Light-sensitive litho printing plate with cured diazo primer layer, diazo resin/salt light-sensitive layer containing a coupler and silicone rubber overlayer

• US 5,225,309 A
• Filed: 03/19/1992
• Issued: 07/06/1993
• Est. Priority Date: 02/08/1990
• Status: Expired due to Fees

• Current Assignee: Konica Corporation (Konica Minolta Inc.), Mitsubishi Kasei Corp. (Mitsubishi Chemical Group Corp.)
• Original Assignee: Konica Corporation (Konica Minolta Inc.), Mitsubishi Kasei Corp. (Mitsubishi Chemical Group Corp.)
• Inventors: Suzuki, Norihito, Goto, Kiyoshi, Kasakura, Akeo, Tomiyasu, Hiroshi, Noguchi, Kazuo
• Primary Examiner(s): Bowers, Jr., Charles L.
• Assistant Examiner(s): Young, Christopher G.
• Application Number:
  US07/853,852
• Time in Patent Office: 474 Days
• Field of Search: 430/145, 430/156, 430/162, 430/302, 430/303, 430/158, 430/163, 430/171, 430/175, 430/180, 430/181, 430/182
• US Class Current: 430/158
• CPC Class Codes: G03F 7/0752 in non photosensitive layers or as additives, e.g. for dry lithography
• CPC Class Codes: G03F 7/105 having substances, e.g. indicators, for forming visible images

Abstract

Disclosed is a light-sensitive litho printing plate comprising:

a support, a light-sensitive layer and a silicone rubber layer provided thereon,

wherein said light-sensitive layer contains a substance,

whereby said substance forms a color during developing or after developing.

Claims

1. A light-sensitive litho printing plate comprising:

a support, a light-sensitive layer, a silicone rubber layer provided thereon and a primer layer containing a diazo light-sensitive composition provided between said support and said light-sensitive layer which is cured by heating or exposure prior to coating of the light-sensitive layer.

wherein said light-sensitive layer contains a substance in admixture with a photopolymerizable compound, whereby said substance forms a color through a reaction with a coupler during developing or after developing said light-sensitive litho printing plate,

wherein said substance is a diazo resin present in an amount of 10% by weight to 90% by weight and represented by Formula III;

##STR10## wherein R¹, R² and R³ are hydrogen, an alkyl group or an alkoxy group, R⁴ is hydrogen, an alkyl group or a phenyl group, X is an anion and Y is --NH--, --S-- or --O--;

or a diazo compound present in an amount of 5% by weight to 45% by weight and selected from the group consisting of;

##STR11## wherein said light-sensitive layer has admixed therein 0.2% by weight to 40% by weight of a coupler selected from 2-hydroxy-N-(2-methylphenyl)-3-naphthoamide and N-(2-hydroxyethyl)-3,5-dihydroxybenzamide,

wherein said silicone rubber layer is the linear organic polysiloxane represented by formula I;

##STR12## wherein n is an integer of 2 or more, and R is an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, an alkoxy group, a vinyl group, an aryl group or a silanol group.

2. The printing plate of claim 1 wherein said developing is carried out by a processing solution.

3. The printing plate of claim 2 wherein said processing solution contains a coupler.

4. The printing plate of claim 3 wherein the content of said coupler is 0.1% by weight to 20% by weight to said processing solution when said coupler is contained in said processing solution.

5. The printing plate of claim 4 wherein the content of said coupler is 1% by weight to 10% by weight to said processing solution.

6. The printing plate of claim 1 wherein the content of said coupler is 1% by weight to 30% by weight in the solids of the light-sensitive component.

7. The printing plate of claim 1, wherein said diazo resin is present in said substance in an amount of 30% by weight to 70% by weight.

8. The printing plate of claim 1, wherein said diazo compound is present in said substance in an amount of 10% by weight to 30% of weight.

9. The printing plate of claim 1 wherein said silicone rubber is the compound obtained by condensing said polysiloxane and a silane compound represented by following formula:

R_n SiX_4-n (wherein n is an integer of 1 to 3, R is a monovalent group such as an alkyl, aryl, alkenyl or the combination of these, and these groups have functional groups such as halogen, amine, hydroxyl, alkoxy, aryloxy and thiol, X represents --OH, OR², --OAc, ##STR13## Cl, --Br and --I (wherein R² and R³ represent the same as the above R, and R², R³ may be either the same or different.

10. The printing plate of claim 1 wherein said anion is the anion of hexafluorophosphoric acid.