Title:
PLANOGRAPHIC PRINTING PLATE
Document Type and Number:
Japanese Patent JPH1184636
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To improve ink repellency and to widen the latitude of dampening water by incorporating fine silica particles made hydrophilic by surface treatment into a hydrophilic swellable layer. SOLUTION: The planographic printing plate has at least a hydrophilic swellable layer on the substrate and the hydrophilic swellable layer contains fine silica particles made hydrophilic by surface treatment. The average primary particle diameter of the fine silica particles is 0.005-5 p m and the amt. is 5-60 pts.wt. based on 100 pts.wt. solid components in the hydrophilic swellable layer. The fine silica particles made hydrophilic by surface treatment are dispersed in water and form a colloidal state. The fine silica particles have hydroxyl groups on the surfaces and are stabilized by a very small amt. of cations. Since the hydroxyl groups are negatively charged and the cations are added, electric double layers are formed in the shells of the particles and repulsion produced between particles prevents the collision and bonding of the particles and keeps satisfactory water dispersibility. An aq. dispersion of the particles is therefore stable and exhibits flowability even at a high concn.
Inventors:
TAKAHASHI HIROMITSU
GOTO KAZUOKI
TABATA KENICHI
GOTO KAZUOKI
TABATA KENICHI
Application Number:
JP23741797A
Publication Date:
March 26, 1999
Filing Date:
September 02, 1997
Export Citation:
Assignee:
TORAY INDUSTRIES
International Classes:
G03F7/004; B41N1/14; G03F7/00; G03F7/075; (IPC1-7): G03F7/00; B41N1/14; G03F7/004; G03F7/075
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