January 30, 2012

CAS databases provide millions of journal article references from more than 10,000 major scientific journals worldwide, patent and patent family references from 62 patent authorities around the world, and other reputable web sources.

The following patent record is from the CAplusSM database.


Patent Number: US 8088834
Title: Process for making polybutylene terephthalate (PBT) from polyethylene terephthalate (PET)
Inventor(s): Agarwal, Parminder; Cohoon, Kristen; Dhawan, Sandeep; Gallucci, Robert Russell; Kannan, Ganesh; Miller, Kenneth Frederick; Ramaraju, Deepak; Ravi, Gomatam Raghavan; Shah, Dhaval
Patent Assignee(s): General Electric Company, USA; SABIC Innovative Plastics IP B.V.
Source: U.S. Pat. Appl. Publ., 17 pp. CODEN: USXXCO
Language: English


A 3-step process for making modified polybutylene terephthalate random copolymers from a polyethylene terephthalate (I) comprises reacting diols such as ethylene glycol or/and propylene glycol with polyethylene terephthalate at 190 - 250 degrees and normal pressure in the presence of a catalyst, combining the resulting molten mixture with 1,4-butanediol at 190 - 240 degrees under conditions that create a second molten mixture that is subsequently placed under subatmospheric conditions and 240 - 260 degrees that produce the modified polybutylene terephthalate random copolymers.  Thus, a green colored I scrap from bottles having after hydrofloatation viscosity 0.68 - 0.78 dL/g and having <10 ppm PVC was depolymd. during 20 - 120 min with ethylene glycol (II) at II:I ratio 1.26 in the presence of a 100 ppm Ti-containing catalyst at 200 - 260 degrees and 1 - 6 bar followed by transesterification with 1,4-butanediol in the presence of 10 - 14 ppm sodium methoxide and subjecting the resulting mixture a pressure 80 - 95 kPA during 10 - 40 min followed by removing solvents and rest monomers.

Please note:  Abstracts for patent records in CAplus are routinely enhanced to better describe the claimed invention. In this example, CAS enhanced the abstract using additional information found in the patent. Also, because no assignee was listed at the time of publication, CAS indexing included General Electric as an assignee based on information from the USPTO Daily Assignments file. General Electric reassigned to Sabic Innovative Plastics prior to the publication of the U.S. granted patent.

View the full-text U.S. patent from USPTO.

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