Classifications

• • 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
  • C08B35/08—Oxidised amylopectin
• • 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
• • 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
  • D21H19/00—Coated paper; Coating material
  • D21H19/10—Coatings without pigments
  • D21H19/12—Coatings without pigments applied as a solution using water as the only solvent, e.g. in the presence of acid or alkaline compounds
• • 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
  • D21H19/00—Coated paper; Coating material
  • D21H19/36—Coatings with pigments
  • D21H19/44—Coatings with pigments characterised by the other ingredients, e.g. the binder or dispersing agent
  • D21H19/54—Starch

Definitions

• the present invention relates to the use of amylo ⁇ pectin-type starch or derivatives thereof as a finishing agent in papermaking.
• the present invention relates to the use of amylopectin-type starch obtained from potato that has been modified by genetical engineering, to sup ⁇ press the formation of amylose-type starch.
• the print-receiving surface is treated either by a pure starch solution or by a coating slip.
• traditional starch of any known origin potato, maize, wheat and tapioca
• more than one chemical modification step is required in many cases to obtain a product possessing sufficient stability.
• the various modification steps usually include a stabilising step, for instance an etherification reaction with propene dioxide or an esterification reaction with vinyl acetate or acetic anhydride, and a degradation step, such as oxidation, en- zymatic degradation, acid hydrolysis or so-called ther o- chemical conversion.
• substitution of the starch takes place, and the degree of substitution pertaining to the corresponding stabilising step usually amounts to 0.01 - 0.5 mole/mole glucose, preferably 0.05 - 0.20 mole/mole.
• the object of the present invention is to reduce the number of chemical modification steps necessary to obtain a stable finishing agent for use on paper. This object is achieved by using amylopectin-type starch of the kind out- lined in the introduction, which starch additionally pos ⁇ sesses the characteristics defined in the appended claims. Summary of the Invention
• amylo- pectin-type starch or derivatives thereof thus are used as a finishing agent in papermaking.
• amylopectin-type starch as used throughout in the present application text relates to starch obtained from potato that has been submitted to 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 ⁇ trans amylopectin-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) .
• amylopectin-type starch is added in amounts of 0.5-8% by weight, prefer ⁇ ably 2-6% by weight, during the production process.
• the amylopectin in the starch used in accord ⁇ ance with the invention having strongly reduced amylose contents on account of its branched structure, possesses excellent stability.
• only one chemical reaction is required to produce the finishing agent, and consequently surface-sizing and coating products may be manufactured in a manner that is considerably less harmful to the environment than has hitherto been possible.
• the reason therefor is not only the elimination of the modification step but also that it has become possible to alter the degradation step.
• the amount of oxidising agent required to degrade the amylo- pectin in the starch used in accordance with the inven ⁇ tion is approximately 50% lower than the amount required to degrade traditional potato starch.
• sodium hypochlorite, hydroperoxide or some type of persulphate compound, such as sodium persulphate is used as the degradation chemical.
• amylopectin-type starch As a finishing agent for use on paper. Practical tests have shown, however, that the use of amylopectin- type starch gives surprising and unexpected combined effects inasmuch as it permits the finishing agent to be produced by a simplified as well as environmentally less harmful method.
• Oxidised starch based on potato starch was produced in the following manner. 100 kg potato starch were formed into a slurry in water. The pH-value of the slurry was adjusted to 9.5 by means of sodium hydroxide. 23.4 litres of sodium hypochlorite containing an active substance of 150 g/litre active chlorine were added. The pH-value of the reaction was maintained constant by addition of sodium hydroxide. Once the reaction was complete, i.e. when all chlorine had been used up, the reaction was interrupted by neutralisation, by means of hydrochloric acid, to a pH-value of 5.5, whereupon the product was de ⁇ watered and washed before drying. The following values were obtained from an analysis of the product: Dry contents, % 82 . 4 pH of slurry 8 . 0 pH of solution 6 . 4 Conductivity, ⁇ S/cm 155 Contents of carboxyl, 0 . 87 Viscosity at different tempera attuurreess
• Viscosity at different concentrations Viscosity at different concentrations Viscosity, cP, 50°C, 100 rpm 10% 26
• Example 2 At comparatively high concentration levels (25%) , the product exhibits very poor stability at low tempera ⁇ tures (25°C), and already after the lapse of two h the viscosity is more than doubled. This behaviour is typical in traditional oxidised starches, and these products can only be used at low concentration levels and when the temperature is at least 50°C.
• Example 2 At comparatively high concentration levels (25%) , the product exhibits very poor stability at low tempera ⁇ tures (25°C), and already after the lapse of two h the viscosity is more than doubled. This behaviour is typical in traditional oxidised starches, and these products can only be used at low concentration levels and when the temperature is at least 50°C.
• Oxidised amylopectin starch from potato was produced in the following manner. 100 kg amylopectin-type starch was formed into an aqueous slurry. The pH value of the slurry was adjusted to 9.5 by means of sodium hydroxide. 11.0 litres of sodium hypochlorite containing an active substance of 150 g/litre active chlorine was added. The pH value of the reaction was maintained constant by addition of sodium hydroxide. Once the reaction was completed, i.e. when all chlorine had been consumed, the reaction was interrupted by neutralisation, by means of hydrochloric acid, to a pH value of 5.5, whereupon the product was dewatered and washed before drying. The following values were obtained in an analysis of the product:
• Viscosity at different concentrations Viscosity at different concentrations Viscosity, cP, 50°C, 100 rpm 10% 24
• the stability of the product is highly satisfactory, also at low temperatures (25°C), and the viscosity had increased only marginally after storage of the product for up to 3 days.
• the product may be used without diffi ⁇ culty in high concentrations, also if the temperature is allowed to become lower. This is possible in the case of products having potato starch as its base only if the product is stabilised by an esterification or etherifica ⁇ tion reaction.

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

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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Cited By (5)

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Citations (4)

• 1995
  • 1995-07-17 SE SE9502631A patent/SE504641C2/sv not_active IP Right Cessation
• 1996
  • 1996-07-01 EP EP96924216A patent/EP0796371A1/en not_active Withdrawn
  • 1996-07-01 JP JP9506599A patent/JPH10509220A/ja not_active Ceased
  • 1996-07-01 RU RU97106060/12A patent/RU2160805C2/ru not_active IP Right Cessation
  • 1996-07-01 US US08/793,348 patent/US5994532A/en not_active Expired - Fee Related
  • 1996-07-01 WO PCT/SE1996/000873 patent/WO1997004167A1/en not_active Application Discontinuation
  • 1996-07-01 CZ CZ97802A patent/CZ80297A3/cs unknown
  • 1996-07-01 AU AU64733/96A patent/AU6473396A/en not_active Abandoned

Patent Citations (4)

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