Patent US3168495A successfully refreshed from Google Patents.
Patent US3784356A successfully refreshed from Google Patents.
US3784356A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cellulosic flame retardant system
Assignee: Hooker Chemical Corp
•
Filing: 1971-11-10
•
Granted: 1974-01-08
•
Expires: 1991-11-10
Abstract
Abstract A process for imparting flame retardant character to cellulosic containing materials has been devised in which the cellulosic material is treated with an aqueous solution of further polymerizable methylol-phosphorus compound obtained by reacting a tetrakis(hydroxymethyl)phosphonium acid salt e.g., tetrakis(hydroxymethyl)phosphonium chloride with about 0.5 to 1.5 mol proportion of ammonia, in the presence of a carbamic acid derivative, e.g., urea, and the treated material is contacted with an aqueous solution of ammonia thereby curing the methylolphosphorus-compound in and on the cellulosic material.
Inventors
- 👤 G Wagner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:59
CPC Classifications
D; D06; D06M; D06M15/00; D06M15/19; D06M15/37; D06M15/39; D06M15/423; D06M15/43; D06M15/433; D06M15/431; D06M15/432; D06M15/667
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
13 words
The process of claim 1 wherein the tetrakis(hydroxymethyl)-phosphonium acid salt is the chloride.
Claim 2
Dependent Claim
45 words
The process of claim 2 wherein the methylol-phosphorus compound is the product of the reaction of about one mol proportion of tetrakis-(hydroxymethyl)phosphonium chloride with about one mol proportion of ammonia, in the presence of at least about 0.25 mol proportion of a carbamic acid derivative.
Claim 3
Dependent Claim
29 words
The process of claim 3 wherein the treated material is dried to about 50 percent or less moisture retention without substantial fixation of the reaction product on the fiber.
Claim 4
Dependent Claim
14 words
The process of claim 1 wherein the carbamic acid derivative is urea or thiourea.
Claim 5
Dependent Claim
36 words
The process of claim 5 wherein the carbamic acid derivative is urea and is present in the amount of from about 0.5 to about 2 mol proportion per mol proportion of the tetrakis(hydrox methyl)phosphonium acid salt.
Claim 6
Dependent Claim
34 words
The process of claim 5 wherein the reaction product is formed by reacting one mol proportion of tetrakis(hydroxymethyl) phosphonium chloride with about 0.8 mol proportion of ammonia and about 0.5 mol proportion of urea.
Claim 7
Dependent Claim
102 words
Fire retardant cellulosic containing material obtained by treating cellulosic containing material with an aqueous solution of the reaction product of a tetrakis(hydroxymethyl)phosphonium acid salt with from about 0.5 to about 1.5 mol proportion of ammonia in said aqueous solution and at least about 0.25 mol proportion of a carbamic acid derivative selected from the group consisting of urea, thiourea, biuret, guanidine, cyanamide, dicyanamide, and ethyleneurea, said aqueous solution having a pH of above about 1 but below about 8 and treating the material with an aqueous solution of ammonia to cure said phosphonium acid salt in and on the cellulose containing material.
Claim 8
Dependent Claim
32 words
The material as claimed in claim 8 wherein the treated material is drieD to a moisture retention of about 50 percent by weight or less before treating the material with aqueous ammonia.
Claim 9
Dependent Claim
36 words
The material as claimed in claim 8 wherein the reaction product is the product of the reaction of a tetrakis(hydroxymethyl)-phosphonium acid salt with about one mol proportion of ammonium and about 0.5 mol proportion of urea.
Claim 10
Dependent Claim
15 words
The material as claimed in claim 10 wherein the tetrakis-(hydroxymethyl)phosphonium acid salt is the chloride.
References Cited (Backward Citations)
US2772188A
Cited
US2983623A
Cited
US3236676A
Cited
US3247015A
Cited
US3276897A
Cited
US3404022A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-07 | 1977-07-09 | 1978-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-07 | 1981-07-09 | 1982-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-07 | 1985-07-09 | 1986-01-08 | $7700.00 | Window Closed / Lapsed |