| 摘要 |
The present invention relates to a heavy release additive for a release sheet, which comprises a condensation reaction product produced by the dehydrative condensation reaction between (A) a polydiorganosiloxane that has an average polymerization degree of 500 to 10,000 and has at least one hydroxy or hydrolysable group per molecule and (B) a polyorganosiloxane resin that is mainly composed of a (SiO 4/2 ) unit and a (R 3 SiO 1/2 ) unit (wherein R's independently represent a C 1-12 monovalent hydrocarbon group or a C 2-6 alkenyl group each having no aliphatic unsaturated bond), has a ratio of the content of the (R 3 SiO 1/2 ) unit to the content of the (SiO 4/2 ) unit of 0.6 to 1.2 by mole, and contains the hydroxy group and the hydrolysable group in the total content of 2.1 mass% or more and less than 10.0 mass%. When the heavy release additive for a release sheet according to the present invention is added to a polyorganosiloxane composition for a release sheet, the heavy release additive can have the effect of achieving an extremely great peel force compared with cases in which no additive is added. |
