Zinc hydroxystannate-palygorskite clay compound, its preparation and application as fire retardant

The invention provides a zinc hydroxystannate-palygorskite clay compound which is prepared from raw materials of zinc chloride trihydrate, tin chloride and palygorskite clay by the adoption of a coprecipitation method. The compound has high flame retardancy and high smoke suppression, is used to prepare a flame-retardant polyvinyl chloride material, can replace present antimony series flame-retardation smoke suppressant to obtain a high-molecular material with good flame retardancy, smoke suppression and mechanical properties: oxygen index is not less than 34; horizontal burning reaches HB-a level; vertical burning reaches UL94V-0 level; smoke density under the flameless condition is low and is not greater than 286; tensile strength is more than 10.8 MPa and elongation at break is more than 210%. The zinc hydroxystannate-palygorskite clay compound completely satisfies B1 rule on building material combustion grade in GB/T8624-1997 and rules on each performance of wire and cable sheathed wire materials in the i