JPWO2015068829A1 - Tubular aluminum silicate dispersion and method for producing tubular aluminum silicate dispersion - Google Patents

Abstract

The subject of this invention is providing the tubular aluminum silicate dispersion liquid which can be disperse | distributed in an organic material and has adsorptivity and ion exchange property. The tubular aluminum silicate dispersion is characterized in that water is removed from a mixed liquid of tubular aluminum silicate, water, and an organic dispersion medium.

Description

  The present invention relates to a tubular aluminum silicate dispersion and a method for producing a tubular aluminum silicate dispersion.

  Conventionally, imogolite is known as a tubular aluminum silicate. Imogolite is a kind of natural clay component that appears in soils based on descending volcanic ejecta such as volcanic ash and pumice, and is a nano-sized tubular amorphous aluminum silicate. This tubular aluminum silicate has silicon (Si), aluminum (Al), oxygen (O) and hydrogen (H) as main constituent elements, and is composed of many ≡Si—O—Al≡ bonds. The shape is a nanotube-like structure having an outer diameter of 2.0 to 3.0 nm, an inner diameter of 0.5 to 1.5 nm, and a length of several tens of nm to several μm. This tubular aluminum silicate has a unique nano tube shape and high specific surface area, water affinity, ion exchange capacity and material adsorption capacity. Various industrial uses such as a catalyst carrier, a humidity control material, and a heat pump system heat exchange agent that produces a refrigerant using a low-temperature heat source are expected.

  The tubular aluminum silicate is prepared as a dispersion dispersed in water by the production method (see, for example, Patent Documents 1 and 2). In addition, such an aqueous dispersion of tubular aluminum silicate can be used as a cryogen by adjusting the pH to be weakly alkaline (see, for example, Patent Document 3).

However, when such an aqueous dispersion of tubular aluminum silicate is dispersed in an organic dispersion medium, the tubular aluminum silicate aggregates and a uniform dispersion cannot be obtained. Therefore, it is difficult to uniformly disperse the tubular aluminum silicate in an organic material such as a resin, and the use of the tubular aluminum silicate has been limited.
In addition, it is possible to forcibly disperse by adding a large amount of organic dispersion medium to the aqueous dispersion of tubular aluminum silicate, and to disperse uniformly in organic materials such as resins. Therefore, the desired effect of the tubular aluminum silicate cannot be obtained.

  In contrast, a method has been proposed in which the surface of a tubular aluminum silicate is modified with an organic functional group so that the tubular aluminum silicate can be dispersed in an organic dispersion medium (for example, Patent Documents). 4).

JP 2000-128520 A JP 2004-115278 A JP 2005-314165 A Japanese Patent No. 4161509

  However, according to the above-described conventional technology, the affinity with the organic dispersion medium is increased, but the adsorptivity and ion exchange properties inherent in the tubular aluminum silicate are reduced.

  Then, the subject of this invention is providing the tubular aluminum silicate dispersion liquid which can be disperse | distributed in an organic material, and has adsorptivity and ion exchange property, and its manufacturing method.

In order to solve the above problems, according to the present invention,
Provided is a tubular aluminum silicate dispersion characterized in that water is removed from a mixed liquid of a tubular aluminum silicate, water, and an organic dispersion medium.

Moreover, according to the present invention,
A step of mixing a tubular aluminum silicate, water, and an organic dispersion medium to prepare a mixed solution;
Removing water from the mixture;
A method for producing a tubular aluminum silicate dispersion characterized by comprising:

  ADVANTAGE OF THE INVENTION According to this invention, the tubular aluminum silicate dispersion liquid which can be disperse | distributed in an organic material and has adsorptivity and ion exchange property, and its manufacturing method can be provided.

It is an X-ray diffraction pattern of tubular aluminum silicate. It is a scanning electron micrograph of tubular aluminum silicate. It is a conceptual diagram for demonstrating decompression evaporation. It is a conceptual diagram for demonstrating ultrafiltration.

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In addition, in this application, "-" showing a numerical range is used by the meaning containing the numerical value described before and behind that as a lower limit and an upper limit.

The tubular aluminum silicate dispersion of the present invention is characterized in that water is removed from a mixed liquid of tubular aluminum silicate, water, and an organic dispersion medium.
Each material constituting the tubular aluminum silicate dispersion of the present invention will be specifically described below.

《Tubular aluminum silicate》
There is no restriction | limiting in particular as a tubular aluminum silicate which concerns on this invention, A conventionally well-known thing can be used. The tubular aluminum silicate used in the present invention is b / a ≧ 10 when the outer diameter of the tubular aluminum silicate is a and the length is b, that is, imogolite. It is preferable.

(1) Method for producing tubular aluminum silicate The method for producing tubular aluminum silicate is not particularly limited, and for example, it can be produced by the method described in JP2011-42520A. However, the tubular aluminum silicate can be efficiently produced by using the following method.

First, by treating an inorganic silicon compound solution with an ion exchanger, an orthosilicate solution having an electric conductivity of 5 to 500 μS / cm and a pH of 3.5 to 7.5 is prepared (first step). Next, the prepared orthosilicic acid solution, the inorganic aluminum compound solution, and urea or ammonia are mixed, and the mixed solution is adjusted to pH 2.8 to 7.5 and then heated (second step). Then, the obtained reaction product is subjected to solid separation and desalting (third step), and the desired tubular aluminum silicate can be obtained.
Each material and conditions used in such a manufacturing method will be described below.

(1.1) Inorganic silicon compound solution The silicon source constituting the inorganic silicon compound solution is not particularly limited as long as silicate ions are generated when solvated. Examples of such a silicon source include sodium orthosilicate, sodium metasilicate, potassium metasilicate, and water glass.

  As the solvent, a solvent that can easily be solvated with the raw material silicic acid source can be appropriately selected and used. Specifically, water, alcohols, etc. can be used, for example. From the viewpoint of salt solubility and ease of handling during heating, water is preferably used.

  Further, from the viewpoint of suppressing generation of polysilicic acid from silicic acid during ion exchange, the silicon concentration of the inorganic silicon compound solution during ion exchange is preferably 20 mM or less.

(1.2) Ion exchanger As the ion exchanger used for the ion exchange treatment of the inorganic silicon compound solution, an anion exchanger or a cation exchanger is used. Examples of the anion exchanger include an anion exchange membrane and the like, and examples of the cation exchanger include a cation exchange resin and a cation exchange membrane. It is preferable to use a cation exchange resin because it is high and silicon concentration control is easy. Specifically, any conventionally known ion exchanger can be used as long as the orthosilicate solution obtained after the treatment has an electric conductivity of 5 to 500 μS / cm and a pH of 3.5 to 7.5. May be used.

  As the cation exchange resin, either a strong acid cation exchange resin or a weak acid cation exchange resin may be used, or a plurality of cation exchange resins may be used in combination.

  Examples of the strongly acidic cation exchange resin include Amberlite IR120B (manufactured by Organo), Amberlite IR124 (manufactured by Organo), Amberlite 200CT (manufactured by Organo), Amberlite 252 (manufactured by Organo), Diaion SK104. (Mitsubishi Chemical Corporation), Diaion SK110 (Mitsubishi Chemical Corporation), Diaion SK112 (Mitsubishi Chemical Corporation), Diaion PK212 (Mitsubishi Chemical Corporation), Diaion PK216 (Mitsubishi Chemical Corporation), Diaion PK228 (Mitsubishi Chemical), Diaion UBK08 (Mitsubishi Chemical), Diaion UBK10 (Mitsubishi Chemical), Diaion UBK12 (Mitsubishi Chemical), Diaion UBK510L (Mitsubishi Chemical), Diaion UBK530 (Mitsubishi Chemical Corporation), Diaion U K550 (manufactured by Mitsubishi Chemical Corporation) and the like, but not limited thereto.

  Examples of the weak acid cation exchange resin include Amberlite FPC3500 (manufactured by Organo), Amberlite IRC76 (manufactured by Organo), Diaion WK10 (manufactured by Mitsubishi Chemical), Diaion WK11 (manufactured by Mitsubishi Chemical), Dia Examples include, but are not limited to, ion WK100 (manufactured by Mitsubishi Chemical Corporation) and diamond ion WK40L (manufactured by Mitsubishi Chemical Corporation).

  When ion exchange resin is used, as a method of ion exchange treatment of the inorganic silicon compound solution, for example, a batch method or a column method is used.

  In the case of the batch method, a conditioned ion exchange resin is put into a container, an inorganic silicon compound solution whose concentration is adjusted is added thereto, and the mixture is allowed to react for about 2 hours with stirring or shaking at such a strength that the ion exchange resin floats. Thereafter, the ion exchange resin is filtered off, and the filtrate is recovered to obtain an orthosilicate solution. If a magnetic stirrer is used, depending on the type of ion exchange resin, the ion exchange resin may be destroyed. Therefore, it is desirable to perform shaking during mixing. Here, conditioning means returning the ion exchange resin to a state where the ion exchange ability can be exhibited.

  In the case of the column method, an ion-exchange resin that has been conditioned is packed into a column, an inorganic silicon compound solution whose concentration is adjusted is flowed into the column at a constant flow rate, and the solution that flows out of the column is recovered to obtain an orthosilicate solution. obtain.

In the case of the batch method, the electric conductivity of the resulting orthosilicate solution can be adjusted by the degree of stirring or shaking, the reaction time, etc. In the case of the column method, the flow rate of the sample flowing in the column, the volume of the column ( Radius, length, etc.), the amount of ion-exchange resin filling, and the like. That is, the electrical conductivity of the orthosilicate solution can be adjusted by appropriately changing the contact time and the contact area between the inorganic silicon compound solution and the ion exchanger.
The pH of the resulting orthosilicate solution can be adjusted by the type of ion exchange resin used, the contact time between the ion exchange resin and the inorganic silicon compound solution, and the like. Specifically, when a cation exchange resin is used, the pH of the orthosilicate solution obtained becomes lower as the ion exchange proceeds. Therefore, when a strongly acidic cation exchange resin having a high ion exchange rate is used, the pH of the orthosilicate solution is increased. The pH of the orthosilicic acid solution remains high when a weakly acidic cation exchange resin with a lower ion exchange rate is used.

In the present invention, as described above, an ion exchange membrane may be used as the ion exchanger. The ion exchange membrane is an ion filtration membrane formed by molding an ion exchange resin into a film shape, and has a property of blocking the passage of ions having different signs and allowing only ions having the same sign to pass.
When an ion exchange membrane is used, it is preferable to use an anion exchange membrane and a cation exchange membrane together, but each may be used alone by combining with other methods.
The anion exchange membrane is positively charged because the cation group is fixed to the membrane, and only the anion is allowed to pass through without repelling the cation. Such anion exchange membranes are used, for example, for seawater concentration salt production, concentration / removal of metal ions, removal of radioactive ions / substances, and the like. By using such an anion exchange membrane, only the anion in the inorganic silicon compound solution can be permeated to prepare a target orthosilicate solution.
The cation exchange membrane is negatively charged because the anion group is fixed to the membrane, and only the cation is allowed to pass without repelling the anion.

(1.3) pH of orthosilicate solution
The treatment conditions with the ion exchanger are set so that the pH of the orthosilicic acid solution prepared by the treatment with the ion exchanger is 3.5 to 7.5. When the pH is 7.5 or less, it is possible to suppress the formation of polysilicic acid by polymerization of orthosilicic acid in the solution, and when the pH is 3.5 or more, the pH adjustment in the second step The amount of alkali added in can be reduced.

  The pH can be measured by a pH meter using a general glass electrode. Specifically, for example, MODEL (F-71S) (Horiba, Ltd.) can be used. The pH of the orthosilicate solution is as follows: phthalate pH standard solution (pH: 4.01), neutral phosphate pH standard solution (pH: 6.86), and borate pH standard solution (pH: 9.01). 18) is used as a pH standard solution, the pH meter is calibrated at three points, the electrode of the pH meter is placed in an orthosilicic acid solution, and the value after 5 minutes has elapsed and is read. At this time, the liquid temperature of the pH standard solution and the orthosilicate solution can be set to 25 ° C., for example.

(1.4) Electrical conductivity σ of orthosilicate solution
The treatment conditions with the ion exchanger are set so that the electrical conductivity of the orthosilicic acid solution prepared by the treatment with the ion exchanger is 5 to 500 μS / cm. In particular, when ion exchange treatment is performed by a column method using a cation exchange resin, it is possible to adjust the electrical conductivity by adjusting the flow rate of the column. The electric conductivity of the orthosilicate solution is preferably 5 to 100 μS / cm, more preferably 5 to 15 μS / cm.
When the electrical conductivity of the orthosilicate solution is 500 μS / cm or less, the mixing of the salt into the mixed solution prepared in the second step is suppressed, and a tubular aluminum silicate can be produced with a high yield. . Moreover, the treatment time by an ion exchanger can be shortened and productivity can be improved as the electrical conductivity of an orthosilicic acid solution is 5 microsiemens / cm or more.

  Since the electrical conductivity of theoretical pure water is an insulator of about 0.055 μS / cm, it can be said that the electrical conductivity is an index indicating the total amount of ions in the solution, particularly when the solvent of the orthosilicate solution is water.

  The electrical conductivity of the orthosilicic acid solution can be measured with a general electrical conductivity meter, and specifically, for example, it is measured at room temperature (25 ° C.) using ES-51 (Horiba, Ltd.).

(1.5) Inorganic aluminum compound solution The aluminum source constituting the inorganic aluminum compound solution is not particularly limited as long as aluminum ions are generated when solvated. Examples of such an aluminum source include aluminum chloride, aluminum perchlorate, aluminum nitrate, and aluminum sec-butoxide.

  As the solvent, a solvent that can easily be solvated with the aluminum source as a raw material can be appropriately selected and used. Specifically, water, alcohols, etc. can be used, for example. From the viewpoint of salt solubility and ease of handling during heating, water is preferably used.

  Moreover, in a 2nd process, the composition ratio of the tubular aluminum silicate manufactured can be changed by adjusting the preparation amount of the inorganic aluminum compound solution with respect to orthosilicate aqueous solution.

(1.6) Urea or ammonia Either urea or ammonia may be used, and it is preferable to add as a solution adjusted to a predetermined concentration from the viewpoint of handleability.

(1.7) pH adjustment of liquid mixture In a 2nd process, the liquid mixture which mixed the orthosilicic acid solution, the inorganic aluminum compound solution, and urea or ammonia is adjusted to pH 2.8-7.5. In order to adjust the pH to the range, for example, a method of adding a basic solution such as an aqueous solution of sodium hydroxide or an aqueous solution of potassium hydroxide, a method of adding an acidic solution such as hydrochloric acid, acetic acid, or nitric acid, etc. Can be mentioned.

(1.8) Heat treatment In the second step, a treatment for heating the mixed solution after pH adjustment is performed. Although the heating temperature at this time is not specifically limited, It is preferable that it is 80-120 degreeC from a viewpoint of obtaining higher purity tubular aluminum silicate.
There exists a tendency which can suppress precipitation of the boehmite (monohydric aluminum oxide) which is a by-product as heating temperature is 120 degrees C or less. When urea is used, if the heating temperature is too high, rapid thermal decomposition may occur at the beginning of heating, and the ammonia concentration in the mixed solution may rise rapidly, causing the pH to approximate the alkaline side. It is thought that it is unsuitable for manufacture of the tubular aluminum silicate formed in the property-weak acidity.
Further, when the heating temperature is 80 ° C. or higher, the thermal decomposition of urea and the subsequent synthesis rate of the tubular aluminum silicate are improved, and the productivity can be improved.

  The heating time is not particularly limited, but is preferably 12 hours or more and 100 hours or less from the viewpoint of efficiently obtaining the tubular aluminum silicate.

(2) Identification of tubular aluminum silicate The tubular aluminum silicate produced by the method as described above can be identified by measurement by X-ray diffraction and measurement by a scanning electron microscope (SEM).

(2.1) Measurement by X-ray diffraction FIG. 1 shows an X-ray diffraction diagram of a tubular aluminum silicate. As shown in FIG. 1, when the tubular aluminum silicate is formed, a peak value peculiar to the tubular aluminum silicate is obtained in the vicinity of 2θ = 4, 10, and 14, thereby The formation of aluminum silicate can be confirmed.

(2.2) Measurement by Scanning Electron Microscope FIG. 2 shows a scanning electron micrograph (SEM image) of the tubular aluminum silicate. As shown in FIG. 2, when a tubular aluminum silicate is formed, a thread-like structure can be confirmed on the SEM image, thereby confirming the formation of the tubular aluminum silicate. be able to.

《Organic dispersion medium》
As the organic dispersion medium according to the present invention, an organic dispersion medium having compatibility with water is used, and specifically, alcohols are preferable. Examples of alcohols include monohydric alcohols such as methanol, ethanol, propanol, and butanol, ethylene glycol, propylene glycol, diethylene glycol, glycerin, 1,3-butanediol, 1,4-butanediol, and the like. The tubular aluminum silicate dispersion of the present invention may contain two or more alcohols as an organic dispersion medium.

<Tubular aluminum silicate dispersion>
The tubular aluminum silicate of the present invention comprises 1 part by weight of a tubular aluminum silicate, 0 to 100 parts by weight of water, 10 to 3000 parts by weight of an organic dispersion medium, and more organic dispersion medium than water. It is preferable that it is comprised so that many may be included.
In the tubular aluminum silicate dispersion of the present invention, water may be completely removed and the water content may be 0 parts by weight, but preferably it contains a small amount of water. When water is contained in the composition as described above, aggregation of the tubular aluminum silicate in the organic dispersion medium can be more reliably suppressed, and a more excellent dispersion state can be obtained. .
“Water (content) is 0 part by weight” means that water can be analyzed within a range that can be analyzed when water is removed from a mixture of tubular aluminum silicate, water, and organic dispersion medium. Means not detected.

As a manufacturing method of the tubular aluminum silicate of the present invention as described above, a step of preparing a mixed liquid by mixing a tubular aluminum silicate, water, and an organic dispersion medium, and from the mixed liquid Removing water.
In the step of preparing the mixed solution, it is preferable to prepare the mixed solution so that 10% by mass or less of the tubular aluminum silicate is contained in the mixed solution.
The mixed liquid is in a state where the tubular aluminum silicate is uniformly dispersed without being aggregated due to the presence of water, and the organic dispersion medium is compatible with water. The dispersion medium is also uniformly mixed. Since the dispersion liquid of the present invention is constituted by removing water from the mixed liquid, the dispersion liquid of the present invention has a state in which the tubular aluminum silicate is uniformly dispersed without being aggregated in the organic dispersion medium. It has become. For this reason, by mixing such a dispersion with an organic material such as a resin, the tubular aluminum silicate can be uniformly dispersed in the organic material.

  As a method for removing water from the mixed solution, it is sufficient that water can be removed while maintaining a uniform dispersion state of the tubular aluminum silicate in the mixed solution. For example, centrifugation or a drying material ( For example, addition of a molecular sieve, potassium carbonate, silica gel or the like) may be mentioned. The method by centrifugation is preferably used when the specific gravity of the organic dispersion medium to be used is smaller than that of water, and it is preferable because it can be performed in a short time without causing problems such as mixing of impurities. Moreover, the method by addition of a desiccant can be used irrespective of the physical property of an organic dispersion medium.

  Other methods for removing water from the mixed solution include a method of evaporating the mixed solution under reduced pressure and a method of ultrafiltering the mixed solution.

The evaporation under reduced pressure is a method in which the mixed solution is heated under reduced pressure to promote the evaporation of the mixed solution and remove the solvent.
Specifically, in the present embodiment, the mixed solution is heated under reduced pressure (evaporated under reduced pressure) to remove water in the mixed solution. For example, as shown in FIG. 3A, the rotary evaporator 10 can be used, and in a state where the eggplant flask 16 is depressurized via the condenser 12, the mixture liquid is evaporated by heating the eggplant flask 16 while rotating the eggplant flask 16. Then, the evaporated dispersion medium (water) is cooled by the cooling water 14 in the condenser 12 and stored in the receiving flask 20. Thereafter, an organic solvent to be substituted is added to the mixed solution after removing water and evaporated again under reduced pressure to remove water, and the same operation is repeated by adding the organic solvent.
In vacuum evaporation, when the dispersion medium is completely removed, aggregation of the tubular aluminum silicate occurs. Therefore, the lower limit is set to a state in which the dispersion medium remains in an amount of 10 parts by weight or more with respect to the tubular aluminum silicate. Remove water.

Ultrafiltration is a method in which a solvent is removed by forcibly permeating a filtration membrane by applying pressure (or absorbing pressure) while circulating a mixed solution.
For example, as shown in FIG. 3B, the mixed solution is circulated through the filter 32 of the ultrafiltration device 30, and the mixed solution is pressurized (or sucked) in the middle to forcibly permeate the filtration membrane 34. Remove water. Thereafter, an organic solvent for substitution is added to the mixed solution after removing water, and ultrafiltration is again performed to remove water, and the same operation is repeated by adding the organic solvent.
In ultrafiltration, for example, using a filter having the characteristics of Sarvaius stedim's Vivaflow 50 (effective filtration area 50 cm ² , molecular weight cut-off 5000), flow rate 300 ml / min (min), liquid pressure 1 bar, room temperature conditions And can be filtered.

<< Effect of the tubular aluminum silicate dispersion of the present invention >>
The tubular aluminum silicate dispersion of the present invention can be dispersed in an organic material because water is removed from a mixture of a tubular aluminum silicate, water, and an organic dispersion medium. A tubular aluminum silicate having adsorptivity and ion exchange properties can be provided. This is because an organic dispersion medium having compatibility with water coexists in an aqueous dispersion of tubular aluminum silicate that forms a uniform dispersion state in water, and water is removed from the mixture. This is because a tubular aluminum silicate dispersion liquid uniformly dispersed in an organic dispersion medium can be obtained.
In addition, since the tubular aluminum silicate dispersion liquid of the present invention is configured as described above, the concentration of the tubular aluminum silicate in the dispersion liquid is high. The ion exchange property can be sufficiently exhibited.

In addition, when water is removed by centrifuging a mixed solution of tubular aluminum silicate, water and an organic dispersion medium, the tubular aluminum silicate can be obtained in a short time without being mixed with impurities. A salt dispersion can be prepared.
In addition, if vacuum evaporation or ultrafiltration is performed instead of centrifugation, there is no need to perform an operation that induces aggregation of the tubular aluminum silicate, such as salting out or centrifugal separation. Since the aqueous dispersion of silicate can be solvent-substituted as it is, aggregation of the tubular aluminum silicate can be prevented.

  Further, when the organic dispersion medium contains alcohol, a dispersion in which the tubular aluminum silicate is more reliably dispersed can be obtained, and the handling becomes easy.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

<< Preparation of Sample 1 >>
First, sodium orthosilicate was dissolved in ion-exchanged water to prepare 10 L of a 3.0 mM sodium orthosilicate aqueous solution. The prepared sodium orthosilicate aqueous solution was introduced into a cation exchange resin packed in a column and subjected to ion exchange treatment to obtain a 3.0 mM orthosilicate aqueous solution. The flow rate of the column was set so that the electrical conductivity of the resulting orthosilicate aqueous solution was 500 μS / cm or less. In addition, the electrical conductivity of the orthosilicate aqueous solution was measured at 25 ° C. using an electrical conductivity meter ES-51 (manufactured by Horiba, Ltd.). Further, as the cation exchange resin, Amberlite IR120B (manufactured by Organo Co., Ltd.), which is a strongly acidic cation exchange resin, was used so that the pH of the orthosilicate aqueous solution was 5.0. The pH of the orthosilicate aqueous solution was measured by the above method using MODEL (F-71S) (Horiba, Ltd.).

  Next, 2 L of the obtained 3.0 mM orthosilicate aqueous solution, 1 L of 30 mM aluminum nitrate aqueous solution, 1 L of 28 mM urea aqueous solution, 1 L of 3.8 mM NaOH aqueous solution, and 2 L of ion-exchanged water were mixed together. A mixture was prepared so that the molar concentration of Al and Al was 1: 2. Further, 4M NaOH aqueous solution was added dropwise so that the pH of the mixed solution was 3.5. The pH of the prepared mixed solution was measured by the same method as described above. After sufficiently stirring the prepared mixed solution, the mixed solution was heated at 100 ° C. for 80 hours in an autoclave.

  After the mixture returned to room temperature, a 1M volume of 5M NaCl aqueous solution was added to the mixture to cause gelation, followed by centrifugation to obtain a transparent tubular aluminum silicate gel. NaCl, which is a salt contained in the obtained gel, was removed using a dialysis membrane to obtain an aqueous dispersion of tubular aluminum silicate.

  To 10 g of the obtained aqueous dispersion of tubular aluminum silicate, 30 g of ethanol was added and stirred to prepare a gel with water-ethanol mixing (treatment 1). This was centrifuged at 7500 rpm for 10 minutes to separate water (treatment 2). By repeating these treatment 1 and treatment 5 times, a tubular aluminum silicate dispersion of 1 part by weight of tubular aluminum silicate, 5 parts by weight of water and 100 parts by weight of ethanol was prepared. Sample 1 was prepared by mixing 100 parts by weight of this tubular aluminum silicate dispersion with 100 parts by weight of silicone resin.

<< Preparation of Samples 2-8 >>
In the preparation of Sample 1, the type of organic dispersion medium was changed as shown in Table 1, and the same procedure was performed except that the amounts of water and organic dispersion medium were changed so that the composition of the sample was as shown in Table 1. Samples 2 to 8 were prepared. In Sample 8, isopropyl alcohol is used as the organic dispersion medium, and in Table 1, “IPA” is used.

<< Preparation of Sample 9 >>
First, an aqueous dispersion of tubular aluminum silicate was prepared in the same manner as in the preparation of Sample 1.
Subsequently, 30 g of ethanol was added to 10 g of the obtained aqueous dispersion of tubular aluminum silicate, and the mixture was stirred to prepare a gel under water-ethanol mixing (treatment 3). To this was added 3 g of potassium carbonate as a desiccant, and the mixture was stirred for 24 hours to absorb water in potassium carbonate, and then the potassium carbonate was taken out (treatment 4). This treatment 4 was repeated 10 times to prepare a tubular aluminum silicate dispersion of 1 part by weight of tubular aluminum silicate, 10 parts by weight of water and 200 parts by weight of ethanol. Sample 9 was prepared by mixing 100 parts by weight of this tubular aluminum silicate dispersion with 100 parts by weight of silicone resin.

<< Preparation of Samples 10 and 11 >>
In the preparation of Sample 9, the type of the organic dispersion medium was changed as shown in Table 1, and the same procedure was performed except that the amounts of water and the organic dispersion medium were changed so that the composition of the sample was as shown in Table 1. Samples 10 and 11 were prepared. In Sample 11, a mixed dispersion medium of isopropyl alcohol and ethylene glycol is used as the organic dispersion medium. In Sample 11, 100 parts by weight of ethanol and 100 parts of ethylene glycol are used per 1 part by weight of the tubular aluminum silicate. It is prepared to include parts by weight.

<< Preparation of Samples 12 and 13 >>
In the preparation of Sample 1, the amounts of water and organic dispersion medium are changed so that the composition of the sample is as shown in Table 1, and the number of rotations and the time for centrifugation are as shown in Table 1. Samples 12 and 13 were prepared in the same manner except that they were changed.

<< Preparation of Sample 14 >>
First, an aqueous dispersion of tubular aluminum silicate was prepared in the same manner as in the preparation of Sample 1.
Subsequently, 1000 parts by weight of ethanol was mixed with an aqueous dispersion of tubular aluminum silicate composed of 1 part by weight of tubular aluminum silicate and 100 parts by weight of water to prepare a tubular aluminum silicate dispersion. . 100 parts by weight of silicone resin was mixed with 100 parts by weight of this tubular aluminum silicate dispersion to prepare Sample 14.

<< Preparation of Sample 15 >>
Sample 15 was prepared in the same manner as in the preparation of Sample 14, except that the amounts of water and the organic dispersion medium were changed so that the composition of the sample was as shown in Table 1.

<< Preparation of Sample 17 >>
First, sodium orthosilicate was dissolved in ion-exchanged water to prepare 10 L of a 3.0 mM sodium orthosilicate aqueous solution. The prepared sodium orthosilicate aqueous solution was introduced into a cation exchange resin packed in a column and subjected to ion exchange treatment to obtain a 3.0 mM orthosilicate aqueous solution. The flow rate of the column was set so that the electrical conductivity of the resulting orthosilicate aqueous solution was 500 μS / cm or less. In addition, the electrical conductivity of the orthosilicate aqueous solution was measured at 25 ° C. using an electrical conductivity meter ES-51 (manufactured by Horiba, Ltd.). Further, as the cation exchange resin, Amberlite IR120B (manufactured by Organo Co., Ltd.), which is a strongly acidic cation exchange resin, was used so that the pH of the orthosilicate aqueous solution was 5.0. The pH of the orthosilicate aqueous solution was measured by the above method using MODEL (F-71S) (Horiba, Ltd.).

  Next, 2 L of the obtained 3.0 mM orthosilicic acid aqueous solution, 1 L of 12 mM aluminum nitrate aqueous solution, 1 L of 28 mM urea aqueous solution, 1 L of 3.8 mM NaOH aqueous solution, and 2 L of ion-exchanged water were mixed together. A mixture was prepared so that the molar concentration of Al and Al was 1: 2. Further, 4M NaOH aqueous solution was added dropwise so that the pH of the mixed solution was 3.5. The pH of the prepared mixed solution was measured by the same method as described above. After sufficiently stirring the prepared mixed solution, the mixed solution was heated at 100 ° C. for 80 hours in an autoclave.

  After the mixture returned to room temperature, a 1M volume of 5M NaCl aqueous solution was added to the mixture to cause gelation, followed by centrifugation to obtain a transparent tubular aluminum silicate gel. NaCl, which is a salt contained in the obtained gel, was removed using a dialysis membrane to obtain an aqueous dispersion of tubular aluminum silicate.

  To 10 g of the obtained aqueous dispersion of tubular aluminum silicate, 30 g of ethanol was added and stirred to prepare a gel with water-ethanol mixing (treatment 1). This was centrifuged at 7500 rpm for 10 minutes to separate water (treatment 2). By repeating these treatments 1 and 2 10 times, a tubular aluminum silicate dispersion of 1 part by weight of tubular aluminum silicate, 0 part by weight of water and 100 parts by weight of ethanol was prepared. Sample 17 was prepared by mixing 100 parts by weight of this tubular aluminum silicate dispersion with 100 parts by weight of silicone resin.

<< Preparation of Sample 18 >>
Sample 18 was prepared in the same manner as Sample 17 except that the number of repetitions of Process 1 and Process 2 was changed from 10 to 7.

<< Preparation of Sample 19 >>
Sample 19 was prepared in the same manner as in the preparation of sample 18, except that the solvent replacement target in treatment 1 was changed from ethanol to methanol.

<< Preparation of Sample 20 >>
First, sodium orthosilicate was dissolved in ion-exchanged water to prepare 10 L of a 3.0 mM sodium orthosilicate aqueous solution. The prepared sodium orthosilicate aqueous solution was introduced into a cation exchange resin packed in a column and subjected to ion exchange treatment to obtain a 3.0 mM orthosilicate aqueous solution. The flow rate of the column was set so that the electrical conductivity of the resulting orthosilicate aqueous solution was 500 μS / cm or less. In addition, the electrical conductivity of the orthosilicate aqueous solution was measured at 25 ° C. using an electrical conductivity meter ES-51 (manufactured by Horiba, Ltd.). Further, as the cation exchange resin, Amberlite IR120B (manufactured by Organo Co., Ltd.), which is a strongly acidic cation exchange resin, was used so that the pH of the orthosilicate aqueous solution was 5.0. The pH of the orthosilicate aqueous solution was measured by the above method using MODEL (F-71S) (Horiba, Ltd.).

  Next, 2 L of the obtained 3.0 mM orthosilicic acid aqueous solution, 1 L of 12 mM aluminum nitrate aqueous solution, 1 L of 28 mM urea aqueous solution, 1 L of 3.8 mM NaOH aqueous solution, and 2 L of ion-exchanged water were mixed together. A mixture was prepared so that the molar concentration of Al and Al was 1: 2. Further, 4M NaOH aqueous solution was added dropwise so that the pH of the mixed solution was 3.5. The pH of the prepared mixed solution was measured by the same method as described above. After sufficiently stirring the prepared mixed solution, the mixed solution was heated at 100 ° C. for 80 hours in an autoclave.

Using a rotary evaporator, 300 ml of the obtained mixed solution was heated under reduced pressure until the mixed solution became 150 ml (evaporated under reduced pressure) to remove water in the mixed solution.
Next, 150 ml of ethanol is added to the mixed solution after water removal, and after removing the water by evaporation under reduced pressure until the mixed solution becomes 150 ml, 150 ml of ethanol is added again, and the same operation is performed 10 times in total. By repeating, the dispersion medium in the liquid mixture was replaced with ethanol. Further, the concentration of the mixed liquid after solvent substitution was adjusted to prepare a tubular aluminum silicate ethanol dispersion liquid of 1 part by weight of tubular aluminum silicate, 0 part by weight of water, and 100 parts by weight of ethanol.
Sample 20 was prepared by mixing 100 parts by weight of a silicone resin with 100 parts by weight of the tubular aluminum silicate dispersion.

<< Preparation of Sample 21 >>
In the preparation of Sample 20, the vacuum evaporation operation using a rotary evaporator was changed from 10 to 7 times, and tubular aluminum silicate containing 1 part by weight of tubular aluminum silicate, 5 parts by weight of water, and 100 parts by weight of ethanol. A salt dispersion was prepared.
A sample 21 was prepared by mixing 100 parts by weight of a silicone resin with 100 parts by weight of the tubular aluminum silicate dispersion.

<< Preparation of Sample 22 >>
In the preparation of Sample 21, the solvent substitution target was changed from ethanol to methanol, and a tubular aluminum silicate dispersion of 1 part by weight of tubular aluminum silicate, 5 parts by weight of water, and 100 parts by weight of methanol was prepared.
A sample 22 was prepared by mixing 100 parts by weight of a silicone resin with 100 parts by weight of the tubular aluminum silicate dispersion.

<< Preparation of Sample 23 >>
First, sodium orthosilicate was dissolved in ion-exchanged water to prepare 10 L of a 3.0 mM sodium orthosilicate aqueous solution. The prepared sodium orthosilicate aqueous solution was introduced into a cation exchange resin packed in a column and subjected to ion exchange treatment to obtain a 3.0 mM orthosilicate aqueous solution. The flow rate of the column was set so that the electrical conductivity of the resulting orthosilicate aqueous solution was 500 μS / cm or less. In addition, the electrical conductivity of the orthosilicate aqueous solution was measured at 25 ° C. using an electrical conductivity meter ES-51 (manufactured by Horiba, Ltd.). Further, as the cation exchange resin, Amberlite IR120B (manufactured by Organo Co., Ltd.), which is a strongly acidic cation exchange resin, was used so that the pH of the orthosilicate aqueous solution was 5.0. The pH of the orthosilicate aqueous solution was measured by the above method using MODEL (F-71S) (Horiba, Ltd.).

  Next, 2 L of the obtained 3.0 mM orthosilicic acid aqueous solution, 1 L of 12 mM aluminum nitrate aqueous solution, 1 L of 28 mM urea aqueous solution, 1 L of 3.8 mM NaOH aqueous solution, and 2 L of ion-exchanged water were mixed together. A mixture was prepared so that the molar concentration of Al and Al was 1: 2. Further, 4M NaOH aqueous solution was added dropwise so that the pH of the mixed solution was 3.5. The pH of the prepared mixed solution was measured by the same method as described above. After sufficiently stirring the prepared mixed solution, the mixed solution was heated at 100 ° C. for 80 hours in an autoclave.

The obtained mixed solution was subjected to ultrafiltration under the conditions of a flow rate of 300 ml / min (minutes), a liquid pressure of 1 bar, and room temperature using a Vivaflow 50 (effective filtration area of 50 cm ² , a molecular weight cut off of 5000) manufactured by Sartorius stedim. Water in the mixture was removed.
200 ml of ethanol was added to 200 ml of the obtained mixed liquid, and ultrafiltration was performed again. When the liquid volume reached 200 ml, 200 ml of ethanol was added again to perform ultrafiltration, and the solution was concentrated to 200 ml. . This operation was performed 10 times in total, and the dispersion medium in the mixed solution was replaced with ethanol. Further, the concentration of the mixed liquid after solvent substitution was adjusted to prepare a tubular aluminum silicate ethanol dispersion liquid of 1 weight of tubular aluminum silicate, 0 weight part of water and 100 weight part of ethanol.
Sample 23 was prepared by mixing 100 parts by weight of silicone resin with 100 parts by weight of the tubular aluminum silicate dispersion.

<< Preparation of Sample 24 >>
In the preparation of sample 23, the ultrafiltration operation was changed from 10 to 7 times, and a tubular aluminum silicate dispersion of 1 part by weight of tubular aluminum silicate, 5 parts by weight of water, and 100 parts by weight of ethanol was added. Prepared.
A sample 24 was prepared by mixing 100 parts by weight of a silicone resin with 100 parts by weight of the tubular aluminum silicate dispersion.

<< Preparation of Sample 25 >>
In the preparation of Sample 23, the object of solvent replacement was changed from ethanol to methanol, and a tubular aluminum silicate dispersion of 1 part by weight of tubular aluminum silicate, 0 part by weight of water, and 100 parts by weight of methanol was prepared.
100 parts by weight of silicone resin was mixed with 100 parts by weight of this tubular aluminum silicate dispersion to prepare Sample 25.

<< Preparation of Sample 26 >>
In the preparation of Sample 24, the solvent substitution target was changed from ethanol to methanol, and a tubular aluminum silicate dispersion of 1 part by weight of tubular aluminum silicate, 5 parts by weight of water, and 100 parts by weight of methanol was prepared.
Sample 26 was prepared by mixing 100 parts by weight of a silicone resin with 100 parts by weight of the tubular aluminum silicate dispersion.

<< Preparation of Sample 27 >>
In the preparation of sample 26, the ultrafiltration operation was changed from 7 times to 5 times, and the concentration was adjusted so that 1 part by weight of tubular aluminum silicate, 10 parts by weight of water, and 200 parts by weight of ethanol were obtained. A silicate dispersion was prepared.
Sample 27 was prepared by mixing 100 parts by weight of a silicone resin with 200 parts by weight of the tubular aluminum silicate dispersion.

<< Evaluation of Samples 1-15, 17-27 >>
(1) Sulfide gas resistance evaluation Each of the above prepared samples 1 to 15 and 17 to 27 is dropped on an Ag substrate and baked to form an Ag in which a silicone resin layer in which a tubular aluminum silicate is dispersed is formed. A substrate was produced.

Based on the gas exposure test of JIS standard (JIS C 60068-2-43), each of the produced Ag substrates was exposed to a hydrogen sulfide gas 15 ppm atmosphere (temperature 25 ° C., relative humidity 75% RH) for 1000 hours. The reflectance was measured before and after exposure, and the reflectance ratio was calculated from the following formula.
Reflectivity ratio = reflectance after exposure / reflectivity before exposure × 100
Based on the calculated reflectance ratio, the sulfide gas resistance was evaluated according to the following criteria. The evaluation results are shown in Tables 1 and 2.

A: The reflectance ratio is 95% or more.
○: The reflectance ratio is 90% or more and less than 95%.
Δ: The reflectance ratio is 85% or more and less than 90%.
X: The reflectance ratio is less than 85%.

(2) Migration evaluation (ion trap evaluation)
Each of the prepared samples 1 to 15 and 17 to 27 was dropped onto a printed board and baked to produce 20 printed boards each having a silicone resin layer in which a tubular aluminum silicate was dispersed. .

  The produced printed circuit board was energized continuously for 1000 h (hours) in a constant temperature and humidity test tank at 85 ° C. and 85%. After this test, it was observed whether migration of the electrode portion occurred with a microscope, and the number of substrates on which migration occurred was evaluated according to the following criteria. The evaluation results are shown in Tables 1 and 2.

A: The number of migration occurrences is 1 or 0.
○: The number of migration occurrences is two.
Δ: Number of migration occurrences is 3.
X: The number of migration occurrences is 4 or more.

(3) Particle size measurement The particle size of the tubular aluminum silicate was measured for samples 5, 9, 17, 21, and 24 using a Zetasizer / Nano S (manufactured by Malvern) as a particle size measuring device.
Further, as Sample 16 of the comparative example, an aqueous dispersion of tubular aluminum silicate was prepared in the same manner as Sample 1, and the particle diameter of the tubular aluminum silicate was also measured. The measured particle size is shown in Table 3.

(4) Summary In the sample 14, since the mixed solution of the tubular aluminum silicate and the organic dispersion medium was mixed with the silicone resin as it was, the tubular aluminum silicate aggregated, and the tubular aluminum was evaluated in the sulfide gas resistance evaluation and the migration evaluation. Silicate adsorption and ion exchange are not obtained. Although it is thought that the sample 15 can disperse | distribute the tubular aluminum silicate substantially uniformly, since the density | concentration of tubular aluminum silicate is too low, adsorptivity and ion exchange property are not acquired.

On the other hand, Samples 1 to 13 according to the present invention show good results in the sulfide gas resistance evaluation and the migration evaluation.
Since the result of evaluation of resistance to sulfide gas is good, in samples 1 to 13, hydrogen sulfide gas is adsorbed to the tubular aluminum silicate before reaching the Ag substrate, and as a result, corrosion of the Ag substrate is suppressed. The Ag substrate is considered to maintain a high reflectance. Therefore, it can be said that the samples 1 to 13 having good results of the sulfur gas resistance evaluation are excellent in adsorptivity.
Moreover, since the result of migration evaluation is good, in Samples 1 to 13, metal ions that cause migration are adsorbed on the tubular aluminum silicate and ion-exchanged with H ions that do not cause migration. Thus, it is considered that the occurrence of migration is effectively suppressed. Therefore, it can be said that Samples 1 to 13 having good migration evaluation results are excellent in ion exchange properties.

  Further, from the results of the particle size measurement of Samples 5, 9, and 16, the tubular aluminum silicate dispersion of the present invention has a particle size approximately the same as that when the tubular aluminum silicate is dispersed in water. It is shown that the tubular aluminum silicate is uniformly dispersed.

  Therefore, according to this invention, it can be made to disperse | distribute in an organic material and it can be set as the tubular aluminum silicate dispersion liquid which has adsorptivity and ion exchange property.

It has been shown that the above-described effects of the present invention can also be obtained when the organic dispersion medium is changed as in Samples 7 to 8 and Samples 9 to 11.
The above-described effects of the present invention can also be obtained by changing the water removal method as in Samples 5 and 9, and when using centrifugation as the water removal method as in Samples 5, 12, and 13, It has been shown that it can also be obtained by changing the centrifugation conditions.

The effects of the present invention described above are obtained by changing the centrifugation conditions when centrifugation is used as a method for removing water as in samples 17 to 19, and significantly reducing the water in the tubular aluminum silicate dispersion. Has also been shown to be obtained.
It has been shown that the above-described effects of the present invention can be obtained even if the water removal method is changed from centrifugation to vacuum evaporation or ultrafiltration as in samples 20 to 22 and 23 to 27.
In addition, from the results of the particle size measurement of samples 17, 21, and 24, the centrifugation conditions when using centrifugation as the water removal method are changed, or the water removal method is reduced from the centrifugation to vacuum evaporation or ultrafiltration. Even if it is changed to, the tubular aluminum silicate dispersion of the present invention shows a particle size almost the same as when the tubular aluminum silicate is dispersed in water, even in this case, It is shown that the tubular aluminum silicate is uniformly dispersed.
In particular, samples 21 and 24 have a small particle size. This is because the vacuum evaporation or ultrafiltration operation is performed in the preparation of the sample, so there is no need to perform an operation that induces aggregation of the tubular aluminum silicate such as salting out or centrifugation, This is because aggregation of the tubular aluminum silicate is prevented.

  As described above, the present invention is suitable for providing a tubular aluminum silicate dispersion which can be dispersed in an organic material and has adsorptivity and ion exchange properties, and a method for producing the same.

DESCRIPTION OF SYMBOLS 10 Rotary evaporator 12 Condenser 14 Cooling water 16 Eggplant flask 18 Bath 20 Receiving flask 30 Ultrafiltration apparatus 32 Filter 34 Filter membrane

Claims (14)

  A tubular aluminum silicate dispersion liquid obtained by removing water from a mixed liquid of a tubular aluminum silicate, water, and an organic dispersion medium.   The tubular aluminum silicate is 1 part by weight, the water is 0 to 100 parts by weight, the organic dispersion medium is 10 to 3000 parts by weight, and contains more organic dispersion medium than water. The tubular aluminum silicate dispersion described.   The tubular aluminum silicate dispersion liquid according to claim 1 or 2, wherein water is removed from the liquid mixture by centrifuging the liquid mixture.   The tubular aluminum silicate dispersion liquid according to claim 1 or 2, wherein water is removed from the liquid mixture by evaporating the liquid mixture under reduced pressure.   The tubular aluminum silicate dispersion liquid according to claim 1 or 2, wherein water is removed from the liquid mixture by ultrafiltration of the liquid mixture.   6. The tubular aluminum silicate according to claim 1, wherein b / a ≧ 10 when the outer diameter of the tubular aluminum silicate is a and the length is b. Acid salt dispersion.   The tubular aluminum silicate dispersion liquid according to any one of claims 1 to 6, wherein the tubular aluminum silicate is imogolite.   The tubular aluminum silicate dispersion liquid according to any one of claims 1 to 7, wherein the organic dispersion medium contains an alcohol. A step of mixing a tubular aluminum silicate, water, and an organic dispersion medium to prepare a mixed solution;
Removing water from the mixture;
A method for producing a tubular aluminum silicate dispersion characterized by comprising:   The tubular aluminum silicate dispersion is composed of 1 part by weight of tubular aluminum silicate, 0 to 100 parts by weight of water, 10 to 3000 parts by weight of organic dispersion medium, and more organic dispersion medium than water. The method for producing a tubular aluminum silicate dispersion according to claim 8, comprising a large amount.   The method for producing a tubular aluminum silicate dispersion according to claim 9 or 10, wherein, in the step of removing water from the mixed solution, the mixed solution is centrifuged to remove water.   The method for producing a tubular aluminum silicate dispersion according to claim 9 or 10, wherein, in the step of removing water from the mixed solution, the mixed solution is evaporated under reduced pressure to remove water.   The method for producing a tubular aluminum silicate dispersion according to claim 9 or 10, wherein in the step of removing water from the mixed solution, the mixed solution is ultrafiltered to remove water.   14. The method according to claim 9, wherein in the step of preparing the mixed solution, the mixed solution is prepared so that the tubular aluminum silicate is contained in an amount of 10% by mass or less in the mixed solution. A method for producing a tubular aluminum silicate dispersion liquid according to one item.

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