Intermediate transfer member

1. An indirect printing system comprising:

(a) an intermediate transfer member (ITM) having a release layer having an ink reception surface;

(b) a plurality of printing heads configured to apply an ink image to the ink reception surface of the ITM,

wherein:

I. the release layer is formed of a silicone material;

II. the ink reception surface of the release layer is adapted to satisfy at least one of the following structural properties:

(i) a receding contact angle of a droplet of distilled water on said ink reception surface is at most 60°; and

(ii) for a droplet of distilled water deposited on said ink reception surface, a 10 second dynamic contact angle (DCA) is at most 108°; and

III. the release layer has at least one of the following structural properties:

(1) said silicone material consisting essentially of a silicone, or containing, by weight, at least 95% of said silicone; and

(2) functional groups make up at most 5% by weight, of said silicone material.

2. The indirect printing system of claim 1 , wherein said receding contact angle is at most 58°, at most 56°, at most 54°, at most 52°, at most 50°, at most 48°, at most 46°, at most 44°, at most 42°, at most 40°, at most 38°, or at most 37°.

3. The indirect printing system of claim 1 , wherein said functional groups make up at most 3%, at 2%, at most 1%, at most 0.5%, at most 0.2%, or at most 0.1%, by weight, of said silicone material, or wherein said silicone material is substantially devoid of said functional groups.

4. The indirect printing system of claim 1 , wherein a polyether glycol functionalized polydimethyl siloxane is impregnated in said silicone material.

5. The indirect printing system of claim 1 , wherein a total surface energy of the ink reception surface is at least 2 J/m 2 , at least 3 J/m 2 , at least 4 J/m 2 , at least 5 J/m 2 , at least 6 J/m 2 , at least 8 J/m 2 , or at least 10 J/m 2 higher than a total surface energy of a modified ink reception surface produced by subjecting an ink reception surface of a corresponding release layer to 160° C. for 2 hours.

6. The indirect printing system of claim 1 , wherein the silicone material is a cured silicone material, and wherein a total surface energy of the ink reception surface is at least 4 J/m 2 , at least 6 J/m 2 , at least 8 J/m 2 , at least 10 J/m 2 , at least 12 J/m 2 , at least 14 J/m 2 , or at least 16 J/m 2 more than a total surface energy of a hydrophobic ink reception surface of a corresponding release layer prepared by air exposure curing of a silicone precursor of the cured silicone material.

7. The indirect printing system of claim 1 , wherein the silicon material is a silicone cured material, and wherein a receding contact angle of a droplet of distilled water on the ink reception surface is at least 7°, at least 8°, at least 10°, at least 12°, at least 15°, at least 18°, or at least 20° lower than a receding contact angle of a droplet of distilled water on an ink reception surface of a corresponding release layer prepared by air exposure curing of a silicone precursor of the cured silicone material.

8. The indirect printing system of claim 1 , wherein: (i) the release layer of the ITM further has a second surface opposing the ink reception surface, (ii) the release layer is adapted such that polar groups of the ink reception surface have an orientation away from or opposite from the second surface.

9. The indirect printing system of claim 1 , wherein the release layer is adapted such that when the ITM is in an operative mode, with said ink reception surface exposed to an ambient environment, said polar groups of the ink reception surface have an orientation towards or facing said ambient environment.

10. The indirect printing system of claim 1 , configured to transfer the ink image from the ink reception surface of the ITM to substrate.

11. The indirect printing system of claim 1 wherein the silicone material from which the release layer is formed is a cured silicone material and wherein at least one of the following is true:

(1) said cured silicone material consisting essentially of cured silicone, or containing, by weight, at least 95% of said addition-cured silicone;

(2) functional groups make up at most 5%, by weight, of said cured silicone material.

12. The indirect printing system of claim 1 wherein the silicone material from which the release layer is formed is an addition-cured silicone material and wherein at least one of the following is true:

(1) said addition-cured silicone material consisting essentially of an addition-cured silicone, or containing, by weight, at least 95% of said addition-cured silicone;

(2) functional groups make up at most 5%, by weight, of said addition-cured silicone material.

13. An indirect printing system comprising:

(a) an intermediate transfer member (ITM) having a release layer having an ink reception surface, the ITM mounted on a drum or mounted over a plurality of rollers as a belt-like structure; and

(b) a printing station configured to form an ink image, from ink droplets, on the ink reception surface of the ITM,

wherein:

I. the release layer is formed of a silicone material;

II. the ink reception surface of the release layer is adapted to satisfy at least one of the following structural properties:

(i) a receding contact angle of a droplet of distilled water on said ink reception surface is at most 60°; and

(ii) for a droplet of distilled water deposited on said ink reception surface, a 10 second dynamic contact angle (DCA) is at most 108°; and

III. the release layer has at least one of the following structural properties:

(1) said silicone material consisting essentially of a silicone, or containing, by weight, at least 95% of said silicone; and

(2) functional groups make up at most 5%, by weight, of said silicone material.

14. The printing system of claim 13 wherein the ITM is mounted over a plurality of rollers as a belt-like structure.

15. A mounted-ITM system for use in indirect printing, the mounted-ITM comprising:

(a) an intermediate transfer member (ITM) having a release layer having an ink reception surface; and

(b) a support structure selected from the group consisting of: (i) a drum and (ii) a plurality of rollers, said ITM being mounted over the support structure,

wherein:

I. the release layer is formed of a silicone material;

II. the ink reception surface of the release layer is adapted to satisfy at least one of the following structural properties:

(i) a receding contact angle of a droplet of distilled water on said ink reception surface is at most 60°; and

(ii) for a droplet of distilled water deposited on said ink reception surface, a 10 second dynamic contact angle (DCA) is at most 108°; and

III. the release layer has at least one of the following structural properties:

(1) said silicone material consisting essentially of a silicone, or containing, by weight, at least 95% of said silicone; and

(2) functional groups make up at most 5%, by weight, of said silicone material.

16. The mounted-ITM system of claim 15 wherein the ITM is mounted over a plurality of rollers as a belt-like structure.

17. The mounted-ITM printing system of claim 15 wherein the silicone material from which the release layer is formed is a cured silicone material and wherein at least one of the following is true:

(1) said cured silicone material consisting essentially of cured silicone, or containing, by weight, at least 95% of said addition-cured silicone;

(2) functional groups make up at most 5%, by weight, of said cured silicone material.

18. The mounted-ITM system of claim 15 wherein the silicone material from which the release layer is formed is an addition-cured silicone material and wherein at least one of the following is true:

(1) said addition-cured silicone material consisting essentially of an addition-cured silicone, or containing, by weight, at least 95% of said addition-cured silicone;

(2) functional groups make up at most 5%, by weight, of said addition-cured silicone material.

19. The mounted-ITM system of claim 15 , wherein; (i) the release layer of the ITM further has a second surface opposing the ink reception surface, (ii) the release layer is adapted such that polar groups of the ink reception surface have an orientation away from or opposite from the second surface.

20. The mounted-ITM system of claim 15 , wherein the release layer is adapted such that when the ITM is in an operative mode, with said ink reception surface exposed to an ambient environment, said polar groups of the ink reception surface have an orientation towards or facing said ambient environment.