Chlorinated flame retardants

There are a relatively small number of producers of halogenated flame retardants, especially for brominated flame retardants, where three producers account for greater than 80% of world production. Table 10 gives estimates of the volumes of brominated and chlorinated flame retardants used worldwide. Volumes of flame retardants consumed in Japan have been summarized (61). Prices of halogenated flame retardants vary from less than 2.00/kg to as high as 13.00/kg. Cost to the user depends on the level of use of the specific flame retardant and other factors such as the use of stabilizers. 

Table 13. Toxicity Data for Chlorinated Flame Retardants and Intermediates ...

Markezich, R. L. Use of alternate synergists with a chlorinated flame retardant in nylon. In FRCA Meeting, Lancaster, PA Fire retardant chemical association, 1987. 

Markezich, R.L. and Aschbacker, D.G., Chlorinated flame-retardant in combination with other flame retardants, ACS Symp. Ser., 599, 65-75, 1995. 

Beryllium and compounds Other chlorinated flame retardants Other brominated flame retardants... 

Tomy, G., Ismail, N., Rleskach, K., Marvin, C., ittle, M., Keir, M., Helm, R (2007) Temporal trends of brominated and chlorinated flame retardants in lake trout (Salvelinus namaycush) from Ontario (1979-2004). In Rroceedings of the 4th International Workshop on Brominated Flame Retardants, Amsterdam, The Netherlands, 24-27 April 2007 (unpaginated). 

Ismail, N., Gewurtz, S. B., et al. (2009) Brominated and chlorinated flame retardants in Lake Ontario, Canada, lake trout (Salvelinus namaycush) between 1979 and 2004 and possible influences of food-web changes. Environmental Toxicology and Chemistry, 28(5) 910-920. 

There is a need for good alternatives for brominated flame retardants. Apart from other disadvantages, the heavy metal antimony is necessary for the production of brominated (or chlorinated) flame retardants. Antimony oxides, Sb205 (used in reactive flame retardants) and Sb203, are used as synergists to increase the efficiency of bromine and chlorine. Bromine and chlorine (together), and antimony oxides are used at a ratio of 1 3 [7]. 

Aliphatic chlorine flame retardants are represented by chloroparaffins, with chlorine content between 40 and 70%. They typically have a poor thermal resistance, as their dechlorination often starts at 180°C (356°F) hence, their application is restricted by polyethylenes and PVC. 

An example of cycloaliphatic chlorine flame retardants is hexachlorocyclo-pentadiene (Dechlorane Plus , or CFR). It is typically used in polyester resins in which hexachlorocyclopentadiene is converted into functional derivatives by maleic anhydride to give the net anhydride. It is the most stable chlorinated flame retardant (CFR). CFR is commonly used in synergism with antimony oxide, zinc borate, zinc oxide, and iron oxides. In Nylon 66, CFR is often used in concentrations of 8-25%, along with 1-10% of Sb203, zinc borate, or iron oxide [11]. 

Chlorinated flame retardants, 470, 472 Disadvantages, 472 Chlorinated paraffins, 163, 174, 472 Chlorine content, 472 Chloroparaffins, 163,472 Thermal resistance, 472 Chlorinated PVC, 89 Chlorothalonil, 447, 449, 457 Choice Dek, 51, 249, 377 Moment of inertia, 249 Chopped glass fiber, 125 Chromated copper arsenate (CCA), 45,416 Ciba Specialty Chemicals, 453, 528, 534 Ciba, 453, 528, 534 Cincinnati Milacron, 472 Clariant, 166, 174... 

Chlorinated flame retardants are much less effective than the equivalent brominated compounds, and are declining in use. The level of chlorination necessary for sufficient flame retardancy often has a detrimental effect on the desired properties of the polymer. Chlorinated paraffins (aliphatics) are used in plastics, textiles, and coatings. Chlorinated aromatics are not used as FRs. 

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... 

Hexabromobiphenyl flame retardant, inks Paraffin, chlorinated flame retardant, insulation Molybdenum trioxide flame retardant, insulation felts Melamine borate... 

DiGangi J, Blum A, Bergman A, de Wit CA, Lucas, D, Mortimer D, Schecter A, Scheringer M, Shaw SD, Webster TF. (2010, Dec). San Antonio statement on Brominated and Chlorinated flame retardants. Environ Health Perspect., 118(12), A516-A518. 

Brominated and chlorinated flame retardants are sold throughout the world by the major producers or their affiliates. The phosphorus flame retardants are more likely to be sold through regional producers particularly in the Asia/Pacific region. Antimony oxide producers, other than Anzon, are regional, although most of the crude material is sourced from the same place, namely, China. ATH is produced by the major aluminum companies, but is upgraded and treated by other processors who sell to the plastics industry. 

Chlorinated flame retardants, unlike brominated ones, have been declining in use. Whereas brominated FRs are acknowledged to be highly effective, the flame retardancy of chlorinated FRs is not seen as sufficient to overcome the perceived disadvantages. 

Dover Chemical Corp. is a subsidiary of ICC Industries Inc. headquartered in New York City. Dover s products are extremely diverse the chemicals made include brominated and bromo-chlorinated flame retardants, benzophenone and hindered amine light stabilisers, phosphite stabilisers, surfactants, lubricants, metallic stearates, and alkyl phenols. It is also a leading manufacturer of chlorinated hydrocarbon waxes, and there are several chemical products unrelated to plastics. 

More recently a report by Hites, Zhu and Hoh [8] was made about how the DP highly chlorinated flame retardant was detected and identified in ambient air, fish and sediment samples in the Great Lakes of the United States with concentrations having once reached 490 pg/cm concentration at the eastern site of Sturgeon Point, New York State. 

GE Advanced Materials was formed by the merger of the Plastics, Silicons and Quartz Divisions. In 2004 the LX2 plant was opened at Cartagena in Spain. Product developments include copolymer Lexan DVD and ecologically friendly compounds for electric and electronic components which are non-brominated and non-chlorinated flame retardant and which are intended to conform to WEEE, RoHS and certain voluntary ECO ecological standards. Other markets served include PCB as well as mobile phones and their associated battery cases. 

The following sections concern the use of a chlorinated flame retardant (CFR) in plastics. CFR consists of the Diels-Alder adduct of hexachloro-cyclopentadiene and 1,5-cyclo-octadiene. Some experimental results are given, without the proposal of any mecharusms, which exemplify the flame retardancy improvements obtainable by various synergistic combinations. 

The synergist antimony oxide has been used in combination with halo-genated flame retardants for years to impart flame retardancy to plastics [1]. Today, many highly efficient antimony oxide/halogen systems are used to give flame retardancy properties to a wide variety of polymers. Complete or partial substitutes for antimony oxide in certain polymers have been reported [2] they are ferric oxide, zinc oxide, zinc borate and zinc stannate. Most of these synergists are effective with polyamides and epoxies when using a chlorinated flame retardant. 

The chlorinated flame retardant, CFR (see introductory paragraph above for chemical composition), can also be used in nylons, epoxies and polybutylene terephthalate (PBT) to achieve flame retardancy using... 

The synergistic action between chlorinated and brominated flame retardants to impact flame retardant properties to plastics is not currently well known. In 1976, Gordon, Duffy and Dachs [4] reported the use of mixtures of the chlorinated flame retardant, CFR (see above), and DBDPO (dibromodiphenylene-oxide) to flame retard ABS. A more recent patent to Ilardo and Scharf [5] covers the use of mixtures of chlorinated and... 

R.F. Mundhenke and R.L. Markezich Flame Retarded Plastics Using a Chlorinated Flame Retardant and Mixed Synergists, The Fire Retardant Chemical Association (FRCA) Fall Meeting, October, 1993. 

One chlorinated flame retardant that is useful for high processing polymers such as nylon is Dechlorane Plus . This has good thermal stability and is not prone to dehydrochlorination because the reaction would involve formation of double bonds at bridgehead carbons. 

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