PHOSPHITE STABILIZERS FOR IONOMERIC POLYESTER COMPOUNDS
The use of oxidizable phosphorus or phosphorous stabilizers, such as the phosphites, to reduce the color formation of the ionomeric polyester compositions is disclosed.
1 . A composition comprising an oxidizable phosphorus compound and an ionomeric polyester derived from at least one ionomeric monomer wherein at least 90% of the acid units of the ionomeric polyester are derived from the group consisting of terephthalic acid, isophthalic acid, orthophthalic acid, 2,6 dimethylnaphthalic acid, and their respective dimethyl esters and the composition has a total amount of polyester which is the amount of ionomeric polyester polymer plus the amount of non-ionomeric polyester polymer, if present.
2 . The composition of claim 1 wherein the ionomeric monomer is selected from the group consisting of the metal salt of a sulfonate of terephthalic acid, isophthalic acid, orthophthalic acid, 2,6 dimethylnaphthalic acid, and their respective dimethyl esters.
3 . The composition of claim 1 , wherein the oxidizable phosphorus compound is selected from the group consisting of triphenylphosphite, trimethylphosphite, triethylphosphite, (2,4,6-tri-t-butylphenol)2-butyl 2 ethyl 1,3-propanediol phosphite, bis(2,4-di-tert-butylphenyl) Pentaerythritol diphosphite and tetrakis(2,4-di-tert-butylphenyl)4,4-biphenyldiphosphonite.
4 . The composition of claim 2 , wherein the oxidizable phosphorus compound is selected from the group consisting of triphenylphosphite, trimethylphosphite, triethylphosphite, (2,4,6-tri-t-butylphenol)2-butyl 2 ethyl 1,3-propanediol phosphite, bis(2,4-di-tert-butylphenyl) Pentaerythritol diphosphite and tetrakis(2,4-di-tert-butylphenyl)4,4-biphenyldiphosphonite.
5 . The composition of claim 1 , wherein the oxidizable phosphorus compound is present in the range of 15 to 150 parts phosphorus to million parts total polyester polymer.
6 . The composition of claim 2 , wherein the oxidizable phosphorus compound is present in the range of 15 to 150 parts phosphorus to million parts total polyester polymer.
7 . The composition of claim 3 , wherein the oxidizable phosphorus compound is present in the range of 15 to 150 parts phosphorus to million parts total polyester polymer.
8 . The composition of claim 1 , wherein the oxidizable phosphorus compound is present in the range of 30 to 100 parts phosphorus to million parts total polyester polymer.
9 . The composition of claim 2 , wherein the oxidizable phosphorus compound is present in the range of 30 to 100 parts phosphorus to million parts total polyester polymer.
10 . The composition of claim 3 , wherein the oxidizable phosphorus compound is present in the range of 30 to 100 parts phosphorus to million parts total polyester polymer.
11 . The composition of claim 1 , wherein the composition is essentially void of a polyamide polymer.
12 . The composition of claim 2 , wherein the composition is essentially void of a polyamide polymer.
13 . The composition of claim 3 , wherein the composition is essentially void of a polyamide polymer.
14 . The composition of claim 7 , wherein the composition is essentially void of a polyamide polymer.
15 . The composition of claim 1 , wherein the composition further comprises a polyamide polymer in the range of 0.2 percent by weight of the composition to 10 percent by weight of the composition.
16 . The composition of claim 2 , wherein the composition further comprises a polyamide polymer in the range of 0.2 percent by weight of the composition to 10 percent by weight of the composition.
17 . The composition of claim 3 , wherein the composition further comprises a polyamide polymer in the range of 0.2 percent by weight of the composition to 10 percent by weight of the composition.
18 . The composition of claim 7 , wherein the composition further comprises a polyamide polymer in the range of 0.2 percent by weight of the composition to 10 percent by weight of the composition.
19 . The composition of claim 1 wherein the composition is essentially void of an elemental metal reduced by the oxidizable phosphorus compound.
20 . The composition of claim 2 wherein the composition is essentially void of an elemental metal reduced by the oxidizable phosphorus compound.
21 . The composition of claim 3 wherein the composition is essentially void of an elemental metal reduced by the oxidizable phosphorus compound.
22 . The composition of claim 7 , wherein the composition is essentially void of an elemental metal reduced by the oxidizable phosphorus compound.
23 . The composition of claim 17 wherein the composition is essentially void of an elemental metal reduced by the oxidizable phosphorus compound.
24 . The composition of claim 18 wherein the composition is essentially void of an elemental metal reduced by the oxidizable phosphorus compound.
25 . The composition of claim 1 wherein the composition has less than 5 ppm elemental metal.
26 . The composition of claim 2 wherein the composition has less than 5 ppm elemental metal.
27 . The composition of claim 3 wherein the composition has less than 5 ppm elemental metal.
28 . The composition of claim 7 wherein the composition has less than 5 ppm elemental metal.
29 . The composition of claim 17 wherein the composition has less than 5 ppm elemental metal.
30 . The composition of claim 18 wherein the composition has less than 5 ppm elemental metal.
31 . A process for thermally treating the composition of claim 1 , wherein the process comprises the step of:
heating the composition to a temperature above 70° C. for more than 2 minutes in the presence of oxygen.