Abstract: A method includes (i) preparing a printing original plate sheet having an uncured photosensitive resin layer on a surface thereof, wherein compressive strength of the uncured photosensitive resin layer at 25° C. is 1.0 to 3.0 kgf/cm2; (ii) mounting the printing original plate sheet around a cylindrical support in such a manner that a starting terminal of the mounting and an ending terminal of the mounting are overlapped; and (iii) applying pressure to the overlapped area of the starting terminal of the mounting and the ending terminal of the mounting at a temperature range of 10 to 40 ° C. so as to pressure-bond the overlapped area. The method may further include, after the step (iii), a step (iv) for photo-curing the uncured photosensitive resin layer and may further comprise, after the step (iv), a step (v) for grinding, abrading and/or machining the overlapped area.

Abstract: A photosensitive resin composition for CTP flexographic printing original plate containing at least a hydrophobic polymer obtained from water-dispersible latex (A), a hydrophilic polymer (B), a photopolymerizable unsaturated compound (C), a photopolymerization initiator (D), and if necessary, rubber (E), characterized in that, the photopolymerizable unsaturated compound (C) comprises a photopolymerizable oligomer containing no hydroxyl group (C-1), a hydroxyl group-containing photopolymerizable monomer having a pentaerythritol skeleton, a dipentaerythritol skeleton or a glycerol skeleton (C-2) and, optionally, a photopolymerizable monomer containing no hydroxyl group (C-3). The content of the hydroxyl group-containing photopolymerizable monomer (C-2) is 1 to 20% by mass of the photosensitive resin composition. The content of the rubber (E) is preferably 0.5 to 15% by mass of the photosensitive resin composition.

Abstract: A method includes (i) preparing a printing original plate sheet having an uncured photosensitive resin layer on a surface thereof, wherein compressive strength of the uncured photosensitive resin layer at 25° C. is 1.0 to 3.0 kgf/cm2; (ii) mounting the printing original plate sheet around a cylindrical support in such a manner that a starting terminal of the mounting and an ending terminal of the mounting are overlapped; and (iii) applying pressure to the overlapped area of the starting terminal of the mounting and the ending terminal of the mounting at a temperature range of 10 to 40° C. so as to pressure-bond the overlapped area. The method may further include, after the step (iii), a step (iv) for photo-curing the uncured photosensitive resin layer and may further comprise, after the step (iv), a step (v) for grinding, abrading and/or machining the overlapped area.

Abstract: A method is disclosed for producing a flexographic printing plate from a flexographic printing original plate provided with a photosensitive resin layer comprising a photosensitive resin composition containing at least (A) a hydrophobic polymer comprising a water-dispersible latex, (B) a photopolymerizable compound and (C) a photopolymerization initiator, wherein the method comprises a main exposure step, a development step and a post-exposure step, characterized in that a treatment solution containing a first amino-modified silicone having an amine equivalent of 1000 g/mol or less and a second amino-modified silicone having an amine equivalent of 3000 g/mol or more in a mass ratio of from 2.5:1 to 1:6 is contacted with the whole surface of the flexographic printing plate.

Abstract: The present invention provides a method for producing a flexographic printing plate which has an ability to prevent plate surface contamination and a persistency of the effect thereof and which allows a high-quality printing in a large scale. There is disclosed a method for producing a flexographic printing plate from a flexographic printing original plate provided with a photosensitive resin layer comprising a photosensitive resin composition containing at least (A) a hydrophobic polymer comprising a water-dispersible latex, (B) a photopolymerizable compound and (C) a photopolymerization initiator, wherein the method comprises a main exposure step, a development step and a post-exposure step, characterized in that a treatment solution containing a first amino-modified silicone having an amine equivalent of 1000 g/mol or less and a second amino-modified silicone having an amine equivalent of 3000 g/mol or more in a mass ratio of from 2.

Abstract: The present invention provides a water-developable photosensitive resin composition for flexographic printing original plate which highly satisfies both printing durability and fine image reproducibility for 175 lpi. A photosensitive resin composition for a flexographic printing original plate, characterized in that, the composition contains (A) hydrophobic polymers obtained from at least two kinds of water-dispersible latexes, (B) a rubber, (C) a photopolymerizable compound, (D) a photopolymerization initiator, and optionally (E) an aggregation inhibitor and that the ratio by mass of the component (B) to the total mass of the component (A) and the component (B) is within a range of from 1 to 7%. It is preferred that hydrophobic polymer(s) obtained from at least one kind of water-dispersible latex(es) in the above component (A) and the rubber of the component (B) have a common skeleton structure.

Abstract: A developer composition for a printing plate containing (a) alkali metal salt of saturated fatty acid having carbon number of 12 to 18 and (b) alkali metal salt of unsaturated fatty acid having carbon number of 12 to 18 in a weight ratio of from 20:80 to 80:20 in terms of (a):(b). The developer composition may further contain an alkali agent (c). In this case, a weight ratio of (a):(b) may be from 20:80 to 80:20, and the alkali agent (c) may be contained in amount of 0.01 to 10 part(s) by weight to 100 parts by weight in total of the components (a) and (b).

Abstract: The present invention aims to provide a flexographic printing original plate where, although it is a flexible aqueous developing plate, reproducibility of fine lines is good. A flexographic printing original plate which is a photosensitive printing original plate where at least (A) a supporting member, (B) a photosensitive resin layer, (C) a protective layer for preventing the polymerization inhibition due to oxygen in the photosensitive resin layer and (D) a heat-sensitive mask layer are successively layered, characterized in that, the photosensitive resin layer (B) is a layer which is able to be developed by water, Young's modulus of the protective layer (C) is 4 MPa to 35 MPa, layer thickness of the protective layer (C) is 0.2 ?m to 2.0 ?m and Young's modulus (MPa) and layer thickness (?m) of the protective layer (C) satisfy the following formula 1: 1?(Young's modulus)×(Layer thickness)2?18??(Formula 1).

Abstract: The present invention provides a CTP photosensitive flexographic printing original plate which causes no printing blur while the conventional printing durability, developing property and image-reproducing property are still maintained. A photosensitive resin composition for CTP flexographic printing original plate containing at least a hydrophobic polymer obtained from water-dispersible latex (A), a hydrophilic polymer (B), a photopolymerizable unsaturated compound (C), a photopolymerization initiator (D), and if necessary, rubber (E), characterized in that, the photopolymerizable unsaturated compound (C) comprises a photopolymerizable oligomer containing no hydroxyl group (C-1), a hydroxyl group-containing photopolymerizable monomer having a pentaerythritol skeleton, a dipentaerythritol skeleton or a glycerol skeleton (C-2) and, optionally, a photopolymerizable monomer containing no hydroxyl group (C-3).

Abstract: The present disclosure describes a printing original plate capable of being laser-engraved such that printing deficiency caused by residues is avoided, and such that resolution and printing quality are good. A flexographic printing original plate capable of being laser-engraved which is obtained by subjecting a photosensitive resin composition containing (A) at least one latex having a weight-average degree of gelation of 40% or more, (B) photopolymerizable compound and (C) photopolymerization initiator to irradiation to light followed by cross-linking and curing. The photopolymerizable component (B) contains the photopolymerizable oligomer and the ethylenic unsaturated monomer in 10 to 25% by weight and 5 to 40% by weight, respectively, to the weight of the photosensitive resin composition and the ethylenic unsaturated monomer comprises 75 to 5% by weight of monofunctional monomer and 25 to 95% by weight of trifunctional monomer.

Abstract: The present invention provides a photosensitive letterpress printing original plate provided with a heat sensitive mask layer having high light blocking effect and durability yet prepared as a thin film. A photosensitive letterpress printing original plate including at least (A) a supporting member, (B) a photosensitive resin layer, and (C) a heat sensitive mask layer that are successively laminated, wherein the heat sensitive mask layer (C) contains carbon black and, as a dispersion binder therefor, a butyral resin as well as polyamide containing polar group selected from the group consisting of polyamide containing a tertiary amine group, polyamide containing a quaternary ammonium salt group, polyamide containing an ether group and polyamide containing a sulfonic group.

Abstract: The present invention provides a flexographic printing original plate having no wrinkle on the plate surface and having no plate surface abnormality due to laser in spite of the fact that it is a flexible water-developable plate. A photosensitive flexographic printing original plate developable by water in which at least a supporting member, a photosensitive resin layer, a protective layer and a heat-sensitive mask layer are successively laminated, characterized in that, the protective layer contains (A) polyvinyl alcohol, (B) plasticizer and (C) water-dispersible latex in the following rate. Polyvinyl alcohol (A): 25 to 80 parts by weight Plasticizer (B): 15 to 60 parts by weight Water-dispersible latex (C): 5 to 40 parts by weight.

Abstract: The present invention provides a water-based developer where the dispersibility of an image mask layer in a developer is good in a developing step of a water-developable printing original plate of a CTP system. Also, the present invention also provides a water-based developer where the scum dispersibility in the developer is good even the developing is repeatedly conducted in large quantities using the same developer in a developing step of a water-developable printing original plate of a negative system. According to the present invention, there is provided a developer composition for a printing plate containing (a) alkali metal salt of saturated fatty acid having carbon number of 12 to 18 and (b) alkali metal salt of unsaturated fatty acid having carbon number of 12 to 18 in a weight ratio of from 20:80 to 80:20 in terms of (a):(b). The developer composition may further contain an alkali agent (c).

Abstract: The present invention provides a photosensitive flexographic printing original plate provided with a heat sensitive mask layer having high light blocking effect and durability yet prepared as a thin film. A photosensitive flexographic printing original plate including at least (A) a supporting member, (B) a photosensitive resin layer, (C) a protective layer and (D) a heat sensitive mask layer that are successively laminated, wherein the heat sensitive mask layer (D) contains carbon black and, as a dispersion binder therefor, a butyral resin as well as polyamide containing polar group selected from the group consisting of polyamide containing a tertiary amine group, polyamide containing a quaternary ammonium salt group, polyamide containing an ether group and polyamide containing a sulfonic group.

Abstract: The present invention provides a flexographic printing original plate having no wrinkle on the plate surface and having no plate surface abnormality due to laser in spite of the fact that it is a flexible water-developable plate. A photosensitive flexographic printing original plate developable by water in which at least a supporting member, a photosensitive resin layer, a protective layer and a heat-sensitive mask layer are successively laminated, characterized in that, the protective layer contains (A) polyvinyl alcohol, (B) plasticizer and (C) water-dispersible latex in the following rate.

Abstract: The present invention provides a photosensitive letterpress printing original plate provided with a heat sensitive mask layer having high light blocking effect and durability yet prepared as a thin film. A photosensitive letterpress printing original plate including at least (A) a supporting member, (B) a photosensitive resin layer, and (C) a heat sensitive mask layer that are successively laminated, wherein the heat sensitive mask layer (C) contains carbon black and, as a dispersion binder therefor, a butyral resin as well as polyamide containing polar group selected from the group consisting of polyamide containing a tertiary amine group, polyamide containing a quaternary ammonium salt group, polyamide containing an ether group and polyamide containing a sulfonic group.

Abstract: The present invention aims to provide a printing original plate capable of being laser-engraved in which printing deficiency caused by residues is not resulted, resolution is good and printing property is also good. A flexographic printing original plate capable of being laser-engraved which is obtained by subjecting a photosensitive resin composition containing (A) at least one latex having a weight-average degree of gelation of 40% or more, (B) photopolymerizable compound and (C) photopolymerization initiator to irradiation to light followed by cross-linking and curing, wherein the photopolymerizable compound (B) contains the photopolymerizable oligomer and the ethylenic unsaturated monomer in 10 to 25% by weight and 5 to 40% by weight, respectively, to the weight of the photosensitive resin composition and the ethylenic unsaturated monomer comprises 75 to 5% by weight of monofunctional monomer and 25 to 95% by weight of trifunctional monomer.

Abstract: The present invention aims to provide a flexographic printing original plate where, although it is a flexible aqueous developing plate, reproducibility of fine lines is good. A flexographic printing original plate which is a photosensitive printing original plate where at least (A) a supporting member, (B) a photosensitive resin layer, (C) a protective layer for preventing the polymerization inhibition due to oxygen in the photosensitive resin layer and (D) a heat-sensitive mask layer are successively layered, characterized in that, the photosensitive resin layer (B) is a layer which is able to be developed by water, Young's modulus of the protective layer (C) is 4 MPa to 35 MPa, layer thickness of the protective layer (C) is 0.2 ?m to 2.0 ?m and Young's modulus (MPa) and layer thickness (?m) of the protective layer (C) satisfy the following formula 1: 1?(Young's modulus)×(Layer thickness)2?18??(Formula 1).

Abstract: The present invention provides a photosensitive flexographic printing original plate provided with a heat sensitive mask layer having high light blocking effect and durability yet prepared as a thin film. A photosensitive flexographic printing original plate including at least (A) a supporting member, (B) a photosensitive resin layer, (C) a protective layer and (D) a heat sensitive mask layer that are successively laminated, wherein the heat sensitive mask layer (D) contains carbon black and, as a dispersion binder therefor, a butyral resin as well as polyamide containing polar group selected from the group consisting of polyamide containing a tertiary amine group, polyamide containing a quaternary ammonium salt group, polyamide containing an ether group and polyamide containing a sulfonic group.