Smoke and fire retardants for halogen-containing plastic compositions

Method of preparing a flame and smoke resistant halogen-containing plastic composition which comprises incorporating in said plastic composition from 0.5% to 10% of a solid solution of zinc oxide and an oxide selected from the group consisting of magnesium oxide and calcium oxide present in said solid solution being from 0.1 to 10 parts for each part of zinc oxide, all of the percentages and parts expressed on a weight basis, said solid solution having a specific surface area of greater than about 10 M.sup.2 /g.

A flame and smoke resistant agent for plastic compositions, said agent comprising a mixture of antimony trioxide and a solid solution of zinc oxide and an oxide selected from the group consisting of magnesium oxide, calcium oxide and mixtures thereof, the amount of magnesium oxide and calcium oxide present in said solid solution being from 0.1 to 10 parts for each part of zinc oxide, in which there are from 0.1 to 10 parts of antimony trioxide for each part of the solid solution present in said mixture, the parts expressed on a weight basis, said solid solution having a specific surface area of greater than about 10 M.sup.2 /g.

A flame and smoke retardant composition comprising a solid solution of zinc oxide and at least one other oxide selected from the group consisting of calcium oxide, magnesium oxide and mixtures thereof, the amount of magnesium oxide and calcium oxide present in said solid solution being from 0.1 to 10 parts for each part of zinc oxide, said solid solution having a specific surface area greater than about 10 M.sup.2 /g.

A method of preparing a flame and smoke resistant halogen-containing plastic composition which comprises incorporating in said plastic composition from 0.25% to 10% of a solild solution of zinc oxide and an oxide selected from the group consisting of magnesium oxide, calcium oxide and mixtures thereof, the amount of magnesium oxide and calcium oxide present in said solid solution being effective to provide the zinc oxide with sufficient heat stability to permit processing of the plastic composition at temperatures up to about 200.degree. C., all of the percentages and parts expressed on a weight basis, said solid solution having a specific surface area of above about 10 M.sup.2 /g.

A method of producing a flame and smoke retardant for use in halogen containing plastic compositions comprising calcining zinc oxide and another oxide selected from the group consisting of magnesium oxide, calcium oxide, and mixtures thereof at a temperature and for a time effective to produce a solid solution having flame and smoke retardant properties, said another oxide being present in an amount of about 0.1 to 10 parts by weight for each part of zinc oxide, wherein said temperature and time are sufficient to produce a solid solution having a specific surface area of above about 10 M.sup.2 /g.

A flame and smoke resistant halogen-containing plastic composition, said composition containing therein from 0.25% to 10% of a solid solution of zinc oxide and an oxide selected from group consisting of magnesium oxide, calcium oxide and mixtures thereof, the amount of magnesium oxide and calcium oxide present in said solid solution being effective to provide the zinc oxide with sufficient heat stability to permit processing of the plastic composition at temperatures up to about 200.degree. C., said amount being from 0.1 to 10 parts magnesium oxide and calcium oxide for each part of zinc oxide, all of the percentages and parts expressed on a weight basis, said solid solution having a specific surface area of greater than about 10 M.sup.2 /g.