JPS6060905A - Manufacture of peroxide having superior disintegrability in water - Google Patents

Abstract

PURPOSE:To obtain a granular peroxide having superior disintegrability in water by adding a water soluble polymer contg. acylic acid (deriv.) as a monomer component and having a specified average degree of polymn. to a powdery peroxide when the peroxide is granulated. CONSTITUTION:A water-soluble polymer contg. acrylic acid (deriv.) as a monomer component and having <=10,000 average degree of polymn., e.g., sodium polyacrylate is added to powder of a peroxide such as sodium percarbonate or sodium perborate by about 0.1-1% of the amount of the peroxide. An adequate amount of water is added to the mixture, and they are kneaded, extruded with an extrusion granulator, and dried with a fluidized drying machine to obtain the desired granular peroxide having superior disintegrability in water. The granular peroxide is suitable for use as a bleaching agent, a disinfectant or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing granular peroxide having excellent disintegration and spreading properties in water.

The peroxide in the present invention is soda percarbonate.

Refers to hydrogen peroxide derivatives such as sodium percarbonate, sodium sulfate, sodium chloride, and hydrogen peroxide adducts.

These peroxides are industrially useful substances as oxygen bleaches or disinfectants, but in order to be effective in these applications, they must dissolve quickly in water. In addition, it is preferable to granulate the several-dimensional peroxide without dividing it into granules.

The granulator used for granulating peroxide is an extrusion granulator that mixes the mixture with a niegu in the presence of a suitable binder and water and then extrudes it from a perforated plate, or a Henschel mixer.
Mixing granulators such as granulators are commonly used.

Furthermore, a granulation method has also been proposed in which the mixture is kneaded and mixed using a kneader that applies appropriate pressure, is once formed into a certain size, and is then crushed and granulated using a crusher.

However, peroxide simply granulated by these granulation methods has poor disintegration properties and slow dissolution rate when thrown into water.

In order to obtain a peroxide with a high dissolution rate in low temperature water, it is essential to add a good disintegrant.

The present inventors have completed the present invention after studying various additives that can quickly disintegrate and disperse granular peroxide when it is thrown into water, thereby quickly dissolving it. Ta.

That is, the present invention uses acrylic acid or acrylic acid derivatives when granulating powdered peroxide. This is a method for producing a peroxide having excellent disintegration in water, which is characterized by adding a water-soluble polymer as a monomer having an average degree of polymerization of 1oooo or less.

A typical example of the polymer used in the method of the present invention is polyacrylic acid having a relatively low molecular weight and is commercially available under the trade name "Toxanone" (Sanyo Chemical Industries, Ltd.). The amount added can range from 0.01 to 5.0% based on the raw material, sodium percarbonate, but preferably 11 to 1.0%.

The polymer used in the method of the present invention is excellent not only as a disintegrating agent but also as a binder, and can be used without the need for CMC or water glass, which were conventionally added during granulation. It is possible to make granules with a strength of Of course, it is also possible to use these binders together.

Conventionally, disintegrants for granules include cellulose sodium glycolate (CMC), cellulose calcium glycolate,
Starch etc. are known. It is thought that the disintegration mechanism of these conventional disintegrants is that the disintegrants swell in water, causing the granules to split.

The granular peroxide obtained by the method of the present invention has better disintegration and solubility in water than those using these conventional additives, and when the granules are thrown into water, the granules disintegrate very quickly. You can see a split occur. The mechanism of this is not well understood, but it is probably due to ion tension repulsion by the added polymer, and it is thought that the phenomenon progresses extremely quickly compared to the time required for conventional disintegrants to swell. It will be done.

The specific method of the present invention will be explained below with reference to Examples and Comparative Examples.

The "collapse depth" described below is a diameter of 15 crn.

Fill a cylindrical glass container with a height of 60 steel with pure water at 20°C to a height of 50 crn, and let the sample particles fall naturally from a height of 5 crn above the water surface and drop them into the water. The splitting is observed with the naked eye, and the depth from the water surface at that time is expressed in subunits, and the average value of 30 measurements is used.

Example granulation was carried out using the following three methods A, B, and C, and each additive was used in an amount of 1% based on the peroxide, and the results shown in Table 1 were obtained.

Method A: Add additives to peroxide powder, adjust the moisture content so that the moisture content is 14%, mix thoroughly with a mixer, and then
It was extruded through an extrusion granulator equipped with a screen with a diameter of 0.5 tan 96, and dried using a fluidized fluid dryer.
Granules of peroxide were obtained. It was sieved using a standard sieve, and all samples with 24 mesh pass to 60 mesh ON were used.

Method B: Dissolve the additive in water such that the peroxide powder has a water content of 18%.

The peroxide powder is put into a mixing agitation granulator, and the above additive aqueous solution is sprayed while stirring, and stirring is continued for 20 minutes to obtain a granulated product. Thereafter, the same treatment as method A was performed.

Method C: Dissolve the additive in water such that the moisture content of the peroxide powder is 18%.

The raw peroxide and the above aqueous solution were put into a pressurized kneader and kneaded well. After that, eight cross-shaped cutters were installed in a crushing chamber having a diameter of 20 cm and a height of 30 crn. The material was crushed at a rotation speed of 300° rpm. Thereafter, the process was carried out in the same manner as the method.

Comparative Example The results shown in Table 2 were obtained in the same manner as in the Examples except that the additives were changed.

Claims (1)

[Claims] 1. When producing granular peroxide by granulating powdered peroxide, the average degree of polymerization is