BRPI0619473A2 - process for the preparation of organically modified double layered hydroxide - Google Patents

Abstract

The invention relates to a process for preparing an organically modified layered double hydroxide having a distance between the individual layers of the layered double hydroxide of above 1.5 nm and comprising an organic anion as charge-balancing anion, the process comprising the steps of: (a) preparing a precursor suspension comprising a divalent metal ion source and a trivalent metal ion source;(b) solvothermally treating the precursor suspension to obtain the layered double hydroxide, wherein an organic anion is added before or during the formation of the layered double hydroxide of step (b), or following the formation of the layered double hydroxide, so as to obtain the organically modified layered double hydroxide, with the proviso that deoxycholic acid is not the sole organic anion.; The invention further pertains to a process for preparing an organically modified layered double hydroxide having a distance between the individual layers of the layered double hydroxide of above 1.5 nm and comprising an organic anion as charge-balancing anion, the process comprising the steps of: (a) preparing a precursor suspension comprising a divalent metal ion source and a trivalent metal ion source; (b) thermally treating the precursor suspension to obtain the layered double hydroxide, wherein an organic anion is added before or during the formation of the layered double hydroxide of step (b), or following the formation of the layered double hydroxide, so as to obtain the organically modified layered double hydroxide, with the proviso that in step a) the trivalent metal ion source is not reacted with the organic anion at a temperature of between 60 and 85 DEG C for 4 to 8 hours prior to the addition of the divalent metal ion source and step b) is subsequently carried out at a temperature of 90 to 95 DEG C for 4 to 8 hours.

Description

Patent Descriptive Report for "PROCESS FOR PREPARATION OF DOUBLE HYDROXIDE IN ORGANICALLY MODIFIED LAYER".

The present invention relates to an organically modified double layer hydroxide preparation process.

Such processes are known in the art.

WO 99/35185 describes a process of preparing organically modified double layer hydroxide (LDHs) wherein the organic anion is introduced into the LDH by ion exchange. Ion exchange is performed by suspending the LDH in water, after which the pH of the suspension is reduced to less than 4. Then the organic anions are added to the suspension and the pH is adjusted to an excess value of 8. This process is quite complex and usually produces a stream of salt-containing waste.

WO 00/09599 describes the preparation of an LDH comprising organic anions as intercalated anions. Such modified LDHs can be prepared in a variety of ways, using divalent and trivalent metal ion salts such as magnesium aluminum chloride or sodium aluminate salts. The processes described in WO 00/09599 require salts that will terminate at least in part in the waste stream, which is undesirable. It is furthermore observed that the salts used in these processes are relatively expensive.

In all, the economics of the processes described above show a need for processes that are more economically attractive and cause less damage to the environment.

It is therefore an object according to the present invention to provide a simpler and more environmentally friendly process for preparing organically modified double layer hydroxide.

This objective is accomplished with a process for preparing an organically modified layered double hydroxide having a distance of 1.5 nm between the individual layers of the mentioned layered double hydroxide and comprising an organic anion acting as a charge balancing anion, process comprising the steps of:

(a) preparing a precursor suspension comprising a divalent metal ion source and a trivalent metal ion source;

(b) solvothermally treating the precursor suspension to obtain the double layered hydroxide;

wherein an organic anion is added before or during the formation of the layered double hydroxide of step (b), or after the formation of the layered double hydroxide to obtain the organically modified layered double hydroxide, with the proviso that deocoxycholic acid is not the only organic anion.

This objective is also accomplished with a process for preparing an organically modified layered double hydroxide having a distance between the individual layers of the aforementioned 1.5 nm layered double hydroxide and comprises an organic anion as a charge balancing anion, the process comprising the steps of:

(a) preparing a precursor suspension comprising a divalent metal ion source and a trivalent metal ion source;

(b) heat treating the precursor suspension to obtain the layered double hydroxide,

wherein an organic anion is added before or during the formation of the layered double hydroxide of step (b), or after the formation of the layered double hydroxide to obtain the organically modified layered double hydroxide, with the proviso that in step (a) the trivalent metal ion source does not react with the organic anion at a temperature of 60 to 85 ° C for a period of 4 hours to 8 hours prior to the addition of the divalent metal ion source. and step (b) is subsequently performed at a temperature of 90 ° C to 95 ° C over a period of 4 hours to 8 hours.

The divalent metal ion source and the tri-metal ion source used in the processes according to the present invention are not the salts of these metal ions, especially these sources are not the chloride and perchlorate salts of the divalent and trivalent metal ions, or if the trivalent metal ion is aluminum, it is not aluminates. Note that these sources may partially dissolve in the suspension medium.

The sources of divalent and trivalent metal ions are usually the oxide or hydroxide of divalent or trivalent metal ions. Examples of divalent metal ions are Zn2 +, Mn2 +, Ni2 +, Co2 +, Fe2 +, Cu2 +, Sn2 +, Ba2 +, Ca2 + and Mg2 +. Examples of trivalent metal ions are Al3 +, Cr3 +, Fe3 +, Co3 +, Mn3 +, Ni3 +, Ce3 + and Ga3 +. The use of three or more different metal ions in the layered double hydroxide prepared with the process according to the present invention is also contemplated. Of these metal ions the combination of Mg2 + and / or Zn2 + and Al3 + is preferred. Examples of suitable sources of magnesium include magnesium oxide, magnesium hydroxide, magnesium hydroxycarbonate, magnesium bicarbonate, doolomite and sepiolite. Magnesium oxide is preferred. A combination of two or more sources of magnesium is also contemplated. The aluminum source typically is an aluminum hydroxide or oxide. Examples of such an aluminum source are aluminum trihydroxide such as gibbsite and bayerite, aluminum oxo-oxides such as boehmite, diasporium or goetite and transition aluminas, which are known to one of ordinary skill in the art. technique.

The use of the sources of divalent metal ions and trivalent metal ions mentioned above in the process according to the present invention provides a process that is more environmentally friendly, such as producing considerably less salt, if any. produced, present in the waste stream resulting from the process. In addition, sources of divalent and trivalent metal ions, and especially magnesium and aluminum sources, are generally less expensive than the corresponding salts commonly used in the production of double layered hydroxide. Furthermore, the process according to the present invention is generally simpler since it either requires fewer steps and / or does not require further treatment of the waste stream. In addition, these processes can be performed in a much shorter period of time, which in turn can lead to a higher rate of production of organically modified double layered hydroxide compared to conventional processes.

In an embodiment of the process according to the present invention the divalent metal ion source and / or the trivalent metal ion source is activated before the suspension comprising both sources is thermally or solvothermally treated. The term "activated" refers to the activation of divalent and / or trivalent metal ion sources, thereby increasing their reactivity in the process; Such activation may be carried out, for example, by dry or wet grinding and / or acid treatment. A new advantage of activating metal ion sources is that they present significantly less impurities, such as brucite or gibbsite, which are formed during the process. The reduction or absence of such impurity in the product obtained with the present process has the additional advantage that the use of this product in polymeric matrices may lead to a resulting composite material having improved dynamic and / or mechanical properties.

The organically modified double layer hydroxide prepared with the process according to the present invention has a distance between the individual layers of 1.5 nm as mentioned above. This has advantages in the use of such organically modified double layer hydroxide, for example if used in polymeric matrices. In polymeric matrices (for example, in nanocomposite materials or coating compositions) a greater interlayer distance gives the double layered hydroxide according to the present invention the characteristic of being easily processable in the polymeric matrix and this also allows easy lamination and / or exfoliation of the layered double hydroxide, resulting in a mixture of the modified layered double hydroxide with the polymer matrix with improved physical properties. Preferably, the distance between the layers in an LDH according to the present invention is at least 1.5 nm, more preferably at least 1.6 nm, even more preferably at least 1.8 nm and much more. preferably at least 2 nm. The distance between the individual layers can be determined using χ Ray Diffraction and Transmission Electron Microscopy (TEM) 1 as outlined below.

In a preferred embodiment of the present invention, divalent and / or trivalent metal ion sources, and especially magnesium and / or aluminum sources, are ground or activated prior to step (b). In processes according to the present invention divalent and / or trivalent metal ion sources generally have a d50 value of less than 20 μm and a d90 value of less than 50 μm. Preferably, the value of d5o is less than 15 μm and the value of dgo is less than 40 μm, more preferably the value of d5o is less than 10 μm and the value of dgo is less than 30 μm, still more preferably the value of d5 is less than 8 μm and the value of dgo is less than 20 μm and much more preferably the value of d5o is less than 6p and the value of dgo is less than 10 μm. Particle size distribution can be determined using methods known to one of ordinary skill in the art, for example laser diffraction to DIN 13320. This milling step allows the formation of double hydroxide in layers. proceed faster. It can further reduce the amount of impurities such as gibbsite or brucite if the sources of divalent and trivalent metal ions are sources of magnesium and aluminum.

In the context of this patent application the terms "heat treatment" and "thermally" refer to the treatment of the precursor suspension at a temperature of 30 ° C to the boiling point of the precursor suspension at atmospheric pressure. If the suspending medium is water, the temperature of the heat treatment will generally be from 30 ° C to 100 ° C, preferably from 40 ° C to 95 ° C and more preferably from 50 ° C to 90 ° C.

Additionally, the terms "solvothermal treatment" and "solvothermically" refer to treating the precursor suspension at a pressure above atmospheric pressure and a temperature that is generally above the boiling point of the precursor suspension at atmospheric pressure. The pressure is generally 0.1 MPa (1 bar) of 20 MPa (200 bar), preferably 0.2 MPa (2 bar) of 15 MPa (150 bar) and most preferably 0.3 MPa ( 3 bar) of 10 MPa (100 bar). If the suspending medium is water, the temperature is generally 100 ° C or higher, preferably from 100 ° C to 300 ° C, more preferably from 110 ° C to 250 ° C and most preferably from 120 ° C to 200 ° C.

Suitable suspending media for both heat and solvothermal treatments may be water, an organic solvent or mixtures thereof. Suitable examples of organic solvents include alcohols such as methanol, ethanol, 1-propanol and isopropanol and alkanes such as pentane, hexane and heptane and aromatic hydrocarbons such as benzene, toluene and xylene. An especially suitable solvent of the processes according to the present invention is water.

The process according to the present invention may be conducted in the absence of CO2 or any carbonate in the precursor suspension to make sure that no carbonate is incorporated into the layered double hydroxide as a charge equilibrium anion. . This procedure, moreover, allows the organic anion to be incorporated into the layered double hydroxide as a charge balancing anion.

In an embodiment according to the present invention, the organic ion is added to the precursor suspension before or during the procedures of step (b). In this way, organically modified double layer hydroxide is prepared in one step, which generally makes the process simpler and faster and therefore more economically attractive.

Alternatively, the organic anion is added after formation of the layered double hydroxide, in which case the layered double hydroxide comprises mainly hydroxyl as a charge balancing anion. Said hydroxyl as the charge balancing anion can easily be exchanged for the organic anion.

Within the context of the present patent application the term "charge balance anion" refers to anions that compensate for the electrostatic charge deficiencies of the crystalline LDH sheets. Because LDH typically has a layered structure, the load-balancing anions may be located between the layers, on the edge or on the outer surface of the stacked LDH layers. Such anions between the stacked LDH layers are called intercalation ions.

Such a stacked LDH or organic clay may also be delaminated or exfoliated, for example, in a polymeric matrix. Within the context of the present descriptive report the term "slide separation" is defined as a reduction in the mean stacking degree of LDH particles by at least partial delamination of the LDH1 structure thus producing a material containing significantly more leaves. LDH levels by volume. The term "exfoliation" is defined as complete separation into blades, ie disappearance of non-perpendicular periodicity of direction to the LDH leaves, leading to a casual dispersion of individual layers in a medium, thus leaving absolutely no stacking order. .

Swelling or expansion of LDHs, also called interleaving LDHs, can be observed with X-ray diffraction (XRD), because the position of reference reflections, ie d (001) reflections, is indicative of distance between the layers, which are further apart during an interleaving.

The reduction in the average stacking degree can be observed as a scattering, until the disappearance, of the XRD reflections or by an increasing asymmetry of the reference reflections (001).

The characterization of complete slide separation, that is, exfoliation, remains an analytical challenge, but can generally be completed by the complete disappearance of the non (hkO) reflections of the original LDH.

The ordering of the layers, and thus the extent of the separation into slides, can be further visualized with Transmission Electron Microscopy (TEM).

The LDH according to the present invention may be any LDH known to a person skilled in the art. Typically, these LDHs are mineral LDHs that are capable of expanding or swelling. Such LDHs have a layered structure comprising charged crystalline sheets (also referred to as individual LDH layers) with charge balancing anions sandwiched therebetween. The terms "expand" and "increase" within the context of the present patent application refer to an increase in the distance between charged crystalline leaves. Expandable LDHs may bulge in suitable solvents, for example water, and may furthermore be extended and modified by exchanging the charge balance ions for other charge balance (organic) ions, such modification also being known in the art. technique as interleaving.

The organically modified double layer hydroxide according to the present invention has a layered structure corresponding to the general formula:

[M2 + mM3 + n (OH) 2m + 2n] Xz-n / z.bH2 O (I); wherein M2 + is a divalent metal ion such as Zn2 +, Mn2 +, Ni2 +, Co2 +, Fe2 +, Cu2 +, Sn2 +, Ba2 +, Ca2 +, Mg2 + and M3 + is a trivalent metal ion such as Al3 +, Cr3 +, Fe3 +, Co3 +, Mn3 +, Ni3 +, Ce3 + and Ga3 +; men have a value such that m / n ranges from 1 to 10 and b has a value ranging from 0 to 10. X is an organic anion that balances the charge and has at least 8 carbon atoms, or any other anion known as a person skilled in the art as long as at least a part of the interleaving ions is the organic anion having at least 8 carbon atoms.

Examples of other anions known in the art include hydroxide, carbonate, bicarbonate, nitrate, chloride, bromide, sulfonate, sulfate, bisulfate, vanadates, tungstates, borates, phosphates, stacking anions such as HVO4-, V2O74 ions. -, HV2O124-, V3O93-, V10O286-, Mo7O246-, PW12O403-, B (OH) 4- B4O5 (OH) 42-, [B3O3 (OH) 4] -, [B3O3 (OH) 5] 2-, HBO42 -, HGaO32 - 'CrO42 - and Keggin ions.

The LDH of the present invention includes hydrotalcite and anionic hydrotalcite-like LDHs. Examples of such LDHs are hydrotalcite and materials similar to hydrotalcite, meixnerite, manasseite, pyroaurite, sygrenite, stichtite, barberonite, takovite, reevesite, and desutelsite. A preferred LDH is hydrotalcite, which is an LDH having a layered structure corresponding to the general formula:

[Mg 2+ mAl 3 + n (OH) 2m + 2n] X 2 -N / z.bH 2 O (II);

where omen have a value such that m / n ranges from 1 to 10, preferably from 1 to 6, and b has a value ranging from 0 to 10, usually a value from 2 to 6 and often a value of approximately 4. OX is a charge balance ion as defined above. It is preferable that m / n should have a value of 2 to 4, and more particularly a value of about 3.

LDH may be in any crystalline form known in the art, as described by Cavani et al. (Catalysis Today, 11 (1991), pages 173-301) or by Bookin et al. (LDHs and LDH Minerals, (1993), volume 41 (5), pages 558-564). If the LDH is a hydrotalcite, the hydrotalcite may be a polytype having 3H1, 3H2, 3R1 or 3R2 stacking, for example.

The organic anion used in the process according to the present invention may be any organic anion which upon intercalation produces an organically modified double layer hydroxide according to the present invention. The organic anion that may be suitably used in the process may be derived from an organic anion salt or acid. The use of an organic anion originating from a salt such as an alkali metal stearate salt may be advantageous because of its higher solvent solubility compared to the organic anion derived from the corresponding acid. Alternatively, the use of an acid-sourced organic anion may be advantageous as salt ions will not be introduced into the waste stream so that the waste stream does not need additional treatments to remove salt ions, making the process more economical and simpler.

The organic anion suitable for the process according to the present invention generally comprises 8 or more carbon atoms, provided that the only organic anion present as a charge balancing anion is not terephthalate. Such organic anions having at least 8 carbon atoms include mono, di or polycarboxylates, sulfonates, phosphonates and sulfate. Preferably, the organic anion comprises at least 10 carbon atoms, more preferably at least 12 carbon atoms and the organic anion comprises at most 1,000 carbon atoms, preferably at most 500 carbon atoms, more preferably at most 100 carbon atoms. even more preferably at most 50 carbon atoms and most preferably at most 20 carbon atoms. The use of 2 or more organic anions is visualized, at least one of which has at least 8 carbon atoms and the resulting LDH has an interlayer distance of at least 1.5 nm; one or other organic anions may thus have less than 8 carbon atoms.

Organically modified LDHs comprising only a charge balance organic anion selected from the acetate, succinate, benzoate and terephthalate compound group are less preferred, as they have an interlayer distance of less than 1.5 nm and are generally not easily delaminated or exfoliated in polymeric matrices, producing such modified LDHs less suitable for use, for example, in nanocomposite materials or coating compositions. Examples of such organically modified LDHs are provided by US Patent 5,728,366. In addition, having deocoxycholic acid as the only organic ion is also less preferred as it is too expensive.

In addition, deocoxycholic acid contains 2 hydroxyl groups, which can produce exfoliation or slide separation into a very difficult or even impossible polymeric matrix. This is thought to be caused by a kind of stacking behavior due to the interaction between two or more intercalated deocoxycholic acid anions or due to a single deocoxycholic acid anion interacting with two different clay platelets. In one embodiment of the present invention it is desired that deocoxycholic acid is not used as a charge balancing anion.

It is further contemplated that the charge balance organic anion comprises one or more functional groups such as hydroxyl, amine, carboxylic acid and vinyl. If such organically modified LDHs are used in polymeric matrices, these functional groups may interact or react with the polymer.

Suitable examples of organic anions according to the present invention are monocarboxylic acids such as fatty acids and resin ions.

In one embodiment, the organic anion is a fatty acid or salt thereof having from 8 to 22 carbon atoms. A fatty acid can be a saturated or unsaturated fatty acid. Suitable examples of such fatty acids are caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, decenoic acid, plamitoleic acid, oleic acid, linoleic acid, linolenic acid and mixtures thereof. .

In another embodiment according to the present invention, the organic ion is the resin or a salt thereof. The resin is sourced from natural sources, is readily available, and is relatively inexpensive compared to synthetic organic anions. Typical examples of natural resin sources are resin gum, wood resin and taloleum resins.

Resin is commonly a suspension with a wide variety of different isomers of resin tricyclic carboxylic acids normally containing approximately 20 carbon atoms. The tricyclic structures of various resin acids differ mainly in the position of the double bonds. Typically, the resin is a suspension of substances comprising levopearic acid, neoabietic acid, palindic acid, abietic acid, dehydroabietic acid, dry dehydroabietic acid, tetrahydroabietic acid, dihydroabietic acid, pimaric acid and isopimaric acid. Resin sourced from natural sources also includes resins, i.e. resin suspension, notably resins modified by polymerization, isomerization, disproportionation, hydrogenation, and Diels-Alder reactions with acrylic acid, anhydride and acrylic acid esters. The products obtained by these processes are called modified resins. The natural resin may also be chemically altered by any process known in the art, such as, for example, reacting the carboxyl group of the resin with metal oxide, metal hydroxide or salts to form resin soaps or salts (also called resinates). . Such chemically altered resins are called resin derivatives. Such a resin may be modified or chemically altered by introducing an organic group, an anionic group or a cationic group. The organic group may be a substituted or unsubstituted aliphatic group or an aromatic hydrocarbon having from 1 to 40 carbon atoms. The anionic group can be any anionic group known to a person skilled in the art, such as a carboxylate or a sulfonate.

Further details of these resin-based materials can be collected from DF Zinkel and J. Russell (in Naval Stores, production-chemistry-utilization, 1989, New York, Section II, Chapter 9) and JB Class ("Resins, Natural, "Chapter 1: 'Rosin and Modified Rosing' Kirk-Othmer Encyclopedia of Chemical Technology, posted date: December 4, 2000).

The use of LDHs according to the present invention comprising one or more organic anions is also contemplated. In one embodiment, the interleaving anions are a mixture of fatty acid and resin.

Generally, at least 10% of the total sum of intercalating ions in the LDH types according to the present invention are organic anions, preferably at least 30%, more preferably at least 60% and much more preferably at least 90. % of total sum of interleaving ions are organic anions. In a preferred embodiment, at least 10% of the total sum of intercalated anions is an originated fatty acid or a resin-based anion or a suspension of both anions, preferably at least 30%, more preferably at least 60. Most preferably at least 90% of the total sum of interchange ions is an originated fatty acid or a resin based anion or a mixture of both anions.

The present invention is further illustrated by the Examples below.

EXAMPLES

Example 1:

A commercially available fatty acid was used as received. Kortacid® PH05, a mixture of palmitic and stearic acid, was supplied by Oleochemicals GmbH, a company of Akzo Nobel Chemicals.

50 grams of magnesium oxide (Zolitho® 40, for example, Martin Marietta Magnesia Specialties LLC) and 39 grams of aluminum trioxide (Alumill F505) were mixed into 648 grams of demineralized water and ground to an average size. 2.5 pm particle (d50). The slurry was fed to an oil heated autoclave equipped with a high speed stirrer and heated to 80 ° C. Then 102 grams of Kortacid® PH05 were added to the autoclave over a period of 15 minutes. Prior to addition, the fatty acid mixture was heated to 80 ° C. After the acid addition, the autoclave was closed and heated to 170 ° C and kept for 1 hour. Then the autoclave was cooled to approximately 40 ° C and the resulting slurry was removed. The slurry was then centrifuged at 2,000 rpm for approximately 10 minutes. The liquid was decanted and the solids were dried under vacuum in an oven overnight at 80 ° C.

The resulting hydrotalcite-like clay comprising the fatty acid mixture was analyzed with the χ-ray diffraction to determine inter-gallery spacing or d-spacing. The XRD model of hydrotalcite-like clay as prepared above shows lower non-hkO reflections related to hydrotalcite, indicating anionic clay intercalation. The interleaves exhibit a characteristic value at (001) of 29 Å.

Example 2:

A stabilized resin was prepared by self-production by melting the Chinese gum resin and heating to 235 ° C. About 3.5% of Vultac® 2 (Arkema Inc.) by weight, relative to the weight of the resin, was added during the melting. The molten resin was stirred at 235 ° C for 15 hours, after which the resin was cooled and ready for use.

50 grams of magnesium oxide (Zolitho® 40, for example, Martin Marietta Magnesia Specialties LLC) and 39 grams of aluminum trioxide (Alumill F505) were mixed with 648 grams of demineralized water and ground to an average size of 50%. particle (dso) of 2.5 pm. The slurry was fed to an oil heated autoclave equipped with a high speed stirrer and after its closure was heated to 120 ° C. Then 115 grams of stabilized resin as prepared above was added to the autoclave over a period of 30 minutes. Prior to addition, the resin mixture was also heated to 120 ° C. After acid addition, the autoclave was heated to 170 ° C and thus stored for 1 hour. Then the autoclave was cooled to approximately 40 ° C and the resulting slurry was removed. The slurry was then centrifuged at 2,000 rpm for approximately 10 minutes. The liquid was decanted and the solids were dried under vacuum in an oven overnight at 80 ° C.

The resulting hydrotalcite-like clay comprising the fatty acid mixture was analyzed with χ ray diffraction to determine intergaleria spacing or d-spacing. The XRD model of hydrotalcite-like clay as prepared above shows lower non-hkO reflections related to hydrotalcite, indicating anionic clay intercalation. The interleaves exhibit a characteristic value d (001) of 23 Å.

Example 3:

252 grams of magnesium oxide (Zolitho® 40, eg Martin Marietta Magnesia Specialties LLC) and 240 grams of aluminum trihydroxide (Alumill F505) were mixed into 3,513 grams of demeralized water and ground to an average particle size ( d5) from 2.4 pm. Part of this fluid paste (704 grams) was fed into a glass reactor equipped with a nitrogen flow stirrer and a reflux chiller. The slurry was heated to 90 ° C. Then 147 grams of molten Kortacid PH05 (T = 90 ° C) was added to the glass reactor over a 90 minute period. The reaction mixture was stored at 90 ° C for another 19 hours and then cooled below 50 ° C. The resulting slurry was then centrifuged at 2,000 rpm for approximately 10 minutes. The liquid was decanted and the solids were dried under vacuum in an oven overnight at 80 ° C.

The resulting hydrotalcite-like clay comprising the fatty acid mixture was analyzed with x-ray diffraction to determine inter-gallery spacing or d-spacing. The XRD model of hydrotalcite-like clay as prepared above shows lower hydrotalcite-related non (hkO) reflections, indicating anionic clay interleaving. The interleaves exhibit a characteristic value d (001) of 28 Å.

Claims (8)

1. A process for preparing an organically modified layered double hydroxide having a distance between the individual layers of the 1.5 nm layered double hydroxide as mentioned above and comprising an organic anion as a charge balancing anion; a process comprising the steps of: (a) preparing a precursor suspension comprising a divalent metal ion source and a trivalent metal ion source; (b) solvothermal treatment of the precursor suspension to obtain the layered double hydroxide; Where an organic anion is added before or during the formation of the layered double hydroxide of step (b), or after formation of the layered double hydroxide to obtain the organically modified layered double hydroxide, with the proviso that deocoxycholic acid is not the only organic anion. 2. A process for preparing an organically modified layered double hydroxide having a distance between the individual layers of the 1.5 nm layered double hydroxide as mentioned above and comprises an organic anion as a charge balancing anion. a process comprising the steps of: (a) preparing a precursor suspension comprising a divalent metal ion source and a trivalent metal ion source; (b) heat treating the precursor suspension to obtain the layered double hydroxide, wherein an organic anion is added before or during the formation of the layered double hydroxide of step (b), or after formation of the double layer hydroxide. to obtain the organically modified double layer hydroxide, provided that in step (a) the trivalent metal ion source does not react with the organic anion at a temperature of 60 ° C to 85 ° C for a from 4 hours to 8 hours before the addition of the divalent metal ion source and step (b) is subsequently performed at a temperature of 90 ° C to 95 ° C for a period of -4 hours to 8 hours. A process according to claim 1 or 2, wherein the organic ion is added to the aqueous precursor suspension prior to the procedure of step (b). A process according to claim 1 or 2, wherein the organic ion is added after formation of the layered double hydroxide, wherein the layered double hydroxide has mainly hydroxy as a charge equilibrium anion. A process according to any preceding claim, wherein the divalent metal ion is Mg2 + and the tri-metal ion is Al3 +. A process according to any preceding claim, wherein the divalent metal ion source and / or the trivalent metal ion source is ground before step (b), the dso value of the divalent metal ion source and / or the trivalent metal ion source preferably being below 10 μm. 7 A process according to any one of the preceding claims, wherein the organic anion comprises 8 or more carbon atoms, provided that the only organic anion present as a charge balance anion is not terephthalate; the organic anion preferably having from 10 to 40 carbon atoms.