Oxygen scavenging plastic material

1. A polyether-polyester copolymer comprising

(i) polyether segments wherein at least one polyether segment contains at least one polytetramethylene oxide segment;

(ii) polyester segments;

(iii) bridging elements of the structure —CO—R2-CO—, wherein R2 is an optionally substituted bivalent hydrocarbon residue including 1 to 100 carbon atoms; and

(iv) one or two end-caps R1-O—(C 2 -C 4 —O—) e —*, wherein R1 is an optionally substituted hydrocarbon residue, (C 2 -C 4 -O—) represents the same or different C 2 -C 4 -O repeating unit including 2 to 4 carbon atoms, and e is an integer of from 0 to 1000,

wherein the mass ratio Θ defined as the mass ratio between the endcap content and the overall content of all dicarbonyl structure elements (ii) and (iii) is between 0.001 and 100.

2. The polyether-polyester copolymer as claimed in claim 1 , wherein the polyether segments (i) contain ethylene oxide segments, propylene oxide segments or a combination thereof.

3. The polyether-polyester copolymer as claimed in claim 1 , wherein the polyester segments (ii) are represented by formula (II):

wherein

represents a bond to a bridging element (iii),

R2 and R3 independently of each other are an optionally substituted hydrocarbon residue including 1 to 100 carbon atoms, and

u is an integer between 1 and 50.

4. The polyether-polyester copolymer as claimed in claim 1 , wherein bridging elements are described by formula (III)

wherein R2 represents an optionally substituted hydrocarbon residue including 1 to 100 carbon atoms.

5. The polyether-polyester copolymer as claimed in claim 1 , wherein end-caps are described by the following general formula

R1-O—(C 2 -C 4 —O—) e —*,

wherein R1 is an aliphatic hydrocarbon residue of 1 to 24 carbon atoms, an olefinic hydrocarbon residue of 2 to 24 carbon atoms, or an aromatic hydrocarbon residue of 6 to 14 carbon atoms,

wherein said hydrocarbon residues are optionally substituted with C 1 -C 5 -alkoxy, nitro, cyano, sulfo, or a combination thereof, and

wherein e is an integer of between 0 and 500.

6. The polyether-polyester copolymer as claimed in claim 1 , wherein R1-O—(C 2 -C 4 —O—) e —* corresponds to the following formulae

wherein the different monomers of the formulae are randomly distributed, in blocks, or a combination of randomly distributed and block, and

b is an integer between 0 and 250,

a is an integer between 0 and 250,

c is an integer between 0 and 70,

and the sum a+b+c is of from 0 to 570;

wherein R1 is an aliphatic hydrocarbon residue of 1 to 24 carbon atoms, an olefinic hydrocarbon residue of 2 to 24 carbon atoms, or an aromatic hydrocarbon residue of 6 to 14 carbon atoms,

wherein said hydrocarbon residues are optionally substituted with C 1 -C 5 -alkoxy, nitro, cyano, sulfo, or a combination thereof.

7. The polyether-polyester copolymer as claimed in claim 1 , wherein R1 is methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, n-pentyl, iso-pentyl, sec-pentyl, neo-pentyl, 1,2-dimethylpropyl, iso-amyl, n-hexyl, sec-hexyl, n-heptyl, n-octyl, 2-ethyl-hexyl, n-nonyl, n-decyl, tridecyl, isotridecyl, tetradecyl, hexadecyl, octadecyl, methylphenyl cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, or cyclodecyl.

8. The polyether-polyester copolymer as claimed in claim 1 , wherein the polyether-polyester copolymer has a number average molecular weight between 2000 and 1000000 g/mol.

9. The polyether-polyester copolymer as claimed in claim 1 , wherein the mass ratio Ω defined as the mass ratio between the poly(tetramethyleneoxide) content and the overall content of all dicarbonyl structure elements (ii) and (iii) is between 0.1 and 10.

10. The polyether-polyester copolymer as claimed in claim 1 , wherein the mass ratio Θ is between 0.005 and 50.

11. A method of preparing a polyether-polyester copolymer as claimed in claim 1 comprising polycondensation of (i) at least one polyether segment diol containing at least one polytetramethylenoxide segment, (ii) at least one polyester segment having dibasic acids, or anhydrides, (iii) at least one bridging element dibasic acids, or esters or anhydrides and (iv) at least one end-cap R1-O—(C 2 -C 4 —O—) e —* having a hydroxy end group.

12. An active oxygen barrier composition comprising a polyether-polyester copolymer as claimed in claim 1 and a transition metal catalyst.

13. A plastic material comprising:

a component a) which is a thermoplastic polymer;

a component b) which is a polyether-polyester copolymer as claimed in claim 1 ; and

a component c) which is a transition metal catalyst.

14. The plastic material as claimed in claim 13 , which is a masterbatch, a compound or a formed article.

15. The plastic material as claimed in claim 13 which is or which is part of a container or a film.

16. A polyether-polyester copolymer comprising

(i) polyether segments wherein at least one polyether segment contains at least one polytetramethylene oxide segment;

(ii) polyester segments;

(iii) bridging elements of the structure —CO-R2-CO—, wherein R2 is an optionally substituted bivalent hydrocarbon residue including 1 to 100 carbon atoms; and

(iv) one or two end-caps R1-O—(C 2 -C 4 —O—) e —*, wherein (C 2 -C 4 —O—) represents the same or different C 2 -C 4 —O repeating unit including 2 to 4 carbon atoms, and e is an integer of from 0 to 1000, and R1 is methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, n-pentyl, iso-pentyl, sec-pentyl, neo-pentyl, 1,2-dimethylpropyl, iso-amyl, n-hexyl, sec-hexyl, n-heptyl, n-octyl, 2-ethyl-hexyl, n-nonyl, n-decyl, tridecyl, isotridecyl, tetradecyl, hexadecyl, octadecyl, methylphenyl cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, or cyclodecyl.

17. The polyether-polyester copolymer as claimed in claim 16 , wherein the polyether segments (i) contain ethylene oxide segments, propylene oxide segments or a combination thereof.

18. The polyether-polyester copolymer as claimed in claim 16 , wherein the polyester segments (ii) are represented by formula (II):

wherein

represents a bond to a bridging element (iii),

R2 and R3 independently of each other are an optionally substituted hydrocarbon residue including 1 to 100 carbon atoms, and

u is an integer between 1 and 50.

19. The polyether-polyester copolymer as claimed in claim 16 , wherein the mass ratio Θ defined as the mass ratio between the endcap content and the overall content of all dicarbonyl structure elements (ii) and (iii) is between 0.001 and 100.

20. An active oxygen barrier composition comprising a polyether-polyester copolymer as claimed in claim 16 and a transition metal catalyst.