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US4089899A Expired / Lapsed US ⏱️ 0.0 years remaining

Fertilizer compound of the ureaform type and a method for the production thereof

Assignee: Fertilizers and Chemicals Ltd
•
Filing: 1976-03-26
•
Granted: 1978-05-16
•
Expires: 1996-03-26
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Abstract

Abstract The present invention relates to a new fertilizer compound of the ureaform type and to a method for the production thereof. The new ureaform compound is characterized by the low average degree of polymerization between urea and formaldehyde. The new compound has a nitrogen content of over 41% by weight and consists of cold water soluble nitrogen as the main fraction and cold water insoluble as the second fraction which is substantially free of hot water insoluble nitrogen. The new ureaform compound is obtained by the condensation of urea and formaldehyde at a correct ratio between the reagents and termination of the reaction at a stage wherein excessive polymerization is prevented. The reaction is carried out in a controlled system with a pH in the range of 3.5 to 4.2. Particularly useful are the systems H 3 PO 4 -KH 2 PO 4 and H 3 PO 4 -NH 4 H 2 PO 4 . The new compound successfully combines the advantage of both mineral water soluble nitrogen fertilizers and organic water insoluble slow-release nitrogen sources.

Inventors

  • 👤 Dahlia Simeona Greidinger
  • 👤 Liuba Cohen

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 06:31
CPC Classifications
C; C05; C05C; C05C9/00; C05C9/02

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 133 words
A new compound of ureaform type prepared at a controlled reaction system, comprising the acid condensation of urea and formaldehyde, being characterized by a nitrogen content of over 41% by weight, consisting of cold water soluble nitrogen of about 60% of the total nitrogen as the main fraction and cold water insoluble nitrogen as the second fraction of about 40% of the total nitrogen and which is substantially free of hot water insoluble nitrogen and further characterized by the average degree of polymerization between the urea and formaldehyde residues being about 3 to 2 and not lower than 4 to 3, the overall concentration of the starting reagents being between 20% and about 40% by weight and the reaction being terminated prior to the formation of methylene urea products higher than tetramethylene pentaurea.
Claim 2
Dependent Claim 133 words
A new compound of ureaform type prepared at a controlled reaction system, comprising the acid condensation of urea and formaldehyde, being characterized by a nitrogen content of over 41% by weight, consisting of cold water soluble nitrogen of about 60% of the total nitrogen as the main fraction and cold water insoluble nitrogen as the second fraction of about 40% of the total nitrogen and which is substantially free of hot water insoluble nitrogen and further characterized by the average degree of polymerization between the urea and formaldehyde residues being about 3 to 2 and not lower than 4 to 3, the overall concentration of the starting reagents being between 20% and about 40% by weight and the reaction being terminated prior to the formation of methylene urea products higher than tetramethylene pentaurea.
Claim 3
Dependent Claim 27 words
A new compound of ureaform according to claim 1, which has the following analysis: Total Nitrogen: 41-43% Cold Water Insoluble Nitrogen: 16-18% Hot Water Insoluble Nitrogen: 0-2%.
Claim 4
Dependent Claim 65 words
A method for the production of a new compound of ureaform according to claim 1, which comprises the acid condensation of urea and formaldehyde at a temperature of about 20°-40° C, being characterized by terminating the condensation prior to the formation of methylene urea products higher than tetramethylene pentaurea wherein the overall concentration of the starting reagents is between 20% to about 40% by weight.
Claim 5
Dependent Claim 28 words
A method for the production of a new compound of ureaform type according to claim 3, carried out by the dilute solution process or the concentrated solution process.
Claim 6
Dependent Claim 36 words
A method for the production of a new compound of ureaform type according to claim 3, wherein the ratio of the starting reagents is between 3 to 2 moles urea to 2 to 1 mole formaldehyde.
Claim 7
Dependent Claim 32 words
A method for the production of a new compound of ureaform type according to claim 3, wherein the pH of the reaction system is controlled in the range of 3.5 to 4.2.

References Cited (Backward Citations)

US2415705A Cited
US2502996A Cited
US2592809A Cited
US2644806A Cited
US2766283A Cited
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US2916371A Cited
US3150955A Cited
US3231363A Cited
US3870755A Cited
US3333940A Cited
US3712879A Cited
US3759687A Cited
US3970625A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1981-05-15 1981-11-14 1982-05-16 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1985-05-15 1985-11-14 1986-05-16 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1989-05-15 1989-11-14 1990-05-16 $7700.00 Window Closed / Lapsed

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