EP0599209A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method for the molecular weight fractionation of polyhydrogen silsesquioxane
Assignee: Dow Silicones Corp
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Filing: 1993-11-19
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Granted: —
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Expires: 2013-11-19
Abstract
Abstract Disclosed is a highly reproducible method for the molecular weight fractionation of polyhydrogen silsesquioxane that gives a very storage-stable polyhydrogen silsesquioxane having a freely selectable molecular weight. The method involves dissolving polyhydrogen silsesquioxane in active, hydrogen-free nonpolar solvent; adding an active, hydrogen-free polar solvent to the resulting solution in order to precipitate polyhydrogen silsesquioxane; and collecting the desired molecular weight fraction of polyhydrogen silsesquioxane.
Inventors
- 👤 Katsutoshi C/O Dow Corning Toray Mine
- 👤 Takashi C/O Dow Corning Toray Nakamura
- 👤 Motoshi C/O Dow Corning Toray Sakaki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 16:27
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/04; C08G77/12; C08G77/32; C08G77/36
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
47 words
A Method for the molecular weight fractionation of polyhydrogen silsesquioxane comprising: dissolving polyhydrogen silsesquioxane in active hydrogen-free nonpolar solvent; adding active hydrogen-free polar solvent to the resulting solution to precipitate a molecular weight fraction of polyhydrogen silsesquioxane; and collecting the desired molecular weight fraction of polyhydrogen silsesquioxane.
Claim 2
Dependent Claim
21 words
The method of claim 1 wherein the active hydrogen-free nonpolar solvent is selected from aromatic solvents, aliphatic solvents, and ether solvents.
Claim 3
Dependent Claim
13 words
The method of claim 2 wherein the active hydrogen-free nonpolar solvent is toluene.
Claim 4
Dependent Claim
22 words
The method of claim 1 wherein the active hydrogen-free nonpolar solvent is free of impurities and has a dielectric constant ≦ 5.
Claim 5
Dependent Claim
19 words
The method of claim 4 wherein the active hydrogen-free polar solvent is selected from nitriles, chloroacetone, o-chloronitrobenzene, and nitrobenzene.
Claim 6
Dependent Claim
13 words
The method of claim 5 wherein the active hydrogen-free polar solvent is acetonitrile.
Claim 7
Dependent Claim
24 words
The method of claim 4 wherein the active hydrogen-free polar solvent is free of impurities and has a dielectric constant of at least 30.
Claim 8
Dependent Claim
18 words
The method of claim 1 wherein the fractionation is run in an inert gas atmosphere free of moisture.
Claim 9
Dependent Claim
24 words
The method of claim 1 wherein the fractionation is run in a container made of a material from which ionic impurities do not elute.
Claim 10
Dependent Claim
11 words
The method of claim 1 wherein the fractionation process is repeated.
References Cited (Backward Citations)
No citation records indexed.
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