WO 2006/044735 PCT/US2005/037153
METHOD OF PREPARING MODIFIED DIALLYL-N,N-DISUBSTITUTED AMMONIUM
HALIDE POLYMERS
TECHNICAL FIELD
This invention concerns a method of preparing modified diallyl-N,N-disubstituted ammonium
5 halide polymers and use of the polymers in combination with one or more high molecular weight,
water soluble cationic, anionic, nonionic, zwitterionic or amphoteric polymer flocculants for
improving retention and drainage in papermaking processes.
BACKGROUND OF THE INVENTION
10
U.S. Patent No. 6,605,674 describes the preparation of structurally-modified cationic
polymers where monomers are polymerized under free radical polymerization conditions in which a
structural modifier is added to the polymerization after about 30% polymerization of the monomers
has occurred and use of the polymers as retention and drainage aids in papermaking processes.
15 The use of medium molecular weight diallyldimethylammonium chloride/acrylamide
copolymers as retention and drainage aids is reviewed in Hunter et al., "TAPP199 Preparing for the
Next Millennium ", vol. 3, pp. 1345-1352, TAPPI Press (1999).
U.S. Patent No. 6,071,379 discloses the use of diallyl-N-N-disubstituted ammonium
halide/acrylamide dispersion polymers as retention and drainage aids in papermaking processes.
20 U.S. Patent No. 5,254,221 discloses a method of increasing retention and drainage in a
papermaking process using a low to medium molecular weight diallyldimethylammonium
chloride/acrylamide copolymer in combination with a high molecular weight dialkylaminoalkyl
(meth)acrylate quaternary ammonium salt/acrylamide copolymer.
U.S. Patent No. 6,592,718 discloses a method of improving retention and drainage in a
25 papermaking furnish comprising adding to the furnish a diallyl-N,N-disubstituted ammonium
halide/acrylamide copolymer and a high molecular weight structurally-modified, water-soluble
cationic polymer.
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WO 2006/044735 PCT/US2005/037153
U.S. Patent Nos. 5,167,776 and 5,274,055 disclose ionic, cross-linked polymeric microbeads
having a diameter of less than about 1,000 nm and use of the microbeads in combination with a high
molecular weight polymer or polysaccharide in a method of improving retention and drainage of a
papermaking furnish.
5 Nonetheless, there is a continuing need for new compositions and processes to further
improve retention and drainage performance, particularly for use on the faster and bigger modern
papermaking machines currently being put into use.
SUMMARY OF THE INVENTION
10
This invention is a method of preparing a modified diallyl-N,N-disubstituted ammonium
halide polymer having a cationic charge of about 1 to about 99 mole percent comprising
polymerizing one or more acrylamide monomers and one or more diallyl-N, N-disubstituted
ammonium halide monomers in the presence of about 0.1 to less than about 3,000 ppm, based on
15 monomer, of one or more chain transfer agents and optionally about 1 to about 1,000 ppm, based on
monomer, of one or more cross-linking agents.
The polymer program of this invention outperforms other multi component programs referred
to as microparticle programs using colloidal silica or bentonite that are typically used in the paper
industry. Moreover, the shear resistance of the polymer program of this invention appears to be
20 better than that of the bentonite and silica programs. The method of this invention is particularly
useful on the faster and bigger paper machines where the shear resistance of the polymers used is
extremely important.
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WO 2006/044735 PCT/US2005/037153
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plot of flocculation response, measured as the mean chord length for a standard
alkaline furnish treated with modified polymer III, modified polymer V, bentonite or colloidal
5 borosilicate, coagulant (EPI/DMA, NH3 crosslinked) (0.5 lb/ton), anionic flocculant (30 mole/70
mole percent sodium acrylate/acrylamide inverse emulsion polymer, average RSV 40 dL/g, 0.5
lb/ton) and starch (10 lb/ton).
FIG. 2 is a plot of flocculation response, measured as the mean chord length for a standard
European mechanical furnish treated with modified polymer II or bentonite, cationic coagulant
10 (EPI/DMA, NH3 crosslinked), anionic flocculant (30/70 mole percent sodium acrylate/acrylamide
inverse emulsion polymer, average RSV 40 dL/g, 0.5 lb/ton) and starch (10 lb/ton).
FIG. 3 is a plot of flocculation response, measured as the mean chord length for a newsprint
furnish treated with modified polymer II, modified polymer III, bentonite or colloidal borosilicate,
cationic flocculant (10/90 mole percent dimethylaminoethyl acrylate methyl chloride quaternary
15 salt/acrylamide inverse emulsion polymer, average RSV 26 dL/g, 0.5 kg/ton) and starch (4 kg/ton).
Polymers II, III, and colloidal borosilicate are all dosed at 1 kg/ton. Bentonite is dosed at 2 kg/ton.
FIG. 4 is a plot of flocculation response, measured as the mean chord length for a newsprint
furnish treated with modified polymer II, modified polymer III, bentonite or colloidal borosilicate,
anionic flocculant ( 30/70 mole percent sodium acrylate/acrylamide inverse emulsion polymer,
20 average RSV 40 dL/g, 0.25 kg/ton), coagulant (EPI/DMA, NH3 crosslinked) (0.25 kg/ton), and starch
(4 kg/ton). Modified polymers II and III and colloidal borosilicate are all dosed at lkg/ton.
Bentonite is dosed at 2 kg/ton
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WO 2006/044735 PCT/US2005/037153
DETAILED DESCRIPTION OF THE INVENTION
Definitions of Terms
"Acrylamide monomer" means a monomer of formula
5

wherein R1, R2 and R3 are independently selected from H and alkyl. Preferred acrylamide monomers
are acrylamide and methacrylamide. Acrylamide is more preferred.
10 "Alkyl" means a monovalent group derived from a straight or branched chain saturated
hydrocarbon by the removal of a single hydrogen atom. Representative alkyl groups include methyl,
ethyl, n- and iso-propyl, cetyl, and the like.
"Alkylene" means a divalent group derived from a straight or branched chain saturated
hydrocarbon by the removal of two hydrogen atoms. Representative alkylene groups include
15 methylene, ethylene, propylene, and the like.
"Based on polymer active" and "based on monomer" mean the amount of a reagent added
based on the level of vinylic monomer in the formula, or the level of polymer formed after
polymerization, assuming 100% conversion.
"Chain transfer agent" means any molecule, used in free-radical polymerization, which will
20 react with a polymer radical forming a dead polymer and a new radical. In particular, adding a chain
transfer agent to a polymerizing mixture results in a chain-breaking and a concommitant decrease in
the size of the polymerizing chain. Thus, adding a chain transfer agent limits the molecular weight
of the polymer being prepared. Representative chain transfer agents include alcohols such as
methanol, ethanol, 1-propanol, 2-propanol, butyl alcohol, glycerol, and polyethyleneglycol and the
25 like, sulfur compounds such as alkylthiols, thioureas, sulfites, and disulfides, carboxylic acids such
as formic and malic acid, and their salts and phosphites such as sodium hypophosphite, and
combinations thereof. See Berger et al., "Transfer Constants to Monomer, Polymer, Catalyst,
Solvent, and Additive in Free Radical Polymerization, " Section II, pp. 81-151, in "Polymer
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WO 2006/044735 PCT/US2005/037153
Handbook," edited by J. Brandrup and E. H. Immergut, 3d edition, John Wiley & Sons, New York
(1989) and George Odian, Principles of Polymerization, second edition, John Wiley & Sons, New
York (1981). A preferred alcohol is 2-propanol. Preferred sulfur compounds include ethanethiol,
thiourea, and sodium bisulfite. Preferred carboxylic acids include formic acid and its salts. More
5 preferred chain-transfer agents are sodium hypophosphite and sodium formate.
"Cross-linking agent" means a multifunctional monomer that when added to polymerizing
monomer or monomers results in "cross-linked" and/or branched polymers in which a branch or
branches from one polymer molecule become attached to other polymer molecules. Representative
cross-linking agents includeN.N-methylenebisacrylamide, N,N-methylenebismethacrylamide,
10 triallylamine, triallyl ammonium salts, ethylene glycol dimethacrylate, diethylene glycol
dimethacrylate, polyethylene glycol diacrylate, triethylene glycol dimethylacrylate, polyethylene
glycol dimethacrylate, N-vinylacrylamide, N-methylallylacrylamide, glycidyl acrylate, acrolein,
glyoxal, gluteraldehyde, formaldehyde and vinyltrialkoxysilanes such as vinyltrimethoxysilane
(VTMS), vinyltriethoxysilane, vinyltris(p-methoxyethoxy)silane, vinyltriacetoxysilane,
15 allyltrimethoxysilane, allyltriacetoxysilane, vinylmethyldimethoxysilane,
vinyldimethoxyethoxysilane, vinylmethyldiacetoxysilane, vinyldimethylacetoxysilane,
vinylisobutyldimethoxysilane, vinyltriisopropoxysilane, vinyltri-n-butoxysilane,
vinyltrisecbutoxysilane, vinyltrihexyloxysilane, vinylmethoxydihexyloxysilane,
vinyldimethoxyoctyloxysilane, vinylmethoxydioctyloxysilane, vinyltrioctyloxysilane,
20 vinylmethoxydilauryloxysilane, vinyldimethoxylauryloxysilane, vinylmethoxydioleyloxysilane, and
vinyldimethoxyoleyloxysilane, and the like. Preferred cross-linkers include
N.N-methylenebisacrylamide, triallylamine, triallyl ammonium salts and glyoxal.
"Diallyl-N.,N-disubstituted ammonium halide monomer" means a monomer of formula
25 (H2C=CHCH2)2N+R4R5X"
wherein R4 and R5 are independently C1-C20 alkyl, aryl or arylalkyl and X is an anionic counterion.
Representative anionic counterions include halogen, sulfate, nitrate, phosphate, and the like.
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WO 2006/044735 PCT/US2005/037153
A preferred anionic counterion is halogen. A preferred diallyl-N.N-disubstituted ammonium halide
monomer is diallyldimethylammonium chloride.
"Halogen" means fluorine, chlorine, bromine or iodine.
"Modified diallyl-N,N-disubstiruted ammonium halide polymer" means a polymer of one or
5 more diallyl-N,N-disubstituted ammonium halide monomers and one or more acrylamide monomers
where the monomers are polymerized as described herein in the presence of one or more chain
transfer agents and optionally one or more cross-linking agents in order to impart the desired
characteristics to the resulting polymer.
"RSV" stands for reduced specific viscosity. Within a series of polymer homologs which are
10 substantially linear and well solvated, "reduced specific viscosity (RSV)" measurements for dilute
polymer solutions are an indication of polymer chain length and average molecular weight according
to Paul J. Flory, in "Principles of Polymer Chemistry", Cornell University Press, Ithaca, NY, ©
1953, Chapter VII, "Determination of Molecular Weights ", pp. 266-316. The RSV is measured at a
given polymer concentration and temperature and calculated as follows:

15
η = viscosity of polymer solution
20 η0 = viscosity of solvent at the same temperature
c = concentration of polymer in solution.
The units of concentration "c" are (grams/100 ml or g/deciliter). Therefore, the units of RSV are
dL/g. In this patent application, a 1.0 molar sodium nitrate solution is used for measuring RSV,
25 unless specified. The polymer concentration in this solvent is 0.045 g/dL. The RSV is measured at
30 °C. The viscosities r| and η0 are measured using a Cannon Ubbelohde semimicro dilution
viscometer, size 75. The viscometer is mounted in a perfectly vertical position in a constant
temperature bath adjusted to 30 ± 0.02 °C. The typical error inherent in the calculation of RSV for
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WO 2006/044735 PCT/US2005/037153
the polymers described herein is about 0.2 dL/g. When two polymer homologs within a series have
similar RSV's that is an indication that they have similar molecular weights.
"IV" stands for intrinsic viscosity, which is RSV extrapolated to the limit of infinite dilution,
infinite dilution being when the concentration of polymer is equal to zero.
5 "Papermaking process" means a method of making paper products from pulp comprising
forming an aqueous cellulosic papermaking furnish, draining the furnish to form a sheet and drying
the sheet. The steps of forming the papermaking furnish, draining and drying may be carried out in
any conventional manner generally known to those skilled in the art. Conventional microparticles,
alum, cationic starch or a combination thereof may be utilized as adjuncts with the polymer treatment
10 of this invention, although it must be emphasized that no adjunct is required for effective retention
and drainage activity.
Preferred Embodiments
Modified diallyl-N,N-disubstituted ammonium halide polymers are prepared by
15 polymerization of one or more diallyl-N,N-disubstituted ammonium halide monomers and one or
more acrylamide monomers under free radical forming conditions in the presence of one or more
chain transfer agents and optionally one or more cross-linking agents as described below.
The amounts of cross-linking agent and chain transfer agents and the polymerization
conditions are selected such that the modified polymer has a charge density of less than about 7
20 milliequivalents per gram of polymer and a reduced specific viscosity of about 0.2 to about 12 dL/g.
The modified polymer is also characterized in that it has a number average particle size diameter of
at least 1,000 nm if crosslinked and at least about 100 nm if non crosslinked.
The chain-transfer agents may be added all at once at the start of polymerization or
continuously or in portions during the polymerization of the monomers. The chain transfer agents
25 may also be added after polymerization of a portion of the monomers has occurred as described in
U.S. Patent No. 6,605,674 Bl. The level of chain transfer agent used depends on the efficiency of
the chain transfer agent, the monomer concentration, the degree of polymerization at which it is
added, the extent of polymer solubility desired and the polymer molecular weight desired. Typically,
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WO 2006/044735 PCT/US2005/037153
about 0.1 to less than about 3,000 ppm of chain transfer agent, based on monomer, is used to prepare
the modified polymer.
In addition to the chain transfer agents, the monomers may also be polymerized in the
presence of one or more cross-linking agents. When a combination of chain transfer agents and
5 cross-linking agents is used, the amounts of each may vary widely based on the chain-transfer
constant "efficiency" of the chain-transfer agent, the multiplicity and "efficiency" of the cross-linking
agent, and the point during the polymerization where each is added. For example from about 1,000
to about 3,000 ppm (based on monomer) of a moderate chain transfer agent such as isopropyl alcohol
may be suitable while much lower amounts, typically from about 100 to about 1,000 ppm, of more
10 effective chain transfer agents such as mercaptoethanol are useful. Representative combinations of
cross-linkers and chain transfer agents contain about 0.1 to less than about 3,000 ppm, preferably
about 0.1 to about ppm 2,000 and more preferably about 1 to about 1,500 ppm (based on monomer)
of chain transfer agent and about 1 to about 1,000, preferably about 1 to about 700 and more
preferably about 1 to about 500 ppm (based on monomer) of cross-linking agent.
15 Preferred modified diallyl-N,N-disubstituted ammonium halide polymers are selected from
the group consisting of inverse emulsion polymers, dispersion polymers, solution polymers and gel
polymers.
"Inverse emulsion polymer" means a water-in-oil polymer emulsion comprising a cationic,
anionic, amphoteric, zwitterionic or nonionic polymer according to this invention in the aqueous
20 phase, a hydrocarbon oil for the oil phase and a water-in-oil emulsifying agent. Inverse emulsion
polymers are hydrocarbon continuous with the water-soluble polymers dispersed within the
hydrocarbon matrix. The inverse emulsion polymers are then "inverted" or activated for use by
releasing the polymer from the particles using shear, dilution, and, generally, another surfactant. See
U.S. Pat. No. 3,734,873, incorporated herein by reference. Representative preparations of high
25 molecular weight inverse emulsion polymers are described in U. S. Patent nos. 2,982,749; 3,284,393;
and 3,734,873. See also, Hunkeler, et al., "Mechanism, Kinetics and Modeling of the Inverse-
Microsuspension Homopolymerization of Acrylamide, "Polymer, vol. 30(1), pp 127-42 (1989); and
Hunkeler et al., "Mechanism, Kinetics and Modeling of Inverse-Microsuspension Polymerization: 2.
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WO 2006/044735 PCT/US2005/037153
Copolymerization ofAcrylamide with Quaternary Ammonium Cationic Monomers, "Polymer, vol.
32(14), pp 2626-40 (1991).
The aqueous phase is prepared by mixing together in water one or more water-soluble
monomers, and any polymerization additives such as inorganic salts, chelants, pH buffers, and the
5 like.
The oil phase is prepared by mixing together an inert hydrocarbon liquid with one or more oil
soluble surfactants. The surfactant mixture should have a hydrophilic-lypophilic balance (HLB), that
ensures the formation of a stable oil continuous emulsion. Appropriate surfactants for water-in-oil
emulsion polymerizations, which are commercially available, are compiled in the North American
10 Edition of McCutcheon's Emulsifiers & Detergents. The oil phase may need to be heated to ensure
the formation of a homogeneous oil solution.
The oil phase is then charged into a reactor equipped with a mixer, a thermocouple, a
nitrogen purge tube, and a condenser. The aqueous phase is added to the reactor containing the oil
phase with vigorous stirring to form an emulsion. The resulting emulsion is heated to the desired
15 temperature, purged with nitrogen, and a free-radical initiator is added. The reaction mixture is
stirred for several hours under a nitrogen atmosphere at the desired temperature. Upon completion
of the reaction, the water-in-oil emulsion polymer is cooled to room temperature, where any desired
post-polymerization additives, such as antioxidants, or a high HLB surfactant (as described in U.S.
Patent 3,734,873) may be added.
20 The resulting inverse emulsion polymer is a free-flowing liquid. An aqueous solution of the
water-in-oil emulsion polymer can be generated by adding a desired amount of the inverse emulsion
polymer to water with vigorous mixing in the presence of a high-HLB surfactant (as described in
U.S. Patent 3,734,873).
"Dispersion polymer" means a dispersion of fine particles of polymer in an aqueous salt
25 solution, which is prepared by polymerizing monomers with stirring in an aqueous salt solution in
which the resulting polymer is insoluble. See U.S. Pat. Nos. 5,708,071; 4,929,655; 5,006,590;
5,597,859; 5,597,858 and European Patent nos. 657,478 and 630,909.
In a typical procedure for preparing a dispersion polymer, an aqueous solution containing one
or more inorganic or hydrophobic salts, one or more water-soluble monomers, any polymerization
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additives such as processing aids, chelants, pH buffers and a water-soluble stabilizer polymer is
charged to a reactor equipped with a mixer, a thermocouple, a nitrogen purging tube, and a water ,
condenser. The monomer solution is mixed vigorously, heated to the desired temperature, and then
an initiator is added. The solution is purged with nitrogen while maintaining temperature and mixing
5 for several hours. After this time, the mixture is cooled to room temperature, and any post-
polymerization additives are charged to the reactor. Water continuous dispersions of water-soluble
polymers are free flowing liquids with product viscosities generally 100-10,000 cP, measured at low
shear.
In a typical procedure for preparing solution and gel polymers, an aqueous solution
10 containing one or more water-soluble monomers and any additional polymerization additives such as
chelants, pH buffers, and the like, is prepared. This mixture is charged to a reactor equipped with a
mixer, a thermocouple, a nitrogen purging tube and a water condenser. The solution is mixed
vigorously, heated to the desired temperature, and then one or more polymerization initiators are
added. The solution is purged with nitrogen while maintaining temperature and mixing for several
15 hours. Typically, the viscosity of the solution increases during this period. After the polymerization
is complete, the reactor contents are cooled to room temperature and then transferred to storage.
Solution and gel polymer viscosities vary widely, and are dependent upon the concentration and
molecular weight of the active polymer component. The solution/gel polymer can be dried to give a
powder.
20 The polymerization reactions described herein are initiated by any means which results in •
generation of a suitable free-radical. Thermally derived radicals, in which the radical species results
from thermal, homolytic dissociation of an azo, peroxide, hydroperoxide and perester compound are
preferred. Especially preferred initiators are azo compounds including 2,2'-azobis(2-
amidinopropane) dihydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride, 2,2'-
25 azobis(isobutyronitrile) (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile) (AIVN), and the like.
In a preferred aspect of this invention, the modified diallyl-A'.N-disubstituted ammonium
halide polymer has a RSV of from about 0.2 to about 12 dL/g a charge density of less than about 7
milliequivalents/g polymer.
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In another preferred aspect, the diaHyl-N,N-disubstituted ammonium halide monomer is
diallyldimethylammonium chloride and the acrylamide monomer is acrylamide.
In another preferred aspect, the diallyl-N.N-disubstituted ammonium halide polymer has a
cationic charge of about 20 to about 80 mole percent.
5 In another preferred aspect, the modified diallyl-N,N-disubstituted ammonium halide polymer
has a RSV of about 1 to about 8 dL/g.
In another preferred aspect, the chain transfer agent is selected from sodium formate and
sodium hypophosphite.
In another preferred aspect, the polymerization is conducted in the presence of about 0.1 to
10 less than about 3,000 ppm, based on monomer, of sodium formate.
In another preferred aspect, the polymerization is conducted in the presence of about 1 to
about 2,000 ppm, based on monomer of sodium formate.
In another preferred aspect, the chain transfer agent is sodium formate and the cross-linking
agent is N,N-methylenebisacrylamide.
15 In another preferred aspect, the modified diallyl-N,N-disubstituted ammonium halide polymer
is composed of about 30 to about 60 mole percent diallyldimethylammonium chloride monomer and
about 40 to about 70 mole percent acrylamide monomer and has a charge density of less than about 6
milliequivalents/g polymer and a RSV of less than about 8 dL/g.
In another embodiment of this invention, the modified modified diallyl-N,N-disubstituted
20 ammonium halide polymer is used in combination with an effective amount of one or more cationic,
anionic, nonionic, zwitterionic or amphoteric polymer flocculants in order to increase retention and
drainage in a papermaking furnish. Suitable floceulants generally have molecular weights in excess
of 1,000,000 and often in excess of 5,000,000.
The polymeric flocculant is typically prepared by vinyl addition polymerization of one or
25 more cationic, anionic or nonionic monomers, by copolymerization of one or more cationic
monomers with one or more nonionic monomers, by copolymerization of one or more anionic
monomers with one or more nonionic monomers, by copolymerization of one or more cationic
monomers with one or more anionic monomers and optionally one or more nonionic monomers to
produce an amphoteric polymer or by polymerization of one or more zwitterionic monomers and
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optionally one or more nonionic monomers to form a zwitterionic polymer. One or more
zwitterionic monomers and optionally one or more nonionic monomers may also be copolymerized
with one or more anionic or cationic monomers to impart cationic or anionic charge to the
zwitterionic polymer.
5 While cationic polymer flocculants may be formed using cationic monomers, it is also
possible to react certain non-ionic vinyl addition polymers to produce cationically charged polymers.
Polymers of this type include those prepared through the reaction of polyacrylamide with
dimethylamine and formaldehyde to produce a Mannich derivative.
Similarly, while anionic polymer flocculants may be formed using anionic monomers, it is
10 also possible to modify certain nonionic vinyl addition polymers to form anionically charged
polymers. Polymers of this type include, for example, those prepared by the hydrolysis of
polyacrylamide.
The flocculant may be used in the solid form, as an aqueous solution, as a water-in-oil
emulsion, or as dispersion in water. Representative cationic polymers include copolymers and
15 terpolymers of (meth)acrylamide with dimethylaminoethyl methacrylate (DMAEM),
dimethylaminoethyl acrylate (DMAEA), diethylaminoethyl acrylate (DEAEA), diethylaminoethyl
methacrylate (DEAEM) or their quaternary ammonium forms made with dimethyl sulfate, methyl
chloride or benzyl chloride.
In a preferred aspect of this invention, the flocculants have a RSV of at least about 3 dL/g.
20 In another preferred aspect, the flocculants have a RSV of at least about 10 dL/g.
In another preferred aspect, the flocculants have a RSV of at least about 15 dL/g.
In another preferred aspect, the polymer flocculant is selected from the group consisting of
dimethylaminoethylacrylate methyl chloride quaternary salt-acrylamide copolymers.
In another preferred aspect, the polymer flocculant is selected from the group consisting of
25 sodium acrylate-acrylamide copolymers and hydrolyzed polyacrylamide polymers.
The effective amount of the modified diallyl-N,N-disubstituted ammonium halide polymer
and the polymer flocculant depend on the characteristics of the particular papermaking furnish and
can be readily determined by one of ordinary skill in the papermaking art. Typical dosages of the
modified diallyl-.N.N-disubstituted ammonium halide polymer are from about 0.01 to about 10,
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preferably from about 0.05 to about 5 and more preferably from about 0.1 to about 1 kg polymer
actives/ton solids in the furnish.
Typical dosages of the polymer flocculant are from about 0.005 to about 10, preferably from
about 0.01 to about 5 and more preferably from about 0.05 to about 1 kg polymer actives/ton solids
5 in the furnish.
The order and method of addition of the modified diallyl-N,N-disubstituted ammonium
halide polymer and the polymer flocculant are not critical and can be readily determined by one of
ordinary skill in the papermaking art. However, the following are preferred.
In one preferred method of addition, the polymer flocculant and modified diallyl-N,N-
10 disubstituted ammonium halide polymer are dosed separately to the thin stock with the modified
diallyl-./V,7V-disubstiruted ammonium halide polymer added first followed by addition of the polymer
flocculant.
In another preferred method of addition, the polymer flocculant and modified dially-N,N-
disubstituted ammonium halide polymer are dosed separately to the thin stock with the polymer
15 flocculant added first followed by the modified diallyl-N.N-disubstituted ammonium halide polymer.
In another preferred method of addition, the modified diallyl-N,N-disubstituted ammonium
halide polymer is added to tray water, e.g. the suction side of the fan pump prior to thick stock
addition, and the polymer flocculant to the thin stock line.
In another preferred method of addition, the modified diallyl-N,N-disubstituted ammonium
20 halide polymer is added to the dilution head box stream and the polymer flocculant is added to the
thin stock line.
In another preferred method of addition, the modified diallyl-N,N-disubstituted ammonium
halide polymer is added to thick stock, e.g. stuff box, machine chest or blend chest, followed by
addition of the polymer flocculant in the thin stock line.
25 In another preferred method of addition, the modified diallyl-N.N-disubstituted ammonium
halide polymer and the polymer flocculant are fed simultaneously to the thin stock.
In another preferred method of addition, the modified diallyl-N,N-disubstituted ammonium
halide polymer and the polymer flocculant are fed simultaneously to the dilution head box stream.
In another preferred aspect, one or more coagulants are added to the furnish.
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Water soluble coagulants are well known, and commercially available. The water soluble
coagulants may be inorganic or organic. Representative inorganic coagulants include alum, sodium
aluminate, polyaluminum chlorides or PACs (which also may be under the names aluminum
chorohydroxide, aluminum hydroxide chloride and polyaluminum hydroxychloride), sulfated
5 polyaluminum chlorides, polyaluminum silica sulfate, ferric sulfate, ferric chloride, and the like and
blends thereof.
Many water soluble organic coagulants are formed by condensation polymerization.
Examples of polymers of this type include epichlorohydrin-dimethylamine, and epichlorohydrin-
dimethylamine-ammonia polymers.
10 Additional coagulants include polymers of ethylene dichloride and ammonia, or ethylene
dichloride and dimethylamine, with or without the addition of ammonia, condensation polymers of
multifunctional amines such as diethylenerriamine, tetraethylenepentamine, hexamethylenediamine
and the like with ethylenedichloride and polymers made by condensation reactions such as melamine
formaldehyde resins.
15 Additional coagulants include cationically charged vinyl addition polymers such as polymers
and copolymers of diallyldimethylammonium chloride, dimethylaminoethylmethacrylate,
dimethylaminoethylmethacrylate methyl chloride quaternary salt,
methacrylarnidopropylrrirnethylarnmonium chloride, (methacryloxyloxyethyl)trimethyl ammonium
chloride, dialiylmethyl(beta-propionamido)ammonium chloride,
20 (beta-methacryloxyloxyethyl)trirnethyl-ammonium methylsulfate, quaternized polyvinyllactam;
dimethylamino-ethylacrylate and its quaternary ammonium salts, vinylamine and acrylamide or
methacrylamide which has been reacted to produce the Mannich or quaternary Mannich derivatives.
The molecular weights of these cationic polymers, both vinyl addition and condensation, range from
as low as several hundred to as high as one million. Preferably, the molecular weight range should
25 be from about 20,000 to about 1,000,000.
Preferred coagulants are poly(diallyldimethylammonium chloride), EPI/DMA, NH3
crosslinked and polyaluminum chlorides.
The foregoing may be better understood by reference to the following examples that are
presented for purposes of illustration and are not intended to limit the scope of the invention.
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WO 2006/044735 PCT/US2005/037153
Example 1
Preparation of an unmodified 70/30 mole percent acrylamide/diallyldimethylammoniurn chloride
copolymer dispersion Example 1 (Polymer I).
Acrylamide (49.4% aqueous solution, 28.0 g, Nalco Company, Naperville, IL), 175.0 g of a
5 63% aqueous solution of diallyldimethyl ammonium chloride (Nalco Company, Naperville, IL), 44.0
g of a 15% aqueous solution of a homopolymer of dimethylaminoethyl acrylate methyl chloride
quaternary salt (Nalco Company, Naperville, IL), 0.66 g of sodium formate, 0.44 g of
ethylenediaminetetraacetic acid, tetra sodium salt, 220.0 g of ammonium sulfate, 44.0 g of sodium
sulfate, 0.20 g polysilane antifoam (Nalco Company, Naperville, IL), and 332.0 g of deionized water
10 are added to a 1500 ml reaction flask fitted with a mechanical stirrer, thermocouple, condenser,
nitrogen purge tube, and addition port. The resulting mixture is stirred and heated to 42 °C. Upon
reaching 42 °C, 5.0 g of a 10.0% aqueous solution of 2,2'-azobis[2-(2-imidazolin-2-yl)propane]
dihydrochloride (VA-044, Wako Chemicals, Dallas, TX) is added to the reaction mixture and a
nitrogen purge is started at the rate of 1000 mL/min. Forty-five minutes after initiator addition 194.7
15 g of a 49.4% aqueous solution of acrylamide is added to the reaction mixture over a period of 6
hours. At 8 hours after the initiator addition, the reaction mixture is cooled to ambient temperature.
The product is a smooth milky white dispersion with a bulk viscosity of 1500 cP and a reduced
specific viscosity of 4.5 dL/g (0.045% solution of the polymer in 1.0 N aqueous sodium nitrate at 30
°C). The charge density of the resulting polymer is between 3.1 to 4.5 milliequivalents/gram
20 polymer.
Example 2
Preparation of a modified 70/30 mole percent acrylamide/diallyldimethylammonium chloride
copolymer dispersion (Polymer II).
25 To a 1500 ml reaction flask fitted with a mechanical stirrer, thermocouple, condenser,
nitrogen purge tube, and addition port is added 28.0 g of a 49.4% aqueous solution of acrylamide,
175.0 g of a 63% aqueous solution of diallyldimethyl ammonium chloride, 44.0 g of a 15% aqueous
solution of a homopolymer of dimethylaminoethyl acrylate methyl chloride quaternary salt, 0.22 g of
sodium formate, 0.44 g of ethylenediaminetetraacetic acid, tetra sodium salt, 220.0 g of ammonium
15

WO 2006/044735 PCT/US2005/037153
sulfate, 44.0 g of sodium sulfate, 0.20 g polysilane antifoam and 332.0 g of deionized water. The
resulting mixture is stirred and heated to 42 °C. Upon reaching 42 °C, 5.0 g of a 10.0% aqueous
solution of VA-044 is added to the reaction mixture and a nitrogen purge is started at the rate of
1000 mL/min. Forty-five minutes after initiator addition, 194.7 g of a 49.4% aqueous solution of
5 acrylamide is added to the reaction mixture over a period of 6 hours. At 8 hours after the initiator
addition, the reaction mixture is cooled to ambient temperature. The product is a smooth milky
white dispersion with a bulk viscosity of 2180 cP and a reduced specific viscosity of 3.9 dL/g
(0.045% solution of the polymer in 1.0 N aqueous sodium nitrate at 30 °C). The level of chain
transfer agent (i.e. sodium formate) added in the beginning of the reaction is critical to get the
10 desired modified polymers having a charge density of less than about 3 milliequivalents/gram
polymer. The amount of sodium formate in the formulation that can yield less than about 3
milliequivalents/gram polymer is less than 0.66 g sodium formate.
Example 3
15 Preparation of a modified 70/30 mole percent acrylarnide/diallyldimethylammonium chloride copolymer
dispersion (Polymer III).
To a 1500 ml reaction flask fitted with a mechanical stirrer, thermocouple, condenser,
nitrogen purge tube, and addition port is added 28.0 g of a 49.4% aqueous solution of acrylamide,
175.0 g of a 63% aqueous solution of diallyldimethyl ammonium chloride, 44.0 g of a 15% aqueous
20 solution of a homopolymer of dimethylaminoethyl acrylate methyl chloride quaternary salt, 0.11 g of
sodium formate, 0.77 g of a 1% aqueous solution of methylene bisacrylamide (35 ppm based on
monomer, MBA, Aldrich Chemical Company, Milwaukee, WI), 0.44 g of ethylenediaminetetraacetic
acid, tetra sodium salt, 220.0 g of ammonium sulfate, 44.0 g of sodium sulfate, 0.20 g polysilane
antifoam, and 332.0 g of deionized water. The resulting mixture is stirred and heated to 42 °C.
25 Upon reaching 42 °C, 5.0 g of a 10.0% aqueous solution of VA-044 is added to the reaction mixture
and a nitrogen purge is started at the rate of 1000 mL/min. Forty-five minutes after initiator addition,
194.7 g of a 49.4% aqueous solution of acrylamide is added to the reaction mixture over a period of
6 hours. At 8 hours after the initiator addition, the reaction mixture is cooled to ambient
temperature. The product is a smooth milky white dispersion with a bulk viscosity of 1200 cP and a
16

WO 2006/044735 PCT/US2005/037153
reduced specific viscosity of 2.4 dL/g (0.045% solution of the polymer in 1.0 N aqueous sodium
nitrate at 30 °C). The level of chain transfer agent (i.e. sodium formate) and cross-linker (methylene
bisacrylamide) in the formulation can be adjusted to obtain the desired modified polymers having a
charge density of less than about 3 milliequivalents/gram polymer.
5
Example 4
Comparison of modified and unmodified polymers.
A one percent polymer solution is prepared by stirring 198 g of water in a 400 mL beaker at
800 rpm using a cage stirrer, injecting two g of a polymer composition prepared as described in
10 Examples 1-3 along the vortex and stirring for 30 minutes. The resulting product solution is used for
Colloid titration as described below. The Colloid titration should be carried out within 4 hours of
solution preparation.
The results are shown in Table 1.
17
The one percent polymer solution (0.3 g) is measured into a 600 mL beaker and the beaker is
filled with 400 mL of deionized water. The solution pH is adjusted to 2.8 to 3.0 using dilute HC1.
15 Toluidine Blue dye (6 drops) is added and the solution is titrated with 0.0002 N polyvinylsulfonate
potassium salt to the end point (the solution should change from blue to purple). The charge density
in milliequivalent per gram of polymer is calculated as follows:


WO 2006/044735

PCT/US2005/037153

Table 1
Comparison of Modified and Unmodified Polymers

Sample Composition Sodium Measured charge RSV
formate/MBA density (dL/g)
Level (ppm (milliequivalents/gram
based on polymer)
monomer
I 30/70 mole % 3,000/0 3.6 4.5
DADMAC/Acrylamide
II 30/70 mole % 1,000/0 2.1 3.9
DADMAC/Acrylamide
IV1 30/70 mole % 1,000/0 2.9 4.3
DADMAC/Acrylamide
V2 30/70 mole % 500/0 1.8 2.4
DADMAC/Acrylamide
III 30/70 mole % 500/35 1.8 2.4
DADMAC/Acrylamide
'Modified 30/70 mole % DADMAC/Acrylamide copolymer dispersion prepared according to
5 the method of Example 2.
2Modified 30/70 mole % DADMAC/Acrylamide copolymer dispersion prepared according to
the method of Example 2 using the indicated amount of sodium formate.
The data shown in Table 1 indicate that polymers prepared according to the method of this
10 invention are modified relative to polymers prepared as in U.S. Patent No. 6,071,379 as described in
Example 1. The charge density of the modified polymers measured using colloid titration are low
than those prepared as in U.S. Patent No. 6,071,379 as described in Example 1. The charge density
of the modified polymers can be increased upon introduction of shear to the expected greater than
about 3 meq/g polymer. Shearing the modified polymer results in polymer degradation and as a
15 result the cross-linking of the modified polymers is destroyed making all of the charge accessible to
colloid titration.
18

WO 2006/044735 PCT/US2005/037153
Example 5
Tables 3-5 show the results of retention testing on LWC and newsprint papermaking
furnishes treated with representative modified polymers compared to conventional microparticles
and a high molecular weight flocculant.
5 The retention testing is conducted using a Dynamic Drainage Jar (DDJ) according to the
procedure described in TAPPI Test Method T 261 cm-94. Increased retention of fines and fillers is
indicated by a decrease in the turbidity of the DDJ filtrate.
A 125P (76μm) screen is used throughout the testing and the shear rate is kept constant at
1000 rpm. Table 2 shows the typical timing sequence for DDJ testing.
' 10
Table 2
Timing sequence used in DDJ retention measurements.

Time (s) Action
0 Start mixer and add sample furnish
10 Add coagulant if desired
20 Add flocculant if desired
25 Add modified diallyl-N,.N-disubstituted ammonium halide polymer orconventional microparticle
30 Open drain valve and start collecting the filtrate
60 Stop collecting the filtrate
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Table 3
Retention Performance Comparison as FPR for Polymer IV vs. Bentonite in LWC Furnish1

Polymer Dose lb/t FPR(%) Turbidity(NTU) TurbidityReduction(%)
starch blank - 53.4 4248.0 0.0
Cationicflocculantalone 0.5 64.4 3294.0 22.5
Bentonite 4.0 64.6 3066.0 27.8
8.0 66.3 2955.0 30.5
Polymer IV 0.5 66.8 2927.0 31.1
1.0 67.7 2717.0 36.1
5 ' 10 lb/t starch; 3 lb/t poly(diallyldimethylammonium chloride); 0.5 lb/t cationic flocculant
(10/90 mole percent dimethylaminoethylacrylate methyl chloride salt/acrylamide inverse emulsion
polymer, average RSV 26 dL/g); 4 lb/t and 8 lb/t bentonite; and Polymer IV dosed at 0.5 and 1.0 lb/t.
As shown in Table 3, in LWC furnish representative polymer IV in combination with 10/90
10 mole percent dimethylaminoethylacrylate methyl chloride salt/acrylamide inverse emulsion polymer
show superior performance to bentonite at low and high dosage levels.
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WO 2006/044735 PCT/US2005/037153
Table 4
Retention Performance Comparison as FPR for Polymer IV vs. Bentonite in LWC Furnish1

Polymer Dose Ib/t FPR (%) Turbidity(NTU) TurbidityReduction(%)
starch blank - 53.4 4248.0 0.0
Anionicflocculant 0.5 56.4 3945.0 7.1
Bentonite 8.0 58.8 3546.0 16.5
Polymer IV 1.0 65.5 3321.0 21.8
110 lb/t starch; 3 lb/t poly(diallyldimethylammonium chloride); 0.5 lb/t 30/70 mole percent
5 sodium acrylate/acrylamide inverse emulsion polymer, average RSV 40 dL/g.; 4 lb/t and 81b/t
bentonite; and Polymer IV dosed at 0.5 and 1.0 lb/t.
As shown in Table 4, in LWC furnish representative modified polymers IV in combination
with the 30/70 mole % sodium acrylate/acrylamide inverse emulsion polymer show superior
10 performance compared to bentonite in terms of FPR and turbidity reduction.
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WO 2006/044735 PCT/US2005/037153
Table 5
Retention Performance Comparison of Polymers II vs. Bentonite and Colloidal Borosilicate in
Newsprint Furnish1

Polymer Dosagelb/t Turbidity(NTU) FPR (%) TurbidityReduction
starch blank - 4282 73.3 0.0
CationicFlocculant 1.0 2908 80.5 32.1
Colloidalborosilicate 1.02.0 26822385 81.383.1 37.444.3
Bentonite 2.04.0 29992363 79.184.4 30.044.8
Polymer II 1.02.0 26512169 81.985.0 38.149.3
5
1 8 lb/t starch; 1.0 lb/t 10/90 mole percent dimethylaminoethylacrylate methyl chloride
salt/acrylamide inverse emulsion polymer, average RSV 26 dL/g; 1.0 lb/t and 2.0 lb/t colloidal
borosilicate; 2.0 and 4.0 lb/t bentonite; and 1.0 lb/t and 2.0 lb/t Polymer II.
10 As shown in Table 5 for a typical newsprint furnish, representative modified polymer II, in
combination with 10/90 mole percent dimethylaminoethylacrylate methyl chloride salt /acrylamide
inverse emulsion polymer show improved performance compared to bentonite and colloidal
borosilicate in terms of FPR and turbidity reduction.
15 Example 6
Table 7 shows the results of drainage testing on a LWC papermaking furnish treated with
representative modified polymers and a high molecular weight flocculant in the presence and
absence of a conventional microparticle.
Drainage measurements are performed using the Dynamic Filtration System (DFS-03)
20 Manufactured by Mutek (BTG, Herrching, Germany). During drainage measurement using the
Dynamic Filtration System, the furnish (pulp suspension) is filled into the stirring compartment and
subjected to a shear of 650 rpm during the addition of the chemical additives. The furnish is drained
22

WO 2006/044735 PCTAJS2005/037153
through a 60 mesh screen with 0.17 mm wire size for 60 seconds and the filtrate amount is
determined gravimetrically over the drainage period. The results are given as the drainage rate
(g/sec). The drainage is evaluated using the test conditions shown in Table 6.
5 Table 6
DFS-03 Test Conditions

Mixing Speed 650 rpm
Screen 60 Mesh
Sample Size 1000 ml
Shear Time 30 sec
Collection Time 60 sec

Dosing Sequence
t = 0 sec Start
t = 5 sec Coagulant
t = 10 sec Starch
t = 20 sec Flocculant
t = 25 sec Microparticle
t = 30 sec Drain
t = 90 sec STOP

WO 2006/044735 PCT/US2005/037153
Table 7
Drainage Performance Comparison for Polymers II, V vs. Bentonite in LWC Furnish1

Drainage Rate g/sec
No Microparticle 5.2
Bentonite @ 6 lb/t 5.94
Polymer V @ 3 lb/t 6.71
Polymer II @ 3 lb/t 7.53
5 ' 10 lb/t starch; 0.5 lb/t poly(diallyldimethylammonium chloride); 1.0 lb/t 10/90 mole percent
dimethylaminoethylacrylate methyl chloride salt/acrylamide inverse emulsion polymer, average RSV
26 dIVg.
In Table 7, the effect on drainage of Polymers II and V, and bentonite in combination with
10 10/90 mole percent dimethylaminoethylacrylate methyl chloride salt/acrylamide inverse emulsion
polymer is measured. Polymers II and V show significant improvement in drainage compared to
bentonite.
Example 7
15 This example shows the flocculation response, measured as mean chord length for
papermaking furnishes treated with representative modified polymers of this invention. The results
are shown in FIGS 1 -4. :
Flocculation activity is measured by focused beam reflectance measurement (FBRM) using
the Lasentec™ M500 (Lasentec, Redmond, WA). This is a scanning laser microscopy (SLM) device
20 that is used to measure the size distribution of solids in the furnish versus time during coagulation
and flocculation. The technique is described in detail in Alfano et al, Nordic Pulp Paper Res. J., vol.
13(2), p 59 (1998) and U. S. Patent No. 4,871,251.
The number average chord length or mean chord length (MCL) as a function of time is used
to characterize the flocculation response. The peak change in MCL caused by addition of the
24

WO 2006/044735 PCT/US2005/037153
polymer treatments is used to compare their effectiveness. The peak change in MCL gives a
representation of the speed and extent of flocculation under the shear conditions present.
The timing sequence used in the FBRM testing is shown in Table 8.
5 Table 8
Typical timing sequence used in the Lasentec™ M500 FBRM testing.

Time (s) Action
0 Start mixer
6 Add EPI/DMA, NH3 crosslinked
21 Add starch
51 Add flocculant
96 Add modified diallyl-N,N'-disubstituted ammonium halide polymer
156 Stop experiment
In FIG. 1 the flocculation response of representative modified polymers III and V are
10 compared to bentonite and colloidal borosilicate in combination with anionic flocculant (30/70 mole
percent sodium acrylate-acrylamide inverse emulsion polymer) in standard alkaline furnish. The
change in MCL caused by the addition of the modified polymers HI and V is greater than that for
bentonite and colloidal borosilicate. Moreover, the shear resistance of polymers III and V appears to
be better than that of bentonite and colloidal borosilicate.
15 FIG. 2 is a plot of flocculation response of representative modified polymer II and bentonite
in combination with anionic flocculant (30/70 mole percent sodium acrylate/acrylamide inverse
emulsion polymer) in a Standard European Mechanical Furnish. The plot shows a significant
increase in the flocculation response of polymer II with no coagulant (EPI/DMA, NH3 crosslinked)
compared to bentonite.
20 In FIG. 3 the flocculation response of representative polymers II and III are compared to
bentonite and colloidal borosilicate in a newsprint furnish in combination with 10/90 mole percent
dimethylaminoethylacrylate methyl chloride/acrylamide salt inverse emulsion polymer. The change
in MCL caused by the addition of the modified polymers II and III is greater than that for bentonite
and colloidal borosilicate.
25

WO 2006/044735 PCT/US2005/037153
In FIG. 4 the flocculation response of representative modified polymers II and III are
compared to bentonite and colloidal borosilicate in a newsprint furnish in combination with 30/70
mole percent sodium acrylate/acrylamide inverse emulsion polymer. The change in MCL caused by
the addition of the modified polymers II and III is greater than that for bentonite and colloidal
borosilicate.
Changes can be made in the composition, operation and arrangement of the method of the
invention described herein without departing from the concept and scope of the invention as defined
in the claims.
26

WO 2006/044735 PCT/US2005/037153
CLAIMS
1. A method of preparing a modified diallyl-N.N-disubstituted ammonium halide polymer
having a cationic charge of about 1 to about 99 mole percent comprising polymerizing one or more
5 acrylamide monomers and one or more diallyl-N,N-disubstituted ammonium halide monomers in the
presence of about 0.1 to less than about 3,000 ppm, based on monomer, of one or more chain transfer
agents and optionally about 1 to about 1,000 ppm, based on monomer, of one or more cross-linking
agents.
10 2. The method of claim 1 wherein the modified diallyl-N,N-disubstituted ammonium halide
polymer has a RSV of from about 0.2 to about 12 dL/g a charge density of less than about 7
milliequivalents/g polymer.
3. The method of claim 1 wherein the modified diallyl-N,N-disubstituted ammonium halide
15 polymer is selected from the group consisting of inverse emulsion polymers, dispersion polymers,
solution polymers and gel polymers.
4. The method of claim 1 wherein the diallyl-N,N-disubstituted ammonium halide monomer is
diallyldimethylammonium chloride and the acrylamide monomer is acrylamide.
20
5. The method of claim 4 wherein the modified diallyl-N,N-disubstituted ammonium halide
polymer has a cationic charge of about 20 to about 80 mole percent.
6. The method of claim 5 wherein the modified diallyl-N,N-disubstituted ammonium halide
25 polymer has a RSV of about 1 to about 8 dL/g.
7. The method of claim 6 wherein the chain transfer agent is selected from sodium formate and
sodium hypophosphite.
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WO 2006/044735 PCT/US2005/037153
8. The method of claim 7 wherein the polymerization is conducted in the presence of about 0.1
to less than about 3,000 ppm, based on monomer, of sodium formate.
9. The method of claim 7 wherein the polymerization is conducted in the presence of about 1 to
5 about 2,000 ppm, based on monomer, of sodium formate.
10. The method of claim 5 wherein the polymerization is conducted in the presence of about 0.1
to less than about 3,000 ppm, based on monomer of chain transfer agent and about 1 to about 1,000
ppm, based on monomer, of cross-linking agent.
10
11. The method of claim 5 wherein the polymerization is conducted in the presence of about 1 to
about 2,000 ppm, based on product, of chain transfer agent and about 1 to about 700 ppm, based on
monomer, of cross-linking agent.
15 12. The method of claim 5 wherein the polymerization is conducted in the presence of about 1 to
about 1,500 ppm, based on product, of chain transfer agent and about 1 to about 500 ppm, based on
monomer, of cross-linking agent.
13. The method of claim 12 wherein the chain transfer agent is sodium formate and the cross-
20 linking agent isN,N-methylenebisacrylamide.
14. The method of claim 1 wherein the modified diallyl-N,N-disubstituted ammonium halide
polymer is composed of about 30 to about 60 mole percent diallyldimethylammonium chloride
monomer and about 40 to about 70 mole percent acrylamide monomer and has a charge density of
25 less than about 6 milliequivalents/g polymer and a RSV of less than about 8 dL/g.
28

WO 2006/044735 PCT/US2005/037153
15. A method of increasing retention and drainage in a papermaking furnish comprising adding
to the furnish an effective amount of a modified diallyl-N,N-disubstituted ammonium halide polymer
prepared according to the method of claim 1 and an effective amount of one or more high molecular
weight, water-soluble cationic, anionic, nonionic, zwitterionic or amphoteric polymer flocculants.
5
16. The method of claim 15 wherein the high molecular weight, water soluble cationic, anionic,
nonionic, zwitterionic or amphoteric polymer flocculants have a RSV of at least about 3 dL/g.
17. The method of claim 15 wherein the high molecular weight, water soluble cationic, anionic,
10 nonionic, zwitterionic or amphoteric polymer flocculants have a RSV of at least about 10 dL/g.
18. The method of claim 15 wherein the high molecular weight, water soluble cationic, anionic,
nonionic, zwitterionic or amphoteric polymer flocculants have a RSV of at least about 15 dL/g.
15 19. The method of claim 15 wherein the polymer flocculant is selected from the group consisting
of dimethylaminoethylacrylate methyl chloride quaternary salt-acrylamide copolymers.
20. The method of claim 15 wherein the polymer flocculant is selected from the group consisting
of sodium acrylate-acrylamide copolymers and hydrolyzed polyacrylamide polymers.
20
21. The method of claim 15 further comprising adding one or more coagulants to the furnish.
22. The method of claim 21 wherein the coagulant is selected from EPI/DMA, NH3 crosslinked,
poly(diallyldimethylammonium chloride) and polyaluminum chlorides.
25
23. The method of claim 15 wherein the modifiedN,N-diallyl disubstituted ammonium halide
polymer and the polymer flocculant are added to the thin stock.
29

WO 2006/044735 PCT/US2005/037153
24. The method of claim 15 wherein the modified N,N-diallyl disubstituted ammonium halide ■
polymer is added before the polymer flocculant.
25. The method of claim 15 wherein the modified N,N-diallyl disubstituted ammonium halide
5 polymer is added after the polymer flocculant.
26. The method of claim 15 wherein the modified N,N-diallyl disubstituted ammonium halide
polymer is added to tray water and the polymer flocculant is added to the thin stock line.
10 27. The method of claim 15 wherein the modified N,N-diallyl disubstituted ammonium halide
polymer is added to the dilution head box stream and the polymer flocculant is added to the thin
stock line.
28. The method of claim 15 wherein the modified N,N-diallyl disubstituted ammonium halide
15 polymer is added to the thick stock and the polymer flocculant is added to the thin stock line.
29. The method of claim 15 wherein the modified N,N-diallyl disubstituted ammonium halide
polymer and the polymer flocculant are added simultaneously to the thin stock.
20 30. The method of claim 15 wherein the modified N,N-diallyl disubstituted ammonium halide
polymer and the polymer flocculant are added simultaneously to the dilution headbox stream.

A method of preparing a modified diallyl-N,N-disubstituted ammonium halide
polymer and use of the polymer in combination with one or more high molecular
weight, water soluble cationic, anionic, nonionic, zwitterionic or amphoteric polymers
for increasing retention and drainage in a papermaking furnish.