Metal zinc stannates

Poly (vinyl chloride). PVC is a hard, brittle polymer that is self-extinguishing. In order to make PVC useful and more pliable, plaslict/ers I qv) are added. More often than not the plasticizers are flammable and make Ihe formulation less flame-resistant. The Maine resistance of the polyf vinyl chloride) can he increased by ihe addition of an inorganic llamc-rctardunl synergist, e.g., antimony oxide, mixed metal antimony synergists, zinc borate, molybdenum oxide, zinc stannates. and alumina trihydrale. 

Keywords tin, tin oxide, zinc hydroxystannate, zinc stannate, organotin compounds, antimony trioxide, alumina trihydrate, magnesium hydroxide, titanium dioxide, molybdenum trioxide, iron oxide, zinc borate, alumina, halogenated flame retardants, metal halides, thermal analysis, Mossbauer spectroscopy, fire-retardant mechanism, ultrafine powders, coated fillers. 

STANNITE (Mineral). This mineral is a sulfo-stannate of copper and non, sometimes with some zinc, corresponding to the formula. Uii PeSnS j It is tetragonal brittle with uneven fracture hardness, 4 specific gravity, 4.3-4.5 metallic luster color, gray to black, sometimes tarnished by chalcopyiite stieak, black opaque. The mineral occuts associated witli cassilerile, chalcopyiite. tetrahedrite, and pyrite, probably the result of deposition by hot alkaline solution. Stannite occurs in Bohemia Cornwall, England Tasmania Bolivia, and in the United States in South Dakota. It derives its name from the Latin word for tin, stannum. 

A large number of commercially important plating processes occur from complex ion baths in which the metal is a constituent of an anionic complex, e.g. copper, zinc, cadmium, silver and gold are all commonly plated from cyanide baths, and tin plates from a stannate bath in which [SnIV(OH)6]2 is present. Chromium is commonly plated from a chromate bath although in this case the background medium is acid rather than alkaline. Thus the mechanism of deposition of metals from anionic complexes is of particular interest. It will be instructive to comment on two situations, one occurring in alkaline baths, the other in acidic baths. 

Metallic interlayer (MIL) influences the chemical processes of FR. The role of metal ions in the degradation process has been summarized by Lewin and Endo [30], The advantageous effect of a MIL around metal hydroxide flame retardants was utilized at first by Hornsby et al. [31]. They proposed a zinc-hydroxy-stannate (ZnHSt) layer, the detailed chemical-physical structure and 4.7 nm thickness... 

Solution of zinc, aluminium, and tin in concentrated caustic alkalis evolves hydrogen, with formation of the zincate, aluminate, nnd stannate of the alkali-metal ... 

Salts Compounds formed by the union of acids and bases, by the action of alkalies upon metals, or by the direct union of elements. The term is often incorporated in the common name of salts used as pharmaceuticals bitter salts, epsom salt, or Seidlitz salt (magnesium sulfate), preparing salt (sodium stannate), Preston s salts (ammonium chloride), Rochelle salt or Seignette s salt (potassium and ammonium tartrate), salt of Mars (ferrous sulfate), salt of Saturn (lead acetate), salt of tartar (potassium carbonate), salt of tin (stannous chloride), salt of wisdom (mercury bichloride and ammonium chloride), sore-throat salt (fused potassium nitrate), vinegar salts (calcium acetate), and vomiting salt (zinc sulfate). The term is also applied to some acids, such as salt of lemon or sour salt (citric acid), salt of sorrel (oxalic acid), and spirit of salt (muriatic acid). ... 

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