Antimony pentoxide

Antimony Pentoxide. The second most widely used antimony synergist is antimony pentoxide [1313-60-9] Sb20, produced by the oxidation... 

Table 2. Properties of Antimony Pentoxide and Sodium Antimonate...

Powdered antimony pentoxide is used primarily in plastics. Stabilizers used to prevent the particles from growing are caustic, and can react with the halogen in the formulation. This can result in color formation and a lower flame-retarding efficiency of the system. 

Antimony pentoxide is priced about two to three times higher than the trioxide. However, because it is more efficient than the trioxide, the pentoxide is at least cost-equivalent. Antimony pentoxide is manufactured by both Philadelphia Quartz and Laurel Industries under the Nyacol and Fkeshield trade names. 

Hexafluoroantimonic acid [72121 -43-8] HSbF 6H20, is prepared by dissolving freshly prepared hydrous antimony pentoxide ia hydrofluoric acid or adding the stoichiometric amount of 70% HF to SbF. Both of these reactions are exothermic and must be carried out carefully. 

Nitric acid oxidizes antimony forming a gelantinous precipitate of a hydrated antimony pentoxide (8). With sulfuric acid an indefinite compound of low solubihty, probably an oxysulfate, is formed. Hydrofluoric acid forms fluorides or fluocomplexes with many insoluble antimony compounds. Hydrochloric acid in the absence of air does not readily react with antimony. Antimony also forms complex ions with organic acids. 

Antimony Compounds. The greatest use of antimony compounds is in flame retardants (qv) for plastics, paints, textiles, and mbber. Antimony compounds used in flame retardants are antimony pentoxide, sodium antimonate [15593-75-6] Na[Sb(OH) ], and, most importantly, antimony trioxide. These compounds, when used alone, are poor flame retardants however, when combined with halogen compounds, they produce mixtures that are effective. 

Antimony pentoxide also reacts with a variety of dihydroxy compounds. Thus pyrocatechol yields a crystalline substance ia which three molecules of the diol are associated with one atom of antimony (52). The configuration of this substance has not been estabUshed, but the foUowiag stmcture seems reasonable ... 

A number of complex derivatives of antimony pentoxide with polyhydroxy compounds have been iavestigated as dmgs. The most important of these substances is known as antimony sodium gluconate [16037-91-5] C22H2Q02ySb2 9H20 3Na, which is prepared by the reaction of antimony pentoxide, gluconic acid, and sodium hydroxide (53). 

Antimony trioxide (SbaOj). It is produced from stibnite (antimony sulphide). Some typical properties are density 5.2-5.67 g/cm- pH of water suspension 2-6.5 particle size 0.2-3 p,m specific surface area 2-13 m-/g. Antimony trioxide has been the oxide universally employed as flame retardant, but recently antimony pentoxide (SbaOs) has also been used. Antimony oxides require the presence of a halogen compound to exert their fire-retardant effect. The flame-retarding action is produced in the vapour phase above the burning surface. The halogen and the antimony oxide in a vapour phase (above 315 C) react to form halides and oxyhalides which act as extinguishing moieties. Combination with zinc borate, zinc stannate and ammonium octamolybdate enhances the flame-retarding properties of antimony trioxide. 

All of the organohalogen compounds studied were commercial products obtained from various manufacturers and used as received. Only the DBDPO was purified further by recrystallization for some of the chromatography and thermal analysis experiments. Samples of antimony trioxide and antimony pentoxide were also obtained from commercial sources. The ultrapure antimony trioxide, bismuth trioxide, bismuth metal, antimony metal, dibenzofuran and diphenyl ether were all obtained from Aldrich Chemicals. The poly(propylene) (PP) resin was 0.7 mfi, food grade from Novamont and the poly(ethylene) was unstabilized, high molecular weight, HDPE from American Hoechst. 

N-22 7 Nyacol Products, Inc. Pentabromodiphenyl oxide/ Antimony Pentoxide/Water Durable... 

Sb may be made in the laboratory by reduction of antimony pentoxide with potassium cyanide. 

Sb is oxidized by nitric acid, forming a gelatinous precipitate of bydrated antimony pentoxide. It does not react with cold dilute sulfuric acid. However, reaction occurs in bot concentrated acid an oxysulfate of indefinite composition and low acid-solubdity is formed. It reacts with bydrofluoric acid to form soluble antimony trifluoride and pentafluoride. Hydrochloric acid in the absence of air does not readily attack tbe metal however, finely divided antimony reacts with hot concentrated acid forming chloride salt. 

Antimony pentoxide is used as an ion-exchange resin for a number of cations in acidic solution including Na+ (especially for their selective retentions) and as a polymerization and oxidation catalyst. 

It is oxidized to antimony pentoxide, 86205 on treatment with nitric acid and forms potassium antimony tartrate (tartar emetic, KSb(OH)2 C4H2O6) when heated with acid potassium tartrate. 

Antimony Pentachloride Antimony Pentafluoride Antimony Pentasulfide Antimony Pentoxide Antimony Trichloride Antimony Trioxide Antimony Trisulfide Argon... 

Antimony Arsenite.—When powdered antimony is digested with a concentrated aqueous solution of arsenic acid, and the solution then diluted with water, a precipitate forms, which was described by Berzelius 6 as antimony arsenite. He obtained a similar product by heating a mixture of arsenic and antimony pentoxide it remained as a transparent vitreous mass. The exact composition of these products does not appear to have been investigated. 

Equal weights of antimony pentoxide and pure potassium cyanide are treated as above. The regulus is washed with hot water for the removal of impurities. 

For the preparation of the various indefinite hydrates of antimony pentoxide see references 4, 5, 6. 

Sb2Os (c). Mixter9 measured the heat of the reactions of antimony and antimony pentoxide with sodium peroxide, and his data yield, for Sb205 (c), Q/=235.7. 

Quantitative risk assessments have been performed on a variety of flame-retardants used both in upholstered furniture fabric and foam. The National Research Council performed a quantitative risk assessment on 16 chemicals (or chemical classes) identified by the U.S. Consumer Product Safety Commission (CPSC). The results were published in 2000.88 The 16 flame-retardants included in this NRC study were HBCD, deca-BDE, alumina trihydrate, magnesium hydroxide, zinc borate, calcium and zinc molybdates, antimony trioxide, antimony pentoxide and sodium antimonate, ammonium polyphosphates, phosphonic acid, (3- [hydroxymethyl]amino -3-oxopropyl)-dimethylester, organic phosphonates, tris (monochloropropyl) phosphate, tris (l,3-dichloropropyl-2) phosphate, aromatic phosphate plasticisers, tetrakis (hydroxymethyl) hydronium salts, and chlorinated paraffins. The conclusions of the assessment was that the following flame-retardants can be used on residential furniture with minimal risk, even under worst-case assumptions ... 

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