Note: Descriptions are shown in the official language in which they were submitted.
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PROCESS FOR MAKING SULFONATED POLYESTER COMPOUNDS
Field Of The Invention
The present invention is directed to a process of producing sulfonated
polyester
compounds suitable for use as a soil releasing agent and/or textile sizing
agent in which
a sulfonated acid or ester is reacted with a hydroxy-containing compound to
form a
sulfonated hydroxy terminated ester which then undergoes a transesterification
reaction
with a poly (ethylene) terephthate based polyester followed by
polycondensation to form
the desired sulfonated polyester compound. The present invention provides
lower cost,
reduced cycle times and improved yields over conventional processes for the
production
of sulfonated polyester compounds.
Background Of The Invention
Sulfonated polyester compounds are known for removing soil and stains from a
variety of substrates including filaments, fibers; fabrics, films and the like-
Low
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molecular weight sulfonated polyester compounds are typically employed as soil
release agents in laundry detergents while higher molecularweight sulfonated
polyester
compounds have been used for textile sizing.
U.S. Patent No. 3,962,152 discloses a detergent composition containing
polymers as soil release agents which are obtained by reacting dimethyl
terephthalate
with polyethylene glycol.
U.S. Patent Nos. 4,863,619; 4,925,577 and 5,041,230 generally disclose
methods of improving the processability of soil release polymers.
U.S. Patent No. 4,999,128 discloses copolymers of polyethylene
terephthalate/ethylene isophthalate) and related copolymers which are produced
by
reacting the esters with polyethylene glycol.
U.S. Patent No. 5,142,020 discloses soil release promoters and detergents
which are obtained by the polymerization of monomers such as dicarboxylic
acid/ester/anhydride, dihydric alcohols and polyethylene glycols.
Sulfonated polyester compounds have received increased attention as effective
soil release agents. For example, U.S. Patent No. 3,557,039 discloses a stable
aqueous dispersion comprising water and a water insoluble crystallizable block
or graph
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polymeric compound which contains linear polyethylene terephthalate segments
having
sufficient ethylene terephthalate units to confer crystallinity to the
compound. These
polymers are prepared by reacting monomers which include dimethyl sodium
sulfoisophthalate.
U.S. Patent No. 4,427,557 discloses sulfonated copolymers used for preparing
anionic textile treating compositions in which the polymerizable monomers
include
dimethyl sulfoisophthalate.
U.S. Patent No. 4,702,857 discloses sulfonated copolymers used as soil release
agents in detergent formulations in which the copolymers are obtained by
polymerizing
monomers such as dimethyl terephthalate, dimethyl sulfoisophthalate,
polyethylene
glycol and polyethylene glycol monoether.
U.S. Patent No. 5,599,782 also discloses sulfonated polyester compounds
useful as soil release agents. Polymerizable monomers which are mentioned in
the
reference include m-sodiosulfobenzoic acid, dimethylsodiosulfoisophthalate,
dimethyl
terephthalate, terephthalic acid and ethylene glycol.
U.S. Patent No. 5,728,671 discloses sulfonated polyester compounds useful as
soil release agents having whitening properties.
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U.S. Patent No. 5,786,318 discloses polymerizing such monomers as sulfonated
aromatic dicarboxylic acids to produce soil release polymers for detergent
compositions. Other soil release polymers containing sulfonated polymers are
disclosed in U.S. Patent Nos. 5,789,365; 5,789,366; and 5,789,367.
The market for polyester compounds for use as soil releasing agents and/or
textile sizing agents and particularly sulfonated polyester compounds for this
purpose
has increased significantly in recent years. However, increased demand has
spurred
efforts to improve production capability ofthe desired sulfonated polyester
compounds.
Traditional methods of producing sulfonated polyester compounds foruse as soil
releasing agents and/or textile sizing agents are problematical for reasons
which
include expensive starting materials, lengthy process cycle (i.e. the time it
takes from
the initial reaction to the production of a finished product) and low yields
of the desired
product or relative low reactor throughput. By way of example, the production
of a
sulfonated polyester compound through a transesterification reaction of
dimethyl
terephthalic and dimethyl-5-sulfoisophthalate with excess ethylene glycol,
followed by
esterification with terephthalate acid and then polycondensation undergoes a
typical
cycle time of about 38.5 hours for processing a 15 ton batch of polyester.
Since the
reaction produces 35% of distillate, the long cycle time and low yield or
reactor
throughput makes it very difficult to meet the requirements of the growing
market
demand for such sulfonated polyester compounds.
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Summary Of The Invention
The present invention is directed to a process for the production of
sulfonated
polyester compounds in which reaction yields and cycle time are significantly
improved
over conventional processes for the production of the same or similar
compounds. The
present method is generally directed to the production of a sulfonated
polyester
compound suitable for use as a soil releasing agent and/or textile sizing
agent in which
a sulfonated acid or corresponding alkyl ester is reacted with a hydroxy-
containing
compound to produce a sulfonated ester intermediate compound which is then
reacted
with a polyester compound selected to afford the final polyester compound with
a desired
molecular weight.
In a broad aspect, the present invention relates to a method of producing a
sulfonated polyester compound suitable for use as a soil releasing agent or a
textile sizing
agent comprising: a) reacting at least one compound of Formula (I) XS03- R -
(COOY)n
(I) wherein X is a cation, R is an aryl group which may be substituted with an
alkyl group
or an aryl group, Y is selected from the group consisting of hydrogen and an
alkyl group,
and n is a positive integer with at least one compound of Formula (II) R,_
(OH)m (II)
wherein R, is selected from the group consisting of an alkyl group, a
cycloalkyl group and
an aryl group which groups may be substituted with an alkyl group or an aryl
group, and
m is a positive integer to produce at least one ester compound intermediate;
b) reacting
the ester compound intermediate with a homo-or co-poly (ethylene
trephthalacte) to
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produce the sulfonated polyestercompound; and c) isolating said sulfonated
polyestercompound.
In a particular aspect of the present invention, there is provided a method of
producing a sulfonated polyester compound suitable for use as a soil releasing
agent
and/or textile sizing agent comprising:
a) reacting at least one compound of Formula (I)
XS03 - R - (COOY)n (I)
wherein X is a cation,
R is an aryl group,
Y is selected from the group consisting of hydrogen and an alkyl group, and
n is a positive integer
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with at least one compound of Formula (II)
R,- (OH) m (II)
wherein R, is selected from the group consisting of an alkyl group, a
cycloalkyl group and
an aryl group, which may be substituted with an alkyl group or an aryl group,
and m is a
positive integer and optionally with a compound of Formula (III)
RZ - (COOZ)p (III)
wherein RZ is selected from the group consisting of an alkyl group and an aryl
group, Z is selected from the group consisting of hydrogen and an alkyl group,
and p is
a positive integer, and optionally with a compound of Formula (IV)
H O-(-C H z-C H-O-)-q-R4 ( I V)
R3
wherein R3 and R4 are each independently selected from the group consisting of
hydrogen
and an alkyl group, and q is a positive integer to produce at least one ester
compound
intermediate, and reacting the resulting ester compound intermediate with a
homo- or
co-poly (ethylene terephthalate) to produce the sulfonated polyester.
Detailed Description Of The Invention
The method of producing a sulfonated polyester compound in accordance with the
present invention for use as a soil releasing agent and/or textile sizing
agent begins with
the reaction of at least one compound of Formula (I)
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XS03 - R - (COOY)n (I)
wherein X is a cation, R is an aryl group which may be substituted with an
alkyl group
or an aryl group, Y is selected from the group consisting of hydrogen and an
alkyl group
and n is a positive integer. The cations available for X include, for example,
sodium,
lithium, potassium, NH4 and tetrabutylphosphonium. Sodium is the preferred
cation for
the compound of Formula (I). R is an aryl group and includes, for example,
phenyl,
and naphthyl.
The starting sulfonated compound may be in the form of an acid wherein Y is
hydrogen or in the form of an alkyl ester. Preferred alkyl groups are methyl,
ethyl,
propyl and butyl with methyl being the preferred alkyl group. The number of
acid or
ester groups is from 1 to 4, preferably 1 or 2. The most preferred number of
acid or
ester groups is 2.
Examples of suitable compounds of Formula (I) include dimethyl-5-
sodiosulfoterephthalate, 5-sodiosulfoterephthalic acid, 5-lithoisophthalic
acid, 3-
sodiosulfobenzoic acid, and 4-sodiosulfodiphenyl-4, 4'-dicarboxylic acid. The
preferred
compounds of Formula (I) are sodiosulfoisophthalic acid and 3-
sodiosulfobenzoic acid.
The compound of Formula (I) is reacted with a hydroxy-containing compound of
Formula (II) R, - (OH)m. The hydroxy-containing compound can be selected from
monols, diols and polyols. R, is selected from the group consisting of
unsubstituted
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alkyl, cycloalkyl, and aryl groups which may be substituted with an alkyl
group and an
aryl group. Preferred alkyl groups are those having 1-8 carbon atoms most
preferably
methyl, ethyl, propyl, and butyl. Preferred cycloalkyl groups are those having
5 to 8
carbon atoms such as cyclohexanyl. Preferred aryl groups for R, include phenyl
and
naphthyl. M is preferably in the range of from 1 to 4, most preferably 2.
Preferred
compounds of Formula (II) include ethylene glycol, 1, 2- propylene glycol, 1,
3-
propanediol, neopentyl glycol, glycerol, 1, 2 butylene glycol, 1, 4-
butanediol, 2, 2-
dimethyl-1, 3-propanediol, 1, 6-hexanediol and 1, 4-cyclohexanedimethanol.
In addition to compounds of Formulas (I) and (II), the reaction can also be
conducted in the presence of a compound of Formula (III).
RZ - (COOZ)p (III)
depending on the application of the final polymer. RZ is selected from the
group
consisting of an alkyl group and an aryl group, which may be substituted with
an alkyl
group or an aryl group. Z is selected from the group consisting of hydrogen
and an
alkyl group and p is a positive integer. Preferred alkyl groups are those
having 1-12
carbon atoms. Preferred alkyl groups for Z are those having 1-4 carbon atoms.
Preferred values for P are 1 and 2. Exemplary compounds where RZ is an alkyl
group
include adipic, succinic, sebacic, azelaic, glutaric and suberic acids and
their
corresponding alkyl esters. Exemplary compounds where R2 is an aryl group
include
terephthalic, isophthalic, orthophthalic, 1, 2-naphthalene dicarboxylic, 1, 4-
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naphthalenedicarboxylic, 1, 5-naphthalenedicarboxylic, 1, 6-
naphthalenedicarboxylic, 1,
7-naphthalenedecarboxylic,1, 8-naphthalenedicarboxylic, 2, 3-
naphthalenedicarboxylic,
2, 6-naphthalenedicarboxylic, 2, 7-naphthalenedicarboxylic acids and
theircorresponding
alkyl esters.
A compound of Formula (IV) may also be used as an optional starting material
HO-(-CHz-CH-O-)-q-R4 (IV)
Ra
wherein R3 and R4 are each independently selected from the group consisting of
hydrogen
and an alkyl group and q is a positive integer.
Preferred alkyl groups for R3 are those having 1-4 carbon atoms. Preferred
alkyl
groups for R4 are those having 1-12 carbon atoms especially methyl and lauryl.
Preferred
values for q are 2-20. Exemplary compounds of the optional material of Formula
(IV)
include polyethylene glycol, polypropylene glycol and block copolymers of
polyethylene
glycol and polypropylene glycol and their corresponding alkyl monoethers. The
compounds of Formula (IV) preferably have a molecular weight of no more than
about
1, 000.
The reaction of the compounds of Formulas (I) and (II) optionally in the
presence
of at least one compound of Formulas (III) and (IV) is typically conducted at
a temperature
of from about 120 to280°C, preferably from about 130 to190°C.
The reaction is typically
carried out in the presence of a catalyst capable of catalyzing
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esterfication and/or transesterification reactions, such as, for example
titanium (IV)
(triethanolaminato) isopropoxide, titanium (IV) propoxide, titanium (IV)
butoxide,
manganese acetate, antimony trioxide, hydrated monobutyltin oxide and
magnesium
oxide. Other suitable catalysts would be well known to these skilled in the
art. The
preferred catalyst is titanium (IV) (triethanolaminato) isopropoxide.
The reaction of the compounds of Formulas (I) and (II) and optionally at least
one compound of Formulas (III) and (IV) produces at least one ester compound
intermediate. The ester compound intermediate is then reacted continuously or
intermittently with a homo-or co-poly (ethylene terephthalate) to produce the
desired
sulfonated polyester compound. This reaction is typically conducted at a
temperature
of from about 150 to 280°C, preferably form about 180 to 260°C.
Depending on the
desired molecular weight, a vacuum of from about 600 to 0.5 mmHg can be
applied
after all of the poly (ethylene terephthalate) has melted.
The preferred poly (ethylene terephthalate) compounds for reacting with the
ester compound intermediate is a copolymer of polyethylene terephthalate and
comonomers selected from the group consisting of isophthalate, diethylene
glycol,
propylene glycol, and 1, 4-cyclohexanedimethanol. The resulting reaction
produces a
sulfonated polyester compound wherein the position and number of sulfonated
groups
are determined by the suitable selection of the starting materials. By
selecting a
compound of Formula (I) wherein n is 1, at least some of the sulfonated groups
will
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appear as an end group in the polyester chain. By employing at least one
compound
of Formula (I) wherein n is greater than 1, at least some of the sulfonated
groups will
appear intermittently in the polyester compound and not as an end group.
The following examples are illustrative of the embodiments of the invention
and
are not intended to limit the invention as encompassed by the claims forming
part of the
application.
EXAMPLES
Example 1:
To a 1 liter resin reactor equipped with a mechanical stirrer, a packed
refluxing
column, a nitrogen inlet, and a heat source was added 350 g of ethylene
glycol, 200 g
of 5-sodiosulfoisophthalic acid, 20 g of isophthalic acid and 1.2 g of
titanium (IV)
(triethanolaminato) isopropoxide. The mixture was heated to 230° C and
held at that
temperature for 30 minutes. 380 g of polyethylene terephthalate) was added and
the
mixture was heated to 230° C. Another 440 g of polyethylene
terephthalate) was
added and the mixture was heated to 260° C. When the batch temperature
had
reached 260° C, a vacuum was applied to 200 mmHg and the polymer was
held for 20
minutes and then cooled to 160° C for discharge. The resulting polymer
exhibited
excellent soil releasing properties.
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Example 2:
The procedure and materials as set forth in Example 1 were repeated except
that a mixture of 250 g of diethylene glycol and 50 g of ethylene glycol was
used as a
starting material in place of 350 g of ethylene glycol. The resulting polymer
exhibited
excellent soil releasing properties.
Example 3:
The procedure and materials as set forth in Example 1 were repeated except
that 5-lithosulfoisophthalic acid was used to replace 5-sodiosulfoisophthalic
acid. The
resulting polymer exhibited excellent soil releasing properties.
Example 4:
The procedure and materials as set forth in Example 1 were repeated except
that the starting materials were heated to 185°C and held for 30
minutes before the
polyethylene terephthalate was added.
Example 5:
A mixture of 201 g of 5-sodiosulfoisophthalic acid, 300 g ethylene glycol and
150g of polyethylene glycol having a molecular weight of 200 was heated to
185°C and
held for 30 minutes. 380g of a copolymer of poly (ethylene terephthalate -
ethylene
isophthalate) in a 60:40 weight ratio was added to the mixture and the
resulting mixture
was heated to 235°C. Thereafter 440g of the same copolymer was added to
the
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mixture and heated to 250°C under atmospheric pressure for two hours
followed by
cooling to 160°C for discharging. The resulting polymer exhibited
excellent soil
releasing properties.
Example 6:
A mixture of 140g of propylene glycol, 350g of ethylene glycol, 175g of 3-
sodiosulfobenzoic acid and 210g of 5-sodioisophthalic acid was heated to
230°C and
held for 30 minutes. 380g of polyethylene terephthalate) was added to the
mixture
which was then heated to 230°C. Thereafter 440g of the same copolymer
was added
to the mixture and heated to 250°C under atmospheric pressure fortwo
hours followed
by cooling to 160°C for discharging. The resulting polymer exhibited
excellent soil
releasing properties.
Example 7:
A mixture of 140 g of propylene glycol, 350g of ethylene glycol, 175g of 3-
sodiosulfobenzoic acid and 210g of 5-sodioisophthalic acid was heated to
230°C and
held for 30 minutes. 380g of poly (ethylene terephthalate) was added to the
mixture
which was then heated to 230°C. Thereafter an additional 440g of poly
(ethylene
terephthalate) was added and the mixture heated to 250°C. When the
temperature
reached 250°C, a vacuum was applied and the batch was held at 5mmHg for
five hours
before discharge. The resulting polymer exhibited excellent textile sizing
properties.
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Example 8:
450g of ethylene glycol, 160g of isophthalic acid, 171 g of 5-
sodiosulfoisophthalic
acid, 0.08g of antimony trioxide and 0.6 of titanium propoxide were combined
and
heated to 230°C and held for 30 minutes. 360g of poly (ethylene
terephthalate) was
added to the mixture which was heated to 240°C. Thereafter an
additional 380g of
polyethylene terephthalate) was added to the mixture followed by heating to
250°C.
When the temperature reached 250°C a vacuum was applied and the batch
was held
at 5mmHg for five hours before discharge. The resulting polymer exhibited
excellent
textile sizing properties.
Example 9:
400g of ethylene glycol, 171 g of sodiosulfoisophthalic acid, 0.08g of
antimony
trioxide and 0.6g titanium (IV) (triethanolaminato) isopropxide was heated to
185°C and
held for 30 minutes. 400g of a polyethylene terephthalate) containing 20 molar
% of
ethylene isophthalate was added and the batch was heated to 240°C.
Thereafter, an
additional 510g of the same poly (ethylene terephthalate) was added to the
mixture
followed by heating to 250°C. When the temperature reached
250°Cm a 5mmHg
vacuum was applied for three hours followed by discharge of the polymer. The
resulting polymer exhibited excellent textile sizing properties.
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