of said prepolymer have been etherified with a C 4 -C 10 alcohol; b) creating an emulsion of said organic solution in a continuous phase aqueous solution comprising water and a surface-active agent, wherein said emulsion comprises discrete droplets of said organic solution dispersed in said continuous phase aqueous solution, there being formed thereby an interface between the discrete droplets of organic solution and the surrounding continuous phase aqueous solution; and c) causing in situ self-condensation and curing of said amino resin prepolymer in the organic phase of said discrete droplets adjacent to said interface by simultaneously heating said emulsion to a temperature between about 20° C. to about 100° C., and adding to said emulsion an acidifying agent and maintaining said emulsion at a pH of between about 0 to about 4 for a sufficient period of time to allow substantial completion of in situ condensation of said resin prepolymers to convert the liquid droplets of said organic solution to capsules consisting of solid permeable polymer shells enclosing said herbicide.
Claim 30
Dependent Claim
227 words
A process for the microencapsulation of a substantially water-insoluble anilide herbicide within a porous shell to effect a slow release of said herbicide through said shell which comprises: a) providing an organic solution comprising said herbicide and an etherified amino resin prepolymer dissolved therein in which from about 50% to about 98% of the methylol groups of said prepolymer have been etherified with a C 4 -C 10 alcohol; b) creating an emulsion of said organic solution in a continuous phase aqueous solution comprising water and a surface-active agent, wherein said emulsion comprises discrete droplets of said organic solution dispersed in said continuous phase aqueous solution, there being formed thereby an interface between the discrete droplets of organic solution and the surrounding continuous phase aqueous solution; and c) causing in situ self-condensation and curing of said amino resin prepolymer in the organic phase of said discrete droplets adjacent to said interface by simultaneously heating said emulsion to a temperature between about 20° C. to about 100° C., and adding to said emulsion an acidifying agent and maintaining said emulsion at a pH of between about 0 to about 4 for a sufficient period of time to allow substantial completion of in situ condensation of said resin prepolymers to convert the liquid droplets of said organic solution to capsules consisting of solid permeable polymer shells enclosing said herbicide.
Claim 31
Dependent Claim
14 words
A process according to claim 28 in which the herbicide is an α-haloacetanilide herbicide.
Claim 32
Dependent Claim
16 words
A process according to claim 28 in which the amino resin prepolymer is a urea-formaldehyde prepolymer.
Claim 33
Dependent Claim
16 words
A process according to claim 28 in which the amino resin prepolymer is a melamine-formaldehyde prepolymer.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-11-03 | 1996-05-04 | 1996-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-11-03 | 2000-05-04 | 2000-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-11-03 | 2004-05-04 | 2004-11-03 | $7700.00 | Window Closed / Lapsed |