Organic compounds -- part of the class 532-570 series – Organic compounds – Carboxylic acids and salts thereof
Reexamination Certificate
2007-02-06
2007-02-06
Oh, Taylor Victor (Department: 1625)
Organic compounds -- part of the class 532-570 series
Organic compounds
Carboxylic acids and salts thereof
C562S485000, C562S486000
Reexamination Certificate
active
10424042
ABSTRACT:
This invention provides a process a process for recovering terephthalic acid from pulverized products of spent polyethylene terephthalate. This process comprises (1) a decomposition reaction step where the pulverized products of spent polyethylene terephthalate are continuously subjected to decomposition reaction in ethylene glycol in the presence of alkali, which is equimolar or excessmolar relative to the polyethylene terephthalate, so that salt of terephthalic acid and ethylene glycol can be continuously obtained; (2) a solid-liquid separation, dissolution, impurities-removing step where the ethylene glycol is separated from decomposition reaction slurry of salt of terephthalic acid and ethylene glycol, and the solid salt of terephthalic acid is dissolved into water, while insoluble impurities are removed; (3) a neutralization, crystallization step, where solution of said salt of terephthalic acid is neutralized with acid so that terephthalic acid can be crystallized; (4) a solid-liquid separation, washing stop where slurry of terephthalic acid crystals is subjected to solid-liquid separation so that the terephthalic acid crystals can be obtained and washed; and (5) a drying, pulverization step where the washed terephthalic acid crystals are dried and pulverized.
REFERENCES:
patent: 3544622 (1970-12-01), England
patent: 4542239 (1985-09-01), Lamparter et al.
patent: 4755295 (1988-07-01), Donhauser et al.
patent: 5502247 (1996-03-01), Bartos et al.
patent: 6075163 (2000-06-01), Roh et al.
patent: 6580005 (2003-06-01), Yazaki et al.
patent: 09286744 (1997-11-01), None
Aldrich Handbook of Fine Chemicals, 1998-1999, p. 766.
Funakoshi Nobuyuki
Sakano Kozaburo
Tanaka Kazuho
Yazaki Jinichi
Koda & Androlia
Oh Taylor Victor
Tsukishima Kikai Co., Ltd.
LandOfFree
Process for recovering terephthalic acid from pulverized... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for recovering terephthalic acid from pulverized..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for recovering terephthalic acid from pulverized... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3820966