Hydrosilyation cured silicone resins obtained by fractionation
AssigneeDow Corning Corporation
InventorsDimitris E. Katsoulis, Bizhong Zhu, John R. Keryk, Frederick J. McGarry, Zhongtao Li
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Abstract
A process for producing a cured silsesquioxane resin. The process includes fractionating the silsesquioxane resin a plurality of times utilizing an organic solvent in combination with an organic non-solvent. The fractionated resin is then stripped of excess solvent. The stripped resin is then mixed with a cross-linking compound to form a curable composition. The curable composition is cured to form a cured resin having high fracture toughness and strength without the loss of elastic modulus.
Claims28
A process for producing a cured silsesquioxane resin having high fracture toughness and strength without loss of elastic modulus comprising the steps of:
- a) providing a silsesquioxane resin;
- b) fractionating the silsesquioxane;
- c) selecting an appropriate fraction;
- d) mixing the silsesquioxane resin of step c) with a cross-linking compound to form a curable composition;
- e) curing the curable composition to form a cured resin having a higher fracture toughness than that of the resin of step a).
A process for producing a cured silsesquioxane resin having high fracture toughness and strength without loss of elastic modulus comprising the steps of:
- a) providing a silsesquioxane resin;
- b) fractionating the silsesquioxane resin a plurality of times utilizing an organic solvent;
- c) stripping the silsesquioxane resin of step b) of excess solvent;
- d) selecting an appropriate fraction;
- e) mixing the silsesquioxane resin of step c) with a cross-linking compound to form a curable composition;
- f) curing the curable composition to form a cured resin having a higher fracture toughness than that of the resin of step a).
A process for producing a cured silsesquioxane resin having high fracture toughness and strength without loss of elastic modulus comprising the steps of:
- a) providing a silsesquioxane resin comprising polymeric molecular components having a range of molecular weights;
- b) separating the resin into fractions of smaller molecular weight ranges;
- c) selecting the fraction of smaller molecular weight range that upon curing with a cross-linking compound produces a cured resin having a higher fracture toughness and strength than the resin of step a).
Dependencies are inferred from the claim text.