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
  • D21H17/20—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
• • 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
  • D21H17/46—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H17/54—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen
  • D21H17/55—Polyamides; Polyaminoamides; Polyester-amides
• • 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
  • D21H17/69—Water-insoluble compounds, e.g. fillers, pigments modified, e.g. by association with other compositions prior to incorporation in the pulp or paper

Definitions

• This invention relates to a process of sizing of cellulosic fibrous material which is to be formed into sheet products, and more particularly to such a process in which the size used is based on rosin.
• Cellulosic fibrous material which is to be formed into sheet products such as paper, cardboard, paperboard and the like is generally sized such that the final sheet has stiffness and can readily accept printing inks.
• Conventional sizing processes have generally used sizes based on rosin. In a typical process, a size which is based on a rosin acid emulsion or soap is added at the paper machine wet-end.
• a cationic substance This is usually an aluminium salt (the sulphate and the chloride are the most commonly used). This, it is believed, precipitates the rosin acids on to the cellulosic fibres and there forms with them a rosinate complex.
• a process of sizing at a pH of 6-10 a cellulosic fibrous material adapted to be used in the formation of a sheet comprising the addition to the material at the wet-end stage of a sizing material and a cationic material which cationic material is a powdered water-insoluble aluminium compound on the surface of which is present a substance which is cationic at pH 6-10.
• the aluminium compound has initially the form of particles of a fine, free-flowing powder.
• the use of such powders is important to the invention. It has been proposed that dispersions of very fine gelatinous precipitates of aluminium hydroxide be prepared in situ . Such dispersions are not suitable for use in this invention for a number of reasons, including the following:
• aluminium compounds useful in the working of this invention are water-insoluble or at most sparingly water-soluble.
• Suitable compounds include the oxide, hydroxide, diacetate, carbonate and oxalate, the preferred material being the hydroxide (Al(OH)3). It is permissible to use two or more such compounds. All of the compounds are available as free-flowing powders.
• the aluminium compound to be used preferably has a particle size in the range of from 0.5-10 ⁇ m, preferably 1-10 ⁇ m, more preferably 1-5 ⁇ m, most preferably 1-2 ⁇ m. With some exceptions, commercially-available powders are coarser than this, but the appropriate size can readily be achieved by use of conventional wet grinding apparatus such as bead mills.
• the cationic substance which is present on the surface of the aluminium compound particles may be selected from any suitable substances which are cationic at pH 6-10, more preferably 6-9 and most preferably 7-8, and which may be attached to the surface of the aluminium compound particles. Again, two or more such substances may be used. Any known method of attaching a cationic substance to an aluminium compound particle may be used. One method of attachment is simple adsorption, and many cationic substances will adsorb on to the particles when cationic substance and particles are blended. Alternatively, there may be used intermediate compounds which attach particle and cationic substances to each other.
• the preferred cationic substances are polymeric and may be based on a number of chemistries, which include cationic polyacrylamides, polyethyleneimines, polydialkyl dimethylammonium chloride, polyamides and amine/epichlorhydrin and dicyandiamide/formaldehyde condensates.
• the most preferred cationic substances are polytertiary amine and polyquaternary ammonium compounds.
• suitable cationic materials may be found in the "Cartafix” (trade mark) range of Sandoz Ltd., for example "Cartafix” TE and "Cartafix” DPR.
• the ratio of insoluble aluminium compound to cationic substance is from 1:0.001 to 1:0.2 (based on the dry weights of both materials), more preferably 1:0.00 1 to 1:0.1.
• the sizing materials for use in this invention may be selected from any known sizing materials, be they natural or synthetic.
• Suitable sizing materials include colophony, animal size, casein, starch, waxes, fatty acids and tall resins.
• synthetic sizes especially suitable products are those based on ketene dimers, polyvinyl alcohols or polyvinyl acetates.
• modified resin sizes such as are obtained, for example, by reacting colophony with dienophilic acids, a typical example of such a product being commercially available under the trade name "RLE 30" (Roe Lee Paper Chemicals).
• rosin-based sizing materials known tothe art may be used, for example, rosinate soaps, rosin acid emulsions and cationic and nonionic rosin preparations.
• the sizing material and the cationic material are added at a suitable stage in the wet-end.
• the process of the invention is no different from the known art and any suitable stage may be chosen.
• the cationic material is added as an aqueous dispersion of particles and is dispersed therein.
• the invention encompasses both the solid and aqueous dispersion forms of the cationic compound as novel compositions of matter.
• the preferred ratio of cationic material to sizing material is from 1:0.1 to 1:10.0, preferably 1:0.1 to 1:5.0, based on the weight of the dry aluminium compound and the weight of dry sizing material.
• the sizing material is added at a rate of from 0.1 - 2.0%, preferably from 0.2-0.5% by weight of dry cellulosic fibre.
• the sizing material and the cationic material may be added in any order, but the preferred order is sizing material first, followed by cationic material.
• pigments and fillers are examples of materials commonly used in the art.
• All fillers and pigments conventionally used in the manufacture of paper can be used in the process according to the present invention, for example, kaolin, aluminium silicate, calcium silicates, oxyhydrates of aluminium, talcum, satin white, gypsum, barium sulphate, calcium carbonate, magnesite, zinc oxide, titanium dioxide.
• calcium carbonate which may be natural calcium carbonate in finely divided form or precipitated calcium carbonate, is preferred because its degree of whiteness is superior, for example, to that of kaolin, and its favourable flow behaviour permits the achievement of especially high degrees of filling in the paper. In this way, the properties of the paper are also positively influenced; the opacity is increased, the degree of whiteness is improved, the resistance to aging is increased and the mechanical properties are improved.
• One interesting and unexpected aspect of this invention is the ability of the cationic material to neutralize the adverse effects of anionic species which may be present in the wet-end-in the terminology of the art, it can act as a "trash quencher". It has this effect when used in conjunction with a sizing material according to the invention or when used alone. In the former case, it is permissible to exceed the preferred ratio of cationic material to sizing material given hereinabove, the excess cationic material acting as a "trash quencher".
• the invention therefore provides a method of neutralizing the adverse effects of undesirable anionic species present in a cellulosic fibre pulp, comprising the addition thereto of a quantity of an aqueous slurry of a cationic material as hereinabove described sufficient to effect said neutralization.
• the process of the invention has several advantages. It permits the use of the well-known and cheap rosin-based sizes and chalk filler, yet it is a process conducted at neutral or mildly alkaline pHs. The result is a paper which is of better appearance and printability and which lasts much longer.
• the invention therefore provides a sized sheet of cellulosic fibrous material, produced by a process as hereinabove described.
• the process has the additional advantage of being able to work with pulps containing high levels of undesirable anionic species.
• the cationic compounds for use in the process of this invention are readily made from inexpensive materials.
• the slurry is milled at a speed of 3000 rpm for 20 minutes, after which time the mean particle size is 2 to 5 ⁇ m and the viscosity 560 mPa (Brookfield viscometer, spindle 3, speed 100 rpm).
• the yield is 300 parts.
• a bleached cellulose pulp comprising 50% sulphate softwood and 50% sulphate hardwood is refined at 4% consistency to a freeness of 35°SR and then diluted with water to 2% (dry weight). To 3 parts (dry weight) aliquots of this pulp slurry are added various levels of rosin acid (RLE 30), followed 60 sec. later by different amounts of the cationic material whose preparation is described hereinabove. The pH of the slurry is adjusted to 7.5 with dilute sodium hydroxide.
• the yield of the slurry is 300 parts.
• Hand sheets are made according to the method of Example 1(b), using varying proportions of the resin size of that Example and the slurry whose preparation is described hereinabove.
• the Cobb values obtained are as follows: Rosin Size (solids/fibre) Cationic slurry (solids/fibre) Cobb (60 s) 0.3% 0.2% 26.3 0.3% 0.3% 23.7 0.5% 0.3% 21.4 0.5% 0.4% 20.2
• Hand sheets are made as described in Example 1 (b), keeping the level of size constant at 0.2% and varying the amount of cationic compound.
• the Cobb values obtained are as follows. Rosin Size (%) (solids/fibre) Cationic Slurry (%) (solids/fibre) Cobb (60) (g/m2) 0.2 0.05 22.7 0.2 0.10 15.2 0.2 0.30 14.9 0.2 0.50 15.9 0.2 1.00 16.0

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Inorganic Chemistry (AREA)
• Paper (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=10702061

Family Applications (1)

Country Status (9)

Cited By (2)

• 1991
  • 1991-09-27 GB GB919120564A patent/GB9120564D0/en active Pending
• 1992
  • 1992-09-22 EP EP92810722A patent/EP0534906A1/fr not_active Withdrawn
  • 1992-09-24 CA CA002079074A patent/CA2079074A1/fr not_active Abandoned
  • 1992-09-25 ZA ZA927395A patent/ZA927395B/xx unknown
  • 1992-09-25 FI FI924325A patent/FI924325A/fi not_active Application Discontinuation
  • 1992-09-25 JP JP4256723A patent/JPH05222694A/ja active Pending
  • 1992-09-25 BR BR929203767A patent/BR9203767A/pt not_active Application Discontinuation
  • 1992-09-25 MX MX9205456A patent/MX9205456A/es unknown
  • 1992-09-25 AU AU25394/92A patent/AU2539492A/en not_active Abandoned

Non-Patent Citations (1)

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