Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Reexamination Certificate
2000-08-04
2002-10-29
Truong, Duc (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
C528S212000, C528S217000, C528S486000, C528S492000, C528S495000, C528S497000, C528S501000
Reexamination Certificate
active
06472499
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a process for the preparation of poly(arylene ether) resins. In particular, it relates to a process for preparing high intrinsic viscosity poly(arylene ether) resins.
Commercially available poly(arylene ether) resins typically have number average molecular weights of about 7,000 to about 30,000 and intrinsic viscosities of about 0.25 to about 0.60 deciliters per gram (dL/g) measured in chloroform at 25° C. While high molecular weights are correlated with high intrinsic viscosities, there is no simple conversion between the two measures because of the complex dependence of intrinsic viscosity on the particular molecular weight distribution of a sample. Preparation of poly(arylene ether) resins, including some high intrinsic viscosity resins, is described in commonly assigned U.S. Pat. No. 3,219,625 to Blanchard et al. This reference generally describes the preparation of poly(phenylene ether) resins using copper catalysts with halide, methoxy and pyridino ligands. Example 8 describes the preparation of poly(2,6-dimethylphenylene ether) with an intrinsic viscosity of 1.46 dL/g from a reaction mixture in which the molar ratio of 2,6-dimethylphenol to copper catalyst (calculated per mole of copper atoms) was 13.5.
Commonly assigned U.S. Pat. No. 3,306,875 to Hay generally describes a synthetic method utilizing a tertiary amine-basic cupric salt complex as oxygen-carrying catalyst. Example 11 of this reference demonstrates the preparation of poly(2,6-dimethylphenylene ether) having an intrinsic viscosity of 2.07 dL/g. In this example, the molar ratio of starting material 2,6-dimethylphenol to copper catalyst is 4.05, and the solids content of the reaction mixture is 5.7%.
Commonly assigned U.S. Pat. No. 4,028,341 to Hay generally describes a method of synthesizing poly(phenylene ether) resins wherein the catalyst comprises copper ion, bromide, a secondary diamine and a tertiary amine. Example XIV describes the preparation of a poly(2,6-dimethyl-1,4-phenylene ether) having an intrinsic viscosity of 1.215 dL/g using a molar ratio of phenol to copper of 1100. The methods of this reference are not suitable for large scale manufacturing of polyphenylene ethers due to a variety of factors, including inadequate polymerization rates, irreproducible product molecular weights, decreases in product molecular weight during isolation, and difficulties encountered in product precipitation.
Commonly assigned U.S. Pat. No. 4,092,294 to Bennett, Jr. et al. generally describes a method of synthesizing polyphenylene ethers using a catalyst comprising copper, a secondary diamine, a tertiary amine, a secondary monoamine and a bromine compound. Polyphenylene ethers prepared in the examples exhibited intrinsic viscosities in the range 0.5 to 0.6 dL/g.
U.S. Pat. No. 4,440,923 to Bartmann et al. generally describes a method of producing polyphenylene ethers by reacting a di-ortho-substituted phenol with oxygen in the presence of a copper-amine complex, an activator of a polyvalent alcohol, an alkali or alkaline earth hydroxide, and, optionally, the hydrobromide of a secondary amine. Example 7 in this reference describes the preparation of a poly(2,6-dimethyl-1,4-phenylene ether) with an intrinsic viscosity of 0.72 dL/g using a molar ratio of phenol to copper of 55.0.
A mechanistic study of 2,6-dimethylphenol polymerization by Endres et al. describes the synthesis of polyphenylene ether products with intrinsic viscosities as high as 1.35 dL/g (see G. F. Endres, A. S. Hay, and J. W. Eustance,
Journal of Organic Chemistry,
volume 28, pages 1300-1305 (1963)). Procedures from this reference were employed by Smid et al. to synthesize polyphenylene ethers for use in asymmetric hollow fiber membranes (see J. Smid, J. H. M. Albers, and A. P. M. Kusters,
Journal of Membrane Science,
volume 64, pages 121-128 (1991)). However, the procedures are not suitable for large scale manufacturing of polyphenylene ethers for a variety of reasons, including low reaction rates and low fractional yields of the desired C—O coupling.
European Patent Application No. 298,531 A1 to Albers et al. describes a gas separation apparatus with asymmetric hollow fibers comprising high molecular weight poly(2,6-dimethylphenylene ether)s, particularly poly(2,6-dimethylphenylene ether)s having weight average molecular weights of 10
5
to 5×10
6
. No guidance is provided for preparing poly(2,6-dimethylphenylene ether)s in this molecular weight range.
U.S. Pat. No. 5,348,569 to Bikson et al. describes modified poly(phenylene ether) based membranes for enhanced fluid separation. Poly(phenylene ether) resins were purified to remove low molecular weight components (leaving a number average molecular weight greater than 25,000), then sulfonated to yield the materials employed in the gas separation membrane.
There remains a need for an economical and readily scalable process to directly afford high molecular weight poly(arylene ether) resins suitable for use in such applications as gas separation.
BRIEF SUMMARY OF THE INVENTION
Poly(arylene ether) resins having intrinsic viscosities not less than 0.8 dL/g are conveniently and economically produced in a process comprising:
reacting oxygen with a phenol in the presence of a metal complex catalyst comprising a catalyst metal to form a poly(arylene ether), wherein the reaction is conducted in an organic solvent, the phenol concentration is about 5 to about 15 weight percent of the sum of phenol and solvent, the molar ratio of catalyst metal to the phenol is about 1:100 to about 1:200, and the phenol has the formula
wherein X is selected from the group consisting of hydrogen, chlorine, bromine and iodine; Q is a monovalent substituent selected from the group consisting of hydrogen, hydrocarbon radicals having from 1 to about 8 carbon atoms, halohydrocarbon radicals having from 2 to about 8 carbon atoms and at least two carbon atoms between the halogen atom and the phenol nucleus, hydrocarbonoxy radicals having from 1 to about 8 carbon atoms, and halohydrocarbonoxy radicals having from 1 to about 8 carbon atoms and at least two carbon atoms between the halogen atom and the phenol nucleus; Q′, Q″ and Q′″ are, independently, selected from the same group as Q and in addition halogen with the proviso that Q, Q′, Q″ and Q′″ are all free of a tertiary alpha carbon atom;
recovering the catalyst metal using an aqueous sequestrant solution; and
isolating the poly(arylene ether) by precipitation, wherein the isolated poly(arylene ether) has an intrinsic viscosity greater than about 0.8 dL/g measured at 25° C. in chloroform.
DETAILED DESCRIPTION OF THE INVENTION
A method of preparing poly(arylene ether)s comprises:
reacting oxygen with a phenol in the presence of a metal complex catalyst comprising a catalyst metal to form a poly(arylene ether), wherein the reaction is conducted in an organic solvent, the phenol concentration is about 5 to about 15 weight percent of the sum of phenol and solvent, the molar ratio of catalyst metal to the phenol is about 1:100 to about 1:200, and the phenol has the formula
wherein X is selected from the group consisting of hydrogen, chlorine, bromine and iodine; Q is a monovalent substituent selected from the group consisting of hydrogen, hydrocarbon radicals having from 1 to about 8 carbon atoms, halohydrocarbon radicals having from 2 to about 8 carbon atoms and at least two carbon atoms between the halogen atom and the phenol nucleus, hydrocarbonoxy radicals having from 1 to about 8 carbon atoms, and halohydrocarbonoxy radicals having from 1 to about 8 carbon atoms and at least two carbon atoms between the halogen atom and the phenol nucleus; Q′, Q″ and Q′″ are, independently, selected from the same group as Q and in addition halogen with the proviso that Q, Q′, Q″ and Q′″ are all free of a tertiary alpha carbon atom;
recovering the catalyst metal using an aqueous sequestrant solution; and;
isolating the poly(arylene ether) by
Braat Adrianus J. F. M.
Ingelbrecht Hugo G. E.
General Electric Company
Truong Duc
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