METHOD FOR PRODUCING BRANCHED PENTASILOXANE

• Main Author: SAKUTA KOJI
• Format: Patent
• Language: English
• Published: 10.02.2005
• Edition: 7
• Subjects: ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAININGELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN,SULFUR, SELENIUM OR TELLURIUM; APPARATUS THEREFOR; CHEMISTRY; GENERAL METHODS OF ORGANIC CHEMISTRY; METALLURGY; ORGANIC CHEMISTRY

PROBLEM TO BE SOLVED: To provide a method for producing a branched pentasiloxane, particularly provide a method for producing a high-purity tetrakistrimethylsiloxane in a high yield. SOLUTION: In the method characterised in that tetraalkoxysilane represented by formula (1) and hexamethyldisiloxane represented by formula (2) are subjected to hydrolytic condensation reaction to produce branched pentasiloxane represented by formula (3), 1 mole of tetraalkoxy silane of formula (1), 2.0 to 10.0 moles of hexamethyldisiloxane of formula (2), 0.01 to 0.5 mol of an acid catalyst and 2.5 to 10.0 moles of water are used where, in the step where water is added, the reaction is carried out at a temperature from 0 to < 30°C for 30 minutes to 5 hours, then the reaction temperature is raised to 30 to 100°C for 30 minutes to 5 hours after the addition of water is completed, to produce the branched pentasiloxane (3) [wherein the formula (1) is represented by Si(OR)4; the formula (2) is represented by (CH3)3SiOSi(CH3)3and the formula (3) is represented by SiäOSi(CH3)3}4]. COPYRIGHT: (C)2005,JPO&NCIPI