Planographic printing
AssigneeKodak Polcyhrome Graphics LLC
InventorsBarry Jolliffe, Harjit Singh Bhambra, Robert M. Organ
Life of this patent
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Abstract
A method for forming a planographic printing member is disclosed. A hydrophilic layer is formed on a support by contacting the support with a silicate solution that contains a silicate and a particulate material. An image layer is provided over the hydrophilic layer. The hydrophilic layer is treated to ensure that the image layer is able to change color on exposure. The hydrophilic layer may be treated with an acid, with a buffer formulation, with a colloidal suspension, or with a salt. Preferably the hydrophilic layer is treated with aluminum sulphate.
Claims30
A method of preparing a planographic printing member, said method comprising the steps of:
- a) forming a hydrophilic layer on a support by contacting the support with a silicate solution comprising:
- water;
- a soluble alkali metal silicate;
- and
- a particulate material;
- in which:
- the soluble alkali metal silicate is in solution and the particulate material is dispersed in the silicate solution;
- the molar ratio of SiO2 to M2O, in which M is an alkali metal, in the soluble alkali metal silicate is at least 2.5 and less than 6;
- and
- the silicate solution comprises 5 to 20 wt % of the soluble alkali metal silicate;
- b) applying a modifying means over said hydrophilic layer;
- and
- c) providing an image layer over said hydrophilic layer, wherein an indicator means is associated with said image layer, said indicator means indicating whether said image layer is in a first or a second state.
A planographic printing member, said planographic printing member prepared by the method comprising the steps of:
- a) forming a hydrophilic layer on a support by contacting the support with a silicate solution comprising:
- water;
- a soluble alkali metal silicate;
- and
- a particulate material;
- in which:
- the soluble alkali metal silicate is in solution and the particulate material is dispersed in the silicate solution;
- the molar ratio of SiO2 to M2O, in which M is an alkali metal, in the soluble alkali metal silicate is at least 2.5 and less than 6;
- and
- the silicate solution comprises 5 to 20 wt % of the soluble alkali metal silicate;
- b) applying a modifying means over said hydrophilic layer;
- and
- c) providing an image layer over said hydrophilic layer, wherein an indicator means is associated with said image layer, said indicator means indicating whether said image layer is in a first or a second state.
A method of preparing a planographic printing member, said method comprising the steps of:
- a) forming a hydrophilic layer on a support by contacting the support with a silicate solution comprising:
- water;
- a soluble alkali metal silicate;
- and
- a particulate material;
- in which:
- the soluble alkali metal silicate is in solution and the particulate material is dispersed in the silicate solution;
- the molar ratio of SiO2 to M2O, in which M is an alkali metal, in the soluble alkali metal silicate is at least 2.5 and less than 6;
- and
- the silicate solution comprises 5 to 20 wt % of the soluble alkali metal silicate;
- b) applying a modifying means over said hydrophilic layer.
Dependencies are inferred from the claim text.