KR20080075030A - Method for producing detergent particles - Google Patents

Abstract

A method for producing detergent particles including the steps of spray-drying a slurry containing an anionic surfactant and increasing bulk density of the resulting particles with a high-speed mixer, wherein a mixing treatment is carried out at a given breaking load at 25°C and at a given degree of particle growth, i.e. an average particle size after a treatment of increasing a bulk density / an average particle size before a treatment of increasing a bulk density, wherein an extent of an increase in the bulk density before and after the treatment of increasing a bulk density is from 20 to 800 g/L.

Description

Method for producing detergent particle group {METHOD FOR PRODUCING DETERGENT PARTICLES}

The present invention relates to a method for producing a detergent particle group.

Currently, detergents on the market are largely classified into high-bulk density detergents (greater than 600 g / L), medium-bulk density detergents (400 to 600 g / L), low-bulk density detergents (250 g / L or more and 400 g / L). Less than L), liquid detergents, and the like. For example, high-bulk density detergents have been mainly used in Japan, but there is also a great demand for medium to low-bulk density detergents in Asia, Oceania, Europe and the like.

For low-bulk density detergents, the mainstream of its preparation is a process for preparing said detergent comprising the steps of combining anionic surfactants and other builders in the form of a slurry and spray-drying the slurry. On the other hand, for medium to high-bulk density detergents, the mainstream of their preparation is to formulate anionic surfactants and other builders in the form of slurries, and after spray-drying the slurries, increasing the bulk density for spray-dried particles. A method of making said detergent comprising the steps of applying a treatment.

In the preparation of the above medium to high-bulk density detergents, when the spray-dried particles are increased in bulk density by a high speed mixer equipped with a high speed shear mechanism or the like, generally the average particle is undesirably increased as the bulk density is increased. The size is increased. Therefore, it is known that disadvantages such as a decrease in solubility and product yield occur, and there is a real demand for improvement in both solubility and product yield. In view of these drawbacks, for example, in JP-A-Hei-1-247498, Freud number 50 to 1200 using a specialized rotary mixer in which the mixing blades are arranged in a spiral form. A method has been reported that includes continuously treating spray-dried particles to increase bulk density according to a method of applying very high shear, such as. However, the method has great constraints on the apparatus and operating conditions, and the increase in bulk density is up to 200 g / L.

 Until now, continuous mixing treatment of spray-dried particles containing anionic surfactants in a high speed mixer results in adhesion and aggregation of particles that cause viscosity of the anionic surfactants. Thus, the breakdown load gradually increases to even exceed at least 9,800 mN, resulting in coarse particles with an increase in bulk density.

Summary of the Invention

The present invention provides a method for preparing a group of detergent particles, comprising the steps of spray-drying a slurry containing anionic surfactant and increasing the bulk density of the resulting particles using a high speed mixer, the method comprising producing a detergent particle group at 25 ° C. of 9,800 mN or less. The mixing treatment is carried out at the breaking load value and the particle growth degree of 1.1 or less, that is, [average particle size after bulk density increase treatment / average particle size before bulk density increase treatment], where the bulk density increase before and after the bulk density increase treatment It relates to a method which is 20 to 800 g / L.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows that particle | grains are put into an adapter container and the molded object is made for the measurement of the breaking load value of particle | grains.

2 is a diagram showing an additional load on a molded article obtained by compression molding.

It is a figure which shows that a detergent molded object collapses by a load.

The present invention relates to a value in which the surface adhesion of the detergent particle group during the treatment does not exceed a certain value when expressed by a high-speed mixer equipped with a high-speed shearing mechanism or the like for a detergent particle (expressed as a breaking load value). And a process for treating the detergent particle population under conditions with a lower surface of 9,800 mN or less).

According to the present invention, medium to high bulk density detergents can be prepared without causing a decrease in solubility and product yield accompanied by an increase in bulk density. In addition, since the surface adhesiveness does not become a value higher than a predetermined value, it is less likely that the detergent particle group adheres inside the high speed mixer, and the detergent particle group having stable powder properties can be produced even during continuous production.

According to the present invention, the effect of enabling the preparation of medium-to high-bulk density detergents while suppressing particle growth is exhibited.

These and other advantages of the present invention will become apparent from the following detailed description.

The term "destructive load value" in the present invention refers to an index indicating the surface adhesion of the detergent particle group. The higher the breaking load value is, the higher the surface adhesiveness is, so that granulation proceeds in the detergent particles, resulting in the formation of coarse detergent particles.

In the present invention, the desired detergent particles can be prepared by appropriately combining the conditions as shown below to adjust the breaking load value to an appropriate level.

Compositionally, spray-dried particles containing anionic surfactants, organic polymers, and water-rich particles have high breakdown loads. Under the mixed processing conditions, the higher the peripheral speed of the main shaft, the faster the rate of increase of the breaking load value.

The term "detergent particle" in the present invention refers to a particle obtained by mixing the spray-dried particles containing anionic surfactants, other builders and the like, and the term "detergent particle group" means an aggregate thereof. In addition, the detergent composition as mentioned below contains a detergent particle group and also contains a detergent component (for example, a fluorescent substance, an enzyme, a perfume, an antifoam, a bleach, a bleach activator, etc.) added in addition to the detergent particle group. It means a composition to be.

<Spray-Dry Particles>

Spray-dried particles in the present invention are particles obtained by spray-drying an aqueous slurry containing anionic surfactants, other builders and the like. Each component used for this invention is demonstrated below.

1.Anionic Surfactants

Commonly used anionic surfactants can be used, such as linear alkylbenzenesulfonates, α-olefinsulfonates, alkyl sulfates, olefinsulfonates, fatty ester sulfonates, alkyl ether sulfates, and the like. Included. Such anionic surfactants may be used as a single component or in combination of two or more components. In addition, the counterion is preferably an alkali metal, more preferably sodium. Among the anionic surfactants, linear alkylbenzenesulfonate sodium (LAS-Na) is preferable from the viewpoint of economic advantages, storage stability and foamability, and more preferably LAS-Na having an alkyl group having an average carbon number of 10 to 15.

The aforementioned anionic surfactants are contained in the slurry in terms of detergency, preferably at least 10% by weight, more preferably at least 15% by weight, even more preferably at least 20% by weight of the resulting spray-dried particles. . In addition, the above-mentioned anionic surfactants are preferably not more than 40% by weight, more preferably 30% by weight of the spray-dried particles produced, in view of expanding the control range of the bulk density while suppressing the formation of coarse particles. It is contained in the slurry in an amount of up to%, even more preferably up to 25% by weight.

In the present invention, the essential components of the spray-dried particles are only anionic surfactants, but from the viewpoint of cleaning power, particle size distribution, and particle strength, other components commonly used in detergent compositions may optionally be contained in the spray-dried particles. have. For example, other components include water-soluble solid alkali inorganic substances, chelating agents, water-soluble inorganic salts, water-soluble polymers, water-insoluble excipients, nonionic surfactants, cationic surfactants, other auxiliary components, and the like. Especially, it is preferable to mix | blend a water-soluble solid alkali inorganic substance, a chelating agent, a water-soluble inorganic salt, and a water-soluble polymer with the said spray-dried particle.

In addition, the spray-dried particles of the present invention may optionally be blended with the substances set forth below.

2. Water-soluble solid alkali inorganic material

The term "water soluble solid alkali inorganic material" refers to an alkaline inorganic material that is solid at ambient temperature (20 ° C), wherein the material is at least 1 g, preferably at least 5 g, more preferably in 100 g of water at 20 ° C. It is preferable that 10 g or more can be dissolved. Although there is no restriction | limiting in particular as said water-soluble solid alkali inorganic substance, Alkali metal salt, a silicate, etc. which have a hydroxide group, a carbonate group, or a hydrogencarbonate group can be used. As said water-soluble solid alkali inorganic substance, sodium hydroxide, sodium carbonate, sodium hydrogencarbonate, potassium carbonate, sodium silicate, etc. are mentioned, for example. Especially, sodium carbonate is preferable as an alkali chemicals which show the suitable pH buffer range in washing liquid. The water soluble solid alkali inorganic material is preferably contained in the slurry in an amount of at least 5% by weight, more preferably at least 10% by weight, even more preferably at least 20% by weight of the resulting spray-dried particles. The water-soluble solid alkali inorganic material is preferably not more than 40% by weight, more preferably not more than 38% by weight, even more preferably 35% by weight of the resulting spray-dried particles from the viewpoint of not impairing the degree of freedom of blending. It contains in a slurry below.

3. Chelating Agent

Chelating agents may be formulated into spray-dried particles to inhibit inhibition of cleaning action by metal ions, examples of which are water soluble chelating agents and water-insoluble chelating agents.

As the amount of the chelating agent, the chelating agent is preferably 3 to 60% by weight, more preferably 5 to 40% by weight, even more preferably 10, of the spray-dried particles in view of the metal ion capturing ability. It is preferable to adjust the amount to be contained in an amount of from 40% by weight. Chelating agents include water-soluble chelating agents and water-insoluble chelating agents, and a plurality of chelating agents may also be blended simultaneously in the spray-dried particles, in which case it is preferable to arbitrarily adjust the total content to be the above-mentioned amounts.

The water-soluble chelating agent is not particularly limited as long as it is a substance having metal ion trapping ability. Water-soluble chelating agents which can dissolve 1 g or more in 100 g of water at 20 ° C are preferable, and for example, tripolyphosphate, orthophosphate, pyrophosphate and the like can be used. Among them, tripolyphosphate is preferable, and tripolyphosphate is preferably contained at 60% by weight or more, more preferably 70% by weight or more, even more preferably 80% by weight or more of the total water-soluble chelating agent. As the counterion, alkali metal salts are preferred, and sodium and / or potassium salts are more preferred.

A water-insoluble chelating agent may be added to the spray-dried particles for the purpose of improving the metal ion trapping ability and improving the strength of the spray-dried particles. Preference is given to water-insoluble chelating agents which can be dissolved in less than 1 g in 100 g of water at 20 ° C. For example, from the viewpoint of dispersibility in water, water-insoluble chelating agents having an average particle size of 0.1 to 20 탆, preferably 0.5 to 10 탆 are preferred. Preferred water-insoluble chelating agents include crystalline aluminosilicates, which include, for example, A-type zeolites, P-type zeolites, X-type zeolites and the like. Type A zeolites are preferred in view of metal ion trapping capacity and economic advantages.

As a content of crystalline aluminosilicate, it is preferable to mix | blend the said crystalline aluminosilicate from a viewpoint of a metal ion trapping ability so that the total amount of a chelating agent may be in the said range. On the other hand, from the viewpoint of suppressing the residue during washing, the crystalline aluminosilicate is preferably contained at 30 wt% or less, more preferably 20 wt% or less of the spray-dried particles.

4. Water Soluble Inorganic Salt

In order to improve the ionic strength of the washing liquid and to improve the effects such as sebum contamination cleaning, it is preferable to blend the water-soluble inorganic salt with the spray-dried particles. The water-soluble inorganic salt is not particularly limited as long as it is a substance having excellent solubility and not adversely affecting the cleaning power. For example, water-soluble inorganic salts which can be dissolved at least 1 g in 100 g of water at 20 ° C are preferred. As a water-soluble inorganic salt, the alkali metal salt or ammonium salt etc. which have a sulfate group or a sulfite group are mentioned, for example. Especially, it is preferable to use sodium sulfate, sodium chloride, sodium sulfite, or potassium sulfate with high ion dissociation degree as an excipient. Moreover, it is also effective to use together with magnesium sulfate from a viewpoint of a dissolution rate improvement.

The water-soluble inorganic salt is preferably contained in the range of 5 to 80% by weight, more preferably 10 to 70% by weight, even more preferably 20 to 60% by weight of the spray-dried particles.

5. Water soluble polymer

For the purpose of improving particle strength by forming a film on spray-dried particles, a water soluble polymer may be added to the spray-dried particles. As a water-soluble polymer, an organic polymer and an inorganic polymer are mentioned. For example, a carboxylate polymer, carboxymethyl cellulose, soluble starch, saccharides, polyethylene glycol, etc. are mentioned as an organic polymer, Amorphous silicate etc. are mentioned as an inorganic polymer. Among them, the carboxylate polymers are preferable, and carboxylates of acrylic acid among the polymer-salt and a salt of polyacrylic acid of maleic acid copolymer (counter ions: Na, K, NH _4, and so on) are more preferred. Carboxylate polymers having an average molecular weight of 1,000 to 8,000 are preferred, and those having an average molecular weight of at least 2,000 and having at least 10 carboxyl groups are more preferred. The organic polymer is preferably contained in an amount of 0.1 to 10% by weight, more preferably 0.5 to 5% by weight of the spray-dried particles. In addition, the inorganic polymer is preferably contained in an amount of 0.1 to 20% by weight, more preferably 0.5 to 10% by weight of the spray-dried particles.

6. Water-insoluble excipients

The water-insoluble excipient is not particularly limited as long as it is a material having excellent dispersibility in water and which does not adversely affect the cleaning power. Examples of the water-insoluble excipient include crystalline or amorphous aluminosilicates, silicon dioxide, hydrated silicic acid compounds, clay compounds such as barite and bentonite. In view of dispersibility in water, the water-insoluble excipient preferably has an average size of the primary particles of 0.1 to 20 탆, more preferably 0.5 to 10 탆.

Water-insoluble excipients are preferably contained in an amount of up to 50% by weight, more preferably up to 30% by weight of the spray-dried particles, in view of economic advantages and dispersibility.

7.moisture

Moisture is contained in terms of bulk density increase rate, preferably at least 0% by weight, more preferably at least 3% by weight, even more preferably at least 5% by weight of the spray-dried particles. On the other hand, in view of the ease of breaking load control, the moisture is preferably contained in an amount of 20% by weight or less, more preferably 15% by weight or less of the spray-dried particles.

8. Other Auxiliary Components

Phosphors, pigments, dyes and the like may also be blended in the spray-dried particles.

By spray-drying the slurry prepared by adding and mixing each of the above-mentioned components, the spray-dried particles used in the present invention can be obtained. Here, there is no particular limitation on the moisture content of the slurry and the spray-drying conditions. For example, the spray-dried particles are obtained according to the method described in Tokkyocho Koho: Shuchi Kanyo Gijutsu Shu (Clothes Powder Detergent), 10 (1998) -25 (7159).

<Preferred composition>

In view of the fact that the use of crystalline sodium aluminosilicate and sodium silicate in the spray-dried particles dramatically decreases the bulk density increase rate, sodium silicate is preferably used when the crystalline sodium aluminosilicate and sodium silicate are used in combination. Is contained in an amount of up to 20%, more preferably up to 15%, even more preferably up to 10% by weight of the spray-dried particles. Sodium crystalline aluminosilicate and sodium silicate are preferably combined up to 50% by weight, more preferably up to 45% by weight, even more preferably up to 40% by weight, even more preferably up to 30% by weight of the spray-dried particles. It is contained in% or less.

Detergent particle group

In the present invention, the detergent particle group is obtained by adjusting the breaking load value to be in the range of 9,800 mN during the treatment of increasing the bulk density for the aforementioned spray-dried particles. A process of increasing bulk density for the spray-dried particles, for example at break load values of 9,800 mN or less; Or by adding a predetermined amount of surface tack inhibitor to the spray-dried particles before the breaking load value exceeds 9,800 mN, thereby continuing the treatment to increase the bulk density and repeating the above steps. A detergent particle group of g / L to 1500 g / L is obtained.

The manufacturing method of the detergent particle group used for this invention is demonstrated below.

The breaking load value of the detergent particle group at the end of the treatment of increasing the bulk density or when a certain amount of the surface tackifier is added is preferably 9,800 mN or less, more preferably, from the viewpoint of suppressing the particle size growth. It is 7840 mN or less, More preferably, it is 5,880 mN or less. On the other hand, from the viewpoint of the bulk density increase rate, the breaking load value is preferably 490 mN or more, more preferably 980 mN or more, and even more preferably 1,960 mN or more. The method of measuring the breaking load is described in the Examples disclosed below.

Surface Adhesion Inhibitor

In the detergent particle group of the present invention, the final bulk density can be adjusted by adding a surface tack inhibitor and continuing the treatment during the treatment of increasing the bulk density for the purpose of suppressing particle size growth by increasing the surface adhesion of the detergent particles.

As the surface adhesion inhibitor, any known ones commonly used may be used, and sodium tripolyphosphate, crystalline or amorphous aluminosilicate, crystalline sodium silicate, diatomaceous earth, silica, and the like are suitably used. Especially, 1 or more types chosen from the group which consists of sodium tripolyphosphate and crystalline aluminosilicate which respectively have a chelate ability is preferable. By surface-modifying the detergent particle group using a substance having a chelating ability, the chelating ability acts from the initial stage of cleaning, and the cleaning power is improved. Crystalline aluminosilicate is more preferable from the viewpoint of the flow characteristic, and sodium tripolyphosphate is more preferable from the viewpoint of rinsing property.

At this time, the particles used as the surface tack inhibitor, in terms of coating ability, the average particle size corresponding to the size of 1/10 or less, preferably 1/20 or less of the average particle size of the detergent particle group, and during the production From the viewpoint of handling, it is preferable to have an average particle size corresponding to a size of 1/3000 or more, preferably 1/600 or more of the average particle size of the detergent particle group.

In addition, the surface tack inhibitor is preferably contained in an amount of at least 1% by weight, more preferably at least 2% by weight, even more preferably at least 3% by weight of the detergent particle group. On the other hand, the surface adhesion inhibitor is preferably contained in an amount of 20% by weight or less, more preferably 15% by weight or less and even more preferably 10% by weight or less of the detergent particle group.

Although it is not essential to add the liquid binder in the present invention, in the treatment of increasing the bulk density, a liquid binder may be added to collect the fine powders generated together to increase the fluidity. Examples of the liquid binder include water, liquid nonionic surfactants, aqueous solutions of water-soluble polymers (polyethylene glycol, acrylic acid-maleic acid copolymers, etc.), and arbitrary liquid components in detergent particle groups such as fatty acids. Liquid binders may be used in combination of two or more components, examples of which include: (1) adding a liquid binder mixture of two or more components previously mixed, (2) adding each liquid binder simultaneously and ( 3) an addition method including adding each liquid binder alternately. Also in any method, it is preferable to use water together from a viewpoint of lowering manufacturing cost. The liquid binder is preferably 10 parts by weight or less, more preferably 5 parts by weight or less and even more preferably 3 parts by weight or less based on 100 parts by weight of the spray-dried particles in view of suppressing aggregation of the detergent composition. It is contained in an amount. In addition, from the viewpoint of the fine powder reduction effect, the liquid binder is contained in an amount of preferably 0.1 parts by weight or more, more preferably 0.3 parts by weight or more, based on 100 parts by weight of the spray-dried particles.

Examples of the method of adding the liquid binder include continuous addition or divided addition, or batch addition, which are performed at the end of the treatment for increasing the bulk density from the viewpoint of satisfying both suppression of particle growth and incorporation of the generated fine powder into the detergent particle group. It is preferable to add.

The means for carrying out the treatment of increasing the bulk density is not particularly limited as long as it is an apparatus capable of mixing spray-dried particles, surface tack inhibitors, and flow aids. However, from the viewpoint of providing high shear force to the spray-dried particles, vertical granulators having a disintegrating mechanism, horizontal granulators having a disintegrating mechanism, a rotary mixer having a baffle plate, and the like are preferable.

In the case of using the vertical granulator, the peripheral speed of the main shaft is preferably 1 to 7 m / s, and preferably 2 to 5 m / from the viewpoint of the rising speed of the bulk density and the ease of suppressing the breaking load value. s is more preferred. Further, the rotation speed of the blade, which is a disintegration mechanism, is preferably 500 to 4,000 rpm, more preferably 1,000 to 2,000 rpm from the same viewpoint as mentioned above. When the above-mentioned horizontal granulator is used, the main speed of the main shaft is preferably 0.5 to 3 m / s. Moreover, as for the rotation speed of the blade which is a disintegration mechanism, 500-4,000 rpm is preferable, and 1,000-2,000 rpm is more preferable.

Detergent particle group in the present invention is characterized in that the particle growth after the treatment to increase the bulk density, that is, the average particle before the treatment to increase the average particle size / bulk density after the treatment to increase the bulk density in terms of solubility and product yield. Size] is 1.1 or less, preferably 0.6 to 1.1, more preferably 0.7 to 1.1, even more preferably 0.8 to 1.1. In the present invention, the degree of bulk density increase before and after the treatment for increasing the bulk density of the detergent particle group is 20 to 800 g / L, preferably 30 to 600 g / L, more preferably 40 to 500 g / L.

Here, for the detergent particles in the present invention, the surface modification by the flow aid may be performed after the treatment of increasing the bulk density in order to further improve the fluidity and the storage stability.

As the average particle size of the flow aid, one having the same average particle size as the surface tack inhibitor can be used.

In addition, the flow aid is contained in an amount of preferably 2 to 20 parts by weight, more preferably 5 to 15 parts by weight with respect to 100 parts by weight of the detergent particle group from the viewpoint of flow characteristics.

In addition, in the manufacturing step of the detergent particle group in this invention, the substance used for a detergent composition can be arbitrarily added suitably.

Detergent composition

The detergent composition of the present invention contains a detergent component (for example, a fluorescent substance, an enzyme, a perfume, an antifoaming agent, a bleach, a bleach activator, etc.) added separately in addition to the detergent particle group. The detergent composition of the present invention having the above-mentioned constitution can be produced by appropriately mixing each of the above-mentioned components by a known method. In addition, the detergent particle group of this invention is contained in the detergent composition, Preferably it is 50-100 weight%, More preferably, it is contained in the quantity of 70-100 weight%.

The following examples further illustrate the invention and demonstrate embodiments of the invention. These examples are provided for illustrative purposes only and should not be construed as limitations on the present invention.

Example  One

Preparation of Spray-Dried Particles

Spray-dried particles were prepared by the following procedure.

292.32 kg of water at 60 ° C. and 40.71 kg of an aqueous 48% by weight aqueous sodium hydroxide solution were added in sequence to a 1 m ³ mixing vessel with stirring blades with a jacket set at 60 ° C. After the mixture was stirred for 5 minutes, 146.53 kg of linear alkylbenzenesulfonic acid (LAS: alkyl group having 10 to 15 carbon atoms in average) was added thereto. After stirring the mixture for 10 minutes, there were 238.46 kg of sodium sulfate, 63.60 kg of sodium carbonate, 57.24 kg of sodium tripolyphosphate, 127.20 kg of 40% by weight aqueous sodium silicate No. 2 and 2.13 kg of 60% by weight aqueous polyethylene glycol (PEG) solution. Added. Thereafter, the mixture was stirred for 120 minutes to obtain a slurry. The moisture content in this slurry was 42% by weight.

This slurry was sprayed at a spray pressure of 35 kg / cm ² using a pressure spray nozzle placed near the top of the spray-drying tower to obtain spray-dried particles. The hot gas supplied to the spray-drying tower was supplied to the bottom of the tower at a temperature of 205 ° C. and discharged from the tower to a temperature of 95 ° C. The composition of the resultant spray-dried particle group is shown in Table 1.

<Production of detergent particle group>

Spray obtained by the above-mentioned procedure on a High-Speed Mixer (manufactured by Fukae Powtec Kogyo Corp .; Model FS-400; High Water Capacity: 455 L; Jacketed) passing the hot water at 40 ° C. through the jacket at 40 L / min. -100 kg of dry particles and 1.18 kg of transport zeolite (Type A zeolite: average particle size 3 μm) were fed and the mixture was stirred for 13 minutes at 4 m / s circumferential speed of the main shaft and 1,800 rpm of disintegration wing (chopper) It was. Thereafter, 4.72 kg of the A-type zeolite (average particle size: 3 μm) was added thereto as a flow aid, and surface modification was performed at 4 m / s of the main shaft and 1,800 rpm of the disintegrating vane for 30 seconds, and the detergent was added. A particle group was obtained. Table 2 shows the conditions for producing the detergent particle group.

<Measurement result of the particle group of detergent>

Table 3 shows the results of measuring the physical properties and the dissolution ratio of the detergent particle group before and after the treatment for increasing the bulk density (indicated by "bulk density increase treatment"). The bulk density increase treatment time was 15 minutes and the treatment was terminated when the breaking load reached 4,900 mN. The detergent particle group had a bulk density of 660 g / L, a grain growth of O.70, a granulation yield of 99% and a dissolution rate of 99%, and exhibited high granulation yield and dissolution rate even after increasing the bulk density.

The physical properties of the spray-dried particles and the detergent particle group can be measured by the method described below.

<Destructive load value>

As shown in Figs. 1 to 3, an adapter having a diameter of 30 mm was mounted on a rheometer (manufactured by Fudo Kogyo Kabushiki Kaisha). Thereafter, a detergent particle group having a weight of [g] calculated by dividing the value of bulk density [g / L] by 20 in a cylindrical container made of metal was set, and a load of 9,800 mN was applied at room temperature for 3 minutes. Was compressed. Next, the detergent particle group was taken out of the container, the pedestal was raised at an elevation rate of 2 cm / min, and a force was applied when the molded body was broken by applying a force to the particle group formed by compression.

<Average particle size>

The detergent particle group was vibrated for 5 minutes with a Ro-Tap sieve shaker (rotational speed: 265 rpm, tapping speed: 145 tpm) using a standard sieve according to JIS Z 8801. After vibrating the particle group for 5 minutes, the average particle size was measured from the particle size distribution based on the weight according to the size of the opening of each sieve.

<Bulk density>

The bulk density could be measured by the bulk density measuring method according to JIS K 3362.

Particle Growth

Particle growth is represented by the following formula:

(Average particle size after treatment to increase bulk density) / (average particle size before treatment to increase bulk density).

<Granulation yield>

Granulation yield was made into the ratio of the detergent particle group which has the size of 1400 micrometer- sieve (standard sieve) -opening-pass according to JISZ8801.

The dissolution rate could be measured by the following method.

<Dissolution rate>

1 L of hardened water (molar ratio: Ca / Mg: 7/3) adjusted to 5 ° C. corresponding to 71.2 mg CaCO ₃ / L in a hardness of 1-L beaker (105 mm inner diameter and 150 mm high cylindrical, for example 1-L glass beaker manufactured by Iwaki Glass Co., Ltd.). With the water temperature kept constant at 5 ° C. in the water bath, the stirring bar [length: 35 mm and diameter: 8 mm, for example, model: “TEFLON SA” (manufactured by MARUGATA-HOSOGATA) from ADVANTEC) The water was stirred at a rotational speed (800 r / min) so that the depth of the vortex was about 1/3. Accurately sample-reduced and weighed groups of detergent particles (1400 μm-sieve-opening passage) were added and dispersed in water under stirring to keep 1.0000 g ± 0.0010 g, and the dispersion was kept stirring. The dispersion of the detergent particle group in the beaker 60 seconds after the particle group addition was filtered with a standard sieve (diameter 100 mm) having a sieve opening of 74 μm according to JIS Z 8801 (corresponding to ASTM No. 200) of known weight. Thereafter, the group of detergent particles in the water state remaining on the sieve was recovered together with the sieve into an open container of known weight. At this time, the operation time from the start of filtration to the recovery of the sieve was 10 seconds ± 2 seconds. The insoluble residue of the collect | recovered detergent particle group was dried for 1 hour with the electric dryer heated at 105 degreeC. The dried insoluble residue was then cooled by holding in a desiccator (25 ° C.) with silica gel for 30 minutes. After cooling the insoluble residue, the total weight of the insoluble residue, the sieve and the container of the dried detergent particle group was measured, and the dry weight of the detergent particle group remaining on the sieve was measured. Then, the dissolution rate (%) of the detergent particle group was computed by the following formula. At this time, the weight was measured using a precision balance.

Dissolution rate (%) = {1- (T / S)} × 100

[Wherein S is the weight (g) of the detergent particle group injected, and T is the dry weight (g) of the detergent particle group remaining on the sieve].

Example  2 to 5 and Comparative example  1 and 2

<Preparation of Spray-Dried Particles>

Using 1,000 kg of slurry composition, the same procedure as in Example 1 was carried out to obtain spray-dried particles each having a composition as shown in Table 1.

<Preparation of detergent particle group>

The spray-dried particles were subjected to the same procedure as in Example 1 under the conditions shown in Table 2 to obtain a detergent particle group.

<Measurement result of the particle group of detergent>

Table 3 shows the measurement results of the physical properties obtained in the same manner as in Example 1. Examples 2 to 5, in the same manner as in Example 1, terminated the treatment of increasing the bulk density with a breaking load value of 9,800 mN or less, or adding a surface tack inhibitor to the detergent particle group so that the breaking load value did not exceed 9,800 mN. By continuing the treatment to increase the bulk density, the result was a high granulation yield and a high dissolution ratio even after the treatment to increase the bulk density.

On the other hand, in Comparative Example 1, the spray-dried particles having a higher moisture content than the composition of Example 1 were subjected to a treatment of increasing the bulk density until the breaking load exceeded 9,800 mN, and the detergent particle group was bulk. The density was 807 g / L, the particle growth degree was 6.90, the granulation yield was 30%, and the dissolution ratio was 88%. Both the granulation yield and the solubility decreased. In Comparative Example 2, a treatment for increasing the bulk density was performed for 3 minutes, but no increase in bulk density was observed.

According to the present invention, it is possible to prepare medium to high-bulk density detergents without causing a decrease in solubility or a decrease in product yield accompanying the bulk density increase treatment.

Equivalent

Although the present invention has been described as such, it will be apparent that it can be varied in many ways. Such changes should not be considered outside the spirit and scope of the present invention, and all such modifications are intended to be included within the scope of the following claims as will be apparent to those skilled in the art.

Claims (3)

A method for preparing a detergent particle group comprising spray-drying a slurry containing an anionic surfactant and increasing the bulk density of the resulting particles using a high speed mixer, comprising: a breaking load value at 25 ° C. of 9,800 mN or less; The mixing treatment is carried out at a particle growth degree of 1.1 or less, that is, [average particle size after bulk density increase treatment / average particle size before bulk density increase treatment], wherein the bulk density increase degree before and after the bulk density increase treatment is 20 to 800 g. How / L is. The method of claim 1, wherein the surface tack inhibitor is added in an amount that satisfies the breaking load value of 9,800 mN or less, and then the mixing treatment is further performed. The method of claim 1 or 2, wherein the surface tack inhibitor is at least one compound selected from the group consisting of sodium tripolyphosphate and crystalline aluminosilicate.

Images