Patent ID: 6613494
Filing Date: 2003-09-02
Classification: B41C

Abstract:
A method for preparing a positive working imageable element, the imageable element comprising, in order:a hydrophilic substrate; a bottom layer; and an overlayer comprising an overlayer material; the method comprising: applying the overlayer over the bottom layer of a precursor comprising the bottom layer and the hydrophilic substrate, and forming the imageable element; in which: the overlayer is applied from a solution of the overlayer material in a solvent; the bottom layer comprises a positive working composition imageable by heat, by near infrared radiation, or by infrared radiation; the positive working composition comprises a phenolic resin; the overlayer material reduces the alkali solubility of the phenolic resin; the bottom layer is essentially insoluble in the solvent; and the overlayer is less than about 0.03 &mgr;m thick; in which the overlay material is: (a) a water-soluble salt of a compound of the structure: Râ€²O(CH2CH2O)nCH2X, â€ƒin which X is â€”CO2H, â€”CH2OSO3H, or â€”CH2OPO3H2; n is about 3 to about 50; and Râ€² is a substituted or unsubstituted aromatic or aliphatic group; (b) a compound of the structure: HO(CH2CHRO)nCH2X, â€ƒin which R is H or CH3; X is â€”CO2H, â€”CH2OSO3H, or â€”CH2OPO3H2; and n is about 3 to about 50; or (c) a nonionic fluorosurfactant.