Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Patent
1996-07-31
1998-03-10
Mosley, Terressa
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
528176, 528182, 528207, C08G 6306
Patent
active
057262756
DESCRIPTION:
BRIEF SUMMARY
The invention pertains to a process for the batchwise preparation of poly-p-phenylene terephthalamide polymer by means of reacting approximately equimolar amounts of p-phenylene diamine and terephthaloyl dichloride in a solution containing N-methyl-2-pyrrolidone and calcium chloride.
Such a process is well-known. For instance, Netherlands patent specification NL 157327 describes the preparation of PPTA in a solution of NMP and calcium chloride. However, this patent specification makes no mention of any process by which the batchwise preparation of PPTA can be performed economically, optionally via upscaling. For, the scale on which PPTA is prepared in the examples of said patent specification is too small for economical preparation, and the preparative processes mentioned are not suitable for upscaling.
Neither do other prior art documents teach such a process. Thus, also EP 55 190 (U.S. Pat. No. 4,579,895) makes reference to the batchwise preparation of poly-p-phenylene terephthalamide. This reference, however, is by merely mentioning that the polycondensation of p-phenylene diamine and terephthaloyl dichloride can be carried through in a discontinuous or in a continuous process. Also other background disclosures pertaining to the preparation of poly-p-phenylene terephtalamide do not teach economically feasible batch processes. In Patent Abstracts of Japan, vol. 012, no.172 (C-497) JP 62/280223 is summarized as pertaining to the polymerization of p-phenylene diamine and terephtaloyl chloride in a specific solvent system, in order to achieve a high degree of polymerization. A similar disclosure, using a different solvent system, is JP 61/123632, summarized in Patent Abstracts of Japan, vol. 010, no. 314 (C-380).
The invention pertains to a process by which PPTA can be prepared economically on a commercial scale.
The invention consists in that in a preparation of the type described in the opening paragraph the reaction is carried out in a cylindrical reaction vessel equipped with a single mixing gear used as stirrer and granulator, the contents of the reaction vessel are whirlingly mixed as terephthaloyl dichloride is added, the formed polymer is crumbled, and the reaction and the crumbling take place in one and the same reaction vessel. The minimum rate of rotation required for whirling mixing is set immediately prior to the start of TDC metering. This rate of rotation will either be maintained during TDC metering, or it can be increased during the metering. The latter course, however, is not required. This minimum rate of rotation is the stirrer and granulator speed required to ensure even distribution over the cylindrical wall of the mixing vessel of all of the liquid in the reaction vessel, such that there will be virtually complete covering of the cylindrical wall by the liquid present in the vessel. In this process the mixing members move through the ring of liquid and pass very closely in front of the walls of the reaction vessel. It is assumed that the required proper mixing of the TDC into the liquid results not just from the movement of the mixing members through the liquid, but also from the whirling motions occurring in the liquid immediately behind the mixing members.
In this context a single mixing gear used as stirrer and granulator refers to a mixing gear comprised of members which can be employed for both stirring and granulating. Hereinafter such a mixing gear will also be referred to by the term "mixing mill."
According to a suitable embodiment of the process for preparing PPTA according to the invention, NMP and calcium chloride are charged to the reaction vessel and then thoroughly mixed, or else the NMP and the calcium chloride are mixed outside the vessel and the mixture is then charged to the reaction vessel. Next, PPD is added to this mixture in the reaction vessel, and the whole is thoroughly mixed. Alternatively, these three components can be charged to the reaction vessel in a different order, but this is attended with a number of practical drawbacks. One eminently practical meth
REFERENCES:
patent: 4057536 (1977-11-01), Jones, Jr.
patent: 4308374 (1981-12-01), Vollbracht et al.
patent: 4579895 (1986-04-01), Cuidard et al.
patent: 4863991 (1989-09-01), Poppe et al.
Derwent Patent Abstract 68709B/38 (1979), abstracting JP 54/100,496.
Patent Abstracts of Japan, vol. 10, No. 314 (C-380), Oct. 1986, abstracting JP 61/123,632.
Patent Abstracts of Japan vol. 12, No. 172 (C-497), May 1988, abstracting JP 62/280,223.
Bannenberg-Wiggers Angelica Elizabeth-Maria
Surquin Joannes Marinus
van Omme Johannes A.
Akzo Nobel N.V.
Fennelly Richard P.
Morris Louis A.
Mosley Terressa
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