US4023955A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Controlled release fertilizer
Assignee: Lafarge North America Inc
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Filing: 1974-10-04
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Granted: 1977-05-17
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Expires: 1994-10-04
Abstract
Abstract A solid controlled release fertilizer of a discrete particle of a fertilizer material encapsulated within a coating of partially hydrated cement is provided. In a preferred embodiment, the partially hydrated cement coated fertilizer particle is encapsulated within a thin semipermeable elastomer coating. In another embodiment, the thin semipermeable elastomer is in turn encapsulated within a second partially hydrated cement coating which contains micronutrient trace elements.
Inventors
- 👤 Otto H. Mueller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:50
CPC Classifications
C; C05; C05C; C05C9/00; C05G; C05G5/00; C05G5/30
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
72 words
A solid controlled release fertilizer comprising a discrete particle of fertilizer material having: a. a substantially uniform first coating of a cement partially hydrated with up to about 30 weight percent water; b. a substantially uniform second coating around said first coating of a thin semipermeable elastomer; and c. a substantially uniform third coating around said second coating of a partially hydrated homogeneous cement-fertilizer mixer containing thoroughly dispersed therein micronutrient trace elements.
Claim 2
Dependent Claim
72 words
A solid controlled release fertilizer comprising a discrete particle of fertilizer material having: a. a substantially uniform first coating of a cement partially hydrated with up to about 30 weight percent water; b. a substantially uniform second coating around said first coating of a thin semipermeable elastomer; and c. a substantially uniform third coating around said second coating of a partially hydrated homogeneous cement-fertilizer mixer containing thoroughly dispersed therein micronutrient trace elements.
Claim 3
Dependent Claim
42 words
The fertilizer of claim 1 wherein said cement-fertilizer coating contains cement selected from a group consisting of masonry cement, Portland cement and masonry cement containing lime; and wherein both of the first and third coatings contain thoroughly dispersed therein micronutrient trace elements.
Claim 4
Dependent Claim
49 words
The fertilizer of claim 1 wherein the extent of hydration does not exceed that hydration effected by addition of fine droplets of water to a nonhydrated cement powder wherein said water is present in amounts from about 2% to about 6% by weight based on the cement component only.
Claim 5
Dependent Claim
33 words
The fertilizer of claim 3 wherein said cement is Portland cement and wherein said water is present in amounts from about 3% to about 6% by weight based on the cement component only.
Claim 6
Dependent Claim
33 words
The fertilizer of claim 3 wherein the cement is masonry cement and wherein said water is present in amounts from about 2% to about 41/2% by weight based on the cement component only.
Claim 7
Dependent Claim
21 words
The fertilizer of claim 3 wherein said elastomer is selected from a group consisting of styrenebutadiene, acrylic esters, and alkyd resins.
Claim 8
Dependent Claim
79 words
A process of manufacturing a controlled release fertilizer comprising: a. coating a discrete particle of fertilizer material with a substantially uniform first coating of cement partially hydrated with up to about 30 weight percent water; b. coating the fertilizer particle of step (a) with a substantially uniform second coating of semipermeable elastomer; and c. coating the fertilizer particle of step (b) with a substantially uniform third coating of a homogeneous mixture of a partially hydrated cement and a fertilizer.
Claim 9
Dependent Claim
79 words
A process of manufacturing a controlled release fertilizer comprising: a. coating a discrete particle of fertilizer material with a substantially uniform first coating of cement partially hydrated with up to about 30 weight percent water; b. coating the fertilizer particle of step (a) with a substantially uniform second coating of semipermeable elastomer; and c. coating the fertilizer particle of step (b) with a substantially uniform third coating of a homogeneous mixture of a partially hydrated cement and a fertilizer.
Claim 10
Dependent Claim
33 words
The process of claim 7 wherein said homogeneous mixture contains cement selected from a group consisting of masonry cement, Portland cement and masonry cement containing lime and a fertilizer of micronutrient trace elements.
Claim 11
Dependent Claim
59 words
The process of claim 8 wherein the third coating is accomplished by intimately contacting said fertilizer particle of step (b) with an effective amount of a non-hydrated cement micronutrient powder mixture in the presence of fine droplets of water, said water being present in amounts from about 2% to about 6% by weight based on the cement component only.
Claim 12
Dependent Claim
43 words
The process of claim 9 wherein masonry cement is present in the amount of about 22 lbs. of masonry cement per 100 lbs. of fertilizer, and micronutrients are present in the amount of about 50% by weight based upon the cement component only.
Claim 13
Dependent Claim
26 words
The process of claim 9 wherein said water is present in amounts from about 2% to about 41/2% by weight based on the cement component only.
Claim 14
Dependent Claim
9 words
The product produced by the process of claim 11.
Claim 15
Dependent Claim
42 words
The process of claim 9 wherein Portland cement is present in amounts of about 7 lbs. of Portland cement per 100 lbs. of fertilizer and micronutrients are present in the amount of about 50% by weight based on the cement component only.
Claim 16
Dependent Claim
26 words
The process of claim 13 wherein said water is present in amounts from about 3% to about 6% by weight based on the cement component only.
Claim 17
Dependent Claim
9 words
The product produced by the process of claim 14.
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) | 1980-05-16 | 1980-11-15 | 1981-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-16 | 1984-11-15 | 1985-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-16 | 1988-11-15 | 1989-05-17 | $7700.00 | Window Closed / Lapsed |