Treatment of release layer

Patent metadata

Field	Value
Publication number	US-9643400-B2
Application number	US-201314382930-A
Country	US
Kind code	B2
Filing date	Mar 5, 2013
Priority date	Mar 5, 2012
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

There is provided 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 a polymeric resin and a colorant is jetted onto said layer, the claimed method comprising contacting the release layer, prior to jetting the ink, with an aqueous solution or dispersion of a positively charged polymeric chemical agent reducing the tendency of a jetted ink droplet to bead up on the intermediate transfer member. Other embodiments, such as hydrophobic release layers having such chemical agents disposed thereupon and printed ink images comprising the same, are also described.

First claim

What is claimed is:

1. A printing process comprising jetting an aqueous inkjet ink containing a negatively charged polymeric resin and a colorant onto a hydrophobic release layer of an intermediate transfer member, further comprising, prior to said jetting, contacting the hydrophobic release layer with an aqueous solution or dispersion of a polymeric chemical agent having a positive charge density of at least 3 meq/g of polymeric chemical agent and an average molecular weight of at least 1,000, provided that if the positive charge density of the polymeric chemical agent is less than 6 meq/g of polymeric chemical agent then the average molecular weight of the polymeric chemical agent is at least 5,000, wherein the polymeric chemical a ent is selected from the group consisting of linear polyethylene imine, branched polyethylene imine, modified polyethylene imine, poly(diallyldimethylammonium chloride), poly(4-vinylpyridine), polyallylamine, a vinyl pyrrolidone-dimethylaminopropyl methacrylamide co-polymer, a vinyl caprolactam-dimethylaminopropyl methacrylamide hydroxyethyl methacrylate terpolymer, a quaternized copolymer of vinyl pyrrolidone and dimethylaminoethyl methacrylate with diethyl sulfate, a guar hydroxypropyltrimonium chloride, a hydroxypropyl guar hydroxypropyltrimonium chloride, and combinations thereof, and further comprising, after said jetting, transferring the ink to a substrate.

2. The method of claim 1 , further comprising removing the aqueous solvent of the polymeric chemical agent prior to said jetting.

3. The method of claim 2 , wherein said jetting comprises jetting an ink drop to form a ink film on the polymeric chemical agent on the hydrophobic release layer, wherein the ratio of charges in the ink film to the charges in the polymeric chemical agent in the region covered by said ink film is at least 2:1.

4. The method of claim 3 , wherein the aqueous inkjet ink comprises a solvent containing water and, optionally, a co-solvent, the water constituting at least 8 wt. % of the ink;
said colorant being dispersed or at least partly dissolved within said solvent, the colorant constituting at least 1 wt. % of the ink;
said negatively charged polymeric resin is dispersed or at least partially dissolved within the solvent, the organic polymeric resin constituting 6 to 40 wt. % of the ink,
wherein the average molecular weight of the organic polymeric resin is at least 8,000,
the ink having (i) a viscosity of 2 to 25 centipoise at at least one temperature in the range of 20-60° C. (ii) a surface tension of not more than 50 milliNewton/m at at least one temperature in the range of 20−60° C. or (iii) both a viscosity of 2 to 25 centipoise at at least one temperature in the range of 20−60° C. and a surface tension of not more than 50 milliNewton/m at at least one temperature in the range of 20−60° C.;
and wherein:
(1) the ink is such that, when substantially dried, (a) at at least one temperature in the range of 90° C. to 195° C., the dried ink has a first dynamic viscosity in the range of 1,000,000 (1×10 6 ) cP to 300,000,000 (3×10 8 ) cP, and (b) at at least one temperature in the range of 50° C. to 85° C., the dried ink has a second dynamic viscosity of at least 80,000,000 (8×10 7 ) cP, wherein the second dynamic viscosity exceeds the first dynamic viscosity;
(2) the weight ratio of the resin to the colorant is at least 1:1; or
(3) (i) the ink is such that, when substantially dried, (a) at at least one temperature in the range of 90° C. to 195° C., the dried ink has a first dynamic viscosity in the range of 1,000,000 (1×10 6 ) cP to 300,000,000 (3×10 8 ) cP, and (b) at at least one temperature in the range of 50° C. to 85° C., the dried ink has a second dynamic viscosity of at least 80,000,000 (8×10 7 ) cP, wherein the second dynamic viscosity exceeds the first dynamic viscosity; and (ii) the weight ratio of the resin to the colorant is at least 1:1.

5. The method of claim 2 , wherein the aqueous inkjet ink comprises a solvent containing water, the method further comprising, after said jetting, removing the solvent from the jetted aqueous inkjet ink; and transferring the image to a substrate.

6. The method of claim 5 , wherein (a) the solvent of the aqueous inkjet ink may optionally comprise, in addition to water, a co-solvent, the water constituting at least 8 wt. % of the ink; (b) the colorant is dispersed or at least partly dissolved within said solvent, the colorant constituting at least 1 wt. % of the ink; and (c) the negatively charged polymeric resin is dispersed or at least partially dissolved within the solvent, the organic polymeric resin constituting 6 to 40 wt. % of the ink,
wherein the average molecular weight of the organic polymeric resin is at least 8,000,
the ink having (i) a viscosity of 2 to 25 centipoise at at least one temperature in the range of 20-60° C., (ii) a surface tension of not more than 50 milliNewton/m at at least one temperature in the range of 20-60° C., or (iii) both a viscosity of 2 to 25 centipoise at at least one temperature in the range of 20-60° C. and a surface tension of not more than 50 milliNewton/m at at least one temperature in the range of 20-60° C.;
and wherein:
(1) the ink is such that, when substantially dried, (a) at at least one temperature in the range of 90° C. to 195° C., the dried ink has a first dynamic viscosity in the range of 1,000,000 (1×10 6 ) cP to 300,000,000 (3×10 8 ) cP, and (b) at at least one temperature in the range of 50° C. to 85° C., the dried ink has a second dynamic viscosity of at least 80,000,000 (8×10 7 ) cP, wherein the second dynamic viscosity exceeds the first dynamic viscosity;
(2) the weight ratio of the resin to the colorant is at least 1:1; or
(3) (i) the ink is such that, when substantially dried, (a) at at least one temperature in the range of 90° C. to 195° C., the dried ink has a first dynamic viscosity in the range of 1,000,000 (1×10 6 ) cP to 300,000,000 (3×10 8 ) cP, and (b) at at least one temperature in the range of 50° C. to 85° C., the dried ink has a second dynamic viscosity of at least 80,000,000 (8×10 7 ) cP, wherein the second dynamic viscosity exceeds the first dynamic viscosity and (ii) the weight ratio of the resin to the colorant is at least 1:1.

7. The method of claim 5 , wherein the hydrophobic release layer comprises a cross-linked silanol- or silane-modified or -terminated polydialkylsiloxane.

8. The method of claim 1 , wherein the aqueous inkjet ink comprises a solvent containing water and optionally a co-solvent, the water constituting at least 8 wt. % of the ink; the colorant is dispersed or at least partly dissolved within said solvent and constitutes at least 1 wt. % of the ink; the polymeric resin is dispersed or at least partially dissolved within the solvent and constitutes 6 to 40 wt. % of the ink; the average molecular weight of the polymeric resin is at least 8,000; prior to jetting the ink has (i) a viscosity of 2 to 25 centipoise at at least one temperature in the range of 20-60° C., (ii) a surface tension of not more than 50 milliNewton/m at at least one temperature in the range of 20-60° C., or (iii) a viscosity of 2 to 25 centipoise at at least one temperature in the range of 20-60° C. and a surface tension of not more than 50 milliNewton/m at at least one temperature in the range of 20-60° C.; and wherein:
(1) the ink is such that, when substantially dried, (a) at at least one temperature in the range of 90° C. to 195° C., the dried ink has a first dynamic viscosity in the range of 1,000,000 (1×10 6 ) cP to 300,000,000 (3×10 8 ) cP, and (b) at at least one temperature in the range of 50° C. to 85° C., the dried ink has a second dynamic viscosity of at least 80,000,000 (8×10 7 ) cP, wherein the second dynamic viscosity exceeds t

Assignees

• Landa Corp Ltd

Inventors

• Landa Benzion
• Abramovich Sagi
• Nakhmanovich Gregory
• Avital Dan
• Golodetz Galia
• Sheinman Yehoshua

Classifications

• B41J2002/012

  with intermediate transfer member · CPC title

• C09D11/30

  Inkjet printing inks · CPC title

• C09D11/10

  based on artificial resins · CPC title

• B41J2/0057 Primary

  where an intermediate transfer member receives the ink before transferring it on the printing material · CPC title

• B41J2/01 Primary

  Ink jet · CPC title