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1. (EP0802896) METHOD FOR PURIFYING CRUDE NAPHTHALENEDICARBOXYLIC ACID

Office : European Patent Office
Application Number: 96935500 Application Date: 30.10.1996
Publication Number: 0802896 Publication Date: 29.10.1997
Publication Kind : B1
Prior PCT appl.: Application Number:JP1996003180 ; Publication Number: Click to see the data
IPC:
C 07C
C 07C
C07C 51/487
C 07C
C07C 51/493
C07C 63/38
C CHEMISTRY; METALLURGY
07
ORGANIC CHEMISTRY
C
ACYCLIC OR CARBOCYCLIC COMPOUNDS
51
Preparation of carboxylic acids or their salts, halides, or anhydrides
42
Separation; Purification; Stabilisation; Use of additives
487
by treatment giving rise to chemical modification
C CHEMISTRY; METALLURGY
07
ORGANIC CHEMISTRY
C
ACYCLIC OR CARBOCYCLIC COMPOUNDS
63
Compounds having carboxyl groups bound to carbon atoms of six-membered aromatic rings
33
Polycyclic acids
337
with carboxyl groups bound to condensed ring systems
34
containing two rings
38
containing two carboxyl groups both bound to carbon atoms of the condensed ring system
C CHEMISTRY; METALLURGY
07
ORGANIC CHEMISTRY
C
ACYCLIC OR CARBOCYCLIC COMPOUNDS
51
Preparation of carboxylic acids or their salts, halides, or anhydrides
42
Separation; Purification; Stabilisation; Use of additives
487
by treatment giving rise to chemical modification
C CHEMISTRY; METALLURGY
07
ORGANIC CHEMISTRY
C
ACYCLIC OR CARBOCYCLIC COMPOUNDS
51
Preparation of carboxylic acids or their salts, halides, or anhydrides
42
Separation; Purification; Stabilisation; Use of additives
487
by treatment giving rise to chemical modification
493
whereby carboxylic acid esters are formed
C CHEMISTRY; METALLURGY
07
ORGANIC CHEMISTRY
C
ACYCLIC OR CARBOCYCLIC COMPOUNDS
51
Preparation of carboxylic acids or their salts, halides, or anhydrides
42
Separation; Purification; Stabilisation; Use of additives
487
by treatment giving rise to chemical modification
493
whereby carboxylic acid esters are formed
C CHEMISTRY; METALLURGY
07
ORGANIC CHEMISTRY
C
ACYCLIC OR CARBOCYCLIC COMPOUNDS
63
Compounds having carboxyl groups bound to carbon atoms of six-membered aromatic rings
33
Polycyclic acids
337
with carboxyl groups bound to condensed ring systems
34
containing two rings
38
containing two carboxyl groups both bound to carbon atoms of the condensed ring system
CPC:
C07C 51/487
Applicants: MITSUI CHEMICALS INC
Inventors: IWASAKI HIROSHI
HIROKANE NOBUYA
ISHIBASHI MASAYASU
INOKI SATOSHI
Priority Data: 12189996 16.05.1996 JP
29310195 10.11.1995 JP
9603180 30.10.1996 JP
Title: (DE) VERFAHREN ZUR REINIGUNG VON ROHER NAPHTHALENDICARBONSÄURE
(EN) METHOD FOR PURIFYING CRUDE NAPHTHALENEDICARBOXYLIC ACID
(FR) PROCEDE DE PURIFICATION D'ACIDE NAPHTATLENEDICARBOXYLIQUE BRUT
Abstract:
(EN) The invention provides a method for purifying a crude naphthalenedicarboxylic acid comprising the steps of mixing a crude naphthalenedicarboxylic acid and a water/alcohol solvent to esterify a part of the naphthalenedicarboxylic acid, thereby dissolving a naphthalenedicarboxylic ester into the solvent, and then contacting the resulting reaction mixture with hydrogen in the presence of a hydrogenation catalyst to hydrogenate impurities which are contained in the crude naphthalenedicarboxylic acid and which are capable of being hydrogenated, thereby dissolving and removing hydrogenation products into the water/methanol solvent. A mixture of a naphthalenedicarboxylic acid and a naphthalendicarboxylic ester with reduced impurity contents, or a high-purity naphthalenedicarboxylic acid can be obtained.
(FR) La présente invention concerne un procédé de purification d'acide naphtatlènedicarboxylique brut. Ce procédé comprend le mélange d'un solvant eau-alcool et d'acide naphtalènedicarboxylique brut pour estérifier une partie de ce dernier, ce qui dissout un ester naphtalènedicarboxylique dans le solvant. Après cela, on met le mélange de réaction ainsi obtenu en contact avec de l'hydrogène en présence d'un catalyseur d'hydrogénation, pour hydrogéner les impuretés qui sont contenues dans l'acide naphtalènedicarboxylique brut et qui peuvent être hydrogénées. Cela dissout et élimine les produits de l'hydrogénation dans le solvant eau-méthanol. On parvient ainsi à obtenir un mélange d'un acide naphtalènedicarboxylique et d'un ester naphtalènedicarboxylique à teneur en impuretés réduite ou bien un acide naphtalènedicarboxylique très pur.
Also published as:
US5872284JPH10512596 CN1168131CA2209907KR1019980701285WO/1997/017318