Sustainable carbon blacks for coloring mineral binders

Abstract

The present invention relates to binder compositions, articles obtained from such binder compositions, the use of such binder compositions and a process for preparing such binder compositions.

Description

SUSTAINABLE CARBON BLACKS FOR COLORING MINERAL BINDERSTECHNICAL FIELD

[0001] The present invention relates to binder compositions, articles obtained from such binder compositions, the use of such binder compositions and a process for preparing such binder compositions.TECHNICAL BACKGROUND

[0002] Mineral binders such as concrete, cement, mortar, and exterior plaster are often colored to enhance their aesthetic appeal. Cement is the most widely used and adaptable material in the construction industry for its properties and cost.

[0003] Pigments for mineral binder systems exposed to outdoor conditions must be resistant to light, industrial atmospheres and alkaline media. In addition, they must have a weather resistance comparable to that of the binder and be easy to handle.

[0004] Black pigments are the preferred colorants for mineral binder systems because they offer a wide range of colors and shades that can be achieved by using them alone or in combination with other pigments. The most common black pigments are black iron oxides and carbon blacks.

[0005] Carbon blacks offer excellent coloring properties and chemical stability, resistance to light and alkaline media. However, carbon blacks are of limited use in systems exposed to outdoor conditions due to leaching and washing of the carbon black pigment from the mineral binder system. Therefore, there is a strong and ongoing desire to overcome the problem of fading with weathering of carbon black containing bodies. WO 96 / 18689 A1 relates to mineral binder systems containing a carbon black product as a colorant. WO 96 / 37447 A1 relates to a mineral binder system containing silicon-containing carbon black products as colorants.

[0006] In a world marked by climate change, resource scarcity and limited recycling, it is essential to look for sustainable solutions (sustainable carbon blacks) that contribute to a healthier planet and a more circular economy.

[0007] Recovered blacks (rCB) are carbon blacks typically obtained from end-of-life products containing carbon black, such as scrap tires, and obtained by recycling processes that typically involve two steps, a pyrolysis step to decompose organic components such as rubbers or plastics, and a demineralization step to dissolve inorganic additives or impurities.

[0008] Tire pyrolysis of end-of-life products containing carbon black is usually carried out at low temperatures and produces a liquid, gaseous and solid fraction, namely oil, gas and recovered carbon black (rCB)Zchar. The solid fraction (rCB / char) and the pyrolysis vapors containing the liquid and gaseous fractions, are separated in the pyrolysis reactor. The liquid phase is then condensed from the pyrolysis vapors and separated from the gaseous fraction. The liquid fraction can then be used to produce new or virgin carbon black in an entrained flow reactor such as a furnace reactor. US 2002 / 0117388 A1 relates to the pyrolysis of waste rubber materials, including scrap tires.

[0009] rCB is a complex mixture resulting from the compounds used in pyrolysis. The compounds used in the pyrolysis process may contain various components other than carbon black, such as inorganic additives and fillers (e.g., zinc oxide, silicon oxide and calcium carbonate) and traces of steel.

[0010] It is desirable to provide a more sustainable solution. Recyclable materials used in the coloring of mineral binders and the production of colored construction products are more environmentally friendly and contribute to the conservation of limited fossil resources, creating opportunities for the realization of a circular economy. It is also desirable to provide deep colored products with a high optical density. Depending on the area of application, it is also desirable for the colored mineral binders and the colored building products to have properties that are suitable for harsh conditions such as outdoor weathering. Simple handling and production are also desirable.

[0011] It is therefore an objective of the present invention to provide binder compositions which contribute to the conservation of limited fossil resources, create opportunities for the realization of a circular economy and providearticles having a deep color with high optical density while withstanding weathering conditions.SUMMARY OF INVENTION

[0012] It has surprisingly been shown, that the objective can be solved by the binder composition as disclosed in the independent claims. Specific or preferred variants of the present invention are set forth in the dependent claims.

[0013] The following clauses summarize some aspects of the present invention.

[0014] A first aspect of the present invention relates to a binder composition comprising (a) a mineral binder, and (b) recovered carbon black, wherein the recovered carbon black is obtained by pyrolysis of one or more material(s) comprising carbon black.

[0015] A second aspect of the present invention relates to the binder composition according to the first aspect, wherein the recovered carbon black (b) comprises silica, zinc oxide (ZnO), zinc sulfide (ZnS), and combinations thereof.

[0016] A third aspect of the present invention relates to the binder composition according to the first or second aspect, wherein the recovered carbon black (b) has a zinc content in a range of from 0.5 to 10.0 mass %, preferably from 2.0 to 6.0 mass %, more preferably from 2.5 to 5.5 mass %, even more preferably from 3.0 to 5.0 mass %, most preferably from 3.5 to 4.5 mass %, wherein the zinc content is based on the total mass of the recovered carbon black and wherein the zinc content is determined by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES).

[0017] A fourth aspect of the present invention relates to the binder composition according to any one of the preceding aspects, wherein the recovered carbon black (b) has a silicon (Si) content in a range of from 0.5 to 10.0 mass %, preferably from 1.5 to 7.0 mass %, more preferably from 1.8 to 6.0 mass %, even more preferably from 2.0 to 5.0 mass %, most preferably from 2.2 to 4.5 mass %, wherein the mass % is based on the total mass of the recovered carbon black and wherein the silicon content isdetermined by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES).

[0018] A fifth aspect of the present invention relates to the binder composition according to any one of the preceding aspects, wherein the binder composition comprises 0.1 to 10.0 wt.-% of recovered carbon black (b), preferably 1 .0 to 9.0 wt.%, more preferably 1 .5 to 8.0 wt.%, more preferably 2.0 to 7.0 wt.%, even more preferably 2.5 to 6.0 wt.% most preferably 3.0 to 6.0 wt.%, the weight percentage is based on the total solids weight of the binder composition.

[0019] A sixth aspect of the present invention relates to the binder composition according to any one of the preceding aspects, wherein the recovered carbon black (b) has a BET surface area in a range of from 30 to 200 m2 / g, preferably from 30 to 180 m2 / g, more preferably from 30 to 150 m2 / g, most preferably from 30 to 100 m2 / g, determined according to ASTM D6556-21 .

[0020] A seventh aspect of the present invention relates to the binder composition according to any one of the preceding aspects, wherein the recovered carbon black (b) has an ash content in a range of from 1 to 40 mass %, preferably from 5 to 30 mass %, more preferably from 10 to 30 mass %, even more preferably from 10 to 25 mass %, most preferably from 15 to 25 mass %, wherein the mass% is based on the total mass of the recovered carbon black and wherein the ash content is determined according to ASTM D1 506-15.

[0021] An eighth aspect of the present invention relates to the composition according to any one of the preceding aspects, wherein the recovered carbon black (b) has an oxygen content in a range of from 0.5 to 10.0 mass %, preferably from 1.0 to 3.0 mass %, more preferably from 1.5 to 3.0 mass %, even more preferably from 1.5 to 2.5 mass %, wherein the mass % is based on the total mass of the recovered carbon black and wherein the oxygen content is determined by elemental analysis as described in the specification.

[0022] A ninth aspect of the present invention relates to the binder composition according to any one of the preceding aspects, wherein the recovered carbon black (b) has a sulfur content in a range of from 0.5 to 8.0 mass %, preferably from 1 .0 to 4.0 mass %, more preferably from 2.0 to 4.0 mass %, even more preferably from 2.0 to 3.0 mass %, wherein the mass % is based on the total mass of the recovered carbon black and wherein the sulfur content is determined by elemental analysis as described in the specification.

[0023] A tenth aspect of the present invention relates to the binder composition according to any one of the preceding aspects, wherein the recovered carbon black (b) has a carbon content in a range of from 60 to 98 mass %, preferably from 60 to 85 mass %, more preferably from 65 to 80 mass %, even more preferably from 70 to 80 mass %, wherein the mass % is based on the total mass of the recovered carbon black and wherein the carbon content is determined by elemental analysis as described in the specification.

[0024] An eleventh aspect of the present invention relates to the binder composition according to any one of the preceding aspects, wherein the recovered carbon black (b) has a transmittance of toluene extract at 425 nm in a range of more than 0.01 %, preferably more than 10 %, more preferably more than 30%, wherein the transmittance of toluene extract is determined according to ASTM D1618-18.

[0025] A twelfth aspect of the present invention relates to the binder composition according to any one of the preceding aspects, wherein the recovered carbon black (b) has an organic residue of less than 60 mass %, preferably less than 30 mass %, more preferable less than 10 mass %, wherein the mass % is based on the total mass of the recovered carbon black and wherein the organic residue is determined according to ASTM D8474-22.

[0026] A thirteenth aspect of the present invention relates to the binder composition according to any one of the preceding aspects, wherein the material(s) comprises a rubber material, a plastic material and a combination thereof.

[0027] A fourteenth aspect of the present invention relates to the binder composition according to the thirteenth aspect, wherein the rubber material comprises tires.

[0028] A fifteenth aspect of the present invention relates to the binder composition according to any one of the preceding aspects, wherein the composition further comprises an admixture, preferably an anionic surfactant, more preferably a salt of lignosulfonate, most preferably sodium lignosulfonate.

[0029] A sixteenth aspect of the present invention relates to the binder composition according to the fifteenth aspect, wherein the binder composition comprises 0.05 wt.-% to 10.0 wt.-% of the admixture, preferably 0.1 wt.% to 5.0 wt.-%, more preferably 0.2 wt.-% to 3.0 wt.-%, most preferably 0.3 to 2.0 wt.-%, the weight percentage is based on the total solids weight of the binder composition.

[0030] A seventeenth aspect of the present invention relates to the binder composition according to any one of the preceding aspects, wherein the mineral binder (a) is selected from the group consisting of cement, concrete, mortar, plaster, ferrocement, and ferro concrete.

[0031] An eighteenth aspect of the present invention relates to an article made of the binder composition according to any one of the preceding aspects.

[0032] A nineteenth aspect of the present invention relates to use of the binder composition according to any one of the first to seventeenth aspects as a construction material.

[0033] A twentieth aspect of the present invention relates to a process for the preparation of a binder composition, comprising mixing a mineral binder (a) and a recovered carbon black (b), wherein the recovered carbon black is obtained by the pyrolysis of a material comprising carbon black.

[0034] A twenty-first aspect of the present invention relates to the process according to the twentieth aspect, wherein the mineral binder (a) is as defined in any one of the thirteenth, fourteenth, and seventeenth aspects.

[0035] A twenty-second aspect of the present invention relates to the process according to the twentieth or twenty-first aspect, wherein the recovered carbon black (b) is as defined in any one of the second to twelfth aspects.

[0036] A twenty-third aspect of the present invention relates to the process according to the twentieth to twenty-second aspects, wherein the binder composition comprises an admixture, wherein the admixture preferably is as defined in the fifteenth or sixteenth aspect.

[0037] These and other optional features and advantages of the present invention will be described in more detail in the following description.BRIEF DESCRIPTION OF FIGURES

[0038] Figure 1 shows the visual appearance of the concrete sample of example 1 . The concrete sample on the left is colored with Bayferrox® 330 and the concrete sample on the right is colored with rCB-1 .

[0039] Figure 2 shows the visual appearance of the concrete sample of example 2 before (left) and after (right) extraction in a Soxhlet for 67 hours.

[0040] Figure 3 shows the visual appearance of the concrete sample of example 3- 1 to 3-6.

[0041] Figure 4 shows the visual appearance of the concrete sample of example 3- 7 to 3-13.

[0042] Figure 5 shows the visual appearance of the concrete sample of example 3- 14 to 3-22.

[0043] Figure 6 shows the visual appearance of the concrete sample of example 3- 1 to 3-6 before and after the weathering test for 1 ,000 hours.

[0044] Figure 7 shows the visual appearance of the concrete sample of example 3- 7 to 3-10 before and after the weathering test for 1 ,000 hours.

[0045] Figure 8 shows the visual appearance of the concrete sample of example 3- 14 to 3-22 before and after the weathering test for 1 ,000 hours.DETAILED DESCRIPTION

[0046] As used herein, the term "comprising" is understood to be open-ended and to not exclude the presence of additional undescribed or unrecited elements, materials, ingredients or method steps etc. The terms "including", "containing" and like terms are understood to be synonymous with "comprising". As used herein, the term "consisting of' is understood to exclude the presence of any unspecified element, ingredient or method step etc.

[0047] As used herein, the singular form of “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.

[0048] Unless indicated to the contrary, the numerical parameters and ranges set forth in the following specification and appended claims are approximations. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical values, however, contain errors necessarily resulting from the standard deviation in their respective measurement.

[0049] Also, it should be understood that any numerical range recited herein is intended to include all subranges subsumed therein. For example, a range of “1 to 10” is intended to include any and all sub-ranges between and including the recited minimum value of 1 and the recited maximum value of 10, that is, all subranges beginning with a minimum value equal to or greater than 1 and ending with a maximum value equal to or less than 10, and all subranges in between, e.g., 1 to 6.3, or 5.5 to 10, or 2.7 to 6.1.

[0050] All parts, amounts, concentrations etc. referred to herein are by weight, unless specified otherwise.

[0051] The present invention relates to a binder composition comprising (a) a mineral binder, and (b) a recovered carbon black.

[0052] As used herein, the term “carbon black” relates to a material composed substantially, e.g., to more than 80 wt.%, or more than 90 wt.% or more than95 wt.%, based on its total weight of carbon. The production of carbon blacks is per se well known in the art and for example outlined in J.-B. Donnet et al., “Carbon Black: Science and Technology”, 2ndedition as well as in H. Ferch “Pigmentrufte”, 1stedition, Curt R. Vincentz Verlag, Hannover (1995) and will be further described below. Different industrial processes for the production of carbon blacks are available and include, e.g., the furnace process, gas black process, acetylene black process, thermal black process or lamp black process, as for example described in J.-B. Donnet et al., "Carbon Black: Science and Technology", 2ndedition. The carbon blacks obtained by these industrial processes can also be referred to as “industrial carbon blacks” or “virgin carbon blacks”

[0053] The recovered carbon black (rCB) is obtained by pyrolysis of one or more material(s) comprising carbon black. The one or more material(s) comprising carbon black are usually end-of-use carbon black-containing materials. The recovered carbon black (rCB) can be recovered carbon black (rCB) as defined in ASTM D8178-20a.

[0054] According to the present invention, the one or more material(s) comprising carbon black can comprise a rubber material, a plastic material and a combination thereof, preferably a rubber material. According to the present invention, the one or more material(s) comprising carbon black can be a rubber material, a plastic material and a combination thereof. According to the present invention, the one or more material(s) comprising carbon black can be a rubber material.

[0055] As used herein, the term “rubber material” refers to materials composed of rubber, e.g., composed of at least 50 wt.-% of rubber, based on the total weight of the rubber material. The term “rubber” includes both natural and synthetic rubbers or mixtures thereof. Natural rubber can be obtained from rubber trees (Helvea brasiliensis), guayule, and dandelion. Synthetic rubber can comprise styrene-butadiene rubber such as emulsion-styrene-butadiene rubber and solution-styrene-butadiene rubber, polybutadiene, polyisoprene, ethylene-propylene-diene rubber, ethylene-propylene rubber, butyl rubber, halogenated butyl rubber, chlorinated polyethylene, chlorosulfonatedpolyethylene, acrylonitrile-butadiene rubber, hydrogenated acrylonitrilebutadiene rubber, polychloroprene, acrylate rubber, ethylene-vinylacetate rubber, ethylene-acrylic rubber, epichlorohydrin rubber, silicone rubber, fluorosilicone rubber, fluorocarbon rubber or mixture of combinations of any of the foregoing.

[0056] The rubber material can comprise tires, conveyer belts, gaskets, such as door gaskets, drive belts, floor mats, shoe soles, belts, cable sheaths, hoses, and mixtures thereof. Preferred rubber materials comprise tires. Typically, waste tires, which are also known as “end-of-life” tires (ELT) are used in the pyrolysis to obtain rCB. As used herein, “waste tires” or “end-of-life tires” refer to tires, such as truck tires, passenger tires, off-road tires, aircraft tires, agricultural tires, and earth-mover tires, which are not suitable for use on vehicles due to, e.g., wear or irreparable damage such as punctures.

[0057] As used herein, the term “plastic material” refers to materials composed of plastic, e.g., composed of at least 50 wt.-% of plastic, based on the total weight of the plastic material. The plastic material can comprise a thermoplastic polymer, a thermosetting polymer, a thermoplastic elastomer, preferably low and high density polyethylene and polypropylene, polyvinyl chloride, melamine-formaldehyde resin, phenolic resin, epoxy resin, polyamide, polyester, polyoxymethylene, polymethyl methacrylate, polycarbonate, polystyrene, polyurethane, polyphenylene oxide, polysiloxane, polyacryloamide, polyaryletherketone, polysulfone, polyetherimide, acrylonitrile styrene acrylate or acrylonitrile butadiene styrene polymer and mixtures or co-polymers of any of the foregoing.

[0058] The pyrolysis of one or more material(s) comprising carbon black generally involves heating the materials to temperatures, e.g., of at least 300 °C in the absence of oxygen in order to volatilize and decompose the materials, producing oil, gas, and char / rCB. The pyrolysis may, but does not necessarily, be followed by a demineralization step to dissolve any inorganic additives or impurities. The rCB and the pyrolysis vapors containing the oil and the gas are separated within the pyrolysis reactor. The char / rCB usuallyleaves the reactor through a different outlet than the vapors. The vapors are then separated into the gas and the oil by condensation.

[0059] The process of pyrolysis of material(s) comprising carbon black, such as rubber materials, is well known in the art and involves heating the material(s) comprising carbon black, such as rubber materials, in the absence of oxygen. Suitable processes for obtaining rCB, include, but are not limited to those which are described in EP 2 427 533 A1 , EP 4 038 163 A1 and US 2023 / 227730 A1 . Suitable examples of recovered carbon black include, but are not limited to, Thermolysekoks commercially available from Pyrum Innovations AG (Germany), and recovered carbon blacks (rCB), such as RCB 615 commercially available from Reoil Sp. Z o.o. (Poland).

[0060] According to the present invention, the recovered carbon black (b) can comprise silica, zinc oxide (ZnO), zinc sulfide (ZnS) and a combination thereof.

[0061] The recovered carbon black (b) can comprise, zinc oxide (ZnO) and / or zinc sulfide (ZnS). According to the present invention, the recovered carbon black (b) can have a zinc content of at least 0.5 mass %, such as of at least 1.0 mass %, or of at least 1.5 mass %, or of at least 2.0 mass %, or of at least 2.5 mass%, or of at least 3.0 mass % or of at least 3.5 mass %, wherein the zinc content is based on the total mass of the recovered carbon black. The recovered carbon black (b) can have a zinc content of 10.0 mass % or less, such as of 9.0 mass% or less, or of 8.0 mass % or less, or of 7.0 mass %, or of 6.0 mass % or less, or of 5.5 mass % or less, or of 5.0 mass % or less, or of 4.5 mass % or less, wherein the zinc content is based on the total mass of the recovered carbon black. The zinc content is determined according to Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) as described below. A person skilled in the art will appreciate that any range between any of the explicitly disclosed lower and upper limit is herein disclosed. Accordingly, the recovered carbon black (b) can have a zinc content in a range of from 0.5 to 10.0 mass %, preferably from 2.0 to 6.0 mass %, more preferably from 2.5 to 5.5 mass %, even more preferably from 3.0 to 5.0 mass %, most preferably from 3.5 to 4.5 mass %,wherein the zinc content is based on the total mass of the recovered carbon black.

[0062] The recovered carbon black (b) can comprise silica. According to the present invention, the recovered carbon black (b) can have a silicon (Si) content of at least 0.5 mass %, such as of at least 0.8 mass %, or of at least 1.0 mass %, or of at least 1.2 mass %, or of at least 1.5 mass %, or of at least 1 .8 mass %, or of at least 2.0 mass %, or of at least 2.2 mass%, or of at least 2.5 mass %, wherein the mass % is based on the total mass of the recovered carbon black. The recovered carbon black (b) can have a silicon (Si) content of 10.0 mass % or less, such as of 9.0 mass% or less, or of 8.0 mass % or less, or of 7.0 mass % or less, or of 6.5 mass % or less, or of 6.0 mass % or less, or of 5.5 mass % or less, or of 5.0 mass % or less, or of 4.5 mass% or less, wherein the mass % is based on the total mass of the recovered carbon black. The silicon content is determined by to Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) as described below. A person skilled in the art will appreciate that any range between any of the explicitly disclosed lower and upper limit is herein disclosed. Accordingly, the recovered carbon black (b) can have silicon (Si) content in a range of from 0.5 to 10.0 mass %, preferably from 1 .5 to 7.0 mass %, more preferably from 1.8 to 6.0 mass %, even more preferably from 2.0 to 5.0 mass %, most preferably from 2.2 to 4.5 mass %, wherein the mass % is based on the total mass of the recovered carbon black. The silica can help to fix the pigment more firmly into the binder system, i.e. overcome the problem of fading with weathering.

[0063] According to the present invention, the recovered carbon black (b) can comprise silica and zinc oxide (ZnO) and / or zinc sulfide (ZnS).

[0064] According to the present invention, the recovered carbon black (b) can have a BET surface area of at least 30 m2 / g, such as of at least 40 m2 / g, or of at least 50 m2 / g. The recovered carbon black (b) can have a BET surface area of 200 m2 / g or less, such as of 180 m2 / g or less, or of 150 m2 / g or less, or of 120 m2 / g or less, or of 100 m2 / g or less. The recovered carbon black (b) according to the present invention can have a BET in a range between anyof the recited lower and upper limit values. The recovered carbon black (b) according to the present invention can have a BET surface area in a range of from 30 to 200 m2 / g, preferably from 30 to 180 m2 / g, more preferably from 30 to 150 m2 / g, most preferably from 30 to 100 m2 / g. The BET is determined according to ASTM D6556-21 .

[0065] According to the present invention, the recovered carbon black (b) can have an ash content of equal to or more than 1 mass %, such as of equal to or more than 3 mass %, or of equal to or more than 5 mass %, or equal to or more than 10 mass %, or equal to or more than 15 mass %, wherein the mass% is based on the total mass of the recovered carbon black. The recovered carbon black (b) can have an ash content of 40 mass % or less, such as of 35 mass % or less, or of 30 mass % or less, or of 25 mass % or less, wherein the mass% is based on the total mass of the recovered carbon black. The recovered carbon black (b) according to the present invention can have an ash content in a range between any of the recited lower and upper limit values. The recovered carbon black (b) can have an ash content in a range of from 1 to 40 mass %, preferably from 5 to 30 mass %, more preferably from 10 to 30 mass %, even more preferably from 10 to 25 mass %, most preferably from 15 to 25 mass %, wherein the mass% is based on the total mass of the recovered carbon black. The ash content is determined according to ASTM D1506-15.

[0066] According to the present invention, the recovered carbon black (b) can have an oxygen content of at least 0.5 mass %, such as of at least 1 .0 mass %, or of at least 1 .5 mass %, wherein the mass % is based on the total mass of the recovered carbon black. The recovered carbon black (b) can have an oxygen content of 10.0 mass % or less, such as of 8.0 mass % or less, or of 5.0 mass % or less, or of 3.0 mass % or less, or of 2.7 mass % or less, or of 2.5 mass % or less, wherein the mass % is based on the total mass of the recovered carbon black. The oxygen content is determined by elemental analysis as described below in more detail. A person skilled in the art will appreciate that any range between any of the explicitly disclosed lower and upper limit is herein disclosed. Accordingly, the recovered carbon black (b)can have an oxygen content in a range of from 0.5 to 10 mass %, preferably from 1 .0 to 3.0 mass %, more preferably from 1 .5 to 3.0 mass %, even more preferably from 1 .5 to 2.5 mass %, wherein the mass % is based on the total mass of the recovered carbon black.

[0067] According to the present invention, the recovered carbon black (b) can have a sulfur content of at least 0.5 mass %, such as of at least 1 .0 mass %, or of at least 1 .5 mass %, or of at least 2.0 mass %, wherein the mass % is based on the total mass of the recovered carbon black. The recovered carbon black (b) can have a sulfur content of 8.0 mass % or less, such as 6.0 mass % or less, or of 5.0 mass % or less, or of 4.0 mass % or less, or of 3.7 mass % or less, or of 3.5 mass % or less, or of 3.0 mass % or less, wherein the mass % is based on the total mass of the recovered carbon black. The sulfur content is determined by elemental analysis as described below in more detail. A person skilled in the art will appreciate that any range between any of the explicitly disclosed lower and upper limit is herein disclosed. Accordingly, the recovered carbon black (b) can have a sulfur content in a range of from 0.5 to 8.0 mass %, preferably from 1 .0 to 4.0 mass %, more preferably from 2.0 to 4.0 mass %, even more preferably from 2.0 to 3.0 mass %, wherein the mass % is based on the total mass of the recovered carbon black.

[0068] According to the present invention, the recovered carbon black (b) can have a carbon content of at least 60 mass %, such as of at least 65 mass %, or of at least 70 mass %, wherein the mass % is based on the total mass of the recovered carbon black. The recovered carbon black (b) can have a carbon content of 98 mass % or less, such as 95 mass % or less, or of 90 mass % or less, or of 85 mass % or less, or of 80 mass % or less, wherein the mass % is based on the total mass of the recovered carbon black. The carbon content is determined by elemental analysis as described below in more detail. A person skilled in the art will appreciate that any range between any of the explicitly disclosed lower and upper limit is herein disclosed. Accordingly, the recovered carbon black (b) can have a carbon content in a range of from 60 to 98 mass %, preferably from 60 to 85 mass %, preferablyfrom 65 to 80 mass %, more preferably from 70 to 80 mass %, wherein the mass % is based on the total mass of the recovered carbon black.

[0069] According to the present invention, the recovered carbon black (b) can have a transmittance of toluene extract at 425 nm in a range of more than 0.01 %, preferably more than 10 %, more preferably more than 30%. The transmittance of toluene extract is determined according to ASTM D1618- 18.

[0070] According to the present invention, the recovered carbon black (b) can have an organic residue of less than 60 mass %, preferably less than 30 mass %, more preferable less than 10 mass %, wherein the mass % is based on the total mass of the recovered carbon black. The recovered carbon black (b) can have an organic residue of at least 0.001 mass %, wherein the mass % is based on the total mass of the recovered carbon black. A person skilled in the art will appreciate that any range between any of the explicitly disclosed lower and upper limit is herein disclosed. Accordingly, the recovered carbon black (b) can have an organic residue in a range of from 0.001 to 60 mass %, preferably from 0.001 to 30 wt.-%, more preferably from 0.001 to 10 wt.-%, wherein the mass % is based on the total mass of the recovered carbon black. The recovered carbon black (b) can be substantially free of an organic residue. As used herein, the term “substantially free” means that the recovered carbon black has an organic residue of at most 0.001 mass %, wherein the mass % is based on the total mass of the recovered carbon black. The recovered carbon black (b) can be completely free of an organic residue. As used herein, the term “completely free” means that the recovered carbon black does not comprise any organic residue. The organic residue is determined according to ASTM D8474-22.

[0071] According to the present invention, the binder composition may comprise at least 0.1 wt.-% of the recovered carbon black (b), such as at least 0.5 wt.-%, or at least 1 .0 wt.-%, or at least 1 .5 wt.-%, or at least 2.0 wt.-%, or at least 2.5 wt.-%, or at least 3.0 wt.-%. The binder composition may comprise 10.0 wt.-% or less of the recovered carbon black (b), such as 9.0 wt.-% or less, or 8.0 wt.-% or less, or 7.0 wt.-% or less, or 6.0 wt.-% or less. Theweight percentage is based on the total solids weight of the binder composition. A person skilled in the art will appreciate that any range between any of the explicitly disclosed lower and upper limit is herein disclosed. Accordingly, the binder composition can comprise 0.1 to 10.0 wt.-% of recovered carbon black (b), preferably 1.0 to 9.0 wt.%, more preferably 1.5 to 8.0 wt.%, more preferably 2.0 to 7.0 wt.%, even more preferably 2.5 to 6.0 wt.% most preferably 3.0 to 6.0 wt.%.

[0072] The recovered carbon black (b) may be milled or grinded. Milling and grinding of the recovered carbon blacks can be achieved by dry milling such as by using an impact classifier mill, a jet mill, or an air classifier mill; or by wet milling, such as by using a bead mill, or a rotor-stator.

[0073] The term "mineral binder" stands in particular for a binder which reacts in the presence of water in a hydration reaction to form solid hydrates or hydrate phases. According to the present invention, the mineral binder (a) can be selected from the group consisting of cement, concrete, mortar, plaster ferrocement, and ferro concrete.

[0074] As used herein, "cement" means any inorganic substance capable of setting and hardening with water as a result of the interaction of water with the constituents of the substance to act as a binder for materials. Cement is understood to be a finely ground, hydraulically hardening binder, i.e., a mixture of non-metallic and inorganic components which, after the addition of water, forms a suspension, the cement paste, which solidifies due to hydration reactions and hardens to form durable and room -resistant cement paste. Cement is rarely used on its own, but rather to bind aggregates together. Cement is used with fine aggregates to make mortar for masonry, or with sand and gravel aggregates to make concrete. To produce concrete, mortar and plaster, other additives can be used in addition to the main components of aggregate, sand, cement and water. The additives include rock flour, such as limestone powder, as well as fly ash or silica fume. The most common type of cement is Portland cement.

[0075] As used herein, "concrete" means any type of building material containing aggregates embedded in a matrix (cement or binder) that fills the space among the aggregates and glues them together. Typically, the aggregates are mixed with the binder and water and mixed together to form a fluid slurry that can be shaped into the desired form. The binder hardens into a matrix that binds the aggregates together to form a 'stone like' material that has many uses.

[0076] As used herein, "mortar" refers to the material used in masonry (e.g., to bind building blocks, bricks). Typically, aggregate in the form of a fine powder, for example, a binder and an aqueous solvent (water) are mixed to form said material in the form of a paste. However, it will be appreciated that mortar can also be formed.

[0077] As used herein, "plaster" refers to a building material used for protective or decorative coating of walls and ceilings and for molding and casting decorative elements. Usually, plaster is a soft mixture of sand and cement and sometimes lime with water, for spreading on walls, ceilings, or other structures, to form a smooth hard surface when dried.

[0078] As used herein, "ferrocement" refers to a system of construction using mortar or plaster (lime or cement, sand, and water) applied over an “armature” of metal mesh, woven, expanded metal, or metal-fibers, and closely spaced thin steel rods such as rebar.

[0079] As used herein, "ferro concrete" also known as “reinforced concrete” refers to a composite material in which concrete is reinforced with steel inserts in the form of wires, rods or mats. The reinforcement is usually steel bars (rebar) and is usually embedded passively in the concrete before the concrete sets.

[0080] The binder composition of the present invention can further comprise an admixture. The admixture preferably is a substance capable of controlling and / or modifying the flow properties and / or the setting behavior of the binder composition. Any conventionally known admixtures for mineral bindersystems can be incorporated in the binder composition of the present invention. The admixture can be selected from accelerators, air entraining agents, corrosion inhibitors, further pigments, (super)plasticizers, stabilizer, retarders, pumping agents, surfactants, water resisting aids, and combinations thereof. Suitable examples of admixtures are further described, for example, in DIN EN 934-2:2012-08, DIN EN 934-3:2012-09, and DIN EN 934-4:2009-09.

[0081] Accelerators can speed up the hydration (hardening) of the binder composition. Suitable examples of accelerators include, but are not limited to, calcium chloride, salts of nitrate, nitrite, formate and thiocyanate, such as calcium nitrate and sodium nitrate. Air entraining agents can be added to entrain air bubbles in the binder composition, which can reduce damage during freeze-thaw cycles, and can increase durability. Suitable examples of air entraining agents include, but are not limited to, fatty acid salts. Corrosion inhibitors can be used to minimize the corrosion of steel and steel bars in articles comprising the mineral binder. Suitable examples of corrosion inhibitors include, but are not limited to, calcium nitrite, and amino alcohols. Pigments can be used to change the color of the binder composition for aesthetics. The further pigment being different than recovered carbon black may be an organic or inorganic pigment. Suitable examples of pigments include, but are not limited to, TiO2, BaSCM, Sb2O3, ZnO, magnetite, Mn02, Cd2SSe, FeO, Fe2O3, FesCM, ZnCrCM, SnS2, CdS, BiVCM, Cr2O3, CoZnC , CU2CO3(OH)2, CaCuSi40 , Co-aluminate virgin carbon black, and ultramarine. (Super)plasticizers can increase the workability of the binder composition. Suitable examples of plasticizers include, but are not limited to, lignosulfonates, sulfonated melamine formaldehydes, sulfonated naphthalene formaldehydes and polycarboxylate ethers. (Super)plasticizers can be used to reduce the water content of a concrete while maintaining workability, and are sometimes referred to as water reducers for this purpose. Such treatment improves its strength and durability properties. Retarders can be used to slow hydration of the binder composition and are used in large or difficult pours where partial setting is undesirable before completion of the pour. Suitable examples of retarders are sugar, sucrose,sodium gluconate, glucose, citric acid, and tartaric acid. Pumping aids can improve pumpability, thicken the binder composition, reduce separation and bleeding. Suitable examples of pumping aids include, but are not limited to polyethylene oxides). Water resisting aids can reduce surface absorption and water permeability of the mineral binder by acting on the capillary structure of the mineral binder paste. Suitable examples of water resisting aids include, but are not limited to silica fume, bitumen, stearate and oleate.

[0082] Suitable examples of surfactants comprise non-ionic, anionic and cationic surfactants. Non-ionic surfactants may comprise alkylphenol alkoxylates, alkoxylated polysaccharides, fatty acid amide alkoxylates, alkoxylated alkylamines with an alkyl radical consisting of 6-20 carbon atoms, alkylglycosides, hydrophobized starch, and hydrophobized cellulose. Anionic surfactants may comprise salts of lignosulfonate, alkyl ether carboxylates, alkyl sulfates, alkyl ether sulfates, lauryl ether sulfonates, naphthalene sulfonates, alkyl sulfosuccinates, alkyl phosphates, alkyl ether phosphonates, alkyl benzene sulfonates, and combinations thereof, preferably salts of lignosulfonate. Cationic surfactants may comprise Cs- alkyl hydroxyethyl dimethylammonium chloride, Cs-io alkylamidodimethyl propylamine, and combinations thereof.

[0083] In particular, the binder composition of the present invention comprises a surfactant, preferably an anionic surfactant, more preferably a salt of lignosulfonate, more preferably sodium lignosulfonate.

[0084] According to the present invention, the binder composition may comprise at least 0.05 wt.-% of the admixture, such as at least 0.1 wt.-%, or at least 0.15 wt.-%, or at least 0.2 wt.-%, or at least 0.25 wt.-%, or at least 0.3 wt.-%, or at least 0.35 wt.-%. The binder composition may comprise 10.0 wt.-% or less of the admixture, such as 8.0 wt.-% or less, or 7.0 wt.-% or less, or 6.0 wt.-% or less, or 5.0 wt.-% or less, or 4.0 wt.-% or less, or 3.0 wt.-% or less, or 2.0 wt.-% or less, or 1 .5 wt.-% or less, or 1 .0 wt.-% or less, or 0.7 wt.- % or less, or 0.5 wt.-% or less. The weight percentage is based on the total solids weight of the binder composition. A person skilled in the art will appreciate that any range between any of the explicitly disclosed lower andupper limit is herein disclosed. Accordingly, the binder composition can comprise 0.05 wt.-% to 10.0 wt.-% of the admixture, preferably 0.1 wt.% to 5.0 wt.-%, more preferably 0.2 wt.-% to 3.0 wt.-%, most preferably 0.3 to 2.0 wt.-%.

[0085] The mineral binder composition may further comprise water.

[0086] The present invention further relates to an article made of the binder composition according to the present invention. Articles can be prepared from the binder compositions of the present invention by methods known to those skilled in the art. Examples of such articles include, but are not limited to, roofing tiles, wall panels and building faces.

[0087] In addition, the present invention relates to use of the binder composition according to the present invention as a construction material.

[0088] The present invention also relates to a process for the preparation of a binder composition, in particular the binder composition described above. The process comprises mixing a mineral binder (a) and a recovered carbon black (b), wherein the recovered carbon black is obtained by the pyrolysis of a material comprising carbon black. The mineral binder (a), the recovered carbon black (b), the weight ranges as well as optional further components, such as admixtures may be as described above.

[0089] The mixing step may be performed by hand or by use of a mixing machine, such as a mixer, more specifically a concrete mixer. The binder composition of the present application may be a dry powder. The dry powder is then suitable for use on the addition of water to form a shapeable binder slurry. By providing the binder composition as a dry powder it is suitable for storing before use. When it is desired to use the dry powder the method further comprises: adding water to form a ready-to-use binder slurry, shaping the binder slurry; and allowing the binder slurry to dry and / or cure.

[0090] Alternatively, the recovered carbon black (b) is added to the mineral binder (a), followed by the addition of water to form a mineral binder slurry.

[0091] Having generally described the present invention above, a further understanding can be obtained by reference to the following specific examples. These examples are provided herein for purposes of illustration only, and are not intended to limit the present invention, which is rather to be given the full scope of the appended claims including any equivalents thereof.EXAMPLES

[0092] All parts and percentages indicated throughout the Examples refer to weight, unless specified otherwise. Recovered carbon blacks

[0093] Different recovered carbon blacks (rCB) were used. rCB1 and rCB2 are RCB 615 commercially available from Reoil Sp. Z o.o. (Poland). rCB1 was used as bought and rCB2 was milled before use. rCB3 and rCB4 are Thermolysekoks commercially available from Pyrum Innovations AG (Germany). Both rCB3 and rCB4 were milled before use. Some characteristics of the used rCBs are summarized in Table 1 .

[0094] Table 1 :1dry measurement, detailed description5determined according to ASTM D8474-22 provided below6determined according to ASTM D 1509-952determined by elemental analysis [C, H,N, S, O] or ICP-OES [Zn, Si], detailed description provided below determined according to ASTM D6556-21 determined according to ASTM D1618Particle size distribution

[0095] The particle size distribution is determined by dry measurement with the measurement system from Sympatec GmbH (Germany) consisting of VIBRI: conveyor unit (by vibration); RODOS: compressed air dispersion; and HELOS BR: measuring unit, laser diffraction. As sample preparation, 0.5 g of the dried material was filled into the funnel. During the measurement, the sample is fed with the VIBRI unit to the compressed air dispersion unit RODOS by vibration. Measurement is accomplished in HELOS BR unit using laser diffraction. OPTICAL concentration (copt) was automatically filtered between 5-15% during the measurement. Three separate measurements of 10 sec using each 0.5 g of the material were recorded. Before each measurement, a background measurement of 15 sec was recorded to minimize noise. The obscuration range was controlled by the feeding ratewith automatic adjustment in the range of 5-15% using an integral factor of 0.2 and a constant hopper gap of 1 mm. The dispersing air pressure was set to 3 bar. Reported values (volume distribution) represent the average of three measurements after the data analysis using a standard analysis model in the instrument software.Elemental analysis of C, H, N, and S content

[0096] Elemental analysis of carbon, hydrogen, nitrogen, and sulfur was conducted following DIN 51732:2014 using a vario EL cube CHNS ELEMENTARANALYSATOR from Elementar Analysensysteme GmbH (Germany). The sample preparation was done by weighting 2-3 mg of dried carbon black (125°C for 1 h) into zinc capsules followed by flowing 35 s helium over the sample before closing the capsules with a press. The reported values of the element concentration (%) represent the average of five measurements after the data analysis using a standard analysis model in the instrument software. For the determination of oxygen concentration sodium hydroxide was filled in the adsorption tube. Other than that, the procedure remains the same as for the CHNS analysis.Analysis of Zn and Si content

[0097] The analysis of the Zn content was conducted following method A in ASTM D8371 -20 using an ICP-OES (Spectra Arcos III) from SPECTRO Analytical Instruments GmbH (Germany) and a microwave (turboWAVE inert) from MLS Mikrowellen-Labor-Systeme GmbH (Germany). For the sample preparation, 0.3-0.4 g of the material was weighted into a microwave tube with a capacity of 15 cm3and wetted with 1 ml of pure water (<0.055 pS / cm). Afterward, 10 cm3of concentrated nitric acid (>65 %) was added to the tube and treated in the microwave. The sample was then measured with ICP- OES.

[0098] The analysis of the Si content was conducted using an ICP-OES (iCAP 6300) from Thermo Fisher (USA) after acid digestion of the sample in a microwave (turboWAVE inert) from MLS Mikrowellen-Labor-Systeme GmbH(Germany). A combination of concentrated nitric acid (>65 %) and concentrated hydrofluoric acid (~ 49%) (usually in a volume ratio of 1 :1 ) was used to completely digest the sample whereby microwave heating was deployed to facilitate dissolution. The digested sample was diluted with distilled water to a suitable concentration. The sample was measured with ICP-OES, whereby the device is equipped with a sample introduction kit suitable for HF. In ICP-OES, silicon can be measured with two wavelengths of 288.158 nm and 251 .611 nm. A calibration of the ICP-OES test device is performed using a standard material, such as a commercial standard solution (1 ,000g / L Si in nitric acid (1 mol / L) with 2wt.-% HF commercially available from Bernd Kraft GmbH (Germany)) after appropriate dilution.Standard black pigments

[0099] Standard commercial black pigments were used as benchmarks for comparison, namely Bayferrox® 330 (commercially available from Lanxess Deutschland GmbH (Germany)) and Granufin® CARBON(commercially available from OXERRA Deutschland GmbH & Co. KG (Germany)). Bayferrox® 330 is an iron oxide (FesO4) and Granufin® CARBON comprises >98 % of carbon black (CAS number: 1333-86-4) and small amounts of organic additives. Some characteristics of these black pigments are summarized in Table 2.

[0100] Table 2:1dry measurement as described above2determined according to DIN EN ISO 787-5: 19953determined according to ASTM D1506-154determined according to DIN 55913-2: 1972Virgin carbon blacks

[0101] Various virgin carbon blacks were used for comparison, namely Lamp Black® 101 (lamp black), Printex® A (furnace black), Printex® 300 (furnace black), and Carbon Black N990 (thermal black). All the virgin carbon blacks are commercially available from Orion Engineered Carbon GmbH (Germany). Some characteristics of these virgin carbon blacks are summarized in Table 3.

[0102] Table 3:1dry measurement, as described above2determined according to ASTM D1506-15

[0103] Example 1 (concrete with rCB1 or Bayferrox® 330):

[0104] To prepare the binder composition, 20 g of rCB-1 or 20 g of Bayferrox® 330 were used per 500 g of concrete ready mix (RZB RuckZuckBeton commercially available from Sievert Baustoffe GmbH & Co KG (Germany)) and 60-70g of water. The dry components of the binder composition were mixed using a Rhdnrad mixer for 10 minutes and the resulting dry mix was transferred to a measuring cup. After the addition of water, the composition was mixed by hand until a homogeneous mass was obtained. The concrete composition was poured into selected test molds, whereby the same amount was poured into each mold, and dried for 28 days at room temperature (about 23 °C) resulting dried concrete samples. The total weight content of both rCB-1 and Bayferrox® 330 in the concrete composition obtained was 3.8% by weight. The total weight content is based on the total solid weight of the concrete composition.

[0105] From the visual appearance of the samples, it is clear that the concrete sample colored with rCB-1 has a deeper black color than the sample prepared with Bayferrox® 330 (see Figure 1 ). These observations wereconfirmed by the optical density measurements shown in Table 4. The optical density was measured using the spectrophotometer eXact Advanced (commercially available from x-rite, Inc. (USA)) using an aperture of 6 mm; the function: density, CIE L*a*b*; the measurement geometry: 45°:0° ring illumination optics, ISO 13655:2017; and the measurement conditions: MO (No filter), illuminants D65.

[0106] Table 4:

[0107] A negative b* value represents a blue undertone. A positive b* value in the yellow range indicates a brown undertone. The blue undertone is generally preferred for technical applications as it gives a more saturated result and a more brilliant color impression.

[0108] Example 2 (weathering behavior):

[0109] To estimate the weathering behavior of the respective colored concrete samples described in Example 1 , an extraction for 67 h was carried out using a Soxhlet apparatus (extraction cup length ~20.5 cm, diameter 3 cm). A 250 mL Soxhlet apparatus was connected to a 500 mL round bottom flask containing 350-400 mL of tap water. Concrete test pieces for extraction were ~9-10 cm in length and 2.5 cm in diameter.

[0110] The visual appearance of the concrete samples before and after 67 hours of Soxhlet extraction is shown in Figure 2. It is evident that even after 67 hours of extraction, the concrete colored with rCB-1 has a deeper black color than that prepared with Bayferrox® 330.

[0111] Example 3 (binder composition with different types of carbon blacks and black pigments in different concentrations):

[0112] To prepare the binder compositions, the appropriate quantities of black pigment, rCB or vCB were mixed with the appropriate quantities of ready- mixed concrete and water, and optionally admixture, as described in Table 5 (the weight percent of the pigments is based on the total solids content of the composition). A total of 800 g of dry components were used. The dry components were mixed using a Rhdnrad mixer for 60 minutes and the resulting dry mixture was transferred to a measuring cup. After the addition of water, the prepared formulation was manually mixed until a homogeneous mass was obtained. The final-colored concrete mass was poured into the selected test molds (100 g each) and dried for 28 days at room temperature (about 23 °C). The total weight content of black pigments and carbon blacks (rCB and vCB) are shown in Table 5.

[0113] Table 5:1: Dispersing admixture based on modified sodium lignosulfonate (Vanisperse CB, commercially available by Borregaard AS (Norway))

[0114] The best visual results are obtained with Examples 3.7 to 3.13, especially Ex. 3.10 and in particular Ex. 3.8, as can be seen in Figures 3 to 5.

[0115] Weathering test

[0116] Weathering test was done according to DIN EN ISO 4892-2 method A-B1 : 2021-11.

[0117] The samples were weathered according to DIN EN ISO 4892-2 method A in Suntest XLS Spray device for 1000 h under the following conditions:- Standard reference black sample temperature: 65 ± 3°C- Irradiation strength Euv(3oo-4oo nm): 60 W / m2- Irradiation time: 1000 h- Dry cycle duration: 102 min - Rain cycle duration: 18 min

[0118] Visual assessment of the samples was carried out after 1000 hours of weathering using the Grey Scale Method (GM) in accordance with DIN EN 20105-A02: 1994-10. A GM value of 5 is the maximum achievable.

[0119] The samples in Examples 3.1 to 3.22 were subjected to the standard weathering test as described above, whereby the weathering testing was performed for 1 ,000 h. The obtained results are summarized in Table 6. In addition, Figures 6 to 8 represents the visual juxtaposition of the samples before and after the weathering testing for 1 ,000 h.

[0120] Table 6:

[0121] The concretes colored with rCB-1 and the rCB-1 / admixture mixture show the best coloristic results, which remain stable even after 1 ,000 h of weathering.

Claims

CLAIMS1 . A binder composition comprising a) a mineral binder, and b) recovered carbon black, wherein the recovered carbon black is obtained by pyrolysis of one or more material(s) comprising carbon black.

2. The binder composition according to claim 1 , wherein the recovered carbon black (b) comprises silica, zinc oxide (ZnO), zinc sulfide (ZnS), and a combination thereof.

3. The binder composition according to claim 1 or 2, wherein the recovered carbon black (b) has a zinc content of from 0.5 to 10.0 mass %, preferably from 2.0 mass % to 6.0 mass %, more preferably from 2.5 to 5.5 mass %, even more preferably from 3.0 to 5.0 mass %, most preferably from 3.5 to 4.5 mass %, wherein the zinc content is based on the total mass of the recovered carbon black and wherein the zinc content is determined according to Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES); and / or wherein the recovered carbon black (b) has a silicon (Si) content in a range of from 0.5 to 10.0 mass %, preferably from 1.5 to 7.0 mass %, more preferably from 1.8 to 6.0 mass %, even more preferably from 2.0 to 5.0 mass %, most preferably from 2.2 to 4.5 mass %, wherein the mass % is based on the total mass of the recovered carbon black and wherein the silicon content is determined by to Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES).

4. The binder composition according to any one of the preceding claims, wherein the binder composition comprises 0.1 to 10.0 wt.-% of recovered carbon black (b), preferably 1 .0 to 9.0 wt.%, more preferably 1 .5 to 8.0 wt.%, more preferably 2.0 to 7.0 wt.%, even more preferably 2.5 to 6.0 wt.% most preferably 3.0 to 6.0 wt.%, the weight percentage is based on the total solids weight of the binder composition.

5. The binder composition according to any one of the preceding claims, wherein the recovered carbon black (b) has a BET surface area in a range of from 30 to 200 m2 / g, preferably from 30 to 180 m2 / g, more preferably from 30 to 150 m2 / g, most preferably from 30 to 100 m2 / g, determined according to ASTM D6556-21 .

6. The binder composition according to any one of the preceding claims, wherein the recovered carbon black (b) has an ash content in a range of from 1 to 40 mass %, preferably from 5 to 30 mass %, more preferably from 10 to 30 mass %, even more preferably from 10 to 25 mass %, most preferably from 15 to 25 mass %, wherein the mass% is based on the total mass of the recovered carbon black and wherein the ash content is determined according to ASTM D1506-15.

7. The binder composition according to any one of the preceding claims, wherein the recovered carbon black (b) has an oxygen content in a range of from 0.5 to 10 mass %, preferably from 1 .0 to 3.0 mass %, more preferably from 1 .5 to 3.0 mass %, even more preferably from 1 .5 to 2.5 mass %; and / or a sulfur content in a range of from 0.5 to 8.0 mass %, preferably from 1 .0 to 4.0 mass %, more preferably from 2.0 to 4.0 mass %, even more preferably from 2.0 to 3.0 mass %; and / or a carbon content in a range of from 60 to 98 mass %, preferably from 60 to 85 mass %, more preferably from 65 to 80 mass %, even more preferably from 70 to 80 mass %, wherein the mass % is based on the total mass of the recovered carbon black and wherein the oxygen content, the sulfur content and the carbon content is determined by elemental analysis as described in the specification.

8. The binder composition according to any one of the preceding claims, wherein the material comprises a rubber material, a plastic material and a combination thereof.

9. The binder composition according to claim 8, wherein the rubber material comprises tires.

10. The binder composition according to any one of the preceding claims, wherein the binder composition further comprises an admixture, preferably an anionic surfactant, more preferably a salt of lignosulfonate, most preferably sodium lignosulfonate.

11. The binder composition according to claim 10, wherein the binder composition comprises 0.05 wt.-% to 10.0 wt.-% of the admixture, preferably 0.1 wt.% to 5.0 wt.-%, more preferably 0.2 wt.-% to 3.0 wt.-%, most preferably 0.3 to 2.0 wt.-%, the weight percentage is based on the total solids weight of the binder composition.

12. The binder composition according to any one of the preceding claims, wherein said mineral binder (a) is selected from the group consisting of cement, concrete, mortar, plaster, ferrocement, and ferro concrete.

13. An article made of the binder composition according to any one of the proceeding claims.

14. Use of the binder composition according to any one of claims 1 to 12 as a construction material.

15. A process for the preparation of a binder composition, in particular the binder composition according to any one of claims 1 to 12, comprising mixing a mineral binder (a) and a recovered carbon black (b), wherein the recovered carbon black is obtained by the pyrolysis of a material comprising carbon black.

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