Paper filler

FIELD: textile, paper.

SUBSTANCE: filler is designed for paper making and can be used in pulp-and-paper industry. Filler contains calcium salt and cellulose derivative with lattice ionic fractional substitutionality up to approximately 0.65, where filler is essentially free from either cellulose fibre or fibrils or lignocellulose. Filler contains calcium salt and cellulose derivative with lattice ionic fractional substitutionality up to approximately 0.65, where cellulose derivative can contain cationic groups. Besides the invention refers to production process of filler involving mixing the agent substance containing calcium salt and cellulose derivative with lattice ionic fractional substitutionality up to approximately 0.65, essentially without cellulose fibre or fibrils or lignocellulose. Other production process of filler consists in mixing the agent substance containing calcium salt and cellulose derivative with lattice ionic fractional substitutionality up to approximately 0.65, where cellulose derivative contains cationic groups. The invention refers to method for making paper including preparation of aqueous suspension containing cellulose fibre, suspension addition with filler containing calcium salt and cellulose derivative with lattice ionic fractional substitutionality up to approximately 0.65, where filler is essentially free from either cellulose fibre or fibrils or lignocellulose; dehydration of suspension thus making web or paper sheet. The invention also refers to method for making paper including preparation of aqueous suspension containing cellulose fibre; suspension addition with filler containing calcium salt and cellulose derivative with lattice ionic fractional substitutionality up to approximately 0.65, where cellulose derivative contains cationic groups; dehydration of suspension thus making web or paper sheet.

EFFECT: higher sizing efficiency with good drainage, retention and serviceability of papermaking machine.

24 cl, 3 tbl, 4 ex

 

The present invention relates to a filler containing a salt of calcium derived cellulose. The invention additionally relates to a method for manufacturing a filler, the filler in the manufacture of paper, for paper production, in which the filler is used as an additive, and the paper containing the filler.

Prerequisites to the creation of inventions

Paper with a high content of filler matches taking place trends in the paper industry not only saving the fibers used, but also due to a higher quality product, such as greater opacity of paper, and greater suitability for printing. Fillers based on calcium carbonate is usually used because of their good ability to scattering of light. The main drawback in the manufacture of paper with a high content of fillers, especially with fillers having a large surface area, is the large consumption of adhesive. Thus, with increase in the content of filler in the paper requires a greater amount of adhesive to obtain the corresponding results of the sizing. Therefore, the pulp suspension is more difficult to glue with increasing amount of filler.

The sizing of the jus in the m carry out to achieve the water-repellent properties of paper or cardboard and reduce capillary distribution of moisture from the edges. It also has an impact on the mechanical properties of paper and cardboard, such as dimensional stability, coefficient of friction, malleability and resistance to bending. In addition, the sizing can be improved suitability for printing, especially by regulating the distribution of printing ink and adhesion.

The sizing process includes the deposition of hydrophobic substances, usually referred to as adhesive substances on the surface of the fiber. Commonly used adhesives are adhesives, not reacts with cellulose, for example, adhesives based on rosin, and an adhesive substance that reacts with cellulose, such as alkylether (AKD) and anhydrides of the acids, for example of alkenyl succinic anhydride (ASA). It is known, however, that adhesive that reacts with the cellulose, i.e. AKD and ASA, are subjected to hydrolysis, which counteracts the desired reaction with the fiber. In addition, the disadvantages sizing may occur in the finished product due to inversion or migration adhesives, evaporation adhesives, mechanical wear of the product, etc.

Bartz et al. found that during high fluidity AKD-wax certain amount of AKD can penetrate, and then can be captured by the porous structure of the filler (Bartz W.; Darroch M.E.; Kurrle F.L., "Alkyl ketene dimer sizing efficiecy and reversion in calcium carbonate filled papers, Tappi Journal, Vol. 77, No. 12, 1994). This especially happens with PCC neravnomernoi shape having a porous structure in the form of sockets and a large surface area. Voutilainen has shown that fillers with a large surface area adsorb AKD even better than fiber (Voutilainen, P., "Competitive Adsorption of Alkyl Ketene Dimer on Pulp Fibers and CaCO3Fillers", Proceedings from International Paper and Coating Chemistry Symposium, 1996). The presence of oxides of Al and Si on the surface of the filler may also result adsorbirovanny cationic starch contained in the particles of the AKD. It was also hypothesized that between AKD and filler of calcium carbonate, there is a strong interaction or probably even a connection. These mechanisms of action of fillers made in assumptions, of course, are undesirable, and should be attempted to minimize these interactions.

In U.S. patent No. 5514212 proposed to improve the efficiency of the sizing, to modify the surface of the pigment is anionic complex starch-soap. Brewed corn or potato starch mixed with salts of fatty acids and precipitate on the surfaces of the pigment when mixed with precipitated suspension of calcium or composition for the manufacture of paper with a high content of calcium ions.

In U.S. patent No. 5972100 proposed structure consisting of gluing ve is esta, reacts with cellulose (e.g., AKD), cationic dispersing agents (for example, cationic starch or polyamides) and filler. In addition to the improved sizing, application of the invention provides an independent and separate regulation as the load of filler and sizing.

In addition, in the International application WO 95/13324 said about the calcium carbonate treated with a derivative of cellulose, such as sodium carboxymethylcellulose (CMC) with a degree of substitution of 0.7. Mentioned treated calcium carbonate is used as filler in alkaline suspensions for the manufacture of paper, resulting in a degree of whiteness of the paper increases.

In U.S. patent No. 3730830 disclosed a method of making paper, and more specifically the paper, including the process of using synthetic polymer fibers. Before adding synthetic fibers in the fibrous suspension, the suspension containing the carboxymethyl cellulose and synthetic fiber, add inorganic pigment or carbon black, thus achieving a uniform distribution of polymer fibers between the pulp fibers in the paper pulp.

There is still a need for filler, by which we could improve the process of making paper and write a paper uluchshenie properties. It would be desirable to create a filler, which could produce a paper with a high content of filler, possessing very good properties for printing and mechanical properties. It would also be desirable to create a filler, which could reduce the need for sizing and thus increase the efficiency of the sizing. It would also be desirable to create a filler, which would be compatible with assistive technology for drainage and retention, and thus could provide good drainage, retention and high performance paper machine. It would also be desirable to create a simple and effective method of manufacturing a filler having the above-mentioned properties.

Brief description of the invention

The present invention, in General, refers to the filler containing a salt of calcium derived cellulose. The present invention additionally, in General, refers to the filler containing a salt of calcium derived cellulose - carboximetilzellulozu. The invention also generally relates to a method for filling by mixing compounds containing a salt of calcium derived from cellulose, a way to use filler as an additive in the paper manufacturing process, and so is e - the paper containing the filler. The invention additionally, in General, relates to a method of making paper, in which the filler is injected into the aqueous suspension of pulp.

More specifically, the invention relates to a filler containing a salt of calcium and a derivative of cellulose with a degree of substitution of ionic groups in the grid component to about 0,65. The invention also relates to a filler containing a salt of calcium and a derivative of cellulose with a degree of substitution carboxialkilnuyu groups of up to about 0,65. The invention additionally relates to a method for producing a filler comprising mixing a substance containing a salt of calcium derived from cellulose with a degree of substitution of ionic groups in the grid component to about 0,65. The invention also relates to a method for producing a filler comprising mixing a substance containing a salt of calcium derived from cellulose with a degree of substitution carboxialkilnuyu groups of up to about 0,65. The invention additionally relates to the filler, which can be obtained through the use of these methods. The invention additionally relates to a method of making paper, comprising: obtaining a water suspension containing pulp fibers; introducing the suspension of a filler containing a salt of calcium derived cellulose setupenu substitution of ionic groups in the grid, component to about 0,65, and dewatering the slurry to form a cloth or sheet of paper. The invention also relates to a method of making paper, comprising: obtaining a water suspension containing pulp fibers; introducing the suspension of a filler containing a salt of calcium and a derivative of cellulose with a degree of substitution carboxialkilnuyu groups of up to about 0,65, and dewatering the slurry to form a cloth or sheet of paper. In the method of manufacturing a paper filler can be entered in the pulp suspension by adding calcium salt and a derivative of cellulose in the form of a single composition.

Detailed description of the invention

The present invention created a new filler suitable for use in the manufacture of paper. Unexpectedly, it was found that when applying the filler according to the invention can reduce the influence of some of the shortcomings associated with the fillers commonly used in the manufacture of paper and included in the paper. More specifically, through the use of a filler according to the present invention in the process of making paper, you can obtain a paper having very good properties for printing, for example, good smoothness, high opacity and whiteness; their improved mechanical is Tami, for example, strength in the dry state, tensile strength, coherence Scott and stiffness in bending; improved efficiency sizing. Additional benefits of the present invention are good and/or improved dewatering and very good retention, which leads to benefits from the point of view of equipment performance.

It was found that when using the present invention and the application of the filler together with an adhesive substance can reduce the need for gluing substance and, therefore, generally to increase the efficiency of sizing. Increased efficiency sizing is observed when using different types of adhesives, including adhesives, entering and not entering into the reaction with cellulose, and more specifically, the adhesive that reacts with cellulose, such as cetindamar and anhydrides of carboxylic acids. In particular, the application of the invention is achieved by increased efficiency of the ring, and the stability of the sizing of paper containing a filler, especially a paper with a high content of filler and/or when using a filler with a high surface area.

According to the present invention was also unexpectedly found that a derivative of cellulose can be mixed, and it may be more effective is but adsorbed or attached to the substance, containing a salt of calcium, while a simple process. The filler according to the invention can be considered as a modified filler, or filler, which represents a processed derivative of cellulose.

According to the present invention, it was found that very good results can be obtained by adding compounds containing a salt of calcium and a derivative of cellulose in the pulp suspension in a pre-mixed or pre-processed form. Pre-treatment of a substance containing a salt of calcium derived cellulose provide a friendly way for individual processing of only one component of the suspension of cellulose to obtain a modified filler which can be used instead of the usual filler or partial replacement of conventional filler. Not trying to explain this phenomenon by any theory, the authors believe that a derived cellulose adsorbed substance containing a salt of calcium, when mixing the components.

The filler according to the invention contains a salt of calcium and a derivative of cellulose. Examples of suitable calcium salts include calcium carbonate, calcium sulfate and calcium oxalate (preferred salt is calcium carbonate) and mixtures thereof. Calcium carbonate is the tsya the main component of limestone, marble, chalk, and dolomite. Calcium carbonate can be obtained directly from the above-mentioned existing in nature types of stone, and it is called powdered calcium carbonate (GCC). Calcium carbonate can also be obtained by a chemical process, and it is usually called precipitated calcium carbonate (PCC). Calcium carbonate is preferably derived from calcium hydroxide and of substances which are formed of carbon ions in the aqueous phase, for example from a carbonate of an alkali metal or carbon dioxide. As GCC and PCC can be used in the present invention, it is preferable to use PCC, including any existing crystalline or morphological forms, such as calcareous spar, rhombohedral, prismatic, tabular, cubic form and neravnomernoi forms, and acicular aragonite form. PCC usually has a specific surface area of about 2-20 m2/g is suitable specific surface area of about 7-12 m2/year

The calcium salt may be represented as essentially pure salt of calcium, including mixtures of one or more calcium salts. It can also be presented in the form of mixtures with one or more other components. The term "substance containing a salt of calcium" here refers to a substance containing a salt of calcium and optional one or more number what about the other components. Examples of other suitable components of this type include fibers or fibrils of cellulose, lignocellulose or similar plant material, inorganic clay, kaolin, talc, titanium dioxide, hydrogenated aluminum oxide, barium sulfate, etc. Preferably using to other components suited for use in the manufacture of paper.

In substances containing a salt of calcium, including fibers or fibrils of cellulose, lignocellulose or similar plant material, a salt of calcium may be at least partially deposited on the fibers or fibrils. The average thickness of the fibrils may be about 0.01 to 10.0 μm, a suitable thickness is component to about 5 μm, and preferable up to about 1 μm. The average length of the fibrils can be about 10-500 microns. Examples of suitable substances containing a salt of calcium include composite materials disclosed in U.S. patent№ 5731080, № 5824364, № 6251222, № 6375794 and no 6599391, the essence of which is incorporated into the present application by reference. Commercially available composite materials of this type include SuperFill ® M-Real Oy.

The filler according to the invention additionally contains a derivative of cellulose. Preferably, a derivative of cellulose was soluble or at least partially water-soluble and the and water-dispersible, preferably water-soluble or at least partially water-soluble. Preferably, a derivative of cellulose was ion. Derivative of cellulose may be anionic, cationic or amphoteric, preferably anionic or amphoteric. Examples of suitable cellulose derivatives include cellulose ethers, such as anionic and amphoteric cellulose ethers, preferably anionic cellulose ethers. Derived pulp preferably contains an ionic or carrying a charge group or a replacement group. Examples of suitable ionic groups are anionic and cationic groups. Examples of suitable anionic groups include carboxylate, such as carboxyethyl; sulfonate such as sulfoalkyl; phosphate and phosphonate groups in which the alkyl group may be methyl, ethyl, propyl and mixtures thereof; more preferred methyl; preferably derived cellulose contained anionic group comprising carboxylate group, for example carboxialkilnuyu group. A counter ion of the anionic groups are usually alkali metal or alkaline-earth metal; suitable is sodium.

Examples of suitable cationic groups of the cellulose derivatives according to the invention include salts of amines; suitable are salts of tertiary amines and Quaternary ammonium the e group, preferably Quaternary ammonium group. Replacement group attached to the nitrogen atom of amines and Quaternary ammonium groups may be the same or different and can be selected from a range including: alkyl, cycloalkyl and alkoxyalkyl group; and one, two or more alternative groups together with the nitrogen atom can form a heterocyclic ring. Replacement of the group independently from each other typically contain from 1 to about 24 carbon atoms, preferably from 1 to about 8 carbon atoms. The cationic nitrogen groups can be attached to the cellulose or its derivative by the chain of atoms, which appropriately includes atoms of carbon and hydrogen and may be atoms of oxygen (O) and/or nitrogen (N). Typically, the chain of atoms is alkylenes group with 2-18 carbon atoms, and preferably from 2 to 8 carbon atoms, possibly interrupted or substituted by one or more heteroatoms, such as O or N, such as accelerograph or hydroxypropranolol group. Among the preferred cellulose derivatives containing cationic groups include derivatives obtained by reaction of cellulose or its derivative with the agent causing the quaternization selected from 2,3-epoxypropyltrimethylammonium ammonium chloride, 3-chloro-2-hydroxypropyltrimethylammonium lorida ammonium, and mixtures thereof.

Derived cellulose according to the present invention can contain non-ionic groups, such as alkyl or hydroxyalkyl group such as hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl and their mixtures, such as hydroxyethylated, hydroxypropylmethyl, hydroxybutyrate, hydroxyethylated, hydroxypropyl, etc. In a preferred embodiment of the invention a derivative of cellulose contains both ionic groups and nonionic groups.

Examples of suitable cellulose derivatives according to the invention include: karboksimetsiltsellyulozy, for example carboxymethylcellulose, karboksimetilcelljuloza, karboksimetilcelljuloza, sulfobacillus, karboksimetiltselljuloza (CM-HEC), carboxymethyl cellulose in which the cellulose is substituted by one or more non-ionic replacement of groups; preferable is carboxymethylcellulose ("CMC"). Examples of suitable cellulose derivatives and methods for their preparation are disclosed in U.S. patent No. 4940785 included, therefore, in the present application by reference.

According to a preferred embodiment of the invention, the filler contains a salt of calcium, including fibers or fibrils of cellulose or lignocellulose and cellulose derivative containing cationic groups. Katie the groups can be any of those listed in this application.

In another preferred embodiment of the invention, the filler contains a salt of calcium essentially free of fibers or fibrils of cellulose or lignocellulose, and cellulose derivative, which may be either anionic or cationic, or amphoteric.

The term "degree of substitution" (DS) here understand the number of substituted places in the ring of beta-anhydroglucose rings derived cellulose. Each anhydroglucose ring cellulose has three hydroxyl groups that may be suitable for substitution, the maximum value of the degree of substitution (DS) is 3.0. According to one preferred embodiment of the invention a derivative of cellulose has a degree of substitution of ionic groups in the grid (DSNI)constituting up to about 0,65, i.e. derived cellulose has an average degree of substitution of ionic groups in the grid on the level of glucose of up to about 0,65. Ion substitution in the grid can be anionic, cationic or neutral. When the ionic substitution in the grid is anionic, there is an excess of anionic groups in the grid (the number of anionic groups in the grid = average number of anionic groups minus the average number of cationic groups, if any, on the level of glucose) and DSNIhas the same value as the degree of substitution of anionic GRU is p in the grid (DS NA). When the ionic substitution in the grid is cationic substitution in the grid, there is an excess of cationic groups in the grid (the number of cationic groups in the grid = average number of cationic groups minus the average number of anionic groups, if any, on the level of glucose) and DSNIhas the same value as the degree of substitution of net cationic groups (DSNC). When the ionic substitution in the grid is a neutral substitution in the grid, the average number of anionic and cationic groups, if any, on the level of glucose equally, and DSNIand DSNAand DSNC0. According to another preferred embodiment of the invention a derivative of cellulose has a degree of substitution carboxialkilnuyu groups (DSCA)constituting up to about 0,65, i.e. derived cellulose has an average degree of substitution carboxialkilnuyu groups on the level of glucose of up to about 0,65. Carboxialkilnuyu groups preferably are carboxyethylidene groups, and DSCAthat here referred to, is equal to the degree of substitution carboxymethyl groups (DSCM). According to the variants of execution of the invention DSNIDSNADSNCand DSCAindependently from each other are typically up to about 0,60, the appropriate value is up to about 0.50 to preferred up to about 0.45, and bol is e preferred - to 0.40, while DSNIDSNADSNCand DSCAindependently from each other are usually at least about 0.01, the appropriate values are at least about 0.05, preferably at least about 0.10, more preferred at least about 0.15. The ranges of values DSNIDSNADSNCand DSCAindependently from each other are usually about 0.01 to 0.60, suitable about from 0.05 to 0.50, preferably about 0,10 - 0,45, and more preferred is about 0,15-0,40.

Derivatives of cellulose, which is anionic or amphoteric, usually have a degree of anionic substitution (DSAin the range from 0.01 to 1.0, while DSNIand DSNAmatches in this application definition; appropriate limits extend from about 0.05, preferably from about 0.10, more preferably from about 0.15, and up to about 0.75, preferably up to about 0.5, and more preferably up to about 0.4. Derivatives of cellulose, which is cationic or amphoteric, may have a degree of cationic substitution (DSWithin the range from 0.01 to about 1.0, while DSNIand DSNCmatches in this application definition; appropriate limits extend from about 0.02, preferably from about 0.03 to, and more preferably from about 0.05, and up to about 0.75, preferably up to about 0.5, and Bo is her preferred up to about 0.4. Suitable cationic groups are Quaternary ammonium groups, and DSc, which is here referred to, is equal to the degree of substitution of Quaternary ammonium groups (DSQN). For amphoteric cellulose derivatives according to the present invention DSAor DSCyou can, of course, to have higher values than 0.65, while DSNAand DSNCaccordingly, the answer given in this application definition. For example, if DSAequal to 0.75, and DSCequal to 0.15, then DSNAequal to 0.60.

Examples of suitable cellulose derivatives having a degree of substitution, defined above, are water-soluble carboxialkilnuyu derivative of cellulose with a low degree of substitution (DS), disclosed in co-pending application for patent, registered in the name of Akzo Nobel N.V. the same number. Suitable solubility water-soluble cellulose derivatives is at least 85 wt.%, calculated on the total weight of dry matter of a derivative of cellulose in an aqueous solution, preferably at least 90 wt.%, more preferably at least 95 wt.%, and most preferably at least 98 wt.%.

Derived cellulose generally has an average molecular weight component of at least 20,000 daltons, preferably at least 50000 daltons, and among the average molecular weight is usually to 1,000,000 daltons, preferably to 500,000 daltons.

Preferably the filler according to the invention a derivative of cellulose at least partially adsorbed on or attached to the calcium salts or other components present in a substance containing a salt of calcium. Usually at least about 10 wt.%, preferably at least about 30 wt.%, more preferably at least about 45 wt.%, and most preferred at least about 60 wt.% derived cellulose adsorbed on or attached to the calcium salts or other components present in the substance containing calcium salts.

The filler according to the invention usually contains a salt of calcium in the amount at least of 0.0001 wt.%; the content of calcium salts may be from about 0,0001% by weight to about of 99.5 wt.%, moreover, a suitable range is from about 0.1 wt.% until about a 90.0 wt.%, and preferably about 60-80 wt.%, based on the weight of solid filler, i.e. calculated on the dry weight of the filler. The filler usually contains a derivative of cellulose in a quantity of at least 0.01 wt.%; moreover, a derivative of cellulose may be from about 0.01 wt.% up to about 30.0 wt.%, the appropriate value is from about 0.1 wt.% to about 20.0 wt.%, and preferably from about 0.3 wt.% up to about 10.0 wt.%, in the calculation of the mass of the solid substance of the filler.

The filler according to the invention can be supplied as a solid, essentially without water. It can also be supplied in the form of an aqueous composition. The content of the aqueous phase, or water, can be adjusted within wide limits depending on the method of manufacture and production assignments.

The present invention also relates to a method for producing a filler comprising a mixture of a derivative of cellulose, such as any of the cellulose derivatives, as defined in this application, with a substance containing a salt of calcium, for example, any substance containing a salt of calcium, as defined in this application containing a salt of calcium and possibly one or more other components. Derivative of cellulose and a substance containing a salt of calcium, appropriately used in such quantities to get the filler according to the invention, containing a derivative of cellulose and a salt of calcium in accordance with the definitions given in this application.

Used derivatives of cellulose and a substance containing a salt of calcium, can be represented as solids or as aqueous compositions, and mixtures thereof. Substance containing a salt of calcium, appropriately used in the form of finely ground material. Mixing can be performed by adding a derivative of cellulose to the filler, and is, and Vice versa, periodic, properities or continuous methods. According to a preferred embodiment of the invention a derivative of cellulose is added in the form of solids in the aqueous composition of matter containing a salt of calcium, and the resulting composition is then suitably subjected to effective dispersion to dissolve the derivative of cellulose. It is preferable to perform the mixing, forming a first aqueous phase, neutral to alkali, suitably aqueous solution of a derivative of cellulose, which is then mixed with the aqueous composition of matter containing a salt of calcium. Before mixing with a substance containing a salt of calcium, the aqueous phase is derived pulp can be subjected to pretreatment, such as homogenization, centrifuge and/or filter, for example for selection of nerastvorimogo derivative of cellulose, if any, from the aqueous phase.

Preferably a derivative of cellulose mixed with a substance containing a salt of calcium, to allow at least partial adsorption is carried on or attached to a substance containing a salt of calcium derived cellulose, preferably so that it can be difficult to remove substances by dilution with water. This can be accomplished by mixing for quite a PR the term period of time to allow adsorption or accession. A suitable mixing time is at least about 1 minute, preferably at least about 5 min, more preferably at least about 10 min, and most preferably at least about 20 minutes Periods of mixing, the components of even a few hours (1-10 h), it is possible, if it is desirable to achieve a high degree of adherence. A suitable quantity of a derivative of cellulose, rolling from the aqueous phase and adsorbed on or attached to a substance containing a salt of calcium or other components present in the material containing a salt of calcium is at least about 10 wt.%, preferably at least about 30 wt.%, more preferably at least about 45 wt.%, and most preferably at least about 60 wt.%.

The pH of the aqueous phase derived cellulose is usually to regulate the specific sorption derived cellulose, providing it is within about 4-13, preferably about 6-10, more preferably about 7.0-8.5 in. Suitable base or acid can be used for pH control. Examples of suitable bases include bicarbonates and carbonates of alkali metals and hydroxides of alkali metals; suitable are: sodium bicarbonate, sodium carbonate and sodium hydroxide. Examples of qualifying the acids include mineral acids, organic acids and acid salts; appropriate is sulfuric acid and its salts, for example aluminum. In General, at lower pH values, i.e. pH of about 4.0 and up to neutral values, adsorption derived cellulose more, but the solubility decreases, whereas at higher pH values, the adsorption decreases, but the solubility increases.

The temperature plays a very important role; when performing processes in conditions without pressure the temperature is usually maintained within the range of about 10-100°C, preferably about 20-80°C. However, the high temperature is preferable; suitable water temperature of the composition during mixing is about 30-70°more preferred is about 40-60°C.

When using compounds containing a salt of calcium, which also includes other components other than calcium salts, such as fibers or fibrils of cellulose or lignocellulose, mixing and joining derivative of cellulose can be performed simultaneously with the deposition of calcium salts on fibrils or fibers, or after deposition. You can also add a derived cellulose to deposition. In this case, the derived cellulose added to or during grinding, or when separate sorption after grinding. Derivative of cellulose may be adsorbed on or attached to the prophetic the TSS containing a salt of calcium or the surfaces of fibers or fibrils and/or absorbed into the fibers or fibrils. Methods adsorption of such cellulose derivatives such fillers are disclosed in U.S. patents№ 5731080, № 5824364, № 6251222, № 6375794 and no 6599391, the essence of which is incorporated into the present application by reference.

The filler produced by the method according to the invention, can be used as such, for example, in the manufacture of paper. If the filler is presented in the form of an aqueous composition, it can be used directly or can be dried, if desired, for example, for ease of transport.

The present invention also relates to a method of making paper comprising the following steps: providing water suspension containing cellulose fiber (pulp suspension"); the introduction of the filler in the pulp suspension, for example, any of the fillers that are defined in the present application; and dewatering the pulp suspension to form a cloth or sheet of paper. Preferably the filler to enter in the pulp suspension by adding it in the form of a single composition. In an alternative embodiment, a salt of calcium or substance containing a salt of calcium (e.g., any substance containing a salt of calcium, as defined in this application) and a derivative of cellulose (for example the EP, any of the cellulose derivatives, as defined in this application) can be separately added to the pulp suspension, and the filler is formed in place in the pulp suspension.

According to the method in the pulp slurry can, of course, to enter and other components. Examples of such components include conventional fillers, fluorescent brightening substances, adhesives, additives to improve drainage and retention, substances that increase strength in the dry state, substances that increase strength in the wet state, etc. are examples of suitable conventional fillers include kaolin, China clay, titanium dioxide, gypsum, talc, natural and synthetic calcium carbonate, such as chalk, marble and precipitated calcium carbonate, hydrogenated aluminum oxide (trihydroxide aluminum, calcium sulfate, barium sulfate, calcium oxalate, etc. When using filler according to the invention together with a conventional filler filler according to the invention may comprise at least 1 wt.%, a suitable amount is at least 5 wt.%, the preferred amount is at least 10 wt.%, a more preferred amount is at least about 20 wt.%, but the right amount can be up to about 99 wt.% calculated on the dry weight of all fillers. Examples of suitable adhesives include adhesives, not reacts with cellulose, for example, adhesives based on rosin, such Soaps based on rosin, emulsions/dispersions based on rosin; adhesive that reacts with cellulose, such as emulsion/dispersion anhydrides of acids, such alkenyl succinic anhydride (ASA), alkenyl and alkylenediamine (AKD) and multimer. Examples of suitable additives to improve drainage and retention include: organic polymer products, such as cationic, anionic and nonionic polymers including cationic polyethyleneimine; cationic, anionic and non-ionic polyacrylamides, cationic polyamine, cationic starch and cationic guar; inorganic substances such as aluminum compounds, anionic substances in the form of microparticles, such colloidal particles based on silica, clay montmorillonite type, such as bentonite, montmorin-lonic; colloidal aluminum, and combinations thereof. Examples of suitable combinations of additives to improve drainage and retention include: cationic polymers and anionic substances in the form of microparticles, such as cationic starch and anionic colloidal particles based on silica, cation polyacrylamide and anionic colloidal particles based on silica; and to tiny polyacrylamide and bentonite, or montmorillonite. Examples of suitable substances to increase the strength in the wet state are polyamine and polyaminoamide. Paper containing a filler according to the invention and a cationic starch, has a very good strength properties.

According to a preferred embodiment of the invention, at least one adhesive is introduced into the pulp slurry for the manufacture of sized paper containing a filler. Preferably, the adhesive was adhesives such types, which are referred to in this application and which react with cellulose. Suitable cetindamar have the General formula (I)below, in which R1and R2represent a saturated or unsaturated hydrocarbon group, typically saturated hydrocarbons; and suitable hydrocarbon groups containing 8-36 carbon atoms, usually they are straight or branched chain alkyl groups containing 12-20 carbon atoms, for example hexadecyne and octadecyl group. Cetindamar can be in a liquid state at room temperature, i.e. at 25°C, a suitable temperature is 20°C. Typically, the anhydrides of the acids can be characterized by the General formula (II)below, in which R3and R4may be the same or RA is personal and represent saturated or unsaturated hydrocarbon group, appropriately containing 8-30 carbon atoms, or R3and R4together with part-C-O-C -, may form a ring of 5-6 members, optional which is then substituted hydrocarbon groups containing up to 30 carbon atoms. Examples of anhydrides of the acids used commercially include alkyl and alkanniny succinic anhydrides and especially isooctadecyl succinic anhydride.

Among the suitable cetindamar, acid anhydrides, organic isocyanates are compounds disclosed in U.S. patent No. 4522686 included in the present application by reference.

The filler according to the invention can be added to the pulp suspension in quantities that can be changed within wide limits depending on, inter alia, on the type of pulp suspension, of the type manufactured paper, the introduction etc. Filler is usually injected in amounts ranging from 1 wt.% to about 50 wt.%, a suitable amount is about 5-40 wt.%, and it usually takes about 10-30 wt.%, based on the weight of dry fiber. In accordance with this paper according to the invention usually contains a filler according to the invention in the range from 1 wt.% to about 50 wt.%, a suitable amount is about 5-40 wt.%, and it usually takes about 10-30 wt.%, calculated on the dry weight is about fiber.

When using other components in the way these components can be added to the pulp suspension in quantities that can be changed within wide limits depending on, inter alia, on the type and number of components, type of pulp suspensions, filler content, type of manufactured paper, the introduction etc. Adhesives usually injected into the pulp suspension in a quantity of at least about 0.01 wt.%, a suitable amount is at least about 0.1 wt.%, based on the weight of dry fiber, and the upper limit is usually about 2 wt.%, a suitable amount is about 0.5 wt.%. In General, additives to improve drainage and retention injected into the pulp suspension in quantities which provide better drainage and/or retention than is obtained without the use of these additives. Additives to improve drainage and retention, substances that increase paper strength in dry and wet conditions, independently from each other, usually administered in amounts of at least about of 0.001 wt.%, often at least about 0.005 wt.%, calculated on dry fiber, and the upper limit is usually about 5 wt.% and a suitable amount is about 1.5 wt.%.

The term "paper" here is understood not only paper and products from the, but also other cellulosic sheet materials and fabrics, containing cellulose fiber, such as cardboard and products from it. The method can be used for the production of paper from different types of aqueous suspensions of cellulose (cellulose-containing) fiber, and suspension should suitably contain at least 25 wt.%, and preferably at least 50 wt.% such fibers, based on dry substance. The cellulose fiber may be based on the primary fiber and/or recovered fiber, including the fiber wood or annual or perennial plants. The pulp slurry may contain or not contain wood fiber, and it can be based on the fiber from chemical fiber pulp, such as sulphate, sulphite and soluble organic substances fibrous mass, mechanical fibrous mass, such as thermomechanical fibrous mass, chemical-thermomechanical fibrous mass, refiner fibrous fibrous mass and the mass of sawdust, as from hard wood and soft wood; and may also be based on the recovered fiber, optional from fibrous pulp, purified from the printing ink, and mixtures thereof. The pulp suspension may be appropriate to have a pH value in the neutral in relation to the structure to alkaline range, for example, 6-10, preferably about 6.5 to 8.0.

Made the paper can be dried to provide a coating and subjected to calendering. The paper may be coated with, for example, calcium carbonate, gypsum, aluminum silicate, kaolin, aluminum hydroxide, magnesium silicate, talc, titanium dioxide, barium sulphate, zinc oxide, synthetic pigment, and mixtures thereof.

The surface density of the produced paper can be varied within wide limits depending on the type of manufactured paper; typically, the surface density of the paper is in the range of about 20-500 g/m2suitable is the surface density 30-450 g/m2and preferred - 30-110 g/m2. Preferably the invention is used in the production of offset uncoated paper and coated paper for Electrophotography, thin paper, uncoated and coated, containing optional mechanical fiber and paper writing and paper for printing. Especially preferred products is offset paper, coated paper, which combines good luster, great opacity and layering.

The invention is further illustrated by the following examples that are not intended, however, to limit the scope of the invention. These shares and the percentage refers to the mass parts and mA is weighing percentage, accordingly, unless otherwise indicated.

Example 1

Were prepared fillers according to the invention and for comparison by processing material containing a calcium salt derivative of cellulose. As the cellulose derivatives used carboxymethylcellulose (CMC) with a degree of substitution DSNI(DSCA= DSCM= DSA= DSNA= DSNI) 0,3, of 0.32 and 0.7, respectively. Another used carboxymethylcellulose (CMC) was presented Quaternary ammonium carboxymethylcellulose (QN-CMC) with a degree of substitution DSCA= DSCM= DSA= 0,4; DSC= DSQN= 0,17; DSNI= DSNA= 0,4 - 0,17 = 0,23. The average molecular weight used cellulose derivatives were within 100000-400000. Used substance containing a salt of calcium, presented various precipitated by calcium carbonates (PCC), possessing a specific surface area of 5.7 m2/g and 10.0 m2/g, respectively. Other used substances containing a salt of calcium, were presented SuperFill ® (PCC particles within the fibrous mass).

The fillers were prepared by dissolving CMC in water to a concentration of 0.5 wt.%. Then, the resulting composition CMC was added to a suspension of PCC filler and mixed within 25-45 minutes at a temperature of about 50°C. the Filler according to the invention ("the product is obreteniyu") and filler for comparison ("product comparison") were as follows:

The product according to the invention is 1 ("IP1"):CMC (DSNI0,3) treated RCC (5,7 m2/g)
The product according to the invention 2 ("IP2"):CMC (DSNI0,3) treated RCC (10 m2/g)
The product according to the invention 4 ("IP4"):QN-CMC (DSNI0,23) treated with Super-Fill®
Comparative product 1 ("CP1")CMC (DSNI0,7) treated RCC (5,7 m2/g)
Comparative product 2 ("SR")Super-Fill®
Comparative product 3 ("SR")CMC (DSNI0,32) treated with Super-Fill®

Example 2

The sizing of the paper produced according to the invention, was evaluated and compared with the paper used for comparison. The paper according to the invention were made by using the product according to the invention" IP1 according to Example 1. The paper used for comparison, were made by using the "product comparison" CP1 according to Example 1 and a filler not containing a derivative of cellulose.

Paper sheets were made from the fibrous mass consisting of chemical fibrous mass and containing untreated PCC in variable amounts (stated in wt.%, calculated on dry paper), as shown in the Table 1. In the fibrous suspension were added: 2.0 kg (per ton of dry fiber) of a filler according to Example 1, and the filler does not contain a derivative of cellulose; 3.0 kg (per ton of dry fiber) AKD (water dispersion Eka Keydime C223); restraint composition containing cationic starch (Eka PL 1510) and silica particles (Eka NP 780). Cationic starch and silica particles were added in the amount of 0.15 kg per ton of dry fiber). The order of addition was as follows:

Adding CMC - treated PCC0
Adding dispersion AKD30
Adding cationic starch45
Adding silica particles60
The formation of the leaf75

The sheets were made in a standard way, using the installation Dynamical Sheet Former for forming sheet (model "Formette", CTP, Grenoble). To obtain the results of the sizing used method Cobb60(SCAN-P 12:64). The results obtained are presented in Table 1.

td align="center"> CP1
Table 1
Test # The content of the RCC in the paperFillerCobb60
118%45
219%IP125

Example 3

In this Example, an assessment was made of the method of manufacturing paper according to the invention, in which (i) the CMC-treated PCC was added to the fibrous suspension and (ii) the CMC and PCC (raw) was separately added to the fibrous suspension.

Sheets of paper made from the pulp of the same type as in Example 2 with the content of 30 wt.%, calculated on dry paper, untreated PCC (specific surface area of 10 m2/g) or CMC (DSN, 0,3)-treated PCC (10 m2/g) (IP2 according to Example 1). In the fibrous suspension was added to 4 kg/t of dry fiber cationic starch (970 PB); 3.0 kg/t of dry fiber AKD (aqueous dispersion adhesives, Eka Keydime C223)holding the composition containing cationic polyacrylamide (Eka PL 1310), and silica particles (Eka NP 780). Cationic polyacrylamide and silica particles were added in the amount of 0.20 kg per ton of dry paper). When untreated PCC was separately added to 1.0 kg/t CMC possessing DSN, 0,3. Adding CMC-treated PCC was not added to the CMC. The order of addition was as follows:

Adding cationic starch0
Adding CMC-treated PCC/Norrbotten the th PCC 30
Separate addition of CMC35
Adding AKD45
Adding cationic polyacrylamide60
Adding silica particles75
The formation of the leaf90

The sheets were evaluated as in Example 2. The results are presented in Table 2.

Table 2
Test # How to addFillerCobb60
1Adding separateUntreated RCC + SMS65
2SMS-treated RCCIP235

Example 4

The products of Example 1 was used and evaluated in the paper manufacturing process. The paper sheets were made from a fiber furnish containing a mixture of 70 wt.% the pulp of hardwood and 30 wt.% from soft wood, the degree of grinding to 22° and 25° SHR, respectively, in the manner analogous to Example 3, except that it is not used cationic starch, but used raw SuperFill filler® (CP2) or CMC-treated fill the ü SuperFill® (CP3 and IP4), which was added in an amount such that the sheet of paper containing 30 wt.% SuperFill filler®. The order of addition was as follows:

Adding SuperFill filler ®0
Adding cationic polyacrylamide45
Adding silica particles75
Adding AKD90

The results are presented in Table 3.

Table 3
Test # FillerCobb60
1CP280
2CP350
3IP421

1. The filler containing a salt of calcium and a derivative of cellulose having a degree of substitution of ionic groups in the grid cellulose to 0.65, where the filler is essentially free of fibers or fibrils of cellulose or lignocellulose.

2. The filler containing a salt of calcium and a derivative of cellulose having a degree of substitution of ionic groups in the grid to 0.65, where the derived cellulose contains cationic groups.

3. The filler according to claim 1 or 2, in which the degree of substitution is m what Nisha least 0,05.

4. The filler according to claim 1 or 2, in which the degree of substitution is at least 0,15-0,40.

5. The filler according to claim 1 or 2, in which the derivative of cellulose is a cellulose ether.

6. The filler according to claim 1 or 2, in which the derived cellulose contains carboxymethyl group.

7. The filler according to claim 1 or 2, in which the derivative of cellulose containing Quaternary ammonium groups.

8. The filler according to claim 1 or 2, in which the derivative of cellulose is anionic.

9. The filler according to claim 1 or 2, in which the derivative of cellulose is amphoteric.

10. The filler according to claim 1 or 2, in which the derivative of cellulose is at least partially soluble in water.

11. The filler according to claim 1 or 2, which contains a derivative of cellulose in the amount of 0.3-10.0 wt.% in the calculation of the mass of solids filler.

12. The filler according to claim 1 or 2, which contains a salt of calcium in the amount of 60-80 wt.% in the calculation of the mass of solids filler.

13. The filler according to claim 1 or 2, in which the calcium salt is calcium carbonate.

14. The filler according to claim 1 or 2, in which the calcium salt is precipitated calcium carbonate.

15. The filler according to claim 2, which further comprises a fiber or fibrils of cellulose or lignocellulose.

16. The filler according to claim 2, which is essentially free of fibers or fibrils of cellulose and the and lignocellulose.

17. The paper containing the filler according to any one of claims 1 to 16.

18. The paper 17, in which the total content of filler in it is 5-40 wt.% calculated on dry paper.

19. A method of producing a filler, comprising the following steps: mixing compounds containing a salt of calcium derived from cellulose having a degree of substitution of ionic groups in the grid component to 0.65, with essentially no fibers or fibrils of cellulose, or lignocellulose.

20. A method of producing a filler comprising mixing a substance containing a salt of calcium derived from cellulose having a degree of substitution carboxialkilnuyu groups, component to 0.65, where the derived cellulose contains cationic groups.

21. Method of making paper comprising the following stages: obtaining the aqueous suspension containing pulp fibers; introducing the suspension of the filler according to any one of claims 1 to 16; dewatering the slurry to form a cloth or sheet of paper.

22. The method according to item 21, in which the filler is injected into a slurry by adding a single composition containing a salt of calcium derived cellulose.

23. The method according to any of PP or 22, in which the filler is added in a quantity amounting to 5-30 wt.% calculated on dry fiber.

24. The method according to item 21 or 22, which further includes the addition of glue is his substance, reacts with suspension.



 

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