Radiation imagery chemistry: process – composition – or product th – Imaging affecting physical property of radiation sensitive... – Radiation sensitive composition or product or process of making
Reexamination Certificate
2000-12-08
2003-07-22
Baxter, Janet (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Imaging affecting physical property of radiation sensitive...
Radiation sensitive composition or product or process of making
C430S273100, C430S281100, C430S302000, C430S348000, C430S944000, C430S945000, C430S964000, C101S453000, C101S455000, C101S456000, C101S463100, C101S465000, C101S467000
Reexamination Certificate
active
06596462
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a printing plate element and particularly to a printing plate element capable of forming an image by a computer to plate (CTP) system. The invention also relates to the preparation method of the printing plate element or a printing plate.
BACKGROUND OF THE INVENTION
An element for CTP which can be easily handled and has a printing ability comparable with that of a PS plate is required accompanied with the digitization of printing data. Recently, many types of CTP by infrared laser recording have been proposed. Among them, a dry CTP including a developing process of the printing machine is noticed, by which a specific developing process is not required. Examples of such the techniques are described in Japanese Patent Publication Open to Public Inspection, hereinafter referred to as JP O.P.I., Nos. 8-507727, 6-186750, 6-199064, 7-314934, 10-58636 and 10-244773.
These are all printing elements each forming an image area or non image area by ablation of the surface layer thereof. Such the printing elements each has problems that the resolving power and the dot quality are low.
Moreover, it is a problem that the contamination of the interior of the exposing apparatus by the scattered matter caused by the ablation of the surface layer. Accordingly, it is often necessary to have a built-in cleaning means such as a specific sucking device or a contamination preventing means such as to cover the surface of the printing plate element by a cover sheet, for solving such the problem. Furthermore, the process cannot be regarded to a complete dry process since it is necessary to remove the ablation residue remained on the plate surface by a means such as wiping or rinsing by an exclusive device.
Besides, a process is called as a wet type CTP in which the solubility to a developer of the image forming layer of the printing plate element is changed by the exposure to light and the image is formed by the development. Such the process has advantages that the anxiety of contamination of interior of the exposing apparatus is little and the high resolving ability can be obtained. However, other problems are caused, such as that an exclusive alkaline developer is necessary to development and the handling ability in a lighted room of the printing plate element is limited since the change in the solubility of the image forming layer is accompanied with a chemical reaction.
SUMMARY OF THE INVENTION
The object of the invention is to provide a printing plate element which can be easily handled in a lighted room and is capable of directly forming an image by infrared laser irradiation without an anxiety of contamination of the interior of exposing apparatus, and no specific developing treatment is necessary. Moreover, the object of the invention is to provide a printing plate element having a high resolving power which is protected from a stain caused scratches. Furthermore, the object of the invention is to provide a production method of such the printing plate element and a printing plate.
The object of the invention can be attained by the followings:
1. A printing plate element comprising a substrate and a first component layer, wherein the first component layer contains a first material which is water-insoluble or capable of varying from being water-soluble to being water-insoluble at a prescribed temperature of not less than 60° C. and a second material which is water-soluble and has a melting point of 60 to 300° C.;
2. The printing plate element described in 1, wherein the second material is a crystalline material;
3. The printing plate element described in 1, wherein the printing plate element comprises a second hydrophilic component layer provided between the substrate and the first component layer;
4. The printing plate element described in 3, wherein the second component layer is a porous layer;
5. The printing plate element described in 3, wherein the second component layer contains a light-heat conversion material;
6. The printing plate element described in 3, wherein the second component layer contains an alkaline colloidal silica and a water soluble polysaccharide;
7. The printing plate element described in 3, wherein the second component layer has a protruding surface structure having a pitch of from 0.1 to 50 &mgr;m;
8. The printing plate element described in 3, wherein the printing element comprises a third component layer provided between the substrate and the second component layer, the third component layer containing a light-heat conversion material;
9. The printing plate element described in 1, wherein the first material is a material
1
a
which is water-insoluble and has a melting point of 60 to 300° C.;
10. The printing plate element described in 9, wherein the melting point of the second material is higher than that of the material
1
a;
11. The printing plate element described in 9, wherein the material
1
a
is in the form of particles, and having an average particle size of 0.01 to 10 &mgr;m;
12. The printing plate element described in 9, wherein the material
1
a
is at least one selected from the group consisting of polyethylene, microcrystalline wax, a fatty acid and a fatty acid ester;
13. The printing plate element described in 1, wherein the first material is a material
1
b
which is water soluble and capable of coagulating at a temperature of not less than 60° C. to form a water-insoluble coagulant;
14. The printing plate element described in 13, wherein the material
1
b
is at least one selected from the group consisting of a water-soluble protein and a water-soluble glycoprotein;
15. The printing plate element described in 1, wherein the second material has a melting point of 70 to 260° C.;
16. The printing plate element described in 1, wherein the second material is an oligosaccharide;
17. The printing plate element described in
16
, wherein the oligosaccharide is at least one selected from the group consisting of trehalose, maltose, galactose, sucrose, lactose and raffinose;
18. A method of preparing a printing plate comprising the steps of:
(a) imagewise exposing a printing plate element to laser light and
(b) removing an unexposed area of the printing plate element with an aqueous solution,
wherein printing plate element comprising a substrate and a first component layer, wherein the first component layer contains a first material which is water-insoluble or capable of varying from being water-soluble to being water-insoluble at a prescribed temperature of not less than 60° C. and a second material which is water-soluble and has a melting point of 60 to 300° C.,
and wherein in step (b), an unexposed area of the first component layer is removed;
19. The method described in 18, wherein step (b) is performed on a printing machine;
20. A printing plate element comprising a substrate having thereon a layer A containing a material
1
which is water-insoluble or capable of varying from being water-soluble to being water-insoluble at a temperature not less than 60° C., and a material
2
which is water-soluble and crystalline and has a melting point within the range of from 60° to 300° C.;
21. The printing plate element described in 20, wherein the printing plate element has a hydrophilic layer B provided between the layer A and the substrate;
22. The printing plate element described in 21, wherein the hydrophilic layer B is a porous layer;
23. The printing plate element described in 21 or 22, wherein the hydrophilic layer B contains a light-heat conversion material;
24. The printing plate element described in any one of 21 to 23, wherein the hydrophilic layer B contains an alkaline colloidal silica and a water-soluble polysaccharide, and having a protruding structure having a pitch of from 0.1 to 50 &mgr;m on the surface thereof;
25. The printing plate element described in any one of 21 to 24, wherein the printing plate element has a layer C containing a light-heat conversion material provided between the hydrophilic layer B and the substrate;
26. The printing plate element described in any one of 20 to 25, wh
Baxter Janet
Frishauf Holtz Goodman & Chick P.C.
Gilliam Barbara
Konica Corporation
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