Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Reexamination Certificate
1999-12-08
2001-07-03
Boykin, Terressa M. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
C528S198000
Reexamination Certificate
active
06255437
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a polycarbonate prepared using 2,2,4,4-tetramethyl-1,3-cyclobutanediol.
BACKGROUND
Poly (2,2,4,4-tetramethyl-1,3-cyclobutylene carbonate) is useful as a molding resin, possesses excellent weatherability for outdoor applications, and possesses low birefringence needed for compact discs. Polycarbonates are most commonly made by using phosgene. However, use of the highly toxic phosgene and organic solvents, as well as the expense of solution polymerization methods, has prompted chemists to find other methods of producing polycarbonates.
Melt preparation of poly(2,2,4,4-tetramethyl-1,3-cyclobutylene carbonate) is challenging because it has a melting point much higher than its decomposition temperature. At decomposition temperatures, poly(2,2,4,4tetramethyl-1,3-cyclobutylene carbonate) ring-opens to produce carbon dioxide and 2-methyl-4,4-dimethyl-2-pentenal.
U.S. Pat. No. 5,171,830 discloses a melt method for making polyalkylene carbonates by reacting a glycol having at least 4 carbon atoms separating the hydroxyl groups with a diester of carbonic acid in the presence of a catalyst. This excludes 2,2,4,4-tetramethyl-1,3-cyclobutanediol, which has only 3 carbons separating the hydroxyl groups. Glycols which possess hydroxyl groups that are separated by 2 or 3 carbon atoms present a special problem for polycarbonate preparation by methods known in the art. These glycols tend to cyclize to produce five and six membered cyclic carbonates, which tend to vaporize.
Defensive Publication T873,016 discloses a method of producing low molecular weight poly(2,2,4,4-tetramethyl-1,3-cyclobutylene carbonate) by self-condensing the diethyl ester of 2,2,4,4-tetramethyl-1,3-cyclobutanediol. Defensive Publication T873,016 also discloses a method of reacting the glycol using diphenyl carbonate, which results in the formation of a colored polymer.
Methods for producing polycarbonates disclosed in the art produce low molecular weight polycarbonates when 2,2,4,4-tetramethyl-1,3-cyclobutanediol is employed as the glycol component. Japanese Patent 62-155370 discloses a process of reacting dialkyl carbonates with a glycol in the presence of a titanium catalyst. U.S. Pat. No. 3,022,272 discloses a process of reacting a carbonate, excluding dimethyl carbonate, with a glycol. Diphenyl carbonate is disclosed as the preferred carbonate, even though aromatic carbonates produce colored polymers. Lastly, U.S. Pat. No. 3,313,777 discloses a method of producing low molecular weight poly(2,2,4,4-tetramethyl-1,3-cyclobutylene carbonate) by reacting dibutyl carbonate with the glycol. Moreover, the resultant polymer solidified in the reaction vessel, requiring very impractical recovery measures to be taken.
In light of the above, it would be desirable to have a polycarbonate prepared from 2,2,4,4-tetramethyl-1,3-cyclobutanediol and dimethyl carbonate. None of the references discussed above disclose the efficient an method for preparing poly(2,2,4,4-tetramethyl-1,3-cyclobutylene carbonate).
SUMMARY OF THE INVENTION
In accordance with the purpose(s) of this invention, as embodied and broadly described herein, this invention, in one aspect, relates to a polycarbonate represented by the formula (I):
wherein R
1
is H, alkyl, aryl,
R
2
is alkyl, aryl, or alkoxy, R
3
and R
4
are alkyl or aryl having 1 to 20 carbons, and n is from 100 to 100,000.
In a preferred embodiment of the invention, R
1
is
R
2
is a branched or unbranched alkyl or aryl group having 1-20 carbons, and R
3
is methyl.
Advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
DETAILED DESCRIPTION OF THE INVENTION
The present invention may be understood more readily by reference to the following detailed description of preferred embodiments of the invention and the Examples included therein.
Before the present methods are disclosed and described, it is to be understood that this invention is not limited to specific synthetic methods or to particular formulations, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.
In this specification and in the claims which follow, reference will be made to a number of terms which shall be defined to have the following meanings:
The singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise.
“Optional” or “optionally” means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.
The term “intermediate” is defined as methyl carbonate-terminated oligomers formed by the condensation reaction between a glycol and dimethyl carbonate.
The term alkoxy, as used herein, and unless otherwise specified, refers to a moiety of the structure —O-alkyl.
The term aryl, as used herein, and unless otherwise specified, refers to benzyl, phenyl, biphenyl, or naphthyl.
The term alkyl, as used herein, and unless otherwise specified, refers either straight chained or branched chain radicals, such as the methyl, ethyl, n-propyl, iso-propyl, 1-n-butyl, 2-n-butyl, iso-butyl, tert-butyl, n-pentyl, iso-pentyl, neo-pentyl and tert-pentyl radical; hexyl radicals, such as the n-hexyl radical; heptyl radicals, such as the n-heptyl radical; octyl radicals, such as the n-octyl radical and iso-octyl radicals, such as the 2,2,4-tri-methylpentyl radical; nonyl radicals, such as the n-nonyl radical; decyl radicals, such as the n-decyl radical; dodecyl radicals, such as the n-dodecyl radical; and octadecyl radicals, such as the n-octadecyl radical; cycloalkyl radicals, such as the cyclopentyl, cyclohexyl and cycloheptyl radical and methylcyclohexyl radicals.
The alkyl groups preferably include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, aryl, hexyl, and the like.
The alkyl groups described herein, either alone or with the various substituents defined hereinabove are preferably lower alkyl containing from one to six carbon atoms in the principal chain and up to 15 carbon atoms.
The aryl moieties described herein, either alone or with various substituents, contain from 6 to 15 carbon atoms and include phenyl or phenylmethyl. Substituents include alkanoxy, protected hydroxy, halogen, alkyl, aryl, alkenyl, acyl, acyloxy, nitro, amino, amido, etc. Benzyl is the more preferred aryl.
In accordance with the purpose(s) of this invention, as embodied and broadly described herein, this invention, in one aspect, relates to a polycarbonate represented by the formula (I):
wherein R
1
is H, alkyl, aryl,
R
2
is alkyl, aryl, or alkoxy, R
3
and R
4
are alkyl or aryl having 1 to 20 carbons, and n is from 100 to 100,000.
In one embodiment of the invention, R
1
and R
2
independently represent a branched or unbranched alkyl group having 1 to 4 atoms.
In another embodiment of the invention, R
1
is H and R
2
is a branched or unbranched alkyl group having 1-carbons or aryl group having 1-20 carbons.
In yet another embodiment of the invention, R
1
and R
2
independently represent an aryl group having 1 to 20 carbons.
In yet another embodiment of the invention, wherein R
1
is
R
2
is a branched or unbranched alkyl or aryl group having 1-20 carbons, and R
3
is methyl. In this embodiment, it is preferred that R
2
and R
3
are methyl.
In yet another embodiment of the invention, wherein R
1
is
R
2
is methyl and R
4
is a benzyl group.
The polycarbonate of the invention may be made by any process known in the art,
Darnell William Ronald
Fleischer Jean Carroll
Walker Theodore Roseuelt
Boshears B. J.
Boykin Terressa M.
Eastman Chemical Company
Gwinnell H. J.
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