Process for stabilization of polymer compositions
Stabilized flame retardant polymer compositions containing a hydrated metal compound, e.g., a metal hydroxide, as a flame retardant, when added an effective stabilizing amount of an amine oxide, a hydroxyl amine or mixtures thereof, exhibit desirable physical characteristics of pure polymers due to the stabilizer additives, including excellent color stability, while attaining desirable fire-retardance standards.
1 . A stabilized flame retardant composition comprising:
at least one of a polymer resin;
about 5 to 300 parts by weight of a hydrated metal compound per 100 parts by weight of said polymer resin;
an effective stabilizing amount of a synergistic mixture of:
a) a first stabilizer comprising at least one compound selected from the group consisting of: amine oxide stabilizers, hydroxylamine stabilizers, nitrone stabilizers, nitroxyl stabilizers, benzofuranone stabilizers; quinone methide stabilizers, and monoacrylate esters of 2,2′-alkylidenebisphenol stabilizers; and
b) a second stabilizer comprising at least one compound selected from the group consisting of phosphite and phosphonite stabilizers.
2 . The stabilized flame retardant composition of claim 1 , wherein said hydrated metal compound is a metal hydrates or metal oxide.
3 . The stabilized flame retardant composition of claim 1 , wherein said metal hydroxide is selected from magnesium hydroxide and aluminum hydroxide.
4 . The stabilized flame retardant composition of claim 3 , wherein said polymer resin is one of a polypropylene, polyethylene, Polypropylene blends, e.g. thermoplastic olefin (TPO), thermoplastic elastomer (TPE).
5 . The stabilized flame retardant composition of claim 1 , wherein said first stabilizer additive is an amine oxide.
6 . The stabilized flame retardant composition of claim 1 , wherein said first stabilizer additive is a hydroxyl amine.
7 . The stabilized flame retardant composition of claim 3 , containing at least 5 parts by weight of a magnesium hydroxide per 100 parts by weight of a polypropylene.
8 . A process for the stabilization of a composition comprising at least a polymer resin and about 1 to 100 parts by weight of a hydrated metal compound per 100 parts by weight of said polymer resin, said process comprising adding to a polymer resin composition an effective stabilizing amount of a stabilizer additive selected from one of an amine oxide or a hydroxyl amine.
9 . The process of claim 8 , wherein said hydrated metal compound is a metal hydroxide.
10 . The process of claim 8 , wherein said a metal hydroxide is selected from magnesium hydroxide and aluminum hydroxide.
11 . The process of claim 8 , wherein said polymer resin is a polyolefin.
12 . A process for forming articles having improved melt stability and color stability, said process comprising the steps of:
a) melt blending a composition comprising:
at least one of a polymeric resin;
about 1 to 100 parts by weight of a hydrated metal compound per 100 parts by weight of said polymeric resin; and
an effective stabilizing amount of a synergistic mixture of a first stabilizer additive selected from one of an amine oxide or a hydroxyl amine and a second stabilizer additive selected from one of a phosphite or phosphonite stabilizer;
b) forming shaped articles thereof from said blend.
13 . Articles comprising the composition of claim 1 .
14 . The process of claim 12 , wherein said polymeric resin is one of a polypropylene, polyethylene, or polypropylene blends.
15 . The process of claim 12 , wherein said hydrated metal compound is a metal hydrates or metal oxide.
16 . The process of claim 12 , wherein said stabilizer additive is a hydroxyl amine.
17 . The stabilized flame retardant composition of claim 3 , containing at least 5 parts by weight of a magnesium hydroxide per 100 parts by weight of a polypropylene.
18 . The stabilized flame retardant composition of claim 1 , further comprising at least one of an alkaline metal oxide, an alkali metal salt, and an alkaline earth metal.
19 . The stabilized flame retardant composition of claim 18 , further comprising a calcium carbonate.