High resolution, solvent resistant, thin elastomeric printing plates
The present invention relates to a printing element having at least one polymer layer which has photoimageable constituents and a chemically functionalized polymer to make the polymer layer either more hydrophobic or hydrophilic. In one embodiment, the printing element comprises two adjacent polymer layers on a substrate in which the photoimaged layer comprises a polymer chemically modified with hydrophobic fluoroalkyl side groups to provide differential wetting with hydrophilic inks.
1. An article comprising:
a) a hydrophilic substrate;
b) a layer of a crosslinkable hydrophobic polymer disposed on the substrate, wherein the polymer layer comprises:
i) an elastomeric polymer containing hydrophobic fluoroalkyl side groups;
ii) an initiator; and
iii) fluorinated crosslinkable monomer,
wherein the fluorinated crosslinkable monomer is selected from the group consisting of:
and mixtures thereof.
2. The article of claim 1 wherein the elastomeric polymer is a block copolymer of styrene-butadiene-styrene containing pendant hydrophobic fluoroalkyl side groups or styrene-isoprene-styrene containing pendant hydrophobic fluoroalkyl side groups.
3. The article of claim 1 wherein the polymer layer is crosslinked and has an elastic modulus in the range of 10 to 100 MPa.
4. The article of claim 1 wherein the polymer layer is crosslinked and has an elastic modulus in the range of 20 to 40 MPa.
5. The article of claim 1 wherein the initiator is a photoinitiator.
6. The article of claim 1 wherein the polymer layer is constituted to form a relief pattern on the substrate that is suitable for printing.
7. The article of claim 1 wherein the article is a flexographic printing plate.
8. The article of claim 1 wherein the article is a gravure printing plate.
9. The article of claim 6 wherein the relief pattern formed on the polymer layer comprises at least one relief feature having a size and step height (h) between an uppermost relief surface and the substrate, whereby the step height (h): feature size ratio is near unity.
10. The article of claim 1 wherein the article is printing element.