High resolution, solvent resistant, thin elastomeric printing plates
View Patent ↗The present invention relates to a printing element comprising at least one polymer layer on a substrate which has photoimagable constituents and a chemically functionalized polymer to make the polymer layer either more hydrophobic or hydrophilic. In one embodiment of the present invention, 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. A process for making a printing element comprising:
a) providing a hydrophilic substrate
b) depositing a hydrophobic polymer layer on the substrate, the polymer layer comprising:
i) an eastomeric polymer containing hydrophobic fluoroalkyl side groups;
ii) a photoinitiator; and
iii) monomers selected from the group consisting of:
and mixtures thereof;
c) imaging a pattern on the polymer layer forming a crosslinked polymer pattern and a non-crosslinked polymer pattern; and
d) developing the imaged polymer layer wherein the non-crosslinked polymer pattern is dissolved, thereby creating a relief-based image on the printing element.
2. The process of claim 1 wherein the elastomeric polymer is a block copolymer of styrene-butadiene-styrene or styrene-isoprene-styrene containing hydrophobic fluoroalkyl side groups.
3. The process of claim 1 or 2 wherein the single polymer layer has an elastic modulus in the range of 10 to 100 MPa.
4. The process of claim 1 or 2 wherein the single polymer layer has an elastic modulus in the range of 20 to 40 MPa.
5. A process for making a printing element comprising:
a) providing a substrate;
b) depositing a first polymer layer on the substrate wherein the first polymer layer is hdrophhobic and comprises
i) an elastomeric polymer containing hydrophobic fluoroalkyl groups;
ii) an initiator;
iii) monomers selected from the group consisting of:
and mixtures thereof;
c) crosslinking the first polymer layer;
d) depositing a second polymer layer on the first polymer layer wherein the second polymer layer is hydrophilic and comprises;
i) an elastomeric polymer containing hydrophilic hydroxyl groups;
ii) a photoinitiator; and
iii) monomers selected from non-fluorinated acrylate or methacrylate;
e) imaging a pattern on the second polymer layer forming a crosslinked polymer pattern and a non-crosslinked polymer pattern; and
f) developing the imaged second polymer layer wherein the non-crosslinked polymer pattern is dissolved, thereby forming a relief-based image on the printing element.
6. The process of claim 5 wherein the elastomeric polymer in the first polymer layer is a block copolymer of styrene-butadiene-styrene or styrene-isoprene-styrene containing hydrophobic fluoroalkyl side groups and the elastomeric polymer in the second polymer layer is a block copolymer of styrene-butadiene-styrene or styrene-isoprene-styrene containing hydrophilic hydroxyl side groups.
7. The process of claim 5 wherein the first polymer layer and the second polymer layer have an elastic modulus in the range of 10 to 100 MPa.
8. The process claim 5 wherein the first polymer layer and the second polymer layer have an elastic modulus in the range of 20 to 40 MPa.
9. A process for making a printing element comprising:
a) providing a substrate;
b) depositing a first polymer layer on the substrate wherein the first polymer layer is hydrophilic and comprises:
i) an elastomeric polymer containing hydrophilic hydroxyl side groups;
ii) an initiator;
iii) monomers selected from non-fluorinated acrylate or methacrylate;
c) crosslinking the first polymer layer;
d) depositing a second polymer layer on the first polymer layer wherein the second polymer layer is hydrophobic and comprises;
i) an elastomeric polymer containing hydrophobic fluoroalkyl side groups;
ii) a photoinitiator; and
iii) monomers selected from he group consisting of:
and mixtures thereof;
e) imaging a pattern on the second polymer layer forming a crosslinked polymer pattern and a non-crosslinked polymer pattern; and
f) developing the imaged second polymer layer wherein the non-crosslinked polymer pattern is dissolved, thereby forming a relief-based image on the printing element.
10. The process of claim 9 wherein the elastomeric polymer in the first polymer layer is a block copolymer of styrene-butadiene-styrene or styrene-isoprene-styrene containing hydrophilic hydroxyl side groups and the elastomeric polymer in the second polymer layer is a block copolymer of styrene-butadiene-styrene or styrene-isoprene-styrene containing hydrophobic fluoroalkyl side groups.
11. The process of claim 9 wherein the first polymer layer and the second polymer layer have an elastic modulus in the range of 10 to 100 MPa.
12. The process claim 9 wherein the first polymer layer and the second polymer layer have an elastic modulus in the range of 20 to 40 MPa.
13. A process for making a printing element comprising:
a) providing a substrate;
b) depositing a first polymer layer on the substrate wherein the first polymer layer is hydrophilic and comprises:
i) an elastomeric polymer;
ii) an initiator;
iii) monomers selected from non-fluorinated acrylate or methacrylate;
c) crosslinking the first polymer layer;
d) depositing a second polymer layer on the first polymer layer wherein the second polymer layer is hydrophobic and comprises;
i) an elastomeric polymer containing hydrophobic fluoroalkyl side groups;
ii) a photoinitiator; and
iii) monomers selected from the group consisting of:
and mixtures thereof;
e) imaging a pattern on the second polymer layer forming a crosslinked polymer pattern and a non-crosslinked polymer pattern; and
f) developing the imaged second polymer layer wherein the non-crosslinked polymer pattern is dissolved, thereby forming a relief-based image on the printing element.
14. The process of claim 13 wherein the elastomeric polymer in the first polymer layer is a block copolymer of styrene-butadiene-styrene or styrene-isoprene-styrene and the elastomeric polymer in the second polymer layer is a block copolymer of styrene-butadiene-styrene or styrene-isoprene-styrene containing hydrophobic fluoroalkyl side groups.
15. The process of claim 13 wherein the first polymer layer and the second polymer layer have an elastic modulus in the range of 10 to 100 MPa.
16. The process claim 13 wherein the first polymer layer and the second polymer layer have an elastic modulus in the range of 20 to 40 MPa.
17. The process of any of claims 1 , 5 , 9 or 13 wherein the printing element is a flexographic printing plate.
18. The process of any of claims 1 , 5 , 9 or 13 wherein the printing element is a gravure printing plate.
19. The process of claims 1 , 5 , 9 or 13 wherein relief image comprises at least one relief feature having a step height (Δh)-to-feature size ratio of near unity.
20. The process of claims 1 , 5 , 9 or 13 wherein imaging is through a mask.
21. The process of claims 1 , 5 , 9 or 13 further comprising applying an ink to the relief-based image comprising raised relief features formed of the crosslinked polymer pattern to selectively wet the raised feature with the ink, and transferring the ink from the raised features to a substrate.
22. The process of claims 1 , 5 , 9 or 13 further comprising applying an ink to the relief-based image comprising recesses adjacent raised relief features formed of the crosslinked polymer pattern to selectively wet the recesses with the ink, and transferring the ink from the recesses to a substrate.