Title of Invention

"CROSS-LINKED POLYESTER POLYMERS"

Abstract ABSTRACT CROSS-LINKED POLYESTER POLYMERS A crosslinked polyester polymer comprising repeat units derived from a crosslinker and a polymerization mixture derived from (a) a carbonyl compound or oligomer thereof, (b) a glycol wherein said carbonyl compound is HO-R-COOH or RO2CACO2R; A is an alkylene group, arylene group, alkenylene group, or combinations of two or more thereof having 2 to 30 carbon atoms per group; each R is independently selected from (i) hydrogen, (ii) a hydrocarboxyl radical having a carboxylic acid group at the terminus, or (iii) a hydrocarbyl radical having 1 to 30 carbon atoms selected from an alkyl, alkenyl, aryl, alkaryl, aralkyl radical, or combinations of two or more thereof; said oligomer has 1 to 100 repeat units, preferably 2 to 20 units; characterized in that said crosslinker is a glycol-organosilane, which comprises or is produced by combining (a) a glycol and (b) an organosilane comprising DmSiXnZp; D is halogen, a hydroxyl, an alkoxy, or a polyoxyalkyl group; X is a hydrocarbon group containing 1 to 30 carbon atoms selected from an alkyl, alkenyl, aryl, alkaryl, aralkyl, alkylene, arylene, alkenylene, or combinations of two or more thereof; Z is a reactive hydrophobic group selected from a halogen, an ester, an aldehyde, a ketone, or a mercaptan; each of m and n is 1 to 3; and p is 1 to 20.
Full Text FIELD OF THE INVENTION
This invention relates to a crosslinked polyester copolymer, to a composition that can be used to produce the polyester, to a process for producing the composition and the crosslinked polyester copolymer.
BACKGROUND OF THE INVENTION
Polyesters are widely used to manufacture textile fibers, containers, and packaging materials. Polyesters can be manufactured by combining a glycol, such as ethylene glycol, and a carbonyl compound, such as dimethyl terephthalate (DMT) or terephthalic acid (TPA). In the DMT route, DMT reacts with the glycol to form a bis-glycolate ester of terephthalate ("monomer") in an ester exchanger column. The monomer is then polymerized by condensation reactions in one or two prepolymerizers and then a final polymerizer or finisher.
In the TPA route, TPA is combined with the glycol to form a slurry at 60°C to 100 °C followed by injecting the slurry into an esterifier. A linear oligomer with a degree of polymerization 5 to 10 is formed in one or two esterifiers at temperatures from 240°C to 290°C. The oligomer is polymerized in one or two prepolymerizers and then in a final polymerizer at temperatures from 250°C to 300°C. Water is a byproduct of the TPA esterification and polycondensation process.
A problem associated with polyester fibers is their tendency to pill. Pilling is a defect in fabric caused when fibers are rubbed or pulled out of yarns and entangled with intact fibers, forming soft, fuzzy balls on the fabric surface. One of the most common commercial practices to produce pilling resistant fibers is to make lower molecular weight polyester. Unfortunately, spinning is very difficult or impossible with lower molecular weight polyester fibers. A temporary crosslinker or brancher can be used to increase molecular weight and polymer strength for better spinning performance. After spinning, the temporary crosslinks or branches hydrolyze in water. Tetraethoxysilane (TEOS) has been used commercially in DMT process to produce pilling resistance fibers. TPA process,

however, has byproduct water, TEOS forms rocks or sands in the recycle glycol
of TPA process.
The dilemma is mat the temporary crosslmker or brancher must hydrolyze
after spinning, but it must not hydrolyze in TPA polymerization process where
mere is water. US patent 6,407,194 discloses a temporary crosslinker 3-
Glycidoxypropyltrimethoxysilane (QTMS) to improve the pilling resistant of
polyester fibers, which does not form solids in the TPA process. The spinning
performance of polyester containing GTMS, however, is not as good as the
polyester containing TEOS, because GTMS forms permanent crosslinks or
branches due to the hydrophilic epoxy group hi addition to the temporary
crosslinks or branches, resulting hi excessive crosslinks or branches hi the
polyester. According to the invention, GTMS is merely dissolved in the glycol
solution befpre injection, most methanol byproduct from GTMS emits hi the TPA
polymerization process
Most new polyester plants built hi the world are based on the newer TPA
process. Therefore, mere is an increasing need to develop a polyester polymer
having lower molecular weight that is crosslinked with a temporary crossUnker to
increase molecular weight for spuming, which does not form solids hi TPA
process.
An additional consideration for producing polyester polymers is the rate of
crystallization of partially oriented yarn (POY) during spuming. Normal spinning
speeds are typically in the order of 3000-3500 m/min for POY. At higher
spinning speeds, such as 4000-5000 m/min, crystallization of the POY can occur
too fast, resulting hi low orientation hi fibers and deteriorates physical properties
such as tenacity, elongation, and shrinkage. Further, the draw texturing speed of
POY is normally about 900 m/min. Higher draw texturing speed such as 1000
m/min requires POY with lower crystallization.
Also, for container and packaging materials, polyethylene terephthalate
(PET) are often modified with a comonomer such as isophthalic acid (EPA) and
diethylene glycol (DEG) to reduce the crystallization rate during injection or
extrusion blow molding. However, the resulting products have lower strength due
to these additives.
Normal PET fibers require disperse dye at temperature 120 °C to 140 °C
under high pressure. PET copolymer containing additives such as polyethylene
glycol can be dyed at temperature 100 °C or lower under atmospheric pressure,
but its melt strength is low and spinning is more difficult. PET copolymer
containing lPA 15% to 40% by mole has been commercially produced for binder
fibers, tills copolymer can be difficult to spin because me melt strength is low.
Accordingly, mere is a desire to decrease the crystallization rate of the
polyester polymer during sphining without adversely altering the physical
properties of the polyester polymer fiber; to develop a polyester composition and
process suitable for injection and extrusion blow molding for container and
packaging materials, which has low rate of crystallization, good heat resistance,
high strength and clarity; and to develop a polyester copolymer with higher melt
strength for fiber products such as binder fibers, biodegradable fibers,
atmospherically dyeable fibers.
SUMMARY OF THE INVENTION
The present invention comprises a glycol-organosilane composition that
comprises or is produced by combining (a) a glycol and (b) an organosilane
comprising ^£»pCnZp» where D is a halogen, a hydrogen, a hydroxyl, or a
hydrocarbon oxygen group; X is a hydrocarbon or a hydrocarbon oxygen group; Z
is a reactive hydrophobic group or a hydrophilic group; m and n are each about 1
to about 3; and p is 1 to 20. This composition is preferably substantially soluble
in glycol and water.
The invention also comprises a crosslinked polyester copolymer
composition and a process to produce the composition. The composition
comprises repeat units derived from (a) a carbonyl compound or its oligomer, (b)
a glycol, (c) a crosslinker, and (d) optionally a comonomer. A preferred process
for producing the polyester copolymer comprises contacting a crosslinker, and
optionally a comonomer, with a polymerization mixture comprising or consisting
essentially of a glycol and either a carbonyl compound or its oligomer. The
process can be used for increasing the rate of polymerization, for increasing the
pill resistance or strength of a polyester copolymer, or for decreasing the
crystalliiatiori rate during object forming process such as spuming of fibers or
• injection and extrusion blow Molding and stretching of containers and packaging
materials.
DETAILED DESCRIPTION OF THE INVENTION
The terms "crosslinked polyester polymer" and "crosslinked polyester
copolymer" are alternatively used herein referring polyester polymer containing
temporary or permanent crosslinker or brancher, with or without a comonoraer.
The term "temporary crosslinker" herein refers to a composition that
temporary crosslinks or branches polyester molecules, and thereby increases the
molecular weight of the polyester polymer and melt viscosity. The bonds of the
branches or crosslinks (Si-6) formed by the crosslinker can be broken down after
spuming by hydrolysis in water, moisture, alcohol, a weak acid, or a weak base.
The term "permanent crosslinker" herein refers to a composition that
permanently crosslinks or branches polyester molecules. The bonds of the
crosslink an1^ branches d,P not break down in water, an alcohol, a weak acid, or a
weak base.
The term "glycol-organosilane composition" and "glycol-organosilane" as
used herein refers to a product produced from a glycol and an organosilane,
preferably ft is a product produced by partially reacting the organosilane with the
glycol. By partially reacting or reacted, it is meant that about 20% to about 99%,
preferably 50% to 95%, even more preferably 60% to 90%, by mole, of all
reactive functional groups hi the organosilane molecule that can react with a
glycol are reacted with the glycol. The term "reactive functional groups" refers to
those functional groups that can react with a glycol. The term "reactive functional
groups" herein can also refer to those functional groups that can react with an
alcohol, a carbonyl compound, an acid or base as disclosed below.
Wishing not to be bound by theory, ft is believed that, if the extent of
reaction te tcjd low (i.e, less than 20 mole %), the glycol-organosilane composition
cannot be dissolved hi water unless the Z is a hydrophilic group and that if the
extent of reaction is too high (i.e., more men 99%), there can be some undesirable
side reactions. The extent of the reaction can be determined by any suitable
means known to one skilled in the art, such as by chemical analysis of functional
groups or by weighing the byproduct separated by a suitable means such as
distillation or filtration.
Tne glycol-organosilane composition can comprise (a) a glycol and (b) an
organosilane DmSiXnZp, where D is a halogen, a hydrogen, a hydroxyl, or a
hydrocarbon oxygen group; X is a hydrocarbon or a hydrocarbon oxygen group; Z
is a reactive hydrophobic group or a hydrophilic group; m and n are each about 1
to about 3; and p is 1 to 20. Preferably, D is independently a halogen such as a
fluorine, a chlorine, A bromine, an iodine, an alkoxy, or a polyoxyalkyl group;
each X is independently a hydrocarbon group containing 1 to 30 carbon atoms
selected from an alkyl, alkenyl, aryl, alkaryl, aralkyl, alkylene, arylene,
alkenylene, or combinations of two or more thereof; and each Z is independently a
halogen, a carbonyl, a mercaptan, a hydroxy, an epoxy, a polyoxyalkyl group, a
sulfonic acid or a salt thereof, an amine, an isocyan, or combmations thereof; m is
1 to 3; n is 1 to 3; and p is 1 to 20.
Z can be a reactive hydrophobic group or a hydrophilic group. The term
"reactive hydrophobic group" as used herein refers to a hydrophobic group which
can react with other compounds or functional groups such as an alcohol, water, an
acid, a base, or a carbonyl compound. Example of reactive hydrophobic groups
include, but are not limit to, a halogen, an ester, a ketone group, an aldehyde, a
polyoxyalkyl group, or a mercaptan. As a halogen, it can be fluorine, chlorine,
bromjnk jfodhte, or their combinations. When Z is a reactive hydrophobic group,
the organosilane DmJ>iX^Zp is not soluble hi water or ethylene glycol unless it is
partially or completely reacted hi the glycol-organosilane composition.
Examples of the organosilane compounds, where Z is a reactive
hydrophobic group, include, but are not limited to, 3-
acetoxypropyltrimemoxysilane, 3-acetoxypropyltriethoxysilane, 3-
acetoxvpropyltrichlorosilane, 3-methaayloxypropyltrimethoxysilane, 3-
methacryloxypropyltriemoxysilane, 2-(carbomemoxy)emyltrichIorosilane, 2-
(carbomethoxy)emyltrimethoxysilane, 3-chloropropyltrichlorosilane, 3-
chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3-
chloropropylmemyldimethoxysilane, 3-chloropropyhnethyIdiethoxysilane, 3-
mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane,
chloromethyltrichlorosilane, chloromemyltrimethoxysilane, •
cUorometiiyltoethoxysilane, and combinations of two or more thereof.
WhenZisahydrophilicgroiip.theorganosilaneDnjSiXnZpcanbe
substantially soluble in water or glycol at ambient temperature or elevated
temperature from 20 to 100 degree C. Examples of hydrophilic groups include,
but are not limited to, a hydroxy, an epoxy, a sulfonic acid or a salt thereof, a
carboxylic acid or a salt thereof, an amine, and an isocyan. Examples of the
organosilane compounds, where Z is a hydrophilic group, include, but are not
limited to, 3-aminopropyItrimethoxysilane, 3-aminopropyltriethoxysilane,
methylaminopropyltrimethoxysilane, N-[3-
(trimethoxysilyl)propyl]ethylenediamine,
amuioemylaminoprppyltrimeaioxysilane, amhioelhylaniinopropyltriethoxysilane,
3-hyd^xypropyltrimethoxysilane, 3-hydroxypropyltriethoxysilane,
hydroxymethyltriemoxysilane, hydroxymethyltrimethoxysilane, 3-
glycidoxypropyftrimethoxysilane, 3-glycidoxypropyItriethoxysilane, and
The ratio of organosilane compound to glycol can be between 0.001:1 to
1:1, preferably between 0.01:1 to 0.3:1, and most preferably 0.05:1 to 0.2:1 by
mole. The presently preferred glycol is a glycol of the formula (HO)nA(OH)n, hi
which A is an alkylene group, an arylene group, alkenylene group, a hydrocarbon
oxygen group, or their combinations; and n is 1 to 3. Examples of suitable glycols
include, but are not limited to, ethylene glycol, 1,2-propanediol, 1,3-propanediol,
1,2-butanediol, 1,3-butanediol, 1,4-butanediol, pentylene glycol, neopentyl glycol,
1,4-cyclohexanedimethanol, diemylene glycol, triethylene glycol, polyethylene
glycol, polyaQcylene glycol, alkoxylated glycol, or combinations of two or more
thereof. The presently most preferred glycol is an alkylene glycol such as
ethylene glycol, 1,3-propanediol, 1,4-butanediol, or combmations of two or more
thereof.
Optionally, the grycol-organosilane composition can comprise a catalyst.
The catalyst tan be a mineral acid, a Lewis acid, or a base. The molar ratio of
catalyst to organosilane compound can be between about 0.001:1 and about 2:1,
preferably between about 0.01:1 and about 1:1. The catalysts can be
heterogeneous, hi the form of pellets of beads, depending on equipment design, or
homogeneous, Le., completely soluble in the reaction medium. Examples of acid
catalysts Include, but are not limited to, phosphoric acid or salts thereof,
phosphorous acid or salts thereof, hydrochloric acid, sulfuric acid, p-toluenesulfonic
acid, and combinations of two or more thereof. Examples of basic
catalysts include, but are not limited to, tertiary amines, alkali metal hydroxides
and alkali earth metal hydroxides such as lithium hydroxide, sodium hydroxide,
potassium hydroxide, calcium hydroxide, alkali metal alkoxides and alkali earth
metal alkjjxid^s such as lithium methylate, lithium ethylate, sodium methylate,
sodium ethylate, sodium propoxide, potassium methylate, potassium ethylate, and
combmations of two or more thereof. The acid or base catalyst disclosed above
can also participate in the reaction as a reactant to partially or completely react
with the glycol or organosilane.
Optionally, the glycol organosilane composition can also comprise water
hi the range from about 0.1% to about 20% based on the weight of the
composition.
The glycol-oragnosilane can be prepared by any method known to pne
skilled hi the art hi any suitable vessels such as a mixing tank. In a preferred
method, the organosilane, glycol, and optionally catalyst, can be combined, in any.
order, under a suitable condition effective for the production of the composition or
a reaction product Such a condition can include a temperature hi the range of
from about 0 °C to about 220 °C, preferably about 80 °C to about 190 °C, most
preferably 100 °C to 180°C, under a pressure mat can accommodate the
temperature range, and for a period of time sufficient to produce the composition
or the reaction product If desired, the combination can be aided with a mixing
such as a mechanical agitation. The glycol-organosilane composition for use with
the invention can be produced on she where it is to be used. It can also be made
hi another location, optionally at a higher organosilane concentration, and
transported to the site for use. The invention process can be a batch process that is
simple and inexpensive to operate. It can also be carried out by any continuously
methods known to one skilled in the art
The glycol-organosilane composition obtained from a suitable reaction
vessel can be used as produced without further purification. The composition can
also be further purified by any means known to one skilled in the art if desired.
Hie byproduct in the glycol-organosilane composition is preferably partially or
completely removed by any suitable means known to one skilled in the art such as
distillation or filtration. Examples of byproducts, which can present in the range
of from about 0.1% to about 20% based on the weight of the composition,
include, but are not limited to, memanol, ethanol, hydrogen halides such as
hydrogen chloride and hydrogen bromide, halogen metal salts or halogen earth
metal $alt& fyich as lithium chloride, sodium chloride, potassium chloride and
ammonium chloride, itbr example, the solution of 3-
acetoxypropyltrimethoxysilan in glycol can be heated between 40 °C and 200 °C,
preferably between 80 °C and 160 °C, to partially or completely remove and
condense the byproduct memanol and acetic acid.
The glycol-organosilane composition can be dissolved in a solvent in any
suitable manner and in any suitable container, vessel, or reactor at ambient
temperature or elevated temperatures from 20 °C to 200 °C. Examples of suitable
solvents include, but are not limited to, water, alkyl alcohol, ethylene glycol,
isopropylene glycol, butylene glycol, 1-methyl propylene glycol, pentylene
glycol, diemylene glycol, triethylene glycol, polyethylene glycols,
polyoxyethylene glycols, polyoxypropylene glycols, polyoxybutylene glycols, and
combinations of two or more thereof. A preferred solvent is an alkylene glycol,
such as ethylene glycol, l,3*propanediol, 1,4-butanediol, or combinations of two
The glycol-organosilane composition can be used hi a variety of
applications such as (a) as coupling agents; (b) as treatment of surfaces, including
fillers and pigments; (c) as additives to coatings or paints; (d) as additives to
adhesives; (e) as additives to organic monomers (such as acrylics, halogenated
monomer, and polyester monomer) prior to formation of the respective polymers;
(f) as a rubber-processing aid, to treat and couple the inorganic fillers hi
halogenated rubber such as chlorobutadiene rubber, chlorinated butyl rubber,
chlorohydrined rubber, and chlorosulfonated polyethylene, so as to improve their
physical-mechanical properties; and (g) as a temporary crosslinker for polyester
described below.
The invention also provides a crosslinked polyester copolymer
composition. The composition comprises repeat units derived from (a) a carbonyl
compound or oligomer thereof (b) an alkylene glycol, (c) a crosslinker, and (d)
optionally a comonomer.
The carbonyl compound can have the formula of HO-R'-COOH or
RCA'CCR1 in which A1 is an alkylene group, arylene group, alkenylette
group, or combmations of two or more thereof having 2 to 30 carbon atoms per
group; each R1 is independently selected from (i) hydrogen, (ii) a hydrocarboxyl
radical having a carboxylic acid group at the terminus, or (iii) a hydrocarbyl
radical having 1 to 30 carbon atoms selected from an alkyl, alkenyl, aryl, alkaryl,
aralkyl radical, or combmations of two or more thereof.
The preferred carbonyl compound is an organic acid or ester thereof
having the formula of R'COOR1 in which each R1 is the same as that disclosed
above. The more preferred organic acid is an organic acid having the formula of
HQzCA'COjH in which A1 is the same as disclosed above. Each A1 has about 2
to about 30, preferably about 4 to about 20, and most preferably 6 to 10 carbon
atoms per group. Examples of suitable organic acids include, but are not limited
to, terephthalic acid, isophthalic acid, naphtfaalenedicarboxylic acid, oxalic acid,
maleiq acid: Stuctinic acid, glUtaric a£id, adipic acid, and combmations of two or
more thereof. The presently preferred organic diacid is terephthalic acid because
the polyesters produced therefrom have a wide range of industrial applications.
Examples of suitable esters include, but are not limited to, dimethyl terephthalate,
dimethyl isophmalate, dimethyl naphthalenedicarboxylate, dimethyl adipate,
dimethyl glutarate, and combmations of two or more thereof.
Examples of carboxylic acid metal salts or esters thereof includes i S-sulfo
isophmalate metal salt and its ester having the formula of (R2QzArSCOJaOM in
which each R2 can be the same or different and is hydrogen or an alkyl or a
hydroxyalkyl group containing 1 to about 6, preferably 1 to 3, carbon atoms. Ar
is a phenylene group. M can be an alkali metal ion such as sodium or lithum.
Specific examples include dimethyl 5-sulfo-isophthalate sodium salt; dimethyl 5-
sulfo-isophthalate lithium salt, bis-glycolate ester of 5-sulfo-isophthalate sodium
salt, bis-glycolate ester of 5-sulfo-isophthalate lithium salt, sodium salt of 5-sulfoisophtnalic
acid, lithium salt of 5-sulfo-isophthalic acid.
• The oligomer generally can contain 1 to 100 repeat units.
The crosslinker can be a first crosslinker, a second crosslinker, or
combinations thereof The first crosslinker is a glycol-organosilane composition
disclosed above. When the first crosslinker is used, diethylene glycol, triethylene
grycol, polyethylene glycol, polyalkylene glycol, alkoxylated glycol can also be
used hi addition to the alkylene glycol to produce the polyester copolymer.
The second crosslinker can be a carbonyl compound containing 3 or more
carboxyl groups, an alcohol containing 3 or more hydroxyl groups, or a compound
having combinations of 3 or more carbonyl and hydroxyl groups. Examples of
the second crosslinkers include, but are not limited to, trimellitic anhydride, 1,2,4-
benzenetricarboxylic acid, ester of 1^,4-benzenetricarboxylic acid, 1,3,5-
benzenetricarboxylic acid, ester of 1,3,5-benzenetricarboxylic acid, pyromellitic
dianhydride, trimethylolpropane, l,l,l-tris(hydroxymethyl)ethane,
pentaerythritol, tartaric acid, citric acid, gallic acid, pyrogallol, glycol mixture
thereof; and combinations of two of more thereof. Preferably the crosslinker is a
carbonyl compound containing 3 carboxyl groups, such as trimellitic acid or its
anhydride or its grycol ester, trimesic acid or its glycol ester.
The preferred comonomer is a dicarboxylic compound other than
terephmalic acid or its ester or its oligomer, a diol compound other than said
alkylene glycol; or a carbonyl alcohol containing one carboxyl group and one
hydroxyl group. Illustrative examples of the comonomers include, but are] not
limited to, isophthalic acid, phmalic acid, cyclohexane dicarboxylic acid, 1,2-
cyclohexanedicarboxylic anhydride, naphthalenedicarboxylic acid, oxalic acid,
malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, maleic acid,
fumaric acid, maleic anhydride, dimethyl phthalate, dimethyl isophthalate,
dimethyl naphthalenedicarboxylate, dhnethyl cyclohexane dicarboxylate,
dhnethyl glutarate, dimethyl adipate, diethylene glycol, triethylene glycol,
polyethylene grycol, polypropylene glycol, polyoxyethylene glycol,
polyoxyp'fdyierie glycol, bolyoxybutylene grycol, 1,4-cyclohexanedimethanoi,
neopentyl glycol, lactic acid, 2-hydroxybenzoic acid, 4-hydroxybenzoic acid,
mandelic acid, glycol mixture thereof, and combinations of two or more thereof.
The polyester copolymer can contain, by weight, repeat units derived from
the comonomer about 0.1% to about 50%; the crosslinker about SO ppm (parts per
million) to about 5,000 ppm, preferably 200 to 2,000 ppm. The rest of the repeat
- 10 -
units are derived from the carbonyl compound and the alkylene glycol. Low level
of crosslinks or branches is preferred. If the concentration of crosslinker is too
high (i.e., more then 5,000 ppm of polymer weight), excessive crosslink may
form, which adversely affect polyester properties.
The first crosslinker is also referred to as temporary crosslinker while the
second crosslinker is also referred to as permanent crosslinker. A polyester
polymer comprising repeat unit derived, or is produced from, the first crosslinker
is generally referred to as a temporarily crosslinked polyester copolymer while
that produced from the second crosslinker is referred to as permanently
crosslinked polyester copolymer.
I have unexpectedly found that the permanently crosslinked polyester
copolymer containing a comonomer described above can simultaneously increase
the rate of polymerization, reduce the rate of crystallization, and increase the melt
strength during an object forming process such as spuming of fibers and injection,
extrusion or stretching of containers and packaging materials. I also found that
permanently crosslinked polyester copolymer containing a comonomer described
above can simultaneously increase the rate of polymerization, improve the
dyeability and nteft strenglfy therefore improving spinning performance of fibers.
For applications such as containers and packaging materials, a
permanently crosslinked polyester copolymer can increase the rate of,
polymerization, reduce the rate of crystallization, increase the melt strength during
object forming process such as stretching, injection, extrusion and blow molding,
and improve the heat resistance and clarity of the finished products. The
comonomer can be about 0.1% to about 10%, preferably about 0.3% to about 3%,
based on polymer weight
For applications such as atmospherically dyeable fibers, a permanently
crosslinked polyester copolymer can increase the rate of polymerization, increase
the melt strength, improve spuming and dyeability; the comonomer can be about
1% to about 20%, preferably about 3% to about 10%, based on polymer weight.
For applications such as binder fibers and biodegradable fibers, a permanently
crosslinked polyester polymer can increase the rate of polymerization, increase
tiie melt strength and improve spinning; the comonomer can be about 5% to about
50%, preferably about 15% to about 40%, based on polymer weight.
The crosglinked polyester copolymer can also comprise or consist
essentially pf repeat units derived from a carbonyl compound, a glycol, and a
glycol-organosilane as a first crosslinker. The organosilane DmSiX of the
glycol-organosilane composition can be in the range from about 0.02% to about
3%, preferably about 0.06% to about 1%, most preferably from about 0.1% to
about 0.5%, based on me weight of me polyester copolymer. This temporary
crosslinker can simultaneously increase the rate of polymerization and increase
the pill resistance of a polyester copolymer.
The present invention also provides a process for higher speed spinning to
increase assets productivity. The normal spinning speed for partially oriented
yarn (POY) is about 3000 to 3500 meter/min. Spuming speed is limited by the
rate of crystallization during spinning. Temporary crosslinker glycolorganosilane
reduces the crystallization rate therefore spinning speed can be
increased to 3500-5000 m/min. The organosilane DmSD£aZp can be in the range
from about O.Q1% to about 1%, preferably about 0.03% to 0.3%, based on the
weight of the polyester copolymer.
In case high speed spinning of 3500-5000 m/min is not desired, temporary
crosslinker glycol-organosilane can reduce the crystallinity of POY. Normal draw
texturing speed of POY is limited to about 900 m/min. When the crystallinity of
POY decreases at normal speed 3000-3500 m/min due to the temporary
crosslinker, draw texturing speed can be increased to about 1000 m/min.
The glycol-organosilane composition disclosed above forms temporary
crosslinks or branches hi the polyester, which hydrolyze after spinning hi the
presence of moisture, water, an alcohol, a weak acid, or a weak base. It does not
form rocks or sands in the TPA polymerization process where there is water
byproduct After spuming and draw texturing, the temporary crosslinks or
branches break down by hydrolysis with water hi process such as wet drawing and
dye bath or moisture from the air. After hydrolysis, the fibers products are the
same as 1
- 12 -
Preferably, the glycol-organosilane does not form any permanent Crosslink
or branch which affects spinning performance. Because the glycol-organosilane
composition is partially reacted, byproduct such as memanol can be removed
before addihg to polymerization process, byproduct emission in polymerization
The crosslinked polyester polymers disclosed above can be produced by
any method known to one skilled hi the art A preferred process for producing the
polymer comprises contacting a polymerization mixture with a crosslinker and,
for producing a permanently crosslinked polyester copolymer, a comonomer
disclosed above. The polymerization mixture can consist essentially of a glycol
and a carbonyl compound disclosed above. The weight or mole of each
compound required is the weight or mole mat can produce a desired copolyester
disclosed above. For example, the molar ratio of the glycol to carbonyl
compound can be any ratio so long as the ratio can effect the production of
polyester disclosed above. Generally me ratio can be in the range of front about
1:1 to about 10:1, preferably about 1:1 to about 4:1.
A suitable condition to effect the production of a polyester can include a
t the range of from about 200 °C to about 400 °C, and preferably
250 °C to 300 °C under a pressure hi the range of from about 0.001 to about 1
atmosphere (0.1 to 101.3 kPa) for a time period of from about 0.3 to about 20
hours, preferably about 1 to about 10 hours.
Also for example, the glycol-organosilane composition (or comonomer,
second crosslinker, or both) can be added together or separately to the
polymerization process before, during, or after transesterification of the carbonyl
compound; before, during, or after esterification of the carbonyl compound.
Similarly, me glycol-organosilane (or comonomer, second crosslinker, or both)
can be added before, during, or after porycondensation of the carbonyl component
or an oligomer of the carbonyl compound.
Optionally, a sulfonated isophmalate metal salt such as sodium dimethyl
sulfoisophthalate and lithium bis(2-hydroxyethy) 5-sulfoisophthalate or their
glycol splutibn can be added to the polymerization mixture. The sulfonated
isophthalate metal salt and crosslinker or comonomer can be added together or
separately.
I have unexpected found the polyester copolymer comprising a sulfonated
isophthalate metal salt, a carbonyl compound, a glycol, a temporary crosslinker,
and a comonomer is substantially soluble hi basic water solution. The polyester
copolymer composition comprising a sulfonated isophthalate metal salt, a
carbonyl compound, a glycol, with or without a comonomer, and a temporary
crosslinker can be dyed by cationic dyes, or can have better dyeability by disperse
dye. The sulfonated isophthalate metal salt, carbonyl compound, glycol,
temporary crosslinker, and comonomer are the same as those described above.
The comonomer and the crosslinker can be simply mixed, substantially
dissolved, or reacted with a solvent A comonomer and a crosslinker containing
one or mtyre Jiydroxyl groups can be substantially dissolved hi a solvent The
solvent can be an alcohol or water, preferably an alkylene glycol which is a
component of me polymerization mixture.
A comonomer and a crosslinker containing one or more carboxyl groups
can partially react or completely react with a glycol described above, preferably
partially reacted. The preferred partially reacted comonomer-glycol solution or
crosslinker-glycol solution can be prepared at the conditions similar to those
described above to produce partially reacted glycol-organosilane composition.
Optionally a catalyst such as a titanium catalyst can be added to the mixture.
When a comonomer or crosslinker containing one or more carboxyl
groups partially react with the alkylene glycol and substantially dissolve in the
glycol, presently preferred solution is mat about 20% to about 99%, more
preferably about 50% to about 95%, and most preferably 60% to 90%, of the
The
reaction product can bfc used as produced without further purification. The
composition can also be further purified by any means known to one skilled in the
art if desired. For example, a solution of isophthalic acid in glycol or a solution of
trimellitic anhydride hi glycol can be heated between 40 °C and 220 °C,
preferably between 100 °C and 190 °C, to partially or completely remove tod
condense byproduct water.
Optionally, other ingredients of the polymer such as catalyst, to T, optical
brightener, TiOj, or phosphorous compounds can be mixed with the com omerglycol
solution or crosslinker-glycol solution before they are added to the
polymerization mixture.
Any solvent mat can substantially dissolve the comonomer-glycol solut?,
or crosslinker-glycol solution discussed above can be used to dissolve fte
comonomer-glycol solution or crosslinker- glycol composition. The presently
preferred solvent is alkylene glycol such as ethylene glycol, 1,3-propanediol, or
1,4-butanediol.
present of a catalyst and optionally a phosphorous compound. The catalyst,
expressed as element Co, Sb, Mn, Zn, Si, Ge, or Ti, can be present hi the range of
about 1 to. about 5,000 ppm of the reaction medium comprising the carbonyl
compound and glycol, preferably about 10 to about 500 ppm, most preferably 30
to 300 ppm, by weight A presently preferred polycondensatioh catalyst is
antimony. Examples of suitable antimony compounds include, but are not limited
to, antimony oxides, antimony acetate, antimony glycolates, antimony phosphates,
and combinations of two or more thereof.
Any phosphorus compound mat; when used with a polyester catalyst,
produces polyester having low yellowness, as compared to a polyester produced
from the catalyst without such phosphorus compound, can be used. Examples of
suitable phosphorus compounds include, but are not limited to, a phosphoric acid
or salt thereof, a phosphorous acid or salt thereof, a polyphosphoric acid or a salt
thereof a pfaosphonate estefr, a pyrophosphoric acid or salt thereof, a
pyrophosphorous acid or salt thereof, di(polyoxyethylene) hydroxymethyl
phosphonate, triethyl phosphonoacetate, and combinations of two or more thereof.
• The salt can be an alkali metal salt or an alkaline earth metal salt.
Optionally, a TiOj or TiOj slurry can be added to the polymerization
mixture. The polyester produced by the invention process can contain TiO2 about
0.01% to about 5%, preferably about 0.03% to about 2.0%, based on polymer
weight
The invention process can also be carried out using conventional melt or
solid state techniques and in the presence or absence of a toner compound to
reduce the color of a polyester produced. Examples of toner compounds include,
but are not limited to, cobalt aluminate, cobalt acetate, carbazole violet, these
toner compounds are well known to those skilled in the art. The toner compound
can be used in the amount Of about 0.1 ppm to 1000 ppm, preferably about 1 ppm
to about i0p| fpm, based on the weight of polyester polymer produced.
The process of me invention can also be carried out using a conventional
melt or solid state technique and in the presence or absence of an optical
brightening compound to reduce the yellowness of the polyester produced.
Examples of optical brightening compounds include, but are not limited to, 7-
naphthotriazinyl-3-phenylcoumarin and 4,4'-bis(2-benzoxazoIyI) stilbene These
optical brightening compounds are well known to those skilled in the art The
optical brightening compound can be used hi the amount of about 0.1 ppm to
1,000 ppm, preferably about 1 ppm to about 100 ppm, based on the weight of
polyester polymer produced.
EXAMPLES
The following examples are included to further illustrate the invention and
Are not to be constructed as to unduly limit the scope of the invention.
P61ymoleaj weight idetermmed by intrmsicviscoshy(TvO. The
IV is expressed as hydrolyzedlV and unhydrolyzed IV. Unhydrolyzed IV
measures the molecular weight of the polyester containing temporary crosslinks.
Hydrolyzed IV measures the molecular weight of the polyester after its temporary
crosslinks breaks down by hydrolysis. Hydrolyzed IV is measured by the ratio of
!
the viscosity of a solution of 0.8 grams of polymer dissolved at room temperature
hi 10 ml of hexafluproisopropanol (HFIP) containing 100 ppm sulfuric acid to the
viscosity of me sulfuric acid containing HFIP itself, both measured at 25 °C in a
capillary viscometer. Unhydrolyzed IV analysis is similar to that of hydroryzed
IV without the sulfuric acid b HFIP.
EXAMPLE 1
This example compares the water mixtures of organosilane compounds
containing hydrophilic groups and those containing hydrophobic groups. The
16 -
epoxy group of 3-glycidoxypropyhrimethoxysilane (GTMS) and the amino group
of 3-aminopropyltrimcthoxysilane (ATMS) are hydrophilic, GTMS and ATMS
are soluble in water. The ester group of 3-acetoxypropyltrimelhoxysaanej
(APMS) and the chlorine of 3-chloropropyltrimethoxysilane (CPMS) are
hydrophobic, APMS and CPMS are not be soluble in water.
GTMS (10 g) and ATMS (10 g), both from Aldrich Chemical Company,
Milwaukee, WL USA, are separately added to water (SO g) in two beakers;. Each
mixture is agitated and heated to 60°C and hold for 10 minutes. After cooling to
room temperature (about 25°C), each mixture is a clear one-phase solution:
Similarly, APMS (10 g; from Gelest Inc., Morrisville, PA, USA) and
CPMS (10 g; fixnn Aldrich Chemical Company) are separately added to water . (50
g) in two open glass beakers. Each mixture is agitated and heated to 60°C and
hold for 10 minutes. After cooling to room temperature, each organosilane is in
the bottom of the beakers while water is on top. ,
EXAMPLE 2
This example compares me glycol mixtures of organosilane compounds
containing hydrophilic groups and those containing hydrophobic groups.
GTMS (10 g) and ATMS (10 g) are separately added to ethylene glycol
(SO g) in two separate open glass beakers. Each mixture is agitated and heated to
60°C and hold for 10 minutes. After cooling to room temperature, each mixture is
a clear one-phase solution.
Similarly, APMS (10 g) and CPMS (lOg) are separately added to ethylene
glycol (50 g) |n two separaie open glass beakers. Each mixture is agitated find
heated to 60°C and hold for 10 minutes. After cooling to room temperature,
glycol is in the bottom of the beakers and the organosilane on top.
EXAMPLES
This example compares tetraemoxysilane (TEOS), n-propyltriethoxysilane
(PES), and 3-AcetoxypropyttrfmemoxysiIane (APMS). TEOS molecule has four
hydrolysable Si-O-C bonds, but no Si-C bonds. PES molecule has three
hydrolysable Si-O-C bonds and one non-hydrolysable Si-C bond of the propyl
group. APMS molecule also has three hydrolysable Si-O-C bonds and one jnon-
hydrolysable Si-C bond of the propyl group. In addition, APMS molecule has an
ester group bonded to the propyl group. The partially reacted compositions of
TEOS hi ethylene glycol and partially reacted PBS hi ethylene glycol form solid
when they are mixed with water. The partially reacted composition of APMS hi
ethylene glycol is miscible with water, no solid is formed.
Sodium hydroxide (0.04 g) and each of TEOS (from Silbond Corpration,
Western, MI, USA; 20 g), PES (from Gelest Inc., Morrisville, PA; 20 g), and
APMS (20g) are added to 80 g of ethylene glycol hi a 250 ml open flask at room
temperature. Each mixture is agitated and heated at 150°C for 1 hour under a
hood. TEOS, PES, and APMS are partially reacted with ethylene glycol, reaction
byproduct eifoanbl is partially evaporated* Each mixture becomes a clear onephase
solution, which stays as a uniform clear solution after cooling to room
temperature. To test its miscibility with water, three solutions are prepared from
each mixture: (1) 5 g of the clear organosilane solution is added to 45 g of water
hi a 100 ml open beaker; (2) 20 g of the clear organosilane solution is added to 20
g of water hi a 100 ml open beaker; (3) 45 g of the clear organosilane solution is
added to 5 g of water hi a 100 ml open beaker. All aqueous solutions become
clear after stirring. After 8 hours without agnation, solids form in the bottom of
V
the six beakers of TEOS and PES aqueous solutions, but not hi the three beakers
of APMS aqueous solutions.
EXAMPLE 4
This example shows that a glycol organosilane composition is not soluble
hi water when the extent of reaction of organosilane with glycol is too low.
The procedure disclosed in EXAMPLE 3 is repeated with APMS and
CPES (3-Chloropropyltriethoxysilane; Aldrich Chemical) except mat sodium
hydroxide is not present, and the heating time at 150°C is 5 minutes instead of 1
hour. Each of the resulting glycol solutions becomes clear after cooling to room
temperature. Each of the glycol solution mixed with water is clear after stirring.
However, after 8 hours without agitation, each organosilane compound
precipitates to the bottom of the beaker with water and glycol solution on top.
EXAMPLES
Th; example illustrates polymerization of polyester containing temporary
Crosslin)' from a TPA oligomer in a kettle polymerization apparatus.
An oligomer of polyethylene terephthalate with a degree of polymerization
betr ,en 5 and 10 is obtained from a continuous esterification process.
T aphthalic acid is esterified by emylene glycol to form the oligomer in an
f erifier. The polyester esterification and polycondensation process are well
aown to one skilled in the art, only a brief description is provided herein
A pot is preheated to 265°C. A 500 ml resin kettle is provided with an
agitator, a thermocouple, condenser and nitrogen sweep. To this kettle it is added
105 g of eiHylene glycpl, 400 g of oligomer, 8 g of APMS in glycol composition
prepared in l&Lfi 3,6 g of Ti(D220% shirty hi emylene glycol and 4 g of
antimony glycolate solution (containing 1% Sb by weight). The temperature is
increased to 265°C and held there until oligomer is liquefied, the agitator is turned
on at 60 rpm. Temperature is raised to 275°C and vacuum reduced to 120 mm Hg
and held for 20 minutes. The temperature is then increased to 280°C and Vacuum
reduced to 30 mm Hg and hold for 20 minutes. Thereafter, the vacuum is reduced
to 1 mm Hg while temperature is held at 280°C. When the torque reaches 3 kg,
agitator speed is reduced to 40 rpm. Polymerization stops when the torque;
reaches 3 kg again. The polymer melt is poured into aluminum pots, and the
resultant solid is dried hi vacuum oven without heat for 1 hour and ground to pass
through a 2 mm filter. The grounded polymer has good color and is analyzed for
molecular weight. The non-hydrolyzed IV is about 0.55 ml/g at this torque, the
hydrolyzed IV about 0.39 ml/g.
GJPJJ!J? jo ethylene glyool composition is prepared similarly to the APMS in
ethylene glycol composition hi EXAMPLE 3. The recipe and polymerization
procedures are similar to that disclosed above, except mat 4 g of GPES in glycol
composition is added in place of 4 g of APMS in glycol composition. The
grounded polymer has good color and is analyzed for molecular weight. The nonhydrolyzed
IV is about 0.55 ml/g at this torque, the hydrolyzed IV about 0.40
ml/g.
EXAMPLE 6
This example illustrates polymerization of polyester containing permanent
crosslinks from a TPA oligomer in a kettle polymerization apparatus.
Ethylene glycol (EG; 78 g), isophthalic acid (IPA; 20 g) and trimellitic
anhydride (TMA; 2 g; from Aldrich Chemical Company) are added to a 250 ml
flask at rtoijl temperature. The mixture is agitated with a magnetic stirrer and
heated under a hood. The mixture is heated to about 180°C and hold for 2 hours.
IPA and TMA are partially reacted with ethylene glycol, reaction byproduct water
partially evaporated. After heating, the mixture becomes a clear one-phase
solution.
A 500-ml resin kettle is set up the same as that hi EXAMPLE 5. To this
kettle it is added 88 g of ethylene glycol, 400 g of oligomer described in
EXAMPLE S, 20 g of IPA and TMA in ethylene glycol solution prepared in the
above, 10 g of antimony glycolate hi emylene glycol solution (containing 1% Sb
by weight), 2 g of cobalt acetate tetrahydrate in ethylene glycol solution
(containing 1% Co by weight), 4 g of phosphoric acid hi ethylene glycol solution
(containing 1% HaPQi by weight). The polymerization is carried out the same as
disclosed hi EXAMPLE 5. Polymerization stops when the torque reaches 3 kg.
The polyjtn melt is poured into a water bam to solidify the melt; and the resultant
solid is crystallized at 90°C in a vacuum oven for 1 hour and ground to pass
through a 2 mm filter. The grounded polymer is dried hi the oven at 90°C for
another hour. The polymer have good color and can be analyzed for molecular
weight, intrinsic viscosity is about 0.7 ml/g at mis torque.





We claim;
1. A crosslinked polyester polymer comprising repeat units derived from a
crosslinker and a polymerization mixture derived from (a) a carbonyl compound
or oligomer thereof, (b) a glycol wherein said carbonyl compound is HO-R-
COOH or RO2CACO2R; A is an alkylene group, arylene group, alkenylene
group, or combinations of two or more thereof having 2 to 30 carbon atoms per
group; each R is independently selected from (i) hydrogen, (ii) a hydrocarboxyl
radical having a carboxylic acid group at the terminus, or (iii) a hydrocarbyl
radical having 1 to 30 carbon atoms selected from an alkyl, alkenyl, aryl,
alkaryl, aralkyl radical, or combinations of two or more thereof; said oligomer
has 1 to 100 repeat units, preferably 2 to 20 units;
characterized in that said crosslinker is a glycol-organosilane, which comprises or is produced by combining (a) a glycol and (b) an organosilane comprising DmSiXnZP; D is halogen, a hydroxyl, an alkoxy, or a polyoxyalkyl group; X is a hydrocarbon group containing 1 to 30 carbon atoms selected from an alkyl, alkenyl, aryl, alkaryl, aralkyl, alkylene, arylene, alkenylene, or combinations of two or more thereof; Z is a reactive hydrophobic group selected from a halogen, an ester, an aldehyde, a ketone, or a mercaptan; each of m and n is 1 to 3; and p is 1 to 20.
2. A crosslinked polyester polymer as claimed in claim 1 wherein said organosilane is 3-acetoxypropyltrimethoxysilane,3-cetoxypropyltriethoxysilane, 3 - acetoxypropyltrichlorosilane, 3 - methacryloxypropyltrimethoxysilane, 3 - methacryloxypropyltriethoxysilane, 2 - (carbomethoxy)ethyltrichlorosilane, 2- (carbomethoxy)ethyltrimethoxysilane, 3-chloropropyltrichlorosilane, 3-chloropropyltrimethoxy silane, 3-chloropropyltriethoxysilane, 3-mercaptopropyltrimethoxy silane, chloromethyltrimethoxy silane, chloromethyltriethoxysilane, or combinations of two or more thereof.
3. A crosslinked polyester polymer as claimed in claim 2 wherein said glycol-organosilane optionally comprises an acid or a base as a catalyst or reactant; the molar ratio of said acid or said base to said organosilane is between 0.01:1 to 1:1; and said organosilane preferably has its reactive functional groups partially or completely reacted with said acid or said base.
4. A crosslinked polyester polymer as claimed in claim 3 wherein said glycol is ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,4-cyclohexanedimethanol, pentylene glycol, neopentyl glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polyalkylene glycol, alkoxylated glycol, or combinations of two or more thereof.

5. A glycol-organosilane composition as claimed in Claim 1 wherein said organosilane having 20% to 99%, preferably 50% to 95%, most preferably 60% to 90%, of its reactive functional groups reacted with said glycol.
6. A glycol-organosilane composition as claimed in claim 5 wherein said organosilane optionally includes 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxy silane, methylaminopropyltrimethoxy silane, arninoelhylaminopropyltrirnethoxysilane,arninoethylarninopropyltriethoxysilane, 3 -hydroxypropyltrimethoxy silane, 3 -hydroxypropyltriethoxy silane, hydroxymethyltrimethoxy silane, hydroxymethyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxy silane, or combinations of two or more thereof.
7. A crosslinked polyester polymer as claimed in Claim 1 wherein said polymer is produced by contacting a polymerization mixture with a crosslinker and optionally a comonomer wherein said polymerization mixture comprises (a) a carbonyl compound, (b) an alkylene glycol, and optionally (c) a sulfonated isophthalate metal salt; said carbonyl compound is terephthalic acid, a terephthalic acid ester, an oligomer comprising repeat unit derived from terephthalic acid or a terephthalic acid ester, or combinations of two or more thereof; said oligomer has 1 to 100 repeat units, preferably 2 to 20 units;
said crosslinker is a first crosslinker, or a second crosslinker, or combinations thereof; said first crosslinker is a glycol-organosilane as recited in any of claims 5, 6 or 7; said second crosslinker is a carbonyl compound containing 3 or more carboxyl groups, an alcohol containing 3 or more hydroxy! groups, or combinations of 3 or more carbonyl and hydroxyl groups;
Said polymer is produced in a suitable condition to effect the production of a polyester including a temperature in the range of from 200 ° C to 400 ° C, under a pressure in the range of from 0.001 to 1 atmosphere (0.1 to 101.3 kPa) for a time period of from 0.3 to 20 hours.
8. A crosslinked polyester polymer as claimed in claim 7 wherein said
second crosslinker is trimellitic anhydride, 1,2,4-benzenetricarboxylic acid or
ester thereof, 1,3,5-benzenetricarboxylic acid or ester thereof, pyromellitic
dianhydride or ester thereof, glycerol, trimethylolpropane, 1,1,1-
tris(hydroxymethyl)ethane, pentaerythritol, tartaric acid, citric acid, gallic acid,
pyrogallol, glycol mixture thereof, or combinations of two or more thereof; said
second crosslinker is 100 to 5000 ppm by weight of said polyester;
said alkylene glycol is selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, pentylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol, or combinations of two or more thereof; and is preferably selected from ethylene

glycol, 1,3-propanediol, 1,4-butanediol, and combinations of two or more thereof;
said polyester optionally comprises a comonomer, said comonomer is a dicarboxylic compound other than said carbonyl compound, a diol compound other than said alkylene glycol, or a carbonyl alcohol containing one carboxyl group and one hydroxyl group; said comonomer is preferably selected from the group consisting of isophthalic acid, naphthalenedicarboxylic acid, phthalic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, cyclohexane dicarboxylic acid, 1,2-cyclohexanedicarboxylic anhydride, maleic anhydride, maleic acid, fumaric acid, dimethyl phthalate, dimethyl isophthalate, dimethyl naphthalenedicarboxylate, dimethyl glutarate, dimethyl adipate, dimethyl cyclohexane dicarboxylate, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, polyoxybutylene glycol, lactic acid, 2-hydroxybenzoic acid, 4-hydroxybenzoic acid, mandelic acid, glycol mixture thereof, and combinations of two or more thereof; said polyester comprises repeat unit derived from 0.1% to 50% of said comonomer based on the weight of said polyester.
9. A crosslinked polyester polymer as claimed in claim 8 wherein said comonomer or crosslinker containing one or more carboxyl groups are partially reacted with said alkylene glycol before adding to said polymerization mixture.

Documents:

3109-DELNP-2005-Abstract-(05-01-2009).pdf

3109-DELNP-2005-Abstract-(30-12-2008).pdf

3109-delnp-2005-abstract.pdf

3109-DELNP-2005-Claims-(05-01-2009).pdf

3109-DELNP-2005-Claims-(30-12-2008).pdf

3109-delnp-2005-claims.pdf

3109-delnp-2005-complete specification (granted).pdf

3109-delnp-2005-correspodence-others.pdf

3109-DELNP-2005-Correspondence-Others-(30-12-2008).pdf

3109-DELNP-2005-Description (Complete)-(30-12-2008).pdf

3109-delnp-2005-description (complete)-05-01-2009.pdf

3109-delnp-2005-description (complete).pdf

3109-DELNP-2005-Form-1-(30-12-2008).pdf

3109-delnp-2005-form-1.pdf

3109-delnp-2005-form-18.pdf

3109-DELNP-2005-Form-2-(30-12-2008).pdf

3109-delnp-2005-form-2.pdf

3109-DELNP-2005-Form-3-(30-12-2008).pdf

3109-delnp-2005-form-3.pdf

3109-delnp-2005-form-5.pdf

3109-DELNP-2005-GPA-(30-12-2008).pdf

3109-delnp-2005-gpa.pdf

3109-DELNP-2005-Others-Document-(30-12-2008).pdf

3109-DELNP-2005-Petition-137-(30-12-2008).pdf

3109-DELNP-2005-Petition-138-(30-12-2008).pdf


Patent Number 228926
Indian Patent Application Number 3109/DELNP/2005
PG Journal Number 11/2009
Publication Date 13-Mar-2009
Grant Date 12-Feb-2009
Date of Filing 13-Jul-2005
Name of Patentee See attached documents
Applicant Address See attached documents
Inventors:
# Inventor's Name Inventor's Address
1 See attached documents See attached documents
PCT International Classification Number C08G
PCT International Application Number PCT/US2004/000353
PCT International Filing date 2004-01-08
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA