RU2799548C2 - Method of manufacturing paper or cardboard - Google Patents

Abstract

FIELD: paper manufacturing.

SUBSTANCE: invention relates to a method for the manufacture of paper or cardboard. The method includes the steps of adding the final polymer A to the first aqueous fibrous material suspension to obtain a second aqueous fibrous material suspension comprising the final polymer A, dewatering the second aqueous fibrous material suspension comprising the final polymer A on a water-permeable substrate to obtain a wet paper structure, dehydrating the wet paper structures to obtain paper or cardboard. The final polymer A is a polymer obtained by radical polymerization of: (i) 30-90 mol.% N-vinylformamide, (ii) 3-60 mol.% C₁ -C₄ -acrylic acid alkyl ester or C₁ -C₄-alkyl ester of methacrylic acid, (iii) 0-45 mol.% monoethylenically unsaturated carboxylic, sulfonic or phosphonic acids or their salt forms, (iv) 0-9 mol.% acrylonitrile or methacrylonitrile, (v) 0-35 mol. % ethylenically unsaturated monomers other than monomer (i), (ii), (iii) and (iv) to form the starting polymer V, and hydrolyzing the starting polymer V to form the final polymer A.

EFFECT: improved dry strength.

10 cl, 1 dwg, 4 tbl

Description

The present invention relates to a process for making paper or paperboard, comprising the steps of adding a final polymer A to a first aqueous fibrous material slurry, dewatering the resulting second aqueous fibrous material slurry containing the final polymer A on a water-permeable substrate to form a wet paper structure, and dewatering the wet paper structure with receiving paper or cardboard. The resulting paper or paperboard has good dry strength. Other objects of the present invention are paper or paperboard obtained by this process, and the final polymer A and the original polymer V. The original polymer V is a synthetic precursor of the final polymer A.

Trends in today's paper industry sometimes have a significant adverse effect on the dry strength of paper or paperboard. For example, the amount of recycled paper waste continues to grow. This is accompanied by a deterioration in fiber quality. The use of shorter cellulosic fibers with poorer swelling and roughness characteristics is observed. The use of inexpensive raw materials is usually attractive, even if in practice it is associated with the use of shorter cellulosic fibers. It is a constant challenge to reduce the density of paper or board in order to save raw materials. Water circulation in paper machines is constantly decreasing. Therefore, of interest are processes for the manufacture of paper or paperboard which provide good dry strength of the resulting paper or paperboard.

In DE 4328975 A, as an object of the invention, polymers intended for the manufacture of paper are disclosed, in which the proportion of 2-aminodihydropyrrole structural units is from 20 to 90 mol. %. To obtain polymers corresponding to the examples, first, a radical polymerization reaction of N-vinylformamide and acrylonitrile is carried out and the initial polymer is obtained. After completion of the polymerization reaction, this initial polymer is formed as a suspension in water. After filtration, the starting polymer is treated with concentrated hydrochloric acid and heating to about 100° C. results in amidation. The final polymer thus obtained is precipitated using acetone and dried. Received the final polymer "F", for which the original polymer is obtained by the reaction of radical polymerization 50 mol. % N-vinylformamide 50 mol. % acrylonitrile, is listed as the only polymer, the lactam content is, in particular, 1 mol. %:

The final polymers are in particular added to the fibrous material slurry. The paper is made with a long wire paper machine conforming to the TAPPI standard (TAPPI=Technical Society of the Pulp and Paper Industry). For paper made using the final polymer "F", determine the ash content. Also determine the strength of paper made using other final polymers, by determining the value of the burst resistance index. The resulting "G", "K", "Q" and "R" final polymers contain no or only a small amount of 2-aminodihydropyrrole structural units and therefore do not comply with this invention and in the examples of practical implementation they provide worse results.

EP 0 528 409 A discloses, as a subject of the invention, polymers which correspond to those described in DE 4 328 975 A cited above as flocculants. The "Examples" section also shows the final polymer "F", described in DE 4328975 A, designated as the final polymer "P". In the examples, the final polymers are added to the sludge to improve filterability. By analogy with DE 4328975 And the final polymers that do not correspond to this invention do not contain 2-aminodihydropyrrole structural units or contain only a small amount of them.

In DE 4441940 A, polymers are disclosed as a subject of the invention, which contain 5-membered lactams (=pyrrolidin-2-one structural units) as structural units, the proportion of which is from 20 to 100 mol. %. The Examples section shows the improved thermal stability of the final polymers. The final polymers are recommended for use as modifiers for thermoplastic resins, polymer additive for tertiary oil recovery, lubricants, detergent-dispersants, scale inhibitors, polymers added for quick completion of the reaction, viscosifiers for drilling fluid, pipeline-friendly viscosifiers , binders, etc. to obtain polymers corresponding to the examples, first, a radical polymerization reaction of N-vinylformamide and acrylamide is carried out, and in one case of N-vinylformamide, acrylamide and acrylamide-2-methylpropanesulfonic acid, and in the other case of N-vinylformamide and methacrylamide, in each case the original polymer. In the case of using N-vinylformamide and acrylamide, the starting polymer is precipitated using methanol, and in the other two cases, the starting polymer is filtered off as a polymer gel. The starting polymers thus obtained are treated with an aqueous solution of hydrochloric acid. The mixture is precipitated by adding acetone or methanol and then dried. Where appropriate, determine the solubility in water and the reduced viscosity. For the resulting final polymer "C", for which the original polymer is obtained by the reaction of radical polymerization of 50 mol. % N-vinylformamide 50 mol. % acrylamide, the following composition is indicated:

For the resulting final polymer "M", for which the original polymer is obtained by the reaction of radical polymerization of 40 mol. % N-vinylformamide, 40 mol. % acrylamide and 20 mol. % acrylamide-2-methylpropanesulfonic acid, the following composition is indicated:

For the resulting final polymer "N", for which the starting polymer is obtained by the reaction of radical polymerization of N-vinylformamide and methylacrylamide, the following composition is indicated:

US 4,898,915 discloses as an object of the invention polymers which include structural units containing an aromatic or aliphatic amino group and structural units containing at least one of the following substituent: nitrile, aldehyde, carboxylic acid or carboxylic acid ester. In the examples, starting polymers are prepared by polymerizing monomers containing protected amino groups and acrylic acid esters in toluene, said polymerization being catalyzed with a Lewis acid. The crude starting polymers are separated by decantation and by addition of methanol, filtered in the form dissolved in chloroform and precipitated by repeated addition of methanol. To obtain the final polymers, the starting polymers thus obtained are treated with hydrazine in chloroform to form primary amino groups. More precisely, in example 3, methyl acrylate is polymerized with N-vinylphthalimide, the reaction is catalyzed with aluminum ethyl sesquichloride. In Example 6, this starting polymer is dissolved in chloroform and treated with hydrazine. It is indicated that the final polymer obtained contains methoxy groups, amino groups and lactam units. In example 7, the final polymer obtained in example 6, is treated with an aqueous solution of potassium hydroxide at 70°C, while receiving a polymer containing alternating amino groups and carboxy groups. The final polymers are recommended for use as antistatic agents or as viscosifiers in oil production.

In "A novel synthetic procedure for N-vinylformamide and free radical polymerization", S. Sawayama et al., Mitsubishi Kasei R&D Review, 1993, Vol. 7, p. 55-61 in Section 3.5 and with the help of FIG. 4 describes the copolymerization of N-vinylformamide with acrylamide and the copolymerization of N-vinylformamide with styrene, in each case at different mol ratios.

In "Alternating copolymerization of methyl acrylate with donor monomers having a protected amine Group", RN Majumdar et al., Journal of Polymer Science, 1983, Vol. 21, p. 1717-1727, in particular, Example 6 is described in the above document US 4898915, and is called hydrazinolysis of an alternating copolymer of methyl acrylate with N-vinylphthalimide. In FIG. 4 shows the ¹³ C-NMR (Nuclear Magnetic Resonance) spectrum of a methyl acrylate-N-vinylphthalimide copolymer and the ¹³ C-NMR spectrum of an alternating methyl acrylate-N-vinylphthalimide copolymer.

In the publication "Amine functional polymers based on N-ethenylformamide", R. K. Pinschmidt et al., Progress in Organic Coatings, 1996, 27, p.209-218, section 2.1 describes the polymerization of 32 mol. % N-vinylformamide, 38 mol. % butyl acrylate and 30 mol. % methyl methacrylate, carried out in a solvent, such as alcohol, ketone, or an alcohol/toluene mixture, using Vazo 52 radical initiator. using potassium hydroxide in an alcohol-containing solvent proceeds quickly. In the case of using a starting polymer obtained by polymerization of a mixture of acrylate: N-vinylformamide = 1:1, a lactam-containing polymer is precipitated, which is known from the above document US 4898915. In section 3.4 and using scheme 3, the hydrolysis and formation of lactam for copolymers of N -vinylformamide with (meth)acrylates. The high lactam content results in insolubility in common solvents.

In "N-vinylformamide - building block for novel polymer structures", R. K. Pinschmidt et al., Pure Applied Chemistry, 1997, A34(10), p. 1885-1905, in particular, it is described that the hydrolysis of N-vinylformamide with (meth)acrylates or acrylonitrile in an acidic environment proceeds easily and in high yield. This is due to the lack of strong charge repulsion of the vinylamine units contained in these highly alternating alternating copolymers. Upon neutralization or hydrolysis in an alkaline environment, lactam is formed very quickly. This is shown schematically in Fig. 9 and the lactam structure is called insoluble.

GB 752290 discloses as an object of the invention polymers which contain 5-membered lactams (=pyrrolidin-2-one structural units) as structural units. To obtain polymers corresponding to the examples, first, the polymerization reaction of acryloyl chloride is carried out to obtain the original polymer. This starting polymer is dissolved in dimethylformamide and reacted with sodium azide or hydroxylamine. After filtration and addition of acetone, the final polymer precipitates, it is dissolved in water and precipitated by adding hydrochloric acid. In particular, the final polymer containing 70 mol. % lactam structural units, 23 mol. % acid groups and 7 mol. % amino groups, and the final polymer containing 63 mol. % lactam structural units, 24.5 mol. % acid groups and 12.5 mol. % amino groups. The final polymers are recommended for use, in particular, as film formers and in photographic layers.

In "Determination of the sequence distribution and ionization constant of poly(acrylic acid-co-vinylamine) by ¹³ C-NMR", C. Chang et al., Journal of Polymer Science, Polymer Symposium, 1986, 74, p. 17-30, the final polymers, which are obtained by the Schmidt reaction, carried out using polyacrylic acid and nitric acid, and which contain a primary amino group and carboxyl groups, are examined using nuclear magnetic resonance. The formation of lactam is described in the case of the investigated final polymers, in which 12 or 30 or 52% of the carboxy groups are converted into amino groups.

In "Polymers and group interaction. IV. Hofmann reaction on polyvinylamides", M. Mullier et al., Journal of Polymer Science, 1957, XXIII, p. 915-930, in particular, investigate the products obtained from the Hoffmann rearrangement carried out using polyacrylamide and polymethacrylamide. In the examples, polyacrylamides used as starting polymers are reacted with sodium hypochlorite to produce polymers containing amino groups as final polymers. These final polymers contain a large proportion of 5-membered lactam structural units. The polymer below is listed in Table 1 as the final polymer "polymer I", which is obtained by the Hoffmann reaction using polyacrylamide and 1 eq. sodium hypochlorite:

The polymer below is listed in Table 1 as the final polymer "polymer II", which is obtained by the Hoffmann reaction using polymethacrylamide and 1 eq. sodium hypochlorite:

In JP 2016-186023 A, Example 1 describes a radical polymerization reaction of 43 mol. % N-vinylformamide and 57 mol. % methyl methacrylate in methyl ethyl ketone. Example 2 describes a radical polymerization reaction of 24 mol. % N-vinylformamide and 76 mol. % methyl methacrylate in methyl ethyl ketone. The resulting polymers are of interest for applications in optical lenses and the like.

In JP 2017-061602 A, Example 3 describes a radical polymerization reaction of 32 mol. % N-vinylformamide and 68 mol. % methyl methacrylate in methyl ethyl ketone. The resulting polymer is of interest for use in optical components.

In JP 2017-039867 A, Example 4 describes a radical polymerization reaction of 20 mol. % N-vinylformamide and 80 mol. % methyl methacrylate in methyl ethyl ketone. Example 5 describes the reaction of radical polymerization 32 mol. % N-vinylformamide and 68 mol. % methyl methacrylate in methyl ethyl ketone. The resulting polymers are of interest for applications in optical components.

In JP 2017-039868 A, Example 2 describes a radical polymerization reaction of 32 mol. % N-vinylformamide and 68 mol. % methyl methacrylate in methyl ethyl ketone. Example 3 describes a radical polymerization reaction of 48 mol. % N-vinylformamide and 52 mol. % methyl methacrylate in methyl ethyl ketone. Example 4 describes a radical polymerization reaction of 20 mol. % N-vinylformamide and 80 mol. % methyl methacrylate in methyl ethyl ketone. The resulting polymers are of interest for applications in optical components.

There is a need for further paper or paperboard manufacturing processes in which the resulting paper or paperboard has good dry strength. If additives are used in these methods, it is further preferred if their preparation can be carried out on an industrial scale and in the simplest possible manner.

According to the invention, a method has been developed for the manufacture of paper or cardboard, which includes the steps

(A) adding the final polymer A to the first aqueous fibrous material suspension, thereby obtaining a second aqueous fibrous material suspension containing the final polymer A,

where the final polymer A is obtained by

- radical polymerization of the following monomers:

(i) 30 to 90 mol. % monomer of formula I

in which R ¹ =H or denotes FIG. C ₁ -C ₆ -alkyl,

(ii) from 3 to 60 mol. % C ₁ -C ₄ -alkyl ester of acrylic acid or C ₁ -C ₄ -alkyl ester of methacrylic acid,

(iii) from 0 to 45 mol. % monoethylenically unsaturated carboxylic acid, monoethylenically unsaturated sulfonic acid or monoethylenically unsaturated phosphonic acid, or their salt forms,

(iv) 0 to 9 mol. % acrylonitrile or methacrylonitrile,

(v) 0 to 35 mol. % of one or more ethylenically unsaturated monomers other than the monomer (i), (ii), (iii) and (iv),

where the total amount of all monomers (i), (ii), (iii), (iv) and (v) is 100 mol. %, to obtain the original polymer V, and

- hydrolysis of the original polymer V to obtain the final polymer A, where at least part of the groups NC(=O)R ¹ contained in the monomers (i) of formula (I), polymerized to obtain the original polymer V, is hydrolyzed and thus formed primary amino groups , where at least part of the ester groups contained in the monomers (ii), polymerized to obtain the original polymer V, undergoes transformation and at least part of the transformation is the formation of 5-membered lactam structural units containing the obtained primary amino groups, or the formation of carboxy groups or their salt forms,

(B) dewatering a second aqueous fibrous material slurry containing the final polymer A on a water-permeable substrate to form a wet paper structure,

(C) dewatering the wet paper structure, thereby obtaining paper or paperboard.

In step (A), the first aqueous suspension of fibrous material means a composition comprising (a-a) water and (a-b) fibrous material containing cellulose fibers. An alternative term for "fibrous material slurry" is "pulp".

Mechanical and/or chemical techniques can be used to form the first aqueous suspension of fibrous material. Thus, for example, milling an aqueous suspension of fibrous material is a mechanical technique for producing shorter fibers and, in the case of cellulose fibers, also for defibrillating the fibers. The degree of dehydration of the aqueous suspension of fiber is determined by the provided degree of grinding. One technique for determining the degree of freeness of a suspension of fibrous material is to determine the kinetics of dewatering in accordance with the method of Schopper-Rigler and it is expressed in degrees Schopper-Rigler (°ShR).

Natural and/or regenerated fibers can be used as fibrous material. All wood fibers or annual plant fibers commonly used in the paper industry can be used. Annual plants suitable for fibrous materials are, for example, rice, wheat, sugarcane and kenaf. Wood material derived from softwood or hardwood, for example, includes wood pulp, thermomechanical woodpulp (TMP), chemothermomechanical woodpulp (CTMP), pressurized woodpulp, semi-chemical woodpulp, high yield pulp, and refined pulp. mechanical wood pulp (PMM). Coarsely ground wood material usually has a freeness of 40-60°ShF, in contrast to standard wood material with a freeness of 60-75°ShF and fine wood material with a freeness of 70-80° SR. Pulps derived from, for example, softwood or hardwood include chemically treated sulphate, sulfite or soda pulp. In addition, the pulp may also be bleached or unbleached. Unbleached pulp, also known as unbleached kraft pulp, is preferred. The unmilled pulp usually has a freeness of 13-17°ShP, in contrast to the coarse and medium pulp, which has a freeness of 20-40°ShP, and the fine pulp, which has a freeness of 50-60°ShP. Recycled fibers can be obtained, for example, from waste paper. Paper waste can optionally be pre-cleaned of paint. Mixed waste paper typically has a freeness of about 40°ShR, in contrast to deinked waste paper having a freeness of about 60°ShP. Recycled fibers obtained from recycled paper can be used alone or mixed with others, especially natural fibres.

The preferred method is one in which the first aqueous suspension of fibrous material has a degree of freeness, determined by the kinetics of dewatering according to the Schopper-Rigler method, of from 13 to 70°ShF, more preferably from 20 to 60°ShF and especially preferably from 30 to 50° SR.

The first aqueous suspension of fibrous material can be obtained, for example, by processing existing paper or cardboard, for example, by mechanical processing of waste paper in a pulper together with water until the desired consistency of the aqueous suspension of fibrous material is achieved. Another example of combining fibers from two sources is mixing virgin fibrous material slurry with recycled coated paper waste made using virgin fibrous material slurry.

The first aqueous fibrous material slurry may contain not only water (a-a) and fibrous material (a-b), but also other components which are specifically added to the fibrous material slurry in appropriate cases, or which are contained in appropriate cases due to the use of waste paper or available paper.

In the present invention, "dry matter content" means the ratio of the weight of the sample after drying to the weight of the sample before drying, expressed as a mass percent. Preferably, the solids content is determined by drying at 105° C. to constant weight. To do this, drying is carried out at 105°C (±2°C) in an oven until a constant weight is achieved. In accordance with the present invention, a constant mass is achieved if, at a solids content of 1 to 100%, the percentage value rounded to the first decimal place does not change anymore, and at a solids content of 0 to less than 1%, more the value expressed as a percentage, rounded to the second decimal place, does not change. Drying is carried out at ambient pressure, optionally at 101.32 kPa, without correcting for any deviation due to weather conditions or altitude. In the "Examples" section, under the heading "Determination of solids content", a description of a practical implementation is given.

When the dry matter content is from more than 1.5 to 6 wt. %, preferably from 2.0 to 4.0 wt. % based on the weight of the first aqueous fibrous material slurry (corresponding to a fibrous material concentration of more than about 15 to 60 g/l if substantially only fibrous material is contained), in the present invention the mixture is referred to as a thick mass. In the context of the present invention, it should be noted that the difference is that when the dry matter content is from 0.1 to 1.5 wt. %, preferably from 0.3 to 1.4 wt. %, based on the weight of the aqueous suspension of fibrous material (corresponding to a fibrous material concentration of about 1 to 15 g/l, if essentially only fibrous material is contained), the mixture is usually referred to as a slurry. The solids content or dry weight of the aqueous fibrous material suspension means the content of all components that are non-volatile or preferably non-volatile when determining the solids content by drying at 105° C. to constant weight.

Preferably, if the solids content in the first aqueous suspension of fibrous material is from 0.1 to 6 wt. %, more preferably from 0.12 to 5 wt. %, particularly preferably from 0.15 to 4 wt. %, even more preferably from more than 1.5 to 4.0 wt. % and most preferably from 2.0 to 4.0 wt. %.

Preferred is a method in which in step (A) the first aqueous suspension of fibrous material has a solids content of 0.1 to 6 wt. %.

In step (A), the final polymer A is added to the first fibrous material slurry in which the solids content is between more than 1.5 and up to 6.0 wt. %. More preferably, if the resulting second suspension of fibrous material containing the final polymer And, then diluted to provide a solids content of from 0.1 to 1.5 wt. %. Preferably, if in stage (A) the final polymer A is added to the first suspension of fibrous material, in which the solids content is from 0.1 to 1.5 wt. %.

Preferred is a method in which, in step (A), the final polymer A is added to a first aqueous fibrous material slurry in which, at the time of addition, the solids content is from more than 1.5 to 6.0 wt. %.

After adding the final polymer A to the first aqueous suspension of fibrous material, it is preferable to wait with the dehydration carried out in step (B) for 0.5 seconds to 2 hours, more preferably from 1.0 seconds to 15 minutes, and particularly preferably from 2 to 20 s. This provides the required reaction time for the final polymer A.

Preferably, if the amount of final polymer A added is from 0.01 to 3.0 wt. % in terms of solids content in the first aqueous suspension of fibrous material. In the present invention, the amount of the final polymer A is calculated as the polymer content. The polymer content means the weight percent content of the final polymer A in aqueous solution without counterions, i.e. counterions are ignored. Thus, the polymer content means the sum, expressed in mass percent, of the amounts of all structural units of the final polymer A in grams, which are contained in 100 g of an aqueous dispersion or aqueous solution of the final polymer A. In the "Examples" section, in the paragraph under the heading "Polymer content", a description is given practical implementation. More preferred is an amount of 0.02 to 1.0 wt. %, particularly preferred from 0.06 to 0.8 wt. %, more preferably from 0.09 to 0.6 wt. %, even more preferably from 0.12 to 0.5 wt. %, even more preferably from 0.15 to 0.5 wt. % and most preferably from 0.2 to 0.4 wt. %.

Preferred is the method in which in stage (A) the final polymer is added in an amount of from 0.2 to 0.5 wt. % based on the weight of the first suspension of fibrous material, where the solids content in the first suspension of fibrous material is from more than 1.5 and up to 6.0 wt. %. More preferably, if the resulting second suspension of fibrous material containing the final polymer And, then diluted to provide a solids content of from 0.1 to 1.5 wt. %.

The synthetic precursor of the final polymer A is the original polymer V, which is obtained by the reaction of radical polymerization of monomers (i), (ii), optionally (iii), optionally (iv) and optionally (v).

For the polymerization of the monomers (i), (ii), optionally (iii), optionally (iv) and optionally (v) to form the starting polymer V, solution, precipitation, reverse suspension or emulsion polymerization are suitable. Solution polymerization carried out in aqueous media is preferred. Suitable aqueous media are water and mixtures of water and at least one water-miscible solvent, for example an alcohol. Examples of alcohols are methanol, ethanol, n-propanol, ethylene glycol or propylene glycol. The polymerization is carried out by means of radicals, eg using radical polymerization initiators, eg peroxides, hydroperoxides, which are known as redox catalysts, or using azo compounds which decompose to form radicals. Examples of peroxides are alkali metal or ammonium peroxosulfates, diacetyl peroxide, dibenzoyl peroxide, succinyl peroxide, di-tert-butyl peroxide, tert-butylperbenzoate, tert-butylperpivalate, tert-butylperoxy-2-ethylhexanoate, tert-butyl permaleate, cumene hydroperoxide, diisopropylperoxydicarbamate, bis(o- toluoyl)peroxide, didecanoylperoxide, dioctanoylperoxide, dilauroylperoxide, t-butyl perisobutyrate, t-butyl peracetate or di-t-amyl peroxide. An example of a hydroperoxide is tert-butyl hydroperoxide. Examples of azo compounds which decompose to form radicals are azobis-isobutyronitrile, 2,2'-azobis(2-methylpropionamidine)dihydrochloride or 2,2'-azobis-(2-methylbutyronitrile). Examples of so-called redox catalysts are ascorbic acid/iron(II) sulfate/sodium peroxodisulfate, tert-butyl hydroperoxide/sodium disulfite, tert-butyl hydroperoxide/sodium hydroxymethanesulfinate or H ₂ O/CuI.

The polymerization is carried out, for example, in water or in a mixture containing water as a solvent, at a temperature in the range from 30 to 150°C, preferably from 40 to 110°C, and the reaction can be carried out at ambient pressure, at reduced or increased pressure. For solution polymerization, a water-soluble polymerization initiator is selected, for example 2,2'-azobis(2-methylpropionamidine)dihydrochloride. Preferably, the radical polymerization of the monomers is carried out in water or in a water-containing solvent mixture. More preferred is water or a water-containing solvent mixture containing at least 50 wt. % water, based on the total amount of the solvent mixture. Particularly preferred is water or a water-containing solvent mixture containing at least 80 wt. % water, more preferably at least 90 wt. % and even more preferably at least 95 wt. % water. Preferably, the polymerization is carried out in water or in a water-containing solvent mixture having a pH greater than 6, more preferably a pH of 6.1 to 9, and particularly preferably a pH of 6.2 to 6.8. An appropriate pH can be achieved, for example, by adding an acid and/or base, optionally with the addition of a buffer.

Preferred is a process in which the radical polymerization of the monomers is carried out in water or in a water-containing solvent mixture.

When polymerizing the monomers (i), (ii), optionally (iii), optionally (iv), and optionally (v), polymerization regulators can be added to the reaction mixture to form a starting polymer V. Typically, amounts ranging from 0.001 to 5 mol. % in terms of the total amount of all monomers (i), (ii), (iii), (iv) and (v). Polymerization regulators are well known in the literature and are, for example, sulfur compounds, sodium hypophosphite, formic acid or tribromochloromethane. Some examples of sulfur compounds are mercaptoethanol, 2-ethylhexylthioglycolate, thioglycolic acid and dodecylmercaptan.

Preferably, the starting polymer V has a weight average molecular weight M _w of 75,000 to 5,000,000 Da. More preferably, the starting polymer V has a weight average molecular weight _Mw of 100,000 to 4,500,000 Da, particularly preferably 180,000 to 2,500,000 Da, even more preferably 210,000 to 1,500,000 Da and most preferably 250,000 to 1,000,000 Da. The weight average molecular weight can be determined using static light scattering, for example at a pH of 7.0 in a NaN0 ₃ solution.

Examples of monomers (i) of formula I are N-vinylformamide (R ¹ =H), N-vinylacetamide (R ¹ =C ₁ -alkyl), N-vinylpropionamide (R ¹ =C ₂ -alkyl) and N-vinyl butyramide (R ¹ =C ₃ -alkyl). C ₃ -C ₆ Alkyls may be linear or branched. An example of C ₁ -C ₆ -alkyl is methyl, ethyl, n-propyl, 1-methylethyl, n-butyl, 2-methylpropyl, 3-methylpropyl, 1,1-dimethylethyl, n-pentyl, 2-methylbutyl, 3-methylbutyl , 2,2-dimethylpropyl or n-hexyl. Preferably R ¹ is H or C ₁ -C ₄ alkyl, more preferably H or C ₁ -C ₂ alkyl, more preferably H or C ₁ alkyl, particularly preferably H, i. monomer (i) is N-vinylformamide. While one monomer of formula I may be the only one, a mixture of different monomers of formula I is also included as monomer (i). Preferably, if the proportion of the monomer in which R ¹ =H in the total amount of all monomers (i) of formula I is from 85 to 100%, more preferably from 90 to 100%, particularly preferably from 95 to 100% and most preferably from 99 up to 100%.

A method is preferred in which the monomer (i) is N-vinylformamide, i.e. in the formula IR ¹ =H.

Preferably, if the total amount of all monomers (i) is from 50 to 89 mol. % in terms of the amount of all monomers polymerized to obtain the original polymer V, i.e. all monomers (i), (ii), optionally (iii), optionally (iv) and optionally (v), more preferably if it is from 58 to 83 mol. %, particularly preferably from 60 to 83 mol. % and most preferably from 65 to 80 mol. %. The condition remains that the total amount of all monomers (i), (ii), (iii), (iv) and (v) is 100 mol. %.

Examples of the monomers (ii) are methyl acrylate, ethyl acrylate, n-propylacrylate, isopropylacrylate, n-butyl acrylate, sec-butyl acrylate, t-butyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate and t-butyl methacrylate. Although one monomer (ii) may be the only one, the scope of the present invention also includes a mixture of different monomers (ii) used as monomer (i). Preferred are C ₁ -C ₄ -alkyl esters of acrylic acid and C ₁ -alkyl esters of methacrylic acid, more preferred are C ₁ -C ₃ -alkyl esters of acrylic acid and C ₁ -alkyl esters of methacrylic acid, especially preferred are C ₁ -C ₃ -alkyl esters of acrylic acid, even more preferred are C ₁ -C ₂ -alkyl esters of acrylic acid and most preferred are C ₂ -alkyl esters of acrylic acid (=ethyl acrylate). Preferably, the proportion of C ₂ -alkyl ester of acrylic acid in the total amount of all monomers (ii) is from 30 to 100%, more preferably from 50 to 100%, particularly preferably from 80 to 100% and most preferably from 95 to 100%. In the case of using C ₁ -C ₄ -alkyl ester of methacrylic acid, it is preferable if C ₁ -C ₄ -alkyl ester of acrylic acid is also contained, more preferably in the ratio of the amount of C ₁ -C ₄ -alkyl ester of methacrylic acid to the amount of C ₁ -C ₄ -alkyl ester of acrylic acid, amounting to at least 1:1.

A method is preferred in which the monomer (ii) is a C ₁ -C ₃ -alkyl ester of acrylic acid or a C ₁ -alkyl ester of methacrylic acid.

A method is preferred in which the monomer (ii) is C ₁ -C ₂ -acrylic acid alkyl ester.

A method is preferred in which the monomer (ii) is ethyl acrylate.

Preferably, if the total amount of all monomers (ii) is from 5 to 45 mol. % in terms of the amount of all monomers polymerized to obtain the original polymer V, i.e. all monomers (i), (ii), optionally (iii), optionally (iv) and optionally (v), more preferably if it is from 8 to 39 mol. %, particularly preferably from 8 to 30 mol. %, even more preferably from 8 to 25 mol. % and most preferably from 8 to 21 mol. %. The condition remains that the total amount of all monomers (i), (ii), (iii), (iv) and (v) is 100 mol. %.

In the context of the present invention, "ethylenically unsaturated monomer" means a monomer containing at least one C ₂ unit, the carbon atoms of which are connected by a carbon-carbon double bond. If the only substituents are hydrogen atoms, this is ethylene. In the case of substitution with 3 hydrogen atoms, a vinyl derivative is present. In the case of substitution with 2 hydrogen atoms, the E/Z isomer or ethene-1,1-diyl derivative is contained. In the context of the present invention, "monoethylenically unsaturated monomer" means a monomer that contains exactly one C ₂ unit.

If a certain molecule or class of molecules contains a cationic group, then the salt form means that the corresponding anion provides a neutral charge. Such anions are, for example, chloride, bromide, hydrogen sulfate, sulfate, hydrogen phosphate, methyl sulfate, acetate or formate. Preferred is chloride, formate or hydrogen sulfate, especially preferred is chloride or formate. If a certain molecule or class of molecules contains an anionic group, then the salt form means that the corresponding cation provides a neutral charge. Such cations are, for example, cations of alkali metals, alkaline earth metals, ammonia, alkylamines or alkanolamines. Preferred are Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ , Mg ^{2 +} , Ca 2 ⁺ , Sr ^{2 +} , Ba ^{2 +} or NH ₄ ⁺ . More preferred are Li ⁺ , Na ⁺ , K ⁺ , Mg ^{2 +} , Ca ^{2 +} or NH ₄ ⁺ , particularly preferred are Na ⁺ , K ⁺ , Ca ^{2 +} or NHV", even more preferred are Na ⁺ , K ⁺ or NH ₄ ⁺ , even more preferred are Na ⁺ or K ⁺ and most preferred is Na ⁺ .

The monomer (iii) also includes a mixture of individual monomers belonging to the group of monomers (iii).

Examples of the monomer (iii) which is a monoethylenically unsaturated carboxylic acid or its salt form are monoethylenically unsaturated C ₃ -C ₈ mono or dicarboxylic acids or their salt forms. Examples are acrylic acid, sodium acrylate, methacrylic acid, sodium methacrylate, dimethacrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, mesaconic acid, citraconic acid, methylenemalonic acid, allylacetic acid, vinylacetic acid or crotonic acid.

Examples of the monomer (iii), which is monoethylenically unsaturated sulfonic acid or its salt form, are vinyl sulfonic acid, acrylamide-2-methylpropane sulfonic acid, methacrylamido-2-methylpropane sulfonic acid, allyl sulfonic acid, metallyl sulfonic acid, sulfoethyl acrylate, sulfoethyl methacrylate, sulfopropyl acrylate, sulfopropyl methacrylate, 2- hydroxy-3-methacryloxypropylsulfonic acid or styrenesulfonic acid.

Examples of the monomer (iii), which is monoethylenically unsaturated phosphonic acid or its salt form, are vinylphosphonic acid, vinylphosphonic acid monomethyl ester, allylphosphonic acid, allylphosphonic acid monomethylester, acrylamidomethylpropylphosphonic acid or acrylamidomethylenephosphonic acid.

Preferably, the monomer (iii) is a monoethylenically unsaturated carboxylic acid or a monoethylenically unsaturated sulfonic acid, or their salt forms. Preferably, monomer (iii) is monoethylenically unsaturated C ₃ -C ₈ mono or dicarboxylic acid, monoethylenically unsaturated sulfonic acid or vinylphosphonic acid, or their salt forms. More preferably, monomer (iii) is monoethylenically unsaturated C ₃ -C ₈ mono or dicarboxylic acid, vinylsulfonic acid, acrylamide-2-methylpropanesulfonic acid, methacrylamido-2-methylpropanesulfonic acid or vinylphosphonic acid, or salt forms thereof. More preferred are monoethylenically unsaturated C ₃ -C ₈ -mono - or dicarboxylic acids or their salt forms. Especially preferred are acrylic acid, methacrylic acid, vinylsulfonic acid or acrylamide-2-methylpropanesulfonic acid, or their salt forms. Even more preferred are acrylic acid or methacrylic acid, or their salt forms. Most preferred are acrylic acid, sodium acrylate, methacrylic acid or sodium methacrylate. Preferably, if the proportion of acrylic acid and methacrylic acid or their salt forms in the total amount of all monomers (iii) is from 30 to 100%, more preferably from 50 to 100%, particularly preferably from 80 to 100% and most preferably from 95 to 100 %.

A process is preferred in which the monomer (iii) is a monoethylenically unsaturated carboxylic acid or a monoethylenically unsaturated sulfonic acid, or salt forms thereof.

A process is preferred in which the monomer (iii) is acrylic acid, methacrylic acid, vinylsulfonic acid or 2-acrylamido-2-methylpropanesulfonic acid, or salt forms thereof.

Preferably, if the total amount of all monomers (iii) is from 0 to 40 mol. % in terms of the amount of all monomers polymerized to obtain the original polymer V, i.e. all monomers (i), (ii), optionally (iii), optionally (iv) and optionally (v), more preferably if it is from 0 to 30 mol. %, particularly preferably from 0 to 25 mol. %, even more preferably from 1 to 25 mol. %, even more preferably from 2 to 23 mol. %, even more preferably from 3 to 21 mol. % and most preferably from 5 to 18 mol. %. The condition remains that the total amount of all monomers (i), (ii), (iii), (iv) and (v) is 100 mol. %. ??? According to the invention, it has surprisingly been found that certain starting polymers V provide an industrial advantage when hydrolyzed in an alkaline medium to give the final polymer A. And there is no or at least a decrease in the viscosity peak that occurs during hydrolysis in an alkaline environment. The results for the presence, reduction or absence of a viscosity peak are presented in FIG. 1 and Table A-4-1 in the Examples section. The observation of a reduced or even inverted vortex on the stirrer shaft during the hydrolysis studies in the Examples section is indicative of the presence of a viscosity peak and its quantification. In accordance with the present invention, the evaluation results such as none, minimal, small and moderate, indicated in the Examples section, mean a moderate increase in viscosity, which is still acceptable and manageable in the case of industrial production (on an increased scale). Evaluation results such as none, minimal, and small are preferred, while none and minimal are more preferred. Accordingly, the starting polymer V, which contains the monomer (iii), is preferred for use in the process.

Preferred is a method in which the monomer (iii) is used in an amount of 1 to 25 mol. %.

Preferably, if the total amount of all monomers (iv) is from 0 to 7 mol. % in terms of the amount of all monomers polymerized to obtain the original polymer V, i.e. all monomers (i), (ii), optionally (iii), optionally (iv) and optionally (v), more preferably if it is from 0 to 5 mol. %, particularly preferably from 0 to 3 mol. %, even more preferably from 0.5 to 2 mol. % and most preferably from 1 to 1.5 mol. %. The condition remains that the total amount of all monomers (i), (ii), (iii), (iv) and (v) is 100 mol. %.

Monomer (v) also includes a mixture of individual monomers belonging to the group of monomers (v).

Examples of monomers (v) are

(v-1) a monoethylenically unsaturated monomer which has no charge at pH=7,

(v-2) a diethylenically unsaturated monomer which has no charge at pH=7 and contains two conjugated ethylene double bonds,

(v-3) a monoethylenically unsaturated monomer which contains at least one primary, secondary or tertiary amino group, and which has a positive charge at pH=7, or its salt form,

(v-4) a diallyl-substituted amine whose nitrogen atom is not quaternized,

(v-5) a monoethylenically unsaturated monomer that contains at least one permanent positive charge,

(v-6) a monomer that contains at least two ethylenically unsaturated double bonds that are not conjugated and that is different from a diallyl-substituted amine.

In the case of the monomers (v) which have a charge, their salt forms are also respectively included. A permanent positive charge is always contained as a positive charge, regardless of the pH value.

Examples of the monomer (v-1) are monoesters of α,β-ethylenically unsaturated monocarboxylic acids formed with C ₅ -C ₁₈ -alkanols, monoesters of α,β-ethylenically unsaturated monocarboxylic acids formed with C ₂ -C ₁₈ -alkanediols, diesters α,β -ethylenically unsaturated dicarboxylic acids formed with C ₁ -C ₁₈ -alkanols or C ₂ -C ₁₈ -alkanediols, primary amides of α,β-ethylenically unsaturated monocarboxylic acids, N-alkylamides of α,β-ethylenically unsaturated monocarboxylic acids, N,N-dialkylamides α ,β-ethylenically unsaturated monocarboxylic acids, dinitriles of α,β-ethylenically unsaturated dicarboxylic acids, esters formed from vinyl alcohol with C ₁ -C ₁₈ -monocarboxylic acids, esters formed from allyl alcohol with C ₁ -C ₃₀ -monocarboxylic acids, N- vinyl lactams, nitrogen-free heterocycles containing an α,β-ethylenically unsaturated double bond, vinyl aromatic compounds, vinyl halides, vinylidene halides or C ₂ -C ₈ monoolefins.

Monoesters of α,β-ethylenically unsaturated monocarboxylic acids formed with C ₅ -C ₁₈ -alkanols are, for example, n-hexyl acrylate, n-hexyl methacrylate, n-octyl acrylate, n-octyl methacrylate, 1,1,3,3-tetramethylbutyl acrylate, 1 ,1,3,3-tetramethylbutyl methacrylate or 2-ethylhexyl acrylate.

Monoesters of α,β-ethylenically unsaturated monocarboxylic acids formed with C ₂ -C ₁₈ -alkanediols are, for example, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl ethacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate , 3-hydroxybutyl acrylate, 3-hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, 6-hydroxyhexyl acrylate, or 6-hydroxyhexyl methacrylate.

Primary amides of α,β-ethylenically unsaturated monocarboxylic acids are, for example, acrylic acid amide or methacrylic acid amide.

N-Alkylamides of α,β-ethylenically unsaturated monocarboxylic acids are, for example, N-methylacrylamide, N-methylmethacrylamide, N-isopropylacrylamide, N-isopropylmethacrylamide, N-ethylacrylamide, N-ethylmethacrylamide, N-(n-propyl)acrylamide, N-( n-propyl)methacrylamide, N-(n-butyl)acrylamide, N-(n-butyl)methacrylamide, N-(tert-butyl)acrylamide, N-(tert-butyl)methacrylamide, N-(n-octyl)acrylamide , N-(n-octyl)methacrylamide, N-(1,1,3,3-tetramethylbutyl)acrylamide, N-(1,1,3,3-tetramethylbutyl)methacrylamide, N-(2-ethylhexyl)acrylamide or N -(2-ethylhexyl)methacrylamide.

N,N-dialkylamides of α,β-ethylenically unsaturated monocarboxylic acids are, for example, N,N-dimethylacrylamide or N,N-dimethylmethacrylamide.

Esters derived from vinyl alcohol with C ₁ -C ₃₀ monocarboxylic acids are, for example, vinyl formate, vinyl acetate or vinyl propionate.

N-vinyl lactams are, for example, N-vinylpyrrolidone, N-vinylpiperidone, N-vinylcaprolactam, N-vinyl-5-methyl-2-pyrrolidone, N-vinyl-5-ethyl-2-pyrrolidone, N-vinyl-6-methyl -2-piperidone, N-vinyl-6-ethyl-2-piperidone, N-vinyl-7-methyl-2-caprolactam or N-vinyl-7-ethyl-2-caprolactam.

Vinyl aromatic compounds are, for example, styrene or methylstyrene. Vinyl halides are, for example, vinyl chloride or vinyl fluoride. Vinylidene halides are, for example, vinylidene chloride or vinylidene fluoride. C ₂ -C ₈ monoolefins are, for example, ethylene, propylene, isobutylene, 1-butene, 1-hexene or 1-octene.

The preferred monomer (v-1) is 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl ethacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, vinyl pyrrolidone or vinyl acetate.

Examples of the monomer (v-2) are C ₄ -C ₁₀ -olefins containing exactly two double bonds that are conjugated, for example, butadiene or isoprene.

Examples of the monomer (v-3) are esters of α,β-ethylenically unsaturated monocarboxylic acids formed with amino alcohols, mono- and diesters of α,β-ethylenically unsaturated dicarboxylic acids formed with amino alcohols, amides of α,β-ethylenically unsaturated monocarboxylic acids formed with dialkylated diamines , N-vinylimidazole or vinylpyridine.

The acid component of the α,β-ethylenically unsaturated monocarboxylic acid esters formed with amino alcohols is preferably acrylic acid or methacrylic acid. Amino alcohols, preferably C ₂ -C ₁₂ -amino alcohols, can be monoalkylated with C ₁ -C ₈ or dialkylated with C ₁ -C ₈ at the amino nitrogen atom. Examples are dialkylaminoethyl acrylates, dialkylaminoethyl methacrylates, dialkylaminopropyl acrylates or dialkylaminopropyl methacrylates. Some examples are N-methylaminoethyl acrylate, N-methylaminoethyl methacrylate, N,N-dimethylaminoethyl acrylate, N,N-dimethylaminoethyl methacrylate, N,N-diethylaminoethyl acrylate, N,N-diethylaminoethyl methacrylate, N,N-dimethylaminopropyl acrylate, N,N-dimethylaminopropyl methacrylate, N,N -diethylaminopropyl acrylate, N,N-diethylaminopropyl methacrylate, N,N-dimethylaminocyclohexyl acrylate or N,N-dimethylaminocyclohexyl methacrylate.

The acid component of the mono- and diesters of α,β-ethylenically unsaturated dicarboxylic acids formed with amino alcohols is preferably fumaric acid, maleic acid, monobutyl maleate, itaconic acid or crotonic acid. Amino alcohols, preferably C ₂ -C ₁₂ -amino alcohols, can be monoalkylated with C ₁ -C ₈ or dialkylated with C ₁ -C ₈ at the amino nitrogen atom.

Amides, α,β-ethylenically unsaturated monocarboxylic acids formed with dialkylated diamines are, for example, dialkylaminoethylacrylamides, dialkylaminoethylmethacrylamides, dialkylaminopropylacrylamides or dialkylaminopropylmethacrylamides. Some examples are N-[2-(dimethylamino)ethyl]acrylamide, N-[2-(dimethylamino)ethyl]methacrylamide, N-[3-(dimethylamino)propyl]acrylamide, N-[3-(dimethylamino)propyl]methacrylamide , N-[4-(dimethylamino)butyl]acrylamide, N-[4-(dimethylamino)butyl]methacrylamide, N-[2-(diethylamino)ethyl]acrylamide or N-[2-(diethylamino)ethyl]methacrylamide.

Examples of the monomer (v-4) are diallylamine or methyldiallylamine.

Examples of the monomer (v-5) are diallylamines which are quaternized at the nitrogen atom, N-alkyl-N'-vinylimidazolium salt form, N-alkylated vinylpyridinium salt form, acrylamidoalkyltrialkylammonium salt form, or methacrylamidoalkyltrialkylammonium salt form. A diallylamine which is quaternized at the nitrogen atom is, for example, diallyldimethylammonium chloride, diallyldiethylammonium chloride, diallyldipropylammonium chloride or diallyldibutylammonium chloride. The salt form of N-alkyl-N'-vinylimidazolium is, for example, 1-methyl-3-vinylimidazol-1-ium chloride, 1-methyl-3-vinylimidazol-1-ium methyl sulfate or 1-ethyl-3-vinylimidazol-1-ium chloride. The salt form of N-alkylated vinylpyridinium is, for example, 1-methyl-4-vinylpyridin-1-dium chloride, 1-methyl-3-vinylpyridin-1-dium chloride, 1-methyl-2-vinylpyridin-1-dium chloride or 1-ethyl- 4-vinylpyridin-1-dium chloride. The salt form of acrylamidoalkyltrialkylammonium is, for example, acrylamidoethyltrimethylammonium chloride (trimethyl-[2-(prop-2-enoylamino)ethyl]ammonium chloride), acrylamidoethyldiethylmethylammonium chloride (diethylmethyl-[3-(prop-2-enoylamino)ethyl]ammonium chloride), acrylamidepropyltrimethylammonium chloride (trimethyl-[ 3-(prop-2-enoylamino)propyl]ammonium chloride) or acrylamidopropyldiethylmethylammonium chloride (diethylmethyl-[3-(prop-2-enoylamino)propyl]ammonium chloride). The salt form of methacrylamidoalkyltrialkylammonium is, for example, methacrylamidoethyltrimethylammonium chloride (trimethyl-[2-(2-methylprop-2-enoylamino)ethyl]ammonium chloride), methacrylamidoethyldiethylmethylammonium chloride (diethylmethyl-[3-(2-methylprop-2-enoylamino)ethyl]ammonium chloride), methacrylamidopropyltrimethylammonium chloride (trimethyl-[3-(2-methylprop-2-enoylamino)propyl]ammonium chloride) or methacrylamidopropyldiethylmethylammonium chloride (diethylmethyl-[3-(2-methylprop-2-enoylamino)propyl]ammonium chloride).

An example of the monomer (v-6) is tetraallylammonium chloride, triallylamine, methylenebisacrylamide, glycol diacrylate, glycol dimethacrylate, glycerol triacrylate, pentaerythritol triallyl ether, N,N-divinylethylene urea, polyalkylene glycols, or polyols esterified at least twice with acrylic acid and/or methacrylic acid, such as pentaerythritol, sorbitol and glucose.

Monomer (v) is preferred which is not an ester of acrylic acid or methacrylic acid. More preferred is the monomer (v) which is not an ethylenically unsaturated carboxylic acid ester.

Preferably, if the proportion of monomers (v-1) is from 50 to 100% of the total amount of all monomers (v). Particularly preferably, if it is from 80 to 100%; most preferably from 95 to 100%. For the above percentage of total monomers (v), the following monomers (v-1) are particularly preferred: 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl ethacrylate, 2-hydroxypropylacrylate, 2-hydroxypropyl methacrylate, vinyl pyrrolidone or vinyl acetate.

Preferably, if the proportion of monomers (v-3), (v-4) and (v-5) is from 50 to 100% of the total amount of all monomers (v). Particularly preferably, if it is from 80 to 100%; most preferably from 95 to 100%.

Preferably, if the proportion of monomers (v-3), (v-4) and (v-5) is from 50 to 100% of the total amount of all monomers (v). Particularly preferably, if it is from 80 to 100%; most preferably from 95 to 100%.

Preferably, if the total amount of all monomers (v) is from 0 to 25 mol. % in terms of the amount of all monomers polymerized to obtain the original polymer V, i.e. all monomers (i), (ii), optionally (iii), optionally (iv) and optionally (v), more preferably if it is from 0 to 24 mol. %, particularly preferably from 0 to 19 mol. %, even more preferably from 0.01 to 15 mol. %, even more preferably from 0.1 to 8 mol. %, even more preferably from 0.2 to 4 mol. % and most preferably from 0.4 to 2 mol. %. The condition remains that the total amount of all monomers (i), (ii), (iii), (iv) and (v) is 100 mol. %.

In the case of acrylamide as a typical monomer (v-1), it is preferable if the amount of acrylamide is from 0 to 6 mol. %, where indicated in mol. % quantities are given in terms of the total amount of all monomers (i), (ii), (iii), (iv) and (v), and the total amount of all monomers is 100 mol. %. More preferably, if the amount of acrylamide is from 0 to 5 mol. %, particularly preferably from 0 to 3 mol. %, even more preferably from 0 to 2 mol. %, even more preferably from 0 to 1 mol. %, and most preferably, if acrylamide is not contained at all.

The method in which the monomers (v) contain acrylamide in an amount of 0 to 6 mol. % indicated in mol. % quantities are given in terms of the total amount of all monomers (i), (ii), (iii), (iv) and (v), and the total amount of all monomers is 100 mol. %.

The monomer (v-b) acts as a cross-linking agent. If a crosslinking agent is used, it is preferable if the amount used is from 0.001 to 1 mol. % in terms of the total amount of all monomers (i), (ii), (iii), (iv) and (v), and the total amount of all monomers is 100 mol. %, more preferably if it is from 0.01 to 0.5 mol. % and particularly preferably from 0.015 to 0.1 mol. %. Preferably, no monomer (v-6) is used for radical polymerization.

Preferably, the starting polymer V is in the form of an aqueous dispersion or aqueous solution. More preferably, if the water content in the aqueous dispersion or water is from 75 to 95 wt. % and the content of the original polymer V is from 5 to 25 wt. %, where the content of the original polymer V is defined as the content of solids. Determination of solids content is described in the experimental section. Preferably, the aqueous dispersion has a pH greater than 6, more preferably a pH of 6.1 to 9, and particularly preferably a pH of 6.2 to 6.8. An appropriate pH can be achieved, for example, by adding an acid and/or base, optionally with the addition of a buffer.

Preferred is a method in which the following monomers are used for radical polymerization:

(i) from 50 to 89 mol. % monomer of formula I,

(ii) from 5 to 45 mol. % C ₁ -C ₄ -alkyl ester of acrylic acid or C ₁ -C ₄ -alkyl ester of methacrylic acid,

(iii) 0 to 30 mol. % monoethylenically unsaturated carboxylic acid, monoethylenically unsaturated sulfonic acid or monoethylenically unsaturated phosphonic acid, or their salt forms,

(iv) 0 to 9 mol. % acrylonitrile or methacrylonitrile,

(v) 0 to 25 mol. % of one or more ethylenically unsaturated monomers other than the monomer (i), (ii), (iii) and (iv).

Preferred is a method in which the following monomers are used for radical polymerization:

(i) from 58 to 83 mol. % monomer of formula I,

(ii) from 8 to 39 mol. % C ₁ -C ₄ -alkyl ester of acrylic acid or C ₁ -C ₄ -alkyl ester of methacrylic acid,

(iii) 0 to 25 mol. % monoethylenically unsaturated carboxylic acid, monoethylenically unsaturated sulfonic acid or monoethylenically unsaturated phosphonic acid, or their salt forms,

(iv) 0 to 9 mol. % acrylonitrile or methacrylonitrile,

(v) 0 to 25 mol. % of one or more ethylenically unsaturated monomers other than the monomer (i), (ii), (iii) and (iv).

Preferred is a method in which the following monomers are used for radical polymerization:

(i) from 60 to 83 mol. % N-vinylformamide,

(ii) from 8 to 25 mol. % ethyl acrylate,

(iii) from 3 to 21 mol. % acrylic acid or methacrylic acid, or their salt forms,

(iv) 0 to 9 mol. % acrylonitrile or methacrylonitrile,

(v) 0 to 24 mol. % of one or more ethylenically unsaturated monomers other than the monomer (i), (ii), (iii) and (iv).

Preferred is a method in which the following monomers are used for radical polymerization:

(i) from 60 to 83 mol. % N-vinylformamide,

(ii) from 8 to 21 mol. % ethyl acrylate,

(iii) from 3 to 21 mol. % acrylic acid or methacrylic acid, or their salt forms,

(iv) 0 to 9 mol. % acrylonitrile or methacrylonitrile,

(v) 0 to 24 mol. % of one or more ethylenically unsaturated monomers other than the monomer (i), (ii), (iii) and (iv).

The final polymer A is obtained by partial or complete hydrolysis of the original polymer V. As is known, for example, from EP 0438744 A1, pages 8/lines 26-34, the amide group contained in the units of the monomers (i) polymerized to obtain the original polymer, t .e. the NC(=O)R ¹ group contained in the monomer of formula (I) can be at least partially hydrolyzed, resulting in the formation of primary amino groups. When splitting off a carboxylic acid, for example, formic acid or formate in the case of R ¹ =H, a primary amino group is formed. If not all amide groups are hydrolyzed, it is known that, due to the condensation of the primary amino group with the adjacent amide group, a cyclic 6-membered amidine group is formed in the final polymer A, probably in accordance with the reaction scheme below.

In the case of polymerization of ethylene derivatives substituted directly at the ethylene functional group by a cyano group, for example monomer (iv), the starting polymer V additionally contains cyano groups. It is known that the primary amino group contained in the final polymer A, formed due to hydrolysis, can react with one of these cyano groups to form a cyclic 5-membered amidine. In this case, hydrolysis of the amide group results in the formation of a 5-membered amidine group in the final polymer A, according to the reaction scheme below. In the reaction scheme below, the cyano-substituted ethylene derivative in this case is polymerized acrylonitrile.

In both cases described, the hydrolysis of the amide group contained in the monomer of formula I leads to the formation of a primary amino group or an amidine group. The primary amino group or amidine group has a positive charge at pH=7 and this provides a cationic charge in the final polymer A.

Conditions for carrying out the hydrolysis of amide groups, which originate from the monomers of formula I, to obtain the final polymer A, can also lead to the hydrolysis of other groups contained in the original polymer V, which are easily hydrolyzed under these conditions. Thus, for example, it is known from EP 0216387 A2, column 6/lines 7-43, or from WO 2016/001016 A1, pages 17/lines 1-8, that the acetate groups contained in the starting polymer V, which originate from vinyl acetate used as the polymerized monomer (v-1). Accordingly, a secondary hydroxyl group is formed in the final polymer A, as shown below in the present invention.

The presence of monomers (ii) means that the starting polymer V contains ester groups. When carrying out the hydrolysis of the amide groups contained in the final polymer A, which originate from the monomers of the formula I, in an acidic or alkaline medium, at least partial conversion of the ester groups is observed. One conversion reaction is the formation of a 5-membered lactam structural unit containing the resulting amino group. Another transformation reaction is the formation of a carboxy group. The reaction scheme below shows some of the reaction pathways.

The number of monomer units of formula (I) that are polymerized to give the starting polymer V and that are hydrolyzed to give the final polymer A can be determined experimentally by determining the amount of carboxylic acids HOC(=O)R ¹ cleaved from the NC(=O)R groups ¹ . In the case of R ¹ =H, the amount of formic acid or formate released can be determined, for example, by enzymatic analysis using a test kit manufactured by Boehringer, Mannheim. The number of hydrolyzed groups NC(=O)R ¹ contained in the polymerized units of the formula I, referred to the number of all polymerized units of the formula I, multiplied by 100 mol. %, gives the degree of hydrolysis (=SG). Preferably, if hydrolyzed at least 50 to 100 mol. % of monomers (i) polymerized to give the parent polymer V, based on the amount of all monomers (i) polymerized to give the parent polymer V. More preferably, at least 65 to 100% hydrolysed, particularly preferably 70 to 100 %, even more preferably from 72 to 100%, even more preferably from 85 to 99.9%, even more preferably from 94 to 99.5% and most preferably from 94 to 99% of these monomers.

Preferred is a method in which at least 50 to 100 mol. % of monomers (i) polymerized to give the original polymer V, based on the amount of all monomers (i) polymerized to give the original polymer V.

The preferred method is one in which at least 70 and not more than 99.5% of the polymerized monomers (i) are hydrolyzed, based on the amount of all monomers (i) polymerized to give the original polymer V

The number of monomer units (ii) which are polymerized to give the starting polymer V and which are converted to give the final polymer A can be determined experimentally by determining the amount of alcohols cleaved from the ester groups. For determining the amount of alcohol removed, gas chromatography or high pressure liquid chromatography is suitable. The number of converted ester groups contained in the polymerized monomers (ii), referred to the amount of all polymerized monomers (ii), multiplied by 100 mol. % gives the degree of conversion (=SP). Preferably, if at least 50 to 100 mol. % of monomers (ii) polymerized to give the original polymer V, based on the amount of all monomers (ii) polymerized to give the original polymer V. More preferably, if undergoes a conversion of at least 70 to 100%, particularly preferably from 86 to 100%, even more preferably 90 to 100%, even more preferably 95 to 99.9%, even more preferably 98 to 99.5% and most preferably 100% of these monomers.

Preferred is a method in which at least 50 to 100 mol. % of monomers (ii) polymerized to give the original polymer V, based on the amount of all monomers (ii) polymerized to give the original polymer V.

Preferred is a process in which at least 90 and not more than 99.5% of the polymerized monomers (ii) are converted, based on the amount of all monomers (ii) polymerized to form the original polymer V.

Preferred is a method in which at least 70 to 100 mol. % of monomers (i) polymerized to obtain the original polymer V, based on the amount of all monomers (i) polymerized to obtain the original polymer V, and undergoes conversion of at least 90 to 100% of the monomers (ii) polymerized to obtain the original polymer V, in terms of the amount of all monomers (ii), polymerized to obtain the original polymer V.

Preferably, the starting polymer V is subjected to alkaline, acidic or enzymatic hydrolysis, more preferably alkaline or acidic hydrolysis, and particularly preferably alkaline hydrolysis. In the case of acid hydrolysis, the amino groups contained in the final polymer A are in salt form. The achieved degree of hydrolysis (=CH) and the degree of conversion provided (=CP) depend on the acid or base, the amount of acid or base used, the temperature used, and the duration of the reaction. Preferably, if the hydrolysis is carried out at temperatures equal to from 20 to 170°C, more preferably in the range from 50 to 140°C. The hydrolysis can be carried out at normal pressure, at reduced pressure or at elevated pressure, i.e. at a pressure ranging from 100 mbar to 16 bar. Hydrolysis at normal pressure is preferred. For carrying out hydrolysis in an alkaline medium, metal hydroxides of the first and second main groups of the Periodic Table of the Elements, for example lithium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide or calcium hydroxide, and ammonia and ammonia derivatives, for example, triethylamine, monoethanolamine, diethanolamine, triethanolamine or morpholine. Metal hydroxides of the first and second main groups of the Periodic Table are preferred, sodium hydroxide, potassium hydroxide, magnesium hydroxide or calcium hydroxide are more preferred, sodium hydroxide or potassium hydroxide is especially preferred, and sodium hydroxide is most preferred. Inorganic acids such as hydrogen halides, sulfuric acid, nitric acid and phosphoric acid, as well as organic acids such as formic acid, acetic acid, propionic acid, benzosulfonic acid, alkylsulfonic acid and phosphonic acids are suitable for carrying out hydrolysis in an acidic medium. Hydrochloric acid and sulfuric acid are preferred. It is preferable to use 0.2-2.0 eq. acids or bases, calculated on the sum of the mole fractions of N-vinylamides and (meth)acrylic acid esters contained in the starting polymer V. More preferred are amounts from 0.5 to 1.5 equivalents, and particularly preferably 0.7 -1.2 eq. Preferably, if the base or acid is added to the original polymer V in an amount ranging from 30 to 150 mol. % in terms of the amount of monomers (i)polymerized to obtain the original polymer V. Preferably, if the amount is from 90 to 150 mol. %, particularly preferably from 100 to 140 mol. % and most preferably from 110 to 130 mol. %. Preferably, if the base or acid is added in an amount ranging from 30 to 130 mol. % in terms of the amount of all monomers (i), (ii), (iii), (iv) and (v). Preferably, if the hydrolysis is carried out in an aqueous solution, more preferably in an aqueous solution having a water content of from 40 to 95 wt. %, based on the total weight of the aqueous solution, particularly preferably between 60 and 94 wt. % and most preferably ranging from 75 to 93 wt. %.

The preferred method is one in which the starting polymer V is hydrolyzed in an alkaline environment to obtain the final polymer A.

As described above, the original polymers V containing the monomer (iii) have favorable characteristics in the case of hydrolysis in an alkaline environment.

Preferred is a method in which carried out by radical polymerization to obtain the original polymer V using from 1 to 25 mol. % monomer (iii) and the original polymer V is subjected to hydrolysis in an alkaline environment to obtain the final polymer A.

Preferably, the final polymer A contains 5-membered lactam structural units. The structural units contained in the final polymer A are, on the one hand, all monomers (i), (ii), optionally (iii), optionally (iv) and optionally (v), polymerized to obtain the original polymer V. In addition, they are also structural units that can be formed due to hydrolysis. These include the above 6-membered amidines, the above 5-membered amidines, the above ethylene units containing secondary hydroxyl groups, the above 5-membered lactams, and the above acrylic acid or methacrylic acid esters hydrolyzed to form a carboxylic acid. The formation of some of these structural units completely consumes the two polymerized monomers contained in the original polymer V. Thus, the total number of all structural units contained in the final polymer A is the total amount of all monomers (i), (ii), (iii ), (iv) and (v), which are polymerized to form the original polymer V, minus a correction value corresponding to the number of those structural units that were formed from the two polymerized monomers. As an example, below in the present invention, this is represented by formula (II)

in which R ² =H or denotes C ₁ -alkyl and R ³ =H or denotes C ₁ -alkyl, a, b, c, d and e denote percentage mole fractions (=mol.%) of structural units,

f denotes the percentage mole fraction (=mol. %) of at least one polymerized additional structural unit (not shown in formula (II)), and the sum of a, b, c, d, e and f is 100 mol. %.

The final polymer A of formula (II) is preferred. More preferred is the final polymer A of formula (II), where in formula (II) and is equal to from 0.1 to 20 mol. %, b is from 0 to 10 mol. %, with equal to from 25 to 85 mol. %, d is from 1 to 50 mol. %, e is from 1 to 50 mol. %, and f is from 0 to 40 mol. %, and where the sum of the amounts of all structural units a, b, c, d, e and f is equal to 100 mol. %. Particularly preferably, if in the formula (II) and is equal to from 0.1 to 20 mol. %, b is from 0 to 20 mol. %, with equal to from 25 to 85 mol. %, d is from 1 to 50 mol. %, and e is from 1 to 50 mol. %, where the sum of the amounts of all structural units a, b, c, d and e is 100 mol. %. Even more preferably, if in the formula (II) R ² =R ³ =H, and is equal to from 0.1 to 20 mol. %, b is from 0 to 20 mol. %, with equal to from 25 to 85 mol. %, d is from 1 to 50 mol. %, e is from 1 to 50 mol. %, and the number of any other structural units f is from 0 to 40 mol. %, where the sum of the amounts of all structural units a, b, c, d, e and f is 100 mol. %.

Most preferably, if in the formula (II) R ² =R ³ =N, and is equal to from 0.1 to 20 mol. %, b is from 0 to 20 mol. %, with equal to from 25 to 85 mol. %, d is from 1 to 50 mol. %, and e is from 1 to 50 mol. %, where the sum of the amounts of all structural units a, b c, d and e is equal to 100 mol. %.

More preferably, if the content of lactam structural units is from 10 to 60 mol. %, where the percentage value is given in terms of the total amount of all structural units contained in the final polymer A. It is especially preferred if the content is from 15 to 50 mol. %, even more preferably from 17 to 35 mol. %. It is particularly preferred that the above levels apply to the final polymer A in an aqueous medium at a pH value of 3.5 to 9, and particularly preferably at a pH value of 3.5.

A process is preferred in which at least a portion of the ester groups contained in the monomers (ii) polymerized to form the parent polymer V is converted and at least a portion of the conversion is to form 5-membered lactam structural units containing the resulting primary amino groups.

Preferably, the final polymer A has a weight average molecular weight M _w of 8,000 to 8,000,000 Da. More preferably, the final polymer A has a weight average molecular weight _Mw of 16,000 to 4,000,000 Da, particularly preferably 80,000 to 3,600,000 Da, even more preferably 150,000 to 2,000,000 Da and most preferably 170,000 to 1,200,000 Da. The weight average molecular weight can be determined using static light scattering.

Preferably the final polymer A is cationic, more preferably amphoteric-cationic. The final polymer A is cationic if the total amount of all positive charges contained in the final polymer A exceeds the total amount of all negative charges contained in the final polymer A at a given pH value, preferably at a pH value of 7. This takes into account the corresponding possessing structural units and their charges at a nominal pH of 7. The final polymer A is amphoteric-cationic if the total amount of all positive charges contained in the final polymer A exceeds the total amount of all negative charges contained in the final polymer A, and in at the same time, the final polymer A contains negative charges at a given pH, preferably at a pH of 7. This is also true when considering charged structural units at a nominal pH of 7. Amount of monomers (i). polymerized to give the parent polymer V and their degree of hydrolysis to the final polymer A are the most important parameters for providing positive charges in the final polymer A. For this it is possible that the monomers (v) provide a positive charge in the parent polymer V and that this positive charge still exists in the final polymer A also after the hydrolysis carried out to obtain the final polymer A.

Preferably, the final polymer A has a positive charge density. More preferably, the charge density is determined by titrating the polyelectrolyte with potassium polyvinylsulfonate. More preferably, the charge density is determined at a pH value of 3.5 in an aqueous medium. It is particularly preferred if the charge density is determined by titrating the polyelectrolyte with potassium polyvinylsulfonate at pH 3.5 in an aqueous medium. Preferably, if the positive charge density is from 2 to 16 mmol/g, where 1 g refers to the polymer content of the final polymer A. More preferably, if it is from 4 to 14 mmol/g, particularly preferably from 5 to 12 mmol/g .

Preferably, the final polymer A is in the form of an aqueous dispersion or aqueous solution. More preferably, if the water content in the aqueous dispersion or aqueous solution is from 75 to 95 wt. % and the content of the final polymer And is from 5 to 25 wt. %, where the content of the final polymer And is defined as the content of the polymer. Preferably, the aqueous dispersion or aqueous solution has a pH greater than 5, more preferably a pH of 6 to 9, particularly preferably a pH of 6 to 8, and most preferably a pH of 6.1 to 6.8. An appropriate pH value can be achieved, for example, by adding an acid and/or a base. Preferably, if the positive charge density of the final polymer A, which is in the form of an aqueous dispersion or aqueous solution, is from 20 to 120 mmol/100 g, where 100 g refers to an aqueous dispersion or aqueous solution of the final polymer A. More preferably, if it is from 30 to 100 mmol/100 g, particularly preferably 35 to 90 mmol/100 g.

More preferred is a process in which the final polymer A is obtained by - radical polymerization of the following monomers:

(i) from 58 to 83 mol. % monomer of formula I

in which R ¹ =H or denotes C ₁ -C ₆ -alkyl,

(ii) from 8 to 39 mol. % C ₁ -C ₄ -alkyl ester of acrylic acid or C ₁ -C ₄ -alkyl ester of methacrylic acid,

(iii) 0 to 25 mol. % monoethylenically unsaturated carboxylic acid, monoethylenically unsaturated sulfonic acid or monoethylenically unsaturated phosphonic acid, or their salt forms,

(iv) 0 to 9 mol. % acrylonitrile or methacrylonitrile,

(v) 0 to 25 mol. % of one or more ethylenically unsaturated monomers other than the monomer (i), (ii), (iii) and (iv),

where the total amount of all monomers (i), (ii), (iii), (iv) and (v) is 100 mol. %, to obtain the original polymer V, and

- hydrolysis of the original polymer V to obtain the final polymer A, where at least part of the groups NC(=O)R ¹ contained in the monomers (i) of formula (I), polymerized to obtain the original polymer V, is hydrolyzed and thus formed primary amino groups , where at least part of the ester groups contained in the monomers (ii), polymerized to obtain the original polymer V, undergoes transformation and at least part of the transformation is the formation of 5-membered lactam structural units containing the obtained primary amino groups, or the formation of carboxy groups or their salt forms.

Preferably, the final polymer A is added to the first aqueous suspension of fibrous material in the form of an aqueous dispersion or an aqueous solution of the final polymer having a pH value of more than 5, more preferably a pH value of from 6 to 9, particularly preferably a pH value of from 6 to 8, and particularly preferably a pH value of 6.1 to 6.8.

A process is preferred in which, in step (A), the final polymer A is added as an aqueous dispersion or aqueous solution having a pH of 5 to 9 to the first aqueous fibrous material slurry.

The second aqueous suspension of fibrous material containing the final polymer And includes

(a-a) water,

(a-b) fibrous material,

(a-c) final polymer A.

A possible additional component of the second aqueous suspension of fibrous material is (a-d) an organic polymer which is different from the fibrous material and from the final polymer A. The organic polymer (a-d) may be neutral, cationic or anionic.

The neutral organic polymer (a-d) may be uncharged-neutral because it does not include polymeric units containing a functional group that contains at least one charge at a pH value of 7. Examples of a neutral organic polymer (a-d) that does not include any polymeric units containing a functional group that has a charge at a pH value of 7 are polyacrylamide, acrylamide-acrylonitrile copolymer, poly(vinyl alcohol), or vinyl alcohol-vinyl acetate copolymer.

The neutral organic polymer (a-d) can also be amphoteric-neutral because it includes polymer units containing a functional group that has a negative charge at least at a pH value of 7, as well as polymer units containing a functional group that has a positive charge. at least at a pH value of 7, where, in addition, in the functional groups, the number of all negative charges and the number of all positive charges balance each other.

The cationic organic polymer (a-d) may be fully cationic, i. it includes polymeric units containing a functional group that is positively charged at at least a pH of 7, but does not include any polymeric units containing a functional group that is negatively charged at least at a pH of 7. Full examples cationic organic polymer (a-d) are poly(allylamine), poly(diallylamine), poly(diallyldimethylammonium chloride), acrylamide-diallyldimethylammonium chloride copolymer or acrylamide-2-(N,N,N-trimethylammonium)ethyl acrylate chloride copolymer. The cationic organic polymer (a-d) may also be amphoteric-cationic, ie. it includes polymer units containing a functional group that has a positive charge at least at a pH value of 7, and polymer units containing a functional group that has a negative charge at least at a pH value of 7, and in functional groups the amount of all positive charges exceeds the number of all negative charges.

The anionic organic polymer (a-d) may be fully anionic, ie. it includes polymeric units containing a functional group that is negatively charged at at least pH 7, but does not include polymeric units containing a functional group that is positively charged at least at pH 7. Examples of a fully anionic The organic polymers (a-d) are poly(acrylic acid), a copolymer of styrene with n-butyl acrylate and with acrylic acid, or a copolymer of acrylamide with acrylonitrile and with acrylic acid.

The anionic organic polymer (a-d) may also be amphoteric-anionic, ie. it includes polymeric units containing a functional group that has a negative charge at least at a pH value of 7, and polymer units containing a functional group that has a positive charge at least at a pH value of 7, and in functional groups the amount of all negative charges exceeds the number of all positive charges.

Organic polymers (a-d) can also be divided into linear, branched and cross-linked. Crosslinking can be achieved, for example, by adding a crosslinking agent already during the polymerization of the starting monomers, or by adding a crosslinking agent after the completion of the polymerization, in particular immediately before adding the organic polymer (a-d) to the second aqueous suspension of fibrous material. Thus, for example, polyacrylamide can be crosslinked already during the polymerization by adding a crosslinking agent, methylenebisacrylamide, to the acrylamide, or by adding a crosslinking agent, such as glyoxal, after the polymerization. If necessary, you can combine both methods of stitching. Of particular note is the cross-linked organic polymer, which has a high degree of cross-linking, usually already during the polymerization of the monomers. It is contained in the second aqueous fibrous material suspension containing the final polymer A in particulate form, in particular in the form of so-called organic microparticles.

Organic polymers (a-d) can also be divided into natural, modified natural or synthetic. The natural organic polymer is usually a polymer of natural origin, with appropriate isolation steps carried out if necessary, but no special modifications by chemical synthesis are carried out. An example of a natural organic polymer (a-d) is unmodified starch. Cellulose is not an example of a natural organic polymer (a-d), which is a fibrous material (a-b) in the present invention. The modified natural organic polymer is a polymer modified by chemical synthesis steps. An example of a modified natural organic polymer (a-d) is cationic starch. Synthetic organic polymer (a-d) is obtained by chemical synthesis from individual monomers. An example of a synthetic organic polymer (a-d) is polyacrylamide.

It is preferred that in step (A) the organic polymer (a-d) is added to the first fibrous material slurry or to the second fibrous material slurry containing the final polymer A. More preferably, if the organic polymer (a-d) is added, which is a modified natural organic polymer. It is particularly preferred if the organic polymer (a-d) is a cationic starch. Most preferably, the cationic starch is the only organic polymer (a-d) which is added in step (A) to the first fibrous material slurry in addition to the final polymer A or to the second fibrous material slurry containing polymer A.

A possible additional component of the aqueous fibrous material suspension containing the final polymer A is (a-e) filler. The filler (a-e) is an inorganic particle, in particular an inorganic pigment. As inorganic pigments, all pigments based on metal oxides, silicates and/or carbonates which are commonly used in the paper industry can be used, in particular pigments selected from the group consisting of the following: calcium carbonate, which can be used in the form of ground lime, chalk, marble (RCC (ground calcium carbonate)) or precipitated calcium carbonate (PCC), talc, kaolin, bentonite, satinite, calcium sulfate, barium sulfate and titanium dioxide. Inorganic particles is also a colloidal solution of polysilicic acids, in which the silicic acid particles usually have a size of 5 to 150 nm.

In the context of the present invention, the filler (a-e) also includes two or more different fillers. Accordingly, the filler (a-e) used as a possible additional component of the aqueous fibrous material suspension is divided into the first filler (a-e-1), the second filler (a-e-2) and the like.

Preferably, inorganic pigments having an average particle size (volume average size) of ≦10 µm, more preferably 0.3 to 5 µm, particularly preferably 0.5 to 2 µm, are used. Determination of the average particle size (average volume size) of inorganic pigments, as well as particles of a powdered composition in the context of the present invention, is usually carried out according to the method of quasi-elastic light scattering (DIN-ISO 13320-1), for example, using the Mastersizer 2000, manufactured by Malvern Instruments Ltd.

A process is preferred in which, in step (A), the filler (a-e) is added to the first fibrous material slurry or to the second fibrous material slurry containing polymer A.

Preferably, if the total amount of filler (a-e) is from 0 to 40 wt. % in terms of the weight of the obtained paper or cardboard and in terms of the solids content in the filler (a-e), amounting to 100 wt. %, and the content of solids in paper or cardboard, amounting to 100 wt. %. More preferably, if the total amount of filler (a-e) is from 5 to 30 wt. %, particularly preferably from 15 to 25 wt. % and most preferably from 15 to 20 wt. %.

Preferably, if the resulting paper or paperboard contains filler (a-e) in a total amount of 5 to 30 wt. %. Such paper is, for example, wood-free paper. Preferably, if the resulting paper or paperboard contains filler (a-e) in a total amount of 5 to 20 wt. %. Such paper is mainly used as wrapping paper. Preferably, if the resulting paper or paperboard contains filler (a-e) in a total amount of 5 to 15 wt. %. This paper is mainly used for printing newspapers. Preferably, if the resulting paper or board contains filler (a-e) in a total amount of 25 to 40 wt. %. Such paper is, for example, SC (supercalendered) paper.

Preferably, in step (A), the final polymer A is added to the first aqueous fibrous material slurry prior to the addition of the filler (a-e). More preferably, the final polymer A is added before adding the filler (a-e) and before adding the organic polymer (a-d), except in the case of adding cationic starch. It is particularly preferred if the final polymer A is added to the first aqueous fibrous material slurry before the addition of the filler (a-e), before the addition of the organic polymer (a-d) other than cationic starch, and before the addition of any other paper aid (a-f).

In step (A), any added filler (a-e) is preferably added to the second fibrous material slurry containing the final polymer A, which has a solids content of 0.1 to 1.5 wt. %. This addition corresponds to the so-called addition to the liquid mass. The second suspension of fibrous material containing the final polymer A is already available and has this solids content, or it is pre-diluted to provide a solids content of from 0.1 to 1.5 wt. %, based on the content of solids, ranging from more than 0.15 and up to 6.0 wt. %.

In step (A), any added filler (a-e) is preferably added to the second fibrous material slurry containing the final polymer A, where the first portion of the total amount of filler (a-e) to be added is added to the fibrous material slurry containing the final polymer A, which has a solids content of more than 0.15 to 6.0 wt. %, and the second part of the total amount of filler (a-e) to be added is added to the suspension of fibrous material containing the final polymer A, after dilution to ensure a solids content of 0.1 to 1.5 wt. %. It is necessary to add the first part and the second part of the total amount of filler (a-e). The ratio of the mass of the first part to the mass of the second part is from 5 to 0.2.

A possible additional component of the aqueous fibrous material slurry containing the final polymer A is (af) another paper additive. Another paper additive (af) differs from the above components: (a-b), final polymer A using (a-c), (ad) and (a-e) as a component. Another paper additive (af) is, for example, a sizing agent for bulk sizing, a water-soluble salt formed with a ferric metal cation, an antifoam, a non-polymeric wet strength agent, a biocide, an optical brightener or a dye for paper. Examples of sizing agents are alkyl ketone dimers (AAK), alkenyl succinic anhydrides (ASA) and resin glue. Examples of water-soluble salts formed with a trivalent metal cation are aluminum(III) salts, especially AlCl ₃ such as AlCl ₃ -6H ₂ O, Al ₂ (SO ₄ ) ₃ such as Al ₂ (SO ₄ ) ₃ 1⋅8H ₂ O, or KAl(SO ₄ ) ₂ ⋅12H ₂ O. Other paper auxiliaries (af) can preferably be added in normal amounts.

Preferably, another paper aid (a-f) is added to the second fibrous material slurry containing the final polymer A, which has a solids content of 0.1 to 1.5 wt. %. This addition corresponds to the so-called addition to the liquid mass. The second suspension of fibrous material containing the final polymer A is already available and has this solids content, or it is pre-diluted to provide a solids content of from 0.1 to 1.5 wt. %, based on the content of solids, ranging from more than 0.15 and up to 6.0 wt. %.

In the context of the present invention, the other paper aid (a-f) also includes two or more different other paper aids. Accordingly, another paper auxiliary additive (a-f) used as a possible additional component of the second aqueous fibrous material suspension containing the final polymer A is separated into the first other paper auxiliary additive (a-f-l), the second other paper auxiliary additive (a-f -2), etc.

During papermaking, more than one organic polymer (a-d) and more than one filler (a-e) are often added to the aqueous fibrous material slurry. In the case of an organic polymer (a-d), this is carried out, for example, to influence the performance of the papermaking process itself or the performance of the paper produced. Thus, retaining agents, dewatering agents, wet strength agents, or other dry strength agents are used.

Examples of retention aids are cationic, amphoteric or anionic polymers (a-d). Examples are anionic polyacrylamide, cationic polyacrylamide, cationic starch, cationic polyethyleneimine or cationic polyvinylamine. In addition, it is also possible to add inorganic fillers (a to e) as retention aids, which act as so-called anionic microparticles. They include, in particular, colloidal silicon dioxide or bentonite. Combinations of the above substances are possible. In particular, a possible combination is a two-component system, which consists of a cationic polymer and anionic microparticles or an anionic polymer and cationic microparticles. The preferred retention aid is a synthetic organic polymer (a-d) or a two-component system. In the case of a two-component system as a retention aid, for example, the cationic first organic polymer (a-d-1) is contained in combination with an anionic inorganic microparticles, for example, a suitable bentonite used as the first filler (a-e-1).

Examples of another dry strength agent are a synthetic organic polymer (a-d) such as polyvinylamine, polyethyleneimine, polyacrylamide or glyoxylated polyacrylamide, a natural organic polymer (a-d) such as unmodified starch, or a modified natural organic polymer (a-d), such as cationically modified starch or oxidatively or enzymatically degraded starch. Preferably, another dry strength agent is added to the first aqueous fibrous material slurry or to the second aqueous pulp slurry containing the final polymer A, both of which have a solids content of greater than 1.5 to 6.0 wt. %. You can add to the first aqueous suspension of fibrous material or to the second aqueous suspension of fibrous material containing the final polymer A, each of which has a solids content of from 0.1 to 1.5 wt. %.

In step (B), a second aqueous fibrous material slurry containing the final polymer A is applied to a water-permeable substrate. The water-permeable substrate includes a top and bottom side and fine holes that allow water to flow through but generally prevent fibrous components from passing through. The second aqueous fibrous material slurry containing the final polymer A is uniformly applied to the water-permeable substrate. The upper side of the water-pervious substrate is a substantially flat surface at the time of application, i. e. except for pinholes or other irregularities due to the nature of the material and any defined radius of curvature. This makes it possible to obtain a uniformly thin, as uniform as possible wet web of fibrous material or wet paper structure or wet paper sheet. After application of the second aqueous fibrous material slurry containing the final polymer A, part of the water (a-a) flows through the fine holes, while a sheet is formed on the upper side, thus forming a wet paper structure. The wet paper structure thus obtained is flat, i. it has an extremely small height compared to its length and width. The fibrous material contained in the second fibrous material slurry containing the final polymer A and possible other components to be contained in the final manufactured paper or board, for example filler (a-e), ideally remains wholly, or at least substantially remains in the wet paper structure that is formed. In this method, it is effective to use possible additional components in the second aqueous fibrous material suspension containing the final polymer A, which are added to assist in the retention of other components, to assist in dewatering, or to assist in the formation of a uniform sheet, for example, an organic polymer (a-d). In most cases, these possible additional components contained in the suspension of fibrous material also completely remain or at least mainly remain in the resulting web of fibrous material. The portion of the wet paper structure that determines the solids content of the wet paper structure contains retained fibrous material components, optional other components to be contained in the final manufactured paper, and optional additional components. Depending on the retention characteristics of these components, these may include, for example, said fibrous material, organic polymers, fillers, and other paper auxiliaries. After step (B) is completed, the wet paper structure is strong enough to be removed from the water-permeable substrate.

Preferably, the water-permeable substrate used in step (B) is a mesh. The mesh, which contains the bottom side of the mesh and the upper side of the mesh, is a mesh with fine holes. The mesh includes, for example, a metal or plastic mesh. In the case of a paper machine, it is more preferred if the mesh is an endless mesh. After separating the resulting wet paper structure from the endless web, the endless web moves back to deposit the material, where a new second fibrous material slurry containing the final polymer A is applied to the moving endless wire. More preferably, the grid is an infinite grid moving around several cylinders.

The solids content of the wet paper structure obtained in step (B) is preferably 15 to 25 wt. %, more preferably from 18.7 to 24 wt. %, particularly preferably from 18.8 to 23 wt. %, even more preferably from 18.9 to 22 wt. %, even more preferably from 19.0 to 21 wt. % and most preferably from 19.0 to 20.7 wt. %.

Preferred is a process in which, in step (B), the wet paper structure has a solids content of 18.5 to 25 wt. %.

Preferred is a process in which, in step (A), the final polymer A is added to a first aqueous fibrous material slurry which, at the time of addition, has a solids content of between more than 1.5 and up to 6 wt. %, and in which in stage (B) the wet paper structure has a solids content of 18.5 to 25 wt. %.

In step (C), the wet paper structure obtained in step (B) is dehydrated to produce paper or board. Conducted in stage (C) dehydration includes the following stages

(C-1) dewatering the wet paper structure by pressing to thereby obtain a wet paper sheet, (C-2) dewatering the wet paper sheet by applying heat, thereby obtaining paper or board.

The pressing of the wet paper structure carried out in step (C-1) leads to additional dewatering and a corresponding increase in solids content. In the case of press dewatering, mechanical pressure is applied to the wet paper structure. Removing water by applying mechanical pressure is more energy efficient than drying by applying heat. When the wet paper structure is placed on a water-absorbing sheet or tape, such as a felted web, the dewatering is aided by the adsorption of the pressed water. A cylinder is suitable for exerting pressure on the laminated composite. In particular, it is suitable to pass the layered composite through two cylinders, stopping if possible on a water-absorbing tape. The surface of the cylinder is made of, for example, steel, granite or hard rubber. The surface of the cylinder may be coated with a water-absorbing material. Water-absorbing materials have high absorbency, porosity, strength and elasticity. After step (C-1) is completed, a wet paper sheet is obtained. After step (C-1) is completed, the wet paper sheet is strong enough to be carried to the next step (C-2) without the use of a mechanical support. The wet paper sheet preferably has a solids content of 35 to 65 wt. %, more preferably from 37 to 60 wt. %, particularly preferably from 38 to 55 wt. %, most preferably from 40 to 50 wt. %.

In step (C-2), the wet paper sheet obtained in step (C-1) is further dehydrated, whereby paper or paperboard is obtained. The supply of heat to the wet paper sheet is provided, for example, by means of heated plates on which the wet paper sheet is placed, by means of heated cylinders over which the wet paper sheet is passed, by means of IR sources (infrared radiation), by means of warm air passed over wet paper sheet or using a combination of two, three or all of these techniques.

The resulting paper or paperboard has the highest strength compared to that of a wet paper structure or a wet paper sheet. It is assumed that with a dry matter content of 80 wt. %, hydroxyl groups contained in cellulose fibers are increasingly connected by hydrogen bonds, this provides preliminary mechanical felting of the fibers. One indication of the strength of the resulting paper or paperboard is, for example, internal strength.

Preferably, if the solids content in the resulting paper or board is not less than 88 wt. %. More preferably, if the solids content in the resulting paper or board is from 89 to 100 wt. %, particularly preferably from 90 to 98 wt. % and most preferably from 91 to 96 wt. %.

Depending on the basis weight per unit area, which is also called basis weight or density, the name of the flat molded article obtained from the second suspension of fibrous material containing the final polymer A is changed. In the present invention, the dried molded article having a mass per unit an area equal to from 7 to 225 g/m ² is called paper and having a mass per unit area equal to 225 g/m ² is called cardboard. The density of the paper or board is preferably 20 to 400 g/m ² , more preferably 40 to 280 g/m ² , particularly preferably 60 to 200 g/m ² , still more preferably 80 to 160 g/m ² , still more preferably 90 to 140 g/m ² and most preferably 100 to 130 g/m ² .

Preferably, the resulting paper or paperboard is packaging paper, more preferably corrugated paper.

The preferences given for the method of making paper or paperboard also apply to other aspects of the present invention.

Another object of the present invention is paper or paperboard obtained by a process comprising the steps

(A) adding the final polymer A to the first aqueous fibrous material suspension, thereby obtaining a second aqueous fibrous material suspension containing the final polymer A,

where the final polymer A is obtained by

- radical polymerization of the following monomers:

(i) 30 to 90 mol. % monomer of formula I

in which R ¹ =H or denotes C ₁ -C ₆ -alkyl,

(ii) from 3 to 60 mol. % C ₁ -C ₄ -alkyl ester of acrylic acid or C ₁ -C ₄ -alkyl ester of methacrylic acid,

(iii) from 0 to 45 mol. % monoethylenically unsaturated carboxylic acid, monoethylenically unsaturated sulfonic acid or monoethylenically unsaturated phosphonic acid, or their salt forms,

(iv) 0 to 9 mol. % acrylonitrile or methacrylonitrile,

(v) 0 to 35 mol. % of one or more ethylenically unsaturated monomers other than the monomer (i), (ii), (iii) and (iv),

where the total amount of all monomers (i), (ii), (iii), (iv) and (v) is 100 mol. %, to obtain the original polymer V, and

- hydrolysis of the original polymer V to obtain the final polymer A, where at least part of the groups NC(=O)R ¹ contained in the monomers (i) of formula (I), polymerized to obtain the original polymer V, is hydrolyzed and thus formed primary amino groups ,

where at least part of the ester groups contained in the monomers (ii), polymerized to obtain the original polymer V, undergoes transformation and at least part of the transformation is the formation of 5-membered lactam structural units containing the obtained primary amino groups, or the formation of carboxy groups or their salt forms,

(B) dewatering a second aqueous fibrous material slurry containing the final polymer A on a water-permeable substrate to form a wet paper structure,

(C) dewatering the wet paper structure, thereby obtaining paper or paperboard.

The paper or board preferably has an internal strength of 165 to 400 J/m ² , more preferably 190 to 350 J/m ² , particularly preferably 200 to 300 J/m ² and most preferably 220 to 280 J/m ² , where the internal strength corresponds to that determined in accordance with the standard method TAPPI T833 pm-94.

Another object of the present invention is the final polymer A obtained by

- radical polymerization of the following monomers:

(i) from 58 to 83 mol. % monomer of formula I

in which R ¹ =H or denotes C ₁ -C ₆ -alkyl,

(ii) from 8 to 39 mol. % C ₁ -C ₄ -alkyl ester of acrylic acid or C ₁ -C ₄ -alkyl ester of methacrylic acid,

(iii) 0 to 25 mol. % monoethylenically unsaturated carboxylic acid, monoethylenically unsaturated sulfonic acid or monoethylenically unsaturated phosphonic acid, or their salt forms,

(iv) 0 to 9 mol. % acrylonitrile or methacrylonitrile,

(v) 0 to 25 mol. % of one or more ethylenically unsaturated monomers other than the monomer (i), (ii), (iii) and (iv),

where the total amount of all monomers (i), (ii), (iii), (iv) and (v) is 100 mol. %, to obtain the original polymer V, and

- hydrolysis of the original polymer V to obtain the final polymer A, where at least part of the groups NC(=O)R ¹ contained in the monomers (i) of formula (I), polymerized to obtain the original polymer V, is hydrolyzed and thus formed primary amino groups , where at least part of the ester groups contained in the monomers (ii), polymerized to obtain the original polymer V, undergoes transformation and at least part of the transformation is the formation of 5-membered lactam structural units containing the obtained primary amino groups, or the formation of carboxy groups or their salt forms.

The final polymer A is preferred, where the following monomers are used for radical polymerization to give the starting polymer:

(i) from 60 to 83 mol. % N-vinylformamide,

(ii) from 8 to 21 mol. % ethyl acrylate,

(iii) from 2 to 21 mol. % acrylic acid or methacrylic acid, or their salt forms,

(iv) 0 to 9 mol. % acrylonitrile or methacrylonitrile,

(v) 0 to 24 mol. % of one or more ethylenically unsaturated monomers other than the monomer (i), (ii), (iii) and (iv).

Another object of the present invention is the original polymer V, obtained by radical polymerization of the following monomers:

(i) from 58 to 83 mol. % monomer of formula I

in which R ¹ =H or denotes C ₁ -C ₆ -alkyl,

(ii) from 8 to 39 mol. % C ₁ -C ₄ -alkyl ester of acrylic acid or C ₁ -C ₄ -alkyl ester of methacrylic acid,

(iii) 0 to 25 mol. % monoethylenically unsaturated carboxylic acid, monoethylenically unsaturated sulfonic acid or monoethylenically unsaturated phosphonic acid, or their salt forms,

(iv) 0 to 9 mol. % acrylonitrile or methacrylonitrile,

(v) 0 to 25 mol. % of one or more ethylenically unsaturated monomers other than the monomer (i), (ii), (iii) and (iv),

where the total amount of all monomers (i), (ii), (iii), (iv) and (v) is 100 mol. %.

Preferred is the starting polymer V, for which the following monomers are used by radical polymerization:

(i) from 60 to 83 mol. % N-vinylformamide,

(ii) from 8 to 21 mol. % ethyl acrylate,

(iii) from 2 to 21 mol. % acrylic acid or methacrylic acid, or their salt forms,

(iv) 0 to 9 mol. % acrylonitrile or methacrylonitrile,

(v) 0 to 24 mol. % of one or more ethylenically unsaturated monomers other than the monomer (i), (ii), (iii) and (iv).

In FIG. 1 using curve A is a schematic representation of the dependence of viscosity (in mPa.s) on time (h) during the hydrolysis of the first initial polymer obtained from 70 mol. % N-vinylformamide and 30 mol. % methyl acrylate, in an alkaline medium. Curve B schematically represents the dependence of viscosity (in mPa.s) on time (h) during the hydrolysis of the second initial polymer obtained from 70 mol. % N-vinylformamide, 20 mol. % methyl acrylate and 10 mol. % sodium acrylate, in an alkaline environment.

Examples

Percentage values given in the examples are by weight unless otherwise noted.

A) Additives

A-1) Polymer characterization techniques

The solids content of the polymer solution was determined by placing 0.5 to 1.5 g of the polymer solution in a 4 cm diameter metal cap and then drying in a circulating air oven at 140° C. for two hours (=2 h). The ratio of the weight of the sample after drying under the above conditions to the weight of the original weighed sample, multiplied by 100, gives the solids content of the polymer, expressed in wt. %.

The degree of hydrolysis of N-vinylformamide units (=SG) means expressed in mol. % ratio of the amount of hydrolyzed N-vinylformamide units to the amount of N-vinylformamide units originally contained in the polymer. The degree of hydrolysis was determined by enzymatic analysis of formic acid or formate released during hydrolysis (assay kit manufactured by Boehringer, Mannheim).

The degree of conversion of (meth)acrylate units (=SP) means expressed in mol. % ratio of converted (meth)acrylate units to the amount of (meth)acrylate units originally contained in the polymer. In the present invention, the term "transformation" means the elimination of an ester unit, for example by hydrolysis, to form a (meth)acrylate unit or its corresponding salt form, by reaction with an adjacent amino group, thereby forming a lactam. The degree of conversion can be determined by determining the amount of alcohol released during the conversion. This can be determined, for example, by HPLC (high performance liquid chromatography) or gas chromatography, depending on the alcohol evolved.

Polymer content refers to the percentage by weight of polymer in solution without counterions, i.e. counterions are not taken into account. The polymer content means the sum, expressed in mass percent, of the amounts of all structural units of the polymer in grams, which are contained in 100 g of an aqueous solution. It was determined by calculation. In this case, possibly charged structural units in charged form, ie, for example, amino groups in protonated form and acid groups in deprotonated form, are included. Counterions of charged structural units, such as sodium cation, chloride ion, phosphate ion, formate ion, acetate ion, etc., were not taken into account. The calculation can be carried out in such a way that for the mixture, based on the amounts of monomers used and, in appropriate cases, taking into account the degree of hydrolysis (DH) and the degree of conversion (DP), the molar amounts of structural units of the polymer contained after completion of the reaction were determined and converted into mass fractions using molar masses of structural units. The sum of the mass fractions gave the total amount of polymer in this mixture. The polymer content was the ratio of the total amount of polymer to the total weight of the mixture.

K values were determined according to H. Fikentscher, Cellulosechemie ("Cellulose Chemistry"), volume 13, 48-64 and 71-74, under the conditions indicated therein. The values in parentheses indicate the concentration of the solution, calculated taking into account the content of the polymer and solvent.

Charge densities were determined by titrating the polyelectrolyte with potassium polyvinylsulfonate at a pH of 3.5 (see D. Horn, Progress in Colloid & Polymer Science, 65 (1978), pages 251-264).

Unless otherwise indicated, only completely demineralized water was used to prepare the polymers.

Abbreviations for monomers:

EA: ethyl acrylate

MA: methyl acrylate

VFA: N-vinylformamide

Na acrylate: sodium salt of acrylic acid

Na methacrylate: sodium salt of methacrylic acid

AMPS-Na: 2-acrylamido-2-methylpropanesulfonic acid sodium salt

Na vinylsulfonate: sodium salt of vinylsulfonic acid

DADMAC: diallyldimethylammonium chloride

APTAC: (3-acrylamidopropyl)trimethylammonium chloride

AM: acrylamide

To ascertain whether a viscosity peak occurs during hydrolysis, the funnel generated by the rotation of a paddle stirrer (a glass stirrer with a rounded paddle made of Teflon with a diameter of 7.0 cm and a height of 2.5 cm) was observed and evaluated as follows:

The composition of the final polymers of formula III in accordance with the calculation:

where a, b, c, d and e are the percentage mole fractions (=mol. %) of structural units and the sum of a, b, c, d and e is equal to 100 mol. %.

(1)

a = amidinium / (amidinium + VFA + vinyl ammonium + acrylate anion + lactam) × 100

b = WFA / (amidinium + WFA + vinyl ammonium + acrylate anion + lactam) ×100

c = vinylammonium / (amidinium + VFA + vinylammonium + acrylate anion + lactam) × 100

d = acrylate anion / (amidinium + VFA + vinylammonium + acrylate anion + lactam) × 100

e = lactam / (amidinium + VFA + vinyl ammonium + acrylate anion + lactam) × 100 (2)

WFA [mmol/100 g]: concentration of WFA structural units contained in the final product

acrylate anion [mmol/100 g]: concentration of structural units of acrylate anions contained in the final product

vinyl ammonium [mmol/100 g]: concentration of vinyl ammonium structural units contained in the final product

amidinium [mmol/100 g]: concentration of amidinium structural units contained in the final product

lactam [mmol/100 g]: concentration of lactam structural units contained in the final product

In the present invention, the end product means a polymer solution that is obtained by hydrolysis.

(3)

When the degree of transformation, SP, equal to 100 mol. %, the following results are provided:

amidinium \u003d (VFA ⁰ - FA) × PAD / (PFA + PAD)

VFA \u003d (VFA ⁰ - FA) × PFA / (PFA + PAD)

vinylammonium = FA - lactam - amidinium

acrylate anion \u003d AK-Na ⁰ + MA ⁰ + EA ⁰ - FA + PZ

lactam=FA - PZ

(4)

FA [mmol/100 g]: formate content in the final product

PZ [mmol/100 g]: charge density in the final product (alternatively:

[meq/100 g])

PFA: integrated area of the ¹³ C-NMR peak for the carbon atom contained in the carbonyl group of the structural unit VFA contained in the polymer, in the range from 164 to 168 ppm PAD: integrated area of the ¹³ C-NMR derived peak for the imine carbon of the amidinium structural unit contained in the polymer at 152 ppm

WFA ⁰ [mmol/100 g]: concentration of WFA units that would be contained in the final product if no additional reaction of the polymerized monomers took place; calculated at the beginning of polymerization

AK-Na ⁰ [mmol/100 g]: concentration of Na acrylate units that would be present in the final product if no further reaction of the polymerized monomers took place; calculated at the beginning of polymerization

MA ⁰ , EA ⁰ [mmol/100 g]: concentration of methyl or ethyl acrylate units that would be contained in the final product if no additional reaction of the polymerized monomers took place; calculated at the beginning of polymerization

A-2) Obtaining initial polymers by polymerization reaction

Starting polymer VE1: Copolymer (VFA/MA=70 mol %/30 mol %)

Load 1 used 150.4 g of VFA (99%).

Load 2 used 77.3 g MA.

As load 3, 1.13 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride was used, which was dissolved at room temperature (=RT) in 112.1 g of water.

Load 4 was 0.67 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved at RT in 67.2 g of water.

As load 5 used 187.3 g of water.

782.6 g of water and 2.8 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm (=rpm), about 3.9 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 70°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 70°C, the simultaneous addition of 3 downloads 1-3 was started. Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 4 and the reaction mixture was kept at 70° C. for another 1.5 hours. The reflux condenser was then changed to a downward condenser and the internal pressure was slowly reduced to about 300 mbar using a water jet pump, at which point the contents of the reactor began to boil. Under these conditions, 187.3 g of water was distilled off. Then the evacuation was stopped by supplying air, charge 5 was added and the reaction mixture was cooled to RT.

A light yellow viscous solution was obtained having a solids content of 18.8%. The K value of the copolymer was 84 (0.5 wt% in water).

Initial polymer VE2: Copolymer (VFA/MA=70 mol %/30 mol %)

Load 1 used 150.4 g of VFA (99%).

Load 2 used 77.3 g MA.

Load 3 was 1.13 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved at RT in 112.1 g of water.

Load 4 was 0.67 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved at RT in 67.2 g of water.

As load 5 used 176.6 g of water.

782.6 g of water and 2.5 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 3.9 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 69°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 69°C, began the simultaneous addition of 3 downloads 1-3. Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 4 and the reaction mixture was kept at 69° C. for another 1.5 hours. The reflux condenser was then changed to a downward condenser and the internal pressure was slowly reduced to about 320 mbar using a water jet pump, at which point the contents of the reactor began to boil. Under these conditions, 176.6 g of water were distilled off. Then the evacuation was stopped by supplying air, charge 5 was added and the reaction mixture was cooled to RT.

A yellow viscous solution was obtained having a solids content of 19.1%. The K value of the copolymer was 84 (0.5 wt% in water).

Base polymer VE3: Terpolymer (VFA/MA/Na acrylate=70 mol %/29 mol %/1 mol %)

As download 1 used a mixture of 9.3 g 32 wt. % aqueous solution of Na acrylate, the pH of which was provided equal to 6.4, 158.2 g of VFA (99%) and 210.0 g of water.

Load 2 used 78.6 g MA.

Load 3 used 1.19 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 117.5 g of water at RT.

Load 4 was 0.71 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 70.5 g of water at RT.

As load 5 used 172.7 g of water.

547.4 g of water and 2.5 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 4.1 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 69°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 69°C, began the simultaneous addition of 3 downloads 1-3. Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 4 and the reaction mixture was kept at 69° C. for another 1.5 hours. The reflux condenser was then changed to a downward condenser and the internal pressure was slowly reduced to about 320 mbar using a water jet pump, at which point the contents of the reactor began to boil. Under these conditions, 172.7 g of water were distilled off. Then the evacuation was stopped by supplying air, charge 5 was added and the reaction mixture was cooled to RT.

A yellow viscous solution was obtained having a solids content of 19.6%. The K value of the terpolymer was 90 (0.5 wt.% in 5 wt.% aqueous NaCl solution).

VE4 parent polymer: Terpolymer (VFA/MA/Na acrylate=70 mole %/28 mole %/2 mole %)

As download 1 used a mixture of 18.5 g 32 wt. % aqueous solution of Na acrylate, the pH value of which was provided equal to 6.4, 158.0 g of VFA (99%) and 200.0 g of water.

Load 2 used 75.8 g MA.

Load 3 used 1.18 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 117.1 g of water at RT.

Load 4 was 0.71 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 70.3 g of water at RT.

As loading 5 used 184.0 g of water.

551.7 g of water and 2.6 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 4.1 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 70°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 70°C, the simultaneous addition of 3 downloads 1-3 was started. Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 4 and the reaction mixture was kept at 70° C. for another 1.5 hours. The reflux condenser was then changed to a downward condenser and the internal pressure was slowly reduced to about 300 mbar using a water jet pump, at which point the contents of the reactor began to boil. Under these conditions, 184.0 g of water was distilled off. Then the evacuation was stopped by supplying air, charge 5 was added and the reaction mixture was cooled to RT.

A yellow viscous solution was obtained having a solids content of 19.4%. The K value of the terpolymer was 90 (0.5 wt.% in 5 wt.% aqueous NaCl solution).

VE5 parent polymer: Terpolymer (VFA/MA/Na acrylate=70 mol %/25 mol %/5 mol %)

As download 1 used a mixture of 46.1 g 32 wt. % aqueous solution of Na acrylate, the pH value of which was provided equal to 6.5, 157.5 g of VFA (99%) and 200.0 g of water.

Load 2 used 67.4 g MA.

Load 3 used 1.17 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 116.1 g of water at RT.

Load 4 was 0.70 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 69.7 g of water at RT.

As loading 5 used 196.6 g of water.

534.7 g of water and 2.6 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 4.2 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 70°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 70°C, the simultaneous addition of 3 downloads 1-3 was started. Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 4 and the reaction mixture was kept at 70° C. for another 1.5 hours. The reflux condenser was then changed to a downward condenser and the internal pressure was slowly reduced to about 300 mbar using a water jet pump, at which point the contents of the reactor began to boil. Under these conditions, 196.6 g of water were distilled off. Then the evacuation was stopped by supplying air, charge 5 was added and the reaction mixture was cooled to RT.

A yellow viscous solution was obtained having a solids content of 19.4%. The K value of the terpolymer was 93 (0.5 wt.% in 5 wt.% aqueous NaCl solution).

Base polymer VE6: Terpolymer (VFA/MA/Na acrylate=70 mol %/25 mol %/5 mol %)

As download 1 used a mixture of 43.0 g 32 wt. % aqueous solution of Na acrylate, the pH value of which was provided equal to 6.5, 147.0 g of VFA (99%) and 200.0 g of water.

Load 2 used 62.9 g MA.

Load 3 used 0.33 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 32.5 g of water at RT.

Load 4 used 1.42 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 140.9 g of water at RT.

As load 5 used 164.8 g of water.

565.7 g of water and 2.4 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 3.9 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 60°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 60°C, the simultaneous addition of 3 downloads 1-3 was started. Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 4 and the reaction mixture was kept at 60° C. for another 1.5 hours. The reflux condenser was then changed to a downward condenser and the internal pressure was slowly reduced to about 280 mbar using a water jet pump, while the contents of the reactor began to boil. Under these conditions, 164.8 g of water were distilled off. Then the evacuation was stopped by supplying air, charge 5 was added and the reaction mixture was cooled to RT.

A yellow viscous solution was obtained having a solids content of 13.9%. The K value of the terpolymer was 138 (0.1 wt.% in 5 wt.% aqueous NaCl solution).

Base polymer VE7: Terpolymer (VFA/MA/Na acrylate=70 mol %/20 mol %/10 mol %)

As download 1 used a mixture of 91.6 g 32 wt. % aqueous solution of Na acrylate, the pH value of which was provided equal to 6.5, 156.7 g of VFA (99%) and 200.0 g of water.

Load 2 used 53.9 g MA.

Load 3 used 1.15 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 114.3 g of water at RT.

Load 4 was 0.69 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 68.6 g of water at RT.

As loading 5 used 184.4 g of water.

506.5 g of water and 2.6 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 4.2 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 70°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 70°C, the simultaneous addition of 3 downloads 1-3 was started. Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 4 and the reaction mixture was kept at 70° C. for another 1.5 hours. The reflux condenser was then changed to a downward condenser and the internal pressure was slowly reduced to about 320 mbar using a water jet pump, at which point the contents of the reactor began to boil. Under these conditions, 184.4 g of water were distilled off. Then the evacuation was stopped by supplying air, charge 5 was added and the reaction mixture was cooled to RT.

A yellow viscous solution was obtained having a solids content of 19.7%. The K value of the terpolymer was 94 (0.5 wt.% in 5 wt.% aqueous NaCl solution).

Base polymer VE8: Terpolymer (VFA/MA/Na acrylate=70 mol %/15 mol %/15 mol %)

As download 1 used a mixture of 136.7 g 32 wt. % aqueous solution of Na acrylate, the pH value of which was provided equal to 6.5, 155.9 g of VFA (99%) and 200.0 g of water.

As load 2, 40.0 g of MA was used.

Load 3 used 1.14 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 112.6 g of water at RT.

Load 4 was 0.68 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 67.5 g of water at RT.

As load 5 used 227.5 g of water.

478.7 g of water and 2.6 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 4.2 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 70°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 70°C, the simultaneous addition of 3 downloads 1-3 was started. Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 4 and the reaction mixture was kept at 70° C. for another 1.5 hours. The reflux condenser was then changed to a downward condenser and the internal pressure was slowly reduced to about 320 mbar using a water jet pump, at which point the contents of the reactor began to boil. Under these conditions, 227.5 g of water were distilled off. Then the evacuation was stopped by supplying air, charge 5 was added and the reaction mixture was cooled to RT.

A yellow viscous solution was obtained having a solids content of 19.9%. The K value of the terpolymer was 99 (0.5 wt.% in 5 wt.% aqueous NaCl solution).

Base polymer VE9: Terpolymer (VFA/MA/Na acrylate=70 mol %/10 mol %/20 mol %)

As download 1 used a mixture of 181.4 g 32 wt. % aqueous solution of Na acrylate, the pH value of which was provided equal to 6.5, 155.0 g of VFA (99%) and 200.0 g of water.

Load 2 used 26.6 g of MA.

Load 3 used 1.12 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 110.8 g of water at RT.

Load 4 was 0.67 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 66.5 g of water at RT.

As load 5 used 200.5 g of water.

451.1 g of water and 2.6 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 4.1 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 70°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 70°C, the simultaneous addition of 3 downloads 1-3 was started. Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 4 and the reaction mixture was kept at 70° C. for another 1.5 hours. The reflux condenser was then changed to a downward condenser and the internal pressure was slowly reduced to about 320 mbar using a water jet pump, at which point the contents of the reactor began to boil. Under these conditions, 200.5 g of water were distilled off. Then the evacuation was stopped by supplying air, charge 5 was added and the reaction mixture was cooled to RT.

A yellow viscous solution was obtained having a solids content of 20.2%. The K value of the terpolymer was 102 (0.5 wt.% in 5 wt.% aqueous NaCl solution).

Base polymer VE10: Terpolymer (VFA/MA/Na acrylate=70 mol %/25 mol %/5 mol %)

As download 1 used a mixture of 55.9 g 30 wt. % solution of Na methacrylate, the pH value of which was provided equal to 6.5, 156.1 g of VFA (99%) and 200.0 g of water.

Load 2 used 66.8 g MA.

Load 3 was 1.17 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 116 D g of water at RT.

Load 4 was 0.70 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 69.7 g of water at RT.

As load 5 used 185.7 g of water.

526.7 g of water and 2.6 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 4.1 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 68°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 68°C, the simultaneous addition of 3 downloads 1-3 was started. Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 4 and the reaction mixture was kept at 68° C. for another 1.5 hours. The reflux condenser was then changed to a downward condenser and the internal pressure was slowly reduced to about 320 mbar using a water jet pump, at which point the contents of the reactor began to boil. Under these conditions, 185.7 g of water were distilled off. Then the evacuation was stopped by supplying air, charge 5 was added and the reaction mixture was cooled to RT.

A yellow viscous solution was obtained having a solids content of 19.2%. The K value of the terpolymer was 94 (0.5 wt.% in 5 wt.% aqueous NaCl solution).

VE11 parent polymer: Terpolymer (VFA/MA/AMPS-Na=70 mol %/25 mol %/5 mol %)

As download 1 used a mixture of 66 g 50 wt. % aqueous solution of AMPS-Na, the pH value of which was provided equal to 6.5, 144.6 g of VFA (99%) and 210.0 g of water.

Load 2 used 61.9 g MA.

Load 3 used 1.17 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 116.1 g of water at RT.

Load 4 was 0.71 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 69.8 g of water at RT.

As loading 5 used 186.7 g of water.

532.8 g of water and 2.6 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 4.1 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 69°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 69°C, began the simultaneous addition of 3 downloads 1-3. Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 4 and the reaction mixture was kept at 69° C. for another 1.5 hours. The reflux condenser was then changed to a downward condenser and the internal pressure was slowly reduced to about 300 mbar using a water jet pump, while the contents of the reactor began to boil. Under these conditions, 186.7 g of water were distilled off. Then the evacuation was stopped by supplying air, charge 5 was added and the reaction mixture was cooled to RT.

A yellow viscous solution was obtained having a solids content of 20.0%. The K value of the terpolymer was 89 (0.5 wt.% in 5 wt.% aqueous NaCl solution).

VE12 parent polymer: Terpolymer (VFA/MA/Na vinylsulfonate=70 mol%/25 mol%/5 mol%)

As download 1 used a mixture of 79.6 g of 25 wt. % aqueous solution of Na vinylsulfonate, the pH value of which was provided equal to 6.5, 153.9 g of VFA (99%) and 200.0 g of water.

Load 2 used 65.9 g MA.

Load 3 used 1.17 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 116.2 g of water at RT.

Load 4 was 0.70 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 69.7 g of water at RT.

As load 5 used 164.5 g of water.

506.1 g of water and 2.6 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 4.1 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 65°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 65°C, the simultaneous addition of 3 downloads 1-3 was started. Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 4 and the reaction mixture was kept at 65° C. for another 1.5 hours. The reflux condenser was then changed to a downward condenser and the internal pressure was slowly reduced to about 300 mbar using a water jet pump, at which point the contents of the reactor began to boil. Under these conditions, 164.5 g of water were distilled off. Then the evacuation was stopped by supplying air, charge 5 was added and the reaction mixture was cooled to RT.

A yellow viscous solution was obtained having a solids content of 20.7%. The K value of the terpolymer was 87 (0.5 wt.% in 5 wt.% aqueous NaCl solution).

Base polymer VE13: Terpolymer (VFA/MA/DADMAC=65 mole %/30 mole %/5 mole %)

Load 1 used a mixture of 138.7 g of VFA (99%) and 200.0 g of water.

Load 2 used 76.8 g MA.

Load 3 used 1.16 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 115.2 g of water at RT.

Load 4 was 0.70 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 69.2 g of water at RT.

As loading 5 used 174.4 g of water.

554.6 g of water and 37.0 g of 65 wt. % aqueous solution of DADMAC and 2.6 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 4.3 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 67°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and during further polymerization, nitrogen continued to be supplied only through a reflux condenser in order to prevent the penetration of oxygen. At a constant internal temperature of 67°C, began the simultaneous addition of 3 downloads 1-3. Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 4 and the reaction mixture was kept at 67° C. for another 1.5 hours. The reflux condenser was then changed to a downward condenser and the internal pressure was slowly reduced to about 330 mbar using a water jet pump, while the contents of the reactor began to boil. Under these conditions, 174.4 g of water were distilled off. Then the evacuation was stopped by supplying air, charge 5 was added and the reaction mixture was cooled to RT.

A yellow viscous solution was obtained having a solids content of 19.8%. The K value of the terpolymer was 82 (0.5 wt% in water).

VE14 parent polymer: Terpolymer (VFA/MA/APTAC=65 mole %/30 mole %/5 mole %)

Load 1 used 134.9 g of VFA (99%).

Load 2 used 74.7 g MA.

As download 3 used a mixture of 39.8 g 75 wt. % aqueous solution of APTAH and 200 g of water.

Load 4 was 1.17 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 115.3 g of water at RT.

Load 5 used 0.70 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 69.2 g of water at RT.

As load 6 used 170.9 g of water.

557.5 g of water and 2.6 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 4.3 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 69°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 69°C, the simultaneous addition of 4 downloads 1-4 was started. Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 4 was added over 4 hours. 4 and the reaction mixture was kept at 69° C. for another 1.5 hours. The reflux condenser was then changed to a downward condenser and the internal pressure was slowly reduced to about 330 mbar using a water jet pump, at which point the contents of the reactor began to boil. Under these conditions, 170.9 g of water were distilled off. Then the evacuation was stopped by supplying air, charge 5 was added and the reaction mixture was cooled to RT.

A yellow viscous solution was obtained having a solids content of 19.6%. The K value of the terpolymer was 87 (0.5 wt% in water).

Base polymer VE15: Terpolymer (VFA/MA/Na acrylate=70 mol %/15 mol %/15 mol %)

As download 1 used a mixture of 133.1 g 32 wt. % aqueous solution of Na acrylate, the pH value of which was provided equal to 6.5, 151.7 g of VFA (99%) and 200.0 g of water.

As load 2 used 45.3 g of EA.

Load 3 used 1.14 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 112.7 g of water at RT.

Load 4 was 0.68 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 67.6 g of water at RT.

As load 5 used 537.8 g of water.

481.0 g of water and 2.6 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 4.1 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 72°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 72°C, the simultaneous addition of 3 downloads 1-3 was started. Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 4 and the reaction mixture was kept at 72° C. for another 1.5 hours. The reflux condenser was then changed to a downward condenser and the internal pressure was slowly reduced to about 340 mbar using a water jet pump, while the contents of the reactor began to boil. Under these conditions, 137.8 g of water were distilled off. Then the evacuation was stopped by supplying air, charge 5 was added and the reaction mixture was cooled to RT.

A slightly cloudy yellow viscous solution was obtained having a solids content of 15.1%. The K value of the terpolymer was (0.5 wt.% in 5 wt.% aqueous NaCl solution).

Base polymer VE16: Terpolymer (VFA/EA/Na acrylate=70 mol %/20 mol %/10 mol %)

As download 1 used a mixture of 55.3 g 32 wt. % aqueous solution of Na acrylate, the pH value of which was provided equal to 6.5, 94.5 g of VFA (99%) and 200.0 g of water.

As load 2 used 37.6 g of EA.

Load 3 used 0.72 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 71.6 g of water at RT.

As load 4, 0.43 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride was used, which was dissolved in 43.0 g of water at RT.

612.8 g of water and 1.6 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 2.4 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 65°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 65° C., 10% of batch 1 was first added over 3 minutes and mixed briefly. The addition of the remainder of Load 1 (90%) and Loads 2 and 3 was then started simultaneously. The remainder of Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 3 the mixture was kept at 65°C for another 1 hour. Then charge 4 was added over 5 minutes and the temperature of the reaction mixture was raised to 70°C. The mixture was kept at 70°C for 1.5 hours. the condenser and the internal pressure were slowly reduced to about 340 mbar using a water jet pump, whereupon the contents of the reactor began to boil. Under these conditions, 114.1 g of water were distilled off. Then the evacuation was stopped by supplying air and the reaction mixture was cooled to RT.

A slightly cloudy yellow viscous solution was obtained having a solids content of 15.2%. The K value of the terpolymer was 99 (0.5 wt.% in 5 wt.% aqueous NaCl solution).

Base polymer VE17: Terpolymer (VFA/EA/Na acrylate=70 mol %/20 mol %/10 mol %)

As download 1 used a mixture of 55.3 g 32 wt. % aqueous solution of Na acrylate, the pH value of which was provided equal to 6.5, 94.5 g of VFA (99%) and 200.0 g of water.

As load 2 used 37.6 g of EA.

Load 3 used 0.72 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 71.6 g of water at RT.

As load 4, 0.43 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride was used, which was dissolved in 43.0 g of water at RT.

612.8 g of water and 1.6 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 2.4 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 64°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 64° C., 10% of batch 1 was first added over 3 minutes and mixed briefly. The addition of the remainder of Load 1 (90%) and Loads 2 and 3 was then started simultaneously. The remainder of Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 3 the mixture was kept at 64°C for another 1 hour. Then charge 4 was added over 5 minutes and the temperature of the reaction mixture was raised to 70°C. The mixture was kept at 70°C for 1.5 hours. the condenser and the internal pressure were slowly reduced to about 340 mbar using a water jet pump, whereupon the contents of the reactor began to boil. Under these conditions, 138.7 g of water were distilled off. Then the evacuation was stopped by supplying air and the reaction mixture was cooled to RT.

A slightly cloudy yellow viscous solution was obtained having a solids content of 15.6%. The K value of the terpolymer was 103 (0.5 wt% in 5 wt% NaCl aqueous solution).

Base polymer VE18: Terpolymer (VFA/EA/Na acrylate=70 mol %/20 mol %/10 mol %)

As download 1 used a mixture of 55.3 g 32 wt. % aqueous solution of Na acrylate, the pH value of which was provided equal to 6.5, 94.5 g of VFA (99%) and 200.0 g of water.

As load 2 used 37.6 g of EA.

Load 3 used 0.72 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 71.6 g of water at RT.

Load 4 was 0.43 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 43.0 g of water at RT.

612.8 g of water and 1.6 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, was added about 2.6 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 65°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 65° C., 10% of batch 1 was first added over 3 minutes and mixed briefly. The addition of the remainder of Load 1 (90%) and Loads 2 and 3 was then started simultaneously. The remainder of Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 3 the mixture was kept at 65°C for another 1 hour. Then charge 4 was added over 5 minutes and the temperature of the reaction mixture was raised to 70°C. The mixture was kept at 70°C for 1.5 hours. the condenser and the internal pressure were slowly reduced to about 340 mbar using a water jet pump, whereupon the contents of the reactor began to boil. Under these conditions, 126.7 g of water were distilled off. Then the evacuation was stopped by supplying air and the reaction mixture was cooled to RT.

A slightly cloudy yellow viscous solution was obtained having a solids content of 15.4%. The K value of the terpolymer was 101 (0.5 wt.% in 5 wt.% aqueous NaCl solution).

VE19 parent polymer: Copolymer (VFA/MA=70 mol %/30 mol %)

Load 1 used 150.4 g of VFA (99%).

Load 2 used 77.3 g MA.

Load 3 was 1.13 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved at RT in 112.1 g of water.

Load 4 was 0.67 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved at RT in 67.2 g of water.

As load 5 used 168.4 g of water.

784.9 g of water and 2.8 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 3.9 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 70°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and during further polymerization, nitrogen continued to be supplied only through a reflux condenser in order to prevent the penetration of oxygen. At a constant internal temperature of 70°C, the simultaneous addition of 3 downloads 1-3 was started. Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 4 and the reaction mixture was kept at 70° C. for another 1.5 hours. The reflux condenser was then changed to a downward condenser and the internal pressure was slowly reduced to about 320 mbar using a water jet pump, at which point the contents of the reactor began to boil. Under these conditions, 168.4 g of water were distilled off. Then the evacuation was stopped by supplying air, charge 5 was added and the reaction mixture was cooled to RT.

A yellow viscous solution was obtained having a solids content of 18.6%. The K value of the copolymer was 82 (0.5 wt% in water).

Base Polymer VE20: Copolymer (VFA/MA=60 mol %/40 mol %)

Load 1 used 126.4 g of VFA (99%).

Load 2 used 101.0 g MA.

Load 3 used 1.13 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 112.0 g of water at RT.

Load 4 was 0.68 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved at RT in 67.2 g of water.

As load 5 used 188.5 g of water.

785.2 g of water and 2.5 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 3.9 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 67°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 67°C, began the simultaneous addition of 3 downloads 1-3. Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 4 and the reaction mixture was kept at 67° C. for another 1.5 hours. The reflux condenser was then changed to a downward condenser and the internal pressure was slowly reduced to about 300 mbar using a water jet pump, at which point the contents of the reactor began to boil. Under these conditions, 188.5 g of water were distilled off. Then the evacuation was stopped by supplying air, charge 5 was added and the reaction mixture was cooled to RT.

A yellow viscous solution was obtained having a solids content of 18.7%. The K value of the copolymer was 84 (0.5 wt% in water).

Base Polymer VE21: Copolymer (VFA/MA=80 mol %/20 mol %)

Load 1 used 175.4 g of VFA (99%).

Load 2 used 52.6 g MA.

Load 3 used 1.13 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 112.0 g of water at RT.

Load 4 was 0.68 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved at RT in 67.2 g of water.

As load 5 used 163.6 g of water.

784.7 g of water and 2.5 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 3.9 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 69°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and during further polymerization, nitrogen continued to be supplied only through a reflux condenser in order to prevent the penetration of oxygen. At a constant internal temperature of 69°C, began the simultaneous addition of 3 downloads 1-3. Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 4 and the reaction mixture was kept at 69° C. for another 1.5 hours. The reflux condenser was then changed to a downward condenser and the internal pressure was slowly reduced to about 310 mbar using a water jet pump, while the contents of the reactor began to boil. Under these conditions, 163.6 g of water were distilled off. Then the evacuation was stopped by supplying air, charge 5 was added and the reaction mixture was cooled to RT.

A yellow viscous solution was obtained having a solids content of 19.0%. The K value of the copolymer was 84 (0.5 wt% in water).

Base polymer VE22: Terpolymer (VFA/MA/Na acrylate=70 mol %/25 mol %/5 mol %)

As download 1 used a mixture of 46.1 g 32 wt. % aqueous solution of Na acrylate, the pH value of which was provided equal to 6.5, 157.5 g of VFA (99%) and 200.0 g of water.

Load 2 used 67.4 g MA.

Load 3 used 1.17 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 116.1 g of water at RT.

Load 4 was 0.70 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 69.7 g of water at RT.

As load 5 used 552.6 g of water.

534.7 g of water and 2.6 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 4.2 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 74°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 74°C, began the simultaneous addition of 3 downloads 1-3. Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 4 and the reaction mixture was kept at 74° C. for another 1.5 hours. The reflux condenser was then changed to a downward condenser and the internal pressure was slowly reduced to about 300 mbar using a water jet pump, while the contents of the reactor began to boil. Under these conditions, 152.6 g of water were distilled off. Then the evacuation was stopped by supplying air, charge 5 was added and the reaction mixture was cooled to RT.

A yellow slightly viscous solution was obtained having a solids content of 14.5%. The K value of the terpolymer was 81 (0.5 wt.% in 5 wt.% aqueous NaCl solution).

Base polymer VE23: Terpolymer (VFA/EA/Na acrylate=70 mol %/25 mol %/5 mol %)

As download 1 used a mixture of 44.0 g 32 wt. % aqueous solution of Na acrylate, the pH value of which was provided equal to 6.5, 150.6 g of VFA (99%) and 200.0 g of water.

Load 2 used 186.9 g of EA.

Load 3 used 1.17 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 116.1 g of water at RT.

Load 4 was 0.70 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 69.7 g of water at RT.

536.0 g of water and 2.6 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 4.1 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 67°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 67° C., 10% of batch 1 was first added over 3 minutes and mixed briefly. The addition of the remainder of Load 1 (90%) and Loads 2 and 3 was then started simultaneously. The remainder of Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 3 the mixture was held at 67°C for another 1 hour. Then batch 4 was added over 5 minutes. The reaction mixture was held at 67°C for 1.5 hours. about 320 mbar using a water jet pump, the contents of the reactor began to boil. Under these conditions, 186.9 g of water were distilled off. Then the evacuation was stopped by supplying air and the reaction mixture was cooled to RT.

A slightly cloudy yellow viscous solution was obtained having a solids content of 19.9%. The K value of the terpolymer was 90 (0.5 wt.% in 5 wt.% aqueous NaCl solution).

Base polymer VE24: Terpolymer (VFA/EA/Na acrylate=70 mol %/20 mol %/10 mol %)

As download 1 used a mixture of 88.4 g 32 wt. % aqueous solution of Na acrylate, the pH value of which was provided equal to 6.5, 151.1 g of VFA (99%) and 200.0 g of water.

As load 2 used 60.2 g of EA.

Load 3 used 1.16 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 114.4 g of water at RT.

Load 4 was 0.69 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 68.6 g of water at RT.

As load 5 used 158.4 g of water.

508.6 g of water and 2.6 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 4.1 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 67°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 67°C, the simultaneous addition of loads 1, 2 and 3 was started. Load 1 was added over 3 hours, load 2 was added over 3.5 hours and load 3 was added over 4 hours. 3 the mixture was held at 67°C for another 1 hour. Then batch 4 was added over 5 minutes and the reaction mixture was held at 67°C for another 1.5 hours. equal to about 300 mbar using a water jet pump, while the contents of the reactor began to boil. Under these conditions, 158.4 g of water were distilled off. Then the evacuation was stopped by supplying air and the reaction mixture was cooled to RT.

A cloudy yellow viscous solution was obtained having a solids content of 20.1%. The K value of the terpolymer was 99 (0.5 wt.% in 5 wt.% aqueous NaCl solution).

Base polymer VE25: Terpolymer (VFA/EA/Na acrylate=70 mol %/10 mol %/20 mol %)

As download 1 used a mixture of 178.2 g 32 wt. % aqueous solution of Na acrylate, the pH value of which was provided equal to 6.5, 152.3 g of VFA (99%) and 200.0 g of water.

As load 2 used 30.3 g of EA.

Load 3 used 1.12 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 111.0 g of water at RT.

Load 4 used 0.67 g of 2,2''-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 66.5 g of water at RT.

As load 5 used 185.7 g of water.

453.2 g of water and 2.6 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 4.1 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 68°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 68°C, the simultaneous addition of loads 1, 2 and 3 was started. Load 1 was added over 3 hours, load 2 was added over 3.5 hours and load 3 was added over 4 hours. 3 the mixture was held at 68°C for another 1 hour. Then batch 4 was added over 5 minutes and the reaction mixture was held at 68°C for another 1.5 hours. equal to about 310 mbar using a water jet pump, while the contents of the reactor began to boil. Under these conditions, 185.74 g of water were distilled off. Then the evacuation was stopped by supplying air and the reaction mixture was cooled to RT.

A cloudy yellow viscous solution was obtained having a solids content of 20.3%. The K value of the terpolymer was 101 (0.5 wt.% in 5 wt.% aqueous NaCl solution).

Base polymer VE26: Terpolymer (VFA/EA/Na acrylate=70 mol %/20 mol %/10 mol %)

As download 1 used a mixture of 55.3 g 32 wt. % aqueous solution of Na acrylate, the pH value of which was provided equal to 6.5, 94.5 g of VFA (99%) and 200.0 g of water.

As load 2 used 37.6 g of EA.

Load 3 used 0.72 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 71.6 g of water at RT.

As load 4, 0.43 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride was used, which was dissolved in 43.0 g of water at RT.

612.8 g of water and 1.6 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 2.4 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 65°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 65° C., 10% of batch 1 was first added over 3 minutes and mixed briefly. The addition of the remainder of Load 1 (90%) and Loads 2 and 3 was then started simultaneously. The remainder of Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 3 the mixture was kept at 65°C for another 1 hour Then for 5 min was added load 4 and the temperature of the reaction mixture was raised to 70°C. The mixture was kept at 70° C. for 1.5 hours. The reflux condenser was then changed to a descending condenser and the internal pressure was slowly reduced to about 300 mbar using a water jet pump, whereupon the contents of the reactor began to boil. Under these conditions, 120.5 g of water were distilled off. Then the evacuation was stopped by supplying air and the reaction mixture was cooled to RT.

A slightly cloudy yellow viscous solution was obtained having a solids content of 15.1%. The K value of the terpolymer was 102 (0.5 wt.% in 5 wt.% aqueous NaCl solution).

Base polymer VE27: Terpolymer (VFA/MA/AM=70 mol %/25 mol %/5 mol %)

As download 1 used a mixture of 22.6 g 50 wt. % aqueous solution of AM, 159.9 g of VFA (99%) and 210.0 g of water.

As load 2, 68.5 g of MA was used.

Load 3 used 1.19 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 117.9 g of water at RT.

Load 4 was 0.71 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 70.7 g of water at RT.

As loading 5 used 189.6 g of water.

541.8 g of water and 2.6 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, about 4.1 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 69°C and at the same time nitrogen (20 l/h) was supplied to the apparatus to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 69°C, began the simultaneous addition of 3 downloads 1-3. Load 1 was added over 3 hours, Load 2 was added over 3.5 hours and Load 3 was added over 4 hours. 4 and the reaction mixture was kept at 69° C. for another 1.5 hours. The reflux condenser was then changed to a downward condenser and the internal pressure was slowly reduced to about 310 mbar using a water jet pump, while the contents of the reactor began to boil. Under these conditions, 189.6 g of water were distilled off. Then the evacuation was stopped by supplying air, charge 5 was added and the reaction mixture was cooled to RT.

A yellow viscous solution was obtained having a solids content of 21.9%. The K value of the terpolymer was 89 (0.5 wt% in water).

Base polymer VV1: Copolymer (VFA/Na acrylate=70 mol %/30 mol %)

As download 1 used a mixture of 316.7 g 32 wt. % aqueous solution of Na acrylate, 180.5 g of VFA (99%) and 141.0 g of water.

Load 2 used 1.79 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which was dissolved in 176.9 g of water at RT.

573.4 g of water and 3.0 g of 75 wt. % phosphoric acid solution. The reactor was placed in a water bath equipped with a heating-cooling module, which automatically controlled the internal temperature. At a stirring speed of 100 rpm, was added about 5.2 g of 25 wt. % sodium hydroxide solution, thus providing a pH value of 6.5. Then the receiver was heated for 30 min to 80°C and at the same time nitrogen (20 l/h) was supplied to the apparatus in order to replace oxygen. Then the nitrogen supply was stopped and nitrogen continued to be supplied only through a reflux condenser to prevent the penetration of oxygen. At a constant internal temperature of 80° C., simultaneous addition of batches 1 and 2 was started. Load 1 was added over 1.5 hours and batch 2 was added over 2.5 hours. for a further 1 hour. The reflux condenser was then changed to a descending condenser and the internal pressure was slowly reduced to about 460 mbar using a water jet pump, whereupon the contents of the reactor began to boil. Under these conditions, 178.7 g of water were distilled off. Then the evacuation was stopped by supplying air and the reaction mixture was cooled to RT.

A yellowish viscous solution was obtained having a solids content of 24.1%. The K value of the copolymer was 88 (0.5 wt% in 5% NaCl aqueous solution).

A-3) Preparation of final polymers by hydrolysis of initial polymers

Final polymer AE1: Acid hydrolyzed starting polymer VE1 (VFA/MA=70 mol %/30 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 150.1 g of a polymer solution obtained using the starting polymer VE1 was mixed with 1.3 g of 40 wt. % aqueous sodium bisulfite solution at a stirrer speed of 80 rpm and then heated to 80°C. Then 30.0 g of 37 wt. % hydrochloric acid solution (120 mol.% in terms of VFA). The mixture was kept at 80° C. for 5 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 64.8 g of 25 wt. % sodium hydroxide solution.

A slightly hazy yellowish and viscous polymer solution was obtained, having a polymer content of 8.3%. The degree of hydrolysis, SG, was 98 mol. % and the degree of conversion, SP, was 100 mol. %.

Final polymer AE2: Alkaline hydrolyzed starting polymer VE2 (VFA/MA=70 mol %/30 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 170.5 g of a polymer solution prepared using the starting polymer VE2 were mixed with 1.5 g of 40 wt. % aqueous sodium bisulfite solution at a stirrer speed of 80 rpm and then heated to 80°C. Then 56.3 g of 25 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). The mixture was kept at 80° C. for 5 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 20.1 g of 37 wt. % hydrochloric acid solution and 1.3 g of water.

A slightly hazy, yellowish and viscous polymer solution was obtained, having a polymer content of 7.9%. The degree of hydrolysis, SG, was 96 mol. % and the degree of conversion, SP, was 100 mol. %.

Final polymer AE3: Alkaline hydrolyzed starting polymer VE3 (VFA/MA/Na acrylate=70 mol %/29 mol %/1 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 173.4 g of a polymer solution obtained using the starting polymer VE3 were mixed with 1.6 g of 40 wt. % aqueous sodium bisulfite solution and 55.0 g of water at a stirrer speed of 80 rpm, and then heated to 80°C. Then 59.3 g of 25 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). The mixture was kept at 80° C. for 5 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 21.7 g of 37 wt. % hydrochloric acid solution and 9.4 g of water.

A slightly hazy, yellowish and viscous polymer solution was obtained, having a polymer content of 7.7%. The degree of hydrolysis, SG, was 99 mol. % and the degree of conversion, SP, was 100 mol. %.

Final polymer AE4: Alkaline hydrolyzed VE4 terpolymer (VFA/MA/Na acrylate=70 mol %/28 mol %/2 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer for measuring the internal temperature, an addition funnel and a reflux condenser, 174.1 g of a polymer solution prepared using the starting polymer VE4 were mixed with 1.6 g of 40 wt. % aqueous sodium bisulfite solution and 54.0 g of water at a stirrer speed of 80 rpm, and then heated to 80°C. Then 58.8 g of 25 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). The mixture was kept at 80° C. for 5 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 22.5 g of 37 wt. % hydrochloric acid solution and 7.0 g of water.

A slightly hazy, yellowish and viscous polymer solution was obtained, having a polymer content of 7.7%. The degree of hydrolysis, SG, was 98 mol. % and the degree of conversion, SP, was 100 mol. %.

Final polymer AE5: Alkaline hydrolyzed VE5 terpolymer (VFA/MA/Na acrylate=70 mol %/25 mol %/5 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 173.6 g of a polymer solution obtained using the starting polymer VE5 were mixed with 1.6 g of 40 wt. % aqueous sodium bisulfite solution and 62.0 g of water at a stirrer speed of 80 rpm, and then heated to 80°C. Then 58.5 g of 25 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). The mixture was kept at 80° C. for 5 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 23.8 g of 37 wt. % hydrochloric acid solution.

A slightly hazy, yellowish and viscous polymer solution was obtained, having a polymer content of 7.6%. The degree of hydrolysis, SG, was 99 mol. % and the degree of conversion, SP, was 100 mol. %.

Final polymer AE6: Alkaline hydrolyzed VE6 terpolymer (VFA/MA/Na acrylate=70 mol %/25 mol %/5 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 149.9 g of a polymer solution prepared using the starting polymer VE6 were mixed with 1.0 g of 40 wt. % aqueous sodium bisulfite solution and 136.0 g of water at a stirrer speed of 80 rpm, and then heated to 80°C. Then 36.2 g of 25 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). The mixture was kept at 80° C. for 5 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 13.7 g of 37 wt. % hydrochloric acid solution and 7.5 g of water.

A slightly hazy yellowish and viscous polymer solution was obtained, having a polymer content of 4.5%. The degree of hydrolysis of SG was 93 mol. % and the degree of conversion, SP, was 100 mol. %.

Final polymer AE7: Alkaline hydrolyzed VE7 terpolymer (VFA/MA/Na acrylate=70 mol %/20 mol %/10 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 170.4 g of a polymer solution obtained using the starting polymer VE7 were mixed with 1.6 g of 40 wt. % aqueous sodium bisulfite solution and 57.0 g of water at a stirring speed of 80 rpm, and then heated to 80°C. Then 58.90 g of 25 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). The mixture was kept at 80° C. for 5 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 25.1 g of 37 wt. % hydrochloric acid solution and 4.5 g of water.

A slightly hazy, yellowish and viscous polymer solution was obtained, having a polymer content of 7.5%. The degree of hydrolysis, SG, was 99 mol. % and the degree of conversion, SP, was 100 mol. %.

Final polymer AE8: Alkaline hydrolyzed VE8 terpolymer (VFA/MA/Na acrylate=70 mol %/15 mol %/15 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 171.0 g of a polymer solution prepared using the starting polymer VE8 were mixed with 1.6 g of 40 wt. % aqueous sodium bisulfite solution and 63.0 g of water at a stirrer speed of 80 rpm, and then heated to 80°C. Then 57.8 g of 25 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). The mixture was kept at 80° C. for 5 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 27.5 g of 37 wt. % hydrochloric acid solution.

A slightly hazy, yellowish and viscous polymer solution was obtained, having a polymer content of 7.5%. The degree of hydrolysis, SG, was 94 mol. % and the degree of conversion, SP, was 100 mol. %.

Final polymer AE9: Alkaline hydrolyzed VE9 terpolymer (VFA/MA/Na acrylate=70 mol %/10 mol %/20 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer for measuring the internal temperature, an addition funnel and a reflux condenser, 177.9 g of a polymer solution obtained using the starting polymer VE9 were mixed with 1.7 g of 40 wt. % aqueous sodium bisulfite solution and 65.0 g of water at a stirrer speed of 80 rpm, and then heated to 80°C. Then 61.5 g of 25 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). The mixture was kept at 80° C. for 5 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 31.3 g of 37 wt. % hydrochloric acid solution and 1.8 g of water.

A slightly hazy yellowish and viscous polymer solution was obtained, having a polymer content of 7.2%. The degree of hydrolysis, SG, was 99 mol. % and the degree of conversion, SP, was 100 mol. %.

Final polymer AE10: Alkaline hydrolyzed VE10 terpolymer (VFA/MA/Na acrylate=70 mol %/25 mol %/5 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer for measuring the internal temperature, an addition funnel and a reflux condenser, 170.2 g of the VE10 polymer solution obtained above was mixed with 1.5 g of 40 wt. % aqueous sodium bisulfite solution and 50.0 g of water at a stirrer speed of 80 rpm, and then heated to 80°C. Then 56.3 g of 25 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). The mixture was kept at 80° C. for 5 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 22.2 g of 37 wt. % hydrochloric acid solution and 8.4 g of water.

A slightly hazy yellowish and viscous polymer solution was obtained, having a polymer content of 7.2%. The degree of hydrolysis, SG, was 97 mol. % and the degree of conversion, SP, was 100 mol. %.

Final polymer AE11: Alkaline hydrolyzed VE11 terpolymer (VFA/MA/AMPS-Na=70 mol %/25 mol %/5 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer for measuring the internal temperature, an addition funnel and a reflux condenser, 172.1 g of a polymer solution obtained using the starting polymer VE11 was mixed with 1.5 g of 40 wt. % aqueous sodium bisulfite solution and 65.5 g of water at a stirrer speed of 80 rpm, and then heated to 80°C. Then 55.9 g of 25 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). The mixture was kept at 80° C. for 5 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 22.7 g of 37 wt. % hydrochloric acid solution and 7.8 g of water.

A slightly hazy, yellowish and viscous polymer solution was obtained, having a polymer content of 7.5%. The degree of hydrolysis, SG, was 94 mol. % and the degree of conversion, SP, was 100 mol. %.

Final polymer AE12: Alkaline hydrolyzed VE12 terpolymer (VFA/MA/Na vinylsulfonate=70 mol%/25 mol%/5 mol%)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 178.5 g of a polymer solution obtained using the starting polymer VE12 was mixed with 1.7 g of 40 wt. % aqueous sodium bisulfite solution and 75.0 g of water at a stirring speed of 80 rpm, and then heated to 80°C. Then 62.8 g of 25 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). The mixture was kept at 80° C. for 5 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 25.4 g of 37 wt. % hydrochloric acid solution and 5.6 g of water.

A slightly hazy, yellowish and viscous polymer solution was obtained, having a polymer content of 7.7%. The degree of hydrolysis, SG, was 98 mol. % and the degree of conversion, SP, was 100 mol. %.

Final polymer AE13: Alkaline hydrolyzed VE13 terpolymer (VFA/MA/DADMAC=65 mol %/30 mol %/5 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 177.6 g of a polymer solution obtained using the starting polymer VE13 was mixed with 1.5 g of 40 wt. % aqueous sodium bisulfite solution and 70.0 g of water at a stirrer speed of 80 rpm, and then heated to 80°C. Then 53.8 g of 25 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). The mixture was kept at 80° C. for 1 hour. The resulting product was no longer amenable to stirring. The experiment was stopped.

Final polymer AE14: Alkaline hydrolyzed VE14 terpolymer (VFA/MA/APTAC=65 mol %/30 mol %/5 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 178.0 g of a polymer solution obtained using the starting polymer VE14 was mixed with 1.4 g of 40 wt. % aqueous sodium bisulfite solution and 60.0 g of water at a stirrer speed of 80 rpm, and then heated to 80°C. Then 51.8 g of 25 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). The mixture was kept at 80° C. for 5 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 18.1 g of 37 wt. % hydrochloric acid solution and 19.1 g of water.

A slightly hazy, yellowish and viscous polymer solution was obtained, having a polymer content of 7.5%. The degree of hydrolysis, SG, was 95 mol. % and the degree of conversion, SP, was 100 mol. %.

Final polymer AE15: Alkaline hydrolyzed VE15 terpolymer (VFA/EA/Na acrylate=70 mol %/15 mol %/15 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 222.5 g of a polymer solution obtained using the starting polymer VE15 was mixed with 1.5 g of 40 wt. % aqueous sodium bisulfite solution and 10.0 g of water at a stirrer speed of 80 rpm, and then heated to 80°C. Then 56.3 g of 25 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). The mixture was kept at 80° C. for 5 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 25.6 g of 37 wt. % hydrochloric acid solution and 1.1 g of water.

A slightly cloudy yellowish and viscous polymer solution was obtained.

Polymer content: 7.5%

Formate content, FA: 91.4 mmol/100 g

Degree of hydrolysis, SG: 98 mol. %

Degree of conversion, SP: 100 mol. %

Charge density, PZ: 64.0 mmol / 100 g

Viscosity (20 rpm, RW (rotational viscometer), #3 spindle): 185 mPa⋅s

PAD ( ¹³ C-NMR, 152.3 ppm): 1.11

PFA ( ¹³ C-NMR, 164-167 ppm): 0.82

VFA ⁰ : 93.7 mmol/100 g

EA ⁰ : 20.0 mmol/100 g

AK-Na ⁰ : 20.0 mmol/100 g.

Final polymer AE16: Alkaline hydrolyzed VE16 terpolymer (VFA/MA/Na acrylate=70 mol %/20 mol %/10 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 652.7 g of the polymer solution obtained using the starting polymer VE16 was mixed with 4.5 g of 40 wt. % aqueous sodium bisulfite solution and 185.3 g of water at a stirrer speed of 80 rpm, and then heated to 80°C. Then 165.3 g of 25 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). The mixture was kept at 80° C. for 6 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 70.2 g of 37 wt. % hydrochloric acid solution and 12.7 g of water.

A slightly cloudy yellowish and viscous polymer solution was obtained.

Polymer content: 6.6%

Formate content, FA: 74.0 mmol/100 g

Degree of hydrolysis, SG: 94 mol. %

Degree of conversion, SP: 100 mol. %

Charge density, PZ: 51.3 mmol / 100 g

Viscosity (20 rpm, RV, #3 spindle): 268 mPa⋅s

PAD ( ¹³ C-NMR, 152.3 ppm): 1.86 PFA

( ¹³ C-NMR, 164-167 ppm): 2.78

VFA ⁰ : 79.5 mmol/100 g

EA ⁰ : 22.7 mmol/100 g

AK-Na ⁰ : 11.4 mmol/100 g.

Final polymer AE17: Alkaline hydrolyzed VE17 terpolymer (VFA/MA/Na acrylate=70 mol %/20 mol %/10 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 249.5 g of a polymer solution obtained using the starting polymer VE17 was mixed with 1.8 g of 40 wt. % aqueous sodium bisulfite solution and 20.0 g of water at a stirring speed of 80 rpm, and then heated to 80°C. Then 53.9 g of 25 wt. % aqueous sodium hydroxide solution (100 mol.% in terms of VFA). The mixture was kept at 80° C. for 6 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 20.7 g of 37 wt. % hydrochloric acid solution.

A slightly cloudy yellowish and viscous polymer solution was obtained.

Polymer content: 8.4%

Formate content, FA: 83.4 mmol/100 g

Degree of hydrolysis, SG: 85 mol. %

Degree of conversion, SP: 100 mol. %

Charge density, PZ: 56.7 mmol / 100 g

Viscosity (50 rpm, RV, #3 spindle): 1172 mPa⋅s

PAD ( ¹³ C-NMR, 152.3 ppm): 0.90

PFA ( ¹³ C-NMR, 164-167 ppm) 3.82

VFA ⁰ : 98.3 mmol/100 g

EA ⁰ : 28.1 mmol/100 g

AK-Na ⁰ : 14.0 mmol/100 g.

Final polymer AE18: Alkaline hydrolyzed VE18 terpolymer (VFA/MA/Na acrylate=70 mol %/20 mol %/10 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 248.8 g of a polymer solution obtained using the original polymer VE18 was mixed with 1.7 g of 40 wt. % aqueous sodium bisulfite solution and 20.0 g of water at a stirrer speed of 80 rpm, and then heated to 50°C. Then 63.7 g of 25 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). The mixture was kept at 50° C. for 24 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 27.9 g of 37 wt. % hydrochloric acid solution.

A slightly cloudy yellowish and viscous polymer solution was obtained.

Polymer content: 8.2%

Formate content, FA: 88.2 mmol/100 g

Degree of hydrolysis, SG: 91 mol. %

Degree of conversion, SP: 100 mol. %

Charge density, PZ: 67.7 mmol / 100 g

Viscosity (50 rpm, RV, #3 spindle): 866 mPa⋅s

PAD ( ¹³ C-NMR, 152.3 ppm): 0.77

PFA ( ¹³ C-NMR, 164-167 ppm): 3.14

VFA ⁰ : 97.7 mmol/100 g

EA ⁰ : 27.9 mmol/100 g

AK-Na ⁰ : 14.0 mmol/100 g.

Final polymer AE19: Alkaline hydrolyzed copolymer VE19 (VFA/MA=70 mol %/30 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 121.3 g of a polymer solution obtained using the starting polymer VE19 was mixed with 1.1 g of 40 wt. % aqueous sodium bisulfite solution at a stirrer speed of 80 rpm and then heated to 80°C. Then 39.5 g of 25 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). The mixture was kept at 80° C. for 5 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 14.5 g of 37 wt. % hydrochloric acid solution.

A slightly cloudy yellowish and viscous polymer solution was obtained.

Polymer content: 7.9%

Formate content, FA: 97.5 mmol/100 g

Degree of hydrolysis, SG: 99 mol. %

Degree of conversion, SP: 100 mol. %

Charge density, PZ: 64.3 mmol / 100 g

Viscosity (20 rpm, RV, #3 spindle): 794 mPa⋅s

PAD ( ¹³ C-NMR, 152.3 ppm): 10.0

PFA ( ¹³ C-NMR, 164-167 ppm): <0.01

VFA ⁰ : 98.8 mmol/100 g

MA ⁰ : 42.3 mmol/100 g.

Final polymer AE20: Alkaline hydrolyzed copolymer VE20 (VFA/MA=60 mol %/40 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 180.0 g of a polymer solution obtained using the starting polymer VE20 was mixed with 1.3 g of 40 wt. % aqueous sodium bisulfite solution at a stirrer speed of 80 rpm and then heated to 80°C. Then 51.4 g of 25 wt. % aqueous solution of sodium hydroxide (125 mol.% in terms of VFA). The mixture was kept at 80° C. for 5 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 14.2 g of 37 wt. % hydrochloric acid solution and 10.4 g of water.

A slightly cloudy yellowish and viscous polymer solution was obtained.

Polymer content: 8.3%

Formate content, FA: 76.5 mmol/100 g

Degree of hydrolysis, SG: 94 mol. %

Degree of conversion, SP: 100 mol. %

Charge density, PZ: 34.0 mmol / 100 g

Viscosity (20 rpm, RV, #3 spindle): 2320 mPa⋅s

PAD ( ¹³ C-NMR, 152.3 ppm): 5.1

PFA ( ¹³ C-NMR, 164-167 ppm): 0.9

FA ⁰ : 98.8 mmol/100 g

MA ⁰ : 42.3 mmol/100 g.

Final polymer AE21: Alkaline hydrolyzed copolymer VE21 (VFA/MA=80 mol %/20 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 197.6 g of a polymer solution obtained using the starting polymer VE21 was mixed with 2.1 g of 40 wt. % aqueous sodium bisulfite solution at a stirrer speed of 80 rpm and then heated to 80°C. Then 73.8 g of 25 wt. % aqueous solution of sodium hydroxide (116 mol.% in terms of VFA). The mixture was kept at 80° C. for 5 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 32.5 g of 37 wt. % hydrochloric acid solution and 130.2 g of water.

A slightly cloudy yellowish and viscous polymer solution was obtained.

Polymer content: 7.0%

Formate content, FA: 105.8 mmol/100 g

Degree of hydrolysis, SG: 98 mol. %

Degree of conversion, SP: 100 mol. %

Charge density, PZ: 79.5 mmol / 100 g

Viscosity (20 rpm, RV, #3 spindle): 755 mPa⋅s

PAD ( ¹³ C-NMR, 152.3 ppm): 10.0

PFA ( ¹³ C-NMR, 164-167 ppm): 2.9

VFA ⁰ : 108 mmol/100 g

MA ⁰ : 42.3 mmol/100 g.

Final polymer AE22: Alkaline hydrolyzed VE22 terpolymer (VFA/MA/Na acrylate=70 mol %/25 mol %/5 mol %)

In a 500 ml four-neck flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 265.8 g of a polymer solution prepared using the starting polymer VE22 was mixed with 1.8 g of 40 wt. % aqueous sodium bisulfite solution at a stirrer speed of 80 rpm and then heated to 80°C. Then 67.1 g of 25 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). The mixture was kept at 80° C. for 5 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 26.0 g of 37 wt. % hydrochloric acid solution and 3.3 g of water.

A slightly cloudy yellowish and viscous polymer solution was obtained.

Polymer content: 7.7%

Formate content, FA: 94.8 mmol/100 g

Degree of hydrolysis, SG: 98 mol. %

Degree of conversion, SP: 100 mol. %

Charge density, PZ: 66.0 mmol / 100 g

Viscosity (20 rpm, RV, #3 spindle): 325 mPa⋅s

PAD ( ¹³ C-NMR, 152.3 ppm): 1.90

PFA ( ¹³ C-NMR, 164-167 ppm): 2.80

VFA ⁰ : 96.7 mmol/100 g

MA ⁰ : 34.6 mmol/100 g

AK-Na ⁰ : 6.9 mmol/100 g.

Final polymer AE23: Alkaline hydrolyzed VE23 terpolymer (VFA/EA/Na acrylate=70 mol %/25 mol %/5 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 174.4 g of a polymer solution obtained using the original polymer VE23 was mixed with 1.6 g of 40 wt. % aqueous sodium bisulfite solution and 64.0 g of water at a stirrer speed of 80 rpm, and then heated to 50°C. Then 57.5 g of 25 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). The mixture was kept at 50° C. for 24 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 22.7 g of 37 wt. % hydrochloric acid solution and 6.5 g of water.

A slightly cloudy yellowish and viscous polymer solution was obtained.

Polymer content: 7.8%

Formate content, FA: 89.0 mmol/100 g

Degree of hydrolysis, SG: 97 mol. %

Degree of conversion, SP: 100 mol. %

Charge density, PZ: 66.9 mmol / 100 g

Viscosity (50 rpm, RV, #3 spindle): 715 mPa⋅s

PAD ( ¹³ C-NMR, 152.3 ppm): 2.0

PFA ( ¹³ C-NMR, 164-167 ppm): 2.8

VFA ⁰ : 92.5 mmol/100 g

EA ⁰ : 33.0 mmol/100 g

AK-Na ⁰ : 6.6 mmol/100 g.

Final polymer AE24: Alkaline hydrolyzed VE24 terpolymer (VFA/EA/Na acrylate=70 mol %/20 mol %/10 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 173.1 g of a polymer solution obtained using the original polymer VE24 was mixed with 2.6 g of 40 wt. % aqueous sodium bisulfite solution and 65.0 g of water at a stirrer speed of 80 rpm, and then heated to 80°C. Then 58.1 g of 25 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). The mixture was kept at 80° C. for 6 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 24.6 g of 37 wt. % hydrochloric acid solution and 6.0 g of water.

A slightly cloudy yellowish and viscous polymer solution was obtained.

Polymer content: 7.7%

Formate content, FA: 87.9 mmol/100 g

Degree of hydrolysis, SG: 96 mol. %

Degree of conversion, SP: 100 mol. %

Charge density, PZ: 55.0 mmol / 100 g

Viscosity (20 rpm, RV, #3 spindle): 735 mPa⋅s

PAD ( ¹³ C-NMR, 152.3 ppm): 1.93

PFA ( ¹³ C-NMR, 164-167 ppm): 2.65

VFA ⁰ : 92.85 mmol/100 g

AK-Na ⁰ : 13.3 mmol/100 g

EA⁰: 26.5 mmol/100 g.

Final polymer AE25: Alkaline hydrolyzed VE25 terpolymer (VFA/EA/Na acrylate=70 mol %/10 mol %/20 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 185.3 g of a polymer solution obtained using the original polymer VE25 was mixed with 1.7 g of 40 wt. % aqueous sodium bisulfite solution and 65.0 g of water at a stirrer speed of 80 rpm, and then heated to 80°C. Then 63.2 g of 25 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). The mixture was kept at 80° C. for 6 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 31.2 g of 37 wt. % hydrochloric acid solution and 1.3 g of water.

A slightly cloudy yellowish and viscous polymer solution was obtained.

Polymer content: 7.3%

Formate content, FA: 92.0 mmol/100 g

Degree of hydrolysis, SG: 99 mol. %

Degree of conversion, SP: 100 mol. %

Charge density, PZ: 70.1 mmol / 100 g

Viscosity (20 rpm, RV, #3 spindle): 535 mPa⋅s

PAD ( ¹³ C-NMR, 152.3 ppm): 2.18

PFA ( ¹³ C-NMR, 164-167 ppm): 2.20

VFA ⁰ : 92.85 mmol/100 g

EA ⁰ : 26.5 mmol/100 g

AK-Na ⁰ : 13.3 mmol/100 g.

Final polymer AE26: Alkaline hydrolyzed VE26 terpolymer (VFA/EA/Na acrylate=70 mol %/20 mol %/10 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 169.1 g of a polymer solution obtained using the starting polymer VE26 was mixed with 1.2 g of 40 wt. % aqueous sodium bisulfite solution and 20.0 g of water at a stirrer speed of 80 rpm, and then heated to 50°C. Then 29.0 g of 25 wt. % aqueous solution of sodium hydroxide (82 mol.% in terms of VFA). The mixture was kept at 50° C. for 24 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 10.7 g of 37 wt. % hydrochloric acid solution and 5.3 g of water.

A slightly cloudy yellowish and viscous polymer solution was obtained.

Polymer content: 7.9%

Formate content, FA: 63.2 mmol/100 g

Degree of hydrolysis, SG: 72 mol. %

Degree of conversion, SP: 100 mol. %

Charge density, PZ: 39.8 mmol / 100 g

Viscosity (50 rpm, RV, #3 spindle): 594 mPa⋅s

PAD ( ¹³ C-NMR, 152.3 ppm): 4.1

PFA ( ¹³ C-NMR, 164-167 ppm): 4.0

VFA ⁰ : 88.4 mmol/100 g

EA°: 25.3 mmol/100 g

AK-Na ⁰ : 12.6 mmol/100 g.

Final polymer AE27: Alkaline hydrolyzed VE18 terpolymer (VFA/EA/Na acrylate=70 mol %/20 mol %/10 mol %)

In a 2 L steel pressurized reactor equipped with a stirrer, internal temperature thermometer, heating/cooling jacket, monometer, pressure relief valve, reflux condenser and pressurized feed vessel, 1006.2 g of a polymer solution prepared using the starting polymer VE18, with stirring was mixed with 126.4 g of water and heated to 107°C. A pressure of 2.8 bar was provided. 256.8 g of 25 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). At a pressure of 5 bar, sodium hydroxide solution was introduced into the reactor and the mixture was stirred. The temperature was adjusted to 100° C. and maintained for 60 minutes. The reactor was then cooled to RT as quickly as possible. Received 306.9 g of the product and its pH value was set equal to 6.0 by adding 26.4 g of 37 wt. % hydrochloric acid solution and 3.7 g of water.

A slightly cloudy yellowish and viscous polymer solution was obtained.

Polymer content: 7.3%

Formate content, FA: 90.1 mmol/100 g

Degree of hydrolysis, SG: 94 mol. %

Degree of conversion, SP: 100 mol. %

Charge density, PZ: 66.5 mmol / 100 g

Viscosity (20 rpm, RV, #3 spindle): 1030 mPa⋅s

PAD ( ¹³ C-NMR, 152.3 ppm): 1.79

PFA ( ¹³ C-NMR, 164-167 ppm): 1.46

VFA ⁰ : 97.2 mmol/100 g

EA ⁰ : 27.8 mmol/100 g

AK-Na ⁰ : 13.9 mmol/100 g.

Final polymer AE28: Alkaline hydrolyzed VE18 terpolymer (VFA/EA/Na acrylate=70 mol %/20 mol %/10 mol %)

In a 2 L steel pressurized reactor equipped with a stirrer, internal temperature thermometer, heating/cooling jacket, monometer, pressure relief valve, reflux condenser, and pressurized feed vessel, 990.2 g of polymer solution prepared using the starting polymer VE18, with stirring was mixed with 126.4 g of water and heated to 125°C. A pressure of 4 bar was provided. 126.4 g of 50 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). At a pressure of 6 bar, a sodium hydroxide solution was introduced into the reactor and the mixture was stirred. The temperature was adjusted to 120° C. and maintained for 30 minutes. The reactor was then cooled to RT as quickly as possible. Received 295.8 g of the product and its pH value was set equal to 6.0 by adding 26.1 g of 37 wt. % hydrochloric acid solution and 2.9 g of water.

A slightly cloudy yellowish and viscous polymer solution was obtained.

Polymer content: 7.2%

Formate content, FA: 94.7 mmol/100 g

Degree of hydrolysis, SG: 97.4 mol. %

Degree of conversion, SP: 100 mol. %

Charge density, PZ: 68.8 mmol / 100 g

Viscosity (20 rpm, PB, #3 spindle): 940 mPa⋅s

PAD ( ¹³ C-NMR, 152.3 ppm): 1.31

PFA ( ¹³ C-NMR, 164-167 ppm): 1.01

VFA ⁰ : 97.2 mmol/100 g

EA ⁰ : 27.8 mmol/100 g

AK-Na ⁰ : 13.9 mmol/100 g.

Final polymer AE29: Alkaline hydrolyzed VE27 terpolymer (VFA/MA/AM=70 mol %/25 mol %/5 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 156.0 g of a polymer solution obtained using the starting polymer VE27 was mixed with 1.6 g of 40 wt. % aqueous sodium bisulfite solution and 72.9 g of water at a stirring speed of 80 rpm, and then heated to 80°C. Then 60.3 g of 25 wt. % aqueous solution of sodium hydroxide (120 mol.% in terms of VFA). The mixture was kept at 80° C. for 5 hours. The resulting product was cooled to RT and the pH was adjusted to 6.0 by adding 24.1 g of 37 wt. % hydrochloric acid solution and 7.5 g of water.

A slightly hazy, yellowish and viscous polymer solution was obtained, having a polymer content of 7.9%. The degree of hydrolysis, SG, was 93 mol. % and the degree of conversion, SP, was 100 mol. %.

Final polymer AV1: Alkaline hydrolysed VV1 copolymer (VFA/Na acrylate=70 mol %/30 mol %)

In a 500 ml four-necked flask equipped with a stirring paddle, a thermometer to measure the internal temperature, an addition funnel and a reflux condenser, 206.1 g of a polymer solution obtained using the starting polymer VV1 was mixed with 2.3 g of 40 wt. % aqueous sodium bisulfite solution at a stirrer speed of 80 rpm and then heated to 80°C. Then 77.0 g of 25 wt. % aqueous solution of sodium hydroxide (110 mol.% in terms of VFA). The mixture was kept at 80° C. for 5 hours. The resulting product was cooled to RT and the pH was adjusted to 8.5 by adding 32.3 g of 37 wt. % hydrochloric acid solution and 9.6 g of water.

A slightly hazy, yellowish and viscous polymer solution was obtained, having a polymer content of 9.9%. The degree of hydrolysis, SG, was 100 mol. %.

A-4) Detailed description of the obtained polymers

A detailed description of the obtained polymers is given in tables A-4-1 and A-4-2.

Note:

The original polymer VE1, intended to obtain the final polymer AE1, was obtained in almost the same way as the original polymer VE2, intended to obtain the final polymer AE2. Hydrolysis of the starting polymer VE1 in an acidic environment to give the final polymer AE1 does not have a viscosity peak, while hydrolysis of the starting polymer VE2 in an alkaline environment to give the final polymer AE2 shows an extremely high viscosity peak. The presence of the polymerized anionic monomer in the initial polymer V reduces or prevents the appearance of a viscosity peak during hydrolysis in an alkaline medium, which proceeds to obtain the final polymers AE3, AE4, AE5, AE6, AE7, AE8, AE9, AE10, AE11, AE12, AE15, AE17 , AE22, AE23 and AE24. The presence of polymerized diallyldimethylammonium chloride (DADMAC), (3-acrylamidopropyl)trimethylammonium chloride (APTAC) or acrylamide (AM) in the starting polymer V for the final polymers AE13, AE14 and AE29 does not provide this effect.

B) paper

B-1) Receipt of paper material

As a paper material for making paper, a pulp obtained by processing a paper web in a pulper was used. The paper web was "Testliner 2" untreated packaging paper having a basis weight of 120 g/m ² from Thurpapier of Weinfelden (Switzerland). The pulp was obtained by dissolving in drinking water and mechanically processing the paper web in a grinder at a solids content of about 3.5 wt. %. In this case, the pulp usually had a degree of grinding of about 50°ShP (Schopper-Rigler).

B-2) Treatment of paper material with final polymers

Treatment with the final polymers was performed either by "thick stock" treatment at a pulp solids content of about 3.5%, or by a "wet stock" treatment at a pulp solids content of about 0.8%.

In the case of "thick mass treatment", 500 g of pulp was placed in a large glass beaker. Then, with stirring, a 2% aqueous solution of the final polymer was added. The percentage indicated is the polymer content of the final polymer solution. The pulp was treated with 1.315 g of a 2% aqueous solution of the final polymer or with 2.63 g of a 2% aqueous solution of the final polymer, i. using 1.315 g or 2.63 g in terms of 500 g of pulp. This corresponded to the treatment with the final polymer at its content of 0.15% or 0.3%, calculated on the amount of dry paper material. Then 100 g of the treated pulp was transferred to another glass vessel and then diluted with potable water to provide a solids content of 0.8%.

In the "slurry treatment" case, 114.3 g of pulp was placed in a large glass beaker. The pulp was then diluted with potable water to provide a solids content of 0.8%. With stirring, additives were added in the form of a 2% aqueous solution of the final polymer. The percentage indicated is the polymer content of the final polymer solution. The diluted pulp was treated with 0.3 g of a 2% aqueous solution of the final polymer or with 0.6 g of a 2% aqueous solution of the final polymer. This corresponded to the treatment with the final polymer at its content of 0.15% or 0.3%, calculated on the amount of dry paper material.

B-3) Making paper sheets

The objective was to produce paper sheets having a basis weight of 120 g/m ² using as raw material a paper material treated with final polymers having a solids content of 0.8%. Paper sheets were made using a dynamic sheet forming machine manufactured by TechPap (France). A slurry of paper material, i. e. the paper material, optionally treated with the final polymer, was sprayed onto the mesh. The grid was fixed in a vertically located rapidly rotating drum. In this system, the dewatering and formation of the sheet is determined not only by the structure of the sheet, but mainly by the centrifugal forces inside the rotating drum. By changing the speed of rotation of the drum, it is possible to change the centrifugal force acting on the resulting sheet structure. The result is a different degree of dehydration of the sheet, which leads to different solids content in the resulting wet paper structure. In the present invention, this means the solids content of the wet paper structure immediately after it has been removed from the mesh fixed in the drum of the dynamic sheeter. The rotation speed of the drum can be changed in 5 stages from 600 to 1100 rpm, thus it was possible to control the solids content in the range from 15 to 21 wt. %. A small portion of the still wet paper structure was used to determine the solids content immediately after the removal of the wet paper structure from the dynamic sheeting machine wire.

After removing the wet paper structures from the drum of the dynamic sheeter, they were covered on both sides with blotting paper and dewatered with a stationary press at a pressure of 6 bar for 30 s, thus a wet paper sheet was obtained from the paper structure. After that, the solids content in a wet paper sheet usually ranged from 41 to 43 wt. %. If the solids content is significantly less than the lower value, then the thickness of the blotting paper or the number of layers applied can be increased to ensure the value is in the above range.

The resulting wet paper sheet was then re-covered on both sides with clean blotting paper and then fixed in a drying cylinder and held for 10 minutes. The surface temperature of the drying cylinder was about 100°C. A dry paper sheet was obtained. After drying, the dried paper sheets were placed in an air-conditioned chamber for conditioning.

B-4) Determination of the solids content of the paper sample and the internal strength of the dried paper sheets

To determine the solids content (DM) of a paper sample, the Wet Sample Weight (MB) was determined using the wet paper sample using a calibrated balance pan on top that can achieve a weighing accuracy of 0.01 g. the paper sample had an area of at least 10 cm×10 cm. Then, the wet paper sample was placed in a calibrated drying chamber, which can be maintained at a set temperature with a deviation of ± 2°C, and dried at a set temperature of 105°C, to constant weight. Typically, constant weight was achieved after 90 minutes. The still warm dried paper sample was then transferred to a desiccator which contained a suitable drying agent such as silica gel. After cooling to room temperature, the weight of the dry paper sample (MS) was determined using the above weights. Then the solids content in the paper sample, calculated in accordance with the formula CB=100×MS/MW, was indicated in wt. %. The value expressed as a percentage is often indicated with one decimal place. If this percentage value, rounded to the first decimal place, does not change, this indicates that a constant mass is ensured in the case of solids contents ranging from 1 to 100 wt. %. In the case of solids contents ranging from 0 to less than 1 wt. %, this is respectively indicated by a constant value, rounded to the second decimal place, expressed as a percentage. Drying was carried out at ambient pressure, optionally at 101.32 kPa, without correcting for any deviation due to weather conditions or altitude. During drying, the normally prevailing air pressure was maintained, in other words, theoretically equal to 101.32 kPa. No correction was made for slight changes in air pressure due to weather conditions or altitude. In the event that the wet sample did not yet have the consistency of a sheet, eg a fibrous material slurry or pulp, the wet sample was dried on a suitable tray having a large surface area.

To determine the internal strength of a dried paper sheet, the sheet was stored in an air-conditioned chamber at a constant temperature of 23°C and a humidity of 50% for 12 hours. 94. In this procedure, 10 strips of paper 2.5 cm wide and 12.7 cm long were cut from two paper sheets obtained and then dried as described above. Each individual paper sample was attached with double-sided adhesive tape to a separate base plate and metal bracket. The metal bracket was hit with a pendulum, and the test paper sample was torn in a direction parallel to the surface of the paper. The amount of energy needed to carry out this procedure was determined. The instrument used for the study was the Internal-Bond-Test-Station manufactured by TMI (Testing Machines Inc. Islandia, New York USA). The double-sided adhesive tape was a 3M product (width 25.4 mm, type Scotch #140). Using a measuring device was determined by the energy required to break, in terms of standardized surface area, expressed in J/m ² . The internal strength value was the average of 10 individual measurements.

B-5) Dried Paper Sheets Produced and Results To obtain dried paper sheets from the raw paper material used as the reference sample (RB), three wet paper structure samples were obtained having solids contents of 15.7 wt. %, 17.4 wt. % and 20.4 wt. %. The wet paper texture samples were then pressed and dried. For each final polymer, paper materials treated with the final polymer produced wet paper structure samples having two different solids contents ranging from 16.5 to 21 wt. %, and one value of the solids content was less than 18.5 wt. % and one value of the solids content was more than 18.5 wt. %. Table B-5-1 lists the final polymers used and the results obtained.

B-6) Brief description of the results obtained

The values of internal strength for the reference samples (RB1-RB3, without the addition of the final polymer) are about 125 J/m ² . Differences in the values of the internal strength of dried paper sheets, for the manufacture of which a wet paper structure was used, having a solids content of 15.3 to 20.2 wt. % are insignificant.

With an addition of 0.15 g/100 g of Comparative Examples (VB1, VB3, VB5, VB7) polymers, the internal strength is increased by about 20 J/m compared to the strength of the reference samples, regardless of whether the addition is carried out in a thick mass or to the liquid mass, and regardless of the solids content. With an addition of 0.3 g/100 g of the polymers of Comparative Examples (VB2, VB4, VB6, VB8), the internal strength is increased by about 30 J/m ² regardless of whether the addition is to a thick mass or to a liquid mass, and regardless of dry matter content.

With the addition of the number of polymers of the examples proposed in the present invention, constituting 0.15 g/100 g, and at a solids content of <18.5 wt. % (in each case, odd numbers of examples EB1-EB28), the internal strength increases by about 40 J/m ² compared with the strength of the reference samples, regardless of whether the addition is carried out in a thick mass or in a liquid mass. With the addition of the number of polymers of the examples proposed in the present invention, constituting 0.3 g/100 g, and at a solids content of <18.5 wt. % (in each case, even numbers of examples EB1-EB28), the internal strength increases by about 55 J/m ² compared with the strength of the reference samples, regardless of whether the addition is carried out in a thick mass or in a liquid mass.

With the added amount of polymers of the examples proposed in the present invention, constituting 0.15 g/100 g, and when the solids content of >18.5 wt. % (in each case, odd numbers of examples EBZ3-EB60), compared with the strength of the reference samples, the internal strength increases by at least 70 J/m if added to a thick mass and by at least 50 J/m ² if added to liquid mass. With the added amount of polymers of the examples proposed in the present invention, constituting 0.3 g/100 g, and when the solids content of >18.5 wt. % (in each case, even numbers of examples EVZ3-EB60), compared with the strength of the reference samples, the internal strength increases by at least 90 J/m ² if added to a thick mass and by at least 70 J/m ² if added to liquid mass.

When comparing the samples proposed in the present invention, when the dry matter content in the wet paper structure is <18.5 wt. % (EB1-EB28), and the samples proposed in the present invention, with a solids content in the wet paper structure of >18.5 wt. % (EB33-EB60), it can be seen that when adding the same final polymer and using the same added amount, the internal strengths are at least 20 J/m ² higher with a higher solids content in the wet paper structure.

The final polymer AVI used in the comparative examples, formally consists of 70 mol. % containing an amino group of ethylene units and 30 mol. % carboxy-containing ethylene units. The final polymers AE15, AE19, AE22, AE23 and AE24 used in the examples proposed in the present invention also formally consist of about 70 mol. % containing an amino group of ethylene units and 30 mol. % carboxy-containing ethylene units. The degree of hydrolysis, SG, is about 98 mol. % in the case of AE15, 99 mol. % in the case of AE19, 98 mol. % in the case of AE22, 97 mol. % in the case of AE23 and 96 mol. % in the case of AE24. The resulting paper internal strength is affected differently by the end polymers used, depending on whether only sodium acrylate units prepolymerized to form the starting polymer are used to obtain the carboxyl group-containing units of the final polymer, or whether at least additionally or exclusively methyl or ethyl acrylic ester is used. acid, prepolymerized to obtain the original polymer. It is believed that there are different mechanisms for incorporating the monomers and thus different degrees of alternation of the monomer units that are polymerized. With an increase in the degree of alternation, a change in the number of possible 5-membered lactam units can be expected. N-vinylformamide is an electron-rich monomer, while acrylic acid ester, on the contrary, is a monomer with a low electron content. In contrast, buffered acrylic acid having a pH of 6 to 7 is a monomer having a high electron content. Another difference between acrylic acid ester and acrylate is solubility.

Claims (50)

1. A method of making paper or paperboard, comprising the steps of (A) adding a final polymer A to a first aqueous fibrous material suspension, thereby obtaining a second aqueous fibrous material suspension containing a final polymer A, where the final polymer A is obtained by - radical polymerization of the following monomers: (i) from 30 to 90 mol.% of the monomer of formula I

in which R ¹ \u003d H, (ii) 3 to 60 mole % C ₁ -C ₄ alkyl ester of acrylic acid or C ₁ -C ₄ alkyl ester of methacrylic acid, (iii) 0 to 45 mole % monoethylenically unsaturated carboxylic acid, monoethylenically unsaturated sulfonic acid or monoethylenically unsaturated phosphonic acid, or their salt forms, (iv) 0 to 9 mole % acrylonitrile or methacrylonitrile, (v) 0 to 35 mole % of one or more ethylenically unsaturated monomers other than the monomer of (i), (ii), (iii) and (iv), where the total amount of all monomers (i), (ii), (iii), (iv) and (v) is 100 mol.%, to obtain the original polymer V, and - hydrolysis of the original polymer V to obtain the final polymer A, where at least part of the groups NC(=O)R ¹ contained in the monomers (i) of formula (I), polymerized to obtain the original polymer V, is hydrolyzed and thus formed primary amino groups , where at least part of the ester groups contained in the monomers (ii), polymerized to obtain the original polymer V, undergoes transformation and at least part of the transformation is the formation of 5-membered lactam structural units containing the obtained primary amino groups, or the formation of carboxy groups or their salt forms, (B) dewatering a second aqueous fibrous material slurry containing the final polymer A on a water-permeable substrate to form a wet paper structure, (C) dewatering the wet paper structure, thereby obtaining paper or paperboard. 2. The method according to p. 1, in which radical polymerization is used (i) from 50 to 89 mol.% of the monomer of formula I, (ii) from 5 to 45 mol.% C ₁ -C ₄ -alkyl ester of acrylic acid or C ₁ -C ₄ -alkyl ester of methacrylic acid, (iii) 0 to 30 mole % monoethylenically unsaturated carboxylic acid, monoethylenically unsaturated sulfonic acid or monoethylenically unsaturated phosphonic acid, or their salt forms, (iv) 0 to 9 mole % acrylonitrile or methacrylonitrile, (v) 0 to 25 mole % of one or more ethylenically unsaturated monomers other than the monomer (i), (ii), (iii) and (iv). 3. The method according to p. 1, in which radical polymerization is used (i) from 58 to 83 mol.% of the monomer of formula I, (ii) from 8 to 39 mol.% C ₁ -C ₄ -alkyl ester of acrylic acid or C ₁ -C ₄ -alkyl ester of methacrylic acid, (iii) 0 to 25 mole % monoethylenically unsaturated carboxylic acid, monoethylenically unsaturated sulfonic acid or monoethylenically unsaturated phosphonic acid, or their salt forms, (iv) 0 to 9 mole % acrylonitrile or methacrylonitrile, (v) 0 to 25 mole % of one or more ethylenically unsaturated monomers other than the monomer (i), (ii), (iii) and (iv). 4. The method according to claim 1, wherein the monomer (iii) is used in an amount of 1 to 25 mole%. 5. The method according to p. 1, in which the monomer (i) is N-vinylformamide, while in the formula IR ¹ =H. 6. The method according to p. 1, in which the monomer (ii) is selected from C ₁ -C ₃ -alkyl ester of acrylic acid or C ₁ -alkyl ester of methacrylic acid; ethyl acrylate; or their combinations. 7. The method according to p. 1, in which the monomer (iii) is selected from monoethylenically unsaturated carboxylic acid or monoethylenically unsaturated sulfonic acid, or their salt forms; acrylic acid, methacrylic acid, vinylsulfonic acid or 2-acrylamido-2-methylpropanesulfonic acid, or their salt forms; or their combinations. 8. The method according to p. 1, in which the following monomers are used for radical polymerization: (i) from 60 to 83 mol.% N-vinylformamide, (ii) 8 to 21 mole % ethyl acrylate, (iii) from 2 to 21 mole % of acrylic acid or methacrylic acid, or their salt forms, (iv) 0 to 9 mole % acrylonitrile or methacrylonitrile, (v) 0 to 24 mole % of one or more ethylenically unsaturated monomers other than the monomer of (i), (ii), (iii) and (iv). 9. The method according to any one of paragraphs. 1-8, in which: - in stage (A) the first aqueous suspension of fibrous material has a solids content of 0.1 to 6 wt.%; - in step (B), the wet paper structure has a solids content of 18.5 to 25% by weight. 10. Final polymer A, which is obtained by - radical polymerization of the following monomers: (i) from 58 to 83 mol.% of the monomer of formula I

in which R ¹ \u003d H, (ii) from 8 to 39 mol.% C ₁ -C ₄ -alkyl ester of acrylic acid or C ₁ -C ₄ -alkyl ester of methacrylic acid, (iii) 0 to 25 mole % monoethylenically unsaturated carboxylic acid, monoethylenically unsaturated sulfonic acid or monoethylenically unsaturated phosphonic acid, or their salt forms, (iv) 0 to 9 mole % acrylonitrile or methacrylonitrile, (v) 0 to 25 mole % of one or more ethylenically unsaturated monomers other than the monomer of (i), (ii), (iii) and (iv), where the total amount of all monomers (i), (ii), (iii), (iv) and (v) is 100 mol.%, to obtain the original polymer V, and - hydrolysis of the original polymer V to obtain the final polymer A, where at least part of the groups NC(=O)R ¹ contained in the monomers (i) of formula (I), polymerized to obtain the original polymer V, is hydrolyzed and thus formed primary amino groups , where at least part of the ester groups contained in the monomers (ii), polymerized to obtain the original polymer V, undergoes transformation and at least part of the transformation is the formation of 5-membered lactam structural units containing the obtained primary amino groups, or the formation of carboxy groups or their salt forms.

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