JPS5846443B2 - Storage method for solid chlorite and hypochlorite - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a universal method for suppressing as much as possible the generation of gases such as chlorine and nitrogen chloride due to the decomposition of solid chlorites and hypochlorites.

Commonly used chlorites and hypochlorites include sodium chlorite, lithium hypochlorite,
Examples include bleaching powder containing calcium hypochlorite as a main component.

These solid chlorites and hypochlorites are generally put into practical use in powder form or in the form of granules, granules, or tablets.

Furthermore, a dried product with a moisture content of 1% or less is usually used.

These solid chlorites and hypochlorites are widely used as disinfectants, disinfectants, bleaches, etc. in various fields, but they decompose when exposed to the atmosphere. Generates harmful gases such as chlorine and chlorine dioxide.

For this reason, after manufacture, until they are put into practical use, they are generally stored and transported in airtight containers made of paper, plastic, metal, or the like.

However, when the storage and transportation period is long,
Even within these closed containers, a considerable amount of decomposed gas is generated, causing various undesirable and even dangerous events.

By adding additives to solid chlorite and hypochlorite,
Although various methods for suppressing decomposition have been proposed, the effects are not sufficient or the additives have an undesirable effect on the practical use of solid chlorites and hypochlorites.

The method of the present invention has an excellent effect of suppressing the decomposition of solid chlorite and hypochlorite, and even when stored for more than 10 months up to about 3 years, solid chlorite and hypochlorite The decomposition of the acid salt is minimal, and there is no damage to the container or deterioration of the printing ink.
Moreover, it is an object of the present invention to provide a method for preserving solid chlorite and hypochlorite, which has good heat-sealability in a container used, has high strength, and is non-hygroscopic.

In the method for preserving solid chlorite and hypochlorite according to the present invention, one or two types selected from the group consisting of calcium oxide, magnesium oxide, and boronic oxide are added to 100 parts by weight of the synthetic resin. It is stored under sealed conditions in a container made of a multilayer structure in which a synthetic resin layer containing 10 to 200 parts by weight of the above metal oxide is laminated on both the inner and outer surfaces of a synthetic resin layer containing no metal oxide. This method is characterized by

In a preferred embodiment of the method of the present invention, the synthetic resin is a polymer or copolymer of ethylene, propylene, vinyl chloride or vinylidene chloride, or a mixture thereof.

In another preferred embodiment of the method of the present invention, the thickness of the synthetic resin layer mixed with the metal oxide is 20 to 200 mm.
μ, the thickness of the synthetic resin layer not mixed with the metal oxide is 10 to 200 μ.

In yet another preferred embodiment of the method of the present invention, the weight of the metal oxide in the synthetic resin layer mixed with the metal oxide is the weight of the solid chlorite or hypochlorite to be stored. 0.1 to 10%.

The method of the present invention will be explained in more detail below.

In the method of the present invention, synthetic resin layers that do not contain metal oxides are laminated on both the inner and outer surfaces of the synthetic resin layer that contains metal oxides. .

In the method of the present invention, the metal oxide mixed into the synthetic resin of the middle layer is one or more metal oxides selected from the group consisting of calcium oxide, magnesium oxide, and boron oxide.

Metal oxides other than those mentioned above, such as JP-A-55-98274
Metal oxides and metal salts other than those listed in the above publication are significantly less effective than the metal oxides mentioned above.

The above metal oxide is mixed into the synthetic resin as a finely divided anhydride.

It is desirable that the size of the fine powder is smaller than the thickness of the middle layer.

The amount mixed into the synthetic resin is suitably in the range of 10 to 200 parts by weight per 100 parts by weight of the synthetic resin.

If the amount is less than 10 parts by weight, it is difficult to obtain the effects of the method of the present invention.

However, although the method of the present invention can be effective if the container capacity is made small relative to the container surface area, it is not economical in this case.

Moreover, if it exceeds 200 parts by weight, molding becomes difficult.

The amount of metal oxides in the intermediate layer must also be taken into account by the weight of solid chlorite and hypochlorite stored in the container.

Since these metal oxides play a major role in suppressing the decomposition of solid chlorite and hypochlorite, the weight of the metal oxides in the middle layer used in the container is It is necessary that the amount is 0.1% or more of the weight of the solid chlorite or hypochlorite to be stored.

Moreover, even if it exceeds 10%, the decomposition suppressing effect remains unchanged.

The above-mentioned method of mixing the metal oxide into the synthetic resin is carried out in the same manner as the method of mixing general processing aids, fillers, stabilizers, etc.

That is, it is mixed in by a method such as adding it during melt mixing of the synthetic resin or adding it during kneading with a single screw extruder.

The synthetic resin used in the method of the present invention may be of any type as long as it can be molded into a sheet or film.

Among these, polymers or copolymers of ethylene, propylene, vinyl chloride or vinylidene chloride, or mixtures thereof are preferred.

In the method of the present invention, the middle layer and the inner and outer layers are laminated to form three layers.
A container is formed by the triple structure.

The triple structure may be created by any conventional method.

For example, a blown film is formed by coextrusion of three layers, and a bag is formed by heat sealing.

In addition, a bottle is made from a three-layer coextruded parison by blow molding.

In addition, a method of laminating and adhering calender sheets is also used.

The thickness of the middle layer and the inner and outer layers as a three-layer structure is preferably in the range of 40 to 600 μm from the viewpoint of strength and practical use.

However, in the case of storage for a relatively short period of time, the thickness may be thinner than the above-mentioned lower limit thickness, and when it is desired to use a large container, it may be thicker than the above-mentioned upper limit thickness.

Further, it is effective to make the thickness of the inner and outer layers each 10 μm or more.

Therefore, it is preferable that the thickness of the middle layer is 20 to 200 μm, and the thickness of each of the inner and outer layers is 10 to 200 μm.

The method of the present invention is configured as described above.

In an embodiment, from the viewpoint of ease of storage, transportation, and strength, a plurality of three-layered packages are generally housed in an outer container made of stronger cardboard or the like.

In some cases, a three-layer structure container is used twice, and a plurality of the packages are placed in a stronger outer container.

In reality, the blow pin has an outer layer of 100μ, a middle layer of 250μ, an inner layer of 50μ, a total thickness of 400μ, and a capacity of 1 ton (polyethylene is used as the synthetic resin).

) containing solid chlorite or hypochlorite and sealing them with polyethylene caps. 600 bottles were made, stored and transported, and good results were obtained.

In addition, when it is desired to store a relatively large amount of solid chlorite or hypochlorite in a fiber drum, the fiber drum may be lined with the three-layer structure used in the method of the present invention. good.

When the fiber drum has sufficient airtightness, the three-layer structure used in the present invention may be used as a lid.

Furthermore, the container in the method of the present invention is stored in a cardboard box and used as a plurality of containers for storing solid chlorite or hypochlorite, or as a large bag or outer bag for storing microcrystals. You may.

Since the method of the present invention is configured and carried out as described above, it can produce many excellent effects as described below.

That is, solid chlorite and hypochlorite can be stored for a long time of 10 months or more, approximately 3 years, while suppressing their decomposition.

Therefore, when the container is opened, there is almost no odor of decomposed gas such as chlorine or chlorine dioxide, and there is no damage to the container or deterioration of the printing ink.

Furthermore, since both sides of the container are made of synthetic resin layers that do not contain metal oxides, the container has good heat sealability and does not absorb moisture.

Additionally, this container is dog-proof.

Therefore, the method of the present invention is of great practical value.

Next, examples of the method of the present invention will be described.

In the example, several types of solid chlorite and hypochlorite were stored and sealed in a three-layer plastic film bag made of various metal oxides, and after being stored under certain conditions, the condition was observed with the naked eye. Evaluation was made through observation and sensory testing.

In addition, as a comparative example, when a plastic film containing no metal oxide was used for the container, JP-A-55-982
When a single-layer plastic film containing a metal oxide as proposed in Publication No. 74 is used, and a two-layer structure in which a plastic film not containing a metal oxide is laminated only on the outside of the plastic film containing a metal oxide. A storage test using a body film was conducted in the same manner as in Examples.

Specifications, conditions, etc. for each material, test, evaluation, etc. are as follows.

1) Test solid chlorite and hypochlorite (11 Calcium hypochlorite reagent grade highly bleached powder (hereinafter referred to as bleaching powder).

), water content 0.24%, particle size 0.1-0.35%, available chlorine content 6804%.

(2) Sodium chlorite reagent-grade sodium chlorite (hereinafter referred to as juxtaposed soda).

), moisture 0.11%, particle size 0.3-i, om, available chlorine content 69.7%.

2) Metal oxides calcium oxide (Cab), magnesium oxide (M, 9
0) and boron oxide (B203) were used, and in both cases fine powders passing through a 300 mesh sieve (0.04671a or less) were used.

3) Synthetic resins, containers and packaging methods Synthetic resins include polyethylene high-density products and low-density products 1:
A mixture of 1 (PE) was used.

For the layer in which metal oxide is mixed, this is kneaded and melted with a synthetic resin, made into a single-layer or multi-layer inflation film with a thickness of 120μ or 180μ by single-layer, double-layer or triple-layer coextrusion, and then cut and heat-sealed. 2sOm (vertical) x 220. m
After printing the product name, design, directions for use, etc. on the container surface using chlorine-resistant printing ink, put 1 Kp each of solid chlorite or hypochlorite. ,
It was sealed by heat sealing.

4) Storage method The package obtained in the previous section 3) was stored in a constant temperature and humidity chamber at 40° C. and 80% relative humidity for 40 days.

5) Evaluation items and evaluation methods (1) Chlorine odor when opening the inner bag It was evaluated in the following four stages by sensory test.

○ Almost no odor Weak odor △ Fairly strong odor × Extremely strong odor (2) The amount of active ingredients in solid chlorite and hypochlorite was measured by the iotomer I-IJ method and the active ingredients were decomposed. Measure the rate.

Table 1 shows the specifications and conditions in Examples and Comparative Examples, and Table 2 shows the evaluation results.

As is clear from Tables 1 and 2, in the Examples according to the method of the present invention, there was only a slight chlorine odor upon opening.

On the other hand, the evaluation values of the comparative examples that were not based on the method of the present invention were significantly inferior.

In particular, Comparative Examples 1 and 2, which used single-layer plastic films that did not contain metal oxides such as CaO, were evaluated as poor.

Comparative Examples 1 and 2 correspond to the three-layer structure of the present invention without the metal oxide, but are not as good as the actual examples.

Claims (1)

[Claims] 1 Calcium oxide, based on 100 parts by weight of synthetic resin.
A synthetic resin layer containing no metal oxide is provided on both the inner and outer surfaces of the synthetic resin layer containing 10 to 200 parts by weight of one or more metal oxides selected from the group consisting of magnesium oxide and boronic oxide. A method for preserving solid chlorite and hypochlorite, characterized by storing them in a sealed container made of a laminated multilayer structure. 2. Storage of solid chlorite and hypochlorous acid according to claim 1, wherein the synthetic resin is a polymer or copolymer of ethylene, propylene, vinyl chloride, vinylidene chloride, or a mixture thereof. Method. . 3. Claim 1 or 2, wherein the synthetic resin layer mixed with the metal oxide has a thickness of 20 to 200 μm, and the synthetic resin layer not mixed with the metal oxide has a thickness of 10 to 200 μm. Method for preserving solid chlorite and hypochlorite. 4. A patent in which the weight of the metal oxide in the synthetic resin layer mixed with the metal oxide is 0.1 to 10% based on the weight of the solid chlorite or hypochlorite to be stored. A method for preserving solid chlorite and hypochlorite according to claim 3.