METHOD FOR IMPROVED POLYESTER RESIN BLENDS FOR OXYGEN SCAVENGING AND PRODUCTS THEREOF

1 . A method for producing an oxygen scavenging resin comprising:

i. reacting an aromatic diacid or its diester, and an ionic diacid or its diester, with a diol and a metal compound to produce an ionic copolyester,

ii. cooling, cutting and drying the ionic copolyester into solid pellets, and

iii. mixing the dried ionic copolyester with a dried oxidizable polymer, provided that the oxidizable polymer is not a partially aromatic polyamide.

2 . The method of claim 1 wherein the reacting of step a) is esterifying or transesterifying.

3 . The method of claim 1 or 2 further comprising adding an additive after step a) and before step b).

4 . The method of any one of claims 1 - 3 further comprising solid state polymerizing ionic copolyester pellets after step b) and before step c).

5 . The method of claim 1 wherein the aromatic diacid or its diester comprises at least 65 mol-% of terephthalic acid or C 1 -C 4 dialkylterephthalate, based on the total moles of diacid or ester.

6 . The method of claim 1 wherein the aromatic diacid or its diester comprises at least 75 mol-% of terephthalic acid or C 1 -C 4 dialkylterephthalate, based on the total moles of diacid or ester.

7 . The method of claim 1 wherein the aromatic diacid or its diester comprises at least 95 mol-% of terephthalic acid or C 1 -C 4 dialkylterephthalate, based on the total moles of diacid or ester.

8 . The method of claim 1 wherein the diol comprises at least 65 mol-% of ethylene glycol, based on the total moles of diols.

9 . The method of claim 1 wherein the diol comprises at least 75 mol-% of ethylene glycol, based on the total moles of diols.

10 . The method of claim 1 wherein the diol comprises at least 95 mol-% of ethylene glycol, based on the total moles of diols.

11 . The method of any of claims 1 to 10 wherein said ionic diacid or its diester has the formula:

wherein R is hydrogen, a C 1 -C 4 -alkyl or a C 1 -C 4 -hydroxyalkyl,

and M+ is a metal ion in a +1 or +2 valence state.

12 . The method of claim 11 wherein the ionic diacid or its diester is present in an amount of from about 0.01 to about 5 mol.-% of the total moles of diacid or ester.

13 . The method of claim 11 wherein the ionic diacid or its diester is present in an amount of from about 0.1 to about 2 mol.-% of the total moles of diacid or ester.

14 . The method of any one of claims 11 to 13 wherein the metal ion is selected from the group consisting of alkali metals, alkaline earth metals and transition metals.

15 . The method of any one of claims 1 to 14 wherein metal in the said metal compound is selected from the group consisting of the first, second and third group of the Periodic Table.

16 . The method of claim 15 wherein said metal is at least one member selected from the group consisting of cobalt, copper, rhodium, ruthenium, palladium, tungsten, osmium, cadmium, silver, tantalum, hafnium, vanadium, titanium, chromium, nickel, zinc, manganese and mixtures thereof.

17 . The method of any one of claims 15 and 16 wherein the counter ion of said metal is at least one member selected from the group consisting of carboxylates, such as neodecanoates, octanoates, stearates, acetates, naphthalates, lactates, maleates, acetylacetonates, linoleates, oleates, palminates or 2-ethyl hexanoates, oxides, borides, carbonates, chlorides, dioxides, hydroxides, nitrates, phosphates, sulfates, silicates and mixtures thereof.

18 . The method of claim 17 wherein said metal is selected from the group consisting of cobalt and zinc, and said counter ion is selected from the group consisting of acetate, stearate and neodecanoate.

19 . The method of any one of claims 15 to 18 wherein said metal compound is in amount of about 25 to about 200 ppm based on the weight of the ionic copolyester.

20 . The method of claim 19 wherein said metal compound is in amount of about 50 to about 150 ppm based on the weight of the ionic copolyester.

21 . The method of any one of claims 1 - 20 wherein said ionic copolyester has an intrinsic viscosity of about 0.6 to 1.0 dl/g.

22 . The method of clam 21 wherein said intrinsic viscosity is about 0.7 to about 0.85 dl/g.

23 . The method of any one of claims 1 to 22 wherein said oxidizable polymer is a polymer comprising an allylic, a benzylic or a α-hydrogen atom adjacent to a functional group, wherein the a-hydrogen atoms is in the backbone of, or as a pendant side-chain to, the polymer chain.

24 . The method of clam 23 wherein said polymer is selected from the group consisting of copolyester ethers, polyesters containing polybutadiene and polyethylene containing benzylic pendant groups.

25 . The method of claim 23 or 24 wherein said oxidizable polymer is present in an amount of from about 1 to 10 weight % of the ionic copolyester.

26 . The method of claim 25 wherein said oxidizable polymer is present in an amount of from about 2 to 7 weight % of the ionic copolyester.

27 . The method of claim 3 or 11 wherein said additive is selected from the group consisting of heat stabilizers, anti-blocking agents, antioxidants, antistatic agents, UV absorbers, toners (for example pigments and dyes), fillers, branching agents, or other typical agents which do not hinder the oxidation of said oxidizable polymer.

28 . A composition made by any one of the methods of claims 1 to 27 .

29 . A method to produce an article comprising: melting the said composition of claim 28 , and molding the melt into an article.

30 . The method of claim 29 wherein the said article is selected from the group consisting of film, sheet, tubing, pipes, fiber, container preforms, injection and blow molded articles such as rigid containers, thermoformed articles, flexible bags and the like and combinations thereof.

31 . The method of claim 30 wherein said article comprises one or more walls comprising the composition.