Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – Heterogeneous arrangement
Reexamination Certificate
1998-05-06
2003-02-18
Douyon, Lorna M. (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
Heterogeneous arrangement
C510S351000, C510S356000, C510S357000, C510S361000, C510S441000, C510S477000, C510S507000, C510S509000, C510S511000, C264S117000, C264S140000, C008S137000
Reexamination Certificate
active
06521585
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a method for producing crystalline alkali metal silicate granules. More specifically, the present invention relates to a method for producing crystalline alkali metal silicate granules, which can be stably formulated in other detergents without deteriorating the properties of the crystalline alkali metal silicate, and further have extremely high detergent activity. Also, the present invention relates to a granular detergent composition having a high bulk density and a washing method. More specifically, the present invention relates to a granular detergent composition having a high bulk density which has excellent powder properties and is capable of having excellent detergency with a small standard amount of dosage thereof, and a washing method using the above granular detergent composition.
BACKGROUND ART
A method of granulating crystalline silicates, such as crystalline alkali metal silicates, is disclosed in Japanese Patent Laid-Open No. 3-164422. Here, the method for preparing granules having a high bulk density of from 700 to 1000 g/liter comprises powdering crystalline sodium silicate to a size of from 2 to 400 &mgr;m using a mechanical disintegrator, pressing the powdered silicate with a roller compactor (20 to 40 kN/1 cm width) to give dense materials, comminuting by forcing the silicates through screens, and sieving the comminuted materials. However, it would be impossible to prevent the deterioration of the performance owing to its hygroscopic property, which is an inherent property of the crystalline alkali metal silicates, or to suppress the caking phenomenon caused by consolidation of the crystalline alkali metal silicate owing to their hygroscopic properties. Also, the breaking of the granules during conveying is likely to take place.
Japanese Patent Unexamined Publication No. 6-502445 discloses a method for producing a free-flowable aggregate by blending in an energy-intensive mixer an aluminosilicate or a layered silicate with a particular binder. However, the binder which contains water is undesirable for maintaining excellent performance of the crystalline silicates. Also, the aqueous polymer is needed to be added in an amount of 10 parts or more, but this ingredient gives substantially no contribution to the detergency performance, thereby making it disadvantageous for the purpose of concentrating the composition.
Also, Japanese Patent Laid-Open No. 5-209200 discloses a method for producing a nonionic surfactant-containing granulated product, comprising the steps of agitating and blending a mixture of detergent starting materials containing a nonionic surfactant as a main surfactant component in an agitating mixer, the agitating mixer containing an agitating shaft along the center line of the inner portion, agitation impellers arranged along the agitating shaft, and a clearance formed upon rotating the agitating impellers between the agitating impellers and a wall of the agitating mixer, to thereby form a layer of the detergent starting materials adhered to the wall of the agitating mixer; and granulating the obtained mixture while increasing the bulk density of the detergent starting materials by the agitating impellers. However, since the nonionic surfactant is supported by the capillary force or the surface adsorption of the powdery starting materials, the supporting force is weak. Therefore, although the resulting granulated product has no problems at a practical level, sufficient adhesion of the nonionic surfactant-containing powder to the equipment upon conveying or sufficient exudation inhibition cannot be achieved, as compared to that of the present invention when packing the powder in a carton package.
Moreover, to date, various kinds of chelating agents, ion exchange materials, alkalizers, and dispersants have been known to be used for builders to be blended in detergents. Particularly, the phosphorus-based chelating agents such as tripolyphosphates as a main component thereof have good water solubility and detergency, so that they have been formulated as main detergent builder components.
In recent years, however, the use of tripolyphosphates has decreased, since they can cause eutrophication in closed freshwater areas such as lakes and marshes. Instead, crystalline aluminosilicates (zeolites) have been commonly used as substitutes for the metal ion capturing agent. Many patent applications have been filed concerning the formulation of crystalline aluminosilicates in detergents, as typically disclosed in Japanese Patent Laid-Open No. 50-12381. In addition, Yushi (Vol, 32, No.1, pp.36-40 (January 1979)) discloses the substitution to zeolites which took place at that time.
The rapid progress has taken place in changes in use of phosphorus-free detergents by substituting with zeolites, but the formulation of zeolites is merely a substitution of phosphorus-containing builders, which are used to produce detergents with a low bulk density of 0.2 to 0.4 g/cm
3
. Such detergents would require a standard amount of dosage of 40 g and 100 to 200 cm
3
per one washing cycle, the washing cycle being most commonly using about 30 L of the washing liquid per one cycle in Japan. Therefore, in the case where detergents for about 60 to about 100 washing cycles are placed in a carton package, the resulting detergent package becomes undesirably heavy as from 2.5 to 4.5 kg and undesirably bulky as from 6000 to 20000 ml. Therefore, much inconveniences were caused in burdening the conveying costs in the plant and carrying inconveniences and storage space for the consumers.
Therefore, an intense investigation has been made to produce compact detergents. For instance, Japanese Patent Laid-Open Nos. 62-167396, 62-167399, and 62-253699 disclose a remarkable decrease in the amount of crystalline inorganic salts such as sodium sulfate used as powdering aids conventionally contained in detergents. In addition, Japanese Patent Laid-Open Nos. 61-69897, 61-69899, 61-69900, and 5-209200 disclose that an increase in the bulk density of the detergents leads to a production of detergents having a bulk density of from 0.60 to 1.00 g/ml, whose standard amount of dosage is from 25 to 30 g/30 L, thereby resulting in making the detergents compact to a level of a standard volumetric amount of dosage of from 25 to 50 ml/30 L.
However, in conventional detergents, a large amount of surfactants had to be blended in the detergent compositions because mainstream of the technical idea was to make the oily components in dirt soluble by surfactants. Specifically, sebum dirt stains ascribed to human bodies, the most typical dirt stains adhered to clothes (most likely to be observed on collars and sleeves), are taken as examples. The sebum dirt stains contains oily components, such as free fatty acids and glycerides, with a high content of 70% or more (Ichiro KASHIWA et al., “Yukagaku,” 19, 1095 (1969)). The oily components lock carbon and dirt in dust and peeled keratin, so that the resulting substance is observed as dirt stains. In order to wash off the sebum dirt stains, conventional detergents are designed based on a washing mechanism mainly by making these oily components soluble with micelle of surfactants, thereby detaching carbon, dirt, and keratin from clothes. This technical idea has been widely established among those of ordinary skill in the art, and even when the conventional detergents are shifted to compact detergents, substantially no changes took place in the surfactant concentration in the washing liquid. This fact is described in “Dictionary for Detergents and Washing,” Haruhiko OKUYAMA et al., p. 428, 1990, First Edition, Asakura Publishing Company Limited, which shows that there are substantially no changes in concentrations in the washing liquid for components other than sodium sulfate.
Based on these washing principles, the surfactant concentration in the washing liquid has to be made high in order to achieve high washing power, so that a large amount of surfactants has to be blended in the detergent composition. Therefore, a dras
Kasai Katsuhiko
Kubota Teruo
Tamura Shigeru
Tsumadori Masaki
Yamaguchi Shu
Birch & Stewart Kolasch & Birch, LLP
Douyon Lorna M.
Kao Corporation
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