JPS62191417A - Production of amorphous aluminosilicate - Google Patents

Abstract

PURPOSE:To obtain an amorphous aluminosilicate having high oil-absorptivity and ion-exchange capacity, by adding an aqueous solution of a specific alkali metal aluminate to an aqueous solution of an alkali metal silicate and treating the mixture under specific condition. CONSTITUTION:An alkali metal aluminate having low alkali content and having an M2O/Al2O3 molar ratio of 1-2 and H2O/M2O ratio of 6-500 is prepared beforehand. Separately, an alkali metal silicate having an SiO2/M2O molar ratio of 1-4 and H2O/M2O ratio of 12-200 is prepared. The aqueous solution of the above alkali metal aluminate is added to an aqueous solution of the alkali metal silicate at 15-100 deg.C under vigorous agitation. The mixture is heated at 70-100 deg.C to obtain the objective amorphous aluminosilicate.

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 ml/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 drawbacks mentioned above, the silicic acid and calcium silicate powders have the drawback of not having ion exchange ability, and are used for applications that require water softening effects, such as builders 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 1 to 10μ 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 approximately 60 m1/100 g, and high dispersibility in oil or water cannot be expected, and it cannot be used for applications that require high oil absorption.

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

Various methods for producing amorphous aluminosilicate such as "Zeolex" have been studied in the past. For example, JP-A-52-58099 discloses that an aqueous solution of an alkali metal salt of an aluminate is added and mixed into an aqueous solution of an alkali metal silicate at a temperature of 70° C. or lower, and the reaction system is maintained at pH 10.5 or higher. Oil absorption amount 75m1/1
00g or more, ion exchange capacity 200mg CaC0: +/
A method for producing an amorphous alkali metal aluminosilicate fine powder having physical properties of more than 100 g is disclosed. However, this method cannot produce an amorphous aluminosilicate having a high oil absorption of 200 m1/100 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. Also, JP-A-58-156527
The publication discloses that by adding an alkali metal aluminate solution and an alkali metal silicate solution to water at a temperature of 60° C. or lower, or adding an alkali metal silicate solution to an alkali metal aluminate solution at 60° C. By adding at a temperature below ℃, the oil absorption amount is 200ml/100g or more,
A method for producing an amorphous aluminosilicate having cation exchange capacity and physical properties comparable to those of various zeolites is disclosed. However, in this method, all reaction steps are carried out at 60°C or lower, and the molar ratio NazO/A1zO:+ of 1.03 with Nano in the alkali metal aluminate solution used is a large value. ,
It is difficult to obtain an amorphous aluminosilicate having an oil absorption of 260 m1/100 g or more.

Furthermore, the patent concludes that an amorphous aluminosilicate with high oil absorption, that is, physical properties of 200 ml/100 g or more, cannot be produced by adding an aqueous solution of an alkali metal aluminate to an aqueous solution of an alkali metal silicate. ing.

The purpose of the present invention is to provide an amorphous aluminosilicate that is inexpensive, has an unprecedented high oil absorption capacity, and has a high ion exchange capacity.
l/100g or more, ion exchange capacity 100mg Ca
The object of the present invention is to provide a method for producing amorphous aluminosilicate with physical properties of 1 g or more at a high yield.

[Failure to solve the problem]

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 aluminate solution is added to an aqueous alkali metal silicate solution under strong stirring at a temperature of 15 to 100°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, an aqueous alkali metal aluminate solution is
The molar ratio of 81□03 is MZO'/A1203=10
~2.0, and the molar ratio of H2O and MzO is )120/
M20 = 6.0 to 500, and the alkali metal silicate aqueous solution has a molar ratio of Sin and M, 0 of 5iOz/Mz.
The present invention provides a method for producing the amorphous aluminosilicate, which is an aqueous alkali metal silicate solution in which O = 1.0 to 4.0 and the molar ratio of H2O to MZO is H20/M20 = 12 to 200. be. (however,
H is an alkali metal) 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, If necessary, caustic alkali and water may be added to the above two solutions to adjust the concentration and molar ratio. 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) aqueous alkali metal aluminate salt solution and (b) aqueous alkali metal silicate 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 highly concentrated and low alkali alkali metal aluminate solution may be prepared first, and then mixed with the required amount of water and alkali hydroxide. The preparation of a highly concentrated solution at this time is 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, MzO (M is an alkali metal) and Al
The molar ratio of zO3 is Mho/812 to 3 = 1.0 to 2
．． The range is preferably 0, 1.17 to 1.54
It is particularly preferable that the concentration of AIZO:l is in the range of 1.0 to
A range of 30% is desirable, and a range of 5 to 20% 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 SiO□ and M2O is SiO□/Mz
It is desirable to use one in the range of O=1.0 to 4.0. Further, the concentration of the aqueous solution is preferably 25% or less in terms of SiOzfm.

The present invention will be explained in detail below.

First, the above (b) aqueous alkali metal silicate solution is placed in a reaction tank, maintained at a temperature in the range of 15 to 100°C, and the aqueous alkali metal aluminate solution (a) is added under vigorous stirring. The resulting white precipitate slurry is then heated to a temperature of 70 to 100"C, preferably 90 to 100C, and kept at that temperature for preferably at least 10 minutes, but not more than 10 hours, preferably not more than 5 hours, to form a solid high-temperature slurry. An amorphous aluminosilicate having the following structure is obtained: 10
If heat treatment is performed for an extended period of time, aluminosilicate with a crystalline structure instead of an amorphous one may be formed.
Undesirable. If this heat treatment is not performed, it is difficult to obtain an oil absorption amount of 200 m1/100 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 levels of both physical properties, the initial temperature is preferably in the range of 15 to 60°C, particularly 30 to 50°C.
Temperatures in the range of .degree. C. are preferred. 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. When adding (a) to (b), it is preferable to add it gradually in small amounts rather than adding it all at once.

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 described above is that it uses a low-alkali alkali metal aluminate, which has been considered disadvantageous in practice.In the present invention, for example, NazO/ A1zOz=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 5i02/Na0t=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 St/^1 (molar ratio) of the alkali metal aluminate solution and the alkali metal silicate solution.
The maximum value of yield exists between 1 and 2, and therefore, when used in a low pHrJ region, it is possible to obtain a more stable amorphous aluminosilicate with high oil absorption and high ion exchange properties. .

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 are 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 m1/100 g or more.

[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.

Regarding 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 polymerized in the shape of a bunch of grapes and become several thousand particles in size. It 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.

In order to obtain high fat and oil content, the porosity of the network structure formed by the grape bunch-shaped particles bonded together must be large, and when the structure is isolated and dried, the pore size and the surface of the filled liquid must be It is necessary that it not be destroyed by the contraction force determined by the tension.

These structures depend not only on raw material concentration and alkalinity, but also on
Although it is related to the temperature and stirring speed during addition, in the case of the method of the present invention in which an alkali metal aluminate aqueous solution is added to an alkali metal silicate aqueous solution, in particular,
Since silicic acid has the property of gelling as a whole due to polyvalent cations such as aluminum ions, it is difficult to control this, and conventionally it has not been possible to obtain one with an oil absorption capacity of 200 ml/g or more. In the present invention, by using an aqueous solution of alkali metal salt of a low-alkali aluminate, and by controlling the temperature during reaction and aging, it is possible to achieve uniform refinement of the secondary particle size, particle rearrangement by strengthening interparticle bonds, It is thought that an ion-exchange amorphous aluminosilicate having an oil absorption capacity of 200 ml/g or more was obtained due to the combination of effects such as adhesion prevention.

〔Example〕

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited only to these Examples. The method for measuring the measured values in the Examples and Comparative Examples is shown below.

(1) Oil absorption The sample was crushed in a mortar and measured by the oil absorption measuring method according to JIS K 6220.

(2) Loss on ignition A number of grams of the sample is placed in a magnetic crucible that has been prebaked at 800° C. for 1 hour to reach a constant weight in a desiccator, and weighed accurately. The product was then ignited at 800° C. for 1 hour in an electric furnace, and the weight that reached a constant weight was accurately weighed in a desiccator to determine the loss on ignition in weight %.

(Accurately weigh 0.1 g of the 31Ca ion exchange capacity sample in terms of anhydride calculated from the loss on ignition, and prepare a calcium chloride solution (500
ppm), stirred at 25°C for 15 minutes, filtered with suction using two sheets of Toyo Roshi Na5c, taken 50ml of the filtrate, titrated Ca in the filtrate with EDTA, and calculated the Ca exchange capacity of the sample from the value. I asked for it.

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 CO□ 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 Cu K c X-rays using Rotaflex p1200 (trade name) manufactured by Rigaku Denki Co., Ltd.

Example 1 Sodium silicate solution (NazO2, 71% by weight, St
ow 8.29% by weight, Stow/NazO=3.1
5 (mole ratio)) 70g was heated to 90℃, and the diameter was 45m.
1500rp with m magnetic stirrer piece
A sodium aluminate solution (NazO1, 63 wt%, AlKO32, 26 wt%, NazO/AlzO3
= 1.18 (molar ratio)) 108.72 g was added.

After the addition is complete, heat treatment is performed at the same temperature for 15 minutes, followed by filtration and washing. The resulting wet cake is dried at 110°C to a constant weight and pulverized to produce X-ray amorphous aluminosilicate fine powder. 10.1 g was obtained. The yield was 102%. This one has an oil absorption capacity of 250m.
1/100g, ion exchange capacity lllCaC03mg/I
It was g.

Example 2 The white precipitate slurry produced was heated at 100° C. for 1 hour in the same manner as in Example 1, and amorphous aluminosilicate i powder was obtained in the same manner.

This oil absorption capacity was 260 m1/100g and the ion exchange capacity was 103 CaC0+mg/Ig.

Example 3 Sodium silicate solution (NazO3, 8% by weight, 5in
211.6% by weight, 5iOz/NazO=3.15 (
Molar ratio)) 50g was maintained at 40°C and stirred at a rotation speed of 1500 rpm using a magnetic stirrer piece with a diameter of 451, while a sodium aluminate solution (Na2O 2.25% by weight, A
IzOz3.13% by weight, NazO/AlzO+ =
1.18 (molar ratio)) 78.72 g was added. Immediately after the addition was completed, the temperature was heated to 100"C and maintained for 1 hour, and the same operation as in Example 1 was carried out to obtain 10.1g of X-ray amorphous aluminosilicate fine powder. The yield was 1
It was 0.2%. This one has an oil absorption capacity of 250m1/100
g, and the ion exchange capacity was 118 CaCO3 mg/Ig.

Example 4 Sodium silicate solution (Na2O 3.2% by weight, St
, 28.2% by weight, 5iOz/NazO=2.62 (
Molar ratio)) 70.5g was maintained at 60°C and processed in the same manner as in Example 2 to prepare a sodium aluminate solution (Na2O
1.63 heavy economy, 8Iz(h, 2.26% by weight, N
azO/AlzO+ = 1.18 (molar ratio)) 10
After adding 8.72 g, treatment was performed to obtain 9.81 g of amorphous aluminosilicate fine powder. Yield is 99.4
%Met. This item has an oil absorption capacity of 270m1/100g1
The ion exchange capacity was 105CaCO+mg/Ig.

Comparative Example 1 In the same operation as in Example 1, addition was carried out at 50°C,
Thereafter, aging was performed at 50° C. for 1 hour to obtain an amorphous aluminosilicate. The oil absorption capacity of this product is 164ml
/100g, and the ion exchange capacity is 95CaCO3mg
/Ig.

Comparative Example 2 In the same operation as in Example 3, an amorphous aluminosilicate was obtained without performing the heat treatment at 100° C. for 1 hour. The oil absorption capacity of this product is 166m1/100g,
The ion exchange capacity was 85CaCO3mg/Ig.

Comparative Example 3 In the same operation as in Example 4, an amorphous aluminosilicate was obtained without performing the heat treatment at 100° C. for 1 hour. The oil absorption capacity of this product was 185 m1/100 g1, and the ion exchange capacity was 98 CaCOsmg/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 Furuya Proceeding author: April 21, 1985 1. Indication of the case: Japanese Patent Application No. 61-34289 2. Name of the invention: Process for producing amorphous aluminosilicate 3. Amendments made Patent applicant (091) Kao Co., Ltd., agent 41, Nakai Building, 1-3 Nihonbashi Yokoyama-cho, Chuo-ku, Tokyo Column 6 of the detailed description of the invention in the specification, Contents of the amendment

Claims (1)

[Claims] 1. Adding an aqueous alkali metal aluminate solution to an aqueous alkali metal silicate solution under strong stirring at a temperature of 15 to 100°C, and then heat-treating at a temperature of 70 to 100°C. A method for producing amorphous aluminosilicate, characterized by: 2 An alkali metal aluminate salt aqueous solution contains M_2O and A
The molar ratio of l_2O_3 is M_2O/Al_2O_3=1
．． 0 to 2.0, and the molar ratio of H_2O and M_2O is H
It is a low alkali alkali metal aluminate aqueous salt aqueous solution in which _2O/M_2O = 6.0 to 500, and the alkali metal silicate aqueous solution has a molar ratio of SiO_2 and M_2O of Si
O_2/M_2O=1.0-4.0, and the molar ratio of H_2O and M_2O is H_2O/M_2O=12-200.
The method for producing an amorphous aluminosilicate according to claim 1, which is an aqueous solution of an alkali metal silicate. (However, M is an alkali metal)