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
  • 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
  • D21H17/675—Oxides, hydroxides or carbonates
• • 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
• • 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
• • 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
  • D21H19/38—Coatings with pigments characterised by the pigments
• • 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
  • D21H19/38—Coatings with pigments characterised by the pigments
  • D21H19/385—Oxides, hydroxides or carbonates

Definitions

• the present invention relates to mineral fillers, pigments or the like containing carbonate Materials.
• Mineral fillers are widely used in papermaking. Your function consists essentially in increasing the opacity of the paper and possibly also its whiteness. Relatively cheap mineral fillers are kaolin clay, ground or precipitated calcium carbonate, Calcium sulfates, etc. These are cheaper than cellulose fibers and reduce the raw material costs of the Paper.
• the mineral fillers influence many other aspects of the Paper such as Weight, volume, porosity, mechanical properties, especially burst strength, Smoothness of the surface and printing properties.
• the total amount of mineral varies Fillers generally between 5 and 25% by weight.
• Kaolin tones were the most commonly used fillers in acidic papers, while calcium carbonates preferred in alkaline papers mainly because of the higher whiteness compared to clays become.
• the coating (coating) of papers requires pigments with optical and rheological properties, which are within very precisely defined limits.
• Wet-made kaolin and wet-milled Natural calcium carbonates are the most commonly used pigments because of their suitable ones Properties, their relatively low price and their availability in large quantities.
• Pigments of this type such as titanium dioxide, calcined clays, Plastic beads, etc. are used for their whiteness and opacity, but are very expensive.
• Wet-ground natural calcium carbonates are widely used and generally are Kaolinen preferred because it has a better whiteness (93 - 95) compared to the whiteness of the Have kaolins (85-90).
• Precipitated calcium carbonates have many properties that make them a coating pigment make usable. They have a high degree of whiteness and can come in a wide variety of particle sizes are manufactured and are available in large quantities at reasonable prices.
• the smoothness, gloss and printing properties of the coated paper are all influenced by the ability to coat the paper at high solids levels, preferably over 70%. This can be achieved with coating pigments alone, the exceptional rheological properties have as newtonian as possible.
• coating pigment slurries with a solids content of 72 are preferred 76% made.
• the final coating color can add something Water can be added.
• PCC precipitated calcium carbonates
• PCC slurries are sometimes used in coating compositions and are called dry Pigments added instead of slurries.
• the amount of PCC used in coating compositions exceeds hardly 50% by weight of the coating pigment.
• Robert A. Gill has "the behavior of on-site synthesized precipitated calcium carbonates and other calcium carbonate fillers on paper properties "in Nordic Pulp and Paper Research Journal No. 2, 1989 described.
• An object of the present invention is therefore carbonate-containing mineral fillers, pigments or provide similar materials, both as paper filler, especially filler for the Paper pulp as well as a coating pigment, in particular coating pigment, can be used advantageously can.
• the steepness factor preferably has a value of 1.2 to 1.4.
• the R value is preferably 13.
• the BET specific surface area preferably has a value of 6 m 2 / g to 13 m 2 / g, preferably 12 m 2 / g.
• the upper cut preferably has a value of 4 to 7 ⁇ m, in particular 4 ⁇ m.
• the mean statistical particle diameter is preferably 0.5 to 0.9 ⁇ m, more preferably 0.6 to 0.8 ⁇ m and optimally 0.7 ⁇ m.
• the degree of whiteness is preferably> 95.
• the upper cut is preferably between 4 and 7 ⁇ m, preferably 4 ⁇ m.
• Preferably 70 or 95% of the particles are less than 1 ⁇ m.
• Preferably 1 to 7% of the particles are below 0.2 ⁇ m.
• the measured particle distribution is displayed on an X-Y plotter as a total curve (see e.g. Belger, P., Swiss Association of Lacquer and Paint Chemists, XVIIth FATIPEC Congress, Lugano, September 23-28, 1984), with the particle diameter of one on the X axis corresponding spherical diameter and on the Y axis the proportion of the particles in% by weight is applied.
• the product according to the invention was not only designed to provide better chemical and maintain physical properties of paper fillers and coating pigments, but also in order to do justice to the modern paper machines running at very high speed to be able to.
• the products according to the invention can be processed in a manner known per se in such a way that the parameters required according to the invention are achieved. This can be done, for example, by dry grinding and subsequent classification according to particle size using wind sifting. However, within the scope of the invention it is also possible to produce wet-ground or precipitated carbonate-containing mineral fillers, pigments or similar materials with the properties according to the invention.
• the calcium carbonate according to the invention can either be natural ground calcium carbonate or precipitated calcium carbonate, the combination of chemical or physical features according to the invention always being observed.
• the steepness factor is expressed by the ratio Particle diameter in ⁇ m at 50% by weight Particle diameter in ⁇ m at 20% by weight
• This steepness factor is already known from US Pat. No. 4,767,464.
• This patent describes a calcium carbonate with a slope factor of 1.2-2.1 and a fraction of 30 to 98% by weight of particles in the particle diameter range from 0.5 to 1.8 ⁇ m.
• This patent does not describe the specific surface area, the ratio R (see above) and the particle shape as well as the length / width ratio of the particles which play an essential role for the present invention.
• a typical product according to the invention has 50% of the particles below 0.7 ⁇ m and 20% of the particles less than 0.5 ⁇ m.
• Another typical product according to the invention has 50% of the particles below 0.5 ⁇ m and 20% of the Particles under 0.4 ⁇ m.
• Tables III and IIIa show a product according to the invention in comparison to three State-of-the-art products with regard to maximum filling level and opacity, where other physical measurements such as tensile strength etc. are not essential due to the higher degree of filling to be influenced.
• a base paper was used for the coating tests with a composition of sulfate pulp wood-free, 20% by weight pine, 80% by weight birch, freeness 23 ° SR and 20% CaCO 3 No. 3.
• the coating color composition 100 parts calcium carbonate 10.5 parts styrene acrylate latex 0.5 parts carboxymethyl cellulose Solids content 67% (adjusted with water) pH 9 (adjusted with 5% sodium hydroxide solution) and the coating condition Laboratory coater (blade coater) Order quantity 12g per m 2 Coated page: top of screen Paper moisture after brushing: 5.5% used with the following satin condition: Small Wefers-2 roll laboratory calender 4 passes, at 70 Dean Newtons per cm, roller temperature 80 ° C.
• the gloss measurement was carried out in accordance with Tappi standard T 480 OM-90 angle 75 °.
• the calcium carbonate measured is natural ground calcium carbonate.
• a calcium carbonate according to the invention showed unexpectedly good properties as a coating pigment with regard to rheology with a high solids content and with regard to gloss in the coated paper.
• Table IV contains typical calcium carbonates according to the invention.
• precipitated calcium carbonates (as an aqueous slurry) used as a paper filler, especially to improve opacity and on the other hand, natural ground calcium carbonates are used as coating pigments, to take advantage of their good rheology.

Landscapes

• Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Paper (AREA)
• Pigments, Carbon Blacks, Or Wood Stains (AREA)
• Paints Or Removers (AREA)
• Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Cosmetics (AREA)
• Color Printing (AREA)

Applications Claiming Priority (2)

Publications (3)

Family

ID=6439338

Family Applications (1)

Country Status (10)

Families Citing this family (32)

Family Cites Families (12)

• 1991
  • 1991-08-28 DE DE4128570A patent/DE4128570A1/de not_active Withdrawn
• 1992
  • 1992-07-23 NZ NZ243684A patent/NZ243684A/en unknown
  • 1992-07-24 DE DE59204666T patent/DE59204666D1/de not_active Expired - Lifetime
  • 1992-07-24 AT AT92112697T patent/ATE131557T1/de not_active IP Right Cessation
  • 1992-07-24 ES ES92112697T patent/ES2083029T5/es not_active Expired - Lifetime
  • 1992-07-24 EP EP92112697A patent/EP0531685B2/de not_active Expired - Lifetime
  • 1992-08-06 AU AU20861/92A patent/AU657341B2/en not_active Expired
  • 1992-08-26 KR KR1019920015446A patent/KR960006798B1/ko not_active IP Right Cessation
  • 1992-08-27 US US07936269 patent/US5292365B1/en not_active Expired - Lifetime
  • 1992-08-27 MX MX9204944A patent/MX9204944A/es not_active IP Right Cessation
  • 1992-08-27 JP JP4228410A patent/JPH0778147B2/ja not_active Expired - Lifetime

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