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
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
  • C08B35/00—Preparation of derivatives of amylopectin
  • C08B35/04—Ethers
• • 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
  • D21H17/34—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
• • 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 present invention relates to the use of amylo- pectin-type cationic starch obtained from potato as a retention-improving agent in papermaking. More precisely, the invention relates to the use of amylopectin-type cationic starch obtained from potato that has been modi ⁇ fied by genetic engineering to suppress the formation of starch, or derivatives thereof, in order to increase the retention in papermaking. The invention further relates to a complex between the cationic starch of amylopectin type and an anionic component.
• the expression "retention” relates to the proportion of a component present in an original mixture which remains in the mixture at some stage of the process or in the final product.
• starch In conventional use of cationic starch within the papermaking industry the starch must be dissolved either by batchwise cooking for approximately 20 min at 95°C while being comparatively vividly stirred, or by continu- ous cooking in a so-called jet digester at 110-130°C.
• the object of the present invention is to eliminate the above-mentioned problem by using an agent furthering high retention, satisfactory dewatering, and high strength development. This object is obtained by the use of a retention-improving agent of the kind mentioned in the introduction, which agent exhibits the characteristics defined in the appended claims. Summary of the Invention
• amylo ⁇ pectin-type starch or derivatives thereof thus are used as a retention-improving agent in papermaking.
• amylopectin-type starch as used throughout in the present application text relates to starch obtained from potato that has been modified by genetical engineering in order to suppress the formation of amylose-type of starch.
• derivatives thereof relates to chemically, physically and/or enzy ⁇ matically derivatised amylopectin-type starch.
• the amy ⁇ lopectin content of amylopectin-type starch is in excess of 95%, preferably in excess of 98%.
• the remaining ingre-ist-ist-type starch is amylose.
• amylopectin-type starch and derivatives thereof and the methods of their production is found in the Swedish Patent Specification 9004096-5 (Amylogene HB) .
• the expression "retention-improving agent" as used throughout in this application concerns an agent which in addition to producing increased retention also produces improved dewatering and strength development in paper ⁇ making.
• the amylopectin-type starch Prior to its use in accordance with the present in ⁇ vention the amylopectin-type starch should be substituted by cationic groups by chemical modification. Ammonium compounds are used for this purpose, which compounds preferably are quaternary but could also be primary or tertiary.
• the chemical composition of the stock system used in the papermaking determines the degree of substi- tution of the amylopectin-type starch required to obtain optimum results.
• the degree of substitution thus lies between 0.01 and 0.30 (between 0.09 and 2.5%, calculated in the corresponding manner with respect to nitrogen) , preferably between 0.02 and 0.20 (between 0.18 and 1.6%, calculated in the corresponding manner with respect to nitrogen) .
• the preparation of the cationic starch of amylo ⁇ pectin type is important, since the solubility curve of amylopectin-type starch deviates strongly from that of traditional potato starch.
• the dissolution of the cationic starch of amylopectin type should be effected with a minimum of shearing, batchwise or continuously, in the temperature range of 60-130°C, preferably in the tem ⁇ perature range of 65-95°C.
• This dissolving method pro- Jerusalem a solution of amylopectin-type starch the molecular weight of which is maintained, while at the same time the solution is free of swelled granules or residues thereof.
• the result is a well digested solution producing high retention and rapid dewatering, despite a lower energy supply than that required in the preparation of tradi ⁇ tional cationic starch.
• the cationic starch of amylopectin type is added to the stock while being sufficiently stirred to ensure that it is well admixed therein prior to the paper formation.
• the cationic starch of amylopectin type is com ⁇ bined with an anionic component, such as colloidal silicic acid, anionic polyacrylamide or bentonite, and in this case the components are added individually while being sufficiently stirred to ensure that they can inter ⁇ act and act together with the other components of the stock.
• the amounts of the additives required to reach the desired effect depend on the composition of the stock. Suitable additions of the cationic starch of amylopectin type are 1-50 kg/ton paper, preferably 1-20 kg/ton paper.
• the present invention provides highly improved retention levels with respect to the added filling agent as well as to the fine fractions of the fibrous material.
• the dewatering times in the wet end of the papermaking machine used can be kept brief, de ⁇ spite the fact that the amylopectin-type starch has been dissolved to provide maximum retention, i.e. its viscos- ity level is maximum.
• An additional advantage provided by the present invention is that it is applicable to all types and qualities of paper and cardboard products.
• Cationic starch of amy ⁇ lopectin type having a degree of substitution of 0.05 was compared with a traditional cationic potato starch having the same degree of substitution.
• the cationic amylopectin and the cationic starch were dissolved at a number of various temperature levels in the range of 60-130°C, and the added quantities amounted to 2.5, 5.0, 10.0 and 15.0 kg/ton, respectively.
• Cationic starch of amylopectin type having a degree of substitution of 0.05 was compared with traditional cationic potato starch having the same degree of substitution.
• the cationic starch of amylopec ⁇ tin type and the traditional cationic starch were dis- solved at several temperature levels in the range of 60- 130°C and the added quantities amounted to 2.5, 5.0, 10.0 and 15.0 kg/ton, respectively.
• the tests show that the cationic starch of amylopectin type that had been dis- solved to give maximum retention also maintains rapid dewatering conditions contrary to the case of traditional cationic starch, the latter impairing dewatering under the same conditions.
• Example 3 To evaluate the adsorption of the cationic starch of amylopectin type to a stock, laboratory studies were car ⁇ ried out in a DDA apparatus. The pulps contained in the stock consisted to 50% of fully bleached chemical hardwood pulp and to 50% fully bleached chemical softwood pulp, ground to 25°SR. To the stock was added 40% chalk as a filling agent. The pH value of the stock was adjusted to 8.2 and the conductivity was 600 ⁇ S. Prior to the tests in the DDA apparatus the stock was diluted to a concentration of 2 g/litre. Cationic starch of amylopectin type having a degree of substitution of 0.05 was compared with tradi ⁇ tional cationic potato starch having ' the same degree of substitution.
• the cationic starch of amylopectin type and the traditional cationic starch were dissolved at a number of different temperature levels in the range of 60-130°C and the added quantities amounted to 2.5, 5.0, 10.0 and 5.0 kg/ton, respectively.
• the amounts of amylopectin and of starch retained in the pulp cake were determined by means of a method according to which the polymer is de ⁇ graded into glucose by two enzymes. The detection of glucose presence is then effected in a HPLC system.
• the cationic starch of amylopectin type possesses, as mentioned in the foregoing, unique properties inasmuch as it may be pre- pared in such a manner that high retention and satisfac ⁇ tory dewatering are obtained, but it likewise possesses considerable adsorbability of its own.
• a cationic starch of amylopectin type having a degree of substitution of 0.05 was compared with a tradi ⁇ tional cationic potato starch having the same degree of substitution.
• the cationic starch of amylopectin type and the traditional cationic starch were dissolved at a number of various temperature levels in the range of 60- 130°C and the added quantities amounted to 2.5, 5.0, 10.0 and 15.0 kg/ton, respectively.
• colloidal sil ⁇ icic acid was added to ensure that the ratio of respec- tively cationic starch of amylopectin type and tradi ⁇ tional cationic starch to colloidal silicic acid ranged from 1.5:1 to 10:1.
• Optimum preparation and additions of the cationic starch of amylopectin type and of the tradi ⁇ tional cationic potato starch, respectively, and of the colloidal silicic acid gave an improvement of the total retention of 25% and of the filling agent retention of approximately 70% when the cationic starch of amyloectin type was used.
• Example 5 To evaluate the interaction between the cationic starch of amylopectin type and anionic components, and the effects of retention, laboratory studies were carried out in a DDA apparatus.
• a colloidal silicic acid was used as the anionic component.
• the pulps contained in the stock consisted to 50% of fully bleached chemical hard ⁇ wood pulp and to 50% of fully bleached chemical softwood pulp ground to 25°SR.
• To the stock was added 40% chalk as a filling agent.
• the pH value of the stock was adjusted to 8.2 and the conductivity was 600 ⁇ S.
• Prior to the tests in the DDA apparatus the stock was diluted to a concentration of 2 g/litre.
• the drainage times were meas- ured automatically by the instrument and the results were registered by a computer.
• a cationic starch of amylopec ⁇ tin type having a degree of substitution of 0.05 was com ⁇ pared with traditional cationic potato starch having the same degree of substitution.
• the cationic starch of amy- lopectin type and the traditional cationic starch were dissolved at a number of various temperature levels in the range of 60-130°C and the added quantities amounted to 2.5, 5.0, 10.0 and 15.0 kg/ton, respectively.
• the addition of colloidal silicic acid was sufficient to ensure that the ratio of respectively cationic starch of amylopectin type and traditional cationic starch to col ⁇ loidal silicic acid ranged from 1.5:1 to 10:1.
• Cationic starch of amylopectin type having a degree of substitution of 0.05 was compared with traditional cati ⁇ onic potato starch having the same degree of substitu ⁇ tion.
• the cationic starch of amylopectin type and the traditional cationic starch were dissolved at a number of various temperature levels ranging from 60 to 130°C and the added amounts were 2.5, 5.0, 10.0 and 15.0 kg/ton, respectively.
• colloidal silicic acid was sufficient to ensure that the ratio of cationic starch of amylopectin type and traditional cationic starch, respec- tively, to colloidal silicic acid ranged from 1.5:1 to 10:1.
• the amounts of respectively amylopectin and of starch retained in the stock cake were determined by a method according to which the polymers were degraded into glucose by two enzymes. Detection of glucose presence is then carried out in a HPLC system. These studies show the importance of high viscosity (molecular weight) in order to obtain a high degree of adsorption.
• the anionic compo ⁇ nent contributes to increased adsorption of the cationic starch of amylopectin type to a higher extent than in combination with traditional cationic starches.

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• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Biochemistry (AREA)
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• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
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• 1995
  • 1995-07-17 SE SE9502630A patent/SE513411C2/sv not_active IP Right Cessation
• 1996
  • 1996-07-01 RU RU97106074/12A patent/RU2160806C2/ru not_active IP Right Cessation
  • 1996-07-01 JP JP9506600A patent/JPH10509221A/ja not_active Ceased
  • 1996-07-01 EP EP96924217A patent/EP0796372A1/en not_active Withdrawn
  • 1996-07-01 AU AU64734/96A patent/AU6473496A/en not_active Abandoned
  • 1996-07-01 CZ CZ97801A patent/CZ80197A3/cs unknown
  • 1996-07-01 WO PCT/SE1996/000874 patent/WO1997004168A1/en not_active Ceased

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