Abstract: PVC compositions disclosed herein comprise PVC resin, a co-precipitated rare earth additive, and an inorganic flame retardant. These PVC compositions demonstrate an improved flame retardance and have UL94 classification with a sample thickness of about 0.8 mm of V-2 or higher. The co-precipitated rare earth additive contains a rare earth and one or more of zinc, aluminum, and magnesium, wherein the co-precipitated rare earth additive contains about 5 to about 95% by weight rare earth measured on an oxide basis. The inorganic flame retardant can be ATO, MDH, ATH, or mixtures thereof. The co-precipitated rare earth additive provides improved properties in comparison to an identical PVC composition containing the components of the co-precipitated additive but added to the PVC composition as a blend of these components rather than a co-precipitant.

Abstract: PVC compositions disclosed herein comprise PVC resin, a rare earth compound, and an inorganic flame retardant. These PVC compositions demonstrate an improved flame retardance and have UL94 classification with a sample thickness of about 0.8 mm of V-2 or higher. The rare earth compound can be rare earth hydroxides, hydrated rare earth oxides, and mixtures thereof. The inorganic flame retardant can be antimony trioxide (ATO), magnesium dihydroxide (MDH), aluminum trihydrate (ATH), and mixtures thereof. The combination of the rare earth compound and inorganic flame retardant forms a synergistic partnership.