Catalytic production of lactide directly from lactic acid

Details Catalytic production of lactide directly from lactic acid Catalytic production of lactide directly from lactic acid

1990-09-18

1994-07-26

Ivy, C. Warren

Organic compounds -- part of the class 532-570 series

Organic compounds

Heterocyclic carbon compounds containing a hetero ring...

203 14, C07D31912

Patent

active

053328396

ABSTRACT:
The present invention is directed to a method for making lactide from aqueous lactic acid. The invention method comprises converting feed aqueous lactic acid to its vapor phase. The feed vapors then are passed through a reactor maintained at elevated temperature and in which optionally is disposed an alumina catalyst. Withdrawn from the reactor is product lactide, water, and unreacted lactic acid which are subjected to separation for recovery of the lactide product. The separated unreacted lactic acid is eligible for readmission to the process for making additional lactide. This cyclic process embodiment of the present invention comprises the steps of passing make-up aqueous lactic acid feed into a vaporization zone along with unreacted aqueous lactic acid filtrate from another step of the process and therein forming aqueous lactic acid feed vapors. The thus-generated vapors that are passed through a vapor phase reaction zone held at elevated temperature for forming lactide therein. Lactide as a solid is separated from unreacted aqueous lactic acid filtrate; and the filtrate is passed into the vaporization zone in the initial step of the process.

REFERENCES:
patent: 1095205 (1914-05-01), Gruter et al.
patent: 1594843 (1926-08-01), Lawrie
patent: 1995970 (1935-03-01), Dorough
patent: 2163268 (1939-06-01), Carothers et al.
patent: 2174491 (1939-09-01), Watson
patent: 2189572 (1940-02-01), Watson
patent: 2668162 (1954-02-01), Lowe
patent: 2703316 (1955-03-01), Schneider
patent: 2758987 (1956-08-01), Salzberg
patent: 2768973 (1956-10-01), Castle et al.
patent: 3322719 (1967-06-01), Peilstocker
patent: 3435008 (1969-03-01), Schmitt et al.
patent: 3457280 (1969-07-01), Schmitt et al.
patent: 3597450 (1971-08-01), Schmitt et al.
patent: 3736646 (1973-06-01), Schmitt et al.
patent: 3867190 (1975-02-01), Schmitt et al.
patent: 3960152 (1976-06-01), Augurt et al.
patent: 4033938 (1977-07-01), Augurt et al.
patent: 4070375 (1978-01-01), Suzuki
patent: 4727163 (1988-02-01), Bellis
patent: 4797468 (1989-01-01), DeVries
patent: 4835293 (1989-05-01), Bhatia
patent: 4966982 (1990-10-01), Ono et al.
patent: 4990222 (1991-02-01), Aigner et al.
patent: 5023349 (1991-06-01), Bhatia
patent: 5023350 (1991-06-01), Bhatia
patent: 5043458 (1991-08-01), Bhatia
patent: 5053485 (1991-10-01), Nieuwenhuis et al.
patent: 5053522 (1991-10-01), Muller
patent: 5068418 (1991-11-01), Kulprathipanja et al.
patent: 5075115 (1991-12-01), Brine
patent: 5089632 (1992-02-01), Paul
patent: 5091544 (1992-02-01), Bhatia
Bezzi et al., "Dehydration Products of Lactic Acid Typifying the Transformation of Cyclic Esters into Linear Polyesters", Meeting of the Italian Academy of Science, Nov., 1936.
Bischoff et al., "Ueber Das Glycolid und Seine Homologen", pp. 262-265, 1893, Chem. Ber., vol. 26.
Carothers et al., "Studies of Polymerization and Ring Formation. X. The Reversible Polymerization of Six-Membered Cyclic Esters", pp. 761-771, 1932, J. Am. Chem. Soc., vol. 54.
Carothers, "Polymers and Polyfunctionality", pp. 39-53, 1936, Transactions of the Faraday Society, vol. 32.
Deibig et al., "I. Synthesis and Properties of Polytetramethyl Glycolide", pp. 123-131, 1971, Die Makromolekulare Chemie, vol. 145.
Deibig et al., "III. Thermal Behavior of Polytetramethyl Glycolide", pp. 133-139, 1971, Die Makromolekulare Chemie, vol. 145.
Dietzel et al., "Uber Das Chemische Gleichgewicht Zwischen der Milchsaure und Ihren Anhydriden in Wabriger Losung", pp. 1307-1314, 1925, Chem. Ber., vol. 58B.
Filachione et al., "Lactic Acid Condensation Polymers: Preparation by Batch and Continuous Methods", pp. 223-228, 1944, Industrial and Engineering Chemistry, Mar., vol. 36, No. 3.
Hill et al., "Cyclic and Polymeric Formals", pp. 925-928, 1935, J. Am. Chem. Soc., vol. 57.
Holten, "Lactic Acid. Properties and Chemistry of Lactic Acid and Derivatives", pp. 221-231, 1971, Verlag Chemie.
Imasaka et al., "Synthesis of Degradable Terpolymers Responding to External Stimuli Such as pH, Ionic Strength, and Temperature", pp. 715-722, 1991, Makromol. Chem. vol. 192.
Ikada et al., "Stereocomplex Formation Between Enantiomeric Poly(Lactides)", pp. 904-906, 1987, American Chemical Society, Macromolecules, 20.
Jackanicz et al., "Polylactic Acid as a Biodegradable Carrier for Contraceptive Steroids", pp. 227-234, 1973, The Population Counsel, Sep., vol. 8, No. 3.
Jungfleisch et al., "Oragnic Chemistry--On the Dilactide of Left Lactic Acid", pp. 637-639, 1906, Academie Des Sciences, Meeting of Mar. 12.
Kleine et al., "High Molecular Weight, Especially Optically Active Polyesters of Lactic Acid: An Investigation of the Stereochemistry of Macromolecular Compounds", pp. 1-21, 1958, Report from the Research Laboratory for Macromolecular Chemistry, Dec.
Kulkarni et al., "Polylactic Acid for Surgical Implants", pp. 839-843, 1966, Arch. Surg., vol. 93, Nov.
Light, "Lactic Acid Resins", pp .135-136, 1940, Paint Manufacture, Jun.
Watson, "Composition of Lactic Acid. Production of a Highly Concentrated Acid", pp. 399-401, 1940, Industrial and Engineering Chemistry, vol. 32, No. 3.
Wise, "Biopolymeric Controlled Release Systems", pp. 3-28, 1984, CRC Press, vol. 1.
Wise, "Biopolymeric Controlled Release Systems", pp. 187-199, 1984, CRC Press, vol. 2.
Wise, et al., "Lactic/Glycolic Acid Polymers", pp. 237-270, Dynatech R/D Company, Cambridge, Mass., U.S.A. (no date available).

Affiliated with

Also associated with

Rating

Catalytic production of lactide directly from lactic acid does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Catalytic production of lactide directly from lactic acid, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Catalytic production of lactide directly from lactic acid will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1054120