Novolak resins and their use in radiation-sensitive compositions wherein the novolak resins are made by condensing 2,6-dimethylphenol, 2,3-dimethylphenol, a para-substituted phenol and an aldehyde

Granted: Sep 13, 1994 Filed: Dec 7, 1992

This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.