Tunable surfactants in dampening fluids for digital offset ink printing applications

Patent metadata

Field	Value
Publication number	US-10328688-B2
Application number	US-201715496709-A
Country	US
Kind code	B2
Filing date	Apr 25, 2017
Priority date	Apr 27, 2011
Publication date	Jun 25, 2019
Grant date	Jun 25, 2019

Abstract

A dampening fluid useful in offset ink printing applications contains water and a surfactant whose structure can be altered. The alteration in structure aids in reducing accumulation of the surfactant on the surface of an imaging member. The surfactant can be decomposed, switched between cis-trans states, or polymerizable with ink that is subsequently placed on the surface.

First claim

What is claimed is:

1. A method for cleaning an imaging member during offset lithographic printing, comprising:
coating the imaging member with a dampening fluid that comprises water and a surfactant having an alterable structure;
after an ink transfer from the imaging member and before a subsequent latent image forming step on the imaging member, exposing the imaging member to light or heat to alter the structure of the surfactant across the imaging member; and
removing the surfactant from the imaging member, wherein the surfactant includes a cis-trans isomer having a dipole moment.

2. The method of claim 1 , wherein the cis-trans isomer is an azobenzene compound.

3. The method of claim 1 , wherein the cis-trans isomer is an azobenzene compound having the structure of Formula (III):

wherein R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are independently selected from hydrogen, hydroxyl, carboxylic acid, amino, thiol, cyano, nitro, halogen, vinyl, alkoxy, trialkylammoniumalkoxy, sulfonic acid, phosphonate ester, aldehyde, amide, urea, carbamate, carbonate, alkyl, polyoxyalkylene, and ester; and wherein R 1 is different from R 4 .

4. The method of claim 1 , wherein the cis-trans isomer is an azobenzene compound having the structure of Formula (III-a):

wherein R1 is selected from hydroxyl, amino, cyano, nitro, halogen, vinyl, alkoxy, sulfonic acid, aldehyde, and ester.

5. The method of claim 1 , wherein the cis-trans isomer is an azobenzene compound having the structure of Formula (III-b):

wherein R b is alkyl having 2 to 6 carbon atoms; and p is an integer from 1 to 10.

6. The method of claim 1 , wherein the cis-trans isomer is an azobenzene compound having the structure of Formula (III-c):

7. The method of claim 6 , wherein Formula (III-c) includes a nonpolar alkyl sidechain and a polar trialkylammoniumalkoxy sidechain.

8. A method for cleaning an imaging member during offset lithographic printing, comprising:
coating the imaging member with a dampening fluid that comprises water and a surfactant having an alterable structure;
exposing the imaging member to light or heat to alter the structure of the surfactant; and
removing the surfactant from the imaging member, wherein the surfactant includes a cis-trans isomer having a dipole moment, the cis-trans isomer including an azobenzene compound having the structure of Formula (III):

wherein R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are independently selected from hydrogen, carboxylic acid, amino, thiol, cyano, nitro, halogen, vinyl, alkoxy, trialkylammoniumalkoxy, sulfonic acid, phosphate ester, aldehyde, amide, urea, carbonate, carbonate, alkyl, polyoxyalkylene, and ester; and wherein R 1 is different from R 4 .

9. A method for cleaning an imaging member during offset lithographic printing, comprising:
coating the imaging member with a dampening fluid that comprises water and a surfactant having an alterable structure;
exposing the imaging member to light or heat to alter the structure of the surfactant; and
removing the surfactant from the imaging member, wherein the surfactant includes a cis-trans isomer having a dipole moment, the cis-trans isomer including an azobenzene compound having the structure of Formula (III-a):

wherein R1 is selected from hydroxyl, amino, cyano, nitro, halogen, vinyl, alkoxy, sulfonic acid, aldehyde, and ester.

10. A method for cleaning an imaging member during offset lithographic printing, comprising:
coating the imaging member with a dampening fluid that comprises water and a surfactant having an alterable structure;
exposing the imaging member to light or heat to alter the structure of the surfactant; and
removing the surfactant from the imaging member, wherein the surfactant includes a cis-trans isomer having a dipole moment, the cis-trans isomer including an azobenzene compound having the structure of Formula (III-b):

wherein R b is alkyl having 2 to 6 carbon atoms; and p is an integer from 1 to 10.

11. A method for cleaning an imaging member during offset lithographic printing, comprising:
coating the imaging member with a dampening fluid that comprises water and a surfactant having an alterable structure;
exposing the imaging member to light or heat to alter the structure of the surfactant; and
removing the surfactant from the imaging member, wherein the surfactant includes a cis-trans isomer having a dipole moment, the cis-trans isomer including an azobenzene compound having the structure of Formula (III-c):

12. The method of claim 11 , wherein Formula (III-c) includes a nonpolar alkyl sidechain and a polar trialkylammoniumalkoxy sidechain.

13. The method of claim 1 , wherein the exposing the imaging member to light or heat to alter the structure of the surfactant across the imaging member includes exposing entire cross-process lines on the imaging member to light or heat.

14. The method of claim 1 , wherein the exposing the imaging member to light or heat to alter the structure of the surfactant across the imaging member includes exposing entire cross-process lines on the imaging member to light or heat at both imaged and non-imaged areas of the imaging member.

Assignees

• Xerox Corp
• Palo Alto Res Ct Inc
• Palo Alto Res Corporation

Inventors

• Chopra Naveen
• Odell Peter Gordon
• Ready Steven E
• Peeters Eric
• Stowe Timothy D
• Pattekar Ashish
• Biegelsen David K

Classifications

• B08B3/08

  the liquid having chemical or dissolving effect · CPC title

• B41P2227/20

  Means enabling or facilitating exchange of tubular printing or impression members, e.g. printing sleeves, blankets · CPC title

• B41N3/08

  Damping; Neutralising or similar differentiation treatments for lithographic printing formes; {Gumming or finishing solutions, fountain solutions, correction or deletion fluids, or on-press development (treatment of materials containing silver salts G03F7/063; developers per se for processing photosensitive materials G03F7/32)} · CPC title

• B41F35/02

  for forme cylinders · CPC title

• B41F35/06 Primary

  for offset cylinders · CPC title