Patent · US Expired

Method of making a negative-working lithographic printing plate

US7318995B2 · kind B2 · utility

1Cited by
6References
13Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 29, 2005
Grant dateJan 15, 2008
Priority date
Expiry dateSep 29, 2025

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03F7/32
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A method for preparing a negative-working lithographic printing plate is provided which comprises the steps of (1) providing a lithographic printing plate precursor comprising on a grained and anodized aluminum support, having a hydrophilic surface, a coating comprising (i) polymer particles which are core-shell particles having a hydrophobic heat-softenable core and a hydrophilic shell and (ii) an infrared light absorbing agent, (2) exposing said coating to heat, thereby inducing coalescence of said polymer particles at exposed areas of said coating, and (iii) developing said precursor by applying a gum solution to said coating, thereby removing non-exposed areas of said coating from said support.According to the above method the printing plates exhibit after ageing an improved clean-out and a reduced background stain, resulting in toning-free printing.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.