EA032199B1 - Process and device for the preparation of water-absorbent polymer particles and composite material based thereon - Google Patents

Abstract

The present invention generally relates to a process for the preparation of water-absorbent polymer particles; to a plurality of water-absorbent polymer particles; to a composite material comprising said water-absorbent polymer particle or said plurality of water-absorbent polymer particles; to a process for the production of a composite material; to a composite material obtainable by said process; to the use of a water-absorbent polymer particle or a plurality of water-absorbent polymer particles; to a device for the preparation of water-absorbent polymer particles; and to a process for the preparation of water-absorbent polymer particles using said device.

Description

The invention relates to a method for producing water-absorbing polymer particles; to a water-absorbing polymer particle, which can be obtained in this way; to a variety of water-absorbing polymer particles; to a composite material containing said water-absorbing polymer particle or said plurality of water-absorbing polymer particles; to a method for producing a composite material; to composite material that can be obtained by the specified method; the use of a water-absorbing polymer particle or a plurality of water-absorbing polymer particles; to a device for producing water-absorbing polymer particles; and to a method for producing water-absorbing polymer particles using the specified device.

State of the art

Superabsorbents are water-insoluble cross-linked polymers that can absorb a large amount of aqueous fluids, especially physiological fluids, more specifically urine or blood, with swelling and the formation of hydrogels, and also hold these fluids at a certain pressure. Due to these characteristic properties, such polymers are mainly used in hygiene products, such as, for example, baby diapers / diapers, products for patients with incontinence or sanitary napkins.

Obtaining superabsorbents, in General, is carried out by free radical polymerization of monomers containing an acid group in the presence of crosslinking agents; polymers with various absorbent properties can be obtained by choosing the composition of the monomer, crosslinking agents and the polymerization conditions, as well as the processing conditions of the hydrogel obtained after polymerization (for details, see, for example, Mobetp Ziretkogel! Pöluteg Tsslodo. Eb УСιιοίιΐιοίζ. , 1998).

A polymer gel, also called a hydrogel, obtained after polymerization is usually crushed, dried and sorted to obtain superabsorbent in the form of particles with a clearly defined particle size distribution. In the next process step, said superabsorbent particles are often crosslinked to improve absorption characteristics. For this, the particles are mixed with an aqueous solution containing a surface crosslinking agent and optionally additional additives, and the resulting mixture is thermally treated to accelerate the crosslinking reaction.

Monomers containing an acid group can be polymerized in the presence of crosslinkers in a batch process or a continuous process. In continuous and batch polymerization, partially neutralized acrylic acid is usually used as a monomer. Suitable polymerization methods are described, for example, in EP 0 372 706 A2, EP 0 574 260 A1, AO 2003/051415 A1, EP 1 470 905 A1, AO 2007/028751 A1, AO 2007/028746 A1 and AO 2007/028747 A1.

Description

Technical problem

In accordance with the methods for producing water-absorbing polymer particles described in the prior art, a sequence of crushing devices is used to crush the polymer gel. Typically, at least one of these crushing devices known in the art comprises a non-planar cutting edge. Said non-planar cutting edge is an expensive wear part that is difficult to replace. In addition, the prior art crushing device sequence comprises at least three crushing devices for producing polymer gel particles suitable for drying. With the increase in the number of crushing devices, the cost, the number of possible sources of errors and the necessary maintenance increase.

Technical solution

In General, the object of the present invention is to at least partially overcome the disadvantage inherent in the prior art, in the context of obtaining water-absorbing polymer particles.

An additional task is to provide a method for producing water-absorbing polymer particles, in which the complex shape of the cutting edges for crushing the polymer gel is eliminated as much as possible. An additional objective of the present invention is to provide a method for producing water-absorbing polymer particles, which reduces the maintenance required for the crushing device, or the cost of the crushing device, or both. An additional task is to provide a method for producing water-absorbing polymer particles, in which large or non-planar, or large and non-planar cutting edges for crushing the polymer gel are excluded to the maximum. An additional objective of the present invention is to provide a method for producing water-absorbing polymers, in which the used crushing devices are long-term stable. An additional objective of the present invention is to provide a method for producing water-absorbing polymer particles, in which the part of the crushing device, which contains a cutting edge, is easily replaceable. Addition

A further object of the present invention is to provide a method for producing water-absorbing polymer particles, in which the polymer gel particles after crushing and before drying have a narrow particle size distribution, or the number of crushing stages is reduced, or both. An additional objective of the present invention is to provide a method for producing water-absorbing polymers, in which the polymer gel is subjected to gentle crushing. An additional objective of the present invention is to provide a method for producing water-absorbing polymer particles, where the specified method demonstrates a balanced combination: increased operating life of the crushing device, a reduced number of stages of crushing, a reduced drying time of the polymer gel. An additional task is to provide water-absorbing polymer particles obtained in a less expensive way. An additional object of the present invention is to provide a water-absorbing polymer particle or a plurality of water-absorbing polymer particles obtained by a process having at least one, preferably a balanced combination of at least two of the above advantages, where the water-absorbing gel particle shows no deterioration. An additional objective of the present invention is to provide a composite material containing a water-absorbing polymer particle obtained by a method having at least one of the above advantages, where the composite material shows no quality deterioration. An additional objective of the present invention is to provide a device for producing water-absorbing polymer particles in a manner having at least one of the above advantages.

Contribution to the solution of at least one of the above problems is represented by independent claims. The dependent paragraphs represent preferred embodiments of the present invention, which also serve to solve at least one of the above problems.

Beneficial effects

In accordance with the method for producing water-absorbing polymer particles according to the present invention, the amount of crushing device maintenance required or the cost of the crushing device, or both, is reduced. In addition, a composite material containing water-absorbing polymer particles obtained by the method according to the present invention, show no deterioration.

Description of figures

FIG. 1 is a flow chart illustrating process steps according to the present invention;

FIG. 2 is a flow chart illustrating the steps of another process according to the present invention;

FIG. 3 is a flow chart illustrating the steps of another process according to the present invention;

FIG. 4 is a diagram of a first crushing device according to the present invention; FIG. 5 is a diagram of another crushing device according to the present invention;

FIG. 6a) diagram of an additional crushing device according to the present invention, external view;

FIG. 6b) a diagram of the internal parts of the additional crushing device shown in FIG. 6a), in disassembled form; and FIG. 7 is a block diagram of a device for producing water-absorbing polymer particles according to the present invention.

Legend List

100 is a method according to the present invention;

101 - stage (1);

102 - stage (ίί);

103 - stage (ίίί);

104 - stage (ίν);

105 - stage (ν);

106 - stage (νί);

107 - stage (νίί);

108 - stage (νίίί);

109 - stage (ίχ);

110 - stage (x);

111 - stage (χί);

400 - the first crushing device;

401 - the first disk;

402 - the second disk;

403 - the third disk;

- 2 032199

404 - the first axis of rotation;

405 - additional axis of rotation;

406 - the front surface of the second disk;

407 - end surface of the second disk;

408 - the side surface of the second disk;

409 - part of a polymer gel;

410 - the distance between the first disk and the third disk;

411 - the first direction of rotation;

412 - additional direction of rotation

501 - an additional disk;

600 - additional crushing device;

601 - fixed plate with holes;

602 - auger;

603 - feeder;

604 - a rotating plate with holes;

605 - circular cutting edge;

700 - a device for producing particles of a water-absorbing polymer;

701 - the first container;

702 - an additional container;

703 - mixing device;

704 — polymerization reactor;

400 - the first crushing device;

600 - additional crushing device;

705 - belt dryer;

706 - grinding device;

707 - sorting device;

708 - process stream.

Best way to exercise

The contribution to the solution of at least one of these problems is made by a method for producing water-absorbing polymer particles, comprising the technological steps (ί) of obtaining an aqueous solution of a monomer containing at least one partially neutralized, monoethylenically unsaturated monomer containing carboxylic acid groups (α1), and at least one crosslinking agent (α3);

(ίί) optionally adding fine particles of the water-absorbing polymer to the aqueous monomer solution;

(ίίί) adding a polymerization initiator or at least one component of a polymerization initiator system, which contains two or more components, to an aqueous solution of a monomer; (ίν) optionally reducing the oxygen content in the aqueous monomer solution;

(ν) loading the aqueous monomer solution into the polymerization reactor;

(νί) polymerizing the monomers in an aqueous solution of the monomer in the polymerization reactor to obtain a polymer gel;

(νίί) discharging the polymer gel from the polymerization reactor and crushing the polymer gel in a first crushing device to obtain polymer gel particles;

(νίίί) drying the polymer gel particles;

(ίχ) grinding the dried polymer gel particles to obtain water-absorbing polymer particles;

(x) sorting by size of the crushed water-absorbing polymer particles; and (χί) optional surface treatment of crushed and sized water-absorbing polymer particles; where at the technological stage (νίί) the first crushing device comprises a first disk, a second disk and a third disk; where the first disk and the third disk rotate around the first axis of rotation;

where the second disk rotates around an additional axis of rotation; where the second disk contains as surfaces the front surface of the second disk, the end surface of the second disk and the side surface of the second disk connecting the front surface of the second disk to the end surface of the second disk; where the front surface of the second disk, and the end surface of the second disk, and the side surface of the second disk are partially located between the first disk and the third disk; where a portion of the polymer gel is located between the first disk and the third disk.

In this regard, successive stages of the process according to the present invention can be carried out simultaneously or may overlap in time, or both can occur. This applies, in particular, to stages (ί) - (ίν), especially to stages (ίίί) and (ίν).

The front surface of the second disk, and the end surface of the second disk, and the side surface

- 3 032199 of the second disk partially located between the first disk and the third disk - means that neither the front surface of the second disk, nor the end surface of the second disk, nor the side surface of the second disk are completely located between the first disk and the third disk.

The process of the present invention is preferably a continuous process in which an aqueous solution of the monomer is continuously and continuously supplied to the polymerization reactor. The resulting hydrogel is continuously discharged from the polymerization reactor and continuously crushed, dried, crushed and sorted by size in the subsequent process steps. However, this continuous process may be interrupted, for example, to replace some parts of technological equipment such as conveyor belt material, if a conveyor belt is used as a polymerization reactor, to clean some elements of the technological equipment, especially to remove polymer deposits in tanks or pipes, or to start a new process if it is necessary to obtain water-absorbing polymer particles with other absorption characteristics.

Water-absorbing polymer particles, preferred according to the present invention, are particles that have an average particle size in accordance with A8P 220.2 (test method Aogb 81a1aaaaaaaaaa ΕΌΛΝΛ and ΙΝΏΆ) in the range from 10 to 3000 μm, preferably from 20 to 2000 μm and particularly preferably from 150 to 850 microns. In this context, it is particularly preferred that the particle content of the water-absorbing polymers having a particle size in the range from 300 to 600 μm is at least 30 wt.%, Particularly preferably at least 40 wt.% And most preferably at least 50 wt. % relative to the total mass of water-absorbing polymer particles.

In process step (ί) of the process according to the present invention, an aqueous monomer solution is obtained containing at least one partially neutralized, monoethylenically unsaturated monomer having carboxylic acid groups (α1) and at least one crosslinking agent (α3).

Preferred monoethylenically unsaturated monomers having carboxylic acid groups (α1) are those indicated in ΌΕ 10223060 A1 as preferred monomers (α1), thus acrylic acid is particularly preferred.

According to the present invention, it is preferable that the water-absorbing polymer obtained by the method according to the present invention contains monomers having carboxylic acid groups in an amount of at least up to 50 wt.%, Preferably at least up to 70 wt.% And even more preferably at least up to 90 wt.% relatively dry weight. According to the present invention, it is particularly preferred that the water-absorbing polymer obtained by the method according to the present invention is obtained from at least 50 wt.%, Preferably at least 70 wt.% Acrylic acid, which is preferably neutralized to at least 20 mol.%, Especially preferably at least up to 50 mol%. The concentration of partially neutralized, monoethylenically unsaturated monomers having carboxylic acid groups (α1) in an aqueous solution of the monomer that is provided in the process step (ί) is preferably from 10 to 60 wt.%, Preferably from 30 to 55 wt.% And most preferably from 40 to 50 wt.% of the total weight of the aqueous monomer solution.

The aqueous monomer solution may also contain monoethylenically unsaturated monomers (α2), which can be copolymerized with (α1). Preferred monomers (α2) are monomers indicated in ΌΕ 102 23 060 A1 as preferred monomers (α2), thus acrylamide is particularly preferred.

Preferred crosslinking agents (α3) according to the present invention are compounds that have at least two ethylenically unsaturated groups in one molecule (a crosslinking agent of class I), compounds that have at least two functional groups that can interact with the functional groups of the monomers ( α1) or (α2) in a condensation reaction (= condensation crosslinking agents), in an addition reaction or in a ring opening reaction (class II crosslinking agent), compounds which have at least one et an Ilenically unsaturated group and at least one functional group that can interact with the functional groups of the monomers (α1) or (α2) in the condensation reaction, in the addition reaction or in the ring opening reaction (crosslinking agent of class III), or polyvalent metal cations (crosslinking agent class IV). Thus, with crosslinking agents of class I, polymer crosslinking is achieved by radical polymerization of ethylenically unsaturated groups of crosslinking agent molecules with monoethylenically unsaturated monomers (α1) or (α2), and with compounds of crosslinking agents of class II and cations of polyvalent metals of crosslinking agents of class IV crosslinking polymer , respectively, by the condensation reaction of functional groups (a crosslinking agent of class II) or by electrostatic interaction of a polyvalent metal cation (a crosslinking agent t class IV) with the functional groups of the monomer (α1) and (α2). With compounds of the class of crosslinking agents III, the crosslinking of the polymers results in, respectively, a radical

- 4,032,199 by dimerization of ethylenically unsaturated groups, as well as a condensation reaction between the functional groups of the crosslinking agents and the functional groups of the monomers (α1) or (α2).

Preferred crosslinking agents (α3) are all those compounds that are listed in ΌΕ 102 23 060 A1 as crosslinking agents (α3) of classes of crosslinkers I, II, III and IV, therefore, as compounds of the class of crosslinking agents I are particularly preferred Ν, Ν'-methylenebisacrylamide, polyethylene glycol di (meth) acrylates, triallylmethylammonium chloride, tetraallylammonium chloride and allylnoneaethylene glycol acrylate obtained from 9 moles of ethylene oxide per mole of acrylic acid, where Ν, Ν '-methylmene bis is even more preferred Crosslinking Agents IV Particularly preferred Al ₂ (80 ₄ ) ₃ and its hydrates.

Preferred water-absorbing polymers obtained by the method according to the present invention are polymers crosslinked with crosslinking agents of the following classes of crosslinking agents, or crosslinking agents of the following combinations of classes of crosslinking agents, respectively: I, II, III, IV, I II, I III, I IV, III III, I II IV, I III IV, II III IV, II IV or III IV.

Additionally preferred water-absorbing polymers obtained by the method according to the present invention are polymers crosslinked by any cross-linking agents described in ΌΕ 102 23 060 A1 as a cross-linking agent of the class of cross-linking agents I, therefore, particularly preferred as cross-linking agents of the class of cross-linking agents I Ν , Ν'methylenebisacrylamide, poly (ethylene) glycol di (meth) acrylates, triallylmethylammonium chloride, tetraallylammonium chloride and allylnonaethylene glycol acrylate obtained from 9 mol of ethylene oxide and a mole of acrylic acid, where Ν, Ν 'methylenebisacrylamide is even more preferred.

The aqueous monomer solution may further comprise water soluble polymers (α4). Preferred water-soluble polymers (α4) include partially or fully saponified polyvinyl alcohol, polyvinyl pyrrolidone, starch or starch derivatives, polyglycols or polyacrylic acid. The molecular weight of these polymers is not critical, provided that they are water soluble. Preferred water-soluble polymers (α4) are starch or starch derivatives, or polyvinyl alcohol. Water-soluble polymers (α4), preferably synthetic, such as polyvinyl alcohol, can not only serve as a basis for grafting polymerizable monomers. It is understood that these water-soluble polymers can also be mixed with a polymer gel or with an already dried water-absorbing polymer.

The aqueous monomer solution may additionally contain auxiliary substances (α5), and these auxiliary substances include, in particular, complexing agents, such as, for example, EDTA.

The relative amount of monomers (α1) and (α2), and crosslinking agents (α3), and water-soluble polymers (α4), and auxiliary substances (α5) in the aqueous solution of the monomer is preferably chosen so that the structure of the water-absorbing polymer obtained after drying the crushed polymer gel based on 20-99.999 wt.%, preferably 55-98.99 wt.% and particularly preferably 70-98.79 wt.% on monomers (α1), 0-80 wt.%, preferably 0-44 , 99 wt.% And particularly preferably 0.1-44.89 wt.% On monomers (α2), 0-5 wt.%, Preferably 0.001-3 wt.% And especially particularly preferably 0.01 to 2.5 wt.% on crosslinking agents (α3), 0-30 wt.%, preferably 0-5 wt.% and particularly preferably 0.1-5 wt.% on water soluble polymers (α4), 0-20 wt.%, preferably 0-10 wt.% and particularly preferably 0.1-8 wt.% on excipients (α5), and 0.5-25 wt.% , preferably 1-10 wt.% and particularly preferably 3-7 wt.% in water (ab), the sum of the amounts by weight (a1) to (a6) is 100 wt.%.

The optimal concentration values, in particular, of monomers, crosslinking agents and water-soluble polymers, in the monomer solution can be determined by simple preliminary experiments or based on the prior art, in particular from publications I8 4286082, ΌΕ 2706135 A1, I8 4076663, ΌΕ 3503458 A1, ΌΕ 4020780 C1, ΌΕ 4244548 A1, ΌΕ 4333056 A1 and ΌΕ 4418818 A1.

In the process step (ίί), small particles of a water-absorbing polymer may optionally be added to the aqueous monomer solution. Regardless of the optional step (ίί), fine particles of the water-absorbing polymer can be added to the aqueous monomer solution at any stage selected from the group consisting of: after step (w), after step (ίν), and before step (ν), or combinations of at least two of them.

The water-absorbing fine particles are preferably water-absorbing polymer particles, the composition of which corresponds to the composition of the water-absorbing polymer particles described above, while it is preferable that at least 90 wt.% Water-absorbing fine particles, preferably at least 95 wt.% Water-absorbing fine particles, and most preferably at least 99 wt.% of the water-absorbing fine particles have a particle size of less than 200 microns, preferably less than 150 microns and particularly preferably less than 100 microns.

In a preferred embodiment of the process of the present invention, water-absorbing fine particles that may optionally be added to the aqueous monomer solution

- 5,032,199 in the process step (s), are water-absorbing fine particles that are obtained in the process step (x) of the method according to the present invention and which are thus recycled.

These fine particles can be added to the aqueous solution of the monomer using any mixing device known to specialists in this field of technology as suitable for the specified purpose. In a preferred embodiment of the present invention, which is particularly suitable if the process is carried out continuously, as described above, the fine particles are added to the aqueous solution of the monomer in a mixing device in which the first stream of small particles and the second stream of the aqueous monomer solution are directed continuously, but from different positions into a rotary mixing device. This type of mixing plant can be implemented in a so-called “rotor-stator mixer”, which preferably contains a cylindrical, non-rotating stator in the mixing zone, in the center of which is also preferably rotated a cylindrical rotor. The walls of the rotor, as well as the walls of the stator, are usually provided with notches, for example, notches in the form of slots through which a mixture of small particles and an aqueous solution of monomer can be sucked and, therefore, subjected to high shear forces.

In this context, it is particularly preferred that the first stream of fine particles and the second stream of an aqueous monomer solution form an angle of 5 in the range of 60 to 120 °, more preferably in the range of 75 to 105 °, even more preferably in the range of 85 to 95 ° and most preferably form an angle of about 90 °. It is also preferable that the stream of a mixture of small particles and an aqueous solution of monomer exiting the mixer and the first stream of small particles entering the mixer form an angle of 8 in the range of 60 to 120 °, preferably in the range of 75 to 105 °, even more preferably in the range of 85 to 95 ° and most preferably form an angle of about 90 °.

This type of mixing plant can, for example, be implemented using the mixing devices described in ΌΕ-Α-2520788 and ΌΕ-Ά-2617612, the contents of which are incorporated herein by reference. Specific examples of mixing devices that can be used to add fine particles to the aqueous monomer solution in the process step (s) of the present invention are mixing devices that can be purchased from PSA® Husgs StH & Co. KS, Staufen, Germany, under the trade names ΜΗΌ 2000/4, ΜΗΌ 2000/05, ΜΗΌ 2000/10, ΜΌΗ 2000/20, ΜΗΌ 2000/30 and ΜΗΌ 2000/50, where the устройство 2000/20 mixing device is particularly preferred. Additional mixing devices that can be used are those manufactured by Υδίπιΐ STI Balrechten-Dottingen, Germany, for example, under the trade name Soiy ΤΌ8, or Ktetayka AC, Littau, Switzerland, for example, under the brand name Μο ^ αίΓοη®.

The amount of fine particles that can be added to the aqueous monomer solution in the process step (s) is preferably from 0.1 to 15 wt.%, Even more preferably from 0.5 to 10 wt.% And most preferably from 3 to 8 wt.% relative to the mass of an aqueous solution of monomer.

In the process step (w) of the method according to the present invention, a polymerization initiator or at least one component of the polymerization initiator system, which contains two or more components, is added to the aqueous monomer solution.

As initiators of polymerization to initiate polymerization, all initiators that form radicals under polymerization conditions, which are usually used in the preparation of superabsorbents, can be used. These include thermal catalysts, redox catalysts and photoinitiators, the activation of which occurs during energy exposure. Polymerization initiators may be dissolved or dispersed in an aqueous monomer solution. The use of water soluble catalysts is preferred.

As thermal initiators, all compounds known to those skilled in the art that decompose under elevated temperatures to form radicals can be used. Thermal polymerization initiators with a half-life of less than 10 s, more preferably less than 5 s at a temperature of less than 180 ° C, more preferably less than 140 ° C are particularly preferred. Particularly preferred thermal polymerization initiators are peroxides, hydroperoxides, hydrogen peroxide, persulfates and azo compounds. In some cases, it is preferable to use mixtures of various thermal polymerization initiators. Among such mixtures, mixtures containing hydrogen peroxide and sodium or potassium peroxodisulfate, which can be used in any desired proportion, are preferred. Suitable organic peroxides are preferably the peroxide is acetylacetone peroxide, methylethylketone peroxide, benzoyl peroxide, lauroyl peroxide, acetyl peroxide, Capra, isopropyl peroxydicarbonate, 2-ethylhexylperoxydicarbonate, tert-butyl hydroperoxide, cumene hydroperoxide, and peroxides, tert-amilperpivalata, tert-butilperpivalata, tert-butilperneogeksonata, tert-butyl isobutyrate, tert-butylper-2-ethylhexenoate, tert-butylperisononanoate, tert-butylpermaleate, tert-butylperbenzoate, tert-butyl-3,5,5-trimethyl Sanoat and amilperneodekanoata. Also pre

- 6,032,199 the following polymerization thermal initiators are respectful: azo compounds such as azo-bisisobutyronitrile, azo-bis-dimethylvaleronitrile, azo-bis-amidinopropane dihydrochloride, 2,2'-azobis (No. dimethylene) isobutyramidine dihydrochloride-2-carbamide and 4,4'-azobis- (4-cyanovaleric acid). The above compounds are used in conventional amounts, preferably in the range from 0.01 to 5 mol%, preferably from 0.1 to 2 mol%, respectively, with respect to the amount of monomers to be polymerized.

Redox catalysts contain two or more components, usually one or more of the peroxo compounds listed above, and at least one reducing component, preferably ascorbic acid, glucose, sorbose, mannose, hydrosulfite, sulfate, thiosulfate, hyposulfite or ammonium or alkali metal sulfide metal salts such as iron (II) ions or silver ions, or sodium hydroxymethyl sulfoxylate. Preferably, ascorbic acid or sodium pyrosulfite is used as the reducing component of the redox catalyst. Use from 1x10 ^-5 to 1 mol.% The reducing component of the redox catalyst and from 1x10 ^-5 to 5 mol.% The oxidizing component of the redox catalyst, in each case, relative to the amount of monomers used in the polymerization. Instead of the oxidizing component of the redox catalyst or as a complement thereof, one or more preferably water-soluble azo compounds can be used.

The polymerization is preferably initiated by the action of energy radiation, the so-called photoinitiators are usually used as an initiator. They may include, for example, the so-called α-splitters, H-subtracting systems or also azides. Examples of such initiators are benzophenone derivatives, such as Michler's ketone, phenanthrene derivatives, fluorine derivatives, anthraquinone derivatives, thioxantone derivatives, coumarin derivatives and benzoic ether derivatives thereof, azo compounds, such as the aforementioned radical-forming compounds, substituted hexaarylbisimidazoles or acyl. Examples of azides are: 2- (K, I-dimethylamino) ethyl-4-azidocinnamate, 2- (I, M-dimethylamino) ethyl-4-azidonaphthyl ketone, 2- (I, M-dimethylamino) ethyl 4-azidobenzoate, 5-azido-1-naphthyl-2 '- (M, I-dimethylamino) ethylsulfone, N- (4sulfonylazidophenyl) maleimide, No.acetyl-4-sulfonylazidoaniline, 4-sulfonylazidoaniline, 4azidoaniline, 4-azidophenobenzoicobromobenzoic acid 6-bis (p-azidobenzylidene) cyclohexanone; and 2,6-bis (p-azidobenzylidene) -4-methylcyclohexanone. An additional group of photoinitiators are dialkoxy ketals, such as 2,2-dimethoxy-1,2-diphenylethan-1-one. Photoinitiators, when used, are usually used in an amount of from 0.0001 to 5 wt.% Relative to the polymerizable monomers.

According to a further embodiment of the method according to the present invention, it is preferable that in the process step (ίίί) the initiator contains the following components: peroxodisulfate; and sh. an organic initiator molecule containing at least three oxygen atoms or at least three nitrogen atoms;

where the specified initiator contains peroxodisulfate and the molecule of the organic initiator in a molar ratio of from 20: 1 to 50: 1. In one aspect of this embodiment, it is preferred that the concentration of the sha initiator component is from 0.05 to 2% by weight relative to the amount of polymerizable monomers. In another aspect of this embodiment, it is preferred that the organic initiator molecule is selected from the group consisting of 2,2-dimethoxy-1,2-diphenylethan-1one, 2,2-azobis- (2-amidinopropane) dichloride, 2,2-azobis - (cyanovaleric acid) or a combination of at least two of them. In a further aspect of this embodiment it is preferable that peroxodisulfate has the general formula M _{2 2} 0 § _8, wherein M is selected from the group consisting of ΝΗ _4, L1, Να, Ca or at least two of them. The components described above are particularly suitable for UV polymerization initiation in step (νί) of the process of the present invention. The use of this composition additionally leads to a low amount of residual monomer and to a decrease in the yellowing of the water-absorbing polymer particle, which can be obtained by the method according to the present invention.

In this context, it should also be noted that stage (ίίί), the addition of a polymerization initiator, can be implemented before stage (ίν), simultaneously with stage (ίν), or overlap in time with stage (ίν), i.e. with a decrease in the oxygen content in the aqueous monomer solution. When using a polymerization initiator system that contains two or more components, one or more components of such a polymerization initiator system can, for example, be added before the process step (ίν), while the rest of the component or other components that are necessary to complete the activity of the initiator system polymerization, add after the technological stage (ίν), possibly even after the technological stage (ν). Regardless of the optional step (ίν), a decrease in the oxygen content in the aqueous monomer solution can also be carried out prior to the process step (ίίί) in accordance with the present invention.

In the process step (ίν) of the method according to the present invention in an aqueous solution of mo

- 7,032,199 numbers do not necessarily reduce oxygen. Regardless of the optional step (ίν), a decrease in the oxygen content in the aqueous monomer solution can also be carried out before, during or after the process step (ίί) in accordance with the present invention. Preferably, the oxygen content in the aqueous monomer solution is reduced after the addition of fine particles in the process step (ίί).

Whenever a decrease in the oxygen content in an aqueous monomer solution occurs, it can be realized by contacting the aqueous monomer solution with an inert gas such as nitrogen. The inert gas phase brought into contact with the aqueous solution of the monomer does not contain oxygen and, therefore, is characterized by a very low partial pressure of oxygen. Consequently, oxygen passes from the aqueous solution of the monomer to the inert gas phase until the partial pressure of oxygen in the inert gas phase and the aqueous solution of the monomer equalize. Bringing into contact the phases of the aqueous monomer solution with the inert gas phase can be carried out, for example, by passing inert gas bubbles through the monomer solution in the form of a direct flow, counterflow, or at an intermediate feed angle. Good mixing can be achieved, for example, using nozzles, static or dynamic mixers, or bubble columns. The oxygen content in the monomer solution prior to polymerization is preferably reduced to less than 1 ppm by weight, more preferably to less than 0.5 ppm by weight relative to the weight of the monomer solution.

In the process step (ν) of the method according to the present invention, the aqueous monomer solution is loaded into the polymerization reactor, preferably on the conveyor belt, particularly preferably in the forward position of the conveyor belt, and in the process step (νί), the monomers in the aqueous monomer solution are polymerized in the polymerization reactor with obtaining a polymer gel. When polymerization is carried out on a conveyor belt as a polymerization reactor, a sheet of polymer gel is obtained in the back part of the conveyor belt, which is crushed before drying to obtain polymer gel particles.

As the polymerization reactor, any reactor that is considered to be suitable by those skilled in the art for the continuous or batch polymerization of monomers such as acrylic acid in an aqueous solution can be used. An example of a suitable polymerization reactor is a kneading reactor. In a kneading machine, a polymer gel formed by the polymerization of an aqueous solution of a monomer can be subjected to continuous crushing, for example, by means of mixer shafts rotating in opposite directions, as described in AO 2001/38402. Such crushing in the polymerization reactor can be carried out before crushing in the first crushing device.

Another example of a preferred polymerization reactor is a conveyor belt. As a conveyor belt suitable for the method according to the present invention, any conveyor belt that is considered suitable by those skilled in the art as a supporting material onto which an aqueous solution of the monomer described above can be loaded and then polymerized to form a hydrogel can be used.

The conveyor belt usually contains an infinitely moving conveyor belt passing over the supporting elements, and at least two guide rollers, of which at least one has a drive and is adjustable. Optionally, a system for unwinding and feeding a release sheet that can be used in sections on the upper surface of the conveyor belt is provided. The specified system contains a system for feeding and dispensing reaction components, as well as optional radiation means, located in the direction of movement of the conveyor belt after the system for feeding and dispensing, together with cooling and heating devices, as well as a system for removing the polymer gel strand located near the guide roller of the return branch of the conveyor tapes. In order to ensure complete polymerization with the maximum possible product yield in one pass per unit time, in accordance with the present invention, upwardly supporting elements, longitudinal axes, are located near the upper branch of the conveyor belt on both sides of the horizontal support elements, starting in the feed zone and dosing systems which intersect at a point under the upper branch, and which give the conveyor belt supported by them, the shape of a suitable gutter. Thus, in accordance with the present invention, a conveyor belt in the vicinity of the reaction component supply system is supported by a plurality of support and support elements in the form of a gutter that provide the configuration of the fed reaction components in the form of a deep gutter or plate. The desired shape of the gutter is determined by the shape and location of the support elements along the entire path length of the upper branch. In the area of introduction of the reaction components, the support elements should be relatively close to each other, and in the next region, after the polymerization is initiated, the support elements can be located at a slightly greater distance from each other. The angle of inclination of the support elements and the cross-sectional shape of the support elements can be variable for leveling the initially deep trough as it moves toward the end of the polymerization part and restores it to a stretched state. In a further embodiment of the present invention, each support element is preferably formed by a cylindrical or spherical roller capable of rotating from

- 8 032199 relative to its longitudinal axis. By changing the cross section of the roller, as well as the configuration of the roller, it is possible to easily achieve the desired cross-sectional shape of the groove. To ensure proper molding of the gutter from the conveyor belt, when it transitions from a flat state to the shape of the gutter and when it returns back to a flat state, it is preferable to use a conveyor belt that is flexible in the longitudinal and transverse directions.

The tape can be made of various materials, although they should preferably meet the requirements of good tensile strength and flexibility, good fatigue strength with multiple bending stresses, good deformability and chemical resistance to individual components of the reaction under polymerization conditions. One material usually does not meet the specified requirements. Therefore, a multilayer material is usually used as the tape according to the present invention. Mechanical requirements can be met with a framework, for example, woven inserts of natural and / or synthetic fibers, or glass fibers, or steel cord. Chemical resistance can be achieved by coating, for example, from polyethylene, polypropylene, polyisobutylene, halogenated polyolefins such as polyvinyl chloride or polytetrafluoroethylene, polyamides, natural or synthetic rubbers, polyester resins or epoxy resins. A preferred coating material is silicone rubber.

In the process step (νίί) of the method according to the present invention, the polymer gel obtained in the polymerization reactor is crushed to obtain polymer gel particles. Preferred polymer gel particles are particles selected from the group consisting of strands of polymer gel, flakes of polymer gel and lumps of polymer gel, or a combination of at least two of them. Before crushing in the first crushing device according to the present invention can be carried out crushing in a polymerization reactor, such as a kneading reactor. The first crushing device is preferably a separate device that is not identical to the polymerization reactor. Therefore, the polymer gel can be crushed before discharge from the polymerization reactor. The crushing of the polymer gel in the first crusher is carried out after the polymer gel is discharged from the polymerisation reactor. If the polymerization reactor is a conveyor belt, the polymer gel, which is preferably a polymer gel sheet, is discharged from the conveyor belt in the form of a continuous sheet, which has a soft, semi-solid consistency, and then sent for further processing, such as crushing.

Crushing the strand of the polymer gel is preferably carried out in at least two stages:

in the first crushing step, the polymer gel is crushed using a plurality of rotating disks, preferably rotating gears, in a first crushing device. Thus, a plurality of strands of polymer gel are obtained;

in the second stage, a spinning top is used, preferably of a cutter type, preferably having a screw and a hole plate, where the screw that pushes the product through the hole plate is used as an additional crushing device for grinding and grinding polymer gel strands into polymer gel particles which are preferably less than strands of polymer gel. In this process, the holes of the plate with the holes preferably comprise flat cutting edges.

Thereby, an optimal ratio of surface area to volume is achieved, which has a beneficial effect on the drying characteristics at the technological stage (νίίί). The polymer gel, preferably a sheet of polymer gel crushed in this way, is particularly suitable for drying on a tape. Two-stage crushing provides better air access due to air channels located between the granulate particles.

In the process step (νίίί) of the method according to the present invention, the polymer gel particles are dried.

The drying of the polymer gel particles can be carried out in any dryer or oven that those skilled in the art consider suitable for drying the polymer gel particles described above. Examples include rotary tube furnaces, fluidized bed dryers, plate dryers, paddle dryers, and infrared dryers.

Belt dryers are particularly preferred. The belt dryer is a convection drying system for especially gentle processing of products with free access of air. The product to be dried is placed on an endless conveyor belt that passes gas and is treated with a stream of heated gas, preferably air. The drying gas is recycled so that it can become very highly saturated during repeated passes through the product bed. A certain portion of the drying gas, preferably at least 10%, more preferably at least 15% and most preferably at least 20% and preferably up to 50%, more preferably up to 40% and most preferably up to 30% of the amount of gas per passage, is discharged from the dryer into as a highly saturated steam, carrying away a certain amount of water evaporated from the product. The temperature of the heated gas stream is preferably at least 50 ° C, more preferably

- 9 032199 at least 100 ° C and most preferably at least 150 ° C and preferably up to 250 ° C, more preferably up to 220 ° C and most preferably up to 200 ° C.

The size and design of dryers depends on the processed product, production capacity and loading during drying. A belt dryer can be implemented as a system with one tape, several tapes, a multi-stage or multi-tiered system. The present invention is preferably carried out using a belt dryer having at least one belt. Single belt dryers are particularly preferred. To ensure optimal drying characteristics on the tape, the drying properties of water-absorbing polymers are separately determined as a function of the selected technological parameters. For a specific product, the size of the holes and the size of the cells of the tape are selected. Some surface optimization options are also possible, such as electrolytic polishing or Teflon coating.

The particles of the polymer gel to be dried are preferably applied to the belt dryer tape using a rotary tape. Feed height i.e. the vertical distance between the rotary tape and the tape of the belt dryer is preferably at least 10 cm, more preferably at least 20 cm and most preferably at least 30 cm and preferably up to 200 cm, more preferably up to 120 cm and most preferably up to 40 cm. Layer thickness the polymer gel particles to be dried on a belt dryer are preferably at least 2 cm, more preferably at least 5 cm and most preferably at least 8 cm and preferably not more than 20 cm, more preferably not more than 15 cm and most preferably not more than 12 cm. The belt dryer belt speed is preferably not less than 0.005 m / s, more preferably not less than 0.01 m / s and most preferably not less than 0.015 m / s and preferably up to 0.05 m / s, more preferably up to 0.03 m / s and most preferably up to 0.025 m / s.

In addition, in accordance with the present invention, the gel is preferably dried to a water content in the range from 0.5 to 25 wt.%, Preferably from 1 to 10 wt.% And particularly preferably from 3 to 7 wt. % relative to the particles of the dried polymer gel.

In the process step (ίχ) of the method according to the present invention, the dried polymer gel particles are ground to obtain water-absorbing polymer particles.

For grinding particles of dried polymer gel particles, any device that is considered appropriate by those skilled in the art for grinding particles of the dried polymer gel particles described above can be used. As an example of a suitable grinding device, a single-stage or multi-stage roller mill, preferably a two- or three-stage roller mill, a pin mill, a hammer mill or a vibratory mill can be mentioned.

In the process step (x) of the method according to the present invention, the crushed particles of the water-absorbing polymer are sorted, mainly using suitable sieves. In this context, it is particularly preferred that after sorting the particles of the water-absorbing polymer, the content of polymer particles having a particle size of less than 150 μm is less than 10 wt.%, Preferably less than 8 wt.% And, in particular, less than 6 wt.%, And that the content polymer particles having a particle size of more than 850 μm are also less than 10 wt.%, preferably less than 8 wt.% and particularly preferably less than 6 wt.%, each value expressed in relation to the total particle weight of the water-absorbing polymer. It is also preferable that after sorting the particles of the water-absorbing polymer, at least 30 wt.%, More preferably at least 40 wt.% And most preferably at least 50 wt.% Of the particles of the water-absorbing polymer have a particle size of from 300 to 600 μm.

In the process step (χί) of the method according to the present invention, the surface of the crushed and sorted particles of the water-absorbing polymer is optionally treated. As a means for treating the surface of the particles of a water-absorbing polymer, any agent that is considered appropriate by those skilled in the art can be used. Examples of surface treatment include, for example, surface crosslinking, surface treatment with water-soluble salts such as aluminum sulfate or aluminum lactate, surface treatment with inorganic particles such as silicon dioxide, and the like. Preferably, the components used to treat the surface of the polymer particles (crosslinking agents, water-soluble salts) are added to the particles of the water-absorbing polymer in the form of aqueous solutions. After mixing the particles with said aqueous solutions, they are heated to a temperature of from 150 to 230 ° C., preferably from 160 to 200 ° C., to accelerate the surface crosslinking reaction.

In one embodiment, the implementation of the present invention from 5 to 30%, preferably from 5 to 20%, more preferably from 5 to 15%, most preferably from 8 to 12% of the front surface of the second disk or the end surface of the second disk, or preferably both, located between the first disk and the third disk.

In one embodiment of the present invention, in the step (νίί) of the method according to the present invention, the first axis of rotation and the additional axis of rotation form an angle from 0 to 45 °,

- 10 032199 preferably from 0 to 40 °, more preferably from 0 to 35 °, more preferably from 0 to 30 °, more preferably from 0 to 25 °, more preferably from 0 to 20 °, more preferably from 0 to 15 °, more preferably 0 to 10 °, even more preferably 0 to 5 °. Most preferably, the first axis of rotation and the additional axis of rotation are parallel.

In one embodiment of the present invention, the first disk and the third disk rotate in a first rotation direction, wherein the second disk rotates in an additional rotation direction, wherein the first rotation direction is different from the additional rotation direction. Preferably, the first direction of rotation is opposite to the additional direction of rotation. When looking in the direction in which the polymer gel is fed into the first crushing device, the first disk and the third disk rotate in the direction of the second disk. Preferably, the first disk rotates at the same tangential speed as the third disk. Preferably, the second disk rotates at a tangential speed that is different by at least 3%, preferably at least 5%, more preferably at least 10% of the tangential speed at which the first disk or the next disk rotates, or both disks. Preferably, the first disk and the second disk, and more preferably also the third disk, have the same circumference.

In one embodiment of the present invention, the first crushing device further comprises a plurality of additional disks, where each additional disk rotates either around a first axis of rotation or around an additional axis of rotation, while a disk is partially located between adjacent disks that rotate around the first axis of rotation, which rotates around an additional axis of rotation, while between adjacent disks that rotate around an additional axis of rotation, a disk is partially located, which spins around the first rotation axis. In this context, the term “disk” may refer to a first disk, a second disk, a third disk, or one of additional disks. Preferably, each additional disk rotating around a first axis of rotation rotates in a first direction of rotation. Preferably, each additional disk rotating around an additional axis of rotation rotates in an additional direction of rotation. Preferably, each additional disk rotating around a first axis of rotation rotates at a tangential speed with which the first disk rotates. Preferably, each additional disk rotating around an additional axis of rotation rotates at a tangential speed with which the second disk rotates. Preferably, each additional disk rotating around the first axis of rotation has the same circumference as the first disk, or the third disk, or both disks. Preferably, each additional disk rotating around an additional axis of rotation has the same circumference as the second disk. Preferably, the disks rotating around the first axis of rotation rotate towards the disks rotating around the additional axis of rotation, and vice versa.

In one embodiment of the present invention, at least one disk selected from the group consisting of a first disk, a second disk, a third disk, and additional disks, or a combination of at least two of them is a gear. Preferably, the first disk, the second disk, the third disk and each additional disk are gears.

In one embodiment of the present invention, the first disk and the third disk are spaced from each other by a distance of 10 to 90 mm, preferably 15 to 80 mm, more preferably 20 to 70 mm, more preferably 25 to 50 mm, most preferably 30 to 50 mm. Preferably, every two adjacent discs that rotate around one axis of rotation are spaced from each other by a distance of 10 to 90 mm, preferably 15 to 80 mm, more preferably 20 to 70 mm, more preferably 25 to 50 mm, most preferably 30 to 50 mm.

In one embodiment of the present invention, the first crushing device provides for crushing the polymer gel in step (νίί) into at least two, preferably at least three, more preferably at least four, more preferably at least five, more preferably at least 7, more preferably at least 7, more preferably at least 8, more preferably at least 9, most preferably at least 10 strands of polymer gel. A preferred strand of polymer gel has a width of 10 to 90 mm, preferably 15 to 80 mm, more preferably 20 to 70 mm, more preferably 25 to 50 mm, most preferably 30 to 50 mm. In this context, the width of the polymer gel strand is the length over which the polymer gel strand extends in a direction perpendicular to the length of the polymer gel strand. The preferred width of the polymer gel strand is perpendicular to the length of the polymer gel strand and the direction along which the polymer gel strand extends to a length that is the thickness of the polymer gel layer from which the polymer gel strand is obtained.

In one embodiment of the present invention, the first crushing device does not contain a knife. The knife is a cutting device that contains a cutting edge. A preferred cutting edge is a blade.

- 11 032199

In one embodiment of the present invention, in step (νίί) of the method according to the present invention, after crushing the polymer gel using the first crushing device, the particles of the polymer gel are further crushed using an additional crushing device. A preferred additional crushing device is a cutter, such as a meat grinder.

In one embodiment of the present invention, the additional crushing device comprises a knife comprising at least one flat cutting edge, preferably at least 2 flat cutting edges, more preferably at least 3 flat cutting edges, more preferably at least 4 flat cutting edges most preferably at least flat cutting edges. A preferred flat cutting edge is round. Another preferred cutting edge is the edge of the hole. A preferred hole is an opening of a rotary cutter plate with holes.

In one embodiment of the present invention, the additional crushing device comprises a knife that does not contain a non-planar cutting edge.

In one embodiment of the present invention, in the process step (νίί), an adhesive agent is added to the first crushing device or to the additional crushing device, or both devices. A preferred tackifier is a liquid, preferably an emulsion. Preferably, the tackifier is added by spraying or drip feeding, or both are used.

In one embodiment of the present invention, the tackifier is selected from the group consisting of a solvent, polyalkylsiloxane and a surfactant, or a combination of at least two of them. A preferred solvent is water. A preferred polyalkylsiloxane is polydimethylsiloxane.

In one embodiment of the present invention, the surfactant is a compound according to the general formula K - (- O — CH ₂ —CH ₂ -) p-OX, where K is selected from C ₄ C ₂₀ , p is an integer from 10 to 10000, preferably from 50 to 5000, more preferably from 100 to 500, and X represents H or M, where M represents a metal ion. A particularly preferred compound according to the general formula is polyethylene glycol trimethylnonyl ether.

In one embodiment of the present invention, the tackifying agent comprises

a) a solvent in an amount of from 95 to 99 wt.%, preferably from 95.5 to 98.5 wt.%, more preferably from 96.5 to 97.5 wt.%,

b) polyalkylsiloxane in an amount of from 0.5 to 5 wt.%, preferably from 1 to 4 wt.%, more preferably from 2.4 to 3.2 wt.%, and

c) a surfactant in an amount of from 0.01 to 1 wt.%, preferably from 0.05 to 0.7 wt.%, more preferably from 0.1 to 0.3 wt.%, each value relative to the total weight tackifying agent and the amount of wt.% in the amount give 100 wt.%.

In one embodiment of the present invention, the polymer gel discharged in the process step (νίί) contains water in an amount of 40-60 wt.%, Preferably 50-60 wt.%, More preferably 53-56 wt.% Relative to the polymer gel.

In one embodiment of the present invention, the polymer gel discharged in the process step (νίί) is a sheet of polymer gel; where the specified sheet of polymer gel is characterized by a thickness in the range from 10 to 200 mm, preferably from 10 to 100 mm, more preferably from 15 to 75 mm, most preferably from 15 to 50 mm

In one embodiment of the present invention, the polymer gel discharged in the process step (νίί) is a sheet of polymer gel; where the specified sheet of polymer gel is characterized by a width in the range from 30 to 300 cm, preferably from 50 to 250 cm, more preferably from 60 to 200 cm, most preferably from 80 to 100 cm

In one embodiment of the present invention, the polymerization in step (νί) is carried out in the presence of a blowing agent. The blowing agent can be added to the aqueous monomer solution in one of the steps selected from the group consisting of step (ί), step (ίί), step (ίίί), step (ίν), step (ν), and step (ίν), or in a combination of at least two of them. Preferably, the blowing agent is added to the monomer solution in step (ί). The blowing agent must be added before or immediately after the initiation of the polymerization in step (νί). Particularly preferably, a blowing agent is added to the monomer solution after or simultaneously with the addition of an initiator or component of an initiator system. Preferably, the blowing agent is added to the monomer solution in an amount of from 500 to 4000 ppm by weight, preferably from 1000 to 3500 ppm by weight, more preferably from 1500 to 3200 ppm by weight, most preferably from 2000 to 3000 ppm by weight of the total solution monomer.

Foaming agent is a substance capable of forming a cellular structure

- 12 032199 or pores, or both, by foaming during the polymerization of monomers. The foaming process is preferably endothermic. A preferred endothermic foaming process is initiated by the heat generated in the exothermic polymerization or crosslinking reaction, or both. A preferred blowing agent is a physical blowing agent, or a chemical blowing agent, or both. A preferred physical blowing agent is one selected from the group consisting of CEC, HCEC, hydrocarbon and CO ₂ , or a combination of at least two of them. Preferred CO ₂ is liquid CO ₂ . A preferred hydrocarbon is a hydrocarbon selected from the group consisting of pentane, isopentane and cyclopentane, or a combination of at least two of them. A preferred chemical blowing agent is one selected from the group consisting of a carbonate blowing agent, nitrite, peroxide, soda ash, an oxalic acid derivative, aromatic azo compound, hydrazine, azide, Ν, д'-dinitrozoamide and an organic blowing agent, or a combination of at least two of them.

A particularly preferred blowing agent is a carbonate blowing agent. Carbonate blowing agents that can be used in accordance with the present invention are described in I8 5118719A, incorporated herein by reference. A preferred carbonate blowing agent is a carbonate-containing salt or a bicarbonate-containing salt, or both. Another preferred carbonate blowing agent contains an agent selected from the group consisting of CO ₂ as a gas, CO ₂ as a solid, ethylene carbonate, sodium carbonate, potassium carbonate, ammonium carbonate, magnesium carbonate or magnesium hydroxycarbonate, calcium carbonate, barium carbonate, bicarbonate, their hydrates, other cations and natural carbonates, or a combination of at least two of them. A preferred natural carbonate is dolomite. The above carbonate blowing agents, dissolved or dispersed in a monomer solution, release CO2 when heated. A particularly preferred carbonate blowing agent is MdCO ₃ , which can also be represented by the formula (MdCO ₃ ) ₄ -Md (OH) ₂ -5H ₂ O. Another preferred carbonate blowing agent is (NH ₄ ) ₂ CO ₃ . Can also be used MdCO ₃ and (ΝΗ · ι) ₂ в.Ό ₃ in mixtures. Preferred carbonate blowing agents are carbonate salts of polyvalent cations, such as MD, Ca, Ζη, and the like. Examples of such carbonate blowing agents are NCO ₃ , K ₂ CO ₃ , AN ₄ ) ₂ CO ₃ . MdCO ₃ , CaCO ₃ , No. ₁ HCO ₃ , KHCO ₃ , ΝΠ ^ ΗίΌ ,. Md (HCO ₃ ) ₂ , Ca (HCO ₃ ) ₂ , Ζηί.Ό ₃ and BaCO ₃ . Although some polyvalent transition metal cations can be used, some of them, such as the iron (III) cation, can cause staining and can undergo oxidation-reduction reactions or hydrolytic equilibrium in water. This can lead to difficulty controlling the quality of the finished polymer product. In addition, other polyvalent cations, such as N1, Ba, C6, Nd, may be unacceptable due to a potentially toxic or skin-sensitizing effect.

A preferred nitrite is ammonium nitrite. A preferred peroxide is hydrogen peroxide. A preferred aromatic azo compound is a compound selected from the group consisting of triazene, arylazosulfones, arylazotriarylmethanes, hydrazo compounds, diazoester and diazoaminobenzene, or a combination of at least two of them. A preferred hydrazine is phenylhydrazine. A preferred azide is carbonyl azide or sulfonyl azide, or both. Preferred Ν, Ν'dinitrozoamide is HA-dimethyl-NI-dinitrosoterephthalamide.

A contribution to the solution of at least one of the above problems is provided by means of a device for producing water-absorbing polymer particles in a process stream containing

a) a first container configured to receive an aqueous solution of a monomer containing at least partially neutralized, monoethylenically unsaturated monomers containing carboxylic acid groups (α1);

b) an additional container configured to receive at least one crosslinking agent (α3);

c) a mixing device, where the mixing device

ί) is located after the first container and the additional container; ίί) is configured to mix the monomer solution and at least one crosslinking agent (α3);

6) a polymerization reactor, where the polymerization reactor

ί) is located after the first container and the additional container, ίί) is configured to receive an aqueous solution of monomer and at least one crosslinking agent (α3) during the polymerization of monomers in an aqueous solution of monomer, with the formation of a polymer gel;

e) the first crushing device, where the first crushing device

- 13 032199

ί) is located after the polymerization reactor, ίί) contains the first disk, the second disk and the third disk, where the first disk and the third disk rotate around the first axis of rotation, where the second disk rotates around the additional axis of rotation, where the second disk contains the front surface of the second the disk, the end surface of the second disk and the side surface of the second disk connecting the front surface of the second disk to the end surface of the second disk, where the front surface of the second disk and the end surface of the second ka, and the side surface of the second disc part arranged between the first disc and the third disc;

ί) an additional crushing device, where an additional crushing device

ί) is located after the first crushing device; ίί) contains a knife containing a flat cutting edge;

e) a tape dryer, where a tape dryer

ί) is located after the additional crushing device, ίί) is configured to dry the crushed polymer gel,

11) a grinding device, where the grinding device

ί) is located after the belt dryer; ίί) is configured to grind the dried polymer gel to obtain water-absorbing polymer particles;

_)) sorting device, where the sorting device

ί) is located after the grinding device; ίί) is arranged to sort the crushed particles of the water-absorbing polymer.

In this process, the mixing device may be identical to the polymerization reactor. In addition, crushing may be carried out in the polymerization reactor, other than crushing in the first crushing device or crushing in an additional crushing device, or in both devices. A preferred first crushing device is a first crushing device in accordance with the method according to the present invention. A preferred additional crushing device is an additional crushing device in accordance with the method according to the present invention. Preferred components or devices, or both, of the equipment of the present invention are made in accordance with the method of the present invention.

Contribution to the solution of at least one of the above problems is provided by a method for producing water-absorbing polymer particles in a device according to the present invention. Preferably, said process includes process steps (ί) - (χί) according to the present invention.

Contribution to the solution of at least one of the above problems is provided by using a particle of a water-absorbing polymer, which can be obtained by the method according to the present invention. An additional aspect of the present invention relates to a variety of surface-crosslinked particles of a water-absorbing polymer containing

a) a chelating agent, in particular EDTA, in an amount of from 500 to 3000 ppm by weight, preferably from 1000 to 2000 ppm by weight;

b) polyalkylene glycol, in particular polyethylene glycol, in an amount of from 500 to 3,000 ppm by weight, preferably from 1,000 to 2,000 ppm by weight; and

c) 8ίΘ ₂ in an amount of from 500 to 3000 ppm by weight, preferably from 1000 to 2000 ppm by weight;

each value is expressed relative to the mass of a plurality of surface-crosslinked particles of a water-absorbing polymer. According to a further aspect of the present invention, the plurality of surface-crosslinked particles of the water-absorbing polymer further comprise Ad-zeolite, preferably in an amount of from 0.0001 to 1 part by weight, more preferably from 0.001 to 0.5 part by weight. and most preferably from 0.002 to 0.01 parts by weight, each value is expressed relative to the total weight of the plurality of surface-crosslinked particles of the water-absorbing polymer.

The contribution to the solution of at least one of the above problems is provided by a plurality of water-absorbing polymer particles containing polyalkylsiloxane or a compound in accordance with the general formula I - (- O — CH ₂ —CH ₂ -) _p —OX, or both; where in the specified General formula, I represents C ₄ -C ₂₀ , p represents an integer from 10 to 10000, preferably from 50 to 5000, more preferably from 100 to 500, and X represents H or M; where M is a metal ion. A particularly preferred compound according to the general formula is polyethylene glycol trimethylnonyl ether. A preferred polyalkylsiloxane is polydimethylsiloxane.

In one embodiment, the plurality of water-absorbing polymer particles comprises

a) polyalkylsiloxane in an amount of from 0.01 to 1 wt.%, preferably from 0.02 to 0.9 wt.%, more preferably from 0.03 to 0.8 wt.%, more preferably from 0.04 to 0 7 wt.%, More preferably from 0.05 to 0.6 wt.%, More preferably from 0.05 to 0.5 wt.%, More preferably from 0.05

- 14 032199 to 0.4 wt.%, More preferably from 0.05 to 0.3 wt.%, More preferably from 0.05 to 0.2 wt.%, More preferably from 0.05 to 0.15 wt. %, most preferably from 0.07 to 0.11 wt.%, or

B) a compound according to the general formula B - (- O — CH ₂ —CH ₂ -) _p —OX in an amount of from 0.001 to 0.1 wt.%, Preferably from 0.002 to 0.09 wt.%, More preferably from 0.003 to 0.08 wt.%, More preferably from 0.002 to 0.07 wt.%, More preferably from 0.002 to 0.06 wt.%, More preferably from 0.002 to 0.05 wt.%, More preferably from 0.002 to 0.04 wt.%, More preferably from 0.002 to 0.03 wt.%, More preferably from 0.002 to 0.02 wt.%, More preferably from 0.002 to 0.01 wt.%, More preferably from 0.003 to 0, 01 wt.%, More preferably from 0.004 to 0.01 wt.%, Most preferred from 0.005 to 0.009 wt.%, or

C) both compounds, each value expressed in relation to the total mass of a plurality of water-absorbing polymer particles.

The contribution to the solution of at least one of the above problems is provided by a composite material containing a water-absorbing polymer particle according to the present invention or a plurality of water-absorbing polymer particles according to the present invention.

In one embodiment of the present invention, the composite material according to the present invention comprises a material selected from the group consisting of foam, shaped article, fiber, foil, film, cable, sealing material, moisture-absorbing hygiene product, carrier for plant growth and fungal growth regulating agents, packaging material, additives for soil, building material, or a combination of at least two of them. The preferred cable is a blue submarine cable. A preferred moisture-absorbing hygiene article is an article selected from the group consisting of a diaper, tampon and sanitary napkin, or a combination of at least two of them. A preferred diaper is a baby diaper or diaper for adults with incontinence, or both.

The contribution to the solution of at least one of the above problems is provided by a method for producing a composite material in which a water-absorbing polymer particle according to the present invention or a plurality of water-absorbing polymer particles according to the present invention and a substrate and optionally an auxiliary substance are brought into contact with each other.

Contribution to the solution of at least one of the above problems is provided using a composite material, which can be obtained by the method according to the present invention.

Contribution to the solution of at least one of the above problems is achieved by using a water-absorbing polymer particle according to the present invention or a plurality of water-absorbing polymer particles according to the present invention in foam, shaped article, fiber, foil, film, cable, sealing material, moisture-absorbing hygiene product, carrier for plant and fungal growth control agents, packaging material, soil supplement, for controlled release of the active compound Niya, or building material.

Test methods

The following test methods were used in the present invention. In the absence of a test method, a QoS test method was used to measure performance closest to the earliest filing date of this application. In the absence of a QO test method, the ΕΌΛΝΆ test method closest to the earliest filing date of this application was used. In the absence of certain measurement conditions, ambient temperature and pressure (8ATP) were used, that is, a temperature of 298.15 K (25 ° C, 77 ° P) and an absolute pressure of 100 kPa (14.504 ρά, 0.986 atm).

Water content.

The water content after drying was determined by the Karl-Fischer method.

The method of carrying out the invention

Examples

Further, the present invention is explained in more detail using examples and drawings, given as an example, which do not limit it.

A) Preparation of a partially neutralized acrylic acid monomer solution

0.4299 parts by weight water was mixed in a suitable container with 0.27 wt.h. acrylic acid and 0.0001 parts by weight hydroquinone monomethyl ether (ΜΕΗΟ). To the mixture was added 0.2 wt.h. 48 wt.% Sodium hydroxide solution. Received a solution of sodium acrylate monomer with a degree of neutralization of 70 mol.%. The sodium acrylate monomer solution was optionally degassed with nitrogen.

B) Polymerization of a monomer solution.

In the container was mixed 1 wt.h. the monomer solution obtained in stage A), with 0.001 wt.h. trimethylolpropane triacrylate as a crosslinking agent, 0.001 parts by weight sodium peroxodisulfate in ka

- 15 032199 as the first component of the initiator, 0.000034 wt.h. 2,2-dimethoxy-1,2-diphenylethan-1-one (C1Ba® 1gdasige® 651 manufactured by C1Ba 8pcc1a1 (in Syetuia 1ps, Basel, Switzerland) as the second initiator component, up to 0.1 parts by weight of acrylic particles acid (with a particle size of less than 150 μm) to obtain a mixed solution When adding a blowing agent in accordance with Table 1 below, 0.1 parts by weight of sodium carbonate based on the total weight of the mixed solution was added to the mixed solution.

A sufficient amount of the mixed solution was subjected to further processing to obtain a polymer gel and then subsequent particles of a water-absorbing polymer, and then surface-cross-linked particles of a water-absorbing polymer, and then an additionally treated water-absorbing product. Details of the additional processing are presented below.

Then the mixed solution was placed on the belt of a conveyor belt reactor and polymerization by UV radiation was initiated. The length of the conveyor belt was at least 20 m and the width 0.8 m. The conveyor belt was shaped into a groove to hold the solution on the belt during polymerization. The dimensions of the conveyor belt and the speed of transportation of the conveyor belt were chosen so as to obtain a gel of polyacrylic acid at the far end of the belt. At the end of this step, a water-absorbing polymer gel was obtained. The polymer gel had a water content of about 52 wt.% Of the total weight of the polymer gel.

C) Crushing and drying of the polymer gel

The polymer gel formed a strand of polymer gel, which was unloaded from the conveyor belt and crushed in the following stages. The polymer gel was cut into semi-infinite strips of spaghetti gel using a grinder, as shown in FIG. 5. The cutter was then used in accordance with FIG. 6a) and 6b) for cutting strips into pieces of gel from 5 to 10 mm in size, wherein the crushing equipment described above according to the present invention was used in the above examples. In the comparative examples, other crushing devices were used.

Crushed gel was dried on a belt dryer at a temperature of 180 ° C to a water content of 5 wt. % relative to the dried polymer gel. The tape dryer belt contained holes through which hot air was supplied into the polymer gel through nozzles under pressure. The gel on the tape was also blown with hot air from above.

Ό) Shredding and sorting by size.

The dried polymer gel was ground in three stages. First, the dried polymer gel was passed through a HebOI NSM 60/145 granulator (NEVKVOp Meskeket STN) and the obtained particles of the dried polymer gel, which had a size of less than 7 mm, were placed for 2.5 hours in a container to balance the moisture content of the polymer gel particles. The particles of the dried polymer gel were then pulverized in a WiegteMeg, 350.1x1800 type roller mill (3-stage crusher) (Waiegte15! Ex 2egk1teegipd5! Estyk STN) to obtain water-absorbing polymer particles having a particle size of less than 1 mm. Water-absorbing polymer particles were sieved through drum sieves having several gratings. The following grid cell sizes were used: from 20, 30, 40, 50, 60 to 100 US mesh. At least 50 wt.% Of the obtained water-absorbing polymer particles had a particle size in the range from 300 to 600 μm. Less than 5 wt.% Water-absorbing polymer particles in the examples according to the present invention had a size of less than 150 microns, less than 5 wt.% Water-absorbing polymer particles in the examples according to the present invention had a particle size of more than 850 microns. The obtained water-absorbing polymer particles were called the precursor I.

E) Silica treatment.

At the processing stage, the precursor I was mixed in a disk mixer with about 0.01 mass, parts (+ - 10%) of silicon dioxide (81О ₂ ) relative to the total mass of the precursor I and 81О ₂ . Silica was used in the form of 8 | regpa1® 22 manufactured by Ενοηίΐ; ShbikRtek AS, Essen, Germany. When mixing the precursor I with 81O _{2, the} temperature of the precursor was still more than 80 ° C - 100 ° C, preferably 100 ° C. Received the precursor II.

E) Surface stitching.

In the next stage, 1 wt.h. precursor II was mixed with 0.003 mass, parts (+ - 10%) of a surface crosslinking agent relative to the total weight of the mixture of precursor II and crosslinking agent. The surface crosslinking agent consisted of 19 wt.% Water, 40 wt.% Diglycidyl ether of ethylene glycol, 1 wt.% No. 8O ₃ , 40 wt.% Polyethylene glycol with a molecular weight of 400 g / mol, all values relative to the total amount of crosslinking agent. The crosslinking agent ingredients were mixed in a linear static mixer. The cross-linking agent was mixed in a CG1M1x® CM 350 ring layer mixer (Cebibeg LbLde Maxiescheppen Stn, Paderborn, Germany) with the precursor II. The mixture was heated to a temperature of 130 to 160 ° C. Then the mixture was dried in an Apάτάζ Soiba Rabbie Igueg paddle dryer, preferably type CPAE12A120 manufactured by ΛπάπΙζ AC, Graz, Austria, for 45 minutes at a temperature of 130 to 160 ° C. Received surface crosslinked particles of an absorbent polymer.

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In a cooling device in the form of a fluidized bed, the temperature of the surface crosslinked particles of the absorbent polymer was lowered to less than 60 ° C. to obtain cooled surface crosslinked particles of the absorbent polymer, referred to as precursor III.

6) Additional processing.

Then 1 part by weight precursor III was mixed with 0.005 parts by weight of Hell Zeolite. Then the mixture was sieved. A sieve was selected to separate agglomerates of cooled surface-crosslinked particles of an absorbent polymer having a particle size of more than 850 microns. At least 50 wt.% Of the surface crosslinked particles of the absorbent polymer had a particle size in the range of 300 to 600 μm. Less than 5 wt.% Of the surface-crosslinked absorbent polymer particles in the examples according to the present invention had a size of less than 150 microns, less than 5 wt.% Of the surface-crosslinked absorbent polymer particles in the examples according to the present invention had a particle size of more than 850 microns. Received additionally processed surface-crosslinked particles of a water-absorbing polymer.

The following scale was used to compare the measurement results of the parameters presented in tables 1 and 2, for examples and comparative examples. In the order presented below, the measurement results are improved from left to right: -, +, ++, +++.

Table 1. The life of the crushers, the blowing agent used and the drying time.

device life one device life 2 device life 3 foaming agent drying time / kg of particles polymer gel example 1 + + ++ not four- example 2 + + ++ carbonate sodium ++ comparative example 1 + ++ not comparative example 2 + + not comparative example 3 + + carbonate sodium four-

In examples 1 and 2 according to the present invention, the crushers described above were used. In this method, device 1 was a crusher, and device 2 was a cutter. Device 3 was not used. In comparative example 1, the following crushing devices were used: device 1 was a crushing device described in FIG. 1 in I8 2010/0083802 A1; device 2 was a shredder; device 3 was not used. In comparative examples 2 and 3, the following crushing devices were used: device 1 was a crushing device described in FIG. 1 I8 2010/0083802 A1; device 2 was a shredder; device 3 was a cutter. The service life is the life span after which the crushing device of the respective crushing device is subject to replacement or maintenance due to damage or deterioration. The crusher used as device 1 in examples 1 and 2 showed a longer service life than device 1 used in comparative examples 1-3. The life of the device 2 was unchanged in all examples and comparative examples. The life of the device 3 is unlimited in examples 1 and 2, as well as in comparative example 3, since they did not use the device 3. Comparative examples 2 and 3 consistently demonstrate a reduction in the life of the device 3. The drying time and, therefore, the time required for drying crushed polymer gel to a water content of 5 mass. % by weight of the dried polymer gel, as described above, is reduced in the above examples according to the present invention. In addition, the drying time is shorter when using a blowing agent, in this case sodium carbonate. In the indicated method, the drying time was measured after the operation of the corresponding device 1 during the service life, which corresponds to the service life of the device 1 in the comparative examples. As a result, as shown in the above table 1, the crushing device (crusher) according to the present invention provides an increased service life and improved drying due to the reduced number of stages of crushing.

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Table 2. The life of the crusher and the drying time, depending on the degree of overlap of the front and end surfaces of the gear, as well as on the addition of an agent that reduces stickiness.

degree of overlap of the front and end surfaces of the gear [%] reducing agent stickiness Crusher Life drying time / kg of polymer gel particles example 3 3 not + + example 4 five not ++ + example 5 ten not +++ + example 6 ten diluted EC-601 +++ ++

In examples 3-5 according to the present invention used crushing devices in accordance with example 1. In these examples, the degree of overlap of the front and end surfaces of the gear. This means that the proportion of the end surface of the second disk and the front surface of the second disk located between the first and third disk was changed. A change in this fraction leads to a change in the load on the side surfaces of the gear. The life of the crusher increases with increasing specified overlap. The degree of overlap has an upper limit due to the geometry of the rotating axes. During crushing of the polymer gel in the crusher in Example 6, an adhesive agent was added to the crusher. The tackifying agent was obtained from a polydimethylsiloxane emulsion (EC-601 manufactured by Eidepe ΙηάιικίΓν. 166, Yopdkoi, ShsEop-shuop, S1shaye-K1, Suepdpat, Korea) by diluting the emulsion with water to a water content of 97 wt. % by weight of the diluted emulsion. Example 6 demonstrates that adding a tackifying agent to the crusher shortens the drying time of the crushed polymer gel.

In FIG. 1 is a flow chart illustrating steps 101-111 of a method 100 for producing water-absorbing polymer particles according to the present invention. In a first step 101, an aqueous monomer solution is provided containing at least one partially neutralized, monoethylenically unsaturated monomer containing carboxylic acid groups (α1) and at least one crosslinking agent (α3). Preferably, the aqueous solution of the monomer is an aqueous solution of partially neutralized acrylic acid, optionally containing crosslinking agents. In a second step 102, fine particles of a water-absorbing polymer can be added to the aqueous monomer solution. In a third step 103, a polymerization initiator or at least one component of a polymerization initiator system that contains two or more components is added to the aqueous monomer solution. In a fourth step 104, the oxygen content in the aqueous monomer solution is reduced by passing nitrogen through the aqueous monomer solution. In a fifth step 105, the monomer solution is loaded onto a ribbon of a polymerization ribbon reactor as a polymerization reactor 704. The belt is an endless conveyor belt. In a sixth step 106, an aqueous monomer solution is polymerized into a polymer gel. In a seventh step 107, the polymer gel is discharged from the tape. Then, the polymer gel is crushed first in the first crushing device 400, and then in the additional crushing device 600 to obtain particles of the polymer gel. In an eighth step 108, polymer gel particles are loaded onto a tape dryer ribbon and then dried at a temperature of about 120-150 ° C. The dried polymer gel particles are discharged from the belt dryer, and then in the ninth stage 109 are crushed to obtain water-absorbing polymer particles. In a tenth step 110, water-absorbing polymer particles are sorted by size to obtain water-absorbing polymer particles having a well-defined particle size distribution. In an eleventh step 111, the surface of the water-absorbing polymer particles is treated for surface crosslinking.

In FIG. 2 is a flow chart illustrating steps 101-111 of a process 100 for producing water-absorbing polymer particles according to the present invention. The process 100 shown in FIG. 2 is the same as process 100 in FIG. 1, wherein the third process step 103 and the fourth process step 104 overlap in time. When a polymerization initiator is added to an aqueous monomer solution, nitrogen is passed through an aqueous monomer solution to reduce the oxygen content therein.

In FIG. 3 is a flow chart illustrating steps 101, 103, 105-110 of a process 100 for producing water-absorbing polymer particles according to the present invention. The process 100 shown in FIG. 3 is the same as process 100 in FIG. 1, wherein the second stage 102, the fourth stage 104, and the eleventh stage 111 are absent in the process 100 in accordance with FIG. 3.

In FIG. 4 is a diagram of a first crushing device 400 according to the present invention. The first crushing device 400 comprises a first disk 401, a second disk 402 and a third disk 403.

- 18 032199

The first disk 401 and the third disk 403 rotate around the first axis of rotation 404 in the first direction of rotation 411. The second disk 402 rotates around the additional axis of rotation 412 in the additional direction of rotation 412. The first axis of rotation 404 is approximately parallel to the additional axis of rotation 405. The first direction of rotation 411 is opposite an additional direction of rotation 412. The first disk 401 and the third disk 403 rotate toward the second disk 402 and vice versa. The second disk 402 comprises, as surfaces, a front surface 406 of a second disk, an end surface 407 of a second disk and a side surface 408 of a second disk connecting the front surface 406 of the second disk to the end surface 407 of the second disk. The front surface 406 of the second disk, and the end surface 407 of the second disk, and the side surface 408 of the second disk are partially located between the first disk 401 and the third disk 403. In this case, approximately 10% of the front surface 406 of the second disk and approximately 10% of the end surface 407 of the second disk located between the first disk 401 and the third disk 402. The first disk 401, the second disk 402 and the third disk 403 are gears. The polymer gel supplied between the rotating gears is crushed using the first crushing device 400 and parts 409 of the polymer gel are obtained. A portion of the polymer gel 409 is located between the first disk 401 and the third disk 403. The distance 410 between the first disk 401 and the third disk 403 is approximately 45 mm. The first crushing device 400 does not contain a knife.

In FIG. 5 is a diagram of another first crushing device 400 according to the present invention. The first crusher 400 in FIG. 5 comprises a first crusher 400 of FIG. 4. In addition, the first crusher of FIG. 5 contains a plurality of additional disks 501. Each additional disk 501 rotates either around a first axis of rotation 404 or around an additional axis of rotation 405. Between adjacent disks 401, 403, 501, which rotate around a first axis of rotation 404, a disk 402, 501 is partially located, which rotates around an additional axis of rotation 405. Between adjacent disks 402, 501, which rotate around an additional axis of rotation 405, a disk 401, 403, 501 is partially located, which rotates around a first axis of rotation 404. The first crusher 400 in FIG. 5 does not contain a knife. Disks 401, 403, 501, rotating around the first axis of rotation 404, rotate towards the disks 402, 501, rotating around an additional axis of rotation 405, and vice versa. Each additional disk 501 is a gear. The polymer gel supplied between the rotating gears is crushed using the first crushing device 400 and parts 409 of the polymer gel are obtained. Parts 409 of the polymer gel are particles of a polymer gel, in this case strands of a polymer gel.

In FIG. 6a) shows a diagram of an additional crushing device 600 according to the present invention, an external view. The additional crushing device 600 is a cutter (meat grinder) containing a fixed plate 601 with holes, a rotating screw 602 and a device 603 for feeding polymer gel particles, preferably polymer gel strands, to the cutter. The polymer gel strands obtained in the first crusher 400 of FIG. 5 may be further crushed in an optional crusher 600.

In FIG. 6b) is a diagram of the internal parts of the additional crushing device 600 shown in FIG. 6a), unassembled. Additional crushing device 600 includes a screw 602, which rotates with a rotating plate 604 with holes. Thus, auger 602 allows the movement of polymer gel particles, preferably strands of polymer gel, to the fixed plate 601 with holes and through the holes of the fixed plate 601 with holes. As the rotary hole plate 604 rotates relative to the fixed hole plate 601, the circular cutting edges 605 of the holes of the hole rotary plate 604 provide crushing of the polymer gel to produce polymer gel particles 403 (not shown). Circular cutting edges 605 are flat cutting edges. The optional crusher 600 does not contain non-planar cutting edges.

In FIG. 7 is a block diagram of an apparatus 700 for producing water-absorbing polymer particles according to the present invention. The arrows indicate the direction of the process stream 708 obtain water-absorbing polymer particles. The device 700 comprises a first container 701, an additional container 702, a downward mixing device 703, a downward belt polymerization reactor as a polymerization reactor 704, a downward first crushing device 400, a downward additional crushing device 600, a downward belt dryer 705, a downward grinding device 706 and a downward sorting device 706 and a descending device 707, each of which corresponds to the present invention.

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Claims (21)

CLAIM 1. A method of obtaining a water-absorbing polymer particles, including technological stages: (ί) obtaining an aqueous solution of a monomer containing at least one partially neutralized monoethylenically unsaturated monomer containing carboxyl groups (α1) and at least one crosslinking agent (α3); (ίί) adding a polymerization initiator or at least one component of a polymerization initiator system, which contains two or more components, to an aqueous solution of a monomer; (iii) loading an aqueous solution of monomer into a polymerization reactor (704); (ίν) polymerization of monomers in an aqueous solution of monomer in a polymerization reactor (704) to obtain a polymer gel; (ν) unloading the polymer gel from the polymerization reactor (704) and crushing the polymer gel in a first crushing device (400) to obtain polymer gel particles; (νί) drying the polymer gel particles; (νίί) grinding the dried polymer gel particles to obtain water-absorbing polymer particles; (νίίί) sorting by size of crushed water-absorbing polymer particles; where at the technological stage (ν) the first crushing device (400) comprises a first disk (401), a second disk (402) and a third disk (403); where the first disk (401) and the third disk (403) rotate around the first axis of rotation (404); the second disk (402) rotates around an additional axis of rotation (405); the second disk (402) comprises, as surfaces, the front surface (406) of the second disk, the end surface (407) of the second disk and the side surface (408) of the second disk connecting the front surface (406) of the second disk to the end surface (407) of the second disk; where the front surface (406) of the second disk, the end surface (407) of the second disk and the side surface (408) of the second disk are partially located between the first disk (401) and the third disk (403); where part (409) of the polymer gel is located between the first disk (401) and the third disk (403). 2. The method according to claim 1, characterized in that from 5 to 30% of the front surface (406) of the second disk, or the end surface (407) of the second disk, or both surfaces are located between the first disk (401) and the third disk (403) . 3. The method according to claim 1 or 2, characterized in that at the stage (ν) the first axis of rotation (404) and the additional axis of rotation (405) form an angle from 0 to 45 °. 4. A method according to any one of the preceding paragraphs, characterized in that the first disk (401) and the third disk (403) rotate in the first direction of rotation (411), where the second disk (402) rotates in the additional direction of rotation (412), where the first the direction of rotation (411) is different from the additional direction of rotation (412). 5. A method according to any one of the preceding paragraphs, characterized in that the first crushing device (400) further comprises a plurality of additional disks (501), where each additional disk (501) rotates either around the first axis of rotation (404) or around the additional axis of rotation (405); where between adjacent disks (401, 403, 501), which rotate around a first axis of rotation (404), a disk (402, 501) is partially located, which rotates around an additional axis of rotation (405); where between adjacent disks (402, 501), which rotate around an additional axis of rotation (405), partially located disk (401, 403, 501), which rotates around the first axis of rotation (404). 6. A method according to any one of the preceding paragraphs, characterized in that at least one disk selected from the group consisting of a first disk (401), a second disk (402), a third disk (403) and an additional disk (501), or the combination of at least two of them is a gear. 7. The method according to any one of the preceding paragraphs, characterized in that the first disk (401) and the third disk (403) are spaced from each other at a distance (410) of 10 to 90 mm. 8. The method according to any one of the preceding paragraphs, characterized in that the first crushing device (400) provides for the crushing of the polymer gel at the stage (ν) into at least two strands of polymer gel. 9. The method according to any one of the preceding paragraphs, characterized in that the first crushing device (400) does not contain a knife. 10. The method according to any one of the preceding paragraphs, characterized in that at the stage (ν) after crushing of the polymer gel in the first crushing device (400), the polymer gel particles are additionally crushed in an additional crushing device (600). - 20 032199 11. The method according to claim 10, characterized in that the additional crushing device (600) comprises a knife containing at least one flat cutting edge (605). 12. The method according to claim 10 or 11, characterized in that the additional crushing device (600) comprises a knife that does not contain a non-planar cutting edge. 13. The method according to any one of the preceding paragraphs, characterized in that at the technological stage (ν) the tackifying agent is added to the first crushing device (400), or to the additional crushing device (600), or both devices. 14. The method according to item 13, wherein the tackifying agent is selected from the group consisting of a solvent, polyalkylsiloxane and a surfactant, or a combination of at least two of these substances. 15. A device for producing water-absorbing polymer particles in a process stream (708), comprising: a) a first container (701) for receiving an aqueous solution of a monomer containing at least one partially neutralized monoethylenically unsaturated monomer containing carboxyl groups (α1); b) an additional container (702) for receiving at least one crosslinking agent (α3); c) a mixing device (703), where the mixing device (703): ί) is located after the first container (701) and the additional container (702), ίί) is configured to mix the monomer solution and at least one crosslinking agent (α3); 6) a polymerization reactor (704), where the polymerization reactor (704): ί) is located after the first container (701) and the additional container (702), ίί) is designed to receive an aqueous solution of monomer and at least one crosslinking agent (α3) and polymerize the monomers in an aqueous solution of the monomer to form a polymer gel; e) the first crushing device (400), where the first crushing device (400): ί) located after the polymerization reactor (704), ίί) contains the first disk (401), the second disk (402) and the third disk (403), where the first disk (401) and the third disk (403) rotate around the first axis of rotation (404) ), the second disk (402) rotates around an additional axis of rotation (405), the second disk (402) contains as surfaces the front surface (406) of the second disk, the end surface (407) of the second disk and the side surface (408) of the second disk connecting the front surface (406) of the second disk with the end surface (407) of the second disk, where the front surface (406) is second of the second disk, the end surface (407) of the second disk and the side surface (408) of the second disk are partially located between the first disk (401) and the third disk (403); ί) an additional crushing device (600), where an additional crushing device (600): ί) is located after the first crushing device (400), ίί) contains a knife containing a flat cutting edge (605); d) a tape dryer (705), where a tape dryer (705): ί) is located after the additional crushing device (600); ίί) is configured to dry the crushed polymer gel; 11) a grinding device (706), where the grinding device (706): ί) located after the belt dryer (705), ίί) is configured to grind the dried polymer gel to obtain water-absorbing polymer particles; .)) sorting device (707), and the sorting device (707): ί) located after the crusher (706); ίί) is arranged to sort the crushed particles of the water-absorbing polymer. 16. A method of obtaining a water-absorbing polymer particles using the device according to item 15. 17. A plurality of water-absorbing polymer particles containing polyalkylsiloxane, where a plurality of water-absorbing polymer particles are obtained by the method according to any one of claims 1-14, in the process step (ν), the tackifying agent is added to the first crushing device (400), or to an additional crushing device device (600), or in both devices, the tackifier reduces said polyalkylsiloxane. 18. A composite material containing many water-absorbing polymer particles according to 17. 19. A method for producing a composite material, wherein the plurality of water-absorbing polymer particles according to claim 17 and the substrate are brought into contact with each other. 20. Composite material obtained by the method according to claim 19. 21. The use of multiple water-absorbing polymer particles according to 17 in a moisture-absorbing hygiene product. - 21 032199