JP4192774B2 - Method for producing detergent particles having excellent solubility - Google Patents

Description

  The present invention uses a foaming action of an acid precursor substance and carbonate to prepare a whip-like mixture in a stirring and mixing device, and after the volume of the whip-like mixture exceeds a certain value, The present invention relates to a batch-type production method for obtaining detergent particles having excellent solubility by a non-spray process in which a powdering agent is added to form a whipped mixture.

  In recent years, in the manufacturing method of detergent particles, there has been a demand for a method that considers environmental aspects and pursues reduction of consumption resources, energy consumption, and manufacturing process management costs, and a number of manufacturing methods that do not use a spray tower (direct granulation). Law) has been proposed.

  In a conventional method for producing detergent particles, an anionic activator acid precursor substance (typical examples: alkylbenzene sulfonic acid, fatty acid, alkyl sulfate ester, etc.) is neutralized with an aqueous sodium hydroxide solution, followed by nonionic activator and builder. A detergent concentrate (slurry) having a water content of 30 to 50% by weight was spray-dried, and the resulting hollow granular low bulk density particles (water content of 10% by weight or less) were mixed with a liquid binder and others. The above components were added and the slurry was densified with a granulator to produce detergent particles.

  However, in this method, a slurry is prepared, and further, this is spray-dried to evaporate the water, so that water is wasted and a great amount of heat energy is consumed in the spray-drying process (spray process). In addition, many fine powders generated during drying adhere to the inner wall of the spray-drying tower (spray tower) in layers, causing trouble. Moreover, since it is necessary to remove the deposits on the inner wall and clean the fine powder collecting device (cyclone), it is necessary to periodically stop the operation of the spray. Therefore, the manufacturing method using the spray process has a limit in reducing the cost of the final product.

  As a non-spray process for granulating the slurry, a neutralized mixed paste of an anionic surfactant acid precursor and an alkaline agent or a mixed paste of an active agent and other optional components is prepared in Patent Documents 1 to 7 below. Describes a method for producing detergent particles that are powdered.

However, in these non-spray processes, unlike the conventional process in which hollow granular low-density particles are densified with a liquid binder, compacted particles are produced. Even if it is carried out as it is, it is not possible to obtain detergent particles having satisfactory solubility under the current washing conditions at low temperature and low bath ratio.
Japanese National Patent Publication No. 11-504363 Japanese National Patent Publication No. 11-504364 Japanese Patent No. 2818258 Japanese Patent No. 2856915 Japanese Patent No. 3149189 Japanese Patent No. 3225041 Japanese Patent No. 3295083

  The subject of this invention is providing the manufacturing method of the detergent particle | grains which can implement | achieve the reduction of manufacturing cost and the outstanding solubility in view of the said actual condition.

  As a result of diligent research, the present inventors have determined the molar ratio of the acid precursor and carbonate of the anionic surfactant, and whipped using the foaming action by neutralization of the acid precursor and carbonate. A non-spray process in which a mixture is prepared in a stirring and mixing apparatus, and then the whipped mixture volume exceeds a certain value, and then a powdering agent is added to the mixture in the same apparatus and the mixture is granulated. It has been found that the above problems can be solved, and the present invention has been completed.

That is, the batch-type production method of detergent particles having excellent solubility according to the present invention is as follows.
The following step (i) is a method for producing detergent particles having excellent solubility, characterized in that the following step (ii) is continuously performed in the same stirring and mixing apparatus.

Process (i):
(a) An anionic surfactant acid precursor substance and (b) carbonate in a molar ratio of component (a): component (b) = 2: 1 to 1: 2 are charged into a stirring and mixing apparatus and then mixed. , A step of generating a whipped mixture by a foaming action due to a neutralization reaction of component (a) and component (b),
Step (ii):
At the stage where the volume of the whipped-like mixture expands exceeds 2 times the volume immediately after mixing of components (a) and (b), whip-like mixture aluminosilicate and / or silicon dioxide as a powdering agent to the mixture A step of adding detergent at a blended weight ratio of 1/2 to 2/1 to powder the whipped mixture and granulating it at the same time to obtain detergent particles.

  In the method for producing detergent particles according to the present invention, the molar ratio of the acid precursor and carbonate of the anionic surfactant is defined, and the whip-like mixture is formed by utilizing the foaming action by neutralization of the acid precursor and carbonate. Prepared in a stirring and mixing device, and then the whipped mixture volume exceeds a certain value, and then the powdering agent is added to the whipped mixture in the same device to granulate the whipped mixture. Solubility can be achieved together.

  Examples of the acid precursor (a) of the anionic surfactant include alkylbenzene sulfonic acid, alkyl sulfuric acid, alpha olefin sulfonic acid, alkyl sulfonic acid, fatty acid and the like, and alkylbenzene sulfonic acid is particularly preferable. The blending amount of the acid precursor (a) in the detergent particles is preferably 60% by weight or less, more preferably 30 to 50% by weight. When the amount is too large, coarse particles having a particle diameter exceeding 1700 μm are easily formed, and the load of the coarse particle pulverizer in the subsequent process is increased.

  Examples of the carbonate (b) include pulverized products of sodium hydrogen carbonate, light sodium carbonate, and heavy sodium carbonate, and light sodium carbonate is particularly preferable. The particle size of the carbonate (b) is preferably 25 to 500 μm, more preferably 45 to 250 μm.

  The mixing ratio of component (a) and component (b) is 2: 1 to 1: 2, preferably 2: 1 to 2: 3, more preferably 1: 1 to 2: 3 in terms of molar ratio. If the ratio of component (b) to component (a) is too low, component (a) will remain in acid form. If the ratio of component (b) to component (a) is too high, solubility will be significantly deteriorated.

  Examples of powdering agents include crystalline aluminosilicates, silicon dioxide, or mixtures thereof, with crystalline aluminosilicates being particularly preferred. The crystalline aluminosilicate is preferably an A-type synthetic zeolite having an average particle size of 0.5 to 7.0 μm, and more preferably 1.5 to 5.5 μm. The powdering agent is added for the purpose of granulating the whipped mixture prepared in step (i) in step (ii). The mixing ratio of the whipped mixture and the powdering agent is preferably 1/2 to 2/1, more preferably 1/1 to 3/2, in terms of a solid blending weight ratio.

  For the purpose of increasing the strength of the detergent particles, as an optional component, polyethylene glycol having a melting point of 45 ° C. to 70 ° C. and / or a nonionic surfactant can be added to the mixture in step (i) or step (ii). The form of the optional component at the time of use may be in the form of powder, but a paste dissolved by heating is preferable because it can be homogenized faster and shorten the preparation time. The blending amount of this optional component in the detergent is preferably 0.5 to 5.0% by weight, more preferably 2.0 to 4.0% by weight. If the blending amount is too small, there is no effect of addition, and if it is too large, the solubility becomes poor.

  In addition to the above components, in step (i), other anionic surfactants, nonionic surfactants, sodium hydroxide, potassium hydroxide, fluorescent agents, polyacrylic acid sodium and other known components are blended as necessary. In step (ii), known components such as a fluorescent agent, a fragrance, a dye, an enzyme, heavy sodium carbonate, sodium percarbonate, and a bleach activator can be blended as necessary.

  The stirring and mixing device used in the present invention is a mixer of a type in which a stirring shaft is provided inside a mixing tank and a stirring blade is attached to this shaft to mix powder. For example, Henschel mixer (manufactured by Mitsui Miike Chemical Co., Ltd.), high speed mixer (manufactured by Fukae Kogyo Co., Ltd.), vertical granulator (manufactured by Paulek), Redige mixer (manufactured by Matsuzaka Giken Co., Ltd.), Proshare mixer (manufactured by Taiheiyo Kiko Co., Ltd.) And an Eirich mixer (manufactured by Eirich) and the like, and an Eirich mixer (manufactured by Eirich) is particularly preferable.

  In step (i), the volume of the whip-like mixture prepared using the foaming action by neutralization of the acid precursor and carbonate of the anionic surfactant is about the volume immediately after mixing of component (a) and component (b). By setting it to a state exceeding 2 times, the powdering agent can be easily mixed in step (ii), and the particles produced by the pulverization of the whipped mixture are mostly composed of fine particles. Further, by utilizing the foaming action, an effect of relaxing the compaction state of the particles is obtained, and particles having excellent solubility are obtained. The upper limit of the foaming ratio of the volume of the whipped mixture does not affect the effect of the present invention even if it is not limited, since the operation is performed in a closed mixer, but from the viewpoint of productivity of detergent production, The expansion ratio is preferably about 2 to 5 times, more preferably about 2 to 4 times. The expansion ratio is adjusted by adjusting the mixing conditions such as the temperature of the mixture and the stirring time in step (i).

  In order to effectively develop the foaming action by neutralization of the acid precursor and carbonate of the anionic surfactant, the stirring is temporarily stopped, that is, a stirring stop period is placed between step (i) and step (ii). It is preferable. Even if stirring is not completely stopped, the shearing force of the mixer can be lowered and the foaming ratio can be adjusted to a predetermined value by lowering the number of revolutions of stirring.

  Next, in order to specifically explain the present invention, some examples of the present invention and comparative examples for showing comparison with the examples will be given.

Example 1
Process (i)
Soda ash (light ash) (manufactured by Central Glass Co., Ltd.) as component (b), alkylbenzene sulfonic acid (average carbon number of alkyl group: 12, pure content: 96% by weight), and polyethylene glycol (PEG 6000S, Sanyo Kasei) as component (a) Were introduced into the Eirich mixer (type: R02, capacity 5 L) in the amounts shown in Table 1, and the charge was uniform for 240 seconds at a rotation speed of the pan: 40 rpm and a rotation speed of the stirring shaft: 1080 rpm. After stirring and mixing, the operation of the mixer was stopped. The temperature of the obtained whipped mixture was 80 ° C. By stopping the operation of the mixer, the bubbles in the whip-like mixture were remarkably increased due to the foaming action caused by the remaining neutralization reaction of component (a) and component (b).

Step (ii)
180 seconds after the mixer was shut down, the volume of the whipped mixture exceeded twice the volume immediately after mixing of component (a) and component (b). At this stage, in the same stirring and mixing apparatus, crystalline aluminosilicate (A type, average particle size 2 to 5 μm, synthetic zeolite, water content 7 wt%) is added to the whip mixture in the amount shown in Table 1, Stirring was performed for 180 seconds at a rotation speed of the pan: 40 rpm and a rotation speed of the stirring shaft: 2160 rpm. A granular material with good fluidity was obtained, and the powder temperature was 60 ° C. The total charge was 2.06 kg.

Examples 2-5, Comparative Examples 1-3
The same operation as in Example 1 was performed except that the amount of each component was changed as shown in Table 1. However, in Comparative Example 3, when the volume of the whip-like mixture exceeds 1.5 times the volume immediately after the mixing of component (a) and component (b) in step (i), granulation is performed in step (ii). The agent was charged and the whipped mixture was granulated. The volume of the mixture expanded at a magnification shown in Table 1 with respect to the volume before the mixer stopped.

Evaluation test The detergent particles obtained in Examples and Comparative Examples were evaluated for solubility. The evaluation results are shown in Table 1.

Solubility test 10 g of the detergent particle sample was put in a 9.5 cm × 7.0 cm tea pack and closed with a stapler so as not to leak. Five of these were prepared for each sample, and gently put into 30 L of tap water adjusted to 5 ° C. in the washing tub of a two-tank washing machine (SHARP ES-25E) manufactured by Sharp Corporation. This was allowed to stand for 5 minutes after being charged, and stirred in water for 15 minutes in a standard operation, and then the sample tea pack was dehydrated for 1 minute in a dehydration tank and dried at 105 ° C. for 1 hour in a dryer. After drying, the dissolution rate was calculated according to the following formula.

  The evaluation criteria of solubility are as follows.

○: Dissolution rate of 95% or more ×: Dissolution rate of less than 95%.

The particles of the present invention preferably have a dissolution rate of 95% or more from the viewpoint of washing conditions in general households.

The molar ratio in Table 1 is a value calculated by the following formula.

The ratio of the whipped mixture / powdering agent in Table 1 is a value calculated by the following formula.

In Table 1, the composition is expressed as a solid blended weight. The alkylbenzene sulfonic acid has an average alkyl group of 12 alkyl groups and a pure content of 96% by weight. Light sodium carbonate is substantially anhydrous and has a particle size of 45 to 250 μm. The crystalline aluminosilicate is A-type, synthetic zeolite, having a water content of 7% by weight, and particles having a particle diameter of 2.0 to 5.0 μm occupy 90% or more.

Claims (3)

The following step (i) and then the following step (ii) are continuously carried out in the same stirring and mixing apparatus, a method for producing detergent particles having excellent solubility.
Process (i):
(a) An anionic surfactant acid precursor substance and (b) carbonate are added to a stirring and mixing apparatus at a molar ratio of component (a): component (b) = 2: 1 to 1: 2 and then mixed. , A step of generating a whipped mixture by a foaming action by a neutralization reaction of component (a) and component (b),
Step (ii):
At the stage where the volume of the whipped-like mixture expands exceeds 2 times the volume immediately after mixing of components (a) and (b), whip-like mixture aluminosilicate and / or silicon dioxide as a powdering agent to the mixture A step of adding detergent at a blended weight ratio of 1/2 to 2/1 to pulverize the whipped mixture and granulate at the same time to obtain detergent particles.
The method according to claim 1, wherein (a) the acid precursor substance of the anionic surfactant and (b) carbonate are mixed in a molar ratio of component (a): component (b) = 2: 1 to 2: 3.
The production method according to claim 1 or 2, wherein a stirring stop period is set after step (i).