JP6926517B2 - Method for Producing Cyrilized Layered Inorganic Compound - Google Patents

Description

The present invention relates to a method for producing a silylated layered inorganic compound, which chemically modifies the layers of the layered inorganic compound with a silylating agent.

As a method of silylating and modifying the layers of the layered inorganic compound, the metal cations existing between the layers are exchanged with organic onium such as alkylonium to widen the interlayer distance, and then chlorosilanes [R _n SiCl _4-n ] or A method is known in which alkoxysilanes [R ¹ _n Si (OR ² ) _4-n ] are allowed to act to react the hydroxyl groups or metal alkoxylates existing between layers with the silanes.

For example, in Non-Patent Document 1, magadiate is used as a layered inorganic compound, and dodecyltrimethylammonium chloride is allowed to act on the magadiate to exchange sodium ions, which are interlayer cations, with dodecyltrimethylammonium, and then the interlayer distance is widened. It has been described that 3-methacryloxypropyltrimethoxysilane is allowed to act as a silylating agent in the presence of ethanol to form 3-methacryloxypropyl silylation between layers.

Further, in Non-Patent Document 2, magadiaite is used as a layered inorganic compound, and dodecyltrimethylammonium chloride is allowed to act on the magadiaite to exchange sodium ions, which are interlayer cations, with dodecyltrimethylammonium, and then the interlayer distance is widened. It has been described that octyl trichlorosilane is allowed to act as a silylating agent in the presence of toluene to form octylsilylation between layers.

Chem. Mater. 2000, 12,1702-1707 Chem. Mater. 2003, 15,3134-3141

However, in Non-Patent Document 1, in order to proceed the interlayer silylation reaction, it is necessary to use a large excess amount of 3-methacryloxypropyltrimethoxysilane, which is an alkoxysilane, about 35 mol times with respect to the reaction site. It is industrially unsuitable.
In addition, when 3-methacryloxypropyldichloromethylsilane, which is a chlorosilane having a high silylation reactivity, is used, the action of hydrogen chloride produced as a by-product causes the hydrolysis of the ester and the addition of hydrogen chloride to the vinyl group by Michael. It is stated that the use of chlorosilanes is not preferable because the reaction proceeds.

Further, Non-Patent Document 2 describes that the silylation reaction between layers proceeds almost quantitatively by using octyltrichlorosilane which is a chlorosilane as a silylating agent.
However, when chlorosilane is used, a large amount of hydrogen chloride is produced as a by-product, which may corrode the manufacturing equipment. Therefore, it is necessary to use a special manufacturing equipment and to dispose of a large amount of hydrogen chloride. Industrially unsuitable. Furthermore, since the types of chlorosilane-based silylating agents on the market are limited, the types of interlayer modification of inorganic layered compounds using these are limited, and the interlayer modification according to the application is limited, so that it is industrial. Is disadvantageous to.
Further, in the above non-patent documents, ethanol or toluene is used as the organic solvent during the silylation reaction, but there is no specific description regarding other organic solvents.

In view of the above circumstances, it is an object of the present invention to provide a method for producing a silylated layered inorganic compound that efficiently silylates and modifies a wide variety of layers of layered inorganic compounds.

As a result of diligent studies to solve the above problems, the present inventor has found that the above problems can be solved by carrying out a silylation reaction of a layered inorganic compound with a silylating agent in the presence of a specific organic solvent. , The present invention has been completed.

That is, the first invention of the present invention is characterized in that a layered inorganic compound is subjected to a silylation reaction with a silylating agent in the presence of a secondary or tertiary alcohol having a boiling point of 90 ° C. or higher. This is a method for producing an inorganic compound.

The second invention is the method for producing a silylated layered inorganic compound according to the first invention, wherein the aprotic polar solvent or the secondary or tertiary alcohol has a boiling point of 80 ° C. or higher.

The third invention is the method for producing a silylated layered inorganic compound according to the first invention or the second invention, wherein the silylating agent is a compound represented by the following formula (1).
[R ¹ _n Si (OR ² ) _4-n ] (1)
(In the formula (1), R ¹ is independently a hydrogen atom, a saturated or unsaturated alkyl group having a linear or branched chain having 1 to 20 carbon atoms, and a saturated or unsaturated alkyl group having a linear or branched chain having 1 to 8 carbon atoms, respectively. Saturated cycloalkyl groups, aryl groups with 1 to 20 carbon atoms, and aralkyl groups with 1 to 20 carbon atoms, which are vinyl groups, epoxy groups, oxetanyl groups, acryloxy groups, methacryloxy groups, hydroxyl groups, amino groups, alkylamino groups, respectively. It may be substituted with an ammonium group, a thiol group, an isocyanurate group, a ureido group, an isocyanato group, a carboxyl group or a halogen atom, and R ² is independently a hydrogen atom and a saturated or unsaturated alkyl having 1 to 8 carbon atoms, respectively. A group, a saturated or unsaturated cycloalkyl group having 1 to 8 carbon atoms, a trimethylsilyl group, a dimethylsilyl group, or a saturated or unsaturated heterocycloalkyl group having 1 to 8 carbon atoms, where n represents an integer of 0 to 4. .)

Further, the fourth invention is the method for producing a silylated layered inorganic compound according to any one of the first to third inventions, wherein the layered inorganic compound contains any one of a layered silicate, a layered clay mineral and a layered metal oxide. Is.

By using the method for producing a silylated layered inorganic compound of the present invention, it is possible to efficiently silylate and modify the layers of the layered inorganic compound even with a silylating agent having a relatively low reactivity such as alkoxysilanes, depending on the application. Various silylated layered inorganic compounds can be obtained. The silylated layered inorganic compound can be used as various fillers, adsorbents, host compounds for functional molecules, and the like.

It is a conceptual diagram which shows the silylation modification of a layered inorganic compound by a silylating agent.

Hereinafter, the present invention will be described in detail. Unless otherwise specified, the number of copies represents parts by mass and% represents mass%.

The layered inorganic compound in the present invention is not particularly limited, but is graphite, a layered metal chalcogenide, a layered metal oxide (for example, titanium oxide, a layered perovskite compound mainly composed of niobide oxide, titanium niobate, molybdenate). Etc.), layered metal oxyhalides, layered metal phosphates (eg layered antimonate phosphates, etc.), layered clay minerals, layered silicates (eg mica, smectites (montmorillonite, saponite, hectolite, fluorohect) Wright, etc.), Kaolin (Kaolinite, etc.), Magadite, Kenyaite, Kanemite, etc.) and layered compound hydroxides.
Among these, layered silicates, layered clay minerals and layered metal oxides are preferably used because of their availability, etc., but these may be either naturally produced or artificially synthesized. May be good.

In the present invention, first, an alkali metal such as sodium and potassium existing in the layered inorganic compound and a metal cation such as an alkaline earth metal such as magnesium and calcium are exchanged with alkylonium or the like to cause a layered inorganic compound. It is necessary to widen the layers of the above, and as a method of widening the layers, a known method such as interlayer modification with a long-chain alkylammonium salt can be applied.
In the silylated layered inorganic compound in the present invention, as shown in FIG. 1, after the layers of the layered inorganic compound are modified with organic onium or the like and expanded, all or a part of the hydroxyl groups and alkoxy groups of the layered inorganic compound are silylated. A silylated layered inorganic compound is produced by silylation modification (silylation reaction) with an agent.
The organic onium used in the present invention is not particularly limited, but for example, organic ammonium, organic pyridinium, organic imidazolium, organic phosphonium, organic oxonium, organic sulfonium, organic sulfoxonium, organic serenonium, organic carbonium, organic diazonium, and organic Salts such as iodonium, organic pyririnium, organic pyrrolidinium, organic carvenium, organic asylium, organic thiazolinium, organic alsonium, organic stibonium, organic telluronium, etc., among others, of organic ammonium, organic pyridinium, organic imidazolium, organic phosphonium and organic sulfonium. Salts are preferable, and these onium salts are used alone or in combination of two or more.
Although there is no particular limitation on the organic group include an alkyl group of C1 to C22, aralkyl group C7～C22, aryl group _{C6~C22, - (CH 2 -CH (} CH 3) O) m -H group, - (CH _2- CH _2- O) In the _n− H group, m and n are integers from 1 to 20.
The method for modifying the layers of the layered compound with organic onium is not particularly limited, and a known method can be used. For example, by mixing an organic onium and a salt such as a halide ion such as a chloride ion, a bromide ion, or a cation ion with a layered inorganic compound in a solvent such as water or alcohols such as methanol, the layered inorganic compound can be mixed. The interlayer can be modified with the organic bromide by the cation exchange reaction between the exchangeable metal cation and the organic bromide.
The organic cation salt used for interlayer modification is not particularly limited, and for example, dodecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, dihexadecyldimethylammonium chloride, octadecyltrimethylammonium chloride, dimethyloctadecylphenylammonium chloride, triethylbenzylammonium chloride, etc. Dodecyl ammonium chloride, dimethyl dipolyethylene oxide ammonium chloride, dimethyl dipropylene oxide ammonium chloride, dimethyl polyethylene oxide polypropylene oxide ammonium chloride, dimethyl stearyl polyethylene oxide ammonium chloride, dimethyl stearyl polypropylene oxide ammonium chloride, methyl stearyl dipolyethylene oxide ammonium chloride, methyl chloride Stearyldipolypropylene oxide ammonium, benzylmethyldipolyethylene oxideammonium chloride, benzylmethyldipolypropylene oxideammonium chloride, 1-ethylpyridinium bromide, 1-octadecylpyridinium chloride, 3-methyl-1-propylimidazolium bromide, 3-chloride Examples thereof include methyl-1- (2-naphthyl) imidazolium, triphenyl (tetradecyl) phosphonium bromide, ethyldimethylsulfonium chloride, and triphenylsulfonium bromide.

The silylating agent in the present invention means all of the compounds that cause a silylation reaction, and so-called silane coupling agents are also included in the silylating agent in the present invention.
The silylating agent in the present invention is not particularly limited, but is preferably one in which the hydrolyzable group is an alkoxy group, not chlorosilanes as a by-product of hydrogen chloride, for example, a compound represented by the following formula (1). Is preferable.
[R ¹ _n Si (OR ² ) _4-n ] (1)
(In the formula (1), R ¹ is independently a hydrogen atom, a saturated or unsaturated alkyl group having a linear or branched chain having 1 to 20 carbon atoms, and a saturated or unsaturated alkyl group having a linear or branched chain having 1 to 8 carbon atoms, respectively. Saturated cycloalkyl groups, aryl groups with 1 to 20 carbon atoms, and aralkyl groups with 1 to 20 carbon atoms, which are vinyl groups, epoxy groups, oxetanyl groups, acryloxy groups, methacryloxy groups, hydroxyl groups, amino groups, alkylamino groups, respectively. It may be substituted with an ammonium group, a thiol group, an isocyanurate group, a ureido group, an isocyanato group, a carboxyl group and a halogen atom, and R ² is independently a hydrogen atom and a saturated or unsaturated alkyl having 1 to 8 carbon atoms, respectively. A group, a saturated or unsaturated cycloalkyl group having 1 to 8 carbon atoms, a trimethylsilyl group, a dimethylsilyl group, or a saturated or unsaturated heterocycloalkyl group having 1 to 8 carbon atoms, where n represents an integer of 0 to 4. .)

In the silylating agent represented by the formula (1), when a plurality of hydrolyzable groups are present in one molecule, a single hydrolyzable group such as a methoxy group, an ethoxy group or a propoxy group is present. However, a plurality of them may be mixed, and may be substituted with a higher alkoxy group such as a butoxy group or a pentoxy group. Further, the functional group may be protected by an appropriate protecting group.
Among these, those having a methoxy group, an ethoxy group and a propoxy group are preferable, and those having a methoxy group and an ethoxy group are particularly preferable, because they are excellent in silylation reactivity.

Examples of the silylating agent represented by the formula (1) include vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyldimethylmethoxysilane, and the like. 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3- Methacryloxypropyl dimethylmethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltri Methoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltri Ethoxysilane, 3-triethoxysili-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N- (vinylbenzyl) -2-aminoethyl-3-amino Hydrochloride of propyltrimethoxysilane, tris- (trimethoxysilylpropyl) isocyanurate, 3-ureidopropyltrialkoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyandiapropyltriethoxysilane , 8-glycidoxyoctyltrimethoxysilane, 8-methacryloxyoctyltrimethoxysilane, N-2- (aminoethyl) -8-aminooctyltrimethoxysilane, 7-octenyltrimethoxysilane, 4- (trimethoxy) Cyril) butyric acid, 4- (trimethoxysilyl) butyrate 1,1-dimethylethyl, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n- Propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, undecyltrimethoxysilane, Dodecyltrimethoxysilane, tetradecyltrimethoxysilane, hexadecyltrimethoxysilane, octadecyltrimethoxysilane, 1,2-bis (trimethoxysilyl) ethane, 1,6-bis (trimethoxysilyl) hexane, 1,4- Examples thereof include bis (trimethoxysilyl) benzene, trifluoropropyltrimethoxysilane, methoxytrimethylsilane, dimethoxydimethylsilane, trimethoxymethylsilane, triethoxysilane, tetramethoxysilane and tetraethoxysilane.

Further, although not particularly limited, a silylating agent other than alkoxysilane can also be used. For example, hexamethyldisilazane, chlorotrimethylsilane, hexamethyldisilazane, trimethylsilyltrifluoromethanesulfonate, triethylchlorosilane, tertiarybutyldimethylchlorosilane, chlorotriisopropylsilane, 1,3-dichloro-1,1,3,3-tetra. Isopropyldisiloxane, chloromethyltrimethylsilane, triethylsilane, allyltrimethylsilane, 3-methacryloxypropyltrichlorosilane, 3-methacryloxypropylmethyldichlorosisilane, tris (N, N-dimethylamino) methylsilane, bis (N, N) -Dimethylamino) dimethylsilane and (N, N-dimethylamino) trimethylsilane and the like.
In these silylating agents, when a plurality of hydrolyzable groups are present in one molecule, even if a single hydrolyzable group such as an alkoxy group, a halogen atom or an alkylamino group is present, a plurality of hydrolyzable groups are present. May be mixed.

Further, even if a titanium-based coupling agent, an aluminum-based coupling agent, a zirconia-based coupling agent, or the like is used instead of the above silylating agent, the same effect as that of the present invention is exhibited.

The organic solvent used for the silylation reaction in the present invention is an aprotic polar solvent or a secondary or tertiary alcohol, preferably having a boiling point of 80 ° C. or higher, more preferably 90 ° C. or higher, and further. It is preferably 100 ° C. or higher.
The aprotonic polar solvent is not particularly limited, but is limited to nitriles such as acetonitrile and propionitrile, ethers such as tetrahydrofuran, ketones such as acetone, ethylmethyl ketone, diethyl ketone and methylene isopropyl ketone, N, N-. Examples thereof include amides such as dimethylformamide and sulfoxides such as dimethylsulfoxide.
The secondary or tertiary alcohol is not particularly limited, but 2-propanol, 2-butanol, 1-methoxy-2-propanol, 2-pentanol, 3-pentanol, 2-hexanol, 3-. Examples include aromatic alcohols such as hexanol, 1-ethoxy-2-propanol, 1-propanol-2-propanol, 1-butoxy-2-propanol, 2-methyl-2-propanol and phenol.
Of these, acetonitrile, tetrahydrofuran, methylisopropanolketone, 2-propanol, 2-butanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol and 1-propanol-2-propanol are preferable, and 2-butanol. And 1-methoxy-2-propanol are more preferred.

Since the production method of the present invention uses an aprotic polar solvent or a secondary or tertiary alcohol as the organic solvent for the silylation reaction, O-alkyl is a side reaction of hydroxyl groups and alkoxy groups derived from the layered inorganic compound. It is inferred that the silylation reaction is unlikely to occur and that the boiling point of the organic solvent used is high, so that the silylation reaction temperature rises, the silylation reaction is accelerated, and the silylation rate increases.
Further, it is preferable to use secondary or tertiary alcohols because side reactions such as by-production of silanol due to hydrolysis of the silylating agent described later and condensation between the silylating agents are suppressed. It is inferred that this is the solvent effect due to the alcoholic hydroxyl group.

During the silylation reaction in the present invention, it is preferable to add water to the reaction system. The water to be added may be neutral, acidic or alkaline, and is not particularly limited, but ion-exchanged water, distilled water, pure water and ultrapure water are preferable.
The amount of water added is preferably 0.1 to 3 mol times, particularly preferably 1 to 2 mol times, with respect to the total amount of the hydroxyl group and the alkoxyl group which are the reaction points of the layered inorganic compound.
If the amount of water added is less than 0.1 mol times, the addition effect is small, and if it exceeds 3 mol times, side reactions such as silanol by-product due to hydrolysis of silanol agents and condensation between silylating agents proceed. There is a fear.

The amount of the silylating agent used in the silylation reaction is not particularly limited, but is preferably 0.1 to 30 mol times, more preferably 1 with respect to the total amount of the hydroxyl group and the alkoxy group which are the reaction points. It is ~ 20 mol times, more preferably 1-10 mol times.
If the amount of the silylating agent used is less than 0.1 mol times, the silylation reaction rate becomes low, while if it exceeds 30 mol times, it is industrially disadvantageous in terms of raw material cost.

The silylation rate with respect to the ion exchange capacity of the reaction point between the layers of the layered inorganic compound is not particularly limited because it is selected according to the purpose, but the silylation rate is preferably 0.15 or more, and further 0. More preferably, it is 25 or more. On the other hand, if the silylation rate exceeds 2.0, the layers of the layered inorganic compound may be excessively covered with the silylating agent-derived component, which is not preferable.
When the specific aprotonic polar solvent of the present invention, secondary or tertiary alcohol, is used as the reaction solvent, O-alkyl caused by the reaction solvent, which is a side reaction of hydroxyl groups and alkoxy groups derived from the layered inorganic compound. Since the chemical reaction can be suppressed, the amount of the silylating agent required to achieve the desired silylation rate can be reduced as compared with the case of using ethanol, which is a conventional primary alcohol. ..

The reaction temperature in the silylation reaction is not particularly limited, but is preferably 0 to 200 ° C, more preferably 50 to 160 ° C, and even more preferably 70 to 150 ° C. Usually, the reaction is carried out at the boiling point (under heating / reflux) of an aprotic polar solvent or a secondary or tertiary alcohol used as a reaction solvent.

The amount of the aprotic polar solvent or the secondary or tertiary alcohol used in the silylation reaction is not particularly limited, but is 1 to 30 times by mass, more preferably 1 to 30 times the mass of the layered inorganic compound used as a raw material. It is 5 to 25 times by mass, more preferably 10 to 20 times by mass.

The silylation reaction in the present invention may or may not use a catalyst, but may include carboxylic acids such as hydrogen chloride, formic acid, acetic acid and oxalic acid, and sulfonic acids such as phosphoric acid, nitric acid, sulfuric acid and methyl sulfonic acid. Known acids and known bases such as ammonia, trimethylamine, triethylamine, tetramethylammonium hydroxide, sodium hydroxide and potassium hydroxide can be added as catalysts.
In that case, the catalyst to be added is preferably 0.01 to 1 mol times, more preferably 0.01 to 0.1 mol times, the total amount of the hydroxyl group and the alkoxy group which are the reaction points.

The silylated layered inorganic compound obtained by the silylation reaction is preferably isolated, washed and then dried. The method for isolation, washing and drying is not particularly limited, and known methods for isolating, washing and drying layered inorganic compounds and inorganic fine particles can be used.
For example, as an isolation method, the reaction solution is allowed to stand, or after centrifugation to separate the solid and liquid, the supernatant is removed by decantation, or by filtration operations such as natural filtration, pressure filtration, and reduced pressure filtration. Examples include filtering the layered inorganic compound.
The pressure during pressure filtration is not particularly limited, and may be in the range of 1 to 5 atm, for example. The pressure during vacuum filtration is not particularly limited and may be in the range of 0 to 1 atm.

As a cleaning method, the solid obtained after decantation is redispersed in water or an organic solvent, and then decanted in the same manner, or water or an organic solvent is poured over the collected solid to wash the solid. How to do it.
The water used for cleaning may be neutral, acidic or alkaline, and is not particularly limited, but is preferably ion-exchanged water, distilled water, pure water and ultrapure water.
The organic solvent used for cleaning is not particularly limited, and examples thereof include alcohols such as methanol and ethanol, ketones such as acetone and ethyl methyl ketone, alkanes such as hexane, and aromatics such as toluene. At this time, in order to improve the contact between the layered inorganic compound and water, an organic solvent such as an appropriate polar solvent can be used in combination.

As a method for drying the solid obtained above, the organic solvent can be air-dried at normal temperature and pressure, or the organic solvent can be removed while appropriately heating or cooling at room temperature under reduced pressure.
The pressure at the time of depressurization is not particularly limited and may be in the range of 0 to 1 atm. The temperature is also not particularly limited, preferably −10 to 200 ° C., more preferably 0 to 150 ° C., and particularly preferably 10 to 100 ° C.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.
<Synthesis Example 1> Synthesis of sodium magadiate (hereinafter referred to as Na-magadiate) 18.34 g of sodium silicate (manufactured by Fuji Chemical Co., Ltd., trade name: sodium silicate No. 4), silica gel (manufactured by Wako Pure Chemical Industries, Ltd., Product name: Wakogel Q-63) 7.28 g and pure water 54.37 g are mixed and then sealed in a high-pressure reaction decomposition container (manufactured by San-Ai Kagaku Co., Ltd., product name: HU-100) and 30 at 170 ° C. Heated for hours. The product was collected by suction filtration, washed with a dilute aqueous NaOH solution (pH: 9-10) and pure water, and dried at 40 ° C. for 2 days to obtain 15.9 g of Na-magadiate.
The bottom spacing of Na-magadite obtained using an X-ray diffractometer (manufactured by BRUKER, trade name: D8 ADVANCE) was determined to be 1.54 nm.

<Synthesis Example 2> Synthesis of DTMA-magadiate, which is a precursor of silylated magadiate (layer-related modification of Na-magadiate with dodecyltrimethylammonium (hereinafter referred to as DTMA))
_{100 g of Na-magadiate (chemical formula: Na 2} Si ₁₄ O ₂₉ · nH ₂ O) obtained in Synthesis Example 1, 6500 g of pure water and 175 g of dodecyltrimethylammonium chloride were mixed and stirred at room temperature for 7 days. Then, the solid was sucked and collected, washed with methanol, and dried at 60 ° C. to obtain 94 g of DTMA-magadiate.
As a result of measuring the mass of Na in the obtained DTMA-magadite using an atomic absorption spectrometer (AA-6200, manufactured by Shimadzu Corporation), the Na content was less than 0.04% by mass, and almost all cations were exchanged. I confirmed that it was done.
The composition of DTMA-magadiate obtained using an elemental analyzer (Yanako Analytical Industry Co., Ltd., CHN coder MT-5) and a thermogravimetric analyzer (Hitachi High-Tech Science Corporation, TG / DTA6300) was calculated. _{It was 1.57} H _0.35 Si ₁₄ O ₂₉ · nH ₂ O.
Further, the bottom surface interval of DTMA-magadiite obtained by using an X-ray diffractometer (manufactured by BRUKER, D8 ADVANCE) was determined to be 2.80 nm.

< Comparative example 2 >
100 g of DTMA-magadiate obtained in Synthesis Example 2 was dried under reduced pressure at 100 ° C. and about 100 Pa for 2 hours, and then dispersed in 1560 g of 2-propanol dried with molecular sieve 3A. Here, 257 g (7 mol times of the reaction site) of 3-methacryloxypropyltrimethoxysilane (hereinafter referred to as MAC-TRIMS) was mixed, and the mixture was stirred under a nitrogen atmosphere while heating under reflux for 48 hours. Then, the solid was collected by suction filtration, washed with methanol, and dried at 60 ° C. to obtain 90 g of silylated magadite (hereinafter referred to as MACPS-magadite).
CHN element analyzer (Yanako Analytical Industry Co., Ltd., CHN coder MT-5), thermogravimetric analyzer (Hitachi High-Tech Science Co., Ltd., TG / DTA6300) and atomic absorption spectrometer (Shimadzu Corporation, AA-6200) The composition of MACPS-magadiate obtained using) was calculated to be 3-methacryloxypropylsilyl (MACPS) _0.45 DTMA _0.50 Me _1.05 Si ₁₄ O ₂₉ · nH ₂ O.
The bottom surface spacing of MACPS-magadite obtained using an X-ray diffractometer (D8 ADVANCE manufactured by BRUKER) was determined and found to be 2.31 nm.
In addition, ^{when analyzed by 29} Si nuclear magnetic resonance (NMR) (JNM-ECA 400 type, manufactured by JEOL Ltd.), the peak ^{of Q 3} derived from silanol of magadiate shifts to that of ^{Q 4 due to silylation modification.} Therefore, it was confirmed that the silylation reaction proceeded between the layers.

<Example 1 >
The same treatment as in Comparative Example 2 was carried out except that 2-propanol was changed to 1-methoxy-2-propanol (propylene glycol monomethyl ether (PGM)) to obtain MACPS-magadiate.

< Reference example 1 >
The same treatment as in Comparative Example 2 was carried out except that 2-propanol was changed to acetonitrile (AN) to obtain MACPS-magadiate.

<Comparative example 1>
The same treatment as in Example 1 was carried out except that 2-propanol was changed to ethanol (EtOH) to obtain MACPS-magadiate.

The compositions of the silylated layered inorganic compounds obtained in Example 1 , Comparative Examples 1 and 2, and Reference Example 1 are CHN elemental analysis (manufactured by Yanaco Analytical Industry Co., Ltd., trade name: CHN coder MT-5), thermal weight. It was calculated by analysis (Hitachi High-Tech Science Co., Ltd., trade name: TG / DTA6300) and Na elemental analysis (manufactured by Shimadzu Corporation, trade name: elemental absorptiometer AA-6200), and the results are shown in Table 1.
In addition, the silylation rate in Table 1 is determined by a maximum of two silylating agents that can directly react with the total amount of hydroxyl groups and alkoxy groups derived from _{Si 14} O ₂₉ derived from the main skeleton of the layered inorganic compound magadite. Therefore, it is a value obtained by dividing the analysis value of MACPS ( _{molar ratio to Si 14} O ₂₉ ) by 2.

The following abbreviations in Table 1 mean:
IPA: 2-propanol PGM: 1-methoxy-2-propanol AN: acetonitrile EtOH: ethanol MACPS: 3-methacryloxypropylsilyl DTMA: dodecyltrimethylammonium Me: methyl N. D. : Not detected

As can be seen from Table 1, 1-methoxy-2-propanol (1-methoxy-2 -propanol) as the reaction solvent was compared with Comparative Example 1 in which ethanol was used as the reaction solvent and Comparative Example 2 in which 2-propanol was used as the reaction solvent, as in the prior art. propylene glycol monomethyl ether (PGM)) example 1 using is the side reaction is O- alkylation reaction is suppressed, that improved silylation rate, effectively layered inorganic compound is silylated Recognize.

Claims (3)

A method for producing a silylated layered inorganic compound, which comprises carrying out a silylation reaction of a layered inorganic compound with a silylating agent in the presence of a secondary or tertiary alcohol having a boiling point of 90 ° C. or higher. The method for producing a silylated layered inorganic compound according to claim 1, wherein the silylating agent is a compound represented by the following formula (1).
[R ¹ _n Si (OR ² ) _4-n ] (1)
(In the formula (1), R ¹ is independently a hydrogen atom, a saturated or unsaturated alkyl group of a linear or branched chain having 1 to 20 carbon atoms, and a saturated or unsaturated group of a linear or branched chain having 1 to 8 carbon atoms, respectively. Saturated cycloalkyl group, aryl group having 1 to 20 carbon atoms, and aralkyl group having 1 to 20 carbon atoms, which are vinyl group, epoxy group, oxetanyl group, acryloxy group, methacryloxy group, hydroxyl group, amino group, alkylamino group, respectively. It may be substituted with an ammonium group, a thiol group, an isocyanurate group, a ureido group, an isocyanato group, a carboxyl group or a halogen atom, and R ² is independently a hydrogen atom and a saturated or unsaturated alkyl having 1 to 8 carbon atoms, respectively. A group, a saturated or unsaturated cycloalkyl group having 1 to 8 carbon atoms, a trimethylsilyl group, a dimethylsilyl group, or a saturated or unsaturated heterocycloalkyl group having 1 to 8 carbon atoms, where n represents an integer of 0 to 4. .) The method for producing a silylated layered inorganic compound according to claim 1 or 2 , wherein the layered inorganic compound contains any one of a layered silicate, a layered clay mineral and a layered metal oxide.

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