JPS6410040B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for producing a high-density granular detergent, and more particularly, to a method for producing a high-density granular detergent that has excellent dispersion and solubility even in cold water. [Prior Art] In recent years, there has been an increasing demand for high-density powder detergents from the viewpoint of resource conservation, transportation of detergents, and convenience for housewives in carrying and storing detergents. As high-density powder detergents, for example, JP-A-48-
Publication No. 61511 contains 30% or more of surfactant,
Bulk density is 0.5g/ ^cm3 or more and particle size is 0.5mm to 5
Granulated detergent compositions within the mm range are disclosed. Further, JP-A-53-36508 discloses a detergent having a bulk density of 0.55 g/cm ³ or more, which is prepared by dry blending 30 to 70% of a surfactant and a specific amount of various detergent builders. Further, JP-A-58-132093 discloses granular detergent compositions containing intimately mixed anionic surfactants and anionic polymers. It is prepared by adding water-soluble neutral or alkaline salts and mixtures thereof by preparing a non-soap anionic surfactant that is previously intimately mixed with certain water-soluble anionic polymers. Water and anionic surfactants act to retard the dissolution of granules, even in high-density (e.g. 0.67 g/cm ³ ) granular detergents obtained by incorporating other detergent ingredients into the spray-dried granular mixture. The aim is to improve the dispersion and solubility of granular detergents by eliminating or delaying the formation of highly viscous "gum" phases. [Problems to be solved by the invention] However, such high-density powder detergents generally do not have satisfactory dispersion and solubility, and in the example described in JP-A-58-132093 mentioned above, However, under conditions such as those commonly used in winter in Japan, where a group of detergent particles is left for a certain period of time without being subjected to a relatively large mechanical force, Its dispersion and solubility are still insufficient, and no fundamental solution has been reached. For example, cold water of 5° C. is water at a temperature that can generally be used for home laundry in Japan during the winter. When using a normal fully automatic washing machine with cold water like this, the washing cycle starts by pouring water by first adding the laundry and detergent and then turning on the start switch. During the water injection period, the group of detergent particles slowly penetrates with water without being subjected to much physical mechanical force, and at the same time, a paste-like mixture of extremely high concentration of detergent ingredients and water is formed on the particle surface. phase is formed and particles coalesce. The entire population of particles is covered with a hydrated, highly viscous paste-like phase that cannot be redispersed by the mechanical force of subsequent stirring and cannot be completely dissolved within the normal washing time. , which was highly undesirable for consumers. Further, the formation of such a highly viscous pasty phase is particularly likely to occur when the surfactant component in the composition is mainly an anionic surfactant. On the other hand, with low-density detergents such as conventional spray-dried detergents, the detergent particles are porous and contain a large amount of air, so they float easily on water and disperse due to buoyancy, and even if the particles coalesce together in water. However, because the density of the group itself is low and it contains a relatively large amount of air,
Since it is easily redispersed and dissolved by mechanical force, such problems are unlikely to occur. From these points of view, in high-density granular detergents,
As in the example of JP-A-58-132093 mentioned above, we focused on surfactants, especially anionic surfactants, in detergent compositions, and in order to suppress the formation of a highly viscous pasty phase, We tried adding various thinning agents and hydrotropes, but as mentioned above, under the Japanese winter washing conditions, although a slight improvement effect was observed, no fundamental solution was achieved. It has become clear that the formation of a highly viscous pasty phase between the anionic surfactant and water is a contributing factor to the inhibition of dispersion and solubility of high-density granular detergents, but is not the main cause. [Means for Solving the Problems] The inventors of the present invention conducted further intensive studies to find the main cause, and found that when a high-density granular detergent is placed in extremely low-temperature water, the surface of the detergent particle group Upon penetration of water, hydration of the surfactant occurs, and water-soluble salts hydrate while emitting heat of hydration, and then elute, and the water that has eluted the salts further penetrates into the inside of the mass. As time passes, the salt solution becomes more concentrated, and eventually the surrounding low-temperature system absorbs heat and the temperature drops, resulting in a supersaturated state and precipitation of crystals. It makes the paste-like phase harder, and also changes the phase itself into a strong hydrated solid-like phase by connecting the precipitated crystals, which can be easily dispersed and dissolved even when mechanical force is applied afterwards. It became clear that this was making things difficult. In other words, it has become clear that the presence of water-soluble and crystalline salts is the main cause of inhibiting the dispersion and solubility of high-density granular detergents in cold water. On the other hand, water-soluble and crystalline inorganic salts are essential components required to improve the manufacturing suitability and washing performance of detergents. As a result of intensive studies to solve these problems, the present inventors have limited the content of water-soluble and crystalline salts, which are the main cause of inhibiting dispersion and solubility in high-density granular detergents, to below a specific amount. Among the water-soluble and crystalline salts, alkaline ones are made into particles,
The present invention has been completed based on the discovery that a high-density granular detergent with excellent dispersion solubility and cleaning performance in cold water can be obtained by dry mixing the fabric in a specific proportion and localizing the detergent. That is, the present invention comprises (a) 20 to 60% by weight of an organic surfactant, (b) 2 to 15% by weight of water-soluble and crystalline inorganic salts, and (c) 25 to 78% by weight of other inorganic salts. and the water-soluble and crystalline inorganic salts are one or more selected from the group consisting of sodium carbonate, sodium sulfate, sodium tripolyphosphate, sodium pyrophosphate, and sodium orthophosphate, and If it contains sodium, the sodium carbonate content is 10% by weight.
For high-density granules with a bulk density of 0.5 g/cm ³ or more (hereinafter referred to as high-density granular detergent fabric), sodium carbonate, sodium tripolyphosphate,
The bulk density of one or more water-soluble and crystalline alkaline inorganic salts selected from the group consisting of sodium pyrophosphate and sodium orthophosphate is
The present invention provides a method for producing a high-density granular detergent, characterized by dry blending 5 to 25% by weight of particles with an average particle size of 100 to 1000 μ and a density of 0.5 g/cm ³ or more. In the present invention, high density refers to a bulk density of 0.5 g/cm ³ or more, preferably 0.6 g/cm ³ or more. Examples of the organic surfactant used in the high-density granular detergent fabric of the present invention include the following. Anionic surfactants include linear or branched alkylbenzene sulfonates, alkyl or alkenyl ether sulfates, alkyl or alkenyl sulfates, olefin sulfonates, alkanesulfonates, saturated or unsaturated fatty acid salts, alkyl or alkenyl ether carboxylates, α-sulfo fatty acid salts or esters, amino acid type surfactants, N-acylamino acid type surfactants, alkyl or alkenyl acidic phosphate esters, alkyl or alkenyl phosphate esters or their salts, etc., amphoteric Surfactants include carboxy or sulfobetaine type surfactants; nonionic surfactants include polyoxyalkylene alkyl or alkenyl ethers, polyoxyethylene alkyl phenyl ethers, higher fatty acid alkanolamides or alkylene oxide additions thereof; Examples of cationic surfactants include quaternary ammonium salts, sucrose fatty acid esters, fatty acid glycerin monoesters, and alkylamine oxides. Preferred surfactants include linear or branched alkylbenzene sulfonates, alkyl or alkenyl ether sulfates, alkyl or alkenyl sulfates, olefin sulfonates, alkanesulfonates, saturated or unsaturated fatty acid salts,
carboxy or sulfobetaine type surfactants,
Examples thereof include polyoxyalkylene alkyl or alkenyl ether, polyoxyethylene alkyl phenyl ether, higher fatty acid alkanolamide or a salt thereof. The blending amount of the organic surfactant is in the range of 20 to 60% by weight, preferably 25 to 60% by weight. If the content is less than 20% by weight, sufficient washing performance cannot be obtained, and if it exceeds 60% by weight, the manufacturing suitability and the powder physical properties of the resulting detergent will deteriorate, which is not preferable. Among these organic surfactants, anionic surfactants in particular tend to form a viscous paste phase in water and are easily affected by the presence of large amounts of water-soluble and crystalline salts. When a surfactant was used as the main component, its dispersion solubility in cold water was particularly insufficient. Therefore, the effects of the present invention are particularly significant when the anionic surfactant content in the organic surfactant used is 70% by weight or more. The water-soluble and crystalline inorganic salts whose content is limited in the present invention, such as sodium carbonate, sodium sulfate, sodium tripolyphosphate, sodium pyrophosphate, and sodium orthophosphate, have relatively larger differences in solubility depending on temperature than other salts. ,
It is easy to precipitate crystals from an aqueous solution, and it is easy to take up a relatively large amount of crystallization water at low temperatures, making it easy to connect crystals together and having a strong structure, which is a major factor that inhibits the dispersion and solubility of high-density detergents. In addition to the same reason, sodium carbonate has a large calorific value due to hydration, so it elutes in high concentration even in cold water with exothermic heat, and therefore there is a large difference in solubility when the temperature drops due to heat being taken away by the surrounding low-temperature system. It is easy to cause crystals to precipitate, and
Below 32°C, it becomes a decahydrate salt, and by taking in a large amount of crystal water, the undissolved crystals themselves become hydrated crystals and expand in volume, making it easier to connect hydrated crystals and making their structure stronger. Therefore, its content is particularly limited. The blending amount of these water-soluble and crystalline inorganic salts in the detergent fabric of the present invention is determined from the viewpoint of powder physical properties.
It needs to be at least 15% by weight from the viewpoint of low-temperature solubility. In the case of sodium carbonate, it is desirable to suppress it to less than 10% by weight for the reasons mentioned above. The detergent fabric of the present invention contains builder substances such as water-soluble but non-crystalline inorganic salts, water-insoluble inorganic salts, and other conventional detergent ingredients to enhance manufacturing suitability and washing performance. Examples of these inorganic salts include silicates with a molar ratio of SiO ₂ to alkali metal salt of greater than 1.0 (sodium silicate No. 1, No. 2, No. 3 sodium silicate, etc.), aluminosilicates represented by type A zeolite, etc. of inorganic builders, and their content ranges from 25 to
It is 78% by weight. There are no particular limitations on the method for producing the high-density granular detergent fabric of the present invention, but for example,
61511, a method of adding an alkali agent and acid-resistant detergent component to an unneutralized anionic surfactant, neutralizing it, adding zeolite, etc., and pulverizing it, or a method of spray drying. It can be manufactured by granulating a powdered detergent to increase its bulk density. The particle size of high-density granular detergent fabric is usually 40~2000μ,
In particular, it is desirable that the thickness be in the range of 125 to 2000μ. In the present invention, water-soluble and crystalline inorganic salts such as those described above are mixed homogeneously with other detergent ingredients including organic surfactants, rather than existing in a delocalized state. It has been found that a larger total amount of water-soluble and crystalline salts can be blended by dry mixing and localizing the particles with particles made of other detergent ingredients. This is because when delocalized in detergent particles, when the detergent particle population is penetrated by water, water-soluble and crystalline salts dissolve more evenly in all parts, and enter the surrounding low-temperature system. When heat is removed and the temperature drops and crystals precipitate, crystals are precipitated in all parts of the paste phase where organic surfactants and other detergent components are mixed, making the paste phase harder. This is because the crystals are easy to connect with each other. In contrast, according to the present invention, water-soluble and crystalline inorganic salts are dry-mixed as particles into high-density granular detergent fabric and localized, thereby reducing the phenomenon of low-temperature solubility reduction as described above. be able to. For the same reason, even if the total amount of water-soluble and crystalline inorganic salts is the same, a larger proportion of water-soluble and crystalline inorganic salts that are dry-mixed into the detergent dough than blended into the detergent dough exhibits better dispersion and solubility. In the present invention, in order to enhance washing performance, by dry blending 5 to 25% by weight of alkaline, water-soluble and crystalline inorganic salt particles to the high-density granular detergent fabric, we have developed a method that is equivalent to that of conventional spray-dried detergents. It is possible to obtain a high-density granular detergent composition that can achieve good washing performance and also has good dispersion and solubility in cold water by dry after-blending. If the content of water-soluble and crystalline inorganic salts is less than 20% by weight, washing performance can be supplemented by increasing the content of other inorganic builders and organic divalent metal ion scavengers; Since cheaper inorganic salts can be used, it is desirable that the content thereof be 20% by weight or more. Alkaline water-soluble and crystalline inorganic salts are the water-soluble and crystalline inorganic salts mentioned above.
Mention may be made of sodium carbonate, sodium tripolyphosphate, sodium pyrophosphate, and sodium orthophosphate. In the present invention, in order to achieve localization as described above, it is better for the water-soluble and crystalline inorganic salt particles to be dry-mixed to have a large particle size rather than a fine one. Since the dissolution rate thereof is too slow and undesirable as a detergent, particles having an average particle size of 100 to 1000 μ, preferably 200 to 600 μ are suitably used. Further, the bulk density of the inorganic salt particles is 0.5 g/cm ³ or more, preferably 0.6 g/cm ³ or more, and in particular, it is preferably about the same as the bulk density of the detergent fabric. If the difference in bulk density between the detergent fabric and the salt particles is too large, the salt particles may be too localized due to particle classification, resulting in an area containing too many salt particles. Similarly, there is a possibility that the dispersion and solubility of that part may be deteriorated. Also, if the particle size of the salt particles is too small,
On the other hand, it is not preferable because it is too delocalized and there is a risk that the dispersion and solubility will deteriorate, similar to when a large amount is blended into the detergent fabric. Furthermore, the composition of the present invention may contain the following components in appropriate amounts as required. 1) Anti-recontamination agents: polyethylene glycol, polyvinyl alcohol, polyvinylpyrrolidone, carboxymethyl cellulose, etc. 2) Bleach, fluorescent dyes, enzymes, etc. As bleaching agents, use sodium percarbonate, sodium perborate, sodium sulfate/sodium chloride/hydrogen peroxide adduct, and as brighteners, commercially available fluorescent dyes, fragrances, Enzymes such as protease, amylase, lipase, and cellulase, blue tint agents, bleach activators, and the like may also be added as necessary. 3) Organic divalent metal ion scavenger Salts of phosphonic acids such as ethane-1,1-diphosphonate, salts of phosphonocarboxylic acids such as 2-phosphonobutane-1,2-dicarboxylic acid, aspartic acid, glutamic acid, etc. Salts of amino acids, aminopolyacetates such as nitrilotriacetate and ethylenediaminetetraacetate, polymer electrolytes such as polyacrylic acid and polyaconitic acid, salts of organic acids such as oxalic acid and citric acid, JP-A-54-52196 The polyacetal carboxylic acid polymer or its salt, etc. described in . [Examples] Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following Examples. Example 1 A high-density granular detergent fabric (A) having the composition shown in Table 1 was produced, and the water-soluble and crystalline salt particles (B) shown in Table 2 were added to (A).
Table 2 shows the results of a comparative study on the bulk density and dispersion solubility of high-density granular detergents dry-mixed.

【table】

[Table] In Table 1, (a) is an organic surfactant, and (b) is a water-soluble and crystalline inorganic salt defined by the present invention.
In addition, polyethylene glycol has an average molecular weight of approximately
13000 was used, but this is a dispersant,
It is not included in the organic surfactants in (a). Furthermore, since zeolite is water-insoluble and sodium silicate No. 2 is amorphous and does not form defined crystals from an aqueous solution, neither of them is included in the water-soluble and crystalline salts (b). The manufacturing method of high-density granular detergent and the measuring method of bulk density and dispersion solubility will be explained below. However, the manufacturing method is a preferred example of manufacturing the high-density granular detergent used in this example, and there are no particular limitations. It is not something that will be done. 1) Detergent production method: By preparing slurries each having a water content of 50% by weight with the composition (P) in Table 1 and spray drying them,
A detergent powder (P) having a bulk density of around 0.3 g/cm ³ was obtained.
Next, (P) was put into a high-speed mixer (stirring rolling granulator, manufactured by Fukae Kogyo Co., Ltd.),
Composition (Q) of finely powdered zeolite moistened with water is added and crushed and granulated to give a bulk density of 0.6g/cm ³ to 0.8g/
cm ³ of dense granular detergent was obtained. At this time, the water in the composition (Q) acts as a granulation binder for the crushed detergent powder (P), and the zeolite fine powder in the composition (Q) acts as a carrier for the water as the granulation binder. , also acts as a granulation aid to suppress the formation of coarse particles. Also,
As the granulation binder, the nonion in the composition (P) may be liquefied and sprayed onto the detergent powder during granulation. Finally, fine powder zeolite (R) and water-soluble and crystalline salt particles (B) are dry-mixed to the high-density granular detergent (P) + (Q) obtained in this way to improve fluidity. A high-density granular detergent with excellent anti-caking properties was obtained. Additionally, small amounts of thermally unstable additives, such as enzymes and bleaching agents, are preferably incorporated by dry mixing in this last step. In this example, after crushing and granulation, the material was passed through a screen with an opening of 1 mm to remove coarse particles with a particle size of 1 mm or more. According to this manufacturing method, the crushing and granulation conditions (type of granulator, granulation temperature,
(granulation time, type of granulation binder, etc.), the opening of the screen through which it passes after granulation, the recycling of coarse particles, etc., and the amount and bulk of water-soluble and crystalline salt particles (B) to be dry mixed. By selecting the density and particle size, a granular detergent having a desired bulk density and particle size can be obtained. 2) Measurement of detergent bulk density (apparent specific gravity) Measured by the method of JIS K-3362 3) Measurement of detergent dispersion solubility Using a 2.8Kg Aozora PF-2650 fully automatic washing machine manufactured by Hitachi Co., Ltd., the bottom of the washing tub Place 40g of detergent at one end, add 2kg of clothing (60 parts by weight of cotton underwear and 40 parts by weight of polyester/cotton blend shirts) on top of it, and pour tap water at the specified temperature at a flow rate of 8/min. Pour water slowly over 5 minutes until the temperature reaches 40°C, being careful not to let the water hit directly. Thereafter, stirring is started, and after stirring for 3 minutes, stirring is stopped, the water is drained, and after dehydration for 3 minutes, detergent remaining on the clothes and the washing tub is visually determined. The judgment criteria are shown below. ○: No residual detergent ○△: Slightly small particles of residual detergent △: Many small particles of residual detergent or a few lumps of residual detergent ×: Considerable lumps of residual detergent remaining In this measurement method, detergent particle groups are , during water injection, it is exposed to water for 5 minutes with almost no physical mechanical force, and after the water has penetrated, it is subjected to mechanical force due to stirring.

【table】

[Table] Example 2 Bulk density of high-density granular detergent prepared by manufacturing high-density granular detergent fabric (A) with the formulation shown in Table 3 and dry-mixing water-soluble and crystalline salt particles (B) into (A) and dispersion solubility were compared. The detergent manufacturing method and various measurement methods are the same as in Example 1. The results are shown in Table 4.

【table】

【table】

【table】

[Table] Example 3 Bulk density of high-density granular detergent made by manufacturing high-density granular detergent fabric (A) with the formulation shown in Table 5 and dry-mixing water-soluble and crystalline salt particles (B) into (A) and dispersion solubility were compared. The detergent manufacturing method and various measurement methods are the same as in Example 1. The results are shown in Table 6.

【table】

【table】

[Table] Example 4 Bulk density of high-density granular detergent made by manufacturing high-density granular detergent fabric (A) with the formulation shown in Table 7 and dry-mixing water-soluble and crystalline salt particles (B) into (A) Comparative studies were conducted regarding dispersion solubility and washability. The detergent manufacturing method and various measuring methods were the same as in Example 1, and the detergency evaluation was performed by the method described below. The results are shown in Table 8.

【table】

[Cleanability evaluation method]

Preparation of naturally contaminated cloth A cotton/Tetoron blend (9cm x 30cm) was sewn onto the collar of a shirt and an adult male was allowed to wear it for two days. After wearing, a piece of cloth with stains that were symmetrical about the center point was selected, and the cloth was cut in half at the symmetrical point of the stain and used for experiments. Evaluation of cleanability A half-woven fabric washed with the sample cleaning agent and a half-woven fabric washed with the standard cleaning agent (Experiment No. 20) were evaluated by pairwise comparison by visual judgment. Cleanability was ranked based on standard soiling, which ranks the degree of soiling in 10 levels. The cleaning performance was expressed as a score for the cleaning power of the comparison sample detergent, with the reference detergent being set as 100 (Table 8 shows the average score of 10 sheets). Conditions Practical two-tank washing machine, strong rotation Tap water 30 Detergent 25g Temperature 20℃ Time 10 minutes Rinse time 5 minutes with tap water (overflow rinse) Bath ratio 1/30 (dress shirts 400g + underwear 600g +
tablecloth)

【table】

Claims (1)

[Scope of Claims] 1 (a) 20 to 60% by weight of an organic surfactant, (b) 2 to 15% by weight of water-soluble and crystalline inorganic salts, and (c) 25 to 78% of other inorganic salts. % by weight, and the water-soluble and crystalline inorganic salt is one or more selected from the group consisting of sodium carbonate, sodium sulfate, sodium tripolyphosphate, sodium pyrophosphate, and sodium orthophosphate, In addition, when containing sodium carbonate, for high-density granules with a bulk density of 0.5 g/cm ³ or more with a sodium carbonate content of less than 10% by weight, sodium carbonate, sodium tripolyphosphate, and pyrophosphoric acid are added. The bulk density of one or more water-soluble and crystalline alkaline inorganic salts selected from the group consisting of sodium and sodium orthophosphate is
A method for producing a high-density granular detergent, which comprises dry blending particles of 0.5 g/cm ³ or more and an average particle size of 100 to 1000 μ in an amount of 5 to 25% by weight. 2. The method for producing a high-density granular detergent according to claim 1, wherein the content of anionic surfactant in the organic surfactant is 70% by weight or more.