JP2918824B2 - Dechlorination agent and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is useful for reducing residual harmfulness and bleaching of residual chlorine by reducing residual chlorine in tap water to chlorine ions by reducing the residual chlorine in tap water with a dechlorination agent, particularly calcium sulfite. And a method for producing the same.

[0002]

2. Description of the Related Art In general, as a dechlorinating agent, calcium sulfite powder granulated to a certain size (0.5 to 5 mm) using a water-insoluble binder is known.
As a method of using the method, a method in which granulated calcium sulfite particles are directly filled in a cartridge or packed in a non-combustible cloth and set in a cartridge, and then attached to a water tap is adopted.

[0003]

However, in the conventional dechlorinating agent, since a water-insoluble binder is used for granulating calcium sulfite, the calcium sulfite coated with the binder is not in contact with water. The water does not dissolve in the water, and its dechlorination ability is significantly lower than the amount of calcium sulfite that originally treats free chlorine in tap water, that is, the dechlorination capacity. Was. Although the problem that the dechlorination treatment capacity is reduced can be solved to some extent by reducing the amount of binder added during granulation, in order to obtain a granulated body having practical strength, the amount of binder added must be maintained to some extent. Therefore, there is a problem that the dechlorination treatment capacity of the conventional dechlorination treatment agent is at most about 35% of the raw material before granulation.

[0004] Therefore, a main object of the present invention is to provide a dechlorination agent and a method for producing the same, which make the most of the dechlorination ability of calcium sulfite itself.

[0005]

According to the present invention, as a means for solving the above problems, a calcium sulfite powder is used as a main component, and the calcium sulfite powder is contained in a weight ratio of 1 to 30% by weight with respect to the calcium sulfite. The present invention provides a dechlorinating agent bound by a binder having a water solubility, a low dissolution rate, and a viscosity of a 2% aqueous solution of 100 cP or more.

[0006]

According to the present invention, there is provided a dechlorination treatment characterized by comprising calcium sulfite powder as a main component and a water-soluble substance having a low dissolution rate as a binder for binding the calcium sulfite powder. Agent is obtained. The dechlorinating agent is, for example, a binder soluble in water and having a low dissolution rate is mixed with calcium sulfite powder, and the mixture is subjected to a general granulation method such as extrusion granulation, stirring granulation, and uniaxial press molding. , And can be manufactured by granulation and / or molding using a general molding method such as CIP molding.

The water-soluble binder having a low dissolution rate includes sodium starch glycolate, sodium starch phosphate, carboxymethylcellulose calcium, sodium carboxymethylcellulose, methylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, hydroxypropylcellulose, and the like. Representative examples include, but are not limited to, sodium alginate, propylene glycol alginate, sodium polyacrylate, polyvinyl alcohol, and sodium silicate, which are essentially soluble in water and have a slow dissolution rate. Anything is fine. These binders can be used alone or in combination of two or more.

Further, as the binder, a commercially available product sold for food or medicine may be used. In this case, those having various solubilities are commercially available depending on the degree of polymerization, the substitution rate, and the like. For example, methylcellulose has a low methylation degree (substitution degree of 0.1 to 0.1) depending on the substitution degree per glucose group.
9), medium methylation degree (substitution degree 1.6 to 2.0) and high methylation degree (substitution degree 2.4 to 2.8). Although these are commercially available, it is preferable to use those having a cold water-soluble substitution degree of 1.6 to 2.0.

Further, the binder is usually 2%
Those having an aqueous solution viscosity of 100 cP or more are suitable. This is because if the 2% aqueous solution viscosity is less than 100 cP, it is difficult to obtain granules having sufficient strength. In addition, the mixing ratio of the binder to calcium sulfite is basically selected according to the water flow conditions and the set capacity of the final product.
An amount corresponding to 1 to 30% based on the amount (weight) of calcium sulfite is preferred. If the amount of the binder is 1% or less, the sustained release effect of gradually dissolving and releasing calcium sulfite cannot be obtained. This is because chlorine capacity is reduced.

According to the present invention, calcium sulfite granules and compacts having a high chlorination ability can be easily produced, and the calcium sulfite as the raw material before granulation has a dechlorination capacity of 80%. % Of dechlorinating agent that can be demonstrated with an efficiency of more than 10%, and its ability is high. Can be reduced.

[0011]

Example 1 Polyvinyl alcohol was used as a binder, dissolved in 1 L of water, added at a ratio of 5 parts by weight to 100 parts by weight of calcium sulfite powder, and kneaded sufficiently. Extrusion molding was performed with a diameter of 2 mm, and this was dried to obtain a spherical granule, which was used as a sample A of a dechlorinating agent.

[0012]

Example 2 Using methylcellulose as a binder,
This was added in an amount of 5 parts by weight with respect to 100 parts by weight of calcium sulfite, thoroughly mixed and homogenized, and then pressed to obtain a 20 mmφ spherical granule, which was dechlorinated. Sample B of the treatment agent was used.

[0013]

COMPARATIVE EXAMPLE Ethyl cellulose was used as a water-insoluble binder, dissolved in ethanol, added at a ratio of 5 parts by weight with respect to 100 parts by weight of calcium sulfite, kneaded sufficiently, and then mixed with a diameter of 2 mm. To obtain a spherical granule, which was used as sample C of the dechlorinating agent.

Separately, a commercially available dechlorinating agent containing calcium sulfite as a main component and ethyl cellulose as a binder was prepared as Sample D.

5 g of each of the above samples was put into a vinyl chloride cartridge, and tap water having a residual free chlorine concentration of 0.4 ppm was added to 1 cartridge.
Water is passed at 0 L / min, and the free residual chlorine after water is passed is 0.
The amount of water at the time of exceeding 01 ppm was regarded as the treated water amount. Table 1 shows the chlorination capacity of each sample based on the theoretical chlorination amount (4823 L) of the calcium sulfite used as the reference (100).

[0016]

Table 1 Sample binder Amount of treated water Chlorination ability A Polyvinyl alcohol granules 4000L 82.9% B Methyl cellulose molded products 4800L 99.5% C Ethyl cellulose granules 1500L 31.0% D Commercially available granules 53L 0 .7%

From the results shown in Table 1, it can be seen that the dechlorinating agent according to the method of the present invention is remarkably superior in chlorination ability as compared with the conventional one of the comparative example.

[0018]

As is clear from the above description, the present invention uses a substance soluble in water and having a low dissolution rate as a binder to granulate or mold calcium sulfite. The calcium sulfite is gradually dissolved and released, and the dechlorination capacity of the calcium sulfite itself can be exhibited with an efficiency of 80% or more.

Claims (2)

(57) [Claims] 1. A calcium sulfite powder and a water-soluble binder having a low dissolution rate for binding the calcium sulfite powder, wherein the water-soluble binder is added in an amount of 1 to 30% by weight based on the calcium sulfite powder, and The water-soluble binder is sodium starch glycolate, sodium starch phosphate, carboxymethylcellulose calcium, carboxymethylcellulose sodium, methylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, hydroxypropylcellulose, sodium alginate, propylene glycol alginate, sodium polyacrylate. , Polyvinyl alcohol, sodium silicate, and a 2% aqueous solution having a viscosity of 100%. A dechlorinating agent having a cP or more. 2. Sodium starch glycolate, sodium starch phosphate, carboxymethylcellulose calcium, carboxymethylcellulose sodium, methylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, hydroxypropylcellulose, sodium alginate, propylene glycol alginate, sodium polyacrylate , Polyvinyl alcohol and sodium silicate, which are soluble in water and have a low dissolution rate, and a 2% aqueous solution having a viscosity of 100 cP
A method for producing a dechlorinating agent, characterized in that the above water-soluble binder is added to the calcium sulfite powder in an amount of 1 to 30% by weight, mixed and granulated.