| 摘要 |
PROBLEM TO BE SOLVED: To provide a low-viscosity composition that has excellent characteristics possessed by the conventional addition-curable silicone composition and can give a high-hardness material when cured. SOLUTION: The addition reaction-curable organopolysiloxane composition having a viscosity at 25°C of not more than 10,000 mPa s includes (A) a substantially straight-chain organopolysiloxane having two or more aliphatic unsaturated groups in one molecule in an amount of 100 pts.mass, (B) an organopolysiloxane resin composed of at least one of unit selected from the group consisting of a R<SP>1</SP><SB>3</SB>SiO<SB>1/2</SB>unit, a R<SP>1</SP>SiO<SB>3/2</SB>unit and an SiO<SB>2</SB>unit and further a R<SP>1</SP><SB>2</SB>SiO unit which may optionally be present (wherein R<SP>1</SP>seach independently denote a 1-10C monovalent hydrocarbon group, an alkoxy group or a hydroxy group) and having two or more aliphatic unsaturated groups in one molecule in an amount of 50-300 pts.mass, (C) a cyclic organopolysiloxane having three or more aliphatic unsaturated groups in one molecule in an amount of 5-30 pts.mass based on 100 pts.mass of the total of the component (A) and the component (B), (D) an organohydrogenpolysiloxane having on the average two or more hydrogen atoms bonded to silicon atoms in one molecule in such an amount that the hydrogen atoms bonded to silicon atoms in the component amounts to 0.8-5 mol per mol of the total of the aliphatic unsaturated groups in the component (A), the component (B) and the component (C), and (E) a platinum group metal-based catalyst in an effective amount. COPYRIGHT: (C)2009,JPO&INPIT
|
