WO2025223927A1

WO2025223927A1 - Curable compositions comprising at least one silane-modified polymer and bauxite residue

Info

Publication number: WO2025223927A1
Application number: PCT/EP2025/060323
Authority: WO
Inventors: Sascha Schaefer; Abel David Salazar La Rosa
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 2024-04-22
Filing date: 2025-04-15
Publication date: 2025-10-30
Anticipated expiration: 2026-10-22

Abstract

The invention relates to a curable composition comprising. I. at least one silane-modified polymer; II. at least one bauxite residue; III. at least one aminosilane or aminosilane oligomer; IV. optionally, surface treated calcium carbonate; V. optionally, surface treated silica; VI. optionally, at least one catalyst; and VII. optionally, at least one plasticizer. The invention also relates to adhesive, sealant, and/or coating materials comprising said composition and the use of said composition.

Description

Curable compositions comprising at least one silane-modified polymer and bauxite residue

The invention relates to curable compositions comprising at least one silane-modified polymer, at least one bauxite residue, at least one aminosilane or aminosilane oligomer, and optionally other components and a curing catalyst, wherein said composition has excellent rheological properties and mechanical strength. The invention also relates to adhesives, sealants, and/or coating materials comprising said composition and use of said composition.

Elastic bonding and sealing materials are used in many different applications ranging from building and construction, assembly, mobility and many more. These materials can absorb mechanical and thermal stress and are key to provide reliability to devices, buildings, and vehicles during their lifetime. Especially in the rail industry, silane-modified polymer-based products are used in the assembly, bonding and sealing in the interior as well as the exterior. A main focus is the bonding and sealing of windows, so called dgx type applications.

However, more sustainable adhesives, sealants and coating materials are sought to contribute to a more circular economy by using either bio-renewable raw materials or waste materials.

In the art, most approaches to increase sustainability of elastic sealants, adhesives and coating materials concentrate on the polymers being used. Additionally, some additives have been replaced by more environmentally friendly options e.g., light stabilizers on tocopherol basis. Besides that, efforts are underway to move away from harmful substances such as catalysts on tin basis. However, these efforts either concentrate on the organic raw materials that are part of the formulation like polymers or substitute only materials that are used in low amounts such as stabilizers and catalysts. So far, few attempts have been undertaken to replace the inorganic filler package most adhesives in this area are using which is calcium carbonate.

Red mud, now more frequently termed bauxite residue, is an industrial waste generated during the processing of bauxite into alumina using the Bayer process. It is composed of various oxide compounds, including the iron oxides which give its red color. Over 95% of the alumina produced globally is through the Bayer process; for every ton of alumina produced, approximately 1 to 1 .5 tons of red mud are also produced. Annual production of alumina in 2020 was over 133 million tons resulting in the generation of over 175 million tons of red mud.

Due to this high level of production and the material's high alkalinity, if not stored properly, it can pose a significant environmental hazard. To date, use of bauxite residues have not been used in adhesives, sealants, and/or coating materials, especially in SMP formulations. So far, bauxite residue found few applications as a filler and a binder for example in the cement industry, the construction and building industry, as source of rare earth elements and other metals and as filler/reinforcement for some composite materials in the automobile industry where it is used as flame retardant.

WO2014114284A2_relates to an inorganic, halogen-free flameproofing agent produced from modified, carbonised red mud (MKRS-HT) which can be used as a flame retardant in the high- temperature range, as well as an inorganic, halogen-free flameproofing agent produced from modified, carbonized and rehydrated red mud (MR2S-NT) which can be used as a flameproofing agent both in the low-temperature range and also in the high-temperature range, and also relates to methods for producing same and the use thereof as flame retardants. The document further relates to a fireproofed material system and methods for producing same. Furthermore the flameproofing agent according to the document can be used in further applications, such as for example for heat insulation and for heat storage, for sound insulation and for shielding from electromagnetic waves, as a substitute for barite and as a substitute for antimony trioxide.

The document discloses an inorganic, halogen-free flameproofing agent produced from modified, recarbonized red mud (MKRS-HT) with a mineral composition of 10 to 50% by weight of iron compounds, 12 to 35% by weight of aluminum compounds, 5 to 17% by weight of silicon compounds, 2 to 10% by weight of titanium dioxide, 0.5 to 6% by weight of calcium compounds, and where appropriate unavoidable impurities, wherein the weight ratio of Fe (II) carbonate to the oxides of iron is at least 1 .

However, adhesives, sealant and coating compositions as well as curable compositions are not mentioned in that document.

It was therefore the objective of the present invention to find possibilities to overcome the disadvantages and drawbacks of conventional materials discussed above. In particular, the present invention aimed at more sustainable adhesives, sealant, and/or coating materials, which exhibit an excellent combination of properties including material reliability, cost-efficiency, easy usability, excellent mechanical properties, good health and safety profile, good tolerance of UV irradiation, good paintability and allow for easy implementation in applications.

The present invention has achieved said objectives by providing a curable composition in accordance with claim 1 . Preferred embodiments of said curable composition are described in the depending claims. In addition, particularly suitable applications of bauxite residue and said curable composition are protected by further an independent product claim and further independent use claims.

The present invention provides a curable composition comprising I. at least one silane-modified polymer;

II. at least one bauxite residue;

III. at least one aminosilane or aminosilane oligomer;

IV. optionally surface treated calcium carbonate;

V. optionally surface treated silica;

VI. optionally, at least one catalyst; and

VII. optionally, at least one plasticizer.

The present invention also relates to an adhesive, sealant, or coating material comprising said curable composition, to the use of at least one bauxite residue in an adhesive, sealant, or coating material, and to the use of said curable composition as an adhesive, sealant, or coating material.

The solution of the present invention is advantageous in several aspects. The present invention shows possibilities to overcome the disadvantages and drawbacks of conventional materials discussed above. In particular, the present invention provides more sustainable adhesives, sealants and coating materials, allowing for a more circular economy by waste materials and at the same time exhibiting an excellent combination of properties including o Low viscosity which allows for higher filler loading o a particularly good material reliability; o an extremely high cost-efficiency of the claimed solution; o an extremely easy usability of the claimed, usually no priming step is required for application of the materials of the invention; o excellent mechanical properties, including excellent Shore A, elongation, and tensile strength of the cured material. o particularly good health and safety profile because of reducing and at best avoiding of harmful substances, such as remaining isocyanates in the materials of the invention; o particularly good tolerance of UV irradiation, especially compared to conventional PUs; o particularly good paintability.

Thus, the claimed invention provides low cost, high performance and sustainable adhesive, sealant, or coating materials. Especially, by using bauxite residue, which is a multi-ton scale by-product of the aluminum industry, as a filler material in adhesive, sealant, and coating materials a circular and a more sustainable economy is achieved. Since fillers in said adhesive, sealant and coating materials are a huge part of the total formulation, use of a more sustainable filler alternative leads to a significant improvement of the overall sustainability of such a product, which is usually not observed for other sustainable solutions. At the same time, a similar performance of the adhesive, sealant, and coating materials according to the invention comprising said bauxite residue is observed, compared to conventional adhesive, sealant and coating materials comprising usual fillers, such as calcium carbonate. However, a remarkable lower viscosity at similar filler loadings is observed for the adhesive, sealant and coating materials according to the invention, which is another advantage of the adhesive, sealant and coating materials according to the invention over the adhesive, sealant and coating materials of the prior art since achievement of higher filler loadings and/or lower cost formulations and easier application are possible.

In addition, the curable composition of the invention exhibits a pronounced flame-retardant effect.

Finally, the solution of the invention can be easily implemented in applications, especially because of excellent curing behavior, as illustrated by outstanding skin over time and depth of cure.

The term “curable composition” is understood to be a substance or mixture of multiple substances, which is curable by physical or chemical measures. In this regard, these chemical or physical measures can be, for example, the supplying of energy in the form of heat, light, or other electromagnetic radiation, but also simply bringing into contact with atmospheric moisture, water, or a reactive component. The composition thereby changes from an original state to a state that has a higher hardness. In preferred embodiments, the curable composition of the present invention is a moisture curable composition.

As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise.

The term "at least one," as used herein, means 1 or more, i.e., 1 , 2, 3, 4, 5, 6, 7, 8, 9, or more. With reference to an ingredient, the indication refers to the type of ingredient and not to the absolute number of molecules. "At least one polymer" thus means, for example, at least one type of polymer, i.e., that one type of polymer or a mixture of several different polymers may be used. Together with the weight indication, the indication refers to all compounds of the stated type which are contained in the composition/mixture, i.e., that the composition contains no further compounds of this type besides the stated quantity of the compounds in question.

The terms “comprising”, “comprises” and “comprised of’ as used herein are synonymous with “including”, “includes”, “containing” or “contains”, and are inclusive or open-ended and do not exclude additional, non-recited members, elements or method steps. If used, the phrase "consisting of’ is closed and excludes all additional elements. Further, the phrase "consisting essentially of excludes additional material elements but allows the inclusion of non-material elements that do not substantially change the nature of the invention. When amounts, concentrations, dimensions and other parameters are expressed in the form of a range, a preferable range, an upper limit value, a lower limit value or preferable upper and limit values, it should be understood that any ranges obtainable by combining any upper limit or preferable value with any lower limit or preferable value are also specifically disclosed, irrespective of whether the obtained ranges are clearly mentioned in the context.

The term “about”, as used herein in connection with a numerical value, relates to a variance of ±20%, preferably ±10% of the respective value.

The words "preferred", "preferably", “desirably” and “particularly”, and synonyms thereof, are used frequently herein to refer to embodiments of the disclosure that may afford particular benefits, under certain circumstances. However, the recitation of one or more preferable, preferred, desirable or particular embodiments does not imply that other embodiments are not useful and is not intended to exclude those other embodiments from the scope of the disclosure.

As used throughout this application, the word “may” is used in a permissive sense - that is meaning to have the potential to - rather than in the mandatory sense.

As used herein, room temperature is 23°C plus or minus 2°C. As used herein, “ambient conditions” means the temperature and pressure of the surroundings in which the composition is located or in which a coating layer or the substrate of said coating layer is located.

The molecular weights given in the present text refer to number average molecular weights (M_n), unless otherwise stipulated. All molecular weight data refers to values obtained by gel permeation chromatography (GPC) carried out using Water 2695 HPLC equipped with 3 Polypore columns and using a Rl detector at 35 °C. Stabilized Tetrahydrofuran (THF) was used as eluent at 1 mL/min flow rate. The calibration of the device was carried out using polystyrene standards.

As used herein, “polydispersity” refers to a measure of the distribution of molecular mass given in a resin sample. The polydispersity is calculated by dividing the weight average molecular weight (M_w) by the number average molecular weight (M_n).

For convenience in the description of the process of this invention, unsaturation provided by CH2=CH- CH2- terminal groups is referred to as “allyl” unsaturation.

As used herein, the term "hydrocarbon residue" is intended to refer to radicals or diradicals which are primarily composed of carbon and hydrogen atoms. Thus, the term encompasses aliphatic groups such as alkyl, alkenyl, and alkynyl groups; aromatic groups such as phenyl; and alicyclic groups, such as cycloalkyl and cycloalkenyl.

As used herein, “Ci-Cs alkyl” group refers to a monovalent group that contains 1 to 8 carbon atoms, that is a radical of an alkane and includes linear and branched organic groups. Examples of alkyl groups include but are not limited to: methyl; ethyl; propyl; isopropyl; n-butyl; isobutyl; sec-butyl; tert-butyl; n- pentyl; n-hexyl; n-heptyl; and 2-ethylhexyl. In the present invention, such alkyl groups may be unsubstituted or may be substituted with one or more substituents such as halo, nitro, cyano, amido, amino, sulfonyl, sulfinyl, sulfanyl, sulfoxy, urea, thiourea, sulfamoyl, sulfamide and hydroxy. The halogenated derivatives of the exemplary hydrocarbon radicals listed above might, in particular, be mentioned as examples of suitable substituted alkyl groups. In general, however, a preference for unsubstituted alkyl groups containing from 1 to 6 carbon atoms (Ci-Ce alkyl) - for example unsubstituted alkyl groups containing from 1 to 4 atoms (C1-C4 alkyl) - should be noted.

As used herein, the term “C2-C8 alkenyl” group refers to an aliphatic hydrocarbon group which contains 2 to 8 carbon atoms and at least one carbon-carbon double bond, e.g., ethenyl, propenyl, butenyl, or pentenyl and structural isomers thereof such as 1- or2-propenyl, 1-, 2-, or 3-butenyl, etc. Alkenyl groups can be linear or branched and substituted or unsubstituted. If they are substituted, the substituents are as defined above for alkyl.

As used herein, the term “C2-C8 alkynyl” group refers to an aliphatic hydrocarbon group which contains 2 to 8 carbon atoms and at least one carbon-carbon triple bond, e.g., ethynyl (acetylene), propynyl, butynyl, or pentynyl and structural isomers thereof as described above. Alkynyl groups can be linear or branched and substituted or unsubstituted.

The term “C3-C10 cycloalkyl” is understood to mean a saturated, mono-, bi- ortricyclic hydrocarbon group having from 3 to 10 carbon atoms. Examples of cycloalkyl groups include cyclopropyl; cyclobutyl; cyclopentyl; cyclohexyl; cycloheptyl; cyclooctyl; adamantane; and, norbornane.

As used herein, a ”Ce-Ci8 aryl” group used alone or as part of a larger moiety - as in “aralkyl group” - refers to optionally substituted, monocyclic, bicyclic and tricyclic ring systems in which the monocyclic ring system is aromatic or at least one of the rings in a bicyclic or tricyclic system is aromatic. The bicyclic and tricyclic ring systems include benzofused 2-3 membered carbocyclic rings. Exemplary aryl groups include phenyl; indenyl; naphthalenyl; tetrahydronaphthyl, tetrahydroindenyl; tetrahydroanthracenyl; and, anthracenyl. And a preference for phenyl groups may be noted. As used herein, an “aralkyl” group refers to an alkyl group that is substituted with an aryl group. As example of an aralkyl group is benzyl.

The terms “Ci-Ceo alkylene” group and “C1-C20 alkylene” group refer respectively to divalent groups that contain from 1 to 60 of from 1 to 20 carbon atoms, that are radicals of an alkane and include linear, branched, or cyclic groups, which groups may be substituted or unsubstituted and may optionally be interrupted by at least one heteroatom.

Where mentioned, the expression “contain at least one heteroatom” means that the main chain or side chain of a residue comprises at least one atom that differs from carbon atom and hydrogen. Preferably the term “heteroatom” refers to nitrogen, oxygen, silicon, sulfur, phosphorus, halogens such as Cl, Br, F. Oxygen (O) and nitrogen (N) may be mentioned as typical heteroatoms in the context of the present invention.

As used herein, the term “hydrocarbon residue” includes saturated or unsaturated hydrocarbon residues.

As used herein, the term “halogen” refers to fluorine, chlorine, bromine, or iodine and correspondingly the term “halide” denotes fluoride, chloride, bromide, or iodide anions.

The terms "flameproofing agent", "flame-retardant agent", "flame retardant" and "OHFR agents" or also the abbreviation "FR" (English: flame retardant) should be understood as synonyms within the context of the present invention. These are understood within the context of the present invention to include in particular non-toxic, halogen-free inorganic flameproofing agents, in particular modified recarbonized bauxite residue (MKRS-HT) or modified, recarbonized and rehydrated bauxite residue.

Within the context of the present invention the "low-temperature range"” is understood to be the temperature range between 220°C. and 350°C.

Within the context of the present invention the "high-temperature range" is understood to be the temperature range between 350°C. and 500°C.

The term "fireproofed material system" is understood to mean an object in which a combustible material is brought into contact with a flame-retardant agent so that the ignition of the combustible material present in the object by fire or heat is prevented or slowed down. In particular the flameretardant agent is permanently associated with the combustible material, for example by blending or coating. "Combustible materials" or "flammable materials" are understood to be any materials which are combustible or flammable, in particular polymers and non-volatile hydrocarbons. Examples are acrylic dispersions, acrylic resins, elastomers, epoxy resins, latex dispersions, melamine resins, polyamide (PA), polyethylene (PE), PE copolymers, thermoplastic PE copolymers, cross-linked PE copolymers, phenolic resins, polyester resins (UP), polyurethane, polypropylene (PP), polyvinyl chloride (PVC), PVC plastisols, thermoplastic elastomers such as for example TPE, TPA, TPU, etc., vinyl ester resins and bitumen. "Combustible" and "flammable" should be understood here as synonyms.

“Bauxite residue”, which can be used interchangeably with “spent ore” or “red mud” (RM) is understood to be the residue from the Bayer process which is produced in the extraction of ATH from bauxite. Further information concerning bauxite residue may be found in WO 2012/126487 A1 , the disclosure of which is hereby incorporated as an integral part of this application. Modified recarbonized bauxite residue (MKRS-HT) is understood to be a product which is produced from bauxite residue (RM) by recarbonization and optionally drying, grinding, admixture of other substances, coating of the surface, etc. Modified recarbonized and rehydrated bauxite residue is understood to be a product which is produced from bauxite residue (RM) by recarbonization as well as rehydration and optionally drying, grinding, admixture of other substances, coating of the surface, etc.

According to the present invention, the curable composition comprises at least one silane-modified polymer (I).

Preferred silane-modified polymers (I) include a-silane and y-silane type modified polymers. The silane-modified polymers generally refer to silane-modified polyether polyols, i.e., polymers featuring hydrolysable silyl groups at the terminal ends of the respective prepolymer main chain.

According to a preferred embodiment of the invention, the curable composition comprises at least one compound of Formula (I)

Y-[(CR¹2)b-SiRa(OR²)3-a]x (I) wherein, in Formula (I),

Y denotes an x-valent polymer radical bonded via nitrogen, oxygen, sulfur, or carbon,

R is independently selected from a monovalent, optionally substituted, SiC-bonded hydrocarbon radical, R¹ is independently selected from hydrogen ora monovalent, optionally substituted hydrocarbon radical which may be attached to the carbon atom via nitrogen, phosphorus, oxygen, sulfur, or carbonyl group, R² is independently selected from hydrogen or a monovalent, optionally substituted hydrocarbon radical, x is an integer from 1 to 10, preferably 1 , 2 or 3, especially preferably 1 or 2, a is 0, 1 , 2, preferably 0 or 1 , more preferably 1 and b is independently selected from an integer from 1 to 10, preferably 1 , 3 and 4, particularly preferably 1 and 3, in particular s.

Examples of radicals R are alkyl radicals, such as the methyl, ethyl, n-propyl, iso-propyl, 1-n-butyl, 2- n-butyl, iso-butyl, tert, pentyl radical; hexyl radicals, such as the n-hexyl radical; heptyl radicals, such as the n-heptyl radical; octyl radicals, such as the n-octyl radical, iso-octyl radicals and the 2,2,4- trimethylpentyl radical; nonyl radicals, such as the n-nonyl radical; decyl radicals, such as the n-decyl radical; dodecyl radicals, such as the n-dodecyl radical; octadecyl radicals, such as the n-octadecyl radical; cycloalkyl radicals, such as cyclopentyl, cyclohexyl, cycloheptyl and methylcyclohexyl radicals; alkenyl radicals, such as vinyl, 1 -propenyl and 2-propenyl radicals; aryl radicals, such as the phenyl, 2- propenyl and 2-propenyl radicals; and phenyl-, naphthyl, anthryl and phenanthryl radicals; alkaryl radicals, such as o-, m-, p-tolyl radicals, xylyl radicals and ethylphenyl radicals; and aralkyl radicals, such as the benzyl radical, the a- and the B-phenylethyl radical.

The R radical is preferably a monovalent hydrocarbon radical having 1 to 6 carbon atoms which is optionally substituted by halogen atoms, particularly preferably an alkyl radical having 1 or 2 carbon atoms, in particular methyl radical.

Examples of radicals R¹ are hydrogen atoms, the radicals indicated for R and optionally substituted hydrocarbon radicals bonded to the carbon atom via nitrogen, phosphorus, oxygen, sulfur, carbon, or carbonyl groups.

Preferably, R¹ is hydrogen or hydrocarbon radicals with 1 to 20 carbon atoms, especially hydrogen.

Examples of R² are hydrogen or the examples given for R.

Preferably, the R² radicals are hydrogen or alkyl radicals containing 1 to 10 carbon atoms, optionally substituted by halogen atoms, particularly preferably alkyl radicals containing 1 to 4 carbon atoms, in particular the methyl and ethyl radicals. For the purposes of the present invention, polymers on which the polymer residue Y is based, are all polymers in which at least 50%, preferably at least 70%, particularly preferably at least 90%, of all bonds in the main chain are carbon-carbon, carbon-nitrogen, or carbon-oxygen bonds. Polymer residues Y are preferably organic polymer residues which are polyoxyalkylenes, such as polyoxyethylene, polyoxypropylene, polyoxybutylene, polyoxytetramethylene, polyoxyethylenepolyoxypropylene copolymer and polyoxypropylene-polyoxybutylene copolymer as polymer chain; which preferably are bonded to each group -[(CR¹2)b-SiR_a(OR²)3-_a]x via -NH-C(=O)-NH-, -NR'-C(-O)- NH- , NH-C(=O)-NR'-, wherein R' may be the same or different and has a meaning specified for R, or represents a group -CH(COOR")-CH2-COOR", wherein R" can be the same or different and has the meaning specified for R. Examples of radicals R' include cyclohexyl-, cyclopentyl-, n- and iso-propyl-, n-, iso- and t-butyl-, the various stereoisomers of the pentyl radical, hexyl radical or heptyl radical and the phenyl radical. R' is preferably a group - CH(COOR")-CH2-COOR" or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, particularly preferably a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, which is optionally substituted by halogen atoms; R" is preferably an alkyl group having 1 to 10 carbon atoms, particularly preferably a methyl, ethyl or propyl radical.

In Formula (I), the radical Y preferably denotes polyester radicals, polyether polyol radicals, poly(meth)acrylate radicals and/or polyolefin radicals, or copolymer radicals thereof, more preferably polyoxyalkylene radicals, especially polyoxypropylene radicals.

Compounds of Formula (I) can have the groups -[(CR¹2)b-SiR_a(OR²)3-_a]x bound in the manner described at any desired position in the polymer, such as located at the terminal ends or located in between the terminal ends, i.e. as side groups of the polymer main chain, particularly preferably at the terminal ends of the polymer chain.

The end groups of the compounds according to Formula (I) are preferably those of the Formula (III)

-NH-C(=O)-NR'-(CR¹ ₂)b-SiR_a(OR²)_3-a (III), wherein the residues and indices are as above defined.

Particularly, a compound according to Formula (I) may denote silane-terminated polyester, silane- terminated polyether polyols, silane-terminated poly(meth)acrylates, silane-terminated polyolefins and/or copolymers of the aforementioned, more preferably silane-terminated polyethers, in particular silane-terminated polypropylene glycols having dimethoxymethylsilyl, trimethoxysilyl, diethoxymethylsilyl or triethoxysilyl end groups bonded via -NH-C(=0)-NR'-(CR¹2)b-groups, wherein R', R¹ and b are as defined above.

The average molecular weights M_n of the compounds according to Formula (I) are preferably at least 400 g/mol, particularly preferably at least 600 g/mol, in particular at least 800 g/mol and preferably at most 30,000 g/mol, particularly preferably at most 19,000 g/mol, in particular at most 13,000 g/mol.

According to various preferred embodiments, the curable composition comprises at least one silane- modified polymer having at least one silane-functional group of the Formula (IV)

-Xo-R³-Si(R⁴)_k(R⁵)₃-k (IV), wherein

X is a divalent linking group containing at least one heteroatom;

R³ is selected from divalent hydrocarbon residues having 1 to 12 carbon atoms; each R⁴ is, independently of one another, selected from a hydrocarbon radical containing 1 to 20 carbon atoms and each R⁵ is, independently of one another, selected from a hydroxyl group or a hydrolysable group, wherein R⁴ and R⁵ are substituents directly bound with the Si atom orthe two of the substituents R⁴ and R⁵ form a ring together with the Si atom to which they are bound; k is 0, 1 or 2; and o is 1 .

In this context, the divalent bonding group (linking group) X comprising at least one heteroatom is understood to be a divalent chemical group which links the polymer backbone of the polymer with the residue R³ of the Formula (IV).

In various embodiments, the divalent linking group X in the Formula (IV) is urea.

The urea group can be obtained if a terminal secondary amino group on the polymer is used, which reacts with a terminal isocyanate group that is present in the respective reactant. This means that a polymer that is terminally substituted with an amino group is reacted with an isocyanatosilane. Urea groups advantageously increase the strength of the polymer chains and of the overall crosslinked polymer.

In preferred embodiments, the linking group X is -N(R”)-C(=O)-N(R”)-, wherein R” is defined above. The index "o" corresponds to 1 , i.e., the linking group X links the polymer backbone with the residue R³ (o = 1).

The residue R³ is a divalent hydrocarbon residue having 1 to 12 carbon atoms. The hydrocarbon residue can be a linear, branched, or cyclic alkylene residue and can be substituted or unsubstituted. The hydrocarbon residue can be saturated or unsaturated. In preferred embodiments, R³ is a divalent hydrocarbon residue having 1 to 6 carbon atoms. The curing rate of the composition can be influenced by the length of the hydrocarbon residues which form one of the binding links or the binding link between polymer backbone and silyl residue. Particularly preferably, R³ is a methylene, ethylene, or n- propylene, in particular a methylene or n-propylene.

Alkoxysilane-functional compounds having a methylene group as binding link to the polymer backbone - so-called “a silanes” - have a particularly high reactivity of the silyl group.

In general, a lengthening of the binding hydrocarbon chain leads to reduced reactivity of the polymers. In particular, “y silanes” - which comprise the unbranched propylene residue as binding link - have a balanced ratio between necessary reactivity (acceptable curing times) and delayed curing (open assembly time, possibility of corrections after bonding).

R⁴ and R⁵ are substituents directly bound with the Si atom or the two of the substituents R⁴ and R⁵ can form a ring together with the Si atom to which they are bound. In preferred embodiments, R⁴ and R⁵ are the substituents directly bound with the Si atom.

Each R⁴ in the Formula (IV) is, independently of one another, selected from a hydrocarbon radical containing 1 to 20 carbon atoms, preferably Ci to Ca alkyl groups, more preferably a methyl or an ethyl.

Each R⁵ in the Formula (IV) is, independently of one another, selected from a hydroxyl group or a hydrolysable group, preferably Ci to Ca alkoxy groups, or Ci to Ca acyloxy groups.

In preferred embodiments, each R⁵ is, independently of one another, selected from Ci to Ca alkoxy groups, in particular methoxy, ethoxy, i-propyloxy, or i-butyloxy group. Since k is 1 , combinations of more than one group are also possible. However, acyloxy groups, such as an acetoxy group -O-CO- CHa, can also be used as hydrolysable groups.

In preferred embodiments, k is 0 or 1 . In particularly preferable embodiments, the silyl group, i.e., -Si(R⁴)k(R⁵)3-k, is selected from alkyldialkoxysilyl, preferably selected from methyldimethoxysilyl or ethyldiethoxysilyl, most preferably methyldimethoxysilyl. Alkoxy groups are advantageous, since no substances which irritate mucous membranes are released during the curing of compositions comprising alkoxy groups. The alcohols formed by hydrolysis of the residues are harmless in the quantities released, and evaporate.

In general, polymers comprising dialkoxysilyl groups have highly reactive linking points which permit rapid curing, high degrees of crosslinking and thus good final strengths. The particular advantage of dialkoxysilyl groups lies in the fact that, after curing, the corresponding compositions are more elastic, softer, and more flexible than systems comprising trialkoxysilyl groups. They are therefore suitable in particular for use as sealants but can also serve as adhesives. In addition, they split off even less alcohol during curing and are therefore of particular interest when the quantity of alcohol released is to be reduced.

Methoxy and ethoxy groups as comparatively small hydrolysable groups with low steric bulk are very reactive and thus permit a rapid cure, even with low use of catalyst. They are therefore of particular interest for systems in which rapid curing is desirable.

Interesting configuration possibilities are also opened up by combinations of the two groups. If, for example, methoxy is selected for one of the R⁵ and ethoxy for the other R⁵ within the same alkoxysilyl group, the desired reactivity of the silyl groups can be adjusted particularly finely if silyl groups carrying exclusively methoxy groups are deemed too reactive and silyl groups carrying ethoxy groups not reactive enough for the intended use.

In addition to methoxy and ethoxy groups, it is of course also possible to use larger residues as hydrolysable groups, which by nature exhibit lower reactivity. This is of particular interest if delayed curing is also to be achieved by means of the configuration of the alkoxy groups.

The silane-functional group of Formula (IV) can be a lateral group within the polymer chain of the respective polymer or a terminal group of the respective polymer. In preferred embodiments, the silane- functional group of Formula (IV) is a terminal group of the polymer.

In preferred embodiments, the polymer has two silane-functional groups of Formula (IV). In this case, the polymer can have at least one lateral silane-functional group of Formula (IV) and at least one terminal silane-functional group of Formula (IV); or, at least two lateral silane-functional groups of Formula (IV); or, at least two terminal silane-functional groups of Formula (IV). In particularly preferred embodiments, the polymer has two terminal silane-functional groups of Formula (IV). Then, each polymer chain comprises two linking points at which the condensation of the polymers can be completed, splitting off the hydrolyzed residues in the presence of atmospheric moisture. In this way, regular and rapid crosslinkability is achieved so that bonds with good strengths can be obtained. In addition, by means of the quantity and the structure of the hydrolysable groups - for example by using methoxy groups or longer residues - the configuration of the network that can be achieved as a long-chain system (thermoplastics), relatively wide-mesh three-dimensional network (elastomers) or highly crosslinked system (thermosets) can be controlled, so that inter alia the elasticity, flexibility and heat resistance of the finished crosslinked compositions can be influenced in this way.

In preferred embodiments, the polymer backbone of the polymer is selected from polyester, polyethers, poly(meth)acrylates, polyolefins, or copolymers of at least two polymers, such as polyether and poly(meth)acrylic acid ester copolymers.

A “polyether”, “polyoxyalkylene”, or “polyalkylene glycol”, as used interchangeably herein, is understood to be a polymer in which the organic repeating units comprise ether functionalities C-O-C in the main chain. Examples for such polymers are polypropylene glycol and polyethylene glycol and copolymers thereof. Polymers having lateral ether groups, such as cellulose ethers, starch ethers and vinyl ether polymers, as well as polyacetals such as polyoxymethylene (POM) are not included in the polyethers.

In particularly preferred embodiments, the silane-modified polymer has a polyether backbone. Polyethers have a flexible and elastic structure, with which compositions having excellent elastic properties can be produced. Polyethers are not only flexible in their backbone, but at the same time strong. Thus, for example, polyethers are not attacked or decomposed by water and bacteria, in contrast to, e.g., polyesters, for example.

The number average molecular weight M_n of the polyether on which the polymer is based is for preference 500 to 100,000 g/mol (Daltons), more preferably 500 to 50,000, particularly preferably 1 ,000 to 30,000 and in particular 2,000 to 20,000 g/mol, most preferably 8,000 to 20,000 g/mol. Number average molecular weights of at least 500 g/mol are advantageous for the polyethers of the present invention since the corresponding compositions have a balanced ratio of viscosity (ease of processing), strength and elasticity.

A “polyol” is understood to be a compound which contains at least two OH groups, irrespective of whether the compound contains other functional groups. However, a polyol used in accordance with the present invention preferably contains only OH groups as functional groups or, if other functional groups are present, none of these other functional groups is reactive at least to isocyanates under the conditions prevailing during the reaction of the polyol(s) and diisocyanate(s).

The polyols to be used in accordance with the invention have an OH value of preferably about 1 to about 250.

Besides the polyethers, the polyol mixture may contain other polyols. For example, it may contain polyester polyols with a molecular weight of about 200 to about 30,000.

The amount of one or more silane-modified polymers (I), i.e., one type of silane-modified prepolymer or different kinds of silane-modified prepolymers, i.e., two or more different kinds of silane-modified prepolymers, as herein defined above, is typically in the range of about 5 to about 95 wt.-%, preferably in the range of about 10 to about 90 wt.-%, even more preferably in the range of about 15 to about 85 wt.-%, particularly preferably in the range of about 10 to about 50 wt.-%, for instance about 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 45, 50, 55, 60, 65, 70, 75, 80 or 85 wt.-%, based on the total weight of curable composition.

According to the present invention, the curable composition comprises at least one bauxite residue (ID-

Preferred bauxite residue contains Fe2Os and silicic acid. Particularly suitable bauxite residues comprises

5-30 wt.%, preferably 15-18 wt.-%, of AI2O3, based on the total weight of the bauxite residue;

5-60 wt.-%, preferably 24-50 wt.-%, of Fe2Os, based on the total weight of the bauxite residue;

0-15 wt.-%, preferably 3 -15 wt.-%, of TiC>2, based on the total weight of the bauxite residue; 3-50 wt.-%, preferably 5 - 20 wt.-%, of SiC>2, based on the total weight of the bauxite residue; 1-12 wt.-%, preferably 5-12%, of Na2O, based on the total weight of the bauxite residue; and 1-14 wt.-%, preferably 1-3 wt.-%, of CaO, based on the total weight of the bauxite residue.

In addition, particularly suitable bauxite residue comprises trace elements, preferably selected from the group consisting of iron (Fe), copper (Cu), cobalt (Co), iodine (I), manganese (Mn), chlorine (Cl), molybdenum (Mo), selenium (Se), zirconium (Zr), and zinc (Zn).

For particularly suitable bauxite residue ashing at temperature greater than 500°C until no decrease in weight is observed, results in a weight decrease of less than 15 wt.-%, preferably of 8-12 wt.-%, based on the total weight of the tested bauxite residue. Preferably, the bauxite residue is neutralized, detoxified and surface treated. By using detoxified bauxite, it is safe to use from health and safety, an environmental as well as an end-of-life perspective. Additionally, surface treatment allows for a higher filler loading without compromising viscosity and yield point. An acidic or alkaline pH can negatively affect shelf life of the uncured adhesive and can also lead to faster degradation of the cured material. Hence, it is desired to produce a formulation close to a neutral pH.

Preferably a bauxite residue comprising a mineral composition of

10 to 50% by weight of iron compounds,

12 to 35% by weight of aluminum compounds,

5 to 17% by weight of silicon compounds,

2 to 10% by weight of titanium dioxide,

0.5 to 6% by weight of calcium compounds, and optionally impurities is used, wherein the bauxite residue preferably recarbonized and the weight ratio of Fe (II) carbonate to the oxides of iron is at least 1 .

In the preferably recarbonized bauxite residue (MKRS-HT) the weight ratio of Fe (II) carbonate to the oxides of iron is preferably at least 1 , more preferably at least 2, more preferably at least 3, more preferably at least 4, more preferably at least 5, more preferably at least 7, more preferably at least 9, more preferably at least 19. For clarification, if for example the weight ratio of Fe (II) carbonate to the oxides of iron amounts to 19 and assuming that all the iron compounds are present either as Fe (II) carbonate or as oxides of iron, 95% by weight of the iron compounds will be present as Fe (II) carbonate and 5% by weight of the iron compounds will be present as oxides of iron.

Alternatively, a bauxite residue comprising bauxite residue comprising a mineral composition of 10 to 50% by weight of iron compounds,

12 to 35% by weight of aluminum compounds,

5 to 17% by weight of silicon compounds,

2 to 10% by weight of titanium dioxide,

0.5 to 6% by weight of calcium compounds, and optionally impurities is preferably used, wherein the bauxite residue preferably recarbonized and rehydrated and the weight ratio of Fe (II) carbonate and the weight ratio of the sum of iron hydroxide and iron oxide hydroxide to the oxides of iron is at least 1 .

In the recarbonized and rehydrated bauxite residue the weight ratio of Fe (II) carbonate and iron hydroxide/oxide hydroxides to the oxides of iron is preferably at least 1 , more preferably at least 2, more preferably at least 3, more preferably at least 4, more preferably at least 5, more preferably at least 7, more preferably at least 9, more preferably at least 19. For clarification, if for example the weight ratio of Fe (II) carbonate to the oxides of iron amounts to 2 and the weight ratio of the sum of iron hydroxide and iron oxide hydroxide to the oxides of iron also amounts to 2 and assuming that all the iron compounds are present either as Fe (II) carbonate, iron hydroxide, iron oxide hydroxide or as oxides of iron, 40% by weight of the iron compounds will be present as Fe (II) carbonate, 40% by weight of the iron compounds will be present as iron hydroxide or iron oxide hydroxide and 20% by weight of the iron compounds will be present as oxides of iron.

In the recarbonized and rehydrated bauxite residue, in addition to the hydroxides/oxide hydroxides of the iron and Fe (II) carbonate, hydroxides/oxide hydroxides of the aluminum are preferably also present which can produce a further intensification of the flame- retard a nt effect on the basis of its endothermic characteristics. In this case the weight ratio of the sum of aluminum hydroxide and aluminum oxide hydroxide to aluminum oxide is preferably at least 1 , more preferably at least 1 .5, more preferably at least 2, more preferably at least 3, more preferably at least 4, more preferably at least 5, more preferably at least 7, more preferably at least 9, more preferably at least 19.

Unless explicitly noted otherwise, the following statements apply both to the recarbonized bauxite residue (MKRS-HT) and also to the recarbonized and rehydrated bauxite residue (MR2S-NT), which taken together are also designated below simply as “modified bauxite residue”.

The mineral composition of the preferably modified bauxite residue preferably comprises:

10 to 50% by weight of iron compounds,

12 to 35% by weight of aluminum compounds,

5 to 17% by weight of silicon compounds,

2 to 10% by weight of titanium dioxide,

0.5 to 6% by weight of calcium compounds, and optionally impurities.

In this case, the mineral composition of the preferably modified bauxite residue may comprise 10 to 45, 30 to 50, or 20 to 40% by weight of iron compounds.

In this case, the mineral composition may comprise 12 to 30, 20 to 35, or 15 to 25% by weight of aluminum compounds.

In this case, the mineral composition may comprise 5 to 15, 8 to 17, or 7 to 16% by weight of silicon compounds, in particular SiC>2. In this case, the mineral composition may comprise 4 to 10, 2 to 8, or 3 to 9% by weight of titanium dioxide (TiC>2).

In this case, the mineral composition may comprise 1 to 6, 0.5 to 2.5, or 0.6 to 1 .5% by weight of calcium compounds, in particular CaO.

In this case, each of the ranges given above may be combined.

"Impurities" are understood to be constituents which occur as impurities in the starting materials, for example in the bauxite subjected to a Bayer process, or impurities which are produced or introduced in the product due to manufacturing tolerances. In particular due to the heterogeneity of the bauxite residue, such impurities are mostly inevitable. However, they do not contribute decisively to the effects of the preferably modified bauxite residue.

In a modification of the invention, the proportion of water-soluble sodium compounds, expressed in percentage by weight of Na2O, in the preferably modified bauxite residue is no more than 0.03, preferably 0.003 to 0.03% by weight.

In a further modification of the invention, the average particle size (d50) in the preferably modified bauxite residue is no more than 50 pm, preferably 0.5 to 10 pm or 1 to 5 pm (preferably modified bauxite residue on a microscale) or 100 to 900 nm or 200 to 750 nm (preferably modified bauxite residue on a nanoscale).

In a further modification of the invention, the residual moisture content of the preferably modified bauxite residue amounts to no more than 0.4% by weight, preferably no more than 0.3% by weight, preferably no more than 0.2% by weight.

The chemical composition of particularly preferred bauxite residue is set out in Table 1 , the chemical composition of particularly preferred recarbonized bauxite residueis set out in Table 2 and the chemical composition of particularly preferred recarbonized and rehydrated bauxite residue is set out in Table 3. Table 1

Table 2

Table 3

Furthermore, it is preferable that the surface of the modified bauxite residue is provided with at least one substance which improves the compatibility of the particles of the modified bauxite residue with a polymer matrix. In this way, the incorporation of the modified bauxite residue into the other material, i.e., a polymer matrix, can be simplified and the bonding of the components can be improved. Likewise, in this way the characteristic profile of the polymer compound can be controlled in a targeted manner. In this case, it has proven advantageous that the substance is a surface modifying agent, selected from the group consisting of organosilanes, organotitanates, organo-zirconium aluminates, carboxylic acid derivatives, softeners, oligomer and polymer precursors, ionomers, boric acid and the metal salts and derivatives thereof, zinc stannates, zinc hydroxystannates or combinations thereof.

In a further preferred embodiment, the bauxite residue is present in combination with flameproofing agent synergists, in particular organoclays (nanoclays), tin compounds and borates.

It is likewise preferable that the bauxite residue also contains at least one further flame-retardant additive in a proportion up to 70% by weight, preferably 5 to 60% by weight, more preferably 10 to 50% by weight, more preferably 15 to 40% by weight.

A further particularly suitable flame-retardant additive is an endothermally reacting substance, preferably an endothermally reacting substance selected from the group consisting of aluminum hydroxide, boehmite, gibbsite, goethite, magnesium hydroxide, huntite, brucite or mixtures thereof.

In the present invention, it is advantageous that the bauxite residue is physically treated, in particular ground or disagglomerated, preferably together with synergists, in particular organoclays (nanoclays), tin compounds and borates, and/or at least one further flame-retardant additive.

In addition, the bauxite residue is preferably surface modified. The surface modification of the bauxite residue preferably comprises providing the surface of the bauxite residue with a surface modifying agent which is selected from the group consisting of organosilanes, organotitanates, organo- zirconium aluminates, carboxylic acid derivatives, softeners, oligomer and polymer precursors, ionomers, boric acid and the metal salts and derivatives thereof, zinc stannates, zinc hydroxystannates or combinations thereof.

The surface modification/sealing serves to guarantee an optimal bonding of the polymer molecules in the interphase to the bauxite residue. In this way, the compound characteristics are controlled in a targeted manner.

By reduction of the bauxite residue in an acidic medium it is possible to obtain from the Fe (III) compounds present in the bauxite residue Fe (II) salt solutions, from which iron (II) carbonate (siderite) can be precipitated by addition of fer example NaHCCh, Na2COs or CaCCh. Without wishing to be tied to a theory, the inventors assume that by a recarbonization of the bauxite residue with the formation of iron (II) carbonate a material can be obtained which exhibits its endothermic effect by cleavage into oxide and CO2 up to temperatures of more than 500° C. In addition to the endothermic reaction acts the released CO2 acts as a flameproofing agent.

The method for producing the recarbonized bauxite residue preferably comprises the steps of: a) providing bauxite residue, b) reducing the iron (III) compounds contained in the bauxite residue in acidic solution to iron (II) compounds, c) adding a carbonate compound to the solution containing iron (II) compounds obtained in step b), wherein iron (II) carbonate (siderite) is formed.

Preferred reducing agents which can be used in step b) are sulfur-containing reducing agents, in particular (N32S2O4) and sulfur dioxide (SO2).

The reduction of the iron (III) compounds contained in the bauxite residue to iron (II) compounds according to step b) preferably takes place in weak acidic solution, for example at a pH value of 4 to 6, in particular a pH value of 4.5 to 5.5.

Preferred carbonate compounds which can be used in step c) are alkali carbonates, alkali hydrogen carbonates and alkaline earth carbonates, in particular sodium carbonate (Na2COs), sodium hydrogen carbonate (NaHCCh) and calcium carbonate (CaCCh). As is clear to the person skilled in the art on the basis of his specialist knowledge, the pH value of the solution containing acidic iron (II) compounds obtained in step b) must if appropriate be adjusted in a suitable manner before step c) in order to obtain iron (II) carbonate (siderite) by addition of a carbonate compound.

The recarbonized and rehydrated bauxite residue may be produced, in that recarbonized bauxite residue (MKRS-HT), such as is for example described above, and rehydrated bauxite residue, such as is described for example in WO 2012/126487 A1 , the disclosure of which is hereby incorporated in its entirety, are produced separately from one another and then mixed together to obtain the recarbonized and rehydrated bauxite residue.

However, by suitable conduct of the reaction it is also possible for both a rehydration and also a recarbonization to proceed in the bauxite residue to obtain the recarbonized and rehydrated bauxite residue. In order to guide the modification in a targeted manner in one or the other direction suitable technical measures can be adopted, such as for example conduct of the reaction under (oxidative) inert process gas, special drying followed directly by surface modification ("sealing") for a preferred modification in the direction of siderite. On the other hand, if predominantly goethite is to be produced, the reaction will proceed with atmospheric oxygen or alternatively ozone which will oxidize the Fe (II) salt solutions to Fe (III) salt solutions. As the pH value rises goethite will be produced which can likewise be dried and sealed at the surface.

By a targeted process management under inert gas or with atmospheric oxygen, drying and surface modification, it is possible to produce a recarbonized and rehydrated bauxite residue tailored for the required use.

The so-called inert process gas/protective gas should be free from all oxidizing components, especially (atmospheric) oxygen. In particular a process gas is used which is composed of equal parts of nitrogen and argon (TIG welding quality is sufficient) and which is circulated.

The (re)carbonised and rehydrated RM, or modified, (re)carbonised RM may also be produced, in that RM is only rehydrated and iron (III) or iron (II) compounds are transformed in isolation to iron (II) carbonate are being and both compounds are then mixed in arbitrary form. The iron (II) carbonate produced in isolation can be treated physically and/or chemically, in order to achieve special application-specific effects. The end products can be produced in both ways so as to be chemically identical.

According to a preferred embodiment, the curable composition comprises at least one bauxite residue (component (II)) in an amount of 0.5 to 90 wt.-%, more preferably 10 to 80 wt.-%, based on the total weight of curable composition.

According to the present invention, the curable composition comprises at least one aminosilane or aminosilane oligomer (III), preferably as adhesion promoters.

Said aminosilanes may be selected from the group consisting of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, aminomethyltrimethoxysilane, aminomethyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, (N-2-aminoethyl)-3-aminopropyltrimethoxysilane, (N-2-amino- ethyl)-3-aminopropyltriethoxysilane, diethylenetriaminopropyltrimethoxysilane, phenylamino-methyl- trimethoxy-silane, (N-2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-(N- phenylamino)propyl-trimethoxysilane, 3-piperazinylpropylmethyldimethoxysilane, 3-(N,N- dimethylaminopropyl)amino-propylmethyldimethoxysilane, tri[(3-triethoxysilyl)propyl]amine, tri[(3- trimethoxysilyl)propyl]amine, 3-(N,N-dimethylamino)propyltrimethoxysilane, 3-(N,N-dimethylamino)- propyltriethoxysilane, (N,N-dimethylamino)methyltrimethoxysilane, (N,N-dimethylamino)methyl- triethoxysilane, 3-(N,N-diethylamino)propyltrimethoxysilane, 3-(N,N-diethylamino)- propyltriethoxysilane, (N,N-diethylamino)methyltrimethoxysilane, (N,N- diethylamino)methyltriethoxysilane, bis(3-trimethoxysilyl)propylamine, bis(3- triethoxysilyl)propylamine, 4-amino-3,3-dimethylbutyltrimethoxy silane, 4-amino-3,3- dimetylbutyltriethoxy silane, N-(n-butyl)-3-aminopropyltrimethoxysilane, oligomers obtained from the condensation of at least one of the above-mentioned aminosilanes, and mixtures thereof, particularly preferably from the group consisting of 3-aminopropyltrimethoxysilane, 3- aminopropyltriethoxysilane, aminomethyltrimethoxysilane, aminomethyltriethoxysilane, 3-(N,N- dimethylamino)propyl-tri methoxysilane, 3-(N,N-dimethylamino)propyltriethoxysilane, (N,N- dimethylamino)methyl-trimethoxysilane, (N,N-dimethylamino)methyltriethoxysilane, 3-(N,N- diethylamino)propyltri methoxysilane, 3-(N,N-diethylamino)-propyltriethoxysilane, (N,N- diethylamino)methyltrimethoxysilane, (N,N-diethylamino)methyl-triethoxysilane, bis(3- trimethoxysilyl)propylamine, bis(3-triethoxysilyl)propylamine, 4-amino-3,3-dimethylbutyltrimethoxy silane, 4-amino-3,3-dimetylbutyltriethoxy silane, N-(n-butyl)-3-aminopropyltrimethoxysilane, oligomers obtained from the condensation of at least one of the above-mentioned aminosilanes, and mixtures thereof. The above-mentioned monomeric aminosilanes or oligomers can be oligomerized together with alkyl-, alkenyl- or aryl-alkoxysilanes, preferably methyltri(m)ethoxysilane, ethyltri(m)ethoxysilane, propyltri(m)ethoxysilane, vinyltri(m)ethoxysilane, n-butyltri(m)ethoxysilane, isobutyltri(m)ethoxysilane, phenyltri(m)ethoxysilane, and/or octyltri(m)ethoxysilane.

In various embodiments, the curable composition in accordance with the claimed invention may further comprise at least one additional aminosilane as described above, for example one of the tertiary aminosilanes. “Tertiary aminosilane”, as used herein, refers to an aminosilane wherein the nitrogen atom of the amino group is covalently linked to three non-hydrogen residues.

According to a preferred embodiment, the curable composition comprises at least one aminosilane or aminosilane oligomer (component (III)) in an amount of 0.05 to 10 wt.-%, more preferably 0.2 to 5 wt.- %, based on the total weight of curable composition.

According to preferred embodiments, the curable composition comprises surface treated calcium carbonate (IV).

Preferred surface treated calcium carbonate particles comprise a treatment layer on the surface of the calcium carbonate particles comprising i. at least one aliphatic aldehyde and/or salty reaction products thereof, and/or ii. at least one mono-substituted succinic anhydride consisting of succinic anhydride monosubstituted with a group selected from a linear, branched, aliphatic and cyclic group having a total amount of carbon atoms from at least C2 to C30 in the substituent and/or salty reaction products thereof, and/or

Hi. at least one polydialkylsiloxane, and/or iv. at least one alkylsilane, and/or v. at least one aliphatic carboxylic acid or a salt thereof, and/or vi. mixtures of the materials according to i. to v.

Particularly preferred surface treated calcium carbonate particles comprise a hydrophobic coating and are preferably coated with alkylsilane with comprising 4 to 22 carbon atoms e.g., hexadecyltrimethoxysilane, hexadecyltriethoxysilane, octyltriethoxysilane, octyltrimethoxysilane and others or aliphatic carboxylic acid or a salt thereof. Saturated or unsaturated carboxylic acids comprising 4 to 22 carbon atoms, preferably comprising 6 to 16 carbon atoms, more preferably comprising 10 to 12 carbon atoms are also particularly preferred for said coating, wherein saturated carboxylic acids are most preferred. In that context, use of lauric acid and of stearic acid, especially of stearic acid is particularly favored.

According to a preferred embodiment, the curable composition comprises at least one surface treated calcium carbonate (component (IV)) in an amount of 0 to 90 wt.-%, more preferably 0 to 50 wt.-%, based on the total weight of curable composition.

According to preferred embodiments, the curable composition comprises surface treated silica (V).

The silica preferably has a BET surface area of 5 to 250 m²/g. When it is used, it can cause additional increase in the viscosity of the curable composition in accordance with the claimed invention to achieve a thixotropic formulation and it can contribute to strengthening the cured composition.

It is likewise conceivable to use silica with a BET surface area, advantageously with 100 to 250 m²/g, particularly 110 to 170 m²/g, as a filler. Because of the higher BET surface area, the same effect, e.g., strengthening ofthe cured composition, can be achieved at a smallerweight proportion of silicic acid. Further substances can thus be used to improve the composition described herein in terms of other requirements.

According to a preferred embodiment, the curable composition comprises at least one surface treated silica (component (V)) in an amount of 0 to 20 wt.-%, more preferably 0 to 5 wt.-%, based on the total weight of curable composition.According to preferred embodiments, the curable composition comprises at least one catalyst (VI), preferably selected from tin catalysts, titanium catalysts, aluminum catalysts, or zirconium catalysts, more preferably tin catalysts or titanium catalysts, or mixtures thereof.

In various embodiments, the curing catalyst may be a tin compound, preferably an organotin compound or an inorganic tin salt. Tin in these tin compounds is preferably bivalent or tetravalent. The curing catalyst can be added to the composition particularly as a crosslinking catalyst. Suitable inorganic tin salts are, for example, tin(ll) chloride and tin(IV) chloride. Organotin compounds (tin organyles) are used preferably as the tin compounds, however. Suitable organotin compounds are, for example, the 1 ,3-dicarbonyl compounds of bivalent or tetravalent tin, for example, the acetylacetonates such as di(n- butyl)tin(IV) di(acetylacetonate), di(n-octyl)tin(IV) di(acetylacetonate), (n-octyl)(n-butyl)tin(IV) di(acetylacetonate); the dialkyl tin(IV) dicarboxylates, for example, di-n-butyltin dilaurate, di-n-butyltin maleate, di-n-butyltin diacetate, di-n-octyltin dilaurate, di-n-octyltin diacetate, or the corresponding dialkoxylates, for example, di-n-butyltin dimethoxide; oxides of tetravalent tin, for example, dialkyltin oxides, such as, for example, di-n-butyltin oxide and di-n-octyltin oxide; and the tin(ll) carboxylates such as tin(ll) octoate or tin(ll) phenolate.

Suitable furthermore are tin compounds of ethyl silicate, dimethyl maleate, diethyl maleate, dioctyl maleate, dimethyl phthalate, diethyl phthalate, dioctyl phthalate, nonadecylic acid, myristic acid, such as, for example, di(n-butyl)tin(IV) di(methyl maleate), di(n-butyl)tin(IV) di(butyl maleate), di(n- octyl)tin(IV) di(methyl maleate), di(n-octyl)tin(IV) di(butyl maleate), di(n-octyl)tin(IV) di(isooctyl maleate); and di(n-butyl)tin(IV) sulfide, (n-butyl)2Sn(SCH2COO), (n-octyl)2Sn(SCH2COO), (n- octyl)₂Sn(SCH₂CH₂COO), (n-octyl)₂Sn(SCH2CH2COOCH2CH₂OCOCH2S), (n-butyl)₂-Sn(SCH₂COO-i- CaHi7)2, (n-octyl)2Sn(SCH2COO-i-CaHi7)2, and (n-octyl)2Sn(SCH2COO-n-CaHi7)2.

Preferably, the tin compound is selected from 1 ,3-dicarbonyl compounds of bivalent or tetravalent tin, the dialkyltin(IV) dicarboxylates, the dialkyltin(IV) dialkoxylates, the dialkyltin(IV) oxides, the tin(ll) carboxylates, and mixtures thereof.

Particularly preferably, the tin compound is a dialkyltin(IV) oxide (e. g. di-n-octyltin oxide) or dialkyltin(IV) dicarboxylate, particularly di-n-butyltin dilaurate, di-n-butyltin diacetate, or di-n-octyltin dilaurate.

Additionally, or alternatively, other metal-based condensation catalysts may be used, including, without limitation, compounds of titanium such as organotitanates or chelate complexes, cerium compounds, zirconium compounds, molybdenum compounds, manganese compounds, copper compounds, aluminum compounds, orzinc compounds ortheir salts, alkoxylates, chelate complexes, or catalytically active compounds of the main groups or salts of bismuth, lithium, strontium, or boron.

Further suitable (tin-free) curing catalysts are, for example, organometallic compounds of iron, particularly the 1 ,3-dicarbonyl compounds of iron such as, e.g., iron(lll) acetylacetonate.

Boron halides such as boron trifluoride, boron trichloride, boron tribromide, boron triiodide, or mixtures of boron halides can also be used as curing catalysts. Particularly preferred are boron trifluoride complexes such as, e.g., boron trifluoride diethyl etherate, which as liquids are easier to handle than gaseous boron halides.

Further, amines, nitrogen heterocycles, and guanidine derivatives are suitable in general for catalysis. An especially suitable catalyst from this group is 1 ,8-diazabicyclo[5.4.0]undec-7-ene (DBU).

Titanium, aluminum, and zirconium compounds, or mixtures of one or more catalysts from one or more of the just mentioned groups may also be used as catalysts.

Suitable as titanium catalysts are compounds that have hydroxy groups and/or substituted or unsubstituted alkoxy groups, therefore titanium alkoxides of the general formula

Ti(OR^z)₄, wherein R^z is an organic group, preferably a substituted or unsubstituted hydrocarbon group having 1 to 20 C atoms, and the 4 alkoxy groups -OR^Z are identical or different. Further, one or more of the -OR^Z groups can be replaced by acyloxy groups -OCOR^Z.

Likewise suitable as titanium catalysts are titanium alkoxides in which one or more alkoxy groups are replaced by a hydroxy group or halogen atoms.

Further, titanium chelate complexes can be used.

Aluminum catalysts can also be used as curing catalysts, e.g., aluminum alkoxides

AI(OR^Z)₃, wherein R^z has the above meaning; i.e., it is an organic group, preferably a substituted or unsubstituted hydrocarbon group having 1 to 20 C atoms and the three R^z groups are identical or different. In the case of aluminum alkoxides as well, one or more of the alkoxy groups can be replaced by acyloxy groups - OC(O)R^Z.

Further, aluminum alkoxides can be used in which one or more alkoxy groups are replaced by a hydroxy group or halogen atoms. Of the described aluminum catalysts, the pure aluminum alcoholates are preferred in regard to their stability to moisture and the curability of the mixtures to which they are added. In addition, aluminum chelate complexes are preferred.

Suitable as zirconium catalysts are, e.g.: tetramethoxyzirconium or tetraethoxyzirconium.

Diisopropoxyzirconium bis(ethyl acetoacetate), triisopropoxyzirconium (ethyl acetoacetate), and isopropoxyzirconium tris(ethyl acetoacetate) are used with very particular preference.

Further, zirconium acylates, halogenated zirconium catalysts, or zirconium chelate complexes can also be used.

In addition, carboxylic acid salts of metals or also a mixture of a number of such salts can be employed as curing catalysts, whereby these are selected from the carboxylates of the following metals: calcium, vanadium, iron, zinc, titanium, potassium, barium, manganese, nickel, cobalt, and/or zirconium.

Of the carboxylates, the calcium, vanadium, iron, zinc, titanium, potassium, barium, manganese, and zirconium carboxylates are preferred, because they exhibit a high activity. Calcium, vanadium, iron, zinc, titanium, and zirconium carboxylates are particularly preferred. Won and titanium carboxylates are very particularly preferred.

Further, phosphorous containing organic compounds or mixtures thereof can be used as alternative to metal based catalysts. Examples are triethylphosphat or 2-ethylhexyl-phosphat.

Alternatively strong Bronstedt acids, especially organic acids such as dodecylbenzenesulfonic acid can be used as catalysts.

According to a preferred embodiment, the curable composition comprises at least one catalyst (component (VI)) in an amount of 0 to 5 wt.-%, more preferably 0 to 1 wt.-%, based on the total weight of curable composition.

According to preferred embodiments, the curable composition comprises at least one plasticizer (VII).

Examples of optionally employed plasticizers are dimethylpolysiloxanes which are liquid at room temperature under a pressure of 1013 hPa and are terminated with trimethylsiloxy groups, in particular having viscosities at 20° C. in the range between 20 and 5,000 mPas; organopolysiloxanes which are liquid at room temperature under a pressure of 1 ,013 hPa and consist substantially of SiO₃/₂, SiO₂/₂, and SiOi/2 units, referred to as T, D, and M units; and also high-boiling hydrocarbons, such as, for example, paraffin oils or mineral oils consisting substantially of naphthenic and paraffinic units.

The optionally employed plasticizer (VII) preferably comprises linear polydimethylsiloxanes having trimethylsilyl end groups.

The curable composition in accordance with the claimed invention can furthermore contain hydrophilic plasticizers. These are used to improve the moisture absorption and thereby to improve the reactivity at low temperatures. Suitable as plasticizers are, for example, esters of glutaric acid, ester of abietic acid, adipic acid esters, azelaic acid esters, benzoic acid esters, butyric acid esters, acetic acid esters, esters of higher fatty acids having approximately 8 to approximately 44 carbon atoms, epoxidized fatty acids, fatty acid esters and fats, glycolic acid esters, phosphoric acid esters, phthalic acid esters, linear or branched alcohols containing 1 to 12 carbon atoms, propionic acid esters, sebacic acid esters, sulfonic acid esters, thiobutyric acid esters, trimellitic acid esters, citric acid esters, and esters based on nitrocellulose and polyvinyl acetate, as well as mixtures of two or more thereof.

For example, of the phthalic acid esters, dioctyl phthalate, dibutyl phthalate, diisoundecyl phthalate, or butylbenzyl phthalate is suitable, and of the adipates, dioctyl adipate, diisodecyl adipate, diisodecyl succinate, dibutyl sebacate, or butyl oleate.

Also suitable as plasticizers are the pure or mixed ethers of monofunctional, linear or branched C4-16 alcohols or mixtures of two or more different ethers of such alcohols, for example, dioctyl ether (obtainable as Cetiol OE, BASF, Dusseldorf).

Endcapped polyethylene glycols are also suitable as plasticizers, for example, polyethylene or polypropylene glycol di-C1 -4-alkyl ethers, particularly the dimethyl or diethyl ethers of diethylene glycol or dipropylene glycol, and mixtures of two or more thereof.

Suitable plasticizers are endcapped polyethylene glycols, such as polyethylene or polypropylene glycol dialkyl ethers, where the alkyl group has up to four C atoms, and particularly the dimethyl and diethyl ethers of diethylene glycol and dipropylene glycol. An acceptable curing is achieved in particular with dimethyldiethylene glycol also under less favorable application conditions (low humidity, low temperature). Reference is made to the relevant technical chemistry literature for further details on plasticizers. Also suitable as plasticizers are diurethanes, which can be prepared, for example, by reacting diols, having OH end groups, with monofunctional isocyanates, by selecting the stoichiometry such that substantially all free OH groups react. Optionally excess isocyanate can then be removed from the reaction mixture, for example, by distillation. A further method for preparing diurethanes consists of reacting monofunctional alcohols with diisocyanates, whereby all NCO groups are reacted if possible.

The curable composition in accordance with the claimed invention may contain the plasticizer preferably in an amount of 0 to 40% by weight, preferably in an amount of 0 to 30% by weight based in each case on the total weight of the curable composition in accordance with the claimed invention.

If a mixture of plasticizers is used, the amounts refer to the total amount of plasticizers in the curable composition in accordance with the claimed invention.

According to a preferred embodiment, the curable composition comprises at least one plasticizer (component (VII)) in an amount of 0 to 50 wt.-%, more preferably 0 to 25 wt.-%, based on the total weight of curable composition.

The curable composition in accordance with the claimed invention can comprise at least one additional auxiliary substance, preferably selected, for example, from the group consisting of plasticizers, extenders, stabilizers, antioxidants, fillers, reactive diluents, drying agents, UV stabilizers, rheological aids, thixotropy modifiers and/or solvents. Of particular importance are typically plasticizers, fillers, thixotropy modifiers and stabilizers, comprising antioxidants and UV stabilizers.

Preferably, the curable composition in accordance with the claimed invention therefore contain at least one auxiliary substance.

It is conceivable that the viscosity of the curable composition in accordance with the claimed invention is too high for certain applications. It can then be reduced in a simple and expedient way usually by using a reactive diluent, without any signs of demixing (e.g., plasticizer migration) occurring in the cured mass.

Solvents and/or plasticizers can be used, in addition to or instead of a reactive diluent, for reducing the viscosity of the curable composition in accordance with the claimed invention.

Suitable as solvents are aliphatic or aromatic hydrocarbons, halogenated hydrocarbons, ketones, ethers, esters, ester alcohols, keto alcohols, keto ethers, keto esters, and ether esters. However, curable compositions in accordance with the claimed invention that are free of organic solvents may be preferred due to ecological and/or health concerns. In various embodiments, the curable composition in accordance with the claimed invention is thus substantially free of organic solvent.

In the context of the present invention, the term “substantially free” refers to compositions comprising less than about 1 wt.-%, preferably less than about 0.5 wt.-%, more preferably less than about 0.1 wt.% of the respective ingredient. For instance, a composition substantially free of organic solvent comprises, in the context of the present invention, less than about 1 wt.-% organic solvent.

In preferred embodiments, the curable composition in accordance with the claimed invention comprises the following components in the stated proportions by weight:

(i) from 5 % by weight to 95 % by weight, preferably 10 % by weight to 50 % by weight, of said at least one silane-modified polymer, based on the total weight of the composition; and/or

(ii) from 0.5 % by weight to 90 % by weight, preferably 10 % by weight to 80 % by weight, of said at least one bauxite residue, based on the total weight of the curable composition; and/or

(iii) from 0.05 % by weight to 10 % by weight, preferably to 0.2 % by weight to 5 % by weight, of said at least one aminosilane or aminosilane oligomer, based on the total weight of the curable composition; and/or

(iv) from 0 % by weight to 90 % by weight by weight, preferably 0 % by weight to 50 % by weight, of said surface treated calcium carbonate, based on the total weight of the curable composition; and/or

(v) from 0 % by weight to 20 % by weight, preferably 0 % by weight to 5 % by weight, of said surface treated silica, based on the total weight of the curable composition;

(vi) from 0 % by weight to 5 % by weight, preferably 0% to 1 % by weight, of said at least one catalyst, based on the total weight of the curable composition;

(vii) from 0 % by weight to 50 % by weight, preferably 0 % to 25% by weight, of said at least one plasticizer, based on the total weight of the curable composition, wherein the proportions by weight preferably add up to 100 wt.-%.

With regard to the preferred representatives of the individual components and the preferably used quantities thereof, the statements made above in the description of the respective components apply.

The preparation of the curable composition of the claimed invention can take place by simple mixing of the at least one silane-modified polymer (I), at least one bauxite residue, the surface treated silica (II), the surface treated calcium carbonate (III), and the at least one additional aminosilane or oligoaminosilane, and optionally the other ingredients described herein. This can take place in suitable dispersing units, e.g., a high-speed mixer. In this case, preferably, care is taken that the curable composition of the present invention does not come into contact with moisture as far as possible, which could lead to an undesirable premature curing. Suitable measures are sufficiently known and comprise, for example, working in an inert atmosphere, possibly under a protective gas, and drying/heating of individual components before they are added.

The invention also relates to an adhesive, sealant, or coating material comprising the curable composition according to the invention.

The invention further relates to the use of at least one bauxite residue in an adhesive, sealant, or coating material, preferably in a curable composition, in particular, in a curable composition according to the present invention. In addition, the present invention preferably also relates to the use of at least bauxite residue as flame retardant in an adhesive, sealant, or coating material, preferably in a curable composition, in particular, in a curable composition according to the present invention.

Besides, the present invention relates to a fireproofed curable composition, comprising

I. at least one silane-modified polymer;

II. at least one bauxite residue;

III. at least one aminosilane or aminosilane oligomer;

IV. optionally surface treated calcium carbonate;

V. optionally surface treated silica;

VI. optionally, at least one catalyst; and

VII. optionally, at least one plasticizer.

Furthermore, the invention also relates to the use of the curable composition according to the invention as an adhesive, sealant, or coating material.

Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although the foregoing descriptions describe some example embodiments in the context of certain example combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and/or functions than those explicitly described above are also contemplated as may be set forth in some of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

The following examples serve to illustrate the invention, but the invention is not limited thereto.

Examples

Unless otherwise stated, the examples which follow are carried out at a pressure of the surrounding atmosphere, in other words approximately at 1 ,000 hPa, and at room temperature, in other words at approximately 23° C., and/or at a temperature which comes about when the components are combined at room temperature without additional heating or cooling, and also at a relative atmospheric humidity of approximately 50%. Furthermore, all figures for parts of percentages, unless otherwise stated, are by weight.

The formulations were prepared as described in the tables below, wherein the components were added to the reaction vessel in the following order: First the plastic mixing vessel was charged with the polymer, followed by the addition of filler and plasticizer. The mixture was mixed in a Hauschild Speedmixer® under vacuum at room temperature. Then silanes were added and mixed again. Finally, the catalyst was added and the resulting paste mixed at room temperature under vacuum.

The resulting product was subjected to curing performance tests as follows:

Density: 10g samples are prepared. Density was determined by water displacement.

Tensile strength and elongation: The tensile strength and elongation at break were determined in accordance with DIN 53504. The samples were cured in a mold at room temperature over seven days. The specimen type S2 (Dog bone) was used and the speed of the pull head in the dynamometer was 200mm/min.

Skin-over time (SOT): Skin-over time (SOT) is defined as the time reguired for the material to form a non-tacky surface film. The determination of the skin over time is carried out according to DIN 50014 under standard climate conditions (23 +/- 2°C, relative humidity 50 +/- 5%). The temperature of the sealant must be 23 +/- 2°C, with the sealant/adhesive stored for at least 24 h beforehand in the laboratory. The sealant/adhesive is applied to a sheet of paper and spread out with a putty knife to form a skin (thickness about 2 mm, width about 7 cm). The stopwatch is started immediately. At intervals, the surface is touched lightly with the fingertip and the finger is pulled away, with sufficient pressure on the surface that an impression remains on the surface when the skin formation time is reached. The skin-over time is reached when sealing compound no longer adheres to the fingertip. The skin-over time (SOT) is expressed in minutes.

Shore A hardness: Shore A hardness was measured according to ISO 868.

Viscosity: The viscosity of the polymers was measured on an Anton Paar Rheometer MCR 302e, 23°C, 10 s-1 , 0,5 mm gap, 25 mm plate, by Casson equation/model.

Table 4

¹: MA 491 available from Kaneka (Japan). MA 491 is described as a mixture of both a polyether and polyacrylate based silane-modified polymer

²: DBE-5 dibasic ester available from Sigma-Aldrich, an affiliate of Merck KGaA (Germany)

³: Printex 60 available from Orion Engineered Carbon (USA)

⁴: Hakuenka CCR H5 available from Shiraishi Omya GmbH (Austria)

⁵ Martinal OL-104 LEO available from Huber Martinswerk (Germany)

⁶: Bauxite residue available from Proferro GmbH (Germany) ⁷: Aerosil 974 available from Evonik Industries AG (Germany)

⁸: Geniosil GF 96 available from Wacker Chemie AG (Germany)

⁹: Geniosil XL 10 available from Wacker Chemie AG (Germany); water scavenger

Table 5

Claims

Claims:

1 . A curable composition comprising

I. at least one silane-modified polymer;

II. at least one bauxite residue;

III. at least one aminosilane or aminosilane oligomer;

IV. optionally, surface treated calcium carbonate;

V. optionally, surface treated silica;

VI. optionally, at least one catalyst; and

VII. optionally, at least one plasticizer.

2. The curable composition according to claim 1 , wherein said at least one silane-modified polymer has the Formula (I)

Y-[(CR¹2)b-SiRa(OR²)3-a]x (I) wherein, in Formula (I),

R is independently selected from a monovalent, optionally substituted, SiC-bonded hydrocarbon radical,

R¹ is independently selected from hydrogen or a monovalent, optionally substituted hydrocarbon radical which may be attached to the carbon atom via nitrogen, phosphorus, oxygen, sulfur, or carbonyl group,

R² is independently selected from hydrogen or a monovalent, optionally substituted hydrocarbon radical, x is an integer from 1 to 10, preferably 1 , 2 or 3, especially preferably 1 or 2, a is 0, 1 , or 2, and b is independently selected from an integer from 1 to 10, preferably 1 , 3 and 4, particularly preferably 1 and 3, in particular s.

3. The curable composition according to claim 1 or 2, wherein the bauxite residue comprises Fe2C>3 and silicic acid, preferably comprises

5-30 wt.%, more preferably 15-18 wt.-%, of AI2O3, based on the total weight of the bauxite residue;

5-60 wt.-%, more preferably 24-50 wt.-%, of Fe2Os, based on the total weight of the bauxite residue;

0-15 wt.-%, more preferably 3 -15 wt.-%, of TiC>2, based on the total weight of the bauxite residue; 3-50 wt.-%, more preferably 5 - 20 wt.-%, of SiC>2, based on the total weight of the bauxite residue;

1-12 wt.-%, more preferably 5-12%, of Na2O, based on the total weight of the bauxite residue; and

1-14 wt.-%, more preferably 1-3 wt.-%, of CaO, based on the total weight ofthe bauxite residue.

4. The curable composition according to any one of claims 1 to 3, wherein the bauxite residue is neutralized, detoxified and surface treated.

5. The curable composition according to any one of claims 1 to 4, wherein said aminosilanes is selected from the group consisting of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, aminomethyltrimethoxysilane, aminomethyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, (N-2-aminoethyl)-3-aminopropyltrimethoxysilane, (N-2-amino-ethyl)-3-aminopropyltriethoxysilane, diethylenetriaminopropyltrimethoxysilane, phenylamino-methyl-trimethoxy-silane, (N-2-aminoethyl)-3- aminopropylmethyldimethoxysilane, 3-(N-phenylamino)propyl-trimethoxysilane, 3- piperazinylpropylmethyldimethoxysilane, 3-(N,N-dimethylaminopropyl)amino- propylmethyldimethoxysilane, tri[(3-triethoxysilyl)propyl]amine, tri[(3- trimethoxysilyl)propyl]amine, 3-(N,N-dimethylamino)propyltrimethoxysilane, 3-(N,N- dimethylamino)-propyltriethoxysilane, (N,N-dimethylamino)methyltrimethoxysilane, (N,N- dimethylamino)methyl-triethoxysilane, 3-(N,N-diethylamino)propyltrimethoxysilane, 3-(N,N- diethylamino)-propyltriethoxysilane, (N,N-diethylamino)methyltrimethoxysilane, (N,N- diethylamino)methyltriethoxysilane, bis(3-trimethoxysilyl)propylamine, bis(3- triethoxysilyl)propylamine, 4-amino-3,3-dimethylbutyltrimethoxy silane, 4-amino-3,3- dimetylbutyltriethoxy silane, N-(n-butyl)-3-aminopropyltrimethoxysilane, oligomers obtained from the condensation of at least one of the above-mentioned aminosilanes and mixtures thereof, preferably from the group consisting of 3-aminopropyltrimethoxysilane, 3- aminopropyltriethoxysilane, aminomethyltrimethoxysilane, aminomethyltriethoxysilane, 3- (N,N-dimethylamino)propyl-trimethoxysilane, 3-(N,N-dimethylamino)propyltriethoxysilane, (N,N-dimethylamino)methyl-trimethoxysilane, (N,N-dimethylamino)methyltriethoxysilane, 3- (N,N-diethylamino)propyltrimethoxysilane, 3-(N,N-diethylamino)-propyltriethoxysilane, (N,N- diethylamino)methyltrimethoxysilane, (N,N-diethylamino)methyl-triethoxysilane, bis(3- trimethoxysilyl)propylamine, bis(3-triethoxysilyl)propylamine, 4-amino-3,3- dimethylbutyltrimethoxy silane, 4-amino-3,3-dimetylbutyltriethoxy silane, or N-(n-butyl)-3- aminopropyltrimethoxysilane, or oligomers obtained from the condensation of at least one of the above-mentioned aminosilanes, or mixtures thereof.

6. The curable composition according to any one of claims 1 to 5, wherein the surface treated calcium carbonate comprises particles comprising a treatment layer on the surface of the calcium carbonate particles comprising i. at least one aliphatic aldehyde and/or salty reaction products thereof, and/or ii. at least one mono-substituted succinic anhydride consisting of succinic anhydride mono-substituted with a group selected from a linear, branched, aliphatic and cyclic group having a total amount of carbon atoms from at least C2 to C30 in the substituent and/or salty reaction products thereof, and/or

7. The curable composition according to any one of claims 1 to 6, wherein the surface treated silica has a BET surface area of 5 to 250 m²/g.

8. The curable composition according to claim any one of claims 1 to 7, wherein the catalyst is selected from tin catalysts, titanium catalysts, aluminum catalysts, or zirconium catalysts, preferably tin catalysts or titanium catalysts, or mixtures thereof.

9. The curable composition according to any one of claims 1 to 8, wherein the plasticizer is selected from the group consisting of dimethylpolysiloxanes, esters of glutaric acid, ester of abietic acid, adipic acid esters, azelaic acid esters, benzoic acid esters, butyric acid esters, acetic acid esters, esters of higher fatty acids having approximately 8 to approximately 44 carbon atoms, epoxidized fatty acids, fatty acid esters and fats, glycolic acid esters, phosphoric acid esters, phthalic acid esters, linear or branched alcohols containing 1 to 12 carbon atoms, propionic acid esters, sebacic acid esters, sulfonic acid esters, thiobutyric acid esters, trimellitic acid esters, citric acid esters, and esters based on nitrocellulose and polyvinyl acetate, as well as mixtures of two or more thereof, pure or mixed ethers of monofunctional, linear or branched C4-16 alcohols or mixtures of two or more different ethers of such alcohols, endcapped polyethylene glycols, and diurethanes.

10. The curable composition according to any one of claims 1 to 9, wherein the composition comprises at least one additional auxiliary substance, preferably selected from the group consisting of plasticizers, extenders, stabilizers, antioxidants, fillers, reactive diluents, drying agents, UV stabilizers, rheological aids, thixotropy modifiers and/or solvents.

1 1 . The curable composition according to any one of claims 1 to 10, wherein the bauxite residue is recarbonized, preferably recarbonized and rehydrated.

12. The curable composition according to any one of claims 1 to 1 1 , wherein

(i) the amount of said at least one silane-modified polymer is from 5 % by weight to 95 % by weight, preferably 10 % by weight to 50 % by weight, based on the total weight of the composition; and/or

(ii) the amount of said at least one bauxite residue is from 0.5 % by weight to 90 % by weight, preferably 10 % by weight to 80 % by weight, based on the total weight of the composition; and/or

(iii) the amount at least one aminosilane or aminosilane oligomer is from 0.05 % by weight to 10 % by weight, preferably to 0.2 % by weight to 5 % by weight, based on the total weight of the curable composition; and/or

(iv) the amount of said surface treated calcium carbonate is from 0 % by weight to 90 % by weight by weight, preferably 0 % by weight to 50 % by weight, based on the total weight of the curable composition; and/or

(v) the amount of said surface treated silica is from 0 % by weight to 20 % by weight, preferably 0 % by weight to 5 % by weight, based on the total weight of the curable composition; and/or

(vi) the amount of said at least one catalyst is from 0 % by weight to 5 % by weight, preferably 0% to 1 % by weight, based on the total weight of the curable composition; and/or

(vii) the amount of said at least one plasticizer is from 0 % by weight to 50 % by weight, preferably 0 % to 25% by weight, based on the total weight of the curable composition.

13. An adhesive, sealant, or coating material comprising the curable composition according to any one of claims 1 to 12.

14. Use of at least one bauxite residue in an adhesive, sealant, or coating material.

15. Use of a curable composition according to any one of claims 1 to 12 as an adhesive, sealant, or coating material.