초록 ▼

A planographic printing member comprising a substrate, an oleophilic layer, an infra-red sensitive/ablatable layer, and a hydrophilic layer. The hydrophilic layer is derived from a silicate solution, optionally containing particulate materials such as alumina and/or titania. The printing member may

A planographic printing member comprising a substrate, an oleophilic layer, an infra-red sensitive/ablatable layer, and a hydrophilic layer. The hydrophilic layer is derived from a silicate solution, optionally containing particulate materials such as alumina and/or titania. The printing member may be exposed to radiation from a laser which ablates the infra-red sensitive/ablatable layer to reveal areas of the oleophilic layer. An exposed printing member may be used in wet lithographic printing.

대표청구항 ▼

[ What is claimed:] [1.] A method of preparing a planographic printing member, the planographic printing member comprising a support, an ablatable layer, and a hydrophilic layer, the method comprising the step of forming the hydrophilic layer by application of a fluid comprising:(a) water;(b) a solu

[ What is claimed:] [1.] A method of preparing a planographic printing member, the planographic printing member comprising a support, an ablatable layer, and a hydrophilic layer, the method comprising the step of forming the hydrophilic layer by application of a fluid comprising:(a) water;(b) a soluble alkali metal silicate; and(c) a particulate material; in which:either the ablatable layer is between the support and the hydrophilic layer or the hydrophilic layer is between the support and the ablatable layer;the soluble alkali metal silicate is in solution and the particulate material is dispersed in the fluid;the molar ratio of SiO.sub.2 to M.sub.2 O, in which M is an alkali metal, in the soluble alkali metal silicate is at least 2.5 and less than 6; andthe fluid comprises 5 to 20 wt % of the soluble alkali metal silicate.