Photosensitive resin composition and resin plate for flexography

Abstract

The present invention provides a photosensitive resin composition which comprises an urethane resin obtained by reacting (A) a carboxyl group-containing polymer having an acid value of 30 mg KOH/g or more and a glass transition temperature of 30° C. or more, (B) a compound having two isocyanate groups in one molecule, (C) a compound having two hydroxyl groups in one molecule and (D) a photopolymerizable unsaturated monomer having one hydroxyl group in one molecule, and a photopolymerization initiator, and a resin plate for flexography using the photosensitive resin composition, whereby the photosensitive resin composition having water developing properties, high in sensitivity and impact resilience, and excellent in water resistance, ink resistance and press life of a hardened portion forming a line pattern area of a printing plate material and the resin plate for flexography prepared by the use of the photosensitive resin composition can be provided.

1 . A photosensitive resin composition comprising an urethane resin obtained by reacting (A) a carboxyl group-containing polymer having an acid value of 30 mg KOH/g or more and a glass transition temperature of 30° C. or more, (B) a compound having two isocyanate groups in one molecule, (C) a compound having two hydroxyl groups in one molecule and (D) a photopolymerizable unsaturated monomer having one hydroxyl group in one molecule, and a photopolymerization initiator.  
     
     
         2 . A photosensitive resin composition comprising an urethane resin obtained by reacting (A) a carboxyl group-containing polymer having an acid value of 30 mg KOH/g or more and a glass transition temperature of 30° C. or more, (B) a compound having two isocyanate groups in one molecule, (C) a compound having two hydroxyl groups in one molecule and (D) a photopolymerizable unsaturated monomer having one hydroxyl group in one molecule, a photopolymerizable unsaturated monomer and a photopolymerization initiator.  
     
     
         3 . A photosensitive resin composition comprising an urethane resin comprising as structural units (A) a carboxyl group-containing polymer having an acid value of 30 mg KOH/g or more and a glass transition temperature of 30° C. or more, (B) a compound having two isocyanate groups in one molecule, (C) a compound having two hydroxyl groups in one molecule and (D) a photopolymerizable unsaturated monomer having one hydroxyl group in one molecule, and a photopolymerization initiator.  
     
     
         4 . The photosensitive resin composition according to any one of    claims 1    to    3   , wherein said urethane resin is a resin obtained by reacting component (B), component (C), component (D) and component (A) in this order.  
     
     
         5 . The photosensitive resin composition according to any one of    claims 1    to    4   , wherein component (A) is an acrylic polymer.  
     
     
         6 . The photosensitive resin composition according to any one of    claims 1    to    4   , wherein component (B) is hexamethylene diisocyanate.  
     
     
         7 . The photosensitive resin composition according to any one of    claims 1    to    5   , wherein component (C) is polyether diol.  
     
     
         8 . The photosensitive resin composition according to any one of    claims 1    to    4   , wherein component (D) is a hydroxyl group containing unsaturated acrylic acid ester series monomer.  
     
     
         9 . The photosensitive resin composition according to    claim 8   , wherein the hydroxyl group-containing unsaturated acrylic acid ester series monomer is 2-hydroxyethyl acrylate.  
     
     
         10 . A resin plate for flexography using the photosensitive resin composition of any one of    claims 1    to    9   .  
     
     
         11 . A resin plate for flexography, which uses the photosensitive resin composition of any one of    claims 1    to    9    and has a photosensitive resin layer having an impact resilience of 30% or more according to JIS K6301-11.