JPS60118606A - Stabilized sodium percarbonate granule - Google Patents

Abstract

PURPOSE:Sodium percarbonate granules having improved water-vapor resistance, solubility, and storage stability, obtained by coating sodium percarbonate granules with boric acid or partially neutralized borate, or it and a water repellent. CONSTITUTION:Sodium percarbonate is sprayed with an aqueous solution containing 1-10wt% orthoboric acid or partially neutralized borate (e.g., Na2O. 2B2O5), and, if necessary, 0.02-0.2 water repellent [e.g., sodium siliconate (trade name)], and dried. Consequently, sodium percarbonate granules stable to water in a getergent composition and humidity in air, having no fear of decomposition at all even if it is brought into contact with zeolite in the detergent composition, stable during storage and in a state where it is blended with a detergent, slightly showing loss in active oxygen, having improved solubility at low temperature, is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides that upon storage, particularly in systems formulated with detergents,
Relating to sodium percarbonate granules stabilized against moisture decomposition.

It is well known that peroxygen compounds such as sodium percarbonate and sodium perphosphate are incorporated into powdered cleaning compositions as bleaching ingredients.

Sodium percarbonate, sodium perphosphate, etc. dissolve and decompose during washing, exerting a bleaching effect. in this case,
Sodium perborate has a slow dissolution rate at low temperatures, and is not particularly preferred as a bleaching ingredient in detergents in terms of its bleaching effect, especially in Japan where water or lukewarm water is primarily used.

On the other hand, demand for sodium percarbonate has increased rapidly in recent years because it has a high dissolution rate at low temperatures and can sufficiently exhibit bleaching effects.

However, sodium percarbonate is more sensitive to moisture than sodium percarbonate, and is relatively easily decomposed by moisture in the cleaning composition or moisture in the air at room temperature. Furthermore, the detergent composition also contains a substance that promotes the decomposition of sodium percarbonate, such as zeolite, and when it comes into contact with this substance, it tends to be easily decomposed.

Therefore, it is more carbonated than before)! Various methods have been proposed to prevent or suppress the decomposition of 1um and to obtain stabilized sodium percarbonate.

One common method is to coat granules with sodium percarbonate. In this case, as a covering material,
Stabilizing substances such as sodium silicate; protective inorganic substances such as magnesium sulfate, magnesium chloride, calcium chloride, barium chloride; or coating with a thin film using water-soluble organic substances such as polyethylene glycol; , a method of coating with a hydrophobic substance such as paraffin, fatty acid or its glycerin ester, or an alkanolamide derivative.

However, the stabilizing effect of the above-mentioned former method is not necessarily sufficient, and the present situation is that it is considerably decomposed and deactivated during storage. On the other hand, with the latter method, it is necessary to coat a considerable amount in order to fully exhibit the effect of preventing decomposition, and if a sufficient amount is coated to prevent decomposition, the dissolution rate will be significantly slowed down and bleaching will occur. It is insufficient in terms of effectiveness.

In view of the above-mentioned circumstances, the present inventors have conducted various studies on the coating agent for sodium percarbonate grains, and have used halonic acid or partially neutralized borate, and if desired, combined with a water repellent. By coating with
It has been found that stabilized percarbonate granules with excellent solubility can be obtained.

That is, the present invention provides a stabilized percarbonate coated with halonic acid or a partially neutralized borate, or with a ferrous acid or a partially neutralized borate and a water repellent. ) Regarding 11um particulate matter.

The sodium percarbonate granules of the present invention are stable against moisture in the cleaning composition or humidity in the air, and are free from the risk of being decomposed even if they come into contact with zeolite, etc. in the cleaning composition. It is stable during storage and when added to detergents, shows almost no loss of active oxygen, and has good solubility in sweetfish.

Boric acid used in the present invention refers to orthoboric acid, and partially neutralized borates are water-soluble alkali metal salts. This salt has the general formula “xM20-y1
It is a salt represented by 32Q5+ZH20, x/y=115 or 1/2, and has an aqueous solution pH of 5 to 8, preferably pH 6 to 7.5. Such a borate can be prepared, for example, by adding sodium carbonate to an aqueous solution of halonic acid while stirring until the pH of the solution reaches the desired pH.
Can be adjusted more easily.

Specifically, such borates include, for example, Na
2O-2B20s, sodium borate represented by Na2O-58205, Li2O.2B2Qs.

One example is lithium borate represented by Li2O.5B205. Among the above, partially neutralized borates are more preferred because they allow the spray solution to have a higher concentration when coating the sodium percarbonate particles.

The above boric acid or borate used in the present invention is 1 to 10% (by weight) based on sodium percarbonate,
It is preferably used at a concentration of 2 to 596 (by weight). If it is less than 1% by weight, it will be difficult to achieve a uniform coating and insufficient stabilization will occur. %, sufficient stabilization can be achieved, but on the other hand, the energy cost required for evaporating water after coating increases, making it impractical. In addition, if the pH of the solution is alkaline, exceeding 8, the hygroscopicity of the coated granules will increase and the stability will decrease. If the pH is lower than 6, a neutralization reaction occurs during spray drying, resulting in a large decrease in active oxygen, which is not preferable.

Furthermore, if a water repellent is used in conjunction with the coating of the sodium percarbonate particles, the dissolution rate will decrease somewhat, but the high humidity stability will further increase, so this is sometimes preferred. Examples of the water repellent include Tatoeba Sodium Silibnate (for example, Dry Seal C, trade name of Hatoshi Silicone), Po1onCx silicone oil K F 99 of Shin-Etsu Silicone (
The main component is methyl hydrodiene polysiloxane), Sanyo Chemical Industries' Fiisotol H (paraffin emulsion containing zirconium salt), and the like. The water repellent is preferably used in an amount of 0.02 to 0.296 (by weight) based on sodium percarbonate. If the amount of water repellent used is too large, the dissolution rate of the coated sodium percarbonate particles will be significantly reduced, which is undesirable.

A preferred embodiment of the odor coating method of the present invention is to spray an aqueous solution of halonic acid or a partially neutralized borate onto the oscillating sodium percarbonate granules by spraying and drying. Coating can also be done by other methods. In addition, when using a water repellent in combination, it is common to mix the water repellent solution with an aqueous solution of boric acid or a partially neutralized borate; After drying, the water repellent solution can be sprayed and dried in two stages for coating, which is one of the preferred embodiments when high humidity stability is particularly important.

The sodium percarbonate granules obtained by the present invention are extremely stable compared to those coated with conventional inorganic substances such as silicates and magnesium salts, and are more stable than those coated with fr organic substances such as fatty acids. Excellent dissolution rate,
A percarbonate with excellent stability and good solubility in a humid atmosphere! Since it is a 1 um granular material, it is suitable for blending into cleaning compositions.

Examples of the present invention are shown below.

Example 1 20 g of hydrolic acid (5% based on sodium percarbonate particles) was mixed with 80 g of water, and sodium carbonate powder was gradually added while stirring. When the pH of the liquid reached 7, the sodium carbonate powder was added. was discontinued to obtain a precipitate-free solution. In this case, the amount of sodium carbonate powder added is 6.2 g, which corresponds to about 7296 of the theoretical amount required for neutralization, and the above solution is a partially neutralized solution of sodium borate. Is recognized.

While rocking 400 g of sodium percarbonate particles in a fluidized bed, the above solution was applied to the particles for 60 minutes, and the temperature was 500 g.
13/min, gas inlet temperature 70°C1 temperature in fluidized bed
Spraying under conditions of 45°C followed by 15 min under flow at 55°C.
Let dry for a minute. Table 1 shows the physical properties of the obtained sodium percarbonate granules and the storage stability when added to detergents.

Example 2 20g (5% based on sodium percarbonate grains) of 5
A solution dissolved in 200 g of warm water at 0° C. was sprayed onto 400 g of sodium percarbonate particles in a fluidized bed while rocking them under the same conditions as in Example 1, followed by drying. Table 1 shows the physical properties of the obtained sodium percarbonate granules and the storage stability when added to a detergent.

Example 6 20 g of fluoric acid was mixed with water BOgVC, 0.8 g of sodium methyl siliconate (trade name, manufactured by Dry Seal C Toshi Silicon) was added as a silicon concentration, and carbonic acid was added as in Example 1. Sodium powder is added when the pH of the liquid is 7.
A precipitate-free solution was obtained. The solution was sprayed onto the percarbonate (II) particles under the same conditions as in Example 1.
Dry. Table 1 shows the physical properties of the obtained sodium percarbonate granules and the storage stability when added to a detergent.

Example 4 The process was carried out in the same manner as in Example 1, except that the concentration of borate to be sprayed onto the V rum grains (percarbonate) was 2.5%, which was half of that in Example 10 (2.5% for the 11 um grains of percarbonate). . Table 1 shows the physical properties of the obtained sodium percarbonate granules and the storage stability when added to a detergent.

Example 5 Sodium percarbonate, the concentration of borate to be sprayed on the grains was adjusted to the ffi of Example 1 (10% for the sodium percarbonate grains)
The same procedure as in Example 1 was carried out except for the following. Table 1 shows the physical properties of the obtained sodium percarbonate granules and the storage stability when added to a detergent.

Example 6 100 g of a 20% sodium borate solution with a pH of 7 obtained in the same manner as in Example 1 was mixed with 400 g of sodium percarbonate particles.
After spraying under the conditions of Example 10, after drying for 15 minutes, 16 g of a sodium methyl siliconate solution diluted to a silicon concentration of 55% was sprayed over a period of 10 minutes to form a silicon coating. Subsequently, it was dried for 15 minutes. Table 1 shows the physical properties of the obtained sodium percarbonate granules and their storage stability when added to detergents.
Shown below.

Comparative Example 1 The same procedure as in Example 1 was used except that a solution of 20 g of sodium metabolate (596 per sodium percarbon grain) dissolved in 80 gK of water was used, and a sample was coated with sodium metabolate. Sodium percarbonate granules were obtained. The physical properties of the granules and the storage stability when added to detergents are shown below.
Shown in 1.

Comparative Example 2 41 g of magnesium sulfate heptahydrate was dissolved in 160 g of water, and the solution was sprayed onto sodium percarbonate particles for 45 minutes under the same conditions as in Example 1. (approximately 5%) was dried for 15 minutes to obtain sodium percarbonate granules coated with magnesium sulfate. Table 1 shows the physical properties of the granules and the storage stability when added to detergents.

Comparative Example 5 The same procedure as in Example 1 was carried out except that a solution in which 20 g of sodium orthosilicate was dissolved in 8° gK of water was used. Table 1 shows the physical properties and storage stability of the granules.

Comparative Example 4 Myristic acid with a melting point of 55.5°C was melted at 70"C, and 20g of the liquid was sprayed in a fluidized bed at 65°C while shaking 400g of sodium peroxide particles. Thereafter, cold air was applied. was introduced and cooled for 20 minutes to obtain sodium percarbonate granules coated with myristic acid.The physical properties and storage stability of the granules are shown in Table 1.

*2 Dissolution rate refers to 5g of sample placed in 1B pure water at 25°C, and placed at a height of 6 degrees from the bottom of the beaker with a wingspan of 25 mm.
A glass stirring blade with a blade height of 40+m was installed, and the mixture was stirred at a constant rotational speed of 25 Orpm, and the time required for SPC to dissolve was measured, which was determined as the dissolution rate.

Storage test method Commercially available phosphorus-free synthetic detergent (water content: 8.296% (Karl Fischer analysis)) 2.7 g.

5 g of a blend of 0.5 g of SPC or coated SPC was placed in a 10 JIt sealed polyethylene container and subjected to a storage test in a heat cycle constant temperature bath in which 40° C. for 12 hours and 20° C. for 12 hours were alternately repeated. 1
The active oxygen content of the soot/pulls stored for 5, 50, and 60 days was determined by sodium thiosulfate titration (titration of I2 produced by KI and peroxide). The initial active oxygen was set as 100, and the residual rate of each oral sample was calculated.

Claims (1)

[Claims] oxalic acid or partially neutralized borate, or
Stabilized sodium percarbonate granules coated with oxalic acid or partially neutralized borate and a water repellent