Method for the molecular weight fractionation of polyhydrogen silsesquioxane
AssigneeDow Corning Toray Silicone Co., Ltd.
InventorsKatsutoshi Mine, Takashi Nakamura, Motoshi Sasaki
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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.
Claims14
A Method for the molecular weight fractionation of polyhydrogen silsesquioxane comprising:
- dissolving polyhydrogen silsesquioxane in active hydrogen-free nonpolar solvent;
- adding sufficient active hydrogen-free polar solvent to the resulting solution to precipitate an upper molecular weight fraction of the polyhydrogen silsesquioxane;
- and
- collecting the desired molecular weight fraction of polyhydrogen silsesquioxane.
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 in order to precipitate polyhydrogen silsesquioxane that exceeds the desired average molecular weight;
- removing the precipitated polyhydrogen silsesquioxane from the remaining polyhydrogen silsesquioxane solution;
- adding active hydrogen-free polar solvent to the resulting solution in order to precipitate polyhydrogen silsesquioxane having the desired average molecular weight;
- and
- collecting the precipitated polyhydrogen silsesquioxane having the desired average molecular weight.
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 in order to precipitate polyhydrogen silsesquioxane;
- removing the precipitated polyhydrogen silsesquioxane from the remaining polyhydrogen silsesquioxane solution;
- dissolving the precipitated polyhydrogen silsesquioxane in active hydrogen-free nonpolar solvent;
- adding active hydrogen-free polar solvent to the resulting solution in order to precipitate polyhydrogen silsesquioxane that exceeds the desired average molecular weight;
- removing the precipitated polyhydrogen silsesquioxane from the solution;
- and
- collecting the desired polyhydrogen silsesquioxane solution.
Dependencies are inferred from the claim text.