Process for producing aqueous dispersion of purified...

Details Process for producing aqueous dispersion of purified... Process for producing aqueous dispersion of purified...

2007-07-03

2007-07-03

Wu, David W. (Department: 1713)

Synthetic resins or natural rubbers -- part of the class 520 ser

Synthetic resins

Processes of preparing a desired or intentional composition...

C524S544000, C554S191000, C526S243000, C210S662000

Reexamination Certificate

active

11282624

ABSTRACT:
A process for producing an aqueous dispersion of purified polytetrafluoroethylene (PTFE), comprising passing a crude aqueous dispersion of PTFE comprising from 10 to 50 mass % of PTFE fine particles having an average particle diameter of from 0.1 to 0.5 μm, from 0.05 to 1.0 mass %, based on PTFE, of a fluorine-containing carboxylic acid salt (APFO) and from 2 to 20 mass %, based on PTFE, of a nonionic surfactant through a column packed with a weak basic AER upward at a linear velocity of 0.1 to 2 mm/sec with a contact time of 0.2 to 4 hours to reduce the APFO concentration. The process can increase the absorption of APFO by the anion exchange resin, prevents agglomeration of PTFE during passage and makes it easy to elute the absorbed APFO.

REFERENCES:
patent: 4999131 (1991-03-01), Shimizu et al.
patent: 5164080 (1992-11-01), Furuno
patent: 6825250 (2004-11-01), Epsch et al.
patent: 6833403 (2004-12-01), Blädel et al.
patent: 6861466 (2005-03-01), Dadalas et al.
patent: 2002/0168773 (2002-11-01), Ito et al.
patent: 2005/0189299 (2005-09-01), Malvasi et al.
patent: 2006/0128872 (2006-06-01), Zipplies et al.
patent: 2006/0135654 (2006-06-01), Swearingen et al.
patent: 2006/0175261 (2006-08-01), Noelke et al.
patent: 2006/0183842 (2006-08-01), Johnson
patent: 2001-62313 (2001-03-01), None
patent: 2002-532583 (2002-10-01), None
patent: 2005-200650 (2005-07-01), None
patent: WO 00/35971 (2000-06-01), None
“Handbook of Fluorine resins”, published by Nikkankogyo Shimbun, pp. 28-29, 1990.
Takeshi Suwa, et al., “Melting and Crystallization Behavior of Poly (tetrafluoroethylene). New Method for Molecular Weight Measurement of Poly (tetrafluoroethylene) Using a Differential Scanning Calorimeter”, Journal of Applied Polymer Science, vol. 17, 1973, pp. 3253-3257.
“Handbook of Fluorine resins”, published by Nikkankogyo Shimbun, pp. 32-33, 1990.

Affiliated with

Also associated with

Rating

Process for producing aqueous dispersion of purified... 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 producing aqueous dispersion of purified..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for producing aqueous dispersion of purified... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3753065