EP0740014A1 - Agent amélioré pour le contrÔle de la poix - Google Patents

Agent amélioré pour le contrÔle de la poix Download PDF

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Publication number
EP0740014A1
EP0740014A1 EP96301664A EP96301664A EP0740014A1 EP 0740014 A1 EP0740014 A1 EP 0740014A1 EP 96301664 A EP96301664 A EP 96301664A EP 96301664 A EP96301664 A EP 96301664A EP 0740014 A1 EP0740014 A1 EP 0740014A1
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EP
European Patent Office
Prior art keywords
polymer
pitch control
control agent
pitch
coated
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Application number
EP96301664A
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German (de)
English (en)
Inventor
Keith Robert Rogan
Roderick Michael Plasted
John Michael Adams
Paul Alan Rey
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Imerys Minerals Ltd
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ECC International Ltd
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Publication date
Application filed by ECC International Ltd filed Critical ECC International Ltd
Publication of EP0740014A1 publication Critical patent/EP0740014A1/fr
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    • 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
    • D21H21/02—Agents for preventing deposition on the paper mill equipment, e.g. pitch or slime control
    • 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
    • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
    • D21C9/08—Removal of fats, resins, pitch or waxes; Chemical or physical purification, i.e. refining, of crude cellulose by removing non-cellulosic contaminants, optionally combined with bleaching
    • D21C9/086—Removal of fats, resins, pitch or waxes; Chemical or physical purification, i.e. refining, of crude cellulose by removing non-cellulosic contaminants, optionally combined with bleaching with organic compounds or compositions comprising organic compounds

Definitions

  • This invention relates to a pitch control agent suitable for incorporation in cellulose pulp compositions, to reduce the adverse effects of the deposition of pitch derived from wood pulp in the manufacture of paper and board, and to a process for controlling the deposition of pitch.
  • Pitch is the name given by paper manufacturers to the substance, derived from colloidally dispersed components of wood resin, which deposits on the wire mesh belts, or "wires", of paper making machines and on the rolls and dewatering felts.
  • the components of wood resin are released into pulp and paper mill circulatory waters at the pulping stage of the papermaking process. In these waters they have a transitory existence as an unstable oil-in-water emulsion. In a short time coalescence occurs followed by deposition.
  • the pitch deposits are sticky and can block holes in the wire thus reducing drainage through the wire, and can also reduce the absorptive capacity of the felt. They can pick fibres from the formed paper web, often causing holes or weak areas, and occasionally appear in the paper as brown lumps or patches.
  • Pitch is a mixture of chemical compounds of which the principal components which can be extracted by means of organic solvents are organic acids, for example fatty and resin acids (such as oleic acid), and neutral organic material, for example fats (such as triolein).
  • organic acids for example fatty and resin acids (such as oleic acid)
  • neutral organic material for example fats (such as triolein).
  • the effectiveness of a pitch control agent can be determined in the laboratory by investigating the uptake of triolein and/or oleic acid by the agent.
  • Both hardwoods and softwoods contain fatty acids and neutral organic materials, but only softwoods contain significant amounts of resin acids. This latter material occurs in wood mainly in the ray cells and resin canals or ducts. Therefore, softwoods or gymnosperms such as pine, spruce and fir, in general cause more serious pitch problems than hardwoods, such as birch, maple, oak and poplar. Certain species of pine are particularly rich in resin acids.
  • the process by which the paper pulp is prepared is also important.
  • the wood may be reduced to pulp by mechanical grinding alone, or with the aid of a chemical cooking process.
  • the two most important chemical cooking processes are the sulphite process in which the ground wood is cooked in an acid solution of calcium bisulphite saturated with sulphur dioxide, and the sulphate or Kraft process in which the cooking is performed in an alkaline solution comprising sodium hydroxide, sodium sulphide and sodium hydrosulphide.
  • pulp is prepared by the sulphate process the pitch problem is less severe than when the pulp is prepared by the mechanical or sulphite processes because, in the sulphate process, the cooking solution is alkaline and most of the pitch-forming material is saponified and removed in solution by washing.
  • adsorbent material which will adsorb the pitch in the form of small droplets, generally smaller than about 2 ⁇ m in diameter.
  • Adsorbent materials used for this purpose include bentonite, talc and diatomaceous silica.
  • the pitch is chemically stabilised so that it remains in suspension in process water and is removed from the process.
  • EP-A-0569085 describes a method for inhibiting the deposition of pitch and "stickies" on the surfaces of pulping and paper making machinery and/or for removing the deposits therefrom, wherein an effective amount of a melamine-aldehyde type polymer is added to a pulp slurry or furnish in contact with the machinery.
  • EP-A-0232015 describes a method for the control of pitch in an aqueous system used during pulp or paper making wherein there is added to the system or to the pulp or paper making machinery a water-soluble, polyquaternary branched polymer derived from (a) an epihalohydrin, a diepoxide or a precursor for an epihalohydrin or a diepoxide; (b) an alkyl amine having a functionality with respect to an epihalolydrin of 2; and (c) an amine which has a functionality with respect to a epihalolydrin greater than 2 and which does not posses any carbonyl groups.
  • US-3582461 concerns the use as a pitch control agent of water-soluble di-cyandiamide-formaldehyde condensates.
  • Zirconium chemicals have also been used to control pitch. See, for example, U.S. Pat. No. 4,950,361.
  • the purpose of the present invention is to provide a pitch control agent which is more effective than the agents used in the prior art in the control of pitch in a pulping and/or paper making process.
  • a method of controlling the deposition of pitch in a pulping and/or paper making process which comprises adding a pitch control agent to a stream or slurry of cellulosic fibres and characterised in that the pitch control agent comprises a particulate inorganic material comprising at least one silicon-containing compound whose particles are coated with a coating material comprising a nitrogen-containing polymer having one or more triazine rings.
  • paper includes all paper related products made in a manner similar to paper by processing of cellulosic fibres derived from pulp.
  • a pitch control agent for use in the method according to the first aspect which agent comprises a particulate inorganic material comprising at least one silicon-containing compound whose particles are coated with a coating material comprising a nitrogen-containing polymer having one or more triazine rings.
  • the method according to the first aspect may provide inhibition of pitch deposits on and/or removal of pitch deposits from pulping and/or paper making machinery or equipment.
  • the stream or slurry to which the said pitch control agent is added may comprise for example a furnish, stock or other paper making stream or slurry which contacts the surface of the machinery or equipment to be protected from pitch build-up.
  • the said nitrogen-containing polymer may comprise a homopolymer or alternatively it may comprise a co-polymer comprising one or more nitrogen-containing monomer units and one or more other cationic monomer units. Any suitable cationic monomer unit may be used; an example is diallyldimethylammonium chloride (dadmac).
  • inorganic silicon-containing compounds are relatively ineffective as pitch control agents in pulping and paper making.
  • polymers containing triazine rings generally have only a moderate capacity for adsorbing pitch.
  • the capacity of the polymer to adsorb pitch is unexpectedly increased to a large degree.
  • the particulate inorganic material should have surfaces which provide negatively charged sites which ionically bond with positively charged sites on the polymer molecule to provide suitable particle coatings.
  • the silicon-containing compound or compounds may be silica or a silicate of, for example, calcium, magnesium or aluminium.
  • the compound(s) may be provided by a naturally-occurring mineral, eg. selected from talc, clay minerals, mica or wollastonite, and/or may be synthetic.
  • the or each silicon-containing compound present is an aluminosilicate, for example a clay mineral of the kandite or smectite type.
  • Clay minerals of the kandite group for example kaolinite, dickite, nacrite and halloysite, have been found to be particularly advantageous.
  • the kandite clay mineral may be used in its natural hydroxylated or hydrous state, or may be calcined to drive off chemically combined water. Such a mineral may comprise a mixture of clay compounds.
  • kaolin either calcined or uncalcined, having a particle size distribution such that at least 80%, preferably at least 90% by weight, have an equivalent spherical diameter of less than 2 microns (micrometres) is employed to provide the particulate inorganic material.
  • Kaolin which has not been treated during processing by chemical additives, eg. dispersants, is prefered.
  • the particles of the kaolin or other silicon-containing inorganic particulate material to be polymer-coated have a specific surface area which is greater than 12m 2 /gm in order to maximise the surface area to be coated by the polymer.
  • the amount of the nitrogen-containing polymer material used to coat the particulate inorganic material has been found to be critical, but varies according to the nature of the inorganic material.
  • kandite clays which are of relatively low cation exchange capacity, require from 0.5 to 1.5% by weight, preferably from 0.7 to 1.3% by weight, based on the weight of the clay(s) present, of the nitrogen-containing polymer.
  • the nitrogen containing polymer may be a polymer of the melamine-aldehyde type.
  • a melamine-aldehyde type polymer is a polymer formed from: (a), melamine or a substituted melamine; and (b) a compound described by the following formula: wherein R 1 and R 2 , which may be the same or different, are selected from the group consisting of H and straight or branched C 1-4 alkyl groups.
  • EP-A-0569085 gives examples of suitable polymers.
  • the nitrogen-containing polymer preferably comprises the amino derivative of a triazine and the aldehyde in a molar ratio of 1:1 to 1:6.
  • the molecular weight (which is the weight average molecular weight) of the polymer is preferably in the range from 500 to 50,000, most preferably in the range from 500 to 5,000.
  • Suitable melamine aldehyde-type polymers are commercially available from Calgon Corporation, Pittsburgh USA, under the tradenames CA-289 and WT-2511 and SURROUND. These products have molecular weights of about 2,000 to 5,000.
  • the nitrogen-containing polymer will have a cationicity which varies with pH. This will affect the physical form of the polymer. At very low pH values the polymer will exist for months as discrete, highly stable colloidal particles with a high level of hydrophilicity. On the other hand, at high pH values the catonicity of the polymer is insignificant giving a very low level of hydrophilicity (ie., a high level of hydrophobicity). This produces almost instantaneously a network of flocculated particles. In consequence, the uptake of the polymer by the anionic sites present on the particles of the inorganic particulate material will vary with pH. Significant uptake will occur over a pH range which will be generally from pH1 to pH7.
  • the uptake will reach a maximum at a particular pH value in this range.
  • the up take of melamine formaldehyde by kaolin is significant over the range pH3 to pH7 and reaches a maximum at about pH5.
  • the coating of the inorganic particulate material by the nitrogen-containing polymer should be carried out using a process in which the pH of the polymer when it contacts the inorganic particulate material is maintained in the range pH1 to pH7.
  • the polymer may be present in a medium having a lower pH, eg. in the range pH1 to pH4, when it is applied to coat the inorganic particulate material so that it is in an appropriate colloidal form.
  • the polymer may be added in the form of a colloidal suspension in a suitable acidic aqueous medium.
  • a method of preparing a pitch control agent having a particulate inorganic material comprising at least one silicon-containing compound coated with a nitrogen-containing polymer having one or more triazine rings comprises mixing an aqueous suspension of the particulate inorganic material with a solution or suspension comprising the nitrogen containing polymer.
  • the pH of the solution or suspension comprising the nitrogen-containing polymer is adjusted to a value such that the polymer is present in the form of colloidal particles before the solution or suspension is added to the aqueous suspension.
  • the pH may for example be not greater than than pH4, eg. pH1 to pH4.
  • the polymer may be present as a colloidal suspension in an acidic aqueous medium.
  • the polymer may form from 1% to 20%, eg. from 5% to 15%, by weight of the solution or suspension containing it (prior to addition to the suspension containing the inorganic particulate material).
  • the aqueous suspension of the particulate inorganic material may include one or more additives normally employed in the preparation of such suspensions.
  • the suspension may incorporate a dispersing agent such as a sodium polyacrylate (up to about 2% by weight of the dry weight of particulate material present).
  • the product formed by mixing of the two components ie. suspension of particulate inorganic material and solution or suspension of nitrogen-containing polymer, may be further treated to enhance the pitch control capacity of the product.
  • the product of the said mixing step may be dewatered and/or dried so that the water content of the polymer-coated inorganic particulate material is preferably less than 10%, most preferably less than 2% by weight.
  • Dewatering may be achieved in one of a number of ways well known to those skilled in the art, eg. filtration or centrifugation. Drying may conveniently be performed at an elevated temperature, eg. in the range 30°C to 150°C using a current of gas, eg. air or an inert gas such as nitrogen.
  • the product of the said mixing step in the method of the third aspect may be heated without incurring substantial loss of water therefrom.
  • the capacity of the polymer coated particulate inorganic material to adsorb pitch is likewise increased still further when the nitrogen-containing polymer has been coated on to the particulate inorganic material by a process which includes a step in which a suspension of a mixture of the two components is subjected to heating.
  • This heating step is conveniently performed at a temperature in the range of from 30°C to 100°C, and without substantial loss of water from the suspension, such that the solids content of the suspension remains substantially constant throughout the heating step.
  • the heating step is most preferably performed at a temperature in the range of form 35°C to 75°C.
  • the product'of the mixing step in the second aspect may be heated with the loss of some of the water present in the suspension (but without application of a current of gas).
  • the capacity of the polymer coated inorganic particulate material to adsorb pitch is likewise increased still further when the nitrogen-containing polymer has been coated on to the inorganic particulate material by a process which includes a step in which a suspension of a mixture of the two components is subjected to heating.
  • the heating step is conveniently performed at a temperature in the range of from 30°C to 75°C.
  • the solids content of the suspension after the heating step is preferably in the range of from 30% to 100% by weight.
  • the pitch control agent according to the second aspect of the present invention may be added to the pulp being produced or processed to make paper in various ways and at various points of addition.
  • the pitch control agent will be used in the same way as known inorganic pitch control agents such as talc.
  • the pitch control agent can be added at early stages of the process of pulp producing or processing but it is preferred that it is added later in the process eg. at a stage together with filler particles where such particles are mixed with water to form an aqueous suspension or in a tank in which a suspension of the filler particles is mixed with the pulp or paper making cellulosic fibres or in a so-called head box.
  • the pitch control agent may be added in batches at one or more locations in the pulp or paper making plant or, alternatively, in one or more continuous additions. Samples of the wood pulp or fibres being treated may be analysed (prior to treatment) to determine the amount of pitch control agent required. Alternatively, the pitch control agent may be added only when pitch deposition is detected.
  • the pitch control agent may be added so as to allow maximum contact between the pitch control agent and the pitch to be controlled. Multiple points of addition may be used.
  • the pitch control agent may conveniently be added to a paper making stock suspension, which generally comprises an aqueous suspension containing from about 0.5% to about 1% by bone dry weight of cellulosic fibres.
  • the amount of the pitch control agent added is generally in the range from 0.5% to 25% by weight, based on the bone dry weight of cellulosic fibres.
  • the pitch control agent according to the second aspect of the present invention is added in the paper making process together with particulate filler material added to fill the paper composition.
  • Materials useful as filler materials are well known in the art and comprise for example one or more of materials selected from clay (eg., calcined or uncalcined kaolin), calcium carbonate, calcium sulphate.
  • the pitch control agent added in this way, optionally together with one or more other pitch control agents, eg. talc, will act as a paper filler material.
  • a paper composition in a fourth aspect includes cellulosic fibres and inorganic particulate material as filler and is characterised in that the inorganic particulate material includes a pitch control agent according to the second aspect of the present invention.
  • the pitch control agent according to the second aspect of the present invention may form up to 30% by weight of the added filler material in the said paper composition, preferably from 10% to 25% of the added filler material.
  • the amount of filler added with depend upon the type of paper being produced.
  • the said paper composition will also include pitch adsorbed by the pitch control agent. Since the amount of pitch is likely to be less than 0.3% of the weight of the paper composition it will not have an adverse effect on the paper quality. Generally, the amount of pitch adsorbed by the pitch control agent will be up to about 20% by weight of the pitch control agent present.
  • Figure 1 is a graphical plot of the amount of triolein controlled by a number of different pitch control agents.
  • Curves A to F represent the pitch control agents of the same designations in Example 1 below.
  • the amount of pitch control is in ⁇ mol per 100mg of pitch control agent.
  • the amount of pitch controlled is in ⁇ mol per gramme.
  • Figure 2 is a graph illustrating the effectiveness of pitch control agents embodying the invention as a function of amount of polymer used for particle coating.
  • Figure 3 is a schematic flow sheet illustrating a paper making process.
  • Example 1 Samples to simulate pitch containing a high proportion of neutral organic material were prepared by mixing various different amounts of triolein, measured in micromols, with 10cm 3 of ethanol. Each 10cm 3 sample of solution of triolein in ethanol was mixed with 99g of water, to give a triolein oil-in-water emulsion, and there were then added thereto 1g samples of each of a series of pitch control agents described below.
  • the pitch control agent was shaken with the oil-in-water emulsion of triolein for 15 minutes, after which the solid component of the mixture was removed by means of a centrifuge and the triolein which remained in the aqueous phase unadsorbed by the pitch control agent was extracted first with 10cm 3 of hexane and then with three successive 10cm 3 aliquots of chloroform.
  • the hexane and chloroform solutions were combined together in a vessel and the solvents were removed by passing a current of air over the mixed solutions at 60°C to leave a deposit of fat on the walls of the vessel.
  • This fat deposit was then extracted with 20cm 3 of the mobile phase of a high performance liquid chromatography (HPLC) system and the solution shaken for 30 minutes. A small quantity of the solution was then injected into an HPLC column and the quantity of triolein measured by determining the area of the appropriate peak. The difference between the oriqinal quantity of triolein introduced and the quantity of triolein present in the hexane and chloroform solvents gave the quantity which had been controlled (i.e. adsorbed) on the pitch control agent.
  • HPLC high performance liquid chromatography
  • the pitch control agents were prepared as follows:-
  • the accompanying Figure shows a graphical plot of the amount of triolein controlled in ⁇ mol.g -1 against the concentration of triolein remaining in the aqueous phase, and the superiority, in particular, of pitch control agent A, as compared with conventional pitch control agent D, can be clearly seen.
  • pitch control agents were prepared using a dry kaolin clay of the type described under “B” in Example 1 and the method of preparation described under "A", except that a different amount of the acidified colloidal suspension of the melamine-formaldehyde polymer was used in each case.
  • a 1g sample of each pitch control agent was shaken for 15 minutes with a triolein oil-in-water emulsion prepared by mixing 10ml of a solution of 220 ⁇ mol of triolein in 10cm 3 of ethanol with 99g of water.
  • triolen oil-in-water emulsion prepared exactly as described above were shaken with amounts of the melamine-formaldehyde polymer which were equivalent to the amounts present in the pitch control agents prepared as described above, but the melamine-formaldehyde was added in a precipitated form, as described under "E" in Example 1, rather than as a coating on an inorganic silicon-containing compound.
  • a first pitch control agent (J) was provided identical to that used under heading "B" in Example 1, the amount of the melamine-formaldehyde polymer which was coated on to the kaolin clay being 1% by weight, based on the weight of dry clay.
  • a second pitch control agent (K) was prepared using the kaolin clay described under "B” in Example 1, but, in the method of preparation, the steps of filtering, drying and pulverising, which were described under "A” in Example 1, were omitted. Instead, the pitch control agent was made available as a suspension containing 28.3% by weight of dry solids.
  • a first pitch control agent (L) was prepared using the kaolin clay described under "B” in Example 1, but, in the method of preparation, the steps of filtering, drying and pulverising, which were described under "B” in Example 1, were omitted. Instead, the suspension at the relatively low pH value of 3.1 was transferred from the stainless steel mixing pot of the Waring Blendor laboratory mixer to a 1 litre round-bottomed flash with a ground glass neck. The suspension was then heated at 35°C for 16 hours with a reflux condenser inserted into the neck of the round-bottomed flask to ensure that substantially no water was lost from the suspension. In this way, the solids content of the suspensions was kept at about 30% by weight. The suspensions was allowed to cool to room temperature before being added to the triolein-in-water emulsions.
  • a second pitch control agent (M) was prepared using the kaolin clay described under “B” in Example 1, and the method described above under “L”, except that the suspension at a pH value of 3.1 was heated to 70°C instead of to 35°C.
  • Figure 2 illustrates how the amount of melamine aldehyde polymer coated onto the surface of an inorganic particulate material can affect the pitch adsorbing ability of the coated material.
  • the coated material is kaolin coated with a melamine formaldehyde polymer to different coating thicknesses.
  • the kaolin and polymer are as in Example 1 (Pitch Control Agent "B").
  • the pitch adsorbing ability is represented by the ability of the various coated materials to adsorb triolein. As seen in Figure 2, the triolein adsorption increases rapidly as the weight percentage of the polymer coating on the kaolin is increased from zero to about 0.25%.
  • a particular coating weight percentage corresponds to a coating weight percentage value calculated from theory which is the amount of the polymer just required to satisfy the negatively charged sites present on the surface of the kaolin.
  • the value X can be considered to be the optimum theoretical coating weight percentage required.
  • the efficacy of the materials embodying the invention was measured by a different laboratory method, using tall oil as a synthetic pitch (rather than triolein) as described below.
  • Tall oil contains oleic acid.
  • the synthetic pitch solution was prepared by adding 40 g potassium hydroxide and 600 g denatured ethanol to 160 g distilled tall oil, and stirring until the potassium hydroxide is completely dissolved.
  • FIG 3 illustrates a paper making process in which a pitch control agent embodying the present invention, herein "PCA", is used.
  • the PEA may be one of the materials prepared above, eg. as in Example 1.
  • aqueous stock containing 2% by weight of cellulosic fibres (obtained by beating and refining a bleached sulphite pulp) is mixed in a stirred tank 1 with 1.5% by weight, based on the weight of dry cellulosic fibres, of fortified rosin size and 3.0% by weight of powdered aluminium sulphate.
  • the resulting stock of sized fibres is delivered by a pump 2 through a conduit 3 to a constant head tank 4 from which the overflow is returned to tank 1 through a conduit 5.
  • Clean water is supplied via a conduit 16 to a second constant head tank 6 from which the overflow is passed through a conduit 7 to a reservoir (not shown).
  • the stock of sized fibres flows from tank 4 through a conduit 8, and water flows from tank 6 through a conduit 9, to a tank 10 where they are mixed in the proportions 3 parts by weight of water to 1 part by weight of suspension to dilute the stock to 0.5% by weight of cellulosic fibres.
  • a tank 11 provided with an impeller there are mixed together in batches of approximately 8 litres total volume water, filler including PCA (in an amount as specified hereinbefore) and other optional additives eg. cationic starch as a retention aid.
  • the speed of the impeller is such that a vortex is first formed in the tank 11.
  • the mixture so formed is run through a conduit 12 to the tank 10 and is mixed therein with the stock of sized fibres to give a uniform mixture.
  • the resulting mixture is run through a conduit 13 to the head box 14 of a paper making machine 15 where for each loading of the suspension formed in the tank 11 a web of paper is formed on the wire of the machine 15 and then dewatered and thermally dried
  • the PCA may be added to the pulp when it is formed, before its addition to the tank 1 or in any one or more of the tank 1, tank 4, tank 6, tank 10 or head box 14.
  • the paper produced in the manner described with reference to Figure 3 contains amongst other things PCA and pitch (adhered thereto) in quantities in the ranges specified above.
  • the melamine-formaldehyde polymer used in the above Examples was material supplied under the product name SURROUND (Trade Mark) by Calgon Corporation of Pittsburgh, USA. It has a weight average molecular weight of about 4300 and a melamine to formaldehyde molar ratio of from 3.2:1 to 3.5:1.

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  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Paper (AREA)
  • Paints Or Removers (AREA)
EP96301664A 1995-03-16 1996-03-12 Agent amélioré pour le contrÔle de la poix Withdrawn EP0740014A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9505323 1995-03-16
GBGB9505323.7A GB9505323D0 (en) 1995-03-16 1995-03-16 Improved pitch control agent

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EP0740014A1 true EP0740014A1 (fr) 1996-10-30

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EP (1) EP0740014A1 (fr)
JP (1) JPH08325987A (fr)
AU (1) AU706819B2 (fr)
BR (1) BR9601042A (fr)
GB (1) GB9505323D0 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6030704A (en) * 1996-06-21 2000-02-29 Ecc International Ltd. Granular materials comprising inorganic silicon-containing material
US7449086B2 (en) 2005-09-21 2008-11-11 Nalco Company Use of synthetic metal silicates for decreasing the deposition of contaminants during a papermaking process
EP2546410A1 (fr) 2011-07-11 2013-01-16 Omya Development AG Particules de carbonate de calcium hydrophobes
EP2933375A1 (fr) 2014-04-16 2015-10-21 Omya International AG Adsorption et/ou réduction de la quantité de matières organiques dans un milieu aqueux par l'utilisation de carbonate de calcium précipité colloïdal

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102505564A (zh) * 2011-11-18 2012-06-20 广东工业大学 一种造纸循环白水中胶粘物的控制剂的制备方法

Citations (4)

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Publication number Priority date Publication date Assignee Title
EP0132132A2 (fr) * 1983-07-14 1985-01-23 E.I. Du Pont De Nemours And Company Charges inorganiques modifiées avec du polymère d'alcool vinylique et de la résine cationique de mélamine-formaldéhyde
WO1989006294A1 (fr) * 1988-01-07 1989-07-13 Cyprus Industrial Minerals Company Procede de reduction de poix dans la reduction en pate et la fabrication de papier
EP0349311A2 (fr) * 1988-06-29 1990-01-03 Ecc International Limited Contrôle de la poix
EP0569085A1 (fr) * 1992-05-05 1993-11-10 Calgon Corporation Produit pour combattre la poix ou les dépôts collants

Family Cites Families (2)

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Publication number Priority date Publication date Assignee Title
US5221436A (en) * 1988-06-29 1993-06-22 Ecc International Limited Pitch control using clay coated with an inorganic gel
JP2903699B2 (ja) * 1990-11-09 1999-06-07 味の素株式会社 インキ組成物

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0132132A2 (fr) * 1983-07-14 1985-01-23 E.I. Du Pont De Nemours And Company Charges inorganiques modifiées avec du polymère d'alcool vinylique et de la résine cationique de mélamine-formaldéhyde
WO1989006294A1 (fr) * 1988-01-07 1989-07-13 Cyprus Industrial Minerals Company Procede de reduction de poix dans la reduction en pate et la fabrication de papier
EP0349311A2 (fr) * 1988-06-29 1990-01-03 Ecc International Limited Contrôle de la poix
EP0569085A1 (fr) * 1992-05-05 1993-11-10 Calgon Corporation Produit pour combattre la poix ou les dépôts collants

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6030704A (en) * 1996-06-21 2000-02-29 Ecc International Ltd. Granular materials comprising inorganic silicon-containing material
US7449086B2 (en) 2005-09-21 2008-11-11 Nalco Company Use of synthetic metal silicates for decreasing the deposition of contaminants during a papermaking process
EP2546410A1 (fr) 2011-07-11 2013-01-16 Omya Development AG Particules de carbonate de calcium hydrophobes
WO2013007717A1 (fr) 2011-07-11 2013-01-17 Omya Development Ag Particules de carbonate de calcium hydrophobé
EP2933375A1 (fr) 2014-04-16 2015-10-21 Omya International AG Adsorption et/ou réduction de la quantité de matières organiques dans un milieu aqueux par l'utilisation de carbonate de calcium précipité colloïdal
WO2015158657A1 (fr) 2014-04-16 2015-10-22 Omya International Ag Adsorption et/ou réduction de la quantité de matières organiques dans un milieu aqueux par carbonate de calcium précipité colloïdal
US10046984B2 (en) 2014-04-16 2018-08-14 Omya International Ag Adsorbing and/or reduction of the amount of organic materials in an aqueous medium by using colloidal precipitated calcium carbonate

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AU706819B2 (en) 1999-06-24
BR9601042A (pt) 1998-01-06
JPH08325987A (ja) 1996-12-10
AU4805396A (en) 1996-09-26
GB9505323D0 (en) 1995-05-03

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