Offset jet printing ink

Claim 2

An ink composition for use in jet printing for preparation of offset masters consisting essentially of an aqueous alkaline solution of a water-soluble direct dye, at least one resin which is soluble in aqueous alkaline media with a pH of at least 7.5, but insoluble in aqueous media with a pH under 7.0, and is hydrophobic on drying, said resin being selected from the group consisting of styrene-maleic anhydride resins and their ester derivatives, and a water-soluble plasticizer for the resin selected from the group consisting of alkylene glycols, polyalkylene glycols, their corresponding alkyl ethers and mixtures thereof.

Claim 3

A composition as defined in claim 1 wherein the resin is a mixture of the styrene-maleic anhydride resin and a water-soluble acrylic extender resin.

Claim 4

A composition as defined in claim 1 wherein the resin is added to the composition in the form of an aqueous solution containing a base.

Claim 5

A composition as defined in claim 3 wherein the base is selected from the group consisting of an ammonium hydroxide and an alkanolamine.

Claim 6

A composition as defined in claim 3 wherein the base is present in an amount sufficient to maintain the pH of the composition of at least 7.5.

Claim 7

A composition as defined in claim 3 wherein the base is ammonium hydroxide.

Claim 8

A composition as defined in claim 1 wherein the resin constitutes from 1 to 10% by weight of the composition.

Claim 9

A composition as defined in claim 1 wherein the composition has a viscosity in the range of 1 to 10 centipoise at 25* C.

Claim 10

A composition as defined in claim 1 wherein the glycols and glycol ethers have average molecular weights less than 400.

Claim 11

A composition as defined in claim 1 wherein the plasticizer constitutes from 2.5 to 30% by weight of the composition.

Claim 12

A composition as defined in claim 1 wherein the dye contains an ionizable material in an amount sufficient to provide a specific resistivity of 50 to 5,000 ohm-cm.

Claim 13

A composition as defined in claim 1 wherein the dye constitutes from 0.5 to 5% by weight of the composition.

Claim 14

A composition as defined in claim 1 which includes dispersed carbon black.

Claim 15

A composition as defined in claim 1 which includes a solubilizing organic base to maintain the pH of the composition.

Claim 16

A composition as defined in claim 1 which includes a preservative.

Claim 17

An ink composition for use in jet printing for preparation of offset masters consisting essentially of an aqueous alkaline solution of a water-soluble direct dye, at least one resin which is soluble in aqueous alkaline media with a pH of at least 7.5, but insoluble in aqueous media with pH under 7.0, and is hydrophobic on drying, said resin being selected from the group consisting of styrene-maleic anhydride resins and their ester derivatives and carboxylated polyvinyl acetate resins, and a water-soluble plasticizer for the resin selected from the group consisting of alkylene glycols, polyalkylene glycols, their corresponding alkyl ethers and mixtures thereof.

Claim 18

An ink composition for use in jet printing for preparation of offset masters consisting essentially of an aqueous alkaline solution of a water-soluble direct dye, at least one resin which is soluble in aqueous alkaline media with a pH of at least 7.5, but insoluble in aqueous media with pH under 7.0, and is hydrophobic on drying, said resin being selected from the group consisting of styrene-maleic anhydride resins and their ester derivatives and carboxylated polyvinyl acetate resins, and a water-soluble plasticizer for the resin selected from the group consisting of alkylene glycols, polyalkylene glycols, their corresponding alkyl ethers and mixtures thereof.

Claim 19

A composition as defined in claim 16 wherein the composition has a viscosity within the rAnge of 1 to 10 centipoise at 25* C.

Claim 20

AN INK COMPOSITION FOR USE IN JET PRINTING CONSISTING ESSENTIALLY OF AN AQUEOUS ALKALINE SOLUTION CONTAINING 0.5 TO 5% BY WEIGHT OF A WATER-SOLUBLE DIRECT DYE CONTAINING AN IONIZABLE MATERIAL IN AN AMOUNT SUFFICIENT TO PROVIDE A SPECIFIC RESISTIVITY OF 50 TO 500 OHM (CM) 1 TO 10% BY WEIGHT OF AT LEAST ONE RESIN WHICH IS SOLUBLE IN AQUEOUS ALKALINE MEDIA WITH A PH OF AT LEAST 7.5 BUT INSOLUBLE IN AQUEOUS MEDIA WITH A PH UNDER 7/0, AND IS HYDROPHOBIC ON DRYING SAID RESIN BEING SELECTED FROM THE GROUP CONSISTING OF STYRENE-MALEIC ANHYDRIDE RESINS AND THEIR DERIVATIVES AND CARBOXYLATED POLYVINYL ACETATE RESINS AND FROM 2.5 TO 30% BY WEIGHT OF A WATER SOLUBLE PLASTICIZER FOR THE RESIN SELECTED FROM THE GROUP CONSISTING OF ALKYLENE GLYCOLS POLYALKYLENE GLYCOLS THEIR CORRESPONDING ALKYL ETHER AND MIXTURES THEREOF WITH THE GLYCOLS AND GLYCOL ETHERS HAVING AN AVERAGE MOLECULAR WEIGHT LESS THAN 400 WITH THE INK COMPOSITION HAVING A VISCOSITY WITHIN THE THE RANGE OF 1 TO 10 CENTIPOISE AT 25*C.

Claim 21

AN INK COMPOSITION FOR USE IN JET PRINTING CONSISTING ESSENTIALLY OF AN AQUEOUS ALKALINE SOLUTION CONTAINING 0.5 TO 5% BY WEIGHT OF A WATER-SOLUBLE DIRECT DYE CONTAINING AN IONIZABLE MATERIAL IN AN AMOUNT SUFFICIENT TO PROVIDE A SPECIFIC RESISTIVITY OF 50 TO 500 OHM (CM) 1 TO 10% BY WEIGHT OF AT LEAST ONE RESIN WHICH IS SOLUBLE IN AQUEOUS ALKALINE MEDIA WITH A PH OF AT LEAST 7.5 BUT INSOLUBLE IN AQUEOUS MEDIA WITH A PH UNDER 7/0, AND IS HYDROPHOBIC ON DRYING SAID RESIN BEING SELECTED FROM THE GROUP CONSISTING OF STYRENE-MALEIC ANHYDRIDE RESINS AND THEIR DERIVATIVES AND CARBOXYLATED POLYVINYL ACETATE RESINS AND FROM 2.5 TO 30% BY WEIGHT OF A WATER SOLUBLE PLASTICIZER FOR THE RESIN SELECTED FROM THE GROUP CONSISTING OF ALKYLENE GLYCOLS POLYALKYLENE GLYCOLS THEIR CORRESPONDING ALKYL ETHER AND MIXTURES THEREOF WITH THE GLYCOLS AND GLYCOL ETHERS HAVING AN AVERAGE MOLECULAR WEIGHT LESS THAN 400 WITH THE INK COMPOSITION HAVING A VISCOSITY WITHIN THE THE RANGE OF 1 TO 10 CENTIPOISE AT 25*C.