JPS5598190A - Improved preparation of octamethylcyclotetrasiloxane - Google Patents

Improved preparation of octamethylcyclotetrasiloxane

Info

Publication number
JPS5598190A
JPS5598190A JP477079A JP477079A JPS5598190A JP S5598190 A JPS5598190 A JP S5598190A JP 477079 A JP477079 A JP 477079A JP 477079 A JP477079 A JP 477079A JP S5598190 A JPS5598190 A JP S5598190A
Authority
JP
Japan
Prior art keywords
formula
compound
dimethylsiloxane
products
pressure
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP477079A
Other languages
Japanese (ja)
Inventor
Keizo Hirakawa
Makoto Honda
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Asahi Chemical Industry Co Ltd
Original Assignee
Asahi Chemical Industry Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Asahi Chemical Industry Co Ltd filed Critical Asahi Chemical Industry Co Ltd
Priority to JP477079A priority Critical patent/JPS5598190A/en
Publication of JPS5598190A publication Critical patent/JPS5598190A/en
Pending legal-status Critical Current

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  • Silicon Polymers (AREA)

Abstract

PURPOSE: To obtain the title compound, which is starting material for siloxane oils, by separating and removing by-products from volatile products while reacting dimethylsiloxane under suitable conditions, and by recycling the by-products under a specific reaction pressure.
CONSTITUTION: Volatile cyclic dimethylsiloxane (D) is distilled off while reacting dimethylsiloxane in an inert solvent, e.g. diphenyl ether, in the presence of an alkali catalyst, e.g. KOH, in a reactor. By-product dimethylsiloxane containing the compound of formula I is separated and removed from D to give the compound of formula II. The by-product D containing at least the compound of formula I thus separated is recycled to the reactor under a pressure expressed by the formula 0.03 P4≤Pr-Ps≤0.14 P4 (Pr is the reaction pressure; P4 is the vapor pressure of pure compound of formula II; Ps is the vapor pressure of pure solvent; P4 and Ps are at the reaction temperature) to form the compound of formula II.
COPYRIGHT: (C)1980,JPO&Japio
JP477079A 1979-01-22 1979-01-22 Improved preparation of octamethylcyclotetrasiloxane Pending JPS5598190A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP477079A JPS5598190A (en) 1979-01-22 1979-01-22 Improved preparation of octamethylcyclotetrasiloxane

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP477079A JPS5598190A (en) 1979-01-22 1979-01-22 Improved preparation of octamethylcyclotetrasiloxane

Publications (1)

Publication Number Publication Date
JPS5598190A true JPS5598190A (en) 1980-07-25

Family

ID=11593078

Family Applications (1)

Application Number Title Priority Date Filing Date
JP477079A Pending JPS5598190A (en) 1979-01-22 1979-01-22 Improved preparation of octamethylcyclotetrasiloxane

Country Status (1)

Country Link
JP (1) JPS5598190A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63120738A (en) * 1986-10-27 1988-05-25 ダウ　コーニング　コーポレーション Method for reducing activity of silicone polymer
US6262289B1 (en) 1997-06-11 2001-07-17 Kaneka Corporation Process for preparing cyclic oligosiloxanes

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63120738A (en) * 1986-10-27 1988-05-25 ダウ　コーニング　コーポレーション Method for reducing activity of silicone polymer
JPH0517246B2 (en) * 1986-10-27 1993-03-08 Dow Corning
US6262289B1 (en) 1997-06-11 2001-07-17 Kaneka Corporation Process for preparing cyclic oligosiloxanes

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