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
  • D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
  • D21H21/06—Paper forming aids
  • D21H21/10—Retention agents or drainage improvers
• • 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
  • D21H17/37—Polymers of unsaturated acids or derivatives thereof, e.g. polyacrylates
• • 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
• • 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
  • D21H17/68—Water-insoluble compounds, e.g. fillers, pigments siliceous, e.g. clays

Definitions

• the invention relates to a process for the production of paper, paperboard and cardboard by dewatering a paper stock in the presence of at least one vinylamine units-containing polymer and at least one particulate, anionic, crosslinked, organic polymer.
• EP-A-0 462 365 is a process for the production of paper is known, which is used as a retention agent high molecular weight cationic polymers together with particulate, anionic, crosslinked or uncrosslinked, organic polymers and optionally additionally bentonite or finely divided silica.
• the crosslinked organic polymers have a particle size of less than 750 nm.
• a water-soluble, cationic, polymeric flocculant is first metered into a pulp so that cellulose flakes are formed, which are then mechanically separated and treated with a water-soluble anionic, branched, polymeric retention agent having an intrinsic viscosity of more than 3 dl / g and a tandelta value at 0.005 Hz of at least 0.5.
• the stock is then dewatered on a sieve with foliation.
• WO-A-01/34908 and WO-A-01/34909 Similar methods of making paper are out WO-A-01/34908 and WO-A-01/34909 known.
• the dewatering of the paper stock can be carried out in the absence of a water-soluble, cationic polymer flocculant.
• the anionic branched polymeric retention agent has an intrinsic viscosity greater than 1.5 dl / g. However, it is always used in combination with clay or silica (siliceous material) as a flocculant system.
• WO-A-02/33171 there is known a method of making paper by treating a stock with a flocculant system consisting of siliceous material and organic microparticles having a particle diameter of less than 750 nm in the non-swollen state.
• the microparticles are crosslinked. They have a solution viscosity of at least 1.1 mPas and a copolymerized crosslinking agent content of more than 4 mol ppm, based on the monomer units.
• a retention aid system consisting of (i) at least one cationic polymer, (ii) at least one silicate such as silica gel or bentonite and / or an anionic or amphoteric organic polymer and (iii) at least one particulate crosslinked anionic polymer having a particle size of at least 1 ⁇ m and an intrinsic viscosity of less than 3 dl / g.
• a fixing agent such as polyaluminum chloride, polydiallyldimethylammonium chloride, polymers containing vinylamine units or dicyandiamide resins is metered in.
• the invention has for its object to provide a further method for the production of paper available.
• the component (ii) of the retention aid system may contain either only the linear, anionic polymer or bentonite and / or silica gel as well as both components, which are then metered separately or mixed with the pulp. However, it is also possible to use as component (ii) at least one branched, anionic, water-soluble polymer and / or bentonite and / or silica gel or a linear, anionic polymer and a branched, anionic, water-soluble polymer.
• the components (ii) and (iii) of the retention aid system can likewise be fed to the paper stock separately or as a mixture.
• Vinylamine-containing polymers (i) are known. They are usually prepared from homopolymers or copolymers of N-vinylformamide by hydrolysis of the formyl groups from the vinylformamide units present in the respective polymers to form vinylamine units. The hydrolysis of the formyl groups can be carried out with acids or bases as well as enzymatically. Vinylamine units containing polymers are described for example in US-A-4,421,602 . US-A-5,334,287 . EP-A-0216387 . US-A-5,981,689 . WO-A-00/63295 .
• the vinylformamide units contained in the homopolymers or copolymers are hydrolyzed, for example, to 5 to 100 mol%, preferably 15 to 98 and in particular 20 to 95 mol%.
• polyvinylamines obtainable by hydrolysis of poly-N-vinylformamides.
• the molecular weight M w of the polymers containing vinylamine units is, for example, 10 000 to 15 million, usually 30 000 to 5 million and in particular 1 million to 5 million.
• component (i) of the retention aid system used comprises a mixture of (a) a polymer comprising vinylamine units with a molecular weight of from 10,000 to 500,000, preferably from 45,000 to 350,000, and (b) a polymer containing vinylamine units a molecular weight of at least 1 million.
• the weight ratio of (a) :( b) can be in a wide range for example, from 90:10 to 10:90. Most often, it is in the range of 60:40 to 40:60.
• the polymers containing vinylamine units can be used in any form, e.g. in the form of the free bases.
• the polyvinylamines are present in this form when the hydrolysis of the poly-N-vinylformamide was carried out with the aid of bases such as sodium hydroxide solution or potassium hydroxide solution. If, in the hydrolysis of polymers containing N-vinylformamide units, acids such as hydrochloric acid, sulfuric acid or phosphoric acid are used, the corresponding salts of the acids are formed.
• polymers containing vinylamine units can also be used in quaternized form, for example, polymers containing vinylamine units can be quaternized with methyl chloride, dimethyl sulfate, ethyl chloride or benzyl chloride.
• the polymers containing vinylamine units are used, for example, in an amount of 0.003 to 0.3% by weight, based on dry paper stock. These polymers are used as sole cationic retention aids.
• the component (ii) of the retention aid system comprises at least one linear, anionic polymer having a molecular weight of at least 1 million and / or at least one branched, anionic, water-soluble polymer and / or bentonite and / or silica gel.
• Preferably used linear polymers have a molecular weight M w of at least 2 million, usually 2.5 to 20 million. They are prepared, for example, by polymerizing (a) acrylamide and / or methacrylamide and (b) acrylic acid, methacrylic acid, maleic anhydride, maleic acid, itaconic acid, crotonic acid, 2-acrylamido-2-methylpropanesulfonic acid, vinylsulfonic acid and / or the salts of said acids.
• anionic polymers of component (ii) are copolymers of acrylamide and acrylic acid or Na acrylate, copolymers of acrylamide and methacrylic acid, copolymers of acrylamide and Na vinyl sulfonate and copolymers of acrylamide and 2-acrylamido-2-methylpropanesulfonic acid.
• the proportion of anionic monomers in the copolymer can be, for example, 5 to 95 mol%.
• Branched, anionic, water-soluble polymers are known, cf. WO-A-98/29604 .
• EP-B-1 167 392 and EP-A-0 374 458 They have an intrinsic viscosity of more than 3 dl / g. They are obtainable for example by reverse suspension polymerization of anionic monomers such as acrylic acid, methacrylic acid, vinylsulfonic acid and / or their salts in the presence of at least one crosslinker in an amount of less than 6 mol ppp, based on the monomers used, if in the absence of a regulator polymerized.
• the polymerization of the anionic monomers is carried out in the presence of at least one regulator, as is apparent from the abovementioned references, the polymerization of the anionic monomers is carried out in the presence of from 6 to 25 mol ppm of at least one crosslinker become.
• Crosslinkers are known compounds which contain at least two ethylenically unsaturated double bonds in the molecule, such as methylenebisacrylamide, pentaerythritol triacrylate or glycol diacrylate.
• linear, anionic polymer and / or the branched, anionic, water-soluble polymer of component (ii) are used, for example, in an amount of 0.003 to 0.3 wt .-%, based on dry pulp.
• component (ii) may optionally contain bentonite and / or silica gel.
• Bentonite in the context of the invention should be understood as meaning finely divided, water-swellable minerals, e.g. Bentonite itself, hectorite, attapulgite, montmorillonite, nontronite, saponite, sauconite, hormitol and sepiolite.
• modified and unmodified silicic acids are suitable as silica gel.
• Bentonite and / or silica gel are usually used in the form of an aqueous slurry. If bentonite and / or silica gel are used in the process according to the invention, the amount is from 0.01 to 1.0, preferably from 0.1 to 0.5,% by weight, based on dry paper stock.
• the retention aid system contains as component (iii) particulate, anionic, crosslinked, organic polymers having an average particle diameter of at least 1 ⁇ m and an intrinsic viscosity of less than 3 dl / g.
• component (iii) particulate, anionic, crosslinked, organic polymers having an average particle diameter of at least 1 ⁇ m and an intrinsic viscosity of less than 3 dl / g.
• These are, for example, known aqueous polymer dispersions, water-in-oil polymer dispersions or so-called water-in-water polymer dispersions which either have a high neutral salt concentration or are stabilized with protective colloids.
• the average particle diameter of the crosslinked anionic polymer particles is, for example, in the range of 1 to 20 ⁇ m, preferably 1 to 10 ⁇ m.
• Examples of monomers (a) are ethylenically unsaturated C 3 - to C 5 -carboxylic acids, ethylenically unsaturated sulfonic acids and / or salts of the acids mentioned.
• Specific examples of such monomers are acrylic acid, methacrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid, styrenesulfonic acid, sulfopropyl acrylate, sulfopropyl methacrylate, vinylsulfonic acid and the alkali metal, alkaline earth metal and ammonium salts of said monomers. Preference is given to using the sodium, potassium and / or ammonium salts of acrylic acid or methacrylic acid.
• Suitable monomers (b) are, for example, acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, N-vinylformamide, N-isopropylacrylamide, N, N-dimethylacrylamide, N-vinylpyrrolidone, vinyl acetate, acrylic esters of monohydric alcohols having 1 to 6 carbon atoms, methacrylic esters of monohydric alcohols having 1 to 6 carbon atoms and styrene.
• the water-insoluble or sparingly soluble monomers are used in the polymerization only in amounts such that they also copolymerize with the water-soluble monomers, e.g. in amounts of less than 20 mol%, preferably less than 10 mol%.
• crosslinker is used in the preparation of the particulate, anionic polymers.
• Crosslinkers are compounds which contain at least two ethylenically unsaturated double bonds in the molecule, e.g. Methylenebisacrylamide, glycol diacrylate, glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, allyl acrylate, allyl methacrylate, triallylamine and butanediol diacrylate.
• the amounts of crosslinker used in the polymerization are, for example, 7 to 500 ppm, preferably 15 to 200 ppm (in each case calculated in molar amounts), based on the monomers used.
• the particulate anionic crosslinked polymers are preferably prepared in the absence of a polymerization regulator. However, the polymerization can be carried out in the presence of a regulator, but then usually requires higher amounts of crosslinkers to obtain suitable particulate anionic polymers.
• the crosslinked anionic polymer particles are preferably prepared by the reverse emulsion polymerization method. In this process, an aqueous monomer solution is emulsified in a hydrocarbon oil with the aid of at least one water-in-oil emulsifier and then polymerized. The resulting polymer particles can be isolated from the W / O emulsion and recovered, for example, in the form of a powder.
• polymer particles from aqueous dispersions or the water-in-water dispersions.
• aqueous dispersions of the particulate, anionic, crosslinked polymers which have a polymer concentration of, for example, 15 to 50% by weight.
• N, N'-methylenebisacrylamide as crosslinking agent in amounts of, for example, from 5 to 10,000, in particular from 15 to 1000, ppm by weight for the preparation of the anionic, crosslinked polymer particles.
• the anionic crosslinked polymer particles have an intrinsic viscosity of less than 3 dl / g, e.g. in the range of 2 to 2.95 dl / g, determined according to ISO 1628/1, October 1988, "Guidelines for the standardization of methods for the determination of viscosity number and polymer in dilute solution".
• the particulate, anionic, crosslinked, organic polymer (iii) is used, for example, in an amount of from 30 to 1000 g / t, preferably from 30 to 600 g / t of dry stock.
• the retention aid system comprising components (i), (ii) and (iii) can be used, for example, by initially metering at least one compound of component (i) into the thick material and then diluting the mixture with water.
• component (i) into the thin material (solids content of, for example, from 0.7 to 1.5% by weight), then optionally subject it to shearing, and then to the organic polymer of component (ii) and the component ( iii) add.
• the organic polymers of components (ii) and (iii) may also advantageously be added in the form of a mixture to the thin material.
• component (ii) If bentonite and / or silica gel are used as component (ii), the inorganic constituents of this component are metered before or after the addition of the organic polymers of component (ii) or else they are added separately at the same time. However, they can also be used alone as component (ii) of the retention aid system.
• component (i) If two different polyvinylamines are used as component (i), the component containing vinylamine units with a molecular weight of 45,000 to 350,000, for example, is already metered into the thick material (solids content> 1.5% by weight), the pulp is diluted by adding Water, adding the other vinylamine units-containing polymer to component (i), then subjecting the mixture to a shear stage, adding component (ii) and component (iii) of the retention aid system and thereafter dewatering the stock. However, it is also possible first to meter component (iii) and then component (ii) to the thin material.
• component (i) can also proceed by first adding component (i) to the stock as described above, then metering component (ii), subjecting the mixture to a shear stage and then adding component (iii) before the stock is dehydrated.
• component (ii) it is also possible to proceed in such a way that, after the last shear stage in front of the headbox, first of all component (i) and then the organic anionic polymer of component (ii) and component (iii) and then the inorganic compounds of component (ii) dosed.
• the component (ii) employed is an organic polymer and bentonite and / or silica gel. This can be done, for example, by first metering the inorganic compound of component (ii) into the thin material before or after shearing, then in any order components (i) and (iii) and optionally the organic linear polymer of the component ( ii) inflicts.
• Other variants for the addition of the components of the retention agent system are possible. The most advantageous dosing order of components (i), (ii) and (iii) depends on local conditions.
• the process of the present invention provides significantly improved retention over the use of cationic polyacrylamides in combination with an anionic polymer and a particulate crosslinked anionic polymer having a particle size of less than 1 micron.
• the sole use of polymers containing vinylamine units as a constituent of the retention agent system leads to an improvement in the drainage properties in comparison to the cationic polyacrylamides conventionally used in retention aid systems.
• All the paper materials can be processed by the process according to the invention. It is possible, for example, to start from cellulose fibers of all kinds, both natural and recovered fibers, in particular fibers from waste paper. Suitable pulps for the production of the pulps are all qualities customary for this purpose, for example wood pulp, bleached and unbleached pulp and pulps from all annual plants.
• Wood pulp includes, for example, groundwood, thermomechanical pulp (TMP), chemo-thermo-mechanical pulp (CTMP), pressure groundwood, semi-pulp, high yield pulp, and refiner mechanical pulp (RMP).
• TMP thermomechanical pulp
• CMP chemo-thermo-mechanical pulp
• RMP refiner mechanical pulp
• pulp for example, sulphate, sulphite and soda pulps come into consideration.
• unbleached pulp also referred to as unbleached kraft pulp, is used.
• Suitable annual plants for the production of pulps are, for example, rice, wheat, sugar cane and kenaf.
• For the preparation of the pulp waste paper can also be used with advantage, which is used either alone or in admixture with other fibers or it is based on fiber mixtures of a primary material and recycled coated Committee, eg bleached pine sulfate mixed with recycled coated Committee.
• the retention aid system (i), (ii) and (iii) can be used together with the usual process chemicals in the manufacture of paper and paper products.
• Typical process chemicals include, for example, additives such as starch, pigments, optical brighteners, dyes, biocides, paper strength agents, sizing agents, fixatives, and defoamers.
• the additives mentioned are used in the usual amounts.
• starches such as native starches or modified starches, in particular cationically modified starches, can be used as starches.
• Suitable fixing agents are, for example, poly-dimethyldiallylammonium chloride, dicyandiamide resins, epichlorohydrin-crosslinked condensation products of a dicarboxylic acid and a polyamine, polyaluminum chloride, aluminum sulfate and polyaluminum chlorosulphate.
• Sizing agents are e.g. Rosin size, alkyl diketenes or alkenyl succinic anhydrides.
• PAM Copolymer of acrylamide and dimethylaminoethyl acrylate, quaternized with methyl chloride, cationicity 15 mol%, molecular weight M w 5 million
• the intrinsic viscosity was determined according to ISO 1628/1, October 1988, "Guidelines for the standardization of methods for the determination of viscosity number and polymer in dilute solution".
• the molecular weights of the polymers were determined by light scattering.
• the retention effect (total retention FPR and ash retention FPAR) was determined according to Britt Jar. For all examples, a stock of 70% by weight TMP (thermomechanical pulp), 30% by weight bleached pine sulfate and 30% by weight ground calcium carbonate was used. The paper stock was diluted to a solids content of 0.77% by weight and in each case admixed with the components of the retention aid system given in Table 1, with the following sequence: optionally PVAm 1, PVAm2 or PAM (Comparative Examples), Lin.PAM / PAS and optionally bentonite. If bentonite was used, then dosed bentonite and Lin.PAM / PAS simultaneously. The retention values are given in Table 1.
• Dewatering time was determined in a Schopper-Riegler tester by dewatering 1 liter each of the fiber slurry to be tested therein and determining the time necessary to pass 600 ml of filtrate. The results are shown in Table 1.
• Retention agent [kg / t] Lin.PAM / PAS [kg / t] Bentonite [kg / t] FPR [%] FPAR [%] Drainage time [sec] formation 1 0.4 PVAm 2 0.3 95 91 31 162 2 0.4 PVAm 1 0.3 95 92 31 165 3 0.2 PVAm 1 0.3 96 96 26 170 0.2 PVAm 2 4 0.4 PVAm 2 0.15 1.0 96 96 24 169 5 0.4 PVAm 2 0.15 1.0 94 89 34 165 Comparative Example No.

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• 2005
  • 2005-09-13 DE DE102005043800A patent/DE102005043800A1/de not_active Withdrawn
• 2006
  • 2006-09-05 EP EP06793230.1A patent/EP1926855B1/de not_active Not-in-force
  • 2006-09-05 CN CN2006800336181A patent/CN101263263B/zh not_active Expired - Fee Related
  • 2006-09-05 WO PCT/EP2006/066019 patent/WO2007031442A1/de active Application Filing
  • 2006-09-05 ES ES06793230.1T patent/ES2526200T3/es active Active
  • 2006-09-05 US US12/065,688 patent/US7918965B2/en not_active Expired - Fee Related
  • 2006-09-05 JP JP2008530479A patent/JP5091139B2/ja not_active Expired - Fee Related
  • 2006-09-05 CA CA2624998A patent/CA2624998C/en not_active Expired - Fee Related

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