RU2194818C2 - Paper manufacture process - Google Patents

Abstract

FIELD: paper-and-pulp industry. SUBSTANCE: dehydration and retention agents are added to suspension containing cellulose fibers and optionally fillers, said dehydration and retention agent being cationic organic polymer and finely broken material. Suspension is then formed and dehydrated on screen. Cationic organic polymer has nonaromatic hydrophobic group, in particular C3-C12-alkyl group. Invention also provides cationic vinyl addition polymer including at least one polymerized noncationic monomer containing nonaromatic hydrophobic group and at least one cationic monomer. EFFECT: enhanced dehydration and retention. 21 cl, 6 tbl, 7 ex

Description

 The invention relates to the manufacture of paper, and more specifically, to a method of manufacturing paper, in which a cationic organic polymer containing a hydrophobic group and anionic micronized material are added to the paper pulp. This method provides improved dehydration and retention.

Background of the invention
In papermaking, an aqueous suspension containing cellulosic fibers and optional fillers, called paper pulp, is fed into a pressure vessel, from which the pulp is pushed onto a forming grid. Water is drained from the pulp along a forming grid, so that a wet paper web is formed on this mesh, and this web is then dehydrated and dried in the drying zone of the paper machine. Water obtained from pulp dehydration, called white water, which usually contains fine particles, such as fine fibers, filler and additives, is usually recycled in the papermaking process. The pulp is traditionally introduced additives that facilitate dehydration and retention, in order to accelerate the dehydration process and increase the absorption of small particles on cellulose fibers, so that they are retained in these fibers on the grid. Cationic organic polymers like cationic starch and cationic acrylamide-based polymers are widely used as dehydration and retention agents. These polymers can be used individually, but are most often used in combination with other polymers and / or anionic micronized materials, such as, for example, anionic mineral particles like colloidal silicon dioxide and bentonite.

 A known method of making paper, comprising adding a dispersion of polymer and microparticles to an aqueous cellulosic suspension to obtain paper, which solves the technical problem of providing a polymer dewatering and holding means in the form in which it can be delivered to the paper mill without problems. The invention according to this patent also solves the problem of providing a polymer dehydration and retention agent that can be easily synthesized, as well as the problem of providing polymer dispersions with a better dewatering and retention effect than previously used polymer dispersions / EP-A-0805234 /.

 A method for making paper is also known from US-A-5,098,520, which includes the steps of adding to the cellulosic slurry for making paper, first a high molecular weight cationic polymer and then an average molecular weight anionic polymer. However, this patent does not intend to use a dehydration and retention agent containing a cationic organic polymer and anionic microparticle material, and also does not mention the production of paper from suspensions with high conductivity.

 U.S. Patents 4,980,025; 5,368,833; 5,603,805; 5607552 and 5858174, as well as international patent application WO 97/18351, disclose the use of cationic and amphoteric polymers based on acrylamide and anionic mineral particles as pulp additives in papermaking. Now these additives are among the most effective dehydration and retention agents used. Similar systems are disclosed in European Patent Application 805234.

SUMMARY OF THE INVENTION
In accordance with the present invention, it has been found that improved dehydration and retention can be achieved by using dehydration and retention agents including a cationic organic polymer containing a hydrophobic group and anionic micronized material. In particular, the present invention relates to a method for making paper from a suspension containing cellulosic fibers and optional fillers, which comprises adding a cationic organic polymer and anionic micronized material to the suspension, forming and dewatering the suspension on a mesh, the cationic organic polymer containing a non-aromatic hydrophobic group . In a preferred embodiment of the present invention, this method also includes forming and dewatering the slurry on a grid to obtain a wet paper web containing cellulosic fibers or paper and white water, recycling white water and optionally introducing fresh water to obtain a slurry containing cellulosic fibers and optional fillers and to be dehydrated in order to obtain paper, while the amount of fresh water introduced is less than 30 tons per ton of dry paper received and dehydrated alive on grid suspension has a conductivity of not less than 2.0 mS / cm. The specified technical result is achieved by the full set of features disclosed in paragraphs 1-16.

 The result of the present invention is improved dewatering and / or retention, and the present method allows to increase the speed of the paper machine and to use lower dosages of additives that provide the corresponding effect of dehydration and / or retention, resulting in an improved papermaking process and economic benefits. The method of the present invention is suitably used for the treatment of cellulosic suspensions in closed-cycle plants where white water is repeatedly supplied for recycling with the introduction of only small amounts of fresh water. This method is also suitably applicable to paper processes using high salt cellulosic suspensions, thus having high levels of conductivity, for example, processes with extensive white water recirculation and limited fresh water supply and / or processes that use fresh water having a high salt content.

 The cationic organic polymer containing a hydrophobic group, according to the present invention also called the "base polymer", can be linear, branched or cross-linked, for example, in the form of micronized material, preferably mainly linear. Preferably, the base polymer is water soluble or water dispersible. The hydrophobic group of the main polymer is non-aromatic and can be a side group attached to the polymer chain (main chain) or, more preferably, the hydrophobic group can be attached to a heteroatom, such as a nitrogen or oxygen atom, while the nitrogen atom does not necessarily carry a charge, and this heteroatom, in turn, can be attached to a polymer chain, for example, through a chain of atoms. The hydrophobic group contains at least 2, and usually at least 3 carbon atoms, suitably from 3 to 12 and preferably from 4 to 8 carbon atoms. The hydrophobic group is suitably a hydrocarbon chain. Examples of suitable hydrophobic groups include linear, branched and cyclic alkyl groups, such as ethyl; propyl, for example n-propyl and isopropyl; butyl, for example n-butyl, isobutyl and t-butyl; pentyl, for example n-pentyl, neopentyl and isopentyl; hexyl, for example n-hexyl and cyclohexyl; heptyl, for example n-heptyl and cycloheptyl, octyl, for example n-octyl; nonyl, for example n-nonyl; decyl, for example n-decyl; undecyl, for example n-undecyl; and dodecyl, for example, n-dodecyl. Linear and branched chain alkyl groups are usually preferred.

где радикал R₁ представляет собой водород или СН₃; и каждый из радикалов R₂ и R₃ представляет собой предпочтительно алкильную группу, содержащую от 1 до 3 атомов углерода, приемлемо от 1 до 2 атомов углерода; А представляет собой кислород или NH; В означает алкиленовую группу, содержащую от 2 до 8 атомов углерода, приемлемо от 2 до 4 атомов углерода, или гидроксипропиленовую группу; R4 представляет собой заместитель, содержащий гидрофобную группу, приемлемо неароматическую углеводородную группу, содержащую не менее 2 атомов углерода, приемлемо от 3 до 12 и предпочтительно от 4 до 8 атомов углерода; и Х^- представляет собой анионный противоион, обычно галогенида, такого как хлорид. Группа R₄ обычно включает и предпочтительно выбирается из числа вышеупомянутых линейных, разветвленных или циклических алкильных групп, а общее число атомов углерода в группах R₂, R₃ и R₄ обычно не меньше 4, приемлемо не меньше 5 и предпочтительно не меньше 6. Примеры пригодных для использования катионных мономеров, содержащих неароматическую гидрофобную группу, включают (мет)акрилоксиэтил-N, N-диметил-N-n-бутиламмонийхлорид, (мет)акрилоксиаминоэтил-N,N-диметил-N-n-бутиламмонийхлорид, (мет)акрилоксипропил-N,N-диметил-N-t-бутиламмонийхлорид, (мет)акрилоксиаминопропил-N,N-диметил-N-t-бутиламмонийхлорид, (мет)акрилоксиаминопропил-N,N-диметил-N-n-гексиламмонийхлорид, (мет)акрилоксиэтил-N,N-диметил-N-n-гексиламмонийхлорид, (мет)акрилоксиэтил-N,N,-диметил-N-метилциклогексиламмоний-хлорид и (мет)акрилоксиамино-пропил-N,N-димeтил-N-мeтилциклогексиламмонийхлорид.The base polymer may be selected from homopolymers and copolymers derived from one or more monomers comprising at least one monomer containing a hydrophobic group, an acceptable ethylenically unsaturated monomer, and the base polymer is preferably a vinyl addition polymer. As used herein, the term “vinyl addition polymer” refers to a polymer obtained by the addition polymerisation reaction of one or more vinyl monomers or ethylenically unsaturated monomers, which include, for example, acrylamide-based monomers and acrylate-based monomers. According to a first embodiment of the present invention, useful base polymers include cationic vinyl addition polymers obtained by polymerizing a cationic monomer containing a non-aromatic hydrophobic group, or a mixture of monomers comprising such a monomer. Preferably, when the cationic monomer containing a non-aromatic hydrophobic group is described by the general formula (I)

where the radical R ₁ represents hydrogen or CH ₃ ; and each of the radicals R ₂ and R ₃ is preferably an alkyl group containing from 1 to 3 carbon atoms, suitably from 1 to 2 carbon atoms; A represents oxygen or NH; B means an alkylene group containing from 2 to 8 carbon atoms, suitably from 2 to 4 carbon atoms, or a hydroxypropylene group; R4 is a substituent containing a hydrophobic group, an acceptable non-aromatic hydrocarbon group containing at least 2 carbon atoms, suitably from 3 to 12 and preferably from 4 to 8 carbon atoms; and X ^- is an anionic counterion, usually a halide, such as chloride. The group R ₄ usually includes and is preferably selected from the above linear, branched or cyclic alkyl groups, and the total number of carbon atoms in the groups R ₂ , R ₃ and R _{4 is} usually not less than 4, acceptable not less than 5 and preferably not less than 6. Examples suitable cationic monomers containing a non-aromatic hydrophobic group include (meth) acryloxyethyl-N, N-dimethyl-Nn-butylammonium chloride, (meth) acryloxyaminoethyl N, N-dimethyl-Nn-butylammonium chloride, (meth) acryloxypropyl-N, N dimethyl-Nt-butylammonium chloride, (meth) acry loxyaminopropyl-N, N-dimethyl-Nt-butylammonium chloride, (meth) acryloxyaminopropyl-N, N-dimethyl-Nn-hexylammonium chloride, (meth) acryloxyethyl-N, N-dimethyl-Nn-hexylammonium chloride, (meth) acryloxyethyl-N, , -dimethyl-N-methylcyclohexylammonium chloride; and (meth) acryloxyamino-propyl-N, N-dimethyl-N-methylcyclohexylammonium chloride.

где радикал R₁ представляет собой водород или группу СН₃; А означает кислород или NH; В представляет собой алкиленовую группу, содержащую от 2 до 8 атомов углерода, приемлемо от 2 до 4 атомов углерода, или гидроксипропиленовую группу, или наоборот, оба радикала А и В не означают ничего, когда между С и N находится простая связь (O=С-NR₅R₆); каждый из радикалов R₅ и R₆ представляет собой водород или заместитель, содержащий гидрофобную группу, приемлемо углеводородную группу, предпочтительно алкил, содержащий от 1 до 6, приемлемо от 1 до 4 и обычно от 1 до 3 атомов углерода. Примеры пригодных для использования сополимеризуемых мономеров этого типа включают (мет)акриламид; мономеры на основе акриламида, такие как N-алкил(мет)акриламиды и N,N-диалкил(мет)акриламиды, например, N-n-пропилакриламид, N-изопропил(мет)акриламид, N-n-бутил (мет)акриламид, N-изобутил(мет)акриламид и N-t-бутил(мет)акриламид; и диалкиламиноалкил(мет)акриламиды, например, диметиламиноэтил(мет)акриламид, диэтиламиноэтил(мет)акриламид, диметиламинопропил(мет)акриламид и диэтиламинопропил(мет)акриламид; мономеры на основе акрилата, такие как диалкиламиноалкил(мет)акрилаты, например, диметиламиноэтил(мет)акрилат, диэтиламиноэтил(мет)акрилат, t-бутиламиноэтил(мет)акрилат и диметиламиногидроксипропилакрилат; и виниламиды, например, N-винилформамид и N-винилацетамид. Предпочтительные сополимеризуемые неионные мономеры включают акриламид и метакриламид, т. е. (мет)акриламид, и основной полимер предпочтительно представляет собой полимер на основе акриламида.The base polymer may be a homopolymer obtained from a cationic monomer containing a non-aromatic hydrophobic group, or a copolymer obtained from a mixture of monomers comprising a cationic monomer containing a non-aromatic hydrophobic group, and one or more copolymerizable monomers. Suitable copolymerizable nonionic monomers include those described by the general formula (II)

where the radical R ₁ represents hydrogen or a group of CH ₃ ; A means oxygen or NH; B represents an alkylene group containing from 2 to 8 carbon atoms, suitably 2 to 4 carbon atoms, or a hydroxypropylene group, or vice versa, both radicals A and B mean nothing when there is a simple bond between C and N (O = C -NR ₅ R ₆ ); each of the radicals R ₅ and R ₆ represents hydrogen or a substituent containing a hydrophobic group, an acceptable hydrocarbon group, preferably an alkyl containing from 1 to 6, suitably from 1 to 4 and usually from 1 to 3 carbon atoms. Examples of suitable copolymerizable monomers of this type include (meth) acrylamide; acrylamide-based monomers such as N-alkyl (meth) acrylamides and N, N-dialkyl (meth) acrylamides, for example Nn-propylacrylamide, N-isopropyl (meth) acrylamide, Nn-butyl (meth) acrylamide, N-isobutyl (meth) acrylamide and Nt-butyl (meth) acrylamide; and dialkylaminoalkyl (meth) acrylamides, for example dimethylaminoethyl (meth) acrylamide, diethylaminoethyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide and diethylaminopropyl (meth) acrylamide; acrylate-based monomers such as dialkylaminoalkyl (meth) acrylates, for example dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate and dimethylaminohydroxypropyl acrylate; and vinylamides, for example, N-vinylformamide and N-vinylacetamide. Preferred copolymerizable nonionic monomers include acrylamide and methacrylamide, i.e., (meth) acrylamide, and the base polymer is preferably an acrylamide-based polymer.

где радикал R₁ представляет собой водород или СН₃, каждый из радикалов R₂, R₃ представляет собой водород или, что более предпочтительно, алкильную группу, содержащую от 1 до 3 атомов углерода, приемлемо от 1 до 2 атомов углерода; А означает кислород или NH; В представляет собой алкиленовую группу, содержащую от 2 до 8 атомов углерода, приемлемо от 2 до 4 атомов углерода, или гидроксипропиленовую группу; радикал R₇ представляет собой водород, углеводородную группу, приемлемо алкил, содержащий от 1 до 3 атомов углерода, приемлемо от 1 до 2 атомов углерода, или заместитель, содержащий ароматическую группу, приемлемо фенильную или замещенную фенильную группу, которая может быть присоединена к азоту с помощью алкиленовой группы, обычно содержащей от 1 до 3 атомов углерода, приемлемо от 1 до 2 атомов углерода, например, бензильную группу (-CH₂-C₆H₅) или фенилэтильную группу (-СН₂-СН₂-С₆Н₅); и Х^- означает анионный противоион, обычно метилсульфат или галогенид, такой как хлорид. Примеры пригодных для использования катионных сополимеризуемых мономеров включают соли, полученные при добавлении кислоты, и четвертичные аммониевые соли диалкиламиноалкил(мет)акрилатов и диалкиламиноалкил(мет)акриламидов, упомянутых выше, обычно полученных при использовании таких кислот, как НСl, Н₂SO₄ и т.п., или агентов кватернизации, таких как метилхлорид, диметилсульфат, бензилхлорид и т.п.; и диаллилдиалкиламмонийгалогениды, такие как диаллилдиметиламмонийхлорид. Могут быть также использованы сополимеризуемые анионные мономеры, такие как акриловая кислота, метакриловая кислота, различные сульфированные виниловые мономеры и т. п., предпочтительно в малых количествах.Suitable copolymerizable cationic monomers include those described by the general formula (III)

where the radical R ₁ represents hydrogen or CH ₃ , each of the radicals R ₂ , R ₃ represents hydrogen or, more preferably, an alkyl group containing from 1 to 3 carbon atoms, suitably from 1 to 2 carbon atoms; A means oxygen or NH; B represents an alkylene group containing from 2 to 8 carbon atoms, suitably from 2 to 4 carbon atoms, or a hydroxypropylene group; the radical R ₇ represents hydrogen, a hydrocarbon group, suitably alkyl containing from 1 to 3 carbon atoms, suitably from 1 to 2 carbon atoms, or a substituent containing an aromatic group, suitably a phenyl or substituted phenyl group, which may be attached to nitrogen with using an alkylene group, usually containing from 1 to 3 carbon atoms, from 1 to 2 carbon atoms are acceptable, for example, a benzyl group (—CH ₂ —C ₆ H ₅ ) or a phenylethyl group (—CH ₂ —CH ₂ —C ₆ H ₅ ); and X ^- means an anionic counterion, usually methyl sulfate or a halide such as chloride. Examples of suitable cationic copolymerizable monomers include acid-added salts and quaternary ammonium salts of dialkylaminoalkyl (meth) acrylates and dialkylaminoalkyl (meth) acrylamides mentioned above, usually obtained using acids such as HCl, H ₂ SO _4, and t etc., or quaternization agents such as methyl chloride, dimethyl sulfate, benzyl chloride and the like; and diallyldialkylammonium halides such as diallyldimethylammonium chloride. Copolymerizable anionic monomers such as acrylic acid, methacrylic acid, various sulfonated vinyl monomers, etc., preferably in small amounts, can also be used.

где радикал R₁ означает водород или СН₃; А представляет собой кислород или NH; В представляет алкиленовую группу, содержащую от 2 до 8 атомов углерода, приемлемо от 2 до 4 атомов углерода, или гидроксипропиленовую группу, или наоборот, А и В не имеют никаких значений, тогда как между С и N существует одинарная связь (O= C-NR₈R₉); каждый из радикалов R₈ и R₉, представляет собой водород или заместитель, содержащий гидрофобную группу, приемлемо углеводородную группу, предпочтительно алкил, содержащий от 1 до 6 атомов углерода, по крайней мере, один из радикалов R₈ и R₉ представляет собой заместитель, содержащий гидрофобную группу, приемлемо алкильную группу, содержащую от 2 до 6 и предпочтительно от 3 до 4 атомов углерода. Общее число атомов углерода в группах R₈ и R₉ обычно составляет не меньше 2, приемлемо не меньше 3 и чаще от 3 до 6. Примеры пригодных для использования сополимеризуемых мономеров этого типа включают мономеры на основе акриламида, такие как N-алкил(мет)акриламиды, например, N-этил(мет)акриламид, N-n-пропил(мет)акриламид, N-изопропил(мет)акриламид, N-n-бутил(мет)акриламид, N-t-бутил(мет)акриламид, N-изобутил-(мет)акриламид, N-n-бутоксиметил(мет)акриламид и N-изобутоксиметил(мет)акриламид; N-алкиламиноалкил(мет)акриламид; N,N-диалкиламиноалкил(мет)акриламиды, а также мономеры на основе акрилатов, такие как N-алкиламиноалкил(мет)акрилаты и N,N-диалкиламиноалкил(мет)акрилаты, например, t-бутиламино-2-этил(мет)акрилат.According to a second embodiment of the present invention, suitable base polymers include cationic vinyl addition polymers obtained by polymerizing a mixture of monomers comprising at least one non-cationic ethylenically unsaturated monomer containing a non-aromatic hydrophobic group and at least one cationic ethylenically unsaturated monomer, non-aromatic the hydrophobic group has the meanings indicated above, and the present invention further relates to a cationic vinyl polymer with unity, comprising a non-aromatic hydrophobic group, its preparation and use, as defined in the claims below. Suitable non-cationic monomers containing a non-aromatic hydrophobic group include non-ionic monomers, preferably a non-ionic monomer described by the general formula (IV)

where the radical R ₁ means hydrogen or CH ₃ ; A represents oxygen or NH; B represents an alkylene group containing from 2 to 8 carbon atoms, 2 to 4 carbon atoms are acceptable, or a hydroxypropylene group, or vice versa, A and B have no meanings, while there is a single bond between C and N (O = C- NR ₈ R ₉ ); each of the radicals R ₈ and R ₉ represents hydrogen or a substituent containing a hydrophobic group, an acceptable hydrocarbon group, preferably alkyl containing from 1 to 6 carbon atoms, at least one of the radicals R ₈ and R ₉ represents a substituent, containing a hydrophobic group, an acceptable alkyl group containing from 2 to 6 and preferably from 3 to 4 carbon atoms. The total number of carbon atoms in the groups R ₈ and R _{9 is} usually not less than 2, acceptable not less than 3 and more often from 3 to 6. Examples of suitable copolymerizable monomers of this type include acrylamide-based monomers such as N-alkyl (meth) acrylamides, e.g. N-ethyl (meth) acrylamide, Nn-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, Nn-butyl (meth) acrylamide, Nt-butyl (meth) acrylamide, N-isobutyl- (meth) ) acrylamide, Nn-butoxymethyl (meth) acrylamide and N-isobutoxymethyl (meth) acrylamide; N-alkylaminoalkyl (meth) acrylamide; N, N-dialkylaminoalkyl (meth) acrylamides, as well as acrylate-based monomers such as N-alkylaminoalkyl (meth) acrylates and N, N-dialkylaminoalkyl (meth) acrylates, for example t-butylamino-2-ethyl (meth) acrylate .

где радикал R₁ представляет собой водород или СН₃; А означает кислород или NH; В представляет собой алкиленовую группу, содержащую от 2 до 4 атомов углерода, приемлемо от 2 до 3 атомов углерода, предпочтительно этилен (-CH₂-CH₂-) или пропилен (-CH₂-CH (CH₃) - или -СН (СН₃)-СН₂-); n - целое число не меньше 1, приемлемо от 2 до 40 и предпочтительно от 3 до 20; R₁₀ представляет заместитель, содержащий гидрофобную группу, приемлемо алкил, содержащий не менее 2 атомов углерода, приемлемо от 3 до 12 и предпочтительно от 4 до 8 атомов углерода. Примеры пригодных для использования сополимеризуемых мономеров этого типа включают алкил(моно-, ди- и полиэтиленгликоль)(мет)акрилаты и алкил(моно-, ди- и полипропиленгликоль)(мет)акрилаты, например, этилтригликоль(мет)акрилат и бутилдигликоль(мет)акрилат.Other suitable non-cationic monomers containing a non-aromatic hydrophobic group include non-ionic monomers described by the general formula (V)

where the radical R ₁ represents hydrogen or CH ₃ ; A means oxygen or NH; B represents an alkylene group containing from 2 to 4 carbon atoms, suitably from 2 to 3 carbon atoms, preferably ethylene (—CH ₂ —CH ₂ -) or propylene (—CH ₂ —CH (CH ₃ ) - or —CH ( CH ₃ ) —CH ₂ -); n is an integer of at least 1, acceptable from 2 to 40, and preferably from 3 to 20; R ₁₀ represents a substituent containing a hydrophobic group, suitably alkyl containing at least 2 carbon atoms, suitably from 3 to 12 and preferably from 4 to 8 carbon atoms. Examples of suitable copolymerizable monomers of this type include alkyl (mono-, di- and polyethylene glycol) (meth) acrylates and alkyl (mono-, di- and polypropylene glycol) (meth) acrylates, for example ethyl triglycol (meth) acrylate and butyl diglycol (meth ) acrylate.

 The cationic monomer can be selected from any of the aforementioned cationic monomers, including cationic monomers described by the general formula (I) and (III), as well as diallyldialkylammonium halides such as diallyldimethylammonium chloride. The monomer mixture according to the second embodiment of the present invention may also include other copolymerizable monomers, such as, for example, nonionic monomers described by the above general formula (II), which may not contain a hydrophobic group, suitably acrylamide and methacrylamide, and the aforementioned anionic monomers.

 The main polymers according to the present invention can be obtained from a mixture of monomers, usually containing from 1 to 99 mol%, suitably from 2 to 50 mol% and preferably from 5 to 25 mol% of a monomer containing a non-aromatic hydrophobic group, and from 99 to 1 mol% , suitably 98 to 50 mol% and preferably 95 to 75 mol% of other copolymerizable monomers, which preferably include acrylamide or methacrylamide ((meth) acrylamide), the mixture of monomers suitably contains from 98 to 50 mol% and preferably from 95 to 75 mol % (meth) acrylamide, amount percent in amounts to 100. In accordance with a first embodiment of the present invention monomers comprising non-aromatic hydrophobic group is cationic. According to a second embodiment of the present invention, the monomer containing a non-aromatic hydrophobic group is non-cationic, and the monomer mixture thus also includes a copolymerizable cationic monomer, which is suitably present in an amount of from 2 to 50 mol% and preferably from 5 to 25 mol% .

The base polymer of the present invention can be prepared by polymerizing monomers in a known manner, and the polymerization reaction is suitably carried out in the aqueous phase or the reverse emulsion phase. The monomer (s) used, including the hydrophobic group-containing monomer described above, are preferably at least partially soluble in the aqueous phase. Polymerization processes are well known, and Encyclopedia of Polymer Science and Engineering, Vol.1-18, John Wiley & Sons, 1985, which is hereby incorporated by reference, may be cited. The polymerization is suitably initiated in an aqueous phase containing monomers, a conventional free radical polymerization initiator and optionally a chain transfer agent to modify the molecular weight of the polymer, and is suitably carried out in the absence of oxygen in an inert gas atmosphere, for example, in a nitrogen atmosphere. The polymerization is suitably carried out with stirring, at temperatures between 20 and 100 ^o C, preferably between 40 and 90 ^o C.

 Typically, the charge density of the base polymer is in the range of 0.2 to 5.0 meq / g dry polymer, suitably 0.6 to 3.0. The weight average molecular weight of the synthetic base polymers is usually not less than about 500,000, suitably more than about 1,000,000, and preferably more than about 2,000,000. The upper limit is not critical; it can be approximately 30,000,000, usually 25,000,000 and an acceptable 20,000,000.

 The base polymer of the present invention can be in any state of aggregation, for example, in solid form, for example, in powder form, in liquid form, for example in the form of solutions, emulsions, dispersions, including salt dispersions, etc. When added to the paper composition, the base polymer is suitably in liquid form, for example, in the form of an aqueous solution or dispersion.

The anionic mineral micronized material according to the present invention can be selected from mineral and organic particles. Anionic mineral particles that can be used according to the present invention include anionic particles based on silica and clay smectite type. Preferably, the anionic mineral particles are in the size range of colloidal particles. Silica-based anionic particles, i.e. particles based on SiO ₂ or silicic acid are preferably used, and such particles are usually supplied in the form of aqueous colloidal dispersions, so-called sols.

 Examples of suitable particles based on silicon dioxide include colloidal silicon dioxide and various types of polysilicic acid. Silica-based sols can also be modified to contain other elements, such as aluminum and / or boron, which may be contained in the aqueous phase and / or in the silica-based particles. Suitable silica particles of this type include colloidal, aluminum-modified silica and aluminum silicates. Mixtures of such suitable silica particles may also be used. Dehydration and retention aids including suitable silica-based anion particles are disclosed in US Pat. Nos. 4,388,150; 4,927,498; 4,954,220; 4,961,825; 4980025; 5,277,994; 5,167,891; 5,368,833; 5,447,604; 5,470,435; 5,543,014; 5,571,494; 5,573,674; 5,584,966; 5,603,805; 5,688,482 and 5,707,493, which are incorporated herein by reference.

The silica-based anionic particles suitably have an average particle size of less than about 50 nm, preferably less than about 20 nm, and more preferably in the range of from about 1 to about 10 nm. As is customary in silicon dioxide chemistry, particle size refers to the average size of primary particles that may or may not be aggregated. The specific surface area of the silica-based particles is suitably about 50 m ² / g and preferably more than 100 m ² / g. Typically, the specific surface area can be up to about 1700 m ² / g, and preferably up to 1000 m ² / g. The specific surface can be measured by titration with NaOH in a known manner, for example, as described by Sears in Analytical Chemistry 28 (1956): 12, 1981-1983 and in US Pat. No. 5,176,891. Thus, this specific surface area is the average specific surface of the particles.

In a preferred embodiment of the present invention, the anionic mineral particles are silica-based particles having a specific surface area in the range of 50 to 1000 m ² / g, preferably 100 to 950 m ² / g. This type of silica particle sol also encompasses modified sols, such as silica-based aluminum sols and silica-boron sols. Preferably, the silica-based particles are present in the ash having an S-value in the range of 8 to 45%, preferably 10 to 30%, and containing silica-based particles with a specific surface in the range of 300 to 1000 m ² / g suitably from 500 to 950 m ² / g and preferably from 750 to 950 m ² / g, as noted above, such sols can be modified with aluminum and / or boron. For example, the surface of the particles can be modified with aluminum to a degree of from 2 to 25% of the substitution of silicon atoms. S-value can be measured and calculated as described by Iler & Dalton in J. Phys. Chem. 60 (1956), 955-957. The S-value indicates the degree of aggregation or microgel formation, and lower S-values indicate a higher degree of aggregation.

In another preferred embodiment of the present invention, the silica particles are selected from polysilicic acid and a modified polysilicic acid having a high specific surface area, suitably above about 1000 m ² / g. The specific surface area may be in the range of 1000 to 1700 m ² / g, and preferably 1050 to 1600 m ² / g. The modified polysilicic acid sols may contain other elements, for example aluminum and / or boron, which may be in the aqueous phase and / or in particles based on silicon dioxide. In this chemistry, polysilicic acid is also referred to as polymeric silicic acid, polysilicic acid microgel, polysilicate and polysilicate microgel, which are all encompassed by the term polysilicic acid used in this application. Aluminum-containing compounds of this type are often also referred to as polyaluminosilicate and polyaluminosilicate microgel, both of which are encompassed by the terms colloidal, aluminum-modified silica and aluminum silicate as used herein.

Smectite type clays that can be used in the method of the present invention are known and include natural, synthetic and chemically treated materials. Examples of usable smectite clays include montmorillonite / bentonite, hectorite, beidelite, nontronite and saponite, preferably bentonite, and especially bentonite which preferably has a specific surface area of 400 to 800 m ² / g after swelling. Suitable clays are disclosed in US Pat. Nos. 4,753,710; 5071512 and 5607552, which are incorporated into this application by reference.

 Anionic organic particles that can be used according to the present invention include highly crosslinked anionic vinyl polymers of addition, suitably copolymers comprising an anionic monomer such as acrylic acid, methacrylic acid, and sulfonated or phosphonated vinyl addition monomers, usually copolymerizable with nonionic monomers such as (meth) acrylamide, alkyl (meth) acrylates, etc. Suitable anionic organic particles also include a ionic condensation polymers, for example sols of melaminesulfonic acid.

 In addition to cationic organic polymers containing a hydrophobic group and anionic micronized material, the dewatering and retention agents (agents) of the present invention may also include other components, such as, for example, low molecular weight cationic organic polymers and / or aluminum compounds. The term “dehydration and retention aids” as used herein refers to two or more components (agents, agents or additives) that, when introduced into the pulp, provide better dehydration and / or retention compared to these parameters without administration such components.

 Low molecular weight (hereinafter referred to as HMM) cationic organic polymers that can be used include those that are commonly referred to and used as trash traps (AMUs) for anionic substances.

 AMUs are known as neutralizing and / or fixing agents for harmful anionic substances present in the pulp, and their use in combination with dehydration and retention agents often provides further improvement in dehydration and retention. HMM cationic organic polymer may be natural or synthetic, and preferably it is HMM synthetic polymer. Suitable organic polymers of this type include HMM high charge cationic organic polymers such as polyamines, polyamidoamines, polyethyleneimines, diallyldimethylammonium chloride homo- and copolymers, (meth) acrylamides and (meth) acrylates. With regard to the molecular weight of the base polymer, the molecular weight of the NMM of the cationic organic polymer is preferably lower, it is suitably not less than 2000 and preferably not less than 10000. The upper limit of the molecular weight is usually about 700,000, about 500,000 is acceptable and usually about 200,000.

 The aluminum compounds that can be used according to the present invention include alum, aluminates, aluminum chloride, aluminum nitrate and polyaluminium compounds such as polyaluminium chlorides, polyaluminium sulfates, polyaluminium compounds containing both ions - chloride and sulfate, polyaluminium silicatesulfates and mixtures thereof. Polyaluminium compounds may also contain other anions other than the chloride ion, for example, anions from sulfuric acid, phosphoric acid, organic acids such as citric acid and oxalic acid.

 The components of the dewatering and retention agents of the present invention can be added to the pulp in the usual manner and in any order. It is preferable to introduce the base polymer into the pulp before introducing the anionic micronized material, even if the reverse order of administration can be used. It is also preferable to introduce the base polymer prior to the shear stage, which can be selected from pumping, mixing, clarification, etc. , and introduce anionic particles after such a shear step. When using HMM, a cationic organic polymer and / or aluminum compound, such components are preferably introduced into the pulp prior to the introduction of the base polymer and anionic micronized material. Conversely, HMM cationic organic polymer and the base polymer can be introduced into the pulp almost simultaneously, either individually or in a mixture, for example, as disclosed in US patent 5858174, which is incorporated into this description by reference.

The components of the present dewatering and retention agents are added to the pulp to be dehydrated in quantities that can vary widely, depending on inter alia, type and number of components, type of pulp, filler content, filler type, injection point, salt content, etc. Typically, these components are added in an amount that achieves better dehydration and / or retention than those achieved in the absence of these components. The base polymer is usually added in an amount of at least 0.001%, often at least 0.005% by weight based on the dry weight of the pulp, and the upper limit is usually 3% and 1.5% by weight is acceptable. Anionic micronized material is usually added in an amount of at least 0.001% by weight, often at least 0.005% by weight, based on the dry pulp residue, and the upper limit is usually 1.0% and suitably 0.6% by weight. When using anionic particles based on silicon dioxide, the total input amount of them is acceptable in the range from 0.005 to 0.5% by weight, calculated on SiO ₂ and based on the dry residue of the pulp, preferably in the range from 0.01 to 0, 2% by weight. When using a cationic organic polymer in the NMM method, it can be added in an amount of at least 0.05% based on the dry weight of the pulp to be dehydrated. It is acceptable when this amount is a value lying in the range of values from 0.07 to 0.5%, preferably in the range of values from 0.1 to 0.35%. In the case when an aluminum compound is used in the implementation of the present method, its total amount introduced into the pulp to be dehydrated depends on the type of aluminum compound used and other expected effects. For example, it is well known that aluminum compounds are used as precipitants for rosin-based sizing agents. Typically, the total input amount is not less than 0.05%, calculated on Al ₂ O ₃ and the dry matter mass of the pulp. It is acceptable when this amount is in the range of 0.5 to 3.0%, preferably in the range of 0.1 to 2.0%.

The method of the present invention is preferably used in the manufacture of paper from a suspension containing cellulosic fibers and optional fillers, which has a high conductivity. Typically, the specific conductivity of the pulp that is dehydrated on the grid is not less than 0.75 mS / cm, acceptable not less than 2.0 mS / cm, preferably not less than 3.5 mS / cm. Very good results were obtained with conductivity levels above 5.0 mS / cm and even above 7.5 mS / cm. The conductivity can be measured on standard equipment, such as, for example, the WTW LF 539 instrument supplied by Christian Berner. The above values are suitably determined by measuring the specific conductivity of the cellulosic suspension, which is supplied to the pressure vessel or which is located in the pressure vessel of the paper machine, or, conversely, by measuring the specific conductivity of white water obtained by dewatering the suspension. High levels of conductivity indicate a high content of salts (electrolytes), while various salts can be based on mono-, bi- and multivalent cations, such as alkali metal cations, for example, Na ⁺ and K ⁺ , alkaline earth metals, for example Ca ^{2 +} and Mg ²⁺ , aluminum ions, for example Al ³⁺ , Al (OH) ²⁺ and polyaluminium ions, and mono-, di- and multivalent anions, such as halides, for example, Cl ^- , sulfates, for example, SO ₄ ^{2 -} and HSO ₄ ^- , carbonates, for example, CO ₃ ^{2 -} and HCO ₃ ^- , silicates and lower organic acids. The present invention is particularly applicable in the manufacture of paper from pulp having a high salt content of divalent and multivalent cations, and usually this content is not less than 200 ppm, acceptable not less than 300 ppm, and preferably not less than 400 ppm. The source of salts can be cellulosic fibers and fillers used in pulp preparation, in particular in separate plants, where concentrated aqueous suspensions of fiber from a paper mill are usually mixed with water and get diluted w suspension suitable for paper manufacture in the paper mill. The source of salt can also be various additives introduced into the pulp, fresh water supplied to the process, or they can be introduced intentionally, etc. In addition, the salt content is usually higher in those processes in which extensive white water is recycled, which can lead to a significant accumulation of salts in the water circulating in the process.

 Accordingly, the present invention is also suitable for use in papermaking processes in which white water is widely recycled, i.e. with a high degree of use of white water, for example, where 0 to 30 tons of fresh water are used per tonne of dry paper obtained, typically less than 20, acceptable less than 15, preferably less than 10 and noticeably less than 5 tons of fresh water per ton of paper. Recycling the white water obtained in the process, suitably includes mixing white water with cellulosic fibers and / or optional fillers to form a suspension to be dehydrated; preferably, when it involves mixing white water with a slurry containing cellulosic fibers and optional fillers, before the slurry enters the dewatering mold. White water may be mixed with the suspension before, between, or after the administration of dehydration and retention agents. Fresh water can be introduced into the process at any stage; for example, it can be mixed with cellulose fibers in order to obtain a suspension, and it can be mixed with a suspension containing cellulose fibers to dilute it so that a suspension to be dehydrated is formed before or after mixing the pulp with white water and before between or after the administration of dehydration and retention agents.

 Of course, other additives that are traditional for the papermaking industry can be used in combination with the additives of the present invention, such as, for example, dry strength agents, wet strength agents, sizing agents, for example, rosin-based sizing agents and ketene dimers and acid anhydrides, optical brighteners, dyes, etc. The cellulosic suspension or pulp may also contain conventional mineral fillers, such as, for example, kaolin, Chinese clay, titanium dioxide, gypsum, talc and natural and synthetic calcium carbonates, such as chalk, ground marble and precipitated calcium carbonate.

The method of the present invention is used to make paper. Used in the present description, the term "paper", of course, includes not only paper and its production, but also other sheet or roll products, such as, for example, cardboard (weighing up to 250 g / cm ³ ) and thin cardboard, and their production. This method can be used to make paper from various types of suspensions of cellulose-containing fibers, and such suspensions should suitably contain not less than 25% by weight and preferably not less than 50% by weight of such fibers based on the dry residue. These suspensions can be based on fibers from chemical pulp, for example, sulfate, sulfite and organosolve pulps, mechanical pulp, for example sulfite and organosolve pulp, mechanical pulp, such as thermomechanical pulp, chemo-thermomechanical pulp, refiner pulp and wood-fiber pulp as from coniferous and deciduous species of wood, and can also be based on secondary fibers, not necessarily from pulps after removing paint, and mixtures thereof.

 The invention is further illustrated by the following examples, which, however, do not limit the scope of its claims. Parts and% refer to parts by weight and% by weight, respectively, unless otherwise indicated.

Example 1
Cationic polymers are prepared by polymerizing a mixture of monomers according to the following general procedure:
The monomers and initiator, 2,2'-azobis (2-amidinopropane) dihydrochloride (Wako V-50), are introduced into the aqueous phase and the polymerization is carried out for approximately 24 hours at 45 ^{° C.} under stirring under nitrogen atmosphere. The cationic polymer, which was obtained as a clear gel, was dissolved in water and used as a 0.1% aqueous solution.

The polymers of the present invention, P1 and P2, and polymers intended for comparative purposes, Ref. l and Ref. 2, are prepared from the indicated monomers in the indicated amounts:
P1: acrylamide (90 mol%), and acryloxyethyl dimethyl n-butylammonium chloride (10 mol%);
P2: acrylamide (90 mol%) and acryloxyethyl dimethylmethylcyclohexylammonium chloride (10 mol%);
P3: acrylamide (90 mol%), methacryloxyaminopropyltrimethylammonium chloride (5 mol%), and methacryloxyethyl t-butylamine (5 mol%);
P4: acrylamide (90 mol%), methacryloxyaminopropyltrimethylammonium chloride (5 mol%), and N-isopropylacrylamide (5 mol%);
P5: acrylamide (90 mol%), methacryloxyaminopropyltrimethylammonium chloride (5 mol%), and Nt-butyl acrylamide (5 mol%);
Ref. 1: acrylamide (90 mol%), and acryloxyethyltrimethylammonium chloride (10 mol%).

 Ref. 2: acrylamide (95 mol%), and acryloxyethyltrimethylammonium chloride (5 mol%).

Example 2
The dewatering and retention rates are evaluated using a Dynamic Drainage Analyzer Analyzer (DDA) supplied by Akribi, Sweden, which measures the dewatering time of a certain amount of pulp passing through the mesh while removing the plug and creating a vacuum on the opposite side of the mesh on which the pulp is located. The retention of the first pass (mixture) is evaluated by measuring with the help of a nephelometer the turbidity of the filtrate, white water obtained by dehydration of the pulp.

Use a paper composition based on 56% by weight of pulp from bleached with TMP / SGW peroxide pulp (80/20), 14% by weight of bleached birch / pine sulfate pulp (60/40), enriched to 200 ^o CSF, and 30% by mass of Chinese clay. To the pulp, add 40 g / l of colloidal fraction, bleached water from the SC plant, filtered through a 5 μm gauze and concentrated using a UV filter, 200,000 fraction. Pulp volume is 800 ml, 0.14% consistency and pH 7.0 . The conductivity was adjusted to about 2.5 mS / cm by adding calcium chloride (400 ppm Ca).

 The pulp is mixed in a container with a flow turbulator at a speed of 1500 rpm throughout the experiment, and the components are added as follows: i) the cationic polymer is introduced into the mixture, followed by stirring for 30 seconds, ii) the anionic micronized material is introduced into the mixture with followed by stirring for 15 seconds, iii) dehydrate the mixture while recording the dehydration time.

The cationic polymers tested in this example are polymers P1 and Ref.1 according to example 1. The anionic micronized material used in this example is a sol of particles based on silica of the type disclosed in US Pat. No. 5,368,833. The sol has
s-value of about 25% and contains particles of silicon dioxide with a specific surface area of about 900 m ² / g, which are surface-modified with aluminum to a degree of 5%. Silica-based sols are added to the mixture in an amount of 1.5 kg / ton based on SiO ₂ and dry pulp residue.

 Table 1 shows the values of dehydration times and retention values at various dosages P1 and Ref.1, calculated on the dry polymer of the dry pulp residue (kg / t).

Example 3
In this series of experiments, the effect of dehydration and retention is evaluated by the method described in example 2.

 The same paper composition was used as in Example 2. The loading volume was 800 ml and a pH of about 7, and the conductivity was adjusted to 7.0 mS / cm by adding calcium chloride (1300 ppm Ca), thereby simulating very high electrolyte content and a high degree of use of white water.

The anionic mineral material of Example 2 is likewise used in this example and added in an amount of 1.5 kg / t based on SiO ₂ and on dry pulp residue.

In this example, polymers P1, P2 and Ref.1 are used, as in example 1. In table. 2 shows data on the effect of various dosages P1, P2 and Ref.1 on the effect of dehydration and retention calculated on SiO ₂ and based on the dry residue of paper pulp.

Example 4
In this series of experiments, the effect of dehydration and retention is evaluated in accordance with the procedure described in example 2.

The paper mixture used in this example is similar to the mixture used in example 3 and has a specific conductivity of about 7.0 mS / cm (1300 ppm Ca). Anionic mineral material, as in example 2, is added in an amount of 1.5 kg / t, calculated on SiO ₂ and the dry residue of the mixture. Polymers P3 and Ref.1 were used, as in example 1.

 In the table. Figure 3 presents the results of experiments on dehydration at various dosages P3 and Ref.1, calculated on the dry polymer of the dry residue of the mixture.

Example 5
In this series of experiments, the effect of dehydration is evaluated according to the procedure described in example 2.

 The paper mixture used in this series of experiments is similar to that in Example 2 and has a specific conductivity of about 2.5 mS / cm. Used polymers P4, P5 and Ref.2 are the same as in example 1, and they are added in an amount of 2 kg / t, calculated on the dry polymer dry residue of the mixture. Anionic mineral material, as in example 2, is similarly used in this series of experiments.

In the table. 4 presents the results of experiments on dehydration at various dosages of anionic mineral material based on SiO ₂ and the dry residue of the mixture.

Example 6
In this series of experiments, the effects of dehydration and retention are evaluated in accordance with the procedure described in example 2.

 The paper mixture is the same as in Example 2. The volume of the mixture is 800 ml and a pH of about 7. Sodium chloride (550 ppm Na) and calcium chloride are introduced into the mixture in order to bring the specific conductivity to 5.0 mS / cm ( 400 ppm Ca) and 7.0 mS / cm (1300 ppm Ca).

 Polymers P2, P3, Ref. 1 and anionic microparticles, as in Example 1, are similarly used in this series of experiments in combination with a low molecular weight cationic polyamine. Prior to the introduction of the cationic acrylamide-based polymer, polyamine is added to the pulp, followed by stirring for 30 seconds. Polyamine is added in an amount of 3 kg / t, calculated on the dry polymer of the dry residue of the mixture. The main polymers P2, P3 and Ref.l are added in an amount of 1.5 kg / t, calculated on the dry polymer of the dry residue of the mixture.

In the table. 5 presents data on the effect of dehydration and retention at various specific conductivities and dosages of particles based on silicon dioxide, calculated on SiO ₂ and on the dry residue of the mixture.

Example 7
In this series of experiments, the effects of dehydration and retention are evaluated by the same procedure as described in example 2.

 The paper mixture is the same as in Example 2. The volume of the mixture is 800 ml and a pH of about 7. Various amounts of sodium chloride are added to the mixture to bring the specific conductivity to 2.5 mS / cm (550 ppm Na) ( Series of experiments 1-3), 5.0 mS / cm (1470 parts per million Na) (Series of experiments 4-6) and 10.0 ms / cm (3320 parts per million Na) (Series 7-9) .

 The same cationic polymers P1-P3 and Ref.1 are used as in Example 1. The anionic micronized material used is a hydrated suspension of powdered bentonite Na in water.

 In the table. Figure 6 shows the effect of dehydration and retention at various dosages of the cationic polymer based on the dry polymer of the dry residue of the mixture and bentonite based on the dry residue of the dry residue of the mixture.

Claims (34)

 1. A method of manufacturing paper from a suspension containing cellulosic fibers and optional fillers, comprising adding dehydration and retention aids to this suspension, including a cationic organic polymer and anionic micronized material, molding and dewatering the suspension on a mesh, characterized in that the cationic organic polymer contains a non-aromatic a hydrophobic group, which is an alkyl group containing at least 3 carbon atoms, selected from groups such as n-propyl, isopropyl, n-butyl, isobutyl, m-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl and dodecyl and the mesh-dehydrated suspension has a specific conductivity of at least 2.0 mS / cm.  2. The method according to p. 1, characterized in that the cationic organic polymer is a vinyl addition polymer comprising in the polymerized form at least one non-cationic monomer containing a non-aromatic hydrophobic group and at least one cationic monomer.  3. The method according to p. 1 or 2, characterized in that the hydrophobic group is attached to nitrogen or oxygen, which, in turn, is attached to the polymer chain through a chain of atoms.  4. The method according to any one of paragraphs. 1, 2 or 3, characterized in that the hydrophobic group is an alkyl group containing from 4 to 8 carbon atoms.  5. The method according to any one of the preceding paragraphs, characterized in that the cationic organic polymer is an acrylamide-based polymer. 6. The method according to any one of the preceding paragraphs, characterized in that the cationic organic polymer comprises in a polymerized form a cationic monomer containing a non-aromatic hydrophobic group described by the general formula (I)

where the radical R ₁ represents hydrogen or CH ₃ ;
each of the radicals R ₂ and R ₃ represents an alkyl group containing from 1 to 2 carbon atoms;
A means oxygen or NH;
B represents an alkylene group containing from 2 to 4 carbon atoms, or a hydroxypropylene group;
R ₄ means a substituent containing an alkyl group containing from 4 to 8 carbon atoms;
X ^- means anionic counterion. 7. The method according to any one of the preceding paragraphs, characterized in that the cationic organic polymer comprises in a polymerized form a non-ionic monomer containing a non-aromatic hydrophobic group described by the general formula (IV)

where the radical R ₁ represents hydrogen or CH ₃ ;
A means oxygen or NH;
B represents an alkylene group containing from 2 to 4 carbon atoms, or a hydroxypropylene group or, conversely, A and B do not mean anything, while there is a simple bond between C and N (O = C-NR ₈ R ₉ );
each of the radicals R ₈ and R ₉ represents hydrogen or a substituent containing an alkyl group containing from 1 to 6 carbon atoms, at least one of the radicals R ₈ and R ₉ is a substituent containing an alkyl group having from 3 to 4 atoms carbon. 8. The method according to any one of the preceding paragraphs, characterized in that the cationic organic polymer comprises in a polymerized form a non-ionic monomer containing a non-aromatic hydrophobic group described by the general formula (V)

where the radical R ₁ represents hydrogen or CH ₃ ;
A means oxygen;
B represents an alkylene group containing from 2 to 4 carbon atoms;
n is an integer of at least 1;
the radical R ₁₀ represents alkyl having at least 2 carbon atoms.  9. The method according to any of the preceding paragraphs, characterized in that the cationic organic polymer is a vinyl addition polymer obtained from a mixture of monomers comprising from 5 to 25 mol% of a monomer containing a non-aromatic hydrophobic group and from 95 to 75 mol% of other copolymerizable monomers .  10. The method according to any one of the preceding paragraphs, characterized in that the anionic micronized material is selected from particles based on silicon dioxide and bentonite.  11. The method according to any one of the preceding paragraphs, characterized in that the means of dehydration and retention also include a low molecular weight cationic organic polymer.  12. The method according to any one of the preceding paragraphs, characterized in that the suspension to be dehydrated on the grid has a specific conductivity of at least 3.5 mS / cm.  13. The method according to any one of the preceding paragraphs, characterized in that it further includes dewatering the suspension on a grid to obtain a wet paper web and white water, recycling white water and optionally adding fresh water to obtain a suspension to be dehydrated containing cellulosic fibers and optional fillers, the amount of fresh water introduced is less than 30 tons per 1 ton of dry paper obtained.  14. The method according to any one of the preceding paragraphs, characterized in that less than 10 tons of fresh water per 1 ton of dry paper obtained is introduced into the process. 15. A method of manufacturing paper from a suspension containing cellulosic fibers and optional excipients, comprising adding dehydration and retention agents to this suspension, including a cationic organic polymer and anionic micronized material, molding and dewatering the suspension on a mesh, characterized in that the mesh-dehydrated suspension has the specific conductivity is not less than 2.0 mS / cm and the cationic organic polymer contains in the polymerized form one or more monomers, including at least about yn monomer having a non-aromatic hydrophobic group selected from (i) a cationic monomer having a non-aromatic hydrophobic group and represented by the general formula (I)

where the radical R ₁ means hydrogen or CH ₃ ;
each of the radicals R ₂ and R ₃ represents hydrogen or an alkyl group containing from 1 to 3 carbon atoms;
A means oxygen or NH;
B represents an alkylene group containing from 2 to 8 carbon atoms, or a hydroxypropylene group;
R ₄ is a substituent containing a non-aromatic hydrophobic group containing from 3 to 12 carbon atoms;
X ^- means anionic counterion;
(ii) a non-ionic monomer containing a non-aromatic hydrophobic group described by the general formula (IV)

where R ₁ represents hydrogen or CH ₃ ;
A means oxygen or NH;
B represents an alkylene group containing from 2 to 8 carbon atoms, or a hydroxypropylene group, or A and B have no meaning, while there is a simple bond between C and N (O = C-NR ₈ R ₉ );
each of the radicals R ₈ and R ₉ means hydrogen or a substituent containing a non-aromatic hydrophobic group containing from 1 to 6 carbon atoms, at least one of the radicals R ₈ and R ₉ is a substituent containing a hydrophobic group having from 2 to 6 atoms carbon;
(iii) a non-ionic monomer containing a non-aromatic hydrophobic group described by the general formula (V)

where R ₁ represents hydrogen or CH ₃ ;
A means oxygen or NH;
B represents an alkylene group containing from 2 to 4 carbon atoms;
n is an integer of at least 1;
R ₁₀ is a substituent containing a hydrophobic group having at least 2 carbon atoms.  16. The method according to p. 15, characterized in that the cationic organic polymer is a vinyl addition polymer comprising in the polymerized form at least one non-cationic monomer containing a non-aromatic hydrophobic group and at least one cationic monomer.  17. The method according to p. 15 or 16, characterized in that the hydrophobic group is attached to nitrogen or oxygen, which, in turn, is attached to the polymer chain through a chain of atoms.  18. The method according to any one of paragraphs. 15, 16 or 17, characterized in that the hydrophobic group is an alkyl group containing from 4 to 8 carbon atoms.  19. The method according to any one of the preceding paragraphs, characterized in that the cationic organic polymer is an acrylamide-based polymer. 20. The method according to any one of the preceding paragraphs, characterized in that the cationic organic polymer comprises in a polymerized form a cationic monomer containing a non-aromatic hydrophobic group described by the general formula (I)

where the radical R ₁ represents hydrogen or CH ₃ ;
each of the radicals R ₂ and R ₃ represents an alkyl group containing from 1 to 2 carbon atoms;
A means oxygen or NH;
B represents an alkylene group containing from 2 to 4 carbon atoms, or a hydroxypropylene group;
R ₄ means a substituent containing an alkyl group containing from 4 to 8 carbon atoms;
X ^- means anionic counterion. 21. The method according to any one of the preceding paragraphs, characterized in that the cationic organic polymer comprises in a polymerized form a non-ionic monomer containing a non-aromatic hydrophobic group described by the general formula (IV)

where the radical R ₁ represents hydrogen or CH ₃ ;
A means oxygen or NH;
B represents an alkylene group containing from 2 to 4 carbon atoms, or a hydroxypropylene group or, conversely, A and B do not mean anything, while there is a simple bond between C and N (O = C-NR ₈ R ₉ );
each of the radicals R ₈ and R ₉ represents hydrogen or a substituent containing an alkyl group containing from 1 to 6 carbon atoms, at least one of the radicals R ₈ and R ₉ is a substituent containing an alkyl group having from 3 to 4 atoms carbon. 22. The method according to any one of the preceding paragraphs, characterized in that the cationic organic polymer comprises in a polymerized form a non-ionic monomer containing a non-aromatic hydrophobic group described by the general formula (V)

where the radical R ₁ represents hydrogen or CH ₃ ;
A means oxygen;
B represents an alkylene group containing from 2 to 4 carbon atoms;
n is an integer of at least 1;
the radical R ₁₀ represents alkyl having at least 2 carbon atoms.  23. The method according to any one of the preceding paragraphs, characterized in that the cationic organic polymer is a vinyl addition polymer obtained from a mixture of monomers comprising from 5 to 25 mol% of a monomer containing a non-aromatic hydrophobic group and from 95 to 75 mol% of other copolymerizable monomers .  24. The method according to any one of the preceding paragraphs, characterized in that the anionic micronized material is selected from particles based on silicon dioxide and bentonite.  25. The method according to any one of the preceding paragraphs, characterized in that the means of dehydration and retention also include a low molecular weight cationic organic polymer.  26. The method according to any one of the preceding paragraphs, characterized in that the suspension to be dehydrated on the grid has a specific conductivity of at least 3.5 mS / cm.  27. The method according to any one of the preceding paragraphs, characterized in that it further includes dewatering the suspension on a grid to obtain a wet paper web and white water, recycling white water and optionally adding fresh water to obtain a suspension to be dehydrated containing cellulosic fibers and optional fillers, the amount of fresh water introduced is less than 30 tons per 1 ton of dry paper obtained.  28. The method according to any one of the preceding paragraphs, characterized in that less than 10 tons of fresh water per 1 ton of dry paper obtained is introduced into the process. 29. A cationic vinyl addition polymer containing in polymerized form at least one non-cationic monomer comprising a non-aromatic hydrophobic monomer, at least one cationic monomer and (meth) acrylamide, wherein the cationic vinyl addition polymer is obtained from a mixture of monomers comprising from 75 to 95 mol % (meth) acrylamide;
(a) at least one non-cationic monomer having a non-aromatic hydrophobic group containing a monomer represented by the general formula (IV)

where the radical R ₁ represents hydrogen or CH ₃ ;
A and B have no meaning, while between C and N (O = NR ₈ R ₉ ) there is a simple bond;
R ₈ and R ₉ each mean H or a substituent containing an alkyl group having from 1 to 6 carbon atoms, at least one R ₈ and R ₉ is a substituent containing an alkyl group having from 2 to 6 carbon atoms;
(b) at least one cationic monomer containing a cationic monomer selected from the group consisting of
(i) a cationic monomer represented by the general formula (I)

where the radical R ₁ represents hydrogen or CH ₃ ;
each of the radicals R ₂ and R ₃ means hydrogen or an alkyl group containing from 1 to 3 carbon atoms;
A means oxygen or NH;
B represents an alkylene group containing from 2 to 4 carbon atoms, or a hydroxypropylene group;
R ₄ represents a non-aromatic hydrocarbon group containing from 4 to 8 carbon atoms;
X ^- represents an anionic counterion;
(ii) a cationic monomer represented by the general formula (III)

where the radical R ₁ represents hydrogen or CH ₃ ;
each of the radicals R ₂ and R ₃ represents hydrogen or an alkyl group containing from 1 to 3 carbon atoms;
A means oxygen or NH;
B represents an alkylene group containing from 2 to 4 carbon atoms, or a hydroxypropylene group;
the radical R ₇ represents hydrogen, an alkyl group containing from 1 to 3 carbon atoms, a benzyl group or a phenylethyl group;
X ^- means anionic counterion;
(iii) and mixtures thereof.  30. The cationic vinyl addition polymer according to claim 29, wherein the (meth) acrylamide is acrylamide.  31. The cationic vinyl addition polymer according to claim 29 or 30, wherein the non-aromatic hydrophobic group is an alkyl group selected from n-propyl, isopropyl, n-butyl, isobutyl and m-butyl. 32. The cationic vinyl polymer accession according to any one of paragraphs. 29-31, characterized in that the cationic vinyl addition polymer includes, in a polymerized form, a cationic monomer described by the general formula (I)

where the radical R ₁ represents hydrogen or CH ₃ ;
each of the radicals R ₂ and R ₃ means hydrogen or an alkyl group containing from 1 to 3 carbon atoms;
A means oxygen or NH;
B represents an alkylene group containing from 2 to 4 carbon atoms, or a hydroxypropylene group;
R ₄ represents a non-aromatic hydrocarbon group containing from 4 to 8 carbon atoms;
X ^- is an anionic counterion. 33. The cationic vinyl polymer adherence according to any one of paragraphs. 29-32, characterized in that the cationic vinyl addition polymer includes, in a polymerized form, a cationic monomer described by the general formula (III)

where the radical R ₁ represents hydrogen or CH ₃ ;
each of the radicals R ₂ and R ₃ represents hydrogen or an alkyl group containing from 1 to 3 carbon atoms, suitably from 1 to 2 carbon atoms;
A means oxygen or NH;
B represents an alkylene group containing from 2 to 4 carbon atoms, or a hydroxypropylene group;
the radical R ₇ represents hydrogen, an alkyl group containing from 1 to 3 carbon atoms, a benzyl group or a phenylethyl group;
X ^- means anionic counterion.  34. The cationic vinyl polymer accession according to any one of paragraphs. 29-33, characterized in that the cationic vinyl addition polymer is obtained from a mixture of monomers comprising from 5 to 25 mol% of a non-ionic monomer containing a non-aromatic hydrophobic group and from 95 to 75 mol% of other copolymerizable monomers.

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