Claims
- 1. A radiation sensitive plate comprising a substrate formed of grained and anodised aluminium and having a surface coated with a radiation sensitive layer based on a radiation sensitive composition comprising a quaternary ammonium salt of the type which accepts at least one electron on exposure to radiation to form a substance capable of causing metal to be deposited onto said substance from an electroless plating solution in contact with said substance and comprising a salt of said metal and a reducing agent, said quaternary ammonium salt having the general formula ##STR5## wherein R.sup.1 to R.sup.10 are hydrogen or halogen atoms or organic substituents; R.sup.11 and R.sup.12, if present, are each halogen atoms or organic substituents or together represent a divalent organic substituent; Z is zero or an integer; X.sup.- is an anion; m=1 or 2; and at least one of the nitrogen atoms is quaternary.
- 2. A plate according to claim 1 wherein the quaternary ammonium salt is selected from the group consisting of: ##STR6##
- 3. A plate according to claim 1, in which the layer includes a polymeric binder, a spectral sensitiser, a surface active agent or a development accelerator.
- 4. A plate according to claim 1 in which the layer includes a chemical sensitiser.
- 5. A plate according to claim 4 in which the chemical sensitiser has the general formula ##STR7## wherein R.sup.21 is a substituted or unsubstituted aryl group, an aryl alkenyl group or an arylalkyl group; R.sup.22 is a substituted or unsubstituted aryl group, an alkyl group, an arylalkyl group, an arylalkenyl group, a carboxylic acid group, a carboxylic acid salt group, or a hydrogen atom or R.sup.21 and R.sup.22 together represent a bivalent species; and X represents a carboxylic acid group or a carboxylic acid salt group.
- 6. A plate according to claim 5, in which the chemical sensitiser is selected from the group consisting of mandelic acid and derivatives of mandelic acid.
- 7. A plate according to claim 6 in which the chemical sensitiser is ammonium mandelate, p-chloromandelic acid or p-bromomandelic acid.
- 8. A method of manufacturing a lithographic printing plate which method comprises (1) providing a radiation sensitive plate comprising a substrate formed of grained and anodised aluminium and having a surface coated with a radiation sensitive layer based on a radiation sensitive composition comprising a quaternary ammonium salt of the type which accepts at least one electron on exposure to radiation to form a substance capable of causing metal to be deposited onto said substance from an electroless plating solution in contact with said substance and comprising a salt of said metal and a reducing agent, said quaternary ammonium salt having the general formula ##STR8## wherein R.sup.1 to R.sup.10 are hydrogen or halogen atoms or organic substituents; R.sup.11 and R.sup.12, if present, are each halogen atoms or organic substituents or together represent a divalent organic substituent; Z is zero or an integer; X.sup.- is an anion; m=1 or 2; and at least one of the nitrogen atoms is quaternary, (2) image-wise exposing the radiation sensitive plate to radiation, and (3) contacting the image-wise exposed plate with an electroless plating solution comprising a metal salt and a reducing agent to cause deposition of metal onto the radiation-struck areas of the layer to form the image areas of the lithographic printing plate.
Priority Claims (1)
Number |
Date |
Country |
Kind |
27435/75 |
Jun 1975 |
GBX |
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Parent Case Info
This is a division of application Ser. No. 788,299 filed Apr. 18, 1977, now U.S. Pat. No. 4,126,468, which is a continuation-in-part application of our application Ser. No. 700506 filed on June 28, 1976 and now abandoned.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
3316093 |
Cerwonka |
Aug 1967 |
|
3671250 |
Andrews et al. |
Jun 1972 |
|
3954471 |
Andrews et al. |
May 1976 |
|
Divisions (1)
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Number |
Date |
Country |
Parent |
788299 |
Apr 1977 |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
700506 |
Jun 1976 |
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