Treatment of release layer

1. A method for treating a hydrophobic release layer of an intermediate transfer member for use in a printing process in which a negatively charged aqueous inkjet ink including an organic polymeric resin and a colorant is jetted onto said layer, the method comprising contacting the release layer with a chemical agent which is an amine functionalized silicone, the amine functionalized silicone having at least 0.3 wt. % nitrogen per weight of the chemical agent, and an amine number of at least 7 and not more than 300, a molecular weight of at least 500 and not more than 50,000.

2. The method of claim 1 , the chemical agent having no more than one hydroxyl or alkoxy group per molecule of the amine functionalized silicone.

3. The method of claim 1 , wherein silicon atoms constitute at least 33% by weight of the chemical agent.

4. The method of claim 1 , the chemical agent having at least one of (a) at most 1.0 Si—H groups, per molecule of the amine functionalized silicone; and (b) at most 1.0 C═C groups, per molecule of the amine functionalized silicone.

5. The method of any claim 1 , the chemical agent having a kinematic viscosity of at least 10 square millimeters per second (mm 2 /s), and of not more than 1,000,000 mm 2 /s.

6. The method of claim 1 , wherein the positive charge density of the chemical agent is at least 0.1 milliequivalent per gram (meq/g) of the chemical agent.

7. The method of claim 1 , wherein the chemical agent is a polymer which comprises one or more positively chargeable nitrogen atoms, each chargeable nitrogen atom being selected from the group of primary, secondary and tertiary amines and quaternary ammonium groups.

8. The method of claim 1 , wherein the chemical agent is a liquid at about 23° C.

9. The method of claim 1 , wherein the amine functionalized silicone is a compound of formula I:

wherein R is C 1-6 alkyl, the blocks bearing the subscripts x and y may be randomly mixed, the total value of x is from 10 to 5,000, and the total value of y is from 2 to 20.

10. The method of claim 9 , wherein one methyl group of at least one dimethyl siloxane repeat subscripted by x is further substituted by a polyether groups comprising —(OC 2 H 4 ) a (OC 3 H 6 ) b — optionally terminated by a short alkoxyl of 4 carbon atoms or less or an hydroxyl group; a and b being integers.

11. The method of claim 10 , wherein the chemical agent is selected from the group consisting of GP-4 (a compound of formula I wherein R═(CH 2 ) 3 , x=58 and y=4), GP-6 (a compound of formula I wherein R═(CH 2 ) 3 , x=100 and y=4), GP-581 (a compound of formula I wherein R═(CH 2 ) 3 , x=118 and y=11), KF-864 (a compound of formula I having an amine number of about 27-30), X-22 3939A (a compound of formula I wherein part of the dimethyl siloxane repeats are further substituted by polyether groups), and mixtures thereof.

12. The method of claim 1 , wherein the chemical agent is applied to the release layer as a conditioning liquid, and a surplus of said conditioning liquid is evened on or removed from the surface of the transfer member.

13. The method of claim 1 , the method further comprising removing a vehicle or carrier in which the chemical agent is carried, wherein said removing is optionally achieved by evaporation, and wherein the average thickness of the chemical agent on the release layer after evaporation of the vehicle or carrier is not more than 100 nanometers (nm).

14. The method of claim 1 , wherein the hydrophobic outer release layer comprises a silane, silyl or silanol-modified or -terminated polydialkylsiloxane silicone polymer, or hybrids of such polymers.

15. The method of claim 1 , wherein the amine functionalized silicone is a compound of formula II:

wherein x is from 5 to 5,000, and R and R′, which may be the same or different, are each saturated, linear or branched alkyl groups of 1 to 6 carbon atoms.

16. The method of claim 1 , wherein the amine functionalized silicone is a compound of formula III:

wherein the blocks bearing the subscripts x and y may be randomly mixed, the total value of x is from 5 to 5,000, the total value of y is from 1 to 20, and R and R′, which may be the same or different, are each saturated, linear or branched alkyl groups of 1 to 6 carbon atoms.

17. The method of claim 12 , wherein the chemical agent is applied to the release layer so that a thickness of the conditioning liquid on the release layer prior to removal of the bulk of the carrier is less than 100 micrometers (μm).

18. The method of claim 1 , wherein a temperature of the release layer, when contacted with the chemical agent, is at least 40° C. and not more than 150° C.

19. The method of claim 1 , wherein the method further comprises jetting an ink drop to form an ink film on the chemical agent on the release layer, wherein a ratio of charges in the ink film to charges in the chemical agent in a region covered by said ink film is at least at least 10:1.

20. The method of claim 1 , wherein the method further comprises jetting an aqueous inkjet ink image on the release layer having the chemical agent thereupon; the aqueous inkjet ink comprising an aqueous solvent, a colorant which is preferably a pigment, and a negatively chargeable polymeric resin; removing the solvent from the jetted aqueous inkjet ink; and transferring the image to a substrate.