Paper and cardboard manufacture process

FIELD: paper-and-pulp industry.

SUBSTANCE: : process comprises preparation of paper pulp, flocculation of pulp, shear force-involving mechanical treatment of pulp, second flocculation of pulp, drainage of pulp on the screen to form sheet, and subsequent drying of sheet. Flocculation is carried out by adding water-soluble optionally having intrinsic viscosity above 3 dl/g. Polymer is further characterized by oscillation delta tangent value at 0.005 Hz above 1.1.

EFFECT: improved drainage and retention on moving screen, and formation process.

10 cl, 1 dwg, 4 tbl, 4 ex

 

The present invention relates to a method of manufacture of paper and paperboard from pulp fibrous mass with use as flocculants new water-soluble polymers, as well as to new polymers used in their implementation.

During the manufacture of paper and cardboard pulp and liquid fibrous mass drain on a movable grid (often called grid paper machine for casting sheet, which is then dried. It is well known adding to the pulp slurry a water-soluble polymer to cause the effect flocculation of the pulp solids and improve drainage on a movable grid.

To produce more paper many modern paper machines operate with higher speeds. As a result of higher speeds of operation of the machine pay much attention to the drainage systems and retention, which provide increased drainage at the same time maintaining optimal conditions for holding and molding. Achieving an optimal balance of retention, drainage, drying and molding by adding a single polymer additives that promote the retention, involves problems of a technological nature, so it is common practice to sequential addition of two separate materials.

In the R-a 235893 proposed method, where before the stage of processing of shear stress in the fiber for making paper introduced almost linear water-soluble cationic polymer, and then, after this stage of processing shear force, produce re-flocculation by the addition of bentonite. The implementation of this method provides the possibility of improved drainage, and good molding and retention. This method, which has found industrial embodiment of the firm Ciba Specialty Chemicals in the form of technology under the trademarkconfirms its effectiveness for more than a decade.

Were later made various attempts to develop variants of this method by making small modifications in one or more components.

In the US 5393381 described a method of manufacturing paper or cardboard, in which a suspension of the fibers of the fibrous mass of the added water-soluble branched cationic polyacrylamide and bentonite. This branched cationic polyacrylamide is prepared by polymerization in solution of a mixture of acrylamide, cationic monomer, agent education branches and regulator polymerization degree.

In the US 5882525 described method in which a dispersion of suspended solids, such as fibrous mass for producing the texts of paper, to release water type cationic branched water-soluble polymer, the solubility of which is greater than about 30%). This cationic branched water-soluble polymer prepared from the same components as those described in US 5393381, i.e. by polymerization of a mixture of acrylamide, cationic monomer, agent education branches and regulator polymerization degree.

In WO 9S/29604 described method of making paper, in which the pulp suspension to form flakes add cationic polymer additive that promotes retention, these flakes are subjected to mechanical failure, and then re flocculation of the suspension by adding a solution of the second anionic polymer additives that promote retention. This anionic polymer additive that promotes retention, is a branched polymer, which is characterized as having a rheological oscillation value of tan Delta at 0.005 Hz 0.7 or more with the above viscosity TLU (glass viscometer with a suspended level) in deionized water, which is at least three times shows the viscosity of the TLU in the salt solution of the respective polymer obtained in the absence of the agent education branches. Usually attractively anionic water-soluble polymer obtained by polymerization of water-soluble anionic monomer or monomer mixture in the presence of the agent, the formation of branches in low concentration. In comparison with the methods previously developed in the art, the implementation of this method leads to a noticeable improvement in retention.

In EP-A 308752 described method of making paper, in which the composition of the paper add low molecular weight cationic organic polymer, and then the colloidal silicon dioxide and high-molecular-charged acrylamide copolymer with a molecular weight of at least 500000. From the description it appears indicating that the highest range of molecular masses, which reach when receiving low molecular weight cationic polymer added to the composition of the first paper is from 1000 to 500000. Such low molecular weight polymers expect an indispensable manifestation of the characteristic viscosity of up to about 2 DL/g

However, there is a need for further improvement of the methods of making paper by improving retention and preservation or improvement of the molding process.

Thus, the first object of the present invention is a method of making paper comprising preparing a pulp suspension, flocculation of the suspension, mechanical suspension shear force and optional re-flocculation of the suspension, draining the suspension on the grid casting sheet and subsequent drying it is on the sheet, in which the suspension localroot and/or re-localroot the introduction of the water-soluble polymer with a characteristic viscosity of more than 3 DL/g in suspension, characterized in that a water-soluble polymer exhibits a rheological oscillation value of tan Delta at 0.005 Hz more than 1.1.

The value of tan Delta at 0.005 Hz determined using a viscometer with adjustable voltage by oscillation method in an aqueous solution of the polymer in deionized water at a concentration of 1.5 wt.% after processing in the dryer for two hours. In the course of conducting this experiment used the device Carrimed CSR 100, equipped with a 6-inch acrylic cone with a cone angle of 1°58’ and value of pacenote 58 μm (product marked with the position 5664). The used sample is approximately 2 to 3 tubes using the Peltier plate temperature is maintained at the level of 20.0±0,1°C. In the range of sweep from 0,005 to 1 Hz in 12 steps on a logarithmic basis of the applied angular offset 5×10-4radians. The results of the determination of G’ and G’ are recorded and used to calculate values of tan Delta (G’/G’).

The value of tan Delta is the ratio between the loss modulus (viscous) G and the dynamic modulus of elasticity (storage modulus G’ within the system.

Polag the Ute, that at low frequencies (0.005 Hz) the rate of deformation of the sample is sufficiently low for it to have a linear or branched intertwined chains had the opportunity to untwisting. Mesh or cross stitched systems are characterized by a constant tangle of chains and exhibit low values of tan Delta in the whole wide frequency range. Thus, for okharakterizovanie properties of polymers in the aquatic environment are resorting to low-frequency (e.g., 0.005 Hz) measurements.

It was found that polymers which exhibit a rheological oscillation value of tan Delta at 0.005 Hz more than 1.1, reported improved performance in terms of improved retention, while nevertheless maintaining good operational properties dewatering and molding. When creating the present invention it was found that polymers with a high tan Delta ensure a more effective flocculation of cellulosic fibers and other components of the cellulosic fibrous pulp for making paper, causing thus improved retention.

In a preferred form of such water-soluble polymer exhibits a rheological oscillation value of tan Delta at 0.005 Hz more than 1.2 or 1.3. The preferred polymer has characteristics the second viscosity above 4 DL/g and the value of tan Delta at 0.005 Hz more of 1.4 or 1.5. In some cases, the tan Delta can reach values of 1.7 or 1.8 or even 2.0 or more. Thus, this polymer shows a high value of tan Delta.

Having a high value of tan Delta water-soluble polymer can be anionic, nonionic or amphoteric, and preferably cationic. This polymer is produced by polymerization of water-soluble monomer or water soluble Monomeric mixture. Under water implies that water-soluble monomer or water soluble monomer mixture is characterized by a solubility in water of at least 5 g in 100 ml of water. The polymer can be efficiently obtained by any suitable known method of polymerization, for example by polymerization in solution, with formation of an aqueous gel that is cut, dried and pulverized to prepare a powder, or by polymerization with reversed phase, as disclosed in EP-A 150933, EP-A 102760 or EP-A 126528.

Having a high value of tan Delta water-soluble polymer may be derived from a water soluble monomer or monomer mixture comprising at least one cationic monomer and at least 2 miscast./million, preferably from 5 to 200 miscast./million, in particular from 10 to 50 miscast./million, regulator polymerization degree.

In the process of manufacturing boom is in accordance with the invention, a water-soluble polymer can be entered into the fibre pulp for making paper as a separate agent for processing in the paper manufacturing process, although in the preferred embodiment, this polymer can be added as part of a multicomponent floculants system, through which the pulp suspension localroot, and then re-localroot.

One variant of execution of the invention the pulp suspension localroot a water-soluble polymer with a tan Delta at 0.005 Hz more than 1.1, and then the pulp suspension re localroot further adding a water-soluble polymer or, alternatively, another flatulantdingo material. Before re-flocculation of the resulting flakes are not necessarily destroy, for example, by machining shear force. This can be achieved, for example, by passing the flocculated pulp suspension through one or more processing tools with shear force, such as centrifugal sorting, vane pump, etc.

In another embodiment, the pulp suspension localroot introduction flatulantdingo material and the pulp suspension re localroot the introduction of the water-soluble polymer with a value of tan Delta at 0.005 Hz more than 1.1. Before re-flocculation flakes optional destroy.

The pulp slurry can flocculating the introduction of the flocculant to the suspension in any suitable to add a point. This can be made with the ANO, for example, before one of the stages of pumping, centrifugal before sorting or even after centrifugal sorting. Next, the pulp suspension can be re-flocculating at any acceptable point after flocculation. The flocculant and the agent to re-flocculation can be added to the points that are in close proximity, for example, without any processing stage, with the shear force between the points of introduction. In the preferred embodiment, there is at least one processing stage with shear force (selected from the stages of purification, pumping and mixing)separating the point of adding a flocculant and agent to re-flocculation. When the flocculant added at the stage of processing with shear force, such as centrifugal pump or a centrifugal sorting, flocculant to re-flocculation required and can be added after this stage of processing with shear force. This can be done immediately after the processing phase with the shear force or, more usually, on after her. Therefore, the flocculant can be added before the vane pump, and the agent to re-flocculation can be added after the centrifugal sorting. Thus, a polymer with a high value of tan Delta added as a flocculant and/or as an agent for re-flocculation.

Water-soluble p is liner with a high value of tan Delta is necessary and can be added to the fiber in a concentration of from 0.01 to 10 lb/ton (5 to 5000 ppm million), calculated on the dry polymer. In a preferred embodiment, the polymer is added with a flow rate of from 0.1 to 5 pounds per ton (from 50 to 2500 ppm million), mainly from 0.4 to 2 pounds/ton (from 100 to 1000 ppm million).

When having a high value of tan Delta water-soluble polymer used in the paper manufacturing process as part of a multicomponent floculants system, it can be added in the form floculants system and/or system for re-flocculation. In accordance with one preferred object of the invention is such multicomponent florulenta system includes a high value of tan Delta water-soluble polymer and other flatulently material. This floculants material may be any of a number of incorporating water-soluble polymers, water-insoluble polymer microbeads, powder not subjected to cooking polysaccharides and inorganic materials. Suitable floculant materials include inorganic materials such as silicon-containing materials, alum, polyaluminium, aluminofluoride.

When floculants material is a water-soluble polymer, it can be any acceptable water-soluble polymer, such as biopolymers, such as nonionic, anionic, amphoteric and cationic starch or other polysaccharides. Floculant the material may also be any acceptable anionic, cationic, amphoteric or nonionic synthetic water-soluble polymer.

Floculants material may be a silicon-containing material, which is in the form of anionic composition of microparticles. For silicon-containing materials include particles on kremmidiotis basis, kremmidiotis the microgels, colloidal silica, colloidal solution of silicic acid, silica gels, polysilicates, aluminosilicates, polyaluminosilicate, borosilicate, polyarylate, zeolites and clays. The preferred clays are swelling clay; as a rule, they are, for example, clay-type bentonite. Preferred swelling in water of clay, these include clay, which in the water are exposed to the natural swelling, or clay, which can be modified, for example, by ion exchange to give them swelling in water. Suitable swelling in water of clay include, though not limited to, clay, often referred to as hectorite, smectites, montmorillonite, nontronite, saponite, sekonic, gormiti, attapulgite and sepiolites. As flatulantdingo material can be used bentonite as described in EP-A 235895 and EP-A 335575.

In another embodiment, floculants material is colloidal silica is selected from polysilicates and polyaluminosilicate. These include polymetrical the hospitals polysilicon microgels with a specific surface area greater than 1000 m 2/g, for example water-soluble polymicrogyria polyaluminosilicate microgels, which are described in US 5482693, or aluminized polysilicon acid, which is described in US 5176891 or WO-A 98/30753. In addition, as flatulantdingo material can be used colloidal silicic acid, which is described in US 4388150, or colloidal silica, which is described in WO 86/00100.

Floculants material can also serve as a colloidal borosilicate, for example such as described in WO-A 99/16708. Colloidal borosilicate can be prepared by introducing a dilute aqueous solution of alkali metal silicate in contact with the cation exchange resin to obtain silicic acid, and then obtaining the target product by mixing a dilute aqueous solution of a borate of an alkali metal hydroxide alkali metal, resulting in an aqueous solution containing from 0.01 to 30% In2About3the pH value of which ranges from 7 to 10.5.

In one embodiment of the invention features a method of making paper from slurry pulp of fibrous mass comprising a filler. As a filler may be used any of the traditionally used filling materials. For example, the filler may be a clay, such as kaolin, or the filler may be calcium carbonate, which which could serve as ground calcium carbonate, or in particular, precipitated calcium carbonate, or may be the preferred use as a filling material of titanium dioxide. Examples of other filling materials include synthetic polymeric fillers. Usually cellulosic fibrous mass comprising substantial amounts of filler, harder flocculating. This is especially true in cases fillers of particles of very small size, such as precipitated calcium carbonate. Thus, in accordance with the preferred implementation of the present invention proposes a method of manufacturing paper filled with. Fibrous material for the manufacture of paper may include any suitable amount of filler. Usually the pulp suspension comprises at least 5 wt.% filling material. Typically, the amount of filler is up to 40% or more, preferably is in the range from 10 to 40%. The implementation of such a method is the way of making paper, comprising large amounts of filler, for example up to 40% filler, dry sheet.

As flatulantdingo material in combination with a high value of tan Delta water-soluble polymer may be used anionic, nonionic, cationic or amphoteric branched water is actuarily polymer, which is obtained from the water-soluble ethylene-unsaturated monomer or monomer mixture and agent education branches. So, for example, the branched water-soluble polymer can exhibit a) characteristic viscosity of more than 1.5 DL/g and/or viscosity by Brookfield in saline solution of more than about 2.0 MPa·and (b) a rheological oscillation value of tan Delta at 0.005 Hz 0,7 more. In a preferred embodiment of the polymer can be used water-soluble branched anionic polymer, which has a characteristic viscosity above 4 DL/g and the value of tan Delta at 0.005 Hz 0,7 more, such as described in WO 98/29604.

Alternatively flatulently material used in combination with a high value of tan Delta water-soluble polymer comprises crosslinked anionic or amphoteric polymer microparticles, for example as described in EP-A 462365 or EP-A 484617.

In a particularly preferred method of use of multicomponent floculant system comprising a cationic high value of tan Delta (i.e., rheological oscillation value of tan Delta at least 1,1) water-soluble polymeric flocculant, and then as an agent for re-flocculation anionic flatulently the material. Anionic flocculant include siliceous materials such as silica in the form of microparticles, polysilicate, anionic polymeric microbeads and a water-soluble anionic polymers, including both linear and branched water-soluble polymers.

Especially preferred with a high value of tan Delta water-soluble polymers for use in the paper manufacturing process include cationic polymers with a characteristic viscosity of at least 6 DL/g, for example in the range from 7 to 30 DL/g, more preferably from 8 to 20 DL/g, in particular in the range from 9 to 18 DL/g it is Necessary that these polymers showed a rheological oscillation value of tan Delta at 0.005 Hz in the range of 1.3 to 2.0, preferably in the range from 1.5 to 1.8.

The most preferred cationic polymers are copolymers of acrylamide with methylchloride Quaternary ammonium salt dimethylaminoethylacrylate. The second object of the invention is a water-soluble polymer with a characteristic viscosity of at least 3 DL/g, which is obtained from the water-soluble monomer or water soluble Monomeric mixture, characterized in that the cationic polymer exhibits a rheological oscillation value of tan Delta at 0.005 Hz more than 1.1, PR is doctitle more than 1.2 or 1.3. The preferred polymer has a characteristic viscosity above 4 DL/g and the value of tan Delta at 0.005 Hz more of 1.4 or 1.5. In some examples, the value of tan Delta can reach 1.7 or 1.8 or even 2.0 or more.

Such a polymer can be anionic, nonionic or amphoteric, and preferably cationic. This polymer is produced by polymerization of water-soluble monomer or water soluble Monomeric mixture. Under water implies that water-soluble monomer or water soluble monomer mixture is characterized by a solubility in water of at least 5 g in 100 ml of water. The polymer can be efficiently obtained by any suitable polymerization method.

When a water-soluble polymer is nonionic, this polymer can be obtained using one or more water-soluble ethylene-unsaturated nonionic monomers such as acrylamide, methacrylamide, hydroxyethylacrylate, N-vinylpyrrolidone. The preferred polymer derived from acrylamide.

When a water-soluble polymer is anionic, this polymer is produced using one or more ethylene-unsaturated anionic monomers or mixtures of one or more anionic monomers with one or more nonionic you upomyanutyi monomers. Anionic monomers are, for example, acrylic acid, methacrylic acid, maleic acid, crotonic acid, taconova acid, vinylsulfonic acid, arylsulfonate acid, 2-acrylamide-2-methylpropanesulfonic acid and its salts. The preferred polymer is a copolymer of sodium acrylate with acrylamide.

Preferred water-soluble polymer is cationic, it is obtained using one or more ethylene-unsaturated cationic monomer optionally together with one or more referred to in the present description nonionic monomers. The cationic polymer may also be amphoteric, provided that it includes more cationic groups than anionic groups. Cationic monomers include dialkylaminoalkyl(meth)acrylates, dialkylaminoalkyl(meth)acrylamide, including their acid-additive and Quaternary ammonium salts, diallyldimethylammoniumchloride. Preferred cationic monomers include methylchloride Quaternary ammonium salts dimethylaminoethylacrylate and dimethylaminoethylmethacrylate. Particularly preferred polymer includes a copolymer of acrylamide with methylchloride Quaternary ammonium salts dimethylaminoethylacrylate.

This polymer should and can be prepared polymerizat is she in the emulsion with reversed phase with optional subsequent azeotropic dehydration with obtaining a dispersion of polymer particles in oil. Alternatively the polymer can be obtained in the form of bead polymerization in suspension with reversed phase or in powder form by polymerization in aqueous solution, followed by crushing, drying, and then grinding.

Water-soluble polymer may be derived from a water soluble monomer or monomer mixture comprising at least one cationic monomer and the control of degree of polymerization in the amount of at least 2 miscast./million, often at least 5 miscast./million Content regulator polymerization degree can reach 10000 miscast./million, but typically it does not exceed 2500 or 3000 miscast./million Required number of control degrees of polymerization may be equal to from 5 to 200 miscast./million, in particular the content of the control degree of polymerization can range from 10 to 50 miscast./million, calculated on the weight of monomer.

As the regulator of the degree of polymerization can be used by any acceptable control degree of polymerization, such as hypophosphite alkali metals, mercaptans, such as 2-mercaptoethanol, malic acid or thioglycolate acid. Usually the number of control degrees of polymerization depends, apparently, on the effectiveness specifically used for adjusting the degree of polymerization. So, for example, targets may be on stagnati using from about 5 to 25 miscast./million thioglycolic, from 10 to 50 miscast./million hypophosphite alkali metal or from 500 to 2500 miscast./million malic acid.

You can enable together with the monomer and the regulator polymerization degree a certain amount of agent education branches. However, when agent education branches, obtaining polymers with a target rheological properties associated with increasing problems of a technological nature. Therefore, in a preferred embodiment, the agent education branches, if used, include in very small quantities. Especially preferred water-soluble polymers obtained practically in the absence of the agent, the formation of branching and cross-linking agent.

Especially preferred for use in the method according to the invention polymers include cationic polymers with a characteristic viscosity in the range from 6 to 18 DL/g, preferably from 8 to 13 DL/g Requires that such polymers showed a rheological oscillation value of tan Delta at 0.005 Hz in the range of 1.3 to 2.0, preferably in the range from 1.5 to 1.8. The most preferred cationic polymers are copolymers of acrylamide and methylchloride Quaternary ammonium salts dimethylaminoethylacrylate.

A distinctive feature of the present invention is that the poly is a career with a high value of tan Delta also have relatively high molecular weights, indicated by high values of the characteristic viscosity. One way of obtaining such a water-soluble polymer is a polymerization in solution using an aqueous solution of monomers. Usually the concentration of the aqueous monomer solution should be in the range of from 20 to 40%, preferably from about 30 to 35%. This monomer solution should also enable the regulator to the degree of polymerization, such as hypophosphite sodium. You must take precautions to control degree of polymerization to be used in appropriate quantities, appropriate conditions of polymerization. If the controller has a degree of polymerization to be used in too large quantity, the molecular weight of the polymer and, consequently, the characteristic viscosity usually tend to become excessively low. In case of insufficient number of control degrees of polymerization of achieving high values of tan Delta can be fraught with problems of a technological nature.

If the regulator polymerization degree use hypophosphite sodium, his number may be up to 200 miscast./million, and preferably in the range from 10 to 100 miscast./million, in particular from 10 to 50 miscast./million In the process impose reasonable initiation system, for example water Persian is that ammonium, metabisulfite or sodium tertiary butylhydroperoxide, optional with other initiators. When the gel-like polymers are prepared by polymerization in solution, the initiators are usually injected into the monomer solution. In the process, but not necessarily, to enter thermal initiation system. Thermal initiator, as a rule, includes any acceptable initiating the connection, which is at an elevated temperature forms radicals, for example azo compounds, such as azobisisobutyronitrile.

After the polymerization is completed, the polymer gel enable sufficient to cool so that the gel can be processed in the usual way, i.e. by crushing the gel into small pieces, drying up almost dehydrated polymer and then crushed to powder.

Alternatively the polymers get in the form of a bead suspension polymerization or emulsion polymerization in emulsion or dispersion of water in oil, for example, in accordance with the method described in EP-A 150933, EP-A 102760 or EP-A 126528.

The invention is illustrated by the following examples.

Example 1

The production of polymer And

100 miscast. water to prepare aqueous monomer mixture containing 21 miscast. methylchloride Quaternary ammonium salts dimethylaminoethylacrylate, 79 parts is Art. acrylamide, 1750 miscast. Monomeric diethylenetriaminepentaacetic acid, 3 wt.% Monomeric adipic acid and 50 miscast. hypophosphite sodium control (degree of polymerization).

This aqueous monomer mixture emuleret 100 miscast. hydrocarbon liquid Exxsol D40, containing 2.4% of sorbitanoleat in recalculation on weight of monomer and 1.25% of a polymeric stabilizer EL 1599A (technically available on the company Uniqema).

The appropriate amount as tertiary butylhydroperoxide (tert-BGP)and sodium metabisulfite slowly injected with a flow rate sufficient to cause a temperature rise at the rate of 2°C/min, As a rule, the flow rate of the monomer is in the range from 5 to 15 miscast./million

After curing is completed at the stage of dehydration is carried out at elevated temperature and under reduced pressure, from the dispersed phase to remove significant amounts of water and volatile solvent.

Obtaining polymers B and C

Polymers B and C receive the same as the polymer A, except for using, respectively, 0 and 20 miscast./million hypophosphite sodium.

Characterization of polymers from a to b

The polymer And to determine the rheological oscillation value of tan Delta at 0.005 Hz and characteristic viscosity. Rheological oscillation value define a 2-percentage of water which solutions using viscometer AR 1000N. The characteristic viscosity is determined by the preparation of polymer solutions of different concentrations in 1 N. NaCl at 25°in accordance with the standard industrial method.

The results are summarized in table 1.

Table 1
Polymerpart./million hypophosphite sodiumtangent δ at 0.005 HzCharacteristic viscosity (DL/g)
And501,828,5
B00,9414,7
In201,2110,9

Example 2

In the course of conducting a series of tests on laboratory fibrous mass for high-grade paper with application of polymers a, B and C determine the values of retention on the first pass. In each trial of 0.2%solution of the polymer is injected in the amount of 0.5, 0.75 and 1 lb/ton of pulp. Next, the fiber is treated with shear force with a mechanical stirrer, followed by addition of a slurry of activated bentonite at a concentration of 4 lbs/so

The average retention (%) on the first pass are presented in percentages in table 2 and figure 1.

Table is 2
PolymerConcentration (lb / ton)
 0,50,751,0
And87,5092,6096,60
B81,8087,2091,50
In85,5090,7094,60

It is obvious that the polymers a and b with the values of tan Delta respectively to 1.21 1.82 and cause a more efficient retention on the first pass than polymer B with a value of tan Delta of 0.94. The polymer And provides the best retention on the first pass.

Example 3

Analogously to example 1 to prepare a number of polymers, of which three polymer is produced using 0 part./million hypophosphite sodium as a regulator of polymerization degree, three polymer is produced using 20 ppm million hypophosphite sodium and three polymer is produced using 50 part./million hypophosphite sodium as a regulator of the degree of polymerization. For each polymer determine the characteristic viscosity and rheological oscillation value. With the use of the polymers of this range, repeat the example 2 determine the values of retention on the first pass.

Table 3 presents the average results for the of Kerov each group, obtained when the content of hypophosphite sodium.

Table 3
Hypophosphite Na, part./millionThe average characteristic viscosityThe average value of the tangent δ at 0.005 HzThe average retention for the first pass at a concentration of 0.5 lb/tThe average retention for the first pass at a concentration of 0.75 lb/tonThe average retention for the first pass at a concentration of 1 lb/t
013,900,9283,1088,7093,50
2012,901,12or roughly 85.6090,8094,30
5010,501,4087,4092,7095,60

You can clearly see that with increasing concentration of the regulator polymerization degree is a trend towards growth in polymers efficiency retention. The polymers obtained at higher concentrations of the regulator polymerization degree, show increased values of tan Delta.

Example 4

Example 3 is repeated, but using in obtaining a number of polymers 0, 50, 100 and 150 ppm million hypophosphite sodium. Table 4 presents the average pokazatel is holding on the first pass.

Table 4
Hypophosphite Na, part./millionThe average characteristic viscosityThe average retention for the first pass at a concentration of 0.5 lb/tThe average retention for the first pass at a concentration of 0.75 lb/ton
016,980,7of 87.8
5010,685,491,7
100the 11.685,690,45
1508,884,290,9

These results show that the polymers obtained in the presence of 50 and 150 ppm million regulator polymerization degree, show a markedly improved rate of retention on the first pass compared with the polymer obtained in the absence of the Governor of the degree of polymerization.

1. Method of making paper or paperboard comprising preparing a pulp suspension, flocculation of the suspension, mechanical suspension shear force and re-flocculation of the suspension, draining the suspension on the grid casting sheet and the subsequent drying of the sheet, in which the suspension localroot the introduction of the water-soluble polymer with a characteristic viscosity of more than 3 d is/d in suspension, characterized in that a water-soluble polymer is a cationic polymer, which is obtained from the water-soluble monomer or monomer mixture containing at least one cationic monomer, where the specified polymer exhibits a rheological oscillation value of tan Delta at 0.005 Hz more than 1.1 calculated 1.5 wt.% an aqueous solution of the polymer in which the pulp suspension re localroot introduction flatulantdingo material selected from the group comprising silicon-containing material, which is in the form of anionic composition of microparticles, anionic polysaccharides, anionic synthetic water-soluble polymer and crosslinked anionic polymer microparticles, and in which the mechanical treatment is carried out by passing the flocculated pulp suspension through one or more processing tools with shear force, selected from tools such as centrifugal sorting and vane pump.

2. The method according to claim 1, wherein the water-soluble cationic polymer exhibits a rheological oscillation value of tan Delta at 0.005 Hz more than 1.2 calculated 1.5 wt.% an aqueous solution of the polymer.

3. The method according to claim 1 or 2, in which the water-soluble cationic polymer exhibits a characteristic viscosity greater than 4 l is/g and the value of tan Delta at 0.005 Hz in the range of 1.3 to 2.0, calculated 1.5 wt.% an aqueous solution of the polymer.

4. The method according to any one of claims 1 to 3, in which the water-soluble cationic polymer exhibits a characteristic viscosity of at least 6 DL/g

5. The method according to any one of claims 1 to 4, in which a water-soluble monomer or monomer mixture comprises at least one cationic monomer and at least 2 parts/million regulator polymerization degree.

6. The method according to claim 5, in which the regulator is the degree of polymerization is contained in the range of 5 to 200 parts by weight of/million

7. The method according to claim 5, in which the regulator is the degree of polymerization is contained in the range from 10 to 50 parts by weight of/million

8. The method according to any one of claims 1 to 7, in which flatulently material is a silicon containing material selected from the group comprising particles on kremmidiotis basis, kremmidiotis the microgels, colloidal silica, colloidal solution of silicic acid, silica gels, polysilicates, aluminosilicates, polyaluminosilicate, borosilicate, polyarylate, zeolites and clay.

9. The method according to any one of claims 1 to 8, in which floculants material is a silicon-containing material, which is a swelling in water of clay selected from the group comprising hectorite, smectites, montmorillonite, nontronite, saponite, sekonic, gormiti, attapulgite and sepiolites.

10. The method according to any of the FG1-7, in which flatulently material is an anionic branched water-soluble polymer, which is obtained using a water-soluble ethylene-unsaturated anionic monomer or monomer mixture and agent education branches, and in which the polymer has a characteristic viscosity above 4 DL/g and shows the value of tan Delta at 0.005 Hz 0,7 more calculated 1.5 wt.% an aqueous solution of the polymer.



 

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20 cl, 10 tbl, 8 ex

FIELD: pulp-and-paper industry.

SUBSTANCE: method involves preparing cellulose suspension; providing flocculation and draining of suspension on netted surface; molding and drying of resultant sheet. Flocculation of suspension is provided by introducing of water-soluble polymer selected from the group consisted of polysaccharide and synthetic polymer with characteristic viscosity of at least 4 deciliter/g. Repeated flocculation procedure is provided by adding of system including silicon-containing material and water-soluble polymer. According to one of versions, silicon-containing material is added before or simultaneously with water-soluble polymer. According to other version, water-soluble polymer is of anionic kind of polymers, which is added before introduction of silicon-containing material.

EFFECT: improved draining and holding procedures facilitating adequate conditions for paper and cardboard molding procedure.

18 cl, 2 tbl, 4 ex

FIELD: mining industry and mechanical engineering.

SUBSTANCE: the invention is dealt with methods of production of a paper, in particular, with its smoothing. The water suspension containing cellulose fibers and optional fillers (i) add the sizing dispersion containing a sizing agent and a polymer including one or several aromatic groups and (ii) a sizing promoter containing a polymer intercalating one or several aromatic groups. Mould and dry the produced suspension. The sizing dispersion and sizing promoter are added to the water suspension separately. The invention ensures improvement of the process of sizing the cellulose fibers having a high conductivity.

EFFECT: the invention ensures improvement of the process of sizing the cellulose fibers having a high conductivity.

41 cl, 6 tbl, 6 ex

Papermaking process // 2244776

FIELD: paper industry.

SUBSTANCE: invention relates to technology of manufacturing paper from aqueous suspension containing cellulose fibers and optional fillers. Process comprises separately adding to suspension cationic processing polymer with one or several aromatic groups and anionic polymer with one or several aromatic groups. The latter is selected from polymers prepared according to stepped molecule growth mechanism, naturally occurring polysaccharides and aromatic polymers and modifications thereof, provided that, if anionic polymer is polymer prepared according to stepped molecule growth mechanism, then it cannot be anionic condensation polymer based on melaminesulfonic acid. Another condition that could be alternatively fulfilled is that anionic polymer is not anionic polystyrenesulfonate or anionic condensation polymer based on melaminesulfonic acid. Suspension is then molded into sheet and dehydrated on screen.

EFFECT: improved dehydration and/or retention during making of paper from all types of fibrous pulps, including those with high content of salts, and increased strength of dry paper.

19 cl, 10 tbl, 11 ex

The invention relates to the technology of making paper lichtovannaya

The invention relates to methods of making paper (including cardboard) and, in particular, to methods of making paper, reinforced with starch

The invention relates to methods of making paper, and particularly relates to such methods that involve the use of water-soluble polysilicate microgels, especially polyaluminosilicate microgels and aluminiumand polysilicate microgels as auxiliaries to improve uderzhivaemoi filler and enhance dewatering

The invention relates to polymer chemistry, more specifically, firstly, to water-soluble copolymers containing in the structure a nitrogen atom, secondly, to get in solid form, easy grinding and easily soluble in water compositions based on water-soluble Homo - and copolymers containing in the structure a nitrogen atom, thirdly, to a method for producing compositions of water-soluble Homo - and copolymers

The invention relates to compositions (K) for polymerization immobilization of biological macromolecules in the hydrogels in the formation of biochips TO=andA+b+withC+dD+eE, including the a - monomer based on the derivatives of acrylic and methacrylic acids; water-soluble crosslinking agent; With modified biological macromolecule containing unsaturated group, D is a water - soluble compound as the component environment for copolymerization; E - water, where a, b, C, d, e - the percentage (X) of each component in the composition (X= m/v100% solids and X=v/v100% for liquid substances), in which the total content of monomer and crosslinking agent lies in the range of 3-40% (3(a+b)(40), the ratio of monomer and cross-linking agent is within 97: 3-60:40, and the percentage of components C, D and E is in the range of 0.0001%10%; 0%d90%; 5%E.

The invention relates to methods of producing synthetic low molecular weight polyelectrolytes are polymers and copolymers (M<1,5106on the basis of a number of acrylamido, the macromolecules which contain groups capable of ionization in solution, is used as the dispersant aqueous suspensions, stabilizers of emulsions, additives for drilling in extreme conditions, when creating an artificial soil structure

The invention relates to methods of producing synthetic high molecular weight polyelectrolytes are polymers and copolymers on the basis of a number of acrylamido, the macromolecules which contain groups capable of ionization in the solution used in the purification of natural and waste waters, for flotation, as additives for drilling in extreme conditions, when creating an artificial soil structure

The invention relates to the manufacture of paper, and more particularly, to a method of making paper, which paper add weight cationic organic polymer containing a hydrophobic group and an anionic material microecology

The invention relates to new methods and materials to minimize deposition of metal oxides on the tubes of the steam generator to the secondary line pressure of steam generators in nuclear power plants (NPP) using a polymeric dispersant high purity

The invention relates to the chemistry of macromolecular compounds, namely to obtain hydrolyzed polyacrylamide

The invention relates to a method of immobilization of oligonucleotides in polymer hydrogels, including polyacrylamide gel, which carry out the copolymerization of oligonucleotides modified with unsaturated groups of the General formula I with unsaturated monomers, which form the basis of the obtained hydrogel

FIELD: paper-and-pulp industry.

SUBSTANCE: : process comprises preparation of paper pulp, flocculation of pulp, shear force-involving mechanical treatment of pulp, second flocculation of pulp, drainage of pulp on the screen to form sheet, and subsequent drying of sheet. Flocculation is carried out by adding water-soluble optionally having intrinsic viscosity above 3 dl/g. Polymer is further characterized by oscillation delta tangent value at 0.005 Hz above 1.1.

EFFECT: improved drainage and retention on moving screen, and formation process.

10 cl, 1 dwg, 4 tbl, 4 ex

FIELD: chemical industry, chemical technology, polymers.

SUBSTANCE: invention relates to a method for preparing aqueous polymer dispersions of the multipurpose designation. Method for preparing an aqueous dispersion of styrene-acryl copolymer is carried out by preliminary emulsifying a mixture of acrylic monomers with styrene in the presence of emulsifying agent and the following aqueous-emulsion co-polymerization of the reaction mixture in the presence of initiating agent. Monomer mixture comprises additionally acrylamide, and method involves using ammonium persulfate and hydrogen peroxide as an initiating agent. Method involves the successive fractionally dosing feeding ammonium persulfate for two stages followed by addition of a mixture of polymethylsiloxane of molecular mass 55-1000 Da and iron sulfate in their mass ratio = (25-35):1 to the reaction mixture at stirring, cooling the reaction mass and its neutralization to pH = 5-6. Invention provides preparing the stable aqueous polymeric dispersion with diminished size of particles. Invention provides enhancing strength and water resistance of film prepared on its base.

EFFECT: improved preparing method.

1 tbl, 3 ex

FIELD: polymer production.

SUBSTANCE: invention provides composition for preparation of gradient hydrogel polymer material based on copolymers of acrylamide and N,N'-methylene-bis-acrylamide representing following system: (i) mixture of dilute solution containing 2-3% acrylamide, 0.1-0.2% N,N'-methylene-bis-acrylamide, 0.01% ammonium persulfate, and, as viscosity regulator, 0.5-2.0% glycerol or 1:1 mixture of glycerol and polyvinyl alcohol, each taken in amount 3.5-8.0%, in bidistilled water and (ii) and concentrated solution containing 6-45% acrylamide, 0.6-1.0% N,N'-methylene-bis-acrylamide, and 0.04% ammonium persulfate in bidistilled water, said dilute solution constituting 75-80% and said concentrated solution 20-25% of the total weight of the system. Components are distributed in gradient manner in final system. Invention also discloses a method of preparing gradient hydrogel polymer material based on above-indicated copolymers and indicated gradient hydrogel polymer material. Value and direction of gradient of modulus of elasticity of hydrogel polymer materials is controlled by concentration of viscosity regulator.

EFFECT: expanded possibilities for preparing gradient hydrogel polymer materials.

3 cl, 1 tbl, 8 ex

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