JP2012201550A - Organification-treated clay dispersion, and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organification-treated clay dispersion having low viscosity, capable of micro-dispersion of organification-treated clay into a polar organic solvent which has been difficult hitherto.SOLUTION: In the organification-treated clay dispersion formed by dispersing organification-treated clay into a polar organic solvent, the median diameter in particle size distribution measurement is 0.5-5 μm, and the apparent viscosity at 60 turns/min of a 4 mass% concentration dispersion of the organification-treated clay is 1-200 mPa s.

Description

  The present invention relates to a dispersion in which organically treated clay is finely dispersed in a polar organic solvent, and a method for producing the same.

  The organically treated clay is obtained by replacing the exchangeable cation existing between the layers of the layered silicate crystal represented by smectite with a cationic organic compound.

  Organized clay can be dispersed in non-aqueous dispersion media and dispersed in various compounds to adjust and improve rheological properties. For example, paints, printing inks, cosmetics, lubricating greases, etc. It's being used. It is also used as a functional filler for polymer materials such as resins and rubbers, and is used for the purpose of improving the rigidity, strength, heat distortion resistance, flame retardancy, gas barrier properties and the like. Further, it is used as a main ingredient of a film such as a gas barrier film or a water resistant film. The bentonite (layered silicate) organic reaction is generally carried out by stirring and mixing an aqueous solution of a modifier composed of an organic compound and an aqueous dispersion of clay (see Non-Patent Document 1). ).

  However, fine dispersion of organically treated clay is easy to disperse in non-polar organic solvents such as toluene and benzene, but especially regarding dispersion in polar organic solvents, selection of host clay and selection of organic agent type It was common to find fine dispersion conditions empirically after aligning the conditions such as selection of the dispersion solvent. That is, finding these conditions has been regarded as important in the preparation of dispersions of organically treated clay.

For example, Patent Document 1 reports that dispersibility of a highly polar organic solvent is improved by using trioctylmethylammonium ion as an organicizing agent for organically treated clay.
Moreover, in patent document 2, the dispersion | distribution to a polar organic solvent is used by using 2 or more types of the quaternary ammonium ion which has a polyoxyethylene group and the quaternary ammonium ion which has a polyoxypropylene group as an organic treatment agent. It is reported to improve the sex.
Thus, the improvement of the dispersibility of the organically treated clay in the polar organic solvent has been achieved by selecting the kind of the organically treating agent or mixing it.

  Moreover, preparation of the dispersion liquid by a ball mill or a bead mill can be considered as a method of physically finely pulverizing and finely dispersing the particles. In these methods, there are productivity problems such as contamination of the grinding media components such as balls and beads and limit of processing capacity due to batch processing, and necessity of sufficient reaction time. Furthermore, an increase in viscosity can be seen by miniaturization, especially in fields that do not require thickening, such as use as a filler in various polymers, and in the production of barrier films, a large amount of There are problems such as the need for a dispersion medium and the heat of vaporization associated therewith. There is also a concern of crystal shredding.

"Clay Handbook (3rd Edition)", Japan Clay Society, p550-554

JP-A-5-163014 JP-A-7-187657

  As described above, in the conventional method, conditions such as the type of the host clay, the organic treatment agent, and the dispersion solvent are limited as factors determining the dispersibility in the dispersion of the organically treated clay, and only under the limited conditions. Fine dispersion in a polar solvent was possible. In addition, in the fine dispersion method using a ball mill, an increase in viscosity is generally observed, and there is a difficulty in handling in applications that require high concentration and low viscosity. Accordingly, an object of the present invention is to provide an organically treated clay dispersion liquid which can be finely dispersed in a polar organic solvent and which has been difficult, and a method for producing the same.

As a result of intensive studies in view of the above problems, the present inventors processed an organically treated clay dispersion, which was primarily dispersed so that the median diameter of the organized clay in the polar organic solvent was 5 to 100 μm, using a high-pressure pulverizer. As a result, it was found that an organic clay dispersion having a median diameter of 0.5 to 5 μm finely dispersed and having a viscosity lower than that of the conventional method can be produced, and the present invention has been made based on this finding.
That is, the said subject was solved by the following means.
(1) An organically treated clay dispersion in which an organically treated clay is dispersed in a polar organic solvent, the median diameter in the particle size distribution measurement is 0.5 to 5 μm, and the concentration of the organically treated clay is 4 An organically treated clay dispersion having an apparent viscosity of 1 to 200 mPa · s at 60 rpm of a mass% dispersion.
(2) The organically treated clay dispersion according to (1), wherein the primary dispersion is secondarily dispersed by a high-pressure pulverizer using a collision with a high-pressure fluid.
(3) The organically treated clay dispersion according to (2), wherein a median diameter in a particle size distribution of the primary dispersion is 5 to 100 μm.
(4) (a) a step of primarily dispersing the organized clay in a polar organic solvent;
(B) A method for producing an organically treated clay dispersion, comprising the step of secondary dispersion of the primary dispersion with a high-pressure pulverizer by collision of a high-pressure fluid.

The organically treated clay dispersion of the present invention is a dispersion obtained by finely dispersing an organically treated clay that has not been finely dispersed in a conventional method in a polar organic solvent, and has a fine particle size and low viscosity.
According to the method for producing an organically treated clay dispersion of the present invention, the dispersion medium can be a polar organic solvent, and even when the concentration is high, an organically treated clay dispersion having a fine particle size and low viscosity can be produced. it can.

It is a graph showing the relationship between the particle size ratio and the viscosity ratio with respect to the primary dispersion when the dispersion is prepared by various secondary dispersion methods.

(Organized clay primary dispersion)
The organically treated clay dispersion in the present invention is a layered silicate, particularly smectite, in which an organic treatment agent is introduced by an ion exchange reaction or adsorbed on the surface thereof. In particular, the combination of the host clay, the organic agent, and the polar organic solvent as the dispersion medium is not limited, but the dispersion of the dispersion liquid obtained by mixing the dispersion medium and the organically treated clay using a general stirrer or homomixer is used. In the state, it is preferable to use a primary dispersion having a median diameter of 5 to 100 μm in the particle size distribution measurement.

(Layered silicate)
The raw material of the organically treated clay is a layered silicate that can be organically modified by an organic treatment agent, and examples thereof include smectite, vermiculite, swellable mica, and layered polysilicate. They may be either natural products or synthetic products, and the smectite is preferably montmorillonite, beidellite, nontronite, hectorite, soconite, stevensite, or saponite, and montmorillonite is particularly preferred. Moreover, as refined montmorillonite, there exists what is marketed as Kunipia F (brand name, Kunimine Kogyo Co., Ltd. product), for example.

(Organizing agent)
The organic treatment agent used for the organic treatment of the layered silicate in the present invention is not particularly limited, and examples thereof include an organic compound having a polar group, and more preferably an organic compound having a cationic group. , Ammonium salts, phosphonium salts, sulfonium salts, imidazolium salts, and pyridinium salts, with quaternary ammonium salts being particularly preferred.

  Specific examples of the organic treating agent include dipolyoxyethylene alkylmethylammonium salt, alkylbis (2-hydroxyethyl) methylammonium salt, dialkyldimethylammonium salt, alkyltrimethylammonium salt, alkyldimethylbenzylammonium salt and the like. In particular, those having a polar group in the side chain, such as those having a polar group such as a hydroxyl group, such as dipolyoxyethylene alkylmethylammonium salt, alkylbis (2-hydroxyethyl) methylammonium salt, etc. And the like are more preferable because dispersibility in a polar organic solvent is improved.

(Polar organic solvent)
In the production method of the present invention, the polar organic solvent in which the organically treated clay is dispersed is not particularly limited, but is preferably a polar solvent that is liquid at room temperature. For example, tetrahydrofuran, acetone, acetonitrile, N, N-dimethylformamide, dimethyl sulfoxide, N, N-dimethylacetamide, N-methylpyrrolidone, sulfolane, 1,3-dimethyl-2-imidazolidinone, N-methylformamide, formamide 1-butanol, 2-propanol, 1-propanol, ethanol, methanol and the like. Two or more kinds of organic solvents may be mixed and used.

(Distributor)
The dispersing device used for secondary dispersion in the present invention is preferably a wet atomization device that jets a fluid at a high pressure and collides the jets or the jet and the dispersion liquid through nozzle means. Examples of wet atomizers (high-pressure pulverizers) include “Starburst System” (trade name, manufactured by Sugino Machine Co., Ltd.), “NanoJet Pal” (trade name, manufactured by Joko Co., Ltd.), Yoshida Kikai Kogyo Co., Ltd. The wet atomization apparatus of Co., Ltd. is marketed and can be used suitably.

The method for producing the organically treated clay dispersion in the present invention is as follows.
(A) a step of primarily dispersing the organized clay in a polar organic solvent;
(B) including a step of subjecting the primary dispersion to secondary dispersion in a high-pressure pulverization apparatus using high-pressure fluid collision.
The manufacturing method will be described below.

<Process (a)>
The organized clay is mixed with the polar organic solvent and primarily dispersed. The solid dispersion concentration can be freely set as long as it is in a concentration range that can be mixed by a disperser, but is preferably 1 to 15% by mass. More preferably, it is 2-10 mass%. In the primary dispersion, dispersion can be performed by adding organically treated clay to the polar organic solvent, and a commercially available stirrer with a stirrer or a homomixer can be used.

<Step (b)>
The primary dispersion is subjected to secondary dispersion by passing through a high-pressure pulverizer. The pressure in the secondary dispersion may be a pressure of 70 to 250 MPa as long as a sufficient shear force is applied to the dispersion.
The primary dispersion treatment of the present invention is carried out in order to disperse the agglomerated particles of the organically treated clay powder with a polar organic solvent, apply a weak shear with a stirrer or the like, and disperse them to a particle size suitable for high-pressure pulverization treatment. By this treatment, the primary dispersion particle size is adjusted so that the median diameter in the particle size distribution measurement is 5 to 100 μm.
In the secondary dispersion treatment of the present invention, the dispersed particles obtained by the primary dispersion treatment are further finely dispersed by a strong shearing force for the purpose of exfoliating each crystal layer aggregated between the organically treated clay crystals. To make it happen. By this treatment, the secondary dispersion particle size is adjusted so that the median diameter in the particle size distribution measurement is 0.5 to 5 μm.
By causing the primary dispersion to collide with a high-pressure fluid, a strong shearing force can be applied, and separation between crystal layers can be physically promoted without breaking the crystal. That is, it is not an increase in the number of dispersed particles due to crystal breakage but a fine dispersion that does not impair the crystal size, so that it can be finely dispersed to obtain a dispersion having a low viscosity.

The dispersed particle size of the organically treated clay dispersion of the present invention can be analyzed using, for example, a particle size distribution measuring device. For example, the particle diameter of the organically treated clay dispersed in the polar organic solvent can be confirmed by a commercially available particle size distribution measuring apparatus using a dynamic light scattering method or a laser diffraction / scattering method.
The median diameter of the organically treated clay dispersion of the present invention is 0.5 to 5 μm, preferably 0.8 to 2.0 μm.

The viscosity of the organically treated clay dispersion of the present invention can be evaluated using a general viscometer such as a B-type viscometer or an E-type viscometer.
The viscosity of the organically treated clay dispersion of the present invention is 1 to 200 mPa · s, preferably 1 to 60 mPa · s, more preferably 2 when the viscosity is 4% by mass at 60 rpm. ˜20 mPa · s.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited to this.

Examples 1-12, Comparative Examples 1-12
The organically treated clay shown in Table 1 was added to the polar organic solvent shown in Table 1 so as to have a solid content concentration of 4% by mass, and the mixture was stirred with a stirrer at 1000 rpm for 1 hour. The obtained primary dispersion was secondarily dispersed under the conditions described in Table 1. The median diameter and viscosity of the obtained secondary dispersion were measured and evaluated by the methods described below.

(Organized clay)
・ Organized clay A
Kunipia F (trade name, Kunimine Kogyo Co., Ltd.) to alkyl chloride as an organic treatment agent _(C 8 _{-C 18)} dimethyl benzyl ammonium (manufactured by Lion Akzo Co., Ltd., trade name Arquad CB-50) yang A sample which was reacted 1.05 times the ion exchange capacity, washed with sufficient distilled water, dried and pulverized was prepared.
・ Organized clay B
Cation exchange of oleylbis (2-hydroxyethyl) methylammonium chloride (made by Lion Akzo Co., Ltd .; trade name Esocard O / 12) as an organic treatment agent for Kunipia F (trade name, produced by Kunimine Industries Co., Ltd.) The sample was reacted 1.05 times the volume, washed with sufficient distilled water, dried and pulverized.

(Polar organic solvent)
The polar organic solvent used is shown in Table 1 as follows.
DMA: N, N-dimethylacetamide DMF: N, N-dimethylformamide NMP: N-methylpyrrolidone

(Secondary dispersion method condition)
・ High pressure pulverizer Single nozzle Secondary dispersion was performed with the following wet atomizer.
Equipment: Starburst Lab (HJP-25005, trade name, manufactured by Sugino Machine)
Chamber: Single nozzle (nozzle diameter 0.17mm)
Pressure: 100MPa
・ High-pressure pulverizer Oblique impingement nozzle Dispersed secondarily with the following wet atomizer.
Equipment: Starburst Lab (HJP-25005, trade name, manufactured by Sugino Machine)
Chamber: Oblique collision nozzle (nozzle diameter 0.12 mm)
Pressure: 100MPa

・ Ball mill 24h
Equipment: Pot mill turntable (ANZ-50S, trade name, manufactured by Nissho Science Co., Ltd.), pot (MT mark, 1L capacity, purchased from Sansho Co., Ltd.)
Treatment method: A 200 g alumina ball (30 g / piece) was taken from a 200 g sample, transferred into a pot, and treated for 24 hours.

(Median diameter)
Device: LA950V2 (trade name, manufactured by HORIBA)
Measurement method: A dispersion medium and an appropriate amount of a sample were placed in a quartz cell, and the particle size distribution was measured.

(viscosity)
Apparatus: TV-10M rotational viscometer (manufactured by Toki Sangyo Co., Ltd.)
Measurement method: Each sample was stirred with a stirrer at 1000 rpm for 5 minutes, and then the apparent viscosity of each sample was measured with a small amount sample adapter at 60 rpm for 60 seconds.

  From Table 1, the median diameter of the sample which performed the secondary dispersion process by the high pressure crusher process of Examples 1-12 is small compared with the thing which is not the secondary dispersion of Comparative Examples 1-6. Recognize. Similarly, the median diameter is reduced in the secondary dispersion treatment by the ball mill.

  On the other hand, although the median diameter of the dispersed particles is almost the same in the pulverization treatment by the ball mill in Comparative Examples 7 to 12 and those subjected to the high-pressure pulverizer treatment in Examples 1 to 12, the ball mill treatment is compared with the viscosity in the same composition dispersion liquid. Compared with the high-pressure crusher treatment, it is low.

Moreover, in showing the difference between the particle size and the viscosity in each secondary dispersion method, Table 2 below shows the relationship between the particle size ratio and the viscosity ratio in the primary dispersion state (Comparative Examples 1 to 6) and the secondary dispersion state. . The particle size ratio represents the ratio of the median diameter in the primary dispersion state and the secondary dispersion state in the same composition dispersion liquid (organized clay species and solvent species), and is obtained by the following equation.
(Particle size ratio) = (Median diameter of primary dispersion) / (Median diameter of secondary dispersion)
The viscosity ratio represents the ratio of the viscosity (η60) in the primary dispersion state and the secondary dispersion state in the same composition dispersion liquid, and is obtained by the following equation.
(Viscosity ratio) = (Viscosity of primary dispersion) / (Viscosity of secondary dispersion)

  When the results of Table 2 are plotted, the graph shown in FIG. 1 can be obtained. FIG. 1 shows that there is a correlation between the viscosity ratio and the particle size ratio, and the viscosity ratio increases exponentially with respect to the particle size ratio. Furthermore, as a difference due to the difference in the secondary dispersion method, the viscosity ratio with respect to the particle size ratio of the secondary dispersion sample by the ball mill tends to be higher uniformly. That is, the organically treated clay dispersion in the present invention has a lower viscosity than the secondary dispersion obtained by ball milling, although the particle size is fine.

Moreover, in showing the difference between the particle size and the viscosity in each secondary dispersion method, Table 2 below shows the relationship between the particle size ratio and the viscosity ratio in the primary dispersion state (Comparative Examples 1 to 6) and the secondary dispersion state. . The particle size ratio represents the ratio of the median diameter in the primary dispersion state and the secondary dispersion state in the same composition dispersion liquid (organized clay species and solvent species), and is obtained by the following equation.
(Particle size ratio) = (Median diameter of primary dispersion) / (Median diameter of secondary dispersion)
The viscosity ratio represents the ratio of the viscosity (η60) in the primary dispersion state and the secondary dispersion state in the same composition dispersion liquid, and is obtained by the following equation.
(Viscosity ratio) = (viscosity of the secondary dispersion) / (viscosity of the primary dispersion)

Claims (4)

  An organically treated clay dispersion in which an organically treated clay is dispersed in a polar organic solvent, wherein the median diameter in the particle size distribution measurement is 0.5 to 5 μm, and the concentration of the organically treated clay is 4% by mass. An organically treated clay dispersion having an apparent viscosity of 1 to 200 mPa · s at 60 rpm.   The organically treated clay dispersion liquid according to claim 1, wherein the primary dispersion liquid is secondarily dispersed by a high-pressure pulverizer using a collision with a high-pressure fluid.   The organically treated clay dispersion according to claim 2, wherein a median diameter in a particle size distribution of the primary dispersion is 5 to 100 µm. (A) a step of primarily dispersing the organized clay in a polar organic solvent;
(B) A method for producing an organically treated clay dispersion, comprising the step of secondary dispersion of the primary dispersion with a high-pressure pulverizer by collision of a high-pressure fluid.

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