Radiation imagery chemistry: process – composition – or product th – Microcapsule – process – composition – or product
Reexamination Certificate
2001-06-01
2003-10-14
Hamilton, Cynthia (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Microcapsule, process, composition, or product
C430S284100, C430S285100, C430S287100, C430S288100, C430S944000
Reexamination Certificate
active
06632580
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a negative working (or type) lithographic printing plate precursor which comprises a hydrophilic support having provided thereon an image-forming layer, more specifically relates to a lithographic printing plate precursor capable of image-recording by infrared ray scanning exposure on the basis of digital signals, and the image-recorded printing plate precursor can be mounted immediately on a printing machine for plate-making by on-press development.
BACKGROUND OF THE INVENTION
A variety of studies are going ahead on the plate-making technique for computer-to-plate system which has progressed increasingly in recent years. Of such techniques, as those aiming at further rationalization of processes and the solution of the problem of waste solution treatment, lithographic printing plate precursors which can be mounted on a printing machine immediately after exposure without undergoing development process and can be used for printing have been researched and various methods are suggested.
As one method of doing away with a treating process, there is a method called on-press development comprising the steps of loading an exposed printing plate precursor onto the plate cylinder of a printing machine and supplying a fountain solution and an ink with rotating the plate cylinder to thereby remove the non-image domain of the coated layer of the printing plate precursor. That is, this is a method of exposing a lithographic printing plate precursor, loading it immediately onto a printing machine and effecting developing treatment in a general printing process.
Such a lithographic printing plate precursor suitable for on-press development is required to have a photosensitive layer soluble in a fountain solution or an ink solvent and have daylight handleability capable of undergoing development on a printing machine in a bright room.
For example, a lithographic printing plate precursor comprising a hydrophilic support having provided thereon a photosensitive layer comprising a hydrophilic binder polymer having dispersed therein fine particles of a thermoplastic hydrophobic polymer is disclosed in Japanese Patent 2938397. This is disclosed in this patent to coalesce thermoplastic hydrophobic polymer fine particles by the heat of infrared laser exposure to form an image on a lithographic printing plate precursor, and to mount the printing plate precursor on the cylinder of a printing machine to perform on-press development with a fountain solution and/or an ink. Due to the sensitive region being infrared rays, the printing plate precursor is handleable in daylight.
Further, the techniques of coalescing thermoplastic fine particles by heat and making a printing plate by on-press development are also disclosed in JP-A-9-127683 (the term “JP-A” as used herein means an “unexamined published Japanese patent application”) and WO 99/10186.
However, these methods of making an image by the coalescence of fine particles by heat are accompanied by the problem that high press life (i.e., high printing durability) is difficult to obtain, although good on-press developability can be obtained.
SUMMARY OF THE INVENTION
An object of the present invention is to solve this problem, that is, to provide a lithographic printing plate precursor having good on-press developability and high press life (the term “press life” is sometimes called “printing durability” or “run length”.)
The above object of the present invention has been achieved by the following means.
(1) A lithographic printing plate precursor which comprises an image-forming layer which contains a hydrophilic resin, an acid precursor and at least one component selected from fine particles containing a compound having a vinyloxy group and microcapsules containing a compound having a vinyloxy group, on a hydrophilic support.
(2) A lithographic printing plate precursor which comprises an image-forming layer which contains a hydrophilic resin, an acid precursor and at least one component selected from fine particles containing a compound having an epoxy group and microcapsules containing a compound having an epoxy group, on a hydrophilic support.
(3) A lithographic printing plate precursor which comprises a hydrophilic support having provided thereon an image-forming layer containing fine particles containing a thermosetting compound, and a hydrophilic resin.
(4) The lithographic printing plate precursor as described in the above item (1), wherein the fine particles containing a compound having a vinyloxy group or the microcapsules containing a compound having a vinyloxy group contain at least one component of an acid precursor and an infrared ray-absorbing dye.
(5) The lithographic printing plate precursor as described in the above item (1) or (4), wherein the fine particles containing a compound having a vinyloxy group or the microcapsules containing a compound having a vinyloxy group contain a compound having a functional group which reacts with a vinyloxy group.
(6) The lithographic printing plate precursor as described in the above item (1), (4) or (5), wherein the hydrophilic resin contains a functional group which reacts with a vinyloxy group.
(7) The lithographic printing plate precursor as described in the above item (2), wherein the fine particles containing a compound having an epoxy group or the microcapsules containing a compound having an epoxy group contain at least one component of an acid precursor and an infrared ray-absorbing dye.
(8) The lithographic printing plate precursor as described in the above item (2) or (7), wherein the fine particles containing a compound having an epoxy group or the microcapsules containing a compound having an epoxy group contain a compound having a functional group which reacts with an epoxy group.
(9) The lithographic printing plate precursor as de scribed in the above item (2), (7) or (8), wherein the hydrophilic resin contains a functional group which reacts with an epoxy group.
(10) The lithographic printing plate precursor as described in the above item (3), wherein the fine particles containing a thermosetting compound contain an infrared ray-absorbing dye.
(11) The lithographic printing plate precursor as described in the above item (3) or (10), wherein the thermosetting compound is at least a resin selected from a resin having a phenolic skeleton, a melamine resin and a urea resin.
(12) The lithographic printing plate precursor as described in any of the above items (1) to (11), wherein the hydrophilic support is an aluminum support which has been subjected to anodization treatment and hydrophilization treatment.
(13) The lithographic printing plate precursor as described in any of the above items (1) to (3), wherein the printing plate precursor is development processed on a printing machine.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail below.
Image-Forming Layer
A vinyloxy group for use in the present invention is represented by the following formula (I):
wherein R
1
, R
2
and R
3
, which may be the same or different, each represents a hydrogen atom, an alkyl group or an aryl group, and two of R
1
, R
2
and R
3
may be bonded to form a saturated or olefinic unsaturated ring.
More specifically, when any of R
1
, R
2
and R
3
represents an aryl group, the aryl group has generally from 6 to 20 carbon atoms, and may be substituted with an alkyl group, an aryl group, an alkoxyl group, an aryloxy group, an acyl group, an acyloxy group, an alkylmercapto group, an acylamino group, an alkoxycarbonyl group, a nitro group, a sulfonyl group, a cyano group, or a halogen atom.
When any of R
1
, R
2
and R
3
represents an alkyl group or an alkenyl group, the alkyl group and the alkenyl group have a straight chain, branched or cyclic carbon chain generally having from 1 to 20 carbon atoms, and may be substituted with a halogen atom, a cyano group, an alkoxycarbonyl group, a hydroxyl group, an alkoxyl group, an aryloxy group, or an aryl group. Further, when any two of R
1
, R
2
and R
3
are bonded to form a ri
Burns Doane , Swecker, Mathis LLP
Hamilton Cynthia
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