Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/20—Macromolecular organic compounds
  • D21H17/33—Synthetic macromolecular compounds
  • D21H17/34—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H17/41—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups
  • D21H17/44—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups cationic
  • D21H17/45—Nitrogen-containing groups
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/20—Macromolecular organic compounds
  • D21H17/21—Macromolecular organic compounds of natural origin; Derivatives thereof
  • D21H17/24—Polysaccharides
  • D21H17/28—Starch
  • D21H17/29—Starch cationic
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/20—Macromolecular organic compounds
  • D21H17/33—Synthetic macromolecular compounds
  • D21H17/46—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H17/54—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/63—Inorganic compounds
  • D21H17/67—Water-insoluble compounds, e.g. fillers, pigments
  • D21H17/69—Water-insoluble compounds, e.g. fillers, pigments modified, e.g. by association with other compositions prior to incorporation in the pulp or paper
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/20—Macromolecular organic compounds
  • D21H17/33—Synthetic macromolecular compounds
  • D21H17/34—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H17/41—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups
  • D21H17/44—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups cationic
  • D21H17/45—Nitrogen-containing groups
  • D21H17/455—Nitrogen-containing groups comprising tertiary amine or being at least partially quaternised
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/20—Macromolecular organic compounds
  • D21H17/33—Synthetic macromolecular compounds
  • D21H17/46—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H17/54—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen
  • D21H17/55—Polyamides; Polyaminoamides; Polyester-amides
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/20—Macromolecular organic compounds
  • D21H17/33—Synthetic macromolecular compounds
  • D21H17/46—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H17/54—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen
  • D21H17/56—Polyamines; Polyimines; Polyester-imides

Definitions

• the present invention relates to a process for producing high filler content and high dry strength papers.
• fillers are added to the fiber suspension, which is particularly advantageous when the filler is cheaper than the pulp.
• the addition or increased addition of filler can lead to a reduction of the fiber content and thus to a reduction in the production costs of the paper.
• Filler-containing papers or papers with a particularly high filler content are easier to dry than non-filler papers or papers with a lower filler content.
• the paper machine can be operated faster and with lower steam consumption, which both increases productivity and lowers costs.
• the filler slurry is added to the fiber suspension prior to passing it to the former of the paper machine.
• a retention aid or retention aid system is typically added to the filler / pulp suspension to retain as much filler as possible in the paper sheet.
• the addition of the filler to the paper gives the papermaker the opportunity to achieve numerous improvements in sheet properties. These include properties such as opacity, whiteness, feel and printability.
• the filler addition to the fiber suspension also entails disadvantages which can only be partially compensated by the addition of further paper auxiliaries. For a given basis weight, there are limits to the amount of filler that can be used.
• the strength properties of the paper are usually the most important parameters that limit the amount of filler in the paper. Other factors, such as filler retention, dewatering of the pulp suspension, and possibly increased need for chemicals in retention and sizing may also play a role here.
• the loss of strength properties of papers can in some cases be compensated in whole or in part by the use of dry and wet strength agents.
• a common procedure is the addition of cationic starch as dry strength in the pulp.
• synthetic dry and wet strength agents are used, for example, based on cationic or anionic polyacrylamides.
• the amount of addition and the strengthening effect are limited in most cases.
• the compensating effect in relation to the loss of strength by increasing the filler and thus also the only realizable Filler increase limited.
• not all strength properties are increased to the same extent and in some cases insufficiently by the use of dry strength agents.
• An important example of this is the on-going work, which is only slightly influenced by the use of starch or synthetic dry strength agents in comparison to other strength parameters.
• the increase in the filler content in paper on the other hand, usually has a very strong negative impact on continuing work.
• the increase in the filler content leads to a decrease in the paper density and the thickness of the paper sheet at the same basis weight.
• the latter leads to a significant decrease in paper stiffness.
• This decrease in paper stiffness can not be compensated in many cases by the use of dry strength agents alone.
• additional measures such as the reduction of mechanical pressure in the press section in the calenders, in calenders or in the dryer section of the paper machine are necessary. The latter compensates the thickness loss by increasing the filler in whole or in part.
• amphoteric water-soluble polymers are added to aqueous suspensions of inorganic particles amphoteric water-soluble polymers, wherein at least a portion of the polymers is adsorbed on the filler surface.
• the amphoteric polymers are preferably prepared by hydrolyzing copolymers of N-vinylformamide, acrylonitrile and acrylic acid in the presence of acids. They contain from 20 to 90 mol% amidine units of the structure in which R 1 and R 2 are each H or a methyl group and X- is an anion.
• the filler slurries treated with such polymers are added to the stock in the preparation of filler-containing papers. The filler treatment improves the drainage of the pulp and also gives an improvement various strength properties of the dried paper and an improvement in the filler retention.
• US 6033524 A discloses a process for producing paper in the presence of an aqueous slurry of finely divided filler-containing components wherein the finely divided fillers are coated with a copolymer and wherein, in addition to the aqueous slurry of finely divided filler-containing components, a cationic polymer is added to the fiber slurry prior to sheet formation ,
• the object was achieved by a process for the production of paper, paperboard and cardboard in the presence of an aqueous slurry of components containing finely divided fillers, wherein the finely divided fillers are at least partially coated with water-soluble amphoteric copolymers, wherein in addition to the aqueous slurry of finely divided fillers Components at least one cationic and / or amphoteric polymer containing as structural element no esters of unsaturated carboxylic acids with quaternized amino alcohols, the fiber suspension added before sheet formation.
• components comprising finely divided fillers are both finely divided fillers alone, i. in pure form or as a so-called fresh filler, as well as finely divided fillers containing raw materials such as the so-called Committee of coated paper, as well as mixtures in any composition thereof understood.
• the dosage of the cationic and / or amphoteric polymers may be at various points in the papermaking process. Conceivable is a dosage in the thick matter range, but also a dosage in the thin material of the fiber suspension. A split addition at different points in the manufacturing process is also possible.
• the at least one cationic and / or amphoteric polymer is added to the fiber suspension immediately after the addition of the aqueous slurry of components containing finely divided fillers. Immediately means that between the dosages of the components no further process step, i. no dosage of other paper auxiliaries or, for example, the action of shear forces on the suspension is.
• the cationic and / or amphoteric polymer contains no structural elements of esters of unsaturated carboxylic acids, for example C 3 - C 8 carboxylic acids, with quaternized amino alcohols, for example N, N, N-trimethylammoniumethanol.
• Typical representatives are, for example Catiofast® ® PR 8153 and PR 8154 ® Catiofast® the BASF Aktiengesellschaft, which are commonly used as fixatives in the paper industry.
• Polyethyleneimines are, for example, in WO 97/25367 and the literature cited therein.
• Graft products of ethyleneimines on amidoamines or polyamines are, for example, those in German Offenlegungsschrift DE 24 34 816 described nitrogenous condensation products.
• Cationic starches are disclosed, for example, in Günther Tegge, Medicare und Medicarederivate, Behr's Verlag, Hamburg, 1984. These are, for example, potato starch, corn starch, wheat starch, rice starch, tapioca starch, sago starch, manioc starch and rye starch. These starches are for example reacted with 2,3- (epoxy) -propyltrimethylammoniumchrlorid.
• Polymers containing vinylamine units are known, cf. US 4,421,602 . US 5,334,287 . EP-A 216 387 . US 5,981,689 . WO 00/63295 . US 6,121,409 and US 6,132,558 , They are prepared by hydrolysis of open-chain N-vinylcarboxylic acid amide units containing polymers. These polymers are obtainable, for example, by polymerizing N-vinylformamide, N-vinyl-N-methylformamide, N-vinylacetamide, N-vinyl-N-methylacetamide, N-vinyl-N-ethylacetamide and N-vinylpropionamide. The monomers mentioned can be polymerized either alone or together with other monomers. Preference is given to N-vinylformamide.
• Suitable monoethylenically unsaturated monomers which are copolymerized with the N-vinylcarboxamides are all compounds which can be copolymerized therewith.
• vinyl esters of saturated carboxylic acids of 1 to 6 carbon atoms such as vinyl formate, vinyl acetate, N-vinylpyrrolidone, vinyl propionate and vinyl butyrate and vinyl ethers such as C 1 - to C 6 -alkyl vinyl ethers, for example methyl or ethyl vinyl ether.
• Suitable comonomers are esters of alcohols having, for example, 1 to 6 carbon atoms, amides and nitriles of ethylenically unsaturated C 3 - to C 6 -carboxylic acids, for example methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate and dimethyl maleate, acrylamide and methacrylamide and also acrylonitrile and methacrylonitrile.
• carboxylic acid esters are derived from glycols or polyalkylene glycols, in each case only one OH group being esterified, for example hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate and acrylic acid monoesters of polyalkylene glycols having a molecular weight of 500 to 10,000.
• esters of ethylenically unsaturated carboxylic acids with amino alcohols such as Dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, dimethylaminopropyl acrylate, dimethylaminopropyl methacrylate, diethylaminopropyl acrylate, dimethylaminobutyl acrylate and diethylaminobutyl acrylate.
• amino alcohols such as Dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, dimethylaminopropyl acrylate, dimethylaminopropyl methacrylate, diethylaminopropyl acrylate, dimethylaminobutyl acrylate
• the basic acrylates can be used in the form of the free bases, the salts with mineral acids such as hydrochloric acid, sulfuric acid or nitric acid, the salts with organic acids such as formic acid, acetic acid, propionic acid or sulfonic acids or in quaternized form.
• Suitable quaternizing agents are, for example, dimethyl sulfate, diethyl sulfate, methyl chloride, ethyl chloride or benzyl chloride.
• Suitable comonomers are amides of ethylenically unsaturated carboxylic acids such as acrylamide, methacrylamide and N-alkyl mono- and diamides of monoethylenically unsaturated carboxylic acids having alkyl radicals of 1 to 6 carbon atoms, e.g. N-methylacrylamide, N, N-dimethylacrylamide, N-methylmethacrylamide, N-ethylacrylamide, N-propylacrylamide and tert-butylacrylamide and basic (meth) acrylamides, e.g.
• acrylamide, methacrylamide and N-alkyl mono- and diamides of monoethylenically unsaturated carboxylic acids having alkyl radicals of 1 to 6 carbon atoms e.g. N-methylacrylamide, N, N-dimethylacrylamide, N-methylmethacrylamide, N-ethylacrylamide, N-propylacrylamide and tert-butylacryl
• N-vinylpyrrolidone N-vinylcaprolactam
• acrylonitrile methacrylonitrile
• N-vinylimidazole substituted N-vinylimidazoles
• N-vinyl-2-methylimidazole N-vinyl-4-methylimidazole
• N-vinyl-5-methylimidazole N-vinyl-2-ethylimidazole
• N-vinylimidazolines such as N-vinylimidazoline, N-vinyl-2-methylimidazoline and N- vinyl-2-ethylimidazoline.
• N-vinylimidazoles and N-vinylimidazolines are also used, except in the form of the free bases, in neutralized or quaternized form with mineral acids or organic acids, the quaternization preferably being carried out with dimethyl sulfate, diethyl sulfate, methyl chloride or benzyl chloride. Also suitable are diallyldialkylammonium halides, e.g. Diallyl dimethyl ammonium chloride.
• the polymerization of the monomers is usually carried out in the presence of radical-forming polymerization initiators.
• the homopolymers and copolymers can be obtained by all known processes, for example by solution polymerization in water, alcohols, ethers or dimethylformamide or in mixtures of various solvents, by precipitation polymerization, reverse suspension polymerization (polymerizing an emulsion of a monomer-containing aqueous phase in an oil phase and polymerizing a water-in-water emulsion, for example, in which an aqueous monomer solution is dissolved or emulsified in an aqueous phase and polymerized to form an aqueous dispersion of a water-soluble polymer, such as in US Pat WO 00/27893 described.
• the homo- and co-polymers containing copolymerized N-vinylcarboxamide units are partially or completely hydrolyzed as described below.
• the degree of hydrolysis of the homopolymers and copolymers used is 85 to 95 mol%.
• the degree of hydrolysis of the homopolymers is synonymous with the content of the polymers of vinylamine units.
• hydrolysis of the ester groups to form vinyl alcohol units may occur. This is especially the case when the hydrolysis of the copolymers in the presence of sodium hydroxide solution.
• Polymerized acrylonitrile is also chemically altered upon hydrolysis. This produces, for example, amide groups or carboxyl groups.
• the vinylamine units containing homo- and copolymers may optionally contain up to 20 mol% of amidine units, for example, by reaction of formic acid with two adjacent amino groups or by intramolecular reaction of an amino group with an adjacent amide group, for example, of copolymerized N-vinylformamide.
• the average molecular weights M w of the polymers containing vinylamine units are, for example, 500 to 10 million, preferably 750 to 5 million and particularly preferably 1 000 to 2 million g / mol (determined by light scattering).
• This molar mass range corresponds, for example, to K values of 30 to 150, preferably 60 to 100 (determined according to H. Fikentscher in 5% strength aqueous saline solution at 25 ° C., a pH of 7 and a polymer concentration of 0.5% by weight. ).
• Particular preference is given to using polymers comprising vinylamine units which have K values of from 85 to 95.
• the polymers containing vinylamine units have for example a charge density (determined at pH 7) of 0 to 18 meq / g, preferably of 5 to 18 meq / g and especially of 10 to 16 meq / g.
• the polymers containing vinylamine units are preferably used in salt-free form.
• Salt-free aqueous solutions of polymers containing vinylamine units can be prepared, for example, from the above-described salt-containing polymer solutions by means of ultrafiltration on suitable membranes at separation limits of, for example, 1,000 to 500,000 daltons, preferably 10,000 to 300,000 daltons.
• Derivatives of polymers containing vinylamine units can also be used. It is thus possible, for example, to prepare a large number of suitable derivatives from the vinylamine units by amidation, alkylation, sulfonamide formation, urea formation, thiourea formation, carbamate formation, acylation, carboxymethylation, phosphonomethylation or Michael addition of the amino groups of the polymer.
• the polymers containing vinylamine units also include hydrolyzed graft polymers of, for example, N-vinylformamide on polyalkylene glycols, polyvinyl acetate, Polyvinylalkolhol, polyvinylformamides, polysaccharides such as starch, oligosaccharides or monosaccharides.
• the graft polymers are obtainable by free-radically polymerizing, for example, N-vinylformamide in aqueous medium in the presence of at least one of the stated grafting bases together with copolymerizable other monomers and then hydrolyzing the grafted vinylformamide units in a known manner to give vinylamine units.
• Preferred polymers containing vinylamine units are vinylamine homopolymers of N-vinylformamide having a degree of hydrolysis of from 1 to 100 mol%, preferably from 25 to 100 mol%, and from 1 to 100 mol%, preferably from 25 to 100 mol% Copolymers of N-vinylformamide and vinyl formate, vinyl acetate, vinyl propionate, acrylonitrile, methyl acrylate, ethyl acrylate and / or methyl methacrylate having K values of from 30 to 150, in particular from 60 to 100. Particular preference is given in the process according to the invention to the aforementioned homopolymers of N-vinylformamide used.
• Typical representatives of these homopolymers of N-vinylformamide are known under the trade names Catiofast® ® VFH, Catiofast® ® VSH and Catiofast® ® VMP of BASF Aktiengesellschaft.
• the cationic and / or amphoteric polymers to be used in the process according to the invention are particularly preferred in an amount of from 0.0001 to 1% by weight, based on the solids content of the paper stock suspension, preferably from 0.0005 to 0.5% by weight in an amount of 0.001 to 0.2 wt .-% and in particular in an amount of 0.005 to 0.1 wt .-%, each based on the solids content of the pulp suspension, added to the fiber suspension.
• the addition of the at least one cationic and / or amphoteric polymer to the fiber suspension achieves enormously increased filler retention compared to the prior art, i. It can be prepared by the novel process papers with a high filler content. As a result, the pulp content is reduced in the production, which leads to a reduction in the production cost of the paper.
• papers prepared by the process according to the invention in addition to the increased filler content improved dry strength. This is especially characterized by properties such as dry breaking length, tear propagation, internal strength and bending stiffness.
• the paper gloss can also be significantly increased by the treatment according to the invention of the fillers. This is especially true for woody papers such as e.g. SC-paper.
• the gloss increase means an increase in paper quality, which allows the paper manufacturer to obtain a higher selling price.
• the finely divided fillers to be used in the process according to the invention are known from the literature. These are finely divided fillers which are at least partially coated with water-soluble amphoteric copolymers. Such aqueous slurries are made JP-A 08059740 . WO 04/087818 and the file number DE 103 34 133 A1 known. These references are hereby incorporated by reference.
• the water-soluble amphoteric copolymers disclosed in these references have as a common structural feature that they contain Amidinein whatsoever, both five- and six-membered.
• finely divided fillers alone, i. in pure form or as a so-called fresh filler, as well as finely divided fillers containing raw materials such as the so-called committee of coated paper, as well as mixtures in any composition thereof understood by the term finely divided fillers components.
• aqueous slurries of 100% fresh filler are used in the process according to the invention.
• aqueous slurries can be used in the process according to the invention, the filler content is obtained to 100% from the Committee of coated paper. It does not matter whether it is the Committee of one or two sides coated paper.
• aqueous slurries of mixtures in any desired composition of fresh filler and scrap of coated paper are used.
• aqueous slurries of mixtures in any desired composition of fresh filler and scrap of coated paper are used.
• such a blend may consist of 90% fresh filler and 10% filler from the coated paper broke, each based on the filler content of the aqueous slurry.
• the ratio can also be reversed, namely fresh filler: filler from the coated paper broke of 10%: 90%.
• Possible blends of fresh filler to filler from the broke paper committee are e.g. 15%: 85%, 20%: 80%, 30%: 70%, 40%: 60%, 50%: 50%, 60%: 40%, 70%: 30%, 80%: 20% and 85% : 15%. As described above, however, mixtures in any composition are possible.
• the mixing ratio is in the range of 15% (fresh filler) to 85% (filler of the coated paper broke) to 60% (fresh filler) of 40% (filler of the coated paper broke).
• the percentages in each case relate to the total filler content in the aqueous slurry.
• the filler base e.g. Calcium carbonates, which are present in the form of ground lime (GCC), lime, chalk, marble or in the form of precipitated calcium carbonate (PCC).
• GCC ground lime
• PCC precipitated calcium carbonate
• Talc, kaolin, bentonite, satin white, calcium sulfate, barium sulfate and titanium dioxide can likewise be used as fillers.
• the particle diameter of the fillers is preferably less than 2 ⁇ m, for example between 40 and 90% of the filler particles have a particle diameter of ⁇ 2 ⁇ m.
• the fillers are present as aqueous slurries.
• Precipitated calcium carbonate is usually present as an aqueous slurry in the absence of dispersants.
• an anionic dispersant for example polyacrylic acid having an average molar mass M w of, for example, from 1,000 to 40,000 daltons, is generally used. If the fillers contain a high solids content (eg 60% or more), the fillers are milled in the presence of an anionic dispersant.
• anionic dispersant it is used, for example, from 0.01 to 0.6% by weight, preferably from 0.2 to 0.5% by weight, for the preparation of aqueous filler slurries.
• the slurries dispersed in water in the presence of anionic dispersants contain, for example, 10-60% by weight, usually 15-50% by weight, of at least one filler.
• WO 04/087818 and the DE 103 34 133 A1 described water-soluble amphoteric polymers are added to the aqueous slurries.
• a water-soluble amphoteric polymer for example, from 0.1 to 5% by weight, based on fillers, of a water-soluble amphoteric polymer, of up to from 1 to 60% by weight of at least one fine-particle filler-comprising aqueous slurry JP-A 08059740 .
• WO 04/087818 and the DE 103 34 133 A1 Add or add an aqueous slurry of a finely divided filler in an aqueous solution of an amphoteric polymer and mix the components respectively.
• This treatment of the aqueous slurry of particulate fillers with the amphoteric polymers can be carried out continuously or batchwise.
• the treatment of the fillers with the amphoteric polymer takes place in a continuous mode.
• the amphoteric polymer can be added as a dilute solution between the filler tank and the filler pump. The dilution and the shear forces in the filler pump guarantee a thorough mixing of the filler with the polymer.
• the finely divided fillers are at least partially coated or impregnated with the water-soluble amphoteric polymers.
• the solid content of the dilute polymer solution of the water-soluble amphoteric polymers may be between 20% by weight and 0.01% by weight.
• the treatment with the water-soluble amphoteric copolymers can be carried out, for example, by dissolving the scrap of coated paper in the presence of the water-soluble amphoteric copolymers.
• the treatment with water-soluble amphoteric copolymers is carried out after dissolution of the coated paper committee.
• filler from the committee also finely divided fillers are obtained, which are at least partially coated or impregnated with water-soluble amphoteric copolymers.
• the polymer-treated filler slurry passes directly into the thick or thin paper machine pulp. It is also conceivable that the treated filler be metered in both the thick and in the thin paper machine.
• the process according to the invention is suitable both for the production of wood-free papers and wood-containing papers.
• the process according to the invention leads to a significant increase in the filler content in the paper, without causing any significant losses in the paper properties of dry strength.
• the filler content is increased without loss of strength by the addition of at least one cationic and / or amphoteric polymer.
• the production of paper, paperboard and cardboard by the process according to the invention is usually carried out by dewatering a slurry of cellulose fibers.
• Suitable cellulosic fibers are all conventional types, for example cellulose fibers from wood pulp and fibers obtained from annual plants.
• Wood pulp includes, for example, groundwood, thermomechanical pulp (TMP), chemothermomechanical pulp (CTMP), pressure groundwood, semi-pulp, high yield pulp, and refiner mechanical pulp (RMP) as well as waste paper.
• pulps that can be used in bleached or unbleached form. Examples include sulphate, sulphite and soda pulps. Bleached pulps, also referred to as bleached kraft pulp, are preferably used.
• the fibers mentioned can be used alone or in a mixture.
• papers having a high filler content are understood in particular to be papers having a filler content of from 3 to 45% by weight, based on the solids content of the paper stock suspension, preferably from 10 to 45% by weight, more preferably from 15 to 40 wt .-% and particularly preferably from 20 to 35 wt .-%, each based on the solids content of the paper stock suspension having.
• the invention will be further illustrated by the following non-limiting examples. The percentages in the examples are by weight unless otherwise indicated in the context.
• the electrophoretic mobility and the zeta potential were determined by laser optics.
• the samples were diluted with an aqueous KCl solution (eg 10 mmoles) to a concentration for the measurement of 1% by volume.
• the measuring instrument used was the Zetasizer 3000 HS from Malvern Instruments Ltd ..
• the molecular weights M w of the polymers were determined by means of static light scattering. The measurements were carried out at pH 7.6 in a 10 mmol aqueous saline solution.
• the K values were after H. Fikentscher, Cellulose Chemistry, Vol. 13, 48-64 and 71-74 (1932 ) in 1.0% aqueous brine at 25 ° C, at a pH of 7 and a polymer concentration of 0.1% by weight.
• the fillers used were precipitated chalk, precipitated calcium carbonate (PCC), ground chalk (GCC), kaolin or mixtures of the stated fillers.
• Five different copolymer-pretreated fillers were used in the examples of this invention.
• TMP Thermo-Mechanical Pulp
• groundwood was whisk-free in a ratio of 70/30 at a solids concentration of 4% in the laboratory pulper until a grinding degree of 60-65 was reached.
• the pH of the substance was in the range between 7 and 8.
• the milled substance was then diluted by the addition of water to a solids concentration of 0.35%.
• aqueous filler slurries of the pretreated fillers in combination with polymers containing vinylamine units in the production of filler-containing paper 500 ml of the stock suspension were placed in each case and the slurries of the pretreated fillers and a vinylamine units were metered into this pulp containing polymer (Catiofast® VMP).
• the metered amount of the polymers containing vinylamine units was in each case 0.1% of polymer, based on the solids content of the paper stock suspension.
• a cationic polyacrylamide retention aid (Polymin ® KE 2020) in this mixture.
• the metered amount of the retention agent was in each case 0.01% polymer, based on the solids content of the paper stock suspension.
• the amount of slurry was adjusted by means of several preliminary tests so that the amount of pretreated filler was about 20%.
• the paper sheets were each produced on a Rapid-Köthen sheet former according to ISO 5269/2 with a sheet weight of 80 g / m 2 and then dried for 7 minutes at 90 ° C and then calendered with a line pressure of 200 N / cm.
• Paper sheets were prepared analogously to Examples 1 to 5 with the corresponding pretreated fillers. However, it has been dispensed with the addition of polymers containing vinylamine units.
• a mixture of bleached birch sulphate and bleached pine sulphite was blotted open in a ratio of 70/30 at a solids concentration of 4% in the laboratory pulper until a freeness of 55-60 was reached.
• the opened substance is an optical brightener (Blankophor ® PSG) and a cationic starch (HICAT ® 5163 A) were then added.
• the digestion of the cationic starch was carried out as a 10% starch slurry in a jet cooker at 130 ° C and 1 minute residence time.
• the metered amount of the optical brightener was 0.5% commercial goods, based on the solids content of the paper stock suspension.
• the dosage of cationic starch was 0.5% starch, based on the solids content of the stock suspension.
• the pH of the substance was in the range between 7 and 8.
• the milled substance was then diluted by the addition of water to a solids concentration of 0.35%.
• aqueous filler slurries of the pretreated fillers in combination with polymers containing vinylamine units in the production of filler-containing paper 500 ml of the stock suspension were placed in each case and the slurries of the pretreated fillers and a vinylamine units were metered into this pulp containing polymer (Catiofast® VFH).
• the metered amount of the polymers containing vinylamine units was in each case 0.1% of polymer, based on the solids content of the paper stock suspension.
• a cationic polyacrylamide retention aid (Polymin ® KE 2020) in this mixture.
• the metered amount of the retention agent was in each case 0.01% polymer, based on the solids content of the paper stock suspension.
• the amount of slurry was adjusted by means of several preliminary tests so that the amount of pretreated filler was about 16%.
• the paper sheets were each produced on a Rapid-Köthen sheet former according to ISO 5269/2 with a sheet weight of 80 g / m 2 and then dried for 7 minutes at 90 ° C and then calendered with a line pressure of 200 N / cm.
• Paper sheets were prepared analogously to Examples 15 to 18 with the corresponding pretreated fillers. However, it has been dispensed with the addition of polymers containing vinylamine units.
• a mixture of bleached chemical pulp and groundwood was blotted open in a ratio of 20/80 at a solids concentration of 4% in the laboratory pulper until a freeness of 55-60 was reached.
• the pH of the substance was in the range between 7 and 8.
• the milled substance was then diluted by the addition of water to a solids concentration of 0.35%.
• the amount of dosed filler slurry of the filler 2 and the untreated kaolin clay mixture was adjusted by means of several preliminary experiments so that the amount of filler 2 and untreated kaolin clay was about 20%.
• the total filler content was thus about 40%.
• the paper sheets were produced on a Rapid-Köthen sheet former according to ISO 5269/2 with a sheet weight of 80 g / m 2 and then dried for 7 minutes at 90 ° C and then calendered with a line pressure of 200 N / cm.
• Paper sheets were produced analogously to Example 26. It was the corresponding filler untreated, that is free of amphoteric copolymers used. However, the addition amount of the filler slurry in the sheet formation was increased so much that the equivalent filler content of the respective filler type of Example 26 was achieved.
• the double-coated woodfree paper having a basis weight of 104 g / m 2 used in the examples contained a total of 38.4% of filler by analysis of the ashing data (500 ° C for 2 hours in the ashing furnace). According to the paper manufacturer, the raw paper used for the production of the coated grade was produced with a filler content of about 23% (ground calcium carbonate, GCC). The weight on each side was 12 gsm. The coating pigment used was precipitated calcium carbonate.
• a mixture of bleached birch sulphate and bleached pine sulphite was blotted open in a ratio of 70/30 at a solids concentration of 4% in the laboratory pulper until a freeness of 55-60 was reached.
• the whisker and the coated broke spread in the presence of the amphoteric copolymer were mixed in a 1: 1 ratio.
• the total material, an optical brightener (Blankophor ® PSG) and a cationic starch (HICAT ® 5163 A) were then added.
• the digestion of the cationic starch was carried out as a 10% starch slurry in a jet cooker at 130 ° C and 1 minute residence time.
• the metered amount of the optical brightener was 0.5% commercial goods, based on the solids content of the paper stock suspension.
• the dosage of cationic starch was 0.5% starch, based on the solids content of the stock suspension.
• the pH of the substance was in the range between 7 and 8. The total material was then diluted by the addition of water to a solids concentration of 0.35%.
• the paper sheets were each produced on a Rapid-Köthen sheet former according to ISO 5269/2 with a sheet weight of 80 g / m 2 and then dried for 7 minutes at 90 ° C and then calendered with a line pressure of about 200 N / cm.
• a mixture of bleached birch sulphate and bleached pine sulphite was blotted open in a ratio of 70/30 at a solids concentration of 4% in the laboratory pulper until a freeness of 55-60 was reached.
• the whisker and the coated broke spread in the presence of the amphoteric copolymer were mixed in a 1: 1 ratio.
• the total material, an optical brightener (Blankophor ® PSG) and a cationic starch (HICAT ® 5163 A) were then added.
• the digestion of the cationic starch was carried out as a 10% starch slurry in a jet cooker at 130 ° C and 1 minute residence time.
• the metered amount of the optical brightener was 0.5% commercial goods, based on the solids content of the paper stock suspension.
• the dosage of cationic starch was 0.5% starch, based on the solids content of the stock suspension.
• the pH of the substance was in the range between 7 and 8. The total material was then diluted by the addition of water to a solids concentration of 0.35%.
• the paper sheets were each produced on a Rapid-Köthen sheet former according to ISO 5269/2 with a sheet weight of 80 g / m 2 and then dried for 7 minutes at 90 ° C and then calendered with a line pressure of about 200 N / cm.
• a mixture of bleached birch sulphate and bleached pine sulphite was blotted open in a ratio of 70/30 at a solids concentration of 4% in the laboratory pulper until a freeness of 55-60 was reached.
• the whipped material was then mixed with the coated broke in the ratio 1: 1.
• the total material, an optical brightener (Blankophor ® PSG) and a cationic starch (HICAT ® 5163 A) were then added.
• the digestion of the cationic starch was carried out as a 10% starch slurry in a jet cooker at 130 ° C and 1 minute residence time.
• the metered amount of the optical brightener was 0.5% strength, based on the solids content of the paper stock suspension.
• the dosage of cationic starch was 0.5% starch, based on the solids content of the stock suspension.
• the pH of the substance was in the range between 7 and 8.
• the total material was then diluted by the addition of water to a solid
• the paper sheets were each produced on a Rapid-Köthen sheet former according to ISO 5269/2 with a sheet weight of 80 g / m 2 and then dried for 7 minutes at 90 ° C and then calendered with a line pressure of about 200 N / cm.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Inorganic Chemistry (AREA)
• Paper (AREA)

Priority Applications (1)

Applications Claiming Priority (3)

Publications (2)

Family

ID=36602111

Family Applications (1)

Country Status (8)

Families Citing this family (10)

Family Cites Families (18)

• 2005
  • 2005-12-14 ES ES05819674.2T patent/ES2554691T3/es active Active
  • 2005-12-14 EP EP05819674.2A patent/EP1828481B1/de active Active
  • 2005-12-14 PL PL05819674T patent/PL1828481T3/pl unknown
  • 2005-12-14 JP JP2007545938A patent/JP5130049B2/ja not_active Expired - Fee Related
  • 2005-12-14 PT PT58196742T patent/PT1828481E/pt unknown
  • 2005-12-14 WO PCT/EP2005/013430 patent/WO2006066769A2/de active Application Filing
  • 2005-12-14 US US11/721,929 patent/US8778139B2/en active Active
  • 2005-12-14 CA CA2590489A patent/CA2590489C/en active Active

Also Published As

Similar Documents

Legal Events