Fuji Photo Film Company, Limited

Hiroyuki Ohishi

Eiichi Kato

Seishi Kasai

Takao Nakayama

Kazuo Ishii

Sadao Osawa

Makoto Momota

Process for preparing ink jet system printing plate

A process for preparing an ink-jet system printing plate, wherein an image is formed according to a hot melt type ink-jet system by heat-melting an ink composition that is solid at ordinary temperature, spraying droplets of the ink composition in a hot melt state from nozzles onto an intermediate transferrer to form an image, and contact-transferring the image on the intermediate transferrer to an image receiving layer of a planographic printing plate precursor, the image receiving layer being provided on a water-resistive support and containing zinc oxide and a binder resin, and thereafter, a nonimage area of the image receiving layer is desensitized by chemical reaction treatment to prepare a planographic printing plate.

Process for preparing ink-jet system printing plate

A block copy sheet for lithographic printing plate to be interposed between a plate cylinder and a lithographic printing plate having a front surface and a back surface, at least the back surface being made of a material other than metals, wherein the block copy sheet have convex portions provided on a surface thereof, the convex portions having a predetermined shape so as to concave the back surface of the lithographic printing plate when pressed against the back surface of the lithographic printing plate, and wherein (1) the convex portions comprises a composite particle having protrusions provided on the surface thereof and having a hardness greater than that of the back surface of the lithographic printing plate and a particle diameter of from 1 &mgr;m to 100 &mgr;m, or (2) the convex portions comprises non-spherical fillers having an average length of from 1 &mgr;m to 200 &mgr;m and the contact area of the convex portions and the back surface of the lithographic printing plate is from 0.6% to 3.0% of the area of the back surface of the lithographic printing plate.

Block copy sheet for lithographic printing plate

The present invention provides for a camera-ready copy sheet to be inserted between a plate cylinder and a lithographic printing plate at least the back side of which is made of a non-metallic material. The copy sheet has asperities of a predetermined shape on the front side that are urged against the back side of the lithographic printing plate to depress it. The height of the projections in the asperities ranges from 5 &mgr;m to 50 &mgr;m. The sum per unit area of maximum cross-sectional areas of planes in the projections that are parallel to the surface of the sheet ranges from 0.2% to 4% of the unit area.

Camera-ready copy sheet for lithograpic printing plate

The present invention provides for a camera-ready copy sheet to be inserted between a plate cylinder and a lithographic printing plate at least the back side of which is made of a non-metallic material. The copy sheet has asperities of a predetermined shape on the front side that are urged against the back side of the lithographic printing plate to depress it. These asperities are formed of projections that consist of at least two groups of particles. A larger particle group having a particle size larger than an intermediate between maximum and minimum particle sizes has an average size at least twice an average size of a smaller particle group having a particle size smaller than the intermediate. The sum per unit area of maximum cross-sectional areas of planes in the particles of the larger particle group that are parallel to the surface of the sheet ranges from 0.1% to 4% of the unit area.

Camera-ready copy sheet for lithographic printing plates

The present invention provides a process for the preparation of a hot-melt ink jet process printing plate capable of printing many sheets of printed matters having a sharp image quality free of background stain. The present invention concerns a novel process for the preparation of an ink jet process lithographic printing plate which comprises preparing a direct imaging lithographic printing plate precursor comprising a water-resistant support having an image-receiving layer containing an inorganic pigment and a hydrophilic binder resin as main components provided thereon, and then jetting through a nozzle ink droplets obtained by heating and melting a solid ink composition at ordinary temperatures onto the image-receiving layer to form an image thereon by a hot-melt ink jet process, characterized in that the image-receiving layer comprises as the inorganic pigments a particulate silica having an average grain diameter of from 1 to 6 .mu.m and an ultrafinely particulate colloidal inorganic pigment having an average grain diameter of from 10 to 50 nm in a weight ratio of 40:60 to 70:30 and as the hydrophilic binder resin gelatin in a weight ratio of 85:15 to 40:60 relative to that of the inorganic pigments and thus exhibits water resistance attained by the curing action of a gelatin-curing compound.

Process for the preparation of ink jet process printing plate

A method for preparation of a printing plate by an electrophotographic process comprising forming a peelable transfer layer capable of being removed upon a chemical reaction treatment on a surface of an electrophotographic light-sensitive element, forming a toner image by an electrophotographic process on the transfer layer, heat-transferring the toner image together with the transfer layer onto a receiving material having a surface capable of providing a hydrophilic surface suitable for lithographic printing at the time of printing, and removing the transfer layer on the receiving material upon the chemical reaction treatment wherein the transfer layer is formed by an electrodeposition coating method using thermoplastic resin grains (AL) each containing a rein (A.sub.1) having a glass transition point of from 10.degree. C. to 140.degree. C. or a softening point of from 35.degree. C. to 180.degree. C. and a resin (A.sub.2) having a glass transition point of not more than 45.degree. C. or a softening point of not more than 60.degree. C. and its glass transition point or softening point is at least 2.degree. C. lower than that of the resin (A.sub.1). The transfer layer according to the present invention has excellent transferability onto a receiving material under transfer conditions of low temperature and high speed to form transferred images of good qualities thereby providing prints of good image qualities.

Method for preparation of printing plate by electrophotographic process

A method for preparation of a printing plate by an electrophotographic process comprising forming a peelable transfer layer capable of being removed upon a chemical reaction treatment on a surface of an electrophotographic light-sensitive element, forming a toner image by an electrophotographic process on the transfer layer, heat-transferring the toner image together with the transfer layer onto a receiving material having a surface capable of providing a hydrophilic surface suitable for lithographic printing at the time of printing, and removing the transfer layer on the receiving material upon the chemical reaction treatment wherein the transfer layer has a stratified structure composed of a first transfer layer (T.sub.1) which is contact with the surface of electrophotographic light-sensitive element and is formed by an electrodeposition coating method using thermoplastic resin grains (AL) each containing a rein (A.sub.1) having a glass transition point of from 10.degree. C. to 140.degree. C. or a softening point of from 35.degree. C. to 180.degree. C. and a resin (A.sub.2) having a glass transition point of not more than 45.degree. C. or a softening point of not more than 60.degree. C. wherein the glass transition point or softening point of resin (A.sub.1) is at least 2.degree. C. higher than that of resin (A.sub.2) and a second transfer layer (T.sub.2) provided thereon mainly containing a resin (A.sub.2). The transfer layer according to the present invention has excellent transferability onto a receiving material under transfer conditions of low temperature and high speed to form transferred images of good qualities thereby providing a printing plate which produces prints of good image qualities.

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Shizuoka, Japan

Hiroyuki Ohishi