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The invention concerns a pigment, filler or mineral containing a natural calcium carbonate, treated with one of more providers of H3O+ ions and gaseous CO2, allowing a reduction in the weight of paper for a constant surface area without loss of physical properties when it is used as a pigment or coa

The invention concerns a pigment, filler or mineral containing a natural calcium carbonate, treated with one of more providers of H3O+ ions and gaseous CO2, allowing a reduction in the weight of paper for a constant surface area without loss of physical properties when it is used as a pigment or coating filler for the said paper. In particular, the invention concerns a pigment, filler or mineral containing a natural calcium carbonate or dolomite or mixtures of talc and calcium carbonate, of kaolin and carbonate or carbonate alone or in combination with natural and/or synthetic fibres or similar, treated with one or more medium-strong or strong providers of H3O+ ions in the presence of gaseous CO2. Applications are particularly in the paper industry, obtaining in particular good sheet properties i.e. a reduction its weight for a given surface area.

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The invention claimed is: 1. An aqueous suspension comprising a component (1) comprising one or more pigments, fillers or minerals, and optionally (2) a dispersant polymer, wherein, a) said component (1) comprises a natural carbonate and the reaction product or products of said carbonate with gaseo

The invention claimed is: 1. An aqueous suspension comprising a component (1) comprising one or more pigments, fillers or minerals, and optionally (2) a dispersant polymer, wherein, a) said component (1) comprises a natural carbonate and the reaction product or products of said carbonate with gaseous CO2 and with one or more medium-strong to strong H3O+ ion-providers, b) wherein said suspension has a pH greater than 7.5 measured at 20° C., and wherein paper filled or coated by treating with said suspension, at a constant area and thickness, weighs less than paper treated with said suspension but without said reaction products, wherein the natural carbonate is a natural calcium carbonate (CaCO3), and wherein the quantity in moles of the one or more medium-strong to strong H3O+ ion-providers relative to the number of moles of CaCO3 is in total between 0.1 and 2. 2. The aqueous suspension according to claim 1, wherein the strong H3O+ ion-provider is selected from the group consisting of hydrochloric acid, sulphuric acid and mixtures thereof, and the medium-strong H3O+ ion-provider is selected from the group consisting of H2SO3, HSO4-, H3PO4, oxalic acid and mixtures thereof. 3. The aqueous suspension according to claim 1, wherein the pigment, filler or mineral has a BET specific surface area, measured in accordance with the ISO 9277 Standard, of between 5 m2/g and 200 m2/g. 4. The aqueous suspension according to claim 1, wherein the pigment, filler or mineral has the following characteristics: a mean grain diameter, measured by the sedimentation method on a Sedigraph 5100®, between 50 and 0.1 micrometers, and a BET specific surface area, measured in accordance with ISO 9277, ranging from 15 m2/g to 200 m2/g. 5. The aqueous suspension according to claim 4 wherein the pigment, filler or mineral has the following characteristics: a mean grain diameter, measured by the sedimentation method on a Sedigraph 5100®, between 7 and 0.7 micrometers, and a BET specific surface area, measured in accordance with ISO 9277, ranging from 30 m2/g to 60 m2/g. 6. The aqueous suspension according to claim 4, wherein the pigment, filler or mineral presents the following characteristics: a mean grain diameter, measured by the sedimentation method on a Sedigraph 5100®, between 25 and 0.5 micrometers, and a BET specific surface area, measured in accordance with ISO 9277, ranging from 20 m2/g to 80 m2/g. 7. The aqueous suspension of claim 1, further comprising a dispersant polymer. 8. A paint comprising the aqueous suspension of claim 7 and a latex. 9. The aqueous suspension claimed in claim 1 wherein the natural calcium carbonate is selected from the group consisting of marble, calcite, chalk and carbonate containing dolomite. 10. The aqueous suspension according to claim 1, wherein the quantity in moles of the medium-strong to strong H3O+ ion-providers relative to the number of moles of CaCO3 is in total between 0.25 and 1. 11. The aqueous suspension according to claim 1, wherein the pigment, filler or mineral has a BET specific surface area, measured in accordance with the ISO 9277 Standard, of from 20 m2/g to 80 m2/g. 12. The aqueous suspension according to claim 1, wherein the pigment, filler or mineral has a BET specific surface area, measured in accordance with the ISO 9277 Standard, of from 30 m2/g to 60 m2/g. 13. The aqueous suspension of claim 1, comprising the at least one medium-strong H3O+ ion-provider. 14. The aqueous suspension of claim 13, wherein the at least one medium-strong H3O+ ion-provider is selected from the group consisting of phosphoric acid, H2SO3, HSO4-, oxalic acid and mixtures thereof. 15. The aqueous suspension of claim 1, comprising the at least one strong H3O+ ion-provider. 16. The aqueous suspension of claim 15, wherein the at least one strong H3O+ ion-provider is selected from the group consisting of H2SO4 hydrochloric acid and mixtures thereof. 17. A process for coating paper comprising applying the aqueous suspension as claimed in claim 1 onto a sheet of paper. 18. A process for making a paper sheet with a paper filler, the process comprising: diluting a wood and fibre pulp or paste, with water, in the presence of the aqueous suspension of claim 1 to form a mixture, agitating the mixture, and forming the paper sheet from the mixture. 19. The process of claim 18, further comprising, after forming the paper sheet, drying the formed paper sheet. 20. The process as claimed in claim 18, further comprising, after agitating the mixture, adding a retaining agent. 21. A paint comprising the aqueous suspension of claim 1 and a latex. 22. A process for manufacturing a sheet of paper or board, the process comprising: diluting a pulp or paste, with water, in the presence of the aqueous suspension of claim 1 to form a mixture, agitating the mixture, and forming the paper sheet or board from the mixture, wherein said paper sheet or board comprises fibres not originating from wood. 23. A method of printing comprising digitally applying ink onto the paper or board, wherein the paper or board is made by a process comprising diluting a pulp or paste, with water, in the presence of the aqueous suspension of claim 1 to form a mixture, agitating the mixture, and forming the paper sheet or board from the mixture, wherein said paper sheet or board comprises fibres not originating from wood. 24. A process for treating pigments, fillers or minerals in an aqueous suspension, wherein said pigments, fillers, or minerals comprise a natural carbonate, the process comprising treating said pigments, fillers or minerals, in an aqueous suspension, with a combination of one or more medium-strong to strong H3O+ ion-providers and with gaseous CO2 to provide treated pigments, fillers or minerals, wherein the final pH of the suspension is greater than 7.5 when measured at 20° C., wherein a paper filled or coated with the treated pigments, fillers, or minerals weighs less than a paper filled or coated with the pigments, fillers or minerals that have not been treated with a combination of one or more medium-strong to strong H3O+ ion-providers and with gaseous CO2, wherein both the paper treated with the treated pigments, fillers or minerals and the paper treated with the pigments, fillers or minerals that have not been treated with a combination of one or more medium-strong to strong H3O+ ion-providers and with gaseous CO2 have equal areas and thicknesses, wherein the natural carbonate is a natural calcium carbonate (CaCO3), and wherein the quantity in moles of the medium-strong to strong H3O+ ion-providers relative to the number of moles of CaCO3 is in total between 0.1 and 2. 25. The process according to claim 24, wherein the gaseous CO2 comes from an external CO2 supply, from the recirculation of CO2, from the continuous addition of the same or another medium-strong to strong provider of H3O+ ions as used in the treatment, or from an excess pressure of CO2. 26. The process as claimed in claim 25, wherein the gaseous CO2 has a pressure of from 0.05 to 5 bars. 27. The process according to claim 24, wherein the strong provider or providers of H3O+ ions is selected from the group consisting of hydrochloric acid and sulphuric acid and the medium-strong provider or providers of H3O+ ions is selected from the group consisting of H2SO3, HSO4-, H3PO4, oxalic acid, and combinations thereof. 28. A process for treating pigments, fillers or minerals in an aqueous suspension, comprising: a) treating the pigments, fillers or minerals with one or more medium-strong to strong providers of H3O+ ions b) treating the product of a) with gaseous CO2, and c) raising of the pH of the product of b) beyond 7.5, measured at 20° C., in a time interval after the end of stages a) and b) of between 1 hour and 10 hours without addition of a base, or immediately after the end of stages a) and b) with the addition of a base, wherein a paper filled or coated with the treated pigments, fillers, or minerals weighs less than a paper filled or coated with the pigments, fillers or minerals that have not been treated with one or more medium-strong to strong H3O+ ion-providers and with gaseous CO2, wherein both the paper filled or coated with the treated pigments, fillers, or minerals and the paper filled or coated with the pigments, fillers, or minerals that have not been treated with one or more medium-strong to strong H3O+ ion-providers and with gaseous CO2 have equal areas and thicknesses, wherein the pigments, fillers or minerals comprise a natural calcium carbonate (CaCO3), and wherein the quantity in moles of the one or more medium-strong to strong providers of H3O+ ions relative to the number of moles of CaCO3 is in total between 0.1 and 2. 29. The process according to claim 28, wherein stages a) and b) may be repeated several times. 30. The process according to claim 28, wherein the pH measured at 20° C. is between 3 and 7.5 during stages a) and b) of the treatment and the treatment temperature is between 5° C. and 90° C. 31. The process as claimed in claim 30 wherein the treatment temperature is between 45 and 60° C. 32. The process according to claim 28, wherein the duration of stage b) of the treatment is between 0 hours and 10 hours. 33. The process as claimed in claim 32 wherein the duration of stage b) of the treatment is between 2 hours and 6 hours. 34. The process according to claim 28, further comprising the addition of a dispersing agent, and optionally a reconcentration, after c). 35. The process as claimed in claim 28, wherein c) is the final stage in the process. 36. A process for treating pigments, fillers or minerals in an aqueous suspension, wherein said pigments, fillers, or minerals comprise a natural carbonate wherein the natural carbonate is a natural calcium carbonate (CaCO3), the process comprising treating said pigments, fillers or minerals, in an aqueous suspension, with a combination of one or more medium-strong to strong H3O+ ion-providers and gaseous CO2 to provide the treated pigments, fillers or minerals, wherein the final pH of the suspension is greater than 7.5 when measured at 20° C., wherein a paper filled or coated with the treated pigments, fillers, or minerals weighs less than a paper filled or coated with the pigments, fillers or minerals that have not been treated with one or more medium-strong to strong H3O+ ion-providers and with gaseous CO2, wherein both the paper filled or coated with the treated pigments, fillers or minerals and the paper filled or coated with the pigments, fillers or minerals that have not been treated one or more medium-strong to strong H3O+ ion-providers and with gaseous CO2 have equal areas and thicknesses, wherein the pigments, fillers, or minerals comprising a natural carbonate are selected from the group consisting of a natural carbonate, a carbonate containing a dolomite, a mixture of a natural carbonate with at least one substance, a mixture of a carbonate containing a dolomite with at least one substance, and mixtures thereof; wherein the at least one substance is selected from the group consisting of talc, kaolin, titanium oxide (TiO2), magnesium oxide (MgO), a mineral inert towards medium-strong H3O+ ion-providers, and mixtures thereof, and wherein the quantity in moles of the one or more medium-strong to strong providers of H3O+ ions relative to the number of moles of CaCO3 is in total between 0.1 and 2. 37. The process according to claim 36, comprising the natural carbonate, wherein the natural carbonate is a marble, a calcite or a chalk. 38. A treated aqueous suspension comprising treated pigments, fillers, or minerals, wherein the treated pigments, fillers, or minerals comprise a natural carbonate, wherein the natural carbonate is a natural calcium carbonate (CaCO3) selected from the group consisting of a natural calcium carbonate, a natural calcium carbonate containing a dolomite, a mixture of a natural calcium carbonate with at least one substance, a mixture of a natural calcium carbonate containing a dolomite with at least one substance, and mixtures thereof; wherein the at least one substance is selected from the group consisting of talc, kaolin, titanium oxide (TiO2), magnesium oxide (MgO), a mineral inert towards medium-strong H3O+ ion-providers, and mixtures thereof; and wherein the treated aqueous suspension is produced by a process comprising treating said pigments, fillers or minerals, in an aqueous suspension, with a combination of one or more medium-strong to strong H3O+ ion-providers and with gaseous CO2 to provide the treated pigments, fillers or minerals, wherein the final pH of the treated suspension is greater than 7.5 when measured at 20° C., wherein a paper filled or coated with the treated pigments, fillers, or minerals weighs less than a paper filled or coated with the pigments, fillers, or minerals that have not been treated with one or more medium-strong to strong H3O+ ion-providers and with gaseous CO2, wherein both the paper treated with the treated pigments, fillers or minerals and the paper treated with the pigments, fillers, or minerals that have not been treated with one or more medium-strong to strong H3O+ ion-providers and with gaseous CO2 have equal areas and thicknesses, wherein the quantity of moles of the medium-strong to strong H3O+ ion-providers relative to the number of moles of CaCO3 is in total between 0.1 and 2. 39. A process for coating paper comprising applying the treated aqueous suspension as claimed in claim 38 onto a sheet of paper. 40. A process for coating and manufacturing a sheet of paper comprising coating and impregnating, in any order, a sheet of paper with the treated aqueous suspension claimed in claim 38 wherein said treated aqueous suspension acts as a paper filler and as a preparation for coating and pigmentation of the surface of the paper. 41. A process for manufacturing a sheet of paper or board, the process comprising: diluting a pulp or paste, with water, in the presence of the treated aqueous suspension of claim 38 to form a mixture, agitating the mixture, and forming the sheet of paper or board from the mixture. 42. A sheet or board produced by the process of claim 41. 43. A method of printing comprising digitally applying ink onto the paper or board claimed in claim 42.