TW201305054A - Boehmite and method for preparation thereof - Google Patents

Abstract

The subject of this invention is to provide a boehmite having a higher aspect ratio, a boehmite having excellent filling property to the object to be filled and substantially inhibiting the anisotropy of the object to be filled, or a boehmite having higher specific area. In addition, the subject of this invention is to provide a method of preparing a boehmite with higher yield and higher efficiency. This invention relates to a needle-like boehmite, characterized by being obtained from hydrothermal synthesis of aluminum hydroxide with acetate, formate, propionate, sulfate or nitrate of magnesium, nickel, manganese or cobalt in the presence of water under pressurization at a temperature of 180-250 DEG C. The boehmite is needle-like in shape and has an average particle length of 1-10 micrometer and an aspect ratio greater than 30 and less than 90.

Description

Soft alumina and its manufacturing method

The present invention relates to a boehmite having various forms such as a plate shape, a cubic shape, and a needle shape, and a method for producing the same.

The soft boehmite is represented by the chemical composition of AlO(OH) or Al ₂ O ₃ ‧H ₂ O, and is generally a chemically stable alumina produced by heat-treating or hydrothermally treating alumina trihydrate in air. Monohydrate. The boehmite has a reinforcing material, a flame retardant, a glittering material, a refractory material, a tackifier, a lubricating material, a coating inner filler, an ink receiving material, a heat conduction, a brake material, and a wire as a filler to be filled. Uses for expansion control, various fillers for gas barriers, etc. Further, the boehmite has a catalyst carrier, an electrically conductive filler base material, a refractory material, a heat resistant material, a high purity alumina, an easily fired alumina, a ceramic, a humidity sensor, a separation membrane, and a filtration. A variety of raw materials, oil-absorbing materials, water absorbing materials, fingerprint collection powders, color-developing reinforcing materials, and various forms of alumina precursors (raw materials) having a plate shape, a cubic shape, and a needle shape for use in devices, electronic components, and fluorescent materials. And other uses.

It is currently known that boehmite having such various uses has various forms. For example, a boehmite having a plate-like (flaky shape) and a needle-like (fibrillar) form (see Patent Document 1) and a hexagonal plate shape extending in a specific crystal axis (a-axis) direction are known. A boehmite (see Patent Document 2), a boehmite having a polygonal plate shape represented by a square plate shape (see Patent Document 3), a spindle shape, a needle shape, a scaly shape, a hexagonal plate shape, and a square angle (square) ) A boehmite in a plate form (see Patent Document 4).

Patent Document 1: Japanese Laid-Open Patent Publication No. 55-116622

Patent Document 2: Japanese Laid-Open Patent Publication No. 60-46923

Patent Document 3: Japanese Laid-Open Patent Publication No. Hei 5-279019

Patent Document 4: Japanese Patent Publication No. 4-50105

However, when the conventionally known boehmite is used for the above-mentioned use, there is a problem that the filling property to the filler is low, the anisotropy of the filler is not sufficiently suppressed, or the specific surface area is small. Moreover, the conventional method for producing boehmite also has problems such as low yield and long manufacturing time.

In view of the above, it is an object of the present invention to provide a boehmite having a relatively high aspect ratio and a high degree of filling property, which is excellent in the filling property of a filler and capable of sufficiently suppressing the anisotropy of the filler, or a high specific surface area. Soft boehmite. Further, an object of the present invention is to provide a method for producing a soft boehmite with good yield and high efficiency.

In order to solve the above problems, the gist of the present invention is an acicular boehmite characterized by comprising an acetate, a formate, a propionate of magnesium hydroxide, magnesium, manganese or cobalt in the presence of water. The sulfate or the nitrate is in a pressurized state, and is obtained by hydrothermal synthesis at a temperature of 180 to 250 ° C, and has a needle shape, an average particle length of 1 to 10 μm, and an aspect ratio of more than 30 and 90 or less.

The gist of the present invention is a plate-like boehmite characterized by having an aspect ratio of 10 to 35 and a specific surface area of 10 to 30 m ² /g.

The gist of the present invention is a method for producing a slab-like boehmite: in the presence of water, a compound selected from at least one alkaline earth metal selected from the group consisting of calcium, strontium, and barium is pressurized with aluminum hydroxide at 150 to 300 The temperature of ° C is allowed to react, and the reaction product is subjected to acid treatment, washed with water and the residual alkaline earth metal compound is removed.

The gist of the present invention is a hexagonal plate-like boehmite characterized by having a substantially hexagonal plate shape, a ratio of a long diameter to a short diameter of 1 to 1.3, and an aspect ratio of 40 to 100.

The gist of the present invention is a method for producing hexagonal plate-shaped boehmite, characterized in that sodium, potassium, barium, calcium and barium are added to a sodium salt, a calcium salt or an ammonium salt of aluminum hydroxide and boric acid or boric acid. The hydroxide or aluminate of at least one of them is used as a pH adjuster to adjust the pH to 8 or more, and in this state, hydrothermal treatment is carried out at a temperature of 130 to 250 °C.

The gist of the present invention is a method for producing boehmite, which comprises dry curing of aluminum hydroxide powder while heating in a water vapor atmosphere using a pressure vessel.

The gist of the present invention is a cubic-shaped soft boehmite characterized by having a long diameter of 1.3 to 3.5 μm, a length to thickness ratio (long diameter/thickness) of 2.00 to 3.50, and a ratio of a long diameter to a short diameter (long diameter/short length) The diameter is 1.68 to 1.37, and the ratio of the short diameter to the thickness (short diameter/thickness) is 1.42 to 2.55.

The gist of the present invention is a method for producing acicular boehmite by subjecting a magnesium compound and aluminum hydroxide to a pressurized state in the presence of water, and reacting at a temperature of 190 to 250 °C.

The gist of the present invention is a whisker-like metal compound which is produced by using a formate, acetate, propionate or hydroxide of magnesium, manganese, nickel or zinc with aluminum hydroxide and iron hydroxide. At least one of them is mixed and hydrothermally treated.

The gist of the present invention is a method for producing a whisker-like metal compound, characterized in that a formate, acetate, propionate or hydroxide of magnesium, manganese, nickel or zinc is combined with aluminum hydroxide and iron hydroxide. At least one of them is mixed and hydrothermally treated.

The gist of the present invention is a plate-shaped boehmite characterized by having an outer diameter of 2.5 to 15 μm and an aspect ratio of 100 to 350.

The present invention is directed to a method for producing a slab-like boehmite, characterized in that at least one selected from the group consisting of sodium, potassium, barium, calcium, and strontium is added to a polymer of aluminum hydroxide and a (meth) acrylate-based polymer. The hydroxide or aluminate is used as a pH adjuster to adjust the pH to 8 or more, and in this state, hydrothermal treatment is carried out at a temperature of 130 to 250 °C.

The gist of the present invention is a disc-shaped boehmite characterized by having an outer diameter of 0.5 to 15 μm and an aspect ratio of 10 to 100, and containing at least one element selected from the group consisting of calcium, strontium, barium and strontium.

The gist of the present invention is a method for producing a disc-shaped boehmite characterized by comprising an organic acid salt, a nitrate or a sulfate (A) selected from calcium, barium, strontium or barium, and a hydroxide of an alkali metal. At least two of (B) and the alkaline earth metal hydroxide (C) are hydrothermally treated with aluminum hydroxide at a temperature of 130 to 300 °C.

The gist of the present invention is a flat-shaped boehmite in which an organic substance is inserted, and the organic substance is inserted into a diol having at least one C ₃ or more of a hydroxyl group, a condensed ethylene glycol, or an amino alcohol. Any one of them.

The invention will be specifically described below by way of examples.

[Examples 1 to 3]

In Examples 1 to 3, the following compounds were mixed in a specific ratio, and filled in an autoclave with water to carry out hydrothermal synthesis. The hydrothermal synthesis was carried out by "heating to 205 ° C at a temperature elevation rate of 80 ° C / hour after standing, maintaining the temperature and pressure for 10 hours". After completion of the reaction, the reaction solution was naturally cooled, and the reaction product was collected by filtration. The reaction product was washed with water and dried at a temperature of 105 ° C to obtain acicular boehmite having the properties contained in Items 1 and 2 of the patent application, respectively.

Example 1: magnesium sulfate 23 mol%, aluminum hydroxide 100 mol%

Example 2: Nickel acetate 58 mol%, aluminum hydroxide 100 mol%

Example 3: zinc acetate 58 mol%, aluminum hydroxide 100 mol%

[Examples 4 to 8]

In the fourth to eighth embodiments, the following compounds were mixed in a specific ratio, and filled in an autoclave together with 5000 g of water, and the inside of the autoclave was pressurized and the mixture was allowed to stand, and heated at a heating rate of 200 ° C / hour. Up to 200 ° C. This temperature was maintained for 12 hours to cause the mixture in the autoclave to react. Next, the mixed liquid after the reaction was cooled by natural cooling, and the mixed liquid was filtered to obtain a reaction product. The reaction product was subjected to an acid treatment, washed with water, and the aqueous reaction product was dried at 105 ° C to obtain a plate-like boehmite having the characteristics contained in the third item of the patent application.

Except for Example 4, the heating temperature was set to 170 °C.

Example 4: 337 g of barium hydroxide octahydrate, 1000 g of aluminum hydroxide

Example 5: 337 g of barium hydroxide octahydrate, 1000 g of aluminum hydroxide, and 30 g of sodium hydroxide

Example 6: 79 g of calcium hydroxide and 1000 g of aluminum hydroxide

Example 7: 55 g of calcium hydroxide, 44 g of calcium sulfate, and 1000 g of aluminum hydroxide

Example 8: 283 g of barium hydroxide octahydrate, 1000 g of aluminum hydroxide

[Examples 9 to 10 and Comparative Example 1]

Examples 9, 10 and Comparative Example 1 were obtained by mixing the following compounds in a specific ratio, filling them into an autoclave together with 39.0 kg of water and setting the temperature in the autoclave to 170 °C. The temperature was maintained for 10 hours, and the mixture was allowed to stand under a naturally occurring pressure to react the reaction raw material in the autoclave, and the product after the reaction was washed with water, filtered, and dried to obtain a hexagon having the characteristics recited in claim 6 Plate-like bauxite (except Comparative Example 1). Comparative Example 1 is a hexagonal plate-like boehmite having an aspect ratio of 30.

Example 9: 2.5 mol of boric acid, sodium hydroxide (pH adjuster) 25 mol, aluminum hydroxide (average particle diameter 0.5 μm) 100 m

Example 10: 2.0 mol of boric acid, sodium aluminate (NaAlO ₂ , pH adjuster) 25 mol, aluminum hydroxide (average particle diameter 2.5 μm) 100 m

Comparative Example 1: Sodium hydroxide (pH adjuster) 25 mol, aluminum hydroxide (average particle diameter 0.5 μm) 100 m

[Examples 11 to 13]

In Examples 11 to 13, 1 kg of aluminum hydroxide powder having the following particle diameters was filled in a container, and the mixture was heated to a temperature of 1 to 10 hours in a saturated water vapor atmosphere using an autoclave while performing dry curing. After the curing, the cooled autoclave was naturally placed, dried at 130 ° C, and the slab-like boehmite was obtained by the method described in the claims 9 to 11. The manufacturing time of soft boehmite by dry curing is shorter than that of soft boehmite produced by wet curing.

In addition, dry curing means that no water is added to the aluminum hydroxide of the starting material, but the powder is maintained for curing. In addition, wet curing is an antonym of dry curing, and it is said that it adds a water to aluminum hydroxide, and it is paste-form (liquid-form), and it is carrying out maintenance.

Example 11: Aluminum hydroxide having an average particle diameter of 0.8 μm, 170 ° C

Example 12: Aluminum hydroxide having an average particle diameter of 2 μm, 170 ° C

Example 13: Aluminum hydroxide having an average particle diameter of 0.8 μm, 150 ° C

[Embodiment 14]

In Example 14, 100 g of aluminum hydroxide and 300 g of water (water ratio of 3) were thoroughly mixed, placed in an autoclave, and subjected to hydrothermal treatment at 180 ° C for 12 hours under a naturally occurring pressure (about 900 kPa). The resultant is subjected to dehydration and drying to obtain a cube-shaped boehmite having the characteristics as set forth in claim 12 of the patent application.

[Examples 15 to 17]

In Examples 15 to 17, the following compounds were mixed with water in a specific ratio and placed in an autoclave. While the mixture was stirred at a number of revolutions of 150 rpm, the mixture was heated to 205 ° C at a temperature elevation rate of 80 ° C / hour, and the mixture was maintained at this temperature and pressure for 5 hours to cause a reaction mixture in the autoclave. The stirring was stopped, and the reaction liquid was naturally cooled, and the reaction product was collected by filtration. The reaction product was washed with water, and dried at a temperature of 105 ° C to obtain white acicular boehmite by the method described in Patent Nos. 14 and 15. According to this production method, acicular boehmite can be produced with high productivity and high efficiency.

Further, in Example 16, the mixture was allowed to stand without stirring, and heated to 215 ° C for 10 hours. Further, in Example 17, it was heated to 190 °C.

Example 15: 0.92 kg of magnesium acetate tetrahydrate, 2.0 kg of aluminum hydroxide, and 4.0 kg of water

Example 16: 0.69 kg of magnesium acetate tetrahydrate, 0.37 kg of calcium acetate, 2.0 kg of aluminum hydroxide, and 5.0 kg of water

Example 17: 0.92 kg of magnesium acetate tetrahydrate, 2.0 kg of aluminum hydroxide (average particle diameter: 10 μm), and 4.0 kg of water

[Examples 18 to 22]

In Examples 18 to 22, the following compounds were mixed in a specific ratio and hydrothermally treated at a temperature of 200 ° C for 48 hours to obtain whisker-like bauxite (whisker-like metal compound) of claim 16 of the patent application. . Further, the boehmite was fired at a temperature of 1000 ° C for 1 hour to obtain a mixture of MgAl ₂ O ₃ (whisker-like metal composite oxide) and alumina contained in claim 18 of the patent application.

In addition, the whisker-like metal compound is a reaction product formed by mixing at least one of aluminum hydroxide and iron hydroxide with an organic acid metal compound and performing hydrothermal treatment, and is called AlOOH having a whisker-like morphology. (soft boehmite) or FeOOH.

Example 18: Magnesium acetate 23.1 mol, aluminum hydroxide (particle size 1 μm) 100 m

Example 19: Magnesium formate 57.8 mol, aluminum hydroxide (particle size 1 μm) 100 m

Example 20: Manganese acetate 23.1 mol, aluminum hydroxide (particle size 1 μm) 100 m

Example 21: Nickel propionate 57.8 mol, aluminum hydroxide (particle size 1 μm) 100 m

Example 22: Zinc acetate 23.1 mol, aluminum hydroxide (particle size 1 μm) 100 m

[Example 23, Comparative Example 2]

In Example 23 and Comparative Example 2, the following compounds were filled into an autoclave in a specific ratio together with 39.0 kg of water and the temperature in the autoclave was set to 170 °C. While maintaining this temperature for 10 hours, it was allowed to stand under a naturally occurring pressure, and the reaction raw material in the autoclave was reacted, washed, filtered, and the product after the reaction was dried to obtain a plate having the characteristics as set forth in claim 20 of the patent application. Boehmite (except Comparative Example 2). Comparative Example 2 is a plate-like boehmite having an aspect ratio of 50.

Example 23: Aluminum hydroxide (average particle diameter: 0.5 μm)) 100 mol, acrylate copolymer (manufactured by Showa Polymer; AE-710W) 50% by weight, sodium hydroxide (pH adjuster) 25 mol

Comparative Example 2: aluminum hydroxide (average particle diameter 0.5 μm) 100 mol, ammonium phosphate 0.5 wt%, aluminum hydroxide (pH adjuster) 25 mol

[Examples 24 to 29]

In Examples 24 to 29, the following compounds were placed in an autoclave in a specific ratio together with 39.0 kg of water, and the temperature in the autoclave was set to 170 °C. While maintaining this temperature for 10 hours, it was allowed to stand under a naturally occurring pressure, and the reaction raw material in the autoclave was reacted, washed, filtered, and the product after the reaction was dried to obtain a disk having the characteristics recited in claim 22 Soft boehmite.

Example 24: Calcium acetate 8.3 mol, aluminum hydroxide (average particle diameter 3 μm) 100 mol, sodium hydroxide 4.2 mol

Example 25: Calcium acetate 11.1 mol, aluminum hydroxide (average particle diameter 3 μm) 100 mol, calcium hydroxide 7.8 mol

Example 26: 5.6 mol of sodium hydroxide, aluminum hydroxide (average particle diameter 3 μm) 100 mol, calcium hydroxide 11.1 mol

Example 27: Barium acetate 11.1 mole, aluminum hydroxide (average particle diameter 3 μm) 100 mol, barium hydroxide 3.3 m

Example 28: Calcium nitrate 11.1 mol, aluminum hydroxide (average particle diameter 3 μm) 100 mol, sodium hydroxide 11.1 mol, calcium hydroxide 1.6 mol

Example 29: Calcium formate 11.1 mol, aluminum hydroxide (average particle diameter 3 μm) 100 mol, potassium hydroxide 5.6 m

[Example 30]

In Example 30, 64 mmol of aluminum hydroxide and 98.6 mmol of 1,2-propanediol were heat-treated at 200 ° C for 20 hours in the presence of 167 mmol of carbamide using an autoclave. Thereafter, the obtained sample was washed successively with distilled water and ethanol, and dried in an air bath at 120 ° C for 2 hours, whereby a flat-formed boehmite having the properties contained in claim 24 of the organic matter inserted therein was obtained.

Claims (25)

An acicular boehmite in which the aluminum hydroxide and the magnesium, nickel, manganese or cobalt acetate, formate, propionate, sulfate or nitrate are pressurized in the presence of water, to 180~ It is obtained by hydrothermal synthesis at a temperature of 250 ° C. The soft boehmite has a needle shape, an average particle length of 1 to 10 μm, and an aspect ratio of more than 30 and 90 or less. The acicular boehmite according to claim 1, wherein the magnesium, nickel, manganese or cobalt acetate, formate, propionate, sulfate or nitrate is hydrogen and molar ratio. The mixing ratio of alumina is set to 1:0.5 to 1:40 to carry out hydrothermal synthesis. A plate-like boehmite having an aspect ratio of 10 to 35 and a specific surface area of 10 to 30 m ² /g. A method for producing a slab-like boehmite according to item 3 of the patent application, wherein a compound selected from at least one alkaline earth metal selected from the group consisting of calcium, strontium and barium is pressurized with aluminum hydroxide in the presence of water. The reaction is carried out at a temperature of 150 to 300 ° C, and the reaction product is subjected to an acid treatment, washed with water and the residual alkaline earth metal compound is removed. The method for producing a slab-like boehmite according to the fourth aspect of the invention, wherein the alkaline earth metal compound is at least one compound selected from the group consisting of hydroxides, oxides, chlorides, sulfates, and organic acid salts. A hexagonal plate-like boehmite having a substantially hexagonal plate shape, a ratio of a long diameter to a short diameter of 1 to 1.3, and an aspect ratio of 40 to 100. A method for producing a hexagonal plate-shaped boehmite according to item 6 of the patent application scope, which is a sodium salt, a calcium salt or an ammonium salt of aluminum hydroxide and boric acid or boric acid, which is selected from the group consisting of sodium, potassium, barium, calcium and The hydroxide or aluminate of at least one of the crucibles is adjusted to have a pH of 8 or more as a pH adjuster, and is hydrothermally treated at a temperature of 130 to 250 ° C in this state. A method for producing a hexagonal plate-shaped boehmite according to item 6 of the patent application, which is a method for treating aluminum hydroxide with nitric acid, acetic acid, formic acid, propionic acid, sulfuric acid, acrylic acid, methacrylic acid, polyacrylic acid or sodium of such acids a salt, a calcium salt, or an ammonium salt, wherein a hydroxide or an aluminate selected from at least one of sodium, potassium, rubidium, calcium, and barium is added as a pH adjuster, and the pH is adjusted to 8 or more, and in this state, The hydrothermal treatment is carried out at a temperature of 130 to 250 °C. A method for producing boehmite is a dry curing of aluminum hydroxide powder while heating in a water vapor atmosphere using a pressure vessel. The method for producing a softed boehmite according to claim 9, wherein the manufactured boehmite is in the form of a plate. A method for producing boehmite according to claim 9 or 10, wherein the heating temperature is 140 to 300 °C. A cube-shaped boehmite having a long diameter of 1.3 to 3.5 μm, a length to thickness ratio (long diameter/thickness) of 2.00 to 3.50, and a ratio of a long diameter to a short diameter (long diameter/short diameter) of 1.68 to 1.37, which is short. The ratio of the diameter to the thickness (short diameter/thickness) is from 1.42 to 2.55. A method for producing a cube-shaped boehmite according to item 12 of the patent application, wherein the water ratio is set so that the concentration of sodium ions contained in the reaction filtrate after the formation of the soft boehmite is 0.001 to 0.100% by mass, and hydrogen is added. Alumina is used as a raw material for hydrothermal synthesis. A method for producing acicular boehmite is a method in which a magnesium compound and aluminum hydroxide are pressurized in the presence of water, and are reacted at a temperature of 190 to 250 °C. The method for producing acicular boehmite according to claim 14, wherein the magnesium compound is at least one compound selected from the group consisting of magnesium acetate, magnesium hydroxide and magnesium borate. a whisker-like metal compound by mixing at least one of magnesium, manganese, nickel or zinc formate, acetate, propionate or hydroxide with aluminum hydroxide and iron hydroxide Manufactured by heat treatment. A method for producing a whisker-like metal compound of claim 16 which is a method for preparing a formate, acetate, propionate or hydroxide of magnesium, manganese, nickel or zinc with aluminum hydroxide and iron hydroxide At least one of them is mixed and hydrothermally treated. A whisker-like metal composite oxide represented by the following formula (1) and having a spinel structure, AB _2-X C _X O ₄ (1) (wherein A represents magnesium, manganese, nickel or zinc An atom, B represents an iron atom, C represents an aluminum atom, and x has a range of 0 < x ≦ 2). A method for producing a whisker-like metal composite oxide, which is obtained by firing a whisker-like metal compound of claim 16 at a temperature of 500 to 1600 °C. A plate-like boehmite having an outer diameter of 2.5 to 15 μm and an aspect ratio of 100 to 350. A method for producing a slab-like boehmite according to claim 20, which is a method for adding at least one selected from the group consisting of sodium, potassium, barium, calcium and strontium to a polymer of aluminum hydroxide and (meth) acrylate. A hydroxide or aluminate is used as a pH adjuster to adjust the pH to 8 or more, and in this state, hydrothermal treatment is carried out at a temperature of 130 to 250 °C. A disc-shaped boehmite having an outer diameter of 0.5 to 15 μm and an aspect ratio of 10 to 100, and containing at least one element selected from the group consisting of calcium, strontium, barium and strontium. A method for producing a disc-shaped boehmite according to Item 22 of the patent application, which is an organic acid salt, a nitrate or a sulfate selected from calcium, barium, strontium or barium at a temperature of 130 to 300 ° C (A) At least two of the alkali metal hydroxide (B) and the alkaline earth metal hydroxide (C) are hydrothermally treated with aluminum hydroxide. A flat-shaped boehmite in which an organic substance is inserted, and the organic substance is inserted into any one of a diol having a C ₃ or more of a hydroxyl group, a condensed ethylene glycol, or an amino alcohol. . A method for producing a flat-shaped boehmite according to item 24 of the patent application, which is an organic substance which is in a solvent having a high dielectric constant and has C for at least one of each of the ends An organic substance which is heat-treated by any one of _three or more hydroxyl group-containing glycols, condensed ethylene glycols, and amino alcohols.