HUE033367T2 - Surface-reacted precipitated calcium carbonate and uses thereof - Google Patents

Description

Description [0001] The present invention concerns the technical field of high BET specific surface area mineral fillers based on precipitated calcium carbonate (PCC), which is also known as synthetic calcium carbonate.

[0002] Such fillers find applications in a number of domains, including in paper, namely as a filler or a coating pigment, in tissue paper, in paints, in plastics, in water treatment, and notably as a means of removing pitch and endocrine disrupting compounds (EDC).

[0003] The calcium carbonate mineral is generally distinguished according to two classes: ground (or natural) calcium carbonate (GCC), and precipitated calcium carbonate (PCC).

[0004] GCC is understood to be a naturally occurring form of calcium carbonate, mined from sedimentary rocks such as limestone or chalk, or from metamorphic marble rocks. GCC is almost exclusively of the calcitic polymorph, which is said to be trigonal-rhombohedral and represents the most stable of the calcium carbonate polymorphs.

[0005] By contrast, calcium carbonate polymorphs of the PCC type often inelude, in addition to calcites, less stable polymorphs of the aragonitic-type, which has an orthorhombic, acicular crystal shape, and hexagonal vateritic-type, which has an even lower stability than aragonite. The different PCCforms may be identified according to their characteristic x-ray powder diffraction (XRD) peaks.

[0006] PCC synthesis most commonly occurs by a synthetic precipitation reaction that ineludes a step of contacting carbón dioxide with a solution of calcium hydroxide, the latter being most often provided on forming an aqueous suspensión of calcium oxide, also known as burnt lime, and the suspensión of which is commonly known as milk of lime. Depending on the reaction conditions, this PCC can appear in various forms, including both stable and unstable polymorphs. Indeed, PCC often represents a thermodynamically unstable calcium carbonate material.

[0007] When referred to in the context of the present invention, PCC shall be understood to mean synthetic calcium carbonate produets obtained by carbonation of a slurry of calcium hydroxide, commonly referred to in the art as a slurry of lime or milk of lime when derived from finely divlded calcium oxide particles in water.

[0008] Indeed, it is a significant advantage of the present invention, as will be understood hereafter, that it implements a PCC obtained by such a common process. It will, of course, be understood by the skilled man that further additives, precipitation conditions or steps prior to or following this precipitation may be implemented when forming such PCC by carbonation of a lime slurry; however, he will immediately recognise the advantage of being able to implement the process of the present invention on any such PCC, including a very basic PCC obtained by simply carbonating a puré lime slurry.

[0009] GCC and PCC forms of calcium carbonate are, on occasion and on an unpredictable basis, observed to present different Chemical properties, and frequently it is not possible to use GCC in the same applications as PCC and viceversa.

[0010] For example, it was found that the technology described in EP 1 149 136 relating to an: "aqueous suspensión of one or more pigments, fillers or minerals, which may contain a dispersant polymer to stabilise the rheology of the suspensión, characterised by the fact that: a) it contains a natural carbonate and the reaction product or produets of the said carbonate with gaseous C02 and the reaction productor produets of the said carbonate with one or more medium-strong to strong H30+ ion-providers, and b) it has a pH greater than 7.5 measured at 20° C", is not transferable to PCC.

[0011] It has been found that when implementing PCC in place of GCC (where GCC acts as the "natural carbonate") in the technology of EP 1 149 136 and notably when reproducing technology of EP 1 149 136 in the case where the C02 is generated by continuous addition of the H30+-ion provider, the specific surface area of the resulting PCC-based product failed to develop sufficiently.

[0012] Indeed, the technology of EP 1 149 136 is of particular interest as it provides a means of structuring the surface and significantly increasing the specific surface area of the GCC starting material by controlled deposition of an at least partially crystalline calcium salt thereon, and such that the calcium source for this deposited material is the GCC mineral itself.

[0013] The skilled man, who is eager to obtain such a high surface area material, but wishes to have the option of using a PCC-based starting material, as this material may, for example as afunction of availability and particular physical properties, present certain advantages over GCC, is therefore left looking for a solution to implement the above technology.

[0014] In the prior art, it is of note that while a number of documents focus on the introduction of particular additives during the PCC formation process, few documents provide any teaching relating to the use of a fully formed PCC as an adduct in a process to surface-react this PCC.

[0015] US 4,367,207 describes a particular process to prepare PCC. It is stated that care is taken to neutralise any unreacted calcium hydroxide still present in the carbonated slurry, such as by addition of a sufficient amount of organic orinorganic polybasic acid, namely citric, maleic, malic, malonic, phthalic, tartaric, boric, phosphoric, sulfurous orsulfuric acid.

[0016] WO2005/123593relates to a process wherein citric acid is admixed with a calcium hydroxide slurry and the slurry carbonated to produce a slurry of PCC, which is thereafter dewatered to produce a high solids PCC composition. It is stated that, optionally, citric acid may be added in conjunction with or subsequent to the addition of a dispersant to the produced high solids PCC composition, though this option is neither further described norexemplified. Additionally, it is indicated that phosphoric acid may be added to the PCC slurry at a given, limited concentration never exceeding 0.8 % by weight on the weight of PCC, to maintain the surface area of this PCC.

[0017] W02005/102931 describes a process wherein a first amount of organophosphate is added to a calcium hydroxide slurry, prior to addition of alumimum sulphate and thereafter C02 to form a PCC. A second amount of organophosphate is then added to the PCC slurry, followed by screening and dewatering of this slurry to form a concentrated PCC composition. As above, it is indicated that a limited amount of phosphoric acid never exceeding 1.5 % by weight on the weight of PCC, may be admixed with the PCC slurry to stabilise and maintain the PCC surface area.

[0018] EP0 406 662 describes a process for manufacturing a synthetic carbonate in which a pre-mix is made of CaC03 in aragonite form with lime: to this slurry is added a "phosphoric acid derivative" such as phosphoric acid or its salts or various phosphates, and finally C02 is introduced in order to produce conventional carbonation. The purpose of this patent is specifically to obtain a PCC with a particular acicular crystalline form, of which the industrial manufacture was not previously possible. Phosphoric acid is used in EP 0 406 662 in order to produce specifically the aragonite form vía an unidentified "phosphoric acid calcium" which provides new nucleation seeds for the required crystalline form.

[0019] It was found by the applicant that the addition of calcium ions via a base (lime) in the process of EP 0 406 662 does not lead to the desired surface-reacted PCC.

[0020] Indeed, when the Applicant attempted to implement a process wherein the solubilised calcium ion source was calcium hydroxide as described in EP 0 406 662, particularly atthe high calcium hydroxide levels described therein, the Applicant found that a material was obtained wherein the calcium forming any at least partially crystalline material atthe surface did not origínate from the PCC starting material, but rather from the added calcium hydroxide.

[0021] US 5,043,017 describes the acid-stabilisation of calcium carbonate, and in particular of PCC, by action of a calcium-chelating agent, such as calcium hexametaphosphate, and a conjúgate associated base, which can be an alkaline metal salt of a weak acid (phosphoric, citric, boric, acetic, etc.). Indeed, the goal of US 5,043,017 is entirely in opposition to the need of the present invention to maintain the acid-reactivity of the PCC in order to generate solubilised calcium ions, these ions being needed to form a surface area-generating crystal on the PCC surface.

[0022] US 4,244,933 describes calcium carbonate particles comprising a core and projections thereon, prepared by a first step of spraying an aqueous suspensión of calcium hydroxide into a reactor from its top in countercurrent relation to the carbón dioxide gas passed upwards through the reactor to convert part of the calcium hydroxide to calcium carbonate, followed by a second step of spraying the resulting mixture into another reactor from its top in countercurrent relation to the carbón dioxide gas passed upwards through the reactor to promote carbonation of the calcium hydroxide, and a third similar step to complete carbonation, wherein the first or second step implements phosphoric acid and water-soluble salts thereof. These water soluble salts are said to be sodium, potassium, zinc and the like salts of phosphoric acid.

[0023] Finally, whereas EP 1 769 035 discloses a dry mineral pigment characterised in that it contains a product formed in situ by the múltiple reaction between a calcium carbonate and: the product or producís of the reaction of the said carbonate with one or more moderately strong to strong H30+ ion donators; the product or producís of reaction of the said carbonate with gaseous C02 formed in situ and/or originating from an external supply; one or more compounds of formula R-X.

[0024] However, no further teaching is provided in this documentto obtain a high specific surface area surface-reacted precipitated calcium carbonate.

[0025] In summary, the prior art: focuses largely on the optimisation of the adducts used during PCC formation, rather than on contacting already formed PCC with particular additives in order to increase the BET specific surface area of this PCC; discloses that when PCC is combined with an anión in the form of a soluble acid or acid salt, and which has an insoluble corresponding calcium salt, such as phosphoric acid, either no additional means are referenced to provide the needed solubilised calcium ions, and this anión only serves to maintain, and not to significantly develop, the BET specific surface area of the PCC; discloses that when PCC is combined with an anión in the form of a soluble acid or acid salt, and which has an ¡nsoluble corresponding calcium salt, such as phosphoric acid, and calclum ions are provided, these calcium ions are provided in a form which the Applicant has found do not lead to the desired surface-reacted PCC.

[0026] Entirely by surprise, the Applicant has found that control of particular parameters during such a process as defined hereafter, and notably control of the solubilised calcium ions available at one or more specific points in this process, is key to the success of forming a high specific surface area surface-reacted precipitated calcium carbonate.

[0027] Namely, the Applicant has developed a process for the preparation of a pigment comprising a surface-reacted precipitated calcium carbonate (PCC), the process comprising the following steps: a) providing at least one precipitated calcium carbonate (PCC)-comprising pigment; b) providing H30+ ions; c) providing at least one anión being capable of forming water-insoluble calclum salts, said anión being solubilised in an aqueous médium;

d) contacting said PCC-comprising pigment with said H30+ ions and with said solubilised anions in an aqueous médium to form a slurry of surface-reacted PCC-comprising pigment, wherein said surface-reacted PCC comprises an insoluble, at least partially crystalline calcium salt of said anión formed on the surface of at least part of the PCC provided in step a); characterised in that an excess of solubilised calcium ions is provided during Step d) and said at least partially crystalline calcium carbonate salt ofsaid anión extendsfrom the surface of at least part of the PCC of said PCC-comprising pigment provided in Step a).

[0028] For the purpose of the present Application, insoluble materials are defined as those which, when mixed with deionised water and filtered at 20°C to recover the liquid fíltrate, provide less than or equal to 0.1 g of recovered solid material following evaporation at 95 to 100°C of 100 g of said liquid fíltrate. Soluble (or solubilised) materials are defined as materials leading to the recovery ofgreaterthan 0.1 g of recovered solid material following evaporation at95to 100°C of 100 g ofsaid liquid fíltrate.

[0029] For the purpose of the present Application, said excess solubilised calcium ions shall correspond to an excess of solubilised calcium ions relative to the solubilised calcium ions naturally generated on dissolution of PCC by H30+ ions, where said Fl30+ ions are provided solely in the form of a counterion to the anión, i.e. vía the addition of the anión in the form oían acid or non-calcium acid salt, and in absence of anyfurther calcium ion or calcium ion generating source.

[0030] Said excess solubilised calcium ions provided during step d) are preferably provided vía one or more of the following Routes:

Route IA: addition of a soluble neutral or acid calcium salt;

Route I IA: addition oían acid ora neutral or acid non-calcium salt which generates a soluble neutral oracid calcium salt in situ.

[0031] Said H30+ ions may be provided vía one or more of the following Routes:

Route IB: addition of acid or an acid salt of said anión;

Route I IB: addition of an acid or an acid salt which simultaneously serves to provide all or part ofsaid excess solubilised calcium ions.

[0032] For the purpose of the present invention, an "acid" is defined as a Bronsted-Lowry acid, that is to say, it is an hl30+ ion-provider. An “acid salt" is defined as an HsO+ ion-provider that is partially neutralised by an electropositive element. A "salt" is defined as an electrically neutral ionic compound formed of anions and cations. A "partially crystalline salt" is defined as a salt that, on XRD analysis, presents an essentially discrete diffraction diagram.

[0033] For the purpose of the present invention, a surface-reacted PCC is a material comprising PCC and an insoluble, at least partially crystalline, calcium salt of said solubilised anión.

[0034] In a preferred embodiment, the insoluble calcium salt extends from the surface of at least part of the PCC.

[0035] The calcium ions forming said at least partially crystalline calcium salt of said anión origínate largely from the starting PCC material.

[0036] Without wishing to be bound by any theory, the Applicant believes that in order to form a high specific surface area surface-reacted calcium carbonate, wherein the calcium ions forming the insoluble, at least partially crystalline, calcium salt of said anión are provided largely by the calcium carbonate starting material, it is necessary not only to libérate these calcium ions from this calcium carbonate, but to do so under conditions such that said calcium ions are maintained sufficiently mobile to preferentially precipítate, not on the calcium carbonate surface from which they evolve, but rather on any already formed calcium anión crystals extending from the calcium carbonate surface, such that said crystals grow outward from the carbonate surface and do not cover the undissolved carbonate before sufficient calcium ions are released therefrom to generate the needed crystal surface to achieve the desired specific surface area.

[0037] Without wishing to be bound by any theory, the Applicant believes that PCC synthesised via carbonation of a lime slurry contains unreacted calcium hydroxide entrapped in the PCC core that migrates to locations along the PCC surface. The Applicant theorises that this calcium hydroxide at the PCC surface (or that is brought to the surface if the PCC surface is etched, such as by addition of an acid), forms a layer at this surface within which an equilibrium is established between liberated calcium and hydroxide ions and calcium hydroxide still associated with the PCC surface. The Applicant theorises that on simple addition of the medium-strong to strong H30+ ion-provider (hereafter referred to as acid) via a compound which also serves as the anión source, as is the most common case in EP 1 149 136 where H3PO4 is implemented, this acid is neutralised on encountering the hydroxide ions atthe PCC surface, and this neutral-isation influences the equilibrium in place between the calcium and hydroxide ions and surface-associated calcium hydroxide within the mentioned PCC surface layer, such that an excess of calcium ions are generated at the PCC surface, driving rapid precipitation of this calcium, not so that outward, surface generating growth of an at least partially crystalline material continúes, as desired, beyond the limits of this surface layer, but rather so that an at least partially crystalline material forms on the PCC surface in immediate proximity, essentially encompassing this PCC and rendering it unreactive on further acid addition.

[0038] The Applicant believes that it is necessary to act against this phenomenon by acting on the equilibrium in place within said layer to limit the concentration of free hydroxyl groups therein, which would otherwise neutralise the H30+ ions needed to libérate calcium from PCC and thereby prevent surface area generation. The Applicant has found that this may be achieved by increasing the solubilised calcium ion concentration, namely by providing more solubilised calcium ions than would be generated by the acidicoracid saltform of the anión alone. It is of note that these additionally provided solubilised calcium ions do not serve to directly form the desired at least partially crystalline material so much as they act to ensure that the equilibrium at the PCC surface is such that needed calcium ions can continué to be obtained from PCC.

[0039] The amountof calcium hydroxide present atthe PCC surface and thatgenerates the equilibrium layerwill vary as a function of the PCC synthesis conditions. Thus, the amount of additionally provided solubilised calcium ions has to be adapted, so that specific surface area is generated.

Characterisation of Step a): PCC -comprising pigment starting material [0040] According to Step a) of the process for preparing the product of the present invention, a) at least one pigment comprising precipitated calcium carbonate (PCC) is provided.

[0041] It is among the merits of the Applicant that he has identified specific reaction condition that allows for the generation of surface area on contacting a PCC-comprising pigment with an anión and H30+ ions, via the formation of a calcium crystal, wherein the calcium source is essentially the PCC starting material, ie. the PCC provided in the pigment of step a). Moreoever, the Applicant has identified the conditions such that this process functions when using any form of PCC in the pigment starting material, including calcitic polymorphs such as scalenohedral or rhombohedral calcite, or metastable vaterite and aragonite.

[0042] Indeed, the PCC in said PCC-comprising pigment of Step a) may, optionally, be synthesised in the presence of crystal modifiers, such as EDTA or other chelants. Preferably, upon wet grinding said PCC-comprising pigment under the following conditions, the pH of the wet grinding slurry is observed to rise to a greater extent than would be observed upon grinding a corresponding slurry wherein said PCC is entirely replaced with calcitic GCC, attesting to the release of unreacted hydroxide from said PCC: 1) replacing the aqueous phase of the slurry with deionised water to form a slurry featuring a solids contení, as measured according to the measurement method provided in the Examples section herebelow, of 15 % by weight; 2) grinding the slurry of Step 1) in a grinding chamber using aluminium oxide grinding beads having a diameter of between 1.0 and 1.6 mm, added in an amount so as tofill approximately 80% of the volume of the grinding chamber, and at a grinding speed of 2500 rpm at 24°C for 180 minutes, under a slurry re-circulation rate of 700 ml/minutes.

[0043] Namely, the pH, as measured according to the measurement method provided in the Examples section herebelow, is observed to rise by more than 2 during this grinding.

[0044] In a preferred embodiment, the PCC of said PCC-comprising pigment of Step a) is hydrophilic, as determined in accordance with the measurement method provided in the Examples section herebelow.

[0045] In a preferred embodiment, the PCC of said PCC-comprising pigment of Step a) is issued from a process of involving at least one step of comminution. A step of comminution is defined as a mechanical Processing step resulting in the reduction of the original partióle size. Such comminution steps may, for examples, be performed under conditions such that refinement predominantly results from impacts with a secondary body, ie. in one or more of: a ball mili, a rod mili, a vibrating mili, a roll crusher, a centrifugal impact mili, an attrition mili, a pin mili, a hammer mili, a pulveriser, a shredder, a de-clumper, a knife cutter, or other such equipment known to the skilled man, or may be performed under conditions such that autogenous grinding takes place.

[0046] In a preferred embodiment, the PCC ofsaid PCC-comprising pigmentof Step a) has a weight median diameter of 0.01 to 10 μ(η, and more preferably of 0.5 to 2 μηι, as measured according to the measurement method provided in the Examples section herebelow.

[0047] In anoptional embodiment, said PCC-comprising pigmentof Step a) alsocomprises one or more of the following: tale, clay, plástic hollow-sphere pigments or titanium dioxide.

[0048] In another embodiment, said PCC-comprising pigment of Step a) consists solely of PCC.

[0049] In a preferred embodiment, said PCC-comprising pigmentof Step a) is provided in theform of an aqueousslurry.

[0050] In this preferred embodiment, said slurry preferably has a pH of less than 11, preferably of less than 10.5, as measured according to the measurement method described in the Examples section herebelow, prior to Step c).

[0051] In this preferred embodiment, said PCC-comprising pigment is optionally dispersed. Conventional dispersants known to the skilled person can be used. The dispersant can be anionic or cationic. A preferred dispersant is one based on polyacrylic acid. Such dispersants are preferably dosed so as to account for 0.35 % by weight of the weight of said PCC-comprising pigment.

Characterisation of Step b): H30+ ion source [0052] According to Step b) of the process of the present invention, H30+ ions are provided. Said HsO+ ions serve to partially dissolve PCC, generating calcium ions for subsequent precipitation of an insoluble, at least partially crystalline calcium salt of the anión at the PCC surface.

[0053] Said H30+ ions may be provided via one or more of the following Routes:

Route IB: addition of acid oran acid salt ofsaid anión;

Route I IB: addition of an acid or an acid salt which simultaneously serves to provide all or part ofsaid excess solubilised calcium ions, ie. by direct addition of soluble calcium ions and/or by dissolution of the PCC starting material to libérate calcium ions.

[0054] In the case of Route I IB, said acid or acid salt which simultaneously serves to provide all or part ofsaid excess solubilised calcium ions is preferably selected from the group comprising sulphur-comprising acids, such as sulphuric acid, hydrochloric acid, perchloric acid, formic acid, lactic acid, acetic acid, nitric acid, and acid salts thereof, such as soluble calcium acid salts thereof.

[0055] Especially, said acid or acid salt is selected from the group comprising sulphur-comprising acids, such as sulphuric acid, hydrochloric acid, acetic acid and acid salts thereof, such as soluble calcium acid salts thereof.

[0056] Preferably, following the addition of said H30+ ions to the slurry, the pH of this slurry, as measured according to the measurement method given in the Examples section herebelow, drops temporarily to a valué below 6.0.

Characterisation of Step c): anión forming the insoluble calcium crystal on PCC

[0057] According to Step c) of the process of the present invention, at least one anión, being capable of forming water-insoluble calcium salts, said anión being solubilised in an aqueous médium, is provided. Said insoluble corresponding calcium salt may, in addition to said anión, inelude OH- ions and/or crystal water.

[0058] Said anión of Step c) may be added in the form of a soluble neutral or acid salt, or in the form of an acid, provided it is solubilised before and/or during Step d).

[0059] Said anión may be generated by speciation of an additive provided to the process. For example, P043- and HP042_ may be generated via addition of H3P04 or a salt of H2P04_.

[0060] Preferably, said anión is selected from one or more of the following: phosphate-comprising anions such as P043- and HP042_, oxalate anions (C2042-), carbonate-comprising anions in the form of C032-, phosphonate anions, succinate anions, orfluoride anions. More preferably, said anión is selected from among: phosphate-comprising anions such as P043- and HP042_, oxalate anions (C2042-), phosphonate anions, succinate anions, and fluoride anions. Most preferably, said anión is a phosphate-comprising anión such as P043- and HP042_.

[0061] In the embodiment where a carbonate-comprising anión is implemented, said carbonate-comprising anión may be generated in situ via the introduction of gaseous C02 to the slurry. In such a case, the skilled man will know how to implement this introduction in order to favour the conversión of C02 to C032', such as through the selection of the appropriate temperature.

[0062] In a preferred embodiment, said anión is added in a quantity corresponding to between 5 and 50 %, preferably between 15 and 30 %, by weight based on the weight of said PCC provided in Step a).

Characterisation of Step d): contacting the PCC-comprising pigment and the anión [0063] According to Step d) of the process of the present invention, said PCC-comprising pigment is contacted, either simultaneously or in distinct steps, with said H30+ ions and with said solubilised anions in an aqueous slurry environment.

[0064] In a preferred embodiment, said anión is contacted with said PCC after contacting said PCC with said HsO+ ions.

[0065] Moreoever, the process of the present invention is characterised in that excess solubilised calcium ions are provided during Step d).

[0066] Said excess solubilised calcium ions are preferably provided via one or more of the following Routes:

Route IA: addition of a soluble neutral or acid calcium salt;

Route I IA: addition of an acid ora neutral oracid non-calcium saltwhich generates a soluble neutral oracid calcium salt in situ.

[0067] In the case where said excess solubilised calcium ions are provided via Route IA, it may, for example be added as CaCI2 or Ca(N03)2.

[0068] The solubilised calcium ions are preferably provided in a quantity corresponding to greater than or equal to 3%, preferably greater than or equal to 5%, by weight based on the weight of said PCC provided in Step a).

[0069] In a preferred embodiment, Stepd) is carried outattemperaturesof above 50°C, and preferably of above 60°C.

[0070] In a preferred embodiment, Step d) the slurry is mixed so as to develop an essentially laminar flow.

[0071] In an optional embodiment, Step d) takes place in the presence of at least one compound selected from the group consisting of silicate, silica, earth alkali metal alumínate, or mixtures thereof.

[0072] In this optional embodiment, said silicate is preferably selected from an aluminium silicate, or an earth alkali metal silicate.

[0073] In an optional embodiment, Step d) takes place in the presence of an inert gas, which is bubbled through the slurry. One such gas may be C02, provided that the when the skilled man implements C02 as an inert gas, he adapts the slurry conditions to llmit the conversión of this C02 to a soluble carbonate.

[0074] In an optional embodiment, Step d) takes place in the presence of a further additive which increases the ionic strength of the slurry, such as an inert, non-calcium salt. Such salts ¡nclude, for example, NaCI or KN03.

[0075] In a preferred embodiment, the aqueous phase of the obtained surface-reacted PCC slurry may be replaced with deion ised water. In a more preferred embodiment, the aqueous phase of said surface-reacted PCC slurry ¡scollected and recirculated into the process according to the present invention as a means to provide all or part of the solubilised calcium ions. This is particularly of interest when the process according to the invention is a continuous process.

[0076] The obtained surface-reacted PCC slurry may be concentrated, optionally up to the point of obtaining a dry surface-reacted PCC product. In the case of a dry product, this product may additionally be treated with fatty acids. In the case of a dry product, this product may be additionally washed with water.

[0077] Thus, a slurry of surface-reacted PCC-comprising pigment is obtained, wherein said surface-reacted PCC comprisesan insoluble, at least partially crystalline calcium salt ofsaid anión, which preferably extendsfrom thesurface of at least part of the PCC of said PCC-comprising pigment; provided in Step a).

[0078] This surface-reacted PCC features a BET specific surface area that is greater than the BET specific surface area obtained following contacting the same PCC provided in Step a), either simultaneously or in distinct steps, with the same solubilised anión of Step b) and with H30+ ions, such that: the H30+ ions are provided solely via the addition ofsaid anión, ie. said H30+ ions are provided in a molar quantity that is less than or equal to that required to theoretically balance the ionic charge ofsaid anión; and, neither Route IA ñor Route IB are implemented.

[0079] In a preferred embodiment, the resulting surface-reacted PCC has a BET specific surface area that is at least three times, and more preferably seven times, greater than the BET specific surface area of the PCC in the PCC-comprising pigment provided in Step a).

[0080] Said BET specific surface area and all BET specific surface areas relating to the present invention are determined in accordance with the measurement method defined in the Examples section herebelow.

[0081] In a preferred embodiment, the obtained slurry comprising surface-reacted PCC has a solids contení, as meas-ured according to the measurement method described in the Examples section hereafter, of up to 25 %, preferably between 5 and 20% by weight.

[0082] In a preferred embodiment, a dispersant is added to said slurry.

[0083] Preferably, upon wet grinding said surface-reacted PCC-comprising pigment under the following conditions, the pH of the wet grinding slurry is observed to rise by at least 2 during this wet grinding process: 1) replacing the aqueous phase of the slurry with deionised water to form a slurry featuring a solids contení, as measured according to the measurement method provided in the Examples section herebelow, of 15 % by weight; 2) grinding the slurry of Step 1) in a grinding chamber using aluminium oxide grinding beads having a diameter of between 1.0 and 1.6 mm, added in an amount so as tofill approximately 80% of the volume of the grinding chamber, and at a grinding speed of 2500 rpm at 24°C for 180 minutes, under a slurry re-circulation rate of 700 ml/minutes.

[0084] In a preferred embodiment, said surface-reacted PCC has a calcium salí of the anión: calcium carbonate content mass ratio of 5:95 to 95:5, preferably of 20:80 to 60:40, and more preferably of 25:75 to 50:50, as determined according to the TGA measurement described in the Examples section herebelow.

[0085] Said surface-reacted PCC preferably has a pore volume of 1 to 2.2 cm3/g, as determined according to the measurement method provided in the Examples section herebelow.

[0086] Said surface-reacted PCC preferably has a BET specific surface area of from 20 to 120 m2/g, preferably from 55 to 115 m2/g, more preferably from 60 to 100 m2/g, as determined according to the measurement method provided in the Examples section herebelow.

[0087] Upon XRD analysis of said surface-reacted PCC, according to the measurement method provided in the Examples section herebelow, said XRD analysis preferably presents the peaks corresponding to an at least partially crystalline calcium of the anión. In a preferred embodiment, said salts inelude one or more of the following: octacalcium phosphate (OCP), hydroxyapatite (HAP) ortricalcium phosphate (TCP).

[0088] Said surface-reacted PCC slurry may be used in paper, tissue paper, plastics, paints, water treatment and to remove EDC compounds.

[0089] The following examples ¡Ilústrate the invention without restricting its scope.

EXAMPLES

Measurement methods [0090] The following measurement methods are used to evalúate the parameters given in the examples and claims. Hydrophilicity of a material [0091] Materials were classified as hydrophilic or not according to the following test. 50 mi of each of the following mixture ofwater:ethanol are prepared in 100 mi beakers: 100:0, 90:10, 80:20, 70:30, 60:40, 50:50,40:60, 30:70, 20:80, 10:90, 0:100. Thereafter, 0.5 g of the material to be tested is passed through a sieve located over the mouth of the beaker (under slight agitation of this sieve to ensure that all of the material passes through it, said sieve openings being sized so as to allow the slowed passage of the material under slight agitation), and allowed to fall freely upon the liquid surface. As of the moment that sieving is completed, the behaviourof the material at the liquid surface is observed over a period of 5 minutes to assign a grade to the material in each beaker as follows: 0 = essentially all of the material sinks within 30 seconds; 0.25 = essentially all of the material sinks within 5 minutes; 0.5 = more than 50% of the material sinks within 5 minutes; 0.75 = more than 25% of the material sinks within 5 minutes; 1 = essentially none of the filler sinks within 5 minutes.

[0092] The grades assigned are plotted as afunction of the watenethanol ratio. Materials were classified as hydrophilic a zero valué was observed for a watenethanol mixture of 100:0 to 50:50.

Pore volume of a material [0093] Tablets were madefrom suspensionsofthe material to be tested. The tablets areformed by applying a constant pressure to the suspension/slurry for several hours such that water is released by filtration through a fine 0.025 μηι filter membrane resulting in a compacted tablet of the pigment. The tablets are removed from the apparatus and dried in an oven at 80°C for 24 hours.

[0094] Once dried, single portions from each of the tablet blocks were characterised by mercury porosimetry for both porosity and pore size distribution using a Micromeritics Autopore IV mercury porosimeter. The máximum applied pres-sure of mercury was 414 MPa, equivalent to a Laplace throat diameter of 0.004 μηι (i.e. ~ nm). The mercury intrusión measurements were corrected for the compression of mercury, expansión of the penetrometer and compressibility of the solid phase of the sample. Further details of the measuring method are described in Transport in Porous Media (2006) 63: 239-259.

Specific Surface Area (SSA) of a material [0095] The specific surface area is measured via the BET method according to ISO 9277 using nitrogen, following conditioning of the sample by heating at 250°C for a period of 30 minutes. Prior to such measurements, the sample is filtered, rinsed and dried at 110°C in an oven for at least 12 hours.

Particle size distribution (mass % partióles with a diameter < X) and weight median grain diameter (d50) of a particulate material [0096] Weight median grain diameter and grain diameter mass distribution of a particulate material are determined via the sedimentation method, i.e. an analysis of sedimentation behaviour in a gravimetric field. The measurement is made with a Sedigraph™ 5120.

[0097] The method and the instrument are known to the skilled person and are commonly used to determine grain size of fillers and pigments. The measurement is carried out in an aqueous solution of 0.1 wt% Na4P207. The samples were dispersed using a high speed stirrer and ultrasonic. X-ray Diffraction (XRD) [0098] Crystallographic structures of materials were identified based on the XRD analytical technique using Brucker AXS:D8 Advance instrumentation, scanning 2 to 70° 2theta at a scanning speed of 0.5 seconds/step and a step size of 0.01° 2theta. Analysis of the resulting spectra was based on the PDF 2 database of reference spectra issued by the International Centre for Diffraction Data. pH of an aqueous slurry [0099] The pH of the aqueous suspensión is measured using a standard pH-meter at approximately 22°C. pH rise on wet grinding a material [0100] The pH rise observed on wet grinding a material is evaluated according to the following process: 1) the aqueous phase of the slurry is replaced with deionised water to form a slurry featuring a solids content, as measured according to the measurement method provided in the Examples section herebelow, of 15 % by weight; 2) the slurry of Step 1) is ground in a grinding chamber using aluminium oxide grinding beads having a diameter of between 1.0 and 1.6 mm, added in an amount so as tofill approximately 80 % of the volume of the grinding chamber, and at a grinding speed of 2500 rpm at 24°C for 180 minutes, under a slurry re-circulation rate of 700 ml/minutes, and measuring the pH over time.

Solids content of an aqueous slurry [0101] The slurry solids content (also known as "dry weight") is determined using a Moisture Analyser HR73 commer-cialised by Mettler-Toledo with the following settings: temperature of 120°C, automatic switch off 3, standard drying, 5-20 g of slurry.

Calcium anión salt:calcium carbonate mass ratio in a sample of material [0102] Calcium anión salt:calcium carbonate mass ratio was evaluated based on the weight of calcium carbonate in a dried and washed sample of material, which is determined by thermogravimetric analysis (TGA) using a Mettler Toledo TGA 851 using a sample of 500 +/- 50 mg and scanning temperatures as follows: 25 to 200°C at a rate of 20°C/minute; 200°C maintained 15 minutes; 200 to 400°C at a rate of 20°C/minute; 400°C maintained 15 minutes; under an air flow of 80 ml/min and a nitrogen gas flow of 15 ml/min. This measurement provides a mass of C02 gas released from the sample, relative to which a mass of calcium carbonate is calculated. The difference between this calcúlate mass of calcium carbonate and the mass of the sample provided corresponds to the mass of calcium anión salt

Preparation of PCC-comprising pigments of Step a) [0103] The following is a description of the preparation of the PCC-comprising pigments of Step a) implemented in subsequent tests described hereafter.

Preparation of a slurry of undispersed, scalenohedral and calcitic PCC (PCC1) [0104] PCC1 was synthesised by bubbling C02 through a slurry of calcium hydroxide so as to obtain a product in slurry featuring the specific surface area and weight median particle diameter, as determined according to the measurement methods hereabove, given in Table 1, and formed of essentially the scalenohedral morphology of the calcite phase as determined by XRD analysis. The slurry solids was adjusted to 17 % by weight. The pH of this slurry, as measured according to the measurement method given above, was between 8 and 9.5.

[0105] A sample of this PCC was subsequently wet ground to measure the pH evolution, according to the test method given above. During this grinding, the slurry pH was observed to rise by more than 2 and more than a corresponding slurry wherein the surface-reacted PCC was entirely replaced with GCC.

[0106] A sample of this PCC was alsosubjectedto the hydrophilicity test given above, and determined to be hydrophilic. Preparation of a slurry of dispersed, scalenohedral and calcitic PCC (PCC2) [0107] PCC2 was synthesised by bubbling C02 through a slurry of calcium hydroxide so as to obtain a product in slurry featuring the specific surface area and weight median particle diameter, as determined according to the measurement methods hereabove, given in Table 1, and formed of essentially the scalenohedral morphology of the calcite phase as determ ined by XRD analysis. The slurry solids was adjusted to 40 % by weight in the presence of a polyacrylate-based dispersant. The pH of this slurry, as measured according to the measurement method given above, was between 8 and 9.5.

[0108] A sample of this PCC was subsequently wet ground to measure the pH evolution, according to the test method given above. During this grinding, the slurry pH was observed to rise by more than 2 and more than a corresponding slurry wherein the surface-reacted PCC was entirely replaced with GCC.

[0109] A sample of this PCC was also subjected to the hydrophilicity test given above, and determined to be hydrophilic. Preparation of a slurry of undispersed, aragonitic PCC (PCC3) [0110] PCC3 was synthesised by bubbling C02 through a slurry of calcium hydroxide so as to obtain a product in slurry featuring the specific surface area and weight median particle diameter, as determined according to the measurement methods hereabove, given in Table 1, and formed of essentially the aragonitic morphology as determined by XRD analysis. The slurry solids was adjusted to 17 % by weight. The pH of this slurry, as measured according to the measurement method given above, was between 8 and 9.5.

[0111] A sample of this PCC was subsequently wet ground to measure the pH evolution, according to the test method given above. During this grinding, the slurry pH was observed to rise by more than 2 and more than a corresponding slurry wherein the surface-reacted PCC was entirely replaced with GCC.

[0112] A sample of this PCC was also subjected to the hydrophilicity test given above, and determined to be hydrophilic. Preparation of a slurry of undispersed, rhombohedral PCC (PCC4) [0113] PCC4 was synthesised by bubbling C02 through a slurry of calcium hydroxide so as to obtain a product in slurry featuring the specific surface area and weight median particle diameter, as determined according to the measurement methods hereabove, given in Table 1, and formed of essentially the rhomobohedral morphology as determined by XRD analysis. The slurry solids was adjusted to 17 % by weight. The pH of this slurry, as measured according to the measurement method given above, was between 8 and 9.5.

[0114] A sample of this PCC was subsequently wet ground to measure the pH evolution, according to the test method given above. During this grinding, the slurry pH was observed to rise by more than 2 and more than a corresponding slurry wherein the surface-reacted PCC was entirely replaced with GCC.

[0115] Asampleofthis PCC was alsosubjected to the hydrophilicity testgiven above, and determined to be hydrophilic. Example 1 [0116] The following Example is illustrative the prior art, and involves contacting a PCC pigment with H30+ and a phosphate-comprising anión in the absence of additional soluble calcium ions.

[0117] In a stainless Steel reactor, an aqueous slurry is prepared by adjusting the solids contentof the aqueous slurry of the PCC described in the Table herebelow, such that the slurry obtained has a solids contentof 10 % by dry weight. The temperature of this slurry is thereafter brought to and maintained at 70°C.

[0118] Under stirring such that an essentially laminar flow is established, H3P04 in an amount corresponding to 30 % by weight on PCC weight and to approximately 3x10-3 moles H3P04 per gram PCC is added to the PCC slurry over a period of 10 minutes. Following this addition, the slurry is stirred for an additional 5 minutes.

[0119] The resulting slurry is allowed to sit overnight before filtering and drying the obtained product. The final specific surface area of this dry product is the measured and reported in the Table below.

Table 1

Example 2 [0120] The following Exam piéis illustrative of the invention, and involves contacting PCC1 with a phosphate-comprising anión (provided in the form of an acid), in the presence of excess soluble calcium ions, where soluble calcium ions are generated on contacting the PCC with an acid or an acid salt having a soluble corresponding calcium salt.

[0121] In a stainless Steel reactor, an aqueous slurry is prepared by adjusting the solids contentof the aqueous slurry of PCC1 described hereabove, such that the slurry obtained has a solids contentof 10 % by dry weight. The temperature of this slurry is thereafter brought to and maintained at a reaction temperature defined in the Table herebelow under "Tslurry".

[0122] Under stirring such that an essentially laminar flow is established, an acid or an acid salt having a soluble corresponding calcium salt (Additivel) in an amount corresponding to a given mole equivalents H30+ ions per gram PCC on contacting the precipitated calcium carbonate (which corresponds to a generation of a given mole equivalents of solubilised calcium ions, per gram PCC, both of these given valúes being listed in the Table herebelow), is added to the PCC slurry.

[0123] Thereafter, H3P04 in an amount corresponding to 30 % by weight on PCC weight and to approximately 3x10'3 moles H3P04 per gram PCC is added to this slurry over a period of 10 minutes. Following this addition, the slurry is stirred for an additional 5 minutes. During this period, the pH of the slurry was observed to decrease temporarily to a valué of less than 6.0.

[0124] The final solids of the obtained slurry was between 8 and 12% by weight.

[0125] The resulting slurry is allowed to sit overnight before filtering and drying the obtained product. The final specific surface area of this dry product is measured and listed in the Table herebelow. Test 1 of Example 1 is also listed in the Table herebelow as a reference.

Table 2

(continued)

[0126] ln all case, when the product obtained according to the process of the invention was wet ground according to the method provided above, the pH during wet grinding rose by more than 2 and more than a corresponding slurry wherein the surface-reacted PCC was entirely replaced with GCC.

[0127] ln all case, when the product obtained according to the process of the invention was analysed by TGA as described above, a calcium anión salt:calcium carbonate mass ratio of between 20:80 and 60:40 was observed.

[0128] XRD analyses of the producís obtained according to the process of the invention indicated the presence of calcium phosphate minerals as well as calcium carbonate.

Example 3 [0129] Thefollowing Example is illustrativeofthe invention, and involvescontacting PCC1 with a phosphate-comprising anión (provided in the form of an acid), in the presence of excess soluble calcium ions, where soluble calcium ions are generated on contacting the PCC with an acid or an acid salt having a soluble corresponding calcium salt, and where said acid or acid salt is dosed at the same time as the phosphate-comprising anión.

[0130] ln a stainless steel reactor, an aqueous slurry is prepared by adjusting the solids contentof the aqueous slurry of PCC1 described hereabove, such that the slurry obtained has a solids contentof 10 % bydry weight. The temperature of this slurry is thereafter brought to and maintained at a reaction temperature defined in the Table herebelow under "Tslurry".

[0131] Under stirring such that an essentially laminar flow is established, an acid or an acid salt having a soluble corresponding calcium salt (Additive 1) in an amount corresponding to a given mole equivalents H30+ ions per gram PCC on contacting the precipitated calcium carbonate (which corresponds to a generation of a given mole equivalents of solubilised calcium ions, per gram PCC, both of these given valúes being listed in the Table herebelow), is added to the PCC slurry, whiles simultaneously adding H3P04 in an amount corresponding to 30 % by weight on PCC weight and to approximately 3x10"3 moles H3P04 per gram PCC is added to this slurry overa period of 10 minutes. Following this addition, the slurry is stirred for an additional 5 minutes. During this period, the pH of the slurry was observed to decrease temporarily to a valué of less than 6.0.

[0132] The final solids of the obtained slurry was between 8 and 12% by weight.

[0133] The resulting slurry is allowed to sit overnight before filtering and drying the obtained product. The final specific surface area of this dry product is measured and listed in the Table herebelow.

[0134] Test 1 of Example 1 is also listed in the Table herebelow as a reference.

Table 3

[0135] In all case, when the product obtained according to the process of the invention was wet ground according to the method provided above, the pH during wet grinding rose by more than 2 and more than a corresponding slurry wherein the surface-reacted PCC was entirely replaced with GCC.

[0136] In all case, when the product obtained according to the process of the Invention was analysed by TGA as described above, a calcium anión salt:calcium carbonate mass ratio of between 20:80 and 60:40 was observed.

[0137] XRD analyses of the producís obtained according to the process of the invention indicated the presence of calcium phosphate minerals as well as calcium carbonate.

Example 4 [0138] Thefollowing Example is illustrativeofthe invention, and involvescontacting PCC1 with a phosphate-comprising anión (provided in the form of an acid), in the presence of excess soluble calcium ions, where soluble calcium ions are provided by the addition of a soluble neutral calcium salt.

[0139] In a stainless steel reactor, an aqueous slurry is prepared by adjusting the solids contentof the aqueous slurry of PCC1 described hereabove, such that the slurry obtained has a solids contentof 10 % bydry weight. The temperature of this slurry is thereafter brought to and maintained at a reaction temperature defined in the Table herebelow under "Tslurry".

[0140] Under stirring such that an essentially laminarflow is established, a soluble neutral calcium salt (Additivel) in an amount corresponding to a given mole equivalents Ca2+ ions per gram PCC (valúes being Usted in the Table herebelow), is added to the PCC slurry.

[0141] Thereafter, H3P04 in an amount corresponding to 30 % by weight on PCC weight and to approximately 3x10"3 moles H3PO4 per gram PCC is added to this slurry over a period of 10 minutes. Following this addition, the slurry is stirred for an additional 5 minutes. During this period, the pH of the slurry was observed to decrease temporarily to a valué of less than 6.0.

[0142] The final solids of the obtained slurry was between 8 and 12% by weight.

[0143] The resulting slurry is allowed to sitovernight before filtering and drying the obtained product. The final specific surface area of this dry product is measured and listed in the Table herebelow. Test 1 of Example 1 is also listed in the Table herebelow as a reference.

Table 4

[0144] In all case, when the product obtained according to the process of the invention was wet ground according to the method provided above, the pH during wet grinding rose by more than 2 and more than a corresponding slurry wherein the surface-reacted PCC was entirely replaced with GCC.

[0145] In all case, when the product obtained according to the process of the invention was analysed by TGA as described above, a calcium anión salt:calcium carbonate mass ratio of between 20:80 and 60:40 was observed.

[0146] XRD analyses of the producís obtained according to the process of the invention indicated the presence of calcium phosphate minerals as well as calcium carbonate.

Example 5 [0147] Thefollowing Example is illustrativeofthe invention, and involvescontacting PCC1 with a phosphate-comprising anión (provided in the form of a salt), in the presence of excess soluble calcium ions, where the soluble calcium ions are generated on contacting the PCC with an acid or an acid salt having a soluble corresponding calcium salt.

[0148] In a stainless steel reactor, an aqueous slurry is prepared by adjusting the solids contení of the aqueous slurry of PCC1 described hereabove, such that the slurry obtained has a solids contení of 10 % bydry weight. The temperature of this slurry is thereafter brought to and maintained at a reaction temperature defined in the Table herebelow under "Tslurry".

[0149] Under stirring such that an essentially laminar flow is established, an acid or an acid salt having a soluble corresponding calcium salt (Additivel) in an amount corresponding to a given mole equivalents H30+ ions per gram PCC on contacting the precipitated calcium carbonate (which corresponds to a generation of a given mole equivalents of solubilised calcium ions, per gram PCC, both ofthese given valúes being listed in the Table herebelow), is added to the PCC slurry.

[0150] Thereafter, Na(3_X)HxP04 where x = 0-1 (the valué of x being indicated in the Table below) in an amount corresponding to approximately 3x10-3 moles Na(3_X)HxP04 per gram PCC is added to this slurry over a period of 10 minutes. Following this addition, the slurry is stirred for an additional 5 minutes. During this period, the pH of the slurry was observed to decrease temporarily to a valué of less than 6.0.

[0151] The final solids of the obtained slurry was between 8 and 12% byweight.

[0152] The resulting slurry is allowed to sit overnight before filtering and drying the obtained product. The final specific surface area of this dry product is measured and listed in the Table herebelow. Test 1 of Example 1 is also listed in the Table herebelow as a reference.

Table 5

[0153] In all case, when the product obtained according to the process of the invention was wet ground according to the method provided above, the pH during wet grinding rose by more than 2 and more than a corresponding slurry wherein the surface-reacted PCC was entirely replaced with GCC.

[0154] In all case, when the product obtained according to the process of the invention was analysed by TGA as described above, a calcium anión salt:calcium carbonate mass ratio of between 20:80 and 60:40 was observed.

[0155] XRD analyses of the products obtained according to the process of the invention indicated the presence of calcium phosphate minerals as well as calcium carbonate.

Example 6 [0156] The following Example is illustrativeof the invention, and involves contacting PCC1 or PCC2 with a phosphate-comprising anión (provided in theform of an acid), in the presence of excess soluble calcium ions, where soluble calcium ions are generated on contacting the PCC with an acid or an acid salt having a soluble corresponding calcium salt, in the presence of a further additional additive which increases the ionic strength of the slurry.

[0157] In a stainless Steel reactor, an aqueous slurry is prepared by adjustlng the solids content of the aqueous slurry of PCC1 or PCC2 described hereabove, such that the slurry obtained has a solids content of 10 % by dry weight. The temperature of this slurry is thereafter brought to and maintained at a reaction temperature defined in the Table herebelow under "Tslurry".

[0158] Under stirring such that an essentially laminar flow is established, an acid or an acid salt having a soluble corresponding calcium salt (Additivel) in an amount corresponding to a given mole equivalents H30+ ions per gram PCC on contacting the precipitated calcium carbonate (which corresponds to a generation of a given mole equivalents of solubilised calcium ions, per gram PCC, both ofthese given valúes being listed in the Table herebelow), is added to the PCC slurry.

[0159] Under continued stirring, a neutral, soluble salt capable of increasing the ionic strength of the slurry is added (Additive 2), in an amount listed in the Table herebelow.

[0160] Thereafter, H3P04 in an amount corresponding to 30 % byweighton PCC and to approximately 3x10-3 moles H3PO4 per gram PCC is added to this slurry over a period of 10 minutes. Following this addition, the slurry is stirred for an additional 5 minutes. During this period, the pH of the slurry was observed to decrease temporarily to a valué of less than 6.0.

[0161] The final solids of the obtained slurry was between 8 and 12% byweight.

[0162] The resulting slurry is allowed to sit overnight before filtering and drying the obtained product. The final specific surface area of this dry product is measured and listed in the Table herebelow. Test 1 of Example 1 is also Usted in the Table herebelow as a reference.

Table 6

[0163] In all case, when the product obtained according to the process of the invention was wet ground according to the method provided above, the pH during wet grinding rose by more than 2 and more than a corresponding slurry wherein the surface-reacted PCC was entirely replaced with GCC.

[0164] In all case, when the product obtained according to the process of the invention was analysed by TGA as described above, a calcium anión salt:calcium carbonate mass ratio of between 20:80 and 60:40 was observed.

[0165] XRD analyses of the producís obtained according to the process of the invention indicated the presence of calcium phosphate minerals as well as calcium carbonate.

Example 7 [0166] The following Example is illustrative of the invention, and involvescontacting PCC3with a phosphate-comprising anión (provided in the form of an acid), in the presence of excess soluble calcium ions, where soluble calcium ions are generated on contacting the PCC with an acid or an acid salt having a soluble corresponding calcium salt.

[0167] In a stainless steel reactor, an aqueous slurry is prepared by adjusting the solids contení of the aqueous slurry of PCC3 described hereabove, such that the slurry obtained has a solids contení of 10 % by dry weight. The temperature of this slurry is thereafter brought to and maintained at a reaction temperature defined in the Table herebelow under "Tslurry".

[0168] Under stirring such that an essentially laminar flow is established, an acid or an acid salt having a soluble corresponding calcium salt (Additive 1) in an amount corresponding to a given mole equivalents H30+ ions per gram PCC on contacting the precipitated calcium carbonate (which corresponds to a generation of a given mole equivalents of solubilised calcium ions, per gram PCC, both ofthese given valúes being listed in the Table herebelow), is added to the PCC slurry.

[0169] Thereafter, H3P04 in an amount corresponding to 30 % byweighton PCC and to approximately 3x10-3 moles H3P04 per gram PCC is added to this slurry over a period of 10 minutes. Following this addition, the slurry is stirred for an additional 5 minutes. During this period, the pH of the slurry was observed to decrease temporarily to a valué of less than 6.0.

[0170] The final solids of the obtained slurry was between 8 and 12% byweight.

[0171] The resulting slurry is allowed to sit overnight before filtering and drying the obtained product. The final specific surface area of this dry product is measured and listed in the Table herebelow.

[0172] Test 2 of Example 1 is also listed in the Table herebelow as a reference.

Table 7

[0173] In all case, when the product obtained according to the process of the invention was wet ground according to the method provided above, the pH during wet grinding rose by more than 2 and more than a corresponding slurry wherein the surface-reacted PCC was entirely replaced with GCC.

[0174] In all case, when the product obtained according to the process of the invention was analysed by TGA as described above, a calcium anión salt:calcium carbonate mass ratio of between 20:80 and 60:40 was observed.

[0175] XRD analyses of the producís obtained according to the process of the invention indicated the presence of calcium phosphate minerals as well as calcium carbonate.

Example 8 [0176] Thefollowing Example is illustrative of the invention, and involvescontacting PCC2with a phosphate-comprising anión (provided in the form of an acid), in the presence of excess soluble calcium ions, where soluble calcium ions are generated on contacting the PCC with an acid or an acid salt having a soluble corresponding calcium salt.

[0177] In a stainless steel reactor, an aqueous slurry is prepared by adjusting the solids content of the aqueous slurry of PCC2 described hereabove, such that the slurry obtained has a solids content of 10 % bydry weight. The temperature of this slurry is thereafter brought to and maintained at a reaction temperature defined in the Table herebelow under "Tslurry".

[0178] Under stirring such that an essentially laminar flow is established, an acid or an acid salt having a soluble corresponding calcium salt (Additivel) in an amount corresponding to a given mole equivalents H30+ ions per gram PCC on contacting the precipitated calcium carbonate (which corresponds to a generation of a given mole equivalents of solubilised calcium ions, per gram PCC, both of these given valúes being listed in the Table herebelow), is added to the PCC slurry.

[0179] Thereafter, H3P04 in an amount corresponding to 30 % by weight on PCC and to approximately 3x10"3 moles H3P04 per gram PCC is added to this slurry over a period of 10 minutes. Following this addition, the slurry is stirred for an additional 5 minutes. During this period, the pH of the slurry was observed to decrease temporarily to a valué of less than 6.0.

[0180] The final solids of the obtained slurry was between 8 and 12% by weight.

[0181] The resulting slurry is allowed to sit overnight before filtering and drying the obtained product. The final specific surface area of this dry product is measured and listed in the Table herebelow.

[0182] Test 2 of Example 1 is also listed in the Table herebelow as a reference.

Table 8

(continued)

[0183] ln all case, when the product obtained according to the process of the invention was wet ground according to the method provided above, the pH during wet grinding rose by more than 2 and more than a corresponding slurry wherein the surface-reacted PCC was entirely replaced with GCC.

[0184] ln all case, when the product obtained according to the process of the invention was analysed by TGA as described above, a calcium anión salt:calcium carbonate mass ratio of between 20:80 and 60:40 was observed.

[0185] XRD analyses of the producís obtained according to the process of the invention indicated the presence of calcium phosphate minerals as well as calcium carbonate.

Example 9 [0186] Thefollowing Example is illustrative of the invention, and involvescontacting PCC4with a phosphate-comprising anión (provided in the form of an acid), in the presence of excess soluble calcium ions, where soluble calcium ions are generated on contacting the PCC with an acid or an acid salt having a soluble corresponding calcium salt.

[0187] ln a stainless steel reactor, an aqueous slurry is prepared by adjusting the solids contení of the aqueous slurry of PCC4 described hereabove, such that the slurry obtained has a solids contení of 10 % by dry weight. The temperature of this slurry is thereafter brought to and maintained at a reaction temperature defined in the Table herebelow under "Tslurry".

[0188] Under stirring such that an essentially laminar flow is established, an acid or an acid salt having a soluble corresponding calcium salt (Additive 1) in an amount corresponding to a given mole equivalents H30+ ions per gram PCC on contacting the precipitated calcium carbonate (which corresponds to a generation of a given mole equivalents of solubilised calcium ions, per gram PCC, both of these given valúes being Usted in the Table herebelow), is added to the PCC slurry.

[0189] Thereafter, H3P04 in an amount corresponding to 30 % by weight on PCC and to approximately 3x10"3 moles H3P04 per gram PCC is added to this slurry over a period of 10 minutes. Following this addition, the slurry is stirred for an additional 5 minutes. During this period, the pH of the slurry was observed to decrease temporarily to a valué of less than 6.0.

[0190] The final solids of the obtained slurry was between 8 and 12% by weight.

[0191] The resulting slurry is allowed to sit overnight before filtering and drying the obtained product. The final specific surface area of this dry product is measured and listed in the Table herebelow.

[0192] Test 2 of Example 1 is also listed in the Table herebelow as a reference.

Table 9

[0193] In all case, when the product obtained according to the process of the invention was wet ground according to the method provided above, the pH during wet grinding rose by more than 2 and more than a corresponding slurry wherein the surface-reacted PCC was entirely replaced with GCC.

[0194] In all case, when the product obtained according to the process of the invention was analysed by TGA as described above, a calcium anión salt:calcium carbonate mass ratio of between 20:80 and 60:40 was observed.

[0195] XRD analyses of the producís obtained according to the process of the invention indicated the presence of calcium phosphate minerals as well as calcium carbonate.

Example 10 [0196] Thefollowing Example is illustrative of the invention, and involvescontacting PCC1 with a phosphate-comprising anión (provided in the form of an acid), in the presence of excess soluble calcium ions, where soluble calcium ions are generated on contacting the PCC with an acid or an acid salt having a soluble corresponding calcium salt.

[0197] In a stainless steel reactor, an aqueous slurry is prepared by adjusting the solids contení of the aqueous slurry of PCC1 described hereabove, such that the slurry obtained features a solids contení of 20 % by dry weight. The temperature of this slurry is thereafter brought to and maintained at a reaction temperature defined in the Table herebelow under "Tslurry".

[0198] Under stirring such that laminar flow is established, an acid or an acid salt having a soluble corresponding calcium salt (Additivel) in an amount corresponding to a given mole equivalents H30+ ions pergram PCCon contacting the precipitated calcium carbonate (which corresponds to a generation of a given mole equivalents ofsolubilised calcium ions, per gram PCC, both of these given valúes being listed in the Table herebelow), is added to the PCC slurry.

[0199] Thereafter, H3P04 in an amount corresponding to 30 % by weight on PCC weight and to approximately 3x10"3 moles H3P04 per gram PCC is added to this slurry over a period of 10 minutes. Following this addition, the slurry is stirred for an additional 5 minutes. During this period, the pH of the slurry was observed to decrease temporarily to a valué of less than 6.0.

[0200] The final solids of the obtained slurry was between 8 and 12% by weight.

[0201] The resulting slurry is allowed to sitovernight before filtering and drying the obtained product. The final specific surface area of this dry product is measured and listed in the Table herebelow.

[0202] Test 1 of Example 1 is also Usted in the Table herebelow as a reference.

Table 10

[0203] In all case, when the product obtained according to the process of the invention was wet ground according to the method provided above, the pH during wet grinding rose by more than 2 and more than a corresponding slurry wherein the surface-reacted PCC was entirely replaced with GCC.

[0204] In all case, when the product obtained according to the process of the invention was analysed by TGA as described above, a calcium anión salt:calcium carbonate mass ratio of between 20:80 and 60:40 was observed.

[0205] XRD analyses of the producís obtained according to the process of the invention indicated the presence of calcium phosphate minerals as well as calcium carbonate.

Claims 1. Slurry of surface-reacted precipitated calcium carbonate (PCC)-comprising pigment obtained by a process, com-prising the following steps: a) providing at least one precipitated calcium carbonate (PCC)-comprising pigment; b) providing H30+ ions; c) providing at least one anión being capable offorming water-insoluble calcium salís, said anión being solubilised in an aqueous médium; d) contacting said PCC-comprising pigment with said H30+ ions and with said solubilised anions in an aqueous médium to form a slurry of surface-reacted PCC-comprising pigment, wherein said surface-reacted PCC com-prises an insoluble, at least partially crystalline calcium salí of said anión formed on the surface of at least parí of the PCC provided in step a); characterised in that - an excess of solubilised calcium ions is provided during Step d); - said at least partially crystalline calcium salí of said anión extends from the surface of at least part of the PCC of said PCC-comprising pigment provided in Step a). 2. The slurry according to claim 1, characterised in that said PCC-comprising pigment of Step a) has a weight median diameter of 0.01 to 10 μ(η, and more preferably of 0.5 to 2 μίτι. 3. The slurry according to any of claims 1 or 2, characterised in that said PCC-comprising pigment of Step a) also comprises one or more of the following: tale, clay, plástic hollow-sphere pigments ortitanium dioxide. 4. The slurry according to any of claims 1 to 3, characterised in that said PCC-comprising pigment of Step a) is provided in the form of an aqueous slurry, said slurry preferably having a pH of less than 11, and more preferably of less than 10.5, prior to Step c). 5. The slurry according to any of claims 1 to 4, characterised in that said H30+ ions of Step b) are provided via one or more of the following Routes: - Route IB: addition of acid or an acid salt of said anión; - Route IIB: addition oían acid oran acid salt which simultaneously serves to provide all or part of said excess solubilised calcium ions, i.e. by direct addition of soluble calcium ions and/or by dissolution of the PCCstarting material to libérate calcium ions. 6. The slurry according to claim 5, characterised in that in the case of Route IIB, said acid or acid salt which simultaneously serves to provide all or part of said excess solubilised calcium ions is preferably selected from the group comprising sulphur-comprising acids, such as sulphuric acid, hydrochloric acid, perchloric acid, formic acid, lactic acid, acetic acid, nitric acid, and acid salís thereof, such as soluble calcium acid salís thereof. 7. The slurry according to any of claims 1 to 6, characterised in that said anión of Step c) is added in the form of a soluble neutral or acid salt, or in the form of an acid, provided it is solubilised before and/or during Step d), and preferably from one or more of the following: phosphate-comprising anions such as P043- and HP042", oxalate anions (C2042"), carbonate-comprising anions in the form of C032-, phosphonate anions, succinate anions or fluoride anions. 8. The slurry according to any of claims 1 to 7, characterised in that said anión is added in a quantity corresponding to between 5 and 50 %, preferably between 15 and 30 %, by weight based on the weight of said PCC provided in Step a). 9. The slurry according to any of claims 1 to 8, characterised in that said anión is contacted with said PCC after contacting said PCC with said H30+ ions. 10. The slurry according to any of claims 1 to 9, characterised in that said excess solubilised calcium ions provided during Step d) are provided via one or more of the following Routes: - Route ΙΑ: addition of a soluble neutral or acid calcium salt; - Route IIA: addition of an acid or a neutral or acid non-calcium salt which generates a soluble neutral or acid calcium salt in situ. 11. The slurry according to claim 10, characterised in that when said excess solubilised calcium ions are provided vía Route IA, they are selected from among one or more of the following: CaCI2 or Ca(N03)2. 12. The slurry according to any of claims 1 to 11, characterised in that solubilised calcium Ions are provided ¡n a quantity correspondlng to greater than or equal to 3%, preferably greater than or equal to 5%, by weight based on the weight of said PCC provided in Step a). 13. The slurry according to any of claims 1 to 12, characterised in that Step d) is carried out at temperatures of above 50°C, and preferably of above 60°C. 14. The slurry according to any of claims 1 to 13, characterised in that Step d) takes place In the presence of at least one compound selected from the group consisting of silicate, silica, earth alkali metal alumínate, or mixtures thereof, said slllcate being preferably selected from an aluminium silicate or an earth alkali metal silicate. 15. The slurry according to any of claims 1 to 14, characterised in that Step d) takes place in the presence of an additive which increases the ionic strength of the slurry, such as an inert, non-calcium salt, said additive being preferably selected from NaCI or KNOs, or mixtures thereof. 16. The slurry according to any of claims 1 to 15, characterised in that said process is a continuous process. 17. The slurry according to any of claims 1 to 16, characterised in that a dispersant is added to said slurry formed in Step d). 18. The slurry according to any one of the preceding claims, characterised in that said surface-reacted PCC comprises an insoluble, at least partially crystalline calcium salt of said anión preferably including one or more of the following: octacalcium phosphate (OCP), hydroxyapatite (HAP) or tricalcium phosphate (TCP). 19. The slurry according to any one of the preceding claims, caracterised in that said surface-reacted PCC has a calcium salt of the anión: calcium carbonate contení mass ratio of 5:95 to 95:5, preferably of 20:80 to 60:40, and more preferably of 25:75 to 50:50. 20. The slurry according to any one of the preceding claims, characterised in that said surface-reacted PCC has a BET specific surface area that is greater than the BET specific surface area obtained following contacting the same PCC provided in Step a), either simultaneously or in distinct steps, with the same solubilised anión of Step b) and with H30+ ions, such that: - the H30+ ions are provided solely vía the addition of said anión, i.e. said H30+ ions are provided in a molar quantity that is less than or equal to that required to theoretically balance the ionic charge of said anión; and, - neither Route IA ñor Route IB are implemented. 21. The slurry according to any one of the preceding claims, characterised in that said surface-reacted PCC has a BET specific surface area that is at least three times, and more preferably seven times, greater than the BET specific surface area ofthe PCC in the PCC-comprising pigment provided in Step a). 22. The slurry according to any one ofthe preceding claims, characterised in that said surface-reacted PCC has a BET specific surface area of from 20 to 120 m2/g, preferably from 55 to 115 m2/g, more preferably from 60 to 100 m2/g. 23. The slurry according to any of the preceding claims, characterised in that said slurry comprising surface-reacted PCC has a solids contení of up to 25 %, and preferably between 5 and 20% by weight. 24. The slurry according to any one of the preceding claims, characterised in that said surface-reacted PCC has a pore volume of 1 to 2.2 cm3/g. 25. Dry surface-reacted PCC-comprising pigment, characterised in that it is obtained from a slurry according to any one of the preceding claims, wherein the dry surface reacted PCC preferably additionally is treated with fatty acids. 26. Use of a surface-reacted PCC according to claim 25 or a surface-reacted PCC slurry according to any one of claims 1 to 24, in paper, tissue paper, plastics, paints, water treatment, or for the removal of EDC compounds.

Patentansprüche 1. Aufschlámmung von einem Pigment, das gefálltes Calciumcarbonat (PCC) umfasst, das an der Oberfláche eine Reaktion eingegangen ist, erhalten durch ein Verfahren, das die folgenden Schritte umfasst: a) Bereitstellen von wenigstens einem gefálltes Calciumcarbonat (PCC) umfassenden Pigment, b) Bereitstellen von H30+-lonen, c) Bereitstellen von wenigstens einem Anión, das in der Lage ist, wasserunlósliche Calciumsalze zu bilden, wobei das Anión in einem wássrigen Médium gelóst ist, d) Inkontaktbringen des PCC umfassenden Pigments mit den H30+-lonen und mit den in einem wássrigen Médium gelósten Anionen unter Bildung einer Aufschlámmung von einem Pigment, das PCC umfasst, das an der Oberfláche eine Reaktion eingegangen ist, wobei das PCC, das der Oberfláche eine Reaktion eingegangen ist, ein unlósliches, wenigstens teilweise kristallines Calciumsalz des Anions umfasst, das sichan der Oberfláche von wenigstens einem Teil des in Schritt a) bereitgestellten PCC gebildet hat, dadurch gekennzeichnet, dass - ein Überschuss gelóster Calciumionen wáhrend Schritt d) bereitgestellt wird, - sich das wenigstens teilweise kristalline Calciumsalz des Anions von der Oberfláche von wenigstens einem Teil des PCCs des in Schritt a) bereitgestellten PCC umfassenden Pigments erstreckt. 2. Aufschlámmung nach Anspruch 1, dadurch gekennzeichnet, dass das PCC umfassende Pigment aus Schritt a) einen gewichtsgemittelten Durch-messervon 0,01 bis 10 μΐη aufweist, und bevorzugter von 0,5 bis 2 μηι. 3. Aufschlámmung nach einem der Ansprüche 1 oder 2, dadurch gekennzeichnet, dass das PCC umfassende Pigment aus Schritt a) auch einen oder mehrere der folgenden umfasst: Talk, Ton, Kunststoffhohlkugelpigmente oderTitandioxid. 4. Aufschlámmung nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, dass das PCC umfassende Pigment aus Schritt a) in der Form einer wássrigen Aufschlámmung bereitgestellt wird, wobei die Aufschlámmung bevorzugt einen pH von kleiner 11 aufweist, und bevorzugter von kleiner 10,5, vor Schritt c). 5. Aufschlámmung nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, dass die H30+-lonen aus Schritt b) über eine oder mehrere der folgenden Routen bereitgestellt werden: - Route IB: Zugabe von Sáure oder einem Sáuresalz des Anions; - Route IIB: Zugabe einer Sáure oder eines Sáuresalzes, die bzw. das gleichzeitig zur Bereitstellung von alien oder einem Teil der überschüssigen, gelósten Calciumionen dient, d.h. durch direkte Zugabe der lóslichen Calciumionen und/oder durch Auflósung des PCC-Ausgangsmaterials, um Calciumionen freizusetzen. 6. Aufschlámmung nach Anspruch 5, dadurch gekennzeichnet, dass im Falle von Route IIB die Sáure oder das Sáuresalz, die bzw. gleichzeitig zur Bereitstellung von alien oder einem Teil der überschüssigen, gelósten Calciumionen dient, bevorzugt ausgewáhlt ist aus der Gruppe umfassend Schwefel umfassende Sáuren, wie Schwefelsáure, Salzsáure, Perchlorsáure, Amei-sensáure, Milchsáure, Essigsáure, Salpetersáure, sowie Sáuresalze davon, wie lósliche Calciumsalze davon. 7. Aufschlámmung nach einem der Ansprüche 1 bis 6, dadurch gekennzeichnet, dass das Anión aus Schritt c) zugegeben wird in der Form eines lóslichen neutralen oder sauren Salzes, oder in der Form einer Sáure, sofern es oder sie vor oder wáhrend Schritt d) gelóst wird, und bevorzugt aus einem oder mehreren derfolgenden: Phosphat umfassende Anionen, wie P043- und FiP042‘, Oxalat-Anionen (C2042-), Carbonat umfassende Anionen in der Form von C032-, Phosphonat-Anionen, Succinat-Anionen oder Fluorid-Anionen. 8. Aufschlámmung nach einem der Ansprüche 1 bis 7, dadurch gekennzeichnet, dass das Anión in einer Menge zugegeben wird, die zwischen 5 und 50 Gew.-% ent-spricht, bevorzugt zwischen 15 und 30 Gew.-%, bezogen auf das Gewicht des in Schritt a) bereitgestellten PCCs. 9. Aufschlámmung nach einem der Ansprüche 1 bis 8, dadurch gekennzeichnet, dass das Anión mit dem PCC in Kontakt gebracht wird nachdem das PCC mit den hi30+-lonen in Kontakt gebracht wurde. 10. Aufschlámmung nach einem der Ansprüche 1 bis 9, dadurch gekennzeichnet, dass die überschüssigen, gelósten Calciumionen, die wáhrend Schritt d) bereitgestellt werden, über eine oder mehrere der folgenden Routen bereitgestellt werden: - Route IA: Zugabe eines lóslichen neutralen oder sauren Calciumsalzes; - Route IIA: Zugabe einer Sáure oder eines neutralen oder sauren Nichtcalciumsalzes, welche bzw. welches ein lósliches neutrales odersaures Calciumsalz in situ erzeugt. 11. Aufschlámmung nach Anspruch 10, dadurch gekennzeichnet, dass die über Route IA bereitgestellten überschüssigen, gelósten Calciumionen ausgewáhlt sind aus einem oder mehreren der folgenden: CaCI2 oder Ca(N03)2. 12. Aufschlámmung nach einem der Ansprüche 1 bis 11, dadurch gekennzeichnet, dass die gelósten Calciumionen in einer Menge bereitgestellt werden, die grósser oder gleich 3 Gew.-% entspricht, bevorzugt grósser oder gleich 5 Gew.-%, bezogen auf das Gewicht des in Schritt a) bereitgestellten PCCs. 13. Aufschlámmung nach einem der Ansprüche 1 bis 12, dadurch gekennzeichnet, dass Schritt d) ausgeführt wird bei Temperaturen von über 50°C, und bevorzugt von über 60°C. 14. Aufschlámmung nach einem der Ansprüche 1 bis 13, dadurch gekennzeichnet, dass Schritt d) in der Gegenwart von wenigstens einer Verbindung stattfindet, welche ausgewáhlt ist aus der Gruppe bestehend ausSilikat, Kieselsáure, Erdalkalimetallaluminat, oderGemischen davon, wobei das Silikat bevorzugt ausgewáhlt ist aus einem Aluminiumsilikat oder einem Erdalkalimetallsilikat. 15. Aufschlámmung nach einem der Ansprüche 1 bis 14, dadurch gekennzeichnet, dass Schritt d) in der Gegenwart von einem Additiv stattfindet, welches die lonenstárke der Aufschlámmung erhóht, wie einem inerten Nichtcalciumsalz, wobei das Additiv bevorzugt ausgewáhlt ist aus NaCI oder KN03, oder Gemischen davon. 16. Aufschlámmung nach einem der Ansprüche 1 bis 15, dadurch gekennzeichnet, dass das Verfahren ein kontinuierliches Verfahren ist. 17. Aufschlámmung nach einem der Ansprüche 1 bis 16, dadurch gekennzeichnet, dass ein Dispergierungsmittel zu der in Schritt d)gebildeten Aufschlámmung zugegeben wird. 18. Aufschlámmung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass das PCC, das an der Oberfláche eine Reaktion eingegangen ist, ein unlósliches, wenigstens teilweise kristallines Calciumsalz des Anions umfasst, bevorzugt einschlieBlich einem oder mehreren derfolgenden: Octacalciumphosphat (OCP), Hydroxyapatit (HAP) oder Tricalciumphosphat (TCP). 19. Aufschlámmung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass das PCC, das an der Oberfláche eine Reaktion eingegangen ist, einen Massen-verháltnisgehalt von einem Calciumsalz des Anions : Calciumcarbonat von 5:95 bis 95:5 aufweist, bevorzugt von 20:80 bis 60:40, und bevorzugter von 25:75 bis 50:50. 20. Aufschlámmung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass das PCC, das an der Oberfláche eine Reaktion eingegangen ist, eine BET spe-zifische Oberfláche aufweist, die grósser ist ais die BET spezifische Oberfláche, die erhalten wird im Anschluss an das Inkontaktbringen desselben PCC, das in Schritt a) bereitgestelltwird, entwedergleichzeitig oder in individuellen Schritten, mit demselben gelósten Anión aus Schritt b) und mit H30+-lonen, so dass: - die H30+-lonen θυεεοΐιϋββΐίοΐι durch die Zugabe des Anions bereitgestellt werden, d.h. die H30+-lonen werden in einer molaren Menge bereitgestellt, die kleinerodergleich dem benótigten oderdem theoretischen Ausgleich der lonenladung des Anions ist; und - weder Route IA noch Route IB werden durchgeführt. 21. Aufschlámmung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass das PCC, das an der Oberfláche eine Reaktion eingegangen ist, eine BET spezifische Oberfláche aufweist, die wenigstens dreimal, und bevorzugter siebenmal grósser ist ais die BET spezifische Oberfláche des PCC in dem in Schritt a) bereitgestellten PCC umfassenden Pigment. 22. Aufschlámmung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass das PCC, das an der Oberfláche eine Reaktion eingegangen ist, eine BET spezifische Oberfláche von 20 bis 120 m2/g aufweist, bevorzugt von 55 bis 115 m2/g, bevorzugter von 60 bis 100 m2/g. 23. Aufschlámmung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die Aufschlámmung, die das PCC, das an der Oberfláche eine Reaktion eingegangen ist, umfasst, einen Feststoffgehaltvon biszu 25Gew.-% aufweist, und bevorzugtzwischen 5 und 20Gew.-%. 24. Aufschlámmung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass das PCC, das an der Oberfláche eine Reaktion eingegangen ist, ein Porenvolumen von 1 bis 2,2 cm3/g aufweist. 25. Trockenes Pigment, das PCC umfasst, das an der Oberfláche eine Reaktion eingegangen ist, dadurch gekennzeichnet, dass es erhalten wird aus einer Aufschlámmung gemáss einem der vorhergehenden Ansprüche, wobei das trockene PCC, das an der Oberfláche eine Reaktion eingegangen ist, bevorzugt zusátzlich mit Fettsáuren behandelt wird. 26. Verwendung eines PCC, das an der Oberfláche eine Reaktion eingegangen ist, gemáss Anspruch 25 oder einer Aufschlámmung eines PCCs, das an der Oberfláche eine Reaktion eingegangen ist, gemáss einem der Ansprüche 1 bis 24 in Papier, Tissue-Papier, Kunststoffen, Farben, bei der Wasserbehandlung, oder für die Entfernung von EDC-Verbindungen.

Revendications 1. Suspensión d’un pigment comprenant du carbonate de calcium précipité (PCC) ayant réagi en surface obtenue par un procédé comprenant les étapes suivantes: a) fournir au moins un pigment comprenant du carbonate de calcium précipité (PCC) ; b) fournir des ions H30+; c) fournir au moins un anión qui est capable de former des seis de calcium insolubles dans l’eau, ledit anión étantsolubilisé dans un milieu aqueux ; d) mettre en contact ledit pigment comprenant du PCC avec lesdits ions H30+ et avec lesdits anions solubilisés dans un milieu aqueux pourformer une suspensión du pigment comprenant du PCC ayant réagi en surface, ledit PCC ayant réagi en surface comprenant un sel caldque au moins partiellement cristallin et insoluble dudit anión formé sur la surface d’au moins une partie du PCC fourni dans l’étape a) ; caractérisée en ce que - un excés d’ions calcium solubilisés est fourni pendant l’étape d) ; - ledit sel caldque au moins partiellement cristallin dudit anión s’étend depuis la surface d’au moins une partie du PCC dudit pigment comprenant du PCC fourni dans l’étape a). 2. Suspensión selon la revendication 1, caractérisée en ce que ledit pigment comprenant du PCC de l’étape a) a un diamétre médian moyen de 0.01 á 10 μ(η, et plus préférablement de 0.5 á 2 μηι. 3. Suspensión selon la revendication 1 ou 2, caractérisée en ce que ledit pigment comprenant du PCC de l’étape a) comprend en outre un ou plusieurs des composants suivants : le tale, l’argile, les pigments plastiques sphériques creux ou le dioxyde de titane. 4. Suspensión selon l’une quelconque des revendications 1 á 3, caractérisée en ce que ledit pigment comprenant du PCC de l’étape a) est fourni sous la forme d’une suspensión aqueuse, ladite suspensión ayant de préférence un pH inférieur á 11, et plus préférablement inférieur á 10.5, avant l’étape c). 5. Suspensión selon l’une quelconque des revendications 1 á 4, caractérisée en ce que lesdits ions HsO+ de l’étape b) sont fournis par une ou plusieurs des voies suivantes : - voie IB : addition d’un acide ou d’un sel d’acide dudit anión ; - voie IIB : addition d’un acide ou d’un sel d’acide quisertsimultanémentáfournir la totalitéou une partie desdits ions calcium solubilisés en excés, c’est-á-dire par addition directe d’ions calcium solubles et/ou pardissolution du produit de départ, le PCC, pour libérer les ions calcium. 6. Suspensión selon la revendication 5, caractérisée en ce que dans le cas de la voie IIB, ledit acide ou sel d’aclde qui sert slmultanément á fournir la totalité ou une partie desdits ions calcium solubilisés en excés est de préférence choisi dans le groupe comprenant les acides á base de soufre, tels que l’acide sulfurique, l’acide chlorhydrique, l’acide perchlorique, l’acide formique, l’acide lactique, l’acide acétique, l’acide nitrique, et les seis d’acide de ceux-ci, tels que les seis calciques d’acide solubles de ceux-ci. 7. Suspensión selon l’une quelconque des revendications 1 á 6, caractérisée en ce que ledit anión de l’étape c) est ajouté sous la forme d’un sel neutre ou d’acide soluble ou sous la forme d’un acide, á condition qu’il soit solubilisé avant et/ou pendant l’étape d), et de préférence á partir d’un ou de plusieurs des composants suivants : anions á base de phosphate tels que P043- et HP042", anions á base d’oxalate (C2042-), anions á base de carbonate sous la forme de C032-, anions á base de phosphonate, anions á base de succinate ou anions á base de fluorure. 8. Suspensión selon l’une quelconque des revendications 1 á 7, caractérisée en ce que ledit anión est ajouté en une quantité correspondant á une plage comprise entre 5 et 50 %, de préférence entre 15 et 30 %, en poids par rapport au poids dudit PCC fourni dans l’étape a). 9. Suspensión selon l’une quelconque des revendications 1 á 8, caractérisée en ce que ledit anión est mis en contact avec ledit PCC aprés la mise en contact dudit PCC avec lesdits ions H30+. 10. Suspensión selon l’une quelconque des revendications 1 á 9, caractérisée en ce que lesdits ions calcium solubilisés en excés fournis pendant l’étape d) sont fournis par une ou plusieurs des voies suivantes : - Voie IA : addition d’un sel calcique neutre ou d’acide soluble ; - Voie IIA : addition d’un acide ou d’un sel non calcique neutre ou d’acide qui produit un sel caldque neutre ou d’acide soluble in situ. 11. Suspensión selon la revendication 10, caractérisée en ce que lorsque lesditsions caldques solubilisés en excés sontfournis par la voie IA, ils sontchoisis parmi un ou plusieurs des composants suivants : CaCI2 ou Ca(N03)2. 12. Suspensión selon l’une quelconque des revendications 1 á 11, caractérisée en ce que les ions calcium solubilisés sont fournis en une quantité correspondant á une valeur supérieure ou égale á 3 %, de préférence supérieure ou égale á 5 %, en poids par rapport au poids dudit PCC fourni dans l’étape a). 13. Suspensión selon l’une quelconque des revendications 1 á 12, caractérisée en ce que l’étape d) est réalisée á des températures supérieures á 50 °C, et de préférence supérieures á 60 °C. 14. Suspensión selon l’une quelconque des revendications 1 á 13, caractérisée en ce que l’étape d) a lieu en présence d’au moins un composé choisi dans le groupe constitué par un silicate, une sílice, un alumínate de métal alcalino-terreux, ou des mélanges de ceux-ci, ledit silicate étant de préférence choisi parmi un silicate d’aluminium ou un silicate de métal alcalino-terreux. 15. Suspensión selon l’une quelconque des revendications 1 á 14, caractérisée en ce que l’étape d) a lieu en présence d’un additif qui augmente la forcé ionique de la suspensión, tel qu’un sel non calcique inerte, ledit additif étant de préférence choisi parmi NaCI ou KN03, ou des mélanges de ceux-ci. 16. Suspensión selon l’une quelconque des revendications 1 á 15, caractérisée en ce que ledit procédé est un procédé continu. 17. Suspensión selon l’une quelconque des revendications 1 á 16, caractérisée en ce qu’un dispersant est ajouté á ladite suspensión formée dans l’étape d). 18. Suspensión selon l’une quelconque des revendications précédentes, caractérisée en ce que ledit PCC ayant réagi en surface comprend un sel calcique au moins partiellement cristallin et insoluble dudit anión, comprenant de préférence un ou plusieurs des composants suivants : le phosphate octa-calcique (OCP), l’hydroxyapatite (HAP) ou le phosphate tricalcique (TCP). 19. Suspensión selon l’une quelconque des revendications précédentes, caractérisée en ce que ledit PCC ayant réagi en surface a un rapport massique de teneur en sel calcique de 1’anion ¡carbonate de calcium de 5:95 á 95:5, de préférence de 20:80 á 60:40, et plus préférablement de 25:75 á 50:50. 20. Suspensión selon l’une quelconque des revendications précédentes, caractérisée en ce que ledit PCC ayant réagi en surface a une surface spécifique BET qui est supérieure á la surface spécifique BET obtenueaprés la mise en contactdu méme PCC fourni dans l’étape a), de maniéresimultanée ou dans des étapes distinctes, avec le méme anión solubilisé de l’étape b) et avec des ions H30+, de sorte que : - les ions HsO+ sontfournis uniquement parl’addition dudit anión, c’est-á-dire que lesdits ions H30+sontfournis en une quantité molaire qui est inférieure ou égale á celle requise pour l’équllibre théorique de la charge ionique dudit anión ; et - ni la voie IA, ni la voie IB ne sont mises en oeuvre. 21. Suspensión selon l’une quelconque des revendications précédentes, caractérisée en ce que ledit PCC ayant réagi en surface a une surface spécifique BET qui est au moins trois fois supérieure, et plus préférablement sept fois supérieure á la surface spécifique BET du PCC dans le pigment comprenant du PCC fourni dans l’étape a). 22. Suspensión selon l’une quelconque des revendications précédentes, caractérisée en ce que ledit PCC ayant réagi en surface a une surface spécifique BET de 20 á 120 m2/g, de préférence de 55 á 115 m2/g, plus préférablement de 60 á 100 m2/g. 23. Suspensión selon l’une quelconque des revendications précédentes, caractérisée en ce que ladite suspensión comprenant du PCC ayant réagi en surface a une teneur en matiéres solides allant jusqu’á 25 %, et de préférence comprise entre 5 et 20 % en poids. 24. Suspensión selon l’une quelconque des revendications précédentes, caractérisée en ce que ledit PCC ayant réagi en surface a un volume de pore de 1 á 2.2 cm3/g. 25. Pigment comprenant du PCC sec ayant réagi en surface, caractérisé en ce qu’il est obtenu á partird’une suspensión selon l’une quelconque des revendications précédentes, dans lequel le PCC sec ayant réagi en surface est de préférence en outre traité avec des acides gras. 26. Utilisation d’un PCC ayant réagi en surface selon la revendication 25 ou d’une suspensión de PCC ayant réagi en surface selon l’une quelconque des revendications 1 á 24, dans du papier, du papier de soie, des plastiques, des peintures, le traitement de l’eau, ou pour l’élimination de composés EDC.

REFERENCES CITED IN THE DESCRIPTION

This list of references cited by the applicant is for the reader’s convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description • EP 1149136 A [0010] [0011] [0012] [0037] · EP 0406662 A [0018] [0019] [0020] • US 4367207 A [0015] · US 5043017 A [0021] • WO 2005123593 A [0016] · US 4244933 A [0022] • WO 2005102931 A [0017] · EP 1769035 A [0023]

Non-patent literature cited in the description • Transport in Porous Media, 2006, vol. 63, 239-259 [0094]

Claims (8)

P # i§IÉÍ # fl Magnetic Teflon Fo rmation C at at at at at at ft ft ft ft ft ft ft ft ft AD ft ft n ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft ft tartalmazó tartalmazó tartalmazó tartalmazó tartalmazó tartalmazó tartalmazó tartalmazó tartalmazó tartalmazó tartalmazó tartalmazó tartalmazó tartalmazó tartalmazó tartalmazó tartalmazó tartalmazó tartalmazó tartalmazó. smash, as in the tunnel of his actions, we have:> a) let IdosapPt! kayiam4arbenltot .. (POS) and then pitation of bitis b) HgO * ien; d) The reassurance of an ounce is less likely to be vlzgldbéistían inclined * s &amp; k. which anlnn has a water hand in hand; : d) a PCCGatalmO plgrnenf with a N-jO ions and a solubilized ammonia is present in an ylxas excipient, resulting in a slurry of a highly reacted FCC4-containing limb, aho! the half-reacted PCC uses the em αfteft antead an okibatalran, more rigidly kfteiáfyes oiyan catholic insects, which mimic blzlosliot part of the PCC phage splice; Maal pfferamyt, that - d) step fofyamán is a soli-subsidy kalduaiion-fetestege! hizfoskunk; - at least the partially crystalline chao-salt of the erolite anions in step a) in the case of a palmprint PCC-like pigmentM corresponds to a part of the rest of the PCC tegaJabb! 2 <The first slice of the sledge, which is a ügy% son of the son of step (a). 3. The substance 2, according to claim 1, is a pigment α diacid of step (a) of the PCC composition of step a), or dibrin, clay, plastic hollow pigment or titanium dioxide. 1 4 The lump of the 1¾ Demand is a slurry; this &lt; 1 &gt; and the pigments containing the PCC content of step a) in the form of a water slurry are dropped into the slurry c), where the pH of the slurry is somewhat lower, 1% less in eibaydseb; rnint 10.5. 4 According to 1-4 Igiayppntokí any kind of slurry, «sal j # | fpra # z ¥ also to step b) s H30's ions on the road to the end of the road ¥ ^ 9y tbhlpn crossfire: - ¾ or ssvv;: sivtr ^ ftett arte é | addition of a salt thereof; · * Lf i ui: an acid or a sour sauce for the homemade * ameiy, a simple servant, the solo is solubilized by the generic or sub-salicylic acid of the kaiclumion superfamily; and adding PCC cloning material to the lymphatic agent, and the potassium lons are the result of the scaling. I, M 5. Demand slurry, J§liarpaivs, that I IB road in the espresso is the acid or sour salt that once or a half times the total or partial safety of the emtretic solubilized caloumion surplus &amp; So is sulfur sulfur, succinic acid, perchloric acid, formic acid. the acid, the eethsay, the nitric acid waxine are the acidic salts thereof, so they are solubilized by a soluble aayab? y catechol group. % M i-6i Points for any kind of melting down, hungry! | É # !! ¥ pi r ^ i? tis &amp; iy, step c), anion is added to a neutral or taya-cell of a halibut, or in the form of an acid, with the bridging step, and / or in the presence of an acid, and is one or more of the following: FOUNDATIONMartafmic anicn, such as PO43 'and HFOy2', oxafaaconons (C20 ^ £ '} (in the form of COs2' carbohydrate-like aliquots * phosphorus ion, cyclinate, or flutter). bo§y the anion, in step a, adding a safe PCC stack to a sub-buffer, at 5% and 50 W of ca. l of 15% and 30%, respectively, i. siamia sludge, toa! ¡ï hogy ï hogy ï ï ï ï ï ï ï ï ï ï P ï P ï P ï P ï ï ï ï P ï ï ï ï ï ï ï ï ï ï ï ï ï ï ï ï ï ï ï ï pCC step-by-step .they are blasted on one or more of the following paths: - A path: the addition of an old or neutral salt of a chimeric salt; - HA: an acid or a neutral or tayaa pushum-pus! the addition of a salt, which is a soluble salty or acidic calcium salt for the slurry of the slurry, in the form of a sepia sepia, 10, in the garden. jéiemezvsj h $$$ 'then, Arnikar is the sibiLiDiKaldurn ^ a-'fefegíi ai lAb is safe, this is ®. prospective brain # or tdbbfe kbzif; ccf m m CaCfe m $ f ChaTeRs 11, Ai 1-11, Any of the Claims; solubilizing lithium ion ions, based on purity, arnety, i.e., based on the number of PCCs annotated in step a). megfeíe! a 3 td * larger or larger than 5 tbp% or greater Claims 11, A-1 -12, wherein any of the above-described slurry, Anal Jollamaiy #, is applied to a temperature of 60 ° C of the d> step, which is heated to 80 ° C. 14, Ai 1-13, claimed by analysts, contemplated that the method is a azicyl, silicic acid; alphaddddddphenvaluminate or a mixture of these at least one compound of the formula I group is displaced in silylate, the silicatate pedlg eiooydsen with the physio-silicon sulfide or an alkylfilter silk lillyl acylate 11, Al 1-14, any of the Claims slurry, i.e., i.e., a stepping-off of a feed material such as an inert material, a cyanobutyl halide, which causes the ionic strength of the slurry, i.e., to be reduced to about 100%. the additive material is NaCl or KNOs or a mixture thereof lilac vase gk kk 16, Ai 1-15, Demand Form Spreadsheets, Analytical, characterized in that the strawberry is a flow-through run-off, <IT, <RTIgt; the amide of the amine is added as a dispersant to the lafy in step d), 18, alizoÉÉPYpoatokibipiNyika Mbdbl zagy; Analyzable PCC reacts with an insoluble anion of an erythiolite anion; at least in the form of crystalline crystalline crystal salts, one or more of the carboxylic acids: octacium phosphate (OOP), hydroxapatate (HAP) or tn-kaldum phosphate (TCP). 16, The eidzo promise barnieiyika seríntl zagy; isi jiim, hoiy on the surface of the dopedophthalophthalamide, has the most convenient yields: 5; 95 also 95: 6 kazg melting 20.80 and 68 :: 40 * and efbnybpebheb 28-25 and 80:50 kozittl tdm g s f ty:: um iate iate iate ^ 20 20 M 20 20 20 20 20 20 szer 20 z 20 20 20 20 20 20 20 20 ei 20 20 iam iam iam iam iam iam iam iam iam iam iam iam iam iam iam iam iam iam iam iam iam iam ) in step b) to PCC in step b)! biyanazon solubilized anlonna! and H3Q 'toa®t &amp; one or the same; alero step-by-step control is obtained by means of: - H3O "ions exclusive to the smlfett anion, i. e. :: As - aera does not make the IA nor m IB trip. 21, The Three-Thirst of the Aidzb Demanding Thumbs Up, Azil | ®tiitysezye, that the top surface of the reacted PCC BEf | ®. 23b is a prior art claim that the surface-treated PCC BET signaling agent is 20 to 120 m 2 / g, low to 5511.5 nkVg, and pink to 60 to 100 m 2 / g, 26, alizolytic sites are any of the most commonly used slurry-containing lacquers of leachate-containing lacquer, and this is predominantly 5 to 20% by weight. The slurry according to any one of the claims 1 to 2, wherein the reacting reagent is prepared by powdering the powder at 1-2; 2 cms / g. $ 2, dry-faced PCC dry pigment, azza! wherein the dry precipitate reacts with the PCC reacted negatively and furthermore by means of a chelating agent, 2c. Reaction surface according to any one of claims 1 to 4. Time-lapse of PCC slurry in paper bamboo slabs, marble pieces, pellets, or "batches" of lava.