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
  • D21H21/14—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 characterised by function or properties in or on the paper
  • D21H21/18—Reinforcing agents
  • D21H21/20—Wet strength agents
• • 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
• • 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
  • D21H17/375—Poly(meth)acrylamide
• • 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
  • D21H17/42—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups anionic
  • D21H17/43—Carboxyl groups or derivatives thereof
• • 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

Definitions

• a process for the production of paper with high dry strength in which a water-soluble cationic polymer, for example polyethyleneimine, is first added to the paper stock and then a water-soluble anionic polymer, for example a hydrolyzed polyacrylamide, is added and the paper stock dewatered on a paper machine with sheet formation.
• the anionic polymers contain up to 30 mol% of acrylic acid copolymerized. Since you have the dry consolidation Ks / Kl medium already added to the paper stock, a coating application is no longer necessary, but the anionic polyacrylamides lead to poor drainage of the stock and a sticking of the felts of the paper machine after a certain runtime.
• the present invention has for its object to provide a process for the production of paper with high dry strength and the lowest possible wet strength, in which compared to the process known from CA-PS 1 110 019 papers with improved dry strength and in the case of use bleached fabrics get papers with higher whiteness.
• the cationic polymers are added to the fabric in order to transfer the negatively charged cellulose fibers.
• the following classes of compounds are suitable as water-soluble cationic polymers (A): polyethyleneimines which, in 10% strength aqueous solution at a pH of 7, have a viscosity in the range from 5 to 100, preferably 10 to 40 mPas (measured at 20 ° C, rotational viscometer, 20 rpm).
• the polymers can be neutralized with organic acids such as formic acid, acetic acid or propionic acid or with inorganic acids such as hydrochloric acid, sulfuric acid or phosphoric acid.
• component (A) Partially to fully hydrolyzed homo- and copolymers of N-vinylformamide are also suitable as component (A).
• the degree of hydrolysis of the N-vinylformamide in these polymers is at least 30 mol% and is preferably in the range from 50 to 100 mol%. For example, if one starts from a homopolymer of N-vinylformamide and hydrolyzes 100%, a polyvinylamine is obtained.
• Copolymers of N-vinylformamide with other monomers for example vinyl acetate, acrylonitrile, Methacrylonitrile, acrylamide and methacrylamide can also be hydrolyzed by the action of acids or bases.
• the degree of hydrolysis stated above always relates to the N-vinylformamide content of the copolymer in the copolymers of N-vinylformamide.
• Saponification of copolymers of N-vinylformamide and vinyl acetate gives polymers which, in addition to the units of the monomers on which these polymers are based, also have units of vinylamine and vinyl alcohol.
• Suitable homopolymers of N-vinylformamide and copolymers of N-vinylformamide with other ethylenically unsaturated monomers have a K value (according to H. Fikentscher) from 50 to 250 and preferably from 100 to 150. The K value of the unsaponified and the saponified N- Vinylformamide polymers agree within the limits of error.
• component (A) are homopolymers and copolymers of N-vinylimidazole and N-vinylimidazoline and their derivatives.
• the copolymers contain at least 30% by weight of N-vinylimidazole or N-vinylimidazoline or their derivatives in copolymerized form.
• suitable derivatives of N-vinylimidazole and N-vinylimidazoline are, for example, the C 1 -C 3 -alkyl-substituted or phenyl-substituted compounds.
• the polymers of N-vinylimidazole and N-vinylimidazoline have K values (determined according to H. Fikentscher) from 50 to 250 and preferably 100 to 150.
• water-soluble cationic polymers are polyamidoamines which are crosslinked with epichlorohydrin. Suitable products of this type are known, for example, from US Pat. No. 2,926,116. They are made by using a dicarboxylic acid. such as adipic acid, with a polyamine e.g. Diethylene triamine or tetraethylene pentamine condensed and the resin obtained crosslinked with epichlorohydrin to the extent that water-soluble reaction products are still obtained. These polymers have a viscosity of 20 to 200 mPas in a 10% strength by weight aqueous solution at a temperature of 20 ° C. (measured with a rotary viscometer at 20 rpm).
• This group of cationic polymers also includes polyamidoamines grafted with ethyleneimine, which are crosslinked with epichlorohydrin or, according to DE-PS 24 34 616, with reaction products which are converted by reaction of the terminal OH groups of polyalkylene oxides with 8 to 100 alkylene oxide units (preferably polyethylene oxides ) can be obtained with at least equivalent amounts of epichlorohydrin.
• cationic polymers (A) are homopolymers of diallyldi-C 1 -C 3 -alkylammonium compounds and diallyl mono-C 1 -C 3 -amines.
• Han can use either the free bases or the halides, especially the chlorides.
• Homopolymers of diallyldimethylammonium chloride and diallyldiethylammonium chloride are particularly suitable.
• the polymers of this class of substances have K values (measured according to H. Fikentscher) from 50 to 150, preferably from 100 to 150.
• polyethyleneimines polyvinylamines which are prepared by hydrolysis of homopolymers of N-vinylformamide or of copolymers of N-vinylformamide and vinyl acetate, acrylamide or acrylonitrile, the degree of hydrolysis, in each case based on polymerized N- Vinylformamide, at least 50 to 100 mol.%, And polyvinylimidazole.
• 0.01 to 3 preferably 0.1 to 0.5% by weight of a cationic compound (A) is used. It is of course also possible to use a mixture of 2 or 3 different cationic compounds in the process according to the invention. If the cationic compounds (A) are strongly basic, they can be used in a form partially or completely neutralized with an acid. The pH of these solutions is then 6 to 8, preferably 7 to 7.5.
• the water-soluble anionic polymers - component (B) - are, for example, homopolymers of ethylenically unsaturated C 3 - to Cs-carboxylic acids. These include, for example, homopolymers of acrylic acid, methacrylic acid, maleic acid, hydrolyzed homopolymers of maleic anhydride and itaconic acid.
• the ethylenically unsaturated carboxylic acids mentioned can be copolymerized with other monomers.
• Suitable as component (B) are copolymers of (a) 35 to 99% by weight of ethylenically unsaturated C 3 to Cs carboxylic acids, (b) 55 to 1% by weight of an amide, nitrile and / or an ester of an ethylenically unsaturated C 3 to Cs carboxylic acid and (c) 0 to 15% by weight of styrene or a C 1 to C 4 alkyl vinyl ether.
• the copolymers preferably contain (a) 40 to 70% by weight of an ethylenically unsaturated C 3 to C 5 carboxylic acid, (b) 60 to 30% by weight of an amide, nitrile and / or an ester of an ethylenically unsaturated carboxylic acid and (c ) 0 to 15 wt.1 styrene or a Ci to C 4 alkyl vinyl ether.
• the sum of the percentages by weight in the copolymer is 100 in each case.
• the esters of ethylenically unsaturated C 3 to Cs carboxylic acids of component (b) of the copolymers are preferably derived from alcohols having 1 to 4 carbon atoms.
• component (B) Especially preferred as component (B) are terpolymers from (a) 40 to 70% by weight. Acrylic acid, (b 1 ) 10 to 50% by weight of acrylamide and (b 2 ) 10 to 50% by weight. Acrylonitrile.
• the anionic water-soluble polymers (B) have a K value (according to H. Fikentscher) from 50 to 250 and preferably from 100 to 150. The K value for the copolymers is determined at 20 ° C. in 5% strength aqueous sodium chloride solution and one Polymer concentration of 0.5% by weight. The pH when determining the K values is 7.
• the anionic component (B) is used in an amount of 0.05 to 3, preferably 0.1 to 1.0, by weight, based on the dry fiber.
• the weight ratio of components (A) to (B) is 1: 0.5 to 10 and is preferably in the range from 1: 2 to 4.
• the anionic component can be neutralized in the form of the free acids or partially or completely with bases Form apply. It is only important here that the partially or completely neutralized polymers are soluble in water.
• Suitable bases are alkali and alkaline earths as well as ammonia and amines, for example sodium hydroxide solution, potassium hydroxide solution, calcium hydroxide, barium hydroxide, ammonia, trimethylamine, ethanolamine and morpholine.
• All known paper and cardboard qualities can be produced by the process according to the invention, e.g. Writing, printing and packaging papers.
• the papers can be produced from a large number of different types of fiber materials, for example from sulfite or sulfate pulp in the bleached or unbleached state, wood, ground or waste paper.
• the paper production takes place in the pH range from 4.5 to 8, preferably at pH values from 6 to 7.
• sulfuric acid or aluminum sulfate can be used.
• the process according to the invention is preferably carried out in the presence of only small amounts of aluminum sulfate.
• the cationic component (A) which is responsible for the recharge of the cellulose fibers, is first added to the substance.
• Component (A) is very quickly fixed on the fibers.
• one or more compounds according to (B) are added to the substance, the mixture is homogenized and, if appropriate, other customary auxiliaries are added, such as retention aids, drainage agents, fillers.
• the anionic components (B) Compared to the known process, when using the anionic components (B), an improvement in the retention of fibers and fillers and of conventional auxiliaries, such as starch or carboxymethyl cellulose, is observed in all paper grades. Another advantage of using the anionic compounds (B) is an improvement in the Drainage of the stock suspension and that the felts of the paper machine do not stick together, even over a long period. Because of these advantageous properties, the method according to the invention is of particular importance for the production of paper from waste paper. In the production of bleached paper grades, there is a significantly higher whiteness of the paper compared to the processes of the prior art.
• the parts given in the following examples are parts by weight, the percentages relate to the weight of the substances.
• the sheets were produced in a Rapid-Köthen laboratory sheet former.
• the dry tear length was determined in accordance with DIN 53 112, sheet 1 and the wet tear length in accordance with DIN 53 112, sheet 2.
• the whiteness of the paper sheets was determined with the aid of a reflection photometer (Elrefo device) in accordance with DIN 53 145.
• the CMT value was determined in accordance with DIN 53 143, the dry burst pressure was determined in accordance with DIN 53 141.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Paper (AREA)
• Holo Graphy (AREA)
• Decoration By Transfer Pictures (AREA)
• Measurement Of Radiation (AREA)
• Compositions Of Macromolecular Compounds (AREA)

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Citations (7)

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• 1985
  • 1985-02-27 DE DE19853506832 patent/DE3506832A1/de not_active Withdrawn
• 1986
  • 1986-02-20 DE DE8686102199T patent/DE3667516D1/de not_active Expired - Lifetime
  • 1986-02-20 JP JP61034020A patent/JPS61201097A/ja active Pending
  • 1986-02-20 AT AT86102199T patent/ATE48667T1/de not_active IP Right Cessation
  • 1986-02-20 EP EP86102199A patent/EP0193111B1/fr not_active Expired
  • 1986-02-21 NZ NZ215254A patent/NZ215254A/xx unknown
  • 1986-02-24 FI FI860787A patent/FI860787A/fi not_active Application Discontinuation
  • 1986-02-26 AU AU54097/86A patent/AU577448B2/en not_active Ceased

Patent Citations (7)

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