JP2011178872A - Organic/inorganic hybrid material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of the thermal dimensional stability which the organic/inorganic hybrid material by an intercalated silicate compound using the conventional quaternary ammonium salt has since when the conventional quaternary ammonium salt bound with a phyllosilicate by ion exchange is made into an organic/inorganic hybrid material, at least one substituent to bind with the nitrogen of the ammonium salt has a long side chain to improve the dispersibility into a resin. <P>SOLUTION: The organic/inorganic composite polymer is developed by converting a quaternary ammonium salt which has a polymerizable substituent whose synthesis raw material is easily available and whose synthesis time is short, can bind with the flat surface of a phyllosilicate by ion exchange, and has four substituents all having a short main chain into an intercalated silicate compound in an aqueous medium and thereafter copolymerizing the intercalated silicate compound with a polymerizable monomer. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to an organic / inorganic hybrid material obtained by copolymerizing a silicate compound intercalated with a quaternary ammonium salt having a polymerizable substituent with a polymerizable monomer.

With recent technological innovations, the required performance of materials continues to increase regardless of organic or inorganic materials.
Layered silicate compounds are easy to obtain, inexpensive, and have excellent gas barrier properties due to their large aspect ratio (Note: Aspect ratio refers to the ratio of length to thickness). In view of flame retardancy, new materials have been developed by combining with polymer materials. However, the affinity of the layered silicate compound itself with the organic polymer material is generally low, and therefore the dispersibility is poor. This is because, in addition to the low affinity between the two, the layered silicate compound itself is composed of a tetrahedral sheet in which silicon dioxide tetrahedrons are continuous in a two-dimensional network, an aluminum oxide octahedron sheet, and the like. This is due to the fact that it is easy to form a large domain itself because it has a structure in which layers are alternately stacked via each other. For this reason, by using an organic onium salt typified by an organic quaternary ammonium salt in an aqueous dispersion medium, the sodium ions joining the layers are replaced and the layers are opened (intercalation) and dispersed simultaneously. A technique for expressing affinity with an organic polymer material by modifying the silicate surface with an organic group has been used (for example, Patent Document 1).

Based on such a background, in recent years, a method for solving the problem of dispersibility by connecting a layered silicate compound and an organic polymer through a direct bond to form a single compound has been reported (Non Patents). References 1 to 3) Among these, Non-Patent Document 1 is a technique for growing a polymer by bonding a silane coupling agent to the end face of the layered silicate and polymerizing a polymerizable monomer therefrom. Since it is not bonded on the plane of the layered silicate but bonded to the end face, there is a drawback that there are few bonding points.
Non-Patent Document 2 is a report that a quaternary ammonium salt containing an ATRP initiating group at a terminal is introduced into the plane of a layered silicate by ion exchange, and a methacrylic ester and a styrene monomer are polymerized therefrom. However, since this quaternary ammonium salt is insoluble in water and it is necessary to use an organic solvent such as acetone for intercalation, the following problems remain. That is, since the dispersibility of the layered silicate compound with respect to acetone is inferior to that of water, the intercalation of the quaternary ammonium salt containing an ATRP initiating group at the terminal is insufficient with respect to the layered silicate compound. The problem of clay agglomerates coexisting therein remains. Acetone is a highly flammable organic solvent, and there remains a problem from the viewpoint of safety. Further, in Non-Patent Document 2, there is a stage that requires a long reaction time (50 hours) in synthesizing a quaternary ammonium salt, and it has been demanded to shorten the synthesis time.
Non-Patent Document 3 describes an organic / inorganic structure in which a layered silicate compound is copolymerized with an ether group having a group copolymerizable with a polymerizable monomer at the terminal and a quaternary ammonium salt composed of three alkyl groups. Although it is reported that a hybrid material was synthesized, one of the four substituents of this quaternary ammonium salt has a long alkyl chain of 14 (E) or 13 carbon atoms in the main chain of the alkyl group. And a group (F) containing a long polymerization group. Therefore, there is a problem in thermal dimensional stability.

JP 2006-56932 A

Chem. Mater. 2006, 18, 3937-3945 J. et al. Polymer Sci. ,: Part A: Polym. Chem. , VOL. 42, 916-924 (2004) Macromolecules 2009, 42, 180-187

The quaternary ammonium salt bonded to the conventional layered silicate by ion exchange has at least one bonded with nitrogen of the ammonium salt in order to improve the dispersibility in the resin when it is an organic / inorganic hybrid material. The substituent has a long side chain. For this reason, the conventional organic / inorganic hybrid material using a silicate compound intercalated with a quaternary ammonium salt (hereinafter appropriately referred to as “intercalated silicate compound”) has a problem in thermal dimensional stability.
Therefore, the present invention intercalates a quaternary ammonium salt having a polymerizable substituent and a short main chain of all four substituents into a layered silicate compound, and the intercalated silicate compound is polymerizable. It aims at solving said subject by developing the polymer copolymerized with the monomer.
In other words, it has a polymerizable substituent that is easily available for synthesis and has a short synthesis time, can be bonded to the plane of the layered silicate by ion exchange, and the main chain of all four substituents is short. The development of an organic / inorganic hybrid material that is an intercalated silicate compound in an aqueous dispersion medium and then copolymerized with a polymerizable monomer. .

The present inventors have found a compound represented by the following formula (1) that has copolymerizability for a wide range of polymerizable monomers and can intercalate into a layered silicate. And it discovered that this compound was effective in order to solve said problem, and completed this invention based on this knowledge.
That is, the present invention has the following configuration.
[1] An organic / inorganic hybrid material obtained by copolymerizing a silicate compound intercalated with a quaternary ammonium salt having a polymerizable substituent represented by the following general formula (1) and a polymerizable monomer.
Here, R1 and R2 are methyl groups. R3 is independently selected from a linear or branched alkyl chain having 1 to 3 carbon atoms or a phenyl group. A is an acryloyl group, methacryloyl group, styryl group, methylene chain terminated with an epoxy group or vinyl ether group, or an ethylene chain terminated with an acryloyl group, methacryloyl group, styryl group, epoxy group or vinyl ether group, and X is It is a halogen atom.
[2] The above [1], wherein the epoxy group of A in the formula (1) according to the above [1] is a glycidoxy group or a group represented by the formula (2) Organic-inorganic hybrid material described in 1.
[3] The above-mentioned [1], wherein the polymerizable monomer copolymerized with the silicate compound intercalated with the quaternary ammonium salt is a radically polymerizable monomer. The organic-inorganic hybrid material according to [2].

Intercalate a quaternary ammonium salt with polymerizable substituents and a short main chain of all four substituents into a layered silicate compound, and copolymerize the intercalated silicate compound with a polymerizable monomer. It is possible to synthesize organic / inorganic hybrid materials.
In addition, the compound of the present invention can be easily produced because it is easy to obtain synthetic raw materials and can be synthesized in a short time.
Since the produced organic / inorganic hybrid material is a copolymer of an intercalated silicate compound and a polymerizable monomer, heat resistance can be improved as compared with other organic compounds.
In addition, conventional organic / inorganic hybrid materials have problems with the thermal dimensional stability of the resin because the substituents that bind to the nitrogen of the ammonium salt have long side chains in order to improve the dispersibility in the resin. However, the compound of the present invention has a short main chain of all four substituents bonded to the nitrogen of the ammonium salt, so that even if it is a copolymer of an intercalated silicate compound and a polymerizable monomer, Excellent dispersibility and thermal dimensional stability.

It is a TEM image of the synthesized organic / inorganic composite polymer (Example 1).

The quaternary ammonium salt compound having a polymerizable substituent of the present invention has a structure represented by the following general formula (1).
Here, R1 and R2 are methyl groups. R3 is independently selected from a linear or branched alkyl chain having 1 to 3 carbon atoms or a phenyl group. A is an acryloyl group, methacryloyl group, styryl group, methylene chain terminated with an epoxy group or vinyl ether group, or an ethylene chain terminated with acryloyl group, methacryloyl group, styryl group, epoxy group or vinyl ether group, and X is It is a halogen atom.

  When R3 in the formula (1) is a linear alkyl chain having 1 to 3 carbon atoms, examples thereof include methyl, ethyl, and propyl. Among these, methyl and ethyl are preferable, and methyl is particularly preferable.

When R3 in the formula (1) is a branched alkyl chain, examples thereof include 1-methylethylene and isopropyl.

A in the formula (1) is ethylene having an acryloyl group, a methacryloyl group, a styryl group, an methylene chain having an epoxy group or a vinyl ether group at the terminal, or an ethylene having an acryloyl group, a methacryloyl group, a styryl group, an epoxy group or a vinyl ether group at the terminal. When it is a chain and A in the formula (1) is an epoxy group, examples thereof include glycidoxy or the formula (2).

And among A in above-mentioned Formula (1), it is preferable that A is a methylene chain which has an acryloyl group or a methacryloyl group at the terminal, or an ethylene chain which has an acryloyl group or a methacrylol group at the terminal.

X1 in Formula (1) is a halogen atom. Specifically, chlorine, bromine and iodine are preferable, among which chlorine and bromine are preferable.

Next, a method for synthesizing a quaternary ammonium salt compound having a polymerizable substituent represented by the formula (1) will be described.
A preferred raw material used for the synthesis of the quaternary ammonium salt compound having a polymerizable substituent represented by the formula (1) of the present invention is a hydroxyalkylammonium salt represented by the formula (3).
Here, R1, R2, and R3 are the same as R1, R2, and R3 shown in Formula (1), and B is a methylene chain or an ethylene chain.

Synthesis of the compound of formula (1) from formula (3) is carried out as follows. The compound of the formula (3) is reacted with a halogenated α-haloalkanoyl compound in the presence of a basic compound such as ammonia, urea, organic amine, etc., and the dehydrohalogenation reaction with the basic compound is used. A reaction mixture containing the compound is obtained.
As a purification method from the reaction mixture, distillation or reprecipitation can be used. In this reaction, a solvent may be used or no solvent may be used, but when the salt produced as a by-product during the reaction is a solid, it is preferable to use a solvent. The solvent is not particularly limited as long as it is a solvent other than a solvent having a hydroxyl group such as water or alcohol, but it is preferable to use a dehydrated ether solvent such as tetrahydrofuran or diethyl ether. As the organic amine, trimethylamine, triethylamine, pyridine, and aniline can be used. The molar ratio of the halogenated α-haloalkanoyl compound to the compound of the formula (3) is 1.0 to 3.0, and the preferred ratio is 1.0 to 1.2. The molar ratio with α-haloalkanoyl is 1.0 to 6.0, and the preferred ratio is 1.0 to 3.6. The reaction concentration can be 1 to 100% by weight in terms of the weight of all raw materials, but is preferably 5 to 40% by weight. The reaction temperature is preferably 0 ° C. or lower in order to prevent side reactions at first, but may be carried out at room temperature after all the raw materials have been mixed. The total reaction time is 1 to 18 hours, preferably 3 to 12 hours.

The compound represented by the formula (1) can produce an organic / inorganic composite by cation exchange in the cation part of the layered silicate and intercalation.
This organic / inorganic composite can also be used as a material imparting flame retardancy by mixing itself with a resin or the like.
The organic / inorganic composite can be copolymerized with a polymerizable monomer to produce an organic / inorganic hybrid material.

Examples of the layered silicate include smectites such as montmorillonite, saponite, hydelite, nontrite, hectorite, and stevensite, and natural or synthetic clay minerals such as vermiculite and halosite. The cation exchange amount of these layered silicates is preferably 10 to 300 meq / 100 g. The aspect ratio is preferably 70 or more, more preferably 80 to 1200.

Next, the reaction between the compound of formula (1) and the layered silicate will be described. First, a layered silicate is dispersed in a solvent. The solvent used here is not particularly limited as long as it disperses the layered silicate and dissolves the formula (1), and each solvent may be different, but water, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-2-propanol, tetrahydrofuran, 1,4-dioxane, acetonitrile and the like are mentioned, among which water, acetone, acetonitrile, 1,4-dioxane are preferable, In particular, the combined use of water and 1,4-dioxane is preferred.

The concentration of the layered silicate with respect to the solvent can be in the range of 0.01 to 30% by weight, preferably 0.05 to 10% by weight, and particularly preferably 0.1 to 5% by weight. Separately, the formula (1) is dissolved in a solvent. The concentration of the formula (1) with respect to the solvent can be in the range of 0.01 to 30% by weight, preferably 0.05 to 10% by weight, and particularly preferably 0.1 to 5% by weight. These layered silicate dispersions and the solution of the formula (1) are mixed in an equivalent ratio that can replace 1 mol% to 100 mol% of the cation in the layered silicate with the cation part of the formula (1). Then, by intercalating the formula (1) between the layers of the layered silicate, the layers are cleaved and simultaneously a polymerizable organic functional group is introduced. Usually, as the reaction proceeds, the product settles, and this is filtered under reduced pressure, washed with a solvent, reduced in pressure to remove volatile components, and purified. The solvent used at this time is not particularly limited as long as it has a good affinity with water and can dissolve and remove alkali metal salts such as sodium chloride and alkaline earth metal salts such as magnesium chloride that flow out as a result of cation exchange. No matter, examples include water, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-2-propanol, tetrahydrofuran, 1,4-dioxane, acetonitrile and the like. Of these, water, 2-methyl-2-propanol, and 1,4-dioxane are preferable because the freeze-drying method can be applied.

Next, a polymerization reaction between an intercalated silicate compound using a quaternary ammonium salt having a polymerizable substituent as an intercalation and a polymerizable monomer will be described. This technique can be carried out without a solvent or in a solvent. Preferred solvents include hydrocarbon solvents such as toluene and xylene, ether solvents such as tetrahydrofuran and diethyl ether, halogenated hydrocarbon solvents such as chloroform and dichloromethane, ketone solvents such as acetone and methyl ethyl ketone, and ester solvents such as ethyl acetate. Solvents, alcohol solvents such as ethanol and 2-propanol, water, and no solvent. Of these, particularly preferred are toluene, tetrahydrofuran, and no solvent.
In this polymerization reaction, the total concentration of all the raw materials in the solution can be 1% to 100% by weight in terms of weight.

The polymerizable monomer is not particularly limited as long as the radical polymerization method can be applied. Methacrylic acid and esters thereof (methyl methacrylate, butyl methacrylate, 2-hydroxyethyl methacrylate, etc.), acrylic acid and esters thereof (Methyl acrylate, butyl acrylate, 2-hydroxyethyl acrylate, etc.), acrylic amides (acrylic amide, N-isopropylacrylic amide, etc.), styrene and derivatives thereof. There is no restriction | limiting in particular in the ratio of Formula (1) and a polymerizable monomer, You may use in the ratio according to the use of the target object.

This polymerization reaction can be carried out by photopolymerization or thermal polymerization depending on the polymerization initiator used. In addition, it is desirable that the polymerization atmosphere be removed in an inert gas atmosphere such as nitrogen or argon by removing as much oxygen and other components as possible to deactivate radicals generated in the course of the reaction. It is. In addition to polymerization in a solvent, polymerization without a solvent is also possible. The polymerization temperature varies depending on the type of polymerization initiator, polymerizable monomer and solvent used.

As described above, in the present invention, a quaternary ammonium salt having a polymerizable substituent, having a substituent that can be bonded to a layered silicate by ion exchange, and having a short main chain of all four substituents is converted into a layered silicate. It is possible to synthesize a polymer obtained by intercalating an acid salt compound and copolymerizing the intercalated silicate compound with a polymerizable monomer.

EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to these Examples.

Measuring Instruments Transmission Electron Microscope (TEM); H-7100 manufactured by Hitachi, Ltd.
Mass spectrometry (GC-MS); JMS-AMII150 manufactured by JEOL Ltd.
Thermal analysis (TG-DTA); TG8120 manufactured by Rigaku Corporation
Thermal analysis (TMA); manufactured by Rigaku Corporation TMA8310
Transmittance and haze; Suga Test Instruments Co., Ltd. Double Beam Haze Computer HZ-2

Example 1
<Synthesis of quaternary ammonium salt>
A three-necked flask with a 100 mL volume equipped with a three-way cock, a thermometer, and a 30 mL dropping funnel is degassed and dried under an argon stream. To this, choline chloride (2.79 g, 0.02 mol), triethylamine (2.02 g, 0.02 mol), and 40 mL of dry diethyl ether are added, followed by ice cooling with stirring. A solution prepared by diluting 2-methacryloyl chloride (2.51 g, 0.024 mol) with 10 mL of dry diethyl ether was added dropwise thereto over about 30 minutes. After dropping, the temperature was returned to room temperature, and the mixture was further stirred for 3 hours. A white precipitate was formed. To this was added 0.1 N dilute hydrochloric acid to dissolve the salt, liquid separation was performed, and the organic phase was separated, neutralized with a saturated aqueous solution of sodium bicarbonate, washed with water, washed with a saturated sodium chloride solution, and then anhydrous sodium sulfate. Was left at room temperature and dehydrated. The low boiling point portion was distilled off with a rotary evaporator to obtain (methacryloylethyl) trimethylammonium chloride VA-1, which was the target product. Yield 3.3 g (160 mmol); Yield 80.0%; GC-MS M / Z 207

<Intercalation to layered silicate 1>
In a 20 mL beaker, 4.15 mL of 1,4-dioxane and 0.83 mL of distilled water were added, 0.415 g (2.00 mmol) of (methacryloylethyl) trimethylammonium chloride was added, and the mixture was stirred at room temperature for 5 minutes to obtain a solution (A ). In another 200 mL beaker, 100 mL of distilled water was added, and 2.00 g (Na equivalent 0.1 mol / 100 g) of layered silicate (“Kunipia F” manufactured by Kunimine Industries Co., Ltd.) was added little by little, and 10 minutes at room temperature. Stir to give a dispersion (B). (A) was added to (B), mixed, and stirred at room temperature for 15 hours. As the reaction progressed, a white precipitate formed and the viscosity increased. The reaction solution was centrifuged at 8000 rpm for 30 minutes, the liquid layer was removed, 100 mL of distilled water was added thereto, and the mixture was stirred at room temperature for 10 minutes. After repeating this operation three times, 200 mL of distilled water was added and dispersed, and purified by lyophilization to prepare the desired intercalated silicate compound VC-1. Yield 1.99 g.

When the thermogravimetric decrease of the intercalated silicate compound VC-1 was measured during the temperature rising process from room temperature to 1000 ° C., a decrease of 4.7 wt% was observed around 780 ° C. From this, it was found that the intercalated silicate compound VC-1 is an organic / inorganic composite having an organic part of about 5% by weight and an inorganic part of 95% by weight.

<Intercalation to layered silicate 2>
Further, the layered silicate was treated in the same manner as “Lucentite SWN” manufactured by Co-op Chemical Co. to prepare an intercalated silicate compound VC-2. Yield 2.05g.

When the thermogravimetric decrease of the intercalated silicate compound VC-2 was measured in the temperature rising process from room temperature to 1000 ° C., a decrease of 4.3% by weight was observed at around 780 ° C. From this, it was found that the intercalated silicate compound VC-2 is an organic / inorganic composite having an organic part of about 4% by weight and an inorganic part of 96% by weight.

<Synthesis of organic / inorganic hybrid materials>
To a 20 mL vial, 1.00 g (10 mmol) of methyl methacrylate was added, and 0.01 g (1.0 wt%) of the intercalated silicate compound VC-2 was added little by little with stirring. After adding 5.00 mg (0.5% by weight) of photopolymerization initiator Darocur and stirring at room temperature for 5 minutes, the reaction solution was poured into a mold and irradiated with light for 1 minute with a metal halogen lamp. -An inorganic hybrid material VCM-1 was obtained.

When the thermal weight reduction of the organic / inorganic hybrid material VCM-1 was measured in the temperature rising process from room temperature to 1000 ° C., in addition to the weight reduction from 300 to 400 ° C., it was 0.83% near 780 ° C. A weight loss was observed.

The thermogravimetric change (linear expansion coefficient) of the organic / inorganic hybrid material VCM-1 was measured in the temperature rising process from room temperature to 200 ° C. and found to be 0.344% (45.3 ppm).

The transmittance and haze of the organic / inorganic hybrid material VCM-1 were measured and found to be 92.49% and 2.91% (film thickness 65 μm).

When the above-mentioned organic / inorganic hybrid material VCM-1 was observed with a transmission electron microscope, it was found that the silicate was uniformly dispersed and the periphery thereof was completely covered with a portion presumed to be an organic polymer. Observed (FIG. 1).

The organic / inorganic hybrid material of the present invention is characterized in that, in particular, the main chain of all four substituents of the intercalate silicate compound is short, thereby maintaining compatibility with the resin, which is transparent and heat resistant. Application as a self-supporting film with excellent dimensional stability can be expected. Specific application fields include optical materials and electronic materials.

Claims (3)

Organic / inorganic hybrid material obtained by copolymerizing a silicate compound intercalated with a quaternary ammonium salt having a polymerizable substituent represented by the following general formula (1) with a polymerizable monomer
Here, R1 and R2 are methyl groups. R3 is independently selected from a linear or branched alkyl chain having 1 to 3 carbon atoms or a phenyl group. A is an acryloyl group, methacryloyl group, styryl group, methylene chain terminated with an epoxy group or vinyl ether group, or an ethylene chain terminated with an acryloyl group, methacryloyl group, styryl group, epoxy group or vinyl ether group, and X is It is a halogen atom. The organic-inorganic hybrid material according to claim 1, wherein the epoxy group of A in formula (1) according to claim 1 is a glycidoxy group or a group represented by formula (2).
3. The polymerizable monomer copolymerized with the silicate compound intercalated with the quaternary ammonium salt is a polymerizable monomer capable of radical polymerization. The organic-inorganic hybrid material described.