| 摘要 |
PROBLEM TO BE SOLVED: To provide an emulsion-based heavy-release additive for release sheet, which has an excellent high-release effect and can secure an intended heavy-release force by addition of a small amount thereof to a curable silicone composition for release sheet, with less temporal deterioration of the release force after curing, and an emulsion composition for release sheet and a release sheet using the same.SOLUTION: An emulsion-based heavy-release additive for release sheet is obtained by dispersing in water a condensation product (A) obtained by dehydration condensation reaction between (A-1) a polydiorganosiloxane which has an average degree of polymerization of 100-300,000 and has at least one hydroxyl or hydrolyzable group per molecule; and (A-2) a polyorganosiloxane resin which is mainly composed of a (SiO) unit and a (RSiO) unit (wherein R independently represents 1-12C monovalent hydrocarbon group or 2-6C alkenyl each having no aliphatic unsaturated bond), and has a ratio of (RSiO) unit to (SiO) unit of 0.6-1.2 by mole and a total content of the hydroxyl and hydrolyzable group of 2.1 mass% or more and less than 10.0 mass%. Accordingly, the additive is added to a curable composition for a release sheet such as release paper or release film, and applied onto a variety of base materials followed by curing, whereby a silicone cured coating film having high release force can be obtained. |
