Flowability adjustment manner of the addition hardening die liquefied silicone rubber constituent and the said constituent for injection molding and injection molding manner null of the silicone rubber

摘要

PROBLEM TO BE SOLVED: To provide an addition-curing type liquid silicone rubber composition which is used for injection molding, hardly deteriorates the viscosity of the rubber material under high shear rates, and does not form the burr of molded articles.;SOLUTION: This flowable addition-curing type liquid silicone rubber composition for injection molding is characterized by comprising (A) 100 pts.mass of an organopolysiloxane containing at least two silicon atom-bound alkenyl groups in one molecule, (B) an organohydrogen polysiloxane containing at least two silicon atom-bound hydrogen atoms in one molecule in an amount of 0.4 to 5.0 silicon atom-bound hydrogen atoms in the component (B) per silicon atom-bound alkenyl group in the component (A), (C) 10 to 40 pts.mass of fumed silica having a BET specific surface area of ≥50 m²/g, and (D) an effective amount of an addition reaction catalyst, and having viscosity of ≤1,000 Pa s at a shear rate of 0.9 s^-1 at 23°C, and having a shear rate 100 s^-1 viscosity/shear rate 200 s^-1 viscosity ratio of ≤3.5.;COPYRIGHT: (C)2007,JPO&INPIT