US3944384A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flame-retardant filaments
Assignee: Akzo Nobel UK PLC
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Filing: 1974-11-04
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Granted: 1976-03-16
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Expires: 1994-11-04
Abstract
Abstract Flame-retardant acrylic filaments containing a flame retardant which is the reaction product of a dibasic acid amide, an oxyacid of phosphorus and a polyhydroxy alcohol, the flame retardant being bound to the acrylic filaments by a cross-linking agent. The filaments are made flame-retardant by applying the flame retardant and cross-linking agent to the filaments and subsequently heating the filaments to chemically bind the flame retardant to the acrylic filaments.
Inventors
- 👤 David John Poynton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:50
CPC Classifications
D; D06; D06M; D06M15/00; D06M15/19; D06M15/37; D06M15/667; Y; Y10; Y10S; Y10S260/00; Y10S260/24
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
67 words
Acrylic filaments containing a flame retardant which is the reaction product of a dibasic acid amide, an oxyacid of phosphorus and a polyhydroxyl alcohol, the flame retardant being bound to the acrylic filaments by a cross-linking agent selected from the group consisting of tetrakis-hydroxymethyl phosphonium salts, tris-hydroxymethyl phosphine oxide and substituted amines containing two or more amine groups substituted by groups selected from hydroxyalkyl and alkoxyalkyl groups.
Claim 2
Dependent Claim
67 words
Acrylic filaments containing a flame retardant which is the reaction product of a dibasic acid amide, an oxyacid of phosphorus and a polyhydroxyl alcohol, the flame retardant being bound to the acrylic filaments by a cross-linking agent selected from the group consisting of tetrakis-hydroxymethyl phosphonium salts, tris-hydroxymethyl phosphine oxide and substituted amines containing two or more amine groups substituted by groups selected from hydroxyalkyl and alkoxyalkyl groups.
Claim 3
Dependent Claim
14 words
Acrylic filaments as claimed in claim 1 wherein the dibasic acid amide is urea.
Claim 4
Dependent Claim
13 words
Acrylic filaments as claimed in claim 1 wherein the polyhydric alcohol is glycerol.
Claim 5
Dependent Claim
16 words
Acrylic filaments as claimed in claim 1 wherein the oxyacid of phosphorus is diammonium hydrogen orthophosphate.
Claim 6
Dependent Claim
36 words
Acrylic filaments as claimed in claim 1 wherein the molar ratio of dibasic acid amide : oxyacid of phosphorus : polyhydric alcohol is in the range of 0.5 - 8 : 1 : 0.6 - 2.5.
Claim 7
Dependent Claim
25 words
Acrylic filaments as claimed in claim 5 wherein the molar ratio of dibasic acid amide to oxyacid of phosphorus is 0.5 - 2 : 1.
Claim 8
Dependent Claim
16 words
Acrylic filaments as claimed in claim 1 wherein the cross-linking agent is a melamine formaldehyde precondensate.
Claim 9
Dependent Claim
20 words
Acrylic filaments as claimed in claim 1 containing 2 to 25 per cent by weight of the said flame retardant.
Claim 10
Dependent Claim
27 words
Acrylic filaments as claimed in claim 1 wherein the proportion of the said flame retardant to the cross-linking agent is 4 : 1 to 1 : 3.
Claim 11
Dependent Claim
55 words
A method of making the acrylic filaments claimed in claim 1 comprising applying to the acrylic filaments while they are in a wet state the said flame retardant and the said cross-linking agent and subsequently heating the filaments at a temperature of 90°C to 150°C to chemically bind the flame retardant to the acrylic filaments.
Claim 12
Dependent Claim
37 words
A method as claimed in claim 9 comprising the initial step of preparing acrylic filaments by a wet spinning process, the flame retardant and the cross-linking agent being applied to the filaments before they have been dried.
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) | 1979-03-16 | 1979-09-15 | 1980-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-16 | 1983-09-15 | 1984-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-16 | 1987-09-15 | 1988-03-16 | $7700.00 | Window Closed / Lapsed |