High purity polyhydrogen silsesquioxane resin for electronic coatings

• US 5,486,564 A
• Filed: 02/13/1995
• Issued: 01/23/1996
• Est. Priority Date: 11/24/1992
• Status: Expired due to Term

• Current Assignee: Dow, Inc.
• Original Assignee: Dow Corning Toray Company Limited (Dow, Inc.)
• Inventors: Nakamura, Takashi, Sasaki, Motoshi, Mine, Katsutoshi
• Primary Examiner(s): Sweet, Mark D.
• Application Number:
  US08/387,697
• Time in Patent Office: 344 Days
• Field of Search: 524/588, 528/10, 528/42, 528/31
• US Class Current: 524/588
• CPC Class Codes: C08G 77/12 containing silicon bound to hydrogen C08G77/045 takes precedence
• CPC Class Codes: C08G 77/36 Fractionation

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.

Claims

1. A high purity electronic coating composition comprising polyhydrogen silsesquioxane resin having a sodium content of 9 ppb or less, a sulfur content of 14 ppm or less and a chlorine content less than 1 ppm.

2. The coating composition of claim 1 wherein the sodium content is 6 ppb or less.

3. The coating composition of claim 1 wherein the sodium content is 2 ppb or less.

4. The coating composition of claim 1 wherein the sulfur content is 5 ppm or less.

5. The coating composition of claim 1 wherein the sulfur content is 4 ppm or less.

6. The coating composition of claim 1 wherein the sulfur content is 2 ppm or less.

7. The coating composition of claim 1 wherein the sulfur content is less than 1 ppm.

8. The coating composition of claim 1 dissolved in a solvent.