ANTIMICROBIAL POLYMER COMPOSITION FOR SHELF-LIFE EXTENSION

1 . A polymer composition comprising:

(A) a thermoplastic polymer matrix (component A);

(B) 50 to 6000 ppm, related to the polymer composition, of zinc pyrithione (component B);

(C) 50 to 6000 ppm, related to the polymer composition, of silver, optionally in uncharged form or in ionic form comprised in a silver salt (component C);

(D) 100 to 6000 ppm, related to the polymer composition, of a zeolite (component D); and optionally

(E) 0 to 5% by weight, related to the polymer composition, of one or more polymer additives (component E).

2 . The polymer composition of claim 1 , wherein the polymer matrix A comprises or consists of at least one olefinic polymer.

3 . The polymer composition of claim 1 , wherein the polymer matrix A is selected from the group consisting of polyethylene, polypropylene, ethylene-vinyl acetate copolymer, and blends of two or more thereof.

4 . The polymer composition of claim 1 , wherein said polymer composition comprises components B:C in a mass ratio in the range of 1.5:1 to 20:1.

5 . The polymer composition of claim 1 , wherein the zeolite (component D) is a hydrophobic particulate zeolite having a mean average particle size in the range of 0.5 to 50 μm.

6 . The polymer composition of claim 1 , wherein said polymer composition comprises:

(A) a thermoplastic polymer matrix (component A) consisting of an olefinic polymer or a blend of olefinic polymers;

(B) 50 to 6000 ppm, related to the polymer composition, of zinc pyrithione (component B);

(C) 50 to 1500 ppm, related to the polymer composition, of silver, optionally in uncharged form or in ionic form comprised in a silver salt (component C);

(D) 200 to 5000 ppm, related to the polymer composition, of a zeolite (component D); and optionally

(E) 0 to 5% by weight, related to the polymer composition, of one or more polymer additives (component E),

wherein said polymer composition comprises components B:C is a mass ratio of between 2:1 and 20:1.

7 . A masterbatch for preparing a polymer composition of claim 1 , comprising or consisting of:

1 to 85% by weight, related to the masterbatch, of zinc pyrithione;

0.5 to 30% by weight, related to the masterbatch, of silver ions comprised in a silver salt; and optionally

up to 85% by weight, related to the masterbatch, of a zeolite; and optionally

up to 60% by weight of a thermoplastic polymer matrix; and optionally

one or more polymer additives; and optionally

one or more solvents,

wherein the zinc pyrithione:silver ion mass ratio on the masterbatch is in the range of 1.5:1 and 20:1.

8 . A method for preparing a polymer composition of claim 1 , said method comprising the following steps:

(i) providing:

a thermoplastic polymer matrix (component A),

zinc pyrithione (component B),

silver ions (component C),

a zeolite (component D), and optionally

one or more polymer additives (component E); and

(ii) blending components A-D and, optionally, E, at a temperature above the melting temperature of component A.

9 . The method of claim 8 , wherein in step (i), the components B and C and, optionally, component D, component E or component D and E are provided as a masterbatch.

10 . The method of claim 8 , wherein blending of step (ii) is performed by coextruding components A-D and, optionally, E.

11 . The method of claim 8 , wherein said method further comprises step (iii) of preparing a film by a step selected from the list consisting of blow film extrusion, cast film extrusion, and extrusion coating on a solid support.

12 . A food packaging comprising or consisting of a polymer composition of claim 1 .

13 . The food packaging of claim 12 , wherein said food packaging is or comprises a film consisting of the polymer composition.

14 . The food packaging of claim 12 for increasing shelf-life of foodstuff, wherein said foodstuff is contacted with the polymer composition.

15 . The food packaging of claim 14 , wherein the foodstuff is a baked good and increasing shelf-life includes preventing or slowing mildewing.