US4842990A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Presensitized negative working waterless planographic printing plate with amorphous silicic acid interlayer and process of making and using
Assignee: Hoechst AG
•
Filing: 1987-08-20
•
Granted: 1989-06-27
•
Expires: 2007-08-20
Abstract
Abstract A presensitized printing plate suitable for waterless planographic printing is disclosed which comprises a layer support, a radiation-sensitive layer containing (a) a compound possessing at least one C--O--C bond, which can be split by acid (b) a compound forming a strong acid upon irradiation, and (c) a water-insoluble binder, an outer, ink-repellent, crosslinked silicone elastomer layer, and an intermediate layer comprising amorphous silicic acid by which the adhesion of the silicone elastomer layer to the radiation-sensitive layer is improved. The photosensitivity of this printing plate is considerably improved, as compared to known negative-working printing plates that can be used for waterless offset printing. The processes of making and using the presensitized printing plate are also disclosed.
Inventors
- 👤 Heinz Herrmann
- 👤 Hans-Joachim Schlosser
- 👤 Susanne Billino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:13
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/075; G03F7/0752
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
69 words
A presensitized printing plate for waterless planographic printing comprising: 1. a support; 2. a radiation-sensitive layer on the support comprising (a) a compound possessing at least one C--O--C bond, which can be split by acid, (b) a compound forming a strong acid upon irradiation, and (c) a water-insoluble binder; 3. an ink-repellent silicone layer; and 4. an amorphous silicic acid layer between the radiation-sensitive layer and the silicone layer.
Claim 2
Dependent Claim
69 words
A presensitized printing plate for waterless planographic printing comprising: 1. a support; 2. a radiation-sensitive layer on the support comprising (a) a compound possessing at least one C--O--C bond, which can be split by acid, (b) a compound forming a strong acid upon irradiation, and (c) a water-insoluble binder; 3. an ink-repellent silicone layer; and 4. an amorphous silicic acid layer between the radiation-sensitive layer and the silicone layer.
Claim 3
Dependent Claim
23 words
A printing plate as claimed in claim 1, wherein the intermediate layer is produced by applying and drying an aqueous silicic acid sol.
Claim 4
Dependent Claim
17 words
A printing plate as claimed in claim 2, wherein the silicic acid sol contains a water-soluble surfactant.
Claim 5
Dependent Claim
31 words
A printing plate as claimed in claim 3, wherein the surfactant is present in an amount between about 1% and 15% by weight relative to the solids content of the sol.
Claim 6
Dependent Claim
28 words
A printing plate as claimed in claim 1, wherein the intermediate layer has a weight per unit area of about 0.01 g/m 2 to 1 g/m 2 .
Claim 7
Dependent Claim
31 words
A printing plate as claimed in claim 1, wherein the compound possessing at least one acid-cleavable C--O--C bond comprises an orthocarboxylic acid derivative, an acetal, an enol ether or a N-acyliminocarbonate.
Claim 8
Dependent Claim
17 words
A printing plate as claimed in claim 1, wherein the water-insoluble binder is soluble in aqueous-alkaline solutions.
Claim 9
Dependent Claim
14 words
A printing plate as claimed in claim 7, wherein the binder comprises a novolak.
Claim 10
Dependent Claim
16 words
A printing plate as claimed in claim 1, wherein the silicone layer comprises a crosslinkable elastomer.
Claim 11
Dependent Claim
22 words
A printing plate as claimed in claim 9, wherein the elastomer comprises a two-component elastomer crosslinkable by condensation reaction at room temperature.
Claim 12
Dependent Claim
19 words
A printing plate as claimed in claim 10, wherein the silicone elastomer contains an alkenyltriacetoxysilane as the crosslinking agent.
Claim 13
Dependent Claim
15 words
A printing plate as claimed in claim 9, wherein the elastomer comprises a multi-component elastomer.
Claim 14
Dependent Claim
33 words
A printing plate as claimed in claim 1, wherein the silicone layer comprises a crosslinked silicone rubber having a weight per unit area of about 1 g/m 2 to 20 g/m 2 .
Claim 15
Dependent Claim
81 words
A process for making a presensitized printing plate for waterless planographic printing comprising the steps of: providing a support layer; coating on said support layer a radiation-sensitive composition comprising (a) a compound possessing at least one C--O--C bond which can be split by acid, (b) a compound forming a strong acid upon irradiation, (c) a water-insoluble binder, and (d) a solvent; coating a silicic acid sol on the radiation-sensitive coating; and coating an ink-repellent silicone elastomer on the silicic acid coating.
Claim 16
Dependent Claim
81 words
A process for making a presensitized printing plate for waterless planographic printing comprising the steps of: providing a support layer; coating on said support layer a radiation-sensitive composition comprising (a) a compound possessing at least one C--O--C bond which can be split by acid, (b) a compound forming a strong acid upon irradiation, (c) a water-insoluble binder, and (d) a solvent; coating a silicic acid sol on the radiation-sensitive coating; and coating an ink-repellent silicone elastomer on the silicic acid coating.
Claim 17
Dependent Claim
33 words
A process for making a printing plate for waterless planographic printing as claimed in claim 14, wherein the silicic acid sol is coated before the solvent has completely evaporated from the radiation-sensitive coating.
Claim 18
Dependent Claim
21 words
A process for making a printing plate as claimed in claim 15, wherein the silicic acid sol further comprises water-miscible solvents.
Claim 19
Dependent Claim
22 words
A process for making a printing plate as claimed in claim 15, wherein the silicic acid sol further comprises a water-soluble surfactant.
Claim 20
Dependent Claim
74 words
A process of using the presensitized printing plate of claim 1 to make a printing form suitable for waterless planographic printing comprising the steps of: imagewise exposing the presensitized plate of claim 1 to radiation to produce exposed and unexposed areas on the immersing the exposed printing plate in an aqueous solution containing a water-miscible organic solvent; and removing the radiation-sensitive layer and the overlying silicone layer from the exposed areas of the plate.
Claim 21
Dependent Claim
15 words
A process as claimed in claim 18, wherein the solution is an aqueous alkaline solution.
Claim 22
Dependent Claim
18 words
A process as claimed in claim 18, wherein the aqueous solution contains at least about 50% of water.
References Cited (Backward Citations)
US2714066A
Cited
US3181461A
Cited
US3511178A
Cited
US4054094A
Cited
US4101323A
Cited
US4247611A
Cited
US4347303A
Cited
US4358522A
Cited
US4311782A
Cited
US4326020A
Cited
US4342820A
Cited
US4376814A
Cited
EP0100938A2
Cited
EP0154980A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-26 | 1992-12-26 | 1993-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-26 | 1996-12-26 | 1997-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-26 | 2000-12-26 | 2001-06-27 | $7700.00 | Window Closed / Lapsed |