Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From sulfur-containing reactant
Reexamination Certificate
1993-09-13
2001-08-28
Pezzuto, Helen L. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From sulfur-containing reactant
C525S537000
Reexamination Certificate
active
06281326
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to poly(arylene sulfide), (PAS) polymers. In one aspect this invention relates to a process for the preparation of poly(arylene sulfide) polymers wherein waste material is used as a reactant in the polymerization.
In one embodiment of this invention, the waste material is obtained as an undesired by-product of a previous poly(arylene sulfide) polymerization. In another embodiment, the waste material is obtained as an undesired product during the purification of a previously prepared poly(arylene sulfide) polymer. In yet another embodiment, the waste material is previously prepared poly(arylene sulfide) polymer obtained from commercial production which is not within the specifications for the desired product. In yet another embodiment, the waste material is poly(arylene sulfide) material that has been sufficiently contaminated during preparation and/or recovery so that it is unacceptable for its originally intended use.
BACKGROUND OF THE INVENTION
Poly(arylene sulfide) polymers are generally known in the art and have been found useful due to their high chemical and thermal resistance. Processes for the preparation of such poly(arylene sulfide) polymers have been disclosed in the art. In a typical preparation, at least one dihaloaromatic compound, a sulfur source, and a polar organic compound are contacted under polymerization conditions. Often certain molecular weight enhancing agents are also added during the polymerization. At the termination of the polymerization, the desirable product is recovered from the polar organic compound, unconsumed reactants and by-product inorganic salts and any water which may be present. Some recovery processes for poly(arylene sulfide) polymers additionally separate desirable higher molecular weight product from the less desirable low molecular weight poly(arylene sulfide) and cyclic and linear oligomers. Occasionally, a recovered poly(arylene sulfide) polymer is subjected to a purification process to remove lower molecular weight portions, oligomers and other impurities from the more desirable higher molecular weight portions.
During commercial production, poly(arylene sulfide) polymer is occasionally produced which is not within the specifications for the desired product. During preparation and/or recovery, polymer product can become contaminated by coming into contact with compounds which are not intended to be a part of the particular product.
In all of the above-mentioned situations, undesired materials must be disposed of in some manner, for example, by placing such material in a landfill or blending such material with other product to render it usable. It would be economically and environmentally desirable to have a process using at least a portion of such undesirable or waste materials so that some of the material need not be disposed of.
OBJECTS OF THE INVENTION
It is an object of this invention to provide a process for preparing a poly(arylene sulfide) polymer which employs poly(arylene sulfide) polymer waste material.
SUMMARY OF THE INVENTION
In accordance with this invention, poly(arylene sulfide) polymers are prepared by contacting a polymerization reaction mixture comprising at least one dihaloaromatic compound, a sulfur source, and a polar organic compound with a poly(arylene sulfide) waste material under polymerization conditions.
In accordance with one embodiment of this invention, the waste material comprises relatively low molecular weight poly(arylene sulfide) polymer when compared to the poly(arylene sulfide) polymer prepared by the invention process.
In accordance with other embodiments of this invention, the waste material comprises poly(arylene sulfide) polymer of equal or higher molecular weight than the poly(arylene sulfide) polymer prepared by the invention process.
This invention provides a method whereby material that is ordinarily discarded or otherwise disposed of can be used in subsequent polymerizations to produce desirable polymer.
REFERENCES:
patent: 3354129 (1967-11-01), Edmonds, Jr. et al.
patent: 3607843 (1971-09-01), Vidaurri, Jr.
patent: 3919177 (1975-11-01), Campbell
patent: 4405767 (1983-09-01), Beever et al.
patent: 4415729 (1983-11-01), Scoggins et al.
patent: 4645826 (1987-02-01), Iizuka et al.
patent: 4730034 (1988-03-01), Nesheinat et al.
patent: 0409105A2 (1991-01-01), None
Ash Carlton E.
Geibel Jon F.
Owen Polly C.
Pezzuto Helen L.
Phillips Petroleum Company
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