Novel polymer and method for producing the same

Abstract

The present invention relates to a novel polyvinylamine polymer, a method for producing the same, and use thereof, particularly for applications in the field of paper production.

Description

Technical Field

[0001] The present invention relates to a novel polyvinylamine polymer, a method for producing the same, and use thereof, particularly for application in the field of paper production.

Background Art

[0002] In the paper industry, there is always a demand for improving the manufacturing methods for paper or cardboard, etc., particularly with regard to cost reduction, yield, productivity, and further the final product characteristics.

[0003] Water-soluble polyamines obtained from Hofmann degradation are known in the paper manufacturing method and are widely used particularly for improving drainage during the formation of paper sheets and for improving their dry resistance. These polymers provide better application performance, enable an increase in the speed of the paper machine, and thus enable an increase in productivity.

[0004] Hofmann degradation is a reaction discovered by Hofmann in the late 19th century, by which it is possible to convert a functional group (e.g., amide) into a primary amine functional group having one less carbon atom. The mechanism of the reaction is described in detail below.

[0005] In the presence of a base (such as soda), a proton is removed from the amide.

[0006]

Chemical formula

[0007] The formed amidate then reacts with the active chlorine (Cl2) of hypochlorite (e.g., in the equilibrium state of NaClO: 2NaOH + Cl2 ⇔ NaClO + NaCl + H2O) to form N-chloramide. To form an anion, the base (NaOH) removes a proton from the chloramide. The anion loses a chlorine ion to form nitrene, which undergoes rearrangement to isocyanate.

[0008]

Chem.

[0009] Carbamate is formed by the reaction of a hydroxide ion and an isocyanate.

[0010]

Chem.

[0011] After decarboxylation of the carbamate (elimination of CO2), a primary amine is obtained.

[0012]

Chem.

[0013] For the conversion of all or part of the amide functional groups of a polymer containing an amide group as an amine functional group, two main factors are involved (expressed as a molar ratio). These are - Coefficient alpha = hypohalite (alkali metal hypohalite and / or alkaline earth metal hypohalite) / amide functional group (and, where applicable, nitrile), - Coefficient beta = hydroxide (alkali metal hydroxide and / or alkaline earth hydroxide) / hypohalite (alkali metal hypohalite and / or alkaline earth metal hypohalite) That is.

[0014] Hofmann degradation initially relates to amide groups but can also be applied to nitrile functional groups (-C≡N), especially those of acrylonitrile polymers.

[0015] Generally, the effectiveness of Hofmann degradation polymers as dry strength agents increases with their cationicity. In other words, in order to increase their cationicity, the polymers used must be highly degraded. Indeed, depending on the degree of alpha of the degradation, it is possible to generate various cationicities associated with the amount of amine functional groups formed on the polymer carbon skeleton.

[0016] The cationicity of the degraded polymer may arise from the amine groups formed that can be protonated, but may also arise from the possible presence of cationic monomers.

[0017] Until recently, only heavy processes using Hofmann degradation product generating units in situ (EP377313), or another polymer (N-vinylformamide polymer based, followed by hydrolysis), which is also a very costly method (US2004 / 118540), have been developed.

[0018] The first practicable industrial solution was proposed at the beginning of 2005 in the applicant's document WO2006075115. In this document, the Hofmann degradation products described are organic polymers produced at a concentration greater than 3.5% by mass. The polymers described in this document can significantly improve the dry strength performance, but their molecular weights are very low, making their interest very limited for applications such as drainage or flocculation.

[0019] The applicant's documents WO2008 / 107620 and WO2010 / 06108 made it possible to partially solve this problem of poor drainage performance. However, the polymers described in these documents show a certain level of performance plateau from the perspective of drainage and yield.

[0020] The applicant's document WO2009 / 013423 also made it possible to increase the drainage performance by proposing a post-treatment of the polymer obtained from the Hofmann reaction. This post-treatment consists of a step of post-branching the copolymer obtained by Hofmann degradation in the presence of at least one polyfunctional branching agent. However, this method had severe limitations, involving highly complex post-branching control (difficult industrialization) and saturation of performance for application amounts greater than 1.5 kg of activity per ton of paper.

[0021] The applicant's document WO2011 / 015783 proposes a novel polymer that can push back the saturation performance, especially with regard to high strength, at about 2 kg of activity per ton.

[0022] Document US10,730,989 relates to a method for producing a (meth)acrylamide copolymer-based papermaking additive.

Prior Art Documents

Patent Documents

[0023]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Patent Document 8

Patent Document 9

Patent Document 10

Non-Patent Literature

[0024]

Non-Patent Literature 1

Summary of the Invention

Problems to be Solved by the Invention

[0025] Despite all of these improvements, there remain unsolved problems associated with Hofmann degradation. The double treatment with base followed by acid in combination with temperature causes a significant decrease in the viscosity of the base polymer. The polymer thus obtained exhibits a reduction in applicable performance.

Means for Solving the Problems

[0026] The applicant has surprisingly discovered that the synthesis of the polymer by the method of the present invention makes it possible to increase the molecular weight of the base polymer without affecting its viscosity. This increase in the molecular weight of the base polymer imparts improved applicable performance to paper from the viewpoint of dry strength while improving drainage, and thus enables an increase in the speed of the paper machine, and therefore, productivity is also thought to be improved.

[0027] The use of the polymer obtained from the present invention is part of the general principle of improving product performance, more specifically, dry strength and drainage characteristics. The improved performance of the polymer according to the present invention makes it possible to reduce the amount of the product required for application, and therefore, this includes reducing the greenhouse gas emissions such as CO2 associated with the production and use of synthetic polymers. In addition, the improvement in drainage reduces the amount of energy required.

[0028] The present invention is a polyvinylamine polymer obtained from the Hofmann degradation reaction of a base polymer, wherein the base polymer is - At least one cationic monomer A, and - At least one nonionic monomer B selected from acrylamide, acrylonitrile, methacrylamide, and mixtures thereof, and - At least one structuring system, At least one compound I selected from allylsulfonic acid, methallylsulfonic acid, allyldisulfonic acid, methallyldisulfonic acid, salts thereof, and mixtures thereof, and Formula (1):

[0029]

Chemical formula

[0030] [Wherein, R1 and R2 are each independently of the other a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, or a CH2-OH group, R1 and R2 are not both hydrogen atoms (when R2 = H, R1 ≠ H; when R1 = H, R2 ≠ H)] At least one compound II of And at least one structuring system containing - Optionally, at least one monomer C that is nonionic, different from monomer B, and different from compound II, and is zwitterionic or hydrophobic, - Optionally, at least one crosslinking agent, and - Optionally, at least one migrating agent Relates to a polyvinylamine polymer containing

[0031] This polyvinylamine polymer is prepared by the following steps: a) A step of forming a solution (S1) containing at least a first fraction (F1) containing at least one monomer selected from monomers A and B and at least one compound selected from compounds I and II, b) A step of polymerization 1 (PO1) of fraction F1 to form a solution of a first gradient polymer (PG1), c) The step of adding a second fraction (F2) containing at least one monomer selected from monomers A and B and at least one compound selected from compounds I and II to a solution containing PG1; d) The step of polymerization 2 (PO2) of fraction F2 to PG1 to form a solution of a second gradient polymer (PG2); e) The step of adding a third fraction (F3) containing at least one monomer selected from monomers A and B and at least one compound selected from compounds I and II to a solution containing PG2; f) The polymerization 3 (PO3) step of fraction F3 to PG2 to form a solution containing a base polymer; g) The steps of diluting the solution containing the base polymer and subjecting the base polymer to Hofmann degradation reaction to obtain a polyvinylamine polymer obtained according to; at least one of fraction F1, F2, or F3 contains at least one monomer A; at least one of fraction F1, F2, or F3 contains at least one monomer B; at least one of fraction F1, F2, or F3 contains at least one compound I; at least one of fraction F1, F2, or F3 contains at least one compound II.

[0032] This polymer does not contain an anionic monomer other than compound I.

[0033] The present invention also relates to a production method for this polyvinylamine polymer.

[0034] The present invention also relates to a production method of paper or cardboard using this polyvinylamine polymer.

[0035] The present invention also relates to the use of this polyvinylamine polymer in the recovery of hydrocarbons (oil and / or gas); in the drilling or cementing of wells (specifically, hydrocarbon wells); in the stimulation of hydrocarbon wells (oil and / or gas), for example, in hydraulic fracturing, conditioning, conversion; in the water treatment of open, closed, or semi-closed cycles; in the treatment of fermentation must; in the treatment of sludge; in construction; in the treatment of timber; in the treatment of hydraulic compositions (concrete, cement, mortar, and aggregates); in mining; in the formulation of cosmetics; in the formulation of detergents; in textile manufacturing; in the geothermal sector; in the manufacture of sanitary napkins; or in agriculture.

[0036] The present invention also relates to the use of the polymer according to the invention as a flocculant, coagulant, binder, fixing agent, viscosity reducer, thickener, absorbent, anti-friction agent, drainage agent, charge-holding agent, dehydrating agent, conditioning agent, stabilizer, fixing agent, film-forming agent, sizing agent, superplasticizer agent, clay inhibitor, or dispersant.

Embodiments for Carrying Out the Invention

[0037] "Polymer" is used to designate a copolymer produced using a structuring system comprising at least two different monomers, namely at least one cationic monomer A and at least one non-ionic monomer B, and at least one compound I and at least one compound II, which may optionally contain at least one zwitterionic hydrophilic monomer and / or one hydrophobic monomer and / or a crosslinking agent and / or a migrating agent.

[0038] In the context of the present invention, the base polymer and the polyvinylamine polymer obtained after Hofmann degradation of the base polymer are water-soluble polymers.

[0039] Water-soluble polymers are 10 g.L in deionized water -1It means a polymer that, when dissolved at a concentration of

[0040] In the present invention, the first and second gradient polymers in steps b) and d) are prepolymers.

[0041] Throughout this specification, the viscosity is measured at 25 °C in an aqueous solution using a Brookfield viscometer.

[0042] In this specification, it is considered that a person skilled in the art can determine a Brookfield viscometer module and a suitable speed for the viscosity range to be measured. In practice, this type of measurement is part of the general knowledge of a person skilled in the art.

[0043] "X and / or Y" designates "X" or "Y", or "X and Y".

[0044] All possible combinations between the various disclosed embodiments, whether these are preferred embodiments or given as examples, are likewise part of the present invention. In addition, when a range of values is given, the end point values are included in these ranges. This disclosure also includes all combinations between the end point values and these ranges of values. For example, the range of values "1 to 20, preferably 5 to 15" includes the ranges "1 to 5", "1 to 15", "5 to 20", and "15 to 20", and the disclosure of the values 1, 5, 15, and 20.

[0045] In this specification, the base polymer designates a water-soluble polymer obtained by the method of the present invention before undergoing the Hofmann degradation reaction according to step g).

[0046] Base polymer The present invention relates to a polyvinylamine polymer obtained from the Hofmann degradation reaction of a base polymer, which is characterized by the method used to obtain it.

[0047] The base polymer according to the present invention is - at least one cationic monomer A, and - at least one nonionic monomer B selected from acrylamide, acrylonitrile, methacrylamide, and mixtures thereof, and - at least one structuring system, comprising (i) at least one compound I selected from allylsulfonic acid, methallylsulfonic acid, allyldisulfonic acid, methallyldisulfonic acid, salts thereof, and mixtures thereof, which is different from at least one monomer A, and (ii) at least one compound II of formula (1):

[0048]

Chemical formula

[0049] [wherein, R1 and R2 are each independently a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, or a CH2-OH group, and R1 and R2 are not both hydrogen atoms at the same time (when R2 = H, R1 ≠ H; when R1 = H, R2 ≠ H)] and at least one structuring system containing is included. is included.

[0050] This base polymer does not contain anionic monomers other than compound I.

[0051] Monomer composition Monomer A The base polymer according to the present invention is a synthetic polymer.

[0052] It may contain one or more cationic monomers (designated as "monomer A").

[0053] Advantageously, the cationic monomer A may in particular be selected from vinyl-type monomers, specifically acrylamide, acrylic, allyl, or maleic having an ammonium functional group, preferably quaternary ammonium. In particular, without limitation, mention may be made of diallyldimethylammonium chloride (DADMAC), acrylamide propyltrimethylammonium chloride (APTAC), and methacrylamide propyltrimethylammonium chloride (MAPTAC), and mixtures thereof. A preferred monomer is diallyldimethylammonium chloride (DADMAC).

[0054] The base polymer advantageously contains from 1 to 60 mol%, preferably from 2 to 50 mol%, more preferably from 3 to 40 mol%, even more preferably from 4 to 30 mol% of the cationic monomer A.

[0055] In a preferred embodiment, the base polymer contains at least 30 mol% of the cationic monomer A.

[0056] Those skilled in the art know, for example, a method for producing a quaternized monomer by an alkyl halide of the R-X type (R is an alkyl group and X is a halogen (specifically methyl chloride)). In addition, the present invention also encompasses DADMAC, APTAC, and MAPTAC-type monomers, and their halide counterions are fluoride, bromide, or iodide instead of chloride.

[0057] Monomer B The base polymer contains one or more nonionic monomers (designated as "monomer B").

[0058] As already shown, the nonionic monomer B is selected from acrylamide, acrylonitrile, methacrylamide, and mixtures thereof.

[0059] The base polymer preferably contains nonionic monomer B in the range of 40 to 99 mol%, preferably 50 to 98 mol%, more preferably 60 to 97 mol%, and even more preferably 70 to 96 mol%.

[0060] Monomer C The base polymer may optionally contain one or more monomers selected from nonionic monomers, zwitterionic monomers, hydrophobic monomers, and mixtures thereof (designated as "monomer C") that are different from monomer B and different from compound II.

[0061] Preferably, when monomer C is nonionic, it may be selected from the group consisting of, in particular, water-soluble vinyl monomers. Preferred monomers belonging to this class are, for example, N-vinylpyrrolidone (NVP), N-vinylimidazole, N-vinylsuccinimide, acryloylmorpholine (ACMO), glycidyl methacrylate, glyceryl methacrylate, diacetone acrylamide, N-vinylformamide, N-vinyl-N-methylformamide, N-vinylacetamide, N-vinyl-N-methylacetamide, N-vinyl-N-ethylacetamide, N-vinyl propianamide, N-vinyl-N-methyl propianamide, N-vinylbutylamide, hydroxyalkyl (meth)acrylate (alkyl of C1-C3), thioalkyl (meth)acrylate (alkyl of C1-C3), and mixtures thereof. A preferred monomer is N-vinylformamide.

[0062] The base polymer of the present invention preferably contains nonionic monomer C in the range of 0 to 40 mol%, preferably 0 to 30 mol%, which is different from monomer B and compound II.

[0063] Advantageously, the zwitterionic monomers that can be used in the context of the present invention are selected in particular from vinyl-type derivatives, specifically acrylamide, acrylic, allyl, or maleic. Preferably, this monomer contains an amine or quaternary ammonium functional group, and a carboxylic (or carboxylate) acid-type functional group, a sulfonic (or sulfonate) acid-type functional group, or a phosphoric (or phosphate) acid-type functional group.The zwitterionic monomer may be selected from acrylate dimethylaminoethyl derivatives, such as 2-((2-(acryloyloxy)ethyl)dimethylammonio)ethane-1-sulfonate, which may be specifically mentioned but not limited thereto, 3-((2-(acryloyloxy)ethyl)dimethylammonio)propane-1-sulfonate, 4-((2-(acryloyloxy)ethyl)dimethylammonio)butane-1-sulfonate, [2-(acryloyloxy)ethyl](dimethylammonio)acetate; methacrylate dimethylaminoethyl derivatives, such as 2-((2-(methacryloyloxy)ethyl)dimethylammonio)ethane-1-sulfonate, 3-((2-(methacryloyloxy)ethyl)dimethylammonio)propane-1-sulfonate, 4-((2-(methacryloyloxy)ethyl)dimethylammonio)butane-1-sulfonate, [2-(methacryloyloxy)ethyl](dimethylammonio)acetate; epropylacrylamide dimethylamino derivatives, such as 2-((3-acrylamidopropyl)dimethylammonio)ethane-1-sulfonate, 3-((3-acrylamidopropyl)dimethylammonio)propane-1-sulfonate, 4-((3-acrylamidopropyl)dimethylammonio)butane-1-sulfonate, [3-(acryloyl)oxy)propyl](dimethylammonio)acetate, dimethylaminopropylmethylacrylamide;, or further, 2-((3-methacrylamidopropyl)dimethylammonio)ethane-1-sulfonate, 3-((3-me dimethylammonio)propane-1-sulfonate, 4-((3-methacrylamidopropyl)dimethylammonio)butane-1-sulfonate, and derivatives such as propyl [3-(methacryloyloxy)](dimethylammonio)acetate, and mixtures thereof.

[0064] Other zwitterionic monomers are described by the applicant in document WO2021123599.

[0065] The base polymer according to the present invention advantageously contains zwitterionic monomer C in an amount between 0.001 and 30 mol%, preferably between 0.01 and 20 mol%, more preferably between 0.1 and 15 mol%.

[0066] Advantageously, the hydrophobic monomer C is an ester of (meth)acrylic acid presenting an alkyl chain of C4 - C 30 an arylalkyl (C4 - C 30 alkyl, C4 - C 30 aryl) which is propoxylated, ethoxylated or ethoxylated and propoxylated; a derivative of (meth)acrylamide presenting an alkyl chain of C1 - C3, an arylalkyl (C4 - C 30 alkyl, C4 - C 30 aryl) or dialkyl (C4 - C 30 alkyl) which is propoxylated, ethoxylated or ethoxylated and propoxylated; an alkylaryl sulfonate (C4 - C 30 alkyl, C4 - C 30 aryl), or a mono - or di - substituted amide of (meth)acrylamide presenting an alkyl chain of C4 - C 30 an arylalkyl (C4 - C 30 alkyl, C4 - C 30 aryl), or a derivative of (meth)acrylamide presenting an alkyl chain of C4 - C 30 an arylalkyl (C4 - C 30 alkyl, C4 - C 30 aryl), or a dialkyl of C4 - C 30 ; an alkylaryl sulfonate (C4 - C 30 alkyl, C4 - C 30 aryl), and mixtures thereof.

[0067] The base polymer generally contains less than 1 mol% of the hydrophobic monomer C. It may also not contain the hydrophobic monomer C.

[0068] When the base polymer according to the invention contains one or more hydrophobic monomers C, they are present in an amount such that the polymer remains water-soluble.

[0069] The amounts of the respective different monomers will be adjusted by those skilled in the art so as not to exceed 100 mol% during the production of the base polymer. Preferably, monomers A and B represent 100 mol% of the monomers of the base polymer.

[0070] Structuring system The structuring system of the base polymer is (i) at least one compound I and (ii) at least one compound II and contains.

[0071] Compound I is preferably selected from allylsulfonic acid, methallylsulfonic acid, allyldisulfonic acid, methallyldisulfonic acid, their salts, and mixtures thereof. Preferably, this is methallylsulfonic acid, for example, sodium methallylsulfonate.

[0072] The chlorinated form preferably corresponds to an alkali metal salt (Li, Na, K...), an alkaline earth metal salt (Ca, Mg...), or an ammonium salt (e.g., ammonium ion or tertiary ammonium). The sodium salt is the preferred salt.

[0073] The base polymer preferably contains compound I between 500 and 50,000 ppm, preferably between 1,000 and 20,000 ppm, more preferably between 2,000 and 10,000 ppm, based on the total mass of monomers A and B (and optionally monomer C) of the base polymer.

[0074] Compound II used in the context of the present invention has the formula (1):

[0075] [Chemical formula]

[0076] [In the formula, R1 and R2 are each independently a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, or a CH2-OH group, R1 and R2 are not both hydrogen atoms (when R2 = H, R1 ≠ H; when R1 = H, R2 ≠ H)] is of this kind.

[0077] The compound II used is preferably selected from N,N-dimethylacrylamide, N,N-diethylacrylamide, N,N-isopropylacrylamide, N-methylolacrylamide, and mixtures thereof. Preferably, it is N,N-dimethylacrylamide.

[0078] The base polymer according to the present invention preferably contains compound II in the range of 500 to 50,000 ppm, preferably in the range of 1,000 to 20,000 ppm, more preferably in the range of 2,000 to 10,000 ppm, based on the total mass of monomers A and B (and optionally monomer C) of the base polymer.

[0079] In the base polymer, the mass ratio of compound I to compound II is preferably in the range of 0.01 to 100, preferably in the range of 0.1 to 10.

[0080] In a preferred embodiment according to the present invention, the amount of compound I is greater than the amount of compound II. Therefore, the mass ratio of compound I to compound II is preferably greater than 1 and 100 or less, preferably greater than 1 and 10 or less.

[0081] Optional The base polymer may further contain at least one crosslinking agent. This crosslinking agent can be selected, for example, from vinyl functional groups, specifically polyethylene unsaturated monomers such as allyl and acrylic (having at least two unsaturated functional groups), or from monomers having at least two epoxy functional groups. For example, methylene bisacrylamide (MBA), triallylamine, tetraallylammonium chloride, 1,2-dihydroxyethylene bis-(N-acrylamide), and mixtures thereof can be mentioned. Preferably, it is methylene bisacrylamide (MBA).

[0082] The amount of the crosslinking agent in the base polymer is advantageously between 5 and 5,000 ppm, more preferably between 50 and 3,000 ppm, based on the total mass of monomers A and B (and optionally monomer C) of the base polymer.

[0083] In a specific embodiment according to the present invention, the base polymer does not contain a crosslinking agent.

[0084] The base polymer according to the present invention may also contain at least one chain transfer agent selected, for example, from methanol, isopropyl alcohol, sodium hypophosphite, 2-mercaptoethanol, and mixtures thereof. Other chain transfer agents include xanthates, dithiocarbonates, dithiocarbamates, and trithiocarbonate types, and mixtures thereof can also be mentioned. Preferably, it is sodium hypophosphite.

[0085] The amount of the crosslinking agent in the base polymer is advantageously between 10 and 10,000 ppm, more preferably between 50 and 5,000 ppm, based on the total mass of monomers A and B (and optionally monomer C) of the base polymer.

[0086] In a specific embodiment according to the present invention, the base polymer does not contain a chain transfer agent.

[0087] Physical characteristics of the base polymer The base polymer advantageously has a weight average molecular weight included between 1,000,000 and 25,000,000 Daltons, preferably between 2,000,000 and 15,000,000 Daltons, more preferably between 3,000,000 and 10,000,000 Daltons. This is the weight average molecular weight.

[0088] The weight average molecular weight is preferably measured by gel permeation chromatography coupled to a MALS detector.

[0089] The base polymer is advantageously obtained and used in liquid form.

[0090] The viscosity of the solution containing the base polymer is advantageously included between 1,000 and 50,000 cps, preferably between 3,000 and 20,000 cps, for example between 5,000 and 20,000 cps.

[0091] Renewable origin In a preferred embodiment according to the invention, the polyvinylamine polymer is produced using at least partially monomers of renewable and non-fossil origin.

[0092] In the context of the present invention, the phrase "renewable and non-fossil origin" designates the origin of a compound resulting from biomass or synthesis gas (syngas), i.e., the result of one or more chemical conversions carried out on one or more raw materials of natural and non-fossil origin. The terms "bio-derived" or "bio-based" can also be used to characterize the renewable and non-fossil origin of a compound. The renewable and non-fossil origin of a compound results from a circular economy and includes, for example, renewable and non-fossil raw materials that have been recycled one or more times previously during a recycling process of materials resulting from biomass, such as materials resulting from polymer depolymerization or from the conversion of pyrolysis oil.

[0093] According to the present invention, "at least partially renewable and non-fossil origin" means a content of bio-derived carbon contained between 5% by mass and 100% by mass, preferably at least 30%, more preferably at least 50%, even more preferably at least 70%, more preferably at least 90%, even more preferably at least 100% based on the total carbon mass of the compound.

[0094] In the context of the present invention, the standard specification ASTM D6866-21, Method B is used to characterize the bio-origin of the compound and determine the bio-derived content of the compound. The value is expressed as the mass percentage of bio-derived carbon relative to the total mass of carbon in the compound.

[0095] Gradient The base polymer and the polyvinylamine polymer according to the present invention are gradient polymers.

[0096] A polymer having a gradient structure is composed of at least two monomers and is a polymer in which the change in the monomer composition is gradual, different from a block polymer that undergoes a sharp change in composition and different from a random polymer that does not have a continuous change in composition. In a gradient polymer, due to the gradual change in composition over the length of the polymer chain, interchain and intrachain repulsive forces are not much observed.

[0097] The gradient can be formed by spontaneous or forced gradients. Spontaneous gradient polymerization is due to different monomer reactivities. Forced gradient polymerization involves varying the monomer composition introduced over the entire polymerization time.

[0098] The forced method of the gradient includes (1) introduction of a first fraction of the monomer into the reactor, (2) addition of at least one additional monomer fraction, preferably different from the first one, and (3) polymerization of the monomer introduced into the reactor. The polymerization of the monomer is initiated by the introduction of the first fraction.

[0099] The addition of the additional monomer fraction may be carried out in parallel with the introduction of the first fraction of the monomer into the reactor (so that the introduction of the fractions can start and end simultaneously). Alternatively, the start of the first monomer supply (first fraction) to the reactor may precede the start of the addition of the second monomer fraction. Alternatively, the first and second fractions can be introduced simultaneously, but the time taken to add the second fraction may be longer than the time taken to add the first fraction to the reactor. This embodiment is also applicable to methods using at least three monomer fractions.

[0100] According to the method of the present invention, the resulting polyvinylamine polymer is formed by the sequential addition of monomers, i.e., it is preferably a forced gradient method.

[0101] The method according to the present invention comprises a first fraction (F1) and at least two additional fractions (F2 and F3). At least one of the fractions F1, F2, and F3 of the method is different from the other fractions. Preferably, the fractions F1, F2, and F3 are different. By different fractions, it means fractions having different monomer compositions (ratio and / or properties of monomers) and / or compounds I and II (ratio and / or properties of compounds I and II), respectively.

[0102] Polymerization method This polyvinylamine polymer comprises the following steps: a) a step of forming a solution (S1) comprising at least a first fraction (F1) containing at least one monomer selected from monomers A and B and at least one compound selected from compounds I and II; b) a step of polymerization 1 (PO1) of fraction F1 to form a solution of the first gradient polymer (PG1); c) a step of adding a second fraction (F2) containing at least one monomer selected from monomers A and B and at least one compound selected from compounds I and II to the solution containing PG1; d) Step of polymerization 2 (PO2) of fraction F2 to PG1 to form a solution of the second gradient polymer (PG2), and e) Step of adding a third fraction (F3) containing at least one monomer selected from monomers A and B and at least one compound selected from compounds I and II to a solution containing PG2, and f) Step of polymerization 3 (PO3) of fraction F3 to PG2 to form a solution containing the base polymer, and g) Steps of diluting the solution containing the base polymer and Hofmann degradation reaction of the base polymer to obtain a polyvinylamine polymer are obtained according to.

[0103] This method may include the addition of additional fractions, but not after step g) of Hofmann degradation.

[0104] The improved performance of the polymer obtained by the method of the present invention may be attributable to the fact that the polymerization is carried out sequentially and continuously, i.e., without interruption.

[0105] By "sequentially", the polymerization of the base polymer monomers is carried out without interruption in several fractions, i.e., the fractions are added continuously and the polymerization does not stop. Each of the different steps a) to f) is carried out sequentially. In other words, to obtain the base polymer at the end of the polymerization, the first fraction of the monomer can be poured in (in a fluid form), polymerized to form the first gradient polymer (PG1), which continues to polymerize with fraction F2 to form the gradient polymer PG2, which itself continues to polymerize with fraction F3. At least one of fractions F1, F2, and F3 is different from the other fractions. Preferably, fractions F1, F2, and F3 are different. By adding different fractions during the polymerization method, it becomes possible to obtain a gradient in the base polymer composition.

[0106] In certain embodiments, the polymerization can be stopped after PO1 and / or PO2 and continued in different localizations. In this embodiment, the fraction F X added to the gradient polymer PG X+1 (X = 1 or 2) polymerizes with and interacts with PG X to form PG X+1 , and the process continues in subsequent steps to ultimately obtain the base polymer.

[0107] When the polymerization is complete, step g) is performed on the base polymer. It may be carried out following the end of the polymerization or at another time (later). Preferably, it is carried out following PO3. In other words, the base polymer used for step g) no longer continues to polymerize. However, it undergoes post-treatment to modify its chemical structure. Since step g) requires dilution of the solution containing the base polymer, it is advantageously carried out in a reactor different from the polymer base synthesis reactor. The dilution of the base polymer is advantageously carried out in water.

[0108] The Hofmann degradation of step g) is advantageously carried out on the polymer using an amide group.

[0109] In the polymerization process according to the present invention, the sum of the molar percentages of the monomers of the different fractions is equal to the sum of the molar percentages of the monomers of the polyvinylamine polymer.

[0110] Step a), formation of the solution (S1) containing the first fraction (F1) Solution (S1) Solution S1 generally - a solvent, - an initiator, - and the first fraction F1 and contains.

[0111] The solvent is advantageously water or a solvent in which the monomers and the base polymer are soluble. Preferably, the solvent is water.

[0112] The polymerization initiator to be used may be any compound that dissociates into radicals under the polymerization conditions. For example, organic peroxides, hydroperoxides, hydrogen peroxide, persulfates, azo compounds, and redox couples. The use of water-soluble initiators is preferred. In some cases, it is advantageous to use a mixture of various polymerization initiators, for example, a mixture of a redox catalyst and an azo compound. A preferred initiator is persulfate.

[0113] In a specific embodiment, solution S1 is formed by mixing a solvent, an initiator, and fraction F1 in a polymerization reactor.

[0114] In this specific embodiment, fraction F1 may be added to the solvent / initiator mixture all at once, in portions, or poured in (in a flowing form), that is, gradually continuously (for example, by dropping). Preferably, fraction F1 is added to the polymerization reactor all at once.

[0115] In a specific embodiment of the present invention, the initiator and fraction F1 are poured into the polymerization reaction containing a solvent (in a flowing form). They may be added separately or pre-mixed. Preferably, they are added separately.

[0116] In a preferred embodiment of the present invention, the initiator is added continuously throughout the polymerization process. In this case, the initiator is advantageously added in parallel with different fractions during different polymerization steps, as well as during possible aging steps of different gradient polymers (PG1 and PG2) and the base polymer.

[0117] In this preferred embodiment of the present invention, the duration of the initiator injection is between 50 minutes and 560 minutes, preferably between 130 minutes and 430 minutes.

[0118] The first fraction (F1) Advantageously, fraction F1 contains monomers (A and / or B, and optionally C) between 10 and 45% by weight, preferably between 15 and 40% by weight, based on the total weight of the monomers (A and / or B, and optionally C) of the base polymer.

[0119] Fraction F1 advantageously contains cationic monomer A between 0 and 65 mol%, preferably between 5 and 55 mol%, based on the total number of moles of monomers in fraction F1.

[0120] Fraction F1 advantageously contains non-ionic monomer B between 35 and 100 mol%, preferably between 45 and 95 mol%, based on the total number of moles of monomers in fraction F1.

[0121] Fraction F1 advantageously contains compound I between 250 and 30,000 ppm, preferably between 500 and 10,000 ppm, more preferably between 1,000 and 7,000 ppm, based on the total weight of monomers A and B (and optionally monomer C) of the base polymer.

[0122] Fraction F1 advantageously contains compound II between 250 and 30,000 ppm, preferably between 500 and 10,000 ppm, more preferably between 1,000 and 5,000 ppm, based on the total weight of monomers A and B (and optionally monomer C) of the polyvinylamine polymer.

[0123] The different monomers and compounds constituting fraction F1 are advantageously added in the form of solutions. These solutions can be added to the polymer reactor separately or as a mixture, all at once, in several portions, or poured in (in a flowing form) to form solution S1. Preferably, the addition is made as a mixture and added all at once.

[0124] When fraction F1 is poured in (in a flowing form), the pouring advantageously continues for between 10 and 80 minutes, preferably between 40 and 70 minutes.

[0125] In a preferred embodiment, fraction F1 is prepared in a reactor (polymerization reactor) before the addition of the initiator.

[0126] In a preferred embodiment, fraction F1 contains at least one monomer B, at least one compound I, and at least one compound II.

[0127] In a preferred embodiment, fraction F1 contains at least one monomer A, at least one monomer B, at least one compound I, and at least one compound II.

[0128] Step b), polymerization of fraction F1 to form the first gradient polymer (PG1) Polymerization 1 (PO1) Prior to polymerization PO1, the atmosphere in the polymerization reactor can be replaced with an inert gas such as nitrogen or argon, for example.

[0129] Polymerization PO1 is generally a radical polymerization. A polymerization initiator, specifically, an initiator that dissociates into radicals under the polymerization conditions, can be used.

[0130] Polymerization PO1 generally starts at a temperature included between 70 and 90 °C, preferably between 75 and 85 °C, and then the polymerization temperature is controlled using cooling means so as not to exceed 95 °C.

[0131] Polymerization PO1 preferably continues for between 10 and 70 minutes.

[0132] Advantageously, when the first monomer, the solvent, and the initiator are in contact, the polymerization starts; in other words, the duration of polymerization PO1 advantageously corresponds to the duration of the pouring of fraction F1.

[0133] Gradient polymer (PG1) At the end of polymerization PO1, a gradient polymer (PG1) is obtained.

[0134] In certain embodiments of the present invention, the gradient polymer PG1 is aged for between 5 and 60 minutes, preferably between 10 and 30 minutes.

[0135] "Is aged" means that after polymerization has ended, the temperature of the medium is maintained between 80 and 90 °C in order to enable an increase in viscosity through internal branching phenomena of the polymer. This definition of aging applies to all steps of the polymerization process.

[0136] Step c) Addition of the second fraction (F2) to the solution containing PG1 Second fraction F2 Advantageously, fraction F2 contains between 30 and 80% by weight, preferably between 40 and 70% by weight, of monomers (A and / or B, and optionally C) with respect to the total weight of the monomers (A and / or B, and optionally C) of the base polymer.

[0137] Fraction F2 advantageously contains between 0 and 50 mol%, preferably between 0 and 40 mol%, of cationic monomer A with respect to the total number of moles of monomers in fraction F2.

[0138] Fraction F2 advantageously contains between 0 and 100 mol%, preferably between 60 and 100 mol%, of non-ionic monomer B with respect to the total number of moles of monomers in fraction F2.

[0139] Fraction F2 advantageously contains between 250 and 30,000 ppm, preferably between 500 and 10,000 ppm, more preferably between 850 and 5,000 ppm, for example between 1,000 and 5,000 ppm, of compound I with respect to the total weight of monomers A and B (and optionally monomer C) of the base polymer.

[0140] Fraction F2 advantageously contains between 250 and 30,000 ppm, preferably between 500 and 10,000 ppm, more preferably between 1,000 and 5,000 ppm, of compound II with respect to the total weight of monomers A and B (and optionally monomer C) of the base polymer.

[0141] The different monomers and compounds that make up fraction F2 are preferably added in the form of a solution. The solution can be added to the polymer reactor separately, as a mixture, all at once, in several portions, or poured in (in a flowing form). Preferably, the addition is carried out as a mixture and poured in (in a flowing form).

[0142] The addition of fraction F2 in a flowing form (e.g., by dropping) enables control of the exotherm of the reaction, which might otherwise become excessively high even when using a cooler.

[0143] The pouring of fraction F2 preferably continues for between 10 and 100 minutes, more preferably between 30 and 90 minutes.

[0144] In a preferred embodiment, fraction F2 contains at least one monomer A and B, at least one compound I, and at least one compound II.

[0145] Step d), polymerization of fraction F2 onto PG1 to form a second gradient polymer (PG2) Polymerization (PO2) Polymerization PO2 is carried out as a continuation of polymerization PO1, which is carried out under the same temperature conditions (preferably 70 - 90 °C).

[0146] Polymerization PO2 preferably continues for between 10 and 100 minutes, more preferably between 30 and 90 minutes.

[0147] Polymerization PO2 starts from the addition of the first monomer of fraction F2.

[0148] Preferably, the duration of polymerization PO2 corresponds to the duration of the pouring of fraction F2.

[0149] Gradient polymer (PG2) At the end of polymerization PO2, a gradient polymer (PG2) is obtained.

[0150] In certain embodiments of the present invention, the PG2 binding is aged for between 5 and 6 minutes, preferably between 10 and 30 minutes.

[0151] Step e) Addition of the third fraction (F3) to the solution containing PG2 Fraction F3 Advantageously, fraction F3 contains between 5 and 40% by weight, preferably between 10 and 30% by weight, of monomers (A and / or B, and optionally C) with respect to the total weight of the monomers of the base polymer.

[0152] Fraction F3 advantageously contains between 0 and 50 mol%, preferably between 0 and 35 mol%, of cationic monomer A with respect to the total number of moles of monomers in fraction F3.

[0153] Fraction F3 advantageously contains between 50 and 100 mol%, preferably between 65 and 100 mol%, of non-ionic monomer B with respect to the total number of moles of monomers in fraction F3.

[0154] Fraction F3 advantageously contains between 0 and 10,000 ppm, preferably between 10 and 5000 ppm, more preferably between 20 and 1,000 ppm, of compound I with respect to the total weight of monomers A and B (and optionally monomer C) of the base polymer.

[0155] Fraction F3 advantageously contains between 0 and 10,000 ppm, preferably between 0 and 1,000 ppm, of compound II with respect to the total weight of monomers A and B (and optionally monomer C) of the base polymer.

[0156] The different monomers and compounds constituting F3 are advantageously added in the form of solutions. These solutions can be added to the polymer reactor separately or as a mixture, all at once, in several portions, or poured in (in a flowing form), i.e., dropwise. Preferably, the addition is made as a mixture and poured in (in a flowing form).

[0157] By adding fraction F3 in a flowing form (e.g., by dropping), it becomes possible to control the heat generation of a reaction that may otherwise become excessively high even when using a cooler.

[0158] The pouring of fraction F3 preferably continues for between 10 minutes and 100 minutes, preferably between 30 minutes and 90 minutes.

[0159] In a preferred embodiment, fraction F3 contains at least one monomer B and at least one compound I.

[0160] In one embodiment, the amount of compound I in fraction F3 is less than 500 ppm, preferably less than 300 ppm, preferably less than 200 ppm, and even more preferably less than 100 ppm.

[0161] Such a small amount enables the desired physical and specific properties of the base polymer and subsequently the final polyvinylamine polymer.

[0162] Step f), polymerization of fraction F3 to PG2 to form the base polymer Polymerization (PO3) Polymerization PO3 is carried out continuously after polymerization PO2, and it is carried out under the same time and temperature conditions as PO2 (advantageously, for 10 to 100 minutes, preferably for 30 to 90 minutes, at 70 - 90 °C).

[0163] Polymerization PO3 starts from the addition of the first monomer of fraction F3.

[0164] Advantageously, the duration of polymerization PO3 corresponds to the duration of the pouring of fraction F3.

[0165] At the end of polymerization PO3, the base polymer is obtained.

[0166] In a particular embodiment of the invention, before removing the residual monomers, the base polymer is aged for between 5 minutes and 60 minutes, preferably between 10 minutes and 30 minutes.

[0167] The reaction is stopped by the addition of an excess of initiator and / or water, and this step is used to remove residual monomers that may be present in the solution containing the base polymer.

[0168] Optional step The method according to the invention can also include additional steps and is not limited to the steps described above.

[0169] In a particular embodiment of the invention, the polymerization method according to the invention can include the addition of additional fractions that make up the base polymer.

[0170] In a preferred embodiment of the invention, the base polymer is aged for between 10 and 100 minutes, preferably between 30 and 90 minutes, after step f) of polymerizing PO3 and prior to step g). When additional fractions are added, the aging is carried out after the last polymerization step and before step g).

[0171] In a particular embodiment of the invention, the crosslinking agent and / or the transfer agent are added during at least one of the steps described above.

[0172] In a particular embodiment of the invention, the crosslinking agent is added to fraction F1 and / or fraction F2.

[0173] When a crosslinking agent is added, it is preferably selected from the crosslinking agents listed above.

[0174] When a crosslinking agent is added, its amount is preferably between 5 and 5,000 ppm, more preferably between 50 and 3,000 ppm, based on the total mass of the base polymer (monomers A, B, and optionally C).

[0175] In a particular embodiment of the invention, the transfer agent is added to fraction F1 and / or fraction F2.

[0176] When a transfer agent is added, it is preferably selected from the transfer agents listed above.

[0177] When a migrating agent is added, its amount is preferably included between 10 and 10,000 ppm, preferably between 50 and 5,000 ppm, relative to the total mass of the base polymer (monomers A, B, and optionally C).

[0178] Step g) Hofmann degradation reaction on the base polymer to obtain a polyvinylamine polymer The Hofmann degradation reaction consists of two main coefficients (expressed as a molar ratio), - Coefficient alpha = hypohalite (alkali metal hypohalite and / or alkaline earth metal hypohalite) / amide and / or nitrile functional group, - Coefficient beta = hydroxide (alkali metal hydroxide and / or alkaline earth hydroxide) / hypohalite (alkali metal hypohalite and / or alkaline earth metal hypohalite) and consists of converting an amide or nitrile functional group to an amine functional group (for example, by formation of vinylamine monomeric units).

[0179] The hypohalite is an oxy-anion, for example, ClO of hypochlorite - and preferably it is sodium hypochlorite.

[0180] "Alkali hypohalite" is at least one alkali metal hypohalite, for example, NaOCl, KOBr, or NaOCl + KOBr. The same applies to alkaline earth hypohalites.

[0181] "Alkali" is used to designate an alkali metal, preferably lithium, sodium, or potassium.

[0182] "Alkaline earth" is used to designate an alkaline earth metal, preferably calcium or magnesium.

[0183] "Alkali hydroxide" refers to the hydroxide (OH - ) of at least one alkali metal, for example, NaOH, KOH, or NaOH + KOH, which is used to specify it. The same applies to alkaline earth hydroxides. Preferably, it is sodium hydroxide.

[0184] Advantageously, the Hofmann degradation reaction comprises at least the following steps: g1) Dilution (advantageously in water) of a solution containing a base polymer to form a diluted base polymer solution (SD1); g2) Addition of hypohalite and hydroxide to SD1 to form a diluted solution (SD2); g3) Reaction between the base polymer, hypohalite, and hydroxide; g4) Obtaining a solution (SD3) containing a polyvinylamine polymer.

[0185] Advantageously, in step g1), the concentration of the base polymer in the diluted solution SD1 of the base polymer is between 1 and 40% by mass, more preferably between 2 and 30%, and even more preferably between 5 and 25% with respect to the mass of SD1.

[0186] Advantageously, in step g2), the alpha coefficient = hypohalite / amide and / or nitrile functional group is between 0.1 and 1.0, preferably between 0.3 and 1.0, and more preferably between 0.5 and 1.0.

[0187] Advantageously, in step g2), the beta coefficient = hydroxide / hypohalite is between 0.5 and 4.0.

[0188] Advantageously, in step g3), the reaction between the base polymer, hypohalite, and hydroxide continues for between 10 seconds and 180 minutes, preferably between 1 minute and 120 minutes, more preferably between 10 minutes and 90 minutes, and even more preferably between 30 minutes and 75 minutes.

[0189] ​ Advantageously, in step g3), the reaction between the base polymer, the hypohalite, and the hydroxide is carried out at a temperature comprised between 10 and 30 °C, preferably between 15 and 25 °C.

[0190] At the end of step g3), the polyvinylamine polymer according to the invention is obtained.

[0191] In a particular embodiment of the invention, at the end of step g3), the polyvinylamine polymer can be functionalized with a dialdehyde in order to produce an aldehyde-functionalized polymer (advantageously, glyoxalated).

[0192] The dialdehyde is advantageously selected from glyoxal, glutaraldehyde, furan-dialdehyde, adipaldehyde, succinaldehyde, dialdehyde starch, 2,2-dimethoxyethanal, diepoxy compounds, and mixtures thereof. Preferably, it is glyoxal.

[0193] In order to stabilize the amine functional groups formed, one or more derivatives of quaternary ammonium as described in JP-A-57-77398 may be added by those skilled in the art to the diluted solution SD1. This quaternary ammonium derivative is intended to prevent the reaction between the amine functional groups and the remaining amide functional groups. In addition, the addition of these agents can be carried out separately, simultaneously, in the mixture or not in the mixture, in any order of introduction, at one or more points of introduction. The addition of these agents is advantageously carried out during step g1).

[0194] In a preferred embodiment of the invention, the pH of solution SD3 is adjusted between 0.5 and 7.5, more preferably between 1.0 and 3.0, by the addition of an acid. The adjustment of the pH is advantageously carried out in the absence of functionalization of the polyvinylamine polymer with a compound containing at least two aldehyde functional groups.

[0195] During Hofmann degradation, the cationicity of the base polymer increases, either completely or not, due to the use / consumption of an alkali or alkaline earth metal hypohalite.

[0196] The polyvinylamine polymer preferably has a cationic charge density greater than 2 meq / g, preferably greater than 5 meq / g, advantageously less than 12 meq / g, preferably less than 11.5 meq / g.

[0197] In certain embodiments of the invention, a microcrystalline cellulose compound is prepared and reacted with the polyvinylamine polymer.

[0198] Advantageously, the microcrystalline cellulose compound is in the form of a suspension in water.

[0199] Advantageously, during this reaction with the microcrystalline cellulose compound, the mass concentration of the polyvinylamine polymer is between 0.5 and 20%, preferably between 1 and 5% in an aqueous solution.

[0200] The reaction of the microcrystalline cellulose compound with the polyvinylamine polymer is advantageously carried out in the absence of polyvinylamine polymer functionalization with a dialdehyde.

[0201] The reaction of the microcrystalline cellulose compound with the polyvinylamine polymer is advantageously carried out at a temperature between 10°C and 60°C, preferably between 20 and 40°C.

[0202] Advantageously, the microcrystalline cellulose compound is selected from nanofibrillated cellulose, microfibrillated cellulose, nanocrystalline cellulose, and nanocellulose.

[0203] Advantageously, between 10% and 100% by weight, preferably between 10 and 50% by weight, of the microcrystalline cellulose compound is added to the polyvinylamine polymer, based on the mass of the polyvinylamine polymer.

[0204] The polyvinylamine polymers of the present invention are produced in solution but can be used in solid form. Under these conditions, the solid form contains not only the polymer but also a portion of the salts obtained at the end of the Hofmann degradation. In practice, the solid form is obtained, in particular, by a method consisting of drying the solution of step g). The technical principles of solid / liquid separation are those of atomization or spraying (consisting of creating a cloud of fine droplets in a hot gas stream over a controlled time period), drum drying, fluidized bed dryers.

[0205] Paper manufacturing method The present invention also relates to a method for manufacturing paper or cardboard, comprising (1) a step of adding a polyvinylamine polymer according to the present invention to an aqueous solution of fibers and (2) a step of forming a sheet of paper or cardboard. Thus, the present invention relates to the use of polyvinylamine polymers in the paper manufacturing method.

[0206] Various steps in the paper production method, cardboard, etc. are known and conform to techniques that are part of the knowledge of those skilled in the art and are known and classical within the knowledge of those skilled in the art, so it is not necessary to explain them in more detail. If necessary, reference can be made to the Handbook for Pulp & Paper Technologists, 4 th Edition, G.A. Smook.

[0207] The polyvinylamine polymers according to the present invention are added to the papermaking process either before or after the formation of a sheet of paper or cardboard, etc. Thus, bringing the cellulose material into contact with the polymers of the present invention is done in various ways, specifically according to typical methods known to those skilled in the art.

[0208] The polyvinylamine polymers can be added to the cellulose material in the form of a diluted or undiluted aqueous solution. It can be applied by impregnation techniques or can be added directly to the fibrous suspension at any point where dry strength agents are normally introduced in the paper manufacturing method.

[0209] Thus, the polymers according to the invention can be introduced into both thick and thin furnish. It can be added in a mixing pump, before the headbox or the filter screen. Preferably, the polymer is introduced before the headbox.

[0210] Preferably, the polymers according to the invention are industrially introduced into the fibrous suspension, i.e., before its dilution with white water (thick furnish). The consistency of the furnish is about 1 - 5% by weight of cellulose fibers.

[0211] The papermaking process according to the invention can be carried out using any type of paper pulp, such as virgin fiber pulp (kraft, sulfite), recycled fiber, deinked pulp, mechanical and thermomechanical pulp, etc.

[0212] The polyvinylamine polymer is advantageously added directly to the fibrous suspension before sheet formation.

[0213] It can be added at a single feed point or at two feed points.

[0214] The papermaking process according to the invention may also include the addition of other additives and / or polymers as required, and by way of example, without limitation, biocides, coagulants, yield improvers, flocculants, starches can be mentioned.

[0215] Use The present invention also relates to the use of this polyvinylamine polymer in the recovery of hydrocarbons (oil and / or gas); in the drilling or cementing of wells (specifically, hydrocarbon wells); in the stimulation of hydrocarbon wells (oil and / or gas), for example, in hydraulic fracturing, conditioning, conversion; in open, closed, or semi-closed circulating water treatment; in the treatment of fermentation mashes; in sludge treatment; in construction; in wood treatment; in the treatment of hydraulic compositions (concrete, cement, mortar, and aggregates); in mining; in the formulation of cosmetics; in the formulation of detergents; in textile manufacturing; in the geothermal sector; in the manufacture of sanitary napkins; or in agriculture.

[0216] The present invention also relates to the use of the polyvinylamine polymer as a flocculant, coagulant, binder, fixing agent, viscosity reducer, thickener, absorbent, anti-friction agent, drainage agent, charge retention agent, dehydrating agent, conditioning agent, stabilizer, fixing agent, film-forming agent, sizing agent, high-performance water reducer, clay inhibitor, or dispersant.

[0217] The present invention and the advantages derived therefrom are more clearly emphasized in the following examples, which are given to illustrate the present invention but are not intended to limit its use.

Examples

[0218] List of Abbreviations DADMAC: Diallyldimethylammonium (Monomer A) AMD: Acrylamide (Monomer B) DMAM: Dimethylacrylamide (Compound II) SMS: Sodium Methallylsulfonate (Compound I) SPS: Sodium Persulfate (Polymerization Initiator) MBA: Methylenebisacrylamide (Crosslinking Agent) PEI: Polyethyleneimine

[0219] Explanation of the Characterization of GPC-MALS Molecular Weight Gel permeation chromatography is a method for separating polymers according to their hydrodynamic volume, which is coupled with MALS detection and enables the measurement of light scattering from several angles.

[0220] Synthetic polymers are analyzed under the following conditions. - Instrument: GPC-2 - Column: Shodex SB-807-HQ & SB-805 custom - Method Temperature: 30 °C Mobile phase: 0.5 M NaNO3, HEPES (pH = 8), 100 ppm NaN3 Injection: 100 μL Flow rate: 0.3 mL / min Detection: (i) Light scattering detector (MALS): absolute molar mass (ii) Refractive index measurement (RI): concentration

[0221] Viscosity is measured using a Brookfield viscometer at 25 °C with a speed of 60 rpm and the Brookfield LV1 module.

[0222] Production of Polymer 1 (P1(INV)) according to the present invention Polymer 1 (P1) First order: Gradient polymer PG1 In a 1-liter reactor equipped with a mechanical stirrer, thermometer, condenser, and nitrogen gas immersion rod, at the bottom of the reactor, introduce a first fraction F1 composed of 146.9 g of water, 50.6 of acrylamide (50% by mass in water), 77.1 g of dimethyldiallylammonium chloride (64% by mass in water), 1 g of citric acid, 0.5 g of dimethylacrylamide, and 0.4 g of sodium methallylsulfonate. Heat the medium and maintain the temperature between 79 and 81 °C using a water bath. The addition of 0.05 g of sodium persulfate makes it possible to start this starter and initiate the polymerization (PO1) of the monomers to form a solution of the first gradient polymer PG1.

[0223] Second order: Gradient polymer PG2 When the exothermic reaction is complete, initiate pouring: Initiator (50 g of SPS at 0.33 mass% in water) over 130 minutes, and simultaneously pour in a second fraction F2 consisting of 25.5 g of water, 101.3 g of acrylamide (50 mass% in water), 77.1 g of DADMAC (64 mass% in water), 0.5 g of dimethylacrylamide, and 0.19 g of sodium methallyl sulfonate over 50 minutes. After pouring in fraction F2, age the gradient polymer PG2 for 10 minutes (the polymerization PO2 to form the gradient polymer PG2 occurs during the pouring of fraction F2 and during the aging).

[0224] Third order: Base polymer Next, begin pouring in a third fraction F3 consisting of 121.3 g of water, 50.6 g of acrylamide (50 mass% in water), and 0.01 g of sodium methallyl sulfonate over 60 minutes. At the end of the addition of fraction F3, age the polymer for 10 minutes (the polymerization PO3 to form the base polymer occurs during the pouring of fraction F3 and during the aging).

[0225] When aging is complete, add 146.9 g of water and 0.15 g of sodium persulfate. When the desired viscosity is obtained, stop the reaction by adding 0.6 g of sodium bisulfite (40 mass% in water) and 146.9 g of water. Apply a new aging period of 60 minutes before cooling. The resulting solution containing base polymer 1 has a pH of 3.5, and an active material of 20 mass%, a viscosity of 3,500 cps, and a molecular weight of 2,650,000 Da obtained by GPC - MALS.

[0226] Hofmann degradation: Polymer 1 (P1) Perform Hofmann degradation according to the applicant's method described in document WO2010 / 061082. At the end of the Hofmann degradation, the polyvinylamine polymer according to the invention (P1(INV)) is obtained.

[0227] Production of Comparative Example Polymers 2 to 3 (CE1 to CE2) Polymer 2 (CE1) According to Example E of Document WO2011 / 015783, Polymer 2 (CE1) is obtained by the reaction of Hofmann degradation.

[0228] Polymer 3 (CE2) Polymer 3 (CE2) is produced according to a protocol that is the same only in two orders for Polymer 1.

[0229] The compositions of different fractions of the polymerization processes of Polymer 1 according to the present invention and the comparative example polymers (CE1 to CE2) are summarized in Table 1a (Table 1).

[0230] In this Table 1a (Table 1), the monomer content described in each fraction represents the molar mass percentage of the AMD (or DADMAC) monomer with respect to the total molar mass of the corresponding monomer in all fractions. Therefore, for example, the sum of the percentages of the AMD monomer in the three fractions is equal to 100%.

[0231] The contents of Compound I (SMS) and II (DMAM) are expressed in mass ppm with respect to the total mass of the monomers in the three fractions.

[0232] [Table 1]

[0233] The physicochemical properties of the obtained base polymers P1 and CE1 to CE2 are described in Table 1b (Table 2) below.

[0234] [Table 2]

[0235] Particularly with respect to the molecular weight of the base polymer, compared with the prior art, the viscosity is of the same degree, but the differences and advantages provided by the present invention are observed.

[0236] Table 1c (Table 3) below shows the viscosity results obtained for the final polymer after the Hofmann degradation reaction.

[0237] [Table 3]

[0238] The method of the present invention provides a polymer solution having a high molecular weight compared to classical methods of polymerization while having a desirable typical viscosity required for the papermaking process.

[0239] Application test The wet pulp used in all of the application examples is obtained by the disintegration of dry pulp to obtain a final aqueous mass concentration of 1%. This is pH-neutral pulp using 100% recycled newsprint fibers.

[0240] Evaluation of drainage performance (DDA) under reduced pressure The DDA (Dynamic Drainage Analyzer) makes it possible to automatically determine the time (in seconds) required to vacuum-dewater a fibrous suspension on a cloth. The polymer is added to the wet pulp (0.6 liters of pulp to 1.0% by mass) in the cylinder of the DDA under stirring at 1000 revolutions per minute. T = 0 s: Stirring of the pulp T = 10 s: Addition of the polymer T = 30 s: Stopping of the stirring and vacuum drainage at 200 mBar for 60 s.

[0241] The pressure under the cloth is recorded as a function of time. As water is drained from the fibrous mat, air passes through it, which causes a break in the slope on the curve representing the pressure under the cloth as a function of time. The time represented in seconds related to this break in slope on the curve corresponds to the drainage time. Therefore, the shorter the time, the better the vacuum drainage.

[0242] Performance in dryness resistance application, 80 g.m -2 basis weight 80 g.m -2 To finally obtain a sheet corresponding to the basis weight of 80 g.m, the necessary amount of pulp is taken as a sample.

[0243] Introduce the wet pulp into a dynamic hand sheet former tank and hold it under stirring. Add different compounds to this pulp according to the previously defined order. Generally, there is a contact time of 30 - 45 seconds between the additions of polymers.

[0244] Make a paper hand sheet using an automatic dynamic hand sheet former. Place the blotting paper and the forming fabric in the tank of the dynamic hand sheet former, then start the rotation of the tank at 1000 revolutions per minute to create a water wall. Distribute the treated pulp on the water wall to form a fibrous mat on the forming fabric.

[0245] After draining the water, collect the fibrous mat, press it under a press with four bars fed out, and then dry it at 117 °C. Pack the obtained sheet overnight in a room with controlled humidity and temperature (50% relative humidity and 23 °C). Then measure the dryness resistance properties of all the sheets obtained by this procedure.

[0246] Measure the bursting strength using a Messmer Buchel M 405 bursting tester according to the TAPPI T403 om - 02 standard specification.

[0247] Measure the length at break in the dry state using a machine with a Testometric AX tensile device according to the TAPPI T494 om - 01 standard specification.

[0248] The amount of polymer added is expressed in kg of active polymer per ton of dry fiber.

[0249] Trials were carried out at 1 kg / t and 1.5 kg / t and are summarized in Table 2 (Table 4). Results are expressed as a percentage increase compared to the blank (no polymer).

[0250]

Table 4

[0251] It is interesting to note that the polymers of the present invention exhibit improved drainage performance (DDA) and mechanical characteristics (burst; DBL; breakage in the dry state) relative to the most efficient products on the market.

Claims

1. A polyvinylamine polymer obtained from the Hofmann degradation reaction of a base polymer, wherein the base polymer is - at least one cationic monomer A, and - at least one nonionic monomer B selected from acrylamide, acrylonitrile, methacrylamide, and mixtures thereof, and - at least one structuring system, (i) at least one compound I selected from allylsulfonic acid, methallylsulfonic acid, allyldisulfonic acid, methallyldisulfonic acid, salts thereof, and mixtures thereof, and (ii) Formula (1): 【Chemical Formula 1】 [wherein R 1 and R 2 are each independently a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, or a CH 2 -OH group, R 1 and R 2 both are not hydrogen atoms at the same time at least one compound II including at least one structuring system and including, the polymer lacks anionic monomers other than compound I, the polyvinylamine polymer is prepared by the following steps: a) Step of forming a solution (S1) containing at least a first fraction (F1) containing (1) at least one monomer selected from monomers A and B and (2) at least one compound selected from compounds I and II; b) Step of polymerization 1 (PO1) of fraction F1 to form a solution of a first gradient polymer (PG1); c) Step of adding a second fraction (F2) containing (1) at least one monomer selected from monomers A and B and (2) at least one compound selected from compounds I and II to the solution containing PG1; d) Step of polymerization 2 (PO2) of fraction F2 to PG1 to form a solution of a second gradient polymer (PG2); e) Step of adding a third fraction (F3) containing (1) at least one monomer selected from monomers A and B and (2) at least one compound selected from compounds I and II to the solution containing PG2; f) Step of polymerization 3 (PO3) of fraction F3 to PG2 to form a solution containing the base polymer; g) Step of diluting the solution containing this base polymer and performing the Hofmann degradation reaction of the base polymer to obtain a polyvinylamine polymer obtained according to, at least one of fractions F1, F2, or F3 contains at least one monomer A, at least one of fractions F1, F2, or F3 contains at least one monomer B, at least one of fractions F1, F2, or F3 contains at least one compound I, At least one of fractions F1, F2, or F3 contains at least one compound II, A polyvinylamine polymer. **Claim 2** The polyvinylamine polymer according to claim 1, wherein at least one cationic monomer A is selected from dimethyldiallylammonium chloride, acrylamidopropyltrimethylammonium chloride, methacrylamidopropyltrimethylammonium chloride, and mixtures thereof. **Claim 3** The polyvinylamine polymer according to any one of claims 1 or 2, wherein the base polymer contains compound I in an amount between 500 and 50,000 ppm based on the total mass of monomers A and B. **Claim 4** The polyvinylamine polymer according to any one of claims 1 to 3, wherein the base polymer contains compound II in an amount between 500 and 50,000 ppm based on the total mass of monomers A and B. **Claim 5** The polyvinylamine polymer according to any one of claims 1 to 4, wherein compound II is selected from N,N-dimethylacrylamide, N,N-diethylacrylamide, N,N-isopropylacrylamide, N-methylolacrylamide, and mixtures thereof. **Claim 6** The polyvinylamine polymer according to any one of claims 1 to 5, wherein the mass ratio of compound I to compound II is included between 0.01 and 100. **Claim 7** The polyvinylamine polymer according to any one of claims 1 to 6, wherein at least one of fractions F1, F2, or F3 is different from the other fractions. **Claim 8** A method for the sequential production of a polyvinylamine polymer, comprising the following steps: a) A step of forming a solution (S1) containing at least a first fraction (F1) containing (1) at least one monomer selected from monomers A and B and (2) at least one compound selected from compounds I and II, At least one monomer A is a cationic monomer, At least one monomer B is a nonionic monomer selected from acrylamide, acrylonitrile, methacrylamide, and mixtures thereof, At least one compound I is selected from allylsulfonic acid, methallylsulfonic acid, allyldisulfonic acid, methallyldisulfonic acid, their salts, and mixtures thereof, At least one compound II has the formula (1): 【Chemical Formula 2】 [wherein, R 1 and R 2 are each independently a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, or a CH 2 -OH group, R 1 and R 2 are not both hydrogen atoms is such that, the polymer does not contain an anionic monomer other than compound I, a process, b) a step of polymerization 1 (PO1) of fraction F1 to form a solution of a first gradient polymer (PG1), c) a step of adding a second fraction (F2) containing (1) at least one monomer selected from monomers A and B and (2) at least one compound selected from compounds I and II to a solution containing PG1, d) a step of polymerization 2 (PO2) of fraction F2 to PG1 to form a solution of a second gradient polymer (PG2), e) a step of adding a third fraction (F3) containing (1) at least one monomer selected from monomers A and B and (2) at least one compound selected from compounds I and II to a solution containing PG2, f) a step of polymerization 3 (PO3) of fraction F3 to PG2 to form a solution containing a base polymer, g) a step of diluting the solution containing the base polymer and performing a Hofmann degradation reaction of the base polymer to obtain a polyvinylamine polymer A method comprising.

9. The method according to claim 8, characterized in that at least one of fraction F1, F2, or F3 is different from the other fractions.

10. The method according to claim 8 or 9, characterized in that the initiator is added continuously throughout the polymerization process.

11. The method according to any one of claims 8 to 10, characterized in that it includes an aging step of 10 to 100 minutes after the step f) of polymerization (PO3) and prior to the step g).

12. The Hofmann degradation reaction has at least the following steps: g1) a step of diluting the solution containing the base polymer to obtain a diluted solution (SD1) of the base polymer, g2) a step of adding an alkali or alkaline earth metal hypohalite and an alkali or alkaline earth metal hydroxide to obtain a diluted solution (SD2), g3) a step of reacting between the base polymer, the alkali metal or alkaline earth hypohalite, and the alkali metal or alkaline earth metal hydroxide, Step of obtaining a solution (SD3) containing a polyvinylamine polymer The method according to any one of claims 8 to 11, characterized by comprising

13. A method for manufacturing paper or cardboard, comprising a step of adding the polyvinylamine polymer according to any one of claims 1 to 7 to an aqueous suspension of fibers, and a step of forming a sheet of paper or cardboard

14. Use of the polyvinylamine polymer according to any one of claims 1 to 7 in the recovery of hydrocarbons; in well drilling or cementing; in stimulating hydrocarbon wells; in water treatment in open, closed, or semi-closed circulation; in the treatment of fermentation mashes; in sludge treatment; in construction; in wood processing; in the treatment of hydraulic compositions; in mining; in the formulation of cosmetics; in the formulation of detergents; in textile manufacturing; in the geothermal sector; in the manufacture of sanitary napkins; or in agriculture

15. Use of the polyvinylamine polymer according to any one of claims 1 to 7 as a flocculant, coagulant, binder, fixing agent, viscosity reducer, thickener, absorbent, anti-friction agent, drainage agent, charge-holding agent, dehydrating agent, conditioning agent, stabilizer, fixing agent, film-forming agent, sizing agent, high-performance water reducer, clay inhibitor, or dispersant

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