JPS62132724A - Production of amorphous aluminosilicate - Google Patents

Abstract

PURPOSE:To obtain the titled inexpensive compound having improved oil absorbing ability and ion exchange ability in high yield, by adding an aqueous solution of an alkali metallic salt of silicic acid to an aqueous solution of an alkali metallic salt of aluminic acid at a specific temperature while stirring vigorously. CONSTITUTION:(B) An aqueous solution of an alkali metallic salt of silicic acid having a molar ratio of SiO2/Na2O of 1.0-4.0 and H2O/Na2O of 12-200 is added to (A) an aqueous solution of an alkali metallic salt of aluminic acid such as an aqueous solution of low alkali sodium aluminate, etc., having a molar ratio of Na2O/Al2O3 of 1.1-1.7 and H2O/Na2O of 6.5-500 at 15-60 deg.C while stirring vigorously. Then the prepared white precipitate slurry is heat- treated at 70-100 deg.C and kept for >=10min to give amorphous aluminosilicate having >=260ml/100g oil absorption amount and >=100mg CaCO3/dry 1g ion exchange ability.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for producing an amorphous aluminosilicate, and more specifically, to an amorphous aluminosilicate that is inexpensive, has high oil absorption, and has high ion exchange properties. The present invention relates to a method for producing fine aluminosilicate powder.

[Conventional technology and its problems]

Until now, amorphous hydrated silica, known as white carbon, has been known as a highly oil-absorbing inorganic powder, and its properties have been used to develop many uses such as rubber filler and paper manufacturing. ing. However, since amorphous silica has a negative surface potential, when it is used, for example, as a filler for paper manufacturing, it is undesirable because it repels the negative surface potential of pulp, resulting in poor yield. In addition, amorphous silica has a lower refractive index than other general silicas due to its high porosity, surface hydroxyl groups, and large amount of adsorbed water. This is undesirable because it is disadvantageous in terms of maintaining opacity.

In addition, as highly oil-absorbing silica, dry silica called Aerosil is known and is used as a filler for rubber and plastics, but this is expensive and is used in the paper manufacturing industry. It is not suitable for use in fields that require inexpensive raw materials.

In addition, recently, a petal-shaped calcium silicate powder commercially available under the trade name "Florite J" exhibits extremely high oil absorption of 500 to 600 mZ/100 g, but this powder is expensive and However, when used for papermaking, it has drawbacks such as causing pitch trouble.

In addition to the above-mentioned drawbacks, the above-mentioned silicic acid and calcium silicate powders have the drawback of not having ion exchange ability, and are used for applications that require a water softening effect, such as bilge for detergents, carriers for agricultural chemicals, etc. Alternatively, it is unsuitable for use in preventing scale formation caused by Ca+Mg ions or contamination.

Crystalline aluminosilicate called zeolite is well known as a substance with high ion exchange ability, and in particular, synthetic zeolite type 4A is currently used in large quantities as a building block for synthetic detergents. However, zeolite itself is a densely packed crystal particle of 5 to 10 microns in size, and although it has many pores on the molecular order, the retention rate of macroscopic voids in terms of oil absorption is extremely small, and its oil absorption ability is very low. It is about 60 mj/100 g, and high dispersibility in oil or water cannot be expected, and it cannot be used for applications that require high oil absorption.

Furthermore, although the amorphous aluminosilicate powder commercially available under the trade name of Zeolex J has the same uses as white carbon, it has low oil absorption and ion exchange ability.

Regarding the manufacturing method of amorphous aluminosilicate such as "ZEOLEX", various studies have been made in the past. By adding and mixing an aqueous salt solution at a temperature below 70°C and keeping the reaction system at pH 10.5 or above, the oil absorption amount is 75 m/10.
0g or more, ion exchange capacity 200mg CaC0,1/g
A method for producing amorphous alkali metal aluminosilicate fine powder having the above-mentioned physical properties is disclosed. However, this method cannot produce an amorphous aluminosilicate having a high oil absorption of 200 nf/100 g or more. Furthermore, JP-A-55-162418 discloses that an alkaline aluminate aqueous solution and an alkaline alkali silicate aqueous solution are continuously supplied to the reaction system at a temperature of 60° C. or lower, and the particle size is large and easy to filter and wash. A method for producing an amorphous aluminosilicate with excellent ion exchange ability is disclosed. However, this product is not produced for the purpose of increasing oil absorption, and in fact, it is difficult to obtain a highly oil-absorbing amorphous aluminosilicate by this method. Furthermore, JP-A-58-156527 discloses that by adding an alkali metal aluminate solution and an alkali metal silicate solution to water at a temperature of 60°C or less, or by adding an alkali metal aluminate solution to water at a temperature of 60°C or less, A method for producing an amorphous aluminosilicate having an oil absorption of 200 ml/100 g or more and a cation exchange capacity comparable to that of various zeolites by adding it to an alkali metal aluminate solution at a temperature of 60°C or lower. is disclosed. However, in this method, all reaction steps are performed at 60°C or lower, and the molar ratio of NagO and AhOs in the alkali metal aluminate solution used is a large value, Na, 0/A1.03. It is difficult to obtain an amorphous aluminosilicate having an oil absorption of 260 m/100 g or more.

The object of the present invention is to provide an amorphous aluminosilicate that is inexpensive, has a high oil absorption capacity unparalleled by conventional products, and has a high ion exchange capacity.
tn1/100g or more, ion exchange capacity 100mg Ca
It is an object of the present invention to provide a method for producing amorphous aluminosilicate having physical properties of 1 g or more of CO5/dry at a high yield.

[Means for solving problems]

As a result of intensive studies to solve the problems of the conventional techniques as described above, the present inventors have developed an alkali metal aluminate solution with a low alkali content and an alkali metal silicate solution. The present invention was completed by discovering that the object could be achieved by reacting under special conditions.

That is, the present invention is characterized in that an aqueous alkali metal silicate solution is added to an aqueous alkali metal aluminate solution under strong stirring at a temperature of 15 to 60°C, and then heat-treated at a temperature of 70 to 100°C. The present invention provides a method for producing an amorphous aluminosilicate, and in a more preferred embodiment, the aqueous alkali metal aluminate solution is
The molar ratio of O and Al2O2 is Na2O/AI2Oi=1.
1 to 1.7, and the molar ratio of 11□0 and Na2O is l1
It is a low alkali alkali metal aluminate aqueous salt aqueous solution in which 2O/Na2O = 6.5 to 500, and the alkali metal silicate aqueous solution has a molar ratio of Sin, Na, and 0 of SiO2.
/Na2O=1.0~4.0, 11□0 and Na
The present invention provides a method for producing the above-mentioned amorphous aluminosilicate, which is an aqueous alkali metal silicate solution having a molar ratio of 2O (I2O/Na2O) of 12 to 200.

The raw materials for producing the highly oil-absorbing and highly ion-exchangeable amorphous aluminosilicate of the present invention are (a) an alkali metal aluminate solution and (b) an alkali metal silicate solution, and if necessary, a caustic solution. The concentration and molar ratio may be adjusted by adding alkali and water to both solutions. In the present invention, the alkali metal refers to a metal belonging to Group 1a of the periodic table, and sodium is usually advantageous.

Next, (a) alkali metal aluminate aqueous solution and (b) alkali metal silicate aqueous solution used in the present invention will be explained.

(a) Alkali metal aluminate aqueous solution Although a commercially available alkali metal salt aqueous solution may be used, an aluminum source such as aluminum hydroxide or activated alumina (usually aluminum hydroxide) is heated and dissolved in an alkali hydroxide. A high concentration and low alkalinity alkali metal aluminate solution may be prepared first, and then mixed with necessary amounts of water and alkali hydroxide. The highly concentrated solution at this time can be stabilized by heating and dissolving the aluminum source in an alkali hydroxide and then rapidly cooling it, but it is desirable to prepare the required amount each time for a solution with a lower alkali. Regarding the aqueous alkali metal aluminate salt solution used in the present invention, Mho (M is an alkali metal) and A
The molar ratio of l2O3 is M20/Al2O3 = 1.0~
The range is preferably 2.0, 1.17 to 1.5
The range of 4 is particularly preferable, and the concentration of Al2O3 is 0.9 to
A range of 10% is desirable, and a range of 1.0 to 5.8% is particularly preferred. This is for reasons of manufacturing and physical properties.

(b) Aqueous solution of alkali metal silicate A commercially available aqueous solution of alkali metal silicate can be used, but the molar ratio of Sing and l'l2O is SiO□/
It is desirable to use one in the range of M,0 = 1.0 to 4.0. Also, the concentration of the aqueous solution is S i Ot t
Desirably, the R degree is 25% or less.

The present invention will be explained in detail below.

First, the above (a) aqueous alkali metal salt aluminate solution is placed in a reaction tank, maintained at a temperature between 15 to 60°C, and the above aqueous alkali metal salt silicate solution (b) is added under vigorous stirring. Then, the white precipitate slurry produced was
It is heated to a temperature of 0 to 100°C, preferably 90 to 100°C, and kept at that temperature for 10 minutes or more, preferably 30 minutes or more, to obtain an amorphous aluminosilicate having a strong higher-order structure. If this heat treatment is not performed, it is difficult to obtain an oil absorption amount of 260 m7/100 g or more. The higher the temperature at the time of initial mixing, the higher the ion exchange performance. However, if the initial temperature becomes too high, the oil absorption ability of the amorphous aluminosilicate obtained will decrease.

In order to obtain high properties in both physical properties, the initial temperature should be 15~15.
A temperature in the range of 60°C is preferred, particularly a temperature in the range of 30 to 50°C. In addition, during heat treatment at 70 to 100° C., strong stirring is not necessary.

This heat treatment is preferably carried out while the reaction system is kept as it is, but may be carried out after partially concentrating by filtration or decantation.

After the reaction is completed, the generated particles may be used as is as a product slurry, but usually a filtration and washing step is performed to separate the mother liquor and remove excess alkali. Subsequent drying gives a very voluminous and brittle mass, which easily disintegrates into a fine powder, yielding the amorphous aluminosilicate of the present invention.

The amorphous aluminosilicate obtained by the method of the present invention has unprecedented high oil absorption, high ion exchange capacity, and a higher refractive index than conventional papermaking white carbon, and can be used as a papermaking filler. If
It is effective because it maintains the opacity of the paper after printing.

Further, by mixing the amorphous aluminosilicate of the present invention and a surfactant, a detergent having excellent detergency can be obtained.

Furthermore, it can be used as a filler for rubber and plastics, a carrier for agricultural chemicals, and the like.

The first feature of the production method of the present invention explained above is that it uses a low-alkali alkali metal aluminate, which has been considered disadvantageous in practice. ＾120゜=1.18 (molar ratio)
It is possible to use the following. Moreover, by using this material and an alkali metal silicate salt having a molar ratio of 5iOz/Na0z=3.2, it is possible to reduce the amount of cleaning of excess alkali and the like. Although such a reaction system requires unprecedented low alkaline conditions, the above-mentioned alkaline aluminate solution can be handled stably.

The second feature of the present invention is the Si/Al (molar ratio) of the alkali metal aluminate solution and the alkali metal silicate solution.
When is approximately 1, the yield is maximum. This shows that raw materials can be used most efficiently. In other words, it is thought that the number of bonds between incorporated aluminum and silicon via oxygen is responsible for influencing the ion exchange ability, but the number of bonds with Si/Al-1 (mol) has the largest number. Since the molar ratio is 1, if a product with this molar ratio can be obtained in a high yield, it means that a product with the physical properties targeted by the present invention can be obtained in a high yield.

In addition, when using a method of mixing both liquids other than the method of the present invention,
It should be added that the yield may be maximized when Si/Al=2 (molar ratio).

The third feature of the present invention is that the siltation slurry produced by adding and mixing both liquids is heat-treated at 70 to 100°C. The slurry reacted under the conditions of the present invention,
If filtration, washing and drying is performed without heat treatment using the method described in JP-A-55-162418, the oil absorption capacity becomes extremely poor and it is difficult to obtain a value of 200 m//100 g or more. Under conditions with a high alkaline content in the reaction system, the oil absorption is 2.
Although it is possible to obtain an oil with an oil absorption capacity of 250+nj/100g or more, it is difficult to obtain one with an oil absorption capacity of 250+nj/100g or more except by the method of the present invention.

[For production]

Hereinafter, how the production method of the present invention brings about the effects unique to the present invention will be described in detail with consideration.

For amorphous super oil absorbents such as wet hydrated silicic acid, there is a model in which spherical primary particles with a particle size of several tens to hundreds of particles are electrically combined into a bunch of grapes to a size of several thousand particles. has been submitted. These aggregated particles are considered to further form tertiary and quaternary flocs (soft aggregates, agglomerated structures).

Basically, the same model applies to the amorphous aluminosilicate of the present invention.

If we consider the basic factors related to oil absorption ability, they are the particle size of primary particles and secondary particles when they aggregate, the porosity determined by the coordination number, and the porosity determined by the coordination number. This is a correlation between the particle size during isolation and drying, the shrinkage force determined by the surface tension of the filled liquid, and the strength of the aggregate structure. In other words, since the oil absorption capacity is evaluated by measuring the final isolated and dried powder, no matter how large the porosity is in the structure of the aggregated particles in the slurry, the drying If the shrinkage force is strong enough to destroy a structure with a high porosity, the oil absorption capacity will not increase after all.

First of all, the aggregate structure with a large porosity is determined by the coordination number of the particles. Generally, the smaller the particle size, the smaller the coordination number and the larger the porosity, but the degree of It varies depending on the conditions. -Different from the case of crystal growth, the lower the concentration and the faster the addition rate, the smaller the secondary particle size, and the stronger the stirring, the more uniform the particle size.

Therefore, if particles are precipitated at a low concentration in a short period of time, aggregated particles with a large porosity should be formed.

The second problem here is the shrinkage force during drying. This contraction force becomes larger as the above-mentioned void radius becomes smaller and as the surface tension of the liquid becomes larger. Therefore, it is understood that the particle size has a maximum value in relation to the shrinkage force. Furthermore, under reaction conditions of 60° C. or lower, there are a considerable number of hydroxyl groups on the surface of the particles, and the particles can be said to be soft. Therefore, the contractile force is particularly weak. On the other hand, when heat treatment is performed, silanol bonds change to siloxane bonds while maintaining the coordination state, and the aggregate structure is strengthened. The surfaces of particles precipitated under high temperatures are already covered with siloxane bonds, and the bonds at the aggregation points become weaker, making them more brittle against shrinkage forces. In this way, it is considered that when the manufacturing method of the present invention is used, the aggregate grain structure becomes the largest and strongest at the time of heat strengthening.

(Example) The present invention will be specifically explained below by showing Examples and Comparative Examples, but the present invention is not limited only to these Examples. The method for measuring the measured values is shown below.

(1) Oil absorption A sample was crushed in a mortar and measured by JIS 6220 oil absorption measurement method.

(2) Ignition Loss A few grams of the sample is put into a magnetic crucible that has been prebaked at 800"C for 1 hour to reach a constant weight in a desiccator and weighed accurately. Then placed in an electric furnace at 800"C for 1 hour. The weight loss on ignition was determined in weight percent by igniting the sample in a desiccator and accurately weighing the weight that reached a constant weight in a desiccator.

(3) Precisely weigh the O and Ig of the Ca ion exchange capacity sample in terms of anhydride calculated from the loss on ignition, and prepare a calcium chloride solution (CaCO).

500ppm) in 100-100℃, and at 25℃
Stir for 5 minutes, perform suction filtration using two Toyo Roshi Th5c sheets, take the filtrate 5QmZ, and remove Ca in the filtrate with EDTA.
The Ca exchange capacity of the sample was determined from the titration.

Note that the calcium ion exchange ability is evaluated to be quite high if the powder is insufficiently washed. In other words, when excess alkali ions remain, they react with 002 gas in the air to form carbonates, which gives the appearance of a high Ca ion exchange capacity. Therefore, the measurement sample must be thoroughly cleaned.

(4) X-ray diffraction Measurement was performed using CuKcr radiation using Rotaflex p1200 (trade name) manufactured by Rigaku Denki Co., Ltd.

Examples 1 to 5 Aluminum hydroxide and caustic soda were mixed, heated and dissolved, and then rapidly cooled to produce 0.3% by weight of Na2020.
, Ah (h 28.2% by weight, Al2O3/Na2O=
A sodium aluminate solution of 0.847 (molar ratio) is prepared in advance. A predetermined amount of water as shown in Table 1 was added to 17.44 g of this solution with stirring, and the mixture was maintained at 30°C. Next, a sodium silicate solution (Na2O3, 8% by weight, 5iOz
11.6% by weight, SiO2/Na2O=3.15(
Molar ratio) ) 50g was added. After the addition was completed, the rotation speed of the stirrer was lowered to 50 rpm, and the temperature was immediately increased to 100°C.
Heating was performed for a period of time, followed by filtration and washing.

The obtained wet cake was left to dry at 110° C. until it reached a constant weight, and then pulverized to obtain the amorphous aluminosilicate of the present invention. The physical property measurement results of this product are shown in Table 1.

Table 1 Example 6 Sodium silicate solution (Nazo 3.8% by weight, Si
n.

11.6% by weight, SiO*/Na2O=3-15 (
molar ratio)) 50g was added to sodium aluminate solution (N
a2O1, 12% by weight, 812O+ 1.55% by weight,
Na to/^hOi=1.18 (molar ratio)) 317
．． It was added to 4g of the sample using a microtube pump at 40°C with strong stirring. Immediately after the addition was completed, the mixture was heated at 100° C. for 1 hour, and then filtered and washed. The obtained wet cake was dried at 110° C. to a constant weight and pulverized to obtain 12.8 g of X-ray amorphous aluminosilicate fine powder. The yield was 93%. This powder exhibited physical properties of oil absorption of 310 mZ/100 g and ion exchange capacity of 112 CaCOzmg/Ig.

Example 7 Sodium silicate solution (Nato 3.9% by weight, 5i
Oz12.0% by weight, SiO2/Na2O=3.15
(Mole ratio) ) 48.3g was added to a sodium aluminate solution (Na2O1, 94% by weight, Al2Oz 1.89
Weight%, NagO/Al2Os=1.59 (mole ratio)
) was added to 338.3 g at 40° C. with strong stirring. Immediately after the addition was completed, the mixture was heated at 100° C. for 1 hour, and then filtered and washed. Hereinafter, the same operation as in Example 6 is carried out.
A linearly amorphous aluminosilicone powder was obtained.

The oil absorption capacity of this product was 265aZ/100g, and the ion exchange capacity was 138CaCQ, mg/Ig.

Example 8 A sodium aluminate solution (Na
go 1.63% by weight, ^hO+ 2.26% by weight, N
a2O/Al2Ox = 1.18 (molar ratio))
2392g was charged and kept at 30°C. To this was added a sodium silicate solution (Nazo 3.8% by weight, 5i (h
550 g of 11.6% overlapping, 5iOt/Na2O=3.15 (molar ratio) was added while rotating a stirring blade with a diameter of about 110+n+w at 650 rpm+. Immediately after the addition was completed, the temperature was heated to 100°C and maintained for 1 hour.
The same operation as in Example 6 was carried out to obtain 142 g of X-ray amorphous aluminosilicate fine powder. Yield is 94%
Met. The oil absorption capacity of this product is 298mZ/100g
The ion exchange capacity was 127 cacO3mg/Ig.

Example 9 A sodium aluminate solution (Na
zo 1.12% by weight, Ah (h 1.55% by weight, N
a, 0/^hOs=1.18 (molar ratio)) 349
2g of sodium silicate solution (Na2O3, 8% by weight, Sing 11.6% by weight) was prepared at a reaction temperature of 28°C.
, SiO2/Na2O=3.15 (molar ratio)) 5
50. The stirring blade with a diameter of about 110mm is 780rpm+
It was added while rotating. Immediately after addition, 100
The mixture was heated to .degree. C. and maintained for 1 hour, and the same operations as in Example 6 were carried out to obtain 141 g of xfa amorphous aluminosilicate fine powder. The oil absorption capacity of this product is 315nj/
100g, ion exchange capacity is 131CaCQ3mg/I
It was g.

Comparative Example 1 In the same operation as in Example 6, an amorphous aluminosilicate was obtained without performing the heat treatment at 100° C. for 1 hour. The oil absorption amount of this material was 70 m/100 g.

Comparative Example 2 In the same operation as in Example 7, an operation of holding at 40° C. for 30 minutes was performed without performing the heat treatment at 100° C. for 1 hour, to obtain an amorphous aluminosilicate. The oil absorption capacity of this product was 223 mZ/100g, and the ion exchange capacity was 82CaCOzmg/Ig.

Comparative Example 3 In the same operation as in Example 8, an amorphous aluminosilicate was obtained without performing the heat treatment at 100° C. for 1 hour. The oil absorption capacity of this product was 198m7/100g, and the ion exchange capacity was 78CaCO3mg/Ig.

〔Effect of the invention〕

As specifically shown in the examples, the amorphous aluminosilicate obtained by the method of the present invention is
It has unprecedented high oil absorption, high ion exchange ability, and a higher refractive index than conventional white carbon for papermaking, so it can be said to be an inorganic material with higher functionality than conventional white carbon. . In addition, the loss of raw materials can be minimized, and since it is a low-alkaline system and the reaction takes place at normal pressure, manufacturing costs are also reduced. Therefore, the amorphous aluminosilicate of the present invention can be used as a filler for paper, especially lightweight paper, as well as an adsorption carrier for gases and fragrances, detergents, toothpaste additives, sebum control agents, agricultural additives, and paint additives. It can be applied to many fields of use, such as additives for ceramic binders.

Applicant's agent Kaoru Furutani Official seal of the procedure chief) 1. Display of incident Patent Application No. 1983-274693 2. Name of the invention amorphous aluminosilicate Production method 3. Person who makes corrections.

Relationship to the case Patent applicant (091) Kao Co., Ltd. Company 4, Agent Nakai Building (6389) 1-3 Nihonbashi Yokoyama-cho, Chuo-ku, Tokyo
Patent attorney Kaoru Furuya 1.

・ 5. Subject to correction! ,! :
1 Detailed explanation of the invention in the specification column 6, contents of the amendment (11 Specification, page 4, line 7 "5-10μ"
” and corrected

Claims (1)

[Claims] 1. Adding an aqueous alkali metal silicate solution to an aqueous alkali metal aluminate solution at a temperature of 15 to 60°C with strong stirring, and then heat-treating at a temperature of 70 to 100°C. A method for producing amorphous aluminosilicate, characterized by: 2 The aqueous alkali metal aluminate salt solution has a molar ratio of Na_2O and Al_2O_3 of Na_2O/Al_2O_3.
= 1.1 to 1.7, and the molar ratio of H_2O and Na_2O is H_2O/Na_2O = 6.5 to 500. The molar ratio of Na_2O is SiO_2/Na_2O=1.0 to 4.0, and the molar ratio of H_2O and Na_2O is H_2O/Na_2.
The method for producing an amorphous aluminosilicate according to claim 1, which is an aqueous alkali metal silicate salt solution in which O=12 to 200.