Security paper

1. A security paper for producing banknotes, check forms, shares, certificates, postage stamps, air tickets or labels for product protection, including a creasable, foldable, multilayer substrate comprising at least one paper layer laminated on both sides all over to plastic foil by way of an adhesive interconnecting the paper layer and plastic foil, wherein at least the plastic foil is equipped with at least one security feature, wherein the plastic foil has a total thickness of 1 to 20 μm on each side of the at least one paper layer and the at least one paper layer has a weight of 50 to 100 g/m 2 .

2. The security paper according to claim 1 , wherein the paper layer is interrupted.

3. The security paper according to claim 1 , wherein the security feature of the plastic foil is selected from a printed image, diffraction structures, a metallization, luminescent substances, thin-film elements, liquid crystals, magnetic pigments, thermochromic substances, photochromic substances and dyes.

4. The security paper according to claim 1 , wherein the security feature is a printed image executed by intaglio printing.

5. The security paper according to claim 1 , wherein the plastic foils on different sides of the paper layer are under different strains.

6. The security paper according to claim 1 , wherein the security paper comprises annual plant fibers.

7. The security paper according to claim 1 , wherein the security paper comprises at least partly of synthetic fibers.

8. The security paper according to claim 1 , wherein the paper layer is equipped at least with a security feature.

9. The security paper according to claim 1 , wherein the security feature in the paper layer is a watermark.

10. The security paper according to claim 1 , wherein the security feature is selected from a security thread, printed image, diffraction structures, a metallization, luminescent substances, thin-film elements, liquid crystals, magnetic pigments, thermochromic substances, photochromic substances and dyes.

11. The security paper according to claim 1 , wherein security features of at least one of the paper layer, the plastic foil or further layers are applied or incorporated in register.

12. The security paper according to claim 1 , wherein security features of at least one of the paper layer, the plastic foil or further layers are applied or incorporated such that they complement each other to form a combined information pattern.

13. A method for producing a creasable security paper for producing banknotes, check forms, shares, certificates, postage stamps, air tickets or labels for product protection, wherein:

a) at least one paper layer is produced in a paper machine, and

b) then the paper layer is laminated on both surfaces of the paper layer all over to plastic foil, the plastic foil being already equipped with at least one security feature or equipped therewith after application, the plastic foil having a total thickness of 1 to 20 μm on each side of the paper layer, wherein the plastic foil is cold-laminated on the paper layer using an adhesive between the paper layer and plastic foil.

14. The method according to claim 13 , wherein the plastic foil is printed after application.

15. The method according to claim 14 , wherein the printing process is intaglio printing.

16. The method according to claim 13 , wherein a water-soluble laminating adhesive is used in cold lamination.

17. The security paper of claim 6 wherein said annual fibers are cotton fibers.

18. The value document of claim 1 , comprising a bank note or check.

19. The security paper of claim 7 , wherein the synthetic fibers are polyamide fibers.

20. The security paper according to claim 1 , wherein the at least one paper layer has a weight of 80-90 g/m 2 .

21. The method for producing a creasable security paper according to claim 13 , wherein the at least one paper layer has a weight of 80-90 g/m 2 .

22. The security paper according to claim 1 , wherein the plastic foil has a total thickness on each side of the at least one paper layer of 6 to 15 μm.

23. The method according to claim 13 , wherein the plastic foil has a total thickness of 6 to 15 μm.