JPWO2020054134A1 - Organic-inorganic composite material - Google Patents

Abstract

An organic-inorganic composite material in which a silica carrier is modified with an organosilicon compound containing a functional group that binds to a transition metal element and an alkoxysilane.
An organic-inorganic composite material characterized in that the absorbance of a solution prepared by removing solids from a mixed solution prepared under the following measurement conditions at a wavelength of 400 [nm] measured by an ultraviolet-visible spectrophotometer is 0.5 or less. It can be confirmed that it is industrially useful only by measuring the absorbance without measuring the physical properties.
[Measurement condition]
<Coloring reagent>
A solution of palladium acetate having a metal-equivalent palladium concentration of 1 [g / l] in tetrahydrofuran (THF) 15 [ml]
<Organic-inorganic composite material as powder>
0.147 [mmol] in terms of organosilicon compound
<Mixed conditions>
Stirrer: length 1 [cm], diameter 4 [mm]
Rotation speed: 300 [rpm]
Mixing container: Inner diameter 25 [mm] Cylindrical closed container Stirring time: 1 [hour]
<Spectrophotometer measurement cell>
Optical path length: 10 [mm]
[Selection diagram] Fig. 1

Description

The present invention relates to an organic-inorganic composite material in which the surface of a silica carrier is modified with an organosilicon compound having a functional group.

By modifying the surface of silica with an organosilicon compound, the chemical and physical properties of the inorganic oxide material can be changed, and such modified silica is an organic material used for various adsorption and catalytic applications. It was known as an inorganic composite material. (Patent Documents 1 to 4, Non-Patent Document 1)

A scavenger, which is used as an adsorbent, separates transition metal ions from a solvent by adsorbing transition metal ions dissolved in a solvent with a functional group of an organic silicon compound and then filtering the transition metal ions together with an inorganic oxide material. Is.

Since such a scavenger adsorbs a transition metal ion with a chemical bond, it is possible to separate a low concentration of the transition metal ion. Therefore, it is particularly useful when separating expensive components such as precious metals from the solution.

An example of a solution containing a noble metal component is a solution used in a reaction using a homogeneous catalyst. The homogeneous catalyst uses a solution of a noble metal salt or a noble metal complex as a catalyst. Hereinafter, unless otherwise specified in this application, the term noble metal salt shall include a noble metal complex. When the concentration of such a noble metal salt is high, it is one of the efficient methods for separating the noble metal component to precipitate and filter the noble metal salt in the solution by means such as neutralization. However, it is difficult to completely separate the noble metal in the solution by such a separation means, and a low-concentration noble metal salt remains in the solvent as a solute. Scavengers are particularly effective in separating noble metal components from such low-concentration noble metal salt solutions. (Patent Document 4, Non-Patent Document 1)

The solution containing a low-concentration noble metal component is not limited to the solution used for the homogeneous catalyst, but also includes a cleaning solution produced in the process of producing a heterogeneous catalyst and a waste solution generated in the process of producing the noble metal compound itself. .. Scavengers are also widely used to separate noble metal components from such low-concentration noble metal solutions.

Further, a composite material of an inorganic carrier and an organosilicon compound as in the present invention is also known as a catalyst. Such a catalyst uses an organic-inorganic composite material in which a metal component as an active species is chemically bonded to a reactive group of an organic silicon compound modifying a silica carrier and the metal component is bonded as a catalyst. Since various complexes can be used as a catalyst, it can be expected to act as a homogeneous catalyst with excellent catalytic activity while taking the form of a heterogeneous catalyst that can be easily used repeatedly as a catalyst or separated from the reaction system (Patent). Documents 1 to 3).

In addition to such uses as scavengers and catalyst carriers, it is an organoinorganic composite material modified with an organosilicon compound used for adsorbing various components from a solution, but silica is used in all of these uses. The organosilicon compound on the carrier needs to be tightly bound to the silica carrier. If there is an organosilicon compound with a weak bond or no bond, the organosilicon compound is released in the solution in a state of being bonded to a transition metal component or the like, and for example, in the case of scavenger use, the separation efficiency by filtration is low. It becomes a thing.

As described above, in the organic-inorganic composite material used for industrial purposes, the organosilicon compound needs to be firmly bonded to the silica carrier, but the organosilicon compound used for modifying the organic-inorganic composite material is modified. Since the structure does not change significantly before and after, it was difficult to identify the strength of the bond, that is, the quality of the performance before use.

In addition, silica is known to have a high physical adsorption capacity as a carrier. In the organic-inorganic composite material, the organosilicon compound chemically bonds on the surface of the silica carrier to strengthen the bond, but even if it is a physical bond, a considerably strong supporting state is maintained. Therefore, there may be no difference in the elution of the organosilicon compound into the filtrate or the washing liquid in the degree of filtration or washing in the supporting process.

In this way, an organoinorganic composite material in which an organosilicon compound is firmly bonded to a silica carrier is expected to have excellent industrial action, but it is not actually manufactured and its physical properties are not measured. I couldn't judge whether it was industrially useful.

Japanese Unexamined Patent Publication No. 9-173855 Japanese Unexamined Patent Publication No. 2004-175793 WO2009 / 110531 Pamphlet Patent No. 4964772

The Chemical Daily, page 5, published March 31, 2015

An object of the present invention is to obtain an organic-inorganic composite material that can be confirmed to be industrially useful only by absorbance measurement without analysis or measurement by an expensive analyzer or complicated means.

As a result of diligent studies to solve the above problems, the present inventor is an organic-inorganic composite material in which a silica carrier is modified with an organic silicon compound containing a functional group that binds to a transition metal element and an alkoxysilane. When the absorbance of the solution containing this organic-inorganic composite material measured by an ultraviolet-visible spectrophotometer is within a specific range, it is industrially useful as a scavenger, catalyst, etc. without measuring the physical properties. Find out and complete the present invention. Further, the present inventor has found that the organic-inorganic composite material can be produced when the water content of the silica carrier before modification is within a specific range, and completed the present invention.

That is, the present invention is an organic-inorganic composite material in which a silica carrier is modified with an organosilicon compound containing a functional group that binds to a transition metal element and an alkoxysilane.
An organic-inorganic composite material characterized in that the absorbance of a solution prepared by removing solids from a mixed solution prepared under the following measurement conditions at a wavelength of 400 [nm] measured by an ultraviolet-visible spectrophotometer is 0.5 or less. be.
[Measurement condition]
<Coloring reagent>
Tetrahydrofuran solution of palladium acetate having a metal-equivalent palladium concentration of 1 [g / l] 15 [ml]
<Organic-inorganic composite material as powder>
0.147 [mmol] in terms of organosilicon compound
<Mixed conditions>
Stirrer: length 1 [cm], diameter 4 [mm]
Rotation speed: 300 [rpm]
Mixing container: Inner diameter 25 [mm] Cylindrical closed container Stirring time: 1 [hour]
<Spectrophotometer measurement cell>
Optical path length: 10 [mm]

Further, in the present invention, in producing an organic-inorganic composite material by modifying a silica carrier with an organosilicon compound containing a functional group that binds to a transition metal element and an alkoxysilane.
The method for producing an organic-inorganic composite material, wherein the water content of the silica carrier before modification is 0.15 wt% or more in terms of mass of the silica carrier.

Furthermore, the present invention is a scavenger containing the organic-inorganic composite material.

Further, the present invention is the above-mentioned organic-inorganic composite material containing a transition metal element and a catalyst containing the same.

In the organic-inorganic composite material of the present invention, the organosilicon compound is strongly bonded to the silica carrier and can be strongly bonded to the transition metal element. Therefore, it is necessary to measure the analysis by an expensive analyzer or complicated means. However, it is industrially useful.

Therefore, the organic-inorganic composite material of the present invention can separate the transition metal element adsorbed as a scavenger with high efficiency by filtration.

Further, if the organic-inorganic composite material of the present invention is bonded to a transition metal element in advance, it can be easily reused as a catalyst such as a heterogeneous catalyst or separated from the reaction system. In addition, the organic-inorganic composite material of the present invention can firmly bond metal ions, which are expected to have higher activity, as the transition metal element instead of a metal as a metal, and thus have high activity like a homogeneous catalyst. Can also be expected.

FIG. 1 is a schematic view of the organic-inorganic composite material obtained in Example 1 of the present invention, and is firmly bonded to a silica carrier in a state in which an organosiliconized product and a palladium component are bonded in a THF solution to which palladium acetate is added. It represents an organic-inorganic composite material that represents the state of doing so. FIG. 2 is a schematic view of the organic-inorganic composite material obtained in Comparative Example 1 of the present invention, showing an incomplete bond between the silica carrier and the organosilicon in a THF solution to which palladium acetate is added.

The organic-inorganic composite material of the present invention is an organic-inorganic composite material in which a silica carrier is modified with an organosilicon compound containing a functional group that binds to a transition metal element and an alkoxysilane.

Examples of the silica carrier used in the organic-inorganic composite material of the present invention include the following.

[Silica carrier shape]
Since the organosilicon compound modifies the silanol group on the surface of silica as a carrier, the shape of the organoinorganic composite material of the present invention is not particularly limited, and it is molded into a spherical shape, a cylindrical shape, a cylindrical shape, or the like. It may have a geometric shape, and for a cylindrical shape, the space may be partitioned by a wall having an arbitrary shape. Further, not only such a molded carrier but also powder or gel-like silica may be used.

The shape of the silica carrier is not limited as described above, but when the organic-inorganic composite material of the present invention is used as a scavenger, the shape is preferably spherical. The spherical shape makes it less likely to cause clogging when filtering from the reaction system, enables quick separation, shortens the working time, and is an industrially advantageous shape.

When a spherical silica carrier is used, its size is not particularly limited and may be appropriately selected depending on the intended use. However, when the organic-inorganic composite material of the present invention is used as a scavenger, its particle size The cumulative 10% particle diameter (D10 diameter) on a volume basis is preferably 30 to 100 μm, more preferably 50 to 100 μm. If the particle size is large enough, filtration can be performed efficiently, and if the particle size is not too large, the geometric surface area per unit volume and per weight in the bulk state becomes large, and many of them are present. The organic silicon compound can be supported, and the unit weight of the component to be adsorbed and the amount of the component that can be adsorbed per unit volume also increase. The diameter of the spherical silica is a value measured by a laser diffraction type particle size distribution measuring device.

[Silica physical characteristics]
The physical characteristics of the silica used in the present invention are not particularly limited as they are appropriately selected according to the environment in which the organic-inorganic composite material of the present invention is used, and are generally used as a carrier for a heterogeneous catalyst. It may be a physical characteristic to be used. Specific surface area value, pore volume, pore diameter and the like can be mentioned.

Preferably from 200~1,500m ² / g for the silica support specific surface area, more preferably 500~1,000m ² / g. A high specific surface area value means that the area per weight of the carrier on which the organosilicon compound can be modified is large, and the ability to adsorb transition metals is high. Further, since the specific surface area value is not too large, the stability as a carrier is excellent, and the density of the organosilicon compound modified on the surface of the carrier can be easily optimized. The specific surface area of the silica carrier is a value measured by the nitrogen gas adsorption method.

The pore volume is preferably 0.3 to 5 mL / g, more preferably 0.8 to 2 mL / g. The average pore diameter is preferably 2 to 20 nm, more preferably 3 to 10 nm. The pore volume and the average pore diameter are values measured by the nitrogen gas adsorption method.

[Water content of silica carrier]
Silica carriers that are usually industrially available contain moisture. There are various reasons why the silica carrier contains water, and examples thereof include a capillary condensing action derived from the pores of the silica carrier. Having capillary condensation absorbs moisture in the atmosphere during the manufacturing process and storage. In other words, when the humidity during the manufacturing process or storage is high, the amount of water vapor adsorbed by the pores increases, and when drying, the amount of water vapor adsorbed by the pores decreases. In particular, during drying, the water adsorbed in the pores is also released, and the water content contained in the silica carrier decreases.

The water content of the silica carrier used in the present invention is important in producing the organic-inorganic composite material of the present invention, and is preferably 0.15 wt% or more, preferably 0.15 wt% or more in terms of mass of the silica carrier before modification. ~ 3 wt% is more preferable, and 0.2 to 2 wt% is most preferable. The water content of silica can be adjusted according to conventional methods such as drying and immersion in water. The reason why such a suitable water content exists is not clear, but it is considered that there may be an influence on the silanol groups formed by the surface modification of the silica carrier by the organosilicon compound, especially at the time of low water content. It is speculated that such an influence may be large. If the water content is too high, the surface of the silica carrier may be coated with water molecules, making it difficult to modify with the organosilicon compound, or the silica carrier itself may aggregate and the silica carrier with the organosilicon compound may be aggregated. The surface modification may be non-uniform.

Further, the method for measuring the water content can also be carried out according to a conventional method. For example, the silica carrier can be heat-dried and specified by the weight difference before and after that. In the present invention, the water content specified by the mass difference of the silica carriers before and after the drying treatment at 110 ° C. for 16 hours is defined as the water content of the silica carrier.

Examples of the organosilicon compound used in the organic-inorganic composite material of the present invention, which modifies the silica carrier and contains a functional group bonded to a transition metal element and an alkoxysilane, include the following.

[Organosilicon compound]
The organosilicon compound is not particularly limited as long as it is an organosilicon compound that can be chemically bonded to the surface of the silica carrier and contains a functional group that bonds with a transition metal element and an alkoxysilane, and any known compound available on the market may be used. ..

The functional group bonded to the transition metal element is not particularly limited, and examples thereof include a vinyl group, an epoxy group, a styryl group, a methacryl group, an acrylic group, an amino group, a ureido group, an isocyanate group, and a thiol group. Be done. Of these, the thiol group is also known as a functional group that forms a self-assembled monolayer on the surface of various metals such as gold, silver, copper, platinum, palladium, and mercury, and is also used in scavenger applications for transition metal elements. It can be said that it is preferable.

The alkoxysilane is not particularly limited as long as it can form a siloxane bond (Si—O—Si) with the Si element on the silica carrier. For example, a methoxy group, an ethoxy group, a dialkoxy group, etc. Examples thereof include a trialkoxy group. Of these, those having a methoxy group are inexpensively available on the market and are excellent in price competitiveness for the applications of the present invention, but on the other hand, they may be inferior in bondability to silica carriers. .. According to the present invention, it is possible to select an organic-inorganic composite material modified with an organosilicon compound that is not firmly bonded to a silica carrier by an easy method, and the organic-inorganic composite material suitable for applications such as scavengers can be selected. Can be provided.

Preferred organosilicon compounds include, for example, thiol compounds selected from the following formulas (III) and (IV).

ここで、Ｙは２Ｘ＋１であり、Ｘは０〜５が好ましく、Ｃ_ＸＨ_ＹＯは反応性、扱いやすさ、コスト等を踏まえると、−ＯＣＨ_３、−ＯＣ_２Ｈ_５、がより好ましい。ｂは２ａであり、ａは１〜５が好ましく、２〜３がより好ましい。

Here, Y is 2X + 1, X is preferably _0~5, C X _{H Y} O is reactive, ease of handling, given the cost and the _{like, -OCH 3, -OC 2 H 5} , are more preferable. b is 2a, a is preferably 1 to 5, and more preferably 2 to 3.

ここでＲはシリカ担体のシラノール基と交換する脱離基であれば特に限定されず、例えば、−ＯＨ、−Ｃｌ、−ＣＨ_２−ＣＨ＝ＣＨ_２が挙げられる。ｂは２ａであり、ａは１〜５が好ましく、２〜３がより好ましい。

Here, R is not particularly limited as long as it is a leaving group that exchanges with the silanol group of the silica carrier, and examples thereof include -OH, -Cl, and -CH ₂ -CH = CH ₂ . b is 2a, a is preferably 1 to 5, and more preferably 2 to 3.

Among these thiol compounds, 3-mercaptopropyltrimethoxysilane having the following formula (I) is preferable.

By modifying the silica carrier with such an organosilicon compound, an organic-inorganic composite material having the structure of the following formula (II) can be obtained. When the organic-inorganic composite material has such a structure, Si ³⁺ forms a siloxane bond (Si—O—Si) with the three Si elements on the silica carrier and is firmly supported on the silica carrier.

Examples of the method for modifying the above-mentioned silica carrier with an organosilicon compound containing a functional group that binds to a transition metal element and an alkoxysilane include the following.

[Method for modifying silica carrier]
The method of modifying the silica carrier with an organosilicon compound containing a functional group for binding to a transition metal element and an alkoxysilane is particularly limited as long as it is a method for bonding the organosilicon compound and a silanol group on the surface of the silica carrier with a siloxane bond. However, for example, a method of mixing the silica carrier and the organosilicon compound in a solvent can be mentioned.

Examples of the solvent include aromatic hydrocarbons such as toluene and xylene, aliphatic saturated hydrocarbons such as pentane and hexane, and organic solvents such as alcohols such as methanol and ethanol. These solvents may be used alone or in combination of two or more. At this time, the ratio of the solvent to the silica carrier can be arbitrarily selected, but if the solvent is too small, it becomes difficult to mix the silica carrier and the organosilicon compound, and conversely, if the solvent is too large, the organosilicon compound in the solvent Since the concentration is diluted, it takes a long time to combine. Therefore, the ratio of the solvent to the silica carrier is preferably 1:10 to 100: 1 in terms of volume ratio.

The ratio of the organosilicon compound to the silica carrier can be arbitrarily selected, but if the amount of the organosilicon compound is too small, the concentration of the organosilicon compound on the organoinorganic composite material becomes diluted, and conversely, if it is too large. Since the number of organosilicon compounds that cannot be bonded to the surface of the silica carrier increases, the volume ratio is preferably 1: 1000 to 100: 1. At the time of mixing, it is possible to keep it at room temperature, but it may be heated. When heating is performed here, the temperature is not particularly limited, but is preferably 90 to 150 ° C, more preferably 110 to 130 ° C. By heating, the time required for modifying the silica carrier can be shortened, and the energy cost required for production can be reduced. Further, by not heating too much, the structure of the organosilicon compound is maintained, and the adsorption performance of the metal corresponding to the amount of the organosilicon compound modified on the silica carrier can be exhibited. The organosilicon compound is mixed with the silica carrier in the solvent as described above to obtain an organic-inorganic composite material in which the silica carrier is modified with the organosilicon compound.

The organic-inorganic composite material mixed with the solvent may be separated from the mixed solution from the solvent, washed, and dried as a subsequent step, if necessary. The method applied in such a post-process is not particularly limited, and may be selectively used from the methods widely practiced by those skilled in the art. For example, in the case of separation, physical filtration such as centrifugation, natural filtration, or suction filtration may be used, or a combination of these may be used. In the case of washing, the precipitate or filter after separation may be washed by mixing with the solvent used for mixing the organic silicon compound and the silica carrier, or may be washed by supplying a solvent for filtration. May be combined. As long as it is dried, it may be naturally dried, may be further blown to promote drying, may be heat-dried, may be vacuum-dried, or may be combined. In addition, the organic-inorganic composite material may solidify through the separation and drying steps, but it may be crushed and crushed if necessary.

The organic-inorganic composite material of the present invention thus obtained has a high bond strength between the silica carrier and the organosilicon compound. In order to verify this bond strength, it is necessary to sufficiently stir and mix the THF solution and the organic-inorganic composite material described later, and then measure and evaluate the absorbance. The conditions for this measurement are as follows. It can be said that this measurement condition is a harsh stirring condition based on the catalytic reaction and use as a scavenger, and the degree of desorption of the organosilicon compound under such a condition is an industrially significant index.

[Measurement condition]
<Coloring reagent>
Tetrahydrofuran solution of palladium acetate having a metal-equivalent palladium concentration of 1 [g / l] 15 [ml]
<Organic-inorganic composite material as powder>
0.147 [mmol] in terms of organosilicon compound
<Mixed conditions>
Stirrer: length 1 [cm], diameter 4 [mm]
Rotation speed: 300 [rpm]
Mixing container: Inner diameter 25 [mm] Cylindrical closed container Stirring time: 1 [hour]
<Spectrophotometer measurement cell>
Optical path length: 10 [mm]

[Dissolution of organic-inorganic composite materials]
In the above measurement, 15 [ml] of a tetrahydrofuran (THF) solution of palladium acetate having a metal-equivalent palladium concentration of 1 [g / l] (hereinafter referred to as “THF solution”) was used as the color-developing reagent.

This THF is a solvent often used for synthetic reactions using complexes and is easily available. It has excellent solubility of palladium acetate, is an aprotic solvent, has little effect on siloxane bonds, and is suitable for measurement purposes. You can say that.

First, palladium acetate is added to THF15 [ml] so that the metal-equivalent palladium concentration is 1 [g / l], and the mixture is mixed to prepare a THF solution. The temperature at the time of mixing is not particularly limited, and may be, for example, about 15 to 25 ° C.

Next, an organic-inorganic composite material containing 0.147 [mmol] of an organosilicon compound is mixed with a THF solution under the above conditions to prepare a mixed solution. Here, the amount of the silica carrier is not particularly limited, but the amount [mmol / g] of the organosilicon compound in the organic-inorganic composite material is preferably 0.5 or more, preferably 0.8 or more. More preferably. Since the amount of the organosilicon compound is dominant in the bond with the transition metal such as a noble metal, there is no theoretical problem even if it is less than 0.5, but the amount (ratio) of the organosilicon compound in the organic-inorganic composite material. ) Is too low, the total amount of the organoinorganic composite material required for bonding with a transition metal such as a noble metal becomes too large, which may not be industrially preferable.

On the other hand, a large amount (high) of the organosilicon compound in the organoinorganic composite material indicates that the amount of the organosilicon compound per unit weight of the organoinorganic composite material is large, which is high as an adsorption material. It can be said that it is an index that can be expected to perform. However, the large amount (high) of the organosilicon compound in the organic-inorganic composite material also means that the density of the organosilicon compound on the surface of the silica carrier is high, and although it depends on the surface condition of the silica carrier, it is excessive. In a high density state, it may be difficult to maintain the stability of the bond of the organosilicon compound. Based on these facts, the amount (ratio) of the organosilicon compound in the organic-inorganic composite material is preferably 2 or less, and more preferably 1.5 or less.

In the mixed solution in which the THF solution and the organic-inorganic composite material are mixed in this way, silica as a solid content is further removed to obtain a solution, and the absorbance of the mixed solution is measured. The method for removing the solid content is not particularly limited, and any method may be used: filtration, centrifugation, or separation of the supernatant by precipitating the solid content. However, according to filtration, the absorbance is rapidly stable. Can be measured.

Of these, with regard to filtration, it is preferable that the removal operation in an open system be performed promptly in consideration of the possibility of concentrating the solution due to the volatilization of THF as a solvent. An example of such a filtration means is suction filtration. Further, when the solid content is precipitated and the supernatant is separated, it is necessary to sufficiently precipitate the solid content. Therefore, it is preferable to allow the solid content to stand for 12 hours or more in a closed state. The mixed solution is prepared in this way.

[Absorbance measurement]
The solution prepared above measures the absorbance at a wavelength of 400 [nm] as measured by an ultraviolet-visible spectrophotometer. The solution containing the organic-inorganic composite material of the present invention has an absorbance of 0.5 or less, preferably 0.3 or less.

The absorbance of the solution obtained by simply mixing palladium acetate and THF as described above was 2.6. This can be said to be the coloring of THF with palladium acetate. By interposing the organic-inorganic composite material in this, the palladium component in the THF solution is adsorbed by the organic-inorganic composite material. The THF solution on which the palladium component is adsorbed becomes less colored.

Further, in an organic-inorganic composite material in which the bonding of the organosilicon compound on the surface of the silica carrier is weak, the organosilicon compound bonded to palladium is separated from the surface of the silica carrier by stress due to stirring or the like for promoting adsorption. The desorbed organosilicon compound is difficult to remove from the solution by simple filtration. Such a defect is the desorption of the active species from the carrier in the case of catalyst use, and in the reuse of the catalyst by filtration from the reaction system, the amount of the active species supported decreases with each filtration. Not only is the activity as a catalyst reduced, but there is also the problem of contamination of the reactant with the active species. Also, in scavenger applications, transition metal elements such as noble metals adsorbed by organic silicon compounds desorbed from the silica carrier cannot be removed by filtration, leading to a decrease in the recovery rate of the transition metal elements.

From the above, it is possible to determine whether or not the organic-inorganic composite material is industrially useful from the value of the absorbance by measuring the absorbance under the above conditions.

Further, the performance of the organic-inorganic composite material of the present invention can be judged not only by measuring the absorbance but also by measuring the amount of transition metal elements such as precious metals such as palladium actually adsorbed on the organic-inorganic composite material. good. In that case, the transition metal element may be quantified by an arbitrary method effective for quantification of metal such as ICP emission spectroscopic analysis, but it may be derived from Lambertbert's law based on the absorbance.

[Bindable transition metal element]
The transition metal element to which the organic-inorganic composite material of the present invention can be bonded is not particularly limited, and examples thereof include palladium, platinum, copper, mercury, silver, and lead.

[Use of organic-inorganic composite materials]
The organic-inorganic composite material of the present invention can be used, for example, as a scavenger for a transition metal element as long as the transition metal element is not bonded.

Further, the organic-inorganic composite material of the present invention is used as a catalyst for hydrogenation or the like as long as the transition metal elements such as palladium, platinum and copper having a catalytic action are bonded among the transition metal elements. be able to. The method for binding the transition metal element to the organic-inorganic composite material of the present invention is not particularly limited, and may be mixed with a carrier in a solvent, stirred, appropriately heated, or the like.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

Example 1
Preparation of organic-inorganic composites:
In a reaction vessel filled with nitrogen gas, n-paraffin: 120 L, silica carrier (specific surface area value: 750 m ² / g, pore volume: 1.24 ml / g, average pore diameter: 6.6 nm, average particle diameter). (D10): 62 μm, water content: 0.31 wt%): 40 kg and 3-mercaptopropyltrimethoxysilane (organosilicon compound of formula (I)): 12 kg were stirred for 8 hours while raising the temperature to 120 ° C. Then, the heating was stopped, the mixture was left to stand for 16 hours, the reaction vessel was cooled to room temperature by water cooling, and the solid content was filtered using a filter. The filtered solid content was vacuum dried while heating at 60 ° C. to obtain a powdered organic-inorganic composite material.

The laser diffraction type particle size distribution measuring device HRA manufactured by Microtrac Bell Co., Ltd. was used to measure the particle size of the silica carrier, and the specific surface area and average pore size measured by Shimadzu Corporation were measured. A pore distribution measuring device ASAP2420 was used, and TriStar II 3020 manufactured by Micromeritics was used for measuring the pore volume and the average pore diameter.

Comparison example 1
Preparation of organic-inorganic composites:
An organic-inorganic composite material was prepared by the same apparatus and the same procedure except that the silica carrier of Example 1 was dried and used having a water content of 0.1 wt%.

Trial Example 1
The performance of the organic-inorganic composite materials obtained in Example 1 and Comparative Example 1 as a scavenger was evaluated.

[Measurement of supported amount of organosilicon compound]
With respect to the organic-inorganic composite material obtained as described above, the amount of sulfur elements was measured using ICP emission spectroscopic analysis, and the amount of organic silicic acid compounds supported on the silica carrier was measured. As the sample used for the ICP emission spectroscopic analysis, a sample obtained by alkali-melting an organic-inorganic composite material with caustic soda and sodium peroxide at 800 ° C. was extracted with water and then defined. The results are shown in Table 1.

As described above, the amount of the organosilicon compound supported on the silica carrier was substantially the same.

[Absorbance measurement]
Regarding the organic-inorganic composite materials of Example 1 and Comparative Example 1, 0.147 [mmol] in terms of the amount of 3-mercaptopropyltrimethoxysilane charged and palladium acetate having a metal-equivalent palladium concentration of 1 [g / L] It was mixed with 15 [ml] of a tetrahydrofuran solution under the following conditions.
<Mixed conditions>
Stirrer: length 1 [cm], diameter 4 [mm]
Rotation speed: 300 [rpm]
Mixing container: Inner diameter 25 [mm] Cylindrical closed container (screw tube with cap)
Temperature: 23 ° C
Stirring time: 1 [hour]

The mixed solution thus obtained was suction-filtered, and the absorbance of the obtained filtrate at each wavelength of 400 [nm] was measured under the following conditions. Table 2 shows the results together with a reference example of a solution consisting of only 15 [ml] of a tetrahydrofuran solution of palladium acetate having a metal-equivalent palladium concentration of 1 [g / l].

<Measuring device>
Ultraviolet-visible spectrophotometer: U-3310 manufactured by Hitachi High-Tech Science Corporation
Spectrophotometer measurement cell: made of quartz, optical path length 10 [mm]

[Scavenger performance evaluation]
The palladium content of the filtrates prepared for the absorbance measurement of Example 1 and Comparative Example 1 was measured by ICP emission spectroscopy, and the palladium adsorption rate was determined from the difference from the amount charged as palladium acetate, and used as a scavenger. Performance was compared. The results are shown in Table 3.

In Example 1 and Comparative Example 1, a clear difference in coloring behavior and palladium adsorption performance was observed due to a slight difference in water content of the silica carrier before modification. It was also found that its performance can be predicted by measuring the absorbance.

The organic-inorganic composite material of the present invention can be used for scavengers, catalysts and the like.
that's all

Claims (10)

An organic-inorganic composite material in which a silica carrier is modified with an organosilicon compound containing a functional group that binds to a transition metal element and an alkoxysilane.
An organic-inorganic composite material characterized in that the absorbance of a solution prepared by removing solids from a mixed solution prepared under the following measurement conditions at a wavelength of 400 [nm] measured by an ultraviolet-visible spectrophotometer is 0.5 or less.
[Measurement condition]
<Coloring reagent>
Tetrahydrofuran solution of palladium acetate having a metal-equivalent palladium concentration of 1 [g / l] 15 [ml]
<Organic-inorganic composite material as powder>
0.147 [mmol] in terms of organosilicon compound
<Mixed conditions>
Stirrer: length 1 [cm], diameter 4 [mm]
Rotation speed: 300 [rpm]
Mixing container: Inner diameter 25 [mm] Cylindrical closed container Stirring time: 1 [hour]
<Spectrophotometer measurement cell>
Optical path length: 10 [mm] The organic-inorganic composite material according to claim 1, wherein the amount [mmol / g] of the organosilicon compound in the organic-inorganic composite material is 0.5 or more. The organic-inorganic composite material according to claim 1 or 2, wherein the organosilicon compound is of the following formula (I).

The organic-inorganic composite material according to any one of claims 1 to 3, which has the structure of the following formula (II).

The organic-inorganic composite material according to any one of claims 1 to 4, further comprising a transition metal element. The organic-inorganic composite material according to claim 5, wherein the transition metal element is palladium. In producing an organic-inorganic composite material by modifying a silica carrier with an organosilicon compound containing a functional group that binds to a transition metal element on the silica carrier and an alkoxysilane.
The method for producing an organic-inorganic composite material according to any one of claims 1 to 4, wherein the water content of the silica carrier before modification is 0.15 wt% or more in terms of mass of the silica carrier. The method for producing an organic-inorganic composite material according to claim 7, wherein the organosilicon compound is of the following formula (I).

A catalyst comprising the organic-inorganic composite material according to claim 5 or 6. A scavenger comprising the organic-inorganic composite material according to any one of claims 1 to 4.

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