Dupont Electronic Polymers LP

Hiroshi Okazaki

Michael T Sheehan

Edward G Zey

A process for preparing a blocked derivatized poly(4-hydroxystryrene)-DPHS having a novolak type structure which comprises the steps of (i) supplying a solution of methanol containing 4-hydroxyphenylmethylcarbinol, (ii) subjecting said solution to an acid catalyzed displacement reaction for a sufficient period of time and under suitable conditions of temperature and pressure to convert substantially all of said carbinol to 4-hydroxyphenylmethylcarbinol methyl ether in solution, (iii) polymerizing said ether containing solution in the presence of a suitable acid catalyst for a sufficient period of time and under suitable conditions of temperature and pressure to form a novolak type polymer; and (iv) reacting said polymer with a vinyl ether, a dialkyl dicarbonate, or a mixture of vinyl ether and a dialkyl dicarbonate to form the blocked DPHS. New compositions of matter which comprise the blocked derivatized poly(4-hydroxystyrene) prepared in the above manner and which have application in the electronic chemicals market such as in a photoresist composition and MEMS, and in other areas such as in varnishes, printing inks, epoxy resins, copying paper, tackifiers for rubber, crude oil separators, toner resins for photocopying, antireflective coatings, and the like.

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Corpus Christi, TX, United States of America

Hiroshi Okazaki