Abstract: A method is disclosed for producing a recycled developer from a waste developer generated by development of a water-developable flexographic printing original plate that has a photosensitive resin layer made from a photosensitive resin composition containing a water-dispersible resin. The method includes: leaving the waste developer to stand still in a tank so as to emerge and flocculate the photosensitive resin composition dispersed in the waste developer and thus form a solid-liquid mixed phase containing a resin flocculate beneath a liquid surface of the waste developer; and discharging the solid-liquid mixed phase containing the resin flocculate from an outlet formed on a side surface of the tank and obtaining, as a recycled developer, a liquid left in the tank, characterized in that a level of the waste developer in the tank at the time of starting the discharge is higher than the lowest position of an aperture of the outlet.

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: 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 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).