Konica Corporation

Konishiroku Photo Industry Co., Ltd.

Kazuhiro Shimura

Masafumi Uehara

Shinya Watanabe

Akira Nogami

Akio Iwaki

Atsuo Yamazaki

Keiichi Yumiki

The improved method of development is implemented with an automatic processor for developing presensitized offset printing plates with a substantially virgin aqueous solution that contains an alkali silicate and that is supplied for each printing plate, said aqueous solution containing calcium ions in an amount of up to 10 mg/L. The improved developing apparatus comprises a means of mixing a concentrated developing solution with diluent water to prepare a working solution and a means of applying the working solution onto the surface of a presensitized offset printing plate being transported. The apparatus is characterized by further including a mechanism that performs ion-exchange on the diluent water before it is mixed with the concentrated developing solution.

Method and apparatus for developing presensitized offset printing plates

A developing solution of an imagewise exposed, presensitized offset printing plate is disclosed. The developing solution has a pH of at least 12.5, and contains a low content of a silicate in an amount of up to 1.0 wt % as SiO.sub.2, a surfactant in an amount of 0.01 to 10 wt %, an aromatic carboxylic acid in an amount of 0.1 to 10 wt %, and an amine compound represented by the following general formula (I) in an amount of 0.1 to 10 wt %:

Method of developing presensitized offset printing plates and developing

Disclosed are a method and an apparatus for processing with a developing solution repeatedly used, both an imagewise exposed, positive-working presensitized lithographic printing plate and an imagewise exposed negative-working presensitized lithographic printing plate. The plates each comprise an aluminum support and a light-sensitive layer formed thereon. A replenishing solution is added to the developing solution to compensate for the degradation of the developing solution brought about by development and/or by carbon dioxide in the air. The method comprises the steps of; measuring a reflection density of the light-sensitive layer of the printing plates to discriminate the type of the printing plate, selecting a predetermined developing condition according to the discriminated type of the printing plate, and developing the printing plates according to the selected developing condition.

Method and apparatus for processing presensitized lithographic printing

A method of developing a waterless light-sensitive lithographic printing plate having a support and, provided thereon, a light-sensitive layer comprising a diazo resin and a silicone gum layer with a developer is disclosed. The developer comprises an organic carboxylic acid or salt thereof, water, and at least one of a sulfite and a surfactant.

Method for developing a waterless light-sensitive lithographic plate

A method and a device of dividing an aqueous processing waste solution of a non-silver halide light-sensitive material into solid and water are disclosed comprising the steps of:

Method of treating an aqueous processing waste solution of a non-silver

A positive-working photosensitive composition comprising (a) an o-quinonediazide compound and (b) a condensed resin containing a condensation unit composed of an aromatic compound having a carboxylic group and a phenolic ahydroxyl group, and an aldehyde or ketone is disclosed. Said condensation unit has the following formula (I): ##STR1## wherein R.sub.1 is a hydrogen atom, a hydroxyl group, an acyloxy group, an alkyl group, an alkoxy group or a halogen atom, which may be the same or different when n is 2; R.sub.2 and R.sub.3 are each a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms, a phenyl group or a substituted phenyl group, which may be the same or different; and n is 1 or 2.

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Hino, Japan

Kazuhiro Shimura