Hypromellose phthalate and method for producing hypromellose phthalate
US-10961323-B2 · Mar 30, 2021 · US
Hydroxypropyl methyl cellulose phthalate, method for producing the same, and composition for hot-melt extrusion
US12473425B2 · US · B2
| Field | Value |
|---|---|
| Publication number | US-12473425-B2 |
| Application number | US-202117448771-A |
| Country | US |
| Kind code | B2 |
| Filing date | Sep 24, 2021 |
| Priority date | Oct 1, 2020 |
| Publication date | Nov 18, 2025 |
| Grant date | Nov 18, 2025 |
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- Title
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Abstract
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There is provided a method for efficiently produce hydroxypropyl methyl cellulose phthalate (HPMCP) having excellent flowability, where acetic acid in a reaction product mixture subjected to a wash and recovery step can be reduced. More specifically, there is provided a method for producing HPMCP including an esterification step of esterifying hydroxypropyl methyl cellulose (HPMC) with phthalic anhydride in acetic acid as a solvent to obtain a reaction product solution containing HPMCP; a water addition step of adding water to the reaction product solution to obtain a water-added reaction product solution; an acetic acid removal step of removing at least a portion of the acetic acid from the water-added reaction product solution to obtain a mixture having an acetic acid content reduced; and a wash and recovery step of washing the mixture and recovering the HPMCP.
First claim
Opening claim text (preview).
The invention claimed is: 1 . A method for producing hydroxypropyl methyl cellulose phthalate comprising: an esterification step of esterifying hydroxypropyl methyl cellulose with phthalic anhydride in acetic acid as a solvent to obtain a reaction product solution containing hydroxypropyl methylcellulose phthalate; a water addition step of adding water to the reaction product solution in such an amount of the water as not to precipitate the hydroxypropyl methyl cellulose phthalate to obtain a water-added reaction product solution; an acetic acid removal step of removing at least a portion of the acetic acid from the water-added reaction product solution to obtain a mixture having an acetic acid content reduced; and a wash and recovery step of washing the mixture and recovering the hydroxypropyl methyl cellulose phthalate, wherein the acetic acid removal step comprises evaporating the acetic acid by heating and stirring the water-added reaction product solution under a reduced pressure, and an amount of the acetic acid removed in the acetic acid removal step corresponds to 10.0% or more of the solvent acetic acid. 2 . The method for producing hydroxypropyl methyl cellulose phthalate according to claim 1 , wherein the mixture having an acetic acid content reduced is in a solid form, and the method further comprises a pulverization step of pulverizing the mixture in a solid form between the acetic acid removal step and the wash and recovery step.
Assignees
Inventors
Classifications
resulting in granules or microspheres of the matrix type containing more than 5% of excipient · CPC title
Polysaccharides, e.g. alginate, cellulose derivatives; Cyclodextrin (homeopathic globules A61K9/1623) · CPC title
- C08B13/00Primary
Preparation of cellulose ether-esters · CPC title
Spheres · CPC title
Fibres; Fibrils · CPC title
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- What does patent US12473425B2 cover?
- There is provided a method for efficiently produce hydroxypropyl methyl cellulose phthalate (HPMCP) having excellent flowability, where acetic acid in a reaction product mixture subjected to a wash and recovery step can be reduced. More specifically, there is provided a method for producing HPMCP including an esterification step of esterifying hydroxypropyl methyl cellulose (HPMC) with phthalic…
- Who is the assignee on this patent?
- Shinetsu Chemical Co
- What technology area does this patent fall under?
- Primary CPC classification C08B13/00. Mapped technology areas include Chemistry & Metallurgy.
- When was this patent published?
- Publication date Tue Nov 18 2025 00:00:00 GMT+0000 (Coordinated Universal Time) (B2). Legal status and post-grant events are not shown on this page.
- What related patents are in patentsdb?
- We list 4 related publications on this page (citations in our corpus or others sharing the same primary CPC).