U.S. patent application number 11/901478 was filed with the patent office on 2008-05-08 for process for producing polyester with metal phosphonic acid complex catalysts.
Invention is credited to Stephen M. Andrews, Preetam P. Ghogale, Paul A. Odorisio, Deepak M. Rane, Suhas D. Sahasrabudhe, Paragkumar N. Thanki, Thomas Thompson, Jianzhao Wang, Si Wu.
Application Number | 20080108779 11/901478 |
Document ID | / |
Family ID | 38596097 |
Filed Date | 2008-05-08 |
United States Patent
Application |
20080108779 |
Kind Code |
A1 |
Andrews; Stephen M. ; et
al. |
May 8, 2008 |
Process for producing polyester with metal phosphonic acid complex
catalysts
Abstract
Disclosed is a method for the preparation of a polyester, which
method comprises in a first step, reacting a dicarboxylic acid or a
C.sub.1-C.sub.4 dicarboxylic diester with a diol at a suitable
temperature and pressure to effect esterification or
transesterification to prepare a precondensate and in a second
step, reacting the precondensate to effect polycondensation at a
suitable temperature and pressure to prepare a high molecular
weight polyester, where a metal phosphonic acid complex compound of
the formula ##STR1## is employed in the first step, in the second
step or in both the first and second steps as a reaction catalyst;
and wherein n is 0, 1, 2, 3, 4, 5 or 6; p is an integer from 1 to
30; M is a metal selected from the group consisting of Li, Na, K,
Cs, Be, Ca, Mg, Sr, Ba, Al, Sb, Cd, Mn, Fe, Co, Ni, Cu and Zn; v is
the valency of the metal M and is 1, 2 or 3; q is an integer from 1
to 20 where q=2p/v; and R.sub.1 is hydrogen, straight or branched
chain alkyl of 1 to 36 carbon atoms, straight or branched chain
alkenyl of 1 to 36 carbon atoms, cycloalkyl of 5 to 8 carbon atoms
or aryl of 6 to 10 carbon atoms; or is said alkyl, alkenyl,
cycloalkyl or aryl substituted by one to four hydroxyl, halogen,
straight or branched chain alkoxy of 1 to 8 carbon atoms, straight
or branched chain alkyl of 1 to 8 carbon atoms or amino groups. The
metal complex catalyst compound is in particular ##STR2##
Inventors: |
Andrews; Stephen M.; (New
Fairfield, CT) ; Wang; Jianzhao; (Yorktown Heights,
NY) ; Thompson; Thomas; (Highland Mills, NY) ;
Thanki; Paragkumar N.; (Mumbai, IN) ; Rane; Deepak
M.; (Mumbai, IN) ; Sahasrabudhe; Suhas D.;
(Mumbai, IN) ; Ghogale; Preetam P.; (Mumbai,
IN) ; Odorisio; Paul A.; (Leonia, NJ) ; Wu;
Si; (Ossining, NY) |
Correspondence
Address: |
JoAnn Villamizar, Patent Department;Ciba Speciality Chemicals Corporation
540 White Plains Road
P. O. Box 2005
Tarrytown
NY
10591-9005
US
|
Family ID: |
38596097 |
Appl. No.: |
11/901478 |
Filed: |
September 17, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60845723 |
Sep 19, 2006 |
|
|
|
Current U.S.
Class: |
528/275 |
Current CPC
Class: |
C08G 63/84 20130101;
C08G 63/189 20130101; C08G 63/183 20130101 |
Class at
Publication: |
528/275 |
International
Class: |
C08G 63/02 20060101
C08G063/02 |
Claims
1. A method for the preparation of a polyester, which method
comprises in a first step, reacting a dicarboxylic acid or a
C.sub.1-C.sub.4 dicarboxylic diester with a diol at a suitable
temperature and pressure to effect esterification or
transesterification to prepare a precondensate and in a second
step, reacting the precondensate to effect polycondensation at a
suitable temperature and pressure to prepare a high molecular
weight polyester, where a metal phosphonic acid complex compound of
the formula ##STR15## is employed in the first step, in the second
step or in both the first and second steps as a reaction catalyst;
and wherein n is 0, 1, 2, 3, 4, 5 or 6; p is an integer from 1 to
30; M is a metal selected from the group consisting of Li, Na, K,
Cs, Be, Ca, Mg, Sr, Ba, Al, Sb, Cd, Mn, Fe, Co, Ni, Cu and Zn; v is
the valency of the metal M and is 1, 2 or 3; q is an integer from 1
to 20 where q=2p/v; and R.sub.1 is hydrogen, straight or branched
chain alkyl of 1 to 36 carbon atoms, straight or branched chain
alkenyl of 1 to 36 carbon atoms, cycloalkyl of 5 to 8 carbon atoms
or aryl of 6 to 10 carbon atoms; or is said alkyl, alkenyl,
cycloalkyl or aryl substituted by one to four hydroxyl, halogen,
straight or branched chain alkoxy of 1 to 8 carbon atoms, straight
or branched chain alkyl of 1 to 8 carbon atoms or amino groups.
2. A method according to claim 1 where the metal phosphonic acid
complex compound is of the formula ##STR16## wherein n is 0, 1, 2,
3, 4, 5 or 6; p is an integer from 1 to 30 where p=(vq)/2; M is a
metal selected from the group consisting of Li, Na, K, Cs, Be, Ca,
Mg, Sr, Ba, Al, Sb, Cd, Mn, Fe, Co, Ni, Cu and Zn; v is the valency
of the metal M and is 1, 2 or 3; q is an integer from 1 to 20 where
q=2p/v; and R.sub.2 and R.sub.3 are independently hydrogen,
hydroxyl, halogen, straight or branched chain alkoxy of 1 to 8
carbon atoms, straight or branched chain alkyl of 1 to 8 carbon
atoms or amino; and R.sub.4 is hydrogen or straight or branched
chain alkyl of 1 to 8 carbons atoms.
3. A method according to claim 1 where the metal phosphonic acid
complex compound is of the formula ##STR17## wherein n is 0, 1, 2,
3, 4, 5 or 6; p is an integer from 1 to 30 where p=(vq)/2; M is a
metal selected from the group consisting of Li, Na, K, Cs, Be, Ca,
Mg, Sr, Ba, Al, Sb, Cd, Mn, Fe, Co, Ni, Cu and Zn; v is the valency
of the metal M and is 1, 2 or 3; q is an integer from 1 to 20 where
q=2p/v; and R.sub.4 is hydrogen or straight or branched chain alkyl
of 1 to 8 carbons atoms.
4. A method according to claim 1 where the metal phosphonic acid
complex compound is of the formula ##STR18## where p is an integer
from 1 to 30 where p=(vq)/2; M is a metal selected from the group
consisting of Li, Na, K, Cs, Be, Ca, Mg, Sr, Ba, Al, Sb, Cd, Mn,
Fe, Co, Ni, Cu and Zn; v is the valency of the metal M and is 1, 2
or 3; and q is an integer from 1 to 20 where q=2p/v.
5. A method according to claim 1 where the metal phosphonic acid
complex compound is of the formula ##STR19## wherein n is 0, 1, 2,
3, 4, 5 or 6; p is an integer from 3 to 30; q is an integer from 2
to 20 where q=2p/3; and R.sub.1 is hydrogen, straight or branched
chain alkyl of 1 to 36 carbon atoms, straight or branched chain
alkenyl of 1 to 36 carbon atoms, cycloalkyl of 5 to 8 carbon atoms
or aryl of 6 to 10 carbon atoms; or is said alkyl, alkenyl,
cycloalkyl or aryl substituted by one to four hydroxyl, halogen,
straight or branched chain alkoxy of 1 to 8 carbon atoms, straight
or branched chain alkyl of 1 to 8 carbon atoms or amino groups.
6. A method according to claim 1 where the metal phosphonic acid
complex compound is of the formula ##STR20## wherein n is 0, 1, 2,
3, 4, 5 or 6; R.sub.1 is hydrogen, straight or branched chain alkyl
of 1 to 36 carbon atoms, straight or branched chain alkenyl of 1 to
36 carbon atoms, cycloalkyl of 5 to 8 carbon atoms or aryl of 6 to
10 carbon atoms; or is said alkyl, alkenyl, cycloalkyl or aryl
substituted by one to four hydroxyl, halogen, straight or branched
chain alkoxy of 1 to 8 carbon atoms, straight or branched chain
alkyl of 1 to 8 carbon atoms or amino groups.
7. A method according to claim 1 where the metal phosphonic acid
complex compound is of the formula ##STR21## wherein n is 0, 1, 2,
3, 4, 5 or 6; R.sub.2 and R.sub.3 are independently hydrogen,
hydroxyl, halogen, straight or branched chain alkoxy of 1 to 8
carbon atoms, straight or branched chain alkyl of 1 to 8 carbon
atoms or amino; and R.sub.4 is hydrogen or straight or branched
chain alkyl of 1 to 8 carbons atoms.
8. A method according to claim 1 where the metal phosphonic acid
complex compound is of the formula ##STR22## wherein n is 0, 1, 2,
3, 4, 5 or 6; and R.sub.4 is hydrogen or straight or branched chain
alkyl of 1 to 8 carbons atoms.
9. A method according to claim 1 where the aluminum phosphonic acid
complex compound is ##STR23##
10. A method according to claim 1 where a dicarboxylic acid is
reacted with a diol to prepare a precondensate and where the
dicarboxylic acid is terephthalic acid, isophthalic acid,
o-phthalic acid, naphthalene dicarboxylic acid, cyclohexane
dicarboxylic acid, cyclohexanediacetic acid,
diphenyl-4,4'-dicarboxylic acid, succinic acid, maleic acid,
glutaric acid, adipic acid, sebacic acid or a mixture thereof.
11. A method according to claim 1 where a dicarboxylic diester is
reacted with a diol to prepare a precondensate and where the
dicarboxylic diester is a C1-C4 dialkyl diester of terephthalic
acid, isophthalic acid, o-phthalic acid, naphthalene dicarboxylic
acid, cyclohexane dicarboxylic acid, cyclohexanediacetic acid,
diphenyl-4,4'-dicarboxylic acid, succinic acid, maleic acid,
glutaric acid, adipic acid, sebacic acid or a mixture thereof.
12. A method according to claim 10 where the diacid is terephthalic
acid, isophthalic acid or 2,6-naphthalene dicarboxylic acid.
13. A method according to claim 11 where the diester is dimethyl
terephthalate.
14. A method according to claim 1 where the diol is ethylene
glycol, diethylene glycol, triethylene glycol, propane-1,3-diol,
propane-1,2-diol, butane-1,4-diol, pentane-1,5-diol,
hexane-1,6-diol, 1,4-cyclohexanedimethanol,
3-methylpentane-2,4-diol, 2-methylpentane 1,4-diol,
2,2-diethylpropane-1,3-diol, 1,4-di-(hydroxyethoxy)benzene,
2,2-bis(4-hydroxycyclohexyl)-propane,
2,4-dihydroxy-1,1,3,3-tetramethylcyclobutane,
2,2-bis-(3-hydroxyethoxyphenyl)propane,
2,2-bis-(4-hydroxypropoxyphenyl)ethane or a mixtures thereof.
15. A method according to claim 1 where the diol is ethylene
glycol, 1,4-cyclohexanedimethanol or butane-1,4-diol.
16. A method according to claim 1 where the polyester is
poly(ethylene terephthalate), poly(ethylene
2,6-naphthalene-2,6-dicarboxylate) or poly(1,4-butylene
terephthalate).
17. A method according to claim 1 where the first step is performed
at a temperature from about 200 to about 300.degree. C.
18. A method according to claim 1 where the second step is
performed at a temperature from about 250 to about 300.degree. C.
and at a pressure from about 10 to about 0.1 torr.
19. A method according to claim 1 where the catalyst is employed at
a level from about 1 to about 1500 ppm by weight, based on the
weight of dicarboxylic acid or dicarboxylic diester and diol.
20. A method according to claim 1 where the catalyst is employed at
a level from about 1 to about 1000 ppm by weight, based on the
weight of dicarboxylic acid or dicarboxylic diester and diol.
Description
[0001] This application claims benefit of U.S. provisional app. No.
60/845,723, filed Sep. 19, 2006, the disclosure of which is hereby
incorporated by reference.
[0002] The invention relates to a method for the preparation of
polyesters, in particular polyethylene terephthalate, which method
comprises employing certain metal phosphonic acid complex
catalysts.
BACKGROUND
[0003] Polyesters, such as polyethylene terephthalate (PET) are
prepared industrially in a two stage process. The first stage in
PET preparation involves the direct esterification of terephthalic
acid with ethylene glycol, or alternatively transesterification of
a C.sub.1-C.sub.4 dialkylterephthalate with ethylene glycol to form
a low molecular weight precondensate. In a second stage, the
precondensate is polycondensed to form high molecular weight
polyethylene terephthalate. Both stages typically employ catalytic
acceleration.
[0004] Depending on the end use of the polyester, a further solid
state polymerization (SSP) is employed to arrive at the desired
viscosity.
[0005] Numerous compounds have been proposed as esterification,
transesterification or polycondensation catalysts. Choice of
catalyst effects the color, strength and processing properties of
the end product. Choice of catalyst effects for example the amount
of aldehyde generation. Catalyst selection also controls
selectivity of the reaction and provides for final products reduced
in unwanted impurities such as diethylene glycol, cyclic oligomers
and carboxylic acid end groups.
[0006] U.S. published app. No. 2003083191 is aimed at polyester
polymerization catalysts that are combination of aluminum or an
aluminum compound and a phosphorus metal salt compound. The
aluminum compounds are for example carboxylates, inorganic acid
salts, aluminum alkoxides, aluminum chelate compounds or
organoaluminum compounds.
[0007] U.S. published app. No. 2004058805 is aimed at polyester
polymerization catalysts that comprise at least one member selected
from aluminum and aluminum compounds as a first metal-containing
component in the presence of at least one phosphorus compound
selected from formula 1 and 2. ##STR3##
[0008] U.S. Pat. Nos. 3,310,575 and 3,824,192 disclose metal
(O-alkyl)-3,5-di-t-butyl-4-hydroxybenzylphosphonates. The metal
phosphonates are taught as polymer stabilizers.
[0009] U.S. Pat. No. 6,383,970 teaches solid acid catalysts.
[0010] TW 526235 discloses a production process for polyester
resin.
[0011] Suitable catalysts for the preparation of polyesters, in
particular polyethylene terephthalate are still being sought. Said
catalysts are employed in the first or second stages of
preparation, or in both stages.
SUMMARY
[0012] Disclosed is a method for the preparation of a polyester,
which method comprises
[0013] in a first step, reacting a dicarboxylic acid or a
C.sub.1-C.sub.4 dicarboxylic diester with a diol at a suitable
temperature and pressure to effect esterification or
transesterification to prepare a precondensate and
[0014] in a second step, reacting the precondensate to effect
polycondensation at a suitable temperature and pressure to prepare
a high molecular weight polyester,
[0015] where a metal phosphonic acid complex compound of the
formula ##STR4## is employed in the first step, in the second step
or in both the first and second steps as a reaction catalyst; and
wherein
[0016] n is 0, 1, 2, 3, 4, 5 or 6;
[0017] p is an integer from 1 to 30;
[0018] M is a metal selected from the group consisting of Li, Na,
K, Cs, Be, Ca, Mg, Sr, Ba, Al, Sb, Cd, Mn, Fe, Co, Ni, Cu and
Zn;
[0019] v is the valency of the metal M and is 1, 2 or 3;
[0020] q is an integer from 1 to 20 where q=2p/v; and
[0021] R.sub.1 is hydrogen, straight or branched chain alkyl of 1
to 36 carbon atoms, straight or branched chain alkenyl of 1 to 36
carbon atoms, cycloalkyl of 5 to 8 carbon atoms or aryl of 6 to 10
carbon atoms; or is said alkyl, alkenyl, cycloalkyl or aryl
substituted by one to four hydroxyl, halogen, straight or branched
chain alkoxy of 1 to 8 carbon atoms, straight or branched chain
alkyl of 1 to 8 carbon atoms or amino groups.
DETAILED DESCRIPTION
[0022] The metal phosphonic acid complex compound is for example of
the formula ##STR5## wherein
[0023] n is 0, 1, 2, 3, 4, 5 or 6;
[0024] p is an integer from 1 to 30 where p=(vq)/2;
[0025] M is a metal selected from the group consisting of Li, Na,
K, Cs, Be, Ca, Mg, Sr, Ba, Al, Sb, Cd, Mn, Fe, Co, Ni, Cu and
Zn;
[0026] v is the valency of the metal M and is 1, 2 or 3;
[0027] q is an integer from 1 to 20 where q=2p/v; and
[0028] R.sub.2 and R.sub.3 are independently hydrogen, hydroxyl,
halogen, straight or branched chain alkoxy of 1 to 8 carbon atoms,
straight or branched chain alkyl of 1 to 8 carbon atoms or amino;
and
[0029] R.sub.4 is hydrogen or straight or branched chain alkyl of 1
to 8 carbons atoms.
[0030] The metal phosphonic acid complex compound is for example of
the formula ##STR6## wherein
[0031] n is 0, 1, 2, 3, 4, 5 or 6;
[0032] p is an integer from 1 to 30 where p=(vq)/2;
[0033] M is a metal selected from the group consisting of Li, Na,
K, Cs, Be, Ca, Mg, Sr, Ba, Al, Sb, Cd, Mn, Fe, Co, Ni, Cu and
Zn;
[0034] v is the valency of the metal M and is 1, 2 or 3;
[0035] q is an integer from 1 to 20 where q=2p/v; and
[0036] R.sub.4 is hydrogen or straight or branched chain alkyl of 1
to 8 carbons atoms.
[0037] The metal phosphonic acid complex compound is for example of
the formula ##STR7## where
[0038] p is an integer from 1 to 30 where p=(vq)/2;
[0039] M is a metal selected from the group consisting of Li, Na,
K, Cs, Be, Ca, Mg, Sr, Ba, Al, Sb, Cd, Mn, Fe, Co, Ni, Cu and
Zn;
[0040] v is the valency of the metal M and is 1, 2 or 3; and
[0041] q is an integer from 1 to 20 where q=2p/v.
[0042] The metal phosphonic acid complex compound is for example of
the formula ##STR8## wherein
[0043] n is 0, 1, 2, 3, 4, 5 or 6;
[0044] p is an integer from 3 to 30;
[0045] q is an integer from 2 to 20 where q=2p/3; and
[0046] R.sub.1 is hydrogen, straight or branched chain alkyl of 1
to 36 carbon atoms, straight or branched chain alkenyl of 1 to 36
carbon atoms, cycloalkyl of 5 to 8 carbon atoms or aryl of 6 to 10
carbon atoms; or is said alkyl, alkenyl, cycloalkyl or aryl
substituted by one to four hydroxyl, halogen, straight or branched
chain alkoxy of 1 to 8 carbon atoms, straight or branched chain
alkyl of 1 to 8 carbon atoms or amino groups.
[0047] The metal phosphonic acid complex compound is for example of
the formula ##STR9## wherein
[0048] n is 0, 1, 2, 3, 4, 5 or 6;
[0049] R.sub.1 is hydrogen, straight or branched chain alkyl of 1
to 36 carbon atoms, straight or branched chain alkenyl of 1 to 36
carbon atoms, cycloalkyl of 5 to 8 carbon atoms or aryl of 6 to 10
carbon atoms; or is said alkyl, alkenyl, cycloalkyl or aryl
substituted by one to four hydroxyl, halogen, straight or branched
chain alkoxy of 1 to 8 carbon atoms, straight or branched chain
alkyl of 1 to 8 carbon atoms or amino groups.
[0050] The metal phosphonic acid complex compound is for example of
the formula ##STR10## wherein
[0051] n is 0, 1, 2, 3, 4, 5 or 6;
[0052] R.sub.2 and R.sub.3 are independently hydrogen, hydroxyl,
halogen, straight or branched chain alkoxy of 1 to 8 carbon atoms,
straight or branched chain alkyl of 1 to 8 carbon atoms or amino;
and
[0053] R.sub.4 is hydrogen or straight or branched chain alkyl of 1
to 8 carbons atoms.
[0054] The metal phosphonic acid complex compound is for example of
the formula ##STR11## wherein
[0055] n is 0, 1, 2, 3, 4, 5 or 6; and
[0056] R.sub.4 is hydrogen or straight or branched chain alkyl of 1
to 8 carbons atoms.
[0057] The aluminum phosphonic acid complex compound is in
particular the compound ##STR12##
[0058] The aluminum catalyst is prepared for example as disclosed
in U.S. Pat. No. 3,310,575, the disclosure of which is incorporated
by reference.
[0059] Alkyl having up to 36 carbon atoms is a branched or
unbranched radical, for example methyl, ethyl, propyl, isopropyl,
n-butyl, sec-butyl, isobutyl, tert-butyl, 2-ethylbutyl, n-pentyl,
isopentyl, 1-methylpentyl, 1,3-dimethylbutyl, n-hexyl,
1-methylhexyl, n-heptyl, isoheptyl, 1,1,3,3-tetramethylbutyl,
1-methylheptyl, 3-methylheptyl, n-octyl, 2-ethylhexyl,
1,1,3-trimethylhexyl, 1,1,3,3-tetramethylpentyl, nonyl, decyl,
undecyl, 1-methylundecyl, dodecyl, 1,1,3,3,5,5-hexamethylhexyl,
tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl,
icosyl or docosyl.
[0060] Alkenyl is an unsaturated version of alkyl, for example
allyl, isopropenyl, propenyl, hexenyl, heptenyl, and the like.
[0061] Unsubstituted or alkyl-substituted cycloalkyl is, for
example, cyclopentyl, methyl-cyclopentyl, dimethylcyclopentyl,
cyclohexyl, methylcyclohexyl, dimethylcyclohexyl,
trimethyl-cyclohexyl, tert-butylcyclohexyl, cycloheptyl or
cyclooctyl. For example cyclohexyl and tert-butylcyclohexyl.
[0062] Aryl is phenyl or naphthyl. Alkyl-substituted aryl, which
contains for example 1 to 3, for instance 1 or 2, alkyl groups, is,
for example, o-, m- or p-methylphenyl, 2,3-dimethylphenyl,
2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl,
3,4-dimethylphenyl, 3,5-dimethylphenyl, 2-methyl-6-ethylphenyl,
4-tert-butylphenyl, 2-ethylphenyl or 2,6-diethylphenyl.
[0063] The dicarboxylic acid is selected from the group consisting
of aromatic dicarboxylic acids having 8 to 14 carbon atoms,
aliphatic dicarboxylic acids having 4 to 12 carbon atoms,
cyclo-aliphatic dicarboxylic acids having 8 to 12 carbon atoms, and
mixtures thereof.
[0064] The C.sub.1-C.sub.4 dicarboxylic diesters are dialkyl
diesters of the above-mentioned dicarboxylic acids. The diesters
are for instance dimethyl esters.
[0065] Preferably such diacids are terephthalic acid, isophthalic
acid, o-phthalic acid, naphthalene dicarboxylic acid, cyclohexane
dicarboxylic acid, cyclohexanediacetic acid,
diphenyl-4,4'-dicarboxylic acid, succinic acid, maleic acid,
glutaric acid, adipic acid, sebacic acid and mixtures thereof.
[0066] Especially preferred acids and esters are terephthalic acid,
dimethyl terephthalate, isophthalic acid and 2,6-naphthalene
dicarboxylic acid.
[0067] The diols or glycols are derived from the generic formula
HO--R--OH where R is an aliphatic, cycloaliphatic or aromatic
moiety of 2 to 18 carbon atoms.
[0068] Preferably such diols or glycols are ethylene glycol,
diethylene glycol, triethylene glycol, propane-1,3-diol,
propane-1,2-diol, butane-1,4-diol, pentane-1,5-diol,
hexane-1,6-diol, 1,4-cyclo-hexanedimethanol,
3-methylpentane-2,4-diol, 2-methylpentane 1,4-diol,
2,2-diethylpropane-1,3-diol, 1,4-di-(hydroxyethoxy)benzene,
2,2-bis(4-hydroxycyclohexyl)-propane,
2,4-dihydroxy-1,1,3,3-tetramethylcyclobutane,
2,2-bis-(3-hydroxyethoxyphenyl)propane,
2,2-bis-(4-hydroxy-propoxyphenyl)ethane and mixtures thereof.
[0069] Most preferably, the diol is ethylene glycol,
1,4-cyclohexanedimethanol or butane-1,4-diol.
[0070] The polyester is preferably poly(ethylene terephthalate) PET
or poly(ethylene 2,6-naphthalene-2,6-dicarboxylate) or
poly(1,4-butylene terephthalate); most preferably poly(ethylene
terephthalate).
[0071] The polyesters are prepared by methods well known in the
art. Such methods are disclosed for example in U.S. published app.
Nos. 2003083191 and 2004058805 and in U.S. Pat. Nos. 5,744,571,
6,013,756 and 5,453,479. These disclosures are incorporated herein
by reference.
[0072] The first esterification or transesterification step is
performed by mixing together one or more dicarboxylic acids or
dicarboxylic diesters with one or more diols at temperatures in the
range of about 150 to about 300.degree. C., for example from about
200 to about 300.degree. C., from about 260 to about 300.degree.
C., and at pressures of from atmospheric to about 0.2 mm Hg. The
product is a low molecular weight precondensate.
[0073] In the second step, polycondensation is effected by
increasing the temperature and lowering the pressure while excess
diol is removed. The temperature is for example from about 250 to
about 300.degree. C., for example from about 275 to about
300.degree. C. The pressure is reduced to from about 10 to about
0.1 torr, or from about 5 to about 0.5 torr.
[0074] One or both of the steps are advantageously performed in the
presence of a metal phosphonic acid complex catalyst. The present
catalyst is employed at a level of from about 1 to about 1500 ppm
by weight, based on the total weight of dicarboxylic acid or
dicarboxylic diester and diol. For example, the present catalyst is
employed from about 1 to about 1000 ppm or from about 1 to about
500 ppm, based on the total weight of dicarboxylic acid or
dicarboxylic diester and diol. For example, the present catalyst is
employed from about 2 to about 250 ppm by weight, for instance from
about 10 to about 300 ppm by weight, based on the weight of diacid
or diester plus diol.
[0075] The metal phosphonic acid complex catalyst is also
advantageously present for further solid state polymerization. The
present catalysts provide for outstanding results during an
optional solid state polymerization step.
[0076] The invention is further illustrated by the following
Examples. All parts and percentages are by weight unless otherwise
indicated.
Analytical Procedures
[0077] Intrinsic Viscosity (I.V.): 1 g of polymer is dissolved in
100 g of a 3:2 mixture of phenol and tetrachloroethane. The
viscosity of this solution is measured at 35.degree. C. using a
Viscotek relative viscometer Y501C and recalculated to the
intrinsic viscosity.
[0078] PET Pellet Color--The L* value measured on PET pellets using
a DCI spectrophotometer by ASTM D1925, D65 10 degm specular
included. Present Aluminum Phosphonic Acid Complex Catalyst
##STR13##
[0079] 30.0 g (0.1 mole) of
(3,5-di-tert-butyl-4-hydroxy-benzyl)-phosphonic acid is added to a
solution containing 14.0 g (0.25 mole) of KOH dissolved in 300 ml
methanol. Reaction mixture is stirred at room temperature under
N.sub.2 atmosphere for 1 h. This reaction mixture is then added,
drop-wise, to another solution containing 24.1 g (0.1 mole) of
AlCl.sub.3.6H.sub.2O dissolved in 250 ml methanol. After completion
of the addition, reaction mixture is heated at 60.degree. C. under
N.sub.2 atmosphere for 3 h. Reaction mixture is then cooled to room
temperature and solid is filtered. Filtrate is concentrated to give
solid which is boiled with 300 mL of distilled water for 2 h. Solid
is filtered and dried in oven at .about.70.degree. C. till constant
weight is obtained. 31 g of product is obtained.
[0080] Theoretical % C, 50.27; % H, 7.78; % Al, 5.02.
[0081] Found % C, 50.30; % H, 7.90; % Al, 4.97. Comparative
Aluminum Phosphonic Acid Complex ##STR14##
[0082] 3.0 g (0.01 mole) of
(3,5-di-tert-butyl-4-hydroxy-benzyl)-phosphonic acid is added to a
solution containing 0.56 g (0.01 mole) of KOH dissolved in 30 ml
methanol. Reaction mixture is stirred at room temperature under
N.sub.2 atmosphere for 1 h. The reaction mixture is then added,
drop-wise, to another solution containing 0.8 g (0.003 mole) of
AlCl.sub.3.6H.sub.2O in 10 ml methanol. After completion of the
addition, reaction mixture is heated at 60.degree. C. for 3 h.
Reaction mixture is then cooled to room temperature and solid is
filtered. Filtrate is concentrated to give solid which is boiled
with 30 mL distilled water for 2 h. Solid is filtered and dried in
oven at .about.70.degree. C. till constant weight is obtained. 2.9
g of product is obtained.
[0083] Theoretical % C, 58.43; % H, 7.85; % Al, 2.92.
[0084] Found % C, 55.82; % H, 8.44; % Al, 2.72.
EXAMPLE 1
[0085] 87.3 g terephthalic acid and 2.7 g isophthalic acid are
mixed with 40.5 g EG (ethylene glycol) and subjected to typical
esterification conditions (under .about.40 psi nitrogen pressure
for .about.7 hours at 275.about.280.degree. C.). The water from
reaction will distill out of the apparatus beginning about
140.degree. C. The reaction is continued until no more water is
generated.
[0086] 35 g blank precondensates from the esterification are mixed
with 0.0288 g (.about.800 ppm) of the present aluminum phosphonic
acid complex catalyst. The solid mixture is heated and stirred at
275.degree. C. under nitrogen purge. The melted mixture is
subsequently polycondensed under a gradually increasing vacuum from
atmosphere to full vacuum (.about.0.8 torr) at 275.degree. C. over
90 minutes. The polycondensation is continued under full vacuum for
another 90 minutes. A polyethylene terephthalate is obtained with
an intrinsic viscosity of 0.55 dl/g.
EXAMPLE 2
[0087] 87.3 g terephthalic acid and 2.7 g isophthalic acid are
mixed with 40.5 g EG and 0.025 g Sb.sub.2O.sub.3 and subjected to
typical esterification conditions (under .about.40 psi nitrogen
pressure for .about.7 hours at 275.about.280.degree. C. temp). The
generated water from the reaction will distill out of the apparatus
beginning about 140.degree. C. The reaction is continued until no
more water is generated.
[0088] 40 g of precondensates containing 240 ppm Sb.sub.2O.sub.3
from the esterification are mixed with 0.0200 g (.about.500 ppm) of
the present aluminum phosphonic acid complex catalyst. The solid
mixture is heated and stirred at 275.degree. C. under nitrogen
purge. The melted mixture is subsequently polycondensed under a
gradually increasing vacuum from atmosphere to full vacuum
(.about.0.9 torr) at 275.degree. C. over 90 minutes. The
polycondensation is continued under full vacuum for another 90
minutes. A polyethylene terephthalate is obtained with an intrinsic
viscosity of 0.70 dl/g.
General Polyester (PET) Synthesis Procedure A
[0089] General polymerization procedure for 4 L polycondensation
batch reactor. A batch reactor is used which is equipped with a
pressurized, heated autoclave reactor with impeller stirrer, inert
gas inlet system, a fractionating column to separate water of
reaction and ethylene glycol during esterification phase removing
water from the reaction and returning ethylene glycol to the
reaction mass; a sidearm transfer line connected to collection
vessel and vacuum system capable of collecting reaction coproducts
ethylene glycol and water during vacuum polycondensation; a
discharge valve system at the bottom of the reactor for discharge
and isolation of polymer product. Various process points are
instrumented with thermocouples and pressure transducers to monitor
or control the reaction system.
Materials
PTA, purified terephthalic acid (8.933 moles, 1484 grams)
PIA, purified isophthalic acid (0.276 moles, 46 grams)
EG, ethylene glycol (11.11 moles, 689 grams)
(optionally) a suppressant to reduce diethylene glycol formation
(e.g.) Choline hydroxide as a 45% methanolic solution
antimony trioxide, 240 ppm
Other additives, as desired
[0090] The EG (120 mole %) is added and stirring begun. A mixture
of 97 mole % PTA with 3% PIA is charged to the reactor along with
antimony trioxide. Solid additives may be added at this point,
& washed into the reactor with EG. Optionally any liquid
catalyst or additives can be added via syringe with several
milliliters of EG. The DEG (diethylene glycol) suppressant may be
added via pipette & washed in with EG. Reactor is purged with
nitrogen then closed.
[0091] For the esterification phase, the reaction mass is
conditioned for 20 minutes at a temperature range 93-105.degree.
C., stirring at 20 rpm. Heaters are set at 275.degree. C. &
sidearm is set to 150.degree. C. Stirring is raised incrementally
over 30 minutes, up to 60 rpm when melt temperature reads
200.degree. C. The esterification step is conducted at nominally 50
psig nitrogen pressure and reaches an ultimate temperature of
270.degree. C. The time of esterification begins when water is
observed in sight glass of collector (that is, water distills out
of fractionating column begins). When the reactor melt temperature
reaches nominally 260.degree. C., the heater setpoints are adjusted
downward to a final setpoint of about 243.degree. C. which allows a
final esterification temperature of about 270.degree. C.
[0092] It takes about 1 hour 45 minutes from beginning of the batch
(time zero) until the beginning of water distillation from the
fractionating column into the water collector. It takes an
additional 120 minutes to complete esterification (i.e. when top of
column temperature has dropped & stabilized at 125-135.degree.
C.).
[0093] The next phase of the process sometimes referred to as
Atmospheric Esterification (alias pre-polycondensation) occurs when
the reactor pressure is released and brought to atmospheric
pressure. Atmospheric esterification is conducted for 30 minutes at
270.degree. C. Additives optionally may be added to the reactor at
this point using a septum on the addition port and a large gauge
syringe.
[0094] The next phase of the process, vacuum polycondensation,
occurs when the reactor pressure (i.e. applying a vacuum) is
reduced over 60 minutes down to 1 torr or less via programmed
vacuum reduction step-down program. Upon reaching final vacuum
level, polycondensation continues for about 60 minutes at a final
melt temperature target of 285-286.degree. C. Over this total
polycondensation time, the reactor stirring speed is reduced in
increments as the polymer molecular weight (i.e. melt viscosity)
increases. Typically the reactor is held at 60 rpm for 105 minutes,
then at 50 rpm for 15 minutes, at 40 rpm for 10 minutes, and at 15
rpm for 15 minutes until polymer discharge. The total time of
polycondensation may differ slightly since the reaction endpoint is
generally determined by a motor torque value & not by reaction
time. Polycondensations of significantly faster reaction rate will
reach the endpoint torque value sooner than a standard polyester
formulation, such as the case with improved catalysts or
coadditives in the formulation. Upon reaching a given motor torque
level the polymerization reaction is considered completed. At this
time the batch is discharged from the bottom of the reactor,
stranded through a water trough and converted to chip. The
esterification time is 104 minutes and polycondensation time is 60
minutes. A polyester is produced with dilute solution viscosity
value 0.63 dL/g, and carboxylic acid endgroup 24 meq/kg.
EXAMPLE 3
[0095] A polyester is produced per the general polyester (PET)
synthesis procedure A. Instead of adding antimony oxide, a 15 gram
slurry of EG containing 1.42 grams of the present aluminum
phosphonic acid complex catalyst is added to the reactor at the end
of atmospheric esterification stage of the process. The remainder
of the polymerization process is conducted as described above. The
esterification time is 96 minutes and polycondensation time is 80
minutes. A polyester is produced with dilute solution viscosity
value 0.61 dl/g, and carboxylic acid endgroup 12 meq/kg.
General Polyester (PET) Synthesis Procedure B
[0096] A 2 L detachable autoclave reactor equipped with an external
aluminum block heater, an anchor type stirrer, inert gas inlet
system, a fractionating column to separate water of reaction and
ethylene glycol during esterification phase removing water from the
reaction and returning ethylene glycol to the reaction mass; a
sidearm transfer line connected to a collection vessel and vacuum
system capable of collecting reaction co-products, ethylene glycol
and water, during vacuum polycondensation; and a discharge valve
system at the bottom of the reactor for discharge and isolation of
polymer product is used. The reactor vessel is instrumented with a
thermocouple and pressure transducer to monitor the reaction
system.
Materials
PTA, purified terephthalic acid (2.680 moles, 445.23 grams)
PIA, purified isophthalic acid (0.083 moles, 13.77 grams)
EG, ethylene glycol (3.587 moles, 222.66 grams)
(optionally) a suppressant to reduce diethylene glycol formation
(e.g. Choline hydroxide as a 45% methanolic solution)
Polycondensation catalyst: antimony trioxide, 240 ppm
Other additives, as desired
[0097] Terephthalic acid (97%), isophthalic acid (3%), ethylene
glycol (130%) and choline hydroxide are mixed in a 2 L stainless
steel reactor to form a paste. When employed, the polycondensation
catalyst, antimony trioxide, is mixed with terephthalic acid during
the paste preparation. The reaction mixture is purged and
pressurized to 40 psig with nitrogen then heated up to
239-243.degree. C. with stirring at 60 rpm in 70 minutes while
pressure is raised to 50 psig. At this point a temperature drop is
observed in the reactor which is indicative of the onset of
esterification and distillation of water-of-reaction through the
fractionating column. The reaction mixture is then further heated
at 50 psig for 2 hours 20 minutes while the reactor temperature is
slowly raised to 250-252.degree. C.
[0098] The next phase of the process sometimes referred to as
Atmospheric Esterification (alias pre-polycondensation) occurs when
the reactor pressure is released and brought to 0 psig
(atmospheric) in 5 minutes. Additives optionally may be added to
the reactor at this point using a septum on the addition port and a
large gauge syringe. During the atmospheric esterification the
reaction temperature is slowly raised to 260-262.degree. C. over a
40 minute period.
[0099] Following the atmospheric esterification step, the reactor
pressure is reduced from atmospheric to full vacuum, 1.0 torr or
less, while reaction temperature is slowly raised to
280-284.degree. C. within 1 hour. Upon reaching final vacuum level,
the polycondensation step continues until the desired molecular
weight of the polymer is achieved and the reaction temperature
increases to a final melt temperature target of 296-298.degree. C.
The progress of the polycondensation is monitored by recording the
motor torque amperage. Once a desired amperage reading (2.00 amp)
is reached, the stirrer is stopped, and polymer is collected via
discharge from a drain valve at the bottom of the reactor, stranded
through a water trough and converted to chip. The polycondensation
time is counted from the end of the vacuum letdown point until the
stop of stirrer and vacuum. The polycondensation time is 120
minutes. A polyester is produced with dilute solution viscosity
value 0.62 dL/g and L* value 74.4.
EXAMPLE 4
[0100] A polyester is produced per the general example B procedure
above. Instead of adding antimony oxide, a 16 gram slurry of EG
containing 0.21 grams (400 ppm) of the present aluminum phosphonic
acid complex catalyst is added to the reactor at the end of
atmospheric esterification stage of the process. The remainder of
the polymerization process is conducted as described above. The
polycondensation time is 93 minutes. A polyester is produced with
dilute solution viscosity value 0.63 dL/g and L* value 82.4.
EXAMPLE 5
[0101] A polyester is produced per the general example B procedure
above. Instead of adding antimony oxide, a titanium containing
catalyst (equivalent to 2.5 ppm Ti) is added with terephthalic acid
at the beginning of esterification and a 16 gram slurry of EG
containing 0.11 grams (200 ppm) of the present aluminum phosphonic
acid complex catalyst is added to the reactor at the end of
atmospheric esterification stage of the process. The remainder of
the polymerization process is conducted as described above. The
polycondensation time is 99 minutes. A polyester is produced with
dilute solution viscosity value 0.62 dL/g.
General Solid State Polycondensation (SSP) Procedure C
[0102] The polycondensation in the melt as described in the general
procedure B above is followed by a solid state polycondensation
(SSP) to further increase the molecular weight as measured by
monitoring the dilute solution intrinsic viscosity (I.V.).
[0103] The following description illustrates the general
procedure:
[0104] 500 grams of polyethylene terephthalate pellets prepared
according to general example B, using 240 ppm of antimony oxide, is
placed in a drying oven for 16 hours at 110.degree. C. under a
vacuum of 50 torr to dry the pellets. The dried pellets are
transferred into a vacuum tumbling dryer. During continuous
tumbling of the polyethylene terephthalate under a vacuum of 1 to 2
torr, the temperature is raised to 216.degree. C. over a 2 hour
period. After 10 hours at 216.degree. C., the polyethylene
terephthalate pellets are cooled. A polyester is produced with
dilute solution intrinsic viscosity value (I.V.) 0.71 dL/g and L*
value 85.2.
EXAMPLE 6
[0105] A polyester is produced by the procedure of Example 4 and
500 grams of the polyethylene terephthalate pellets are further
reacted according to the Solid State Polycondensation (SSP)
procedure C at 217.degree. C. over a 10 hour period. A polyester is
produced with dilute solution intrinsic viscosity value (I.V.) 0.82
dL/g and L* value 88.7.
EXAMPLE 7
[0106] Examples 2 and 5 are repeated, replacing antimony oxide and
the titanium based catalyst with germanium oxide. Excellent results
are achieved.
[0107] As shown, the present aluminum phosphinic acid complex
catalyst may be employed together with other known catalysts, for
example antimony, titanium or germanium catalysts.
* * * * *