U.S. patent application number 09/895990 was filed with the patent office on 2002-03-14 for polyester polycondensation with catalyst and a catalyst enhancer.
Invention is credited to Chen, Bin, Dowling, Conor M., Seshadri, Sri R..
Application Number | 20020032300 09/895990 |
Document ID | / |
Family ID | 25405424 |
Filed Date | 2002-03-14 |
United States Patent
Application |
20020032300 |
Kind Code |
A1 |
Dowling, Conor M. ; et
al. |
March 14, 2002 |
Polyester polycondensation with catalyst and a catalyst
enhancer
Abstract
The present invention is based upon the discovery that
nontitanyl oxalates can enhance the catalytic functionality of
titanyl oxalate catalysts. This invention provides a novel
catalytic composition containing a titanyl oxalate catalyst and a
metallic oxalate catalyst enhancer and optionally containing a
metallic cocatalyst such as an antimony based catalyst. A
synergistic relationship has been discovered between titanyl
oxalate catalyst and the catalyst enhancer. A synergistic
relationship has also been discovered between the titanyl oxalate
catalyst, catalyst enhancer and a metallic cocatalyst such as
antimony oxide or antimony triacetate. Also provided is an improved
process of producing polyester by the polycondensation of polyester
forming reactants in the presence of a catalytically effective
amount of a polycondensation catalyst, wherein the improvement
comprises utilizing, as the polycondensation catalyst, the novel
catalyst composition containing a titanyl oxalate such as lithium
titanyl oxalate and a catalyst enhancer such as a nontitanyl
metallic oxalate like lithium oxalate and optionally containing a
metallic catalyst such as antimony oxide or antimony triacetate.
The improved process produces an improved polyester having lower
acetaldehyde numbers and good color. The titanyl oxalate/catalyst
enhancer composition can be used as a polycondensation catalyst in
combination with other catalysts to achieve synergistic catalytic
activity. Preferred is a combination of lithium or potassium
titanyl oxalate, Li.sub.2 or K.sub.2TiO(C.sub.2O.sub.4).sub.2,
lithium or potassium oxalate, Li.sub.2 or
K.sub.2(C.sub.2O.sub.4).sub.2 with antimony oxide or antimony
triacetate or antimony trisglycoxide.
Inventors: |
Dowling, Conor M.; (Blue
Bell, PA) ; Chen, Bin; (Wayne, PA) ; Seshadri,
Sri R.; (Holland, PA) |
Correspondence
Address: |
Nicholas J. DeBenedictis
ATOFINA Chemicals, Inc.
Patent Department - 26th Floor
2000 Market Street
Philadelphia
PA
19103-3222
US
|
Family ID: |
25405424 |
Appl. No.: |
09/895990 |
Filed: |
June 29, 2001 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
09895990 |
Jun 29, 2001 |
|
|
|
09747115 |
Dec 22, 2000 |
|
|
|
6258925 |
|
|
|
|
60175006 |
Jan 7, 2000 |
|
|
|
Current U.S.
Class: |
528/272 ;
502/152; 502/153; 502/154; 502/157; 502/170; 502/171 |
Current CPC
Class: |
C08G 63/83 20130101;
B01J 2531/0205 20130101; C08G 63/82 20130101; C08G 63/84 20130101;
B01J 2531/46 20130101; C08G 63/87 20130101; B01J 31/2239 20130101;
B01J 31/26 20130101; B01J 2531/10 20130101; C08G 63/85 20130101;
B01J 31/04 20130101; B01J 2531/20 20130101; B01J 2531/52 20130101;
B01J 21/063 20130101 |
Class at
Publication: |
528/272 ;
502/170; 502/152; 502/153; 502/154; 502/157; 502/171 |
International
Class: |
C08G 063/02; B01J
031/00 |
Claims
We claim:
1. A catalyst combination comprising a titanyl oxalate of the
formula X.sub.mTiO(C.sub.2O.sub.4).sub.2(H.sub.2O).sub.n, where
each X is independently selected from the group consisting of: H,
Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, and ammonium m=1 or 2 and a
catalyst enhancer comprising oxalic or carboxylic acid containing 1
to 26 carbon atoms or their corresponding Li, Na, K, Rb, Cs, Be,
Mg, Ca, Sr, Ba or ammonium salt.
2. An enhanced catalyst comprising a titanium compound of the
formula X.sub.mTiY.sub.o X is selected from the group consisting
of: H, Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba and ammonium, m=1 or
2, Y is a ligand of the formula C.sub.aH.sub.bO.sub.c, a=0 to 30,
b=0 to 60, and c=1 to 10; o=2, 3, 4, and a catalyst enhancer of an
oxalic acid or its corresponding Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr,
Ba or ammonium salt.
3. The catalyst of claim 1 further comprising an additional
catalyst enhancer of a compound containing antimony or
germanium.
4. The catalyst of claim 2 further comprising an additional
catalyst enhancer of a compound containing antimony or
germanium
5. An enhanced catalyst combination comprising an antimony
containing catalyst and a catalyst enhancer of oxalic acid or its
corresponding Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba or ammonium
salt.
6. An enhanced catalyst combination comprising a germanium
containing catalyst and a catalyst enhancer of oxalic acid or its
corresponding Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, B a or ammonium
salt.
7. The catalyst combination of any of claims 1 through 4 wherein
the concentration of titanium is from 0.1 to 100 ppm.
8. The combination of claim 1 wherein the catalyst enhancer is
selected from the group consisting of lithium titanyl oxalate,
potassium titanyl oxalate and ammonium titanyl oxalate.
9. The combination of claim 2 wherein the catalyst enhancer is
selected from the group consisting of lithium oxalate,
Li.sub.2C.sub.2O.sub.4, sodium oxalate, Na.sub.2C.sub.2O.sub.4,
potassium oxalate, K.sub.2C.sub.2O.sub.4, rubidium oxalate,
Rb.sub.2C.sub.2O.sub.4, and cesium oxalate,
Cs.sub.2C.sub.2O.sub.4.
10. The combination of claim 1 wherein the titanyl oxalate is
selected from the group consisting of metallic titanyl oxalates of
the formula M.sub.2TiO(C.sub.2O.sub.4).sub.2(H.sub.2O).sub.n
wherein each M is independently selected from potassium, lithium,
sodium, cesium and a nonmetallic cation such as ammonium.
11. The combination of claim 1 wherein the catalyst enhancer is
lithium oxalate and the titanyl oxalate is lithium titanyl
oxalate.
12. The combination of claim 5 wherein the antimony containing
catalyst is selected from the group consisting of antimony
triacetate, Sb(CH.sub.3COO).sub.3, antimony trisglycoxide
Sb.sub.2(OCH.sub.2CH.sub.2O- ).sub.3, antimony oxide
(Sb.sub.2O.sub.3).
13. The combination of claim 1, wherein the catalyst enhancer
oxalate comprises from 0.1 part to 80 parts by weight of the
combination based upon the weight of titanium.
14. The combination of claim 2, wherein the catalyst enhancer
comprises from 0.1 part to 80 parts by weight of the combination
based upon the weight of titanium.
15. The combination of claim 5, wherein the catalyst enhancer
comprises from 0.1 part to 80 parts by weight of the combination
based upon the weight of antimony.
16. The combination of claim 6, wherein the catalyst enhancer
comprises from 0.1 part to 80 parts by weight of the combination
based upon the weight of germanium.
17. The combination of claim 3, wherein the enhancer comprises from
0.1 part to 80 parts by weight of the composition.
18. The combination of claim 4, wherein the enhancer comprises from
0.1 part to 80 parts by weight of the composition.
19. An improved process of producing a polyester by the catalyzed
polycondensation of polyester forming reactants in the presence of
a polycondensation catalyst, wherein the improvement comprises
utilizing as the catalyst the combination of claim 1.
20. An improved process of producing a polyester by the catalyzed
polycondensation of polyester forming reactants in the presence of
a polycondensation catalyst, wherein the improvement comprises
utilizing as the catalyst the combination of claim 2.
21. An improved process of producing a polyester by the catalyzed
polycondensation of polyester forming reactants in the presence of
a polycondensation catalyst, wherein the improvement comprises
utilizing as the catalyst the combination of claim 5.
22. An improved process of producing a polyester by the catalyzed
polycondensation of polyester forming reactants in the presence of
a polycondensation catalyst, wherein the improvement comprises
utilizing as the catalyst the combination of claim 6.
23. An improved process of producing a polyester by the catalyzed
polycondensation of polyester forming reactants in the presence of
a polycondensation catalyst, wherein the improvement comprises
utilizing as the catalyst the combination of claim 7.
24. An improved process of producing a polyester by the catalyzed
polycondensation of polyester forming reactants in the presence of
a polycondensation catalyst, wherein the improvement comprises
utilizing as the catalyst the combination of claim 9.
25. An improved polyester containing the combination of claim
1.
26. The improved polyester of claim 24 wherein the catalyst
combination comprises from 0.1 part to 80 parts per million of the
polyester.
27. The improved polyester produced by the process of claim 19.
28. An improved polyester containing the composition of claim
2.
29. The improved polyester of claim 24 wherein the polyester is
polyethylene terephthalate.
30. The combination of claim 1 dissolved in a solvent 31. The
combination of claim 30 wherein the solvent is ethylene glycol.
Description
[0001] REFERENCE TO RELATED APPLICATION
[0002] This application is a continuation-in-part of U.S. patent
application Ser. No. 09/747,115, filed Dec. 22, 2000, which claims
priority of U.S. Provisional Application No. 60/175,006, filed Jan.
7, 2000, which disclosures are incorporated herein by
reference.
BACKGROUND OF THE INVENTION
[0003] This invention relates to synergistic combinations of
titanium containing catalysts and catalyst enhancers of carboxylic
acid or oxalic acid or their Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba
and ammonium salts that are useful for manufacturing polyesters.
The synergistic combination of the titanium containing catalysts
with a catalyst enhancer such as an oxalic acid, an oxalic acid
salt or a carboxylic acid or a carboxylic acid salt provides fast
reactions with improved properties such as reduced acetaldehyde
content and good color properties for the resulting polyester at
substantially reduced catalyst levels.
DESCRIPTION OF THE PRIOR ART
[0004] Polycondensation reactions that produce polyesters require
an extremely long period of time that is significantly reduced by a
suitable catalyst. Various types of catalysts are used to shorten
the reaction time. For example, antimony trioxide antimony
triacetate and antimony trisglycoxide are generally used as
polycondensation catalysts.
[0005] Titanyl oxalate compounds have been suggested as catalysts
for polycondensation reactions to produce polyesters. However,
titanyl oxalate catalysts when used as polycondensation catalysts
for polyesters have caused color problems in the resulting
polyester.
[0006] Polyesters are obtained by esterification, ester interchange
or polycondensation of dibasic acids such as terephthalic acid and
isophthalic acid or esters thereof, functional derivatives of acid
chlorides and glycols such as ethylene glycol and tetramethylene
glycol or oxides thereof and functional derivatives of carbonic
acid derivatives. In this case, a single polyester is obtained when
one dibasic acid component and glycol component are used. Mixed
copolyesters can be obtained when at least two or more types of
dibasic acid component and glycol component are mixed, esterified
or subjected to ester interchange and then subjected to
polycondensation. When a single polyester or two or more initial
polycondensates of a mixed copolyester are subjected to
polycondensation, an ordered polyester is obtained. In this
invention, the term polyester is a general designation for these
three types.
[0007] Prior literature has disclosed titanyl oxalate compounds for
use as polycondensation catalysts for polyesters. The titanyl
oxalate compounds disclosed include potassium titanyl oxalate,
ammonium titanyl oxalate, lithium titanyl oxalate, sodium titanyl
oxalate, calcium titanyl oxalate, strontium titanyl oxalate, barium
titanyl oxalate, zinc titanyl oxalate and lead titanyl titanate.
However, based upon the examples in such literature references,
only potassium and ammonium titanyl oxalate have actually been used
to catalyze the polyester forming reaction. See for example
Japanese Patent Publication 42-13030, published on Jul. 25, 1967.
European Patent application EP 0699700 A2 published Mar. 6, 1996
assigned to Hoechst and entitled "Process for production of
Thermostable, Color-neutral, Antimony-Free Polyester and Products
Manufactured From It" discloses the use as polycondensation
catalyst, however only potassium titanyl oxalate and titanium
isopropylate were used for such a catalyst, and, while improved
color and antimony free polyester are disclosed, cobalt or optical
brighteners were also employed. Other patents have disclosed
potassium titanyl oxalate as a polycondensation catalyst for making
polyester such as U.S. Pat. No. 4,245,086, inventor Keiichi Uno et
al., Japanese Patent JP 06128464, Inventor Ishida, M. et al. U.S.
Pat. No. 3,951,886, entitled "Process of Producing Polyester Resin"
of Hideo, M. et al, at column 3, line 59 to column 4, line 10,
contains a disclosure of titanyl oxalate catalysts for polyesters
including a listing of many types of titanyl oxalate catalyst.
However, only potassium titanyl oxalate and ammonium titanyl
oxalate were used in the examples and lithium titanyl oxalate was
not even listed among their preferred titanyl oxalate
catalysts.
[0008] Titanium based catalysts have shown very high
polycondensation activity, however; the resulted polyesters are
yellowish color which will limit their applications. Therefore,
prior art activity has been directed towards the development of
modified titanium catalysts. Titanium compounds are not a good sole
catalyst. Ti requires a cocatalysts or modifiers/promoters to form
composite catalyst. Titanium compounds in the general formula of
Ti(OR).sub.4, Ti.sup.(III)Ti.sup.(IV).sub.yO.sub.(3+4y- )/2,
RO[Ti(OR).sub.2O].sub.nR have been widely claimed by others.
Cocatalysts or modifiers/promoters, such as antimony compounds, tin
compounds, zirconium compounds, silicon compounds, cobalt compound,
aluminum compounds, alkali metal compounds, rare earth metal
compounds, magnesium compounds, germanium compounds, zinc
compounds, lanthanide series compounds, phosphorus compounds,
halides, sulfur containing compounds, ammonia hydroxide, and
amines, have been claimed together with Ti compounds.
[0009] U.S. Pat. No. 6,166, 170, E.I. du Pont de Nemours and
Company, issued on Dec. 26, 2000 discloses a catalyst composition
of a titanium compound, a complexing agent, and an aqueous solution
of hypophosphorous acid or a salt. The titanium compound has a
general formula, Ti(OR).sub.4, combined with a zirconium compound,
Zr(OR).sub.4. The complex agents are hydroxycarboxylic acids,
alkanolamines, aminocarboxylic acids and their combinations of two
or more.
[0010] U.S. Pat. No. 6,066,714, E.I. du Pont de Nemours and
Company, issued on May 23, 2000, discloses an organic titanium
compound, a phosphorus compound, an amine, and a solvent as a
catalyst. The organic compound is Ti(OR).sub.4. The phosphorus
compound is either (RO).sub.x(PO)(OH).sub.3-x or
(RO).sub.y(P.sub.2O.sub.3)(OH).sub.4-y. The amine is a tertiary
amine. Aluminum, cobalt, antimony compounds and their combination
were claimed as cocatalysts.
[0011] U.S. Pat. No. 6,034,203, E.I. du Pont de Nemours and
Company, issued on Mar. 7, 2000, discloses a catalytic process that
can be used in oligomerization, polymerization, or
depolymerization. The catalyst has the formula of
M.sub.xTi.sup.(III)Ti.sup.(IV).sub.yO.sub.(x+3+4y)/2, where M is an
alkali metal, such as Li; x and y are numbers greater than or equal
to zero wherein if x equals zero, y is a number less than 1/2.
[0012] U.S. Pat. No. 5,981,690, E.I. du Pont de Nemours and
Company, issued on Nov. 9, 1999. This patent shows a catalyst
solution containing an organic titanate ligand, organic silicates
and/or zirconates, and phosphorus compounds. Titanium has a formula
of Ti(OR).sub.4; silicon and zirconium compounds can be organic
ortho silicate and zirconate; phosphorus compound can be an organic
phosphonic or phosphinic acid. The solvent used was ethylene
glycol. The catalyst was claimed to be used in fabrication of PET,
PEI, PPT, PBT, and etc.
[0013] U.S. Pat. No. 5,866, 710, Tioxide Specialties Limited,
issued on Feb. 2, 1999 (EP 0 812 818 Al, published on Dec. 17,
1999). A process of preparing an ester is disclosed in the presence
of a catalyst and a base, the product from orthoesters and
condensed orthoesters of zirconium and titanium. The orthoesters
have the formula of M(OR).sub.4; the condensed orthoesters,
RO[M(OR).sub.2O]R; where M is either zirconium or titanium. This
compound can be illustrated as the following,
M(OR).sub.4, if n=1
(RO).sub.3MOM(OR).sub.3, if n=2
(RO).sub.3MOM(OR).sub.2OM(OR).sub.3, if n=3,
[0014] and etc.
[0015] The base can be selected sodium hydroxide, potassium
hydroxide, ammonium hydroxide, sodium carbonate, magnesium
hydroxide and ammonia.
[0016] WO 00/71252 Al, ACMA Limited, published on Nov. 30, 2000. An
esterification catalyst composition was disclosed. The catalyst
contains 1) hydrolysis product of orthoesters and condensed
orthoesters of titanium, zirconium or aluminum; 2) an alcohol
containing at least two hydroxyl groups; 3) an organophosphorus
compound containing at least one P--OH group and a base; 4) a
compound of germanium, antimony or tin.
[0017] WO 99/28033 Al, Tioxide Specialties, published on Jun. 10,
1999. An esterification catalyst composition was disclosed. The
catalyst contains 1) hydrolysis product of orthoesters and
condensed orthoesters of titanium, zirconium or aluminum; 2) an
alcohol containing at least two hydroxyl groups; 3) an
organophosphorus compound containing at least one P-OH group and a
base.
[0018] WO 97/47675 Al, Imperial Chemical Industries PLC, published
on Dec. 18, 1997 also EP 0906356 jointly with E. I. Du Pont De
Nemours & Company Inc. A catalyst is disclosed that is obtained
by reacting an alkyl titanate or alkyl zirconate, an alcohol, a
2-hydroxy carboxylic acid and a base. A cobalt (II) salt, a
phosphorus compound, and a sodium compound were claimed as catalyst
components.
[0019] U.S. Pat. No. 5,874,517, Hoechst Celanese Corporation,
issued on Feb. 23, 1999. An improved low acetaldehyde process was
disclosed. The process utilized mixed Ti and Sb catalysts, however;
potassium titanyl oxalate was suggested as a sole catalyst (col. 6,
lines 21 and 22). Potassium titanyl oxalate as a polycondensation
catalyst was claimed in claims 15 to 20.
[0020] U.S. Pat. No. 5,902,873, General Electric Company, issued on
May 11, 1999; (EP 0 909 774 Al, published on Apr. 21, 1999. A
catalyst composition for the preparation of a polyester on
copolyester is disclosed. The catalyst was composed of 1) a
titanium or zirconium based compound, general formula, Ti(OR).sub.4
or Zr(OR).sub.4, the titanium compounds were water-stable; 2) a
lanthanide series compound, such as lanthanum, samarium, europium,
erbium, terbium, and cerium; 3) a hafnium based compound; 4) a
phosphate-forming compound, such as alkali metal phosphates, alkali
metal phosphates, alkali hypophosphates, and alkali metal
polyphosphates. The combination of the above components was
claimed. In particular, titanium oxide acetylacetonate was claimed
(in claim 3, col. 13, lines 52 and 53).
[0021] U.S. Pat. No. 6,133,404, National Institute of Technology
and Quality, issued on Oct. 17, 2000. A polyester and formation
process is disclosed in the presence of a composite catalyst that
consists of a titanium compound, a zinc compound, an antimony
compound, and a phosphorous compound. This catalyst improved the
rate of polyester production and properties of the polymers, in
particular, biodegradability of the polymer. The titanium compound
has the following general formula,
Ti(OR).sub.4,
(RO).sub.4TiHP(O)(OR').sub.2
ROTi[OM(O)R"].sub.3,
[0022] where M is selected from carbon atom, phosphorous atom,
sulfur atom, and their mixtures.
[0023] The zinc compound can be zinc oxide, zinc acetate, zinc
chloride, zinc hydroxide and their mixtures. An antimony compound
can be selected from antimony chloride, antimony acetate, antimony
oxide and their mixtures. A phosphorous compound can be one of the
following, Phosphoric acid compounds, phosphite compounds,
phosphonic acid compounds, phosphinic acid compound, and their
mixtures.
[0024] U.S. Pat. No. 5,714,570, Korea Institute of Science and
Technology, issued on Feb. 3, 1998. A method for the preparation of
polyester by use of a composite catalyst was revealed. The
composite catalyst consists of a compound of Sb, a compound of Ti,
and a compound of Sn. A compound of Ti has a general formula of
(R.sub.1O).sub.4TiHP(O)(OR.sub.2).sub.2, and Tin compound,
(R.sub.3).sub.2SnX, where X is selected from sulfur, oxygen,
halogen, and a compound containing an ether, a thio or an ester
bond. In particular, potassium titanium oxyoxalate was claimed as
shown in claim 9 (col. 10, lines 52 and 53) other metals (such as
germanium, zinc, manganese, alkali, and alkali earth) compounds
were also claimed. It was disclosed that antioxidant, such as a
hindered phenol, was used in the process.
[0025] U.S. Pat. No. 6,143,837, Sinco Ricerche, S.P.A, issued on
Nov. 7, 2000. A process of preparation of polyester resin utilizing
Ti compound catalyst was disclosed. The activity of Ti catalysts
was shown to be four time higher than S21 catalyst. The titanium
compounds can be selected from the group consisting of alkoxides of
titanium, acetyl acetonates of titanium, dioxide of titanium, and
titanium phosphites. Silica mixed with Ti was used in their
examples (but not claimed). A cobalt compound was suggested to be
used as a colorants.
SUMMARY OF THE INVENTION
[0026] The present invention is based upon the discovery of a
synergistic combination of a titanium containing catalyst and a
catalyst enhancer. This invention provides a novel catalytic
mixture comprising a titanium containing catalyst of the formula
X.sub.mTiO(C.sub.2O.sub.4).sub.2(H.sub- .2O).sub.n, where X is
selected from the group consisting of H, Li, Na, K, Rb, Cs, Be, Mg,
Ca, Sr, Ba, and ammonium, m=1 or 2; and a catalyst enhancer
comprising oxalic acid or carboxylic acid containing 1 to 26 carbon
atoms or their corresponding Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba,
or ammonium salt. Also provided is a novel enhanced catalyst
mixture comprising a titanium compound of the formula
X.sub.mTiY.sub.o with X selected from the group consisting of: H,
Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba and ammonium, m=1 or 2, Y is
a ligand of the formula C.sub.aH.sub.bO.sub.c, a=0 to 30, b=0 to
60, and c=1 to 10; o=2, 3, 4, and a catalyst enhancer of an oxalic
acid or its corresponding Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba or
ammonium salt. An improved three component enhanced catalyst
mixture can be obtained by the addition of second catalyst to
either of the above enhanced catalyst mixtures, the second catalyst
being a compound containing antimony or germanium. Also provided
are enhanced antimony containing catalysts comprising the mixture
of an antimony containing catalyst and an enhancer of an oxalic
acid or its corresponding Li, Na, K, Rb Cs, Be, Mg, Ca, Sr, Ba or
ammonium salt.
[0027] This invention also provides an improved process of
producing polyester by the polycondensation of polyester forming
reactants in the presence of a catalytically effective amount of a
polycondensation catalyst, wherein the improvement comprises
utilizing, as the polycondensation catalyst, the synergistic
combination of a titanium containing catalyst and the catalyst
enhancer described in the preceding paragraph. A novel polyester is
also provided containing the synergistic combination of a titanium
containing catalyst and the catalyst enhancer described in the
preceding paragraph. The improved process produces an improved
polyester having lower acetaldehyde numbers and good color. The
titanium containing catalyst and catalyst enhancer composition can
be used as a polycondensation catalyst in combination with other
catalysts to achieve synergistic catalytic activity.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The production of polyester by polycondensation of polyester
forming reactants is well known to those skilled in the polyester
art. A conventional catalyst for the reaction is antimony oxide.
The present invention is based upon the discovery of a synergistic
relationship between titanium containing catalysts and carboxylic
or oxalate catalyst enhancers. The catalyst and catalyst enhancer
is surprisingly superior in catalyst performance for
polycondensation reactions by providing good catalyst activity at
reduced catalyst loadings and superior brightness in the resulting
polyester.
[0029] Reactants for forming polyesters via a polycondensation
reaction are well known to those skilled in the art and disclosed
in patents such as U.S. Pat. No. 5,198,530, inventor Kyber, M., et
al., U.S. Pat. No. 4,238,593, inventor B. Duh, U.S. Pat. No.
4,356,299, inventor Cholod et al, and U.S. Pat. No. 3,907,754,
inventor Tershasy et al, which disclosures are incorporated herein
by reference. The art is also described in "Comprehensive Polymer
Science, Ed. G. C. Eastmond, et al, Pergamon Press, Oxford 1989,
vol. 5, pp. 275-315, and by R. E. Wilfong, J. Polym. Science,
54(1961), pp. 385-410. A particularly important commercial specie
of polyester so produced is polyethylene terephthalate (PET).
[0030] In addition to catalyzing polycondensation reactions, the
synergistic catalyst combinations of the present invention are
effective for catalyzing esterification and transesterification
reactions when used in catalytically effective amounts with
reactants known to participate in esterification or
transesterification reactions. A catalytically effective amount is
suitable.
[0031] An improved three component enhanced catalyst composition
can be obtained by the addition of second catalyst to enhanced
catalyst composition defined above, the second catalyst being a
compound containing antimony or germanium.
[0032] TITANIUM OXALATE CATALYSTS:
[0033] Examples of titanium oxalate catalysts of the formula
X.sub.mTiO(C.sub.2O.sub.4).sub.2(H.sub.2O).sub.n, where each X is
independently selected from the group consisting of H, Li, Na, K,
Rb, Cs, Be, Mg, Ca, Sr, Ba and ammonium, m=1 or 2 are well known.
Titanyl oxalates comprise compounds of the formula:
X.sub.mTiO(C.sub.2O.sub.4).su- b.2(H.sub.2O).sub.n, where X is
selected from the group consisting of: H, Li, Na, K, Rb, Cs, Be,
Mg, Ca, Sr and Ba, m=1 or 2. Titanyl oxalates include metallic
titanyl oxalates of the formula M.sub.2TiO(C.sub.2O.sub.-
4).sub.2(H.sub.2O).sub.n wherein each M is independently selected
from potassium, lithium, sodium and cesium such as lithium or
potassium titanyl oxalate and nonmetallic titanyl oxalates such as
ammonium titanyl oxalate. The titanyl oxalate may be anhydrous
(n=0) or contain some water of hydration, i.e. n representing the
amount of water of hydration. Preferred are H, Li, Na, K, Ca, Cs
and ammonium.
[0034] CARBOXYLIC ACID OR SALT:
[0035] Examples of a catalyst enhancer for the titanium oxalate
catalysts are a carboxylic acid containing 1 to 26 carbon atoms or
its corresponding carboxylic acid salt having an anion selected
from the group consisting of Li, Na, K, Rb Cs, Be, Mg, Ca, Sr, Ba
and ammonium. As used herein, "carboxylic acid" includes
dicarboxylic acid. Examples of such carboxylic acids or salts are
well known and include sodium acetate, sodium propionate, sodium
citrate, sodium butyrate, sodium formate, sodium fumarate, malonic
acid, potassium acetate, potassium benzoate, succinic acid,
glutaric acid, adipic acid, maleic acid. Preferred are potassium
acetate, potassium benzoate.
[0036] Titanium Containing Catalysts:
[0037] Examples of titanium containing compounds of the formula
X.sub.mTiY.sub.o with X selected from the group consisting of: H,
Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba and ammonium, m=0, 1, or 2, Y
is a ligand of the formula C.sub.aH.sub.bO.sub.c, a=0 to 30, b=O to
60, and c=1 to 10; o=2, 3, 4, include: acetylacetonate (a=5, b=7,
and c=2); i-propoxide (a=3, b=7, and c=l); butoxide (a=4, b=9, and
c=1); bis(2,2,6,6,-tetramethy-3,5-heptanedionato), i.e. a=11, b=19,
and c=2. Preferred are acetylacetonate, i-propoxide,
bis(2,2,6,6,-tetramethy-3,5-h- eptanedionato).
[0038] Oxalic Acid or Salt:
[0039] Examples of a catalyst enhancer for said titanium containing
compounds are oxalic acids or its corresponding Li, Na, K, Rb Cs,
Be, Mg, Ca, Sr, Ba, or ammonium oxalic acid. Preferred are H, Li,
Na, K, Ca, Cs, and ammonium.
[0040] Antimony Containing Catalysts:
[0041] Examples of antimony containing catalysts that can be added
to the synergistic combination of enhanced titanium oxalate or
titanium containing catalysts defined above are Sb.sub.2O.sub.3,
Sb(CH.sub.3COO).sub.3, and Sb.sub.2(OCH.sub.2CH.sub.2O).sub.3.
[0042] Germanium Containing Catalysts:
[0043] Examples of germanium containing catalysts that can be added
to the synergistic combination of enhanced titanium oxalate or
titanium containing catalysts defined above are GeO.sub.2,
Ge(OC.sub.2H.sub.5).sub- .4, Ge[OCH(CH.sub.3).sub.2].sub.4,
Ge(OCH.sub.3).sub.4. Preferred is GeO.sub.2.
[0044] Enhanceable Antimony Containing Catalysts:
[0045] Examples of antimony containing catalysts that can be
enhanced with a carboxylic acid or salt or an oxalic acid or salt
are Sb.sub.2O.sub.3, Sb(CH.sub.3COO).sub.3,
Sb.sub.2(OCH.sub.2CH.sub.2O).sub.3.
[0046] Cocatalyst:
[0047] Cocatalysts that function in combination with the titanium
containing catalyst and the enhancer include antimony triacetate,
Sb(CH.sub.3COO).sub.3, antimony glycoxide,
Sb.sub.2(OCH.sub.2CH.sub.2O).s- ub.3, antimony oxide.
(Sb.sub.2O.sub.3).
[0048] An effective amount for enhancing the catalytic activity of
titanyl oxalate catalysts or a titanium containing catalyst is at
least about 0.1 part of enhancer per part of titanyl oxalate
catalyst. Preferred is from about 0.1 part to about 100 parts
enhancer per part of catalyst based upon the total weight of
titanium in the catalyst.
[0049] When used in combination with an enhancer, a catalytically
effective amount of titanium containing catalyst should be added to
the polyester forming reactants, generally at least 0.1 part based
upon the weight of titanium. Preferred is from about 1 part to
about 40 parts per million of catalyst based on the weight titanium
in the catalyst and the weight of the of polyester forming
reactants.
[0050] When used in combination with an enhancer, a catalytically
effective amount of an antimony containing catalyst should be added
to the polyester forming reactants. Preferred is from about 1 part
to about 240 parts per million of catalyst based on the weight
antimony in the catalyst and the weight of the of polyester forming
reactants. For enhancing an antimony containing catalyst, an
effective amount for of an enhancer for the catalytic activity of
an antimony containing catalyst is at least about 0.1 part of
enhancer per part of antimony containing catalyst based the weight
of antimony in said antimony containing catalyst. Preferred is from
about 0.1 part to about 80 parts enhancer per part of catalyst
based upon the total weight of titanium in the catalyst.
[0051] The preferred amount of a antimony or germanium containing
catalyst for use in combination with the enhanced titanium oxalate
or titanium containing catalyst described above is from about 0.1
parts to about 80 parts based upon the weight of titanium.
Preferred is from 1 to 40 parts of antimony or germanium containing
catalyst.
[0052] The catalyst and enhancer mixtures of the present invention
are used to make polyester typically by first dissolving them in a
solvent that is compatible with polyester forming reactants, or
preferable in one of the reactants itself, such as ethylene
glycol.
[0053] The synergistic performance of the catalyst enhancer in
combination with one or more catalysts for a polycondensation
reaction for the production of PET resin is shown by the following
examples.
EXAMPLES
[0054] In a polyester polycondensation reaction, acetaldehyde (AA)
is an undesirable polymerization by-product. Polymerization rate is
measured as rate at which intrinsic viscosity (IV) increases during
reaction. Intrinsic viscosity change is an indication of the degree
of polymerization that has occurred during the reaction.
Examples 1-20 and A-G
[0055] Catalyst evaluation was performed with a {fraction (3/16)}
stainless steel, 2 L reactor, fitted with a ball valve at the
bottom of the reactor. The vessel was equipped with 3 inlet ports,
one outlet port, one thermowell port and one pressure transducer
port, and was vertically stirred by an electric motor with amperage
monitoring. The laboratory experimental were all conducted on a 4.0
mole scale, using as polyester forming reactants, BHET and a normal
bottle resin autoclave recipe. The experimental catalysts were
added at the time of BHET charging.
[0056] Bis(2-hydroxyethyl)terephthalate (BHET) and catalyst were
added to the reactor and the contents blanketed with nitrogen. The
mixtures were heated under reduced pressure with constant stirring.
The ethylene glycol (EG) produced during the polymerization was
removed and trapped. The polymerization was at 280.degree. C. ,
under the vacuum of typically around 1 torr. The reaction was
terminated when the stirrer torque reached a level, indicated by
amperage to the stirrer motor, typical for a polymer of IV
.about.0.6. The molten state polymer under nitrogen (containing
less than 2 ppm of oxygen) blanket was discharged from the bottom
ball valve and quenched into a bucket filled with cold water. 1/4"
diameter and {fraction (1/16)}" thick pellets (for color
measurement) were made by filling the molten polymer in a press
molder and chilled immediately in cold water.
[0057] The solution intrinsic viscosity (IV) was measured by
following the ASTM D 4603 method. Acetaldehyde (AA) was measured at
150.degree. C. using gas chromatography (GC) equipped with a
headspace analyzer. The brightness (L*) and yellowness (b*) were
determined by the Hunter Lab's instrument and method.
[0058] Twenty-seven examples were performed using the above
procedure and various catalysts and catalyst enhancer amounts.
[0059] Example A catalyst-180 ppm potassium oxalate-reaction
time=124 mins.
[0060] Example B catalyst-2 ppm titanium from potassium titanyl
oxalate-reaction time=118 mins.
[0061] Example C catalyst-6 ppm titanium potassium titanyl
oxalate-reaction time=71 mins.
[0062] Example D catalyst-25 ppm antimony from antimony (III)
oxide-reaction time=122 mins.
[0063] Example 1 catalyst-2 ppm titanium from potassium titanyl
oxalate+90 ppm potassium oxalate-reaction time=111 mins.
[0064] Example 2 catalyst-90 ppm potassium oxalate+25 ppm antimony
from antimony (III) oxide-reaction time=120 mins.
[0065] Example 3 catalyst-180 ppm potassium oxalate+50 ppm antimony
from antimony (III) oxide-reaction time=130 mins.
[0066] Example 4 catalyst-90 ppm potassium oxalate+100 ppm antimony
from antimony (III) oxide-reaction time=112 mins.
[0067] Example 5 catalyst-2 ppm titanium from potassium titanyl
oxalate+90 ppm potassium oxalate+25 ppm antimony from antimony
(III) oxide-reaction time=105 mins.
[0068] Example E catalyst-240 ppm antimony from antimony (III)
oxide-reaction time=90 mins.
[0069] Example F catalyst-240 ppm antimony from antimony (III)
oxide-reaction time=100 mins.
[0070] Example 6 catalyst-2 ppm titanium from potassium titanyl
oxalate+90 ppm potassium oxalate+25 ppm antimony from antimony
(III) oxide-reaction time=73 mins.
[0071] Example 7 catalyst-2 ppm titanium from potassium titanyl
oxalate+90 ppm ammonium oxalate+25 ppm antimony from antimony (III)
oxide-reaction time=78 mins.
[0072] Example 8 catalyst-2 ppm titanium from ammonium titanyl
oxalate+90 ppm potassium oxalate+25 ppm antimony from antimony
(III) oxide-reaction time =79 mins.
[0073] Example 9 catalyst-2 ppm titanium from ammonium titanyl
oxalate+90 ppm ammonium oxalate+25 ppm antimony from antimony (III)
oxide-reaction time=77 mins.
[0074] Example 10 catalyst-2 ppm titanium from potassium titanyl
oxalate+90 ppm potassium acetate+25 ppm antimony from antimony
(III) oxide-reaction time=81 mins.
[0075] Example 11 catalyst-2 ppm titanium from potassium titanyl
oxalate+90 ppm potassium benzoate+25 ppm antimony from antimony
(III) oxide-reaction time=72 mins.
[0076] Example 12 catalyst-2 ppm titanium from
bis(2,2,6,6-tetramethy-3,5-- heptanedionato) oxotitanium+90 ppm
potassium oxalate+25 ppm antimony from antimony (III)
oxide-reaction time=72 mins.
[0077] Example 13 catalyst-2 ppm titanium from
di(i-propoxide)bis(2,2,6,6--
tetramethyl-3,5-heptanedionato)titanium+90 ppm potassium oxalate+25
ppm antimony from antimony (III) oxide-reaction time=100 mins.
[0078] Example 14 catalyst-2 ppm titanium from titanium oxide
acetylacetonate+90 ppm potassium oxalate+25 ppm antimony from
antimony (III) oxide-reaction time=114 mins.
[0079] Example 15 catalyst-2 ppm titanium from potassium titanyl
oxalate+90 ppm calcium oxalate+25 ppm antimony from antimony (III)
oxide-reaction time=109 mins.
[0080] Example 16 catalyst-2 ppm titanium from potassium titanyl
oxalate+45 ppm oxalic acid+25 ppm antimony from antimony (III)
oxide-reaction time=108 mins.
[0081] Example 17 catalyst-2 ppm titanium from potassium titanyl
oxalate+90 ppm sodium oxalate+25 ppm antimony from antimony (III)
oxide-reaction time=108 mins.
[0082] Example 18 catalyst-2 ppm titanium from lithium titanyl
oxalate+50 ppm lithium oxalate+25 ppm antimony from antimony (III)
oxide-reaction time=102 mins.
[0083] Example G catalyst-60 ppm germanium from germanium
oxide-reaction time=149.
[0084] Example 19 catalyst-10 ppm germanium from germanium oxide+90
ppm potassium oxalate-reaction time=130 mins.
[0085] Example 20 catalyst-2 ppm titanium from potassium titanyl
oxalate+90 ppm potassium oxalate+7 ppm germanium from germanium
oxide-reaction time=123 minutes.
EXAMPLE RESULTS AND DISCUSSION
[0086]
1 AMOUNT POLY TIME AA EXAMPLE (mg) (mins.) IV (ppm) L* b* A 185.5
124 0.252 66.1 80.3 3.6 B 15.4 118 0.583 52.9 76.6 8.3 C 46.5 71
0.583 42.7 78.4 7.1 D 30.8 122 0.230 53.7 na na 1 106.4 111 0.591
52.6 76.6 7.7 2 125.9 120 0.461 24.4 68.3 5.8 3 246.8 130 0.536
46.1 80.4 6.5 4 215.6 112 0.587 38.3 77.6 6.0 5 137.0 105 0.596
42.4 81.4 5.3 B 298.9 90 0.593 34.9 69.9 5.3 F 296.7 100 0.586 34.3
70.0 5.9 6 137.2 73 0.514 26.8 79.6 3.4 7 137.6 78 0.520 32.4 77.3
4.7 8 133.6 79 0.519 33.8 80.4 4.1 9 134.2 77 0.542 19.4 78.6 5.6
10 137.1 81 0.538 22.0 78.3 5.3 11 208.9 72 0.534 18.2 75.5 6.1 12
140.7 72 0.540 19.9 66.4 5.2 13 145.5 100 0.590 45.6 65.7 5.2 14
134.3 114 0.589 42.9 71.9 6.8 15 137.9 109 0.597 42.9 78.3 6.2 16
92.7 108 0.607 39.7 76.2 6.9 17 137.5 108 0.600 43.0 80.8 5.0 18
95.7 102 0.583 37.7 80.4 5.9 G 89.8 149 0.586 43.9 79.9 5.1 19
106.3 130 0.494 41.3 64.9 3.7 20 117.9 123 0.583 42.5 74.1 8.4
[0087] In comparing examples A, B, C and 1, 180 ppm potassium
oxalate alone a polymer with a IV of 0.252 after 124 minutes. Using
example B as a baseline, mer with a similar IV, 118 minutes were
needed for 2 ppm titanium in potassium titanyl oxalate while only
71 minutes were needed for 6 ppm titanium as shown in example C.
The addition of potassium oxalate to potassium titanyl oxalate
enhanced the rate of polymerization as can be seen in example
1.
[0088] In comparing examples A, D, 2, 3, 4 E and F, 180 ppm
potassium oxalate alone produced a polymer with an IV of 0.252
after 124 minutes, 25 ppm of antimony in antimony oxide produced a
polymer with an IV of 0.230 after 122 minutes. It is shown in
examples 2, 3, and 4 that the addition of potassium oxalate to
antimony enhanced the polymerization rate, reduced the amount of
acetaldehyde, and also increased the brightness as compared to
examples E and F.
[0089] In comparing examples B and 5, using the combination of
potassium titanyl oxalate, potassium oxalate, and antimony oxide,
the polymerization rate was faster, the acetaldehyde concentration
was lower, the resulting polymer was more brighter and less
yellow.
[0090] In comparing examples 5, E and F, the three component
catalyst produced more brighter and less yellow polymer than
antimony oxide. It is conceivable that the rate for three
components can be further enhanced and the amount of acetaldehyde
in the resulting polymer can be further reduced by adjusting the
composition of the three components.
[0091] In comparing examples 6 to 9, replacing potassium with
ammonium in three components catalyst reduced the polymerization
rate slightly. The resulting polymer by ammonium containing
catalyst was slightly more yellow.
[0092] In comparing examples 5, 6, 10 to 14, different ligands such
as oxalate, acetate, benzoate, bis
2,2,6,6,-tetramethy-3,5-heptanedionate, i-propoxidate,
acetylacetonate have been used. The catalysts containing these
ligands polymerized BHET in a comparable rate with oxalate
containing catalyst. However, the polymers using catalyst
containing ligands rather than oxalate were less bright and more
yellow. Therefore, the oxalate embodiment of the present invention
is preferred over the ligand containing embodiment of the
invention.
[0093] In comparing examples 5, 15 to 18, although catalysts
containing H, Li, Na, K, and Ca can polymerize BHET in a similar
rate, Li containing catalyst produced the least amount of
acetaldehyde in the resulting polymer and are therefore
preferred.
[0094] In comparing examples G, 19 and 20, the germanium catalyst
can be enhanced by potassium oxalate.
* * * * *