Flame-retardant polyurethane foam

Abstract

A thermoset foam comprises from 0.2 to 4.0 wt. % of at least one aliphatic brominated polyether polyol, from 2.0 to 7.0 wt. % of at least one aromatic brominated polyester polyol, and from 2.0 to 7.5 wt. % of at least one flame retardant comprising organo-phosphate, organo-phosphonate, or organo-phosphite, wherein the ratio of the amount of aliphatic bromine expressed as a percentage of total bromine to the amount of aromatic bromine expressed as a percentage of total bromine is from 10:90 to 50:50.

Claims

1. A thermoset polyurethane foam made from a formulation, the formulation comprising at least one isocyanate, at least one bromine-free polyol, at least one aliphatic brominated polyether polyol, and at least one aromatic brominated polyester polyol; the formulation being free of n-propyl bromide (nPBr) and tris(1-chloro-2-propyl) phosphate (TCPP), the formulation comprising: from 0.2 to 4.0 wt. % of at least one reactive aliphatic brominated polyether polyol, from 2.0 to 7.0 wt. % of at least one aromatic brominated polyester polyol, and from 2.0 to 7.5 wt. % of at least one flame retardant comprising organo-phosphate, organo-phosphonate, or organo-phosphite, wherein the ratio of the amount of aliphatic bromine expressed as a percentage of total bromine to the amount of aromatic bromine expressed as a percentage of total bromine is from 10:90 to 50:50; and wherein the foam passes ASTM E84 and UL 723 tunnel fire tests in core, faced, and slit configurations, the thermoset polyurethane foam having a total halogen content of 1.61 to 2.55 percent.

2. The foam of claim 1 wherein the flame retardant further comprises an oligomeric alkyl phosphate.

3. The foam of claim 2 wherein the flame retardant is a blend of triethyl phosphate and oligomeric alkyl phosphate.

4. The foam of claim 3 wherein the ratio of triethyl phosphate to oligomeric alkyl phosphate is from 90:10 to 50:50.

5. A composite comprising the foam of claim 1 and at least one facesheet attached to at least one external surface of the foam.

6. The composite of claim 5 wherein the facesheet comprises resin impregnated fiber, plastic, wood or metal.

7. The composite of claim 6 wherein the metal is aluminum.

8. The foam of claim 1 wherein thermoset polyurethane foam has a total bromine content of 1.58 to 2.39 percent.

Description

EXAMPLES

(1) The following examples are given to illustrate the invention and should not be interpreted as limiting it in any way. Examples prepared according to the current invention are indicated by numerical values. Control or Comparative Examples are indicated by letters.

(2) Materials used in the PIR formulations are given in Table 1 and the formulations in Table 2. All parts in Table 2 are by parts per hundred of polyol unless otherwise indicated. Table 3 summarizes the percentages of certain components in the formulations. Fire testing results of comparative and inventive examples are in Table 4.

(3) TABLE-US-00002 TABLE 1 Raw Materials Reference Supplier Brief Description IP9005 Dow Chemical Company, Midland, Polyester polyol MI T563 Terol ® 563 from Huntsman, The Aromatic polyester polyol Woodlands, TX HT5502 Tereate ® HT5502 from Invista, Aromatic polyester polyol Seaford, DE PAPI 20 Dow Chemical Company, Midland, Polymeric methylene MI diphenyldiisocyanate (PMDI) PAPI 27 Dow Chemical Company, Midland, Polymeric methylene MI diphenyldiisocyanate (PMDI) V504 Vorasurf ® V504 from Dow Polyethylene oxide -butylene Chemical Company, Midland, MI oxide-polyethylene oxide triblock polymer surfactant TMR 20 Dabco ® TMR20 from Evonik A potassium carboxylate salt Industries, Parsippany, NJ catalyst 470X Voranol ® 470X from Dow A Mannich polyether 30 30 Chemical Company, Midland, MI polyol 9887E Pel-Cat 9887E from Ele Catalyst blend Corporation, McCook, IL 9887F Pel-Cat 9887F from Ele Catalyst blend Corporation, McCook, IL nPBR 1 bromopropane blowing agent TBP Tetrabromophthalatediol from Flame retardant Chemtura Corporation, Philadelphia, PA TCCP Tris(chloroisopropyl)phosphate flame retardant B251 Ixol ™ B251 from Solvay, Houston, Aliphatic brominated polyol - TX triethylphosphate flame retardant blend. TEP Triethylphosphate flame retardant PNX Fryol ™ PNX from ICL Industrial Alkylphosphate flame Products, Creve Coeur, MO retardant Pentane Blowing agent comprising 80 wt. % c-C5 (CAS nr. 287-92-3) and 20 wt. % i-C5 (CAS nr. 78- 78-4) DMB 2,2 dimethylbutane blowing agent 1233zd 1-chloro-3,3-trifluoropropene blowing agent. Mixture of E- and Z- isomers Water Deionized water

(4) TABLE-US-00003 TABLE 2 PIR Formulations Component Comp. Ex. A Comp. Ex. B Ex. 1 Ex. 2 Ex. 3 IP9005 100 100 T563 100 HT5502 100 100 PAPI 20 346 346 609 725 610 PAPI 27 V504 4 4 5.9 7.2 5.98 XX-5314 12.2 TMR 20 10.43 14.22 11 470X 8.82 12.05 9.3 9887E 7.5 9887F 6.7 nPBr 15.91 TBP 12.7 12.8 28.15 39.79 28.67 TCPP 20.1 19.2 B251 4.27 23.29 4.35 TEP 27.64 37.27 28.99 PNX 4 4.08 water 0.8 0.8 2.5 2.7 2.5 Pentane 29.2 27.1 46.51 59.6 49.96 1233zd 12.8

(5) TABLE-US-00004 TABLE 3 Component Percentages Component Comp. Ex. A Comp. Ex. B Ex. 1 Ex. 2 Ex. 3 Trimer % 17.7 17.8 18.0 18.4 17.9 Pentane % 5.45 5.12 5.49 5.84 5.76 Br % 3 1.09 1.59 2.39 1.58 Aliphatic 1.93 0 0.16 0.71 0.16 Br % Cl % 1.64 1.66 0.03 0.16 0.03 Halogen % 4.64 2.75 1.62 2.55 1.61 P % 0.46 0.47 0.64 0.62 0.66

(6) TABLE-US-00005 TABLE 4 Fire Test Results Test Regime Comp. Ex. A Comp. Ex. B Ex. 1 Ex. 2 Ex. 3 ASTM E84 Pass Pass Pass Pass Pass or UL 723 core FSI ASTM E84 Pass Fail Pass Pass Pass or UL 723 slit FSI NFPA 286 Pass N/A Pass Pass Pass Walls Only UL1715 Pass Fail Fail Pass Pass Walls and Ceilings

(7) The data in Table 3 shows: Comp Ex B: without nPBr, the foam boards did not pass E84 slit configuration or UL1715 even though the pentane % was lowered and had relatively high halogen content. Ex 1: with proper Br release profile, the boards were able to pass E84 slit with much lower total halogen. Ex 2: with proper Br release profile, by increasing the reactive aliphatic bromine %, enabled the boards to pass E84 slit and UL 1715 in walls and ceilings configuration. Ex 3: with synergy effect between FR package and silicon surfactant, the boards were able to pass UL1715 full room corner with lower total halogen compared to the control (Comp Ex A).