Junichi MATSUBARA,Naosuke MARUYAMA,Mitsuhiro YOSHIDA
申请号：
US15797876
公开号：
US20180116968A1
申请日:
2017.10.30
申请国别(地区):
US
年份:
2018
代理人:
摘要：
There are provided HPMCAS (hypromellose acetate succinate) having such a property that a solution of the HPMCAS in a solvent has a controlled viscosity； and a method for producing the HPMCAS. More specifically, provided are HPMCAS having such property that a solution of 10 parts by weight of the HPMCAS in 100 parts by weight of a mixed solvent having a weight ratio of methylene chloride to methanol of 1:1 has a viscosity at 20° C. of 135 mPa·s or less； and a method for producing the HPMCAS including an esterification step of adding acetic anhydride and succinic anhydride to a solution of hypromellose in glacial acetic acid in the presence of sodium acetate to obtain a reaction product mixture, wherein the succinic anhydride is added intermittently, and a precipitation step of mixing the reaction product mixture with water to precipitate the HPMCAS.
