Production of support for lithographic printing plate

• US 6,540,901 B2
• Filed: 07/02/2001
• Issued: 04/01/2003
• Est. Priority Date: 07/17/2000
• Status: Expired due to Fees

• Current Assignee: Agfa Graphics Nv (Agfa-Gevaert N.V.)
• Original Assignee: Agfa-Gevaert N.V.
• Inventors: Mayers, Felton Rudolph, Chau, Tu Vinh
• Primary Examiner(s): Wong, Edna
• Application Number:
  US09/897,241
• Publication Number:
  US 20020043168A1
• Time in Patent Office: 638 Days
• Field of Search: 428/472.2, 428/469, 428/409, 101/463.1, 101/465, 205/205, 205/220, 205/324, 205/219, 205/214
• US Class Current: 205/214
• CPC Class Codes: B41N 3/034 characterised by the electrochemical treatment of the aluminum support, e.g. anodisation, electro-graining; Sealing of the anodised layer; Treatment of the anodic layer with inorganic compounds; Colouring of the anodic layer
• CPC Class Codes: B41N 3/038 Treatment with a chromium compound, a silicon compound, a phophorus compound or a compound of a metal of group IVB; Hydrophilic coatings obtained by hydrolysis of organometallic compounds

Abstract

The present invention provides a process for the manufacture of a substrate for use in the production of lithographic printing plates, the process comprising the steps of:

(a) providing an aluminum substrate;

(b) graining at least one surface of the substrate;

(c) applying an anodic layer to the at least one grained surface;

(d) treating the at least one grained and anodized surface with an aqueous solution comprising at least one salt of a metal from Group IB, IIB, IVA, IVB, VB, VIA, VIB, VIIB or VIII of the Periodic Table; and

(e) treating the at least one treated surface with an aqueous solution comprising at least one orthophosphate salt of an alkali metal.

Claims

1. A process for the manufacture of a substrate for use in the production of lithographic printing plates, said process comprising the steps of:

(a) providing an aluminum substrate;

(b) graining at least one surface of said substrate;

(c) applying an anodic layer to said at least one grained surface;

(d) treating said at least one grained and anodized surface with an aqueous solution comprising at least one salt of a metal from Group IB, IIB, IVA, IVB, VB, VIA, VIB, VIIB or VIII of the Periodic Table; and

(e) treating said at least one treated surface with an aqueous solution comprising at least one orthophosphate salt of an alkali metal.

2. A process as defined in claim 1 wherein said orthophosphate salt of an alkali metal comprises trisodium orthophosphate, disodium hydrogen orthophosphate, sodium dihydrogen orthophosphate, tripotassium orthophosphate, dipotassium hydrogen orthophosphate or potassium dihydrogen orthophosphate.

3. A process as defined in claim 1 wherein said salt of a metal from Group IB, IIB, IVA, IVB, VB, VIA, VIB, VIIB or VIII of the Periodic Table comprises a salt of titanium, zirconium, hafnium, molybdenum, tungsten, vanadium, manganese, nickel, copper, zinc, tin, niobium, tantalum, cerium, selenium, silicon, cobalt or iron.

4. A process as defined in claim 1 wherein said salt of a metal from Group IB, IIB, IVA, IVB, VB, VIA, VIB, VIIB or VIII of the Periodic Table includes the metal as the cation.

5. A process as defined in claim 4 wherein said salt comprises a sulfate, phosphate, nitrate, acetate, fluoride or chloride salt of titanium, zirconium or hafnium.

6. A process as defined in claim 1 wherein said salt of a metal from Group IB, IIB, IVA, IVB, VB, VIA, VIB, VIIB or VIII of the Periodic Table includes the metal as part of a complexed anion.

7. A process as defined in claim 6 wherein said salt comprises an alkali metal fluorozirconate.

8. A process as defined in claim 7 wherein said alkali metal fluorozirconate comprises potassium hexafluorozirconate.

9. A process as defined in claim 1 wherein said aluminum substrate comprises aluminum or an aluminum alloy containing small amounts of at least one of manganese, nickel, cobalt, zinc, iron, copper, magnesium, titanium, vanadium, silicon or zirconium.

10. A process as defined in claim 1 wherein said graining step comprises a mechanical or electrochemical graining treatment.

11. A process as defined in claim 10 wherein said electrochemical graining treatment comprises passing a substrate through a solution of a mineral or organic acid, or a mixture thereof, whilst applying an electric current to the acid solution.

12. A process as defined in claim 1 wherein said anodic layer is applied to said at least one grained surface of the substrate by passing said substrate through an aqueous mineral or organic acid, or a mixture thereof, whilst applying an electric current to the acid solution.