JPH0568407B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for producing high-purity organic smectite clay, and more specifically, cristobalite contained as an impurity in smectite minerals is removed, and the clay has excellent swelling properties, thickening properties, and transparency in organic solvents. This invention relates to a method for producing organic smectite clay with excellent properties such as (Prior Art and Technical Problems of the Invention) Organic smectite clay is produced by reacting a smectite group clay mineral with an organic cationic compound such as a quaternary organic ammonium salt, and introducing the above compound between the layers of a layered crystal structure. This organic smectite clay exhibits swelling properties and thickening effects in organic liquids such as various organic solvents, oils, and hardening resin syrups, so it can be used as thickeners, antisettling agents, and gelling agents. It is used for various purposes such as rheological properties control agent. However, most of the conventional organic smectite clays contain cristobalite as an impurity, and are still not fully satisfactory in terms of properties such as swelling properties, thickening properties, and transparency. In addition to smectite, naturally occurring clay minerals include
It contains impurities such as quartz, feldspar, and cristobalite. Among these impurities, quartz and feldspar have different specific gravity from smectite, so they can be easily separated by means such as elutriation, but cristobalite is different from smectite. It has a specific gravity close to that of
Furthermore, since it exists in the form of a mixed crystal with smectite, it is difficult to separate it by ordinary physical means. As described above, since it is difficult to remove cristobalite from the raw clay stage, it is thought to be mixed into the final organic smectite as an impurity, resulting in a decrease in the initial properties. (Gist of the Invention and Object of the Invention) The present inventors have discovered that when an organic cationic compound and an alkali are applied to a clay mineral containing cristobalite, regardless of the order of their addition,
Since cristobalite and alkali can react selectively to convert cristobalite into soluble alkali silicate, and organic smectite exhibits hydrophobicity in an alkaline aqueous medium, the relationship between alkali silicate and pure organic smectite is It has been found that the separation is extremely effective and easy. That is, an object of the present invention is to provide a method for producing high-purity organic smectite clay from which cristobalite impurities are removed. Another object of the present invention is to have high purity and swellability.
The object of the present invention is to provide a method for producing organic smectite clay, which has excellent properties such as thickening properties and transparency, and is useful as a rheological property control agent. Still another object of the present invention is to provide a method for easily separating cristobalite and organic smectite clay with good workability and high separation efficiency. (Structure of the Invention) According to the present invention, there is a step of reacting a clay mineral mainly composed of smectite and containing cristobalite with an organic cationic compound, and a step of reacting the clay mineral and an alkali so that the crystal structure of the cristobalite substantially disappears. Provided is a method for producing high-purity organic smectite clay, which is characterized in that the steps of conditioning and reaction are performed in this order, in the reverse order, or simultaneously, and the generated alkali silicate is separated from the organic smectite clay. (Characteristics and Effects of the Invention) As already pointed out, the present invention includes separation and removal of cristobalite from smectite clay minerals.
This technique has a remarkable feature in that it is carried out in the reverse order of conventional techniques, that is, it is carried out at the stage of organic smectite clay synthesis instead of at the raw clay stage. The cristobalite contained in the raw clay has the property of reacting with alkali relatively easily to form an alkali silicate. However, when the raw clay itself is exposed to an alkali, the smectite itself swells, resulting in an alkali silicate. It becomes extremely difficult to separate the solution and purified clay by means such as sedimentation and filtration. On the other hand, according to the present invention, when a cationic organic compound and an alkali are made to act on a clay mineral containing cryutobalite, the cationic organic compound selectively reacts with smectite and the alkali selectively reacts with cristobalite, and the alkali reacts selectively with smectite and cristobalite. It was discovered that the alkali silicate produced by the reaction between cristobalite and alkali has no adverse effect on organic smectite or its production reaction. Furthermore, it has been found that, very advantageously, since organic smectite exhibits hydrophobicity in an alkaline aqueous medium, separation of alkali silicate and pure organic smectite can be carried out extremely effectively and easily. be. In fact, the organosmectite clay according to the invention
As is clear from the X-ray diffraction diagram in FIG. 1, it shows almost no diffraction peak (d=4.07 Å) characteristic of cristobalite, and it is clear that the purity is significantly superior. Furthermore, because of its high purity, it has outstanding swelling properties, thickening properties, and transparency, and this fact will become clear by referring to the examples described below. Furthermore, alkali silicate and organic smectite can be easily separated in a short time by sedimentation, filtration, etc. Furthermore, alkali silicate can be recovered in a highly concentrated state, which reduces pollution and wastewater. It has the advantage that there are few processing problems and the by-product alkali silicate can be effectively reused. (Preferred Embodiment of the Invention) In the present invention, clay minerals include smectite clay minerals, such as acid clay, bentonite,
So-called montmorillonite group clay minerals such as subbentonite and fuller's earth, and one or a combination of two or more of beidellite, saponite, nontronite, etc., are preferably used. These clay minerals are rarely produced in pure form, and are often found in quartz,
It is produced together with impurities such as feldspar and cristobalite. Impurities such as feldspar and quartz can be separated and removed by physical means such as elutriation and classification. The amount of cristobalite contained in clay minerals varies considerably depending on the type of clay, the ore deposit, etc., but is generally in the range of 5 to 40% by weight. According to the present invention, a clay mineral is reacted with an organic cationic compound and an alkali, and cristobalite contained in the clay mineral is converted into an alkali silicate regardless of the order of the reaction. The reaction between the raw clay mineral and the organic cationic compound can be carried out under conditions known per se.
Further, as the organic cationic compound, any compound known per se can also be used. Suitable examples of cationic compounds include, but are not limited to: Quaternary organic ammonium salt; especially the following formula

[Chemical formula] In the formula, each of R ₁ , R ₂ , R ₃ and R ₄ is a monovalent hydrocarbon group under the condition that at least one of them is an alkyl group having 10 to 24 carbon atoms, and is an anion, a quaternary ammonium salt of . For example, dimethyl dialkylammonium halides, dimeldialkylammonium sulfates, dimethylbenzylalkylammonium halides, dimethylbenzylalkylammonium sulfates, and derivatives thereof (herein, the alkyl group is one having 10 or more carbon atoms, such as lauryl or stearyl). The following formula

A quaternary ammonium salt of the formula: where R ₅ is an alkyl group having 8 to 24 carbon atoms. For example, alkylpyridinium such as dodecylpyridinium chloride.
Chloride. Primary, secondary and tertiary amines or acid addition salts thereof; pyridine, piperidine, morpholin,
piperazine, diethylaniline, laurylamine, stearylamine, triethanolamine,
Or these hydrochlorides. Amino acids or derivatives thereof; alkyldiethylenetriamineacetic acid, glutamic acid, aspartic acid, ω-aminolauric acid, ω-aminocapryic acid. Amides; stearylamide, oleylamide, stearyldiethanolamide, formamide, acetylamide. Ureas; urea, thiourea, tetramethylurea. hydrazines. Glianidins. Among these, quaternary ammonium salts are particularly desirable. In order to cause the organic cationic compound to react, the clay mineral is dispersed in an aqueous medium, and the above-mentioned compound is added thereto as an aqueous solution or a solution in a water-miscible organic solvent such as alcohol, and the reaction is caused to occur. The above-mentioned compounds are water-soluble themselves or are water-soluble in the form of acid addition salts, and are added to the reaction system in the form of an aqueous solution. Compounds with poor water solubility are added to the reaction system as a solution in a water-miscible organic solvent such as alcohol or ketone. The reaction conditions are not particularly limited, but generally the desired organic smectite viscosity is produced at a temperature of room temperature to 80° C. in 5 to 120 minutes. In order to effectively introduce organic compounds between layers, the pH of the reaction system should be between 3 and 3.
13, preferably maintained in the range of 4 to 12, and the amount of organic cationic compound added, depending on the required properties, is 50 to 200 millivalent, especially 70 to 130, per 100 g of raw clay mineral. The milliquivalent range is appropriate. The amount of alkali to be used is such that the crystal structure of _cristobalite can be virtually completely disappeared. Specifically, the amount of alkali (alkali Metal oxide standards) may be used. As the alkali, an alkali hydroxide such as sodium hydroxide or potassium hydroxide, an alkali carbonate salt such as sodium carbonate, or a mixture thereof is used. The alkaline treatment can be carried out wet or dry in the presence of water; in the former case, the alkaline solution and the clay mineral are brought into contact with each other under stirring. In the latter case, the alkali treatment is performed by adding an alkali or an alkaline solution to the clay mineral and kneading this composition by utilizing the water contained in the clay mineral. Although the treatment can proceed at room temperature, it is generally desirable to heat the treatment to a temperature of 80 to 160° C. in order to accelerate the reaction. An alkali silicate is produced by the reaction of cristobalite with an alkali, and this alkali silicate is separated from the purified smectite by filtration or extraction with an alkaline aqueous medium, and if necessary, washed with water. At this time, according to the present invention, it is also a feature of the present invention that the alkali silicate can be separated extremely easily and within a short time. In the above explanation, an organic cationic compound is made to act on the thermal mineral, and then an alkali is made to act on it, but there is selectivity in the reaction between smectite and the organic cationic compound, and in the reaction between critobalite and an alkali. Therefore, there is no restriction on the order of the reaction, and it is also possible to first act on the clay mineral with an alkali and then on the organic cationic compound, or to act on the clay mineral simultaneously with the organic cationic compound and the alkali. You can also do it. The invention is illustrated by the following example. Test method The test method for each item in this specification was as follows. 1 X-ray diffraction measurement conditions Equipment: X-ray diffraction device manufactured by Rigaku Denki Co., Ltd. (X-ray generator Cat. No., 4036Al. Goniometer Cat. No.
2125D1. Counting device Cat. No. 5071) Target Cu Filter Ni Detector SC Tube voltage 35KVP Tube current 15mA Full Scale 8000cps Time Constant 1sec Scanning Speed 2°/min Chat Speed 2cm/min Radiation angle 1/6° Slit width 0.3mm Viewing angle: 6° 2 Swelling degree measurement method: Add 2 g of organic smectite in 10 portions to a graduated cylinder with a stopper containing 100 ml of toluene. At this time, wait until the previous amount has settled before adding the next amount. After adding 2 g, leave it to stand, and after 24 hours, read the sedimentation volume and use it as the degree of swelling. 3 Apparent viscosity measurement method Place 500ml of toluene in the beaker from step 1 and add 20g of organic smectite. Using a homomixer (M type, Tokushu Kika Kogyo Co., Ltd.), the rotation speed
After high-speed stirring at 10,000 rpm for 1 minute,
Let stand for a while. Using a horizontal shaker, the amplitude is 40 mm.
Shake at a frequency of 150 times/min for 5 minutes, transfer to a measuring chamber,
Apparent viscosity was measured at 30 rpm using a B-type viscometer (No. 1 rotor). Example 1 Smectite viscosity produced from the Odo district of Niigata Prefecture was made into an aqueous slurry with a solid content of 10%. Impurities other than bentonite and cristobalite were removed by elutriation to obtain a slurry with a solid content of 3.5%. 27% of this solid content was cristobalite. 2 kg of this slurry was heated to a temperature in the range of 60°C to 65°C with stirring, and a solution of 28.7 g of distearyl dimethylene ammonium chloride and 50 ml of isopropyl alcohol heated to 60°C was added. After continued stirring for 30 minutes, the slurry was filtered and the resulting wet cake was dispersed in 700 ml of water. Heat this slurry to 90℃ while stirring and add 12g of sodium hydroxide.
was added and reacted for 2 hours, filtered and washed with water, and heated to 95℃.
After drying for 20 hours, the powder was crushed to obtain a highly pure organic smectite powder. Example 2 The same operation as in Example 1 was carried out except that the amount of distearyldimethylammonium chloride was changed to 21.4 g. Example 3 The same operation as in Example 1 was carried out except that the size of distearyldimethylammonium chloride was changed to 37.3 g. Example 4 Smectite viscosity produced from the Nakajo area of Niigata Prefecture was elutriated in the same manner as in Example 1 to obtain a slurry with a solid content of 4.3%. 18% of this solid content was lisktobalite. 1.6 kg of this slurry was heated to a temperature in the range of 60°C to 65°C with stirring, and a heated solution of 23.3 g of stearylbenzyldimethylammonium chloride and 100 ml of water was added. After stirring for 30 minutes, strain the slurry into the resulting cake.
Add 50g of 20% sodium hydroxide aqueous solution, mix well, autoclave the resulting paste at 130℃ for 1 hour, disperse in 500ml of water, filter and wash with water, dry at 105℃ for 18 hours, and then crush. As a result, high purity smectite powder was obtained. Example 5 The same operation as in Example 4 was carried out except that the amount of stearylbenzyldimethylammonium chloride was changed to 18.6 g. Example 6 The same operation as in Example 4 was carried out except that the amount of stearylbenzyldimethylammonium chloride was changed to 27.9 g. In Examples 7 to 12, the elutriated smectios slurry prepared in Example 1 was used. This slurry has a solids content of 3.5% and a solids content of 27%.
% was cristobalite. Example 7 Add sodium hydroxide to 2 kg of smectite slurry
After adding 12 g and heating to 90°C with stirring and reacting for 2 hours, the temperature was raised to 60-65°C, and a solution of 28.7 g of distearyldimethylammonium chloride and 50 ml of isopropyl alcohol heated to 60°C was added. After stirring for 30 minutes, filter the slurry and wash with water at 60℃.
The mixture was dried for 40 hours and ground to obtain a highly pure organic smectite powder. Example 8 Example 7 was repeated except that the amount of diestearyldimethylammonium chloride was changed to 21.4 g. Example 9 The same procedure as in Example 7 was carried out except that the amount of distearyldimethylammonium chloride was changed to 37.3 g. Example 10 2 kg of smectite slurry was heated to 90°C, and 28.7 kg of distearyldimethylammonium chloride was heated to 90°C.
A solution of 12 g of sodium hydroxide dissolved in 150 ml of isopropyl alcohol and 12 g of sodium hydroxide in 150 ml of water were simultaneously added (5 minutes) under stirring using a metering pump, and the reaction was carried out at 90°C for 2 hours. Summer. This was filtered and washed with water, dried at 60°C for 40 hours, and pulverized to obtain a powder of high purity organic smectite. Example 11 The experiment was carried out in Example 10 except that the amount of distearyldimethylammonium chloride was changed to 21.4 g. Example 12 The experiment was carried out in Example 10 except that the amount of distearyldimethylammonium chloride was changed to 37.3 g. Comparative Example 1 2 kg of the same elutriated smectite slurry used in Example 1 was heated to a temperature in the range of 60 to 65°C with stirring to form distearyldimethylammonium chloride.
28.7 g was added to 50 ml of isopropyl alcohol and the solution heated to ℃ was added. After continuing stirring for 30 minutes, the slurry was filtered and washed with water, dried at 95°C for 20 hours, and then ground to obtain organic simectite powder. Comparative Example 2 1.6 kg of the same elutriated smectite slurry used in Example 4 was heated to a temperature in the range of 60 to 65° C. with stirring, and a solution of 23.3 g of stearylbenzyldimethylammonium chloride dissolved in 100 ml of water was added. After stirring for 30 minutes, the slurry was filtered and washed with water, dried at 105℃ for 18 hours, and then ground.
Organic smectite powder was obtained. Examples 1 to 12
Table 1 shows the swelling degree and apparent viscosity measured using toluene as a solvent for the organic smemtite viscosities prepared in Comparative Examples 1 and 2.

【table】 [Brief explanation of the drawing]

FIG. 1 is a diagram showing X-ray diffraction images of the organic smectite viscosity of Example 1 and the organic smectite viscosity of Comparative Example 1.

Claims (1)

[Claims] 1 A step of reacting a clay mineral mainly composed of smectite and containing cristobalite with an organic cationic compound, and a step of reacting the clay mineral with an alkali under conditions in which the crystal structure of cristobalite substantially disappears. A method for producing high-purity organic smectite clay, which is characterized by separating the generated alkali silicate from the organic smectite clay in order, in the reverse order, or simultaneously.