摘要:
Disclosed is a support for a lithographic printing plate which, when measured over a 400 μm×400 μm surface region thereon using a three-dimensional non-contact roughness tester, has at most 5.0 convex portions of a height from centerline of at least 0.70 μm and an equivalent circle diameter of at least 20 μm, and has at least 800 concave portions of a depth from centerline of at least 0.50 μm and an equivalent circle diameter of at least 2.0 μm. Presensitized plates which are obtainable by using the support for a lithographic printing plate according to the present invention have an excellent scumming resistance and an extremely long press life.
摘要:
There is provided an aluminum alloy blank for a lithographic printing plate including iron in a range of 0.20 to 0.80 wt %; and the balance being aluminum, a crystal grain refining element, and unavoidable impurity elements. The unavoidable impurity elements may include silicon and copper, wherein a content of silicon is in a range of 0.02 to 0.30 wt % and a content of copper is equal to or below 0.05 wt %. A solid solution amount of silicon is in a range of 150 ppm to 1500 ppm.
摘要:
A roll for metal rolling has a roughened surface formed by an electrolytic treatment in an electrolytic solution while using the roll as an anode. When the roll is used to emboss an aluminum plate, it is possible to obtain an aluminum plate with an uneven structure having regulated positions of levels of peaks and a larger number of the peaks. A presensitized plate formed by use of the aluminum plate as a support has excellent printing performances particularly in the number of printed sheets and sensitivity.
摘要:
Disclosed is a method of manufacturing a lithographic printing plate support including the step of: subjecting an aluminum plate at least to electrochemical graining treatment in which alternating current is passed through the aluminum plate in an aqueous solution containing hydrochloric acid so that the total amount of electricity when the aluminum plate serves as an anode is at least 250 C/dm2, thereby obtaining a lithographic printing plate support, wherein the aluminum plate contains not more than 30 ppm of Cu and 10 to 200 ppm of at least one element selected from the group consisting of Ga, V, Zn, In, Ni, Pb and Cr, contains at least 15 ppm of Fe in a form of a solid solution, and has a pattern of recessed and protruded portions formed on a surface thereof. By this method, a lithographic printing plate support which can be used for a presensitized plate excellent in various properties such as press life, scumming resistance and resistance to piling is obtained without performing mechanical graining treatment using nylon brushes and an abrasive.
摘要:
According to the present invention, since the concavo-convex pattern of the embossing form is formed by electrical discharge machining, the peaks on the surface of the resultant embossing form are all of the same level or height, which enables the enhancement of the service life of the embossing form. Further, since the concavo-convex pattern of the embossing form is formed by electrical discharge machining, even a complicated and minute concavo-convex pattern can be formed. Accordingly, when applying the method of the present invention to, for example, the production of a substrate for a lithographic plate, an aluminum substrate for a lithographic plate which excels in plate wear, sensitivity and resistance to stains can be produced. And when applying the same to the production of an aluminum decorative laminate, an aluminum decorative laminate which excel in glossiness and paint adhesion can be produced.
摘要:
A process for producing an aluminum support for a planographic printing plate, the process comprising the steps of: (a) preparing an aluminum plate; (b) disposing said aluminum plate in an aqueous acidic solution; and (c) electrochemically surface-roughening said aluminum plate using an alternating current, wherein a ratio QC/QA of a cathode-time quantity of electricity of said aluminum plate QC to an anode-time quantity of electricity of said aluminum plate QA is from 0.95 to 2.5. An aluminum support for a planographic printing plate formed by the process. A planographic printing master plate comprising at least a positive-type or negative-type light-sensitive layer on the aluminum support.
摘要:
Disclosed is a production method of an aluminum support for a lithographic printing plate, capable of stable and low-cost production of an aluminum support for a lithographic printing plate, the support being scarcely subject to generation of treatment unevenness called streaks or grainy unevenness ascribable to the different in the aluminum dissolving rate due to the difference in the orientation of the crystal grain. The aluminum support is produced by surface graining and then polishing an aluminum plate or by polishing an aluminum plate while etching it in an aqueous acid or alkali solution. The aluminum plate may be subjected to polishing and then to anodization or may be subjected to polishing, to surface graining, again to or not to polishing and then to anodization. A production method for producing a high-quality support for a lithographic printing plate, free of local unevenness is also disclosed.
摘要:
A lithographic printing plate support is provided which becomes a support of a PS plate which has excellent ability to withstand repeated printing, and in which defects in appearance, such as dirtying and the like, do not occur. Also provided are a method of manufacturing the lithographic printing plate support and a PS plate which has such merits.
摘要:
A support for lithographic printing plate which is obtained by performing surface roughening treatments including electrolytic graining on an aluminum alloy plate containing Fe, Si, Cu, Ti, Mg and Ni in specified amounts, with the balance being Al and incidental impurities. The Ni content, Cu content and the average surface roughness of the roughened support surface satisfy a specified relationship. A lithographic printing plate prepared from the support have longer press life, higher resistance to staining and better surface quality.
摘要:
A support for a lithographic printing plate obtained by performing surface graining and anodizing of an aluminum alloy plate, wherein the foregoing aluminum alloy plate contains specific contents of Fe, Si, Cu, Ti, Zn and Mg, with the balance being Al and incidental impurities. The presensitized plate obtained from this support for a lithographic printing plate is excellent in press life and in resistance to dot ink stain when processed into a lithographic printing plate. Preferably, the support for a lithographic printing plate, with regard to the surface of the support, has a center line average roughness Ra in the range of 0.2-0.6 &mgr;m, a maximum height Rmax in the range of 3.0-6.0 &mgr;m, a ten-point mean roughness Rz in the range of 2.0-5.5 &mgr;m, a center line peak height Rp in the range of 1.0-3.0 &mgr;m, a center line valley depth Rv in the range of 2.0-3.5 &mgr;m, a mean spacing Sm in the range of 40-70 &mgr;m, an average inclination &Dgr;a in the range of 6.0-12.0°, and a peak count Pc in the range of 100-200.