Hydroxypropyl methyl cellulose phthalate and method for producing the same
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United States of America Patent
Stats
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Jan 16, 2024
Grant Date -
May 6, 2021
app pub date -
Oct 29, 2020
filing date -
Nov 1, 2019
priority date (Note) -
In Force
status (Latency Note)
Importance
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US Family Size
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Abstract
There is provided a method for producing hydroxypropyl methyl cellulose phthalate (HPMCP), including an esterification step of reacting hydroxypropyl methyl cellulose with a carboxybenzoylating agent in the presence of an aliphatic carboxylic acid in a kneader reactor equipped with two or more stirring blades rotating around their own axes and orbitally revolving, to obtain a reaction product solution containing HPMCP; a precipitation step of precipitating the HPMCP by mixing the reaction product solution with water to obtain a suspension of the precipitated HPMCP; and a washing and recovery step of washing the HPMCP in the suspension and recovering the washed HPMCP. Further, there is provided HPMCP having yellowness at 20° C. of 10.0 or less, as determined in a 10% by mass solution of the HPMCP in acetone.
First Claim
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Family
| Country | kind | publication No. | Filing Date |
|---|---|---|---|
| JP | B2 | JP7273691 | Nov 01, 2019 |
| EP | B1 | EP3816191 | Oct 28, 2020 |
| CN | B | CN112778429 | Oct 28, 2020 |
| KR | A | KR20210053220 | Oct 28, 2020 |
International Classification(s)
- 2020 Application Filing Year
- C08B Class
- 312 Applications Filed
- 139 Patents Issued To-Date
- 44.56 % Issued To-Date
Cited Art Landscape
Patent Citation Ranking
- 0 Citation Count
- C08B Class
- 0 % this patent is cited more than
- 1 Age
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