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USE OF WATER SOLUBLE MULTIVALENT METAL SALTS FOR THE IMPROVEMENT OF IMAGE QUALITY ON PLAIN PAPERS

IP.com Disclosure Number: IPCOM000027563D
Original Publication Date: 1997-Dec-31
Included in the Prior Art Database: 2004-Apr-08
Document File: 4 page(s) / 220K

Publishing Venue

Xerox Disclosure Journal

Abstract

The incorporation of multivalent metal salts into receiver sheets and ink compositions is known. It is proposed herein to deposit water soluble multivalent metal salts onto papers by methods such as ink jet printing (including continuous stream, piezoelectric, thermal ink jet, and other drop-on-demand ink jet methods), lithographic printing, flex0 printing, or the like in an image pattern prior to printing on the paper with an aqueous ink. For example, the salt solution can be contained in a separate customer replaceable unit comprising a printhead and an ink cartridge for use in a thermal ink jet printer. Or, a cartridge can comprise a partitioned printhead separately connected to different colored ink supplies as well as a supply of the salt solution.

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XEROX DISCLOSURE JOURNAL

USE OF WATER SOLUBLE MULTIVALENT METAL SALTS FOR THE IMPROVEMENT OF IMAGE QUALITY ON PLAIN PAPERS John Wei-Ping Lin

Proposed Classification
U. S. C1. 106/020R Int. C1. C09d 11/00

The incorporation of multivalent metal salts into receiver sheets and ink compositions is known. It is proposed herein to deposit water soluble multivalent metal salts onto papers by methods such as ink jet printing (including continuous stream, piezoelectric, thermal ink jet, and other drop-on-demand ink jet methods), lithographic printing, flex0 printing, or the like in an image pattern prior to printing on the paper with an aqueous ink. For example, the salt solution can be contained in a separate customer replaceable unit comprising a printhead and an ink cartridge for use in a thermal ink jet printer. Or, a cartridge can comprise a partitioned printhead separately connected to different colored ink supplies as well as a supply of the salt solution.

A water soluble metal salt containing an element of Group 11, 111, or IV, such as Ca", Mg*, Zn", Ba*, Sr", A*, B", Fe", Fe*, Sn", Sn-, Ti-, Zr-, In", or the like, is dissolved in water with or without a polymer (either a cationic or a nonionic polymer) and other optional additives (such as leveling agents, surfactants, humectants, penetrants, drying agents, buffers, chelating agents, anticurl agents, or the like). Examples of suitable anions include halide ions (chloride, fluoride, bromide, iodide), nitrate, organic acid anions such as formate, acetate, propionate, toluene sulfonate, benzoate, and the like, sulfate, and the like. Specific examples of useful metal salts include magnesium chloride, barium chloride, calcium propionate, zinc chloride, ferrous chloride, aluminum sulfate, potassium aluminum sulfate, aluminum nitrate, ferric chloride, ferric nitrate, tin chloride, and the like. These multivalent metal cations in the image area can form strong ionic linkages with anionic dye moieties such as sulfate, carboxylate, and phosphate anions and cause immobilization and/or precipitation of the colorant.

The salt solution is deposited onto the paper in an imagewise pattern in any desired pattern, such as half tone, quarter tone, solid area, or the like. Additionally, if desired, the salt solution can be deposited onto the paper in the area where a color or black ink borders on an area of a different color to avoid intercolor bleeding. The salt solution can be applied under a colored image, over a colored image, and/or adjacent to a colored image. Optionally, the paper can be heated before, during, and/or after printing with the salt solution and the inks to accelerate drying and the chemical reaction between the

XEROX DISCLOSURE JOURNAL - Vol. 22, No. 6 NovemberDecernber 1997 263

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USE OF WATER SOLUBLE MULTIVALENT METAL SALTS FOR THE IMPROVEMENT OF IMAGE QUALITY ON PLAIN PAPERS(C0Nl"D)

cations of the metal salts and...