Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Reexamination Certificate
1999-10-06
2001-05-22
Hampton-Hightower, P. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
C528S026000, C528S126000, C528S128000, C528S170000, C528S171000, C528S172000, C528S173000, C528S174000, C528S176000, C528S179000, C528S182000, C528S185000, C528S188000, C528S220000, C528S229000, C528S353000, C525S425000, C525S436000, C525S439000
Reexamination Certificate
active
06235866
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to the preparation of polyether polymers and intermediates therefor. More particularly, it relates to the preparation of bis(halophthalimides), their isolation as a slurry and their use in slurry form for the preparation of polyetherimides.
Various types of aromatic polyethers, particularly polyetherimides but also including polyethersulfones, polyetherketones, and polyetheretherketones, have become important as engineering resins by reason of their excellent properties. These polymers are typically prepared by the reaction of salts of dihydroxyaromatic compounds, such as bisphenol A disodium salt, with dihaloaromatic molecules. For example, polyetherimides are conveniently prepared by the reaction of salts of dihydroxyaromatic compounds with bis(halophthalimides) as illustrated by 1,3-bis[N-(4-chlorophthalimido)]benzene (hereinafter sometimes “ClPAMI”), which has the structure
For polysulfones and polyetherketones, bis(4-fluorophenyl) sulfone, bis(4-chlorophenyl) sulfone and the analogous ketones are typically employed.
According to U.S. Pat. Nos. 5,229,482 and 5,830,974, the preparation of aromatic polyethers may be conducted in solution in relatively non-polar solvents, using a phase transfer catalyst which is substantially stable under the temperature conditions employed. Solvents disclosed in U.S. Pat. No. 5,229,482 include o-dichlorobenzene, dichlorotoluene, 1,2,4-trichlorobenzene and diphenyl sulfone. In U.S. Pat. No. 5,830,974, monoalkoxybenzenes such as anisole, diphenylether, or phenetole are employed. Solvents of the same types may be used for the preparation of bis(halophthalimide) intermediates for polyetherimides.
Each of these patents requires introduction into the reaction mixture of the bis(halophthalimide) as a substantially pure, isolated compound. This is often difficult, since solid bis(halophthalimides) are typically of very low density and fluffy, making weighing and handling burdensome. It would be desirable, for both technical and cost reasons, to handle such reactants as slurries in an organic solvent instead of in dry solid form.
In order to isolate bis(halophthalimides) in slurry form, however, it is often preferred to prepare them by a method which employs the reactants, namely diamino compound and halophthalic anhydride, in equimolar proportions so as to avoid competing reactions. According to such prior art as U.S. Pat. No. 3,787,364, the employment of substantially equimolar proportions of reactants can result in the necessity for extremely long reaction times, typically up to 3 days. This is true even when such active solvents as glacial acetic acid are employed. When non-polar solvents are employed, it has typically been necessary to employ one reactant, most often the chlorophthalic anhydride, in excess, whereupon said reactant is still present after completion of the reaction and can cause competing reactions to take place upon synthesis of the polyetherimide.
SUMMARY OF THE INVENTION
The present invention is based in part on the discovery that bis(halophthalimides) may be prepared in high yield and conversion by the reaction of halophthalic anhydride and diamino compound, even in equimolar amounts, and may be isolated in slurry rather than solid form, if certain reaction conditions are maintained. These include relatively high reaction temperatures, relatively high solids content and the presence of a suitable catalyst.
The invention in one of its aspects is a method for preparing a bis(halophthalimide) in organic slurry form which comprises effecting contact at a temperature of at least 100° C. between the constituents of a mixture comprising at least one diamino compound, at least one halophthalic anhydride, a relatively non-polar organic liquid and an imidization catalyst, said mixture having a solids content of at least about 5% by weight, thereby producing a slurry of said bis(halophthalimide) in said liquid.
It has also been discovered that bis(halophthalimides) and similar dihaloaromatic compounds may be employed in slurry form for the preparation of the corresponding polyether polymers. Another aspect of the invention, therefore, is a method for preparing an aromatic polyether polymer which comprises contacting, in at least one relatively non-polar organic liquid as diluent, substantially equimolar amounts of at least one alkali metal salt of a dihydroxy-substituted aromatic hydrocarbon and a slurry in said organic liquid of at least one substituted aromatic compound of the formula
Z(A
1
—X
1
)
2
, (I)
wherein Z is an activating radical, A
1
is an aromatic radical and X
1
is fluoro, chloro, bromo or nitro, in the presence of a catalytically active amount of a phase transfer catalyst.
REFERENCES:
patent: 3787364 (1974-01-01), Wirth et al.
patent: 4257953 (1981-03-01), Williams
patent: 4273712 (1981-06-01), Williams
patent: 5229482 (1993-07-01), Brunelle
patent: 5830974 (1998-11-01), Schmidhauser et al.
patent: 5908915 (1999-06-01), Brunelle
patent: 6001957 (1999-12-01), Puyenbroek et al.
patent: 6011122 (2000-01-01), Puyenbroek
patent: 6020456 (2000-02-01), Brunelle et al.
Caringi Joseph John
Howson Paul Edward
Kailasam Ganesh
Khouri Farid Fouad
Phelps Peter David
Brown S. Bruce
General Electric Company
Hampton-Hightower P.
Johnson Noreen C.
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