Patent US4019889A successfully refreshed from Google Patents.
US4019889A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Slow acting fertilizer
Assignee: ESTECH BRANDED FERTILIZERS Inc A DE CORP
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Filing: 1975-07-21
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Granted: 1977-04-26
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Expires: 1995-07-21
Abstract
Abstract Fertilizer compositions which are slowly and uniformly leached and made available to the plant over a relatively long period of time resulting in more efficient utilization of the fertilizer by the plant are provided by bonding fertilizer material with the hemihydrate of calcium sulfate.
Inventors
- 👤 Joseph P. Kealy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:13
CPC Classifications
C; C05; C05B; C05B17/00; C05G; C05G5/00; C05G5/30; C05G5/35
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
130 words
A method for producing granular pellets of about 2 mm to about 25 mm having slow release characteristics and particularly useful for garden line plants which comprises charging plant food containing isobutylidene diurea and vitreous masses of P 2 O 5 into a mixer, steaming the plant food to a temperature of about 140° F. to 210° F. so as to give a moisture content of between about 2% and about 8%, charging calcium sulfate hemihydrate into the mixer in an amount such that the ultimate pellets contain about 10-50%, by weight, of hydrated calcium sulfate and about 90-50%, by weight, of plant food, adding hot water to the charged mixture in an amount sufficient for crystallization of the calcium sulfate, forming a granuable mixture and subsequently drying the granules.
Claim 2
Independent Claim
130 words
A method for producing granular pellets of about 2 mm to about 25 mm having slow release characteristics and particularly useful for garden line plants which comprises charging plant food containing isobutylidene diurea and vitreous masses of P 2 O 5 into a mixer, steaming the plant food to a temperature of about 140° F. to 210° F. so as to give a moisture content of between about 2% and about 8%, charging calcium sulfate hemihydrate into the mixer in an amount such that the ultimate pellets contain about 10-50%, by weight, of hydrated calcium sulfate and about 90-50%, by weight, of plant food, adding hot water to the charged mixture in an amount sufficient for crystallization of the calcium sulfate, forming a granuable mixture and subsequently drying the granules.
Claim 3
Dependent Claim
35 words
The process of claim 1 wherein the vitreous matrix comprises about 1 to 20% K 2 O and about 1% to 20% K 2 O and about 1% to 25% P 2 O 5 .
Claim 4
Dependent Claim
26 words
The process of claim 2 wherein the plant food is steam treated for about 1 to 3 minutes before being contacted with the calcium sulfate hemihydrate.
Claim 5
Dependent Claim
25 words
The method of claim 1 wherein the calcium sulfate hemihydrate is crystallized by means of water having a temperature in excess of about 150° F.
Claim 6
Dependent Claim
19 words
The method of claim 4 wherein the water is in the range of about 170° F. to 210° F.
Claim 7
Dependent Claim
13 words
The method of claim 1 wherein the granuable mixture is also steam treated.
Claim 8
Dependent Claim
23 words
The method of claim 1 wherein a holding time of about 10 to 15 minutes is employed before the granules are tumble dried.
References Cited (Backward Citations)
GB949408A
Cited
US3149956A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-25 | 1980-10-25 | 1981-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-25 | 1984-10-25 | 1985-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-25 | 1988-10-25 | 1989-04-26 | $7700.00 | Window Closed / Lapsed |