Flame-retardant flexible

The product is a hquid recommended for flame retarding flexible urethane foams in furniture or automotive seating. It also appears to be useful in polystyrene foam, textile backcoating, and polyester resins. 

Once ignited they produced considerable amounts of heat and smoke. Flame retarded flexible PU foams became available in 1954-55, i.e. within a few years of flexible PU foams becoming available in commercial quantities(22). These FR PU foams contained trichloroethyl phosphate or brominated phosphate esters and resisted ignition from small flame sources. Unfortunately they may burn when subjected to a larger ignition source or when covered by a flammable fabric and may then produce as much heat and more smoke than the standard grade of PU foam(3). This was identified by UK room tests in the early 1970 s and has been confirmed more recently by furniture calorimeter tests at the NBS(21). 

Wallace, W.R. Baumforth, R.J. Flame retardant flexible foam, PCT US Patent 5719199 assigned to Kay-Metzeler Limited, 1998. 

Chemical Description Bromo-Chlor. Paraffin Low cost, highly efficient flame retardant with good color and color stability. Used to flame retard flexible and rigid polyurethane foam, textiles, carpet backing, PVC and adhesives. 

Figure 13. Density profile of integral-skin flexible polyurethane foam. Flame Retardant Flexible Foams...

The high flammability and toxic-gas generation of flexible and rigid urethane foams have been major problems in the urethane-foam industry, and accordingly considerable efforts have been focused on the production of substantially flame-retardant flexible foams. 

Flame retardant flexible foams are very difficult to obtain due to the low crosslink density, low aromaticity, open cell structure and long polyolic aliphatic chains. Generally, flame retardants flexible foams are produced with additive flame retardants, for example with powdered melamine + tris (2-chloropropyl) phosphate [14]. 

Tetrabromobisphenol A di-2-hydroxyethyl ether Tetradecabromodiphenoxybenzene Tetrakis (2-chloroethyl) ethylene diphosphate Tris (2,3-dichloropropyl) phosphate flame retardant, EPS Tribromophenyl allyl ether flame retardant, ethyl cellulose Diphenyl octyl phosphate flame retardant, ethylene copolymers Ethylenebis (tetrabromophthalimide) flame retardant, expandable PS Dibromoethyidibromocyclohexane Tetrabromobisphenol A bis (allyl ether) Tetrabromocyclooctane flame retardant, extruded PS Tetrabromocyclooctane flame retardant, fabrics Antimony pentoxide Methylphosphonic acid, (5-ethyl-2-methyl-2-oxido-1,3,2-dioxaphosphorinan-5-yl) methyl methyl ester flame retardant, fibers Antimony pentoxide Tetrabromoethane flame retardant, filament winding Epoxy resin, brominated flame retardant, film Tetrabromobis (2-ethylhexyl) phthalate flame retardant, fire-retardant material Chlorinated paraffins (C12, 60% chlorine) Chlorinated paraffins (C23, 43% chlorine) flame retardant, flexible PU foam bedding Tetrakis (2-chloroethyl) ethylene diphosphate flame retardant, flexible PU foam furniture Tetrakis (2-chloroethyl) ethylene diphosphate flame retardant, flexible PU foam transportation Tetrakis (2-chloroethyl) ethylene diphosphate flame retardant, flexible PU foams furniture, automobile seating... 

The key material cited is a glass- and ceramic-based system including other ingredients to tailor it for adhesion, flame retardance, flexibility and general compatibility. Avtec advise that it is important to work with their formulation engineers to tailor a system to the eustomer s requirements, especially the chosen catalyst used to avoid any unwanted and unforeseen ehemical reactions. The effect on viscosity is minimal until a 30% loading is reached. A bonus appears to be the enhancement of the appearance and overall aesthetics of moulded parts. 

PVC Alkyl /aryl phosphates Flame retardant flexible compounds... 

It is useful for the preparation of flame-retardant flexible or rigid polyurethane foams. In the foam applications, where it is often used as a blend with a triaryl phosphate such as in SAYTEX RB 7980 (higher hydroxyl number) or RX 8500 (lower hydroxyl number). Its advantage is that it allows flexible polyurethane foam to reach high temperatures in the water-blown foaming step without scorch (thermal damage). 

Chen Ming-Jun, Shao Zhu-Bao, Wang Xiu-Li, Chen Li, and Wang Yu-Zhong. Halogen-free flame-retardant flexible polyurethane foam with a novel nitrogen-phosphorus flame retardant. Ind. Eng. Chem. Res. 51 no. 29 (2012) 9769-9776. 

Flame-retardant flexible PVC compounds that use brominated plasticizers or other additives are likely to contain a tin maleate powder, used as stabilizer in the flame retardant. Available products include Mark 2100A and Reatinor 1044. 

Pure PVC is relatively nonflammable and has in fact been used in a number of applications as the FR component in thermoplastic composites. However, in flexible compounds, the plasticizer converts vinyl into a fire hazard. Non-FR plasticizers such as phthalates and adipates can contribute greatly to the flammability of a composite, as they can be 30 percent or more of its ingredients. Substituting these plasticizers with less flammable types can alter the combustion behavior. There are many different ways of flame-retarding flexible vinyl a typical approach is to use an organopho-sphate as a partial or full substitution of the plasticizer component. However, because of the relative costs of phosphate esters, most users will formulate to the minimum levels necessary to pass FR requirements. 

Uses Used for prod, of flame retarded flexible polyether PU foam synergistic with flame retardants... 

Barium Metaborate. Barium metaborate is used both as a flame retarder and as an antihmgicide for many flexible poly(vinyl chloride) apphcations (19). 

Alumina trihydtate is also used as a secondary flame retardant and smoke suppressant for flexible poly(vinyl chloride) and polyolefin formulations in which antimony and a halogen ate used. The addition of minor amounts of either zinc borate or phosphoms results in the formation of glasses which insulate the unbumed polymer from the flame (21). 

Molybdenum trioxide is a condensed-phase flame retardant (26). Its decomposition products ate nonvolatile and tend to increase chat yields. Two parts of molybdic oxide added to flexible poly(vinyl chloride) that contains 30 parts of plasticizer have been shown to increase the chat yield from 9.9 to 23.5%. Ninety percent of the molybdenum was recovered from the chat after the sample was burned. A reaction between the flame retardant and the chlorine to form M0O2 012 H20, a nonvolatile compound, was assumed. This compound was assumed to promote chat formation (26,27). 

Table 8. Flammability of Flame-Retardant-Treated Flexible PVC ...

Molybdenum Oxide. Molybdenum compounds incorporated into flexible PVC not only increase flame resistance, but also decrease smoke evolution. In Table 10 the effect of molybdenum oxide on the oxygen index of a flexible PVC containing 50 parts of a plasticizer is compared with antimony oxide. Antimony oxide is the superior synergist for flame retardancy but has Httle or no effect on smoke evolution. However, combinations of molybdenum oxide and antimony oxide may be used to reduce the total inorganic flame-retardant additive package, and obtain improved flame resistance and reduced smoke. 

Alumina Trihydrate. Alumina trihydrate is usually used as a secondary flame retardant in flexible PVC because of the high concentration needed to be effective. As a general rule the oxygen index of flexible poly(vinyl chloride) increases 1% for every 10% of alumina trihydrate added. The effect of alumina trihydrate on a flexible poly(vinyl chloride) formulation containing antimony oxide is shown in Figure 5. 

Pentabromodiphenyl Oxide. Pentabromodiphenyl oxide [32534-81-9] (PBDPO) is prepared from diphenyl oxide by bromiaation (36). It is primarily used as a flame retardant for flexible polyurethane foams. For this appHcation PBDPO is sold as a blend with a triaryl phosphate. Its primary benefit ia flexible polyurethanes is superior thermal stabiUty, ie, scorch resistance, compared to chloroalkyl phosphates (see Phosphate esters). 

Antagonism between antimony oxide and phosphoms flame retardants has been reported in several polymer systems, and has been explained on the basis of phosphoms interfering with the formation or volatilization of antimony haUdes, perhaps by forming antimony phosphate (12,13). This phenomenon is also not universal, and depends on the relative amounts of antimony and phosphoms. Some useful commercial poly(vinyl chloride) (PVC) formulations have been described for antimony oxide and triaryl phosphates (42). Combinations of antimony oxide, halogen compounds, and phosphates have also been found useful in commercial flexible urethane foams (43). 

Blends of triaryl phosphates and pentabromodiphenyl oxide are leading flame-retardant additives for flexible urethane foams. A principal advantage is their freedom from scorch. 

Nonreactive additive flame retardants dominate the flexible urethane foam field. However, auto seating appHcations exist, particularly in Europe, for a reactive polyol for flexible foams, Hoechst-Celanese ExoHt 413, a polyol mixture containing 13% P and 19.5% Cl. The patent beHeved to describe it (114) shows a reaction of ethylene oxide and a prereacted product of tris(2-chloroethyl) phosphate and polyphosphoric acid. An advantage of the reactive flame retardant is avoidance of windshield fogging, which can be caused by vapors from the more volatile additive flame retardants. 

Usage of phosphoms-based flame retardants for 1994 in the United States has been projected to be 150 million (168). The largest volume use maybe in plasticized vinyl. Other use areas for phosphoms flame retardants are flexible urethane foams, polyester resins and other thermoset resins, adhesives, textiles, polycarbonate—ABS blends, and some other thermoplastics. Development efforts are well advanced to find appHcations for phosphoms flame retardants, especially ammonium polyphosphate combinations, in polyolefins, and red phosphoms in nylons. Interest is strong in finding phosphoms-based alternatives to those halogen-containing systems which have encountered environmental opposition, especially in Europe. 

Formulations for one-shot polyether systems are similar to those used for flexible foams and contain polyether, isocyanate, catalyst, surfactant and water. Trichloroethyl phosphate is also often used as a flame retardant. As with polyesters, diphenylmethane di-isocyanate is usually preferred to TDI because of its lower volatility. Tertiary amines and organo-tin catalysts are used as with the flexible foams but not necessarily in combination. Silicone oil surfactants are again found to be good foam stabilisers. Volatile liquids such as trichlorofluoro-methane have been widely used as supplementary blowing agents and give products of low density and of very low thermal conductivity. 

C.F. Cullis, Combustion of Flexible Polyurethane Foams. Mechanism and Evaluation of Flame Retardance , Combust Flame 24 (2), 217-30 (1975) CA 83, 82287 (1975)... 

A good example of the many successftil DfE Partnerships is the Furniture Flame Retard-ancy Partnerhip. Pentabromodiphenylether (PentaBDE) was the primary flame retardant used in low density, flexible polyurethane furniture foam. Due to concerns over its use and the fact that the chemical was found widespread in the environment and in human tissue and breast milk, PentaBDE was voluntarily phased out of production by US manufacturers in January 2004. The industry needed alternatives in order to meet furniture flame retardancy requirements, but did not have the human and environmental health and safety information needed in order to compare the alternatives. DfE worked with the furniture manufacturers, foam manufacturers, and flame-retardant chemical suppliers along with governmental and environmental groups to evaluate possible alternatives. 

In recent years, many poly(phosphazenes), [RoPN]n, with a variety of substituents at phosphorus have been prepared and they often exhibit useful properties including low temperature flexibility, resistance to chemical attack, flame retardancy, stability to UV radiation, and reasonably high thermal stability. (1,2) Compounds containing biologically, catalytically, or electrically active side groups are also being investigated. (3,4)... 

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