US4340491A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cold water-insoluble polyvinyl alcohol pouch for the controlled release of active ingredients
Assignee: Reckitt and Colman North America Inc
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Filing: 1981-05-08
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Granted: 1982-07-20
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Expires: 2001-05-08
Abstract
Abstract A pouch for the controlled release of active ingredients into an aqueous medium comprising liquid or solid active ingredients enclosed in a sealed envelope of cold water-insoluble polyvinyl alcohol.
Inventors
- 👤 Ping I. Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:23
CPC Classifications
C; C11; C11D; C11D17/00; C11D17/04; C11D17/041; C11D17/042; C02; C02F; C02F1/00; C02F1/50; C02F1/68; C02F1/685; C02F1/688
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
110 words
A sealed pouch for the controlled release of active ingredient into an aqueous medium having a maximum temperature of 60° C. consisting of an envelope of cold water-insoluble polyvinyl alcohol in film form, said polyvinyl alcohol being at least about 99% hydrolyzed and having a minimum degree of swelling in water of about 120%, and enclosed therein an effective amount of an active ingredient having at least a minimum solubility in water, the pH of the aqueous medium containing said active ingredient being in the range of from 2.5-10.0; said sealed pouch having a maximum ratio of weight of active ingredient to pouch volume of about 50 lb/ft 3 .
Claim 2
Dependent Claim
110 words
A sealed pouch for the controlled release of active ingredient into an aqueous medium having a maximum temperature of 60° C. consisting of an envelope of cold water-insoluble polyvinyl alcohol in film form, said polyvinyl alcohol being at least about 99% hydrolyzed and having a minimum degree of swelling in water of about 120%, and enclosed therein an effective amount of an active ingredient having at least a minimum solubility in water, the pH of the aqueous medium containing said active ingredient being in the range of from 2.5-10.0; said sealed pouch having a maximum ratio of weight of active ingredient to pouch volume of about 50 lb/ft 3 .
Claim 3
Dependent Claim
24 words
The pouch of claim 1, wherein said active ingredient is selected from the group consisting of detergents, non-chlorinated bleaches, pesticides, drugs, bactericides and dyes.
Claim 4
Dependent Claim
12 words
The pouch of claim 2, wherein said active ingredient is a bactericide.
Claim 5
Dependent Claim
11 words
The pouch of claim 1, wherein said pH range is 4.0-10.0.
Claim 6
Independent Claim
160 words
A method for the controlled release of active ingredient into an aqueous medium having a maximum temperature of 60° C. consisting of the steps of (1) preparing a sealed pouch of cold water-insoluble polyvinyl alcohol in film form, said polyvinyl alcohol being at least about 99% hydrolyzed and having a minimum degree of swelling in water of about 120%, and enclosed therein an effective amount of an active ingredient having at least a minimum solubility in water; said sealed pouch having a maximum ratio of weight of active ingredient to pouch volume of about 50 lb/ft 3 ; (2) introducing said sealed pouch into said aqueous medium; (3) swelling said polyvinyl alcohol film; (4) introducing the aqueous medium into said pouch to dissolve said active ingredient; the aqueous medium containing said active ingredient having a pH in the range of 2.5-10.0; and (5) allowing said active ingredient to diffuse through said swollen film and be released into said aqueous medium.
Claim 7
Independent Claim
160 words
A method for the controlled release of active ingredient into an aqueous medium having a maximum temperature of 60° C. consisting of the steps of (1) preparing a sealed pouch of cold water-insoluble polyvinyl alcohol in film form, said polyvinyl alcohol being at least about 99% hydrolyzed and having a minimum degree of swelling in water of about 120%, and enclosed therein an effective amount of an active ingredient having at least a minimum solubility in water; said sealed pouch having a maximum ratio of weight of active ingredient to pouch volume of about 50 lb/ft 3 ; (2) introducing said sealed pouch into said aqueous medium; (3) swelling said polyvinyl alcohol film; (4) introducing the aqueous medium into said pouch to dissolve said active ingredient; the aqueous medium containing said active ingredient having a pH in the range of 2.5-10.0; and (5) allowing said active ingredient to diffuse through said swollen film and be released into said aqueous medium.
Claim 8
Dependent Claim
24 words
The method of claim 5, wherein said active ingredient is selected from the group consisting of detergents, non-chlorinated bleaches, pesticides, drugs, bactericides and dyes.
Claim 9
Dependent Claim
12 words
The method of claim 6, wherein said active ingredient is a bactericide.
Claim 10
Dependent Claim
11 words
The method of claim 5, wherein said pH range is 4.0-10.0.
Claim 11
Dependent Claim
24 words
The method of claim 5, wherein introduction step (4) is on a non-continuous basis so as to provide intermittent diffusion according to step (5).
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) | 1985-07-19 | 1986-01-18 | 1986-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-07-19 | 1990-01-18 | 1990-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-07-19 | 1994-01-18 | 1994-07-20 | $7700.00 | Window Closed / Lapsed |