Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Reexamination Certificate
1997-12-23
2001-01-30
Mosley, Terressa (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
Reexamination Certificate
active
06180748
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to a process for deactivating a polymerization catalyst used for the preparation of polycarbonates.
BACKGROUND
Poly(2,2,4,4-tetramethyl-1,3-cyclobutylene carbonate), the polycarbonate of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, has been formed by melt polymerization processes employing basic alkali metal catalysts. But the polycarbonate is somewhat thermally unstable due to the presence of basic alkali metal catalyst residue.
Various methods of adding acidic material to destroy the basic catalyst residues which remain in polycarbonates and cause instability have been reported in the literature. For example, U.S. Pat. No. 3,022,272 discloses that materials such as aromatic sulfonic acid, organic acid halides and chlorocarbonates, dialkyl sulfates, and acid salts of inorganic acids such as ammonium sulfate are useful “catalyst killers.”
The acidic materials that have been used for this purpose have practical disadvantages. The aromatic sulfonic acids, acid halides and, to a lesser extent, the acid salts of inorganic acids, are corrosive and some, particularly the strong acids such as toluenesulfonic acid, have been found to produce undesirable color in the finished product. The dialkyl sulfates, while not so corrosive, are known to be both toxic and possibly carcinogenic, and the presence of traces of them in the final product would present a problem for the consumer, especially if the plastic was used in food or cosmetic containers.
Another problem with many known deactivation methods is that the catalyst is not completely deactivated. Evidence of remaining active catalyst is shown in U.S. Pat. No. 3,022,272 which discloses that, after deactivation of the catalysts, the interesterification can be further continued to a limited extent in order to further increase the molecular weight of the polymer.
U.S. Pat. No. 2,210,617 discloses a process for preparing a polycarbonate in the presence of an alkali metal catalyst. After polymerization, the excess alkali metal is removed by washing with a strong acid such as hydrochloric acid. The polymerization is then completed by further heating under vacuum.
U.S. Defensive Publication T873,016 discloses removal of basic alkali metal catalyst residues from poly(2,2,4,4-tetramethyl-1,3-cyclobutylene carbonate) in the solid state or in solution. The process therein is conducted by contacting the polymer with an acidic organic compound having solvent power and an ionization constant of about 2×10
−1
to 2.5×10
−6
, followed by extraction either with the acid, or by dissolving the polymer in a water-immiscible solvent and extracting the solution with water.
In light of the above, it is highly desirable to provide a process for increasing the thermal stability of poly(2,2,4,4-tetramethyl-1,3-cyclobutylene carbonate) containing active alkali metal catalysts by completely deactivating the catalyst residue contained in the polymer. It would be especially desirable to provide a catalyst deactivation method which does not require the use of strongly acidic, corrosive, or volatile materials, nor washing or extraction of the catalyst from the polymer.
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 process of deactivating a polycarbonate, comprising admixing the polycarbonate containing an active alkali metal catalyst residue with an effective amount of a deactivator represented by a formula selected from the group consisting of:
wherein,
R
1
-R
7
and R
9
are, independently, hydrogen; aliphatic hydrocarbon of from 1 to 20 carbon atoms; substituted aromatic hydrocarbon of from 6 to 20 carbon atoms; or unsubstituted aromatic hydrocarbon of from 6 to 20 carbon atoms;
R
8
and R
10
-R
13
are, independently, substituted or unsubstituted aromatic hydrocarbon of from 6 to 20 carbon atoms; or aliphatic hydrocarbon of from 1 to 20 carbon atoms;
A is a tetrafunctional hydrocarbon group; and
x is an integer of from 1 to 3,
at a temperature and time sufficient to deactivate the alkali metal catalyst to form a deactivated polycarbonate, wherein the deactivated catalyst is not removed from the deactivated polycarbonate.
The invention further relates to a process of deactivating a polycarbonate, comprising admixing the polycarbonate containing an active alkali metal catalyst residue with a phosphorous compound at a temperature and time sufficient to deactivate the alkali metal catalyst to form a deactivated polycarbonate, wherein the deactivated catalyst is not removed from the deactivated polycarbonate.
The invention further relates to a process of deactivating a polycarbonate, comprising:
(a) admixing
i) a solid state polycarbonate comprising an active alkali metal catalyst; and
ii) a deactivator having the formula (Ia), (Ib), (Ic), (II), or (IIIa); and
(b) heating the admixture of step (a) at a temperature sufficient to melt the admixture and deactivate the alkali metal catalyst to produce a deactivated polycarbonate, wherein the deactivated catalyst is not removed from the deactivated polycarbonate.
The invention further relates to a process of making a deactivated polycarbonate, comprising:
(a) polymerizing a first polycarbonate in the presence of an alkali metal catalyst to produce an activated polycarbonate; and
(b) admixing the activated polycarbonate with an effective amount of a deactivator represented by a formula selected from the group consisting of:
wherein,
R
1
-R
7
and R
8
are, independently, hydrogen; aliphatic hydrocarbon of from 1 to 20 carbon atoms; substituted aromatic hydrocarbon of from 6 to 20 carbon atoms; or unsubstituted aromatic hydrocarbon of from 6 to 20 carbon atoms;
R
8
and R
10
-R
13
are, independently, substituted or unsubstituted aromatic hydrocarbon of from 6 to 20 carbon atoms; or aliphatic hydrocarbon of from 1 to 20 carbon atoms;
A is a tetrafunctional hydrocarbon group; and
x is an integer of from 1 to 3,
at a temperature and time sufficient to deactivate the alkali metal catalyst to form a deactivated polycarbonate, wherein the deactivated catalyst is not removed from the deactivated polycarbonate.
The invention further relates to a polycarbonate produced by the processes described above.
The invention further relates to a polycarbonate comprising a deactivated alkali metal catalyst, wherein the deactivated metal catalyst is a salt produced by the reaction between a deactivator and an alkali metal catalyst.
The invention further relates to a process of deactivating poly(2,2,4,4-tetramethyl-1,3-cyclobutylene carbonate) comprising reacting poly(2,2,4,4-tetramethyl-1,3-cyclobutylene carbonate) containing active alkali metal catalyst residue with an effective amount of a deactivator represented by a formula selected from the group consisting of:
wherein R is independently selected from the group consisting of hydrogen, aliphatic hydrocarbons having 1 to 20 carbon atoms, substituted aromatic hydrocarbons containing 6 to 20 carbon atoms, unsubstituted aromatic hydrocarbons containing 6 to 20 carbon atoms, and mixtures thereof; R′ is selected from the group consisting of substituted aromatic hydrocarbons containing 6 to 20 carbon atoms, and unsubstituted aromatic hydrocarbons containing 6 to 20 carbon atoms;
R″ is independently selected from the group consisting of hydrogen, substituted aromatic hydrocarbons containing 6 to 20 carbon atoms, and unsubstituted aromatic hydrocarbons containing 6 to 20 carbon atoms;
A is a tetrafunctional hydrocarbon group;
x is 1 to 3; and
y is the sum of (3−x)
at a temperature and time sufficient to form a deactivated polycarbonate.
Additional 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 under
Darnell William R.
Fleischer Jean C.
Walker Theodore R.
Boshears Betty J.
Eastman Chemical Company
Gwinnell Harry J.
Mosley Terressa
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