HALOGEN FREE FLAME RETARDANT WATERBORNE COATING COMPOSITION FOR TEXTILE

Abstract

The present invention relates to a flame retardant waterborne coating composition comprising: a) water dispersed hydroxyl-terminated polyurethane particles, and b) isocyanate crosslinker, wherein (i) the hydroxyl-terminated polyurethane contains phosponate oligomer as a building block in an amount of from 3 to 75 parts by weight relative to the hydroxyl-terminated polyurethane, wherein the phosphonate oligomer contains units according to the following structural formula in which n is an integer from 1 to 20, R is a C.sub.1-20 alkyl, C.sub.2-20 alkene, C.sub.2-20 alkyne, C.sub.5-20 cycloalkyl or C.sub.6-20 aryl, and R.sub.2 is an aliphatic or aromatic group, (ii) the hydroxyl number of the hydroxyl-terminated polyurethane is from 5 to 180 mg KOH/g polyurethane, (iii) the molar ratio of hydroxyl groups present in the hydroxyl-terminated polyurethane to isocyanate groups of the crosslinker is from 0.2 to 2.0.

##STR00001##

Claims

1. A flame retardant waterborne coating composition comprising: a) water dispersed hydroxyl-terminated polyurethane particles, and b) isocyanate crosslinker, wherein (i) the hydroxyl-terminated polyurethane contains phosponate oligomer as a building block in an amount of from 3 to 75 parts by weight relative to the hydroxyl-terminated polyurethane, wherein the phosphonate oligomer contains units according to the following structural formula ##STR00005## in which n is an integer from 1 to 20, R is a C.sub.1-20 alkyl, C.sub.2-20 alkene, C.sub.2-20 alkyne, C.sub.5-20 cycloalkyl or C.sub.6-20 aryl, and R.sub.2 is an aliphatic or aromatic group, (ii) the hydroxyl number of the hydroxyl-terminated polyurethane is from 5 to 180 mg KOH/g polyurethane, (iii) the molar ratio of hydroxyl groups present in the hydroxyl-terminated polyurethane to isocyanate groups of the crosslinker is from 0.2 to 2.0.

2. The flame retardant waterborne coating composition according to claim 1, wherein n is from 1 to 10, R.sub.2 is an aromatic group and is preferably derived from bisphenol-A.

3. The flame retardant waterborne composition according to claim 1, wherein R is a methyl group.

4. The flame retardant waterborne coating composition according to claim 1, wherein the phosphonate oligomer used in the preparation of the hydroxyl terminated polyurethane is a phosphonate diol selected from the group consisting of a random co-oligo(phosphonate carbonate), a block co-oligo(phosphonate carbonate), a random co-oligo(phosphonate ester), a block co-oligo(phosphonate ester) or any mixture thereof.

5. The flame retardant waterborne coating composition according to claim 1, wherein the phosphonate oligomer building block has a structure according to one of the following formulae: ##STR00006## in which R.sup.1 and R.sup.2 are aliphatic or aromatic hydrocarbons, and n is an integer from 1 to 20, preferably from 1 to 10.

6. The flame retardant waterborne coating composition according to claim 1, wherein the hydroxyl number of the phosphonate oligomer used in the preparation of the hydroxyl terminated polyurethane is from 10 to 200 mg KOH/g phosphonate oligomer, preferably from 40 to 120 mg KOH/g phosphonate oligomer.

7. The flame retardant waterborne coating composition according to claim 1, wherein the OH equivalent weight of the phosphonate oligomer used in the preparation of the hydroxyl terminated polyurethane is from 280 to 5,610, preferably from 450 to 1400.

8. The flame retardant waterborne coating composition according to claim 1, wherein the phosphonate oligomer used in the preparation of the hydroxyl terminated polyurethane is a copolymer of bisphenol-A and diphenyl methyl phosphonate.

9. The flame retardant waterborne coating composition according to claim 1, wherein the amount of hydroxyl-terminated polyurethane is from 10 to 99 wt. %, preferably from 20 to 97 wt. % and more preferably from 25 to 75 wt. % (relative to the total coating composition).

10. The flame retardant waterborne coating composition according to claim 1, wherein the composition is bromine free, preferably halogen free.

11. The flame retardant waterborne coating composition according to claim 1, wherein the hydroxyl-terminated polyurethane is obtained by reacting (a) from 5 to 50 parts by weight of at least one polyisocyanate, (b) from 3 to 75 parts by weight of at least one phosphonate diol oligomer as defined in claim 1, (c) from 0.5 to 30 parts by weight of at least one isocyanate-reactive polyol containing non-ionic, ionic and/or potentially ionic water dispersing groups, (d) from 0 to 75 parts by weight of at least one isocyanate-reactive polyol not comprised by (b) or (c), to obtain an isocyanate-terminated polyurethane prepolymer, and reacting the isocyanate-terminated polyurethane prepolymer with (e) from 0 to 20 parts by weight of neutralizing agent, and (f) from 1 to 20 parts by weight of at least one active hydrogen-containing chain-extending compound, which is capable of forming hydroxyl groups, whereby the amounts of (a), (b), (c) and (d) are given relative to the total amount of components used to prepare the isocyanate-terminated polyurethane prepolymer from which the building blocks of the isocyanate-terminated polyurethane prepolymer are emanated, and whereby the amounts of (e) and (f) is given relative to the weight amount of the isocyanate-terminated polyurethane prepolymer.

12. The flame retardant waterborne coating composition according to claim 11, wherein the polyol (d) comprises a polyester polyol, a polyether polyol and/or a polycarbonate polyol; preferably the polyol (d) comprises a polyester polyol preferably made from ethylene glycol and adipic acid and/or a polyester polyol made from diethylene glycol and adipic acid.

13. The flame retardant waterborne coating composition according to claim 11, wherein the polyol (c) comprises (c.1) from 0.5 to 10 wt. %, preferably from 1 to 6 wt. % of an isocyanate-reactive polyol containing ionic and/or potentially ionic water-dispersing groups having a molecular weight of from 100 to 500 g/mol, (c.2) from 0 to 20 wt. %, preferably from 5 to 15 wt. % of at least one isocyanate-reactive polyol containing non-ionic water-dispersing groups, where the amounts of (c.1) and (c.2) are given relative to the total amount of components used to prepare the isocyanate-terminate polyurethane prepolymer from which the building blocks of the isocyanate-terminate polyurethane prepolymer are emanated.

14. A coated fabric which is obtained by applying to a textile a coating composition according to claim 1.

15. The coated fabric according to claim 14, wherein the textile containing fibers, preferably polyester fibres, polypropylene fibres, and/or polyamide fibres.

16. An article comprising the coated fabric according to claim 14.

17. The article of claim 16, wherein the article is selected from the group consisting of furniture, a drapery, a garment, linen, a mattress, a carpet, a tent, a sleeping bag, a toy, a decorative fabric, an upholstery, a wall fabric, a curtain, a canopy, clothing apparel, vehicle upholstery, an awning, an airline seat, an airbag cover and combinations thereof.

Description

EXAMPLES AND COMPARATIVE EXPERIMENTS

Example 1

Synthesis of an OH Functional Water Borne Polyurethane Dispersion Containing Nofia OL 1001 Phosphonate Diol.

[0058] The following were charged to a resin kettle and capped with nitrogen: Polyester polyol composed of adipic acid, diethylene glycol, and trimethyol propane, (353.96 g, 1150 eq.wt., 0.3078 eq.), Nofia OL 1001 (25.53 g, 710.1 eq.wt., 0.0360 eq.), dimethylol propionic acid (12.99 g, 67.07 eq.wt., 0.1937 eq.), dicyclohexylmethane-4,4-diisocyanate (109.44 g, 131.1 eq.wt., 0.8348 eq.), bismuth neodeconate catalyst (0.15 g), methylethylketone (142.88 g). The mixture was heated to 78 C for 3 hours. The free NCO value was determined by dibutyl amine titration and found to be 1.98% (theory 1.93%). Triethylamine (10.19 g 101.19 eq.wt., 0.1085 eq.) was added and the mixture was stirred for 10 minutes. Water (786.8 g) was added with rapid mixing to form a water borne polyurethane dispersion. A mixture of N(2-hydroxyethyl)ethylenediamine (13.84 g, 52.075 amine eq.wt., 0.2658 eq.) was mixed with water (30 g) and added to the dispersion slowly. The mixture was stirred for 1 hour then it was vacuum stripped to remove the methylethylketone. A solvent free water borne polyurethane dispersion was produced containing 40% solids. The hydroxyl number of the polyurethane was 14.4.

[0059] 142.5 g of this water borne polyurethane dispersion was compounded with Bayhydur 302 (7.5 g) and K-Stay 730 associative thickener (1.6 g) to give a coating with a viscosity of 60,000 cps. The molar ratio of hydroxyl groups present in the hydroxyl-terminated polyurethane to isocyanate groups of the crosslinker was 0.47. The compounded coating was coated on 200 denier nylon oxford fabric with a knife over roll coater and then heat cured for 90 seconds at 163 degrees C. The coating wt. on fabric is 40.7 g per m.sup.2 (1.2 ounce per square yard).

[0060] The fabrics coated with these water borne polyurethane flame retardant coatings were tested with vertical flame retardant tests CPAI-84 A Specification for Flame-Resistant Materials Used in Camping Tentage and NFPA 701 Fire Tests for Flame-Resistant Textiles and Films.

[0061] To pass the CPAI-84 test the maximum individual char length is 25.5 cm (10.04 inches) and the maximum average char length is 21.6 cm (8.5 inches). The maximum individual after flame is 4 seconds with a maximum average of 2 seconds.

[0062] To pass the NFPA 701 test the max individual char length is 16.8 cm (6.60 inches) and the maximum average is 14 cm (5.50 inches). The maximum individual after flame is 2 seconds.

[0063] The results are given below.

TABLE-US-00001 Individual char Individual Example 1 length in cm after flame (before leaching) (inches) (seconds) Warp 8.4 (3.3) 0.0 Warp 8.4 (3.3) 0.0 Warp 8.9 (3.5) 0.0 Fill 8.9 (3.5) 0.0 Fill 9.4 (3.7) 0.0 Fill 9.7 (3.8) 0.0 Average 8.9 (3.5) 0.0
The coated fabric of Example 1 with the Nofia OL 1001 in the PU backbone passed the Vertical FR CPAI-84 and NFPA 701 tests with an average char length of 8.9 cm (3.5 inches) and no after flames.
The coated fabric of Example 1 was leached in water for 72 hours and the water was changed every 24 hours. The leached fabric was retested in the flame retardant tests: The results are given below.

TABLE-US-00002 Example 1 Individual char Individual (after 72 hours length in cm after flame leaching in water) (inches) (seconds) Warp 9.4 (3.7) 0.0 Warp 9.4 (3.7) 0.0 Warp 8.6 (3.4) 0.0 Fill 9.4 (3.7) 0.0 Fill 9.1 (3.6) 0.0 Fill 9.4 (3.7) 0.0 Average 9.1 (3.6) 0.0
The flame retardant results after leaching were excellent with an average char length of 9.1 cm (3.6 inches) and no after flames, thus both the CPAI-84 and NFPA 701 tests were passed.
Thus the flame retardant Nofia OL 1001 is not leached out of the coating.

Comparative Experiment A

[0064] An identical water borne polyurethane dispersion to that described for Example 1 was produced except that the Nofia OL1001 was left out. The hydroxyl number of the polyurethane was 14.5.

[0065] The water borne polyurethane dispersion for Comparative Experiment A was compounded in the same way as in Example 1 and also coated on 200 denier nylon fabric. The molar ratio of hydroxyl groups present in the hydroxyl-terminated polyurethane to isocyanate groups of the crosslinker was 0.47. The coating wt. on fabric is 40.7 g per m.sup.2 (1.2 ounce per square yard).

[0066] The cured coated fabrics were tested for flame retardant properties using the Vertical FR CPAI-84 test and the NFPA 701 test. The results are given below.

TABLE-US-00003 Individual char Individual length in cm after flame Comp Ex A (inches) (seconds) Warp 8.9 (3.5) 0.0 Warp 8.4 (3.3) 0.0 Warp 8.6 (3.4) 0.0 Fill 10.2 (4.0) 3.0 Fill 8.9 (3.5) 0.0 Fill 10.2 (4.0) 15.0 Average 9.1 (3.6) 3.0

[0067] Example 1 with the Nofia OL 1001 in the PU backbone passed the Vertical FR CPAI-84 and NFPA 701 tests with an average char length of 8.9 cm (3.5 inches) and no after flames. Comparative A, without the phosphonate diol in the backbone of the polymer, failed the Vertical FR CPAI-84 test because the average after flame was 3 seconds and an individual value was 15 seconds. It also failed the NFPA 701 test because 2 of the individual after flame values were above 2 seconds.

[0068] The coated fabric of Comparative Experiment A was not submitted to leaching since the coated fabric of Comparative Experiment A did not even pass the CPAI-84 and NFPA-701 flame retardant tests before the coated fabric was leached in water.

Example 2

[0069] An OH functional water borne polyurethane dispersion containing Nofia OL 3001 phosphonate diol was synthesized with the same composition as for example 1 except that Nofia OL 3001 was used in place of Nofia OL 1001. The Nofia OL 3001 is a copolymer made from bisphenol-A and diphenyl methyl phosphonate. The Nofia OL3001 has an OH number of 50 and an OH equivalent weight of 1122. This OH functional (hydroxyl number of the polyurethane 14.2) water borne polyurethane dispersion containing Nofia OL 3001 phosphonate diol was compounded with Bayhydur 302, and thickened to 60,000 cps with K-Stay 730 associative thickener. The molar ratio of hydroxyl groups present in the hydroxyl-terminated polyurethane to isocyanate groups of the crosslinker was 0.47. The compounded coating was coated on 200 denier nylon oxford fabric with a knife over roll coater and then heat cured for 90 seconds at 163 degrees C. The coating wt. on fabric is 40.7 g per m.sup.2 (1.2 ounce per square yard) and for the coated fabric tested after 72 hours leaching in water 37.3 g per m.sup.2 (1.1 ounce per square yard).

The cured coated fabric was tested for flame retardant properties using the Vertical FR CPAI-84 test and the NFPA 701 test.

TABLE-US-00004 Individual char Individual length in cm after flame (inches) (seconds) Example 2 (before leaching) Warp 9.9 (3.9) 0.0 Warp 8.6 (3.4) 0.0 Warp 8.9 (3.5) 0.0 Fill 10.2 (4.0) 0.0 Fill 9.1 (3.6) 0.0 Fill 10.2 (4.0) 0.0 Average 9.4 (3.7) 0.0 Example 2 (after 72 hours leacing in water) Warp 9.7 (3.8) 0.0 Warp 8.6 (3.4) 0.0 Warp 7.4 (2.9) 0.0 Fill 8.9 (3.5) 0.0 Fill 7.6 (3.0) 0.0 Fill 9.9 (3.9) 0.0 Average 8.6 (3.4) 0.0
The flame retardant results were excellent with average char lengths of 9.4 cm (3.7 inches) before leaching and 8.6 cm (3.4 inches) after leaching and zero after flames in both cases. These results passed both the CPAI-84 and NFPA 701 tests. Thus the flame retardant Nofia OL 3001 is not leached out of the coating.

Example 3

[0070] An OH functional water borne polyurethane dispersion with a polyester polyol composed of ethylene glycol and adipic acid was synthesized as follows:

[0071] The following were charged to a resin kettle and capped with nitrogen: Polyester polyol composed of adipic acid, and ethylene glycol (320 g, 1000 eq.wt., 0.320 eq.), trimethylolpropane (2.46 g, 44.73 eq.wt., 0.550 eq.), Nofia OL 1001 (29 g, 710.1 eq.wt., 0.0408 eq.), dimethylol propionic acid (25 g, 67.07 eq.wt., 0.3727 eq.), dicyclohexylmethane-4,4-diisocyanate (149 g, 131.1 eq.wt., 1.1365 eq.), bismuth neodeconate catalyst (0.10 g), methylethylketone (149 g). The mixture was heated to 78 C for 3 hours. The free NCO value was determined by dibutyl amine titration and found to be 2.50% (theory 2.42%). Triethylamine (19.61 g 101.19 eq.wt., 0.1938 eq.) was added and the mixture was stirred for 10 minutes. Water (995 g) was added with rapid mixing to form a water borne polyurethane dispersion. A mixture of N(2-hydroxyethyl)ethylenediamine (18.22 g, 52.075 amine eq.wt., 0.3498 eq.) was mixed with water (49 g) and added to the dispersion slowly. The mixture was stirred for 1 hour then it was vacuum stripped to remove the methylethylketone. A solvent free water borne polyurethane dispersion was produced containing 35% solids. The hydroxyl number of the polyurethane was 18.0.

[0072] This OH functional water borne polyurethane dispersion (142.5 g) was compounded with Bayhydur 302 (7.5 g) and K-Stay 730 associative thickener (1.7 g) to give a coating with a viscosity of 60,000 cps. The molar ratio of hydroxyl groups present in the hydroxyl-terminated polyurethane to isocyanate groups of the crosslinker was 0.59. The compounded coating was coated on 200 denier nylon oxford fabric with a knife over roll coater and then heat cured for 90 seconds at 163 degrees C. The coating wt. on fabric is 40.7 g per m.sup.2 (1.2 ounce per square yard). The vertical flame retardant results were tested:

TABLE-US-00005 Example 3 Individual char Individual (before length in cm after flame leaching) (inches) (seconds) Warp 7.6 (3.0) 0.0 Warp 8.9 (3.5) 0.0 Warp 11.2 (4.4) 0.0 Fill 9.9 (3.9) 0.0 Fill 9.1 (3.6) 0.0 Fill 8.6 (3.4) 0.0 Average 9.1 (3.6) 0.0 Example 3 Individual char (after 72 hours length in cm After leacing in water) (inches) flame Warp 8.4 (3.3) 0.0 Warp 9.9 (3.9) 0.0 Warp 8.9 (3.5) 0.0 Fill 9.4 (3.7) 0.0 Fill 10.7 (4.2) 0.0 Fill 9.7 (3.8) 0.0 Average 9.4 (3.7) 0.0
The flame retardant results were excellent with average char lengths of 9.1 cm (3.6 inches) before leaching and 9.4 cm (3.7 inches) after leaching and zero after flames in both cases. These results passed both the CPAI-84 and NFPA 701 tests.

Example 4 and Comparative Experiments B and C

[0073] OH functional water borne polyurethane dispersion containing Nofia OL 1001 phosphonate diol (Ex 1) resp. Fyrol 6 (Comp B) resp. Exolit OP 550 (Comp C) were prepared and the amounts of the three flame retardant additives were adjusted to keep the weight percent of phosphorous the same in all cases.

[0074] The Exolit OP 550 is a non-halogenated phosphorus polyol based on oligomeric organophosphates. It has a hydroxyl number of 170 and an OH equivalent weight of 330 and it contains 17% phosphorous by weight.

Fyrol 6 is diethyl-N,N-bis(2-hydroxyethyl)aminomethyl phosphonate. It has a hydroxyl number of 460 and an OH equivalent weight of 122 and it contains 12.4% phosphorous by weight.

[0075] The Nofia OL 1001 is a copolymer made from bisphenol-A and diphenyl methyl phosphonate. The Nofia OL1001 has an OH number of 90 and an OH equivalent weight of 623 and it contains 8.5% phosphorous by weight.

[0076] Polyurethane dispersions containing these 3 different halogen free, phosphorous based, flame retardants in the backbone of the polymer were made using Desmodur W (H.sub.12MDI), and ethylene glycol adipate polyester polyol and DMPA. The polymers were chain extended with N-(2-hydroxyethyl)ethylene diamine (HEEDA) to make them OH functional. The amounts of the three flame retardant additives were adjusted to keep the weight % phosphorous the same in all three cases. The hydroxyl number of the polyurethanes were respectively 18.0 with the Nofia OL 1001, 28.8 with the Fyrol 6, and 18.5 with the Exolit OP 550.

[0077] Synthesis of a polyurethane dispersion containing Nofia OL 1001: Ethylene glycol adipate polyester polyol (320 g, 1000 eq.wt., 0.320 eq.), trimethylolpropane (2.46 g, 44.73 eq.wt., 0.0550 eq.), dimethylolpropionic acid (25 g, 67.07 eq.wt., 0.3727 eq.), Nofia OL 1001 (29.0 g, 623.3 eq.wt., 0.0465 eq.), Desmodur W (149.0 g, 131.1 eq.wt., 1.1365 eq.) and methylethylketone (150 g) were charged to a resin kettle under nitrogen and mixed and heated to 78 C for 2 hours. The NCO value was determined by dibutyl amine titration and found to be 2.50% (theory 2.42%). Triethylamine 19.61 g, 101.19 eq.wt., 0.1938 eq.) was added and the mixture was stirred for 10 minutes. Water (995 g) was added with rapid mixing and then a mixture of HEEDA (18.22 g, 52.075 amine eq.wt., 0.3499 eq.) and water (49 g) was added slowly. The mixture was stirred for 1 hour and then the methylethylketone was removed by vacuum stripping, leaving a solvent free water borne polyurethane dispersion.

[0078] Synthesis of a polyurethane dispersion containing Fyrol FR6: Ethylene glycol adipate polyester polyol (320 g, 1000 eq.wt., 0.320 eq.), trimethylolpropane (2.46 g, 44.73 eq.wt., 0.0550 eq.), dimethylolpropionic acid (25 g, 67.07 eq.wt., 0.3727 eq.), Fyrol FR6 (19.88 g, 121.96 eq.wt., 0.1630 eq.), Desmodur W (185.0 g, 131.1 eq.wt., 1.411 eq.) and methylethylketone (220 g) were charged to a resin kettle under nitrogen and mixed and heated to 78 C for 2 hours. The NCO value was determined by dibutyl amine titration and found to be 2.77% (theory 2.72%). Triethylamine (19.61 g, 101.19 eq.wt., 0.1938 eq.) was added and the mixture was stirred for 10 minutes. Water (1087 g) was added with rapid mixing and then a mixture of HEEDA (31.09 g, 52.075 amine eq.wt., 0.5970 eq.) and water (49 g) was added slowly. The mixture was stirred for 1 hour and then the methylethylketone was removed by vacuum stripping, leaving a solvent free water borne polyurethane dispersion.

[0079] Synthesis of a polyurethane dispersion containing Exolit O,P 550: Ethylene glycol adipate polyester polyol (320 g, 1000 eq.wt., 0.320 eq.), trimethylolpropane (2.46 g, 44.73 eq.wt., 0.0550 eq.), dimethylolpropionic acid (25 g, 67.07 eq.wt., 0.3727 eq.), Exolit O,P 550 (14.50 g, 330 eq.wt., 0.0439 eq.), Desmodur W (149.0 g, 131.1 eq.wt., 1.1365 eq.) and methylethylketone (150 g) were charged to a resin kettle under nitrogen and mixed and heated to 78 C for 2 hours. The NCO value was determined by dibutyl amine titration and found to be 2.30% (theory 2.19%). Triethylamine 19.61 g, 101.19 eq.wt., 0.1938 eq.) was added and the mixture was stirred for 10 minutes. Water (972 g) was added with rapid mixing and then a mixture of HEEDA (18.22 g, 52.075 amine eq.wt., 0.3499 eq.) and water (49 g) was added slowly. The mixture was stirred for 1 hour and then the methylethylketone was removed by vacuum stripping, leaving a solvent free water borne polyurethane dispersion.

[0080] The water borne polyurethane dispersions were then compounded with Bayhydur 302 isocyanate crosslinker and thickened and coated on 200 denier nylon fabric. The molar ratio of hydroxyl groups present in the hydroxyl-terminated polyurethane to isocyanate groups of the crosslinker was 0.33 in all cases. The coating wt. on fabric is 40.7 g per m.sup.2 (1.2 ounce per square yard) for Ex 4 and 49.2 g per m.sup.2 (1.45 ounce per square yard) (Comp C) and 45.8 g per m.sup.2 (1.35 ounce per square yard) (Comp B). The flame retardant properties were tested using the CPAI-84 test:

TABLE-US-00006 Resin Coating Vertical FR CPAI-84 composition wt. on fabric Individual char Self Individual FR in g per m.sup.2 length in cm Extinguish after flame backbone (oz./yd. 2) (inches) (seconds) (seconds) Ex. 4 Nofia 40.7 (1.2) Warp 11.7 (4.6) 10.0 0.0 1001 Warp 9.9 (3.9) 7.0 0.0 Warp 8.6 (3.4) 6.0 0.0 Fill 9.1 (3.6) 4.0 0.0 Fill 11.7 (4.6) 2.0 0.0 Fill 11.4 (4.5) 7.0 0.0 Average 8.4 (3.3) 0.0 Comp Fyrol 6 49.2 (1.45) Warp BEL 90.0 Ex B Warp 22.4 (8.8) 17.0 Warp BEL * 120.0 Fill BEL * 100.0 Fill 20.8 (8.2) 16.0 Fill BEL * 90.0 Average 27.4 (10.8) 72.0 Comp Exolit 45.8 (1.35) Warp 17.0 (6.7) 8.0 Ex C OP550 Warp 20.8 (8.2) 90.0 Warp 19.8 (7.8) 30.0 Fill 10.4 (4.1) 2.0 Fill BEL * 75.0 Fill 17.5 (6.9) 50.0 Average 19.3 (7.6) 42.0 BEL * = burned entire length

[0081] The polymer containing the Nofia OL 1001 polymer passed the CPAI-84 test and the NFPA-701 flame retardant test with an average char length of 8.4 cm (3.3 inches) and no after flames. The polymer containing Fyrol 6 failed the test with an average char length of 27.4 cm (10.8 inches) and an average after flame of 72 seconds. The polymer containing the Exolit OP 550 also failed the test with an average char length of 19.3 cm (7.6 inches) and an average after flame of 42 seconds. These data show that in these OH functional waterborne polyurethane dispersions the Nofia OL 1001 has superior flame retardant performance over Exolit OP 550 and Fyrol 6.

[0082] The fabric that was coated with the polymer that contained the Nofia 1001 polymer and crosslinked with Bayhydur 302 (Example 4) was submitted to 3 wash cycles in a washing machine and the flame retardant properties were retested:

TABLE-US-00007 Example 4 Individual char Individual (after 3 length in cm after flame wash cycles) (inches) (seconds) Warp 9.1 (3.6) 0 Warp 8.9 (3.5) 0 Warp 10.9 (4.3) 0 Fill 8.9 (3.5) 0 Fill 8.6 (3.4) 0 Fill 8.9 (3.5) 0 Average 9.1 (3.6) 0

[0083] Even after 3 wash cycles, the coated fabric according to the invention passed the CPAI-84 and NFPA-701 flame retardant tests with an average char length of 9.1 cm (3.6 inches) and zero after flames. Thus the flame retardant Nofia OL 1001 is not washed out of the coating.

[0084] The coated fabric of Comparative Experiment B and C were not submitted to washing since these coated fabrics did not even pass the CPAI-84 and NFPA-701 flame retardant tests before the coated fabrics were washed.

Comparative Experiment D

[0085] The polymer containing the Nofia 1001 polymer (140 g) was thickened with K-stay 730 (1.9 g) to 60,000 cps and coated on 200 denier nylon fabric without an isocyanate crosslinker and then heat cured for 90 seconds at 163 C. The coating weight on the cured fabric was 40.7 g per m.sup.2 (1.2 oz./square yard). The cured fabric was submitted to 3 wash cycles in a washing machine. The coating was badly delaminated from the fabric. Thus the uncrosslinked coating is not durable to wash cycles.

[0086] The flame retardant properties of this coated fabric were tested as described above and the following results were obtained:

TABLE-US-00008 Individual char Individual length in cm after flame (inches) (seconds) Warp 8.1 (3.2) 0 Warp 18.3 (7.2) 15 Warp 9.9 (3.9) 0 Fill 15.7 (6.2) 6 Fill 13.7 (5.4) 30 Fill 17.8 (7.0) 22 Average .sup.14 (5.5) 12

[0087] The uncrosslinked coating failed the CPAI-84 and NFPA-701 flame retardant tests with an average after flame value of 12 seconds. This indicates that the uncrosslinked flame retardant coating is not as durable as the isocyanate crosslinked polyurethane coating as for example in Example 1.