Fuji Photo Film Company, Limited

Koichiro Aono

Yoshimasa Aotani

Yasuhiro Annoura

Takanori Masuda

Tsutomu Kato

Hiroshi Takahashi

Hirokazu Sakaki

Ikuo Kawauchi

Hiroshi Misu

Fumikazu Kobayashi

Akira Nishioka

Fumihiro Tokunaga

Kei Okuno

A method for evaluating planographic printing plates according to the present invention includes: a step (A) of exposing a planographic printing plate precursor by irradiating a thin-line image of a one-pixel line and at least one thin-line image selected from two- to eight-pixel lines by incrementally altering the plate-surface energy; developing the exposed plate precursor with a standard developer; and identifying an exposure intensity (hereinafter, 'thin-line sensitivity') that respectively provides the images thus formed, with the same density; a step (B) of preparing another planographic printing plate precursor under the same conditions as in the step (A) and identifying the thin-line sensitivity, except that the planographic printing plate precursor is developed with a test developer; a step (C) of comparing the thin-line sensitivities respectively obtained in the steps (A) and (B); and a step (D) of adjusting plate-making conditions when the results of the comparison in the step (C) show a difference between the respective thin-line sensitivities that exceeds a predetermined value.

Method for evaluating planographic printing plates and quality-control method thereof

A clearance between an upper knife and a lower knife of a slitter is set at 30 to 100 &mgr;m, and the slitter cuts a sensitized printing plate. In the sensitized printing plate cut by the slitter, there is a shear droop which is 20 to 30 &mgr;m high at the cut part, and a burr which is less than 50 &mgr;m high. If the maximum height of a surface roughness of a cut surface of the sensitized printing plate is 1.2 &mgr;m to 12 &mgr;m on the average, a hydrophilic property of the cut part improves and the stain of a frame can be decreased.

Method and apparatus for manufacturing sensitized printing plate

A quality control method for a planographic printing plate having disposed on a substrate a photosensitive layer formed by a resin soluble in an aqueous alkali solution and a compound that absorbs light to generate heat, the quality control method having the steps of: (A) exposing, to an ultraviolet ray, a gray scale for evaluating a positive type planographic printing plate made by exposure to an ultraviolet ray, followed by development with a standard developing solution having a standard formula, and measurement of the sensitivity of the gray scale processed by the standard developing solution; (B) exposing, to an ultraviolet ray, a gray scale for evaluating a positive type planographic printing plate made by exposure to an ultraviolet ray in the same manner as in the step (A), followed by development with a developing solution to be evaluated, and measurement of the sensitivity of the gray scale processed by the developing solution to be evaluated; (C) comparing the sensitivity of the gray scale processed by the developing solution to be evaluated with the sensitivity of the gray scale processed by the standard developing solution; and (D) adjusting exposure/development conditions when the difference between the sensitivities exceeds a predetermined value as a result of the comparison of the sensitivity of the gray scale processed by the developing solution to be evaluated with the sensitivity of the gray scale processed by the standard developing solution.

Quality control method for a planographic printing plate

Light-sensitive compositions comprise a light-sensitive diazo resin, a binder and a compound having a pivaloyl group. Lithographic printing plates prepared by using the light-sensitive compositions of the invention are excellent in ink receptivity.

Light-sensitive composition and presensitized plate with light-sensitive

A process for preparing a positive-acting photosensitive lithographic printing plate precursor is described, comprising a combination of the steps of (a) electrolytically graining an aluminum plate in a nitric acid-based electrolyte, (b) etching the grained plate with an alkali, (c) anodizing the etched plate, and (d) forming a photosensitive layer containing an o-quinonediazide on the anodized plate.

Process for preparing positive-acting photosensitive lithographic

A negative working light-sensitive composition and a lithographic printing plate using the composition are described. The printing plate is comprised of a hydrophilic support and a thin layer of a negative working light-sensitive composition on the support. The light-sensitive composition contains a light-sensitive diazo compound and a compound capable of increasing absorption over the light-sensitive wavelength region of the composition with increasing exposure time.

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Shizuoka-ken, Japan

Koichiro Aono