RU2183646C2 - Aqueous dispersions - Google Patents

Abstract

FIELD: biotechnological methods. SUBSTANCE: invention relates to compositions containing aqueous dispersion, which can be used in biotechnology to dehydrate and purify wastes and which consists of (i) first cationic water-soluble or water-swelling polymer having at least one recurrent motif of formula I:

(I), in which R₁ denotes hydrogen or methyl, A oxygen or imino, B alkylene or branched alkylene or oxyalkylene group having 1 to 5 carbon atoms, R₂ is methyl, ethyl, or propyl group, R₃ alkyl or substituted alkyl group R₄ with 1 to 10 carbon atoms, or aryl or substituted aryl group with 6 to 10 carbon atoms, X denotes counter ion, and R₂, R₃ and R₄ contain in sum at least 4 carbon atoms; (ii) at least one second water-soluble polymer other than the first one; (iii) cosmotropic salt, and (iv) chaotropic or anionic organic salt. Invention also provides other embodiments of aqueous dispersion. EFFECT: lowered bulk viscosity, increased content of active solids, and minimized amount of diluent. 7 cl, 15 tbl, 293 ex

Description

 The invention relates to aqueous dispersions containing water-soluble polymers, methods for producing said dispersions and methods for using said dispersions in water treatment, dehydration, water treatment, paper production, in the oil industry, soil conditioning, food processing, mineral processing and biotechnology.

 US Pat. No. 4,380,600 describes a method for producing an aqueous dispersion of water-soluble polymers. The aqueous dispersion may contain an inorganic salt. However, a disadvantage of the aqueous dispersions given in the examples is the high bulk viscosity.

 In US patent 4673704 and EP 0170394 A2 describes products containing particles of high molecular weight polymer gel with a size of about 20 microns, connected by a continuous, continuous phase, which is an aqueous solution of an emulsifier that maintains the water content of the particles in equilibrium with the water content in the aqueous phase, which prevents agglomeration of particles in a liquid product. Although these patents are called "Aqueous Polymer Dispersions", the products described therein differ from the aqueous dispersions of US Pat. No. 4,380,600 and from the aqueous dispersions of the present invention in that the particles described in US Pat. Nos. 4,673,704 and EP 0170394 are not suspended in a continuous matrix of the aqueous phase, and usually in contact with each other, moving from one phase to another. US patent 4778836 and EP 0169674 B1 describe a method for dispersing a polymer gel in an aqueous solution of an emulsifier and a working polymer. US 4,522,968 describes a method for dispersing certain powdered, water-soluble homopolymers or copolymers in an aqueous solution containing a polymer of ethylene oxide and / or propylene oxide.

 US Pat. Nos. 4,929,655 and 5,006,590 describe methods for preparing aqueous dispersions of water-soluble polymers by polymerization of benzyl-containing monomers in the presence of an organic high molecular weight multivalent cation and a multivalent anionic salt. The monomer containing a benzyl group can be replaced by a hydrophobic monomer containing an alkyl group, as in patent EP 0525751. Numerous references relate to these and similar polymers, for example, US 5332506; 5,332,507; 5,330,650; 5,292,793; 5,435,922; 5,466,338; EP 0 595 156 Al; EP 0 630 909 A1; EP 0 657 478 A2; EP 0 629 583 A2; EP 0 617 991 Al; EP 0 183 466 B1; EP 0 637 598 A2; EP 0 717 056 A2; JP 61-6396; JP 61-6397; JP 61-6398; JP 62-262799; JP 64-15130; JP 2-38131; JP 62 15251; JP 61-138607; Hei 6-329866 and JP 62-100548. Although the aqueous dispersions provided in these references have a relatively low bulk viscosity, in order to make the polymer insoluble in saline, it is necessary to include specific monomers containing aromatic or hydrophobic alkyl groups, which is undesirable since certain monomers can be expensive and weaken the effect of the polymer at a certain application.

Космотропные соли в основном понижают растворимость веществ в воде. Например, в соответствии с рядом "Hofmeister" для осаждения катионных водорастворимых полимеров, содержащих гидрофобные группы, выбирают сильные космотропные соли, содержащие сульфатные и фосфатные анионы, как это использовано в патентах США 4929655 и 5006590 так же, как и в ЕР 0 630 909 А1, ЕР 0 525 751 А1 и ЕР 0 657 478 А2. С другой стороны, хаотропные соли в основном увеличивают растворимость веществ в воде.In the scientific literature, the effect of salts on the solubility of various substances in an aqueous solution is well described. In the Hofmeister series, anions are arranged according to their ability to increase or decrease the solubility of substances in water. Although the position of the anions in the series, depending on the substance, can vary, the most common series of anions is as follows:

Cosmotropic salts generally reduce the solubility of substances in water. For example, in accordance with the Hofmeister series, strong cosmotropic salts containing sulfate and phosphate anions are selected for precipitation of cationic water-soluble polymers containing hydrophobic groups, as used in US Pat. Nos. 4,929,655 and 5,006,590, as well as in EP 0 630 909 A1 , EP 0 525 751 A1 and EP 0 657 478 A2. On the other hand, chaotropic salts mainly increase the solubility of substances in water.

 There are many methods for determining whether a salt is predominantly cosmotropic or chaotropic. Salts containing anions such as sulfate, fluoride, phosphate, acetate, citrate, tartrate and hydrogen phosphate are cosmotropic salts. Salts containing anions such as thiocyanate, perchlorate, chlorate, bromate, iodide, nitrate and bromide are chaotropic. The chloride anion located in the middle of the Hofmeister series is considered either weakly chaotropic or weakly cosmotropic, depending on the characteristics of the system. In the present invention, inorganic salts containing the chloride anion, being sometimes chaotropic, tend to be cosmotropic.

It has been reported that small amounts of sodium thiocyanate, for example, about 0.1% of the total weight, may be useful as stabilizers for polymer dispersions, for example, EP 0 657 478 A2, where (NH ₄ ) ₂ SO _{4 was} used to precipitate the polymer. It has been reported that sodium thiocyanate and sodium iodide are used as stabilizers of hydroxylamine-containing water-soluble polymer systems, as in EP 0 514 649 Al. US Pat. No. 3,234,163 teaches that small amounts of thiocyanate salts, preferably from 0.1 to 1% based on the weight of the polymer, are stabilizers for polyacrylamide solutions.

The Hofmeister series has been studied in solutions of high molecular weight water soluble polymers. The effect of various salts on the solubility of synthetic water-soluble polymers was investigated, for example, Shuji Saito, J. Polym. Sci .: Pt. A, Vol. 7, pp. 1789-1802 (1969). The author studied the effect of various anions on the solubility of polymers and argues that "This sequence of anions, apparently, does not depend on the type of opposite cations and is in accordance with the lyotropic series of Hofmeister anions. It was similarly found that the viscosity of polyacrylamide, defined in 1 N solution of various salts, increases in the order HPO ₄ ^2- <H ₂ O <Br ^- <NO ₃ ^- <I ^- = BrO ₃ ^- <ClO ₃ ^- = SCN ^- (M. Leca, Polymer Bulletin, Vol.16, pp .537-543, 1986). It is reported that the viscosity in solutions of a more chaotropic salt is higher than the viscosity in solutions of a less chaotropic or cosmotropic It has also been reported that some new cationic polyelectrolytes, also called ionic polymers, are insoluble in either 0.4 M potassium iodide or 0.4 M potassium thiocyanate (D. Casson and A. Rembaum Macromoleculs, Vol. 5, 1, 1972, pp. 75-81). It has also been reported (WF. Lee and CC. Tsai, J.AppI.Polym.Sci., Vol.52, pp. 1447-1458, 1994) that poly (trimethylacrylamidopropyl ammonium iodide ) does not dissolve in 0.5 M Na ₂ ClO ₄ or 0.5 M NaNO ₃ .

 Some anionic organic salts, such as hydrotropic salts or surfactants, also tend to increase the solubility of substances in water. However, there are reports that poly (allylammonium chloride) precipitates in solutions containing the sodium salt of p-ethylbenzene sulfonate, p-propylbenzenesulfonate or naphthalenesulfonate. Poly (4-vinylpyridine) quaternized with butyl chloride and poly (allylammonium chloride) are precipitated from NaI solutions (M. Satoh, E. Yoda and J. Komiyama, Macromolecules, Vol.24, pp. 1123-27, 1991) and solutions containing p-ethylbenzenesulfonate sodium salt. US Pat. No. 5,130,358 describes compositions containing hydrocarbon sulfonate surfactants and hydrophilic cationic polymers. Mixtures of chaotropic salts or anionic organic salts and cosmotropic salts can be used to precipitate cationic polymers (US application (attorney reference number 96052) with the same filing date as this application).

 Aqueous dispersions of water-soluble polymers are described in US patents 5,403,883; 5,480,934; 5,541,252; EP 0 573 793 A1 and WO 95/11269. The problem remains that the aqueous dispersions cited in these references have a relatively high bulk viscosity.

 US Pat. Nos. 5,498,678 and EP 0 604 109 A2 describe a method for preparing structured copolymer beads from aqueous solutions of water-soluble monomers also containing an inorganic salt and dispersant. Hei 7-62254 and Hei 6-25540 describe mixtures of aqueous dispersions and water-in-oil emulsions. US Pat. No. 5,045,587 describes the addition of a neon surfactant and an oily liquid to an aqueous dispersion to maintain fluidity. Sho-52-71392 describes mixtures of cationic polymers and US Pat. Nos. 4,835,206 and EP 0,262,945 B1 describe homogeneous mixtures of water-soluble polymers. US Pat. Nos. 4,588,508 and 4,699,951 describe bimodal cationic polymers for water purification. US patent application Serial 08 / 408,743 describes water-in-oil emulsion mixtures.

 Despite attempts to create satisfactory aqueous dispersions, the problem remains of creating aqueous dispersions of high molecular weight water-soluble polymers with a low bulk viscosity, a high content of active solids, and a minimum amount of diluent that dissolves quickly and can be prepared with various cations.

 This problem is solved in the present invention regarding new aqueous dispersions of high molecular weight water-soluble or water-swellable polymers, as well as methods for their preparation and methods of using these aqueous dispersions. Accordingly, the aqueous polymer dispersion comprises: (a) a first cationic water-soluble or water-swellable polymer; (b) at least one second water-soluble polymer other than the first specified polymer; (c) a cosmotropic salt; and (d) a chaotropic salt, where the amounts of the components indicated in (b), (c) and (a) are such that, in the absence of component (b), a homogeneous composition is obtained. Another object of the invention is an aqueous dispersion of polymers containing: (a) a first cationic water-soluble or water-swellable polymer; (b) at least one second water-soluble polymer other than the first specified polymer; (c) a cosmotropic salt; and (d) a chaotropic salt, where the amounts of the components indicated in (b), (c) and (d) are such that, in the absence of component (b), a homogeneous composition is obtained.

 Another object of the invention is also an aqueous dispersion of polymers containing (a) a discrete phase containing a polymer comprising mainly a first cationic water-soluble or water-swellable polymer having at least one repeating unit of formula (I).

где R₁ представляет Н или СН₃, А представляет O или NH, В представляет алкиленовую или разветвленную алкиленовую или оксиалкиленовую группу, имеющую от одного до пяти атомов углерода, R₂ представляет метильную, этильную или пропильную группу, R₃ представляет метильную, этильную или пропильную группу, R₄ представляет метильную, этильную или пропильную группу, Х представляет противоион и R₂, R₃ и R₄ вместе содержат в сумме по крайней мере 4 атома углерода; и (b) по крайней мере один второй водорастворимый полимер, отличный от первого указанного полимера.

where R ₁ represents H or CH ₃ , A represents O or NH, B represents an alkylene or branched alkylene or oxyalkylene group having from one to five carbon atoms, R ₂ represents a methyl, ethyl or propyl group, R ₃ represents methyl, ethyl or a propyl group, R ₄ represents a methyl, ethyl or propyl group, X represents a counterion, and R ₂ , R ₃ and R ₄ together contain a total of at least 4 carbon atoms; and (b) at least one second water-soluble polymer, different from the first specified polymer.

Another object of the invention is an aqueous polymer dispersion containing (a) a first cationic water-soluble or water-swellable polymer having at least one repeating unit of formula (I), where R ₁ represents H or CH ₃ , A represents O or NH, B represents alkylene or a branched alkylene or oxyalkylene group having from one to five carbon atoms, R ₂ represents a methyl, ethyl or propyl group, R ₃ represents a methyl, ethyl or propyl group, R ₄ represents an alkyl or substituted an alkyl group having from 1 to 10 carbon atoms, or an aryl or substituted aryl group having from 6 to 10 carbon atoms, X represents a counterion and R ₂ , R ₃ and R ₄ together contain at least 4 carbon atoms in total; and (b) at least one second water-soluble polymer other than the first polymer, wherein in the absence of component (b) a homogeneous composition is obtained.

 Another object of the invention is also a method for producing an aqueous dispersion of polymers, comprising polymerizing vinyl-containing monomers to form an aqueous dispersion comprising a first cationic water-soluble or water-swellable polymer, wherein said polymerization is carried out in the presence of an aqueous composition comprising (a) at least one second water-soluble polymer, excellent from the first specified polymer; (b) a cosmotropic salt; and (c) a chaotropic salt, wherein the amounts of the components indicated in (a), (b) and (c) are such that, when polymerization is carried out in the absence of component (a), a homogeneous composition is obtained.

 Another object of the invention is also a method for producing an aqueous dispersion of polymers, comprising polymerizing vinyl-containing monomers to form an aqueous dispersion comprising a first cationic water-soluble or water-swellable polymer, wherein said polymerization is carried out in the presence of an aqueous composition comprising (a) at least one second water-soluble polymer, excellent from the first specified polymer; (b) a cosmotropic salt; and (c) an anionic organic salt, wherein the amounts of the components indicated in (a), (b) and (c) are such that, when polymerization is carried out in the absence of component (a), a homogeneous composition is obtained.

где R₁ представляет Н или СН₃, А представляет О или NH, В представляет алкиленовую или разветвленную алкиленовую или оксиалкиленовую группу, имеющую от одного до пяти атомов углерода, R₂ представляет метильную, этильную или пропильную группу, R₃ представляет метильную, этильную или пропильную группу, R₄ представляет метильную, этильную или пропильную группу, Х представляет противоион и R₂, R₃ и R₄ вместе содержат в сумме по крайней мере 4 атома углерода; и где указанную полимеризацию осуществляют в присутствии водной композиции, содержащей по крайней мере один второй водорастворимый полимер, отличный от первого названного полимера.Another object of the invention is also a method of producing an aqueous dispersion of polymers, which comprises the polymerization of vinyl additive monomers containing at least one monomer of the formula (II), with the formation of an aqueous dispersion containing the first cationic water-soluble or water-swellable polymer,

where R ₁ represents H or CH ₃ , A represents O or NH, B represents an alkylene or branched alkylene or oxyalkylene group having from one to five carbon atoms, R ₂ represents a methyl, ethyl or propyl group, R ₃ represents methyl, ethyl or a propyl group, R ₄ represents a methyl, ethyl or propyl group, X represents a counterion, and R ₂ , R ₃ and R ₄ together contain a total of at least 4 carbon atoms; and where the specified polymerization is carried out in the presence of an aqueous composition containing at least one second water-soluble polymer, different from the first named polymer.

Another object of the invention is also a method of producing an aqueous dispersion of polymers, which comprises the polymerization of vinyl additive monomers containing at least one monomer of the formula (II), with the formation of an aqueous dispersion containing a first cationic water-soluble or water-swellable polymer, where R ₁ represents H or CH _3, A is O or NH, B is an alkylene or branched alkylene or oksilalkilenovuyu group having from one to five carbon atoms, R ₂ represents a methyl, ethyl or propyl Rupp, R ₃ represents methyl, ethyl or propyl group, R ₄ represents an alkyl or substituted alkyl group having from 1 to 10 carbon atoms, or an aryl or substituted aryl group having from 6 to 10 carbon atoms, X is a counterion and R ₂ , R ₃ and R ₄ together contain a total of at least 4 carbon atoms; and where the specified polymerization is carried out in the presence of an aqueous composition containing at least one second water-soluble polymer in an amount different from the first specified polymer; and wherein said amount of said second polymer is such that a homogeneous composition is obtained if said polymerization is carried out in the absence of said second polymer.

 Another object of the invention is also a method of mixing two or more aqueous dispersions, comprising mixing (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 dispersion (a) differs from said dispersion (b) , with the formation of a third aqueous dispersion.

 Another object of the invention is a method for dewatering a suspension of dispersed solid particles, which comprises (a) mixing an aqueous dispersion of polymers or their aqueous impurities in an effective amount for dehydration with a suspension of dispersed solid particles and (b) dewatering said suspension of dispersed solid particles, wherein said aqueous dispersion includes (i) a first cationic water soluble or water swellable polymer; (ii) at least one second water-soluble polymer other than the first polymer; (iii) a cosmotropic salt; and (iv) a chaotropic salt, where the amounts of the components indicated in (ii), (iii) and (iv) are such that in the absence of component (ii) a homogeneous composition is obtained.

 Another object of the invention is a method for dewatering a suspension of dispersed solid particles, which comprises (a) mixing an aqueous dispersion of polymers or their aqueous impurities in an effective amount for dehydration with a suspension of dispersed solid particles and (b) dewatering said suspension of dispersed solid particles, wherein said aqueous dispersion includes (i) a first cationic water soluble or water swellable polymer; (ii) at least one second water-soluble polymer other than the first polymer; (iii) a cosmotropic salt; and (iv) an anionic organic salt, wherein the amounts of the components indicated in (ii), (iii) and (iv) are such that in the absence of component (ii) a homogeneous composition is obtained.

Another object of the invention is a method for dewatering a suspension of dispersed solid particles, which comprises (a) mixing an aqueous dispersion of polymers or their aqueous impurities in an effective amount for dehydration with a suspension of dispersed solid particles and (b) dewatering said suspension of dispersed solid particles, wherein said aqueous dispersion contains (i) a dispersed phase containing a polymer comprising essentially a first cationic water-soluble or water-swellable polymer having at least a repeating unit of the formula (I), wherein R ₁ represents H or CH _3, A is O or NH, B is an alkylene or branched alkylene or oxyalkylene group having from one to five carbon atoms, R ₂ represents methyl, ethyl or propyl group , R ₃ represents a methyl, ethyl or propyl group, R ₄ represents a methyl, ethyl or propyl group, X represents a counterion and R ₂ , R ₃ and R ₄ together contain at least 4 carbon atoms in total; and (ii) at least one second water-soluble polymer, different from the first specified polymer.

Another object of the invention is a method for dewatering a suspension of dispersed solid particles, which comprises (a) mixing an aqueous dispersion of polymers or their aqueous impurities in an effective amount for dehydration with a suspension of dispersed solid particles and (b) dewatering said suspension of dispersed solid particles, wherein said aqueous dispersion comprises (i) a first cationic water-soluble or water-swellable polymer having at least one recurring unit of the formula (i), wherein R ₁ represents H Is CH, A is O or NH, B is an alkylene or branched alkylene or oxyalkylene group having from one to five carbon atoms, R ₂ represents methyl, ethyl or propyl group, R ₃ represents methyl, ethyl or propyl group, R ₄ represents an alkyl or substituted alkyl group having from 1 to 10 carbon atoms, or an aryl or substituted aryl group having from 6 to 10 carbon atoms, X represents a counterion and R ₂ , R ₃ and R ₄ together contain at least 4 atoms in total carbon; and (ii) at least one second water-soluble polymer, different from the first specified polymer, where in the absence of component (ii) a homogeneous composition is obtained.

Another object of the invention is a method for producing substantially dry water-soluble or water-swellable vinyl additive polymer particles, comprising (a) spray drying an aqueous dispersion containing a vinyl additive polymer in a gas stream for about 8 to 120 s and an outlet temperature of about 70 to 150 ^{° C.} and (b) collecting the obtained polymer particles.

Another subject of the invention are also substantially dry, water-soluble or water-swellable polymer particles, comprising (a) a first cationic water-soluble or water-swellable polymer; (b) at least one second water-soluble polymer other than said first polymer; (c) a cosmotropic salt and (a) a chaotropic salt, wherein in about 90% or more of said polymer particles, each individual particle contains both said component (a) and said component (b), said particles have a bulk density of from about 0, 4 to about 1.0 g / cm ³ .

Another object of the invention is also a method comprising (a) mixing a composition comprising predominantly dry water-soluble or water-swellable polymer particles containing (i) a first cationic water-soluble or water-swellable polymer, (ii) at least one second water-soluble polymer other than said first polymer , (iii) a cosmotropic salt and (iv) a chaotropic salt, wherein in about 90% or more of said polymer particles, each individual particle contains both said component (i) and said component ( ii) said particles have a bulk density of from about 0.4 to about 1.0 g / cm ³ with water to form an aqueous polymer mixture, (b) mixing said aqueous polymer mixture in an effective dehydration amount with a suspension of dispersed solid particles, and (c) dewatering said suspension of dispersed solid particles.

Another object of the invention is also a method comprising (a) mixing a composition comprising predominantly dry water-soluble or water-swellable polymer particles containing (i) a first cationic water-soluble or water-swellable polymer, (ii) at least one second water-soluble polymer other than said first polymer , (iii) a cosmotropic salt and (iv) an anionic organic salt, wherein in about 90% or more of said polymer particles, each individual particle contains both said component (i) and said component (ii), said particles have a bulk density of from about 0.4 to about 1.0 g / cm ³ , with water to form an aqueous polymer mixture, (b) mixing said aqueous polymer mixture in an effective dehydration amount with a suspension of dispersed solid particles; and (c) dewatering said suspension of dispersed solid particles.

Another object of the invention is also a method comprising (a) mixing a composition comprising predominantly dry water-soluble or water-swellable polymer particles containing (i) a first cationic water-soluble or water-swellable polymer having at least one repeating unit of formula (I), where R ₁ represents H or CH ₃ , A represents O or NH, B represents an alkylene or branched alkylene or oxyalkylene group having from one to five carbon atoms, R ₂ represents methyl, ethyl or propyl R ₃ represents a methyl, ethyl or propyl group, R ₄ represents an alkyl or substituted alkyl group having from 1 to 10 carbon atoms, or an aryl or substituted aryl group having from 6 to 10 carbon atoms, X represents a counterion and R ₂ , R ₃ and R ₄ together contain a total of at least 4 carbon atoms; and (ii) at least one second water-soluble polymer other than the first specified polymer, wherein in about 90% or more of said polymer particles, each individual particle contains both said component (i) and said component (ii), said particles have bulk density from about 0.4 g / cm ³ to about 1.0 g / cm ³ , with water to form an aqueous polymer mixture, (b) mixing the specified aqueous polymer mixture in an effective dehydration amount with a suspension of dispersed solid particles and (c a) dehydration of the decree hydrochloric suspension of dispersed solids.

где R₁ представляет Н или СН₃, А представляет О или NH, В представляет алкиленовую или разветвленную алкиленовую или оксиалкиленовую группу, имеющую от одного до пяти атомов углерода, R₂ и R₃ каждый независимо представляет метильную, этильную или пропильную группу, R₄ представляет алкильную или замещенную алкильную группу, имеющую от 1 до 10 атомов углерода, или арильную или замещенную арильную группу, имеющую от 6 до 10 атомов углерода, Х представляет противоион и R₂, R₃ и R₄ вместе содержат в сумме по крайней мере 4 атома углерода, преимущественно по крайней мере 5 атомов углерода. В некоторых случаях R₄ преимущественно представляет метильную, этильную или пропильную группу. В других случаях R₄ преимущественно представляет алкильную или замещенную алкильную группу, имеющую от 1 до 10 атомов углерода. В других случаях R₄ преимущественно представляет бензил. Х преимущественно представляет хлорид, бромид, иодид, метилсульфат или этилсульфат.The aqueous dispersions of the present invention comprise a first cationic water-soluble or water-swellable polymer, preferably a vinyl additive polymer. The cationic charge of the first said cationic polymer can vary over a wide range due to the cationic repeating units, which can vary from about 1% to about 100%, preferably about 5% or more, more preferably about 10% or more, even more preferably about 20 % and above, more preferably about 30% or more, mainly about 100% or less, more preferably about 80% or less, more preferably about 70% or less with respect to all moles of repeating units in p First cationic polymer indicated. Cationic repeating units can be obtained by subsequent reaction of the polymer, but it is more preferable to obtain them by polymerization of cationic monomers. Cationic monomers can include any cationic monomer, including diallyldialkylammonium halide, cationic (meth) acrylates and cationic (meth) acrylamides commonly used in the preparation of water-soluble polymers, mainly diallyldimethylammonium halide, as well as the acid and quaternary salts of dialkylaminoalkyl (alk) and alkyl (alk) acrylamide. Cationic repeating units can be prepared by polymerizing quaternizable monomers, such as dialkylaminoalkyl (alk) acrylate and dialkylaminoalkyl (alk) acrylamide, followed by acidification or quaternization. Most preferably, the first cationic polymer contains cationic repeating units of formula (I), preferably obtained by polymerization of the corresponding monomers of formula (II):

where R ₁ represents H or CH ₃ , A represents O or NH, B represents an alkylene or branched alkylene or oxyalkylene group having from one to five carbon atoms, R ₂ and R ₃ each independently represents a methyl, ethyl or propyl group, R ₄ represents an alkyl or substituted alkyl group having from 1 to 10 carbon atoms, or an aryl or substituted aryl group having from 6 to 10 carbon atoms, X represents a counterion and R ₂ , R ₃ and R ₄ together contain at least 4 in total carbon atom, preferably at least 5 carbon atoms. In some cases, R ₄ predominantly represents a methyl, ethyl or propyl group. In other instances, R ₄ preferably represents an alkyl or substituted alkyl group having from 1 to 10 carbon atoms. In other instances, R _{4 is} preferably benzyl. X is preferably chloride, bromide, iodide, methyl sulfate or ethyl sulfate.

 The first cationic water-soluble or water-swellable polymer may be a copolymer and contain other cationic or non-ionic repeating units. Non-ionic repeating units can be obtained from water-soluble monomers, such as N-vinyl pyridine, N-vinyl pyrrolidone, hydroxyalkyl (meth) acrylates, etc., mainly (meth) acrylamide, or can be formed from hydrophobic monomers having a low solubility in water, until the inclusion of low solubility in water, i.e. hydrophobic, repeating units will not turn the resulting polymer into a water-insoluble or water-swellable polymer. The number of repeating units of water-soluble non-ionic monomers contained in the first cationic polymer may be from 0% to about 99%, preferably about 10% or more, more preferably about 20% or more, more preferably about 30% or more; preferably about 90% or less, more preferably about 80% or less, more preferably about 70% or less with respect to all moles of repeating units in said polymer. Hydrophobic monomers may be hydrocarbon monomers, i.e. styrene, butadiene, 1-alkene, vinylcyclohexane, etc., other vinyl monomers such as vinyl halide, other mainly aliphatic or aromatic compounds with polymerizable double bonds or monomers having an average solubility in water, such as acrylonitrile. The hydrophobic monomers are predominantly alkyl (alk) acrylates or aryl (alk) acrylates in which the alkyl or aryl groups contain 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 alkyl or aryl groups contain about 1-12 carbon atoms, such as methyl (meth) acrylamide, ethyl (meth) acrylamide, tert-butyl (meth) ac rilamide, dimethyl (meth) acrylamide, hexyl (meth) acrylamide, ethylhexyl (meth) acrylamide, isoalkyl (meth) acrylamide, cyclohexyl (meth) acrylamide or aromatic (meth) acrylamide. In the first cationic water-soluble or water-swellable polymer, the amounts of hydrophobic nonionic repeating units can be from 0 to about 15%, preferably from about 2 to about 10%, with respect to all moles of repeating units in said polymer. Despite the fact that hydrophobic repeating units in some cases can weaken the effect of the polymer, their incorporation into the polymer in controlled amounts has a beneficial effect on the specific characteristics of the aqueous dispersion, i.e. degree of solubility, bulk viscosity, cost, ease of processing, operation, etc. To achieve the effect, depending on the specifics of the implementation, it is desirable that the polymer does not contain hydrophobic repeating units or contain them in a certain selected amount.

 Considering the effect of solids on bulk viscosity, the amount of the first cationic water-soluble or water-swellable polymer is preferably above 5% or more, preferably about 10% or more, more preferably about 20% or more relative to the total weight of the aqueous dispersion. Basically, the amount of solid particles does not exceed such an amount that increases bulk viscosity to an undesirable level. In practice, the amount of the first cationic polymer in the aqueous dispersion is about 75% or less, preferably about 60% or less, more preferably about 50% or less, based on the total weight. The weight average molecular weight of the first cationic polymer in the aqueous dispersion is not critical and depends on the particular application, but generally it is higher than about 1,000,000, mostly higher than about 2,000,000, more mainly higher than about 5,000,000 and most mainly higher than about 10,000,000.

 The molecular weights of the polymers are weight average and can be determined by known methods, mainly using light scattering.

 The aqueous dispersions of the present invention mainly comprise a discrete phase of small water droplets containing a polymer that includes a predominantly first cationic water-soluble or water-swellable polymer that are dispersed in a continuous aqueous phase, although trace amounts of the first polymer can be detected in the continuous phase. Basically, the first cationic water-soluble or water-swellable polymer comprises more than 50%, preferably more than 70%, of the polymer contained in a shallow water droplet. The amount of the first cationic polymer in discrete and continuous phases can be determined using known methods of analysis, for example, using Raman microscopy. Although large aqueous droplets or gel particles can be obtained by adding a dry or gel polymer to other components, as is done in US Pat. Nos. 4,673,704 or EP 0 170 394 A2, aqueous dispersions of the present invention are more preferred since it is desirable that the first cationic the polymer was in the form of small droplets that were suspended in a continuous matrix of the aqueous phase and essentially did not contact each other. Although the aqueous dispersions obtained by the monomer polymerization method described herein can sometimes have an average droplet size of about 30 microns or more, basically the average droplet size is less than 30 microns, preferably less than 20 microns, more preferably less than 15 microns or less. The size of the nonspherical droplet is determined by the length along the main axis. The size and shape of the droplet depend on the reaction conditions, such as stirring speed, reactor shape, type of stirrer, etc. The size of the droplets is determined by polymerization in the presence of one or more insoluble polymer seeds, while these polymer seeds are insoluble in an aqueous solution containing an inorganic salt at the same concentration as the specified aqueous dispersion.

 The aqueous dispersions of the present invention comprise a second water-soluble polymer, preferably a vinyl additive polymer, which is different and mostly incompatible with the first water-soluble or water-swellable cationic polymer. The second polymer is considered different from the first polymer if it has different individual physical characteristics from the first, i.e., composition, charge, molecular weight, molecular weight distribution, distribution of repeating units along the polymer chain, etc., determined by known methods, for example, spectroscopy, chromatography, etc. The second polymer is considered incompatible with the first polymer when the solutions of two polymers at the concentrations in which they are contained in the aqueous dispersion do not form a homogen th mixture by mixing or do not form a homogeneous mixture in the formation of a polymer by polymerizing the monomers in the presence of another polymer. In the aqueous dispersion of the present invention, the second predominantly cationic water-soluble polymer is dissolved in the continuous aqueous phase, although trace amounts thereof can be detected in the discrete phase. The amount of the second polymer in discrete and continuous phases can be determined by known analytical methods, for example, by Raman microscopy. The second polymer may be any non-ionic water-soluble polymer, preferably polyalkylene oxide, polyvinyl alcohol, polyvinyl pyridine, polyvinyl pyrrolidone, polyhydroxyalkyl (alk) acrylate, etc., more preferably poly (meth) acrylamide. Most preferably, the second water soluble polymer is a cationic polymer. The second polymer can be any cationic polymer and its charge can vary over a wide range by varying the content of cationic repeating units from about 1 to about 100%, preferably about 10% or more, more preferably about 20% or more, even more preferably about 30% or more with respect to all moles of repeating units in the specified polymer. Although in some cases the second cationic polymer may contain about 70% or less, or even about 50% or less of cationic repeating units, preferably the second polymer is substantially cationic, i.e. contains more than 50% cationic repeating units in relation to all moles of repeating units in the specified polymer; more preferably about 80% or more repeating cationic units. Cationic repeating units can be obtained by polymerization of cationic monomers or a subsequent polymer reaction as described above, and can be a copolymer containing other cationic repeating units or non-ionic repeating units, as described above. The second cationic water-soluble polymers predominantly contain repeating units of diallyldialkylammonium halide, chloromethyl quaternary salt of dialkylaminoalkyl (alk) alkrylalkylalkylaminoalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylaminoalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkylalkyl ) acrylamide. It is particularly preferred that the second cationic water-soluble polymers contain repeating units of diallyldimethylammonium chloride, dimethylaminoethyl (meth) acrylate chloromethyl quaternary salt or dimethylaminoethyl methacrylate dimethyl sulfate quaternary salt. One or more second cationic polymers may be used.

 Depending on the particular application, to ensure maximum cationic charge density of the aqueous dispersion, it is preferred that the second polymer be cationic. In specific embodiments of the invention, in the presence of salt, it is desirable that the second polymer be cationic, because in a saline solution, cationic polymers are often more soluble than non-ionic polymers.

 The amount of the second, mainly cationic, water-soluble polymer contained in the aqueous dispersion controls the properties of this dispersion, i.e. performance characteristics, bulk viscosity, charge, molecular weight, dissolution coefficient, physical stability, e.g. solidification, etc. Basically, the amount of said second polymer is about 5% or more, preferably about 10% or more, more preferably about 20% or more, most preferably about 30% or more relative to the weight of the first cationic water-soluble polymer. In practice, the amount of the second water-soluble polymer in the aqueous dispersion is 100% or less, preferably about 80% or less, more preferably about 50% or less, relative to the weight of the first cationic water-soluble polymer. In some preferred embodiments of the invention, the amounts of the first and second polymers are effective for forming an aqueous dispersion. In some cases, in the absence of a second polymer, an aqueous dispersion is not formed and instead a homogeneous composition is formed. In practice, the amount of the first and second polymer is found experimentally, usually various standard quantities are used depending on the individual properties of the first and second polymers, the total polymer solids content, bulk viscosity, price, ease of preparation, product characteristics, etc.

 The weight average molecular weight of the second water-soluble polymer contained in the aqueous dispersion is selected to provide the most desired effect, i.e. bulk viscosity, performance, price, etc., but generally above about 10,000, more preferably above about 1,000,000. The molecular weights of the polymers are weight average and can be determined by known methods, mainly by light scattering. The second water-soluble polymer is mainly in the continuous phase of the aqueous dispersion, although trace amounts thereof may also be present in dispersed droplets. Advantageously, the aqueous dispersions of the present invention are heterogeneous compositions in which more than 50%, mainly about 75% or more, of the first cationic water-soluble or water-swellable polymer are in the form of a dispersed phase of water droplets that are dispersed in an aqueous solution that contains more than 50%, mainly about 75% or more of a second, mainly cationic, water soluble polymer.

 The aqueous dispersions of the present invention may contain a third water-soluble or water-swellable polymer, which is different from the first or second polymers. For example, the third polymer may also be contained in droplets dispersed in an aqueous solution, as described above for the first cationic polymer. The third polymer may also be dissolved in an aqueous solution along with the second polymer, as described above for the second polymer. Advantageously, the third polymer is cationic.

 A third aqueous dispersion containing three or more polymers can be obtained by mixing the first and second aqueous dispersions of the present invention, where the first and second aqueous dispersions are different from each other. Mixing is carried out by stirring using a conventional mixer. Mixing is useful for balancing the properties inherent in individual aqueous dispersions, i.e. operational properties, charge, content of solid polymer particles, price, molecular weight, etc. Unexpectedly, in many cases, the mixtures are stable, that is, they remain in the form of aqueous dispersions having a low bulk viscosity, i.e., lower than 10,000 cP, for a week or more, even when the level of the salt or the second polymer in the mixture is significantly different from the level necessary to obtain a stable one or more dispersed polymers. Also unexpectedly, the bulk viscosity of the mixture is often lower than the bulk viscosity of any of the individual aqueous dispersions.

 The molecular weight of the aqueous dispersion, as used in the present invention, is simply the weight average molecular weight of the polymers contained therein, obtained by determining the total dispersion of the corresponding molecular weight using, for example, light scattering. Since the aqueous dispersion contains two or more different polymers, each of which may have a different molecular weight and a different molecular weight distribution, the molecular weight distribution of the aqueous dispersion can be multimodal. The molecular weight of the aqueous dispersion is generally about 1,000,000 or more, preferably more than 2,000,000, more preferably about 3,000,000 or more, most preferably about 5,000,000 or more.

In some cases, it may be more convenient to characterize the aqueous dispersion through standard viscosity instead of molecular weight. As used here, "standard viscosity" is defined as follows: the aqueous dispersion is diluted with water to form an aqueous mixture (in the case of a water-swellable polymer) or an aqueous solution (in the case of a water-soluble polymer) with a polymer concentration of about 0.2%; 8.0 g of this mixture or solution are mixed together with 8.6 g of 2M NaCl; measure the viscosity of the mixture at 25 ^o With a rotary cylindrical viscometer, i.e. on a Brookfield viscometer equipped with a UL adapter at 60 rpm. The standard viscosities of the aqueous dispersions of the present invention are generally about 1.5 cP or higher, preferably about 1.8 cP or higher, more preferably about 2.0 cP or higher, more preferably about 2.5 cP, depending on the particular application.

 The aqueous dispersions of the present invention can be mixed with water-in-oil emulsions or with water-soluble polymer microemulsions to form compositions that, although they contain oil, contain less oil than the water-in-oil emulsions or microemulsions from which they are made. Therefore, these compositions can give less side pollution, have a lower flammability, etc.

 In some cases of the present invention, salt is required. Effective amounts of salt reduce the bulk viscosity of the aqueous dispersion. The salt may be any inorganic salt, preferably a cosmotropic salt, i.e. chloride, sulfate, phosphate or hydrophosphate salt, more preferably ammonium sulfate, sodium chloride and sodium sulfate, more preferably sodium sulfate and ammonium sulfate. The counterion can be any opposite ion, for example, metal ions of groups IA and IIA, ammonium ion, etc., mainly ammonium, sodium, potassium and magnesium. You can use a mixture of salts, and to achieve the desired bulk viscosity or any other desired effect, choose the appropriate amount of salt. Since the salt can have a weakening effect, in some advantageous embodiments of the invention, the salt is added in such quantities as to achieve a homogeneous composition in the absence of a second water-soluble polymer. In these cases, an aqueous dispersion is formed not under the influence of salt, but due to the interaction of the first and second polymers. Effective or viscosity-reducing amounts of salt can be determined experimentally and are generally chosen in such a way as to reduce bulk viscosity without polymer precipitation. In other cases, the salt can be added only in such quantities as are necessary to achieve homogeneity of the composition in the absence of the first cationic polymer. In cases where the salt is useful but not necessary, the salt level may be higher than 0%, preferably about 3% or higher, more preferably about 5% or higher with respect to the total weight, depending on the solubility of the salt in the aqueous dispersion. In cases where the presence of salt is necessary, its amount is chosen so as to beneficially affect the properties of the product, such as price, bulk viscosity, etc. and may fluctuate above 1%, preferably about 3% or more, more preferably about 5% or more with respect to the total weight, depending on the solubility of the salt in the aqueous dispersion. Often the undesirable effect of salt is observed when its content is above 30%, so the salt level is mainly about 30% or less, mainly about 25% or less, relative to the total weight. In practice, the salt level is determined experimentally, i.e. comparing the positive properties of the product, such as low bulk viscosity with high salt content, with the negative aspects of the presence of salt, such as price and dilution effect.

It has been unexpectedly found that mixtures of chaotropic salts with cosmotropic salts or anionic organic salts with cosmotropic salts tend to reduce the bulk viscosity of the aqueous dispersion. In many cases, salt mixtures are more effective than using a single salt. Useful chaotropic salts include thiocyanates, perchlorates, chlorates, nitrates, bromides, iodides and mixtures thereof, mainly sodium thiocyanate and sodium iodide. Useful Anionic Organic Salts
include anionic surface-active and anionic hydrotropic salts, mainly aryl and substituted aryl sulfonates, having from 6 to 22 carbon atoms, mainly from 6 to 18 carbon atoms, and alkyl and substituted alkyl sulfonates, having from 2 to 22 carbon atoms, preferably from 4 to 18 carbon atoms, and mixtures thereof. Particularly preferred anionic organic salts are dialkyl sulfosuccinates, diaryl sulfosuccinates, benzenesulfonates, benzenesulfonates, naphthalenesulfonates, naphthalene disulfates and mixtures thereof; 1,3-benzenesulfonates are most preferred. The counterions for chaotropic and anionic organic salts can be any ordinary opposing ions, i.e. metal ions of group IA, ammonium ions, etc. , mainly ions of ammonium, sodium and potassium. Effective or viscosity-reducing amounts of chaotropic and anionic organic salts can be determined experimentally and are generally selected so as to reduce bulk viscosity without polymer precipitation. In some amounts of a chaotropic salt or an anionic organic salt and cosmotropic salt, they are chosen such as to obtain a homogeneous composition in the absence of a second cationic polymer; i.e., the salt concentration is such that the first cationic polymer does not precipitate in the absence of a second cationic polymer. Basically, the amount of chaotropic or anionic organic salts is about 10% or less, mainly about 5% or less, and mostly 0.5% or more, mainly 1% or more, relative to the total weight. At a very low content of a chaotropic or anionic organic salt, the effect of viscosity reduction is negligible, while at a high level of concentration, the salt can cause unwanted precipitation or separation. To achieve a certain bulk viscosity, the amount of cosmotropic salts used together with a chaotropic and anionic organic salt is generally lower than the amount of a single cosmotropic salt used, but remains within the limits indicated above for the case of using single inorganic or cosmotropic salts.

The aqueous dispersions of the present invention have a bulk viscosity that is lower than the bulk viscosity of similar comparable dispersions. A comparable aqueous dispersion is one that is identical to the dispersion of the present invention in many functional aspects, but does not have the specific elements inherent in the dispersion of the present invention. The bulk viscosities of aqueous dispersions of the present invention are generally lower than the bulk viscosities of comparable aqueous dispersions that contain predominantly the same solid polymer particles, have the same cationic charge and weight average molecular weight, but do not have important features of the dispersions of the present invention, i.e. . do not have a repeating unit of formula (I); do not contain repeating units of formula (I) in the amount in which they are contained in the aqueous dispersions of the present invention; cannot be obtained by a method comprising the polymerization of vinyl additive monomers containing at least one monomer of the formula (II); cannot be obtained by a method involving the polymerization of vinyl additive monomers containing the same amount of monomers of formula (II) that is used in the processes of the present invention, etc. For example, a composition comprising an aqueous dispersion comprises: (a) a dispersed phase containing a polymer that comprises primarily a first cationic water-soluble or water-swellable polymer having at least one repeating unit of 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 that the radicals R _2, R ₃ and R ₄ in the corresponding recurring unit of formula (I) with avnimoy aqueous dispersion together contain three carbon atoms in place of 4 or more carbon atoms in the corresponding recurring unit of formula (I) of the claimed aqueous dispersion.

It was unexpectedly found that aqueous dispersions having repeating units of formula (I) in which R ₂ , R ₃ and R ₄ contain 4 or predominantly 5 carbon atoms have bulk viscosities that are substantially lower than bulk viscosities of identical aqueous dispersions, except that R ₂ , R ₃ and R ₄ contain only 3 carbon atoms. The volumetric viscosity of aqueous dispersions is usually influenced, for example, by the sum of the polymer solid particles, the salt content, the type of polymer, the ratio of the first cationic polymer to the second cationic polymer, etc., as indicated here. Although in some cases, aqueous dispersions having a bulk viscosity of about 20,000 cP or more or even about 200,000 cP or more may be suitable, for ease of handling and use, aqueous dispersions with significantly lower bulk viscosities are preferred. In accordance with the present invention, aqueous dispersions having bulk viscosities of about 20,000 cP or less, preferably about 10,000 cP or less, more preferably about 8,000 cP or less, even more preferably about 5,000 cP or less, most preferably about 2,500 cP, can be obtained in practice. Bulk viscosity can be measured by a conventional method known in the art, preferably on a rotary cylindrical viscometer, as described in the examples below.

The most preferred aqueous dispersions are those which have as many of the following beneficial properties as possible: a relatively high solids content of the cationic polymer, preferably 20% or more, more preferably 25% or more with respect to the total weight; high molecular weight, preferably 2,000,000 or more, more preferably 5,000,000 or more; low environmental impact (low VOC, lack of organic solvents and aromatic groups, for example, aromatic- or benzyl-containing oils or repeating units); minimum diluent contents (predominantly 20% or less salt, based on the total weight, and not containing or substantially devoid of hydrophobic repeating polymer units); bulk viscosity of about 2000 cP or less; in the repeating units of formula (I), R ₂ , R ₃ and R ₄ together contain 5 carbon atoms; and superior or equivalent performance. In accordance with the present invention, products having all of these properties can be obtained.

 Aqueous dispersions of water-soluble polymers are advantageously prepared by polymerizing the corresponding monomers to form a first cationic water-soluble polymer in the presence of at least one second water-soluble polymer and, in some cases, an inorganic salt. Polymerization can be caused by any initiating means, including oxidation-reduction, thermal initiation and initiation by irradiation. Preferred initiators are 2,2'-azobis (2-amidino-propane) dihydrochloride (V-50), 2,2'-azobis (isobutyronitrile), sodium bromate / sulfur dioxide, potassium persulfate / sodium sulfate and ammonium persulfate / sodium sulfite as well as peroxide redox initiators described, for example, in US Pat. No. 4,473,689. The amounts of initiators are selected in a known manner so as to obtain a polymer with a desired molecular weight. Chain transfer agents, for example, isopropanol, lactic acid, mercaptoethanol and the like. and crosslinking and branching agents, for example methylenebisacrylamide, are added in such known amounts as to further control the properties of the first cationic water-soluble polymer. Depending on the conditions of implementation, i.e. of the types and proportions of the chain carrier and the branching agent, water-swellable or branched, water-soluble polymers can be obtained. In general, the use of large amounts of a branching or cross-linking agent increases the tendency to obtain a water-swellable polymer instead of a water-soluble one, and an increase in the amount of chain transfer agent leads to a decrease in molecular weight. In the case of the combination of a chain transfer agent and a crosslinking agent, it is more likely to obtain water swellable products at a high content of a branching agent and a low content of a chain transfer agent, while at a high content of a chain transfer agent and a low content of a branching agent water-soluble polymers are obtained. Components can be added at any time, i.e., all monomers can be present immediately at the start of the polymerization, or can be added during the polymerization process. In the case of using salt, it can be used all at once or added during the polymerization process, or after its completion. Polymerization process parameters, i.e. temperature and time are selected in a known manner and may vary during the polymerization. The polymerization is carried out mainly in the presence of an inert gas, for example, nitrogen. If necessary, you can add the usual auxiliary means, such as chelating agents, passivators, pH, etc.

 The aqueous dispersions of the present invention have the advantage that they are practically free of diluents, such as surfactants, oils, hydrocarbon liquids, organic solvents, etc. Although viscosity reducing additives may be present in aqueous dispersions, t .e. glycerol, glycerol, alcohol, glycol and the like. , to maintain the beneficial properties inherent in the present invention, their amount should be 2% or less, preferably 1% or less, more preferably 0.1% or less.

 The aqueous dispersions of the present invention can be homogeneous in the absence of a specific component, for example, the specified second water-soluble polymer. Homogeneous compositions are characterized in that they are transparent, translucent and do not represent aqueous dispersions, since they do not contain dispersed droplets, as described above. In aqueous dispersions that cannot be formed in the absence of an effective or sufficient amount of a specific component to form a dispersion, the dispersion-forming component is, depending on the particular embodiment, said first cationic water-soluble polymer or said second cationic water-soluble polymer.

 The water used in the present invention can be water from any source, for example industrial water, river water, distilled water, tap water, etc. Polymerization processes are preferably carried out in aqueous solutions that do not contain significant amounts of materials that adversely affect polymerization . Advantageously, the aqueous dispersions of the present invention tend to dissolve rapidly upon dilution with water.

 To increase the total polymer solids content or to create substantially dry products, the aqueous dispersion of the present invention can be dehydrated. To reduce the water content, you can use any methods known in the art, for example steaming, spray drying, precipitation from a solvent, etc. It has been unexpectedly discovered that partial or incomplete dehydration can lower the bulk viscosity of an aqueous dispersion, despite the tendency for polymer solid particles to increase upon dehydration. Dehydration can be carried out by heating, mainly under reduced pressure, although excessive heating can be detrimental to the properties of the polymer. By removing water, a substantially dry mass of polymer can be obtained, which can be crushed to obtain a powdered or, mainly, granular product. By spray drying the aqueous dispersions of the present invention, substantially dry polymer products can be obtained. Spray drying of oil-containing polymer emulsions and dispersions is described in US Patent Application 08 / 668,288, however, there are no reports of spray drying of aqueous dispersions that are free of oils and surfactants. In accordance with the present invention, aqueous suspensions containing a vinyl additive polymer can be spray dried in a large chamber through which hot gas is blown to remove most of the volatile products and release the dried polymer. It was unexpectedly discovered that the means used in spraying an aqueous dispersion in a gas stream are not critical and are not limited by injectors with special hole sizes; You can use any device known in the art. For example, such as rotational atomizers, pressure nozzles, pneumatic nozzles, sound nozzles, etc., which can all be used for spray drying of an aqueous dispersion in a gas stream. When choosing a spray device, speed, viscosity, desired particle size of the dried product, droplet size of an aqueous dispersion, etc. are usually taken into account. The size and shape of the chamber, the number and type of spray devices, and other parameters are selected in accordance with conditions widely known in the art.

 Closed circular (ring) spray dryers can be used, although open cyclic spray drying systems are more preferred. The gas supply can be carried out flowing, countercurrent or mixed, while flowing flow is more preferable. The hot gas or inert gas may be any gas that is not reactive or does not form explosive mixtures with polymer supplied and / or dried by spraying. As suitable inlet gases, gases known in the art can be used, including air, nitrogen and other gases that do not cause undesired decomposition or contamination of the polymer, mainly gases containing about 20% or less oxygen, more preferably about 15% oxygen or less . Inert gases such as nitrogen, helium, etc., which contain about 5% or less oxygen, should preferably be used.

 The dried polymer can be collected by various means, for example, through a simple outlet, a conical classifier, a bag filter, etc. or the polymer may be subjected to further drying steps, such as a fluidized bed or agglomeration. The agents used to collect the dry polymer product are not critical.

There are four main interrelated operational parameters of the spray drying process: inlet gas temperature, outlet gas temperature, product volatility, and residence time in the dryer. The outlet temperature should be about 150 ^{° C.} or lower, preferably about 120 ^{° C.} or lower, more preferably lower than 100 ^{° C.} , even more preferably about 95 ^{° C.} or lower, most preferably about 90 ^{° C.} or lower. In general, the outlet temperature is about 70 ^{° C.} or higher, preferably about 75 ^{° C.} or higher. Therefore, the outlet temperatures are generally about 70 ^{° C.} to about 150 ^{° C.} , preferably about 70 ^{° C.} to about 120 ^{° C.} , more preferably about 70 ^{° C.} , to a lesser extent than 100 ^{° C.} , even more preferably about 70 ^o C to about 95 ^o C, most preferably about 75 ^o C to about 90 ^o C. In some cases, an outlet temperature below about 70 ^o C may be suitable, although this is generally less preferred. For example, when evaluating efficiency, spray drying should be carried out with a long residence time, high gas flow rates and low exit temperature. Basically, the dryer should operate at the lowest possible outlet temperature, consistent with obtaining a satisfactory product.

The inlet temperature, the feed rate, the feed rate and the composition of the water dispersions can collectively influence the outlet temperature. These parameters may vary, providing the desired outlet temperature. The feed rate is not critical and will mainly depend on the size of the dryer and the gas flow rate. The inlet gas temperature is less significant than the outlet gas temperature, and is generally about 140 ^{° C.} or higher, preferably about 160 ^{° C.} or higher. The inlet gas temperature is preferably about 200 ^{° C.} or lower, and more preferably about 180 ^{° C.} or lower. Thus, the inlet gas temperature varies from about 140 to about 200 ^{° C.} , more preferably from about 160 to about 180 ^° C. Actually, the inlet gas temperatures are aimed at avoiding product degradation on one side and avoiding insufficient drying with other.

 The residence time is a conditional value determined by dividing the volume of the dryer by the volumetric gas stream. The residence time is generally at least about 8 seconds, preferably at least about 10 seconds. The residence time is generally not more than about 120 seconds, preferably not more than about 90 seconds, preferably not more than 60 seconds, and most preferably not more than about 30 seconds. Therefore, the preferred residence time range is from about 8 to about 120 seconds, preferably from about 10 to about 90 seconds, more preferably from about 10 to about 60 seconds, and most preferably from about 10 to about 30 seconds. It is known in the art that a longer residence time is expected when large dryers are used or when drying is performed using a less efficient method. For example, when evaluating efficiency, a longer residence time at very low inlet temperatures and low gas flow rates should be assumed. In practice, the residence time useful for the present invention may vary depending on the above values, size and type of spray dryer used, its effectiveness and other parameters. So the residence time indicated here can be modified to adapt to the drying conditions commonly used in the art.

 In the spray drying processes described herein, the size of the polymer particles of the present invention is generally about 10 microns or more in diameter, preferably about 40 microns or more, more preferably about 100 microns, or most preferably about 200 microns or more. Preferably, the polymer particles are not pulverized. The problems of dust and fluidity (rheology) are usually exacerbated when the polymer particles are small, so it is more preferable that the polymer particles are larger. However, very large particles can dissolve rather slowly. Therefore, it is desirable that the polymer particles are about 1200 microns or less in diameter, preferably about 800 microns or less in diameter, more preferably about 600 microns or less, more preferably about 400 microns or less. Basically, at least about 90% of the polymer particles have a size of 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 vary to some extent by changing operating parameters, for example, spray configuration, viscosity of the aqueous dispersion, feed rate, etc. Particles can be substantially spherical or non-spherical; The "diameter" of a non-spherical particle is measured along the main axis.

 Although in some cases the polymer particles are hollow porous structures having at least one gap in their walls, it was found that these characteristic features are not always necessary to obtain particles having the desired properties, for example, fast dissolution time. In many cases, spray drying parameters, such as the type of nozzle, its size, outlet temperature, etc., necessary to obtain particles that are hollow porous structures having at least one gap (hole) in their walls, are unsuitable or uneconomical and more appropriate to produce particles that do not have some or all of these properties.

Particles obtained by spray drying in the present invention can be sorted by removing particles of a larger or smaller size than desired. Larger particles can be crushed by grinding, while smaller particles can be agglomerated. Dimensions can be determined by methods known in the art, for example, by sieving, sorting, optically (light scattering), microscopy, microscopic automatic photo analysis (image analysis), etc. Surprisingly, it was found that the bulk density of the spray dried polymer particles of the present invention is much higher than the bulk density of the dry polymers obtained by the deposition of, for example, water-in-oil emulsions of the same polymer. High density polymer particles are more preferred since they occupy a smaller volume and, as a result, for example, low cost of packaging and storage. Since the densities of the deposited polymers are usually less than about 0.35 g / cm ³ , the bulk density of the spray dried polymer particles of the present invention is generally about 0.35 g / cm ³ or higher, preferably about 0.4 g / cm ³ or higher , more preferably about 0.45 g / cm ³ or higher, and most preferably about 0.50 g / cm ³ or higher. The bulk density of the spray dried polymer particles of the present invention is generally about 1.1 g / cm ³ or less, preferably about 1.0 g / cm ³ or less, more preferably about 0.95 g / cm ³ or less, and most preferably about 0.90 g / cm ³ or less. Therefore, the bulk densities of the spray dried polymer particles of the present invention are generally in the range of about 0.35 to about 1.1 g / cm ³ , preferably about 0.4 to about 1.0 g / cm ³ , more preferably about 0.45 up to about 0.95 g / cm ³ , most preferably about 0.50 to about 0.90 g / cm ³ .

Under the drying conditions indicated here, the polymer particles obtained by the method described herein are substantially dry. As used herein to describe the resulting polymer, the term “substantially dry” means that the polymer contains about 12% or less volatile, preferably about 10% or less, relative to the weight of the spray dried polymer. Basically, the polymer contains about 2% or more volatiles, preferably about 5% or more with respect to the total weight, and most preferably contains from about 8% to about 10% volatiles. Volatiles are measured by determining the weight loss during drying of the polymer product at about 105 ^{° C.} for about 30 minutes.

 It has also been found that agglomeration of the polymer particles of the present invention can improve the flow properties and dissolution time of the polymers. Agglomeration is a known process for increasing particle size and various methods for particle agglomeration are known in the art, for example, “Successfully Use Agglomeration for Size Enlargement”, by Wolfgang Pietsch, Chemical Engineering Progress, April 1996, pp.29-45; "Speeding up Continuous Mixing Agglomeration with Fast Agitation and Short Residence Times", by Peter Koening, Powder and Bulk Engineering, February 1996, pp. 67-84. Known methods can be used to agglomerate the polymer particles of the present invention, such as natural agglomeration, mechanical agglomeration, drum agglomeration or build-up agglomeration, pressure agglomeration, agglomeration in the absence and presence of a binder, etc. Agglomeration may optionally follow drying, for example, drying in a fluidized bed, with the removal of a binder, for example, water. Pressure agglomeration is preferred, but mechanical agglomeration using water as a binder, followed by drying in a fluidized bed, is most preferred.

 Agglomerates formed by agglomeration of polymer particles of the present invention have improved fluidity and an increased dissolution rate compared to non-agglomerated polymer particles. Mostly the agglomerates are not dusty. Typically, about 90% of the agglomerates of the present invention have a size of about 120 microns or more, preferably about 160 microns or more, more preferably about 200 microns or more, most preferably about 300 microns or more. Generally, about 90% of the agglomerates have a 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%, predominantly 95% of the agglomerates have a particle size in the range of from about 120 to about 1500 microns, preferably from about 160 microns to about 1200 microns, more preferably from about 200 microns to about 1100 microns, more preferably from about 300 microns to about 1000 microns.

 Typically, at least about 5% of the agglomerates, preferably at least about 10%, more preferably at least about 15%, are larger than about 900 microns. Agglomerates obtained by agglomeration of the spray dried particles of the present invention can be sorted by removing larger or smaller particles. Preferably, agglomerates larger than 1200 μm and less than 175 μm are removed, for example, by sieving through a sieve. Larger agglomerates can be pulverized by grinding, while smaller particles are usually returned to the agglomerator.

The bulk densities of the agglomerates of the present invention are lower than the bulk densities of the spray dried particles from which they are formed. The bulk densities of the agglomerates of the present invention are generally about 0.35 g / cm ³ or higher, preferably about 0.4 g / cm ³ or higher, more preferably about 0.45 g / cm ³ or higher, and most preferably about 0.50 g / cm ³ or higher. The bulk densities of the agglomerates of the present invention are generally about 1.0 g / cm ³ or less, preferably about 0.95 g / cm ³ or less, more preferably about 0.90 g / cm ³ or less, and most preferably about 0.85 g / cm ³ . Therefore, the bulk densities of the agglomerates of the present invention are generally in the range of about 0.35 to about 1.0 g / cm ³ , preferably about 0.4 to about 0.95 g / cm ³ , more preferably about 0.45 to about 0 90 g / cm ³ , most preferably about 0.50 to about 0.85 g / cm ³ .

 In order to obtain agglomerates of the required size, it is necessary that the polymer particles themselves be of such a size as to be capable of agglomeration. Obviously, agglomeration leads to an increase in the number of particles of medium size, so it is often easier to make a significant increase in particle size than a slight increase in particle size. Therefore, to obtain agglomerates of the required size or the required size range, it is desirable to agglomerate particles substantially smaller than the required size of the agglomerate than those particles that are only slightly smaller than the required size of the agglomerate. Particles capable of agglomeration are mainly those that can be agglomerated in the usual way to obtain agglomerates of the desired size. It is possible, but undesirable, to agglomerate larger particles to obtain agglomerates having a larger size than required, and then remove agglomerates having a size greater than required, as described above.

 The substantially dry polymer particles and agglomerates of the present invention mainly comprise a polymer that is contained in a spray dried aqueous dispersion, as described above.

 Spray drying of the aqueous dispersions of the present invention is advantageous in that typically 90% or more, mainly 95% or more, essentially all of the polymer particles obtained by spray drying, each individual particle contains two or more water-soluble or water-swellable vinyl additive polymers and the effect of stratification (stratification) can be minimized. Layering can occur when two different dry polymers are mixed together, having different particle sizes or different particle size distributions, since larger particles tend to settle at the bottom of the container. The layering effect is that when the mixed product is stored in a container, a polymer having a smaller particle size accumulates at the top. For this reason, changes in those product characteristics that affect the depth of its preservation should be avoided, and it is desirable that each polymer in the mixture have the same particle size, see, for example, EP 479616 A1 and US 35213693. A dry mixture of two different polymers shows a great tendency to layering than the dry mixture obtained by spray drying of the aqueous dispersions of the present invention, since most of each individual spray dried polymer particles of the present invention contains two or more water soluble or water swellable vinyl-addition polymer. Surprisingly, it has been found that spray dried aqueous dispersions of the present invention dissolve faster than polymers obtained by spray drying of standard water-in-oil emulsions of such polymers.

 The suspension of dispersed solid particles can be dehydrated by a method that includes (a) mixing an effective amount of an aqueous dispersion of polymers or their aqueous mixture with a suspension of dispersed solid particles and (b) dewatering said suspension of dispersed solid particles. Essentially dry polymers derived from the aqueous dispersions of the present invention as described above can also be used to dewater suspended solids. For example, a suspension of dispersed solid particles can be dehydrated by a method that includes (a) mixing an effective amount of a substantially dry water-soluble or water-swellable polymer or an aqueous mixture thereof with a suspension of dispersed solid particles and (b) dewatering said suspension of dispersed solid particles. Advantageously, an aqueous dry polymer mixture or an aqueous dispersion is prepared by mixing the dry polymer or aqueous dispersion with water, more preferably 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 a conventional laboratory method.

 Examples of suspensions of dispersed solid particles that can be dehydrated by the means of the present invention include those obtained by dewatering municipal and industrial wastes, clarifying and settling primary and secondary industrial and urban wastes, treating drinking water, etc. Since the polymers described in the present invention, have a number of useful properties, namely essentially do not contain oils, the minimum number of inactive diluents, the complete or partial absence of surface-active in substances, they are especially suitable in cases where some or all of the dehydrated particles or purified water are returned to the environment, such as composting from dirt, applying dehydrated dirt to the soil, granulating to obtain fertilizers, receiving or recycling clarified water, receiving paper etc. Other useful applications that arise from the present invention include soil improvement, afforestation, erosion control, germination and seed protection, etc., where an aqueous dispersion of a dry polymer, mainly an aqueous mixture thereof, is used in the soil.

 Other examples of suspensions of dispersed solid particles that can be dehydrated by the means of the present invention are in the papermaking industry, for example, aqueous dispersions of dry polymer can be used as retention aids, drainage aids, molding aids, washing / thickening / drainage aids (DNT deink application), charge control agents, thickeners or for lightening, ink removal, water purification from ink and stems Yelnia paint sludge, bleaching or dehydration of mud. The polymers of the present invention can also be used in the oil industry for refining oil, cleaning and dewatering waste and removing oils.

 The aqueous dispersions and dry polymers of the present invention can be used as dehydrating and cleaning agents in the food industry, including dehydration of waste, mainly dehydration of waste from processing of poultry, beef, pork and potatoes, as well as in clarification and refining of sugar and sugar beets.

 The aqueous dispersions and dry polymers of the present invention can be used in the mining and mineralogical industries, including dewatering and thickening of coal waste, sedimentation waste and Bayer processes such as sludge and red mud washing, Bayer filtering process, hydrated flocculation and precipitation.

 The aqueous dispersions and dry polymers of the present invention can be used in biotechnology, including dehydration and waste treatment, especially dehydration and purification of fermentation broths.

 The aqueous dispersions of the present invention can be used in the above cases, alone or together or sequentially with other known methods.

 All of the above patents, patent applications, and publications are not combined in one link. Unless otherwise indicated, all percentages given herein are by weight.

In the examples, the standard viscosity (ST) was determined by mixing 8.0 g of a 0.2 wt.% Polymer solution in water with 8.6 g of 2M NaCl and measuring the viscosity of the resulting solution at 25 ^° C using a Brookfield viscometer equipped with an UL adapter at 60 rpm Molecular weights were determined using high performance chromatography using a light scanning detector.

The bulk density of polymer particles and agglomerates was determined by adding particles or agglomerates to a pre-weighed measuring container and “lowering” or slightly mixing the container to cause settling of the particles or agglomerates. By measuring the container and measuring the weighted container, the polymer volume was determined and the bulk density calculated in grams per centimeter cubic (g / cm ³ ).

Example 1. In a flask equipped with a mechanical stirrer, a reflux condenser and a nitrogen supply tube, 17.10 parts of deionized water and 9 parts of a 40% polymer aqueous solution obtained by polymerization of the dimethylaminoethyl methacrylate quaternary methyl chloride salt (poly (DMAEM. MeCl)) are charged with a weight average molecular weight of about 200,000. After completion of the dissolution, 7.08 parts of a 53.64% aqueous solution of acrylamide (AMD) and 14.56 parts of a 72.80% solution of dimethyl sulfate diethylaminoethyl acrylate (DEAEA. DMS) are added and mixed. To this mixture was added 8.1 parts of ammonium sulfate, 0.7 parts of citric acid and 2.02 parts of a 1% solution of chelated tetrasodium salt of ethylenediaminetetraacetic acid (EDTA) and mixed. The pH of the mixture is 3.3. The flask was closed and nitrogen was bubbled for 30 minutes, then polymerization was started by adding 1.44 parts of a 1% aqueous solution of 2,2'-azobis (2-amidinopropane) dihydrochloride (V-50). The reaction mixture is heated to 40 ^{° C.} in 2 hours, the temperature is raised to 50 ^{° C.} and further held for 8 hours. The conversion is above 99%. A stable liquid aqueous dispersion is obtained. The bulk viscosity (RH) of the dispersion, measured using a Brookfield viscometer, a shaft of 4, 30 rpm at 25 ^{° C.} , is 2250 cP, which indicates the fluidity of the dispersion. The dispersion is dissolved and a standard viscosity (SB) of 2.56 cP is obtained.

 Examples 2-8. Aqueous dispersions were prepared as described in Example 1. Table 1 shows the effect of various amounts of polymer and ammonium sulfate salt on bulk viscosity.

Example 9. In a flask equipped with a mechanical stirrer, reflux condenser, thermocouple and tube for supplying nitrogen, 72.60 parts of deionized water and 30.8 parts of a 40% poly aqueous solution (DMAEM.MeCl) were loaded, with a weight average molecular weight of about 222600. After completion of dissolution, 24.37 parts of a 53.33% aqueous solution of acrylamide and 45.93 parts of a 79% aqueous DEAEA • DMS are added and mixed. To this mixture were added 31.9 parts of ammonium sulfate, 2.57 parts of citric acid and 6.9 parts of a 1% EDTA solution and mixed. The pH of the mixture is 3.3. The flask was closed and nitrogen was bubbled for 30 minutes, then polymerization was started by adding 4.93 parts of a 1% V-50 solution. The reaction mixture is heated to 40 ^{° C.} in 2 hours, the temperature is raised to 50 ^{° C.} and held for 4 hours. The conversion is above 99%. A stable liquid aqueous dispersion is obtained. The bulk viscosity of the dispersion, measured using a Brookfield viscometer, a shaft of 4, 30 rpm at 25 ^o C, is 1460 cP, which indicates the fluidity of the dispersion. The dispersion is dissolved and a standard viscosity of 2.40 cP is obtained.

 Examples 10-33. Aqueous dispersions were prepared according to Example 9. Table 2 shows the effect of the total polymer solids, the ratio of the first cationic polymer to the second cationic polymer, the molecular weight of the second cationic polymer and the amount of ammonium sulfate salt on the bulk viscosity of the aqueous dispersion.

Example 34. The polymerization is carried out analogously to example 9, except that poly (DMAEM.MeCl) having a weight average molecular weight of about 395,000 was used. The bulk viscosity of this aqueous dispersion, measured with a Brookfield viscometer, was 4.30 rpm at 25 ^o C, is about 5100 cP, which indicates the fluidity of the dispersion. The dispersion is dissolved and a standard viscosity of 2.35 cP is obtained.

Example 35. The polymerization was carried out analogously to example 34, except that 2.46 parts of a 10% glycerol solution were added. The polymerization process runs smoothly. Stable liquid aqueous dispersions were obtained. The bulk viscosity of this dispersion, measured using a Brookfield viscometer, a shaft of 4, 30 rpm at 25 ^{° C.} , is about 3700 cP, showing improved fluidity. Bulk viscosity is generally lower with respect to bulk viscosity of Example 34, which indicates the effect of glycerol addition on viscosity reduction. The dispersion is dissolved and a standard viscosity of 2.35 cP is obtained.

Example 36. A flask equipped with a mechanical stirrer, a reflux condenser, a thermocouple and a nitrogen supply tube was charged with 39.73 parts of deionized water and 30.1 parts of 41% poly (DMAEM.MeCl), with a weight average molecular weight of about 395,000. After completion 23.77 parts of a 53.57% aqueous solution of acrylamide (AMD) and 45.20 parts of an 80% aqueous solution of DEAEA are added to the dissolution. DMS, and 38.7 parts of a 1% aqueous solution of tertiary butyl acrylamide and mixed. To this mixture were added 49.28 parts of ammonium sulfate, 2.57 parts of citric acid and 3.45 parts of 2% EDTA and mixed. The pH of the mixture is 3.3. The flask was closed and nitrogen was bubbled for 30 minutes, then polymerization was started by adding 2.46 parts of 2% V-50. The reaction mixture is heated to 40 ^{° C.} in 2 hours, the temperature is raised to 50 ^{° C.} and further maintained for 4 hours. The conversion is above 99%. A stable liquid aqueous dispersion is obtained. The volumetric viscosity of the dispersion, measured using a Brookfield viscometer, a shaft of 4, 30 rpm at 25 ^o C, is 1900 cP, which indicates an improvement in fluidity compared to example 34 and demonstrates the effect of attached hydrophobic repeating units of tert-butyl acrylamide. The dispersion is dissolved and a standard viscosity of 2.32 cP is obtained.

Example 37. A flask equipped with a mechanical stirrer, a reflux condenser, a thermocouple and a nitrogen supply tube was charged with 78.84 parts of deionized water and 30.1 parts of 41% poly (DMAEM.MeCl), with a weight average molecular weight of about 395,000. After completion of dissolution add 20.95 parts of a 53.57% aqueous solution of acrylamide (AMD), 42.73 parts of an 80% aqueous solution of DEAEA.DMS and 4.84 parts of an 80% aqueous solution of quaternary benzyl chloride salt of dimethylaminoethyl acrylate (DMAEA.BH) and mix. To this mixture were added 49.28 parts of ammonium sulfate, 2.57 parts of citric acid and 3.45 parts of 2% EDTA and mixed. The pH of the mixture is 3.3. The flask was closed and nitrogen was bubbled for 30 minutes, then polymerization was started by adding 2.46 parts of 2% V-50. The reaction mixture is heated to 40 ^{° C.} in 2 hours, the temperature is raised to 50 ^{° C.} and further maintained for 4 hours. The conversion is above 99%. A stable liquid aqueous dispersion is obtained. The bulk viscosity of the dispersion, measured using a Brookfield shaft, tip 4, 30 rpm at 25 ^o C, is 3840 cP, which indicates the most preferred fluidity. The dispersion is dissolved and a standard viscosity of 2.14 cP is obtained.

Example 38. In a flask with a jacket for heating or cooling, equipped with a mechanical stirrer, reflux condenser, thermocouple and a tube for supplying nitrogen, load 294.47 parts of deionized water and 117.60 parts of a 40% aqueous solution of poly (DMAEM.MeCl), with a weight average molecular weight of about 210,000. After completion of the dissolution, 94.03 parts of a 52.77% aqueous solution of acrylamide (AMD) and 173.18 parts of an 80% aqueous solution of DEAEA.DM are added and mixed. To this mixture were added 130.20 parts of ammonium sulfate, 9.83 parts of citric acid and 13.17 parts of 2% EDTA and mixed. The pH of the mixture is 3.3. The flask was closed and nitrogen was bubbled for 30 minutes, then polymerization was started by the addition of 7.53 parts of 1% (V-50). The reaction mixture is heated to 40 ^{° C.} in 2 hours, the temperature is raised to 50 ^{° C.} and further maintained for 4 hours. The conversion is above 99%. A stable liquid aqueous dispersion is obtained. The bulk viscosity of the dispersion, measured using a Brookfield viscometer, a shaft of 4, 30 rpm at 25 ^{° C. of the} dispersion is 760 cP, indicating a preferred flow. The dispersion is dissolved and a standard viscosity of 2.52 cP is obtained.

Example 39. In a flask equipped with a mechanical stirrer, reflux condenser, thermocouple and tube for supplying nitrogen, load 63.18 parts of deionized water and 30.8 parts of a 40% aqueous solution of poly (DMAEM.MeCl), with a weight average molecular weight of about 230600, After completion of the dissolution, 27.96 parts of a 53.33% aqueous solution of acrylamide (AMD), 26.02 parts of an 80% solution of DEAEA.DMS and 16.94 parts of an 80% aqueous solution of quaternary methyl chloride of dimethylaminoethyl acrylate DMAEA.MeCl are added and mixed. To this mixture, 40.7 parts of ammonium sulfate, 2.57 parts of citric acid and 6.9 parts of 1% EDTA are added and mixed. The pH of the mixture is 3.3. The flask was closed and nitrogen was bubbled for 30 minutes, then polymerization was started by adding 4.96 parts of 1% V-50. The reaction mixture is heated to 40 ^{° C.} in 2 hours, the temperature is raised to 50 ^{° C.} and further maintained for 4 hours. The conversion is above 99%. A stable liquid aqueous dispersion is obtained. The bulk viscosity of the dispersion, measured using a Brookfield viscometer, a shaft of 4, 30 rpm at 25 ^o C, is 3840 cP, which indicates good fluidity. The dispersion is dissolved and a standard viscosity of 2.14 cP is obtained.

 Examples 40-42. The polymerization is carried out analogously to example 39, except that the bulk viscosity is controlled by different contents of ammonium sulfate salt, as shown in table 3. These examples show that aqueous dispersions can be prepared having a low bulk viscosity and a high content of solid polymer particles, where the first the cationic polymer is DMAE.MeCl / DEAEA. DMS / AMD terpolymer.

Example 43. In a flask with a jacket for heating or cooling, equipped with a mechanical stirrer, reflux condenser, thermocouple and a tube for supplying nitrogen, load 260.35 parts of deionized water and 117.6 parts of a 40% aqueous solution of poly (DMAEM.MeCl), with with a weight average molecular weight of about 210,000. After completion of the dissolution, 107.89 parts of a 52.77% aqueous solution of acrylamide (AMD), 99.35 parts of an 80% aqueous solution of DEAEA.DMS and 64.68 parts of an 80% aqueous solution of DMAEA.MeCl are added and mixed . To this mixture, 271.92 parts of ammonium sulfate, 9.83 parts of citric acid and 13.17 parts of 2% EDTA were added and mixed. The pH of the mixture is 3.3. The flask was closed and nitrogen was bubbled for 30 minutes, then polymerization was started by the addition of 7.53 parts of 2.5% (V-50). The reaction mixture is heated to 40 ^{° C.} in 2 hours, the temperature is raised to 50 ^{° C.} and further maintained for 4 hours. The conversion is above 99%. A stable liquid aqueous dispersion is obtained. The bulk viscosity of the dispersion, measured using a Brookfield viscometer, a shaft of 4, 30 rpm at 25 ^o C, is 1240 cP, which indicates good fluidity. The dispersion is dissolved and a standard viscosity of 2.74 cP is obtained.

Example 44. A flask equipped with a mechanical stirrer, a reflux condenser and a nitrogen supply tube was charged with 18.86 parts of deionized water and 9 parts of a 40% poly (DMAEM.MeCl) aqueous solution, with a weight average molecular weight of about 200,000. After completion of dissolution, add 4.39 parts of a 53.64% aqueous solution of acrylamide (DMD) and 15.19 parts of a 79.3% aqueous solution of DEAEA.DMS and mixed. To this mixture was added 8.4 parts of ammonium sulfate, 0.7 parts of citric acid and 2.02 parts of 1% EDTA and mixed. The pH of the mixture is 3.3. The flask was closed and nitrogen was bubbled for 30 minutes, then polymerization was started by adding 1.44 parts of 1% V-50. The reaction mixture is heated to 40 ^{° C.} in 2 hours, the temperature is raised to 50 ^{° C.} and further held for 8 hours. The conversion is above 99%. A stable liquid aqueous dispersion is obtained. The bulk viscosity of the dispersion, measured using a Brookfield viscometer, a shaft of 4, 30 rpm at 25 ^o C, is 850 cP, which indicates the preferred fluidity of the dispersion. The dispersion is dissolved and a standard viscosity (SB) of 2.27 cP is obtained.

 Examples 45-49. Aqueous dispersions were prepared in accordance with Example 44. Table 4 shows the effect of the ratio of the first cationic polymer to the second cationic polymer and the salt content on the bulk viscosity of the dispersion.

Example 51. A flask equipped with a mechanical stirrer, reflux condenser and tube for supplying nitrogen was charged with 92.9 parts of deionized water and 30.1 parts of a 41% aqueous solution of poly (DMAEM.MeCl), with a weight average molecular weight of about 395,000. After completion of dissolution add 15.03 parts of a 53.57% aqueous solution of acrylamide (AMD) and 51.53 parts of an 80% aqueous solution of DEAEA.DMS and mix. To this mixture, 22 parts of sodium sulfate, 2.57 parts of citric acid and 3.45 parts of 2% EDTA are added and mixed. The pH of the mixture is 3.3. The flask was closed and nitrogen was bubbled for 30 minutes, then polymerization was started by adding 2.46 parts of 2% V-50. The reaction mixture is heated to 40 ^° C. in 2 hours, the temperature is raised to 50 ^{° C.} and held for 4 hours. The conversion is above 99%. A stable liquid aqueous dispersion is obtained. The bulk viscosity of the dispersion, measured using a Brookfield viscometer, shaft 4, 30 rpm at 25 ^o C, is 1100 cP. The dispersion is dissolved and a standard viscosity of 2.19 cP is obtained. This example demonstrates the effectiveness of sodium sulfate.

Example 52. A flask equipped with a mechanical stirrer, a reflux condenser, a thermocouple and a nitrogen supply tube was charged with 17.57 parts of deionized water and 9 parts of a 40% poly aqueous solution (DMAEM.MeCl), with a weight average molecular weight of about 200,000. After completion of dissolution add 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 80% aqueous solution of DMAEA.MeCl and mix. To this mixture, 9.6 parts of ammonium sulfate, 0.7 parts of citric acid, 2.02 parts of 1% EDTA are added and mixed. The pH of the mixture is 3.3. The flask was closed and nitrogen was bubbled for 30 minutes, then polymerization was started by adding 1.44 parts of 1% V-50. The reaction mixture is heated to 40 ^{° C.} in 2 hours, the temperature is raised to 50 ^{° C.} and further maintained for 4 hours. The conversion is above 99%. A stable liquid aqueous dispersion is obtained. The bulk viscosity of the dispersion, measured using a Brookfield viscometer, a shaft of 4, 30 rpm at 25 ^o C, is about 800 cP, which indicates good fluidity. The dispersion is dissolved and a standard viscosity of 2.3 cP is obtained.

 Examples 53-80. The polymerization is carried out in accordance with example 52. Table 5 shows the effect of the total polymer solids content, the composition of the first cationic polymer (in% AMD,% DEAEA.DMS and% DMAEA.MeCl in the monomer feed mixture), the ratio of the first cationic polymer to the second cationic polymer and the content of ammonium sulfate salt to the bulk viscosity of the aqueous dispersion.

Example 81. In a flask equipped with a mechanical stirrer, reflux condenser, thermocouple and tube for supplying nitrogen, 89 parts of deionized water and 20.9 parts of a 40% poly (DMAEM.MeCl) aqueous solution are loaded, with a weight average molecular weight of about 190,000. After completion 30.96 parts of a 52.77% aqueous solution of acrylamide, 21.38 parts of an 80% aqueous solution of DEAEA.DMS are added and mixed. To this mixture was added 49.5 parts of ammonium sulfate, 2.57 parts of citric acid, 2.34 parts of 1% EDTA and mixed. The pH of the mixture is 3.3. The flask was closed and nitrogen was bubbled for 30 minutes, then polymerization was started by adding 3.34 parts of 1% V-50. The reaction mixture is heated to 40 ^{° C.} in 2 hours, the temperature is raised to 50 ^{° C.} and further maintained for 4 hours. The conversion is above 99%. A stable liquid aqueous dispersion is obtained. The bulk viscosity of the dispersion, measured using a Brookfield viscometer, a shaft of 4, 30 rpm at 25 ^o C, is about 280 cP, which indicates good fluidity. The dispersion is dissolved and a standard viscosity of 1.60 cP is obtained.

 Examples 82-97. The polymerization is carried out in accordance with example 81. Table 6 shows the effect of the concentration of the chelate (EDTA), the agent that is the carrier of the chain (lactic acid), the composition of the first cationic polymer (in% AMD,% DEAEA.DMS and% DMAEA.MeCl in the monomer feed mixture), the ratio of the first cationic polymer to the second cationic polymer and the content of ammonium sulfate salt to standard viscosity and bulk viscosity.

Example 98. In a flask equipped with a mechanical stirrer, reflux condenser, thermocouple and a tube for supplying nitrogen, 87.97 parts of deionized water and 20.9 parts of a 40% poly aqueous solution (DMAEM.MeCl) are loaded, with a weight average molecular weight of about 190,000. After completion of the dissolution, 33.99 parts of a 52.77% aqueous solution of acrylamide, 11.74 parts of an 80% aqueous solution of DEAEA.DM and 7.64 parts of an 80% aqueous solution of DMAEA are added. MeCl and stirred. To this mixture was added 49.5 parts of ammonium sulfate, 2.57 parts of citric acid, 2.34 g of 2% EDTA and stirred. The pH of the mixture is 3.3. The flask was closed and nitrogen was bubbled for 30 minutes, then polymerization was started by adding 2.34 parts of 1% V-50. The reaction mixture is heated to 40 ^{° C.} in 2 hours, the temperature is raised to 50 ^{° C.} and further maintained for 4 hours. The conversion is above 99%. A stable liquid aqueous dispersion is obtained. The bulk viscosity of the dispersion, measured using a Brookfield viscometer, a shaft of 4, 30 rpm at 25 ^o C, is about 760 cP. The dispersion is dissolved and a standard viscosity of 2.09 cP is obtained.

 Examples 99-100. The polymerization is carried out in accordance with example 97. Table 7 shows the effect of the concentration of the chain carrier agent (lactic acid) on the bulk viscosity.

Example 101. A flask equipped with a mechanical stirrer, a reflux condenser and a nitrogen supply tube was charged with 82.15 parts of deionized water and 30.8 parts of a 20% aqueous solution of poly (diallyldimethylammonium chloride) (poly (DADMAC)), with a weight average molecular weight about 289,000. After completion of the dissolution, 48.24 parts of a 52.77% aqueous solution of acrylamide and 13.27 parts of an 80% aqueous solution of DEAEA.DM are added and mixed. To this mixture was added 49.5 parts of ammonium sulfate, 2.57 parts of citric acid, 1.67 parts of 10% lactic acid, 3.34 parts of 2% EDTA and mixed. The pH of the mixture is 3.3. The flask was closed and nitrogen was bubbled for 30 minutes, then polymerization was started by adding 3.34 parts of 1% V-50. The reaction mixture is heated to 40 ^{° C.} in 2 hours, the temperature is raised to 50 ^{° C.} and held for 4 hours. The conversion is above 99%. A stable liquid aqueous dispersion is obtained. The bulk viscosity of this dispersion, measured using a Brookfield viscometer, a shaft of 4, 30 rpm at 25 ^{° C.} , is about 760 cP, indicating a preferred flow. The dispersion is dissolved and a standard viscosity of 3.67 cP is obtained. This example illustrates aqueous dispersions containing poly (DADMAC) as the second cationic polymer.

Example 102. In a flask with a jacket for heating and cooling, equipped with a mechanical stirrer, reflux condenser, thermocouple and tube for supplying nitrogen, load 262.6 parts of deionized water and 47.4 parts of a 40% aqueous solution of poly (DMAEM.MeCl), with a weight average molecular weight of about 41,500 and 92.60 parts of a 40% aqueous poly solution (DMAEM.MeCl), with a weight average molecular weight of about 205,000. After completion of the dissolution, 88.1 parts of 53.12% aqueous acrylamide solution and 133.9 parts of 72 are added. 6% aqueous diethyl quaternary methyl chloride salt aminoetilakrilata (DEAEA.DMS) and stirred. To this mixture, 144 parts of ammonium sulfate, 2.644 parts of citric acid, 14.4 parts of 1% EDTA are added and mixed. The pH of the mixture is 3.3. The flask was closed and nitrogen was bubbled for 30 minutes, then polymerization was started by adding 14.4 parts of 2% V-50. The reaction mixture is heated to 40-45 ^o C and incubated for 6 hours. The conversion is above 99.9%. A stable liquid aqueous dispersion is obtained. The bulk viscosity of this dispersion, measured using a Brookfield viscometer, a shaft of 4, 30 rpm at 25 ^o C, is about 2200 cP. The dispersion is dissolved and a standard viscosity of 3.31 cP is obtained. This example illustrates an aqueous dispersion containing a third cationic polymer.

Example 103. The polymerization is carried out as in example 102, except that two poly (DMAEM.MeCl) polymers were replaced by one poly (DMAEM.MeCl) having a weight average molecular weight of about 1,500,000. The bulk viscosity of this dispersion measured using a Brookfield viscometer, a shaft of 4, 30 rpm at 25 ^o C, is about 8000 cP. The dispersion is dissolved and a standard viscosity of 2.45 cP is obtained.

Example 104. In a flask with a jacket for heating and cooling, equipped with a mechanical stirrer, reflux condenser, thermocouple and a tube for supplying nitrogen, load 23.8 parts of deionized water and 25.3 parts of a 20% aqueous solution of poly (DADMAC), with a weight average molecular weight weighing 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.DM are added and mixed. To this mixture are added 18 parts of ammonium sulfate, 1.08 parts of citric acid, 0.37 parts of 5% EDTA, 0.9 parts of glycerol and mixed. The pH of the mixture is 3.3. The flask is closed and nitrogen is bubbled in for 30 minutes, then polymerization is started by adding 1.3 parts of 1% V-50 at 40 ^° C. This temperature is maintained for 2 hours and then raised to 50 ^{° C.} and kept at this temperature for 8 hours. acrylamide was about 209 parts per million (ppm). A stable liquid aqueous dispersion is obtained. The bulk viscosity of this dispersion, measured using a Brookfield viscometer, a shaft of 4, 30 rpm at 25 ^{° C.} , was about 2950 cP, indicating a preferred flow. The dispersion is dissolved and a standard viscosity of 2.47 cP is obtained.

 Examples 105-108. The polymerization is carried out analogously to example 104, except that part of the poly (DADMAC) is replaced by poly (DADMAC) with a polymer having a lower weight average molecular weight. Table 8 shows the effect of the inclusion of the third polymer on the bulk viscosity of the aqueous dispersion.

 Example 109. Analogously to example 2, an aqueous dispersion was prepared containing 12.5% ammonium sulfate and 30% polymer solid particles, with a bulk viscosity of about 7200 cP and a standard viscosity of about 2.34 cP.

 Example 110. Analogously to example 9, an aqueous dispersion was prepared containing 15.5% ammonium sulfate and 28% polymer solid particles, with a bulk viscosity of about 2640 cP and a standard viscosity of about 2.4 cP.

 Examples 111-133. To the aqueous dispersions of Examples 109, 110, 103, 1, 102, and 142, various amounts of ammonium sulfate, sodium thiocyanate, or 1,3-benzene disulfonate (1,3-BDS) were added. In this case, the bulk viscosities of the obtained aqueous dispersions are reduced, which follows from Table 9. These examples demonstrate that the bulk viscosities of aqueous dispersions can be reduced by adding salt to the dispersion, and adding 1,3-BDS is more efficient than adding ammonium sulfate in the calculation on the main weight. Almost similar results were obtained by polymerization of monomers in the presence of salts.

 Example 134. About 18 parts of the aqueous dispersion of Example 49 and about 20 parts of the aqueous dispersion of Example 91 were mixed. The resulting aqueous dispersion mixture was stable and very uniform with a bulk viscosity of about 880 cP, thereby showing that variously charged dispersions could be mixed to form an aqueous dispersion having an average charge. The aqueous dispersed mixture had a total charge of about 40% and a CB of 2.5 cP.

 Example 135. About 18 parts of the highly charged aqueous dispersion prepared in Example 48 are mixed and about 18 parts of a weakly charged aqueous dispersion of Example 101. The resulting aqueous dispersion mixture was stable and very uniform with a bulk viscosity of about 2300 cP, thereby showing that it is possible mix differently charged dispersions with the formation of an aqueous dispersion having an average charge. The resulting aqueous dispersion contained four different polymers.

 Example 136 (comparative). The polymerization was carried out analogously to example 9, except that DEAEA. DMS was replaced by an equivalent weight quantity of DMAEA. MeCl. During the polymerization process, the contents of the flask became so viscous that it became impossible to mix. A non-flowing gel product was obtained. This example demonstrates that replacing DMAEA.MeCl with DEAEA.DMS results in a dispersion having a catastrophically low bulk viscosity.

 Example 137 (comparative). The polymerization was carried out analogously to example 50, except that DEAEA. DMS was replaced by an equivalent weight quantity of DMAEA. MeCl. During the polymerization process, the contents of the flask became so viscous that it became impossible to mix. A non-flowing gel product was obtained. This example demonstrates the replacement of DMAEA. МеСl on DEAEA. DMS results in a dispersion having a catastrophically low bulk viscosity.

 Example 138 (comparative). The polymerization was carried out analogously to example 91, except that DEAEA. DMS was replaced by an equivalent weight quantity of DMAEA. MeCl. During the polymerization process, the contents of the flask became so viscous that it became impossible to mix. A non-flowing gel product was obtained. This example demonstrates that replacing DMAEA.MeCl with DEAEA.DMS results in a dispersion having a catastrophically low bulk viscosity.

 Example 139 (comparative). The polymerization was carried out analogously to example 100, except that DEAEA. DMS was replaced by an equivalent weight quantity of DMAEA. MeCl. During the polymerization process, the contents of the flask became so viscous that it became impossible to mix. A non-flowing gel product was obtained. This example demonstrates that replacing DMAEA.MeCl with DEAEA.DMS results in a dispersion having a catastrophically low bulk viscosity.

Example 140. In a flask equipped with a mechanical stirrer, reflux condenser and tube for supplying nitrogen, 20 parts of deionized water and 10.51 parts of a 40% aqueous poly solution (DMAEM.MeCl) are loaded, with a weight average molecular weight of about 210,000. After dissolution is complete, add 6.57 parts of a 53.27% aqueous solution of acrylamide, 14.56 parts of an 80% aqueous solution of DMAEA.MeCl, 4.15 parts of an 80% aqueous solution of DMAEA.BH and mixed. To this mixture, 10.8 parts of ammonium sulfate, 0.4 parts of citric acid, 1.55 parts of 1% EDTA are added and mixed. The pH of the mixture is 3.3. The flask was closed and nitrogen was bubbled for 30 minutes, then polymerization was started by adding 1.08 parts of 1% V-50. The reaction mixture is heated to 40 ^{° C.} for 2 hours, placing the flask in a water bath, and then heated to 50 ^{° C.} for 6 hours. The conversion is above 99%. A stable liquid aqueous dispersion is obtained. The bulk viscosity of this dispersion, measured using a Brookfield viscometer, a shaft of 4, 30 rpm at 25 ^{° C.} , is about 2000 cP, indicating a preferred flow. The dispersion is dissolved and a standard viscosity of 2.2 cP is obtained.

 Examples 141-144. The polymerization is carried out in accordance with example 140. Table 10 shows the effect of the composition of the first cationic polymer (in% AMD,% DMAEA.MeCl and% DMAE.BH in the monomer feed mixture) and the molecular weight of poly (DMAEM.MeCl) on the bulk viscosity of the aqueous dispersion .

 Examples 145-150 (comparative). The polymerization was carried out analogously to example 140 at various ratios of AMD / DMAEA. MeCl / DMAEA. BH / DEAEA. VHI except that poly (DMAEM.MeCl) was not used. During polymerization, the contents of the flask became so viscous that stirring became impossible. Was obtained a homogeneous composition of the polymerization product in the form of a transparent gel, not having fluidity, as shown in table 11.

Examples 151-153. An aqueous dispersion having a bulk viscosity of about 3570 cP was prepared according to Example 13. About 135 parts of the obtained dispersion were placed in a suitable flask and concentrated by heating it at 45 ^{° C.} under a stream of nitrogen. In two stages of this dehydration process, a total of 26 parts of water is removed. The aqueous dispersion remains stable, which indicates that dehydration is effective to achieve a high solids content and to reduce the bulk viscosity of aqueous dispersions, as indicated in table 12.

Example 154. In a flask equipped with a mechanical stirrer, reflux condenser and tube for supplying nitrogen, 277.75 parts of deionized water and 112.0 parts of a 40% poly (DMAEM.MeCl) aqueous solution with a weight average molecular weight of about 200,000 are charged. After completion of dissolution, 89.03 parts of a 53.64% aqueous solution of acrylamide, 164.93 parts of an 80% aqueous solution of DEAEA.DM are added and mixed. To this mixture, 124.0 parts of ammonium sulfate, 9.36 parts of citric acid, 5.02 parts of a 1% EDTA solution are added and mixed. The pH of the mixture is 3.3. The contents are heated to 48 ^{° C.} and nitrogen is bubbled for 30 minutes, then polymerization is started by the addition of 17.92 parts of a 1% aqueous solution of V-50. The reaction mixture was kept at 48 ^{° C. for} 5 hours. After 3.5 hours of polymerization, the bulk viscosity of the aqueous dispersion began to increase markedly. The final bulk viscosity of the dispersion, measured using a Brookfield viscometer, a shaft of 4, 30 rpm at 25 ^o C, is about 8000 cP.

 Examples 155-156. Under the conditions of Example 154, two identical polymerizations were carried out, except that the added amount of ammonium sulfate (4% of the total) was added approximately 3 hours after the start of the polymerization. This prevents any significant increase in bulk viscosity during polymerization and as a result, the final bulk viscosity is lower than the bulk viscosity obtained in example 154, which is shown in table 13.

Examples 157-172. The main polymerization procedure: in a suitable flask, the following components are mixed together, adjusting the pH to about 3.5 to 28 wt.% Solution of ammonium hydroxide, parts:
Acrylamide (55.5 wt.%) - 5.34
DEAEA.DMS (89 wt.%) - 10.35
Citric Acid - 0.58
Ammonium Sulfate - 7.78
Poly (DMAEM.MeC1) (40 wt.% 200,000 mw) - 7.03
Deionized Water - 16.22
V-50 (1 wt.%) - 1.12
EDTU (1 wt.%) - 1.57
Methylenebisacrylamide (MBA) - Changes
Lactic Acid (chain transfer agent) - Changes
Forty parts of the solution are placed in a suitable flask and nitrogen is bubbled. The flask is closed and placed in a 40 ^{° C.} water bath for 2 hours. Then the temperature is raised to 50 ^{° C.} and further maintained for 3 hours. The results shown in Table 14 show that significant amounts of branching agent may be included in the aqueous dispersions of water-soluble and water-swellable polymers. and a chain transfer agent. The values of the aqueous viscosities of the dissolved or dispersed aqueous dispersions were determined in the same way as the standard viscosities indicated above, except that the polymer concentration was 0.135 wt.%.

 Example 173. An aqueous dispersion was obtained in accordance with example 155. The aqueous dispersion had a bulk viscosity of about 240 cP and an aqueous viscosity (obtained in accordance with examples 157-172) of 3.55 cP.

Example 174. The aqueous dispersion of example 173 was spray dried in a laboratory spray dryer. The chamber of the laboratory spray dryer has 760 mm in diameter, a vertical wall height of 860 mm and a conical bottom at an angle of 65 ^o . The nominal velocity of the gas stream passing through the dryer is 180 m ³ / h. The aqueous dispersion is fed from above in the center of the chamber, using a high-speed pump through a two-fluid nozzle, using air for atomization. The outlet gas temperature was 86 ^{° C.} and was controlled by changing the inlet gas temperature (160 ^{° C.} ) and its flow rate (60 ml / min). To create an inert atmosphere, nitrogen is supplied to the dryer from a cooled reservoir. The dried polymer product is discharged through the bottom of the dryer into a cyclone, where the dry product is separated and collected. The time spent in the dryer is about 14 s. Obtained by spray drying, polymer particles containing 3.4% volatile and having a bulk density of about 0.50 g / cm ³ quickly dissolve in water and have a MW of 3.49 cP.

 Example 175. A comparison was made of the dissolution rate of the spray dried polymer from Example 174 with the dissolution rate of a dry polymer of a similar composition obtained by spray drying a commercial water-in-oil emulsion. Solutions were prepared in a wide-necked quart mug using a 2.5-inch magnetic stirrer. The rotation speed was adjusted so that mixing occurred in a mass of water. Dry polymer is slowly added over 5 minutes, avoiding eddies of the stirred mass at the edges. The spray dried polymer of Example 174 is rapidly wetted and completely dissolved in 30-40 minutes, giving a clear solution. In contrast, a dry polymer obtained by spray drying an opposed emulsion does not wet so quickly and completely dissolves within 2 hours. This example illustrates the fact that a dry polymer obtained by spray drying an aqueous dispersion of the present invention dissolves faster than a dry polymer obtained spray-drying the corresponding water-in-oil emulsion.

 Example 176C. The procedure of Example 1 of US Pat. No. 5,403,883 is performed. A dispersion is obtained having a bulk viscosity of about 10,600 cP (shaft 4, 30 rpm).

 Example 177. The procedure of Example 1 of US Pat. The resulting aqueous dispersion has a bulk viscosity of about 6900 cP (shaft 4, 30 rpm), demonstrating an improvement in bulk viscosity compared to Example 176C.

Example 178. In a flask equipped with a mechanical stirrer, reflux condenser and tube for supplying nitrogen, load 22.94 parts of deionized water and 10.5 parts of a 40% aqueous solution of poly (DMAEM.MeCl), with a weight average molecular weight of about 245900. After completion of dissolution, add 6.47 parts of a 54.20% aqueous solution of acrylamide, 7.49 parts of the quaternary propyl chloride salt of dimethylaminoethyl acrylate and mix. To this mixture, 10.8 parts of ammonium sulfate, 0.7 parts of citric acid, 0.76 parts of a 2% EDTA solution are added and mixed. The pH of the mixture is 3.3. The flask was closed and nitrogen was bubbled for 30 minutes, then polymerization was started by adding 0.54 g of a 2% aqueous solution of V-50. The reaction mixture is heated to 40 ^{° C.} in 2 hours and then heated to 50 ^{° C.} and further maintained for 4 hours. The conversion is above 99%. A stable liquid aqueous dispersion is obtained. The bulk viscosity of this dispersion, measured using a Brookfield viscometer, a shaft of 4, 30 rpm at 25 ^o C, is about 1300 cP, which indicates the preferred fluidity. The dispersion is dissolved and a standard viscosity of 2.1 cP is obtained. This example shows that despite comparative example 1 EP 0 525 751 A1, aqueous dispersions can be formed when the first polymer contains repeating units of the dimethylaminoethyl acrylate quaternary propyl chloride salt.

Example 179. An aqueous dispersion was prepared analogously to example 40, except that the first polymer consisted of AMD / DEAAA. DMS / DMAAA. MeCl (60/30/10 moles). The aqueous dispersion had a bulk viscosity of about 3600 cP (shaft 4, 30 rpm at 25 ^o C) and CB 2, 64 cP.

Example 180. An aqueous dispersion was prepared analogously to example 40, except that the first polymer consisted of AMD / DEAAA. DMS / DMAAA. MeCl (60/25/15 moles). The aqueous dispersion had a bulk viscosity of about 1000 cP (shaft 4, 30 rpm at 25 ^o C) and a 2.87 cP.

Examples 181-261. The effectiveness of the water dispersions of the present invention is determined by measuring the speed of free sedimentation (drainage) and sintering of solid particles from dehydrated mud according to the following method: 200 g of mud from sewage from municipal and industrial wastes are weighed in several glasses. Prepare solutions of aqueous suspensions and / m, a commercial control water-in-oil emulsion (60 mol% of AMD / DMAEA.MeCl) so that the polymer concentration is about 0.2%. Different doses of polymer solutions are mixed with dirt samples and mixed at 500 rpm for 10 s or at 1000 rpm for 5 s with the above mixture. The resulting aqueous mixture, precipitated by flakes of (flocculated) dirt, is dehydrated by pouring into a Buchner funnel containing a 35 mm steel colorless sieve; free sedimentation or drainage is determined by measuring milliliters of filtrate collected in 10 s. Sintering of solid particles is determined by drying the compressed mud at 105 ^o C. The results are shown in table 15, in which for each polymer corresponds to the given example, the drainage rate in ml / 10 s, mixing speed in rpm, polymer dose in pounds per ton dry dirt and the amount of sintered solids in weight percent relative to dry solids in the wet solids. The "N / A" annotation in the table means that the exact size of the sintered solids cannot be determined. These examples show that the effectiveness of the aqueous dispersions of the present invention is substantially equivalent to or superior to the effectiveness of a commercial product.

 Examples 262-263. The effectiveness of the aqueous dispersions of Examples 118 and 121 was determined by measuring the speed of free drainage and sintering of solid particles from dehydrated mud, following the procedure of Examples 181-261. Similar results were obtained.

 Example 264. A solution of the spray dried polymer of Example 174 was prepared, with a polymer concentration of about 0.2. Efficiency was determined by measuring the speed of free drainage and sintering of solid particles from dehydrated mud, following the procedure of examples 181-261. Similar results were obtained.

 Examples 265-277. Solutions of aqueous dispersions and spray dried polymers of Examples 9, 44, 61, 67, 102, 103, 118, 121, 140, 142, 174, 179 were prepared; the polymer concentration was about 0.2%. Efficiency was determined by measuring the speed of free drainage, following the procedure of examples 181-261, except that dehydrated 1% suspension of paper particulate matter instead of mud waste. Similar results were obtained.

 Examples 278-293. Aqueous mixtures were prepared by mixing aqueous dispersions of Examples 157-172 with water such that the polymer concentration was about 0.2%. Efficiency was determined by measuring the speed of free drainage, following the procedure of examples 181-261, except that dehydrated 1% suspension of paper particulate matter instead of mud waste. Similar results were obtained.

Claims (7)

1. A composition comprising an aqueous dispersion consisting of (a) a first cationic water-soluble or water-swellable polymer having at least one repeating unit of formula (I)

where R ₁ represents H or CH ₃ ;
A is O or NH;
B is an alkylene or branched alkylene or oxyalkylene group having 1 to 5 carbon atoms;
R ₂ is a methyl, ethyl or propyl group;
R ₃ is a methyl, ethyl or propyl group;
R ₄ is an alkyl or substituted alkyl group having 1 to 10 carbon atoms, or an aryl or substituted aryl group having 6 to 10 carbon atoms,
X is a counterion;
R ₂ , R ₃ and R ₄ together contain a total of at least 4 carbon atoms;
(b) at least one second water-soluble polymer other than the first specified polymer; (c) a cosmotropic salt; and (d) a chaotropic or anionic organic salt, where the amounts of the components indicated in (b), (c) and (d) are such that, in the absence of component (b), a homogeneous composition is obtained. 2. A composition comprising an aqueous dispersion comprising (a) a discrete phase containing a polymer, which comprises primarily a first cationic water-soluble or water-swellable polymer having at least one repeating unit of formula (I)

where R ₁ represents H or CH ₃ ;
A is O or NH;
B is an alkylene or branched alkylene or oxyalkylene group having 1-5 carbon atoms;
R ₂ is a methyl, ethyl or propyl group;
R ₃ is a methyl, ethyl or propyl group;
R ₄ is a methyl, ethyl or propyl group;
X is a counterion;
R ₂ , R ₃ and R ₄ together contain a total of at least 4 carbon atoms;
and (b) at least one second water-soluble polymer, different from the first specified polymer. 3. A composition comprising an aqueous dispersion comprising (a) a discrete phase containing a polymer, comprising primarily a first cationic water-soluble or water-swellable polymer having at least one repeating unit of formula (I)

where R ₁ represents H or CH ₃ ; A is O or NH; B is an alkylene or branched alkylene or oxyalkylene group having 1-5 carbon atoms;
R ₂ is a methyl, ethyl or propyl group;
R ₃ is a methyl, ethyl or propyl group;
R ₄ is an alkyl or substituted alkyl group having 1 to 10 carbon atoms, or an aryl or substituted aryl group having 6 to 10 carbon atoms;
X is a counterion;
R ₂ , R ₃ and R ₄ together contain a total of at least 4 carbon atoms,
and (b) at least one second water-soluble polymer, different from the first specified polymer, where a homogeneous composition is obtained in the absence of the specified component (b).  4. The composition according to p. 2 or 3, additionally containing an inorganic salt selected from the group consisting of chlorides, sulfates, phosphates, hydrogen phosphates and mixtures thereof.  5. The composition according to p. 2, 3 or 4, where the first specified polymer further includes hydrophobic repeating units. 6. A composition comprising substantially dry, water-soluble or water-swellable polymer particles, comprising (a) a first cationic water-soluble or water-swellable polymer having at least one repeating unit of formula (I)

where R ₁ represents H or CH ₃ ;
A is O or NH;
B is an alkylene or branched alkylene or oxyalkylene group having 1 to 5 carbon atoms;
R ₂ is a methyl, ethyl or propyl group;
R ₃ is a methyl, ethyl or propyl group;
R ₄ is an alkyl or substituted alkyl group having 1 to 10 carbon atoms, or an aryl or substituted aryl group having 6 to 10 carbon atoms;
X is a counterion;
R ₂ , R ₃ and R ₄ together contain a total of at least 4 carbon atoms,
(b) at least one second water-soluble polymer other than the first specified polymer; (c) a cosmotropic salt; and (d) a chaotropic or anionic organic salt, wherein in about 90% or more of said polymer particles, each individual particle contains both said component (a) and said component (b), wherein the particles have a bulk density of about 0.4 to about 1.0 g / cm ³ . 7. A composition comprising substantially dry water-soluble or water-swellable polymer particles comprising (a) a first cationic water-soluble or water-swellable polymer having at least one repeating unit of formula (I)

where R ₁ represents H or CH ₃ ;
A is O or NH;
B is an alkylene or branched alkylene or oxyalkylene group having 1-5 carbon atoms;
R ₂ is a methyl, ethyl or propyl group;
R ₃ is a methyl, ethyl or propyl group;
R ₄ is an alkyl or substituted alkyl group having 1 to 10 carbon atoms, or an aryl or substituted aryl group having 6 to 10 carbon atoms;
X is a counterion;
R ₂ , R ₃ and R ₄ together contain a total of at least 4 carbon atoms,
and (b) at least one second water-soluble polymer, different from the first specified polymer, where about 90% or more of the specified polymer particles individually contain both the specified component (a) and the specified component (b), and the particles have a bulk density of about 0.4 to about 1.0 g / cm ³ .

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