COMPOSITIONS FOR SILICONE RUBBER BLANKET AND SILICONE RUBBER BLANKET FOR MICROPATTERNING IN OFFSET PRINTING PREPARED USING SAME

摘要

A silicone blanket rubber composition is provided to ensure excellent hardness and print characteristic, to improve releasability due to swelling characteristic and restitution force, and to prolong lifetime of the blanket rubber. A silicone blanket rubber composition for micropatterning in offset printing comprises high vinyl polysiloxane 5-50 weight% of chemical formula 1: R^1_aSiO_{(4-a)/2}; low vinyl polysiloxane 35-80 weight% of chemical formula 2: R^2_bSiO_{(8-b)/2}; polysiloxane hydride 5-15 weight% of chemical formula 3: R^3_cSiO_{(4-c)/2}; platinum catalyst 10-50 weight ppm; and polymerization inhibitor 0.5-2 weight%. In chemical formula 1, R^1 is an alkenylene group with vinyl group content of 0.1-0.4 mmole/g; and a is a positive number of 1.9-2.05. In chemical formula 2, R^2 alkenylene group with vinyl group content of 0.01-0.1 mmole/g; and b is a positive number of 1.2-4.8. In chemical formula 3, R^3 is C1-C10 alkyl group having an hydride group at both terminals; and c is a positive number of 1.9-2.05.