KR20050083897A - Cellulosic product and process for its production - Google Patents

Abstract

The present invention relates to a process for the production of a cellulosic product which comprises (i) providing an aqueous suspension containing cellulosic fibres, and optional filler; (ii) adding to the suspension a clay having 3R2 stacking; and (iii) dewatering the obtained suspension. The invention also relates to a process for the production of a cellulosic product which comprises (i) providing an aqueous suspension containing cellulosic fibres, and optional filler; (ii) adding to the suspension a cationic clay;(iii) adding to the suspension one or more drainage and retention aids comprising at least one cationic polymer; and (iv) dewatering the obtained suspension. The invention further relates to a cellulosic product comprising clay having 3R2 stacking.

Description

Cellulose Products and Manufacturing Process {CELLULOSIC PRODUCT AND PROCESS FOR ITS PRODUCTION}

The present invention provides a process for producing a cellulose-based product comprising treating cellulose fibers with clay having a 3R ₂ stacked structure, and a process for producing a cellulose-based product comprising treating cellulose fibers with cationic clay. Is related. The present invention also relates to a cellulose based product comprising clay having a 3R ₂ stacked structure.

Pulp suspensions are widely used to make cellulose based products such as, for example, pulp and paper, and also contain compounds that negatively affect the manufacturing process, apart from cellulose fibers. Such compounds are found both in virgin pulp (pulp separating fibers from wood) and in cellulose suspensions originating from recycled pulp.

In virgin pulp suspensions, these disturbing / harmful substances are, in addition to lipophilic and hydrophilic extracts, primary hemicellulose, lignin. Apart from cellulose, these materials are dissolved in process water or colloidally dispersed in the process water in varying ranges during pulping and bleaching operations. Compounds released during pulping and bleaching operations are commonly referred to as pitches. Examples of resins include tree resins such as lipophilic extracts (fatty acid and resin acid, sterols, stearyl esters, triglycerides), fats, terpenes, terpeniods, waxes, and the like. It includes.

In the recycled pulp suspension, to mention a few of the compounds that negatively affect the paper making process, it consists mainly of glue, hot-melt plastics inks and latex, which are commonly referred to as stickies. . Apart from resins and stickies, suspensions may also be used for their interaction with and absorption of added work chemicals such as drainage aids and retention aids, sizing agents. Contains charged contaminants such as various wood polymers and salts of charged, low or no charged compounds that compete with cellulose. Such disturbing compounds are commonly referred to as anionic trash.

All of the foregoing compounds interfere with the pulp and paper making process in various ways. For example, some of the anionic inhibitors precipitate due to changes in the properties of the pulp suspension and eventually deposit on various mechanical parts of paper machines such as, for example, screens and felts. Over time, the deposition will break down the paper machine in the form of a rupture of the paper web, which requires stopping and cleaning the paper machine. Moreover, papermakers tend to recycle white water, more than previously increasing the presence of unstable and harmful substances in suspension.

Various additives have been used to reduce the negative effects of the above-mentioned harmful / unfavorable substances. Talc, for example, has been widely used as an adsorbent resin and sticky. Various types of clays have also been used to reduce the effects of harmful compounds.

Japanese Patent Application Laid-Open No. 1985-94687 relates to a resin-adsorbent containing hydrotalcite.

Summary of the Invention

The present invention generally relates directly to the process of treating cellulose fibers with clay having a 3R ₂ pile structure. The invention also generally relates to a process for treating cellulose fibers with cationic clay. Moreover, the present invention relates directly to a cellulosic product manufacturing process comprising adding clay having a 3R ₂ packed structure to an aqueous suspension containing cellulosic fibers. The present invention also relates directly to cellulosic products comprising clay, which generally has a 3R ₂ deposit structure.

The present invention also provides a process for preparing an aqueous suspension comprising (i) providing an aqueous suspension containing cellulose fibers; (ii) adding clay having a 3R ₂ accumulation structure and optionally one or more dewatering and retention agents to the suspension; And (iii) dehydrating the obtained suspension. The present invention also provides a process for preparing an aqueous suspension comprising (i) providing an aqueous suspension containing cellulose fibers; (ii) adding cationic clay to the suspension; (iii) adding at least one dewatering and retention agent comprising at least one cationic polymer to the suspension; And (iv) dehydrating the obtained suspension. The cellulosic product produced is preferably pulp and / or paper.

Detailed description of the invention

Surprisingly, by treating cellulose fibers with clay according to the invention, it is possible to reduce the negative effects of the presence of unhealthy and harmful substances in aqueous cellulose pulp suspensions on pulp and paper manufacturing processes, in particular problems caused by resins and stickies. Yes it was found.

Also surprisingly with regard to the additives used in the manufacture of pulp and paper, the addition of clays according to the invention, in particular cationic clays and / or 3R ₂ clays, to cellulose suspensions results in unstable substances when compared to the case where no clay is added. In addition to adsorption and removal, it improves the performance of the additives used in the process. Examples of such additives in which improved workability is observed include retention agents and dehydrating agents, size agents and the like, preferably used with one or more dehydrating agents and retention agents in which the clay comprises one or more cationic polymers. The present invention therefore simultaneously further reduces the content of unhealthy and harmful substances in the cellulose suspension and provides improved sizing in the paper making process as well as improved dewatering and retention in the pulp and paper making process. do.

Clays according to the present invention may be derived from naturally occurring clays, chemically and / or physically modified naturally occurring clays and synthetic clays. Naturally occurring clays typically have an intrinsic crystalline structure. However, also synthetically obtained clays may additionally contain amorphous materials having essentially the same chemical composition as the crystalline structure. The amount of amorphous material present in the synthetic clay depends primarily on the reaction parameters used. The term "clay" as used herein refers to clays having essentially crystalline structures and also to clays containing both crystalline and amorphous structures.

Clay is characterized by a layered structure, in which atoms in adjacent layers interact primarily by physical forces, while atoms in the layers are cross-linked by chemical bonds. The clay layer may or may not be charged depending on the type of atoms present inside the layer. If the layers are charged, the space between these layers, or the space designated as interlayer space, contains ions that have opposite charges to the charge of the layer. The term "cationic clay" as used herein refers to clays having anions present in the positively charged layer and interlayer space. The term "anionic clay" as used herein refers to clays having cations present in the negatively charged layer and interlayer space. Typically the ions in the interlayer space are exchangeable.

The clay according to the invention may have anions, also optionally water molecules, which are substantially present in the interlayer space. Examples of conventional anions that may be present in the interlaminar space include NO ₃ ⁻ , OH ⁻ , as well as pillaring or intercalating anions such as V ₁₀ O ₂₈ ^6- and MO ₇ O ₂₄ ^{6-. , Cl -, Br -, I} -, CO 3 2-, SO 4 2-, SiO 3 2-, CrO 4 2-, BO 3 2-, MnO 4 -, HGaO 3 2-, HVO 4 -, and ClO ^_4-mono, such as acetate-dicarboxylate, and La alkylsulfonyl, such as lauryl sulfonate, carbonate, such as carboxylates, oxalates; Typically includes hydroxide and carbonate. Naturally occurring clays of the present invention typically have carbonate anions in the interlayer space.

The clay layer or clayplate suitably contains two or more different metal atoms with different valences. Suitably, one metal atom is divalent and the other metal atom is trivalent. However, the layer may also contain two or more metal atoms. The charge of the layer is determined by the proportion of metal atoms having different valences. For example, higher amounts of triatomic metals will create layers with increased densities of positive charges. Suitably, the clays of the present invention comprise layers containing bivalent and trivalent metals in proportions such that the total layer charge is cationic, with the interlayer comprising anions. Preferably, the layer consists essentially of bivalent and trivalent metals in proportions such that the overall charge of the layer is cationic.

Synthetically produced and naturally occurring clays according to the present invention may be characterized by the following general formula:

[Mm ²⁺ Mn ³⁺ (OH) _{2m + 2n} ] X _{n / z} ^z -bH ₂ O,

Wherein m and n are, independently from each other, an integer having a value such that m / n is in the range of 1 to 10, preferably 1 to 6, more preferably 2 to 4, most preferably about 3; b is an integer having a value ranging from 0 to 10, suitably 2 to 6, often about 4; X _{n / z} ^Z- is an anion, where z is 1 to 10, preferably an integer in the range of 1 to 6, suitable X _{n / z} ^Z- is ^{_{NO 3 -, OH -, Cl}} -, Br -, ^{_{I -, CO 3 2-, SO}} 4 2-, SiO 3 2-, CrO 4 2-, BO 3 2-, MnO 4 -, HGaO 3 2-, HVO 4 -, ClO 4 -, V 10 O 28 6 ^- and MO ₇ O ₂₄ ^6- and filler ring (pillaring) and the intercalation rate St. anion, such as monomethyl acetate such -alkyl sulfonates, such as dicarboxylate, and lauryl sulfonates, such as a carboxylate, oxalate It includes; M ²⁺ is a divalent metal atom, suitably Be, Mg, Cu. A divalent metal atom comprising Ni, Co, Zn, Fe, Mn, Cd, and Ca, preferably Mg; M ³⁺ is a trivalent metal atom, suitably Al, Ga, Ni, Co, Fe, Mn, Cr. Triatoms comprising V, Ti and In, preferably Al are metal atoms. Preferably, the bivalent metal is magnesium, the trivalent metal is aluminum, and constitutes the following general formula:

[Mg _m ^{2 +} Al _n ³⁺ (OH) _{2m + 2n} ] X _{n / z} ^Z -bH ₂ 0.

According to one preferred embodiment of the invention, the clay is cationic. Examples of suitable cationic clays according to the present invention are hydrotalcite, manasseite, pyroaurite, sjogrenite, stitchtite, barbertonite ), Takovite, reevesite, deautelsite, motukoreaite, wermiandite, meixnerite, kolinzyi Coalingite, chloromagalumite, carrboydite, honesite, woodwardite, iowaite, hydrohonessite, mountkitite (mountkeithite) and the like. Examples of terms also used to describe such clays include hydrotalcite-like compounds and layered double hydroxide compounds.

According to another preferred embodiment of the invention, the clay has a specific stack structure, ie 3R ₂ stack structure; This type of clay is also referred to herein as "3R ₂ clay." The 3R ₂ clay is preferably cationic, which may be one of the clays mentioned above. Preferably, this clay is magnesium-aluminum-containing 3R ₂ clay. 3R ₂ clays suitably have three-layer repeats. The 3R ₂ Stacked Structure polytype of clay has a different layered / stacked structure than the 3R ₁ Stacked Structure multitype, also referred to herein as “3R ₁ Clay.” 3R ₁ , and 3R ₂ Clay have 107 and d _hkl 108, while having a close stronger d _hkl reflections in the X- ray intensity caused by reflection can be distinguished from each other by the diffraction / reflection. 3R ₁ clay is 47 ° 2 theta (d _hkl 108 reflection), 3R ₂ clay It has a stronger d _hkl 107 reflection close to 45 ° 2 theta (according to Drits and Bookin) The presence of peaks at both 45 ° 2 theta and 47 ° 2 theta is due to the mixture of 3R ₁ and 3R ₂ clays. The concise 2 theta values for the 107 and 108 d _hkl reflections will depend on the structural parameters of the lattice "a" and "c" for clays such as, for example, Mg-Al clays. There are some other differences in the line diffraction patterns, but this is the most Enemy d _hkl reflections are believed to range. Furthermore, 3R ₂ clay having an accumulation structure has a tissue (morphology) different than the traditional 3R ₁ clay, as can be measured by the SEM experiments a traditional prior art of 3R _One clay has layers of regularly well-formed small plates arranged in a conventional book-stacked form, while 3R ₂ clays have a structure of randomly aggregated irregular piece-like platelets. Appears to be.

Clay having a 3R ₂ stacking structure according to the present invention can be produced by hydrothermal treatment (solvo thermal) of a slurry containing an aluminum raw material and a magnesium raw material. Examples of suitable clays having a 3R ₂ stacking structure, such as Mg-Al clays, and methods of making clays having a 3R ₂ stacking structure according to the invention, for example, include those disclosed in WO 01/12550. , Which is hereby incorporated by reference.

According to one preferred embodiment of the present invention, clay having a 3R ₂ pile structure is added to an aqueous suspension containing cellulose fibers in the process of producing cellulose-based products such as pulp and paper. When 3R ₂ clay was added to this suspension, it was observed that the removal of unfavorable substances such as resins and stickies was improved more than with the addition of traditional clays having a 3R ₁ accumulation structure.

Suitably the clay is added to an aqueous suspension containing cellulose fibers as one of a slurry (suspension) or powder that can be readily dispersed in water (here also referred to as "aqueous cellulose suspension" and "cellulose suspension"), thereby Mixed with Clay powders or suspensions may also contain other compounds that may additionally contribute to the overall effect of the clay, such as, for example, dispersants and / or protective agents. Such agents may have non-ionic, anionic or cationic properties. Examples of suitable protecting agents or colloids are hydroxyethyl- and hydroxypropyl-, methylhydroxypropyl- and ethyl hydroxyethyl-cellulose, methyl- and carboxymethylcellulose, gelatin, starch, guar gum, xanthan gum, polyvinyl alcohol Water-soluble cellulose derivatives such as and the like. Examples of suitable dispersants include ethoxytized fatty acids, fatty acids, alkylphenols or fatty acid amides, ethoxylated and non-ethoxylated glycerol esters, sorbitan esters of fatty acids, non-ionic surfactants, polyols and / or derivatives thereof Nonionic agents such as; Anionic agents such as alkyl or alkylaryl sulfates, sulfonates, ethersulfonates, polyacrylic acids; And esterquats, quaternizes, obtained by reacting a mixture of fatty acids and dicarboxylic acids with alkanolamines, optionally alkoxylate the resulting esters and quaternizing the product. Cationic agents such as fatty acid amides, betaines, dimethyl dialkyl or dialkylaryl ammonium salts, and cationic gemini dispersing agents.

Clay can be added anywhere in the manufacturing process of cellulose products from the point where the wood chips are broken down to the dehydration of the cellulose suspension . Cellulose-based products may be in the form of sheets such as, for example, paper or pulp sheets and paper sheets.

According to a preferred embodiment of the invention, the clay is added to the cellulose suspension of the pulp making process. Clay may be added before and after the pulping process, which may be a kraft, mechanical, thermo-mechanical, chemomechanical, chemical-thermo-mechanical pulping process. Clay may be added immediately before the pulping process or directly to a pulping process such as a digester. However, the clay is preferably added to the cellulose suspension following chemical digestion, such as after brown stock washer treatment or after purification of (chemical-) mechanical pulp. Typically, the cellulose pulp is bleached in a multistage bleaching process that includes different bleaching steps, and the clay may be added to any bleaching sequence. Examples of suitable bleaching steps include, for example, a chlorine bleaching step such as basic chlorine and chlorine dioxide bleaching step, a non-chlorine bleaching step such as ozone, hydrogen peroxide and peracetic acid and a combination of chlorine, non-chlorine bleaching and oxidation step, Optionally in combination with a reduction step such as treatment with dithionite. The clay may be added directly to the bleaching stage at any point between the bleaching and washing stages, preferably to the cellulose suspension of the mixer prior to entering the bleaching tower, and also the clay is partially or wholly removed. It may also be added to washing steps, such as the displacement section.

According to another preferred embodiment of the invention, the clay may be added to the cellulose suspension of the paper making process. Clay may be added to a cellulose suspension, such as white water, before regeneration before entering a thick stock, thin stock, or thin stock feed box at any point in the paper making process. Preferably the clay is added to a thick stock. Cationic clays may also be added at one or more points in the pulp and / or paper making process. For example, in combined pulp and paper making machines, clay may be added to the pulp making process, and also optionally the paper making process, and one or more dehydrating and retaining agents may be added to the paper making process. These processes include dehydrating a cellulose suspension containing clay, diluting the obtained suspension, adding one or more dehydrating agents and retention agents to the diluted suspension, and dehydrating a suspension containing dehydrating and retention agents. It may include.

The term "paper" as used herein includes paper and their products, as well as other cellulose fiber-containing sheets or paper-like products, such as, for example, boards and paperboards, and products thereof. do. The process can be used to make paper from suspensions of different types of aqueous cellulose (cellulose-containing) fibers, which suspension suitably contains at least 25% by weight and preferably at least 50% by weight of fibers, based on the dry matter. shall. Cellulose fibers may be of virgin and / or recycled fibers, and the suspension may be chemical pulp, thermo-mechanical pulp, chemical-thermo-mechanical pulp, refiner pulp, such as sulfate, sulfite and organosolve pulp. And fibers of mechanical pulp, such as groundwood pulp from both hardwood and softwood, recycled fibers, optionally de-inked pulp, or a mixture thereof. If the recycled fibers are suspended, the recycled fibers are commonly treated to separate various fibrous surface treatment compounds such as, for example, latex from fibres, and non-fibrous compositions such as printing inks. In a preferred embodiment, the clay is suitably added to this deinking process.

According to the invention, the clay is calculated as dry clay relative to the dry cellulose suspension, suitably in the amount of from about 0.01% to about 5% by weight, preferably from about 0.05% to up to about 2% by weight. Is added. The invention also relates to a process for the preparation of cellulosic products such as pulp and paper, comprising the step of adding clay and optionally one or more dewatering and retention agents to the suspension having a 3R ₂ deposit structure. In a preferred embodiment, the dehydrating agent and the retaining agent comprise at least one cationic polymer. In another preferred embodiment, the dehydrating and retaining agents include cationic polymers and anionic materials. Examples of suitable anionic materials include anionic organic polymers such as anionic particulate materials such as anionic inorganic and organic particles (anionic microparticulate materials), and anionic vinyl addition polymers such as anionic acrylamide based polymers. . Clays, dehydrating agents and retention agents are preferably used in the papermaking process.

As used herein, the term “dehydrating agent and retention agent” refers to a composition (agent, additive) that provides better dehydration and / or retention when added to an aqueous cellulose suspension than dehydration and retention obtained without them.

The term "cationic polymer" as used herein refers to an organic polymer having one or more cationic groups, preferably an organic polymer having a cationic charge in its entirety. Cationic polymers may also contain anionic groups, and such polymers are commonly referred to as amphoteric polymers.

Cationic polymers according to the invention can be derived from natural and synthetic raw materials. Examples of suitable cationic polymers derived from natural sources are, for example, starch, guar gum, cellulose, chitin, chitosan, glycan, galactan, glucan, xanthan gum, pectin, mannan, dextrins, preferably starch and guar gum; Same polysaccharides. Examples of suitable starches include potatoes, corn, wheat, tapioca, rice, waxy corn, barley and the like. Examples of suitable cationic synthetic polymers include, for example, chain-grown polymers such as vinyl addition polymers such as acrylate-, acrylamide- and vinylamide-based polymers, and step-growth polymers such as, for example, polyurethanes. do. Suitably, the cationic polymer is selected from polysaccharides such as starch, and vinyl addition polymers such as polymers of acrylamide, and mixtures thereof.

The cationic polymers, in particular cationic polysaccharides and vinyl addition polymers, may also comprise aromatic groups which may be present in the polymer backbone, or preferably the aromatic functional groups are attached to or extend from the polymer backbone. It may be a functional group or may be present in an accessory functional group attached to or extending from the polymer backbone (main-chain). Examples of suitable aromatic functional groups include alkyl, aralkyl and alkaryl functional groups such as phenyl, phenylene, naphthyl, xylene, benzyl and phenylethyl; Nitrogen-containing aromatic (aryl) functional groups such as, for example, pyridinium and quinolinium, derivatives thereof, and preferably benzyl.

Examples of suitable cationic organic polymers having aromatic functional groups that can be used in accordance with the present invention include the polymers described in WO 99/55964, WO 99/55965, WO 99/67310 and WO 02/12626. , Which are hereby incorporated by reference. Examples of cationicly charged functional groups that may be present in the cationic polymer as well as in the monomers used to prepare the cationic polymer include quaternary ammonium functional groups, tertiary amino functional groups and acid addition salts thereof. do.

The term "chain-growth polymer" as used herein refers to a polymer obtained by chain-growth polymerization, also referred to as chain reaction polymer and chain reaction polymerization, respectively. Examples of suitable cationic chain-grown polymers are the polymerization of one or more monomers having vinyl functional groups or ethylenically unsaturated bonds, such as, for example, polymers obtained by polymerizing monomeric mixtures comprising cationic monomers or cationic monomers. Vinyl-added polymers prepared by the present invention.

Examples of suitable cationic monomers are, for example, dialidialkylammonium halides such as dialididialkylammonium chloride, acid addition salts and dimethylamino ethyl (meth) acrylate, diethylaminoethyl (meth) acrylate and dimethylaminohydroxypropyl (Meth) acrylates and dialkylamino such as dimethylaminoethyl (meth) acrylamide, diethylaminoethyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, and diethylaminopropyl (meth) acrylamide Quaternary salts of dialkylaminoalkyl (meth) acrylates such as quaternary monomers obtained by treating alkyl (meth) acrylamides with acids such as organic and inorganic acids, alkyl halides such as methyl chloride, and aryls such as benzyl chloride Contains halides. Preferred cationic monomers include benzyl chloride quaternary salts and dimethylaminoethylmethacrylate benzyl chloride quaternary salts. Cationic monomers may be copolymerized with one or more non-ionic and / or anionic monomers. Suitable copolymerizable non-ionic monomers include (meth) acrylamides; Acrylamide based monomers such as N-alkyl (meth) acrylamide, N, N-dialkyl (meth) acrylamide and dialkylaminoalkyl (meth) acrylamide, acrylics such as dialkylaminoalkyl (meth) acrylates Latex monomers, and vinylamide. Suitable anionic monomers copolymerizable include various sulfonated vinyl monomers such as acrylic acid, methacrylic acid and styrenesulfonate. Preferred copolymerizable monomers include acrylamide and methacrylamides such as, for example (meth) acrylamide, and the cationic or amphoteric organic polymer is preferably an acrylamide based polymer.

In particular, the average weight of the molecular weight of the cationic polymer can vary within wide limits depending on the type of polymer used, and is typically at least about 5,000 and usually at least 10,000. More usually, the average weight is at least 150,000, typically at least 500,000, suitably at least about 700,000, preferably at least about 1,000,000 and most preferably at least about 2,000,000. The upper limit is not strict; The upper limit can be about 200,000,000, typically 150,000,000, suitably 100,000,000.

Anionic inorganic microparticulate materials that can be used in accordance with the present invention include anionic silica based particles and anionic clays of the smectite type. The anionic inorganic particles are preferably of particle size in the colloidal range.

Preferably silica based anionic particles, such as SiO ₂ or silicic acid based particles, are used, which are supplied in the form of an aqueous colloidal dispersion, commonly called sol. Examples of suitable particles based on silica include colloidal silica and homos- or copolymers of different types of polysilicic acid. The silica based sol may be modified and may contain other elements such as aluminum, boron, nitrogen, zirconium, gallium, titanium and the like that may be present in the aqueous phase and / or silica based particles. Such suitable types of silica based particles include colloidal ammonium-modified silica and aluminum silicates. Also such suitable mixtures of silica based particles can be used. Dehydrating and retaining agents comprising suitable silica based anionic particles include U.S. Patents 4,388,150; 4,927,498; 35 4,954,220; 4,961,825; 4,980,025; 5,127,994; 5,176,891; 5,368,833; 5,447,604; 5,470,435; 5,543,014; 5,571,494; 5,573,674; 5,584,966; 5,603,805; 5,688,482; And 5,707,493; these are incorporated herein by reference.

Silica based anionic particles suitably have an average particle size in the range of less than about 100 nm, preferably less than about 20 nm and more preferably from about 1 to about 10 nm. As traditional in silica chemistry, particle size refers to the average size of primary particles that may or may not aggregate. The specific surface area of the silica based particles is suitably at least 50 m ² / g and preferably at least 100 m ² / g. In general, the specific surface area may be up to about 1700 m ² / g and preferably up to 1000 m ² / g. Specific surface area is measured by titration with NaOH in well known manner as disclosed in GW Sears in Analytical Chemistry 28 (1956): 12, 1981-1983 and US Pat. No. 5,176,891. The area given therefore represents the average specific surface area of the particles.

According to a preferred embodiment of the invention, the silica based anionic particles have a specific surface area in the range of 50 to 1000 m ² / g, preferably 100 to 950 m ² / g. Also sols of this type of silica based particles include variants having, for example, the elements mentioned above. Preferably, the silica based particles comprise silica based particles having a specific surface area in the range of 300 to 1000 m ² / g, suitably 500 to 950 m ² / g, and preferably 750 to 950 m ² / g. Containing sol having an S-value in the range of 8 to 50%, preferably 10 to 40%, which can be modified as mentioned above. S-values are calculated from Iler & Dalton in J. Phys. Chem. 60 (1956), 955-957 can be measured and calculated as described. S-values indicate the degree of aggregation or microgel formation, and lower S-values indicate the higher degree of aggregation.

According to another preferred embodiment of the invention, the silica based particles are selected from homo- or copolymerized polysilicic acid having a high specific surface area, preferably at least about 1000 m ² / g. The specific surface area may range from 1000 to 1700 m ² / g and preferably from 1050 to 1600 m ² / g. The sol of modified or copolymerized polysilicic acid may contain other elements mentioned above. Also in the art, polysilicates are referred to as polymer silicic acid, polysilicate microgels, polysilicates and polysilicate microgels, all of which may be included in the term poly-silicic acid as used herein. Aluminum-containing compounds of this type are also commonly referred to as polyaluminosilicates and polyaluminosilicate microgels, all of which are included in the terms aluminum-modified colloidal silica and aluminum silicate as used herein.

Also according to another preferred embodiment of the present invention, the dehydrating agent and the retaining agent comprise an anionic clay of the smectite type. Examples of suitable smectite clays are montmorillonite / mentonite, hectorite, baydelite, nontronite and saponite, preferably bentonite and particularly preferably expanded, as well as synthetic smectite-like clays such as laponite, etc. Natural clays such as bentonite having a specific surface area of 200 to 800 m ² / g. Suitable anionic clays are described in US Pat. No. 4,753,710; 5.071,512; And 5,607,552, which are incorporated herein by reference. Also mixtures of silica based anionic particles with an anionic clay of the smectite type can be used.

Anionic organic polymers according to the present invention contain one or more negatively charged (anionic) functional groups. Examples of functional groups that may be present in the polymer as well as in the monomers used to prepare the polymer include functional groups that carry anionic charge and acidic functional groups that carry anionic charge when dissolved or dispersed in water, wherein phosphate, It is collectively referred to as anionic functional groups such as phosphonates, sulfates, sulfonic acids, sulfonates, carboxylic acids, carboxylates, alkoxides and phenol functional groups such as hydroxy-substituted phenyl and naphthyl. The functional group carrying the anionic charge is typically a salt of an alkali metal, alkaline earth or ammonia.

Anionic organic particles that can be used according to the invention are copolymerized with cross-linked anionic vinyl addition polymers, suitably conventionally non-ionic monomers such as (meth) acrylamide, alkyl (meth) acrylates, etc. Copolymers comprising anionic monomers such as acrylic acid, methacrylic acid and sulfonated or phosphonated vinyl addition monomers. Useful anionic organic particles also include anionic condensation polymers such as melamine-sulphonic acid sol.

Anionic polymers that may also form part of the dehydration and retention system include anionic step-growth polymers, chain-growth polymers, polysaccharides, naturally occurring aromatic polymers, and modifications thereof. The term "step-growth polymer" as used herein refers to polymers obtained by step-growth polymerization, each also referred to as step-reaction polymer and step-reaction polymerization. Anionic organic polymers can be linear, branched or cross-linked. Preferably, the anionic polymer is water soluble or water dispersible. In a further preferred embodiment, the anionic organic polymer contains at least one aromatic group. Aromatic groups of the anionic polymers may be present in the substituent backbone or attached to the polymer backbone (chain). Examples of suitable aromatic groups include aryl, aralkyl, alkaryl functional groups and derivatives thereof, such as phenol, tolyl, naphthyl, phenylene, xylene, benzyl, phenylethyl and derivatives of such functional groups. Examples of suitable anionic chain-grown polymers are anionic monomers having carboxylate functional groups such as acrylic acid, methacrylic acid, ethylacrylic acid, crotonic acid, itaconic acid, maleic acid, salts of those described above. , Anhydrides of diacids, and sulfonated vinyl addition monomers, such as sulfonated styrene, which are typically copolymerized with non-ionic monomers such as acrylamide, alkyl acrylates, and the like. And those disclosed in US Pat. Nos. 5,098,520 and 5,185,062, which are incorporated by reference.

Examples of suitable anionic aromatic step-growth polymers are, for example, aldehyde condensates such as formaldehyde with anionic polyurethane and one or more (aromatic) compounds containing one or more anionic functional groups, and condensation polymerization such as urea and melamine. Condensation polymers, such as other optional comonomers useful for, ie, polymers obtained by step-growth condensation polymerization. Examples of preferred anionic step-growth polymers according to the present invention include anionic condensation polymers based on benzene and naphthalene, preferably naphthalene-sulfonic acid based and naphthalene-sulfonate based condensation polymers. .

Examples of suitable anionic polysaccharides include starch, guar gum, cellulose, chitin, chitosan, glycan, galactan, glucan, xanthan gum, pectin, mannan, dextrin, preferably starch, guar gum and cellulose derivatives, and Examples of starch include potatoes, corn, wheat, tapioca, rice, waxy corn and barley, preferably potatoes.

Examples of suitable anionic organic polymers are described in US Pat. Nos. 4,070,236 and 5,755,930; And those described in International Patent Applications WO 95/21295, WO 95/21296, WO 99/67310, WO 00/49227 and WO 02/12626, which are hereby incorporated by reference.

The weight average of the molecular weight of the anionic polymers having aromatic functional groups can vary within wide limits, in particular depending on the type of polymer used, and the weight average is usually at least about 500, suitably at least about 2,000, preferably Is about 5,000 or more. The upper limit is not strict; The upper limit may be about 200,000,000, typically about 150,000,000, suitably about 100,000,000, preferably about 10,000,000.

In addition to the aforementioned cationic polymers, anionic inorganic and organic particles and anionic organic polymers, dehydrating agents and retention agents may also include low molecular weight, highly cationic charged, organic polymers and / or inorganic aluminum compounds. have.

According to one preferred embodiment of the invention, the dehydrating agent and the retaining agent comprise anionic clays of cationic polymer and anionic inorganic microparticulate material, suitably silica based anionic particles or smectite type. According to another preferred embodiment of the invention, the dehydrating and retaining agents comprise cationic polymers and anionic vinyl addition polymers, suitably acrylamide based anionic polymers. Also in accordance with another preferred embodiment of the present invention, the dehydrating agent and the retaining agent include cationic polymers comprising aromatic functional groups. Also according to another preferred embodiment of the present invention, the dehydrating agent and the retaining agent include an cationic polymer comprising an aromatic functional group and an anionic polymer comprising an aromatic functional group.

The composition of the dehydrating and retaining agents can be added to the cellulose suspension in a conventional manner and in any order. When using anionic microparticulate materials, it is preferable to add the cationic polymer to the suspension before adding the microparticulate material, although the order of addition is reversed. It is more preferred to add the cationic polymer before the shearing step, which may be selected in pumping, mixing, washing, etc., and to add the anionic compound after this shearing step. If LMW cationic organic polymers and / or aluminum compounds are used, they are preferably introduced into the suspension prior to introducing the cationic polymer and the anionic composition. Alternatively, the LMW cationic organic polymer and cationic polymer may be introduced into the suspension essentially simultaneously, individually or in a mixture, as disclosed, for example, in US Pat. No. 5,858,174, which is incorporated herein by reference.

If the clays according to the invention are used together with dehydrating and retaining agents, the clay can be added to the suspension either before or after the addition of the dehydrating and retaining agents. However, cationic clays are preferably added prior to dehydrating and retaining agents and other performance chemicals. Suitably, clay is added to thick stocks or thin stocks, and dehydrating and retention agents are added to thin stocks. Clay may also be added to the recycled white water. If two or more dehydrating and retaining agents are used, i.e. using cationic polymers with anionic materials such as silica based particles or anionic organic polymers, the clay may be before, after or before or after adding the dehydrating and retaining agents. In between, or together with a dehydrating and retention agent, can be added to the cellulose suspension (stock). Clay may also be added at several points in the process, for example, back to thick stocks and thin stocks before adding dehydrating and retaining agents.

The dehydrating agent and the retaining agent according to the present invention have a wide range of dehydrating agents depending on the type and number of constituents, the type of cellulose suspension, the salt content, the type of salt, the filler content, the type of filler, the timing of addition, the degree of white water blocking, and the like. It may be added in an amount that can vary within limits. Generally, retention agents and dehydrating agents are added in an amount that provides better dehydration and / or retention than dehydration and / or retention obtained when no composition is added. Cationic polymers are typically added in an amount of at least about 0.001% by weight, often at least about 0.005% by weight, based on the dry cellulose suspension, with an upper limit typically being about 3% by weight, suitably about 1.5% by weight. Typically the amount of cationic polymer treated is from about 0.01% by weight up to about 0.5% by weight. For example, anionic materials such as silica based anionic particles, smectite type anionic clays and anionic organic polymers are typically added in an amount of at least about 0.001% by weight, often at least about 0.005% by weight, based on the dry cellulose suspension. The upper limit is typically about 1.0% by weight, suitably about 0.6% by weight.

When LMW cationic organic polymers are used in the process, they may be added in an amount of at least about 0.001% by weight, based on the dry cellulose suspension. Suitably, the amount added is in the range of about 0.07 up to about 0.5%, preferably about 0.1 to up to about 0.35%. When aluminum compounds are used in the process, the total amount introduced into the dehydrated stock depends on the type of aluminum compound used and other effects desired to be obtained from the aluminum compound. For example, the use of aluminum compounds as precipitants for rosin-based sizing agents is well known in the art. Based on the dry cellulose suspension, the total amount added as Al ₂ O ₃ is typically at least about 0.05% by weight. Suitably the total amount added is in the range of about 0.5 up to about 3.0%, preferably about 0.1 to up to about 2.0%. In addition, traditional additive additives in papermaking are, for example, dry strength agents, wet strength agents, optical brightening agents, dyes, rosin-based sizing agents and ketone dimers. And sizing agents such as cellulose-reactive sizing agents such as succinic anhydride and the like may also be used in combination with the additives of the invention. Cellulose suspensions or stocks are also minerals of traditional types, such as natural and synthetic calcium carbonates, such as, for example, kaolin, white clay, titanium dioxide, gypsum, talc and chalk, ground marble and precipitated calcium carbonate. It may contain a filler.

Moreover, the process can be useful for making paper from cellulose suspensions with high conductivity. In this case, the conductivity of the suspension dehydrated in the wire is usually at least 1.0 mS / cm, suitably at least 2.0 mS / cm, and preferably at least 3.5 mS / cm. Conductivity can be measured, for example, by standard equipment such as the WTW LF 539 instrument supplied by Christian Berner. Suitably, the above mentioned values are determined by measuring the conductivity of the cellulose suspension supplied to or present in the head box of the paper machine or by measuring the conductivity of the white water obtained by dehydrating the suspension.

The invention also relates to, for example, 0 to 30 tonnes per tonne of dry paper produced, typically less than 20 tonnes, suitably less than 15 tonnes, preferably less than 10 tonnes, most preferably less than 5 tonnes per tonne of paper. A high degree of white water blockade where fresh water is used includes paper making processes where white water is recycled or recycled in large quantities.

 However, the present invention is further illustrated in the following examples which do not limit the invention. Unless stated otherwise, parts and% relate to weight parts and weight percentages, respectively.

Thread example 1

Al-Mg clay (CC-14, Akzo Nobel Catalyst BV) with a 3R ₂ stack was compared with commercial talc (Finntalc P05 from Omya) in terms of resin adsorption. The method for measuring the resin adsorption of mineral powder was a modification of the procedure outlined by DA Hughes in Tappi (July 1977, vol. 60, No. 7, p. 144-146). A synthetic resin sample was prepared by first adding potassium hydroxide (1M) to a mixture of 0.65 g gum rosin and 0.35 g oleic acid until a saponification reaction was produced. Modified ethanol was subsequently added to dissolve the synthetic resin.

Resin Adsorption Test Procedure: First, 35 ml of distilled water is added to a glass centrifuge tube, followed by 1 ml of synthetic resin solution and 10 ml of clay (2.5% dry weight) having a 3R ₂ packed structure. The pH of the synthetic resin slurry was adjusted to 6.5 with sulfuric acid. The mixture was subsequently stirred for 2 minutes and centrifuged for 20 minutes at 4500 rpm. The supernatant was then decanted off and the centrifuge tube was dried at 60 ° C. overnight. After drying, 10 ml of chloroform-acetic anhydride (1: 1) reactant was added to the centrifuge tube and stirred to release the absorbed resin. The centrifuge tube was then centrifuged for 20 minutes, yielding a clear reaction on top of the centrifuge tube. The reaction is then poured into a small beaker and 10 drops of cone. Sulfuric acid was added. After 4 minutes, the liquid was measured on a UV-vis spectrophotometer installed at 400 nm, whereby the absorption value was compared with the absorption value of a known amount of resin. Similar tests were also performed on Finntalc P05 samples. The resin adsorption results are summarized in Table 1, where 'resin addition' refers to the amount of resin (mg) added per gram of adsorbent, such as talc or clay; Resin absorption refers to the amount of resin (mg) absorbed per gram of adsorbent, such as talc or clay.

A running number Resin addition [mg / g] Resin Adsorption [mg / g] Talc [0.16 mg / ml] Clay (CC-14) [0.16mg / ml] Talc [0.08 mg / ml] Clay (CC-14) [0.08mg / ml] One 0 0 0 0 0 2 2 1.2 2 1.2 2 3 4 2.3 4 1.2 4 4 6 3 6 1.5 6 5 8 3.1 7.5 1.6 8 6 10 4 9 2 10 7 12 4.3 10 2.1 11.5 8 14 4.2 10.1 2.2 13 9 16 4.5 10.1 2 13 10 18 4.7 11 2.4 13

As can be seen in Table 1, clays with a 3R ₂ pile up structure have significantly improved absorption performance compared to talc.

Example 2

In this embodiment, 3R ₁ accumulation Al-Mg cationic resin adsorption properties of the clay, (CC-8, Sud Chemie) the 3R ₂ Al-Mg cationic clay (CC-17 with the accumulation structure, having a structure Akzo Nobel Catalyst BV).

One mixture of the synthetic resin containing the oleic acid and gum rosin (resin No. 1) of Example 1 and another synthetic resin mixture containing abietic acid were prepared. 1 g of abietic acid and 1 M potassium hydroxide were mixed until a saponification reaction occurred, to prepare an abietic acid containing a resin (resin No. 2). Modified ethanol (250 ml) was added to dissolve the synthetic resin. The same resin adsorption test procedure as outlined in Example 1 was used. The results are summarized in Tables 2 and 3.

Exam number Resin addition (resin 1) [mg / g] Resin Adsorption [mg / g] CC-8 (3R ₁ ) CC-17 (3R ₂ ) One 0 0 0 2 8 5.4 7.1 3 16 9.64 14.1 4 32 21.5 29 5 48 34.4 41

Exam number Resin addition (resin 2) [mg / g] Resin Adsorption [mg / g] CC-8 (3R ₁ ) CC-17 (3R ₂ ) One 0 0 0 2 8 4.45 6.07 3 16 11.1 13.8 4 32 26.5 30.3 5 48 40.3 47.5

As can be seen in Tables 2 and 3, clays with 3R ₂ stacks absorbed not only oleic acid mixtures, but also abietic acids and gum rosin to cationic clays with 3R ₁ stacks.

Example 3

Sticky (melt) absorption of Al-Mg cationic clay (CC-14, Akzo Nobel Catalyst BV) with 3R ₂ stacked structure was compared with talc (Finotalc P05, Omya) using a TOC instrument (Dohrman DC190). TOC (total organic carbon) was determined by combustion at 800 ° C. whereby the carbon was oxidized to carbon dioxide and then analyzed by IR-spectrometry. The results are summarized in Table 4, where 'sticky addition' refers to the amount of sticky weight (mg) added per gram of adsorbent such as clay or talc, and 'sticky absorption' per gram of adsorbent such as talc or clay. Refers to the amount of stickies absorbed (mg).

Exam number Sticky add [mg / g] Sticky's Absorption [mg / g] Talc [0.16 mg / ml] CC-14 [0.16mg / ml] melt Talc [0.08 mg / ml] CC-14 [0.08mg / ml] melt One 0 0 0 0 0 2 2 1.3 2 1.5 2 3 4 1.8 4 1.8 4

 Example 4

The working performance of the dehydrating agent in which clay having a clay 3R ₂ accumulation structure was mixed in the dehydrating agent and the retaining agent was measured by Dynamic Drainage Analyser (DDA) available from Akribi Kemikonsulter AB of Sweden. The DDA measures the time to dewater the aggregate volume of the stock through the wire when the plug is removed and the vacuum (0.35 bar) is applied on the opposite side of the side where the stock is present. The first pass retention was measured by measuring the turbidity of the filtrate and white water obtained by dehydrating the suspension using a nephelometer.

The furnish used is made of demineralized pulp from a papermaking machine having a viscosity of 30 g / l, conductivity of about 1500 μS / cm and pH 7. A sample of Al-Mg cationic clay (CC-9, Akzo Nobel Catalyst BV) with 3R ₂ accumulation structure was added to the pulp suspension. The finished stock was then mixed with a magnetic stirrer and the dwell / contact time of the stock and cationic clay was from 30 minutes up to 1 hour. The finished material was then diluted with water (about 1:10) prior to the DDA test.

Stock / Finish Samples were placed in blocked DDA bottles at time zero. The retention / dehydration chemical was then added in the following order: i) Dry pulp of 0.8 kg / ton of polyacrylamide (Eke PL 1510) after 15 seconds, ii) again after 15 seconds (after 30 seconds of starting) 0.4 kg / ton of dry pulp of silica based anionic particles (Eke NP 780), iii) dehydration of the suspension while automatically recording the dehydration time after 15 seconds again.

The resin adsorption of the filtrate sample obtained in the dehydration test was measured. Resin adsorption was assumed to be related to the absorbance of the UV-vis spectrometer at 280 nm of the filtrate, and the reduction of the UV-vis absorbance was regarded as the resin reduction. The results are shown in Table 5.

Exam number CC-9 added [kg / t] Dewatering Time [s] Resin Reduction [%] One 0 9.3 - 2 5 6.04 19.8 3 10 5.63 21.4

Table 5 clearly shows that the addition of CC-9 to the suspension reduces the dehydration time, and the filtrate contained less resin as CC-9 was added to the suspension.

Example 5

In this embodiment, compared to the Al-Mg cationic clay Al-Mg cationic clay (CC-18) having the 3R ₂ accumulation structure (CC-12) in terms of dehydration has a 3R ₁ accumulation structure. The same finishes and procedures as described in Example 4 were used. Table 6 summarizes the results.

Experiment number CC capacity [kg / t] Dehydration time [sec.] CC-12 (3R ₁ ) CC-18 (3R ₂ ) One 0 16.2 16.2 2 2 15 13.1 3 5 14.9 13.2 4 10 14.8 11.9

From Table 6, the addition of the clay having 3R ₂ the accumulation structure Sikkim further improved dewatering compared to the addition of the cationic clay having 3R ₁ accumulation structure was evident.

Example 6

Here, the dehydration strengthening effect of Al-Mg cationic clay (CC-22) having a 3R ₂ accumulation structure was measured. The same finishing materials and procedures as described in Example 4 were used except that different dehydrating and retaining agents were used. In this example, 0.4 kg / ton of dry pulp of Percol 63 (cationic polyacrylamide provided by CIBA) and 2 kg / ton of dry pulp of Hydrocol SW (smectite type bentonite clay provided by CIBA) were obtained in a similar manner. Added.

CC capacity [kg / t] Dehydration time [sec.] CC-22 (3R ₂ ) 0 11.2 2 9.1 10 8.1

Table 7 shows that the working performance of dehydrating and retention agents, including adding cationic PAM and bentonite clay to the suspension, is improved by adding 3R ₂ type Al-Mg cationic clay.

Example 7

The adsorption of pressure-sensitive adhesive stickies of Al-Mg cationic clays (CC-17, Akzo Nobel Catalyst BV) with 3R ₂ deposits was measured to determine the adsorption of talc (Finntalc P05, Omya). Compared. Pressure-sensitive adhesive stickies are found in offices as consumer goods such as labels, tapes, self-sealed envelopes and post-it notes.

60 g of Tappi journal vol. 79 no 7 July 1996, glued on one side, were cut into small squares and soaked in 1.51 L of cold tap water for 24 hours. Salt solution containing CaCl ₂ .2H ₂ O, Na ₂ SO ₄ .10H ₂ O and 0.5 L of tap water were added to the water-paper mixture to simulate paper machine conditions such as pH and conductivity. The mixture was then separated at 30000 revolutions in a standard pulp dissociator. Filtration removed fibers and fine particles larger than 25 μm. The filtrate was heated to 60 ° C. in a water bath. The pH was changed between 6.8 and 7.4. To the filtrate sample was added Al-Mg clay and talc (PO5) having a 3R ₂ accumulation structure. After addition of CC-17 and talc, the filtrate was mixed with a magnetic stirrer and the settling time of CC-17 and talc was 60 minutes. Adsorption tests were performed by centrifugation at 4500 rpm for 30 minutes. The supernatant was then decanted and TOC was measured. Table 8 shows the results for the adsorption of pressure sensitive adhesives.

Experiment number Talc [kg / t] CC-17 [kg / t] TOC [ppm] One 0 0 550 2 5 525 3 10 498 4 20 400 5 5 401 6 10 292 7 20 115

As shown in Table 8, the adsorption of pressure sensitive adhesives is significantly improved when CC-17 is added as compared to the addition of talc.

Example 8

In this example, sizing work performance was measured. Finishing material of the liquid packaging board maker was treated with Al-Mg cationic clay (CC-22, Akzo Nobel Catalyst BV) and talc (Finntalc P05, Omya) each having a 3R ₂ stack structure. Size chemicals and suspended chemicals were added and paper handkerchiefs were prepared (SCAN-C 26:76). Sizing of the paper was measured with Cobb 60 value (SCAN-P 12:64).

The finish used was a thick-stock of an LPB maker, containing bleached conifer- and hardwood pulp. This finished stock was stirred and heated to 50 ° C. Chemicals were added and the finish was treated for 30 minutes. The thick stock was then diluted with tap water to a viscosity of 5 g / L. This finished stock had a conductivity of pH 8 and 0.7 mS / cm. Prior to making paper, 0.3 kg / ton of dry pulp of AND (Keydime C223, Eka Chemicals), 8 kg / ton of dry pulp of cationic starch (Perlbond 970) and silica based particles (Eke NP 590, Eka Chemicals) 0.5 kg / ton of dry pulp of was added.

The paper had a basis weight of about 73 g / m ² . Table 9 shows the sizing results obtained by adding different amounts of talc and CC-22 to the liquid packaging board finish.

Experiment number Talc [kg / t] CC-22 [kg / t] Cobb 60 One 0 0 40 2 One 44 3 5 60 4 One 35 5 5 34

Example 9

Sizing work performance was measured by adding more Al-Mg cationic clay (CC-22, Akzo Nobel Catalyst BV) and talc (Finntalc P05, Omya) each having a 3R ₂ stacked structure. Paper handkerchiefs were prepared and sizing was measured with Cobb 60 (SCAN-P 12:64) values.

The finish used was a thick-stock of an LPB maker, containing 4% viscosity hydrogen peroxide bleached conifer- and hardwood sulfate pulp. This finished stock was stirred and heated to 50 ° C. Cationic clay or talc was added and the finish was treated for 20 minutes. The thick stock was then diluted to a viscosity of 3.9 g / L with bleach filtrate. In the finished paper AKD, a rosin size of 1.6 kg / t, alum 1.6 kg / t, cationic starch 5.0 kg / t and silica based particles (Eke NP 590, Eka Chemicals) 0.35 kg / t Rapid-Kothen former) was added before preparation. The paper had a basis weight of about 100 g / m ² . Table 10 summarizes the results obtained by sizing the liquid packaging board finish.

Experiment number AKD [kg / t] Talc [kg / t] CC-22 [kg / t] COBB 60 One 0 0 0 258 2 0.5 0 0 250 3 0.8 0 0 131 4 One 0 0 59 5 1.4 0 0 39 6 0.5 5 0 211 7 0.8 5 0 115 8 One 5 0 61 9 1.4 5 0 39 10 0.5 0 10 198 11 0.8 0 10 87 12 One 0 10 45 13 1.4 0 10 33

Table 10 shows that using CC-22 improved sizing performance (lower than Cobb 60) compared to using talc.

Example 10

This example was made in a pulp making machine. Chemical pulp from the dewatering headbox of the pulp machine was treated with Al-Mg cationic clay (CC-22, Akzo Nobel Catalyst BV) having a 3R ₂ pile structure. Since the turbidity of the pulp filtrate was measured, it is shown in Table 11.

The pulp used was a suspension of bleached eucalyptus fibers with a viscosity of 1.2%. This pulp was stirred and heated at 60 ° C. Cationic clay was added and the pulp was treated for 30 minutes. The pulp was then filtered through Britt-Jar with a 200 mesh wire (76.2 um hole diameter). The turbidity of the filtrate was measured on a Hach 2100P turbidimeter. Table 11 shows the results for the turbidity of the filtrate.

Experiment number CC-22 [kg / t] Turbidity [NTU] One 0 53 2 2 43 3 5 23

The turbidity of the filtrate was improved (reduced) when treated with chemical pulp with CC-22.

Example 11

This example was made in a TMP pulp maker. Thermomechanical pulp (TMP) was bleached with hydrogen peroxide and then dehydrated or washed. The filtrate is often referred to as bleach filtrate. The TMP bleach filtrate was stirred and heated at 50 ° C. TMP bleached filtrate was treated with Al-Mg cationic clay (CC-22, Akzo Nobel Catalyst BV) having a 3R ₂ accumulation structure for 30 minutes. The water was centrifuged, and the clear liquid turbidity was measured by measuring the absorbance in a 700 nm wavelength Lasa spectrometer. Table 12 shows the results.

Experiment number CC-22 [kg / t] Turbidity [NTU] One 0 53 2 2 43 3 5 23

The absorbance of the clear liquid phase was improved (reduced) when treated with TMP bleached water with CC-22.

Example 12

This example was made in a deinking pulp (DIP) maker. The pulp of the DIP maker was treated with Al-Mg cationic clay (CC-22. Akzo Nobel Catalyst BV) with a 3R ₂ stacked structure. Since the turbidity of the pulp filtrate was measured, it is shown in Table 13.

The pulp used is taken between the disk filter and the screw press in the DIP maker. The pulp has a viscosity of 7% and is diluted to 4.2% with tap water. This pulp was stirred and heated at 50 ° C. Clay was added and the pulp was treated for 30 minutes. The pulp was then filtered through a GF / A glass fiber filter (pore diameter of 2 μm or less). The turbidity of the filtrate was analyzed on a Hach 2100P turbidimeter. Table 13 shows the results.

Experiment number CC-22 [kg / t] Turbidity [NTU] One 0 71.8 2 2 63.5 3 5 42.3

The turbidity of the filtrate was improved (reduced) when the demelting pulp was mixed with CC-22 before filtration.

Example 13

In a similar manner to Example 12, the pulp of the demelting pulp (DIP) maker was treated with Al-Mg cationic clay (CC-22, Akzo Nobel Catalyst BV) with a 3R ₂ pile structure. The turbidity of the pulp filtrate was then measured and summarized in Table 14.

Experiment CC-22 [kg / t] Turbidity [NTU] One 0 18 2 5 15 3 10 11

The turbidity of the filtrate is improved (reduced) when the demelting pulp is treated with the addition of CC-22 before the filtrate is filtered.

The present invention relates to a cellulose manufacturing process comprising treating cellulose fibers with clay (clay) having a 3R ₂ pile structure, and a cellulose-based product manufacturing process comprising treating cellulose fibers with cationic clay. The present invention also relates to a cellulose based product comprising clay having a 3R ₂ stacked structure.

Claims (27)

Process for producing a cellulosic product comprising the following steps: (i) providing an aqueous suspension containing cellulose fibers and an optional filler; (Ii) adding clay having a 3R ₂ accumulation structure to the suspension; And (Iii) dehydrating the suspension obtained. A process for producing a cellulose-based product comprising the following steps: (i) providing an aqueous suspension containing cellulose fibers and an optional filler; (Ii) adding cationic clay to the suspension; (Iii) adding one or more drainage aids and retention aids comprising one or more cationic polymers to the suspension; And (iv) dehydrating the obtained suspension. Cellulosic products comprising clay with a 3R ₂ pile structure. The process for producing a cellulose-based product or a cellulose-based product according to claim 1, 2 or 3, wherein the cellulose-based product is paper. The process for producing a cellulose-based product or a cellulose-based product according to claim 1, 2 or 3, wherein the cellulose-based product is pulp. The process according to any one of claims 1, 4 and 5, or the product according to any one of claims 3 to 5, wherein the clay is cationic. The process of any one of claims 1, 2, 4-6, or the product of any of claims 3-6, wherein the clay comprises a layer and an interlayer, and The interlayer comprises an anion, wherein the layer comprises a bivalent and trivalent metal atom at a rate such that the overall charge of the layer is cationic, or a cellulose-based product. 8. Process according to any one of claims 1, 2, 4-7, or the product of any one of claims 3-7, wherein the clay is a divalent metal atom (M ²⁺ ) and aluminum, which is magnesium A process for producing a cellulose product or a cellulose product, wherein three atoms contain metal ions (M ³⁺ ). Claim 1, 2, wherein any one of the step of 4 to 8, or according to any one of the products of 3 to 8, wherein the clay is NO ₃ ^-, OH ^-, Cl ^-, Br ^-, I ^{_{-, CO 3 2-, SO 4}} 2-, SiO 3 2-, CrO 4 2-, BO 3 2-, MnO 4 -, HGaO 3 2-, HVO 4 -, ClO 4 -, the filler ring (pillaring) or A process for producing a cellulose-based product or a cellulose-based product, which has an interlayer comprising an anion including an intercalating anion, a carboxylate, a sulfonate or a mixture thereof. 10. The process of any one of claims 1, 2, 4-9, or the product of any of claims 3-9, wherein the clay comprises an interlayer comprising hydroxide, carbonate or mixtures thereof. Cellulose-based product manufacturing process or cellulose-based product characterized in that it has. 11. Process according to any one of claims 1, 2, 4 to 10, or the product of any of claims 3 to 10, wherein the clay is characterized by the following general formula Manufacturing Process of Cellular Products or Cellulose Products: [Mm ²⁺ Mn ³⁺ (OH) _{2m + 2n} ] X _{n / z} ^Z -bH ₂ O, Wherein m and n are, independently from each other, m / n an integer having a value ranging from 1 to up to 10; b is an integer having a value in the range of 0-10, suitably an integer having a value in the range of 2-6, and often about 4; z is an integer from 1 to 10, X _{n / z} ^Z- is an anion, where z is an integer from 1 to 10; M ²⁺ is a divalent metal atom selected from the group consisting of Be, Mg, Cu, Ni, Co, Zn, Fe, Mn, Cd, and Ca, and mixtures thereof; M ³⁺ is a trivalent metal atom selected from the group consisting of trivalent metal atoms, suitably Al, Ga, Ni, Co, Fe, Mn, Cr, V, Ti, In and mixtures thereof. The process of any one of claims 1, 2, 4-11, or the product of any one of claims 3-11, wherein the clay is hydrotalcite, manasseite, pie Pyroaurite, sjogrenite, stichtite, barbertonite, takovite, reevesite, desautelsite, motucore Motukoreaite, wermlandite, meixnerite, coalingite, chloromagalumite, carrboydite, honessite, A process for producing a cellulose-based product or a cellulose-based product, characterized in that it is woodwardite, iowaite, hydrohonessite, mountkite or a mixture thereof. The process according to any one of claims 1, 2 and 4 to 12, or the product according to any one of claims 3 to 12, wherein the clay is a hydrotalcite manufacturing process. Or cellulosic products. 14. A process according to any one of claims 1 to 4 to 13, further comprising the step of adding one or more dehydrating and retaining agents to the suspension. The process of claim 15 wherein the dehydrating and retaining agent comprises at least one cationic polymer. 16. The process according to any one of claims 2, 14 and 15, wherein the dehydrating and retaining agent comprises a cationic polymer and an anionic material. 17. The process according to any one of claims 2, 14-16, wherein the dehydrating and retaining agent comprises a cationic polymer and silica based anionic particles. 18. The cellulose according to any one of claims 2, 14 to 17, wherein the dehydrating and retaining agent comprises a cationic polymer and silica based anionic particles having a specific surface area of at least 100 m ² / g. Manufacturing process of the system product. The method of claim 2, wherein the dehydrating agent and the retaining agent comprise silica based anionic particles present in the cationic polymer and the sol having an S-value ranging from 8 to 50%. Process for producing a cellulose-based product, characterized in that. 20. A process according to any one of claims 2, 14-19, wherein the dehydrating and retaining agent comprises anionic clays of cationic polymer and smectite type.  21. The process of any one of claims 2, 14-20, wherein the dehydrating and retaining agent comprises a cationic polymer and bentonite. 22. The process of any one of claims 2, 14-21, wherein the dehydrating and retaining agent comprises a cationic polymer and an anionic organic polymer. 23. The process of any one of claims 2, 14-22, wherein the cationic polymer is cationic starch or acrylamide based cationic polymer. 24. The process of any one of claims 2 and 14 to 23, wherein the cationic polymer contains at least one aromatic functional group. 25. A process according to any one of claims 2 and 14 to 24, wherein the cationic polymer is added in an amount of at least 0.001% by weight, based on the dry cellulose suspension. 25. The process of any one of claims 1, 2 and 4 to 24, further comprising adding at least one sizing agent to the suspension. 27. The preparation of a cellulose based product according to any one of claims 1, 2 and 4 to 26, wherein the clay is added in an amount of 0.01% by weight or more, calculated as dry clay to a dry cellulose suspension. fair.