IP Library › Granted Patent US 12,391,838
Granted Patent B2
US 12,391,838 · App. 16/543,218 · Granted Aug 19, 2025

Synergistic flame retardant compositions and fiber blends including the same

Inventors: Ramaswamy Nagarajan (Westford, MA); Jayant Kumar (Westford, MA); Ravi Mosurkal (Lowell, MA); Zhiyu Xia (Shrewsbury, MA); Shiran Yu (Lowell, MA); Weeradech Kiratitanavit (Boston, MA)
Assignees: US GOVERNMENT AS REPRESENTED BY THE SECRETARY OF THE ARMY; THE UNIVERSITY OF MASSACHUSETTS
C09D5/18D06M13/148D06M13/282D06M2200/30
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Quick Facts
Patent No.
US 12,391,838
App. No.
16/543,218
Granted
Aug 19, 2025
Kind
B2
Abstract

A synergistic flame retardant composition comprising a phenolic compound comprising condensed tannin, hydrolysable tannin, lignin, cardanol, quercetin, catechin, epicatechin, anthocyanidin, catechol, dopamine, hydroxytyrosol, adrenaline, 4-hydroxyphenylacetic acid, gallic acid, digallic acid, methyl gallate, ellagic acid, phloroglucinol, hexahydroxydiphenic acid, luteic acid, casuarictin, or a combination thereof; and a phosphorus-containing compound comprising a C 5-7 carbocyclic polyol substituted with at least one phosphate group.

Claims (45)

1. A flame resistant textile, comprising:

a fiber blend comprising a natural fiber and a synthetic fiber,

wherein the natural fiber comprises cotton, and

wherein the synthetic fiber comprises nylon;

a synergistic flame retardant composition comprising:

a phenolic compound comprising proanthocyanidin tannic acid;

a phosphorus-containing compound comprising phytic acid; and

a surfactant,

wherein the synergistic flame retardant composition is present in an amount of 0.1 weight percent to about 8 weight percent, based on a total weight of the flame resistant textile, and

wherein the flame resistant textile has:

a heat release capacity of less than or equal to 230 joules per gram-Kelvin, as determined by pyrolysis combustion flow calorimetry,

a total heat release of less than or equal to 11 kilojoules per gram, as determined by pyrolysis combustion flow calorimetry,

a peak heat release rate of less than or equal to 120 kilowatts per square meter, as determined by cone calorimetry,

a total heat release rate of less than or equal to 3.5 megajoules per square meter, as determined by cone calorimetry, or

a combination thereof.

2. The composition of claim 1 , further comprising urea or a derivative thereof, a solvent, or a combination thereof.

3. The composition of claim 1 , further comprising an additional phosphorous-containing compound, wherein the additional phosphorous-containing compound comprises phosphazene, phosphonitrilic chloride, phosphorus ester amide, phosphoric acid amide, phosphonic acid amide, phosphinic acid amide, thiophosphate, thiophosphonate, thiophosphinate, phosphine oxide, resorcinol bis(diphenyl phosphate), phenyl bis(dodecyl) phosphate, phenyl bis(neopentyl) phosphate, phenyl bis(3,5,5′-trimethylhexyl) phosphate, ethyl diphenyl phosphate, 2-ethylhexyl di(p-tolyl) phosphate, bis(2-ethylhexyl) p-tolyl phosphate, tritolyl phosphate, bis(2-ethylhexyl) phenyl phosphate, tri (nonylphenyl) phosphate, bis(dodecyl) p-tolyl phosphate, dibutyl phenyl phosphate, 2-chloroethyl diphenyl phosphate, p-tolyl bis(2,5,5′-trimethylhexyl) phosphate, 2-ethylhexyl diphenyl phosphate, phosphoric acid, ammonium dihydrogen phosphate, ammonium phosphate, triphosphoric acid, polyphosphoric acid, ammonium polyphosphate, vinyl phosphoric acid, polyvinyl phosphoric acid, vinyl phosphonic acid, polyvinyl phosphonic acid, dimethyl phosphate, diethylphosphinic acid, o-ethyl hydrogen methylphosphonothioate, amifostine, glyphosate, zoledronic acid, or a combination thereof.

4. The flame resistant textile of claim 1 , wherein the synthetic fiber and the natural fiber are in the form of a woven fabric, a nonwoven fabric, a knitted fabric, a crocheted fabric, a knotted fabric, an embroidered fabric, a twisted rope, a knitted rope, a braided rope, a crocheted rope, or knotted rope.

5. The flame resistant textile of claim 1 , wherein the amount of the synergistic flame retardant composition is 5 weight percent to 8 weight percent, based on the total weight of the textile.

6. The flame resistant textile of claim 1 , wherein

the phenolic compound is bonded to the natural fiber, the synthetic fiber, or a combination thereof; and

the phosphorus-containing compound is covalently bonded to the natural fiber, the synthetic fiber, or a combination thereof.

7. The flame resistant textile of claim 1 , wherein the phosphorus-containing compound is covalently bonded to the natural fiber by phosphorylation in the presence of an amino compound, wherein the amino compound comprises urea, dicyandiamide, ethylene diamine, or a combination thereof.

8. The flame resistant textile of claim 1 , wherein the flame resistant textile has

a heat release capacity of less than or equal to 230 joules per gram-Kelvin, as determined by pyrolysis combustion flow calorimetry; and

a total heat release of less than or equal to 11 kilojoules per gram, as determined by pyrolysis combustion flow calorimetry.

9. The flame resistant textile of claim 1 , wherein the flame resistant textile has

a peak heat release rate of less than or equal to 120 kilowatts per square meter, as determined by cone calorimetry, and

a total heat release rate of less than or equal to 3.5 megajoules per square meter, as determined by cone calorimetry.

10. The flame resistant textile of claim 1 , wherein the flame resistant textile has a phosphorus content of 3% or less by weight, based on the total weight of the flame resistant textile, as determined by inductively coupled plasma atomic emission spectroscopy.

11. The flame resistant textile of claim 1 , wherein the flame resistant textile has

a char yield of 5 to 50 wt %, based on the total weight of the textile, as determined by thermal gravimetric analysis in air at 750° C., and

a char yield of 10 to 50 wt %, based on the total weight of the textile, as determined by thermal gravimetric analysis in nitrogen at 750° C.

12. The flame resistant textile of claim 1 , wherein the flame resistant textile has a char length of 20 centimeters or less, as determined according to ASTM D6413.

13. The flame resistant textile of claim 1 , wherein a ratio of the natural fiber to the synthetic fiber is 1:2 to 2:1.

14. The flame resistant textile of claim 1 , wherein a ratio of the natural fiber to the synthetic fiber is 1:1.5 to 1.5:1.

15. The flame resistant textile of claim 1 , wherein the synergistic flame retardant composition is present in an amount of 6 weight percent to 8 weight percent, based on a total weight of the flame resistant textile.

16. The flame resistant textile of claim 1 , wherein the synergistic flame retardant composition is present in an amount of 7 weight percent to 8 weight percent, based on a total weight of the flame resistant textile.

17. The flame resistant textile of claim 1 , wherein the synergistic flame retardant composition is present in an amount of about 8 weight percent, based on a total weight of the flame resistant textile.

18. A method for the manufacture of the flame resistant textile of claim 1 , the method comprising contacting the fiber blend and the flame retardant composition under conditions effective to provide the flame resistant textile.

19. The method of claim 18 , wherein the effective conditions comprise curing to provide the flame resistant textile.

20. The method of claim 18 , further comprising

contacting the fiber blend and the phenolic compound to form a first coated textile;

contacting the first coated textile and the phosphorus-containing compound to provide a crude textile; and

curing the crude textile under conditions effective to provide the flame resistant textile.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 11, 2019
From: NAGARAJAN, RAMASWAMY; KUMAR, JAYANT; XIA, ZHIYU; YU, SHIRAN; KIRATITANAVIT, WEERADECH
To: THE UNIVERSITY OF MASSACHUSETTS
Reel/Frame 051246/0095 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 18, 2019
From: MOSURKAL, RAVI
To: US GOVERNMENT AS REPRESENTED BY THE SECRETARY OF THE ARMY
Reel/Frame 050755/0744 →
Continuity (2)
Provisional Application 62719581 · Aug 17, 2018
Related Publication 20200056057A1 · Feb 20, 2020
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