Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
  • D21C5/00—Other processes for obtaining cellulose, e.g. cooking cotton linters ; Processes characterised by the choice of cellulose-containing starting materials
  • D21C5/005—Treatment of cellulose-containing material with microorganisms or enzymes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
  • C08B15/00—Preparation of other cellulose derivatives or modified cellulose, e.g. complexes
  • C08B15/02—Oxycellulose; Hydrocellulose; Cellulosehydrate, e.g. microcrystalline cellulose
• • 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
  • D21H11/00—Pulp or paper, comprising cellulose or lignocellulose fibres of natural origin only
  • D21H11/16—Pulp or paper, comprising cellulose or lignocellulose fibres of natural origin only modified by a particular after-treatment
  • D21H11/20—Chemically or biochemically modified fibres
• • 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
  • 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

Definitions

• the present invention relates to a novel pulp composition for papermaking or paperboard production which contains an oxidized waste paper pulp and / or an oxidized mechanical pulp.
• the invention also relates to paper and board based on such a pulp composition and to a method for producing such a paper or board.
• the invention also relates to the use of oxidized waste paper pulp and / or oxidized mechanical pulp to improve the retention and drainage properties of a pulp suitable for the manufacture of paper or board.
• the invention further relates to the use of oxidized waste paper pulp and / or oxidized mechanical pulp for improvement, i. H. Increasing the dry strength of paper and cardboard.
• waste paper pulp ie a pulp obtained by recycling waste paper, or using mechanical pulp. Since the cost of waste paper pulp or of mechanical material is substantially lower than for fresh pulp, an increase in the proportion of waste paper pulp or of mechanical pulp in the paper pulp or paper pulp. Paperboard production used a great economic advantage for the paper manufacturer. Frequently, however, the quality of the waste paper pulp leaves much to be desired if the structure of the fibers is damaged in the recycling of paper and cardboard or in the mechanical pulping of wood, which leads to lower strength values in the paper. Therefore, the amount of waste paper pulp or mechanical pulp in the pulp used to make the paper or paperboard is limited. However, an increase in the content of waste paper pulp and / or mechanical pulp is desirable for the reasons mentioned above. It has been reported on various occasions to use a stock for papermaking in which the cellulose fibers have previously been subjected to oxidation.
• WO 99/231 17 describes a process for the oxidation of cellulose fibers in paper stocks, in which a paper pulp with an oxidizing enzyme, for. As a laccase, oxidized in the presence of a mediator. As pulps, mechanical, chemical, chemo-mechanical and recycled substances are proposed. The process allegedly leads to improved flexibility, improved water retention capacity (WRV) and increased strength.
• EP 1077286 describes the use of an aldehyde-modified cellulose pulp for the production of paper. The aldehyde groups are incorporated into the cellulose pulp by chemical oxidation, e.g. B. with sodium hypochlorite in the presence of a Mediators, introduced.
• the thus modified cellulose pulp leads in particular to an improved wet tensile strength and to an increase of the ratio of wet to dry tensile strength.
• a similar situation is known from EP 1 106732, in which case additionally a hydroxyl-containing polymer is used.
• WO 00/68500 also describes a process for producing paper having improved wet strength properties using an unbleached or semi-bleached pulp, a semi-pulp or a waste paper pulp which has been treated with a phenol oxidizing enzyme, for example a laccase in the presence of a mediator, e.g. , TEMPO (2,2,6,6-tetramethylpiperidinyloxyl).
• a mediator e.g. , TEMPO (2,2,6,6-tetramethylpiperidinyloxyl).
• WO 01/29309 likewise describes a process for the production of paper in which a pulp is used whose cellulose fibers have been previously treated with an oxidizing agent in the presence of a mediator. Again, the oxidation leads to an improvement in the wet strength properties of the paper.
• a further problem in the production of paper or board is the often unsatisfactory retention properties of the pulp compositions used for paper or board production, in particular those pulp compositions with a high content of waste paper and / or mechanical or thermomechanical material, so that larger quantities must be used on retention aids. Often, the drainage properties of the compositions are unsatisfactory.
• an oxidized pulp in the conventional pulp selected by oxidation of at least one conventional pulp selected from waste paper pulp, mechanical pulp and mixtures thereof, has from 1 to 500 mmol of carboxyl groups and 1 to 200 mmol aldehyde groups per kg of conventional pulp, calculated oven-dry, the retention properties of pulp compositions or of aqueous pulp suspension for papermaking improved by, for example, an increase in the total retention FPR and / or an increase in ash retention, as for example by The "Britt Jar Test Method" TAPPI T-261 can be determined.
• oxidized pulp B leads to an improvement in the dry strength properties of paper or board, without there being a strong increase in the wet strength properties.
• oxidized fibers can improve the dewatering properties of the aqueous pulp suspension, ie the dewatering time is shortened in the papermaking, as z. B. according to ISO standard 5267 can be determined.
• the present invention relates to the use of an oxidized pulp B in which by oxidation of at least one conventional pulp selected from waste paper pulp, mechanical pulp and blends thereof 1 to 500 mmol, especially 5 to 200 mmol, especially 10 to 150 mmol carboxyl groups per kg of conventional pulp and from 1 to 200 mmol, in particular from 2 to 150 mmol and especially from 5 to 100 mmol aldehyde groups per kg of conventional pulp were used to improve the retention properties or to improve the drainage properties of the pulp compositions defined herein and below and / or to improve the dry strength properties, in particular dry tensile strength, tensile strength, tear propagation strength and bursting pressure of paper or board, particularly paper or board, using the fibrous material defined herein and hereinafter fuses arrangementen is produced.
• the present invention relates to the use of an oxidized fiber B, in which by oxidation of at least one selected from paper pulp, mechanical material and mixtures thereof conventional pulp 1 to
• the present invention relates to the use of an oxidized pulp B in which by oxidation of at least one conventional pulp selected from waste paper pulp, mechanical pulp and blends thereof 1 to 500 mmol, especially 5 to 200 mmol, especially 10 to 150 mmol carboxyl groups per kg of conventional pulp and 1 to 200 mmol, in particular 2 to 150 mmol and especially 5 to 100 mmol aldehyde groups per kg of conventional pulp, to improve the dewatering properties of aqueous pulp suspensions, in particular those pulp suspensions containing as fiber constituents the pulp composition shown here and below.
• Another object of the invention is a pulp composition for paper or board production, comprising
• At least one oxidized pulp B in the conventional pulp selected by oxidation of at least one of conventional pulp, mechanical pulp and mixtures thereof 1 to 500 mmol, especially 5 to 200 mmol, especially 10 to 150 mmol carboxyl groups per kg of conventional pulp and 1 to 200 mmol, in particular 2 to 150 mmol and especially 5 to 100 mmol aldehyde groups per kg of conventional pulp were introduced, and c) at least one other, different from A and B, conventional pulp C;
• the total amount of the components A and B account for 30 to 80 wt .-% of the total pulp in the pulp composition and the ingredients A, B and C at least 70 wt .-%, in particular at least 80 wt .-% and especially at least 90 wt. % or 100% by weight of the total mass of pulp in the pulp composition, the stated amounts of constituents A, B and C each being calculated as oven-dry pulp.
• the present invention furthermore relates to a paper stock which contains, as fiber constituents, a pulp composition as described herein, as well as papers or paperboard based on such a pulp composition.
• a pulp composition as described herein, as well as papers or paperboard based on such a pulp composition.
• the use of an oxidized pulp B, as described here, allows, with the same dry strength properties, the proportion of waste paper pulp and / or mechanical pulp in the fiber pulp used for paper or board production. Increase composition at the expense of the more expensive chemical.
• a paper or board produced using a pulp composition according to the invention has, for the same proportion of chemical substance and the same proportion of waste paper and / or mechanical material (oxidized pulp B plus any conventional waste paper pulp present and / or or mechanical fabric) has better dry strength properties than a paper or paperboard made using a pulp composition containing only conventional waste paper pulp or mechanical pulp besides chemical pulp.
• oxidized pulp B plus any existing conventional waste paper pulp and / or mechanical pulp by at least 50%, in particular at least 90%, in the pulp composition without any loss have to accept in the dry strength properties.
• wet strength properties are not or only slightly increased, that is, in an insignificant for a later retrieval height, which is advantageous in terms of any recycling of a paper or cardboard made from this pulp composition. Due to the better retention properties, it is also possible to increase the proportion of filler in the pulp suspension, based on the total amount of substance.
• the pulp composition contains as ingredient A a chemical pulp, d.
• a chemical pulp d.
• Pulp obtained by chemical pulping of a lignocellulosic material such as wood. These include, for example, sulfate pulp, sulfite pulp and / or soda pulps, wherein the pulp may be unbleached or bleached.
• bleached pulps chlorine-bleached or, in particular, low-chlorine or chlorine-free pulps, such as ECF pulp and TCF pulp, are used. Preference is given to unbleached pulp.
• pulp from annual crops such as pulp based on rice, wheat, sugar cane (bark), bamboo or kenaf.
• the chemical pulp is usually used only in small quantities. Already a few wt .-% of the component A, based on the total mass of material in the pulp composition, are usually sufficient to achieve the desired strengths.
• the level of chemical pulp in the fiber composition is in the range of 1 to 50 weight percent, often in the range of 2 to 30 weight percent, and more preferably in the range of 5 to 20 weight percent, based on total fabric weight in the pulp composition.
• the amount of oxidized fibers B namely oxidized waste paper pulp and / or oxidized mechanical pulp, is typically 10 to 79 wt .-%, often 20 to 68 wt .-% and in particular 30 to 55 wt .-%, based on total mass in the pulp composition.
• the amount of chemical pulp A and oxidized pulp B is according to the invention 20 to 80 wt .-%, often 30 to 70 wt .-% and in particular 40 to 60 wt .-%, based on the total mass of matter in the pulp composition.
• the pulp composition contains as constituent C according to the invention at least one further conventional pulp, which is different from the pulps A and B.
• component C in addition to waste paper and mechanical material, d. H. Wood pulp, thermomechanical pulp (TMP) and refiner mechanical pulp (RMP) are preferred. Particularly preferred are waste paper pulp and mechanical pulp and mixtures thereof.
• Very particularly preferred component C is used paper pulp (recycled fibers) and fiber blends which consist of at least 30% by weight, in particular at least 50% by weight, based on the total mass of the constituents C, of recovered paper stock, preferably mixed with mechanical pulp ,
• waste paper material here is any paper into consideration, which was obtained from any type of used, printed or unprinted paper, in particular waste paper according to the list of varieties EN 643, the waste paper of the same or different quality may be such.
• mixed bales (1 .02), Kaufhausaltpapier (1 .04), corrugated board Il (4.03), multi-pressure (3.10), white rotary waste (3.14 / 3.15) and white envelope chips (3.18.01) may include.
• the numbers in parentheses indicate the number assigned to EN 643, respectively. It may also be appropriate waste or packaging made of cardboard or paperboard, including composites of paper, cardboard or cardboard with other materials, such as plastic coatings or linings act.
• the essential aspect of the waste paper pulp used in accordance with the invention is that, in contrast to fresh fiber material which has hitherto not undergone any disruption or which has not yet been processed into paper or paperboard products, it is recycled waste paper material.
• Coated paper also includes coated broke, which in addition to fiber components also contains binders from the coating color.
• constituents B and C generally make up 50 to 99% by weight, frequently 60 to 98% by weight, in particular 70 to 98% by weight, in particular 70 to 95% by weight and especially 80% to 95 wt .-%, based on total mass in the pulp composition.
• the total amount of components A, B and C is at least 70% by weight, often at least 80% by weight, especially at least 90% by weight, and especially at least 99 or 100% by weight, based on Total mass of material in the pulp composition.
• the pulp composition may contain up to 30% by weight, but often not more than 20 or 10% by weight or essentially no ( ⁇ 1% by weight) of other fiber constituents.
• total mass of matter means the dry mass of the fiber components (oven-dry, water content ⁇ 1%) in the pulp composition.
• the pulp composition contains at least one oxidized pulp selected from oxidized waste paper pulp, oxidized mechanical pulp and mixtures thereof.
• a mechanical material is understood to mean groundwood such as white or brown ground. This is a fiber mass based on the aforementioned substances, in which by an oxidation process 1 to 500 mmol, in particular 5 to 200 mmol, especially 10 to 150 mmol carboxyl groups per kg of conventional pulp and 0 to 200 mmol, in particular 2 to 150 mmol and especially 5 to 100 mmol aldehyde groups per kg of conventional pulp were introduced.
• oxidized waste paper pulp and mixtures of oxidized waste paper pulp with oxidized mechanical pulp in which the proportion of oxidised waste paper pulp is at least 30% by weight, in particular at least 50% by weight, based on the total mass of constituents B.
• the amount of aldehyde and carboxyl groups introduced into the substance by oxidation can be determined by the expert in a manner known per se by determining the absolute content of aldehyde or carboxyl groups before and after oxidation.
• the absolute determination of the aldehyde and carboxyl groups is achieved by customary titration methods, as used in the prior art, for. In EP 1077286 or EP 1 106732, be written.
• the determination of the aldehyde groups is typically carried out by derivatization of the aldehyde with hydroxylammonium chloride and titration of the liberated hydrogen chloride with sodium hydroxide solution.
• the content of carboxyl groups is typically determined by titration with sodium hydroxide solution.
• Oxidation of the conventional material is believed to produce additional aldehyde and carboxyl groups on the surfaces of the cellulose fibers contained in the waste paper pulp, i. H. in the cellulose and hemicellulose constituents of these fibers, are generated, e.g. By oxidation of the C6-OH group in the glucose units of the cellulosic and hemicellulose components of the cellulosic fibers. Furthermore, it is believed that the laccase preferred for the oxidation of the pulps leads to changes in the lignin content of the pulps.
• the molar ratio of the carboxyl groups introduced by oxidation to the aldehyde groups introduced by oxidation is not below 0.8: 1, preferably not below 1: 1 and in particular not below 1.2: 1.
• This molar ratio is preferably in the range from 0.8: 1 to 10: 1, in particular in the range from 1: 1 to 8: 1 and especially in the range from 1, 2: 1 to 5: 1.
• the oxidation of the conventional pulp can be carried out in a conventional manner.
• the amount of aldehyde groups and carboxyl groups introduced by oxidation can be controlled by those skilled in the art by choosing appropriate reaction conditions, reagent amounts, and by determining the necessary reaction conditions and reagent levels by routine experimentation.
• wood pulp such as white or brown sanding can be considered, which can be bleached or unbleached.
• mixed bales (1.02), Kaufhausaltpapier (1.04), corrugated board Il (4.03), multi-pressure (3.10), white rotary waste (3.14 / 3.15) and white envelope chips (3.18.01) may include.
• the numbers in parentheses indicate the number assigned to EN 643, respectively. It may also be equivalent waste or packaging of cardboard or paperboard, including paper, cardboard or paperboard composites with other materials, such as plastic coatings or liners.
• the essential aspect of the waste paper pulp used in accordance with the invention is that, in contrast to fresh fiber material which has hitherto not undergone any disruption or which has not yet been processed into paper or paperboard products, it is recycled waste paper material.
• the waste paper to be considered for oxidation also includes coated broke, which in addition to fiber components also contains binders from the coating color.
• coated broke which in addition to fiber components also contains binders from the coating color.
• both conventional chemical methods and enzymatic oxidation methods can be used.
• the oxidation is carried out enzymatically. This is presumably due to the fact that damage to the cellulose fibers by oxidative cleavage is minimized in this way.
• the conventional waste paper pulp is treated with atmospheric oxygen in the presence of an oxidase or with hydrogen peroxide in the presence of a suitable peroxidase.
• Oxidases such as catechol oxidase (EC 1 .10.3.1), laccases (EC 1 .10.3.2), bilirubin oxidases (EC 1.3.3.5) are preferred.
• the oxidation-mediating enzyme is a laccase. Basically, all laccases are suitable.
• M. thermophila Rhizoctonia sp., In particular Rhizoctonia praticola or Rhizoctonia solani , from Scytotidium sp., in particular S. thermophilium, from Pyricularia sp., in particular Pyricularia oryzae or Coprinus sp. be derived as C. cinereus.
• laccases may also be derived from fungi such as Collybia, Fomes, Lentinus, Pleurotus, Aspergillus, Neurospora, Podospora, Phlebia, for example P. radiata (see WO 92/01046), Coriolus sp., E.g. C. hirsitus (JP 2-238885), or Botrytis. Suitable laccases are known to the person skilled in the art and otherwise commercially available.
• the amount of laccase is usually chosen so that its activity in the range of 0.1 to 14 000 U, in particular in the range of 0.5 to 1 000 U, and more preferably in the range of 1 to 400 U, each based on 1 g of oven-dried conventional substance.
• the enzyme activity can be determined in the usual way with the aid of the substrate syringaldazine (4,4 '- (azinobis (methanylyliden)) bis (2,6-dimethoxyphenol)).
• the rate of oxidation of syringaldazine to the corresponding quinone (4,4'-azobis (methanylylidene)) bis (2,6-dimethoxycyclohexa-2,5-diene-1-one) is determined by measuring the absorbance at 530 nm , 1 unit (U) corresponds to the turnover of 1 ⁇ syringaldazine per minute.
• the paper pulp or the mechanical material is usually transferred into an aqueous suspension and mixed with the enzyme. By moving the suspension or by introducing oxygen, the amount of oxygen required for the oxidation is introduced.
• peroxidases for the oxidation of hydrogen peroxide is of course also added as an oxidizing agent.
• Fresh water, but also process water, can be used as water for the preparation of the aqueous suspension of the waste paper pulp or mechanical pulp.
• the consistency in the aqueous suspension is typically in the range from 1 to 100 g / l, in particular in the range from 5 to 80 g / l and especially in the range from 10 to 50 g / l (in each case based on oven-dry paper stock or mechanical material)
• the pH of the aqueous suspension depends in a manner known per se on the optimum pH for the particular enzyme and can be adjusted by adding acids or bases or buffers, in particular by adding sodium hydroxide solution, potassium hydroxide solution or a buffer such as potassium dihydrogen phosphate buffer and optionally controlled in the course of the oxidation by the addition of base.
• the pH of the aqueous recovered pulp suspension is in the range of 3 to 10, and more preferably in the range of 4 to 9.
• the temperature at which the oxidation is carried out depends on the oxidant used. In the case of an enzymatic oxidation, the temperature preferably depends on the optimum temperature for the activity of the particular enzyme chosen. Typically, the temperature is in the range of 20 to 40 ° C.
• the oxidation time depends in a conventional manner on the type and amount of each selected oxidant and the other reaction conditions such as temperature and pH, in the case of enzymatic oxidation of activity and
• the oxidation time is in the range of 5 minutes to 24 hours, more preferably in the range of 10 minutes to 18 hours and more preferably in the range of 20 minutes to 12 hours.
• the oxidation of the conventional pulp takes place in the presence of at least one mediator compound, hereinafter also referred to as redox mediator.
• the function of the redox mediator is that the oxidizing agent does not react directly with the OH groups in the glucose units of the cellulose and hemicellulose components or with the lignin constituents, but first oxidizes the mediator, which in turn oxidizes the material contained in the conventional pulp (Hemi ) Cellulose fibers or lignin causes.
• the use of a mediator is particularly advantageous in the case of enzymatic oxidation.
• Suitable mediator compounds are in principle all compounds described in the prior art for this purpose, for example those described in US Pat
• Benzothiazoline compounds such as 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonate) (ABTS), 2- (p-aminophenyl) -6-methylbenzothiazole-7-sulfonic acid and 3-methyl-2-benzothiazolinone;
• Naphthalene compounds such as. 6-hydroxy-2-naphthalenecarboxylic acid, 7-methoxy-2-naphthol, 7-amino-2-naphthalenesulfonic acid, 5-amino-2-naphthalenesulfonic acid, 1, 5-diaminonaphthalene and 7-hydroxy-1,2-naphthimidazole;
• Phenothiazine compounds such as 10-methylphenothiazine, 10-phenothiazinepropionic acid (PPT), N-hydroxysuccinimide-10-phenothiazine propionate, 10-ethyl-4-phenothiazinecarboxylic acid, 10-ethylphenothiazine, 10-propylphenothiazine, 10-isopropylphenothiazine, Methyl phenothiazine-1-ylpropionate, 10-phenylphenothiazine, 10-allyl-phenothiazine, 10- (3- (4-methyl-1-piperazinyl) -propyl) -phenothiazine, 10- (2-pyrrolidinomethyl) -phenothiazine, 10- (2 -Hydroxyethyl) phenothiazine, 2-acetyl-10-methylphenothiazine or 10- (3-hydroxypropyl) phenothiazine;
• Benzidine compounds such as. Benzidine or 3,3'-dimethoxybenzidine;
• Stilbene compounds such as 4-amino-4'-methoxystilbene, 4,4'-diaminostilbene-2,2'-disulfonic acid or iminostilbene;
• Phenoxazine compounds such as 10-phenoxazine-propionic acid (POP), 10-methylphenoxazine, or 10- (2-hydroxyethyl) phenoxazine;
• Biphenylamines such as N-benzylidene-4-biphenylamine or 4,4'-dimethoxy-N-methyldiphenylamine;
• phenol compounds described in WO 96/10079 such as acetosyringone, syringaldehyde, methylsyringate, syringic acid, ethylsyringate, propylsyringate, butylsyringate, hexylsyringate, octylsyringate, vanillic acid, NAH, HOBT, PPO and violoric acid;
• TEMPO 2,2,6,6-tetramethylpiperidinyl-1-oxy
• derivatives of TEMPO such as acetamido-TEMPO, BI-TEMPO, 4-hydroxy-TEMPO, 4-methoxy-TEMPO, 4-benzyloxy- TEMPO, 4-amino-TEMPO, 4-acetylamino-TEMPO, 4-ethylcarbonylamino-TEMPO, 4-propylcarbonylamino-TEMPO, 4-isopropylcarbonylamino-TEMPO,
• Such sterically hindered nitroxyl compounds are preferred according to the invention.
• the amount of mediator is generally 1 mg to 100 g, preferably 10 mg to 50 g and in particular 100 mg to 10 g, each based on 1 kg of oven-dry pulp.
• the oxidation is carried out using a laccase as described above in combination with a sterically hindered nitroxyl compound.
• the oxidation occurs in the absence of a mediator compound.
• atmospheric oxygen for enzymatic oxidation using atmospheric oxygen, it is usually necessary to atmospheric oxygen in the aqueous suspension of the fibrous material to be oxidized contribute. This is usually achieved by moving the suspension, for example by stirring in suitable vessels, preferably vessels, which are provided with internals to improve the mixing. Optionally, it is also possible to inject atmospheric oxygen into the reaction mixture.
• the oxidized pulp B obtainable in this way can be used for the production of a pulp composition according to the invention.
• the pulp composition may contain up to 10% by weight of further fiber constituents, based on the total fiber mass in the composition, eg. B. Returned Coated Committee.
• the oxidized pulp B is mixed with chemical pulp A and optionally further, conventional pulp e.
• the procedure is usually such that the aqueous suspension of the oxidized pulp B, as obtained after oxidation, with the pulp component A, preferably also in the form of an aqueous suspension, and optionally conventional pulp C, preferably also in Form of an aqueous suspension, mixed.
• the pulp component A preferably also in the form of an aqueous suspension
• optionally conventional pulp C preferably also in Form of an aqueous suspension
• the oxidized pulp B will not be converted to a dry form, but will be mixed directly with the other constituents of the pulp composition in the form of the aqueous suspension obtained during the oxidation.
• the present invention further relates to a process for producing a paper or cardboard comprising the following steps:
• the relative amount of fibers being such that the total amount of ingredients A and B is from 30 to 80% by weight of the total pulp in the pulp suspension and the total amount of ingredients A, B and C is at least 70% by weight. % of the total pulp in the pulp composition, each calculated as oven-dry substance.
• the relative amounts of the constituents A, B and C in the aqueous pulp suspension correspond to the relative amounts given for the pulp composition and are in particular in the ranges specified there as being preferred.
• step i) of the process an aqueous pulp suspension is then prepared, which contains the oxidized pulp, chemical pulp A and conventional pulp C, in particular the pulp specified as being preferred, in the amounts specified for the pulp composition.
• aqueous pulp suspension then conventional additives and fillers, if required for the paper quality, given.
• customary additives are the additives customary in paper production for improving or modifying the paper properties, such as fillers, sizing agents, wet and dry strength agents, antiblocking agents, flame retardants, antistatic agents, water repellents, dyes and optical brighteners, and process chemicals, such as retention, flocculation and dehydrating agents, fixatives, slimicides, wetting agents, defoamers, biocides and the like.
• wet strength agents are the polyamides commonly used for this purpose, epichlorohydrin resins, melamine-formaldehyde resins and cationic glyoxylated polyacrylamides.
• dry strength agents examples include native starches, starch derivatives, dextranes, cationized starch, cationic glyoxylated polyacrylamides, polyvinylamines, cationic, anionic or amphoteric polyacrylamides and mixtures thereof with inorganic dry strength agents.
• sizing agents are resin glues, casein and comparable proteins, starch, polymer dispersions, reactive sizing agents, in particular alkyldiketenes and alkylsuccinic anhydrides.
• suitable fillers are, in particular, calcium carbonate, such as chalk, kaolin, titanium dioxide, gypsum, precipitated calcium carbonate, talc, silicates.
• retention aids examples include aluminum sulfate and polyaluminum chlorite.
• Microparticle systems of high molecular weight polyacrylamides and bentonite or colloidal silica can also be used as retention aids.
• retention agents it is also possible to use combinations of microparticle systems of high molecular weight polyacrylamides and bentonite or colloidal silica with an anionic organic polymer, in particular anionic, optionally crosslinked polyacrylamides.
• retention agents based on microparticle systems of this type it is known, for example, from EP 462365, WO 02/33171, WO 01/34908 or WO 01/34910.
• ⁇ , ⁇ -dimethylaminopropylacrylamide Use ⁇ , ⁇ -dimethylaminopropylacrylamide.
• Further retention aids are microparticle systems of high-molecular-weight polyvinylamines and anionic, cationic or amphoteric, crosslinked polyacrylamides, as are known, for example, from US 2003/0192664 A1.
• Examples of customary flocculants and dehydrating agents are polyethyleneimines, polyamines having molar masses of more than 50,000, polyamidoamines, which may optionally be prepared by grafting with ethyleneimine and subsequent crosslinking with z. B.
• Examples of conventional fixing agents are: aluminum sulfate, polyaluminum chlorites, as well as the customary for this purpose cationic polymers, eg. Cationic polyacrylamides, polyethylenimines, polyvinylamines, polyimidazolines, polyimidazoles, polyamines, di-cyandiamide resins, poly-DADMAC, Mannich products and Hofmann products.
• cationic polymers eg. Cationic polyacrylamides, polyethylenimines, polyvinylamines, polyimidazolines, polyimidazoles, polyamines, di-cyandiamide resins, poly-DADMAC, Mannich products and Hofmann products.
• the type and amount of the process chemicals and the fillers depends in a manner known per se on the requirements of the paper machine and the desired paper type.
• the pulp suspension is dewatered in a paper machine to form paper or cardboard. If appropriate, it is possible to dilute with water (so-called thin material) before introducing the pulp suspension.
• the addition of the process chemicals can be done both before dilution and after dilution.
• the pulp which optionally also contains fillers, dewatered in the usual manner to form a sheet.
• the dewatering is typically carried out in a paper machine in which the usual paper forming steps are carried out, ie sheet forming in the wire section, compaction to remove the bulk of water in the press section, drying in the dryer section, calendering and calendering possibly supercalendering.
• the dryer section may also comprise a size press in which the paper is treated with a low viscosity size liquor for surface hardening.
• the paper machine may also comprise a coating unit in which the paper is coated with a coating color.
• the pulp composition according to the invention and the papermaking process according to the invention are suitable for the production of basically all types of paper which typically contain waste paper constituents, in particular
• Writing papers ie filled and fully sized papers with smoothed surfaces, typically having a basis weight in the range of 30 to 80 g / m 2 and a filler content in the range of 5 to 30% by weight and whose surfaces are usually painted and containing a proportion of waste paper fibers (total amount of oxidized and unoxidized waste paper fibers) in the range of 10 to 99 wt .-%, based on the total amount of fiber constituents;
• Print papers ie papers which are uncoated or coated and suitable for printing, which typically have a basis weight in the range from 40 to 150 g / m 2 and have a filler content of up to 20% by weight, can typically contain a proportion of recovered paper in the paper Range of 10 to 99 wt .-% (total amount of oxidized and unoxidized recycled paper fibers, based on the total amount of fibers);
• Newsprint papers which typically have a basis weight in the range of 38 to 50 g / m 2 and have a filler content in the range of up to 18% by weight, can typically have a recovered paper content in the range of 10 to 99% by weight.
• % Total amount of oxidized and unoxidized recycled paper fibers, based on total fiber content
• Packaging papers which typically have a basis weight in the range of 70 to 250 g / m 2 and may have a filler content of up to 15 wt .-% which typically have a waste paper content in the range of 10 to 99 wt .-% (total amount of oxidized and unoxidized waste paper fibers, based on the total amount of fiber);
• Cardboard or solid board which typically has a basis weight in the range from 250 to 1000 g / m 2 and can have a filler content of up to 15% by weight, which typically has a waste paper content in the range from 10 to 99% by weight ( Total amount of oxidized and unoxidized recycled paper fibers, based on the total amount of fibers);
• Waste paper made by Hoya (a mixture of used paper grades 1 .02 / 1 .04 / 4.01) and Sappemeer (fibers from paper grades 0012 to 0015) was used.
• TEMPO solid (CAS number: 2564-83-2, catalog number A12733) was obtained as free radical having a purity of 98% from Alfa Aesar GmbH, Düsseldorf, Germany.
• laccases used for the oxidation are given in Table 1, indicating the source of supply together with their respective activities.
• the whipping took place in a pulper from Escher & Wyss.
• the capacity of the device is a maximum of 15 liters.
• Voith pulpers can be used.
• test sheets The production of the test sheets was carried out with a Rapid Kothen leaf former. The following tests were carried out: dry tearing length, wet tearing length, further / tearing work (DIN 531 15) and water retention capacity (WRV) SCAN-C 62:00. The results are shown in Table 3. Table 3
• the properties of fibrous compositions according to the invention are compared with non-inventive fibrous compositions in which the oxidized waste paper pulp contained in the compositions according to the invention has been replaced by conventional waste paper pulp.
• the retention properties total retention and ash retention were compared using the Britt Jar test method Tappi T-261.
• the drainage time EWZ (according to ISO standard 5276) was determined.
• the oxidized pulp used for these experiments was prepared by oxidation of conventional waste paper stock (Hoya) according to the procedure for Experiment 1, varying the amounts of laccase (Trametes versicolor, 250 U) and TEMPO in the manner indicated in Table 4:
• the EWZ dewatering time was determined according to ISO Standard 5276 using a Schopper-Riegler tester, by dewatering 1 liter of an aqueous slurry of the fiber composition to be tested with a consistency of 10 g / l in the apparatus and determining the time in seconds required for the Pass of 400 ml of filtrate were needed.

Landscapes

• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Biochemistry (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Microbiology (AREA)
• Paper (AREA)

Priority Applications (1)

Applications Claiming Priority (3)

Publications (1)

Family

ID=44318338

Family Applications (1)

Country Status (5)

Families Citing this family (4)

Family Cites Families (17)

• 2011
  • 2011-05-04 CN CN2011800224242A patent/CN102869830A/zh active Pending
  • 2011-05-04 WO PCT/EP2011/057134 patent/WO2011138366A1/de active Application Filing
  • 2011-05-04 BR BR112012027210A patent/BR112012027210A2/pt not_active IP Right Cessation
  • 2011-05-04 CA CA2795834A patent/CA2795834A1/en not_active Abandoned
  • 2011-05-04 EP EP11716963A patent/EP2567024A1/de not_active Withdrawn

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events