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US4123248A Expired / Lapsed US ⏱️ 0.0 years remaining

Controlled release fertilizer

Assignee: International Standard Electric Corp
•
Filing: 1977-08-25
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Granted: 1978-10-31
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Expires: 1997-08-25
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Abstract

Abstract A biologically active slow release medium consisting of vitreous matrix including one or more water soluble biologically active constituents together with phosphorus pentoxide which vitreous matrix may include one or more dispersed phases, the vitreous matrix having a slow rate of solution in water, such that when the medium is immersed in water biologically active constituents are slowly released into solution. Nitrogen releasing material is also incorporated into the vitreous (glass) matrix, using an inorganic material that can be added to a melt of the glass to be formed.

Inventors

  • 👤 Cyril F. Drake

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 16:22
CPC Classifications
C; C03; C03C; C03C4/00; C03C4/0035; C05; C05B; C05B17/00

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 92 words
A slow release fertilizer composition comprising a vitreous matrix including a water soluble nitrogen source fertilizer material, a glass modifier, and as a glass former, phosphorous pentoxide, all within the matrix; the vitreous matrix including one or more inorganic oxide phases dispersed therein, the vitreous matrix having a low rate of solution in water such that when the composition is immersed in water the fertilizer is slowly released into solution, wherein said nitrogen source fertilizer material is an inorganic nitrogen containing compound stable at the fusing temperature of the glass being formed.
Claim 2
Dependent Claim 92 words
A slow release fertilizer composition comprising a vitreous matrix including a water soluble nitrogen source fertilizer material, a glass modifier, and as a glass former, phosphorous pentoxide, all within the matrix; the vitreous matrix including one or more inorganic oxide phases dispersed therein, the vitreous matrix having a low rate of solution in water such that when the composition is immersed in water the fertilizer is slowly released into solution, wherein said nitrogen source fertilizer material is an inorganic nitrogen containing compound stable at the fusing temperature of the glass being formed.
Claim 3
Dependent Claim 20 words
A fertilizer composition as claimed in claim 1 wherein the nitrogen source included in the fertilizer composition is calcium cyanamide.
Claim 4
Dependent Claim 22 words
A fertilizer composition as claimed in claim 1 wherein the nitrogen source included in the fertilizer composition is a hydrocyanic acid polymer.
Claim 5
Dependent Claim 39 words
A fertilizer composition as claimed in claim 1 wherein the nitrogen containing constituent is present in powder form, at least some of the particles of which are buffered from the vitreous matrix by a lower melting point metaphosphate coating.
Claim 6
Dependent Claim 16 words
A fertilizer composition as claimed in claim 1 wherein the fertilizer composition contains trace nutrient elements.
Claim 7
Dependent Claim 37 words
A fertilizer composition as claimed in claim 1 wherein the fertilizer composition contains one or more trace elements that are assimilable in plants which when eaten by livestock are biologically active in the prevention of deficiency diseases.
Claim 8
Dependent Claim 18 words
A fertilizer composition as claimed in claim 1 wherein the fertilizer composition contains one or more inorganic fungicides.
Claim 9
Dependent Claim 18 words
A fertilizer composition as claimed in claim 1 which is in powder form for application as a fertilizer.
Claim 10
Dependent Claim 18 words
A fertilizer powder as claimed in claim 8 which is a blend of two or more fertilizer compositions.
Claim 11
Dependent Claim 21 words
A fertilizer powder as claimed in claim 9 wherein the powder comprises particles which have a surface coating of boron phosphate.
Claim 12
Dependent Claim 29 words
A method of treatment of growing plants which method includes the application to the soil in which the plants are growing of a fertilizer as claimed in claim 8.

References Cited (Backward Citations)

US2732290A Cited
US973019A Cited
US2192939A Cited
US2806773A Cited
US3441400A Cited
US3672945A Cited
US3624692A Cited
US3762909A Cited
US3958973A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1981-10-30 1982-05-01 1982-10-31 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1985-10-30 1986-05-01 1986-10-31 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1989-10-30 1990-05-01 1990-10-31 $7700.00 Window Closed / Lapsed

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