Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Reexamination Certificate
2002-04-26
2004-06-29
Truong, Duc (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
C528S205000, C528S208000, C528S211000, C528S422000, C528S485000, C528S486000, C528S488000, C525S330900
Reexamination Certificate
active
06756470
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to polyaromatic ethers, aromatic ether oligomers, phthalonitrile monomers containing aromatic ether oligomer spacers, thermosets made from such phthalonitrile monomers, and processes for making the same.
2. Description of the Prior Art
Phthalonitrile monomers and phthalonitrile polymers of various types are described generally in U.S. Pat. No. 3,730,946, U.S. Pat. No. 3,763,210, U.S. Pat. No. 3,787,475, U.S. Pat. No. 3,869,499, U.S. Pat. No. 3,972,902, U.S. Pat. No. 4,209,458, U.S. Pat. No. 4,223,123, U.S. Pat. No. 4,226,801, U.S. Pat. No. 4,234,712, U.S. Pat. No. 4,238,601, U.S. Pat. No. 4,259,471, U.S. Pat. No. 4,304,896, U.S. Pat. No. 4,307,035, U.S. Pat. No. 4,315,093, U.S. Pat. No. 4,351,776, U.S. Pat. No. 4,408,035, U.S. Pat. No. 4,409,382, U.S. Pat. No. 4,410,676, U.S. Pat. No. 5,003,039, U.S. Pat. No. 5,003,078, U.S. Pat. No. 5,004,801, U.S. Pat. No. 5,132,396, U.S. Pat. No. 5,159,054, U.S. Pat. No. 5,202,414, U.S. Pat. No. 5,208,318, U.S. Pat. No. 5,237,045, U.S. Pat. No. 5,242,755, U.S. Pat. No. 5,247,060, U.S. Pat. No. 5,292,854, U.S. Pat. No. 5,304,625, U.S. Pat. No. 5,350,828, U.S. Pat. No. 5,352,760, U.S. Pat. No. 5,389,441, U.S. Pat. No. 5,464,926, U.S. Pat. No. 5,925,475, U.S. Pat. No. 5,965,268, U.S. Pat. No. 6,001,926, and U.S. Pat. No. 6,297,298, all incorporated herein by reference.
The above references generally teach methods for making and polymerizing phthalonitrile monomers. Such monomers typically have two phthalonitrile groups, one at each end of a connecting spacer chain. The monomers can be cured, where by the cross-linking occurs between cyano groups. These cross-linked networks typically have high thermal and oxidative stability.
Phthalonitrile monomers with aromatic ether oligomeric or polymeric spacers are expected to be useful because they are predicted to have low melting points. Phthalonitrile monomers with a large window between the melting point and the cure temperature are desirable to control the rate of curing and the viscosity during curing.
U.S. Pat. No. 4,259,471 to Keller et al. discloses a phthalonitrile monomer having a polyphenoxy spacer with from 1 to 10 phenyl groups in the spacer chain. The monomer is made by reacting 4-nitrophthalonitrile with an aromatic diol. The aromatic diol is a phenoxy chain with terminal hydroxy groups. The patent states that the aromatic diol can be made by an Ullmann synthesis. However, the patent does not teach how to make the aromatic diol with more than two phenylene groups. It is known in the prior art that an Ullmann synthesis can be used to create a single aromatic ether linkage by reacting a haloaromatic with a hydroxyaromatic in the presence of a stoichiometric amount of a copper complex. There are no known prior reports of the use of an Ullmann synthesis to make an oligomeric or polymeric aromatic ether containing three or more aromatic groups.
U.S. Pat. No. 6,297,298 to Keller et al. recites a phthalonitrile monomer having a polyphenoxy spacer as an embodiment of a general structure. The patent does not disclose any examples of or a process for making this phthalonitrile monomer.
The compound m-bis[m-(m-phenoxyphenoxy)phenoxy]benzene is a commercially available aromatic ether oligomer. There are no other known prior reports of other aromatic ether oligomers
Marcoux et al.,
J. Am. Chem. Soc
. 1997, 119, 10539, discloses a method for synthesizing a diaryl ether from a haloaromatic and a phenol using a catalytic amount of a copper complex and cesium carbonate. This method does not require the harsh conditions of an Ullmann synthesis such as high temperatures. The method also avoids the use of a stoichiometric amount of copper. The publication does not disclose any use of the method to make an aromatic ether oligomer.
There is need for process to make an aromatic ether oligomer and a polyaromatic ether. The resulting aromatic ether oligomer can then be reacted with a nitrophthalonitrile to make a phthalonitrile monomer. The phthalonitrile monomer can then be cured to form a thermoset.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a polyaromatic ether and an aromatic ether oligomer.
It is a further object of the invention to provide a phthalonitrile monomer with an aromatic ether oligomer spacer.
It is a further object of the invention to provide a thermoset made by curing a phthalonitrile monomer with an aromatic ether oligomer spacer.
These and other objects of the invention are accomplished by process of preparing a polyaromatic ether comprising the formula:
wherein Ar is an independently selected divalent aromatic radical, comprising the step of reacting a dihydroxyaromatic with a dihaloaromatic; wherein neither the dihydroxyaromatic nor the dihaloaromatic is present in an excess amount; and wherein the reaction is performed in the presence of a copper compound and cesium carbonate.
The invention further comprises a process of preparing the above polyaromatic ether comprising the step of reacting a halohydoxyaromatic in the presence of a copper compound and cesium carbonate.
The invention further comprises a process of preparing an aromatic ether oligomer comprising the formula:
wherein Ar is an independently selected divalent aromatic radical; wherein T is a terminating group independently selected from the group consisting of —OH and —X; wherein X is independently selected from the group consisting of Br and I; and wherein n is an integer greater than or equal to 1; comprising the step of reacting a dihydroxyaromatic with a dihaloaromatic; wherein the reaction is performed in the presence of a copper compound and cesium carbonate; and wherein either the dihydroxyaromatic or the dihaloaromatic is present in an excess amount.
The invention further comprises a process of preparing a phthalonitrile monomer comprising the formula:
wherein Ar is an independently selected divalent aromatic radical; and wherein n is an even integer greater than or equal to 2; comprising the step of reacting a 3- or 4-nitrophthalonitrile with a hydroxy-terminated aromatic ether oligomer.
The invention further comprises a process of preparing a thermoset comprising the step of curing a mixture comprising the above phthalonitrile monomer.
The invention further comprises the polyaromatic ether, aromatic ether oligomer, phthalonitrile monomer, and thermoset described above.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The synthesis of the thermoset is performed in three steps. First, a dihydroxyaromatic is reacted with a dihaloaromatic to form an aromatic ether oligomer. Second, the aromatic ether oligomer is reacted with a 3- or 4-nitrophthalonitrile to make a phthalonitrile monomer. Third, the phthalonitrile monomer is cured to make a thermoset. Any reference to an ingredient can refer to one embodiment of such ingredient or a combination of one or more embodiments. All polymeric and oligomeric structures claimed include all configurations, isomers, and tacticities of the polymers and oligomers within the scope of the claims. The term “oligomer” as used herein does not place an any upper or lower limit on the chain length of the oligomer.
1. Formation of the Aromatic Ether Oligomer
In the first step the dihydroxyaromatic is reacted with the dihaloaromatic to form the polyaromatic ether or the aromatic ether oligomer as shown in formula 1.
The halo groups, X, on the dihaloaromatic can be iodo or bromo or a combination thereof. Each Ar is an independently selected divalent aromatic radical. The divalent aromatic radical can be any divalent radical with or without substituents containing one or more fused aromatic rings, one or more non-fused aromatic rings with or without intervening functional groups, or combinations thereof wherein the radical sites are on the same or different aromatic rings. 1,3-Phenylene and 1,4-phenylene are typical divalent aromatic radicals. The divalent aromatic radical can be different in each reactant. The divalent aromatic radical can also be different in multiple embodimen
Dominguez Dawn D.
Keller Teddy M.
Grunkemeyer Joseph T.
Karasek John J.
The United States of America as represented by the Secretary of
Truong Duc
LandOfFree
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