US4014676A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Water treatment for controlling the growth of algae employing biguanides
Assignee: Zeneca Inc
•
Filing: 1973-12-17
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Granted: 1977-03-29
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Expires: 1993-12-17
Abstract
Abstract A method of controlling the growth of bacteria and algae in the water of swimming pools by adding to the water a specified concentration of a polymeric biguanide. Has the advantage over chlorination that at the low concentration employed the polymeric biguanide is non-toxic, non-irritant, tasteless and odorless. The anti-bacterial and anti-algal effect is also highly persistent.
Inventors
- 👤 Graham Carter
- 👤 Anthony John Hinton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:00
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/50
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
38 words
A method for controlling the growth of algae in the water of swimming pools which comprises adding to the water poly(hexamethylene biguanide) hydrochloride, in an amount to provide a concentration of from 1 to 200 parts per million.
Claim 2
Independent Claim
38 words
A method for controlling the growth of algae in the water of swimming pools which comprises adding to the water poly(hexamethylene biguanide) hydrochloride, in an amount to provide a concentration of from 1 to 200 parts per million.
Claim 3
Dependent Claim
22 words
A method as claimed in claim 1 wherein the average molecular weight of the poly(hexamethylene biguanide) hydrochloride is from 1100 to 1800.
Claim 4
Dependent Claim
30 words
A method as claimed in claim 1 wherein the polymeric biguanide or salt thereof is used in an amount to provide a concentration from 4 to 12 parts per million.
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) | 1980-03-28 | 1980-09-27 | 1981-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-28 | 1984-09-27 | 1985-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-28 | 1988-09-27 | 1989-03-29 | $7700.00 | Window Closed / Lapsed |