Note: Descriptions are shown in the official language in which they were submitted.
CA 02346249 2001-04-03
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Aqueous Dispersions
This application is a continuation-in-part of U.S. Application Serial No.
08/726,845, filed October 3, 1996.
Background of the Invention
This invention relates to aqueous dispersions comprised of water-soluble
polymers,
processes for making said dispersions, and methods of using said dispersions
in water
treating, dewatering, water clarification, papermaking, oil field, soil
conditioning, food
processing, mineral processing, and biotechnological applications.
U.S. Patent No. 4,380,600 discloses a process for producing an aqueous
dispersion
of water-soluble polymers. The aqueous dispersion may contain inorganic salt.
However,
the aqueous dispersions exemplified therein have disadvantageously high bulk
viscosities.
U.S. Patent No. 4,673,704 and EP 0 170 394 A2 disclose products comprised of
particles above 20 microns in size of a high molecular weight polymer gel
interconnected
by a continuous phase that is an aqueous solution of an equilibrating agent
that holds the
water content of the particles in equilibrium with the water content of the
aqueous phase
and that prevents substantial agglomeration of the particles in the fluid
product. Although
these references are entitled "Aqueous Polymer Dispersions," the products
disclosed
therein are distinguished from the aqueous dispersions of U.S. Patent No.
4,380,600 and
from the aqueous dispersions of the instant invention in that the particles of
U.S. 4,673,704
and EP 0 170 394 A2 are not generally held suspended in a continuous matrix of
the
aqueous phase but instead generally rest substantially in contact with one
another but slide
over one another. A process for dispersing the polymer gel into an aqueous
solution of an
equilibrating agent and working the polymer while in that medium is disclosed
in U.S.
Patent No. 4,778,836 and EP 0 169 674 B 1. Also, U.S. Patent No. 4,522,968
discloses a
process for dispersing certain powdered water-soluble homopolymers or
copolymers in an
aqueous solution containing a polymer of ethylene oxide and/or propylene
oxide.
U.S. Patent Nos. 4,929,655 and 5,006,590 disclose processes for preparing
aqueous
dispersions of water-soluble polymers by polymerizing benzyl-containing
monomers in the
presence of an organic high molecular multivalent cation and a multivalent
anionic salt.
The benzyl group-containing monomer may be replaced by a hydrophobic alkyl
group-
CA 02346249 2001-04-03
WO 00/20470 PCT/US99/21152
containing monomer as in EP 0 525 751. Numerous references concern these and
similar
polymers, e.g. U.S. 5,332,506; 5,332,507; 5,330,650; 5,292,793, 5,435,922;
5,466,338; EP
0 595 156 A 1; EP 0 630 909 A 1; EP 0 657 478 A2; EP 0 629 583 A2; EP 0 617
991 A 1,
EP 0 183 466 B 1, EP 0 637 598 A2; EP 0 7 i 7 056 A2; JP 61-6396; JP 61-6397;
JP 61-
6398; JP 62-262799; JP 64-1 S 130; JP 2-38131; JP 62 1525 I ; JP 61-138607;
Hei 6-329866;
and JP 62-100548. Although some of the aqueous dispersions in these references
have
relatively low bulk viscosities, the need to include special monomers
containing aromatic
or hydrophobic alkyl groups in order to render the polymer insoluble in salt
solution may
be disadvantageous because the special monomers may be expensive and dilutive
of the
polymer effect in a specific application.
The effect of salts on the solubility of various substances in aqueous
solution is well
discussed in the scientific literature. The "Hofmeister" series ranks anions
according to their
ability to increase or decrease the solubility of substances in water.
Although positions in the
ranking may vary slightly, depending on the substance, a generally accepted
ranking of the
anions is:
Salting-out S042- ~ HP0,2- > F > CT > Bi: > T ~ CIO, > SCN Salting-in
(kosmotropic)
(chaotropic)
Kosmotropic salts generally decrease the solubility of substances in water.
For instance, the
Hofmeister ranking apparently guided the choice of salts for precipitating
cationic water
soluble polymers, containing hydrophobic groups, in U. S. Patent Nos. 4,
929,655 and
5,006,590, as well as EP 0 630 909 A1, EP 0 525 751 A1, and EP 0 657 478 A2,
as
evidenced by their use of strongly kosmotropic salts containing sulfate and
phosphate anions.
On the other hand, chaotropic salts generally increase the solubility of
substances in water.
There are numerous means known to those skilled in the art for determining
whether a
particular salt is kosmotropic or chaotropic. Representative salts which
contain anions such
as sulfate, fluoride, phosphate, acetate, citrate, tartrate and
hydrogenphosphate are
kosmotropic. Representative salts which contain anions such as thiocyanate,
perchlorate,
chlorate, bromate, iodide, nitrate and bromide are chaotropic. The chloride
anion is generally
considered to be at about the middle of the Hofmeister ranking, being either
weakly
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chaotropic or weakly kosmotropic, depending on the particular system. In the
instant
invention, although occasionally chaotropic, inorganic salts which contain the
chloride anion
tend to be kosmotropic.
Small amounts of sodium thiocyanate, for instance about 0.1 % by weight, on
total,
have been reported to be useful as stabilizers for polymer dispersions as in
EP 0 657 478 A2,
where (NH,)zSO4 was used to deposit the polymer. Sodium thiocyanate and sodium
iodide
have been reported to be useful as stabilizers for hydroxylamine-containing
water-soluble
polymer systems, as in EP 0 514 649 Al. U.S. 3,234,163 teaches that small
amounts of
thiocyanate salts, preferably 0.1 to 1 percent, based on the weight of the
polymer, are useful
I O for stabilizing polyacrylamide solutions.
The Hofmeister ranking has been observed in solutions of high molecular
weight,
water-soluble polymers. For instance, the effect of various salts on the
solubility of synthetic,
water-soluble polymers was explored by Shuji Saito, J. Polym. Sci.: Pt. A,
Vol. 7, pp. 1789-
1802 (1969). This author discussed the effect of various anions on polymer
solubility and
stated "This anionic order seems to be independent of the type of counter
cations and is in
line with Hofmeister's lyotropic series for anions." Similarly, in M. Leca,
Polymer Bulletin,
Vol. 16, pp. 537-543, 1986, the viscosity of polyacrylamide, as determined in
1N solutions of
various salts, was found to increase in the order HPO,Z- < H20 < Br < N03 < h
= BrO; < C103
= SCN~. The viscosities were reported to be higher in more chaotropic salt
solutions than in
less chaotropic, or kosmotropic, salt solutions. Certain novel cationic
polyelectrolytes, termed
ionene polymers, were reported (D. Casson and A. Rembaum, Macromolecules, Vol.
5, No.
1, 1972, pp. 75-81 ) to be insoluble in either 0.4 M potassium iodide or 0.4 M
potassium
thiocyanate. It has also been reported (W-F. Lee and C-C. Tsai, J. Appl.
Polym. Sci., Vol. 52,
pp. 1447-1458, 1994) that poly(trimethyl acrylamido propyl ammonium iodide)
did not
dissolve in 0.5 M NaZCIOa or 0.5 M NaN03.
Certain anionic organic salts, such as hydrotropes and surfactants, also tend
to
increase the solubility of substances in water. However, poly(allylammonium
chloride) was
reported (T. Itaya et al., J. Polym. Sci., Pt. B: Polym. Phys., Vol. 32, pp.
171-I77, 1994, and
references 3, 5 and 6 therein; also Macromolecules, Vol 26, pp. 6021-6026,
1993) to
precipitate in solutions containing the sodium salt of p-
ethylbenzenesulfonate, p-
propylbenzenesulfonate or naphthalenesulfonate. Poly(4-vinyl pyridine)
quaternized with
butyl chloride and poly(allylammonium chloride) were reported (M. Satoh, E.
Yoda, and J.
Komiyama, Macromolecules, Vol. 24, pp. 1123-27, 1991) to precipitate in
solutions of NaI
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and also in solutions containing the sodium salt of p-ethylbenzenesulfonate,
respectively.
Compositions comprising sulphonated hydrocarbon surfactants and hydrophilic
cationic
polymers were disclosed in U.S. Patent No. 5,130,358. Mixtures of chaotronic
salts_ or
anionic organic salts, and kosmotropic salts may be used to precipitate
cationic polymers as
in U.S. Application Serial No. 08/725,436, filed even date herewith.
Aqueous dispersions of water-soluble polymers are disclosed in U.S. 5,403,883;
5,480,934; 5,541,252; EP 0 624 617 A1; EP 0 573 793 Al; and WO 95/11269. A
problem
remains in that the aqueous dispersions exemplified in these references still
have relatively
high bulk viscosities.
A process for preparing crosslinked copolymer beads from water-soluble
monomers
in an aqueous solution containing an inorganic salt and a dispersant is
disclosed in U.S.
5,498,678 and EP 0 604 109 A2. Mixtures of aqueous dispersions and water-in-
oil
emulsions are disclosed in Hei 7-62254 and Hei 6-25540. The addition of a
nonic,nic
surfactant and an oleaginous liquid to an aqueous dispersion to maintain
flowability is
disclosed in U.S. Patent No. 5,045,587. Mixtures of cationic polymers are
disclosed in
Sho-52-71392 and homogeneous blends of water-soluble polymers are disclosed in
U.S.
Patent No. 4,835,206 and EP 0 262 945 B 1. Bimodal cationics for water
clarification are
disclosed in U.S. Patent Nos. 4,588,508 and 4,699,951. Blends of water-in-oil
polymer
emulsions are disclosed in U.S. Patent Application Serial No. 08/408,743.
In spite of the effort to make satisfactory aqueous dispersions, the problem
remains
of producing aqueous dispersions of high molecular weight water soluble
polymers that
have advantageously low bulk viscosities, high active solids content, minimal
quantities of
dilutive material, and that dissolve readily and can be prepared with a broad
range of
cationicity.
Summary of the Invention
This problem is solved in the present invention by providing novel aqueous
dispersions of high molecular weight water-soluble or water-swellable
polymers, as well as
processes for making and methods of using said aqueous dispersions.
Accordingly, an
aqueous dispersion of polymers is provided which comprises: (a) a first
cationic water-
soluble or water-swellable polymer; and (b) at least one second water-soluble
polymer
different from said first polymer; and (c) a kosmotropic salt; and (d) a
chaotropic salt,
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WO 00/20470 PCTNS99/21152
wherein the amounts of said (b), (c) and (d) are such that a homogeneous
composition is
obtained in the absence of said (b). In another embodiment, an aqueous
dispersion of
polymers is provided which comprises: (a) a first cationic water-soluble or
water-swellable
polymer; and (b) at least one second water-soluble polymer different from said
first
polymer; and (c) a kosmotropic salt; and (d) an anionic organic salt, wherein
the amounts
of said (b), (c) and (d) are such that a homogeneous composition is obtained
in the absence
of said (b).
In another embodiment, an aqueous dispersion of polymers is provided which is
comprised of (a) a discontinuous phase containing polymer that is comprised
predominately of a first cationic water-soluble or water-swellable polymer
having at least
one first recurring unit of the formula (I),
R~
-C H2-C-
(I) C=O
A
I
B
I
R2-N+ Ra
R4 X -
wherein RI is H or CH3, A is O or NH, B is an alkylene or branched alkylene or
oxyalkylene group having from 1 to S carbons, R2 is a methyl, ethyl, or propyl
group, R3
is a methyl, ethyl, or propyl group, Rq. is a methyl, ethyl or propyl group,
and X is a
counterion; and (b) at least one second water-soluble polymer different from
said first
polymer; wherein, if said first polymer is further comprised of a second
recurring unit of
formula (I) wherein R, is H or CH3, A is O or NH, B is an alkylene or branched
alkylene or
oxyalkylene group having from 1 to 5 carbons, X is a counterion, and R2, R, or
R4 is
selected from the group consisting of C4-C,~ alkyl, benzyl, and C~H4C6H5, then
the amount
of said first recurnng unit is greater than the amount of said second
recurring unit on a
molar basis, and wherein, if said Rz, R3 and RQ in said first recurnng unit
together contain a
total of 3 carbon atoms, then said first polymer is devoid of hydrophobic
recurring units.
In another embodiment, an aqueous dispersion of polymers is provided which
comprises: (a) a first cationic water-soluble or water-swellable polymer
having at least one
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recurring unit of the formula (I), wherein RI is H or CH3, A is O or NH, B is
an alkylene
or branched alkylene or oxyalkylene group having from 1 to 5 carbons, R2 is a
methyl,
ethyl, or propyl group, R3 is a methyl, ethyl, or propyl group, R4 is an alkyl
or substituted
alkyl group having from 1 to 10 carbons, or an aryl or substituted aryl group
having from 6
to 10 carbons, X is a counterion, and R2, R3, and R4 together contain a total
of at least 4
carbon atoms; and (b) at least one second water-soluble polymer different from
said first
polymer, wherein a homogeneous composition is obtained in the absence of said
(b).
In another embodiment, a process for making an aqueous dispersion of polymers
is
provided which comprises polymerizing vinyl-addition monomers to form an
aqueous
dispersion comprised of a first cationic water-soluble or water-swellable
polymer, wherein
said polymerizing is carried out in the presence of an aqueous composition
comprised of
(a) at least one second water-soluble polymer different from said first
polymer; (b) a
kosmotropic salt; and (c) a chaotropic salt, wherein the amounts of said (a),
(b) and (c) are
such that a homogeneous composition is obtained if said polymerizing is
carried out in the
absence of said (a).
In another embodiment, a process for making an aqueous dispersion of polymers
is
provided which comprises polymerizing vinyl-addition monomers to form an
aqueous
dispersion comprised of a first cationic water-soluble or water-swellable
polymer, wherein
said polymerizing is carried out in the presence of an aqueous composition
comprised of
(a) at least one second water-soluble polymer different from said first
polymer; (b) a
kosmotropic salt; and (c) of an anionic organic salt, wherein the amounts of
said (a), (b)
and (c) are such that a homogeneous composition is obtained if said
polymerizing is carried
out in the absence of said (a).
In another embodiment, a process for making an aqueous dispersion of polymers
is
provided which comprises polymerizing vinyl-addition monomers comprised of at
least
one monomer of the formula (II)
I
C H2=C
C=O
I
A
(II) I
B
I
R2,N+ Rs
R4 X
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WO 00/20470 PCTNS99/21152
to form an aqueous dispersion comprised of a first cationic water-soluble or
water-
swellable polymer, wherein Rl is H or CH3, A is O or NH, B is an alkylene or
branched
alkylene or oxyalkylene group having from I to 5 carbons, R2 is a methyl,
ethyl, or propyl
group, R3 is a methyl, ethyl, or propyl group, R4 is a methyl, ethyl or propyl
group, and X
is a counterion; wherein said polymerizing is carned out in the presence of an
aqueous
composition comprised of at least one second water-soluble polymer different
from said
first polymer; wherein, if said vinyl-addition monomers are further comprised
of a second
monomer of formula (II) wherein R, is H or CH,, A is O or NH, B is an alkylene
or
branched alkylene or oxyalkylene group having from 1 to 5 carbons, X is a
counterion, and
RZ, R3 or R, is selected from the group consisting of C; C,~ alkyl, benzyl,
and CZH,C6H5,
then the amount of said first monomer is greater than the amount of said
second monomer
on a molar basis, and wherein, if said R2, R3 and R4 in said first monomer
together contain a
total of 3 carbon atoms, then said first polymer is devoid of hydrophobic
recurring units.
In another embodiment, a process for making an aqueous dispersion of polymers
is
provided which comprises polymerizing vinyl-addition monomers comprised of at
least
one monomer of the formula (II) to form an aqueous dispersion comprised of a
first water
soluble or water-swellable cationic polymer, wherein R1 is H or CH3, A is O or
NH, B is
an alkylene or branched alkylene or oxyalkylene group having from 1 to 5
carbons, R2 is a
methyl, ethyl, or propyl group, R3 is a methyl, ethyl, or propyl group, R4 is
an alkyl or
substituted alkyl group having from 1 to 10 carbons, or an aryl or substituted
aryl group
having from 6 to 10 carbons, X is a counterion, and R2, R3, and R4 together
contain a total
of at least 4 carbon atoms; and wherein said polymerizing is carried out in
the presence of
an aqueous composition comprised of an amount of at least one second water-
soluble
polymer different from said first polymer; and wherein said amount of said
second polymer
is such that a homogeneous composition is obtained if said polymerizing is
carried out in
the absence of said second polymer.
In another embodiment, a process for blending two or more aqueous dispersions
is
provided, comprising intermixing (a) a first aqueous dispersion of a water-
soluble or water-
swellable polymer with (b) a second aqueous dispersion of a water-soluble or
water-
swellable polymer, wherein said (a) is different from said (b), to form a
third aqueous
dispersion.
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In another embodiment, a method of dewatering a suspension of dispersed solids
is
provided which (a) intermixing an aqueous dispersion of polymers, or aqueous
admixture
thereof, in an amount effective for dewatering, with a suspension of dispersed
solids, and
(b) dewatering said suspension of dispersed solids, said aqueous dispersion
being
comprised of (i) a first cationic water-soluble or water-swellable polymer;
and (ii) at least
one second water-soluble polymer different from said first polymer; and (iii)
a kosmotropic
salt; and (iv) a chaotropic salt, wherein the amounts of said (ii), (iii) and
(iv) are such that a
homogeneous composition is obtained in the absence of said (ii).
In another embodiment, a method of dewatering a suspension of dispersed solids
is
provided which comprises (a) intermixing an aqueous dispersion of polymers, or
aqueous
admixture thereof, in an amount effective for dewatering, with a suspension of
dispersed
solids, and (b) dewatering said suspension of dispersed solids, said aqueous
dispersion
being comprised of (i) a first cationic water-soluble or water-swellable
polymer; and (ii) at
least one second water-soluble polymer different from said first polymer; and
(iii) a
kosmotropic salt; and (iv) an anionic organic salt, wherein the amounts of
said (ii), (iii) and
(iv) are such that a homogeneous composition is obtained in the absence of
said (ii).
In another embodiment, a method of dewatering a suspension of dispersed solids
is
provided which comprises (a) intermixing an aqueous dispersion of polymers, or
aqueous
admixture thereof, in an amount effective for dewatering, with a suspension of
dispersed
solids, and (b) dewatering said suspension of dispersed solids, said aqueous
dispersion
being comprised of (i) a discontinuous phase containing polymer that is
comprised
predominately of a first cationic water-soluble or water-swellable polymer
having at least
one first recurring unit of the formula (I), wherein R1 is H or CH3, A is O or
NH, B is an
alkylene or branched alkylene or oxyalkylene group having from 1 to 5 carbons,
R2 is a
methyl, ethyl, or propyl group, R3 is a methyl, ethyl, or propyl group, R4 is
a methyl, ethyl
or propyl group, and X is a counterion; (ii) at least one second water-soluble
polymer
different from said first polymer; wherein, if said first polymer is further
comprised of a
second recurring unit of formula (I) wherein R, is H or CH~, A is O or NH, B
is an alkylene
or.branched alkylene or oxyalkylene group having from 1 to 5 carbons, X is a
counterion,
and RZ, R3 or R, is selected from the group consisting of C4 C,o alkyl,
benzyl, and CZH4C~H5,
then the amount of said first recurring unit is greater than the amount of
said second
recurring unit on a molar basis, and wherein, if said R2, R3 and Ra in said
first recurring unit
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WO 00/20470 PCT/US99/21152
together contain a total of 3 carbon atoms, then said first polymer is devoid
of hydrophobic
recurring units.
In another embodiment, a method of dewatering a suspension of dispersed solids
is
provided which comprises (a) intermixing an aqueous dispersion of polymers, or
aqueous
admixture thereof, in an amount effective for dewatering, with a suspension of
dispersed
solids, and (b) dewatering said suspension of dispersed solids, said aqueous
dispersion
being comprised of (i) a first cationic water-soluble or water-swellable
polymer having at
least one recurring unit of the formula (I), wherein R1 is H or CH3, A is O or
NH, B is an
alkylene or branched alkylene or oxyalkylene group having from 1 to 5 carbons,
R2 is a
methyl, ethyl, or propyl group, R3 is a methyl, ethyl, or propyl group, R4 is
an alkyl or
substituted alkyl group having from I to 10 carbons, or an aryl or substituted
aryl group
having from 6 to 10 carbons, X is a counterion, and R2, R3, and R4 together
contain a total
of at least 4 carbon atoms; and (ii) at least one second water-soluble polymer
different from
said first polymer, wherein a homogeneous composition is obtained in the
absence of said
(ii).
In another embodiment, a process for producing substantially dry water-soluble
or
water-swellable vinyl-addition polymer particles is provided which comprises
(a) spray-
drying a vinyl-addition polymer-containing aqueous dispersion into a gas
stream with a
residence time of about 8 to about 120 seconds and at an outlet temperature of
about 70° C
to about 150° C and (b) collecting resultant polymer particles.
In another embodiment, substantially dry water-soluble or water-swellable
polymer
particles are provided which are comprised of (a) a first cationic water-
soluble or water-
swellable polymer; and (b) at least one second water-soluble polymer different
from said
first polymer; and (c) a kosmotropic salt; and (d) a chaotropic salt, wherein
about 90% or
more of said polymer particles each individually contains both said (a) and
said (b), said
particles having a bulk density of about 0.4 grams per cubic centimeter to
about 1.0 grams
per cubic centimeter.
In another embodiment, there is provided a method comprising (a) intermixing a
composition comprising substantially dry water-soluble or water-swellable
polymer
particles comprised of (i) a first cationic water-soluble or water-swellable
polymer; and (ii)
at least one second water-soluble polymer different from said first polymer;
and (iii) a
kosmotropic salt; and (iv) a chaotropic salt, wherein about 90% or more of
said polymer
9
CA 02346249 2001-04-03
wo oonoa~o Pcrius99m ~ s2
particles each individually contains both said (i) and said (ii), said
particles having a bulk
density of about 0.4 grams per cubic centimeter to about 1.0 grams per cubic
centimeter,
with water to form an aqueous polymer admixture, (b) intermixing said aqueous
polymer
admixture, in an amount effective for dewatering, with a suspension of
dispersed solids,
and (c) dewatering said suspension of dispersed solids.
In another embodiment, there is provided a method comprising (a) intermixing a
composition comprising substantially dry water-soluble or water-swellable
polymer
particles comprised of (i) a first cationic water-soluble or water-swellable
polymer; and (ii)
at least one second water-soluble polymer different from said first polymer;
and (iii) a
kosmotropic salt; and (iv) an anionic organic salt, wherein about 90% or more
of said
polymer particles each individually contains both said (i) and said (ii), said
particles having
a bulk density of about 0.4 grams per cubic centimeter to about 1.0 grams per
cubic
centimeter, with water to form an aqueous polymer admixture, (b) intermixing
said
aqueous polymer admixture, in an amount effective for dewatering, with a
suspension of
dispersed solids, and (c) dewatering said suspension of dispersed solids.
In another embodiment, there is provided a method comprising (a) intermixing a
composition comprising substantially dry water-soluble or water-swellable
polymer
particles comprised of (i) a first cationic water-soluble or water-swellable
polymer having
at least one recurring unit of the formula (I), wherein R1 is H or CH3, A is O
or NH, B is
an alkylene or branched alkylene or oxyalkylene group having from 1 to 5
carbons, R2 is a
methyl, ethyl, or propyl group, R3 is a methyl, ethyl, or propyl group, R4 is
an alkyl or
substituted alkyl group having from 1 to 10 carbons, or an aryl or substituted
aryl group
having from 6 to 10 carbons, X is a counterion, and R2, R3, and R4 together
contain a total
of at least 4 carbon atoms; and (ii) at least one second water-soluble polymer
different from
said first polymer, wherein about 90°!0 or more of said polymer
particles each individually
contains both said (i) and said (ii), said particles having a bulk density of
about 0.4 grams
per cubic centimeter to about 1.0 grams per cubic centimeter, with water to
form an
aqueous polymer admixture, (b) intermixing said aqueous polymer admixture, in
an
amount effective for dewatering, with a suspension of dispersed solids, and
(c) dewatering
said suspension of dispersed solids.
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Detailed Description of Preferred Embodiments
The aqueous dispersions of the instant invention contain a first cationic
water-
soluble or water-swellable polymer, preferably a vinyl-addition polymer. The
cationic
charge of said first cationic polymer may vary over a broad range by
containing from about
1 % to about 100% cationic recurring units, preferably about 5% or greater,
more preferably
about 10% or greater, even more preferably about 20% or greater, most
preferably about
30% or greater, preferably about 90% or less, more preferably about $0% or
less, most
preferably about 70% or less, by mole based on total moles of recurring units
in said first
cationic polymer. Cationic recurring units may be formed by post-reaction of
polymer, but
are preferably formed by polymerization of cationic monomers. Cationic
monomers may
include any cationic monomer, including diallyldiaikylammonium halide,
cationic
(meth)acrylates, and cationic (meth)acrylamides commonly used in preparing
water-
soluble polymers, preferably diallyldimethyiammonium halide, as well as acid
and
quaternary salts of dialkylaminoalkyl(alk)acrylate and
dialkylaminoalkyl(alk)acrylamide.
Cationic recurring units may be formed by the polymerization of quaternizable
monomers
such as dialkylaminoalkyl(alk)acrylate or dialkylaminoalkyl(alk)acrylamide,
followed by
acidification or quaternization. Most preferably, the first cationic polymer
contains
cationic recurring units of the formula (I), preferably formed by
polymerization of the
corresponding monomers of the formula (II):
R1
-CH2-C-
C-O (I)
f
A
B
I
RZ-N+ Rs
R4 X -
ll
CA 02346249 2001-04-03
WO 00/20470 PCT/US99/21152
R~
C H2=C
C=O (n)
I
A
I
B
1
R2-N+ R3
Rd X
wherein R, is H or CH3, A is O or NH, B is alkylene or branched alkylene or
oxyalkylene
having from 1 to 5 carbons, RZ and R, are each individually methyl, ethyl, or
propyl, R4 is
an alkyl or substituted alkyl group having from 1 to l0 carbon atoms, or an
aryl or
substituted aryl group having from 6 to 10 carbon atoms, and X is a
counterion.
Preferably, RZ, R3 and R4 together contain at least a total of 4 carbon atoms,
more preferably
at least S carbon atoms. In certain preferred embodiments, R4 is a methyl,
ethyl or propyl
group. In other preferred embodiments, R4 is an alkyl or substituted alkyl
group having
from 4 to 10 carbon atoms. In other preferred embodiments, R, is benzyl.
Preferably, X is
chloride, bromide, iodide, methylsulfate, or ethylsulfate.
Monomers which may be copolymerized with the cationic monomers mentioned
above may be cationic, nonionic or anionic. Cationic monomers include the
monomers
corresponding to (I) and other cationic monomers such as
diallydimethylammonium chloride,
diallydiethylammonium chloride, etc. Nonionic monomers may include
substantially water-
soluble monomers such as acrylamide, methacrylamide, and N-
isopropylacrylamide, or
monomers which are sparingly soluble in water such as t-butylacrylamide, N,N-
dialkylacrylamide, diacetone acrylamide, ethyl acrylate, methyl methacrylate,
methyl
acrylate, styrene, butadiene, ethyl methacrylate, acrylonitrile, etc. and the
like. Nonionic
monomers may also include monomers which become charged at low pH, such as
dimethylaminoethylacrylate, dimethylaminoethylmethacrylate,
diethylaminoethylacrylate,
diethylaminoethylmethacrylate and corresponding acrylamide derivatives such as
methacrylamidopropyldimethylamine. Preferred nonionic monomers are acrylamide,
t-butyl
acrylamide, methacrylamide, methyl methacrylate, ethyl acrylate and styrene.
Anionic
monomers may include acrylic acid, 2-acrylamido-2-methylpropane sulfonic acid,
styrene
sulfonic acid, their salts and the like. On a mole basis, the polymer contains
fewer anionic
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recurring units than cationic recurring units so that the polymer, although
ampholytic, retains
a net positive cationic charge. Preferably, the polymer contains less than 10
mole% anionic
recurring units, based on the total number of recurring units in the polymer.
The first cationic water-soluble or water-swellable polymer may be a copolymer
and may contain other cationic recurnng units or nonionic recurring units.
Nonionic
recurring units may be formed from water-soluble monomers such as N-
vinylpyridine, N
vinylpyrrolidone, hydroxyalkyl(meth)acrylates, etc., preferably
(meth)acrylamide, or may
be formed from hydrophobic monomers having low water-solubility, so long as
the
inclusion of the poorly water-soluble, e.g. hydrophobic, recurring units does
not render the
resulting polymer water-insoluble or water-nonswellable. The first cationic
polymer may
contain amounts of recurring units of water-soluble non-ionic monomers ranging
from 0%
to about 99%, preferably about 10% or greater, more preferably about 20% or
greater, most
preferably about 30% or greater; preferably about 90% or less, more preferably
about 80%
or less, most preferably about 70% or less, by mole based on total moles of
recurring units
in said polymer. The hydrophobic monomers may be hydrocarbon monomers e.g.
styrene,
butadiene, 1-alkene, vinyl cyclohexane, etc., other vinyl monomers such as
vinyl halide,
other primarily aliphatic or aromatic compounds with polymerizable double
bonds, or
monomers with only moderate water-solubility such as acrylonitrile.
Preferably, the
hydrophobic monomers are alkyl (alk)acrylates or aryl (alk)acrylates in which
the alkyl or
aryl groups contain about 1-12 carbon atoms, such as methyl (meth)acrylate,
ethyl
(meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, hexyl
(meth)acrylate,
ethylhexyl (meth)acrylate, isoalkyl (meth)acrylate, cyclohexyl (meth)acrylate,
or aromatic
(meth)acrylate, or alkyl or aryl (alk)acrylamides in which the alkyl or aryl
groups contain
about 1-12 carbon atoms, such as methyl (meth)acrylamide, ethyl
(meth)acrylamide, t-
butyl (meth)acrylamide, dimethyl (meth)acrylamide, hexyl (meth)acrylamide,
ethylhexyl
(meth)acrylamide, isoalkyl (meth)acrylamide, cyclohexyl (meth)acrylamide, or
aromatic
(meth)acrylamide. The first cationic water-soluble or water-swellable polymer
may
contain amounts of hydrophobic non-ionic recurring units ranging from 0% to
about 15%,
preferably about 2% to about 10%, by mole based on total moles of recurring
units in said
polymer. Although hydrophobic recurring units may be dilutive of the polymer
effect in
certain applications, inclusion in controlled amounts may advantageously
affect a particular
characteristic of the aqueous dispersion, e.g. solubility rate, bulk
viscosity, cost, ease of
processing, performance, etc. Depending on the specific embodiment, it may be
preferable
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for the polymer to be devoid of hydrophobic recurring units, or to contain
chosen amounts
of hydrophobic recurring units so as to achieve an advantageous effect without
disadvantageously increasing the dilutive effect.
The first vinyl-addition monomer of the formula (II) may be copolymerized with
a
second vinyl-addition monomer of the formula (II) wherein R, is H or CHl, A is
O or NH,
B is an alkylene or branched alkylene or oxyalkylene group having from 1 to 5
carbons, X
is a counterion, and Rz, R3 or R4 is selected from the group consisting of C4
C,~ alkyl,
benzyl, and C2H,C6H5. In this case, the amount of the first monomer is
preferably greater
than the amount of the second monomer on a molar basis. Also, if Rz, R3 and R,
in the first
monomer of the formula (II) together contain a total of 3 carbon atoms, then
the monomers
are preferably free of hydrophobic monomers.
Likewise, if the first polymer contained in an aqueous dispersion of the
instant
invention is comprised of a first recurring unit of the formula (I) as set
forth above, and is
further comprised of a second recurring unit of formula (I) wherein R, is H or
CH3, A is O
or NH, B is an alkylene or branched alkylene or oxyalkylene group having from
I to 5
carbons, X is a counterion, and RZ, R3 or R4 is selected from the group
consisting of C4 C,o
alkyl, benzyl, and CZH4C6H5, then the amount of the first recurring unit is
preferably greater
than the amount of the second recurring unit on a molar basis. Also, if RZ, R~
and R4 in the
first recurring unit of the formula (I) together contain a total of 3 carbon
atoms, then the
first polymer is preferably devoid of hydrophobic recurring units.
The amount of the first cationic water-soluble or water-swellable polymer in
the
aqueous dispersion is as high as practicable, taking into account the effect
of high solids on
bulk viscosity, preferably about 5% or greater, more preferably about 10% or
greater, most
preferably about 20% or greater, by weight based on the total weight of the
aqueous
dispersion. Generally, the solids are not increased above an amount which
increases the
bulk viscosity to an impractical level. Practically, the amount of first
cationic polymer in
the aqueous dispersion is about 75% or less, preferably about 60% or less,
more preferably
about 50% or less, by weight based on total weight. The weight average
molecular weight
of the first cationic polymer in the aqueous dispersion is not critical and
depends on the
application, but is generally higher than about 1,000,000, preferably greater
than about
2,000,000, more preferably greater than about 5,000,000, and most preferably
greater than
about 10,000,000. Molecular weights of polymers are weight average and may be
determined by means known to those skilled in the art, preferably by light
scattering.
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The aqueous dispersions of the instant invention are generally comprised of a
discontinuous phase of small aqueous droplets, containing polymer that is
comprised
predominately of the first cationic water-soluble or water-swellable polymer,
that are
dispersed in the aqueous continuous phase, although of course minor amounts of
said first
polymer may be found in the continuous phase. Thus, the first cationic water-
soluble or
water-swellable polymer generally constitutes more than SO%, preferably more
than 75%,
of the polymer in a typical small aqueous droplet. The amount of first
cationic polymer in
the discontinuous and continuous phases may be determined by known analytical
techniques e.g. Raman microscopy. Although large aqueous droplets or gel
particles may
be formed by adding dry or gel polymer to the other components as in U.S.
Patent No.
4,673,704 and EP 0 170 394 A2, the aqueous dispersions of the instant
invention are
preferred because it is generally more desirable for the first cationic
polymer to be in the
form of small droplets which are generally held suspended in a continuous
matrix of the
aqueous phase and do not generally rest substantially in contact with one
another,
Although aqueous dispersions prepared by polymerization of monomers as herein
described may sometimes have an average droplet size of about 30 microns or
more, the
average droplet size is generally less than about 30 microns, preferably less
than 20
microns, more preferably about 15 microns or less. Droplet size of a non-
spherical droplet
is the length along a major axis, Droplet size and shape tend to be a function
of reactor
conditions such as stirring rate, reactor configuration, type of stirrer, etc.
Preferably, the
size of the droplets is chosen by carrying out the polymerization in the
presence of one or
more insoluble polymeric seeds, said polymeric seeds being insoluble in an
aqueous
solution having the same inorganic salt concentration as said aqueous
dispersion.
The aqueous dispersions of the instant invention contain a second water-
soluble
polymer, preferably a vinyl-addition polymer, that is different from and,
preferably,
incompatible with, said first water-soluble or water-swellable cationic
polymer. The
second polymer is different from the first polymer when it can be
distinguished from the
first polymer on the basis of a particular physical characteristic e.g.
chemical composition,
charge, molecular weight, molecular weight distribution, distribution of
recurring units
along the polymer chain, etc., by known characterization methods e.g.
spectroscopy,
chromatography, etc. The second polymer is incompatible with the first polymer
when
solutions of the two polymers, at the concentrations present in the aqueous
dispersion, do
not form a homogenous mixture when blended, or do not form a homogenous
mixture
IS
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when one polymer is formed by polymerization of monomers in the presence of
the other
polymer.
The second, preferably cationic, water-soluble polymer in the aqueous
dispersion of
the instant invention is generally dissolved in the aqueous continuous phase,
although of
course minor amounts may be found in the discontinuous phase. The amount of
second
polymer in the discontinuous and continuous phases may be determined by known
analytical techniques e.g. Raman microscopy. The second polymeyr may be any
nonionic
water-soluble polymer, preferably a polyalkyleneoxide, a polyvinylalcohol,
polyvinylpyridine, polyvinylpyrollidone, polyhydroxylalkyl(alk)acrylate, etc.,
most
preferably poly(meth)acrylamide. Even more preferably, the second water-
soluble polymer
is cationic. The second polymer may be any cationic polymer, and the charge
may vary
over a broad range by containing about 1 % to about 100% cationic recurring
units,
preferably about 10% or greater, more preferably about 20% or greater, even
more
preferably about 30% or greater, by mole based on total moles of recurring
units in the
polymer. Although in some cases the second cationic polymer may contain about
70% or
less, or even about SO% or less, of cationic recurring units, preferably the
second polymer
is predominately cationic i.e. contains more than 50% cationic recurring
units, by mole
based on total moles of recurring units in the polymer; most preferably about
80% or
greater of recurring cationic units, same basis. Cationic recurring units may
be formed by
polymerization of cationic monomers or by post-reaction of polymer as above,
and may be
a copolymer and may contain other cationic recurring units or nonionic
recurring units as
above. Preferred second cationic water-soluble polymers contain recurring
units of
diallyldialkylammonium halide, methyl chloride quaternary salt of
dialkylaminoalkyl(alk)acrylate, dimethyl sulfate quaternary salt of
dialkylaminoalkyl(alk)acrylate, methyl chloride quaternary salt of
dialkylaminoalkyl(alk)acrylamide, or dimethyl sulfate quaternary salt of
dialkylaminoalkyl(alk)acrylamide. Especially preferred second cationic water-
soluble
polymers contain recurring units of diallyldimethylammonium chloride, methyl
chloride
quaternary salt of dimethylaminoethyl(meth)acrylate, or dimethyl sulfate
quaternary salt of
dimethylaminoethyl(meth)acrylate. One or more second cationic polymers may be
used.
Other cationic polymers and copolymers such as polyamines and condensation
polymers
made from monomers such as epichlorohydrin and dimethylamine are also useful
in the
practice of this invention. Polyamines are generally well-known and include
reaction
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products of mono-, di- and/or triamines with epihalohydrin and/or di- or
trihaloalkane, where
the ratio of the various constituents may be manipulated to give a polyamine
product having
the desired molecular weight.
Depending on the application, it may be preferable for the second polymer to
be
cationic in order to maximize the cationic charge density of the aqueous
dispersion. Also,
for embodiments which contain salt, it may be preferable for the second
polymer to be
cationic because cationic polymers are often more soluble in salt solution
than nonionic
polymers.
The amount of the second, preferably cationic, water-soluble polymer in the
aqueous dispersion is generally chosen to control aqueous dispersion
properties e.g.
performance, bulk viscosity, charge, molecular weight, solubility rate,
physical stability,
e.g. settling, etc. Generally, the amount of said second polymer is about 5%
or greater,
preferably about 10% or greater, more preferably about 20% or greater, most
preferably
about 30% or greater, by weight based on the amount of first cationic water-
soluble
polymer. Practically, the amount of second water-soluble polymer in the
aqueous
dispersion is 100% or less, preferably about 80% or less, more preferably
about 50% or
less, by weight based on the amount of first cationic water-soluble polymer.
In certain
preferred embodiments, the amounts of the first and second polymers are
effective to form
an aqueous dispersion. In some embodiments, an aqueous dispersion is not
formed in the
absence of the second polymer, and a homogeneous composition is obtained
instead.
Practically, the amount of first and second polymer may be found by routine
experimentation, and different amounts will ordinarily be used depending on
the identity of
the first and second polymers, the total polymer solids level, the bulk
viscosity, cost, ease
of production, product performance, etc.
The weight average molecular weight of the second water-soluble polymer in the
aqueous dispersion is also generally chosen to provide the most advantageous
effect, e.g.
bulk viscosity, performance, cost, etc., but is generally higher than about
10,000, preferably
greater than about 50,000, more preferably greater than about 500,000, and
most preferably
greater than about 1,000,000. Molecular weights of polymers are weight average
and may
be determined by means known to those skilled in the art, preferably by light
scattering.
The second water-soluble polymer is primarily in the continuous phase of the
aqueous
dispersion, although of course minor amounts may be contained in the dispersed
droplets.
Preferably, the aqueous dispersions of the instant invention are heterogeneous
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compositions in which more than 50%, preferably about 75% or more, of the
first cationic
water-soluble or water-swellable polymer is in the form of a discontinuous
phase of
aqueous droplets that are dispersed in an aqueous solution that is comprised
of more than
50%, preferably about 75% or more, of the second, preferably cationic, water-
soluble
polymer.
The aqueous dispersions of the instant invention may contain a third water-
soluble
or water-swellable polymer that is different from the first or second
polymers. For
instance, the third polymer may also be contained in droplets dispersed in the
aqueous
solution, in which case it may be described as discussed above for the first
cationic
polymer. The third polymer may also be dissolved in the aqueous solution along
with the
second polymer, in which case it may be described as discussed above for the
second
polymer. Preferably, the third polymer is cationic.
A third aqueous dispersion, containing three or more polymers, may be formed
by
blending first and second aqueous dispersions of the instant invention,
wherein the first and
second aqueous dispersions are different from each other. Blending is
generally carned
out by intermixing the aqueous dispersions, typically with stirring. Blending
may be
advantageous to achieve a balance of properties exhibited by the individual
aqueous
dispersions, e.g. performance, charge, total polymer solids, cost, molecular
weight, etc.
Surprisingly, in many cases the blends are stable, e.g. remain in the form of
aqueous
dispersions having low bulk viscosity e.g. less than 10,000 centipoise for
periods of one
week or more, even when the salt or second polymer level in the blend is
greatly different
from the level needed to obtain a stable product for one or both of the
dispersed polymers,
if formulated alone. Also surprisingly, the bulk viscosity of the blend is
often lower than
the bulk viscosity of any of the individual aqueous dispersions.
The molecular weight of the aqueous dispersion, as that term is used herein,
is
simply the weight average molecular weight of the polymers contained therein,
obtained by
subjecting the entire dispersion to a suitable molecular weight
characterization technique
e.g. light scattering. Since the aqueous dispersion contains two or more
different polymers,
each of which may have a molecular weight and molecular weight distribution
different
from the other(s), the molecular weight distribution of the aqueous dispersion
may be
multimodal. The molecular weight of the aqueous dispersion is generally about
1,000,000
or greater, preferably greater than 2,000,000, more preferably about 3,000,000
or greater,
most preferably about 5,000,000 or greater.
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In some cases it may be more convenient to characterize the aqueous dispersion
in
terms of standard viscosity instead of by molecular weight. As used herein,
"standard
viscosity" is determined by: diluting an aqueous dispersion with water to form
an aqueous
admixture (in the case of water-swellable polymers) or solution (in the case
of water-
s soluble polymers) having a polymer concentration of about 0.2%; mixing
together 8.0 g of
this aqueous admixture or solution with 8.6 g of 2M NaCI; and then measuring
the
viscosity of the resultant mixture at 25°C on a rotating cylinder
viscometer e.g. Brookfield
Viscometer equipped with a UL adapter at 60 rpm. The standard viscosities of
the aqueous
dispersions of the instant invention are generally about 1.5 centipoise or
greater, preferably
about 1.8 centipoise or greater, more preferably about 2.0 centipoise or
greater, most
preferably about 2.5 centipoise or greater, depending on the application.
The aqueous dispersions of the instant invention may also be intermixed with
water-in-oil emulsions or microemulsions of water-soluble polymers to form
compositions
which, though they contain oil, contain proportionately less oil than the
water-in-oil
emulsions or microemulsions from which they are derived. Consequently, these
compositions may advantageously produce less secondary pollution, have lower
flammability, etc.
Certain embodiments of the instant invention require salt. Effective amounts
of salt
tend to reduce the bulk viscosity of the aqueous dispersion. The salt may be
any inorganic
salt, preferably a kosmotropic salt e.g. a chloride, sulfate, phosphate, or
hydrogenphosphate
salt, more preferably ammonium sulfate, sodium chloride, and sodium sulfate,
most
preferably sodium sulfate and ammonium sulfate. The counterion may be any
counterion,
e.g. Group IA and Group IIA metal ions, ammonium, etc., preferably ammonium,
sodium,
potassium and magnesium. Mixtures of salts may be used, and the amount of salt
may be
chosen to achieve a desirable bulk viscosity or any other desirable effect.
Since the salt
may have a dilutive effect, in certain preferred embodiments the salt is only
added in
amounts so as to achieve a homogeneous composition in the absence of the
second water-
soluble polymer. In these embodiments, the aqueous dispersion is not formed by
the action
of the salt, but by the interaction of the first and second polymers.
Effective or viscosity-
reducing amounts of salt may be found through routine experimentation and are
generally
chosen to reduce the bulk viscosity without causing precipitation of the
polymer. In other
preferred embodiments, the salt is only added in amounts so as to achieve a
homogeneous
composition in the absence of the first cationic polymer. In embodiments where
salt is
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WO 00/20470 PCTNS99/21152
helpful but not necessary, salt levels may range upwards from 0%, preferably
about 3% or
greater, most preferably about 5% or greater, by weight based on total weight,
depending
on the upper limit to solubility, because solubility of the salt in the
aqueous dispersion is
preferred. In embodiments where salt is necessary, salt levels are chosen to
favorably
influence product attributes such as cost, bulk viscosity, etc. and may range
upwards from
about 1 %, preferably about 3% or greater, most preferably about 5% or
greater, by weight
based on total weight, depending on the upper limit to solubility, because
solubility of the
salt in the aqueous dispersion is preferred. Frequently, no practical effect
of the salt is
observed above about 30%, so salt levels are generally about 30% or less,
preferably about
25% or less, by weight based on total weight. Practically, the salt level may
be determined
by routine experimentation, e.g. balancing the tendency for positive product
attributes e.g.
lower bulk viscosities resulting from higher salt levels, against the negative
aspects of salt
use e.g. cost and dilutive effect.
Surprisingly, it has been discovered that mixtures of chaotropic salts with
kosmotropic salts, or anionic organic salts with kosmotropic salts, have a
tendency to
reduce the bulk viscosity of the aqueous dispersion. In many cases, the salt
mixture is
more effective than either salt alone, on a weight basis. Useful chaotropic
salts include
thiocyanates, perchlorates, chlorates, nitrates, bromides, iodides, and
mixtures thereof,
preferably sodium thiocyanate and sodium iodide. Useful anionic organic salts
include
anionic surfactants and anionic hydrotropic salts, preferably aryl and
substituted aryl
sulfonates having from 6 to 22 carbons, preferably 6 to 18 carbons, and alkyl
and
substituted alkyl sulfonates having from 2 to 22 carbons, preferably 4 to 18
carbons, and
mixtures thereof. Especially preferred anionic organic salts are
dialkylsulfosuccinates,
diarylsulfosuccinates, benzenesulfonates, benzenedisulfonates,
naphthalensulfonates,
naphthalenedisulfonates, and mixtures thereof; 1,3-benzendisulfonates are most
preferred.
Counterions to the chaotropic and anionic organic salts may be any typical
counterion, e.g.
Group IA metal ions, ammonium, etc., preferably ammonium, sodium, and
potassium.
Effective or viscosity-reducing amounts of chaotropic and anionic organic
salts may be
found through routine experimentation and are generally chosen to reduce the
bulk
viscosity without causing precipitation of the polymer. in certain preferred
embodiments,
the amounts of chaotropic salt, or anionic organic salt, and kosmotropic salt
are chosen
such that a homogeneous composition is obtained in the absence of the second
cationic
polymer; i.e. the concentration of the salts is such that the first cationic
polymer is not
CA 02346249 2001-04-03
WO 00/20470 PCT/US99/21152
precipitated in the absence of the second cationic polymer. Generally, amounts
of
chaotropic, or anionic organic, salts are about 10% or less, preferably about
S% or less, and
generally 0.5% or more, preferably 1% or more, by weight based on total
weight. At very
low chaotropic or anionic organic salt levels, the viscosity-reducing effect
of the salt is
negligible, whereas the salt may cause undesirable precipitation or layering
at high levels
of incorporation. To achieve a certain bulk viscositv_ atT1Wl11tc of
l~ncmntrnnir calrc "~o~
with the chaotropic, or anionic organic salt, are generally less than when the
kosmotropic
salt is used alone, but still within the ranges given above for the use of
inorganic or
kosmotropic salts alone.
The aqueous dispersions of the instant invention generally have lower bulk
viscosities than comparable aqueous dispersions. A comparable aqueous
dispersion is
generally one which is substantially identical in many functional aspects, but
lacks a
particular element of the instant invention. In general, the aqueous
dispersions of the
instant invention have lower bulk viscosities than comparable aqueous
dispersions which
have substantially the same polymer solids, cationic charge level and weight
average
molecular weight, but which lack an important feature of the instant invention
e.g. lack a
recurring unit of formula (I); lack the amount of recurnng units of formula I
found in the
aqueous dispersions of the instant invention; not made by a process which
comprises
polymerizing vinyl-addition monomers comprised of at least one monomer of the
formula
(II); nat made by a process which comprises polymerizing vinyl-addition
monomers
comprised of the amount of monomers of the formula (II) used in the processes
of the
instant invention, etc. For instance, in a composition comprising an aqueous
dispersion
comprised of: (a) a discontinuous phase containing polymer that is comprised
predominately of a first cationic water-soluble or water-swellable polymer
having at least
one recurring unit of the formula (I), and (b) at least one second water-
soluble polymer
different from said first polymer, a comparable aqueous dispersion may be one
which
contains the same amount of each component, except the R2, R3 and R4 in the
corresponding recurring formula (I) unit of the comparable aqueous dispersion
together
contain a total of 3 carbon atoms, instead of the 4 or more carbons in the
corresponding
recurring unit of formula (I) in the claimed aqueous dispersion.
Surprisingly, aqueous dispersions having formula (I) recurring units in which
RZ, R3
and R, contain four or, preferably, five carbons generally have bulk
viscosities which are
dramatically lower than the bulk viscosities of aqueous dispersions that are
substantially
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identical except that RZ, R, and R, contain only three carbons. The bulk
viscosity of
aqueous dispersions is typically influenced by e.g. total polymer solids, salt
level, polymer
type, ratio of first cationic polymer to second cationic polymer, etc. as
disclosed herein.
Although aqueous dispersions having bulk viscosities of about 20,000
centipoise (cps) or
more, or even about 200,000 cps or more may be suitable in certain
circumstances, much
lower bulk viscosities are generally preferred for ease of handling. Aqueous
dispersions
having bulk viscosities of about 20,000 centipoise (cps) or less, preferably
about 10,000
cps or less, more preferably about 8,000 cps or less, even more preferably
about 5,000 cps
or less, most preferably about 2,500 cps or less, may be obtained by the
practice of the
instant invention. Bulk viscosity may be measured by any convenient method
known to
those skilled in the art, preferably a rotating cylinder viscometer as
described in the
Examples below.
Aqueous dispersions are preferred which have as many of the following
advantageous attributes as possible: relatively high cationic polymer solids,
preferably
I S 20% or greater, more preferably 25% or greater, by weight based on total;
high molecular
weight, preferably 2,000,000 or greater, more preferably 5,000,000 or greater;
reduced
environmental impact (low VOC; substantially free of organic solvents and
aromatic
groups, e.g. aromatic- or benzyl-containing oils or recurring units); minimal
levels of
diluents (preferably, 20% or less of salt, by weight based on total, and
polymer devoid or
substantially free of hydrophobic recurring units); bulk viscosity about 2,000
cps or less;
for recurring units based on formula (I), R2, R3 and R4 together containing a
total of 5
carbons; and superior or equivalent performance. Products having all of these
attributes
may be obtained by the practice of the present invention.
Aqueous dispersions of water-soluble polymers are preferably formed by
polymerization of the corresponding monomers to form the first cationic water-
soluble
polymer, in the presence of at least one second cationic water-soluble polymer
and, in
certain embodiments, an inorganic salt. Polymerization may be effected by any
initiating
means, including redox, thermal or irradiating types. Examples of preferred
initiators are
2,2'-azobis(2-amidino-propane)dihydrochloride (V-50), 2,2'-
azobis(isobutyronitrile),
sodium bromate/sulfur dioxide, potassium persulfate/sodium sulfite, and
ammonium
persulfate/sodium sulfite, as well as peroxy redox initiators e.g. those
disclosed in U.S.
4,473,689. Initiator levels are chosen in a known manner so as to create
polymers of the
desired molecular weight. Amounts of chain transfer agents, e.g. isopropanol,
lactic acid,
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mercaptoethanol, etc. and branching or crosslinking agents, e.g.
methylenebisacrylamide
may be added in a known manner to further adjust the properties of the first
cationic water-
soluble polymer. Depending on the production conditions, e.g. types and
relative amounts
of chain transfer agent and branching agent, water-swellable or branched,
water-soluble
polymers may be formed. In general, the use of greater amounts of branching or
crosslinking agent increases the tendency for the product to be water-
swellable instead of
water-soluble, and increased amounts of chain transfer agent tend to reduce
molecular
weight. When chain transfer agent and branching agent are used together, water-
swellable
products are more likely to be obtained at high branching agent and low chain
transfer
agent levels, whereas branched, water-soluble polymers may be obtained at high
chain
transfer and low branching agent levels. Components may be added at any time;
e.g. all of
the monomers may be present from the onset of the polymerization, or monomers
may be
added during the course of the polymerization. If salt is used, all of the
salt may be present
from the onset of the polymerization, or salt may be added during the course
of the
polymerization or after polymerization is complete. Likewise, polymerization
parameters
e.g. temperature and time may be chosen in a known manner, and may be varied
during the
course of the polymerization. Polymerization is generally effected in the
presence of an
inert gas, e.g. nitrogen. Conventional processing aids e.g. chelating agents,
sequestrants,
pH adjusters, etc. may be added as required.
The aqueous dispersions of the present invention have advantageous aspects in
that
they are preferably substantially free of dilutive substances such as
surfactant, oil,
hydrocarbon liquids, organic solvents, etc. Although viscosity-reducing
additives e.g.
glycerin, glycerol, alcohol, glycol, etc. may be present in the aqueous
dispersions, amounts
should be 2% or less, more preferably 1 % or less, most preferably 0.1 % or
less, in order to
maintain the advantageous properties of the invention.
The aqueous dispersions of the instant invention may be homogenous in the
absence of a particular component e.g., said second water-soluble polymer.
Homogenous
compositions are generally characterized as being clear or translucent, and
are not aqueous
dispersions because they do not contain dispersed droplets as described above.
Depending
on the embodiment, said first cationic water-soluble polymer or said second
cationic water-
soluble polymer is dispersion-creating in that aqueous dispersions are not
obtained in the
absence of an effective or dispersion-creating amount of the particular
component.
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Waters used in the present invention may be from any source, e.g. process
water,
river water, distilled water, tap water, etc. Preferably, polymerizations are
conducted in
aqueous solutions that do not contain substantial amounts of materials which
detrimentally
affect the polymerization. Advantageously, the aqueous dispersions of the
present
invention tend to dissolve quickly when diluted with water.
The aqueous dispersion of the instant invention may be dehydrated to increase
the
total polymer solids content, or to create substantially dry products. Any
means known in
the art e.g. stripping, spray drying, solvent precipitation, etc. may be used
to reduce the
water content. Surprisingly, partial dehydration may reduce the bulk viscosity
of an
aqueous dispersion, in spite of the tendency for dehydration to increase
polymer solids.
Dehydration may be performed by heating, preferably under reduced pressure,
although of
course excessive heating may be detrimental to polymer properties. A
substantially dry
mass of polymer may be obtained by removal of water, and the mass may be
comminuted
to create a powdery, particulate, or granular product.
Surprisingly, substantially dry polymer products may be obtained by spray-
drying the
aqueous dispersions of the instant invention. Although oil-containing polymer
emulsions
and dispersions have been spray-dried, see e.g. U.S. Patent Application Serial
No.
08/668,288 and references therein, spray-drying of aqueous dispersions, which
are
generally free of oil and surfactants, has not previously been reported. In
accordance with
the instant invention, vinyl-addition polymer-containing aqueous dispersions
may be sprayed-
dried by a suitable means into a large chamber through which a hot gas is
blown, thereby
removing most or all of the volatiles and enabling the recovery of the dried
polymer.
Surprisingly, the means for spraying the aqueous dispersion into the gas
stream are not
particularly critical and are not limited to pressure nozzles having specified
orifice sizes; in
fact, any known spray-drying apparatus may be used. For instance, means that
are well
known in the art such rotary atomizers, pressure nozzles, pneumatic nozzles,
sonic nozzles,
etc. can all be used to spray-dry the aqueous dispersion into the gas stream.
The feed rate,
feed viscosity, desired particle size of the spray-dried product, droplet size
of the aqueous
dispersion, etc. are factors which are typically considered when selecting the
spraying means.
The size and shape of the chamber, the number and type of spraying means, and
other typical
operational parameters may be selected to accommodate dryer conditions using
common
knowledge of those skilled in the art.
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Although closed cycle spray-dryers may be used, open cycle spray-drying
systems are
preferred. Gas flow may be cocuirent, countercurrent or mixed flow, cocurrent
flow being
preferred. The hot gas, or inlet gas, may be any gas that does not react or
form explosive
mixtures with the feed and/or spray-dried polymer. Suitable gases used as the
inlet gas are
gases known to those skilled in the art, including air, nitrogen, and other
gases which will not
cause undesirable polymer degradation or contamination, preferably gases
containing about
20% or less oxygen, more preferably about 15% or less oxygen. Most preferably,
inert gases
such as nitrogen, helium, etc. that contain about 5% or less of oxygen should
be used.
The dried polymer may be collected by various means such as a simple outlet,
classifying cone, bag filter, etc., or the polymer may be subjected to further
stages of drying,
such as by fluid beds, or agglomeration. The means for collecting the dry
polymer product is
not critical.
There are four interrelated operating parameters in the instant spray-drying
process:
gas inlet temperature, gas outlet temperature, product volatiles and residence
time in the
dryer. The outlet temperature generally should be about 150°C or below,
preferably about
120°C or below, more preferably less than 100°C, even more
preferably about 95°C or
below, most preferably about 90°C or below. The outlet temperature is
generally about 70°C
or higher, preferably about 75°C or higher. Therefore, outlet
temperatures are generally
about 70° C to about I50° C, preferably about 70° C to
about 120° C, more preferably about
70° C to less than 100°, even more preferably about 70° C
to about 95° C, most preferably
about 7S°C to about 90°C. Outlet temperatures below about
70°C may be suitable in certain
instances, though generally this is less preferred. For instance, at the cost
of efficiency, spray
drying could be carned out at long residence times, high gas flow rates and
low outlet
temperatures. Generally, the dryer should be operated at the lowest possible
outlet
temperature consistent with obtaining a satisfactory product.
The inlet temperature, the feed rate, and the composition of the aqueous
dispersions may
all affect outlet temperatures. These parameters may be varied to provide a
desired outlet
temperature. Feed rates are not critical, and generally will vary depending on
the size of the
dryer and the gas flow rate. Inlet gas temperature is less critical than
outlet gas temperature,
and is generally about 140°C or above, preferably about 160°C or
above. The inlet gas
temperature is preferably about 200°C or below and more preferably
about 180°C or below.
Thus, preferred inlet gas temperature ranges from about 140°C to about
200°C, more
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preferably from about 160°C to about 180°C. Proper inlet gas
temperatures tend to avoid
product degradation on the high side and to avoid inadequate drying on the low
side.
Residence time is a nominal value obtained by dividing the volume of the dryer
by the
volumetric gas flow. Residence time is generally at least about 8 seconds,
preferably at least
about 10 seconds. Residence time is generally no more than about 120 seconds,
preferably
no more than about 90 seconds, more preferably no more than about 60 seconds,
and most
preferably no more than about 30 seconds. Therefore, the general range of
residence time is
about 8 to about 120 seconds, preferably about 10 to about 90 seconds, more
preferably about
to about 60 seconds, and most preferably about 10 to about 30 seconds. It is
known to
10 those skilled in the art that longer residence times are to be expected
when larger dryers are
used or when the dryer is run in a less efficient manner. For instance, at the
cost of
efficiency, longer residence times would be expected at very low inlet
temperatures and slow
gas flow rates. As a practical matter, the residence times useful in the
present invention may
vary from the values described above, depending on the size and type of spray
dryer used, the
efficiency at which it is operated, and other operational parameters. Thus,
residence times
specified herein may be modified to accommodate dryer conditions using common
knowledge of those skilled in the art.
When produced according to the spray drying processes disclosed herein,
polymer
particles of the instant invention are generally about 10 microns or greater
in diameter,
preferably about 40 microns or greater, more preferably about 100 microns or
greater, most
preferably about 200 microns or greater. It is preferred that the polymer
particles be non-
dusting. Dusting and flow problems are.typically exacerbated when the polymer
particles are
small, so larger polymer particles are generally desirable. However, very
large particles may
dissolve more slowly. Therefore, it is generally desirable for the polymer
particles to be
about 1200 microns or less in diameter, preferably about 800 microns or less
in diameter,
more preferably about 600 microns or less, most preferably about 400 microns
or less.
Generally, at least about 90% of the polymer particles range in size from
about 10 microns to
about 1200 microns, preferably at least about 95%, more preferably at least
about 98%. The
size of the polymer particles can be varied somewhat by altering the
operational parameters
e.g. spray configuration, aqueous dispersion viscosity, feed rate, etc.
Particles may be
substantially spherical or non-spherical; "diameter" of a non-spherical
particle is the
dimension along a major axis.
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Although in some cases the polymer particles are hollow, porous structures
having at
least one opening in their walls, it has been discovered that these features
are not always
necessary in order to obtain particles having desirable properties e.g, fast
dissolution times.
In many cases, the spray-drying parameters e.g, nozzle type, nozzle size,
outlet temperature,
etc. needed to produce particles that are hollow, porous structures having at
least one opening
in their walls are inconvenient or uneconomical, and it is advantageous to
produce particles
that lack some or all of these features.
The particles formed by the spray-drying processes of the instant invention
may be
screened to remove an oversize or undersize fraction. Oversize particles may
be fragmented
by e.g. grinding, whereas undersized particles are generally agglomerated.
Sizes may be
determined by methods known to those skilled in the art e.g. sieving,
screening, light
scattering, microscopy, microscopic automated image analysis, etc.
Surprisingly, the bulk densities of the spray-dried polymer particles of the
instant
invention are generally greater than the bulk densities of dry polymers
prepared by
I S precipitation of e.g. water-in-oil emulsions of the same polymer. Polymer
particles having
greater density may be advantageous because they occupy a smaller volume,
resulting in e.g.
lower shipping and storage costs. Whereas the densities of precipitated
polymers are usually
less than about 0.35 grams per cubic centimeter (g/cc), the bulk densities of
the spray-dried
polymer particles of the instant invention are generally about 0.35 g/cc or
greater, preferably
about 0.4 g/cc or greater, more preferably about 0.45 g/cc or greater, most
preferably about
0.50 g/cc or greater. The bulk densities of the spray-dried polymer particles
of the instant
invention are generally about I.1 g/cc or less, preferably about 1.0 g/cc or
less, more
preferably about 0.95 g/cc or less, most preferably about 0.90 g/cc or less.
Therefore, the
bulk densities of the spray-dried polymer particles of the instant invention
generally range
from about 0.35 to about 1.1 g/cc, preferably about 0.4 to about 1.0 g/cc,
more preferably
about 0.45 to about 0.95 g/cc, most preferably about 0.50 to about 0.90 g/cc.
Under the conditions of drying set forth herein, the polymer particles
produced by the
processes described herein are substantially dry. As used to describe the
polymer produced
herein, "substantially dry" generally means that the polymer contains about
12% or less
volatiles, preferably about 10% or less by weight, based on the weight of the
spray dried
polymer. The polymer generally contains about 2% or more volatiles, preferably
about 5% or
more, by weight based on total weight, and most preferably contains from about
8% to about
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10% volatiles by weight, same basis. The volatiles are measured by determining
the weight
loss on drying the polymer product at about 105°C for about 30 minutes.
It has also been discovered that agglomeration of the polymer particles of the
instant
invention may improve the flow properties and dissolution times of the
polymers.
Agglomeration is a known process for increasing particle size and various
methods for
agglomerating particles are known to those skilled in the art, e.g.
"Successfully Use
Agglomeration for Size Enlargement," by Wolfgang Pietsch, Chemical En
ineerinl; Pro ress,
April 1996, pp. 29-45; "Speeding up Continuous Mixing Agglomeration with Fast
Agitation
and Short Residence Times," by Peter Koenig, Powder and Bulk En ineering,
February
1996, pp. 67-84. Known agglomeration methods such as natural agglomeration,
mechanical
agglomeration, tumble or growth agglomeration, pressure agglomeration,
binderless
agglomeration, agglomeration with binders, etc. may be used to agglomerate the
polymer
particles of the instant invention. Agglomeration may optionally be followed
by drying e.g.
fluid bed drying, to remove binder e.g. water. Pressure agglomeration is
preferred, and
mechanical agglomeration using a water binder, followed by fluid bed drying is
most
preferred.
The agglomerates formed by agglomerating the polymer particles of the instant
invention
tend to have improved flow properties and faster dissolution times when
compared to the
unagglomerated polymer particles. Preferably, the agglomerates are non-
dusting. Typically,
about 90% of the agglomerates of the instant invention have an agglomerate
size of about 120
microns or greater, preferably about 160 microns or greater, more preferably
about 200
microns or greater, most preferably about 300 microns or greater. Generally,
about 90% of
the agglomerates have an agglomerate size of about 1500 microns or less,
preferably about
1200 microns or less, more preferably about 1100 microns or less, most
preferably about
1000 microns or less. Thus, about 90%, preferably 95%, of the agglomerates
have a size in
the range of about 120 to about 1500 microns, preferably about 160 microns to
about 1200
microns, more preferably about 200 microns to about 1100 microns, most
preferably about
300 microns to about 1000 microns Usually, at least about S% of the
agglomerates,
preferably at least about 10%, most preferably at least about IS%, are larger
than about 900
microns. The agglomerates formed by agglomerating the spray-dried particles of
the instant
invention may be screened to remove an oversize or undersize fraction.
Preferably,
agglomerates larger than about 1200 microns and smaller than about 175 microns
are
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WO 00/20470 PCT/US99/21152
removed by e.g. screening. Oversize agglomerates are generally fragmented by
e.g. grinding,
whereas undersized agglomerates are generally recycled into the agglomerator.
The bulk density values of the agglomerates of the instant invention tend to
be lower
than the bulk density values of the spray-dried particles from which they are
formed. The
bulk densities of the agglomerates of the instant invention are generally
about 0.35 g/cc or
greater, preferably about 0.4 g/cc or greater, more preferably about 0.45 g/cc
or greater, most
preferably about 0.50 g/cc or greater. The bulk densities of the agglomerates
of the instant
invention are generally about 1.0 g/cc or less, preferably about 0.95 g/cc or
less, more
preferably about 0.90 g/cc or less, most ,preferably about 0.85 g/cc or less.
Therefore, the
bulk densities of the agglomerates of the instant invention generally range
from about 0.35 to
about 1.0 g/cc, preferably about 0.4 to about 0.95 g/cc, more preferably about
0.45 to about
0.90 g/cc, most preferably about 0.50 to about 0.85 g/cc.
In order to obtain agglomerates of a preferred size, it is preferred that the
polymer
particles themselves be of such a size that they are agglomerable.
Agglomeration obviously
tends to multiply the average particle size, so that it is frequently easier
to cause large
increases in particle size than it is to cause small increases in particle
size. Therefore, to
produce agglomerates of a preferred size or size range, it is generally
preferred to agglomerate
particles that are much smaller than the desired agglomerate size, rather than
particles that are
only slightly smaller. Agglomerable particles are generally those that may be
conveniently
agglomerated to produce agglomerates having a preferred size. It is possible,
but less
preferred, to agglomerate larger particles to produce agglomerates that are
larger than desired,
then remove the oversize agglomerates as described above.
The substantially dry polymer particles and agglomerates of the present
invention are
generally comprised of the polymer that was contained in the aqueous
dispersion that was
spray-dried, as discussed hereinabove.
Spray-drying of the aqueous dispersions of the instant invention is
advantageous because
typically 90% or greater, preferably 95% or greater, most preferably
substantially all, of the
resultant spray-dried polymer particles each individually contains two or more
water-soluble
or water-swellable vinyl-addition polymers, so that stratification effects may
be minimized.
Stratification may occur when two different dry polymers having differing
particle sizes or
particle size distributions are blended together because of the tendency for
the larger particles
to settle towards the bottom of the container. Stratification on storage may
affect blend
product performance as the top of the container tends to become enriched in
the polymer
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WO 00/20470 PCT/US99/21152
having the smaller particle size. For obvious reasons, changes in product
performance as a
function of storage depth are to be avoided, and it is generally preferred
that each polymer in
a blend be of similar particle size, see e.g. EP 479 616 A1 and U.S. Patent
No. 5,213,693. A
dry blend of the two different polymers is likely to exhibit greater
stratification than a dry
S blend obtained by spray-drying the instant aqueous dispersions because the
majority of the
spray-dried polymer particles of the instant invention each individually
contains two or more
water-soluble or water-swellable vinyl-addition polymers. Surprisingly, the
spray-dried
aqueous dispersions of the instant invention tend to dissolve faster than
polymers obtained by
spray-drying conventional water-in-oil emulsions of similar polymers.
A suspension of dispersed solids may be dewatered by a method which comprises
(a) intermixing an effective amount of an aqueous dispersion of polymers, or
aqueous
admixture thereof, with a suspension of dispersed solids, and (b) dewatering
said
suspension of dispersed solids. Substantially dry polymers derived from the
aqueous
dispersions of the instant invention as described above may also be used to
dewater
suspended solids. For instance, a suspension of dispersed solids may be
dewatered by a
method which comprises (a) intermixing an effective amount of a substantially
dry water-
soluble or water-swellable polymer, or aqueous admixture thereof, with a
suspension of
dispersed solids, and (b) dewatering said suspension of dispersed solids.
Preferably, an
aqueous admixture of the dry polymer or aqueous dispersion is prepared by
intermixing the
dry polymer or aqueous dispersion with water, more preferably by dissolving
the dry
polymer or aqueous dispersion in water to form a dilute polymer solution.
Effective
amounts of dry polymer or aqueous dispersion are determined by methods known
in the
art, preferably by routine laboratory or process experimentation.
Examples of suspensions of dispersed solids which may be dewatered by means of
the instant invention are municipal and industrial waste dewatering,
clarification and
settling of primary and secondary industrial and municipal waste, potable
water
clarification, etc. Because of the advantageous aspects of the invention e.g.
substantially
oil-free, minimum amounts of inactive diluents, little or no surfactant, etc.,
the polymers
may be especially well-suited to situations where part or all of the dewatered
solids or
clarified water is returned to the environment, such as sludge composting,
land application
of sludge, pelletization for fertilizer application, release or recycling of
clarified water,
papermaking, etc. Other applications which may benefit from the advantageous
aspects of
the instant inventions include soil amendment, reforestation, erosion control,
seed
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protection/growth, etc., where the aqueous dispersion or dry polymer,
preferably an
aqueous admixture thereof, is advantageously applied to soil.
Other examples of suspensions of dispersed solids which may be dewatered by
means of the instant invention are found in the papermaking area, e.g. the
aqueous
dispersions or dry polymer may be used as retention aids, drainage aids,
formation aids,
washer/thickener/drainage production aid (DNT deink application), charge
control agents,
thickeners, or for clarification, deinking, deinking process water
clarification, settling,
color removal, or sludge dewatering. The polymers of the instant invention may
also be
used in oil field applications such as. petroleum refining, waster
clarification, waste
dewatering and oil removal.
Dewatering and clarification applications for the aqueous dispersions and dry
polymers of the instant invention may also be found in the food processing
area, including
waste dewatering, preferably waste dewatering of poultry beef, pork and
potato, as well as
sugar decoloring, sugar processing clarification, and sugar beet
clarification.
Mining and mineral applications for the aqueous dispersions and dry polymers
of
the instant invention include coal refuse dewatering and thickening, tailings
thickening, and
Bayer process applications such as red mud settling, red mud washing, Bayer
process
filtration, hydrate flocculation, and precipitation.
Biotechnological applications for the aqueous dispersions and dry polymers of
the
instant invention include dewatering and clarification of wastes and
preferably, dewatering
and clarification of fermentation broths.
The aqueous dispersions of the instant invention may be employed in the above
applications alone, in conjunction with, or serially with, other known
treatments.
All patents, patent applications, and publications mentioned above are hereby
incorporated herein by reference. Unless otherwise specified, all percentages
mentioned
herein are understood to be on a weight basis.
The Standard Viscosity (SV) values in the following Examples were determined
by
mixing together 8.0 g of a 0.2 wt. % polymer solution in water and $.6 g of 2M
NaCI, then
measuring the viscosity of the resultant solution at 25°C on a
Brookfield Viscometer
equipped with a UL adapter at 60 rpm. Molecular weights were determined by
high
performance size exclusion chromatography using a light scattering detector.
The bulk density of polymer particles and agglomerates was determined by
adding
the particles or agglomerates to a suitable preweighed measuring container and
"tapping" or
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slightly agitating the container to cause the particles or agglomerates to
settle. The volume of
the polymer was then read from the measuring container, the measuring
container weighed,
and the bulk density calculated in units of grams per cubic centimeter (g/cc).
EXAMPLE 1
A suitable vessel equipped with a mechanical stirrer, reflux condenser, and a
nitrogen inlet tube was charged with 17.10 parts deionized water and 9 parts
of a 40%
aqueous solution of the polymer obtained by polymerizing the methyl chloride
quaternary
salt of dimethylaminoethylmethacrylate (poly(DMAEM.MeCI)), weight average
molecular
weight about 200,000. After completion of dissolution, 7.08 parts of a 53.64%
aqueous
solutian of acrylamide (AMD), and 14.56 parts of a 72.80% solution of the
dimethyl
sulfate salt of diethylaminoethylacrylate (DEAEA.DMS) were added and mixed. To
this
mixture, 8.1 parts ammonium sulfate, 0.7 parts citric acid, and 2.02 parts of
a 1 % solution
of chelant ethylenediaminetetraacetic acid tetrasodium salt (EDTA) were added
and mixed.
The pH of the mixture was about 3.3. The vessel was sealed and sparged with
nitrogen for
30 minutes, and then polymerization was started by adding 1.44 parts of 1 %
aqueous
solution of 2,2'-azobis(2-amidino-propane)dihydrochloride (V-50). The reaction
mixture
was heated to 40° C for 2 hours and then raised to 50° C and
held for an additional 8 hours.
The conversion was greater than 99%. A stable fluid aqueous dispersion was
obtained. The
bulk viscosity (BV) of the dispersion was 2250 centipoise (cps) showing
preferable fluidity
as measured with a Brookfield Viscometer, No. 4 spindle, 30 rpm at 25°
C. The dispersion
was dissolved to give a standard viscosity (SV) of 2.56 cps.
EXAMPLES 2-$
Additional aqueous dispersions were prepared in the same manner as Example 1,
showing the effect of various polymer and ammonium sulfate salt levels on bulk
viscosity
as shown in Table 1.
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Table 1
FIRST SECOND
% TOTAL _POLY_MERPOLYMER %
~
Exam le SOLIDS % SOLIDS % SOLIDS SALT BV c SV (c
No. s s)
1 30 24 6 13.5 2,250 2.56
2 30 24 6 12.5 6,600 2.2
3 30 24 6 13 6,000 2.37
4 30 24 6 13.5 2,960 2.3
30 24 6 13.5 2,300 2.35
6 30 25 5 13.5 2,640 2.61
7 30 24 6 14 3,470 2.39
8 30 24 6 15 7,080 2.17
EXAMPLE 9
A suitable vessel equipped with a mechanical stirrer, reflux condenser,
thermocouple and a nitrogen inlet was charged with 72.60 parts of deionized
water and
30.8 parts of a 40% aqueous solution of poly(DMAEM.MeCI), weight average
molecular
weight about 222,600. After dissolution was complete, 24.37 parts of a 53.33%
aqueous
solution of acrylamide and 45.93 parts of a 79% aqueous solution of DEAEA.DMS
were
added and mixed. To this mixture, 31.9 parts ammonium sulfate, 2.57 parts
citric acid, and
6.9 parts of 1 % solution of EDTA were added and mixed. The pH of the mixture
was about
3.3. The vessel was sealed and sparged with nitrogen for 30 minutes, and then
polymerization was started by adding 4.93 parts of 1 % solution of V-50. The
reaction
mixture was heated to 40°C for 2 hours and then raised to and held at
50°C for 4 hours. The
overall conversion was greater than 99%. A stable fluid aqueous dispersion was
obtained.
The bulk viscosity of this dispersion was about 1460 cps showing preferable
fluidity as
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measured with a Brookfield Viscometer, No. 4 spindle, 30 rpm at 25° C.
The dispersion
was dissolved to give a SV of 2.40 cps.
EXAMPLES 10-33
S
Additional aqueous dispersions were prepared in the same manner as Example 9
demonstrating the effect of total polymer solids, ratio of first cationic to
second cationic
polymer, second cationic polymer molecular weight, and ammonium sulfate salt
level on
the bulk viscosity (BV) of the aqueous dispersion, as shown in Table 2.
Table 2
FIRST SECOND SECOND
EXAMPLE % TOTAL POLYMER POLYMER POLYMER % BV SV
NO. SOL1DS % SOLIDS % SOLIDS MW SALT (cps) (cps)
9 28 22.4 5.6 222,600 14.5 1,460 2.40
10 28 22.4 5.6 194,000 14.5 2,250 2.52
11 28 22.4 5.6 199,300 14.5 1,440 2.52
12 28 22.4 5.6 172,870 14.5 2,940 2.61
13 28 22.4 5.6 221,500 14.5 1,970 2.52
14 28 22.4 5.6 159,000 14.5 2,740 2.59
28 22.4 5.6 145,000 14.5 2,920 2.65
16 28 22.4 5.6 199,300 14.5 2,150 2.86
17 30 24 6 242,900 13.5 2,620 2.49
18 30 24 6 230,600 13.5 3,710 2.4
19 30 24 6 230,600 14 2,200 2.39
30 24 6 230,600 14.5 1,800 2.54
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WO 00/20470 PCTNS99/21152
21 30 24 6 230,600 I 3,260 2.49
S
22 28 22.4 5.6 230,600 1 982 2.49
S
23 28 22.4 5.6 230,600 15.5 900 2.45
24 28 23.5 4.5 230,600 15.5 1,380 2.77
25 27 22.66 4.34 230,600 15.5 1,600 2.61
26 27 22.66 4.34 230,600 16 1,770 2.82
27 30 24 6 230,600 14.5 1,770 2.43
28 28 22.4 5.6 230,600 15.5 1,820 2.56
29 28 22.4 5.6 230,600 I 3,120 2.44
6
30 28 23 5 230,600 15 1,620 2.5
31 28 23 5 230,600 15.5 962 2.67
32 28 23 5 230,600 16 1,500 2.59
33 28 22.4 5.6 230,600 15.5 1,260 2.51
EXAMPLE 34
This polymerization was carried out in the same manner as Example 9, except
that a
poly(DMAEM.MeCI) having a weight average molecular weight of about 395,000 was
used. A stable fluid aqueous dispersion was obtained. The bulk viscosity of
this aqueous
dispersion was about 5100 cps showing preferable fluidity as measured with a
Brookfield
Viscometer, No. 4 spindle, 30 rpm at 25° C. The dispersion was
dissolved to give a SV of
2.35 cps.
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EXAMPLE 35
This polymerization was carried out in the same manner as Example 34, except
that
2.46 parts of 10% glycerol solution was added. Polymerization proceeded
smoothly. A
stable fluid aqueous dispersion was obtained. The bulk viscosity of this
dispersion was
about 3700 cps as measured with a Brookfield Viscometer, No. 4 spindle, 30 rpm
at 25° C
showing improved fluidity. The bulk viscosity was greatly reduced relative to
Example 34,
demonstrating the viscosity-reducing effect of the glycerol additive. The
dispersion was
dissolved to give a SV of 2.35 cps.
EXAMPLE 36
A suitable vessel equipped with a mechanical stirrer, reflux condenser,
thermocouple and nitrogen inlet tube was charged with 39.73 parts deionized
water and
30.1 parts of 41 % poly(DMAEM.MeCI), weight average molecular weight about
395,000.
After completion of dissolution, 23.77 parts of a 53.57% aqueous solution of
acrylamide,
45.20 parts of an 80% aqueous solution of DEAEA.DMS and 38.7 parts of 1 %
aqueous
solution of tertiary butyl acrylamide were added and mixed. To this mixture,
49.28 parts
ammonium sulfate, 2.57 parts citric acid, and 3.45 parts of 2% EDTA were added
and
mixed. The pH of the mixture was about 3.3. The vessel was sealed and sparged
with
nitrogen for 30 minutes, and then polymerization was started by adding 2.46
parts of 2%
V-50. The reaction mixture was raised to 40°C for 2 hours and then
raised to 50" C for an
additional 4 hours. The overall conversion was greater than 99%. A stable
fluid aqueous
dispersion was obtained. The bulk viscosity of this aqueous dispersion was
about 1900 cps
as measured with a BrookfieId Viscometer No. 4 spindle, 30 rpm at 25°
C, showing
improved fluidity compared to Example 34 and demonstrating the effect of
incorporating
hydrophobic recurring units of tertiary butyl acrylamide. The aqueous
dispersion was
dissolved to give a SV of 2.32 cps.
EXAMPLE 37
A suitable vessel equipped with a mechanical stirrer, reflux condenser,
thermocouple and nitrogen inlet tube was charged with 78.84 parts deionized
water and
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30.1 parts of 41 % poly(DMAEM.MeCI), weight average molecular weight about
395,000.
After completion of dissolution, 20.95 parts of a 53.57% aqueous solution of
acrylamide,
42.73 parts of a 80% aqueous solution of DEAEA.DMS and 4.84 parts of a 80%
aqueous
solution of the benzyl chloride quaternary salt of dimethylaminoethyl acrylate
(DMAEA.BzCI) were added and mixed. To this mixture, 49.28 parts ammonium
sulfate,
2.57 parts citric acid, and 3.45 parts of 2% EDTA were added and mixed. The pH
of the
mixture was about 3.3. The vessel was sealed and sparged with nitrogen for 30
minutes,
and then polymerization was started by adding 2.46 parts of 2% V-50. The
reaction mixture
was raised to 40°C for 2 hours, and then raised to and held at
50° C for 4 hours. The overall
conversion was greater than 99%. A stable fluid aqueous dispersion was
obtained. The
bulk viscosity of this dispersion was about 3840 cps as measured with a
Brookfield
Viscometer No. 4 spindle, 30 rpm at 25° C showing preferable fluidity.
The dispersion was
dissolved to give a SV of 2.14 cps.
EXAMPLE 38
A suitable vessel with an external jacket for heating or cooling was equipped
with a
mechanical stirrer, reflux condenser, thermocouple and nitrogen inlet tube.
The vessel was
charged with 294.47 parts deionized water and 117.60 parts of 40% aqueous
solution of
poly(DMAEM.MeCI), weight average molecular weight about 210,000. After
completion
of dissolution, 94.03 parts of a 52.77% aqueous solution of acrylamide and
173.18 parts of
an 80% aqueous solution of DEAEA.DMS were added and mixed. To this mixture,
130.20
parts ammonium sulfate, 9.83 parts citric acid, and 13.17 parts of 2% EDTA
were added
and mixed. The pH of the mixture was about 3.3. The vessel was sealed and
sparged with
nitrogen for 30 minutes, and then polymerization was started by adding 7.53
parts of 1 %
V-50. The reaction mixture was heated to 40°C for 2 hours and then
raised to and held at
50° C for 4 hours. The overall conversion was greater than 99%. A
stable fluid aqueous
dispersion was obtained. The bulk viscosity of this dispersion was about 760
cps as
measured with a Brookfield Viscometer No. 4 spindle, 30 rpm at 25° C
showing preferable
fluidity. The dispersion was dissolved to give a SV of 2.52 cps.
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EXAMPLE 38A
A suitable vessel with an external jacket for heating or cooling was equipped
with a
mechanical stirrer, reflux condenser, thermocouple and nitrogen inlet tube.
The vessel was
charged with 343.7 parts deionized water and 63.8 parts of 49% aqueous
solution of
polyamine (condensation product of dimethylamine and epichlorohydrin with low
amount
multiamine), weight average molecular weight about 344,000. After completion
of
dissolution, 93.47 parts of a 52.8% aqueous solution of acrylamide and 174
parts of an
79.2% aqueous solution of DEAEA.DMS were added and mixed. To this mixture,
130.2
parts ammonium sulfate, 10.25 parts citric acid, 7.6 parts glycerol, and 13.1
parts of 2%
EDTA were added and mixed. The pH of the mixture was about 3.2. The vessel was
sealed
and sparged with nitrogen for about 30 minutes, and then polymerization was
started by
adding 3.93 parts of 2% V-50 at about 48°C. The reaction mixture was
held at this
temperature for 5 hours. The overall conversion was greater than 99%. A stable
fluid
aqueous dispersion was obtained. The bulk viscosity of this dispersion was
about 1020 cps
as measured with a Brookfield viscometer No. 4 spindle, 30 rpm at 25°C
showing
preferable fluidity. The dispersion was dissolved to give a SV of 3.57 cps.
EXAMPLE 39
A suitable vessel equipped with a mechanical stirrer, reflux condenser,
thermocouple and nitrogen inlet tube was charged with 63.18 parts deionized
water and
30.8 parts of 40% aqueous solution of poly(DMAEM.MeCI), weight average
molecular
weight about 230,600. After completion of dissolution, 27.96 parts of a 53.33%
aqueous
solution of acrylamide (AMD), 26.02 parts of a 80% aqueous solution of
DEAEA.DMS
and 16.94 parts of a 80% aqueous solution of the methyl chloride quaternary
salt of
dimethylaminoethylacrylate (DMAEA.MeCI) were added and mixed. To this mixture,
40.7
parts ammonium sulfate, 2.57 parts citric acid, and 6.9 parts of 1 % EDTA were
added and
mixed. The pH of the mixture was about 3.3. The vessel was sealed and sparged
with
nitrogen for 30 minutes, and then polymerization was started by adding 4.93
parts of 1070
V-50. The reaction mixture was raised to 40°C for 2 hours, and then
raised to and held at
50° C for 4 hours. The overall conversion was greater than 99%. A
stable fluid aqueous
dispersion was obtained. The bulk viscosity of this dispersion was about 3840
cps as
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measured with a Brookfield Viscometer, No. 4 spindle, 30 rpm at 25° C
showing good
fluidity. The dispersion was dissolved to give a SV of 2.14 cps.
EXAMPLE 39A
A suitable vessel with an external jacket for heating or cooling was equipped
with a
mechanical stirrer, reflux condenser, thermocouple and nitrogen inlet tube.
The vessel was
charged with 88.37 parts deionized water and 22.1 parts of 49% aqueous
solution of
polyamine (condensation product of dimethylamine and epichlorohydrin with low
amount
multiamine), weight average molecular weight about 344,000. After completion
of
dissolution, 30.9 parts of a 53% aqueous solution of acrylamide and 18.62
parts of an
79.2% aqueous solution of DEAEA.DMS and 28.9 parts of an 80% aqueous solution
of
DMAEA.MeCI were added and mixed. To this mixture, 47.5 parts ammonium sulfate,
3.05
parts citric acid, 2.2 parts glycerol, and 3.8 parts of 0.5% EDTA were added
and mixed.
The pH of the mixture was about 3.2. The vessel was sealed and sparged with
nitrogen for
30 minutes, and then polymerization was started by adding 4.55 parts of 2% V-
50 at about
48°C. The reaction mixture was held at this temperature for 5 hours.
The overall
conversion was greater than 99%. A stable fluid aqueous dispersion was
obtained. The
bulk viscosity of this dispersion was about 2560 cps as measured with a
Brookfield
viscometer No. 4 spindle, 30 rpm at 25°C showing preferable fluidity.
The dispersion was
dissolved to give a SV of 3.44 cps.
EXAMPLES 40-42
Polymerizations were carried out in the same manner as Example 39 except that
the
bulk viscosity was adjusted by varying the level of ammonium sulfate salt as
shown in
Table 3. These Examples demonstrate that aqueous dispersions having low bulk
viscosities
and high polymer solids may be prepared, wherein the first cationic polymer is
a
DMAEA.MeCI / DEAEA.DMS / AMD terpolymer.
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Table 3
FIRST SECOND
EXAMPLE % TOTAL POLYMER POLYMER %
NO. SOLIDS % SOLIDS % SOLIDS SALT BV (cps)SV (cps)
39 28 22.4 5.6 I8.5 2,620 2.99
40 28 22.4 5.6 18 4,310 2.96
41 28 22.4 5.6 19 1,820 2.65
42 28 22.4 5.6 19.5 2,000 2.62
EXAMPLE 43
A suitable vessel equipped with an external jacket for heating or cooling, a
mechanical stirrer, reflux condenser, thermocouple and nitrogen inlet tube was
charged
with 260.35 parts deionized water and 117.6 parts of a 40% aqueous solution of
poly(DMAEM.MeCI), weight average molecular weight about 210,000. After
completion
of dissolution, 107.89 parts of a 52.77% aqueous solution of acrylamide, 99.35
parts of a
80% aqueous solution of DEAEA.DMS and 64.68 parts of a 80% aqueous solution of
DMAEA.MeCl were added and mixed. To this mixture, 271.92 parts ammonium
sulfate,
9.83 parts citric acid, and 13.17 parts of 2% EDTA were added and mixed. The
pH of the
mixture was about 3.3. The vessel was sealed and sparged with nitrogen for 30
minutes,
and then polymerization was started by adding 7.53 parts of 2.5% V-50. The
reaction
mixture was raised to 40°C for 2 hours, and then raised to and held at
50° C for 4 hours.
The overall conversion was greater than 99%. A stable fluid aqueous dispersion
was
obtained. The bulk viscosity of this dispersion was about 1240 cps as measured
with a
Brookfield Viscometer, No. 4 spindle, 30 rpm at 25° C showing good
fluidity. The
dispersion was dissolved to give a SV of 2.74 cps.
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EXAMPLE 44
A suitable vessel equipped with a mechanical stirrer, reflux condenser, and
nitrogen
inlet tube was charged with 18.86 parts deionized water and 9 parts of a 40%
aqueous
S solution of poly(DMAEM.MeCI), weight average molecular weight about 200,000.
After
completion of dissolution, 4.39 parts of a 53.64% aqueous solution of
acrylamide and
15.19 parts of a 79.3% aqueous solution of DEAEA.DMS were added and mixed. To
this
mixture, 8.4 parts ammonium sulfate, 0.7 parts citric acid, and 2.02 parts of
1 % EDTA
were added and mixed. The pH of the mixture was about 3.3. The vessel was
sealed and
sparged with nitrogen for 30 minutes, and then polymerization was started by
adding 1.44
parts of 1 % V-50. The reaction mixture was raised to 40°C for 2 hours
and then raised to
and held at SO° C for 8 hours. The conversion was greater than 99%. A
stable fluid
aqueous dispersion was obtained. The bulk viscosity of this dispersion was
about 850 cps
as measured with a Brookfield Viscometer, No. 4 spindle, 30 rpm at 25°
C showing
preferable fluidity. The dispersion was dissolved to give a SV of 2.27 cps.
EXAMPLES 45-49
Additional aqueous dispersions were prepared in the same manner as Example 44,
demonstrating the effect of ratio of first cationic to second cationic polymer
and salt
content on the bulk viscosity of the dispersion as shown in Table 4.
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Table 4
FIRST SECOND
EXAMPLE % TOTAL POLYMER POLYMER %
NO. SOLIDS % SOLIDS % SOLIDS SALT BV (cps)SV (cps)
44 30 24 6 14 852 2.27
45 30 24 6 12 2,400 2.19
46 30 24 6 13 1,100 2.34
47 30 24 6 15 1,770 2.35
48 30 25 5 13 1,260 2.45
49 30 2S 5 14 4,750 2.4
SO 30 24 6* 14 780 2.2
*Molecular weight of second polymer was about 222,600.
EXAMPLE 51
A suitable vessel equipped with a mechanical stirrer, reflux condenser, and
nitrogen
inlet tube was charged with 92.9 parts deionized water and 30.1 parts of a 41
% aqueous
solution of poly(DMAEM.MeCI), weight average molecular weight about 395,000.
After
completion of dissolution, 15.03 parts of a 53.57% aqueous solution of
acrylamide and
S 1.53 parts of an 80% aqueous solution of DEAEA.DMS were added and mixed. To
this
mixture 22 parts of sodium sulfate, 2.57 parts citric acid, and 3.45 parts of
2% EDTA were
added and mixed. The pH of the mixture was about 3.3. The vessel was sealed
and sparged
with nitrogen for 30 minutes, and then polymerization was started by adding
2.46 parts of
2% V-50. The reaction mixture was raised to 40°C for 2 hours and then
raised to and held
at SO° C for 4 hours. The overall conversion was greater than 99%. A
stable fluid aqueous
dispersion was obtained. The bulk viscosity of this dispersion was about 1100
cps as
measured with a Brookfield Viscometer, No. 4 spindle, 30 rpm at 25" C. The
dispersion
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was dissolved to give a SV of 2.19 cps. This Example demonstrates the
effectiveness of
sodium sulfate.
EXAMPLE 52
A suitable vessel equipped with a mechanical stirrer, reflux condenser,
thermocouple and nitrogen inlet tube was charged with 17.57 parts deionized
water and 9
parts of a 40% aqueous solution of poly(DMAEM.MeCI), weight average molecular
weight about 200,000. After completion of dissolution, 4.77 parts of a 53.64%
aqueous
solution of acrylamide, 12 parts of a 79.3% aqueous solution of DEAEA.DMS and
2.91
parts of an $0% aqueous solution of DMAEA.MeCI were added and mixed. To this
mixture, 9.6 parts ammonium sulfate, 0.7 parts citric acid, and 2.02 parts of
1 % EDTA
were added and mixed. The pH of the mixture was about 3.3. The vessel was
sealed and
sparged with nitrogen for 30 minutes, and then polymerization was started by
adding 1.44
1 S parts of 1 % V-50. The reaction mixture was raised to 40°C for 2
hours and then raised to
and held at 50° C for 4 hours. The overall conversion was greater than
99%. A stable fluid
aqueous dispersion was obtained. The bulk viscosity of this dispersion was
about 800 cps
as measured with a Brookfield Viscometer, No. 4 spindle, 30 rpm at 25°
C showing good
fluidity. The dispersion was dissolved to give a SV of 2.3 cps.
EXAMPLES 53-80
Polymerizations were carried out in the same manner as Example 52. The effect
of
total polymer solids, first cationic polymer composition (in terms of % AMD, %
DEAEA.DMS and % DMAEA.MeCI in monomer feed), ratio of first cationic to second
cationic polymer, and ammonium sulfate salt content on the bulk viscosity of
the aqueous
dispersion is demonstrated as shown in Table 5.
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Table 5
~RSI SECOND
96 96 % % TOTALPOLYMERPOLYMER96
NO.AMD DEAEA.DMSDMAEA.MeCISOLIDS % SOLIDS% SOLIDSSALT BV SV
(cps) (cps)
52 45 40 15 30 24 6 16 802 2.3
53 45 40 15 30 24 6 12 200,000+2.4
54 45 40 15 30 24 6 13 30,9002.35
55 45 40 15 30 24 6 14 4,410 2.35
56 45 40 15 30 24 6 15 1,080 2.42
57 45 40 15 30 24 6 17 1,820 2.32
58 45 40 15 30 24 6 18 15,8002.2
59 45 40 15 30 24 6 19 200,000+
60 45 40 15 30 25 5 15 1,940 2.45
61 45 40 15 30 25 5 16 1,260 2.49
62 45 40 15 30 25 5 17 6,010 2.4
63 45 35 20 30 24 6 15 3,120 2.19
64 45 35 20 30 24 6 16 1,340 2.24
65 45 35 20 30 24 6 17 1,140 2.32
66 45 30 25 30 24 6 16 170,0001.82
67 45 30 25 30 24 6 17 1,890 2.44
68 45 30 25 30 24 6 18 1,400 2.35
69 45 20 35 29.3 23.44 5.86 18 200,000+
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70 45 20 35 29.3 23.44 5.86 18.52,900 2.4
71 45 20 35 29.3 23.44 5.86 19 6,600 2.24
72 45 10 45 28.5 22.8 5.7 18 200,000+2.35
73 45 10 45 28.5 22.8 5.7 19 200,000+2.34
74 45 10 45 28 22.4 5.6 19.6200,000+2.5
75 45 20 35 29 23.2 5.8 18 200,000+2.2
76 45 20 35 29 23.2 5.8 18.55,540 2.27
77 45 20 35 29 23.2 5.8 19 3,570 2.47
78 45 20 35 28.5 23.2 5.8 18 6,350 2.35
79 45 20 35 28.5 23.2 5.8 18.53,060 2.4
80 45 20 35 28.5 23.2 5.8 19 200,000+2.39
EXAMPLE 81
A suitable vessel equipped with a mechanical stirrer, reflux condenser,
thermocouple and nitrogen inlet tube was charged with 89 pans deionized water
and 20.9
parts of a 40% aqueous solution of poly(DMAEM.MeCI), weight average molecular
weight about 190,000. After completion of dissolution, 30.96 parts of a 52.77%
aqueous
solution of acrylamide and 21.38 parts of a 80% aqueous solution of DEAEA.DMS
were
added and mixed. To this mixture, 49.5 parts ammonium sulfate, 2.57 parts
citric acid, and
2.34 parts of 1 % EDTA were added and mixed. The pH of the mixture was about
3.3. The
vessel was sealed and sparged with nitrogen for 30 minutes, and then
polymerization was
started by adding 3.34 parts of 1 % V-S0. The reaction mixture was raised to
40°C for 2
hours and then raised to and held at 50° C for 4 hours. The combined
conversion was
greater than 99%. A stable fluid aqueous dispersion was obtained. The bulk
viscosity of
this dispersion was about 280 cps as measured with a Brookfield Viscometer,
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spindle, 30 rpm at 25" C showing good fluidity. The dispersion was dissolved
to give a SV
of 1.60 cps.
EXAMPLES 82-97
Polymerizations were carried out in the same manner as Example 81. The effect
of
chelant (EDTA) concentration, chain transfer agent (lactic acid), first
cationic polymer
composition (in terms of % AMD, % DEAEA.DMS, and % DMAEA.MeCI in monomer
feed), ratio of first cationic to second cationic polymer, and ammonium
sulfate salt content
on standard viscosity and bulk viscosity are demonstrated as shown in Table 6.
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Table 6
96 FIRST SECOND 96
% % 9o TOTALPOLYMERPOLYMERLACTICEDTA ~ BV SV
NO.AMUDEAEA.DMSDMAEA.MeCISOLIDS% SOLIDS9b SOLIDSACID (ppm)SALT(cps)(cps)
8180 20 19 15.2 3.8 0 1400 22.5280 1.6
8280 20 20 16 4 0 1400 20 142,001.82
0
8380 20 20 7 6 4 0 1400 22.5840 1.6
8480 20 19 15.2 3.8 0.25 1400 22.5200 2.05
8580 20 19 15.2 3.8 0.5 1400 22.5100 I.67
8680 20 19 15.2 3.8 0.75 1400 22.5200 1.87
8780 20 19 15.2 3.8 0 2000 22.5280 1.61
8880 20 19 15.2 3.8 0 3000 22.54 I
800 .81
8980 20 19 15.2 3.8 0.25 2000 22.5270 1.99
9080 20 19 15.2 3.8 0.5 2000 22.52,0002.47
9180 20 19 15.2 3.8' 0.5 2000 22.5140 2.1
9280 20 19 15.2 3.8 0.5 2000 22.5640 2.45
9380 20 19 15.2 3.8 0.65 2000 22.5360 2.4
9480 20 19 15.2 3.8 0.75 2000 22.5225 2.35
9580 10 10 19 15.2 3.8 0 1400 22.5760 2.09
9680 10 10 19 15.2 3.8 0.25 1400 22.5460 2.86
9780 10 10 19 15.2 3.8 0.5 1400 22.5340 2.74
*Molecular weight of second polymer was about 222,600.
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EXAMPLE 98
A suitable vessel equipped with a mechanical stirrer, reflux condenser,
thermocouple and nitrogen inlet tube was charged with 87.97 parts deionized
water and
20.9 parts of a 40% aqueous solution of poly(DMAEM.MeCI), weight average
molecular
weight about 190,000. After completion of dissolution, 33.99 parts of a 52.77%
aqueous
solution of acrylamide, 11.74 parts of a 80% aqueous solution of DEAEA.DMS and
7.64
parts of a 80% aqueous solution of DMAEA.MeCI were added and mixed. To this
mixture,
49.5 parts ammonium sulfate, 2.57 parts citric acid, and 2.34g of 2% EDTA were
added
and mixed. The pH of the mixture was about 3.3. The vessel was sealed and
sparged with
nitrogen for 30 minutes, and then polymerization was started by adding 2.34
parts of 1 %
V-50. The reaction mixture was raised to 40°C for 2 hours and then
raised to and held at
50° C for 4 hours. The overall conversion was greater than 99%. A
stable fluid aqueous
dispersion was obtained. The bulk viscosity of this dispersion was about 760
cps as
measured with a Brookfield Viscometer, No. 4 spindle, 30 rpm at 25° C.
The dispersion
was dissolved to give a 5V of 2.09 cps.
EXAMPLES 99-100
Polymerizations were carried out in the same manner as Example 97. The effect
of
chain transfer agent (lactic acid) concentration on bulk viscosity is
demonstrated as shown
in Table 7.
Table 7
FIRST SECOND LACTIC
% TOTAL POLYMER POLYMER ACID % BV SV
NO. SOLIDS % SOLIDS % SOLIDS % SALT (cps) (cps)
98 19 15.2 3.8 0 22.5 760 2.09
99 19 15.2 3.8 0.25 22.5 460 2.86
100 19 15.2 3.8 0.5 22.5 340 2.74
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EXAMPLE I01
A suitable vessel equipped with a mechanical stirrer, reflux condenser,
thermocouple and nitrogen inlet tube was charged with 82.15 parts deionized
water and
30.8 parts of a 20% aqueous solution of poly(diallyldimethylammonium chloride)
(poly(DADMAC)), weight average molecular weight about 289,000. After
completion of
dissolution, 48.24 parts of a 52.77% aqueous solution of acrylamide and 13.27
parts of an
80% aqueous solution of DEAEA.DMS were added and mixed. To this mixture, 49.5
parts
ammonium sulfate, 2.57 parts citric acid, 1.67 parts of 10% lactic acid, and
3.34 parts of
2% EDTA were added and mixed. The pH of the mixture was about 3.3. The vessel
was
sealed and sparged with nitrogen for 30 minutes, and then polymerization was
started by
adding 3.34 parts of 1 % V-50. The reaction mixture was raised to 40°C
for 2 hours and then
raised to and held at 50° C for 4 hours. The combined conversion was
greater than 99%. A
stable fluid aqueous dispersion was obtained. The bulk viscosity of this
dispersion was
about 960 cps as measured with a Brookfield Viscometer, No. 4 spindle, 30 rpm
at 25° C
showing preferable fluidity. The dispersion was dissolved to give a SV of 3.67
cps. This
Example demonstrates aqueous dispersions having poly(DADMAC) as the second
cationic
polymer.
EXAMPLE lOlA
A suitable vessel with an external jacket for heating or cooling was equipped
with a
mechanical stirrer, reflux condenser, thermocouple and nitrogen inlet tube.
The vessel was
charged with 381.3 parts deionized water and 30.9 parts of 49% aqueous
solution of
polyamine (condensation product of dimethylamine and epichlorohydrin with low
amount
multiamine), weight average molecular weight about 344,000. After completion
of
dissolution, 156.3 parts of a 52.08% aqueous solution of acrylamide and 47.83
parts of an
79.2% aqueous solution of DEAEA.DMS were added and mixed. To this mixture,
193.2
parts ammonium sulfate, 10.25 parts citric acid, 7.16 parts glycerol, and
11.93 parts of 2%
EDTA were added and mixed. The pH of the mixture was about 3.2. The vessel was
sealed
and sparged with nitrogen for 30 minutes, and then polymerization was started
by adding
1.19 parts of 2% V-50 at about 48°C. The reaction mixture was held at
this temperature for
5 hours. The overall conversion was greater than 99%. A stable fluid aqueous
dispersion
was obtained. The bulk viscosity of this dispersion was about 640 cps as
measured with a
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Brookfield viscometer No. 4 spindle, 30 rpm at 25°C showing preferable
fluidity. The
dispersion was dissolved to give a SV of 4.5 cps. This Example demonstrates
aqueous
dispersions having polyamine as the second polymer.
EXAMPLE 102
A suitable vessel equipped with an external jacket for heating or cooling,
mechanical stirrer, reflux condenser, thermocouple and nitrogen inlet tube was
charged
with 262.6 parts deionized water, ,47.4 parts of a 40% aqueous solution of
poly(DMAEM.MeCI), weight average molecular weight about 41,500, and 92.60
parts of a
40% aqueous solution of poly(DMAEM.MeCI), weight average molecular weight
about
205,000. After completion of dissolution, 88.1 parts of a 53.12% aqueous
solution of
acrylamide and 133.9 parts of a 72.6% aqueous solution of the methyl chloride
quaternary
salt of diethylaminoethylacrylate (DEAEA.MeCI) were added and mixed. To this
mixture,
144 parts ammonium sulfate, 2.644 parts citric acid, and 14.4 parts of 1 %
EDTA were
added and mixed. The pH of the mixture was about 3.3. The vessel was sealed
and sparged
with nitrogen for 30 minutes, and then polymerization was started by adding
14.4 parts of
2% V-50. The reaction mixture was raised to and held at 40-45° C for 6
hours. The
conversion was greater than 99.9%. A stable fluid aqueous dispersion was
obtained. The
bulk viscosity of this dispersion was about 2,200 cps as measured with a
Brookfield
Viscometer, No. 4 spindle, 30 rpm at 25° C. The dispersion was
dissolved to give a SV of
3.31 cps. This Example demonstrates an aqueous dispersion having a third
cationic
polymer.
EXAMPLE 103
Polymerization was carried out in the same manner as Example 102, except that
the
two poly(DMAEM.MeCI) polymers were replaced with a single poly(DMAEM.MeCI)
having a weight average molecular weight of about 1,500,000. The bulk
viscosity of this
dispersion was about 8,000 cps as measured with a Brookfield Viscometer, No. 4
spindle,
30 rpm at 25° C showing preferable fluidity. The dispersion was
dissolved to give a SV of
2.45 cps.
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EXAMPLE 104
A suitable vessel equipped with an external jacket for heating, mechanical
stirrer,
reflux condenser, thermocouple and nitrogen inlet tube was charged with 23.8
parts
deionized water and 25.3 parts of a 20% aqueous solution of poly(DADMAC),
weight
average molecular weight about 289,000. After completion of dissolution, 7.9
parts of a
53.1 % aqueous solution of acrylamide and 11.3 parts of a 77.9% aqueous
solution of
DEAEA.MeCI were added and mixed. To this mixture, 18 parts ammonium sulfate,
1.08
parts citric acid, 0.37 part of 5% EDTA, and 0.9 part glycerol were added and
mixed. The
pH of the mixture was about 3.3. The vessel was sealed and sparged with
nitrogen for 30
minutes, and then polymerization was started by adding 1.3 parts of 1 % V-50
at 40°C. This
temperature was held for 2 hours and then was raised to 50° C and
maintained at this
temperature for 8 hours. The residual acrylamide level was about 209 parts per
million
(ppm). A stable fluid aqueous dispersion was obtained. The bulk viscosity of
this
dispersion was about 2,950 cps as measured with a Brookfield Viscometer, No. 4
spindle,
30 rpm at 25° C showing preferable fluidity. The dispersion was
dissolved to give a SV of
2.47 cps.
EXAMPLES 105-108
Polymerizations were carried out in the same manner as Example 104, except
that
part of the poly(DADMAC) was replaced with a poly(DADMAC) polymer having a
lower
weight average molecular weight. The effect on the aqueous dispersion bulk
viscosity of
including the third polymer is shown in Table 8.
Table 8
FIRST SECOND SECOND ~ THIRD THIRD
~
TOTAL POLYMERPOLYMERPOLYMER POLYMER POLYMER % BV SV
NO.SOLIDS% SOLIDS% SOLIDSMW % SOLIDSMW SALT(cps)(cps)
10421.2 14.5 5.06 289,000 20 2,9502.47
10521.2 14.5 3.73 289,000 1.89 10,100 20 2,2002.4
S1
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10621.2 14.5 3.73 289,000 1.89 53,400 20 1,9502.4
10721.2 14.5 3.73 289,000 1.89 67,900 20 2,0202.39
10821.2 14.5 3.73 289,000 1.89 100,000 20 1,9902.42
EXAMPLE 109
An aqueous dispersion containing 12.5% ammonium sulfate and having a polymer
solids of 30%, a bulk viscosity of about 7200 cps and a standard viscosity of
about 2.34 cps
was prepared in the same manner as in Example 2.
EXAMPLE 110
An aqueous dispersion containing 15.5% ammonium sulfate and having a polymer
solids level of 28%, a bulk viscosity of about 2640 cps and a standard
viscosity of about
2.4 cps was prepared in the same manner as in Example 9.
EXAMPLES 111-133
Various amounts of either ammonium sulfate, sodium thiocyanate, or I,3-
benzenedisulfonate (1,3-BDS) were added to the base aqueous dispersions of
Example I09,
Example I10, Example 103, Example 1, Example 102 and Example I42. The bulk
viscosities of the resultant aqueous dispersions were further reduced as shown
in Table 9.
These Examples demonstrate that the bulk viscosity of aqueous dispersions may
be
reduced by adding salt to the dispersion, and that the addition of I,3-BDS may
be more
effective than ammonium sulfate on a weight basis. Substantially similar
results are
obtained by polymerizing the monomers in the presence of the salts.
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Table 9
BV of
No. Base AqueousBase Added % Total % Total BV
Dispersion Aqueous Salt Salt Solids (cps)
Dispersion
111 Example 109 7200 (NH,)250414.21 29.41 2100
112 Example 109 7200 (NH4)ZSO,15.86 28.84 1,000
113 Example 109 7200 (NH4)2S0417.45 28.3 501
114 Example 109 7200 (NH,)250419 27.8 319
115 Example 109 7200 1,3-BDS 13.37 29.7 2200
116 Example 109 7200 1,3-BDS 14.21 29.41 1160
117C Example 109 7200 1,3-BDS 15 29.12 FL
118 Example 110 2640 NaSCN 16.3 27.7 540
119C Example 110 2640 NaSCN 17.15 27.45 FL
1200 Example 110 2640 NaSCN 17.96 27.18 FL
121 Example 103 8000 1,3-BDS 19.6 24.51 1660
122 Example 103 8000 1,3-BDS 21.15 24.04 762
123 Example 103 8000 1,3-BDS 22.64 23.58 FL
124 Example 103 8000 (NH4)ZS0419.6 24.51 3440
125 Example 103 8000 (NH4)zSO,21.15 24.04 1990
126 Example 103 8000 (NH4)ZS0422.64 23.58 1300
127 Example 103 8000 (NH4)250424.07 23.15 982
128 Example 1 2300 (NH4)2S0419 27.8 501
129 Example 102 2200 (NH,)ZSO,19.6 24.51 1002
130 Example 102 2200 (NH4)ZS0421.15 14.04 441
131 Example 102 2200 (NH4)2S0422.64 23.58 301
132 Example 102 2200 (NH4)ZSO,24.07 23.15 200
133 Example 142 10,000 (NH4)ZSO,24.07 23.15 1380
C: Comparative
FL: Formed Layers
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EXAMPLE 134
About 18 parts of the aqueous dispersion of Example 49 and about 20 parts of
the
aqueous dispersion of Example 91 were intermixed with stirring. The resultant
aqueous
dispersion blend was stable and very uniform with a bulk viscosity of about
880 cps,
demonstrating that differently charged dispersions may be blended to prepare
an aqueous
dispersion having an intermediate charge. The aqueous dispersion blend had an
overall
charge of about 40% and a SV of 2.5 cps.
EXAMPLE 135
About 18 parts of a high charge aqueous dispersion prepared as in Example 48
and
about 18 parts of a low charge aqueous dispersion prepared as in Example 101
were
intermixed with stirring. The resultant aqueous dispersion blend was stable
and very
uniform with a bulk viscosity of about 2300 cps, demonstrating that
differently charged
dispersions may be blended to prepare an aqueous dispersion having an
intermediate
charge. The resultant aqueous dispersion contained four different polymers.
EXAMPLE 136 (Comparative)
A polymerization was conducted in the same manner as Example 9, except that
the
DEAEA.DMS was replaced with an equal weight of DMAEA.MeCI. During the process
of polymerization, the contents of the vessel became so viscous that stirring
became
impossible. The praduct was obtained as a gel without fluidity. This Example
demonstrates that replacement of DMAEA.MeCI with DEAEA.DMS results in an
aqueous
dispersion having a dramatically lower bulk viscosity.
EXAMPLE 137 (Comparative)
A polymerization was conducted in the same manner as Example 50, except that
the
DEAEA.DMS was replaced with an equal weight of DMAEA.MeCI. During the process
of polymerization, the contents of the vessel became so viscous that stirring
became
impossible. The product was obtained as a gel without fluidity. This Example
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demonstrates that replacement of DMAEA.MeCI with DEAEA.DMS results in an
aqueous
dispersion having a dramatically lower bulk viscosity.
EXAMPLE 138 (Comparative)
A polymerization was conducted in the same manner as Example 91, except that
the
DEAEA.DMS was replaced with an equal weight of DMAEA.MeCI. During the process
of polymerization, the contents of the vessel became so viscous that stirring
became
impossible. The product was obtained as a gel without fluidity. This Example
demonstrates that replacement of DMAEA.MeCI with DEAEA.DMS results in an
aqueous
dispersion having a dramatically lower bulk viscosity.
EXAMPLE 139 (Comparative)
A polymerization was conducted in the same manner as Example 100, except that
the DEAEA.DMS was replaced with an equal weight of DMAEA.MeCI. During the
process of polymerization, the contents of the vessel became so viscous that
stirring
became impossible. The product was obtained as a gel without fluidity. This
Example
demonstrates that replacement of DMAEA.MeCI with DEAEA.DMS results in an
aqueous
dispersion having a dramatically lower bulk viscosity
EXAMPLE 140
A suitable vessel equipped with a mechanical stirrer, reflux condenser, and
nitrogen
inlet tube was charged with 20 parts deionized water and 10.51 parts of a 40%
aqueous
solution of poly(DMAEM.MeCI), weight average molecular weight about 210,000.
After
completion of dissolution, 6.57 parts of a 53.27% aqueous solution of
acrylamide, 14.56
parts of an 80% aqueous solution of DMAEA.MeCI and 4.15 parts of a 80% aqueous
solution of DMAEA.BzCI were added and mixed. To this mixture, 10.8 parts
ammonium
sulfate, 0.4 parts citric acid, and 1.51 parts of 1 % EDTA were added and
mixed. The pH of
the mixture was about 3.3. The vessel was sealed and sparged with nitrogen for
30 minutes,
and then polymerization was started by adding 1.08 parts of 1 % V-50. The
reaction mixture
was raised to 40°C 2 hours by placing the vessel in a water bath and
then raised to 50° C for
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6 hours. The conversion was greater than 99%. A stable fluid aqueous
dispersion was
obtained. The bulk viscosity of this dispersion was about 2000 cps showing
preferable
fluidity as measured with a Brookfield Viscometer No. 4 spindle, 30 rpm at
25° C. The
dispersion was dissolved to give a SV of 2.2 cps.
EXAMPLES 141-144
Polymerizations were carried out in the same manner as Example 140. The effect
of the composition of the first polymer (given in terms of % AMD, %
DMAEA.MeCI, and
DMAEA.BzCI in monomer feed) and molecular weight of the poly(DMAEM.MeCI) on
the
aqueous dispersion bulk viscosity is shown in Table 10.
Table 10
FIRST SECONDSECOND
96 96 96 96 POLYMERPOLYMERPOLYMER 96 BV SV
TOTAL
NO.AMDDMAEA.MeCIDMAEA.BzCISOLIDS~o 9b MW SALT(cps)(cps)
SOLIDSSOLIDS
14060 2S 1S 2S 18 7 210000 18 2,0002.2
14160 2S 1S 2S 18 7 500,000 I8 13,2002.34
14260 2S IS 2S 18 7 1,500,000I8 10,0002.4
14360 2S IS 2S I8 7 800,000 18 11,5002.2
l4460 29.2 10.8 2S 19 b 200,000 18 8,6802.59
EXAMPLES 145-150 (Comparative)
Polymerizations were carried out in the same manner as Example 140 at
different
ratios of AMD/DMAEA.MeCI/DMAEA.BzCI/DEAEA.DMS except that the
poly(DMAEM.MeCI) was omitted. During the polymerization process, the contents
of the
vessel became very viscous to the point that stirring became impossible. The
resulting
polymerization product was obtained as a clear gel, a homogeneous composition
without
fluidity as shown in Table 11.
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Table 11
% % ~o % ~o % sv
NO. AMD DMAEA.MeCIDMAEA.BzCIDEAEA.DMS SOLIDS SALT (cps)
145C 50 40 10 14.4 20 Gel
146C 45 40 15 14.4 20 Gel
147C 60 29.2 10.8 18 18 Gel
148C 60 25 15 18 18 Gel
149C 55 5 40 18 18 Gel
150C 55 5 40 25 18 Gel
C: Comparative
EXAMPLES 151-153
An aqueous dispersion having a bulk viscosity of about 3570 cps was prepared
in
the same manner as Example 13. The dispersion was concentrated by placing
about 135
parts into a suitable vessel and heating to 45°C under flowing
nitrogen. A total of 26 parts
of water was removed in two stages by this dehydration process. The aqueous
dispersion
remained stable demonstrating that dehydration is effective for achieving high
solids, low
bulk viscosity aqueous dispersions as shown in Table 12.
Table 12
Polymer Bulk
Example No. Solids (%) Viscosity (c~s_l
151 (as polymerized) 28.0 3570
152 31.5 660
153 34.6 3260
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EXAMPLE 154
A suitable vessel equipped with a mechanical stirrer, reflux condenser, and a
nitrogen inlet tube was charged with 277.75 parts deionized water and 112.0
parts of a 40%
aqueous solution of poly(DMAEM.MeCI), weight average molecular weight about
200,000. After completion of dissolution, 89.03 parts of a 53.64% aqueous
solution of
acrylamide, and 164.93 parts of an 80% solution of DEAEA.DMS were added and
mixed.
To this mixture, 124.0 parts ammonium sulfate, 9.36 parts citric acid, and
5.02 parts of a
1 % solution of EDTA were added and mixed. The pH of the mixture was about
3.3. The
contents were heated to 48° C and sparged with nitrogen for 30 minutes,
and then
polymerization was started by adding 17.92 parts of 1 % aqueous solution of V-
50. The
reaction mixture was maintained at 48° C for 5 hours. About 3.5 hours
into the
polymerization the aqueous dispersion bulk viscosity began to noticeably
increase. The
final bulk viscosity of the aqueous dispersion was about 8,000 cps as measured
with a
Brookfield Viscometer No. 4 spindle, 30 rpm at 25° C.
EXAMPLE 155-156
Duplicate polymerizations ware carried out in a similar manner to Example 154
except that an additional amount of ammonium sulfate (4% on total) was added
approximately 3 hours after initiation of polymerization. This prevented any
substantial
increase in bulk viscosity during the polymerization and resulted in a final
bulk viscosity
that was lower than the bulk viscosity obtained in Example 154 as shown in
Table 13.
Table 13
Exam le No. Final Bulk Viscosity (#4 spindle 30 ram)
155 300 cps
156 500 cps
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EXAMPLES 157-172
General Polymerization Procedure: The following components were mixed together
in a
suitable vessel and the pH was adjusted to about 3.5 with a 28 wt. % solution
of
ammonium hydroxide.
AcryIamide (55.5 wt. %) 5.34 parts
DEAEA.DMS (80 wt. %) 10.35
parts
Citric acid 0.58 parts
Ammonium sulfate 7.78 pans
poly(DMAEM.MeCI) (40 wt. %, 200,000 7.03 parts
MW)
Deionized Water 16.22
parts
V-50 ( 1 wt. %) 1.12 parts
EDTA ( 1 wt. %) 1.57 parts
Methylenebisacrylamide (MBA) variable
Lactic acid (chain transfer agent) variable
Forty parts of the solution were placed into a suitable vessel and the
solution was sparged
with nitrogen. The vessel was sealed and placed into a 40°C water bath
for 2 hours. The
temperature was then increased to 50°C and maintained for an additional
3 hours. Results
are summarized in Table 14, showing that substantial levels of branching agent
and chain
transfer agent can be incorporated into aqueous dispersions of water-soluble
and water-
swellable polymers. The aqueous viscosity values were obtained by dissolving
or
dispersing the aqueous dispersions in the same general manner as for the
standard viscosity
values described above, except that the polymer concentration was 0.135 wt. %.
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Table 14
Dispersion
Ex. Lactic MBA (ppm on bulk Aqueous Viscosity
acid monomer) viscosity (#4
No. (wt. % spindle, 30
on rpm)
monomer
157 0 0 - 3.91
158 0.4 0 - 3.41
159 0.8 0 - 3,04
160 0 0 1100 3.71
161 0 2 1000 3.61
162 0 4 1600 3.66
163 0 6 2500 3.31
164 0 0 2200 3.11
165 0 10 3300 1.90
166 0 15 3300 1.77
167 0 20 8100 1.67
168 0 0 1200 2.81
169 0 30 1800 1.46
170 0 40 3500 1.43
171 0 50 - l ,q.q.
172 0 100 - 1.28
EXAMPLE 173
A aqueous dispersion was prepared as in Example 155. The aqueous dispersion
had a bulk
viscosity of about 240 cps and an aqueous viscosity (obtained as in Examples
157-172) of
3.55 cps.
EXAMPLE 174
The aqueous dispersion of Example 173 was spray-dried on a commercially
available
laboratory spray dryer. The chamber of the laboratory spray dryer was 760
millimeters (mm)
in diameter with a 860 mm vertical side and a 65 degree conical bottom.
Nominal gas flow
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through the dryer was about 180 cubic meters per hour. The aqueous dispersion
feed was fed
at the center of the top of the chamber using a variable speed pump, through a
two-fluid
nozzle using air for atomization. The outlet gas temperature was 86 °C
and controlled by
varying the inlet gas temperature (169° C) and the feed rate (60
milliliters/minute). To
provide an inert atmosphere, the spray-dryer was supplied with nitrogen gas
from a cryogenic
storage tank. The dried polymer product was discharged through the bottom of
the dryer
cone to a cyclone where the dry product was removed and collected. Residence
time in the
dryer was about 14 seconds. The resultant spray-dried polymer particles, which
had a
volatiles content of 3.4°lo and a bulk density of about 0.50 grams per
cubic centimeter (g/cc),
were readily soluble in water and had a SV a 3.49 cps.
EXAMPLE 175
The dissolution rate of the spray-dried polymer of Example 174 was compared to
a
dry polymer of similar composition obtained by spray-drying a commercial water-
in-oil
emulsion. Solutions were prepared in a wide mouth quart jar using a 2.5 inch
magnetic
stirring bar. The stirring rate was adjusted so that a deep vortex was
obtained in the water.
The dry polymer was added slowly over a period of 5 minutes at the edge of the
vortex to
avoid clumping. The spray-dried polymer of Example 174 wet more readily and
completely dissolved over a period of 30-40 minutes, giving a clear solution.
In contrast,
the dry polymer obtained by spray-drying an inverse emulsion did not wet as
rapidly and
was not completely dissolved after two hours. This Example demonstrates that a
dry
polymer obtained by spray-drying an aqueous dispersion of the instant
invention dissolved
faster than a dry polymer obtained by spray-drying a corresponding water-in-
oil emulsion.
EXAMPLE 176C
The procedure of U.S. Patent No. 5,403,883 Example 1 was followed. A
dispersion
having a bulk viscosity of about 10,600 cps (#4 spindle, 30 rpm) was obtained.
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EXAMPLE 177
The procedure of U.S. Patent No. 5,403,883 Example 1 was followed, except that
the 2-trimethlyammoniumethyl acrylate chloride was replaced by an equal weight
of
DEAEA.MeCI. The resulting aqueous dispersion had a bulk viscosity of about
6,900 cps
(#4 spindle, 30 rpm), demonstrating improved bulk viscosity as compared to
Example
176C.
EXAMPLE 178
A suitable vessel equipped with a mechanical stirrer, reflex condenser, and a
nitrogen inlet tube was charged with 22.94 parts deionized water and 10.5
parts of a 40%
aqueous solution of poly(DMAEM.MeCI), weight average molecular weight about
245,000. After completion of dissolution, 6.47 parts of a 54.20% aqueous
solution of
acrylamide, and 7.49 parts of the propyl chloride quaternary salt of
dimethylaminoethyl
acrylate were added and mixed. To this mixture, 10.8 parts ammonium sulfate,
0.7 parts
citric acid, and 0.76 parts of a 2% solution of EDTA were added and mixed. The
pH of the
mixture was about 3.3. The vessel was sealed and sparged with nitrogen for 30
minutes,
and then polymerization was started by addition of 0.54g of 2% aqueous
solution of V-50.
The reaction mixture was heated to 40°C for 2 hours and then raised to
50° C and held for
an additional 4 hours. The conversion was greater than 99%. A stable fluid
aqueous
dispersion was obtained. The bulk viscosity of the aqueous dispersion was
about 1300 cps
showing preferable fluidity as measured with a Brookfield Viscometer, No. 4
spindle, 30
rpm at 25° C. The aqueous dispersion was dissolved to give a SV of 2.1
cps. This
Example demonstrates that, despite Comparative Example 1 of EP 0 525 751 Al,
an
aqueous dispersion may be formed when the first polymer contains recurring
units of the
propyl chloride quaternary salt of dimethylaminoethylacrylate.
EXAMPLE 179
An aqueous dispersion was prepared in a similar manner to Example 40 except
that
the first polymer composition was AMD/DEAEA.DMS/DMAEA.MeCI (60/30/10 mole).
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The aqueous dispersion had a bulk viscosity of about 3,600 cps (No. 4 spindle,
30 rpm at
25° C) and a SV of 2.64 cps.
EXAMPLE 180
An aqueous dispersion was prepared in a similar manner to Example 40 except
that
the first polymer composition was AMD/DEAEA.DMS/DMAEA.MeCI (60/25/15 mole).
The aqueous dispersion had a bulk viscosity of about 1,000 cps (No. 4 spindle,
30 rpm at
25° C) and a SV of 2.87 cps.
EXAMPLE 180A-180E
Polymerizations were carried out in a similar manner to Example 39A except
that
the bulk viscosity was adjusted by utilizing the salts shown in Table 14A.
These examples
demonstrate that aqueous dispersions having low bulk viscosities and high
polymer solids
may be prepared, where the first cationic polymer is DMAEA.MeCI/DEAEA.DMS/AMD
(35/5/60 mole) and the second polymer is polyamine, and that the viscosities
may be
adjusted with salts.
Table 14A
First Second
Ex. % Total Polymer Polymer % Salt% SaltBV SV
Solids % Solids% Solids A B c s (c s
180A 26 19.25 6.74 22.50 0 80,0002.86
1808 26 18.57 7.43 22.50 0 10,7002.70
180C 26 18.57 7.43 19.35 3.15 10,2003.24
180D 26 18.57 7.43 19.35 3.15 3,810 3.06
180E 26 18.57 7.43 19.35 3.1 4,310 2.92
S
180A: Salt A = ammonium sulfate
1808: Salt A = ammonium sulfate
180C: Salt A = ammonium sulfate, Salt B = sodium nitrate
180D: Salt A = ammonium sulfate, Salt B = sodium chloride
180E: Salt A = ammonium sulfate, Salt B = sodium sulfate
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EXAMPLES 181-261
The performance of aqueous dispersions of the instant invention was determined
by
measuring free drainage rate and cake solids from dewatered sludge as follows:
Two
hundred grams of sewage sludge from a municipal waste treatment plant were
weighed into
each of a series of jars. Solutions of the aqueous dispersions and of W/O, a
commercial
water-in-oil emulsion control (60/40 mole % AMD/DMAEA.MeCI), were prepared so
that
the concentration of the polymer was about 0.2%. Various doses of the polymer
solutions
were intermixed with the sludge samples and agitated at 500 rpm for 10 seconds
(500
rpm/10 seconds) or at 1000 rpm for 5 seconds (1000 rpm/5 seconds) with an
overhead
mixer. The resultant aqueous mixture of flocculated sludge was dewatered by
pouring it
into a Buchner funnel containing a 35 mesh stainless steel screen; the free
drainage was
determined by measuring the milliliters of filtrate collected in 10 seconds.
Cake solids
were determined by drying the pressed sludge at 105°C. The results are
shown in Table
IS I5, with each polymer identified by previous Example No., free drainage in
units of
milliliters/10 seconds, mixing in rpm/seconds, dosage in units of pounds of
polymer per
ton of dry sludge, and cake solids as a weight percent of dry solids in wet
cake. The
notation "N/A" in the Table means that an accurate cake solids value could not
be obtained.
These Examples show that the performance of the aqueous dispersions of the
instant
invention is substantially equivalent or superior to a comparable commercial
product.
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Table 15
Free Cake
No. Polvmer Mixing Do_ sageDrainage Solids Io
181 102 500/10 24.4 137 17.3
182 I02 500/10 26.7 140 16.9
183 102 500/10 28.9 128 17.1
184 103 500/10 20 138 15.8
185 103 500/10 22.2 15_5 16.5
186 103 500/10 24.4 158 16.5
187 103 500/10 26.7 162 15.7
188C W/O 500/10 24.4 112 15.0
189C W/O 500/10 26.7 122 15.6
190C W/O 500/ 28.9 114 15.2
10
191 102 1000/5 20.2 142 15.5
192 102 1000/5 22.2 145 15.8
193 102 1000/5 26.7 140 15.3
194 103 1000/5 24.4 130 15.7
195 I03 1000/5 26.7 138 15.8
196 103 1000/5 28.9 145 15.2
I97C W/O 1000/5 22.2 112 16.0
198C W/O 1000/5 24.4 120 16.2
199C W/O 1000/5 26.7 110 15.7
200 9 500/10 23 144 16.6
201 9 500/ 27.2 160 I 7.0
10
202 9 500/10 31.4 140 17.1
203 179 500/ 23 144 17.0
I 0
204 179 500/10 27.2 153 17.6
205 179 500/10 31.4 152 17.4
206 180 500/10 23 100 16.9
207 180 500110 27.2 130 16.8
208 180 500/ 3 I .4 I 25 17.1
10
209C W/O 500/10 23 99 14.9
210C W/O 500/10 27.2 92 15.2
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211 9 1000/5 25.1 96 17.6
212 9 1000/5 29.3 97 18.0
213 9 1000/5 31.4 93 17.9
214 179 1000/5 29.3 107 17.7
21 S 179 1000/5 31.4 92 18.4
216 179 1000/5 35.6 104 18.7
2 i 7 180 l 000/525.1 84 16.9
218 180 1404/5 29.3 92 17.9
219 180 I 000/531.4 136 17. i
220 180 1000/5 35.6 104 17.1
221 C W/O 1000/5 25.1 110 16.1
222C W/O 1000/5 29.3 112 16.5
223C W/O 1000/5 31.4 108 16.8
224 44 500/ 22.1 140 17.5
10
225 44 500/10 24.5 138 17.0
226 44 500/10 27 139 17.4
227 44 1000/5 22.1 120 19.0
228 44 1000/5 25.8 11? 19.3
229 44 1000/5 29.4 104 19.5
230C W/O 500/10 18.4 108 NA
231C W/O 500/10 22.I 110 NA
232C W/O 500/10 25.8 66 NA
233C W/O 1000/5 22.1 128 17.9
234C W/O 1000/5 25.8 102 17.6
235 61 500/10 16.9 130 17.2
236 61 500/10 18.6 140 18.0
237 61 500/10 21.9 130 17.3
238 67 500/10 15.2 80 16.8
239 67 500/10 16.9 lOS 17.8
240 67 500/10 18.6 126 18.2
241C W/O 500/10 IS.2 116 16.2
242C W/O 500/ 16.9 116 15.6
10
243C W/O 500/10 18.8 82 1 S.4
244 140 500/10 26.5 138 18.0
245 140 500/ 29.4 140 18.5
10
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246 140 500/10 32.4 130 18.2
247 140 1000/5 29.2 118 17.8
24_8 140 1000/5 32.4 129 18.4
249 140 1000/5 35.7 137 19.0
250 142 500/ 26.5 120 16.9
10
251 142 500/10 29.4 142 17.2
252 142 500/10 32.4 127 17.1
253 142 1000/5 25.9 120 17.3
254 142 1000/5 29.2 140 17.8
255 142 1000/5 32.4 138 18.3
256C W/O 500/10 14.7 76 14.0
257C W/O 500/10 17.6 114 14.8
258C W/O 500/10 20.6 105 14.8
259C W/O 1000/5 22.7 104 16.8
260C W/O 1000/5 25.9 134 16.3
26 I W/O 1000/5 29.2 113 16.7
C
C: Comparative
W/O: Commercially available water-in-oil emulsion copolymer of acrylamide and
DMAEA.MeCI (60/40 mole %)
EXAMPLES 262-263
The performance of the aqueous dispersions of Examples 118 and 121 is
determined by measuring free drainage rate and cake solids from dewatered
sludge by
following the procedure of Examples 181-261. Similar results are obtained.
EXAMPLE 264
A solution of the spray-dried polymer of Example 174 is prepared so that the
concentration of the polymer is about 0.2%. The performance is determined by
measuring
free drainage rate and cake solids from dewatered sludge by following the
procedure of
Examples 181-261. Similar results are obtained.
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CA 02346249 2001-04-03
WO 00/20470 PCT/US99/21152
EXAMPLES 265-277
Solutions of the aqueous dispersions and spray-dried polymers of Examples 9,
44,
61, 67, 102, 103, 118, 121, 140, 142, 174, 179, and 180 are prepared so that
the
concentration of the polymer is about 0.2%. The performance is determined by
measuring
free drainage rate by following the procedure of Examples 181-261, except that
a 1%
suspension of paper solids is dewatered instead of sewage sludge. Similar
results are
obtained.
EXAMPLES 278-293
Aqueous admixtures are prepared by intermixing the aqueous dispersions of
Examples 157-172 with water so that the concentration of the polymer is about
0.2%. The
performance is determined by measuring free drainage rate by following the
procedure of
IS Examples 181-261, except that a 1% suspension of paper solids is dewatered
instead of
sewage sludge. Similar results are obtained.
68
