JPH03254828A - Zeolite slurry dispersant - Google Patents

Abstract

PURPOSE:To obtain a zeolite slurry showing low viscosity in high concn. and excellent in standing stability by adding a dispersant composed of a copolymer of monomers represented by specific general formulae. CONSTITUTION:A copolymer consisting of 25-60mol.% of a monomer represented by formula I (wherein R<1> is hydrogen or a methyl group and X is hydrogen, alkali metal, alkaline earth metal or an org. amino group) and 40-75mol.% of a monomer represented by formula II (wherein R<2> is hydrogen or a methyl group and R<3> is a 1-8C alkyl group) is added. As the org. amino group in the formula (I), ammonium or diethylammonium is designated. As the monomer represented by the formula I, methacrylic acid or a salt thereof is pref. and, as the monomer represented by the formula II, ethyl acrylate is pref. When this copolymer is added to the dispersant of zeolite, a zeolite slurry showing low viscosity in high concn. and excellent in standing stability is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a zeolite slurry dispersant having excellent static stability.

[Prior art]

Zeolites have useful properties such as ion exchange ability, adsorption ability, catalytic ability, and filling properties, so they are widely used industrially as detergent building blocks, water treatment agents, catalysts, and pigments for coated paper. be used -).

Zeolite used industrially has a diameter of 0.1 to 50 μm.
How fine is the particle size? ;Since it is a powder, it cannot be transported in large quantities.
When storing or using it, it is generally handled as a water slurry for convenience of handling.

However, this zeolite slurry has problems in fluidity and static stability when used as is, and is difficult to handle, so various methods have been devised for stabilizing the aqueous slurry.

For example, in Japanese Patent Application Laid-open No. 53-79905,
It is stated that sodium chloride, sodium bicarbonate, sodium carbonate, and the like are effective for achieving static stability.

Further, in Japanese Patent Application Laid-open No. 57-61617, it is described that the combination of alkali carbonate and carboxymethyl cellulose or carboxyl methyl starch is effective5).

However, with these static stabilization methods: 5)
In addition, the viscosity of the zeolite in the aqueous slurry will be lower) and the viscosity will be higher. ;The disadvantage was that the efficiency of bare skin transportation deteriorated.

E2 Problems to be Solved by the Invention The present invention aims to provide a dispersant for zeolite slurry that can improve the concentration of zeolite in the slurry and at the same time reduce the viscosity.

[Means to solve the problem]

The present invention is based on the knowledge that a copolymer of a specific (meth)acrylic carboxylic acid or its salt and a (meth)acrylic ester exhibits an outstanding effect in maintaining the static stability of a zeolite slurry. It was done based on.

That is, the present invention is represented by the general formula [■2: (However, in the formula, R' represents hydrogen or a methyl group, and X represents hydrogen, an alkali metal, an alkaline earth metal, or an organic compound group.) 25 to 60 mol% of monomer (A) and -Momona [■2: (However, in the formula, R2 is hydrogen or a methyl group, R3 is C1 to C
Provided is a zeolite slurry dispersant characterized by containing a copolymer with 40 to 75 mol % of a hexamer (B) represented by the formula (representing an alkyl group of 8).

In the above-mentioned method, examples of the organic amino group include ammonium, diethylammonium, triethylammonium, triethanolammonium, and the like. Moreover, in the above-mentioned hole [IT], R3 has a carbon number of 61 to C8.
The alkyl group is preferred.

The monomers represented by the above-mentioned monomers LIJ and L ([II) can be used alone or as a mixture of two or more kinds.

The monomer (A) represented by the general formula or a salt thereof is suitable.

In addition, as the seven months (B) expressed as -monana [IIE, specifically, methyl acrylate, ethyl acrylate (EA), n-butyl acrylate (n-B u A
), isobutyl acrylate (iso-BuA), 2-ethylhexyl acrylate (2EHA), methyl methacrylate, ethyl methacrylate, butyl methacrylate, or a mixture thereof, with ethyl acrylate being particularly preferred.

In the present invention, 25 to 60 mol%, preferably 25 to 45 mol% of the monomer (A) represented by -Momona+IJ or a salt thereof and the monomer (B) represented by the general formula CI[i 40
~75 mol%, preferably 55 to 75 mol% copolymerized product is used, but it has sulfonic acid groups, phosphoric ester groups, aromatic groups, and polyethylene okindo groups within a range that does not impair performance. Ethylenic monomer, e.g.
It is also possible to use copolymerized products in amounts of ~20 mol%.

The copolymer of the present invention has a viscosity of 1% by weight NaOH neutralized aqueous solution of 30 to 1500 CIl), preferably 100 CIl).
Cp to 1000 cp is suitable.

The above copolymers are generally soluble in water (5) and are added to the zeolite slurry in an emulsified state to be used as a dispersant. - If the monomer represented by Mon'a CII exceeds 60 mol%, the static stability will deteriorate, and - if the monomer represented by Mon'a [■] exceeds 75 mol%, the solubility in water will deteriorate. This results in a copolymer that does not exhibit an excellent static stability effect on zeolite.

Although the copolymer of the present invention can be synthesized by various polymerization methods, it is most easily synthesized by emulsion polymerization. At this time, the emulsifier is a general emulsifier, i.e., anionic surfactant such as alkyl sulfate ester salt, alkyl ether sulfate ester salt, nonionic surfactant such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenol, or PVA ( One or more protective colloid agents such as polyvinyl alcohol), anion-modified PVA, carboxymethyl cellulose, hydroxyethyl cellulose, and phosphates can be used.

As the polymerization initiator, ordinary water-soluble initiators such as persulfates, hydrogen peroxide, water-soluble azoamidine compounds, and water-soluble azoamide compounds are used, but persulfates, sulfites,
Redox initiators such as phosphites can be used. Moreover, it is also possible to use a chain transfer agent in combination to adjust the molecular weight. The reaction is preferably carried out at 50 to 100°C using a method such as adding monomers all at once, adding them in portions, dropping a monomer liquid, dropping a monomer emulsion, or the like.

The obtained copolymer can be used by neutralizing some or all of the carboxyl groups in the copolymer with a water-soluble alkali such as sodium hydroxide or jetanolamine, and dissolving it in water.

According to the dispersant of the present invention, zeolite having an average particle size of 0.2 to 5 μm can be stably dispersed in water, and excellent stationary stability can be obtained. The amount added can be arbitrary, but it is 0 for heptaolide as anhydride.
．． It is suitable to add in an amount of 0.01 to 6% by weight, preferably 0.1 to 4% by weight.

〔Effect of the invention〕

The thus obtained zeolite slurry to which the dispersant of the present invention is added exhibits extremely useful properties in practice, such as not only low viscosity at high concentrations but also excellent static stability. and the zeolite concentration is 30 to 60% by weight, preferably 40 to 55% by weight.
zeolite slurry can be stably obtained.

Therefore, the dispersant of the present invention can be widely used as a dispersion stabilizer for not only natural zeolites but also various synthetic zeolites.

Next, the present invention will be explained in detail with reference to Examples.

[Example 2 Example 1 Method for producing copolymer Monomer components include methacrylic acid: MAA: 33 mol%, ethyl acrylate CEAE 67 mol%, and emulsifiers include LES-Na (lauryl polyoquine ethylene sulfate ester Na salt, E A copolymer was synthesized by emulsion polymerization by continuous dropwise addition of a monomer mixture using potassium persulfate as a polymerization initiator.

That is, 2 g of LES-Na and 250 g of water were placed in a 500 mf separable flask equipped with a reflux condenser, a nitrogen inlet tube, a stirring device, and a monomer mixture dropping funnel.
After raising the temperature to °C, 50 g of a 1.13% potassium persulfate aqueous solution, 3 g of methacrylic acid, and 7 g of ethyl acrylate were added. After stirring for 20 minutes at a stirring speed of 25 rpm under a nitrogen stream to perform initial emulsification, the reaction solution was heated to 70°C, and 57.1 g of methacrylic acid and 132.9 g of ethyl acrylate were added.
A mixture of g was continuously added dropwise over 2 hours. One hour after the completion of the dropwise addition, 1.13% potassium persulfate aqueous solution lag was added.
The mixture was further aged for i=2 hours to consume unreacted monomers.

After cooling the reaction solution, 83 mesh! It was filtered through a filter screen to obtain a copolymer emulsion. The obtained copolymer was diluted with NaOH
The viscosity of a 1% aqueous solution of the neutralized product was 162 CI].

Preparation method of zeolite slurry The copolymer produced by the above method was neutralized with sodium hydroxide and then added to the zeolite at a ratio of 0.5% by weight to form a 44.5% by weight slurry as anhydrous zeolite. was shaped.

That is, 27.1 g of water to 4.45 g of copolymer emulsion
Then, 12.43 g of 1% sodium hydroxide aqueous solution was added and stirred to dissolve the copolymer. Next, 356 g of zeolite (@Mizusawa Kagaku Jiruton B) slurry prepared in advance at 50% by weight was added and stirred for an additional 30 minutes to obtain a 44.5% by weight zeolite slurry.

Copolymer viscosity measurement method After neutralizing the obtained copolymer with 1 equivalent of NaOH relative to the unsaturated carboxylic acid contained therein, 1% of the copolymer
An aqueous solution was prepared at 25° C. and 5 Qrpm.

Measurement was performed using a B-type viscometer for 1 minute.

Viscosity measurement of zeolite slurry Using a BL type viscometer, rotor No., 2.30 rpm,
The value was measured at 25°C for 1 minute.

Evaluation of static stability The adjusted theolide slurry was placed in a colorimetric tube with a 1001 nl scale and stopper, and the sedimentation rate was measured after a week of static storage at room temperature.

Examples 2 to 16 (meth)acrylic carboxylic acid and (
The charging molar ratio of meth)acrylic ester is 25/
75 to 60/40 and combined in the same manner as in Example 1 to obtain dispersants having different monomer compositions and copolymerization ratios. A zeolite slurry was prepared using these dispersants in the same manner as in Example 1, and the standing stability was evaluated.

The amount of dispersant added was also varied from 0.2 to 1.0% by weight, and the standing stability was similarly evaluated.

Comparative Example Comparative Example (1) did not use a dispersant, and Comparative Examples 2 to 4 used a dispersant having the components listed in the table to prepare zeolite slurries, and evaluated in the same manner as in Example 1. In addition, the dispersants of Comparative Examples 2 and 3 were prepared by the same method as Example 1.

The monomer composition of the copolymer, the copolymerization molar ratio, the viscosity of the copolymer, the amount of dispersant added, and the evaluation results are shown in the table.

Claims (1)

[Claims] General formula [I]: ▲There are mathematical formulas, chemical formulas, tables, etc.▼[I] (However, in the formula, R^1 represents hydrogen or a methyl group, and X represents hydrogen, an alkali metal, an alkaline earth 25 to 60 mol% of monomer (A) represented by similar metal or organic amino group) and general formula [II]: ▲There are mathematical formulas, chemical formulas, tables, etc.▼[II] (However, in the formula R^ 2 is hydrogen or methyl group, R^3 is C_
1 to C_3 alkyl group)
B) A zeolite slurry dispersant characterized by containing a copolymer with 40 to 75 mol%.