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:
May. 05, 2015
Filed:
Nov. 05, 2013
Maruzen Petrochemical Co., Ltd., Tokyo, JP;
Tomo Oikawa, Ichihara, JP;
Maruzen Petrochemical Co., Ltd., Tokyo, JP;
Abstract
A method is provided for purifying a resin for photolithography wherein, from an insufficiently purified resin (also referred to as 'crude resin'), low molecular weight impurities such as an unreacted monomer and a polymerization initiator, which cause a development defect of a resist pattern or deterioration of the storage stability of the resin for photolithography can be removed more effectively. The method for purifying a resin for photolithography includes an operation (a) wherein a slurry in which a resin is dispersed in a solution containing a good solvent and a poor solvent is stirred, and then an operation (b) wherein, to said slurry, a poor solvent is added to lower the ratio of the good solvent to the poor solvent, and then, the resin is separated from the solution.