JPS6049128B2 - Zeolite aqueous suspension composition and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aqueous zeolite suspension composition having excellent suspension stability and thixotropic properties.

Water-insoluble alkali aluminosilicates such as zeolites are
It has been known for a long time that it has a combination of properties such as excellent metal ion sequestering ability, buffering ability on the alkali side, and anti-recontamination effect, and that it can be used as a detergent builder by taking advantage of these properties.

However, there are still many problems to be solved in the production, transportation, and handling of zeolite builders.

Zeolite is a substance with dilatancy, and it is difficult to sufficiently dehydrate the crystallized zeolite by means such as filtration, and if this p-filter cake is released under conditions where no external force is applied, it becomes a slurry. Therefore, in order to obtain a dry powder, expensive drying methods such as spray drying must be employed. In addition, the zeolite particles produced tend to coagulate upon drying, and on the other hand, from the viewpoint of builder properties, it is desirable that the zeolite particles be as small as possible. A charge must be made for such grinding operations. Furthermore, the fine dry powder of zeolite is bulky, which increases transportation costs, and causes the problem of contamination of the working environment due to dust during unloading or transfer.
2. In order to solve the above-mentioned problems that occur when handling zeolite in powder form, it is possible to handle crystallized zeolite in the form of an aqueous slurry, but it is recognized that this case also causes troublesome problems. . That is, zeolite particles not only have the property of settling in water, but also form a clinking sediment cake in which the particles are extremely closely packed together due to external forces such as vibrations applied during transportation. Thus, all attempts to handle zeolite in the form of an aqueous slurry have been met with the fact that even removal of zeolite from a container is difficult and has ended in failure. In particular, among the zeolites for detergent builders, the electron microscopic particle size (primary particle size) is smaller than 1 micron and the X-ray method crystal 35 was proposed earlier by the present inventors.
Zeolite builders with a chemical degree of 35 to 75% have the advantages of excellent fine dispersibility in washing liquids, high metal ion sequestering speed through ion exchange, and good resistance to Japanese cedar washing. However, when this zeolite is handled in the form of an aqueous slurry, due to the high water content associated with the fine grain size, if this aqueous slurry is left to stand, a significant amount of supernatant liquid will separate. It was also found that a problem arises in that a highly concentrated precipitate layer is likely to be formed in the bottom layer of the slurry.

The present inventors have discovered that when a certain amount of alkali carbonate is added to the filter cake of this zeolite with a fine particle size, the aqueous suspension composition of this zeolite has remarkable thixotropic properties, and the supernatant The present invention was achieved based on the discovery that the generation of liquid and the formation of a highly concentrated sedimentary layer are suppressed, resulting in a significant improvement in suspension stability.

That is, according to the present invention, it consists of an aqueous medium that is virtually inseparable by filtration and fine zeolite particles dispersed and suspended in the aqueous medium, and the fine zeolite particles have an electron microscope particle size of less than 1 micron and a particle diameter of 35 to 35 mm. The suspension has an X-ray crystallinity of 75% and contains 0.1 to 10% by weight alkali carbonate per zeolite on anhydrous basis and 30 to 5% by weight on anhydrous basis. Provided is a zeolite aqueous suspension composition having a solids concentration of .

An important feature of the present invention is that when alkali carbonate is added to a zeolite perforation cake having specific particle size characteristics, thixotropy, which is completely opposite to the dilatancy inherent in the zeolite perforation cake, is imparted. The second advantage is that high suspension stability can be obtained. This feature is unique to alkali carbonates. Conventionally, as inorganic alkali metal pickles to be incorporated into detergent compositions, in addition to soda carbonate, there are known inorganic alkali metal pickles such as sodium sulfate, sodium silicate, sodium pyrophosphate, and sodium tripolyphosphate.

However, when other salts such as sulfuric acid and sodium silicate are added to the zeolite filtered cake, it still has dilatancy. At the same time, a precipitated layer having a higher solid content concentration than the initial concentration of the slurry is formed in the lower layer of the slurry. This tendency for precipitation is also observed when a nonionic surfactant, which is said to be the most excellent dispersant for zeolite slurry, is added. However, when a certain amount of alkali carbonate was added to the zeolite cake mentioned above, even in the same 2411f1 time exposure test, almost no supernatant liquid was formed, and the whole became a soft jelly. The solids concentration in the tank is maintained almost uniformly in both the upper and lower layers.
The reason for this is not exactly known, but it is thought that the carbonate ions in the system form a complex with the zeolite fine particles, and this complex forms a soft gel-like structure when it contains water. This explains the fact that the aqueous suspensions according to the invention have thixotropic properties and persistent suspension stability. As mentioned above, the present invention has excellent builder properties and thixotropy because the fine zeolite particles in the sake cake have an electron microscope particle size of less than 1 micron and an X-ray crystallinity of 35 to 75%. The present invention provides an aqueous suspension or liquid having excellent properties and suspension stability.

That is, the suspension composition of the present invention has the extremely important advantage of exhibiting excellent builder properties when used in the preparation of detergent compositions.

Since zeolite builder is essentially water-insoluble, its various functions as a builder, such as metal ion sequestering ability, buffering ability on the alkali side, and re-contamination prevention effect, are all performed through the contact interface between zeolite particles and water. It turns out. In the zeolite aqueous suspension of the present invention, as mentioned above, the primary particle size of the dispersed zeolite is extremely fine, and since the particles are stably dispersed and suspended without substantially secondary agglomeration, the surface area of the zeolite is extremely large. It will be appreciated that the sulfur content is large and that an excellent builder effect is achieved. In this specification, the electron microscope particle size (primary particle size) is defined as the minimum dimension of cubic particles of zeolite in an electron micrograph, that is, the maximum length of one side. The value required by law.

Moreover, in this specification, the X-line crystallinity means the crystallinity determined by the X-line diffraction method, and more specifically refers to the value measured by the method described below.

The zeolite used in the present invention is produced by the method described in JP-A-53-47408 by the present inventors, that is, acid clay,
Alternatively, active silicic acid or active aluminosilicic acid is produced by treating other smectite group clay minerals such as montmorillonite with an acid under conditions such that at least the X one-line diffraction peak of surface index (a) 01) substantially disappears; Activated silicic acid or activated alumino silica is treated with alkali hydroxide or water-soluble alkali silicate to form Na2O:SlO2.
Produce an alkali polysilicate or alkali polyaluminosilicate having a molar composition of = 1:3.5 to 1:500; the alkali polysilicate or alkali polyaluminosilicate and an additional amount of alumina content, alkali metal content, and water. to produce a homogenized composition in which each component is in the A-type zeolite forming range; and then heating the homogenized composition to crystallize fine-particle zeolite having a primary particle size of less than 1 μm. However, zeolites derived from sodium silicate or other solid silicic acid raw materials can also be used for the purposes of the present invention, provided they have the crystallinity and particle size characteristics described above.

The zeolite filter cake is obtained by applying the above-mentioned zeolite crystallization mother liquor to filtration using a filter breath, belt filter, drum filter, leaf strainer, etc., and then, if necessary, washing the filter cake with water and then filtering it again. Obtained by investing.

This wet filtration cake of zeolite still contains a considerable amount of water that cannot be separated by filtration due to the dilatancy described above, and according to the present invention, this residual water or the above-mentioned alkali carbonate is used as a medium to strongly filter the water. The zeolite fine particles are redispersed therein by shear stirring. In terms of metal ion sequestering ability, the zeolite used in the present invention generally preferably has a calcium binding ability of 100 mg/y or more, particularly 120 to 180 m9/y, on an anhydride basis.

Calcium binding capacity means CaO binding capacity (exchange capacity) per y of zeolite, and is determined in more detail by the measurement method described below. This ion exchange ability differs depending on the type of crystal structure of the zeolite, and in descending order of ability,
It is known that they are A type, X type and Y type.

5 Thus, it is preferable that the zeolite used in the present invention consists of type A alone or a combination of type A and type X or Y.

In the present invention, soda carbonate is most preferably used as the alkali carbonate, but sodium bicarbonate, lithium carbonate, and potassium carbonate can also be used.

These can be incorporated into the zeolite cake either in the form of anhydrous carbonates or in the form of hydrated salts such as salts. In the present invention, 0.0.
It is also important to use 2 to 10% by weight, especially 1 to 5% by weight, of alkali carbonate.

That is, when the amount of alkali carbonate is less than the above range, it is difficult to impart thixotropic properties, and separation of supernatant water tends to occur, resulting in a decrease in turbidity stability. The upper limit of these amounts is selected within the above range in consideration of economic efficiency and effectiveness. Various means can be employed to incorporate the above-mentioned amounts of alkali carbonate into the zeolite filter cake.

For example, the alkali carbonate can be added in powder or solution form, or the alkali carbonate can be formed in situ by slurrying a sake cake containing free alkali and blowing carbon dioxide into it. Generally, it is preferable to add the alkali carbonate in the form of powder to prevent dilution of the slurry. High shear agitation is used to slurry the p-filter cake without adding water.

In other words, this wet filtration cake of zeolite still contains a considerable amount of moisture that cannot be separated by filtration due to the dilatancy described above, and the zeolite particles are redispersed using this residual moisture and additives as a dispersion medium. ,
For this purpose, it becomes extremely important to use high shear agitation. For shear stirring, for example, a 2-colloid mill, a homogenizer, a dispersion mill, a dispersion mixer, a Kady mill, etc. can be used, and in particular, the peripheral speed of the shear blade or the outer peripheral part of the rotor is 10 r.
Stirring 3 is performed under conditions such that the stirring speed is n/Sec or more, particularly 15 m/Sec or more. The zeolite aqueous suspension composition according to the present invention has a high solids concentration of 30 to 5% by weight on an anhydride basis, and has a significant advantage in reducing transportation costs. 3 as is
It has the distinctive feature of being permanently suspension stabilized.

In addition, this composition generally has a soft jelly-like form, but due to its thixotropic properties, vibrations and
When stirred or the like, it becomes a slurry with excellent fluidity and can be easily handled such as transportation. Furthermore, since the alkali carbonate contained in this suspension is a component commonly used in detergent compositions, it is possible to prevent undesirable foreign components from being mixed into the detergent composition.

Furthermore, unlike surfactants, the additive components used in the present invention do not have any foaming tendency, so they suppress the generation of foam during slurry production or transportation, making it extremely easy to handle. Of course, organic dispersants known per se can also be blended into the composition of the present invention according to procedures known per se.

The invention is illustrated by the following example.

Example 1 In this example, a case will be described in which a synthetic zeolite for detergent builder was produced using acid clay produced in Nakajo Town, Niigata Prefecture as a smectite group clay mineral.

The acidic clay from Nakajo, Niigata Prefecture used in this example contains 45% by weight of water in its natural state, and its main component is SlO272% by weight on a dry matter basis (drying at 110°C). l,A
l2O3l4.2, Fe2O33.87, MgO3.2
5, CaOl. O6. The scorching heat loss was 3.15.

The diameter of this raw acid clay is 5? ×Mold into a cylinder shape with a length of 5 to 20 mm, and add 5
Add sulfuric acid solution with a concentration of 4% by weight into the lead burr tank of d.
00' was added, heated to 90°C, and treated with acid in the form of 4 (2) particles, followed by washing off the sulfate of the basic component that had reacted with the sulfuric acid using a dilute sulfuric acid solution and water using the decantation method. This is removed and then washed with water until the sulfate groups are removed to obtain a granular acid-treated product. This acid-treated product is activated silicic acid (moisture 50
%). Next, in order to produce zeolite, the upper orbital activated silicic acid was first reduced to a concentration of 20 using a ball mill.
%, and wet crushing was performed to obtain an activated silicic acid slurry.

Next, 796 kg of this slurry was placed in a 2D type stainless steel container, and 46.6 k9 of a general commercially available caustic soda solution (containing 4.9% NAOH) was added thereto, and the mixture was stirred at 60°C for 6 hours.
An alkali polysilicate slurry A corresponding to a2O.8.8Si02 was produced.

Next, for the production juice of synthetic zeolite for detergent builder, the following molar proportions of oxide groups were selected as composition molar proportions.

CNa2O/SiO2=0.9 S102/Al.

O3=2.0H20/Na2O=50.0 In order to achieve the above required composition molar ratio, the alkaline aluminate solution to be added to the alkali polynoic acid slurry was prepared by dissolving commercially available aluminum hydroxide in commercially available caustic soda. did.

The composition is Na2Ol8.54%, Al2O3l9. l%,
H2O is 62.4%, corresponding to a molar ratio of Na2O:Al2O3 of 1.6:1. Manufacturing method of synthetic zeolite for purifier builder Water was added to the above polysilicate alkali slurry to adjust the SiO2 concentration to 10%, and then 3.5 d
Water was added to the alkaline aluminate solution at 20°C while stirring in a molded stainless steel container until the Na2O concentration was 12.
．． When the solutions adjusted to 5% and Al2O3 concentrations of 12.8% are mixed for about 80 minutes, the mixed system temporarily passes through a gel state and is obtained as a homogeneous slurry.

Next, the mixture is heated to 95° C. and stirred for 5 hours to form zeolite crystal particles. After crystal formation, p
The reaction product was washed with water and filtered using a filtration method, and a sufficiently dehydrated filtration cake (800° C. drying moisture: 60%) was recovered. Approximately 100k9 of the obtained filter cake was put into a 100-liter stainless steel container and stirred with a powerful stirrer to form a slurry.

This zeolite slurry (C at PFIl2.6/15)
0.88k9 of soda carbonate was added to the mixture and thoroughly stirred in a colloid mill to produce a zeolite slurry.

The crystal type, crystallinity, calcium ion exchange capacity, SusppH, primary particle size, secondary particle size distribution, concentration (
%), viscosity (Cps), and static stability (Ics) and are shown in Table 1.

As Comparative Example 1, an untreated zeolite slurry was described. After the static stability test, Example 1 had a soft jelly-like appearance as a whole, and no sediment was observed at the bottom.

Moreover, in this state, by applying weak stirring, the slurry could easily become the same viscous slurry as before the test. On the other hand, in Comparative Example 1, a supernatant liquid and a hard sediment were observed, and this sediment was not separated even by a spatula. The various physical properties in this specification were measured by the following methods.

In this specification, the term "X one-line diffraction image" refers to one obtained by the powder X one-line diffraction method described below using a Cu-Kd line.

(1) X-line diffraction measurement method X-line diffraction device Goniometer PM manufactured by Rigaku Denki Co., Ltd.
G-S2 and rate meter ECP-D2 were used.

The conditions used were as follows. However, the sample is 105
It was dried for 3 hours in a constant temperature dryer at °C and ground in an agate mortar for use.

Table A below shows typical X-ray diffraction images of type A zeolite. In this specification, an X-line diffraction image that is substantially the same as the above-mentioned X-line diffraction image is one in which the relative intensity of each diffraction peak is within a certain range, generally within ±30%, particularly within ±20%. It means that it can change.

Furthermore, in this specification, crystallinity refers to a value measured by the following method. (11) Measurement of crystallinity (CR) (a) Obtain the X-line diffraction curve of the sample using the powder X-line diffraction method described above.

(b) Points corresponding to 2θ=9 times and 20=39 times of the diffraction curve are connected with a straight line to form a baseline.

(c) The lowest points between the valleys of adjacent diffraction peaks (excluding those where the distance between the diffraction peaks is smaller than one valley) are connected to form an amorphous line. ((d) The area between the base line and the amorphous line is SAl, the area between the amorphous line and the diffraction curve is SO, and the crystallinity (%
).

If the aforementioned X-ray diffraction image contains diffraction peaks of quartz, cristobalite, feldspar, etc. contained in the raw materials, etc., and there is relatively little crystallization into zeolite, crystals other than these zeolites may also be crystallized. Although the degree of crystallinity is determined as a result of calculation as a fraction, it does not pose a problem in terms of relative comparison.

(Iiii) Calcium ion exchange amount (CI) measurement method: Approximately 300 mg/' (DH3O) of hardened stock solution as CaO
The calcium-containing solution was adjusted to have a concentration of .

Collect 500 mL of this calcium-containing solution in a 1e beaker, heat it to 30°C, dry it in a constant temperature dryer at 110°C for 2 hours, put it in a desiccator and let it cool to room temperature. Accurately weigh it using an indicator scale and add it to this calcium-containing solution. Stir with a jar tester (1
20 r'Pm for 20 minutes) to exchange calcium ions in the sample, and then NO. 6. Filtered through No. 6 mulch paper, accurately collected 10 ml of this mulberry liquid, diluted with ion-exchanged water to make about 50 ml, added 4 ml of 8NK0H to adjust the pH to 12, added a few drops of 5% KCN, and then added NN. Indicator 0.1y
was added and titrated using 8 volumes of M/100 EDT to determine the CaO concentration in the solution, and the amount of calcium ion exchange (M9/y) was calculated using the following formula. Calcium ion exchange amount (M9 Harini A-56BFA: CaQ of hard water stock solution)
Agricultural degree (M9/e) B: M/100EDT 8 volume liquid titer (
ml) F: M/100EDT 8 volume liquid factor (Iv)
Primary particle diameter (Dp) measurement method In this specification, the primary particle diameter (Dp) of each sample refers to the diameter of one side of a cubic particle when each particle is directly measured using an electron microscope in a well-dispersed state. Long term.

The measurement method is as follows. Place an appropriate amount of sample fine powder on a glass plate, add approximately the same volume of paraffin wax or vaseline as the sample, mix well with a small stainless steel spatula, add a small amount of ethanol, and mix thoroughly on the glass plate. do. This is placed on a mesh for electron microscopy measurement, immersed in ethanol to elute paraffin, etc., and dried for 1 hour in a dryer at 60 to 70°C to volatilize the ethanol. Direct magnification of electron microscope 1 by conventional method.
It is operated under the conditions of 000 to 2000 times and photographic enlargement magnification 1C) Ffl, and the field of view is changed to obtain 10000 to 200 (4) times magnification electron micrograph images suitable for primary particle measurement of four sheets.

Select six representative particles from among the cubic particle images in the field of view, and use a scale to measure the length of one side of each cubic particle image that is considered to be as parallel to the viewing plane (mesh plane) as possible. However, the maximum value among these measured values was expressed as the primary particle diameter (Dp) in the examples of this specification.

(V) Secondary particle diameter (Ds) measurement method A PSA-2 daylight scanning rapid particle size analysis method was used.

In this measurement method, particles are suspended in a liquid and stirred to uniformly disperse the particles. The dispersed particles settle over time according to Stokes' law, and the difference in particle size creates a concentration distribution of particles in the liquid. Utilizing this principle, this method optically measures the particle concentration distribution after a certain period of time and records the state by photoelectric conversion. The measurement method is as follows.

A 20 m9 sample was placed in a test tube with a stopper (capacity 1077!L), and 5 mt of 0.1% sodium hexametaphosphate solution was added to it.
throw into.

Attach this test tube with a stopper to a shaker and shake it for about 6 times for 1 minute.
Shake for 0 minutes to disperse the sample in the 0.1% sodium hexametaphosphate solution. This dispersed sample is transferred to the measurement cell (
8.5 cm in height, 2.0 cm in width, and 2.0 cTn in width), add ion-exchanged water accurately up to a certain mark (50 m1), set it in the device, stir well, and let it stand still. Activate the stopwatch at the same time. Next, operate the device to draw a particle size distribution curve and check the shape of the curve and approximate measurement time. This is done because unless water is added accurately up to a certain marked line, the top of the curve will sag and accurate values cannot be obtained. If it is determined that a sufficient curve can be obtained, an automatic recorder is activated to draw a particle size distribution curve. The density and viscosity of the solvent at this measurement time and liquid temperature are read from a pre-calculated table, and the particle diameter of the sample is calculated using a predetermined calculation sheet. After that, the recorded curve was divided into equal parts by the particle diameter, and the transmitted light intensity at the equally divided points on the curve was calculated, and the result was 10 g on a logarithmic conversion scale.
Read I. Thereby, the particle size distribution is calculated using a predetermined calculation paper. (Vi) Viscosity measurement method (using a B-type viscometer) Place the slurry to be measured into a 1000 mL beaker, taking care not to introduce air bubbles.

Immerse the measuring rotor of the B-type viscometer to the reference line, and set the rotor rotation speed to 20 r'. P. Read the torsion of the spring after 1 minute at C.m and multiply it by the factor of the rotor to calculate the viscosity. Displayed in P (centiboise). (Transition) Static stability (R, c.) The slurry to be measured adjusted to a concentration of approximately 40 (800°C dry standard) was placed in a 1000 mt type transparent wide mouth bottle (inner diameter approximately 95 m! n1
Height approximately 15077r! ! Pour 750Tn1 into each bottle (t) and cover with a lid. After leaving it in a room at 25°C for 2 minutes, pour off the top slurry using the tilting method and remove the slurry at the bottom of the bottle for about 5y.
The sample was sampled and the solid content concentration was measured in an electric Matsufuru pool at 800°C, and the standing stability R and C9 were determined using the following formula.

Example 2 Approximately 100 kg of the zeolite p-filtered cake (moisture 60°C) prepared in the same manner as in Example 1 was placed in a 100 liter stainless steel container and slurried using a powerful stirrer, and CO2 gas was added at a temperature of 15°C. A viscous zeolite slurry (PHll.O/15°C) was prepared by blowing.

In the same manner as in Example 1, various properties of the slurry zeolite obtained here were investigated and the results are listed in Table 2.

Claims (1)

[Scope of Claims] 1. Consists of an aqueous medium that cannot be substantially separated by filtration and fine zeolite particles dispersed and suspended in the aqueous medium, the fine zeolite particles having an electron microscope particle size of less than 1 micron and a particle size of 35 to 75%. The suspension has an X-ray crystallinity of 0.1 to 10
A zeolite aqueous suspension composition containing % by weight of alkali carbonate and having a solids concentration of 30 to 50% by weight on an anhydride basis. 2 Zeolite contains 100 mg/g or more of C on an anhydride basis
The composition according to claim 1, which is a zeolite having aO exchange ability. 3. The composition according to claim 1, wherein the zeolite is type A zeolite. 4. A freshly produced zeolite filter cake with an electron microscopic particle size of less than 1 micron and an X-ray crystallinity in the range of 35 to 75% is treated with 0.1 to 0.1 to 0.1 per zeolite on an anhydride basis. A method for producing a zeolite aqueous suspension composition, which comprises adding 10% by weight of alkali carbonate and mixing under strong shear stirring. 5. Producing active silicic acid or active aluminosilicic acid by treating a smectite group clay mineral with zeolite with an acid under conditions such that at least the X-ray diffraction peak of surface index [001] substantially disappears; the obtained active silicic acid Alternatively, activated aluminosilicate is treated with alkali hydroxide or water-soluble alkali silicate to produce alkali polysilicate or alkali polyaluminosilicate having a molar composition of Na_2O:SiO_2=1:3.5 to 1:500; Mixing the alkali polysilicate or alkali polyaluminosilicate with additional amounts of an alumina component, an alkali metal component, and water to produce a homogenized composition in which each component is in the A-type zeolite forming range; It is manufactured by heating a chemical composition to crystallize fine-particle zeolite having a primary particle size of less than 1 μm. The method according to claim 4, characterized in that: