Production of paper or cardboard

FIELD: textile, paper.

SUBSTANCE: method includes provision of a thick mixture of cellulose suspension, which contains a filler. The thick suspension mass is dissolved to form a diluted mix of suspension, in which the filler is available in amount of at least 10 wt % in terms of dry mass of dissolved suspension mix. The thick mixture of suspension and/or dissolved mix are flocculated. Polymer system of retention/dehydration is used in flocculation. The dissolved mixture of suspension is dehydrated on a mesh to form a sheet, and then the sheet is dried. In this method the polymer system of retention/dehydration contains the following: i) a water-soluble branched anion-active polymer and ii) a water-soluble cation-active or amphoteric polymer. The anion-active polymer is available in the thick mixture or in the dissolved mixture of suspension prior to addition of cation-active or amphoteric polymer.

EFFECT: improved retention of ash relative to complete retention with higher quality of paper.

16 cl, 21 dwg, 32 tbl, 8 ex

 

The invention relates to a method of manufacturing paper filled with or cardboard. In accordance with the preference of paper or cardboard made from paper pulp containing wood pulp and a filler. In particular, the invention includes methods of making paper with a high content of wood pulp, such as SC paper (SC-paper or coated paper for gravure printing (e.g. LWS). In addition, the invention is also suitable for making paper or paperboard, containing paper weight. The method provides improved retention of the ash relative to the total holding.

It is well known to produce paper in a way that includes the flocculation of pulp diluted raw materials by adding retaining polymer additives and then down flocculated slurry through a moving screen (often called net bumagodelatelnoe machine) and then forming a wet sheet, which is then dried. Some polymers tend to generate fairly coarse accumulations and, although retention and dehydration can be good, unfortunately, the texture and the degree of drying of the resulting sheet may deteriorate. It is often difficult to obtain an optimal balance between retention, dehydration, drying and texture by adding a single the state retaining polymer additives, and therefore common practice to add two separate material one after the other or in some cases simultaneously.

Grade paper with a wood filler, such as SC-paper or coated paper for gravure printing is often done using a soluble double retention system polymer. Apply the use of two water-soluble polymers that are mixed together in an aqueous solution before it is added to the diluted mixture. In General, one of the polymers should have a higher molecular weight than the other. Both polymer usually has to be linear and soluble in water to the extent reasonably possible. Usually low-molecular weight polymer component should have a high charge density of the cation, such as coagulants polyamine, polyethyleneimine, or DD (polymers diallyldimethylammonium chloride). In contrast to the more low molecular weight polymers, more high molecular weight polymer component has a tendency to have a relatively low charge density of the cation. Typically, these more high molecular weight polymers can be cationic polymers based on acrylamide or for example polyvinylene. A mixture of cationic polymers commonly referred to as a retention system cat/cat.

The total production of paper and cardboard, as the world is but used other systems holding. System retention with microspheres using containing silicon oxide material, have been found to be very effective in improving retention and dehydration. EP-A-235,893 describes the way in which the substantially linear cationic polymer is applied to the paper pulp to the stage of cleavage to cause flocculation, passing fokusirovku the mixture through at least one stage of cleavage, and then relocalize, the introduction of bentonite. In addition to a completely linear cationic polymers, slightly crosslinked, for example, can also be used branched polymers as described in EP-A-202780. This method was successfully commercialized chemicals Ciba Specialty Chemicals under the trademark Hydrocol, as it provides increased retention, dewatering and formation.

Examples of other systems microgranules used in industry paper production, are described in EP-A-0041056 and US 4385961 for colloidal silica and in WO-A-9405596, and WO-A-9523021 relatively Zola-based silicon oxide, used in combination with cationic polymers of acrylamide. US 6358364, US 6361652 and US 6361653 each section describes the use of borosilicate in connection with high molecular flocculators and/or starch in this sense.

EP 0041056 reveals the way with the building of paper from an aqueous mixture of paper pulp and binder comprising colloidal silicic acid and cationic starch, which was added to the mixture in order to improve the retention of the components of the mixture, or added to the circulating water in order to reduce the pollution problems or to return the valuable substances from the circulating water.

WO 00/17451 studies system of microgranules for use as a retention and dewatering additives for paper production, including high molecular weight polymer flocculant, acid colloid and coagulant or flocculant average molecular weight. Acid colloid comprises an aqueous solution of water-soluble polymer, all polymers, melamine-aldehyde, preferably melamine-formaldehyde polymers.

In addition to the inorganic water-insoluble material with micro-granules, soluble branched anionic organic polymers are also known methods of paper production.

WO-A-9829604 describes a method of making paper by adding a cationic polymer retention additive to the pulp slurry to form flocculi, mechanically destroy clusters, and then relocalize suspension by the addition of polymer retention additives. Anionic polymeric retention additive is a branched polymer having a rheological oscillation of tan Delta at 0.005 Hz to above 0.7 and/or is having a coefficient of viscosity of deionized SLV is at least three times more than the coefficient of viscosity of the salt solution SLV corresponding polymer made in the absence of branching agent. In this way anionic branched polymer is always added after flocculation with cationic additive retention and mechanical destruction of the thus formed flakes. The method provides significant improvements in retention, dehydration and formation in comparison with the earlier prior art. Highlighted on page 8 that the number of branching agent should not be too high, since the improvement is desirable and in the osushivaniya and retention will not be achieved. However, there is nothing that would indicate improved retention of the ashes relatively complete retention.

US 6616806 shows three components of the method of making paper, adding a substantially water-soluble polymer selected from a polysaccharide or a synthetic polymer with internal viscosity at least 4 DL/g, and then relocalize subsequent addition reprocussions system. Reprocussion system contains containing silicon oxide material and substantially water-soluble polymer. Water-soluble polymer is added before refocussing system is a water-soluble branched polymer, which has an internal in scost above 4 DL/g and shows the magnitude of flow fluctuations tan Delta of about 0.005 Hz to above 0.7. Dehydration is increased without any significant deterioration of the formation in comparison with other known methods of the prior art.

US 6395134 describes a method of making paper using the three components of the system in which the pulp suspension flatwire using water-soluble cationic polymer containing a silicon oxide material and the anionic branched water-soluble polymer formed from ethylene unsaturated monomers having an internal viscosity above 4 DL/g and showing the magnitude of flow fluctuations tangent Delta of about 0.005 Hz to above 0.7. The method provides for more rapid dehydration and better formation than the branched anionic polymer in the absence of colloidal silica. US 6391156 describes a similar method, in which in particular bentonite is used as a silicon oxide material. This method also provides a more rapid dehydration and better formation than the ways in which the cationic polymer and a branched anionic polymer used in the absence of bentonite.

US 6451902 discloses a method for the manufacture of paper, using water-soluble synthetic cationic polymer to the pulp suspension, in particular in the flow of the diluted mass, and that the flock is to regulate, accompanying mechanical breakdown. After centresin add water-soluble anionic polymer and cellulosic material to relocalising pulp suspension. Accordingly, water-soluble anionic polymer can be a linear polymer. The method significantly increases the size of dehydration compared with the cationic polymer and bentonite in the absence of anionic polymer.

Manufacturers of highly filled paper wood-containing pulp face increased environmental, economic and quality pressures, which means that many pulp and paper companies tend to manage closed water systems, reducing the weight of the paper, replacing the primary fiber recycled fiber, as well as an additional increase in the content of the filler in the sheet. The desire to increase the content of the filler with the aim of reducing the relative quantities of expensive necessary fiber and also in order to improve the whiteness, opacity and printability of the paper thus formed. In order to increase the level of ash in the paper, the diluted mixture should be adjusted to higher load of ash. It should be noted that higher loads ash lead to lower overall by keeping the tion, in the case of which the consistency of the diluted mixture must be increased to compensate for this effect. In turn, the consistency of a highly diluted mixture, combined with low retention, often negatively influence the formation of the sheet, the purity of the system, the ability to resist handling and sheet properties, such as dusting and strength.

In addition, the increase in colloidal and fine-grained material in bumagodelatelnoe car tends to adversely affect the performance of flocculation systems needed to keep the filler, fibre and other additives in paper manufacturing. It is believed that these difficulties arise because of the relatively high surface area of fine particles and colloidal material, causing more consumption and reduced the effectiveness of conventional chemicals holding.

In addition, such systems, especially closed systems, where reclaimed reclaimed water recycled, the conductivity tends to increase due to the increase of the electrolyte. Increased conductivity also tends to exacerbate the difficulties in the efficiency of chemicals holding in poor flocculation. In addition, the high conductivity reduces various other additives paper is proizvodstva, such as additive size and strength.

Very concentrated colloidal dispersion systems tend to be unstable under high cleavage conditions that exist in shaping the modern sections bumagodelatelnyh machines and the result may be deposited to form precipitation. A further disadvantage of increasing high levels of sludge is that it may lead to unwanted microbial growth and build-up of mucus. Typical precipitation derived from colloidal and fine grained resin, and adhesive material, fragments of fibers or biological material. It may also adversely affect the efficiency of the method, paper production, not least because of the potential for poor printing properties of paper, weaknesses and fragility of the paper, resulting in a loss of spec paper product that can be re-established only by closing bumagodelatelnoe machines and cleaning. All these inconveniences may adversely affect the profitability bumagodelatelnoe machine.

It would therefore be desirable to store and/or delete as many fine and colloidal material in the form of filler as possible during the way of retention. In addition, it must be achieved at a given original is flax-level retention, which is determined by the needs of the type and quality of paper.

According to the present invention we provide a method of making paper or paperboard with improved retention of the ash relative to the full retention, includes the steps of providing a thick mixture of pulp suspension which contains the filler dilution mass of thick suspension to form a diluted mixture of a suspension, in which the filler is present in the diluted mixture slurry in the amount of at least 10 wt.% in terms of the dry mass of the diluted mixture suspension, flocculation thick mixture of suspension and/or diluted mixtures using polymer retention system/dehydration

dehydration diluted mixture of the suspension on the grid to form a sheet, and then drying the sheet,

in which polymer retention system/dehydration contains:

i) a water-soluble branched anionic polymer and

ii) a water-soluble cationic or amphoteric polymer

where branched anionic polymer is present in a thick mixture or in a diluted mixture of the suspension prior to adding the cationic or amphoteric polymer.

The present method provides a means to enable more preferably the filler in the sheet of paper. Thus, the retention of ash, respectively, which remove fine colloidal material is increased relative to the full retention, the relative level of retention of the fibers will tend to decrease. This has the benefit of allowing the sheets of paper to contain higher levels of filler and a reduced level of fiber. This causes a significant commercial and quality advantages, as the fiber is often more expensive than filler, and improved white, optical properties and printability of paper. In addition, without hurting the reduce resistance machines and paper quality due to the cleanliness of the system and the consistency of polyparaphenylenes. This method is especially useful for creating a variety of paper, containing wood filler, such as paper for gravure printing, such as SC paper (SC-paper, lightweight coated paper (LWC).

Description of fine and colloidal material can be found in Tappi Method T 261 pm-80 "Fines Fraction of Paper Stock by Wet Screening". In Tappi method the term "fine particles" described as part of the sample paper pulp, which will pass through hole 200 sieve (or its nominal equivalent diameter dimension of the hole 76 microns), as used for testing of standard holding device Britt Jar".

In the present invention, we determine destruction of 0.8 to 10 μm range of the lengths of the chords during the method of retention, obtained with a scanning laser is microscopii, often called FBRM. We find a good correlation between the retention of ash and removal of this fraction.

Preferably the water-soluble cationic or amphoteric polymer is a natural polymer or a synthetic polymer, which has an internal viscosity of at least 1.5 DL/g Suitable natural polymers include polysaccharides, which carry a cationic charge, usually after a modification, or an alternative are amphoteric property, and they are cationic and anionic charges. Typical natural polymers include cationic starch, amphoteric starch, chitin, chitosan, etc. Preferably cationic or amphoteric polymer is synthetic. More preferably a synthetic polymer formed from ethylene unsaturated cationic monomer or mixture of monomers, including at least one cationic monomer, and, if amphoteric, at least one cationic monomer and at least one anionic monomer. When the polymer is amphoteric, it is preferred because it carries more cationic groups than anionic groups, so that the amphoteric polymer is predominantly cationic. In General, cationic polymers are preferred. Particularly preferred cationic or amphoteric polymers, and EUT internal viscosity of at least 3 DL/g Usually, the internal viscosity can be at least 4 DL/g, and often it can be up to 20 or 30 DL/g, but preferably will be between 4 and 10 DL/g

The internal viscosity of the polymers can be determined by preparation of an aqueous polymer solution (0.5-1% m/m), relative to the active content of the polymer. 2 g of this 0.5-1% polymer solution was diluted to 100 ml in a volumetric flask with 50 ml of 2M solution of sodium chloride, buffered to pH 7.0 (using 1.56 g of sodium dihydrophosphate and 32.26 g of disodium hydrogen phosphate per liter of deionized water), all diluted to 100 ml with deionized water. The internal viscosity of the polymers was measured using a viscometer with a suspended level Room 1 at 25°C in 1M buffered saline. The value of the intrinsic viscosity is determined according to the method, unless otherwise stated.

The polymer can be prepared by polymerization of water-soluble monomer or water soluble monomer mixture. Dissolved in water, we mean that the water-soluble monomer or water soluble mixture of the monomer has a solubility in water of at least 5 g in 100 ml of water and 25°C. the Polymer can be conveniently prepared by any suitable polymerization method.

Preferably the water-soluble polymer is cationic and is formed from one or more ethylene unsaturated, cationa the effective monomers randomly with one or more nonionic monomers, mentioned here. Cationic monomers include dialkylaminoalkyl (meth) acrylates, dialkylaminoalkyl (meth) acrylamide, including their salts accession acids and Quaternary ammonium salts, diallyldimethylammonium chloride. Preferred cationic monomers include methylchloride Quaternary ammonium salts dimethylaminoethylacrylate and dimethylaminoethylmethacrylate. Suitable nonionic monomers include unsaturated nonionic monomers such as acrylamide, methacrylamide, hydroxyethylacrylate, N-vinyl pyrrolidone. Particularly preferred polymer includes a copolymer of acrylamide with methylchloride Quaternary ammonium salts dimethylaminoethylacrylate.

When the polymer is amphoteric, it is possible to prepare at least one cationic monomer and at least one anionic monomer and optionally at least one nonionic monomer. Cationic monomers and optional nonionic monomers set out above in respect of cationic polymers. Suitable anionic monomers include acrylic acid, methacrylic acid, maleic acid, crotonic acid, taconova acid, vinylsulfonate, arylsulfonate, 2-acrylamide-2-methylpropanesulfonate and their salts.

The polymers can be linear, pascalc what they were prepared substantially in the absence of the agent branching or crosslinking. Alternative polymers can be branched or crosslinked, for example as in EP-A-202780.

Optionally, the polymer can be prepared by polymerization of the opposite phase of the emulsion, optionally followed by dehydration under reduced pressure and temperature, often referred to as azeotropic dehydration to form a dispersion of polymer particles in oil. Alternative polymer may be provided in the form of beads polymerization of the opposite phase of the suspension, or as a powder polymerization of an aqueous solution, followed by crushing, drying and then grinding. The polymers can be produced as beads by suspension polymerization or emulsion water-in-oil or dispersion polymerization emulsion water-in-oil, for example according to the method described in EP-A-150933, EP-A-102760 or EP-A-126528.

Particularly preferably, the polymer is cationic and is formed of at least 10 wt.% cationic monomer or monomers. Even more preferred polymers, including at least 20 or 30 wt.% cationic Monomeric units. It may be desirable to use cationic polymers having a very high degree of nationali, for example more than 50% up to 80 or even 100% of cationic monomer units. Particularly preferably, when the cation of the second active polymer flocculant selected from the group consisting of cationic polyacrylamide, polymers of diallyldimethylammonium chloride, such as diallyldimethylammonium chloride, dialkylaminoalkyl (meth) acrylates (or their salts) and dialkylaminoalkyl (meth) acrylamido (or their salts). Other suitable polymers include polyvinylidene and modified by Manicho polyacrylamides. Particularly preferred polymers include between 20 and 60 wt.% dimethylaminoethylacrylate and/or methacrylate and between 40 and 80 wt.% acrylamide.

Dose of water-soluble cationic or amphoteric polymer should be an effective amount, and should generally be at least 20 g and usually at least 50 g per ton of dry cellulosic suspension. The dose may be up to one or two pounds per ton, but should usually be within the range of 100 or 150 g / tonne to 800 g / tonne. Usually more effective results are achieved when the dose of water-soluble cationic or amphoteric polymer is at least 200 g / tonne, usually at least 250 g / tonne and often at least 300 g / tonne.

Cationic or amphoteric polymer may be added in the sludge or in the flow of the diluted mixture. Preferably cationic or amphoteric polymer is added to the flow of the diluted mixture, for example in front of one stage of the stages of mechanical destru the tion, such as a mixing pump or centresin. Preferably the polymer is added after at least one stage of mechanical destruction.

Particularly effective results are found when water-soluble cationic or amphoteric polymer is used in conjunction with cationic coagulant. Cationic coagulant may be an inorganic material such as alum, polyaluminium, the trihydrate of aluminum chloride and alamoflorida. However, it is preferable that the cationic coagulant is an organic polymer.

Cationic coagulant is optionally water-soluble polymer, which may, for example, be a relatively low molecular weight polymer of relatively high camionnette. For example, the polymer may be homopolymers any suitable ethylene unsaturated cationic monomer, polymerizing to provide internal polymer viscosity to 3 DL/g is Usually internal viscosity generally be at least 0.1 DL/g, and often within the range from 0.2 or 0.5 DL/g to 1 or 2 DL/g of the Polyvinyl chloride of diallyldimethylammonium (DADMAC) are preferred. Other cationic coagulants include polyethylenimine, polyamideimides and polydicyandiamide.

Low-molecular vysokoaktivnye polymer can aprimarily additional polymer, formed by the condensation of amines with other suitable di - or trifunctional varieties. For example, preferred is a polymer that can be formed by the interaction of one or more amines selected from dimethylamine, trimethylamine and ethylene diamine, etc. and epichlohydrin, epichlorohydrin is preferred. Other suitable cationic coagulation polymers include low molecular weight polyvinylidene charge high density. Polyvinylene can be prepared by polymerization of vinylacetate to form polyvinylacetate with subsequent hydrolysis, leading to polyvinylene. In General, cationic coagulants show the charge density of the cation of at least 2 and usually at least 3 mEq/g and can be up to 4 or 5 mEq/g or higher.

Especially preferred that the cationic coagulant is a synthetic polymer of intrinsic viscosity at least 1 or 2 DL/g, often up to 3 DL/g or higher and shows the charge density of the cation is greater than 3 mEq/g, preferably homopolymer of DADMAC. DD can be prepared by polymerization of an aqueous solution of DADMAC monomer using redox initiators, to provide an aqueous solution of the polymer. Alternative aqueous solution of DADMAC monomer may be suspended in a liquid the parts, not miscible with water, using a suspension agents, e.g. surfactants or stabilizers, and polymerisation to form polymer beads DADMAC.

Particularly preferred cationic coagulant is a relatively high molecular weight DADMAC homopolymer, which shows the internal viscosity of at least 2 DL/g, Such a polymer can be manufactured by preparing an aqueous solution containing DADMAC monomer, a radical initiator, or a mixture, which is a radical initiators at or between 0.1 and 5%, based on the monomer and optional chelating agent. Heat this mixture of monomer at a temperature below 60°C in order to polimerizuet monomer to homopolymer with a level conversion between 80 and 99%. Then subsequent processing of this homopolymer heating bilateral temperature between 60 and 120°C. Typically, this DADMAC polymer can be prepared in accordance with the description given in PCT/EP 2006/067244.

An effective amount of the dose of cationic coagulant will typically be at least 20 g and usually at least 50 g per ton of dry cellulosic suspension. The dose may be up to one or two pounds per ton, but should usually be within the range of 100 or 150 g / tonne to 800 g / tonne. Usually more effective results are achieved when the dose of water is soluble cationic or amphoteric polymer is at least 200 g / tonne, usually at least 250 g / tonne and often at least 300 g / tonne.

Water-soluble cationic or amphoteric polymer and cationic coagulant can be added sequentially or simultaneously. Cationic coagulant may be added in a dense mix or dilute the mixture. In some circumstances it may be useful to add a cationic coagulant in a mixing VAT or solvent Chan or alternatively in one or more dense component of the mixture. Cationic coagulant can be added to water-soluble cationic or amphoteric polymer, or alternatively it can be added after the water-soluble cationic or amphoteric polymer. Preferably, however, water-soluble cationic or amphoteric polymer and cationic coagulant is added to the pulp slurry as a mixture. This mixture may be referred to as retention system cat/cat.

In General, water-soluble cationic or amphoteric polymer should have a higher molecular weight (and internal viscosity)than the cationic coagulant.

The amount of the mixture cat/cat should normally be as stated above for each of these two components. In General we find that dosage only one cationic or amphoteric polymer sludge is a mixture of cat/cat is lower in comparison with the system, which is not included branched anionic polymer.

Water-soluble branched anionic polymer may be any suitable water-soluble polymer that has at least some degree of branching or structure, provided that the structuring is not excessive enough to cause insolubility of the polymer.

Preferably the water-soluble branched anionic polymer has

(a) intrinsic viscosity higher than 1.5 DL/g and/or the viscosity Brookfield (viscosity UL) salt solution above about 2.0 MPa·s and

(b) rheological variations of tan Delta at 0.005 Hz of above 0.7 and/or

(c) the coefficient of viscosity of deionized SLV, which is at least three times the coefficient of viscosity salt SLV corresponding unbranched polymer made in the absence of branching agent.

Anionic branched polymer formed from a water soluble monomer mixture containing at least one anionic or potentially anionic ethylene unsaturated monomer and a small amount of a branching agent, for example as described in WO-A-9829604. In General, the polymer may be formed from a mixture of 5-100 wt.% anionic water-soluble monomer and from 0 to 95 wt.% nonionic soluble what about the water monomer.

Usually water-soluble monomers have a solubility in water of at least 5 g/100 cm3. The anionic monomer is preferably selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, crotonic acid, basis of itaconic acid, 2-acrylamide-2-methylpropanesulphoacid, arylsulfonate and vinylsulfonate and their alkali or ammonium salts. The nonionic monomer is preferably selected from the group consisting of acrylamide, methacrylamide, N-vinylpyrrolidone and hydroxyethylacrylate. Particularly preferred branched polymer contains sodium acrylate with a branching agent or acrylamide, sodium acrylate and branching agent.

The branching agent can be any chemical material which causes branching reaction through carboxyl or other side groups (for example, epoxide, silane, polyvalent metal or formaldehyde). Preferably the branching agent is polyethylene unsaturated monomer included in the monomer mixture from which the formed polymer. The amount of branching agent must vary according to the characteristics of the branching agent. Thus, using polyethylene unsaturated acrylic branching agents, such as methylene-bis-acrylamide, the molar amount is usually below 3 molar frequent. per million and preferably below 20 frequent. per million Generally it is below 10 frequent. per million and most preferably below 5 frequent. on million the Optimum amount of branching agent is preferably from about 0.5 to 3 or 3.5 molar frequent. per million or even 3.8 frequent. per million, but in some cases it may be desirable to use a 7 or 10 frequent. in million

Preferably the branching agent soluble in water. Typically, this can be a bifunctional material, such as methylene (bis) acrylamide, or it may be trifunctionally, tetrafunctional or a crosslinking agent of higher functionality, for example the chloride of tetraalkylammonium. Generally because of allyl monomer tends to have a lower constants of polymerization, they are polymerized with less readiness, and thus is common practice, the use of plastic unsaturated allylic branching agents, such as chloride of tetraalkylammonium to use higher levels, for example 5 to 30 or even 35 molar frequent. per million or even 38 frequent. per million and even up to 70 or 100 frequent. in million

Also, it may be desirable to enable the regulator to the degree of polymerization of the chains in the monomer mixture. Where the regulator polymerization degree is enabled, it can be used in amounts of at least 2 frequent. per million by mass and mo is et to be included in the amount up to 200 frequent. per million by weight. Usually the number of control degrees of polymerization can be in the range of 10-50 frequent. per million by weight. Control degree of polymerization may be any suitable chemical, such as sodium phosphate, 2-mercaptoethanol, malic acid or thioglycolate acid. Preferably, however, the anionic branched polymer prepared in the absence of added control degree of polymerization.

Anionic branched polymer is generally in the form of emulsion, water-in-oil or dispersion. Typically, the polymers are produced by polymerization of the opposite phase of the emulsion, to form a reverse phase emulsion. This product usually has at least a particle size of 95 wt.% below 10 microns and preferably at least 90 wt.% below 2 μm, for example substantially above 100 nm and particularly substantially in the range of 500 nm to 1 μm. The polymers can be prepared by conventional methods of polymerization opposite phase emulsion or microemulsion.

Tan Delta at value 0.005 Hz obtained using a rheometer with controlled indignation in the form of vibrations to 1.5 wt.% an aqueous solution of the polymer in deionized water after treatment in the drum for two hours. In the course of this work were used Carrimed CSR 100, equipped with a 6 cm cone, with the cone angle 1°58' and the value at which ecene 58 μm (link 5664). Used sample volume of approximately 2-3 cm3. The temperature was controlled to about 20.0°C±0.1°C using a Peltier module. The angle of deviation of 5×10-4the radian was used during the sweep frequency from 0.005 Hz to 1 Hz in 12 stages on a logarithmic basis. G' and G" dimension is registered and has been used to calculate the value of tangent Delta (G"/G'). The value of tan Delta is the ratio of the modulus (viscous) losses G" to the module (elastic) accumulation G' within the system.

At low frequencies (0.005 Hz) it is believed that the rate of deformation of the sample is sufficiently slow to allow linear or branched confusing chains to unravel. Mesh or custom made systems have a constant tangle of chains and show a low value of tan Delta at the ends of a wide range of frequencies. Therefore, in order to characterize the properties of the polymer in the aquatic environment, there is a low frequency (e.g., 0.005 Hz) measurements.

Anionic branched polymers should have a value of tan Delta at 0.005 Hz of above 0.7. Preferred anionic branched polymers have a value of tan Delta of 0.8 at 0.005 Hz. The value of tan Delta can be at least 2 DL/g, for example at least 4 DL/g, especially at least 5 or 6 DL/g, it May be desirable to provide polymers being is but a higher molecular weight, which show intrinsic viscosity of up to 16 or 18 DL/g, However, the most preferred polymers have an intrinsic viscosity in the range of 7-12 DL/g, especially 8-10 DL/g

Preferred branched anionic polymer can also be characterized in relation to the corresponding polymer made under the same conditions of polymerization, but in the absence of branching agent (i.e., "non-branched polymer"). Unbranched polymer typically has an intrinsic viscosity of at least 6 DL/g and preferably at least 8 DL/g this is Often 16-30 DL/g, the Amount of branching agent is generally such that the internal viscosity is reduced by 10-70%, or sometimes up to 90%, the initial value (expressed in DL/g) for an unbranched polymer mentioned above.

The viscosity Brookfield (viscosity UL) of the polymer was measured by preparing a 0.1 wt.% an aqueous solution of the active polymer in 1M aqueous NaCl solution at 25°C. using a Brookfield viscometer, fitted with UL adapter to 6 revolutions per minute. Thus, the powdered polymer or polymer of opposite phase must be first dissolved in deionized water to form a concentrated solution, and the concentrated solution was diluted with 1M aqueous NaCl. The viscosity of the salt solution is usually higher than 2.0 MPa·s and is often as mi is imum 2.2 and preferably at least 2.5 MPa·S. In many cases it is not more than 5 MPa·s, and the magnitude of 3-4 are usually preferred. They all measured at 60 revolutions per minute.

Viscosity coefficients of the SLV characterizing the anionic branched polymer, determined using a glass viscometer with a suspended level at 25°C. the viscometer was chosen to match according to the viscosity of the solution. The coefficient of viscosity η-ηaboutaboutwhere η and ηaboutare the results of the viscosity of aqueous solutions of polymer and non-solvent, respectively. It can also be referred to as the relative viscosity. Coefficient of viscosity of deionized solution SLV is the coefficient obtained for 0.05% aqueous solution of the polymer prepared in deionized water. Coefficient of viscosity of the salt solution SLV is the coefficient obtained for 0.05% aqueous solution of the polymer prepared in 1M sodium chloride.

The coefficient of viscosity of deionized solution SLV is preferably at least 3 and, in General, at least 4, for example up to 7, 8 or higher. Best results are obtained when it is above 5. Preferably it is higher than the coefficient of viscosity of deionized solution for SLV unbranched polymer, i.e. a polymer made under the same conditions of polymerization, but in the absence of branching agent (and p is that with a higher internal viscosity). If the coefficient of viscosity of deionized solution SLV is not higher than the coefficient of viscosity of deionized solution SLV unbranched polymer, preferably it is at least 50% and usually at least 75% of the coefficient of viscosity of deionized solution SLV unbranched polymer. The coefficient of viscosity of the salt solution SLV usually below 1. The coefficient of viscosity of deionized solution SLV often at least five times, and preferably at least eight times the coefficient of viscosity of the salt solution SLV.

Water-soluble branched anionic polymer may consequently be added to the pulp suspension at a dose of at least 10 g / tonne, calculated on the dry weight. The number can be as much as 2000 or 3000 g / tonne or above. Preferably the dose will be between 100 g / tonne and 1000 g per ton, more preferably between 150 g / tonne and 750 g / tonne. More preferably still, the dose often needs to be between 200 and 500 g / tonne. All doses are based on weight of active polymer on the dry weight of the pulp suspension.

Water-soluble branched anionic polymer may consequently be added at any convenient point in the method, such as a dilute mixture of suspension or alternative in the sludge suspension. In some cases it may be desirable to add the anionic branched polymer in a mixing VAT, the solvent Chan or perhaps one, or more, are components of the mixture. Preferably, however, the anionic branched polymer to be added to the diluted mixture slurry. The exact insertion point can be before one of the stages of cleavage. Typically, these stages include splitting stage mixing, pumping and cleaning or other stages, which include mechanical degradation of cereal. Optional stage splitting selected from one or more of the mixing pumps or centresin. This alternative anionic polymer can be added after one or more mixing pump, but before centresin, or in some cases after centresin.

Phase splitting can be considered as stages of mechanical breakdown, preferably acting on the flocculated suspension thus, as the destruction of the flakes. All system components retention/dehydration can be added to the stage of cleavage, although preferably at least the last component of the system retention/dehydration added to the pulp suspension at the point-of-way where there is no significant shift before dehydration to form a sheet. Thus it is preferable that at least one system component retention/dehydration added to the pulp is Uspenskii, and loose flakes suspension thus formed is then subjected to mechanical splitting, in which the flakes are mechanically destroyed, and then at least one system component retention/dehydration added to relocalising slurry to dewatering.

Anionic branched polymer can be added to the pulp suspension, and then flocculated suspension formed in this way, you can pass through one or more stages of cleavage.

Cationic or amphoteric polymer may be added to re-relocalising suspension, which can then be subjected to further mechanical breakdown. Split Belokurova suspension may also flocculating the addition of the third component. This third component of the system retention/dehydration include, for example, where the cationic coagulant is used in addition to water-soluble cationic or amphoteric polymer and anionic branched polymer. Alternative cationic coagulant can be added to re-relocalising split suspension, which may be subjected to additional mechanical breakdown, followed by an additional stage of flocculation time to relax is by cationic or amphoteric polymer.

However, we have found that particularly effective results in terms of improved retention of the ash relative to the full retention is achieved in the method, where the anionic water-soluble branched polymer is added to the diluted mixture, suspension, followed by adding at least a cationic or amphoteric polymer and preferably also water-soluble cationic coagulant, here called retention system cat/cat.

Therefore water-soluble branched anionic polymer optionally in advance is present in the pulp suspension before adding the water-soluble cationic or amphoteric polymer and using cationic coagulant. This insertion order is unusual, as many known methods is a common practice to add a cationic additive retention and especially any cationic coagulant to any anionic polymer additive retention.

When water-soluble branched anionic polymer is added to the pulp suspension, it usually causes the flocculation of suspended solids. Preferably the pulp suspension is subjected to at least one stage, which causes mechanical destruction before adding the water-soluble cationoid the main or amphoteric polymer or the so-called system cat/cat. In General, the pulp suspension can be passed through one or more of these stages. Typically, these stages are the stages of cleavage, which include the stage of mixing, pumping and purification, such as one of the mixing pumps or centresin. In a more preferred object of the method of water-soluble branched polymer is added before centresin and water-soluble cationic or amphoteric polymer, and where used, the system cat/cat is added to the pulp slurry after centresin.

Paper or cardboard can contain any type of short or long fibers of cellulose, for example cellulose, manufactured sulfite or sulfate (Kraft) method. Unlike wood mass lignin significantly removed from the pulp.

Preferably, the paper or cardboard contains at least 10% wood fiber, calculated on the dry weight of the suspension. Usually the paper with filler sorted filler, representing the dominance of the most fine-grained particles, relative to the increase in the reduction of fine particles, as determined with a scanning laser microscopy in the paper mixture compared with full retention, indicates the potential for higher retention of the ash relative to the total holding.

Being unlimited by theory we believe that manufacturing is a free paper from highly filled (i.e. at least 10 wt.% filler) paper pulp containing wood fiber, the initial processing of the anionic branched polymer, followed by processing of the cationic or amphoteric polymer or cat/cat or otherwise causes interaction, causing a greater retention of fine and colloidal particle size of the filler.

Paper with a filler may be any suitable paper made from a pulp slurry containing wood fiber and at least 10 wt.% filler, calculated on the dry weight of the diluted mixture. For example, the paper may be lightweight coated paper (LWC), or more preferably it is SC paper (SC paper).

Under the wood fiber we mean that the pulp suspension includes wood pulp, which means any wood that is produced wholly or partly by mechanical means, including wood, a stone-ground (SGW), thermomechanical wood pulp (TSR), chemicomechanical wood pulp (STMR), bleached chemicomechanical wood pulp (STMR) or wood treated with high pressure (PGW). Varieties of paper with a wood filler contain different amounts of wood pulp, which is usually included to provide desirable optical is a mini and mechanical properties. In some cases, the mass used in the creation of paper with a filler, may be formed entirely of one or more of the above-mentioned wood wt. In addition to wood weight other weight is often included in the pulp suspension. Usually another mass can form at least 10 wt.% full of fiber content. These other mass included in the formulation of paper, include purified from paint mass and sulfate mass (often called Kraft pulp).

The preferred composition for paper SC is characterized by the fact that the faction fiber contains purified from paint weight wood pulp and sulphate mass. The contents of the pulp may vary between 10 and 75%, preferably between 30 and 60 wt.% the General content of the fiber. The content of the mass, purified from paint (often referred to as DIP)can be anything between 0 and 90%, usually between 20 and 60 wt.% the total number of fibers. The content of sulfate mass usually varies between 0 and 50%, preferably between 10 and 25 wt.% the total number of fibers. The total amount of the components should be 100%.

The pulp slurry may contain other ingredients such as cationic starch and/or coagulants. Usually in paper mixture can be cationic starch and/or coagulants to add system retention/dehydration and this is gaining. Cationic starch may be present in amounts of between 0 and 5%, typically between 0.2 and 1 wt.% cellulose fibers. The coagulant is usually added in an amount up to 1 wt.% cellulose fiber, usually between 0.2 and 0.5%.

Optionally, the filler can be traditionally used filling material. For example, the filler may be a clay, such as kaolin, or may be calcium carbonate, which can be crushed calcium carbonate or preferably precipitated calcium carbonate (PCC). Another preferred filler material includes titanium dioxide. Examples of other filler materials include synthetic polymeric fillers.

In General, the pulp mixture used in this invention will preferably contain substantial amounts of filler, usually more than 10%, calculated on the dry weight of the pulp mixture. However, as a rule, the pulp mixture, which contains a significant quantity of filler is more difficult for flocculation than the pulp mixture to be able to have grades that do not contain or contain less filler. This is especially true for fillers of very fine particle size, such as precipitated calcium carbonate, made in paper mixture as a separate Supplement or, as is sometimes occurs added with purified from paint by mass or other secondary fiber.

The present invention provides the ability to make highly filled paper from a pulp mixture containing high levels of filler and also containing wood fibre, such as SC-paper or coated paper for gravure printing, for example LWC with excellent retention and the formation and maintained at the same level or decreased dehydration, which takes into account the best control dehydration of the mixture on the grid bumagodelatelnoe machine. Usually the paper weight must contain significant levels of filler in the diluted mixture, usually at least 25% or at least 30 wt.% dry suspension. Often the amount of filler in the composition of the paper pulp of polyparaphenylenes before dewatering the slurry to form a sheet, up to 70 wt.% dry suspension, preferably between 50 and 65% filler. Optionally, the last piece of paper will include 40% filler by weight. It should be noted that conventional varieties of paper SC contain between 25 and 35% filler in the sheet.

Preferably the control method using bumagodelatelnuju machine with extremely rapid dehydration, especially those bumagodelatelnye cars that have twin-wire forming part of the extremely rapid dehydration, the features of the machine, called Gapformers or Hybridformers. The invention is particularly suitable for the production of paper grades with a high content of wood mass, such as SC-paper on bumagodelatelnyh machines, where the loss of the filling material must occur otherwise. The method allows the retention and formation to be balanced in an optimized manner, greatly improving the retention of filler usually bumagodelatelnyh machines, known as Gapformers and Hybridformers.

In the method of the present invention, we find that, in General, an initial General retention and retention of ash can be adjusted to any suitable level depending on the needs of fashion and production. Grade SC-paper is usually produced at lower levels of retention and retention of ash than other varieties of paper such as bond paper, filled carbon paper, cardboard or newsprint. In General, the initial levels of total holdings stretch from 30 to 60 wt.%, usually between 35 and 50%. Typically, the retention rate of ash can be in the range from 15 to 45 wt.%, usually between 20 and 35%.

When made paper containing component is wood fiber, especially grade SC-paper, particularly preferred system according to the invention should apply DD to the to the cationic coagulant, especially when the cationic coagulant is used in the system cat/cat, in which DADMAC is used in conjunction with high molecular weight cationic or amphoteric polymers, especially cationic polymer. We find specific improvements in retention of the ash relative to the total holding.

One preferred object includes the creation of paper or paperboard, containing recycled fiber, such as DIP (purified from paint weight). Typically, this paper may be, for example, newsprint or packing paper or cardboard. We found that significant improvements in retention of the ash relative to the full retention obtained in a preferred method according to the present invention, using any cationic coagulant, especially in systems cat/cat, in which the cationic coagulant is used in combination with amphoteric or especially cationic polymer.

The following examples illustrate the invention.

Examples

Ways

1. Preparation of polymers

All polymers and coagulants prepared as a 0.1% aqueous solutions based on the active substances. Premixes consist of 50% of high-molecular polymer and 50% of the coagulant and mixed together as a 0.1% aqueous solutions before they are added to pulp.

Starch was prepared for the 1%aqueous solution.

2. The polymers used in examples

Polymer A: linear polyacrylamide, IV=9, 20% of the charge of the cation. A copolymer of acrylamide with methylchloride Quaternary ammonium salt of dimethylaminoethylacrylate (80/20 wt./wt.) intrinsic viscosity above 9.0 DL/g

Polymer: Anionic branched copolymer of acrylamide to acrylamide sodium (60/40), made from 3.5 to 5.0 frequent. per million by weight methylene (bis) acrylamide, branching agent, as described in the invention. The product has a value of rheological variations of tan Delta at 0.005 Hz 0.9. The product is supplied as a dispersion in mineral oil basis with 50% of active substances.

The polymer: Anionic substantially linear copolymer of acrylamide to acrylamide sodium (60/40 wt./wt.) and IV 0.7 DL/g

Polymer D: 50%aqueous polyamine = solution of poly(epichlorhydrine) with 50% of active substances, 6-7 .0 mEq/g, IV=0.2; GPC molecular weight of 140,000.

Polymer E: DADMAC in aqueous solution with 20% of the active substances and IV 1.4 DL/g, 6.2 mEq/g

Polymer F: linear polyacrylamide, IV=9, the cation charge of 22%. A copolymer of acrylamide with methylchloride Quaternary ammonium salt of dimethylaminoethylacrylate (78/22 wt./wt.) intrinsic viscosity 9.0 DL/g

System a = Polymer And added after SITA

System = Premix 50% polymer and 50% polymer D, added after the sieve.

System = Premix 50% polymer and 50% polymer E, added after sieve.

System D = Polymer And added to the sieve.

System E = Premix 50% polymer and 50% polymer E, added to the sieve.

System F = Polymer F, is added to the sieve.

3. Paper composition

Composition of high-grade paper

This alkaline cellulose slurry bond paper includes solid particles, which are made of about 90 wt.% fiber and about 10% of the filler of calcium carbonate, which precipitates (RCC). Used RCA was "Calopake F" in the dry form from Specialty Minerals Lifford/UK. Applied fiber fraction was a mixture of 70/30 wt.% bleached bleached birch and pine, chopped Schopper Riegler degree of grinding of 48°to ensure sufficiently fine-grained fraction for real testing conditions. The composition was diluted with tap water to the consistency of approximately 0.61 wt.%, contains fine-grained fractions of approximately 18.3 wt.%, separated by approximately 50% fine-grained fractions of fly ash and 50% fine-grained fractions of the fiber. To paper pulp added 0.5 kg/t of chloride of polyalanine (Alcofix 905) and 5 kg/t (total solids) cationic starch (RaisamyI 50021) with the value of DS 0.035 in terms of dry weight. the pH of the composition of high-grade paper is 7.4±0.1, conductivity approximately 500 μs/m and Zeta-potentialproblem-14.3 MB.

Wood composition 1

Wood pulp, bleached peroxide 60 Canadian standard degree of grinding, complemented Calopake F", RCA in dry form from Specialty Minerals Lifford/UK prior to the ash content of the additives is approximately 20.6 wt.%, diluted to a consistency of about 4.8 g/l, containing fine-grained fraction of approximately 33.8 wt.% accordingly Tappi Method T261, which are components of the fine-grained fractions of approximately 54.5% of fine-grained ash fractions and 45.5% fine-grained fractions of the fiber. The final composition has a Schopper Riegler degree of grinding approximately 40°. To paper pulp added 0.5 kg/t of polyaluminosilicate (Alcofix 905) and 5 kg/t (total solids) cationic starch (RaisamyI 50021) with the value of DS 0.035 in terms of dry weight. the pH of the composition of high-grade paper is 7.4±0.1, conductivity is approximately 500 μs/m, and Zeta-potential of approximately-23.5 MB.

Wood composition 2

Wood pulp, bleached peroxide 60 Canadian standard degree of grinding, supplemented with a suspension of calcium carbonate, which precipitates (Omya F14960) to the ash content of the additives is approximately 10.2 wt.%, diluted to the consistency of approximately 4.6 g/l, containing fine-grained fractions of approximately 28 wt.% accordingly Tappi Method T261, in which additives are separated by approximately 35% chalk is eternity ash fractions and 65% fine-grained fractions of the fiber. To paper pulp added 5 kg/t (total solids) cationic starch (RaisamyI 50021) with the value of DS 0.035 in terms of dry weight. LV end-woody composition is 7.5±0.1, conductivity of approximately 400 μs/m and Zeta-potential of approximately 30 mV.

Wood composition 3

Wood pulp, bleached peroxide 60 Canadian standard degree of grinding, supplemented with a suspension of calcium carbonate, which precipitates (Omya F14960) to the ash content of the additives is approximately 21.8 wt.%, diluted to a consistency of about 0.45 wt.%, contains fine-grained fraction of approximately 40 wt.% accordingly Tappi Method T261, fine-grained fraction containing approximately 56% of fine-grained ash fractions and 44% of the fine-grained fractions of the fiber. To paper pulp added 5 kg/t (total solids) cationic starch (RaisamyI 50021) with the value of DS 0.035 in terms of dry weight. LV end-woody composition is 7.5±0.1, conductivity of approximately 400 μs/m and Zeta-potential of approximately - 31 mV.

Wood composition 4

Bleached a stone-ground wood, supplemented with a suspension of calcium carbonate, which precipitates (Omya F14960) to the ash content of approximately 42 wt.%, diluted to a consistency of about 0.5 wt.%, containing melczer the East faction approximately 59.6 wt.% accordingly Tappi Method T261, which included approximately 70% of the fine-grained fractions of fly ash and 30% fine-grained fractions of the fiber. The final composition has a Schopper Riegler degree of grinding approximately 42°. To paper pulp added 5 kg/t (total solids) cationic starch (RaisamyI 50021) with the value of DS 0.035 in terms of dry weight. LV end-woody composition is 7.1±0.1, conductivity approximately 440 μs/m and Zeta-potential of approximately - 43 mV.

SC-composition 1

The pulp mixture is used to give examples of a typical paper composition containing the wood to make the SC-paper. It consists of 18% purified from paint weight, 21.5% of unbleached wood, a stone-ground, and 50% of mineral filler containing 50% calcium carbonate, which precipitates (RCC), and 50% clay. RCC is Omya F14960, aqueous dispersion of calcium carbonate, which precipitates with 1% auxiliary substances for use in the SC-paper. Clay was Intramax SC Slurry from IMERYS. The final mixture had the consistency of 0.75%, total ash content of approximately 54%, degree of grinding 69° SR (Schopper Riegler method), conductivity 1800 μs/m and the content of fine fractions 65%, respectively Tappi Method T261, which included approximately 80% of the fine-grained fractions of fly ash and 20% fine-grained fractions of the fiber. To the paper weight is e added 2 kg/t (total solids) cationic starch (RaisamyI 50021) with the value of DS 0.035 in terms of dry weight.

SC-song 2

The pulp mixture with 50%ash content made with the consistency of 0.75%, respectively, of composition 1, except that used other purified from paint weight. The degree of grinding 64° SR, the content of fine fractions of 50 wt.%.

Covered coffee composition

This paper suspension for covered varieties of wood-containing mass comprises solid particles, which are composed of about 87 wt.% fiber and approximately 13% of the filler of calcium carbonate. Used fraction of fibers contains 50% of bleached wood pulp treated with high pressure (BPGW), 28% Kraft pulp and 22% of the paper marriage with the floor. The consistency of the mixture is approximately 0.68%.

4. The initial General retention and retention of ashes

Paper sheets 19 cm2were made on a moving belt casting machine using 400-500 ml paper mixture, depending on the type of composition and consistency. Leaves were weighed to determine the initial total retention and the retention of ash using the following formula:

FPTR [%] = weight of the leaf [g] / total number of paper mixture, based on the dry weight [g]·100

FPTAR [%] = ash content in the sheet [g] / total number of paper mixture, based on the dry weight [g]·100

<> The initial total holding, for simplicity, often called the General retention is directly related to the mass basis. Similarly, the initial retention of the ashes, for simplicity, often referred to as holding the ash relative to the total holding, directly associated with the ash content in the sheet. It is typical for the retention of filler. In order to demonstrate the invention, by means of real paper sheet compositions, the ratio between the effects of retention of ash, total retention and the overall reduction of fine-grained fractions are shown as a reduction of fine-grained ash fractions and the total number divided by the mass of the basics.

Moving the tape casting machine (MBF) from Helsinki University of Technology simulates the wet part of your normal clinocerinae bumagodelatelnoe machine (odnoetajnaya machine) on a laboratory scale and is used to make sheets of handmade character. Suspension mass formed on the fabric, which is exactly the same used in industrial machines for the production of paper and cardboard. Moving perforated timing belt produces suscribase and pulsating action, modeling elements remove water, the blades and vacuum copying frame, arranged in a grid behold the tion. Under the timing belt is a vacuum copying frame. The level of vacuum, the speed of the belt and the effective time of suction and other operating parameters are controlled by computer system. The normal frequency range ripple 50-100 Hz and the effective time ranges suction from 0 to 500 MS. In addition to the grid has a mixing chamber that is similar to the Britt Jar, where the composition is cleaved driven propeller stirrer before dehydration to form the sheet. A detailed description of the MBF is given in "Advanced wire part simulation with a moving belt former and its applicability in scale up on rotogravure printing paper", Strengell, K., Stenbacka, U., Ala-Nikkola, J. Pulp & Paper Canada 105 (3) (2004), T62-66. Such is also described in detail in "Laboratory testing of retention and drainage", p.87 in Leo Neimo (ed.), Papermaking Science and Technology, Part 4, Paper Chemistry, Fapet Oy, Jyväskyla 1999.

Retention and dewatering chemical agents dosed in this mixing chamber, shown in table 1. It should be noted that the dosing protocols for experiments with a scanning laser microscopy and MBF are the same as in order to combine the results of the Schopper Riegler, scanning laser microscopy and MBF.

Table 1
Moving the tape casting machine
computer-controlled trial Protocol
Time [seconds]Action
0Beginning with stirring at 1500 rpm
12Add 1thretaining additives
30Stirring at 500 rpm; adding 2thretaining additives
45Mixing at 1500 rpm
75Initial dehydration to form sheet

SLM (laser Scanning microscopy)

Scanning laser microscopy, often called FBRM (measurement of the reflectance of the laser focused beam)used in the following examples, is a measure of the size distribution of the particles in the present time and is outlined in U.S. Pat No.4,871,251 issued Preikschat, F.K. and E. (1989). It consists of 780 nm is focused, a rotating laser beam that passed through the target suspension at a speed of 2-4 m/scalici and cereals intersect the laser beam and reflect part of the light back to the sensor duration Time of the light reflection is detected and converted into the length of the chord [m/s·s=m]. Measurements are not influenced by velocity filtering treatment is CA < 1800 rpm, while the scanning speed of the laser is much faster than the speed of mixing. Ripple of reflected light used to form the histogram 90 registered channels of particle size between 0.8 and 1000 μm with the number of particles per time divided by the length of the chord. The original data can be represented in different ways, for example as the number of particles or chord length divided by time. The arithmetic mean, median and their derivatives numbers as well as different ranges of particle size, can be selected to describe the observed way. Industrial tools are available under the trademark "Lasentec FBRM" from Mettler Toledo, Switzerland. For more information about using SLM in order to control the flocculation can be found in the "Flocculation monitoring: focused beam reflectance measurement as measurement tool", Blanco, A., Fuente, E., Negro, C., Tijero, S. Canadian Journal of Chemical Engineering (229), 80(4), 734-740. Published by: Canadian Society for Chemical Engineering. Additional details are available in the "Focused Beam Reflectance measurement as a tool to measure flocculation". Blanco, A.; Fuente, E.; Negro, C.; Monte, C.; Tijero, J. Chemical Engineering Department of Chemistry. Complutense University of Madrid, Madrid, Spain. The Papermakers Conference, Cincinnati, OH, United States, March 11-14, 2001., p.114-126. Publisher: Tappi Press, Atlanta, Ga, CODEN:69BXON Conference.

The aim of the experiments SLM in this invention determines the removal of fine-grained fractions and colloidal material during flocculation, as it gives a good correlation abstain is the FL ash. In this respect it is particularly interesting to know the amount of fine-grained fractions and colloid removal under dynamic conditions splitting at the end of the laboratory experiment, i.e. at the time when you begin creating a list. In accordance with the Protocol at this time, this time is 75 seconds. Retention of fine-grained fractions and colloid retention measured as [%] of the total number of fine-grained fractions, remote from the reference position. Figure 1 illustrates this by building a curve number of fine and colloidal particles between 0.8 and 10 microns on the background of the course of the experiment. A significant overall reduction in the fine-grained fractions (=value of TFR) better retention of fine-grained fraction and colloid retention at the time of way flocculation.

The value of the TFR is calculated as follows:

The experiment consists of taking 500 ml paper mixture and place it in the appropriate mixing beaker. Composition stir and was cut with variable speed motor and propeller, as standardly configured Britt Jar. Applied sequence dosing is the same as used for moving the tape casting machine, and shown in Table 2. It should be noted that for a better understanding of the Oia, the number of TFR can also be a minus sign, for example, when the enlargement of the filler particles rid of stratification by use of splitting. Particles of filler usually before consolidation by adding cationic starch or alum thick mixture before the actual retention system.

Table 2
Scanning laser microscopy
the testing Protocol
Time [seconds]Action
0Beginning with stirring, installed at 1500 rpm
12Add 1thretaining additives
30Set stirring at 500 rpm; adding 2thretaining additives
45Set stirring at 1500 rpm
75Stop experiment

Example I: Composition 1 bond paper with systems a and b

This example demonstrates the invention in the composition of the pulp. Adding water-soluble anionic,the first polymer additives retention (polymer), mechanical destruction of cereal, relocalize suspension, a solution of water-soluble cationic, the second additive retention (system a or b) increases the ash content in the sheet in the mass basis (see table I.1-3 as well as figures 2 and 3). This has the benefit of allowing the paper sheets to contain higher levels of filler and a reduced level of fibers. It also allows the paper manufacturer to produce a certain mass basis, with a higher level of filler, without adjusting the diluted mixture to a higher load of ash. It should be noted that higher loads ash lead to lower full hold, in which case the consistency of the diluted mixture must be increased to compensate for this effect. In turn, the consistency vysokorazvetvlennyi mixture, combined with low retention, often negatively influence the formation of the sheet, the purity of the system, the ability to resist handling and sheet properties, such as dusting and strength.

Example II: Wood composition 1 with the system And

Wood composition in this example was also prepared according to the example of the composition of high-grade paper based on what bauleni starch and RACES. It seems that the new flocculation system (polymer In front of the sieve + system And after sieves) significantly increases the retention of the ash relative to the total holding. Thus, the method provides a means to enable a larger amount of filler in the paper (see tables II.1, II.2 and figure 5). The preferred retention of ash confirmed increased by reducing material fine particles is between 0.8 and 10 microns (see tables II.1, II.2 and figure 2). The dosage of the total number of active substances to achieve a certain level of ash on weight basis, is also reduced by the proposed method.

Example III: Wood composition 2 systems a and b

The purpose of this example is to show that the present method is also able to increase the level of ash on weight basis in compositions containing anionic dispersed filler. Both systems a and b in conjunction with the anionic branched polymer To provide sheets of paper with a significantly increased levels of ash on weight basis (see tables III.1-4 and figures 8 and 9). The effect is also expressed as improved overall reduction of fine particles on a mass basis (see tables III.1-4 as well as figures 6 and 7). Thus, this allows the sheet of paper sod is neigh higher amount of filler and a reduced level of fiber with a high overall retention. In addition, the full dosage of the polymer Into in connection with the system In terms of retention of ash reduced in comparison with the same system as In the method of the prior art (see tables III.3 and III.4).

Example IV: Wood composition 3 with system a, C, D and E.

We also find that the new way in which the anionic branched polymer is present in dense or dilute the mixture before adding the cationic flocculant or system cat/cat, works in wood compositions with elevated levels of ash in dilute mixtures, for example with 20%filler. This fact is illustrated by system a and C in connection with the polymer Century System And is the standard high-molecular additive retention on the basis of acrylamide, while the system is a typical system cat/cat, including high-molecular and low-molecular flocculant DADMAC coagulant. This example may, for example, to simulate the system for improved newsprint, which is usually used both systems (see table IV.1+2, IV.4+5 and figures 10-12). Combining more filler in the sheet, for example, it is useful to improve the optical density, whiteness and printability./p>

In this specific configuration of the reverse insertion order (D and E), in which the cationic retention system added to the anionic branched polymer is not achieved equal levels of ash on weight basis compared with the method of the invention (a and C). Thus, we find that this method provides particularly good results in wood composites (see table IV.1-6 and figures 10-12).

Example V: Woody composition 4 with systems a and b

By means of example V, we can also show that the method of the invention is effective for highly filled paper wood-containing mass, where for example more than 40 wt.% filler is present in the diluted mixture. Both systems a and b show significantly increased the ash content in the sheet relative to the mass basis, as well as a significant increase in the overall reduction of fine particles in the range between 0.8 and 10 microns (see table V.1-4 and figures 13-16). The addition of the anionic branched polymer In front of the system And increases the level of ash in this way from about 25 to about 27.5 wt.% to 55 g/m2if the LLC compared to the same system As (see figure 15). In addition, the polymer provides a correction for the system from approximately 19 to approximately 23% filler by weight to 50 g/m2sheets (see figure 16). This is a specific application of the invention for highly filled wood composition, for example, applicable for manufacture of varieties of LWC and SC paper.

Example VI: SC-composition 1 with systems a and C

Example VI illustrates the invention for the preferred composition of the SC-paper, characterized in that the fiber fraction contains purified from paint wood and chemical mass, also RCA and clay It becomes apparent from figure 17 that the method of the invention clearly increases the level of ash leaf compared with the system A. Thus, changes in the level of ash from about 31 wt.% filler to about 33 wt.% filler for 63 g/m2sheets (see figure 17). When produce paper wood-containing pulp, especially paper SC, the preferred system should use DD as a cationic component, especially when it is used in conjunction with high molecular weight cationic polymer in the system cat/cat. This is the preferred form of the invention shown in figure 18, where DADMAC contains cat/cat si is theme, valid with and without polymer In front of the system S. the Method of the present invention significantly increases the level of ash in the sheet relative to the weight of the basics and adds this path improvements is approximately 3.5 wt.% filler for 61 g/m2sheet. In addition, dosage systems a and C, as well as a full dose of the polymer, for both systems is reduced by the addition of branched anionic polymer with special rheological characteristics (see table VI.1.4).

Example VII: SC-song 2 with systems b and C

Example VII demonstrates the difference in performance between the branched anionic and substantially linear anionic polymer added to the cationic systems hold in terms of retention of the ash relative to the full retention. It seems that the polymer And the linear anionic non-branched polymer is added to the system, does not have the ability to increase overall reduction in fine particles, respectively, the level of ash on weight basis (see tables 3 and 4 as well as figures 19 and 20). In contrast, the polymer Into in connection with the system increases the retention of the ash relative to the full retention, and the relative level Ude the survival of the fiber will tend to decrease. This has the benefit of allowing the sheets of paper to contain higher levels of filler and a reduced level of fiber. This causes a significant commercial and quality advantages, as the fiber is often more expensive than filler, and improves the whiteness, opacity and printability. Also, don't donate and reduce resistance of the machine and the paper quality due to the cleanliness of the system and the consistency of polyparaphenylenes.

Example VIII: Covered coffee composition with system F

The only system flocculant F is compared with and without the addition of anionic branched polymer In front of the sieve in razmerennuju composition for coated magazine paper. It is evident that the method of the invention provides significantly higher retention of the ash relative to the total holding of approximately 68.2 to 68.4% (see tables 1 and 2). From this it follows that the method of the invention also operates in a wood compositions containing a paper marriage with the floor.

1. Method of making paper or paperboard with improved retention of the ash relative to the full retention, including the steps of providing se is the mixture of pulp suspension, which contains a filler dilution thick mixture slurry to form a diluted mixture of a suspension, in which the filler is present in the diluted mixture slurry in the amount of at least 10 wt.% in terms of the dry mass of the diluted mixture suspension, flocculation thick mixture of suspension and/or a diluted mixture slurry by using a polymer liner system/dehydration, dehydration diluted mixture slurry through the screen to form a sheet, and then drying the sheet, in which the polymeric retention system/dehydration include:
i) a water-soluble branched anionic polymer and
ii) a water-soluble cationic or amphoteric polymer
in which the anionic polymer is present in a dense mix or dilute mixture of the suspension prior to adding the cationic or amphoteric polymer.

2. The method according to claim 1, wherein the water-soluble cationic or amphoteric polymer is a natural polymer or a synthetic polymer which has an intrinsic viscosity of at least 1.5 DL/g, preferably at least 3 DL/g

3. The method according to claim 1 or 2, in which the water-soluble cationic or amphoteric polymer is any of cationic starch, amphoteric starch or a synthetic polymer selected from the group consisting of the cationic or amphoteric polyacrylamide, polyvinylene and polydiallyldimethyl chloride (DD).

4. The method according to claim 1, wherein the water-soluble cationic polymer is used in combination with cationic coagulant.

5. The method according to claim 4, in which the water-soluble cationic or amphoteric polymer and cationic coagulant is added to the pulp suspension in the mixture.

6. The method according to claim 4 or 5, in which the cationic coagulant is a synthetic polymer of intrinsic viscosity of up to 3 DL/g and shows the charge density of the cation is greater than 3 mEq/g, preferably homopolymer of DADMAC.

7. The method according to claim 1 in which the anionic polymer is a water-soluble branched polymer that has a
(a) intrinsic viscosity higher than 1.5 DL/g and/or the viscosity Brookfield the above salt solution of approximately 2.0 MPa·s, and
(b) the magnitude of flow fluctuations of tan Delta at 0.005 Hz of above 0.7 and/or
(c) the coefficient of viscosity of deionized SLV, which is at least three times the SLV viscosity of the corresponding unbranched polymer made in the absence of branching agent.

8. The method according to claim 1, in which the pulp suspension containing anionic branched polymer, is subjected to at least one stage, which causes mechanical destruction before adding cationactive the CSO or amphoteric, and where used retention system cat/cat.

9. The method according to claim 1 in which the anionic branched polymer is added before centresin and cationic or amphoteric polymer, and where used retention system cat/cat is added to the pulp slurry after centresin.

10. The method according to claim 1, in which the paper filler is SC paper (SC paper).

11. The method according to claim 1, in which the wood pulp is selected from the group consisting of wood, a stone-ground (SGW), thermomechanical pulp (TSR), chemicomechanical wood pulp (STMR), bleached chemicomechanical wood pulp (STMR) and mixtures thereof.

12. The method according to claim 1, wherein a content of wood fibers is between 10 and 75%, calculated on the dry weight of the pulp suspension, preferably between 30 and 60%.

13. The method according to claim 1, wherein the filler is present in the diluted mixture slurry in the amount of at least 10 wt.% in terms of the dry mass of the diluted mixture suspension.

14. The method according to item 13, in which the filler is selected from the group consisting of calcium carbonate, titanium dioxide and kaolin, preferably calcium carbonate, which precipitates.

15. The method according to item 13 or 14, in which the filler is present in the pulp slurry prior to dewatering, extending t is at least 30 wt.% in terms of dry weight of the suspension, preferably between 50 and 65%.

16. The method according to claim 1, wherein the method is performed on the paper machine GAPformer.



 

Same patents:

FIELD: textile, paper.

SUBSTANCE: method includes provision of a thick mixture of suspension, which contains wood mass and a filler. The thick suspension mix is dissolved to form a diluted mix of suspension, in which the filler is available in amount of at least 10 wt % in terms of dry mass of dissolved suspension mix. The thick mix and/or dissolved mix of the suspension are flocculated, using a polymer system of retention/dehydration. The dissolved mixture of suspension is dehydrated on a sieve to form a sheet, and then the sheet is dried. The polymer system of retention/dehydration contains the following: i) a water-soluble branched anion-active polymer and ii) a water-soluble cation-active or amphoteric polymer. The method may be realised on paper-making machines of quick dehydration, such as GAP former.

EFFECT: improved retention of ash with reduction of dehydration.

16 cl, 26 dwg, 46 tbl, 16 ex

FIELD: textile, paper.

SUBSTANCE: full bleaching/extraction of craft cellulose fibres is carried out with a chorine agent. Afterwards fibres are washed and exposed to contact in solution with at least one optical bleach (OB) upstream the mixing box and the discharge box of the machine. Fibres in solution have consistency from 7 to 15%, pH of solution in process of contact of fibres with OB makes from 3.5 to 5.5, temperature of contact makes from 60 to 80°C, and time of contact is from 0.5 to 6 hours. Additional contact of OB with fibres is carried out in the device for coating application or in the gluing press. Contact may be carried out at the stage of storage, both at high density and low density of the craft-cellulose fibres, and also at the stage of refinement.

EFFECT: improved whiteness and brightness of fibres when using lower quantity of OB.

19 cl, 11 dwg, 12 tbl, 6 ex

FIELD: textile, paper.

SUBSTANCE: according to one version, method includes provision of aqueous suspension that contains cellulose fibres. Addition of cation polysaccharide and polymer P2, which is an anion polymer, to produced suspension after all points of high polymer P1 shearing force, and P1 polymer is an anion polymer. Then water is removed from produced suspension to form paper. According to the other version, auxiliary agents are added for drainage and retention to produced suspension of cellulose fibres after all points of high shearing force. The latter are represented by a cation polysaccharide and polymer P2, being an anion polymer.

EFFECT: improved drainage without deterioration in retention and forming of paper, increased speed of paper-making machine and application of lower doses of polymer.

34 cl, 5 tbl, 5 ex

The invention relates to the production of paper and can be used in the pulp and paper industry (PPI) for securities in a neutral environment on the basis of wood pulp and wood chemical thermomechanical pulp (CTMP), for example offset printing paper and newsprint paper for printing Newspapers and high offset printing methods

FIELD: textile, paper.

SUBSTANCE: method includes provision of a thick mixture of suspension, which contains wood mass and a filler. The thick suspension mix is dissolved to form a diluted mix of suspension, in which the filler is available in amount of at least 10 wt % in terms of dry mass of dissolved suspension mix. The thick mix and/or dissolved mix of the suspension are flocculated, using a polymer system of retention/dehydration. The dissolved mixture of suspension is dehydrated on a sieve to form a sheet, and then the sheet is dried. The polymer system of retention/dehydration contains the following: i) a water-soluble branched anion-active polymer and ii) a water-soluble cation-active or amphoteric polymer. The method may be realised on paper-making machines of quick dehydration, such as GAP former.

EFFECT: improved retention of ash with reduction of dehydration.

16 cl, 26 dwg, 46 tbl, 16 ex

FIELD: textile, paper.

SUBSTANCE: method includes moistening pulp lap with water solution of sodium salt of carboxymethylcellulose (NaCMC), included into composition of the paste made of a filler (chalk), mixed with a solution of NaCMC at the filler ratio of NaCMC equal to 100:(1-2). Production of moisture-saturated air suspension of fibres with filler from it. Forming a fibrous later on a shaping mesh. Moistening of a fibrous layer between two clothes, pressing and drying of a paper leaf. The filler is added as a paste, which contains 30% of dry substance. Moistening of a fibrous layer prior to pressing is carried out with a starch solution with concentration of 0.7-1.3%.

EFFECT: increased retention of filler in paper at simultaneous increase of paper strength index.

3 cl, 1 tbl, 4 ex

FIELD: chemistry.

SUBSTANCE: aqueous polysilicate composition is meant for producing paper and cardboard and can be used in pulp and paper industry. The aqueous polysilicate composition contains a component based on polysilicate microgel combined with particles obtained from colloidal polysilicate. The method of preparing the aqueous polysilicate composition involves mixing aqueous colloidal polysilicate with an aqueous phase of polysilicate microgel. This composition or a composition obtained using the method described above can be used as a flocculant when producing paper and cardboard. The method of producing paper or cardboard involves preparation of a cellulose suspension and flocculation of said suspension using a flocculation system containing said polysilicate composition. The suspension is then drained on a mesh to form a sheet which is then dried.

EFFECT: high efficiency of the disclosed aqueous polysilicate composition owing to improved holding or draining when making paper or cardboard, as well as stability thereof during storage.

24 cl, 11 tbl, 3 ex, 9 dwg

FIELD: textile, paper.

SUBSTANCE: cellulose product comprises thermoplastic microspheres and a charged aromatic acrylamide polymer. The method to produce a cellulose product includes provision of an aqueous solution of suspension that contains cellulose fibres. Addition of thermoplastic microspheres and the charged aromatic acrylamide polymer into the suspension, and dehydration of the produced suspension. Thus made cellulose product may be used as a cardboard for liquid packing.

EFFECT: reduced porosity of a cellulose product as its volume increases and improved resistance of a wick edge to penetration of aqueous liquids for cellulose products.

25 cl, 3 tbl, 4 ex

FIELD: textile, paper.

SUBSTANCE: method of filler treatment includes formation of a mixture of an aqueous suspension of filler and aqueous anion latex. The latter is a dispersion of acrylic polymer with vitrification temperature (T v) from - 3 to 50°C. This mix is mixed with water at the temperature that is higher than T v of latex, at the same time the specified water has temperature of 40-98°C. The specified suspension of the filler comprises a solid disperse filler selected from the group containing kaolin clay, ground calcium carbonate, deposited calcium carbonate, deposited calcium sulfate, talc and mix of two or more of them. The specified acrylic polymer is selected from the group containing copolymers n-butylacrylate-acrylonitrile-sterol and copolymers n-butylacrylate-sterol. The aqueous composition of the filler contains the solid dispersed filler specified above with solid particles of anion latex polymer specified above and adsorbed on them, in aqueous carrier. The treated filler contains the solid dispersed filler specified above with solid particles of anion latex polymer specified above and adsorbed on them. The pulp charge contains pulp fibres and the solid dispersed filler specified above with solid particles of anion latex polymer specified above and adsorbed on it, in aqueous carrier. Method to make paper from the above specified pulp charge containing pulp fibres. The paper product made of pulp fibres and solid disperse filler, where the specified filler has solid particles of anion latex polymer specified above absorbed on it, with size of solid polymer particles of 30-200 nm and in amount of 1-100 kg of latex per 1 t of filler relative to dry mass of solid substances of latex and filler, and the specified filler has average size of particles of 0.1-30 mcm.

EFFECT: improved retention of the filler, continuous execution of the filler treatment method to improve fixation of anion latex on the filler for a short period of time due to irreversible fixation of anion latexes on particles of the filler and time stability of aggregated filler suspension, latex-treated deposited calcium carbonate is more acid-resistant, and when used to make paper from wood mass under neutral conditions less acid is required to control pH.

21 cl, 14 dwg, 8 ex

FIELD: textile, paper.

SUBSTANCE: method includes dissolution of cellulose and its grinding down to specified extent of grinding. Preparation of the first dispersion with application of return water, containing fibres of microcrystal cellulose, produced by its grinding in mixture with titanium dioxide and calcium hydroxide in specified amount. The second dispersion is prepared from cellulose fibres with application of return water. Then the first suspension is mixed with the second, and produced mixture is treated with carbon dioxide. In case of this treatment calcium hydroxide under action of carbon dioxide results in production of chemically deposited chalk and production of paper mass at specified ratio of components. Grinding of microcrystalline cellulose in mixture with titanium dioxide and calcium hydroxide is carried out in vibration mill with provision of impact and wear effect at mixture.

EFFECT: increased extent of fillers retention in paper, improvement of its printing properties, provision of possibility to vary bulk and porosity of paper, provision of possibility to use fully closed cycle of return water.

1 tbl, 8 ex

FIELD: textile, paper.

SUBSTANCE: according to one version, method includes provision of aqueous suspension that contains cellulose fibres. Addition of cation polysaccharide and polymer P2, which is an anion polymer, to produced suspension after all points of high polymer P1 shearing force, and P1 polymer is an anion polymer. Then water is removed from produced suspension to form paper. According to the other version, auxiliary agents are added for drainage and retention to produced suspension of cellulose fibres after all points of high shearing force. The latter are represented by a cation polysaccharide and polymer P2, being an anion polymer.

EFFECT: improved drainage without deterioration in retention and forming of paper, increased speed of paper-making machine and application of lower doses of polymer.

34 cl, 5 tbl, 5 ex

FIELD: textile; paper.

SUBSTANCE: method (in version) concerns paper manufacturing and can be applied in pulp and paper industry. Method involves: (i) supply of water suspension containing pulp fiber, (ii) adding to suspension after the last point of severe shear force exposure of: (a) first anion component of anion organic polymer soluble in water; (b) second anion component of anion organic polymer dispersed in water or branched organic polymer; and (c) third anion component of anion material containing silicon; and (iii) dehydration of obtained suspension to produce paper. Also invention concerns composition (in version) including first, second and third anion components, and application of the composition as flocculation agent in production of pulp mass and paper for water treatment.

EFFECT: improved water drainage and retaining during paper manufacturing out of any type of pulp suspensions, accelerated operation of paper-making machine, reduced polymer dosage applied.

56 cl, 3 tbl, 4 ex

FIELD: textile; paper.

SUBSTANCE: method consists of adding to the paper sheets approximately 0.05 pounds/ton to 15 pounds/ton, in accordance with the dry fibers, one or several polymers, functioning as aldehyde, containing amino or amido group, where, at least, 15 molar percent amino or amido group function with one or several aldehydes and where the functionaling aldehyde polymers have a molecular weight of not less than approximately 100000.

EFFECT: increased activity for drying due to a reduction in the amount of polymer.

14 cl, 5 ex

FIELD: paper.

SUBSTANCE: paper base contains fibers of coniferous and deciduous wood, or their mixtures, which have average length that is more or equal to 75 mcm and have filler fixed to part of these fibers, and also less than 50 wt % of fibers have average length less than 75 mcm from total weight of base. Paper mass is produced by contact of deciduous or coniferous wood fibers or their mixtures having average length of 75 mcm and having filler fixed to part of mentioned fibers, with fibers average length of which is less than 75 mcm, from total weight of base.

EFFECT: improved smoothness of paper.

20 cl, 25 dwg, 3 tbl, 3 ex

FIELD: textile, paper.

SUBSTANCE: method includes provision of a thick mixture of suspension, which contains wood mass and a filler. The thick suspension mix is dissolved to form a diluted mix of suspension, in which the filler is available in amount of at least 10 wt % in terms of dry mass of dissolved suspension mix. The thick mix and/or dissolved mix of the suspension are flocculated, using a polymer system of retention/dehydration. The dissolved mixture of suspension is dehydrated on a sieve to form a sheet, and then the sheet is dried. The polymer system of retention/dehydration contains the following: i) a water-soluble branched anion-active polymer and ii) a water-soluble cation-active or amphoteric polymer. The method may be realised on paper-making machines of quick dehydration, such as GAP former.

EFFECT: improved retention of ash with reduction of dehydration.

16 cl, 26 dwg, 46 tbl, 16 ex

FIELD: textile, paper.

SUBSTANCE: paper base is designed to form a decorative material of a coating. It represents a non-processed paper containing a white pigment and/or fillers and is coated with a covering solution, containing at least one water-soluble modified starch with special distribution of molecules according to molecular weight. Also a decorative paper or decorative material is proposed to form coatings with application of the above-specified paper-base.

EFFECT: improved quality of a finished product due to increased inner strength of fixation with high non-transparency and other mechanical properties, improved stability of paper size stability and increased average size of its pores.

7 cl, 2 tbl, 6 ex

FIELD: textile, paper.

SUBSTANCE: method of filler treatment includes formation of a mixture of an aqueous suspension of filler and aqueous anion latex. The latter is a dispersion of acrylic polymer with vitrification temperature (T v) from - 3 to 50°C. This mix is mixed with water at the temperature that is higher than T v of latex, at the same time the specified water has temperature of 40-98°C. The specified suspension of the filler comprises a solid disperse filler selected from the group containing kaolin clay, ground calcium carbonate, deposited calcium carbonate, deposited calcium sulfate, talc and mix of two or more of them. The specified acrylic polymer is selected from the group containing copolymers n-butylacrylate-acrylonitrile-sterol and copolymers n-butylacrylate-sterol. The aqueous composition of the filler contains the solid dispersed filler specified above with solid particles of anion latex polymer specified above and adsorbed on them, in aqueous carrier. The treated filler contains the solid dispersed filler specified above with solid particles of anion latex polymer specified above and adsorbed on them. The pulp charge contains pulp fibres and the solid dispersed filler specified above with solid particles of anion latex polymer specified above and adsorbed on it, in aqueous carrier. Method to make paper from the above specified pulp charge containing pulp fibres. The paper product made of pulp fibres and solid disperse filler, where the specified filler has solid particles of anion latex polymer specified above absorbed on it, with size of solid polymer particles of 30-200 nm and in amount of 1-100 kg of latex per 1 t of filler relative to dry mass of solid substances of latex and filler, and the specified filler has average size of particles of 0.1-30 mcm.

EFFECT: improved retention of the filler, continuous execution of the filler treatment method to improve fixation of anion latex on the filler for a short period of time due to irreversible fixation of anion latexes on particles of the filler and time stability of aggregated filler suspension, latex-treated deposited calcium carbonate is more acid-resistant, and when used to make paper from wood mass under neutral conditions less acid is required to control pH.

21 cl, 14 dwg, 8 ex

FIELD: textile, paper.

SUBSTANCE: method includes dissolution of cellulose and its grinding down to specified extent of grinding. Preparation of the first dispersion with application of return water, containing fibres of microcrystal cellulose, produced by its grinding in mixture with titanium dioxide and calcium hydroxide in specified amount. The second dispersion is prepared from cellulose fibres with application of return water. Then the first suspension is mixed with the second, and produced mixture is treated with carbon dioxide. In case of this treatment calcium hydroxide under action of carbon dioxide results in production of chemically deposited chalk and production of paper mass at specified ratio of components. Grinding of microcrystalline cellulose in mixture with titanium dioxide and calcium hydroxide is carried out in vibration mill with provision of impact and wear effect at mixture.

EFFECT: increased extent of fillers retention in paper, improvement of its printing properties, provision of possibility to vary bulk and porosity of paper, provision of possibility to use fully closed cycle of return water.

1 tbl, 8 ex

FIELD: textile, paper.

SUBSTANCE: method includes preparation of water dispersion of cellulose fibres. Addition of calcium hydroxide in it at specified ratio in dispersion of cellulose fibres. Further treatment of dispersion with carbon dioxide in process of mixing until calcium hydroxide is fully transformed into calcium carbonate to produce paper mass. The latter comprises cellulose fibres, modified with chemically deposited chalk. At the same time calcium hydroxide is added into dispersion in amount, in conversion to calcium carbonate, equal to its specified percentage content in dry substances of paper. Dispersion of cellulose fibres is prepared with addition of return water of paper-making machine, and dispersion is treated with carbon dioxide after addition of return water to it. Paper mass is produced with specified content of components in it without account of solid substances added in it with return water. Cellulose fibre is selected from row including sulfite, sulfate cellulose, their mixture, leached wood mass of high yield on the basis of fibrillated fibres containing cellulose, hemicellulose and lignin.

EFFECT: increased strength of paper from produced paper mass due to use of closed cycle of water circulation.

1 tbl

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