Xerographic phototypesetting system and toner useful therein

Claim 2

A toner composition for imaging a photolithographic transparency comprising on a 100 weight percent basis: (a) about 80.0 to about 99.5 weight percent of at least one polyester which contains incorporated into the polymer structure thereof about 0.1/99.9 to about 100.0/0.0 mole ratio based on the total acid or hydroxy monomers of at least one methine dye having a spectral absorption peak in the range of about 300 to about 450 nm and the formula: ##STR13## wherein, Y is a lower alkyl radical; X is selected from the group consisting of --CN and ##STR14## and O is selected from the group consisting of --NH 2 --NHY, --N(Y) 2 and ##STR15## (b) about 0.5 to about 20 weight percent of at least one pigment; and (c) about 0.05 to about 5 weight percent of at least one charge control agent, wherein the toner composition has a total transmission density of at least about 3 at a stack height of 10 microns.

Claim 3

The toner composition of claim 1 wherein the polyester, pigment and charge control agent are in the form of particles in the size range of about 1 to about 30 microns.

Claim 4

The toner composition of claim 1 which additionally contains about 80 to about 99.5 weight percent of at least one dye-free polyester.

Claim 5

The toner composition of claim 1 wherein the transmission density is in the range of about 3 to about 6 at said stack height.

Claim 6

The toner composition of claim 1 wherein said polyester is characterized by having (1) an inherent viscosity in the range of about 0.05 to about 0.8 in methylene chloride solution at a concentration of 0.25 grams of said polymer per 100 milliliters of said solution; (2) a glass transition temperature in the range of about 50° to about 120° C.; and (3) a fusing point in the range of about 65° to about 200° C.

Claim 7

The toner composition of claim 1 wherein the methine dye is characterized by the formula: ##STR16##

Claim 8

The toner composition of claim 1 wherein the methine dye is characterized by the formula: ##STR17##

Claim 9

A positive transparency comprising: (a) a self-supporting, flexible transparent support layer having opposed faces; and (b) a toned image formed on one of said faces and adhered thereto, said image comprising a toner composition of claim 1.

Claim 10

A process for making a lithographic plate comprising the steps of: (A) electrophotographically forming a positive transparency whose image is formed from a toner composition which comprises on a 100 weight percent basis: (1) about 80.0 to about 99.5 weight percent of at least one polyester which contains incorporated into the polymer structure thereof about 0.1/99.9 to about 100.0/0.0 mole ratio based on the total acid and hydroxy monomer of at least one methine dye having a spectral absorption peak in the range of about 300 to about 450 nm and the formula: ##STR18## wherein, Y is a lower alkyl radical; X is selected from the group consisting of --CN and ##STR19## and Q is selected from the group consisting of --NH 2 --NHY, --N(Y) 2 and ##STR20## (2) about 0.5 to about 20 weight percent of at least one pigment; and (3) about 0.05 to about 5 weight percent of at least one charge control agent, wherein the toner composition has a total transmission density of at least about 3 at a stack height of 10 microns wherein said toner composition has a total transmission density of at least about 3 at a stack height to 10 microns; (B) imaging a positive.working lithographic plate which is sensitive to incident light; and (C) developing the exposed plate.

Claim 11

A process for making a lithographic plate comprising the steps of: (A) electrophotographically forming a positive transparency whose image is formed from a toner composition which comprises on a 100 weight percent basis: (1) about 80.0 to about 99.5 weight percent of at least one polyester which contains incorporated into the polymer structure thereof about 0.1/99.9 to about 100.0/0.0 mole ratio based on the total acid and hydroxy monomer of at least one methine dye having a spectral absorption peak in the range of about 300 to about 450 nm and the formula: ##STR18## wherein, Y is a lower alkyl radical; X is selected from the group consisting of --CN and ##STR19## and Q is selected from the group consisting of --NH 2 --NHY, --N(Y) 2 and ##STR20## (2) about 0.5 to about 20 weight percent of at least one pigment; and (3) about 0.05 to about 5 weight percent of at least one charge control agent, wherein the toner composition has a total transmission density of at least about 3 at a stack height of 10 microns wherein said toner composition has a total transmission density of at least about 3 at a stack height to 10 microns; (B) imaging a positive.working lithographic plate which is sensitive to incident light; and (C) developing the exposed plate.