JPS5833165B2 - Method for producing stabilized percarbonate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a stabilized percarbonate, and more specifically, when producing a percarbonate by reacting a carbonate with hydrogen peroxide, aminopolycarbonate The present invention relates to a method for producing percarbonate by crystallizing percarbonate in the presence of an amine salt of an acid.

A method of producing percarbonate by reacting hydrogen peroxide and carbonate is generally known, but even if only hydrogen peroxide and carbonate are reacted, the produced percarbonate is extremely unstable and cannot be used. It is not something that can be provided for.

For this purpose, attempts have been made to add stabilizers to the reaction system, and conventionally, pyrophosphate, dipyrophosphate, phosphate,
Alkali metal salts of aminopolycarboxylic acids such as sodium ethylenediaminetetraacetic acid (hereinafter sometimes abbreviated as EDTA) and sodium nitrilotriacetic acid (sometimes abbreviated as NTA below), silicates, tin salts, magnesium salts, etc. alone. Or it is known to be used in combination.

However, even when such stabilizers are used, the stability of the percarbonates produced is still insufficient, although the stability is improved compared to percarbonates produced without the use of these stabilizers.

For example, if percarbonate is added to a product and stored for a long period of time before it is used, percarbonate easily decomposes in the presence of water, so water must be removed sufficiently to prevent decomposition. A drying step is required, but the percarbonate must not decompose during this drying step, and the percarbonate itself must be stable if the drying step is not performed. .

The present inventors have made extensive research efforts to solve these problems, and have found that when hydrogen peroxide and carbonate are reacted, percarbonate is crystallized in the presence of a specific compound, resulting in an extremely stable percarbonate. The present inventors have discovered that it is possible to produce the following, and have completed the present invention.

That is, in producing a percarbonate by reacting hydrogen peroxide with a carbonate, the present invention uses one or more amine salts of aminopolycarboxylic acids consisting of nitrilotriacetic acid, ethylenediaminetetraacetic acid, and diethylenetriaminepentaacetic acid. This is a method for producing a stabilized percarbonate, which is characterized by crystallizing percarbonate in the presence of phosphorus. One or more of the acid salts or silicates, and one of the amine salts of aminopolycarboxylic acids derived from nitrilotriacetic acid, ethylenediaminetetraacetic acid and diethyletriaminepentaacetic acid.
This is a method for producing a stabilized percarbonate, which comprises crystallizing a percarbonate in the presence of a species or two or more species.

More specifically, carbonate and hydrogen peroxide are added simultaneously or alternately, continuously or intermittently to a mother liquor aqueous solution containing carbonate and hydrogen peroxide to cause a reaction, and sodium percarbonate is crystallized as crystals. This is a method for producing a percarbonate, in which one or more of the aminopolycarboxylic acid amine group or the aminopolycarboxylic acid amine salt and a phosphate or a silicate are present in the reaction system. .

The percarbonates thus obtained exhibit very good stability.

Carbonates used in the present invention include sodium carbonate, potassium carbonate, barium carbonate, magnesium carbonate, etc., but sodium carbonate is most preferred.

When added to the mother liquor, it may be anhydrous or have crystal water, and may be powdered or granular, but granular anhydrous is preferable.

Hydrogen peroxide is used in the form of an aqueous solution, and commercially available aqueous hydrogen peroxide solutions can be used.

In addition, examples of amine compounds that form salts with aminopolycarboxylic acids include aliphatic amines that form water-soluble salts, such as lower alkyl amines such as trimethylamine and ethyldimethylamine, and monoethanol dimethyl. Examples include oxyalkylamines such as amine, jetanolamine, jetanol monoethylamine, and triethanolamine.

In the method of the present invention, one or two phosphates or silicates may be used together with the amine salt of the aminopolycarboxylic acid.
By adding more than one species to the reaction system and using it in combination with the aminocarboxylic acid amine salt, a percarbonate with better stability can be obtained due to the synergistic action of the two.

Phosphates used here include orthophosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, metaphosphoric acid, hexametaphosphoric acid,
Examples of the silicates include alkali metal salts such as tetrapolyphosphoric acid, and silicates include alkali metal salts such as ortho-silicic acid, meta-silicic acid, No. 1 silicic acid, No. 2 silicic acid, and No. 3 silicic acid.

According to the present invention, even better results can be obtained by adding a magnesium compound such as magnesium sulfate.

Aminopolycarboxylic acids, which are generally used as stabilizers for percarbonates, are widely used as chelating agents.

It is believed that the chelating agent forms a complex with a substance that decomposes hydrogen peroxide, such as a heavy metal, and prevents the decomposition action of the heavy metal.

However, the amine salt of aminopolycarboxylic acid according to the present invention cannot necessarily be said to be an effective chelating agent when compared to the conventionally used alkali metal salts of aminopolycarboxylic acid such as sodium EDTA. Despite this, it shows an excellent stabilizing effect against percarbonates.

In the present invention, the amount of the amino salt of aminopolycarboxylic acid used is 0.5 to 25% per 1 kg of carbonate used in the reaction.
It is 0 mmol, and the weight of a car is 2.50 mmol.

The amount of phosphoric acid group or silicate used is 10 to 500 mmol as phosphorus or silicon per 1 kg of carbonate.

Next, the present invention will be explained with reference to examples.

Percentages in the examples are by weight.

Example 1 Various additives were added and dissolved in a predetermined ratio to the final sodium carbonate to a mother liquor aqueous solution consisting of 12.8% sodium carbonate and 4.1% hydrogen peroxide.

Then, at 20°C, the stirring Reynolds number (Re) was 10,000.
Under these conditions, sodium carbonate having an average diameter of 280 μm and 60 μm of a hydrogen peroxide aqueous solution were added simultaneously in amounts such that the final slurry concentration was 20 parts, each continuously over a period of 90 minutes.

The obtained soda percarbonate slurry was dehydrated for 3 minutes under a centrifugal acceleration of 900 G and then dried at 60°C.

Stability tests were conducted on the sodium percarbonate thus obtained in the presence of various additives as follows.

(1) Storage test: 50° C., 504 RH constant temperature room [Stored for 20 days, measured the amount of effective oxygen after 20 days, and determined the residual rate of available oxygen immediately after production.

(2) Detergent formulation test Put 9.5 g of detergent dough and 0.5 g of sample into a 50 cc container and stir well.

This is stored in an open state at 40'C and 80% RH for 12 days, and the residual rate of effective oxygen in sodium percarbonate is similarly determined.

The results are shown in Table 1.

Example 2 A solution prepared by dissolving a predetermined amount of magnesium sulfate in 10 g of water was gradually added to a 60% H2O2 aqueous solution si, ssg, and then water was added to bring the total to 100%! It was set as i.

Separately, prepare 285 g of water, add specified amounts of sodium metasilicate (nase hydrate) and a chelating agent, and then add 10 g of sodium carbonate.
2.35g was completely dissolved.

Add water to this ※※ and make the whole 4009.

After keeping this liquid at 20°C, 10 (l) of the solution prepared earlier was added and stirred vigorously.

After leaving it for 1115 minutes, it was placed in a 900G centrifuge for 3 minutes.
The resulting cake was dried at 60° C. for 2 hours.

The properties of the obtained soda percarbonate were measured in the same manner as in Example 1, and the results are shown in Table 2.

Claims (1)

[Scope of Claims] 1. When producing a percarbonate by reacting hydrogen peroxide with a carbonate, one or two amine salts of aminopolycarboxylic acids consisting of nitrilotriacetic acid, ethylenediaminetetraacetic acid, and diethylenetriaminepentaacetic acid are used. 1. A method for producing a stabilized percarbonate, which comprises crystallizing a percarbonate in the presence of more than one species. 2. Claim 1, wherein the amount of the amine salt of aminopolycarboxylic acid added is 2 to 50 mmol per 1 kg of carbonate.
A method for producing a stabilized percarbonate as described in Section 1. 3. In producing percarbonate by reacting hydrogen peroxide and carbonate, aminopolycarbonate consisting of one or more phosphates or silicates, and nitrilotriacetic acid, ethylenediaminetetraacetic acid, and diethylenetriaminepentaacetic acid is used. A method for producing a stabilized percarbonate, which comprises crystallizing the percarbonate in the presence of one or more amine salts of acids. 4 The amount of phosphate or silicate added is 10 to 500 mmol of silicon in the rinse per 1 kg of carbonate, and the amount of amine salt of aminopolycarboxylic acid added is 2 to 5 mmol per 1 kg of carbonate.
A method for producing a stabilized percarbonate according to claim 3, wherein the amount is 0 mmol.