Barrier layer for a packaging laminate and packaging laminate comprising such barrier layer

1. A barrier layer for a packaging laminate, which barrier layer is made of a cellulose-based hydrolysate

wherein

said barrier layer comprises

ignin and oligo- or polysaccharides, said lignin and oligo- or polysaccharides being at least partly covalently bonded to each other in a matrix; and

at least one co-component;

wherein said at least one co-component is bonded to said lignin and oligo- or polysaccharides by primary and/or secondary bonds;

wherein said barrier layer has an oxygen permeability of less than 50 cm 3 /m 2 /24 h measured according to ASTM D3985-95 at an air humidity of 80% RH, 1 atm and a thickness less than 50 μm for said barrier layer.

2. The barrier layer according to claim 1 , wherein said co-component is an oligomer or a polymer.

3. The barrier layer according to claim 1 , wherein said co-component is a polysaccharide.

4. The barrier layer according to claim 1 , wherein said barrier layer further comprises a plasticizer.

5. A packaging laminate for a packaging container for products being sensitive to oxygen, which packaging laminate comprises a base layer, a first outer layer on one side of the base layer and a second outer layer on the other side of the base layer, and a barrier layer adapted to serve as a gas barrier between the base layer and said first outer layer, wherein

said barrier layer comprises

lignin and oligo- or polysaccharides, said lignin and oligo- or polysaccharides being at least partly covalently bonded to each other in a matrix; and

at least one co-component;

wherein said at least one co-component is bonded to said lignin and oligo- or polysaccharides by primary and/or secondary bonds;

wherein said barrier layer has an oxygen permeability of less than 50 cm 3 /m 2 /24 h measured according to ASTM D3985-95 at an air humidity of 80% RH, 1 atm and a thickness less than 50 μm for said barrier layer.

6. The packaging laminate according to claim 5 , wherein said base layer comprises a paper layer or a cardboard layer.

7. The packaging laminate according to claim 5 , wherein said outer layers comprise polyolefin.

8. A package for oxygen sensitive products, which package is produced by folding and heat sealing of a sheet-shaped or web-shaped blank of a packaging laminate according to claim 5 .

9. Method for manufacturing of the barrier layer according to claim 1 , the method comprising:

providing a cellulose-based hydrolysate comprising lignin and oligo- or polysaccharides, wherein said lignin and oligo- or polysaccharides are at least partly covalently bonded to each other in a matrix;

adding at least one co-component;

bonding said at least one co-component by primary and/or secondary bonds to said lignin and oligo- or polysaccharides, such that said barrier layer has an oxygen permeability of less than 50 cm 3 /m 2 /24 h measured according to ASTM D3985-95 at an air humidity of 80% RH, 1 atm and a thickness less than 50 μm for said barrier layer.

10. The method according to claim 9 , wherein said method for manufacturing said barrier layer also comprises evaluating the amount of lignin and oligo- or polysaccharides and/or the amount of and type of functional groups on the lignin and oligo- or polysaccharides in said provided cellulose-based hydrolysate and on the basis of said evaluation selecting an appropriate co-component.

11. The method according to claim 9 , wherein at least a part of said primary and/or secondary bonds are obtained by organic coupling reactions.

12. The method according to claim 9 , wherein the method comprises adding a plasticizer.

13. The package according to claim 8 , wherein the package is for a foodstuff.

14. The barrier layer according to claim 1 , wherein said co-component is selected from the group consisting of chitosan, micro-fibrillated cellulose, CMC, alginate and a combination thereof.