Photosensitive resin composition for relief printing original plate and relief printing original plate using the same
A photosensitive resin composition contains (i) modified partially-saponified polyvinyl acetate having a functional group introduced into a side chain thereof, (ii) tertiary nitrogen atom-containing polyamide, (iii) a photopolymerizable unsaturated compound and (iv) a photopolymerization initiator, characterized in that the above (ii) tertiary nitrogen atom-containing polyamide contains 20 to 50% by mol of a structural unit obtained from cyclohexane-dicarboxylic acid and 50 to 95% by mol of an alicyclic structural unit in total, in relation to a total of an amount of an aminocarboxylic acid unit (including a case wherein lactam is a raw material), an amount of a dicarboxylic acid unit and an amount of a diamine unit in the polyamide molecule. There is also provided a relief printing original plate which is characterized in having, on a support, a photosensitive resin layer formed by using this photosensitive resin composition.
1. A photosensitive resin composition for a relief printing original plate containing (i) modified partially-saponified polyvinyl acetate having a functional group introduced into a side chain thereof, (ii) tertiary nitrogen atom-containing polyamide, (iii) a photopolymerizable unsaturated compound and (iv) a photopolymerization initiator, characterized in that the above (ii) tertiary nitrogen atom-containing polyamide contains 20 to 50% by mol of a structural unit obtained from cyclohexane-dicarboxylic acid and 50 to 95% by mol of an alicyclic structural unit in total, in relation to a total of an amount of an aminocarboxylic acid unit (including a case wherein lactam is a raw material), an amount of a dicarboxylic acid unit and an amount of a diamine unit in the polyamide molecule.
2. The photosensitive resin composition for a relief printing original plate according to claim 1 , wherein an amount of (i) modified partially-saponified polyvinyl acetate having a functional group introduced into a side chain thereof, an amount of (ii) tertiary nitrogen atom-containing polyamide, an amount of (iii) photopolymerizable unsaturated compound and an amount of (iv) photopolymerization initiator used in the photosensitive resin composition for a relief printing original plate are 30 to 65% by mass, 5 to 30% by mass, 5 to 35% by mass and 0.1 to 5% by mass, respectively.
3. The photosensitive resin composition for a relief printing original plate according to claim 1 , wherein the above (ii) tertiary nitrogen atom-containing polyamide is a polyamide which contains a piperazine ring in a molecule.
4. The photosensitive resin composition for a relief printing original plate according to claim 1 , wherein the above (i) modified partially-saponified polyvinyl acetate having a functional group introduced into a side chain thereof contains an ester bond and the functional group in the side chain, and wherein the functional group is a photopolymerizable unsaturated group and/or a carboxyl group.
5. The photosensitive resin composition for a relief printing original plate according to claim 1 , wherein the above (iii) photopolymerizable unsaturated compound contains a photopolymerizable unsaturated compound containing a heterocyclic ring having a 5 to 7-membered ring.
6. A relief printing original plate which is characterized in having, on a support, a photosensitive resin layer formed by using the photosensitive resin composition for a relief printing original plate mentioned in claim 1 .
7. The relief printing original plate according to claim 6 , wherein the relief printing original plate is a relief printing original plate of an analog type.
8. The relief printing original plate according to claim 6 , wherein the relief printing original plate is a relief printing original plate of a laser-engraving type.