The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 16, 2010
Filed:
Oct. 13, 2005
Michael T. Sheehan, Corpus Christi, TX (US);
Edward G. Zey, Corpus Christi, TX (US);
Hiroshi Okazaki, Corpus Christi, TX (US);
Michael T. Sheehan, Corpus Christi, TX (US);
Edward G. Zey, Corpus Christi, TX (US);
Hiroshi Okazaki, Corpus Christi, TX (US);
Du Pont Electronic Polymers L.P., Research Triangle Park, NC (US);
Abstract
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.