Method of making a lithographic printing plate
| Title: | Method of making a lithographic printing plate |
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| Patent Number: | 8,026,043 |
| Publication Date: | September 27, 2011 |
| Appl. No: | 12/093602 |
| Application Filed: | November 09, 2006 |
| Abstract: | A method of making a lithographic printing plate includes the steps of: a) providing a lithographic printing plate precursor including (i) a support having a hydrophilic surface or which is provided with a hydrophilic layer, (ii) a coating on the support including a photopolymerizable layer, a top layer and, optionally, an intermediate layer between the photopolymerizable layer and the support, wherein the photopolymerizable layer includes a polymerizable compound, a polymerization initiator, and a binder, b) image-wise exposing the coating in a plate setter, c) optionally, heating the precursor in a pre-heating unit, and d) treating the precursor in a gumming station, the gumming station including a first and at least a second gumming unit, wherein the precursor is washed in the first gumming unit by applying a gum solution to the coating thereby removing at least a portion of the top layer, and wherein, subsequently, the precursor is developed in the second gumming unit with a gum solution thereby removing non-exposed areas of the photopolymerizable layer from the support and gumming the plate in a single step. |
| Inventors: | Van Damme, Marc (Bonheiden, BE) |
| Assignees: | Agfa Graphics NV (Mortsel, BE) |
| Claim: | 1. A method of making a lithographic printing plate comprising the steps of: a) providing a lithographic printing plate precursor including (i) a support having a hydrophilic surface or which is provided with a hydrophilic layer, (ii) a coating on the support including a photopolymerizable layer, a top layer and, optionally, an intermediate layer between the photopolymerizable layer and the support, wherein the photopolymerizable layer includes a polymerizable compound, a polymerization initiator, and a binder; b) image-wise exposing the coating by a laser in a plate setter; c) optionally, heating the precursor in a pre-heating unit; and d) treating the precursor in a gumming station, the gumming station including a first gumming units and at least a second gumming unit; wherein the precursor is washed in the first gumming unit by applying a gum solution to the coating thereby removing at least a portion of the top layer; and subsequently, the precursor is developed in the second gumming unit with a gum solution thereby removing non-exposed areas of the photopolymerizable layer from the support and gumming the plate in a single step. |
| Claim: | 2. A method according to claim 1 , wherein at least one of the gumming units is provided with at least one roller for rubbing and/or brushing the coating while a gum solution is applied to the precursor by a spraying, jetting, coating, or dipping technique. |
| Claim: | 3. A method according to claim 1 , wherein the first and second gumming unit together have the configuration of a cascade system, whereby the gum solution used in the second gumming unit overflows to the first gumming unit. |
| Claim: | 4. A method according to claim 1 , wherein a replenishing solution is added to the second gumming unit. |
| Claim: | 5. A method according to claim 1 , wherein the gumming station further includes a third gumming unit and the precursor is further developed with a gum solution in the third gumming unit. |
| Claim: | 6. A method according to claim 5 , wherein the first, second, and third gumming units together have the configuration of a cascade system, whereby the gum solution used in the third gumming unit overflows to the second gumming unit, and the gum solution used in the second gumming unit overflows to the first gumming unit. |
| Claim: | 7. A method according to claim 5 , wherein a replenishing solution is added to the third gumming unit. |
| Claim: | 8. A method according to claim 1 , wherein the top layer of the precursor is removed in the first gumming unit by at least 50% by weight relative to the total weight of the top layer. |
| Claim: | 9. A method according to claim 1 , wherein the top layer includes a polyvinylalcohol having a viscosity of at most 10mPA·s, measured at a 4% by weight aqueous solution at 20° C. according to DIN 53 015. |
| Claim: | 10. A method according to claim 1 , wherein the top layer is present in the precursor in an amount ranging between 1.75 g/m2 and 0.25 g/m2. |
| Claim: | 11. A method according to claim 1 , wherein the gum solution has a pH-value ranging between 3 and 9. |
| Claim: | 12. A method according to claim 1 , wherein the laser emits violet light. |
| Claim: | 13. A method according to claim 1 , wherein the laser emits infrared light. |
| Current U.S. Class: | 430/302 |
| Patent References Cited: | 4329422 May 1982 Langlais 4370406 January 1983 Jones 5155011 October 1992 Zertani et al. 6027857 February 2000 Li et al. 6071675 June 2000 Teng 6171735 January 2001 Li et al. 6245481 June 2001 Teng 6387595 May 2002 Teng 6420089 July 2002 Baumann et al. 6482571 November 2002 Teng 6548222 April 2003 Teng 6576401 June 2003 Teng 2003/0031948 February 2003 Fiebag et al. 2003/0165777 September 2003 Teng 2004/0013968 January 2004 Teng 2004/0131974 July 2004 Suzuki 2004/0214105 October 2004 Hoshi et al. 2005/0039620 February 2005 Kakino et al. 0 851 299 July 1998 1 091 251 April 2001 1 342 568 September 2003 1 491 356 December 2004 1 495 866 January 2005 1 500 498 January 2005 1 513 020 March 2005 1 520 694 April 2005 1 557 262 July 2005 63-109442 May 1988 02/101469 December 2002 2004/095141 November 2004 2005/111717 November 2005 2005/111727 November 2005 WO 2005111727 November 2005 2006/037716 April 2006 |
| Other References: | Official communication issued in the International Application No. PCT/EP2006/068260, mailed on Feb. 23, 2007. cited by other Williamson et al.; “Method of Making a Lithographic Printing Plate”; U.S. Appl. No. 12/093,153;. filed May 9, 2008. cited by other Van Damme; “Method of Making a Lithographic Printing Plate”; U.S. Appl. No. 12/093,160; filed May 9, 2008. cited by other Van Damme; “Method of Making a Lithographic Printing Plate”; U.S. Appl. No. 12/093,470; filed May 13, 2008. cited by other Williamson et al.; “Method of Making a Lithographic Printing Plate”; U.S. Appl. No. 12/093;366; filed May 12, 2008. cited by other Gries et al.; “Method of Making a Photopolymer Printing Plate”; U.S. Appl. No. 12/093;473; filed May 13, 2008. cited by other Van Damme; “Method of Making a Lithographic Printing Plate”; U.S. Appl. No. 12/093,376; filed May 12, 2008. cited by other Van Damme; “Method of Making a Lithographic Printing Plate”; U.S. Appl. No. 12/093,600; filed May 14, 2008. cited by other |
| Assistant Examiner: | Johnson, Connie P |
| Primary Examiner: | Kelly, Cynthia |
| Attorney, Agent or Firm: | Keating & Bennett, LLP |
| Accession Number: | edspgr.08026043 |
| Database: | USPTO Patent Grants |
| Language: | English |
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