JP2951745B2 - Method for producing spray-dried detergent particles - 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 a powder detergent including a drying step by a spray drying method. In particular, the present invention relates to a method for improving physical properties of spray-dried detergent particles.

[0002]

2. Description of the Related Art Conventionally, a spray drying method has been widely used for producing a powdery detergent composition. In particular, in powder detergents for clothing, a large amount (generally 30 to 50% by weight) of a bulking agent such as sodium sulfate, which hardly contributes to washing, is added to the composition.
In addition, by spray drying, hollow particle products having a bulk density of about 0.3 g / cm ³ have been produced.

However, such detergents have a low bulk density and, due to the low content of surfactants due to the use of extenders, have a large apparent amount during use and are bulky in commercial form. In addition, transportation costs increased and storage and display space was considerably required. This has caused problems in the secondary market and in handling by consumers. In order to solve these drawbacks, a number of methods for producing high-density granular detergents that can be washed with a small amount of use in recent years and have a compact product form have been proposed, and products produced thereby have been put on the market. I have.

[0004] In the production method of these high bulk density granular detergents, for example, JP-A-61-64798 and JP-A-62-16
No. 9900, JP-A-62-236897, JP-A-2-4909
As shown in the method described in Japanese Patent Publication No. 9-1997, in the process of producing a high bulk density granular detergent, a detergent composition slurry comprising a surfactant and a builder is dried and granulated by a spray drying method, and then this powder is used. A method for producing a high bulk density granular detergent is disclosed. In any of these methods, the amount of the inorganic substance such as sodium sulfate is reduced as compared with conventional detergents in order to reduce the amount used at one time, and the spray-dried detergent composition is used. In the particles, the ratio of organic substances such as surfactants, and furthermore, the proportion of the parts containing free moisture increases.
The detergent composition particles were soft and had high adhesiveness and had poor fluidity as compared with powder detergents containing a large amount of a conventional extender and produced only by the spray drying method. These reductions in powder physical properties are a major obstacle to continuing stable production in a powder detergent manufacturing process that is usually performed continuously, and cause a reduction in productivity. On the other hand, as a method for improving the physical properties of the detergent composition particles, there is, for example, a method described in JP-B-59-21360. In this method, the spray-dried detergent particles are made of an aluminosilicate powder having an average particle size of 5 μm or less and containing substantially no particles exceeding 10 μm, and the detergent particles are positively charged by friction to form an aluminosilicate fine powder. The negatively charged particles adhere to the entire surface of the detergent particles to modify the granular detergent. Here, it is described that it is not preferable to make the surface of the detergent particles sticky or to use a binder such as water in order to firmly adhere the aluminosilicate fine powder to the surface of the detergent particles.
However, normal detergent particles are a few percent (generally 3-10%).
%) Free water, and therefore the amount of static electricity generated by friction is small, and the surface electric resistance of the detergent particles is small. The generated static electricity is rapidly discharged in 0.1 seconds or less. The potential drops. Therefore, even if both are mixed and the aluminosilicate fine powder adheres to the entire surface of the detergent particles, a considerable proportion will immediately fall off, failing to achieve the initial purpose.

Further, Japanese Patent Publication No. 41361/1989 discloses a method of preventing particles from being adhered to the spray drying tower by introducing and turning fine particles into the spray drying tower. According to this method, it is thought that the physical properties of the detergent particles can be improved.However, fine powder introduced into the spray drying tower is exhausted during exhaustion from the spray drying tower, and the fine powder is used for dust collection. Since the separation is difficult, the surrounding environment is contaminated, and in order to prevent the contamination, an excessively large air purification device is required, which is not practical.

[0006]

In view of the above, in order to improve the physical properties of detergent composition particles produced by a spray drying method, to enable stable continuous operation and to improve productivity. As a result of intensive studies to achieve such an object in the manufacturing process of a high bulk density granular detergent including a spray drying process, the present invention has been completed.

[0007] That is, the present invention relates to a method of discharging a spray-dried tower.
In addition, at least one surfactant and at least one washing
Consisting of a pure builder, its surfactants and other organic substances
And the total amount of free water is 40% by weight or more and free
For detergent composition particles having a water content of 3% or more and a temperature of 40 ° C. or more,
Fine particles having an average particle diameter of 0.1 μm or more and 10 μm or less
0.5 parts by weight of powder based on 100 parts by weight of the detergent composition particles
Parts and not more than 5 parts by weight, and the two are mixed by air flow.
And a method for producing spray-dried detergent particles.

The present invention will be described in more detail. Detergent composition particles in which the total amount of surfactants and other organic substances and free water (water excluding stabilized water such as crystallization water) is 40% by weight or more can be conventionally produced at room temperature even if the amount is increased. Contains a large amount of the agent, has higher tackiness than powder detergents produced only by the spray drying method, and immediately after the usual spray drying, the temperature of the spray-dried particles is 40 to
Due to the high temperature of 80 ° C., the adhesiveness becomes higher and the fluidity becomes poor. Therefore, when such detergent composition particles are to be transferred to the next step, adhesion occurs in the transport equipment such as a conveyor transport equipment or a pneumatic transport equipment used in ordinary powder-related equipment, and a hopper It becomes difficult to discharge in storage / measurement facilities such as weighing tanks and measuring tanks, sometimes causing blockage. These obstacles made it necessary to temporarily suspend production and take countermeasures.
Production becomes intermittent and inefficient, and the quality of the products produced varies.

As a method other than the present invention, a method for avoiding these inconveniences is to reduce the temperature of the cleaning composition particles when discharged from the spray-drying tower so that the adhesion of the detergent composition particles due to the influence of the temperature is reduced. A method of relatively reducing the expression of sex. However, when performing this method, the viscosity of the detergent composition particles is relatively reduced, and if an attempt is made to lower the temperature of the detergent composition particles to 40 ° C. or less, which is expected to ensure fluidity, the inside of the spray drying tower It is inevitable to lower the temperature or increase the amount of outside air flowing into the spray-drying tower from the particle outlet of the spray-drying tower, resulting in a decrease in the thermal efficiency of the spray-drying tower. , And further reduce production capacity.

In the present invention, the total amount of the surfactant and other organic substances and the free water is 40% by weight or more, and the free water is 3% or more, and immediately after being discharged from the spray drying tower. The average particle size of the primary particles is 0.1 μm for the highly adhesive detergent composition particles having a temperature of 40 ° C. or higher.
A fine powder having a size of not less than 10 μm or less is added and mixed. In this case, since the surface of the detergent composition particles has high tackiness, the fine powder adheres firmly to the surface of the detergent composition particles to form a particle layer.
The adhesion of the fine powder particles is remarkably strong as compared with the adhesion by a force such as electrostatic attraction, and thereafter, the temperature of the detergent composition decreases, or the detergent composition easily peels off when subjected to another force. Not something like that. And this fine powder particle layer suppresses the expression of the tackiness of the detergent composition particles and improves the fluidity.

The surfactants constituting the detergent composition of the present invention include anionic surfactants such as alkyl benzene sulfonates, alkyl sulfates and soaps, and nonionic surfactants such as polyoxyethylene alkyl esters and higher fatty acid alkanolamides. Surfactants that can be used generally in detergents, such as surfactants.

Examples of other organic substances include organic polymer cleaning aids such as polyacrylates, carboxymethylcellulose salts, and polyethylene glycol, and fluorescent dyes. Examples of the washing builder include sodium aluminosilicate (hereinafter, referred to as zeolite), hard water softeners such as sodium tripolyphosphate, alkaline agents such as sodium carbonate and sodium silicate, and inorganic cleaning aids such as sulfites. .

Further, the detergent composition is constituted by components other than those exemplified here, and a substance exhibiting an effect at the time of washing and a component constituting the detergent composition are mixed in the raw materials to be contained in the detergent composition. Ingredients (eg sodium sulfate by-produced during the production of sodium alkylbenzene sulfonate)
Is optionally contained in the detergent composition as long as the function of the detergent is not hindered.

[0014] The fine powder is preferably selected from substances having a high cleaning contribution because it is finally contained in the detergent composition, and fine powders such as zeolite, sodium tripolyphosphate and sodium carbonate are preferable. .

[0015] Furthermore, if a small amount of the detergent composition particles exhibits a sufficient function to improve the physical properties of the powder, it is preferable to use a substance having a low cleaning contribution such as sodium sulfate, silicon dioxide, bentonite, talc and clay. Fine powders and fine powders of organic substances such as metal soaps can also be used.

The average particle size of the primary particles of the fine powder used is
It must be 0.1 μm or more and 10 μm or less. 0.1 μm
If it is below, it is difficult to handle the fine powder itself,
It has high cohesiveness and is difficult to adhere to the surface of the detergent composition particles in the form of primary particles, which is inconvenient. On the other hand, if it is 10 μm or more, it adheres to the surface of the detergent composition particles in the form of primary particles, but a sufficient effect of improving physical properties is not exhibited.

The amount of the fine powder used depends on the detergent composition particles 10
0.5 parts by weight or more and 5 parts by weight or less based on 0 parts by weight.
If the amount is less than 0.5 part by weight, a sufficient property improving effect cannot be obtained.
If the amount is more than 5 parts by weight, the amount of the fine powder becomes unnecessarily large, and the excessive fine powder soars up as dust in the process after the addition and mixing, thereby deteriorating the working environment and making it difficult to balance the composition of the final detergent composition. It is inconvenient.

Mixing of detergent composition particles and fine powder by air flow
If the method is mists using suction type air transport device after drying, or the like powder and detergent composition particles to the suction port is sucked simultaneously, or fine powder detergent composition particles after spray drying Is added, and the powder is sucked through the suction port of the pneumatic transport device, whereby the detergent composition particles and the fine powder are mixed by the turbulence of the air flow near the suction port.

[0019]

Next, examples of the present invention will be described, but the present invention is not limited to these examples.

The composition of the detergent composition particles in the present embodiment has the following composition.

Sodium linear alkyl benzene sulfonate (C ₁₀ -C ₁₃ ) 30 parts by weight Sodium alkyl sulfate (C ₁₂ -C ₁₆ ) 11 parts by weight Polyoxyethylene alkyl ether (C ₁₂ -C ₁₄ ) [Ethylene oxide average addition mole Number = 10] 4 parts by weight Soap 3 parts by weight Zeolite (4A type, 4.5 salt) 15 parts by weight Sodium carbonate 12 parts by weight Sodium silicate (No. 2) 12 parts by weight Sodium sulfate 2 parts by weight Polyethylene glycol (average molecular weight) 7500) 2 parts by weight Sodium polyacrylate (average molecular weight: 8000) 2 parts by weight Water 7 parts by weight The detergent composition particles are continuously discharged from the spray drying tower at a rate of 3 tons per hour, and the detergent composition particles at that time are discharged. The temperature is 65
° C, bulk density was 0.27 g / cm ³ .

Example 1 Temperature discharged from a spray-drying tower at a rate of 3 tons per hour 65 ° C.
Zeolite was added at a rate of 45 kg / h to the detergent composition particles of Example 1 and immediately transported vertically by a suction-type pneumatic transport device. The conditions of the pneumatic transportation were as follows: the pipe diameter was 60 cm, the pipe length was 25 m, the suction port was 60 cm × 100 cm, and the detergent composition particles / air (weight ratio) during transportation was 0.25. As the evaluation, 400 kg of the bulk density after transport, the breaking load and the detergent composition particles after transport were placed in an inverted quadrangular pyramid-shaped container having an upper surface of 180 cm square, a height of 140 cm, and a lower outlet having a circular shape with a diameter of 50 cm.
The time it took for it to flow out of the lower outlet,
The weight of the detergent composition particles remaining in the container was measured.

Example 2 Example 1 was carried out under the same conditions as in Example 1 except that the fine powder was changed to sodium tripolyphosphate (average particle size: 5.6 μm) and the fine powder supply rate was changed to 75 kg / h.

Comparative Example 1 The procedure of Example 1 was repeated except that no fine powder was added.
Performed under the same conditions as in 1 . Table 1 shows the measurement results of the temperature, the bulk density, the breaking load, the outflow time, and the adhesion amount in the container after transport of the detergent composition particles after mixing in Examples 1 and 2 and Comparative Example 1 .

The breaking load was based on the following measuring method. [Measurement method for breaking load] 15 g of powder is placed in a cylindrical mold having an inner diameter of 40 mm, the surface is leveled, and a 1 kg weight of 39 mm in bottom diameter is placed on the upper surface of the powder for 3 minutes. After that, remove the weight, remove the mold, and put 10g of 40mm in diameter on the upper surface of the completed cylindrical powder cake.
The total weight of the weight when the cake collapses is defined as the breaking load value.

[0026]

[Table 1]

From the results shown in Table 1 , Examples 1 and 2 show Comparative Example 1
It can be seen that the detergent composition particles were quickly discharged from the container due to the improved fluidity, and the amount of adhesion was small because the adhesion was reduced.

Comparative Example 2 In Example 1 , the amount of powdered zeolite added was 210 kg / hour (7% by weight), and the other conditions were the same. One minute after the start of the pneumatic transport operation, in the bag filter, which is an exhaust air purifying device installed at the outlet side of the pneumatic transport device, the pressure difference due to clogging causes a decrease in the transport air flow rate. It was not possible to continue. This is because excessive powder zeolite was added and excessive powder zeolite was attached to and deposited on the filter cloth of the bag filter, thereby inhibiting air flow. From this phenomenon, it is found that it is inconvenient to use more fine powder than necessary.

[0029]

According to the present invention, the physical properties of the spray-dried detergent particles, such as the bulk density, the breaking load, and the amount of adhesion, are improved, so that detergent composition particles having fluidity and reduced particle adhesion are obtained. It becomes possible.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C11D 11/00-11/02 C11D 17/06 B01J 2/00 WPI / L (QUESTEL)

Claims (1)

(57) [Claims] 1. The method according to claim 1 , wherein at least one of the spray-drying towers is discharged.
From one surfactant and at least one cleaning builder
Of the surfactant and other organic substances and free moisture
Total amount is 40% by weight or more and free water is 3% or more
The average particle size of the primary particles is added to the detergent composition particles having a temperature of 40 ° C. or higher.
Fine powder having a diameter of 0.1 μm or more and 10 μm or less
0.5 to 5 parts by weight based on 100 parts by weight of the composition particles
A method for producing spray-dried detergent particles, characterized by adding the following and mixing them by an air stream .