Flame-retardant composition and process for a flexible open-cell polyurethane foam

Abstract

A flame retardant composition for producing a resulting polyurethane foam, a flame retardant process for producing a resulting polyurethane foam, and a resulting polyurethane foam produced by a flame retardant process are described. The resulting polyurethane foam meets the Federal Railroad Administration, National Fire Protection Association, and Federal Transit Administration fire performance testing criteria for cushioning applications in railway, bus, and van industries.

Claims

1. A resulting polyurethane foam produced by a flame retardant process comprising reacting: (a) at least one polyoxyalkylene polyether polyol, (b) at least one organic polyisocyanate, and (c) at least one foaming agent comprising: (i) at least one blowing agent, wherein said blowing agent comprises a primary blowing agent, (ii) at least one surface active agent, and (iii) at least one catalyst, and in the further presence of: (d) at least one flame retardant agent comprising: (i) expandable graphite, (ii) at least one ammonium polyphosphate, and (iii) at least one organophosphorus flame retardant, wherein said resulting polyurethane foam is used for cushioning application materials and wherein the surface flammability of said resulting polyurethane foam does not exhibit any flaming running or flaming dripping, wherein flame spread index of said resulting polyurethane foam is less than or equal to 25 during testing of said resulting polyurethane foam in accordance with ASTM D 3675, wherein specific optical density of smoke value of said resulting polyurethane foam is less than or equal to 100 under flaming mode and non-flaming mode at 1.5 minutes during testing of said resulting polyurethane foam in accordance with ASTM E 662, and wherein specific optical density of smoke value of said resulting polyurethane foam is less than or equal to 175 under flaming mode and non-flaming mode at 4.0 minutes during testing of said resulting polyurethane foam in accordance with ASTM E 662, in satisfaction of fire performance criteria of the Federal Railroad Administration, Federal Transit Administration, and National Fire Protection Association.

2. The resulting polyurethane foam of claim 1 wherein said expandable graphite has a flake size of from about 0.044 mm to about 2.0 mm.

3. The resulting polyurethane foam of claim 1 wherein said expandable graphite is used in an amount of from about 20 parts by weight to about 40 parts by weight per 100 parts by weight of said polyoxyalkylene polyether polyol.

4. The resulting polyurethane foam of claim 1 wherein said ammonium polyphosphate is used in an amount of from about 10 parts by weight to about 30 parts by weight per 100 parts by weight of said polyoxyalkylene polyether polyol.

5. The resulting polyurethane foam of claim 1 wherein said organophosphorus flame retardant is used in an amount of from about 20 parts by weight to about 40 parts by weight per 100 parts by weight of a polyoxyalkylene polyether polyol.

6. The resulting polyurethane foam of claim 1 wherein said polyoxyalkylene polyether polyol has a molecular weight of from about 1000 to about 8000.

7. The resulting polyurethane foam of claim 1 wherein the amount of said organic polyisocyanate is calculated using an isocyanate index of from about 70 to about 130.

8. The resulting polyurethane foam of claim 1 wherein said resulting polyurethane foam has a density ranging from about 2 to about 30 pounds per cubic feet.

9. The resulting polyurethane foam of claim 1 wherein said resulting polyurethane foam is molded or slabstock.

10. The resulting polyurethane foam of claim 9 wherein said resulting polyurethane foam is viscoelastic.

11. The resulting polyurethane foam of claim 1 wherein said ammonium polyphosphate is standard or microencapsulated.

12. The resulting polyurethane foam of claim 1 wherein said catalyst of said foaming agent is an organometallic tin catalyst, an amine catalyst, or a combination thereof.

13. The resulting polyurethane foam of claim 1 wherein said resulting polyurethane foam is water leached in accordance with Federal Standard 191A, Method Number 5830.

14. The resulting polyurethane foam of claim 1 wherein said polyoxy 1 alkylene polyether polyol is a system polyol.

15. The resulting polyurethane foam of claim 1 wherein said foaming agent further comprises an auxiliary blowing agent.

16. The resulting polyurethane foam of claim 1 wherein said foaming agent further comprises a crosslinker.

17. The resulting polyurethane foam of claim 1 wherein said flame retardant process does not include an anti-settling agent.

Description

(1) The following Examples 1 through 21 and Tables 1 through 8 show that the resulting polyurethane foams made in accordance with the embodiments herein have satisfactory fire performance in view of meeting the FRA, FTA, and NFPA testing criteria and in view of other testing criteria. Additionally, the following examples illustrate that the polyurethane foams not made with the flame retardant agent have unsatisfactory fire performance in view of not meeting the FRA, FTA, and NFPA testing criteria.

(2) In Examples 1 through 19 and Tables 1 through 6 the following ingredients were used as indicated in the respective examples and tables:

(3) (a) System polyol, Specflex NF766 from Dow Chemical Corporation.

(4) (b) Polyoxyalkylene polyether polyol, Multranol 3901 (functionality 3, typical hydroxyl number 28, typical molecular weight 6000) from Bayer MaterialScience LLC.

(5) (c) Polyether polyol mixture, Arcol Polyol R-3580 (a blend of 3 polyether polyols, a polymer and acrylonitrile and styrene) from Bayer MaterialScience LLC.

(6) (d) Polyoxyalkylene polyether polyol, Multranol 9199 (functionality 3, typical hydroxyl number 37, typical molecular weight 4525) from Bayer MaterialScience LLC.

(7) (e) Organophosphorus flame retardant, Exolit OP 560 reactive flame retardant with functionality of approximately 2 (hydroxyl number 300 to 500) from Clariant Corporation.

(8) (f) Expandable graphite, Grade 3772 Typical analysis: 18 Mesh (1000 microns or 1.00 mm) 2.54%; 30 Mesh (600 micron or 0.600 mm) 13.15%; 40 Mesh (425 microns or 0.425 mm) 44.93%; 50 Mesh (300 microns or 0.300 mm) 29.62%; 80 Mesh (180 micron or 0.180 mm) 7.17%; 80 Mesh (180 microns or 0.180 mm) 2.59% from Asbury Graphite Mills, Inc.
(f*) Expandable graphite, Grade 3494 Typical analysis: 50 Mesh (300 microns or 0.300 mm) 1.6%; 80 Mesh (180 microns or 0.180 mm) 50.29%; 100 Mesh (150 microns or 0.150 mm) 23.56%; 200 Mesh (75 microns or 0.075 mm) 20.52%; 325 Mesh (44 microns or 0.044 mm) 1.76%; 325 Mesh (44 microns or 0.044 mm) 2.28% from Asbury Graphite Mills, Inc.
(f**) Expandable graphite, Grade Grafguard 160-80N (mean particle size 250 microns or 0.250 mm typical) from GrafTech International Holdings Inc. (formerly Ucar Carbon Company).
(g) Microencapsulated Ammonium polyphosphate, Exolit AP 462, from Clariant Corporation.
(g*) Standard Ammonium polyphosphate, Exolit AP 422, from Clariant Corporation.
(h) Amine catalyst, DABCO 33LV from Air Products and Chemicals, Inc.
(i) Organometallic tin catalyst, DABCO T-12, an organometallic catalyst from Air Products and Chemicals, Inc.
(j) Amine catalyst, DABCO BL-11, from Air Products and Chemicals, Inc.
(k) Crosslinker, Diethanolamine, DEOA from Sagar Enterprises, Inc.
(l) Surface active agent, DABCO DC 5169 from Air Products and Chemicals, Inc.
(m) Surface active agent, Tegostab B 8715 LF 2 from Evonik Goldschmidt Corporation.

(9) (n) Organic polyisocyanate, Voralux HE 150 from Dow Chemical Corporation.

(10) (o) Organic polyisocyanate, Mondur MRS-4 from Bayer MaterialScience LLC.

(11) (p) Toluene diisocyanate (TDI), Lupranate T80, Type 2 Isocyanate, 80:20 mixture of 2-, 4- and 2,6-toluene diisocyanate from BASF Corporation.

(12) (q) Primary blowing agent, water.

(13) (r) Auxiliary blowing agent, Forane 141b from ELF Atofina.

(14) The amount listed for each ingredient is parts by weight of the ingredient per 100 parts by weight of the polyoxyalkylene polyether polyol or system polyol (which, as defined above, comprises the polyoxyalkylene polyether polyol and a foaming agent).

Examples 1 to 3

(15) For Examples 1, 2, and 3 as shown in Table 1, resulting polyurethane foam in the form of a molded foam is produced by mixing the ingredients as indicated in the respective examples. A preheated aluminum mold is used in the production of the molded foam. The aluminum mold has a dimension of about 10 inch9 inch4.75 inch. The aluminum mold was preheated heated to a temperature range of from about 135 F. to about 145 F.

(16) The ingredients as indicated in respective Examples 1, 2, and 3 are combined by mixing microencapsulated ammonium polyphosphate (Exolit AP 462 from Clariant Corporation) with expandable graphite (Grade 3772 available from Asbury Graphite Mills, Inc.) in the respective amounts indicated in Table 1 with system polyol (Specflex NF766 from Dow Chemical Corporation) (which includes a foaming agent) in the presence of an amine catalyst (DABCO 33LV from Air Products and Chemicals, Inc.) and an organometallic tin catalyst (DABCO T-12 from Air Products and Chemicals, Inc.). Organophosphorus flame retardant (Exolit OP 560 reactive flame retardant) was then added to the mixture followed by Voralux HE 150 and mixed.

(17) This mixture then added to preheated aluminum molds and cured by passing through a heat chamber for about 6 minutes to about 8 minutes set at a temperature of about 125 F. The resulting polyurethane foams are then removed from the aluminum molds.

(18) In testing of the resulting polyurethane foams of Examples 1, 2, and 3, the resulting polyurethane foam produced satisfactory fire performance results which met the testing criteria the FRA, FTA, and NFPA. The physical and fire characteristics of the resulting polyurethane foam are shown in Table 1. As shown in Table 1, Flame Spread Index (l.sub.s) values were below 25 with no flaming running or flaming dripping and specific optical density of smoke values (D.sub.s) were below 100 at 1.5 minutes and below 175 at 4.0 minutes.

(19) TABLE-US-00001 TABLE 1 The effect of relative amounts of flame retardant ingredients on physical and flammability characteristics of the resulting polyurethane foam. Examples 1 2 3 Isocyanate Index 80 80 80 Ingredients System polyol (a) 100 100 100 Amine catalyst (h) .025 .025 .025 Organometallic tin catalyst (i) 0.05 0.05 0.05 Expandable Graphite (f) 36 35 30 Ammonium polyphosphate (g) 12 18 25 Organophosphorus Flame retardant (e) 30 25 23 Organic polyisocyanate (n) 80.4 76.8 75.3 Physical Characteristics Density (pct) (as per ASTM 4.39 4.40 4.53 D 3574-Test A) IFD at 25% at 4 inch (lbs) (as per 40.4 30.9 ASTM D 3574-Test B.sub.1) Tensile strength (lb/sq.in) (as per 12.9 11.0 10.2 ASTM D 3574-Test E) Elongation (%) (as per ASTM 40 52 46 D 3574-Test E) Resilience (%)(as per ASTMD 43 43 47 3574-Test H) Flame Spread Index (I.sub.s) (as per ASTM 7.50 7.50 6.75 D 3675 Specific optical density of smoke D.sub.s 1.5 min (Non-flaming mode) 94 95 92 (as per ASTM E 662) D.sub.s 4.0 min (Non-flaming mode) 165 165 171 (as per ASTM E 662) D.sub.s 1.5 min (Flaming mode) 76 58 64 (as per ASTM E 662) D.sub.s 4.0 min (Flaming mode) 162 159 169 (as per ASTM E 662)

Examples 4-7

(20) For Examples 4, 5, 6, and 7 as referenced in Table 2, resulting polyurethane foams in the form of molded foams are respectively prepared with isocyanate index values as indicated and ingredients in the amounts indicated. As with Table 1, the amount listed for each ingredient is parts by weight of the ingredient per 100 parts by weight of the system polyol. Otherwise, Table 2 lists the same ingredients as listed and described in connection with Table 1 and these ingredients are mixed in the same manner as described in connection with Table 1.

(21) A preheated aluminum mold is used in the production of the molded foam. The aluminum mold has a dimension of about 18 inch18 inch4 inch. The aluminum mold is preheated heated to a temperature range of from about 135 F. to about 145 F.

(22) The mixture was then added to preheated aluminum molds and then cured by passing through a heat chamber set at a temperature of about 125 F. for about 6 minutes to about 8 minutes. The resulting polyurethane foam is then removed from the aluminum mold for Examples 4, 5, 6, and 7. In testing of Examples 4, 5, 6, and 7, the resulting polyurethane foam produced in satisfactory fire performance results which met the testing criteria the FRA, FTA, and NFPA. The physical and fire characteristics of the resulting polyurethane foam are shown in Table 2.

(23) As shown in the Table 2, resulting polyurethane foam in Examples 4 through 7 were prepared with an isocyanate index of 70, 80, 90, and 100 and exhibited Flame Spread Index (l.sub.s) values below 10 with no flaming running or flaming dripping and specific optical density of smoke values (D.sub.s) for flaming mode and non-flaming mode during testing in accordance with ASTM E 662 below 100 at 1.5 minutes and below 175 at 4.0 minutes. The maximum corrected specific optical density of smoke value is D.sub.max (con) for flaming mode and non-flaming mode during testing in accordance with ASTM E 662 as shown in Table 2.

(24) Accordingly, the resulting polyurethane foams of Examples 4, 5, 6, and 7 produced satisfactory results in terms of meeting the testing criteria of the FRA, ETA, and NFPA.

(25) TABLE-US-00002 TABLE 2 The effect of isocyanate index variation on physical and flammability characteristics of the resulting polyurethane foam. Examples 4 5 6 7 Isocyanate Index 70 80 90 100 Ingredients System polyol (a) 100 100 100 100 Amine catalyst (h) 0.25 0.25 0.25 0.25 Organometallic tin catalyst (i) 0.05 0.05 0.05 0.05 Graphite (f) 35 35 35 35 Ammonium polyphosphate (g) 18 18 18 18 Organophosphorus Flame retardant (e) 25 25 25 25 Organic polyisocyanate (n) 67.2 76.8 86.4 96.0 Physical characteristics Density (pcf) (as per ASTM 4.68 4.60 4.71 4.76 D 3574-Test A) IFD at 25% at 4 inch (lbs) 29.4 51.3 71.8 86.6 (as per ASTM D 3574-Test B.sub.1) Tensile strength (lb/sq.in) 8.3 12.7 16.0 24.0 (as per ASTM D 3574-Test E) Elongation (%)(as per ASTM 60 49 49 55 D 3574-Test E) Resilience (%)(as per ASTM 46 46 44 42 D 3574-Test H) Compression Set (%) 23.1 18.2 17.8 20.0 (as per ASTM D 3574-Test D, 50% constant deflection) Flame Spread Index (I.sub.s) (as per 7.01 8.21 7.78 8.50 ASTM D 3675) Specific optical density of smoke D.sub.s 1.5 min (Non-flaming mode) 80 79 84 89 (as per ASTM E 662) D.sub.s 4.0 min (Non-flaming mode) 132 134 146 150 (as per ASTM E 662) D.sub.max (corr) (Non-flaming mode) 154 158 163 167 (as per ASTM E 662) D.sub.s 1.5 min (Flaming mode) 68 63 67 48 (as per ASTM E 662) D.sub.s 4.0 min (Flaming mode) 144 149 156 135 (as per ASTM E 662) D.sub.max (corr) (Flaming mode) 180 184 185 169 (as per ASTM E 662)

Examples 5 and 8-13

(26) For Examples 5 and 8-13 as referenced in Table 3, a comparison is shown with respect to a resulting polyurethane foam that uses the flame retardant agent (specifically, Examples 5 and 11 through 13) versus polyurethane foams that do not use the flame retardant agent (i.e., each of the polyurethane foams were not formulated with at least one ingredient of the flame retardant agent) (specifically, Examples 8 through 10). The respective ingredients of Examples 5 and 11 through 13 were combined in the same manner as described previously in connection with Examples 1, 2, and 3. The ingredients as indicated in respective Examples 8-10 are combined by mixing two ingredients of the flame retardant agent in the respective amounts indicated in the Table 3 with system polyol (Specflex NF766 from Dow Chemical Corporation) in the presence of an amine catalyst (DABCO 33LV from Air Products and Chemicals, Inc.) and an organometallic tin catalyst (DABCO T-12 from Air Products and Chemicals, Inc.), The respective amount of Voralux HE 150, calculated based on isocyanate index of 80 was then added and mixed.

(27) Table 3 indicates the amounts listed of the respective ingredients for Examples 5 and 8 through 13.

(28) Only Examples 5 and 11 through 13 show satisfactory fire performance in terms of satisfying the testing criteria of the FTA, FRA, and the NFPA whereas Examples 8 through 10 show unsatisfactory fire performance criteria; accordingly, Examples 8 through 10 do not satisfy the FTA, FRA, and NFPA testing criteria.

(29) The amount listed for each ingredient is parts by weight of the ingredient per 100 parts by weight of the system polyol.

(30) TABLE-US-00003 TABLE 3 The effect of individual flame retardant ingredients on physical and flammability characteristics of polyurethane foam. Examples 5 8 9 10 11 12 13 Isocyanate Index 80 80 80 80 80 80 80 Ingredients System polyol (a) 100 100 100 100 100 100 100 Amine catalyst (h) 0.25 0.25 0.25 0.25 0.25 0.25 0.25 Organometallic tin 0.05 0.05 0.05 0.05 0.05 0.05 0.05 catalyst (i) Expandable Graphite 35 35 35 35 (f) Expandable Graphite 35 (f*) Expandable Graphite 35 (f**) Ammonium 18 18 18 18 18 polyphosphate (g) Ammonium 18 polyphosphate (g*) Organophosphorus 25 25 25 25 25 25 Flame retardant (e) Organic 76.8 58.4 76.8 76.8 76.8 76.8 76.8 polyisocyanate (n) Physical characteristics Density (pcf) 4.60 4.60 4.50 4.34 4.72 4.66 4.15 (as per ASTM D 3574 - Test A) IFD at 25% at 4 inch 51.3 30.82 37.84 43.35 52.9 30.20 31.68 (lbs) (as per ASTM D 3574 -Test B.sub.1) Resilience (%) 46 48 43 37 47 35 43 (as per ASTM D 3574-Test H) Tensile strength (lb/ 12.7 9.1 11.2 14.2 12.8 11.7 13.5 sq. in) (as per ASTM D 3574 - Test E) Elongation (%)(as per 49 51 52 56 46 64 54 ASTM 3574 D - Test E) Resilience (%)(as per 46 48 43 37 47 35 43 ASTM 3574 D - Test H) Compression Set (%) 18.2 15.7 25.7 14.6 21.0 24.5 21.1 (as per ASTM D 3574-Test D, 50% constant deflection) Flame Spread Index 8.21 425.6 442.8 682.8 9.04 16.0 11.0 (I.sub.s) (as per ASTM D 3675) Specific optical density of smoke D.sub.s 1.5 min (Non- 79 63 66 59 82 98 96 flaming mode) (as per ASTM E 662) D.sub.s 4.0 min (Non- 134 106 113 167 140 157 159 flaming mode) (as per ASTM E 662) D.sub.max (corr) (Non- 158 124 153 179 162 191 182 flaming mode) (as per ASTM E 662) D.sub.s 1.5 min (Flaming 63 25 58 309 61 49 54 mode) (as per ASTM E 662) D.sub.s 4.0 min (Flaming 149 80 130 355 155 155 152 mode) (as per ASTM E 662) D.sub.max, (corr) (Flaming 184 115 158 346 193 206 200 mode) (as per ASTM E 662)

(31) Examples 8 Through 10, not Using at Least One Ingredient of Flame Retardant Agent (Examples 8, 9 and 10).

(32) As shown in Table 3, Examples 8, 9, and 10 are polyurethane foams that were formulated without at least one ingredient of the flame retardant agent (i.e., expandable graphite, organophosphorus flame retardant, or ammonium polyphosphate). The polyurethane foams of Examples 8, 9, and 10 had a very high flame spread index value (l.sub.s) during testing in accordance with ASTM D 3675. In addition, the polyurethane foam of Example 10 (which, as shown in Table 3, did not have expandable graphite as an ingredient in its formulation) rapidly ignited, exhibiting flaming running and flaming dripping during testing in accordance with ASTM D 3675 which ultimately consumed the test specimen within a very short period of time and the specific optical density of smoke value (D.sub.s) during testing in accordance with ASTM E 662 was also very high. Additionally, in testing the polyurethane foam of Examples 8 and 9, fly ash formation was observed during testing and exhibited very high flame spread index values (l.sub.s) during testing in accordance with ASTM D 3675. Accordingly, the polyurethane foams of Examples 8, 9, and 10, which all lacked at least one ingredient of the flame retardant agent, did not satisfy the FTA, FRA, and NFPA testing criteria.

(33) Comparison of Resulting Polyurethane Foams Using Standard Vs. Microencapsulated Ammonium Polyphosphate (Example 11 vs. Example 5).

(34) As shown in Table 3, Example 11 shows the flammability and physical characteristics of the resulting polyurethane foam prepared using standard ammonium polyphosphate (Exolit AP 422 from Clariant Corporation) instead of microencapsulated ammonium polyphosphate (Exolit AP 462 grade) which was used in Example 5.

(35) As shown in Table 3, the resulting polyurethane foams of Example 5 and Example 11 exhibited almost identical flammability and physical characteristics for resulting polyurethane foams that were formed using Exolit AP 422 (standard ammonium polyphosphate) and Exolit AP 462 (microencapsulated ammonium polyphosphate).

(36) Accordingly, regardless of whether the resulting polyurethane foam used standard ammonium polyphosphate or microencapsulated ammonium polyphosphate, the resulting polyurethane foam met the FTA, FRA, and NFPA testing criteria.

(37) Effect of Different Grades of Expandable Graphite on Resulting Polyurethane Foams (Examples 12 and 13).

(38) As shown in Table 3, Examples 12 and 13 illustrate use of different grades of expandable graphite with flake size of from about 44 microns (0.044 mm) to about 1000 microns (1.0 mm) in a resulting polyurethane foam. Expandable graphite used in Example 12 was the 3494 grade expandable graphite available from Asbury Graphite Mills, Inc. with particle size distribution from about 44 microns (about 0.044 mm) to about 300 microns (about 0.300 mm).

(39) Expandable graphite used in Example 13, Grafguard 160-80N, was a pH neutral grade of expandable graphite with typical mean particle size of about 250 microns (about 0.250 mm) available from Graftech International Holdings Inc. (formally Ucar Carbon Company).

(40) Accordingly, only the resulting polyurethane foams as shown in Examples 5 and 11 through 13 satisfied the FTA, FRA, and NFPA testing criteria by meeting the requirements of the testing criteria. Additionally, when exposed to high energy flames, the resulting polyurethane foam of Examples 5 and 11 through 13 formed a significant char layer protecting the substrate underneath. Fly ash formation was not observed during ignition of the resulting polyurethane foam.

Example 14

(41) As shown in Table 4, resulting polyurethane foam in the form of a molded foam was prepared with the ingredients in the amounts indicated in Example 14. The amount listed for each ingredient is parts by weight of the ingredient per 100 parts by weight of the polyoxyalkylene polyether polyol. Additionally, a preheated aluminum mold is used in the production of the molded foam. The aluminum mold has a dimension of about 10 inch9 inch4.75 inch. The aluminum mold is preheated heated to a temperature range from about 135 F. to about 145 F.

(42) A mixture of polyoxyalkylene polyether polyol, catalysts, surface active agent, and water as the primary blowing agent as shown in the formulation given in Table 4 was weighed into a paper cup and mixed. Expandable graphite and ammonium polyphosphate was then gradually added with constant mixing followed by the addition of organophosphorus flame retardant. The required amount of organic polyisocyanate was calculated based on an isocyanate index of 80. The organic polyisocyanate was then weighed in a separate container and added to the mixture and then mixed for about 15 seconds.

(43) The mixture was then poured into the preheated aluminum mold and cured for about 8 minutes at room temperature. The resulting foam was removed from the aluminum mold after about 8 minutes to obtain a resulting polyurethane foam that satisfied the FTA, FRA, and NFPA testing criteria by meeting the requirements of the testing criteria.

(44) TABLE-US-00004 TABLE 4 The physical and flammability characteristics of the resulting flexible polyurethane foam in molded form. Example 14 Isocyanate Index 80 Polyoxyalkylene polyether polyol (b) 100 Primary blowing agent (q) 4.50 Surface active agent (I) 1.00 Crosslinker (k) 1.00 Amine catalyst (h) 0.50 Amine blow catalyst (j) 0.10 Organometallic tin catalyst (i) 0.25 Expandable Graphite (f) 35 Ammonium polyphosphate (g) 18 Organophosphorus Flame retardant (e) 25 Organic polyisocyanate (n) 78 Physical characteristics Molded density (pcf) (as per ASTM D 3574-Test A) 4.43 IFD at 25% at 4 inch (lbs) (as per ASTM D 3574-Test B.sub.1) 23.24 Tensile strength (lb/sq. in) (as per ASTM D 3574-Test E) 14.91 Elongation (%) (as per ASTM D 3574Test E) 61 Resilience (%) (as per ASTM D 3574-Test H) 42 Compression Set (%) (as per ASTM D 3574-Test D, 18.07 50% constant deflection) Flame Spread Index (I.sub.s) (as per ASTM D 3675) 6.89 Specific optical density of smoke D.sub.s 1.5 min (Non-flaming mode) (as per ASTM E 662) 73 D.sub.s 4.0 min (Non-flaming mode) (as per ASTM E 662) 124 D.sub.max (corr) (Non-flaming mode) (as per ASTM E 662) 147 D.sub.s 1.5 min (Flaming mode) (as per ASTM E 662) 76 D.sub.s 4.0 min (Flaming mode) (as per ASTM E 662) 156 D.sub.max (corr) (Flaming mode) (as per ASTM E 662) 189

Example 15Prepolymer Method

(45) As shown in Table 5 which references Example 15, a resulting polyurethane foam has been formed using a prepolymer method with the ingredients and amounts indicated. Reactive organophosphorus flame retardant is reacted with organic polyisocyanate and a portion of the organometailic tin catalyst from the foaming agent to form a prepolymer.

(46) System polyol (which, as defined above, includes a polyoxyalkylene polyether polyol and a foaming agent), expandable graphite, and ammonium polyphosphate are then mixed together in the further presence of a remaining portion of the foaming agent to form a component. The prepolymer and the component are then reacted in the further presence of the remaining portion of the foaming agent to obtain a resulting polyurethane foam that satisfied the FTA, FRA, and NFPA testing criteria by meeting the requirements of the testing criteria. The ingredients, the respective amounts of the ingredients, and physical and flammability properties are shown in the Table 5. The amount listed for each ingredient is parts by weight of the ingredient per 100 parts by weight of the system polyol.

(47) TABLE-US-00005 TABLE 5 Resulting Polyurethane Foam Formed Using Prepolymer Method. Example 15 Isocyanate Index 80 Prepolymer Organophosphorus flame retardant (e) 25 Organic polyisocyanate (n) 76.8 Organometallic tin catalyst (i) 0.25 Component System polyol (a) 100 Amine catalyst (h) 0.25 Organometallic tin catalyst (i) 0.20 Expandable graphite (f) 35 Ammonium polyphosphate (g) 18 Physical characteristics Molded density (pcf) (as per ASTM D 3574-Test A) 4.05 IFD at 25% at 4 inch (lbs) (as per ASTM D 3574-Test B) 27.64 Tensile strength (lb/sq. in) (as per ASTM D 3574-Test E) 12.6 Elongation (%) (as per ASTM D 3574-Test E) 65.3 Resilience (%) (as per ASTM D 3574-Test H) 45 Compression Set (%) (as per ASTM D 3574-Test D, 17.15 50% constant deflection) Flame Spread Index (I.sub.s) (as per ASTM D 3675) 7.08 Specific optical density of smoke D.sub.s 1.5 min (Non-flaming mode) 73 D.sub.s 4.0 min (Non-flaming mode) 128 D.sub.max (corr) (Non-flaming mode) 157 D.sub.s 1.5 min (Flaming mode) 81 D.sub.s 4.0 min (Flaming mode) 150 D.sub.max (corr) (Flaming mode) 182

Example 16-19

(48) In Table 6 which references Examples 16 through 19, a preparation of resulting polyurethane foam in a viscoelastic foam has been prepared with ingredients in the respective amounts indicated. The viscoelastic foam was prepared in a molded form and slabstock form. Examples 16 and 19 are related to slabstock foam and Examples 17 and 18 are related to molded foam. In examples 17 and 18 an aluminum mold of about 10 inch9 inch4.75 inch was used for the molded foam. The aluminum mold was preheated at a temperature within the range from about 135 F. to about 145 F. In examples 16 and 19, slabstock foams were prepared in a preheated cardboard box of about 16 inch12 inch12 inch. The cardboard box was preheated at a temperature of about 135 F.

(49) Polyoxyalkylene polyether polyols, catalysts, surface active agent, and blowing agent were weighed into a paper cup and mixed. Expandable graphite and ammonium polyphosphate were then added to the mixture and mixed. Organophosphorus flame retardant was then added and mixed.

(50) The amount of organic polyisocyanate was calculated based on the indicated isocyanate index in Table 6.

(51) The organic polyisocyanate was added to the mixture and the mixture was mixed for about 20 seconds. The mixture was then poured into the preheated aluminum mold to make molded foams and poured into a preheated cardboard box to make slabstock foams, respectively, and the resulting polyurethane foam was removed from the aluminum mold and cardboard box, respectively, after about 10 minutes to obtain a resulting molded and slabstock polyurethane foam that satisfied the FTA, FRA, and NFPA testing criteria by meeting the requirements of the testing criteria.

(52) The amount listed for each ingredient in Table 6 is parts by weight of the ingredient per 100 parts by weight of the polyoxyalkylene polyether polyol.

(53) TABLE-US-00006 TABLE 6 Viscoelastic foam formulations and flammability and physical characteristics of the foam. Examples 16 17 18 19 Ingredients Polyoxyalkylene Polyether polyol (c) 97 97 97 97 Polyoxyalkylene Polyether polyol (d) 3 3 3 3 Primary blowing agent (q) 2.00 2.00 2.00 2.00 Surface active agent (m) 1.25 1.25 1.25 1.25 Amine catalyst (h) 0.90 1.50 1.50 1.50 Amine catalyst (j) 0.20 0.20 0.20 0.20 Organometallic tin catalyst (i) 0.30 0.30 0.30 0.30 Expandable Graphite (f) 35 27 27 27 Ammonium polyphosphate (g) 18 18 18 18 Organophosphorus flame retardant (e) 25 25 25 25 Organic polyisocyanate (n) 50.55 57.67 Organic polyisocyanate (o) 58.93 58.93 Auxiliary blowing agent (r) 5.00 Physical Characteristics Density (pcf) (as per ASTM 5.90 9.50 7.30 6.00 D 3574-Test A) IFD (lbs) at 25% at 3 inch (as per 5.44 ASTM D 3574-Test B.sub.1 ) Tensile strength (lb/sq. in) (as per 6.34 5.84 14.2 ASTM D3574-Test E) Elongation (%) (as per ASTM 85.3 61.3 56.0 D 3574-Test E) Resilience (at 3) (%) (as per ASTM 7 10 11 D 3574-Test H) Compression Set (%) (as per ASTM D 3574-Test D, 50% constant deflection) Flame Spread Index (I.sub.s) 18.26 15.46 10.95 4.80 (as per ASTM D 3675) Specific optical density of smoke D.sub.s 1.5 min (Non-flaming mode) 72 64 64 72 (as per ASTM E 662) D.sub.s 4.0 min (Non-flaming mode) 129 118 123 142 (as per ASTM E 662) D.sub.max (corr) (Non-flaming mode) 142 153 164 184 (as per ASTM E 662) D.sub.s 1.5 min (Flaming mode) 62 58 69 75 (as per ASTM E 662) D.sub.s 4.0 min (Flaming mode) 138 142 168 157 (as per ASTM E 662) D.sub.max (corr) (flaming mode) 171 200 215 219 (as per ASTM E 662)

Example 20

(54) The fire retardancy of the resulting polyurethane foam of Example 5 was tested with an Oxygen Consumption calorimeter in accordance with ASTM E 1354 and the results are shown in Table 7. As shown in Table 7, the resulting polyurethane foam of Example 5 had a peak heat release rate of less than 100 kW/m2. The resulting polyurethane foam has a relatively low peak heat release rate.

(55) TABLE-US-00007 TABLE 7 Peak Heat Release Rate for Example 5 foam using Oxygen Consumption Calorimeter During Testing in Accordance with ASTM E 1354. Foam From Example 5 Isocyanate Index 80 Specimen size 4 in 4 in 4 in 4 in Specimen thickness 2 in Specimen initial mass (prior to testing) 34.5 g Heat flux 50 kW/m.sup.2 Orientation Horizontal Peak heat release rate 88.8 kW/m.sup.2

Example 21

(56) Resulting polyurethane foam test specimens were formulated in accordance with Example 6. For comparison purposes, certain resulting polyurethane foam test specimens were not water leached and other resulting polyurethane foam test specimens were water leached in accordance with Federal Standard 191A, Method 5830, Entitled Leaching Resistance of Cloth; Standard Method (Jul. 20, 1978).

(57) Certain resulting polyurethane foam test specimens were not water leached for comparison purposes. Prior to the flame spread testing (as per ASTM D 3675) and smoke density testing (as per ASTM E 662), the resulting polyurethane foam test specimens were weighed and the average mass was derived as shown in Table 8 under the before leaching column. Then, the resulting polyurethane foam test specimens were flame spread tested for flame spread index (l.sub.s) as per ASTM D 3675 and smoke density tested for smoke density values (D.sub.s and D.sub.max (con)) as per ASTM E 662. Results are shown in the before leaching column in Table 8.

(58) For the resulting polyurethane foam test specimens that were selected for water leaching, the resulting polyurethane foam test specimens were soaked continuously for 24 hours in water that was changed every 15 minutes. After the passage of the 24-hour period, the resulting polyurethane foam test specimens were dried to a constant mass. The resulting polyurethane foam test specimens were weighed and the average mass was derived as shown in Table 8 in the after leaching column.

(59) As shown in Table 8, the difference between the average mass of the resulting polyurethane foam test specimens before leaching and after leaching was insignificant (118.0 grams vs. 117.3 grams, respectively). This result indicated that the flame retardant agent was not leached out from the resulting polyurethane foam. In other words, the flame retardant agent was still bound to the polyurethane matrix of the resulting polyurethane foam.

(60) After the passage of the 24-hour period for conditioning the resulting polyurethane foam test specimens, the resulting polyurethane foam test specimens were flame spread tested for flame spread index (l.sub.s) as per ASTM D 3675 and smoke density tested for smoke density values (D.sub.s and D.sub.max (corr)) as per ASTM E 662. The results are shown in Table 8 in the after leaching column.

(61) The test results for average mass, flame spread index, and smoke density values as shown in Table 8 indicate that the flame retardant agent is bound to the polyurethane matrix of the resulting polyurethane foam even after water leaching and that the surface flammability and specific optical density characteristics of the resulting polyurethane foam are permanent and that they satisfied the FTA, FRA, and NFPA testing criteria by meeting the requirements of the testing criteria even after water leaching.

(62) TABLE-US-00008 TABLE 8 Specific Optical Density and Flame Spread Index Values of Resulting Polyurethane Foam Specimen During Testing in Accordance with Federal Standard 191 A, Method 5830. Foam From Example 6 6 Isocyanate Index 90 90 Leaching Before Leaching After Leaching Specimen size 18 in 6 in x 1 in 18 in 6 in 1 in Average specimen mass 118.0 g 117.3 g Flame Spread Index (I.sub.s) 7.78 6.80 (as per ASTM D 7.78 3675) Specific optical density of smoke D.sub.s 1.5 min (Non-flaming mode) 84 69 (as per ASTM E 662) D.sub.s 4.0 min (Non-flaming mode) 146 124 (as per ASTM E 662) D.sub.max (corr) (Non-flaming mode) 163 142 (as per ASTM E 662) D.sub.s 1.5 min (Flaming mode) 67 57 (as per ASTM E 662) D.sub.s 4.0 min (Flaming mode) 156 127 (as per ASTM E 662) D.sub.max (corr) (Flaming mode) 185 159 (as per ASTM E 662)