JP2001002412A - Amorphous aluminosilicate and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an amorphous aluminosilicate having high oil absorbency. SOLUTION: In this amorphous aluminosilicate, the number average particle diameter of primary particles is <40 nm, and the standard deviation of the number distribution of primary particle diameters is <40%. The amorphous aluminosilicate is produced by mixing the aq. solution of alkali metal silicate with the aq. solution of alkali metal aluminate in the presence of seed particles in at least one of aq., solutions and reacting them with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an amorphous aluminosilicate and a method for producing the same.

[0002]

2. Description of the Related Art Since amorphous aluminosilicates have high oil-absorbing ability, they are widely used in builders for detergents, fillers for papermaking, and the like. I have. In order to exhibit high oil absorption, it is important to control the agglomeration structure of the amorphous aluminosilicate, that is, to control the primary particle diameter. For example, Japanese Patent Application Laid-Open No. 52-58099 discloses a reaction formed by mixing a dilute solution of an alkali metal aluminate with an aqueous solution of an alkali metal silicate while stirring and then stirring the mixture. System pH 1
It discloses that by keeping the ratio at 0.5 or more, the primary particle size of the aluminosilicate can be controlled to 40 to 50 nm, and an amorphous aluminosilicate having an oil absorption capacity of 75 mL / 100 g or more can be produced. However, this production method cannot produce amorphous aluminosilicates with primary particles having a number average particle size of less than 40 nm, and amorphous aluminosilicates with high oil absorption capacity of 150 mL / 100 g or more can be obtained. I can't.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an amorphous aluminosilicate having a high oil absorbing ability and a method for producing the same.

[0004]

The present invention relates to [1] an amorphous aluminosilicate having a number average particle diameter of primary particles of less than 40 nm and a standard deviation of the number distribution of the primary particle diameter of less than 40%. A salt of an aqueous solution of an alkali metal silicate and an aqueous solution of an alkali metal aluminate, wherein seed particles are present in at least one of the aqueous solutions, mixed, and reacted to form an amorphous aluminosilicate. It relates to a manufacturing method.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention has a correlation between the primary particle size of an amorphous aluminosilicate and the oil absorbing ability. The smaller the primary particle size of an amorphous aluminosilicate, the more the formation of aggregates is promoted. , And the primary particle size is uniform (the particle size distribution width is narrow)
This is based on the discovery of development that the more uniform aggregates are formed, the larger the pore volume is, and the higher the oil absorption capacity is.

That is, the number average particle size of the primary particles of the amorphous aluminosilicate of the present invention is 40 nm from the viewpoint of forming aggregates.
Less than 35 nm, preferably less than 35 nm. The number average particle size is
It can be measured based on the method described in Examples described later. The standard deviation of the number distribution of the primary particle diameter is less than 40%, preferably less than 30%, from the viewpoint of uniformity of the aggregate.

The oil-absorbing ability of the amorphous aluminosilicate of the present invention is preferably at least 150 mL / 100 g, more preferably
It is more than 160 mL / 100g. The oil absorption capacity can be measured based on the oil absorption measurement method of JIS K 6220.

The amorphous aluminosilicate has a halo peak at 2θ = 10 to 50 ° in X-ray diffraction,
The X-ray diffraction was performed using an X-ray diffractometer (Rigaku Denki, RAD-200), CuKα ray, 40 kV, 120 mA, slit system: divergence slit 1.00 °, scattering slit 1.00 °, light receiving slit
It is performed under the conditions of 0.30 mm and a scanning speed of 10 ° / min, and the one having a maximum intensity of the halo peak obtained at that time of 300 cps or more is particularly excellent. Further, peaks of other crystalline substances may be included.

The composition of the amorphous aluminosilicate is Si
O ₂ / Al ₂ O ₃ (molar _{ratio) = 0.5~6, M 2 O /} Al 2 O 3 ( molar ratio)
= 0.2 to 4 (where M represents an alkali metal), more preferably SiO ₂ / Al ₂ O ₃ = 1 to 3, and M ₂ O / Al ₂ O ₃ = 1 to 4; Elements contained in the seed particles may also be included. The alkali metal can be used alone or as a mixture of two or more kinds, and is not particularly limited, but sodium is preferable.

When an alkaline earth metal is contained in addition to the above composition, a composition excellent in alkali resistance and heat resistance can be synthesized. Here, the alkaline earth metal can be used alone or as a mixture of two or more kinds, and calcium or magnesium is advantageous among them.For example, calcium chloride, magnesium chloride and the like are used as raw materials when producing an amorphous aluminosilicate. It is preferably used. Although not particularly limited, the content of the alkaline earth metal is 0.001 to 0.1 as a molar ratio to Al ₂ O ₃ [MeO / Al ₂ O ₃ (where Me represents an alkaline earth metal)]. preferable.

The amorphous aluminosilicate having such a structure is prepared by mixing an aqueous solution of an alkali metal silicate and an aqueous solution of an alkali metal aluminate in at least one of the aqueous solutions with seed particles present therein, mixing, and reacting. It can be manufactured by doing. This involves mixing an aqueous solution of an alkali metal silicate and an aqueous solution of an alkali metal aluminate and reacting them to produce an amorphous aluminosilicate. The reaction field is based on the knowledge in the present invention that the primary particle diameter and oil absorption capacity of the final amorphous aluminosilicate are greatly affected. It is characterized in that the primary particle size of the aluminosilicate is controlled.

As the aqueous solution of the alkali metal silicate, commercially available water glass can be used, which may be appropriately diluted with water or an aqueous solution of an alkali metal hydroxide.

The aqueous solution of the alkali metal aluminate is
A commercially available product may be used, or a product obtained by heating and dissolving an aqueous solution containing aluminum hydroxide and an alkali metal hydroxide may be used.

The seed particles may be present in at least one aqueous solution when an aqueous solution of an alkali metal silicate and an aqueous solution of an alkali metal aluminate are mixed and reacted, and may be present in both aqueous solutions. May be. Here, the seed particles provide a heterogeneous reaction field at the solid-liquid interface.

The presence or absence of seed particles in the aqueous solution of the alkali metal silicate or the alkali metal aluminate salt can be determined by measuring the turbidity of each aqueous solution. In comparison, when the turbidity is large, it can be determined that the seed particles are present. For example, in the case of an aqueous solution of an alkali metal silicate, the turbidity of the aqueous solution is 5% or more, and in the case of an aqueous solution of an alkali metal aluminate, the turbidity of the aqueous solution is 15% or more. It can be determined that it exists.

The seed particles may be those obtained by dropping a seed particle-forming substance into each aqueous solution, and may be prepared by adding seed particles prepared beforehand to each aqueous solution. As a specific example of depositing seed particles, an alkaline earth metal salt such as calcium chloride or magnesium chloride as a seed particle forming substance is dropped into a water glass raw material and heated, whereby a white substance considered to be an alkaline earth metal silicate is treated with silicate. A method of precipitating in an aqueous solution of an alkali metal salt is exemplified. Further, there is a method in which water is added to sodium aluminate and heated to about 50 ° C. for a long time to precipitate a white substance considered to be aluminum hydroxide in an aqueous solution of an alkali metal aluminate salt.

When the seed particles are added from the outside, the seed particles may be in a dry state or a wet state regardless of an inorganic compound or an organic compound. When the seed particles are inorganic compounds, they may be crystalline compounds, amorphous compounds, or a mixture of both.

Examples of the inorganic compound include crystalline silica, amorphous silica, calcium silicate, diatomaceous earth, terra alba, zeolite, amorphous aluminosilicate, mullite, kaolin, talc, aluminum oxide, aluminum hydroxide, aluminum hydroxide, etc. Compounds, carbonates such as calcium carbonate, calcium sulfate, and calcium nitrate, sulfates, nitrates, and various metal oxides, and the like, and organic compounds include various ion-exchange resins, acrylic acid, and derivatives thereof and the like. However, the present invention is not limited to these.

Particularly, a silicon compound is used as seed particles to be present in an aqueous solution of an alkali metal silicate, and an aluminum compound is used as a seed particle to be present in an aqueous solution of an alkali metal aluminate. Is preferred in terms of purity and characteristics.

The mixing and the reaction of the aqueous solution of the alkali metal silicate and the aqueous solution of the alkali metal aluminate are performed by mixing the aqueous solution of the alkali metal silicate while stirring the aqueous solution of the alkali metal silicate. The reaction may be carried out while the aqueous solution of the alkali metal aluminate is stirred while the aqueous solution of the alkali metal silicate is mixed. And an aqueous solution of an alkali metal silicate and an aqueous solution of an alkali metal aluminate may be simultaneously mixed and reacted.

The concentration of the alkali metal silicate in the aqueous solution of the alkali metal silicate is preferably from 1 to 80% by weight,
~ 60% by weight is more preferred. The concentration of the alkali metal aluminate in the aqueous solution of the alkali metal aluminate is preferably from 10 to 90% by weight, and more preferably from 20 to 70% by weight.
Is more preferred.

The mixing ratio (weight ratio, a: b) of the aqueous solution of the alkali metal silicate (a) and the aqueous solution of the alkali metal aluminate (b) is preferably 0.1: 1 to 10: 1. , 0.5: 1 to 8: 1. Further, the pH of the mixture is preferably from 12 to 14.

The reaction temperature is usually 10 to 100 ° C., preferably 20 to 100 ° C.
~ 100 ° C. The reaction time varies depending on the reaction temperature, but is usually 0 to 120 minutes, preferably 1 to 60 minutes. After the completion of the reaction, the product can be obtained by a conventional treatment. For example, heat aging is usually performed at a temperature of 30 to 100 ° C. for 1 to 300 minutes to obtain an aqueous solution of an amorphous aluminosilicate. An acid agent such as carbonic acid or sulfuric acid may be further added to the obtained aqueous solution to adjust the pH of the aqueous solution to 8 to 12 to reduce the amount of free alkali ions before use.

The solid concentration in the obtained aqueous solution is 10 m
It is preferably at least ass%, more preferably at least 15 mass%. Solids concentration can be measured based on ignition loss.

An amorphous aluminosilicate powder can be obtained by separating the precipitate of the amorphous aluminosilicate by filtration or centrifugation of the aqueous solution, washing and drying, and then pulverizing. Incidentally, if the drying is insufficient and the water content is too high, the high oil absorption capacity is not exhibited, so the water content is 30 mas.
It is preferably at most s%, more preferably at most 15 mass%. The aqueous solution and powder of the amorphous aluminosilicate thus obtained can be used by being contained in a detergent composition.

[0026]

EXAMPLES Physical properties in Examples 1 to 6 and Comparative Example 1 were as follows.
It was measured by the following method. (1) Oil absorption ability The dried sample is crushed with a cooking cutter and JIS K 62
Measured by 20 oil absorption measurements.

(2) Turbidity The turbidity of an aqueous solution of an alkali metal silicate and an aqueous solution of an alkali metal aluminate immediately before mixing and reaction was measured using a turbidimeter (Murakami Color Materials Laboratory, “Reflection transmission meter HR- 100 ").

(3) Moisture content The sample is placed in a magnetic crucible reaching a constant weight in a desiccator in advance by baking in an electric furnace at 600 ° C. for 1 hour and precisely weighed.
Then, the mixture was ignited in an electric furnace at 600 ° C. for 1 hour, and the weight which reached a constant weight was precisely weighed in a desiccator to determine the water content.

(4) Primary Particle Size SEM photograph (magnification 100,000 times) photographed with a field emission type high-resolution scanning electron microscope (FE-SEM, "S-4000" manufactured by Hitachi, Ltd.) (magnification 100,000) The primary particle diameter (100 or more particles) was measured using a digitizer (manufactured by Graphtec, "Digitizer KW3300"), and the number average value and standard deviation value were obtained.

(5) Powder X-ray Diffraction Powder X-ray diffractometer (“RAD-C” manufactured by Rigaku Denki, light source CuK)
α, tube voltage 40 kV, tube current 120 mA) and 2θ = 5
The 70 ° range was measured at a scan rate of 10 ° / min.

Example 1 No. 3 water glass (Na ₂ O; 9.82) placed in a ₂ L stainless steel container
823 g of CaCl ₂ aqueous solution (3.92 g of CaCl ₂ ) was slowly added to 354 g of 354 g of mass%, SiO ₂ ; 29.87 mass%) with stirring with a Teflon stirring blade (length 11 cm) (300 rpm) over about 10 minutes. . This was heated to 50 ° C. with a mantle heater to make it turbid, and the NaAlO ₂ aqueous solution (Na ₂ O; 21.24
mass%, Al ₂ O _3; with stirring at 28.12 mass%) 320 Teflon stirring blade (length 11cm in g) (300 rpm), was added dropwise over 20 minutes using a roller pump. After dropping, add 10 more
After stirring for 300 minutes (300 rpm), the temperature was raised to 80 ° C. over about 20 minutes, and then ripening was performed for another 10 minutes. The obtained aqueous solution of amorphous aluminosilicate (solid content: 20 mass%) was filtered, washed with water (until the filtrate pH <12), dried at 100 ° C for 13 hours, and cooked for 1 minute with a cooking cutter. The pulverized material was used for physical property evaluation. The powder X-ray diffraction measurement confirmed that the obtained sample was an amorphous aluminosilicate.

[0032] except that the CaCl ₂ amount added in Example 2 was 0.98g to synthesize amorphous aluminosilicates as in Example 1. The powder X-ray diffraction measurement confirmed that the obtained sample was an amorphous aluminosilicate.

Example 3 No. 3 water glass (Na ₂ O; 9.82) placed in a 2 L stainless steel container
mass%, SiO ₂ ; 29.87 mass%) While stirring (354 rpm) with 354 g of a Teflon stirring blade (length 11 cm), a CaCl ₂ aqueous solution (C
aCl ₂ 0.98 g) 83 g was slowly added. An aqueous solution obtained by mixing 320 g of an aqueous solution of NaAlO ₂ (Na ₂ O; 21.24 mass%, Al ₂ O ₃ ; 28.12 mass%) and 740 g of water at 50 ° C. with a mantle heater.
The solution was made cloudy by heating for 1 hour with stirring at 300 rpm while stirring with a Teflon stirring blade (length 11 cm).
The aqueous solution of CaCl ₂ -containing water glass heated to ° C. was dropped over 20 minutes using a roller pump. Thereafter, the same operation as in Example 1 was performed to obtain an amorphous aluminosilicate powder. According to powder X-ray diffraction measurement, the obtained sample was a mixture of amorphous aluminosilicate and aluminum hydroxide.

Example 4 An amorphous aluminosilicate was synthesized in the same manner as in Example 3 except that CaCl ₂ was not added. According to powder X-ray diffraction measurement, the obtained sample was a mixture of amorphous aluminosilicate and aluminum hydroxide.

Example 5 No. 3 water glass (Na) placed in a 2 L stainless steel container_TwoO; 9.82
 mass%, SiO_Two ; 29.87mass%) Teflon stirring blade in 354g
CaCl with stirring at the root (length 11cm) (300rpm) _TwoAqueous solution
(CaCl_Two0.98 g) Add 823 g slowly over about 10 minutes
Thereafter, the mixture was heated to 50 ° C. with a mantle heater to make it cloudy. this
While stirring the solution with a Teflon stirring blade (length 11 cm)
(300 rpm), NaAlO heated to 50 ° C_TwoAqueous solution (Na_TwoO; 21.24
mass%, Al_TwoO_Three ; 28.12 mass%) 320 g roller pump
Was added dropwise over 20 minutes. Hereinafter, the same as in Example 1
The operation was performed to obtain an amorphous aluminosilicate powder. Powder
According to the X-ray diffraction measurement, the obtained sample was amorphous aluminosilicate
It was confirmed to be salt.

Example 6 No. 3 water glass (Na ₂ O; 9.82) placed in a ₂ L stainless steel container
mass%, SiO ₂ ; 29.87mass%), add 40g of CaCl ₂ aqueous solution (CaCl ₂ 0.98g) to 354g while stirring with Teflon stirring blade (length 11cm) (300rpm), then use mantle heater
The mixture was heated to 50 ° C. and turned cloudy. Ion exchange water heated to 50 ° C
A 2L stainless steel container containing 783 g was stirred (300 rpm) with a Teflon stirring blade (length 11 cm) while heating to 50 ° C. with an aqueous solution of NaAlO ₂ (Na ₂ O; 21.24 mass%, Al ₂ O ₃ ; 2).
320 g of each (8.12 mass%) and each solution of the above Ca-containing aqueous solution of water glass were simultaneously dropped over 20 minutes using a roller pump.
Thereafter, the same operation as in Example 1 was performed to obtain an amorphous aluminosilicate powder. From the powder X-ray diffraction measurement, it was confirmed that the obtained sample was an amorphous aluminosilicate.

Comparative Example 1 An amorphous aluminosilicate was synthesized in the same manner as in Example 1 except that CaCl ₂ was not added. The powder X-ray diffraction measurement confirmed that the obtained sample was an amorphous aluminosilicate.

Table 1 shows the composition, physical properties, and the like of the amorphous aluminosilicate obtained in Examples 1 to 6 and Comparative Example 1.

[0039]

[Table 1]

From the results shown in Table 1, the amorphous aluminosilicates obtained in Examples 1 to 6 all have a number average particle diameter of primary particles of less than 40 nm and a standard deviation of the number distribution of the primary particles.
It is less than 40%, indicating that the oil absorbing ability is higher than that of Comparative Example 1.

[0041]

According to the production method of the present invention, amorphous aluminosilicate having a number average particle diameter of primary particles of less than 40 nm, a standard deviation of the primary particle diameter of less than 40%, and an oil absorption capacity of 150 mL / 100 g or more Salt can be produced.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mikio Sakaguchi 1334 Minato, Wakayama-shi Kao Research Laboratory F-term (reference) 4G066 AA13A AA20A AA30A AA30B AA36D BA09 BA20 BA31 BA36 BA38 CA05 FA05 FA37 4G073 BA57 BA63 BD03 CM29 FB19 FB25 FC12 GA01 GA11 UA07 UA08 UB21

Claims (6)

[Claims] An amorphous aluminosilicate having a number average particle diameter of primary particles of less than 40 nm and a standard deviation of a number distribution of the primary particle diameter of less than 40%. 2. The amorphous aluminosilicate according to claim 1, which has an oil absorption capacity of 150 mL / 100 g or more. 3. Production of an amorphous aluminosilicate in which an aqueous solution of an alkali metal silicate and an aqueous solution of an alkali metal aluminate are mixed and reacted with at least one aqueous solution containing seed particles. Method. 4. The method according to claim 3, wherein the seed particles are a silicon compound and are present in an aqueous solution of an alkali metal silicate. 5. The seed particle is an aluminum compound,
The method according to claim 3 or 4, wherein the aqueous solution of the alkali metal aluminate is present. 6. The solid solution according to claim 3, wherein the aqueous solution of the alkali metal silicate and the aqueous solution of the alkali metal aluminate are mixed and reacted to have a solid content concentration of 10 mass% or more. Production method.