US3887511A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Urea-HCHO-dicyndiamide-oxy acid of phosphorus fire-retardant formulation and products
Assignee: HER MAJESTY IN RIGHT OF CANADA FORESTRY, Minister of
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Filing: 1972-11-30
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Granted: 1975-06-03
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Expires: 1992-11-30
Abstract
Abstract A stable fire-retardant formulation for use on wood and other cellulosic products is formed from a urea (about 1-10 moles) and dicyandiamide (about 1-11 moles) partially reacted in aqueous solution of pH about 7.5 to 9 with formaldehyde at from about 60* to 90*C until a clear solution is obtained. This incompletely-reacted clear solution is cooled to below 50*C preferably about 25* to 35*C and mixed with an oxy-acid of phosphorus to give a formulation suitable for impregnation and having a long storage-or pot-life. The amount of formaldehyde should be about 1.2 to 3 moles and the amount of the P acid from about 0.5 to 2 moles, both per mole of urea plus dicyandiamide. The resin can be cured and insolubilized by heating to about 50*-110*C e.g. in situ in the cellulosic product. The product has leach resistant flame-retardancy, glow and decay resistance, and is non-blooming. The natural appearance of wood is not altered by the treatment.
Inventors
- 👤 Subhash C Juneja
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:10
CPC Classifications
C; C08; C08G; C08G12/00; C08G12/02; C08G12/40; B; B27; B27K; B27K2240/00; B27K2240/30; B27K3/00; B27K3/02; B27K3/15; B27K3/153
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
127 words
An aqueous liquid composition comprising an intermediate-stage resin solution formed by reacting: a. a urea b. dicyandiamide c. formaldehyde and d. oxy-acid of phosphorus; in the following relative amounts: a. about 1-10 moles b. about 1-11 moles c. about 1.2-3 moles per mole of (a) plus (b) and d. about 0.5-2 moles per mole of (a) plus (b); which reaction comprises dissolving (a) and (b) in an aqueous solution of (c) having a pH of about 7.5 to 9 and temperature of about 60* to 90*C, cooling to below about 50*C, and slowly adding (d), the solution having present excess or unreacted formaldehyde, acid in amounts sufficient to give an initial pH not significantly above about 3 and having a pot-life of at least about 1 month.
Claim 2
Dependent Claim
127 words
An aqueous liquid composition comprising an intermediate-stage resin solution formed by reacting: a. a urea b. dicyandiamide c. formaldehyde and d. oxy-acid of phosphorus; in the following relative amounts: a. about 1-10 moles b. about 1-11 moles c. about 1.2-3 moles per mole of (a) plus (b) and d. about 0.5-2 moles per mole of (a) plus (b); which reaction comprises dissolving (a) and (b) in an aqueous solution of (c) having a pH of about 7.5 to 9 and temperature of about 60* to 90*C, cooling to below about 50*C, and slowly adding (d), the solution having present excess or unreacted formaldehyde, acid in amounts sufficient to give an initial pH not significantly above about 3 and having a pot-life of at least about 1 month.
Claim 3
Dependent Claim
126 words
AN AQUEOUS LIQUID COMPOSITION COMPRISING AN INTERMEDIATE-STAGE RESIN SOLUTION FORMED BY REACTING: A. A UREA B. DICYANDIAMIDE C. DORMALDEHYDE AND D. OXY-ACID OF PHOSPHOURS; IN THE FOLLOWING RELATIVE AMOUNTS: A. ABOUT 1-10 MOLES B. ABOUT 1-11 MOLES C. ABOUT 1.2-3 MOLES PER MOLE OF (A) PLUS (B) AND D. ABOUT 0.5-2 MOLES PER MOLE OF (A) PLUS (B); WHICH REACTION COMPRISES DISSOLVING (A) AND (B) IN AN AQUEOUS SOLUTION OF (C) HAVING A PH OF ABOUT 7.5 TO 9 AND TEMPERATURE OF ABOUT 60* TO 90*C, COOLING TO BELOW ABOUT 50*C, AND SLOWLY ADDING (D), THE SOLUTION HAVING PRESENTEXCESS OR UNREACHES FORMALDEHYDE, ACID IN AMOUNT SUFFICIENT TO GIVE AN INITIAL PH NOT SIGNIFICANTLY ABOVE ABOUT 3 AND HAVING A POT-LIFE OF AT LEAST ABOUT 1 MONTH.
Claim 4
Dependent Claim
126 words
AN AQUEOUS LIQUID COMPOSITION COMPRISING AN INTERMEDIATE-STAGE RESIN SOLUTION FORMED BY REACTING: A. A UREA B. DICYANDIAMIDE C. DORMALDEHYDE AND D. OXY-ACID OF PHOSPHOURS; IN THE FOLLOWING RELATIVE AMOUNTS: A. ABOUT 1-10 MOLES B. ABOUT 1-11 MOLES C. ABOUT 1.2-3 MOLES PER MOLE OF (A) PLUS (B) AND D. ABOUT 0.5-2 MOLES PER MOLE OF (A) PLUS (B); WHICH REACTION COMPRISES DISSOLVING (A) AND (B) IN AN AQUEOUS SOLUTION OF (C) HAVING A PH OF ABOUT 7.5 TO 9 AND TEMPERATURE OF ABOUT 60* TO 90*C, COOLING TO BELOW ABOUT 50*C, AND SLOWLY ADDING (D), THE SOLUTION HAVING PRESENTEXCESS OR UNREACHES FORMALDEHYDE, ACID IN AMOUNT SUFFICIENT TO GIVE AN INITIAL PH NOT SIGNIFICANTLY ABOVE ABOUT 3 AND HAVING A POT-LIFE OF AT LEAST ABOUT 1 MONTH.
Claim 5
Dependent Claim
12 words
The composition of claim 1 wherein the acid of phosphorus is phosphoric.
Claim 6
Dependent Claim
16 words
The composition of claim 1 wherein the reactants are present in approximate molar ratios equivalent to:
Claim 7
Dependent Claim
18 words
The composition of claim 1 wherein the urea compound is selected from urea, thiourea and neutral salts tHereof.
Claim 8
Dependent Claim
22 words
The composition of claim 1 wherein the solids content is within the range of about 10 to about 70 percent by wt.
Claim 9
Dependent Claim
31 words
The composition of claim 1 wherein the mole ratio of the urea to dicyandiamide is about 3 to 1 and the solids content is at least about 40 percent by wt.
Claim 10
Dependent Claim
75 words
The method of preparing compositions of the type in claim 1 comprising: a. providing an aqueous formaldehyde solution of pH about 7.5 to 9, heated to a temperature of from about 60* to 90*C, b. adding the urea and dicyandiamide to this solution and when dissolved, c. cooling the resulting solution to below about 50*C and d. slowly adding oxy-acid of phosphorus to the cooled solution, thus forming an incompletely-reacted resin solution of prolonged stability.
Claim 11
Dependent Claim
24 words
The method of claim 7 wherein water is added to accelerate the cooling step and to adjust the solids content of the final solution.
Claim 12
Dependent Claim
14 words
The method of claim 7 including thermosetting the incompletely-reacted resin and removing the water.
Claim 13
Dependent Claim
16 words
The method of claim 9 wherein the thermosetting is carried out in or on a substrate.
Claim 14
Dependent Claim
29 words
The method of claim 7 wherein step (a) the pH is about 8 and the temperature about 70*-80*C, and in step (c) the solution is cooled below about 35*C.
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) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |