JP3390958B2 - Method for producing stable sodium percarbonate granules - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing stable sodium percarbonate granules, and more particularly to a method for producing stable sodium percarbonate granules suitable for use as a bleaching agent in detergents and the like.

[0002]

2. Description of the Related Art Sodium percarbonate is widely used as a bleaching agent, a detergent and a bactericide. Sodium percarbonate as a bleaching agent has excellent solubility at low temperatures, has a high bleaching effect, and is a stable compound under normal storage conditions. However, sodium percarbonate has drawbacks such as being unstable in storage in a high humidity state and in blending with a detergent. As a household detergent, a product containing a certain amount of sodium percarbonate as a bleaching agent is particularly desirable. However, in the case of blending with a detergent, contact with a builder such as zeolite or a small amount of water contained in the detergent may lead to loss of its stability, deteriorating the bleaching effect and deactivating the efficacy of the detergent. . Various proposals have heretofore been made to solve these problems. For example,
In Japanese Examined Patent Publication No. 63-56167, a method of coating with a magnesium sulfonate or a magnesium salt of a sulfuric acid ester, and in Japanese Examined Patent Publication No. 63-57362, these magnesium salts are further added with an alkali or alkaline earth metal sulfate. Method of coating with hydrochloride salt
No. 0-118606, a method of coating with boric acid or a partially neutralized borate and a water repellent, and JP-A No. 59-194000, a method of coating with borate and a magnesium compound, JP-B-3. -5279
No. 5 proposes a method of coating with a coating agent containing borate and silicate, and JP-A-50-129500 proposes a method of coating with a surfactant and a mixture of a surfactant and a water-insoluble compound compatible with the surfactant. Has been done. All of these methods are methods of avoiding contact with detergent components and stabilizing sodium percarbonate by coating with a specific agent, but these conventional methods of simply coating or containing the specific agent are used. However, the stabilizing effect in storage in high humidity conditions and in the state of being blended in a detergent is not sufficient, which is not satisfactory in practical use.

An object of the present invention is to solve the above-mentioned problems of the prior art, and in particular, to provide a method for producing sodium percarbonate granules having excellent stability during storage under high humidity conditions and in a state of being compounded in a detergent. To provide.

[0004]

Means for Solving the Problems As a result of intensive research aimed at achieving the above-mentioned object, the inventors of the present invention found a method showing a significantly superior effect as compared with the conventional method, and arrived at the present invention.

That is, in the present invention, when granulating sodium percarbonate into granules, sodium percarbonate is preliminarily mixed with an anionic surfactant and then granulated by a wet granulation method,
The sodium percarbonate granules are then treated with a solution of at least one sulphate salt selected from the group consisting of sodium sulphate, potassium sulphate and magnesium sulphate and a solution of an anionic surfactant to give the granules a sulphate and anion interface. A method for producing stable sodium percarbonate granules, characterized in that an active agent is attached.

In the present invention, first, a fine powder of sodium percarbonate in a wet state is granulated by a well-known wet granulation method, which is characterized by containing an anionic surfactant in advance.

As the sodium percarbonate to be used, it is preferable to use wet crystals obtained by reacting sodium carbonate and hydrogen peroxide in an aqueous solution, but sodium percarbonate fine powder in other states may be used.

The anionic surfactant can be added in the form of powder, aqueous solution, organic solvent solution or the like. Addition with an aqueous solution is desirable for uniform dispersion, but in this case, it is desirable to consider the water content to be suitable for granulation. The total water content at the time of granulation varies depending on the granulator used and the like, but is usually 5 to 20.
It is about% by weight.

The amount of anionic surfactant added at the time of wet granulation is preferably 0.01 to 2 with respect to sodium percarbonate.
% (% By weight, the same applies hereinafter), and more preferably 0.0
It is 5 to 1.0%. If the amount is less than 0.01%, a sufficient effect cannot be obtained, and if it exceeds 2%, the granulation property is deteriorated.

In the wet granulation process of the present invention, in addition to the anionic interfacial lubricant, general additives such as soda ash,
It is also possible to granulate by adding sodium bicarbonate, a chelating agent, a silicate, a magnesium salt and the like, and a binder such as polyacrylate, CMC and polyethylene glycol together.

As the wet granulation method, a known method can be adopted as appropriate, but an extrusion granulation method is particularly preferable. As the extrusion granulation method, there are a screw extrusion method, a ram extrusion method, a roll extrusion method and the like, and any of them can be used, but the screw extrusion method and the screen extrusion method are more preferable. The extrusion molding system may be of any suitable system, but a die system, a screen system, a cylindrical porous roll system, etc. are preferred.

Although granules are obtained in this manner, it is more preferable to form the granules into spherical or cocoon-shaped granules by a rolling granulator or the like after molding by the extrusion granulation method. Thus normal particle size 0.7
Granules of about 1.5 mm are obtained.

The surfactant used in the present invention needs to be an anionic surfactant, and the stabilizing effect of the present invention cannot be obtained with other types of surfactants such as cationic surfactants. The anionic surfactant is preferably a fatty acid salt form, a sulfonate salt form and a sulfate ester salt form, and the constituent salts are preferably sodium salts and potassium salts.

The fatty acid salt type surfactant is preferably a fatty acid salt having ₇ to ₂₆ carbon atoms (hereinafter, the number of carbon atoms is referred to as C ₇ to ₂₆ ), and more preferably a fatty acid salt having C ₁₂ to _18. is there. For example, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, arachidic acid, behenic acid,
Lignoceric acid, cyclohexanecarboxylic acid, hexahydrotoluic acid, oleic acid, zomarinic acid, linolenic acid, linoleic acid, ricinoleic acid, gadrenic acid, erucic acid, ceracoleic acid, cottonseed oil fatty acid, olive oil fatty acid, sunflower oil fatty acid, whale oil fatty acid, beef tallow Fatty acids, horse fat fatty acids, sheep fat fatty acids, lard fat fatty acids, coconut oil fatty acids, palm oil fatty acids, palm kernel oil fatty acids, soybean oil fatty acids, linseed oil fatty acids, castor oil fatty acids, rice bran oil fatty acids, rapeseed oil fatty acids, and hydrogenation There is a fatty acid salt made from animal and vegetable fats and oils such as the above-mentioned fats and oils fatty acids.

The sulfonate type surfactants include alkyl sulfonates, alkylaryl sulfonates and α-olefin sulfonates. The alkylsulfonate is preferably a sulfonate salt having a straight-chain or branched-chain alkyl group consisting of C ₈ ~ _26. More preferably sulfonate having an alkyl group consisting of _C 11 _{~ 18.} For example, decanesulfonic acid, dodecanesulfonic acid, tetradecanesulfonic acid, pentadecanesulfonic acid, hexadecanesulfonic acid, octadecanesulfonic acid, eicosanesulfonic acid; 2-ethyl-1-pentene-1-sulfonic acid, 2-ethyl-1- There are salts of pentene-1-sulfonic acid and 2-ethyl-2-hexene-1-sulfonic acid.

[0016] Preferably the alkyl aryl sulfonate is substituted by straight-chain or branched-chain alkyl substituent, more preferably an alkyl substituent of a straight chain or branched chain consisting C ₁₀ ~ ₁₆ made of C ₂ ~ ₂₀ Examples thereof include benzene, toluene, xylene, ethylbenzene, cumene, naphthalene sulfonate, and formalin condensates such as naphthalenesulfonic acid. For example, dodecyl (linear or branched) benzenesulfonic acid, decylbenzenesulfonic acid, tetradecylbenzenesulfonic acid, octadecylbenzenesulfonic acid, dodecyltoluenesulfonic acid, dodecylxylenesulfonic acid, butylnaphthalenesulfonic acid, dibutylnaphthalenesulfonic acid, isopropyl There are salts such as naphthalene sulfonic acid, diisopropyl naphthalene sulfonic acid, dinaphthyl methane sulfonic acid, monobutyl dinaphthyl methane sulfonic acid, dimonobutyl dinaphthyl methane sulfonic acid and diisopropyl methane sulfonic acid.

[0017] The α- olefin sulfonate are those preferably obtained by sulfonation of α- olefins consisting C ₆ ~ _30, it is a mixture of alkenyl sulfonate and hydroxyalkane sulfonate. For example α
-Hexadecene sulfonated compounds; salts of α-octadecene sulfonated compounds and α-eicosene sulfonated compounds, and the like.

The sulfate ester type surfactants include sulfated oil salts, higher alcohol sulfate ester salts, polyoxyethylene alkyl ether sulfate ester salts, polyoxyethylene alkylaryl ether sulfate ester salts and the like.

The sulfated oil salts include, for example, olive oil sulfate, sulfated castor oil, sulfated peanut oil, sulfated cottonseed oil, sulfated rapeseed oil, sulfated rice bran oil, sulfated whale oil, sulfated fish oil and sulfated beef tallow. It is a salt of sulfated oil made from animal and vegetable fats and oils.

[0020] The higher alcohol sulfate is preferably a primary or secondary sulfates of alcohols consisting of C ₆ ~ _26. More preferably primary or secondary sulfates of alcohols consisting of C ₈ ~ _18. For example, octyl, capryl, nonyl, decyl, undecyl, dodecyl, lauryl, tridecyl, myristyl, pentadecyl, cetyl, heptadecyl, stearyl, oleyl, nonadecyl, eicosyl, ceryl, cyclohexyl, 2-butyloctyl, 2-methylhexyl, 2- Ethylhexyl and 2-cetyl, sulfate ester salt having octyl group, undecane-6-sulfate ester, tridecane-7-sulfate ester, pentadecane-8
-Sulfate, heptadecane-9-sulfate, 2
-Methyl-7-ethylundecane-4-sulfate and salts of 3,9-diethyltridecane-6-sulfate, etc., soybean oil, linseed oil, rapeseed oil, coconut oil, palm oil,
There are sulfate salts of natural higher alcohols made from animal and vegetable oils and fats such as palm kernel oil, beef tallow, and mackerel oil.

The polyoxyethylene alkyl ether sulfuric acid ester salt is preferably a sulfuric acid ester salt of an ethylene oxide addition ether of a higher alcohol composed of C ₆ to ₂₆ , and the ethylene oxide addition group has a polymerization degree of 2 or more. Groups are preferred. More preferably _C 8 ~
_{It is a} higher alcohol composed of ₁₈ and the ethylene oxide addition group is a polyethylene oxide group having a degree of polymerization of 2 or more, more preferably 2 to 6.

For example, polyoxyethylene octyl ether sulfate, polyoxyethylene nonyl ether sulfate, polyoxyethylene decyl ether sulfate, polyoxyethylene dodecyl ether sulfate, polyoxyethylene lauryl ether sulfate, polyoxyethylene oleyl ether There are salts such as sulfuric acid ester, polyoxyethylene myristyl ether sulfuric acid ester, polyoxyethylene cetyl ether sulfuric acid ester and polyoxyethylene stearyl ether sulfuric acid ester.

The polyoxyethylene alkylaryl ether sulfate ester salt is a sulfate salt of an ethylene oxide addition ether of phenol and naphthol substituted with an alkyl group preferably composed of C ₄ to ₁₆ , and more preferably C ₈ to ₁₂ . , Ethylene oxide addition group has a degree of polymerization of 2
More preferably, it is a poly (ethylene oxide) group having a degree of polymerization of 2 to 6.

For example, polyoxyethylene octyl phenyl ether sulfuric acid ester, polyoxyethylene isooctyl phenyl ether sulfuric acid ester, polyoxyethylene diisobutyl phenyl ether sulfuric acid ester, polyoxyethylene nonyl phenyl ether sulfuric acid ester, polyoxyethylene decyl phenyl ether sulfuric acid ester, There are salts such as polyoxyethylene undecyl phenyl ether sulfuric acid ester and polyoxyethylene dodecyl phenyl ether sulfuric acid ester.

Thus, anionic surfactant-containing sodium percarbonate granules having a smooth surface and a high bulk specific gravity can be obtained.

In the present invention, the granules thus obtained are treated with a solution of at least one sulfate selected from the group consisting of sodium sulfate, potassium sulfate and magnesium sulfate and a solution of an anionic surfactant. Sulfate and anionic surfactant are attached to.

This treatment is first treated with a solution of sulfate,
It is then preferred to treat with a solution of anionic surfactant. The form of the solution may be either an aqueous solution or an organic solvent solution, but the aqueous solution is preferable from the viewpoint of ease of processing, economy and the like.

The treatment method is not particularly limited, but a method in which a sulfate and an anionic surfactant are attached to the granules and the solvent can be quickly removed is preferable, and the solution is sprayed onto the granules which are usually in a fluid state. The method of attachment is taken. The fluid state of the granules can be obtained, as is well known, by placing the granules in heated flowing air at about 50 to 100 ° C. The concentrations of the sulfate solution and the anionic surfactant solution used are not particularly limited, and may be, for example, 5
A solution having a concentration of about 30%, preferably about 10% to 30% is usually used. Specific examples of the device that can be used for the adhesion (application) include a pan coating device, a tumbling coating device, and a fluidized coating device. Particularly preferred is a fluid coating device. Thus, the sulfate and the anionic surfactant are coated on the surface of the granules and attached in a partially permeated form.

The amount of sulfate attached to the granule is preferably 1 to 20%, particularly 5 to 15%, based on sodium percarbonate, and the amount of the anionic surfactant is 0.5 to 10%, especially 1 to 10.
5% is preferable. If it is less than these amounts, a sufficient effect cannot be obtained, and if it is too large, the effective oxygen concentration is reduced more than necessary.

The sulfate solution and the anionic surfactant solution may be integrated or the treatment order may be reversed, but as described above, after the treatment with the sulfate aqueous solution, the anionic surfactant solution is used. A particularly remarkable stabilizing effect is obtained when treated with.

The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to the Examples.

(Examples) Examples 1 to 50 Sodium carbonate and hydrogen peroxide were reacted in an aqueous solution,
The produced crystals were separated by centrifugal filtration, and the obtained sodium percarbonate in a wet state was mixed with 3% of sodium carbonate, 0.5% of sodium polyacrylate as a binder, and the anionic surfactant added in granulation in Table 1. 5 to the surfactant shown in
A predetermined amount of a 10% aqueous solution was added, and then the mixture was adjusted to a water content of 11% with pure water and mixed. Next, a screw horizontal extrusion type granulator equipped with a screen having a hole diameter of 0.8 mm was used to form granules, and the granules were dried by a fluid dryer.
While 400 g of the obtained granules were blown with hot air of 100 to 105 ° C. in a fluidized spray coating device, 10 to 25% of the sulfate shown in the section of the sulfate salt of the spray permeation coating agent in Table 1,
It was made into an aqueous solution at 50 ° C., and a predetermined amount was sprayed little by little.

Next, 10 to 20% of the anionic surfactant shown in the section of the anionic surfactant of the spray-penetrating coating agent in Table 1 below,
It was made into an aqueous solution at 50 ° C., and a predetermined amount was sprayed little by little to permeate and coat it. After the spraying was completed, it was dried for 5 minutes as it was. The effective oxygen concentration of the obtained sodium percarbonate granules is 1
It was 1 to 13%. 5 g of the thus-obtained sodium percarbonate granules and 45 g of a commercially available straight chain alkylbenzene sulfonate-based heavy powder detergent (containing 10% synthetic zeolite and 3% water) were mixed well, and a polyethylene open container of 39 mmφ × 85 mmH was prepared. After being left for 48 hours under the conditions of 50 ° C. and 80% relative humidity, the residual available oxygen was measured and the stability (remaining available oxygen ratio) was calculated. The results are shown in Table 1.

Measurement of available oxygen was carried out by sodium iodothiosulfate redox titration method. For comparison, sodium percarbonate granulated granules containing no anionic surfactant and those obtained by permeating and coating a sulfate and an anionic surfactant alone were also tested in the same manner, and the results were compared. Is shown in Table 2.

All percentages are weight indications in terms of pure content that does not include water of crystallization and the like.

[0036]

[Table 1]

[0037]

[Table 2]

[0038]

[Table 3]

[0039]

[Table 4]

[0040]

[Table 5]

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI C11D 17/06 C11D 17/06 D06L 3/02 D06L 3/02 (56) Reference JP-A-6-136390 (JP, A) JP-A-5-319809 (JP, A) JP-A-61-117104 (JP, A) JP-A-61-77607 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C01B 15/10 C11D 3 / 39,7 / 54,17 / 06

Claims (8)

(57) [Claims] 1. When granulating sodium percarbonate into granules, an anionic surfactant is previously added to sodium percarbonate and then granulated by a wet granulation method, and then the sodium percarbonate granules are mixed with sodium sulfate, Characterized in that it is treated with a solution of at least one sulfate selected from the group consisting of potassium sulfate and magnesium sulfate and a solution of an anionic surfactant to attach the sulfate and anionic surfactant to the granules. Method for producing stable sodium percarbonate granules. 2. The adhesion of sulfate and anionic surfactant to the granules is carried out by fluidizing sodium percarbonate granules containing anionic surfactant produced by a wet granulation method in heated air, and then adding sulfuric acid. A process according to claim 1, which is carried out by spraying with a solution of a salt to first permeate the granules with a sulfate and then with a solution of an anionic surfactant to permeately coat the anionic surfactant. 3. The method according to claim 1, wherein the wet granulation method is an extrusion wet granulation method. 4. The method according to claim 1, wherein the anionic surfactant is a fatty acid salt type, a sulfonate type or a sulfate ester type surfactant. 5. The method according to claim 1, wherein the salt forming the anionic surfactant is a sodium salt or a potassium salt. 6. The method according to claim 1, wherein the amount of the anionic surfactant contained during granulation is 0.01 to 2% by weight based on sodium percarbonate. 7. The method according to claim 1, wherein the amount of sulfate to be attached to the granule is 1 to 20% by weight based on sodium percarbonate. 8. The method according to claim 1, wherein the amount of the anionic surfactant attached to the granules is 0.5 to 10% by weight based on sodium percarbonate.