JP2009263419A - Immersion cleaning method for metal product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning method for a metal product, in which more excellent detergency is easily given for a strong thermally transformed oil dirt adhering to the metal product. <P>SOLUTION: The metal product to which the thermal transformed oil dirt adheres is immersed and cleaned in a liquid detergent composition comprising hydrogen peroxide (a), one or more compounds (b) selected from ethylenediamine tetraacetic acid (EDTA), diethylene triamine pentaacetic acid (DTPA), hydroxyethylene diamine triacetic acid (HEDTA) and alkali metal salts of these and an alkali metal silicate (c) and having weight ratio (a)/(b) of (a) to (b) of 0.5 to 15 and pH 10 to 11. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an immersion cleaning method for metal products such as metal cooking utensils and metal tableware.

  Oil and fat stains derived from foods are often altered by the action of heat, sunlight, oxygen in the air, etc., and are in the form of adhesive resin or semi-dried. Various proposals have heretofore been made in order to sufficiently wash such altered oil stains. Among them, a technique using an oxygen-based bleach is known, and Patent Document 1 describes a hard surface containing a specific crystalline alkali metal silicate, a specific bleach activator, and a hydrogen peroxide releaser. It is disclosed that the bleaching composition has a high detergency regardless of the type and degree of soiling and has low damage to the target surface. Patent Document 2 discloses the use of a gluconic acid-based detergent containing sodium percarbonate, sodium gluconate and the like in order to wash oily and fat components and the like that are firmly attached. Patent Document 3 discloses a bleaching cleaning composition containing a peroxo acid salt, a surfactant, and a water softening agent in a predetermined range, respectively, and having a 1% by weight aqueous solution having a pH of 8 to 12.

On the other hand, Patent Document 4 discloses using a cleaning composition for a noodle cooking apparatus containing an oxygen-based bleaching agent in order to remove carbohydrate and protein stains peculiar to an apparatus for handling noodles.
JP-A-9-118898 JP 2001-354997 A JP 2000-204395 A JP 2004-2734 A

  However, metal utensils used in food manufacturing plants and the like are often subjected to high-temperature and long-time work, and oil stains adhere as heat-denatured oil stains that are stronger than when used in general households. . For such heat-denatured oil stains, it may be possible to increase the cleaning power by increasing the amount of sodium percarbonate or hydrogen peroxide, but there is concern over the cost and impact on the substrate. Therefore, a method of increasing the cleaning power while maintaining the conventional amount as much as possible is desirable. In addition, a method capable of obtaining such excellent detergency by a simple method is preferable.

  This invention is providing the washing | cleaning method of the metal product from which the more outstanding cleaning power is easily obtained with respect to the strong heat-denatured oil stain adhering to the metal product.

  The present invention comprises hydrogen peroxide (a) [hereinafter referred to as component (a)], ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), hydroxyethylenediaminetriacetic acid (HEDTA), and alkali metal salts thereof. One or more selected compounds (b) [hereinafter referred to as component (b)] and alkali metal silicate (c) [hereinafter referred to as component (c)], (a) and (b) A metal product having a weight ratio of (a) / (b) = 0.5 to 15 and immersed in a liquid detergent composition having a pH of 10 to 11 and washed with a metal to which heat-denatured oil stains are adhered. The present invention relates to an immersion cleaning method.

  ADVANTAGE OF THE INVENTION According to this invention, the washing | cleaning method of the metal product which can obtain more excellent cleaning power easily with respect to the strong heat-denatured oil stain adhering to the metal product is provided. The cleaning method of the present invention can obtain excellent cleaning power without increasing the hydrogen peroxide concentration. Further, since an excellent detergency can be obtained by a simple method of dipping, it is useful, for example, for cleaning metal products for business use.

  In the present invention, the components (a) to (c) are contained, and the weight ratio of (a) to (b) is (a) / (b) = 0.5 to 15 and the pH is 10 to 11 A metal product to which heat-denatured oil stains are attached is immersed in the liquid detergent composition for cleaning. In the immersion cleaning method of the present invention, it is possible to obtain excellent cleaning power against heat-denatured oil stains attached to metal products without increasing the hydrogen peroxide concentration, and the pH is 10 to 11 Since a liquid detergent composition is used, it is a useful technique because it is excellent in safety of workers engaged in cleaning.

  Despite the use of a safer liquid detergent composition that does not increase the hydrogen peroxide concentration, the reason for the excellent cleaning effect is not clear, but the liquid detergent composition contains hydrogen peroxide. And a specific compound or an alkali metal salt thereof (component (b)) in a specific ratio and as a result of performing an immersion cleaning method, hydrogen peroxide adheres to the metal product and the metal product in the presence of component (b). It is considered that an excellent cleaning effect is exhibited as a result of the physical or chemical efficient action on the interface with the thermally denatured oil stain and the removal of the stain.

  The component (a) is hydrogen peroxide. Examples of the method for containing hydrogen peroxide as component (a) in the liquid detergent composition include, for example, powder or powder of percarbonate, perborate, perphosphate, persilicate, etc. in the liquid. This can be done by dissolving the bodily substances, especially percarbonates, especially sodium percarbonate.

  The component (b) is at least one compound selected from ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), hydroxyethylenediaminetriacetic acid (HEDTA), and alkali metal salts thereof, and ethylenediaminetetraacetic acid (EDTA) , Diethylenetriaminepentaacetic acid (DTPA), and one or more compounds selected from these alkali metal salts are preferable, and ethylenediaminetetraacetic acid and these alkali metal salts are more preferable. Examples of the alkali metal salt include sodium salt and potassium salt, and sodium salt is preferable. By blending the component (b), the detergency of the component (a) in the immersion treatment can be improved.

  The component (c) is an alkali metal silicate, preferably crystalline sodium silicate such as sodium orthosilicate, sodium metasilicate, No. 1 sodium silicate, No. 2 sodium silicate, No. 3 sodium silicate, layered sodium silicate, or the like. Amorphous sodium silicate may be mentioned. (C) By mix | blending a component, when a metal product contains aluminum, base-material damage can be reduced.

  The liquid detergent composition used in the present invention contains the above components (a) to (c), and the remainder can mainly use water.

  The content of the component (a) in the liquid detergent composition used in the present invention is preferably 0.1 to 1% by weight, more preferably 0.12 to 0.8% by weight, still more preferably. Is 0.15 to 0.5% by weight.

  The content of the component (b) in the liquid detergent composition used in the present invention is preferably 0.01 to 0.5% by weight, more preferably 0.02 to 0.3% by weight, More preferably, it is 0.03 to 0.2 weight%.

  The content of the component (c) in the liquid detergent composition used in the present invention is preferably 0.01 to 0.3% by weight, more preferably 0.02 to 0.2, and still more preferably Is 0.03 to 0.2% by weight.

  In the liquid detergent composition, it is preferable that the component (b) is present in a large amount relative to the component (a) from the viewpoint of removing strong heat-modified oil stains adhering to the metal product. However, even if the component (b) is present in a large amount relative to the component (a), the effect is saturated, and it is not economical in that a large amount of the component (b) is used. Therefore, in the present invention, from the viewpoint of removing strong heat-denatured oil stains attached to the metal product and from the viewpoint of economy, the weight ratio of the component (a) to the component (b) in the liquid detergent composition is (a ) / (B) = 0.5-15, preferably 1-12, more preferably 2-10, and even more preferably 3-8.

  The liquid detergent composition has a pH of 10 to 11, preferably 10.0 to 11.0, more preferably 10.5 to 11.0, from the viewpoint of ensuring a safer work environment. is there. This pH is a pH at a temperature (liquid temperature) at the time of immersion cleaning, but may have a pH in this range at 20 ° C.

  The liquid detergent composition may contain a surfactant, another alkali metal salt, an enzyme, a solubilizer, and the like in addition to the components (a) to (c).

  Other alkali metal salts include, for example, buffering agents such as alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, ammonium hydroxide, or amine derivatives such as mono-, di- and triethanolamine, sodium carbonate and potassium carbonate. Alkali metal carbonates such as carbonates and carbonates such as ammonium carbonate can be contained in the liquid detergent composition of the present invention. The content of these agents in the liquid detergent composition is preferably 0.01 to 0.3% by weight, more preferably 0.01 to 0.2% by weight.

  In the present invention, a metal product to which heat-denatured oil stains are attached is immersed in the specific liquid detergent composition, and the metal product is immersed and cleaned. This metal product may contain components other than metal (for example, plastic, earthenware, wood, etc.). The immersion in the liquid detergent composition may be a part of the metal product, but it is usually preferable that the whole is immersed.

  Although the temperature and immersion time of the liquid detergent composition at the time of immersion can be suitably determined in consideration of the target metal product and the degree of dirt, the temperature of the liquid detergent composition is, for example, 20 to 70. The immersion time can be selected from the range of 10 minutes to 12 hours, and further from the range of 30 minutes to 6 hours.

  The metal product after the immersion is rinsed, dried, etc. as necessary, but may be subjected to scrubbing using a sponge or the like after the immersion cleaning.

  The liquid detergent composition used in the present invention can be obtained by mixing a powder composition containing percarbonate, the component (b) and (c) with water to a predetermined concentration. Therefore, in the present invention, a powder composition containing a percarbonate, (b) component and (c) is mixed with water so that the weight ratio of (a) component to (b) component is (a) / ( b) = 0.5 to 15 and the liquid detergent composition obtained in the step (I) and the step (I) of preparing the liquid detergent composition having a pH of 10 to 11 has heat-denatured oil stains. It can be implemented as a method for immersing and cleaning a metal product including the step (II) of immersing and cleaning the attached metal product. The component (b) is preferably ethylenediaminetetraacetic acid sodium dihydrate from the viewpoint that the powder composition used in the step (I) is excellent in storage stability (caking resistance). The component (c) used in the powder composition is preferably No. 2 sodium silicate, and the weight ratio of the component (a) to the component (c) is preferably (a) / (c) = 1-4.

  Examples of the metal product to be subjected to the cleaning method of the present invention include stainless steel and aluminum metal products. In addition, the metal products that are the subject of the present invention include metal products for kitchens such as fryer, metal tray, and metal tableware (metal cooking utensils, metal (Including tableware, metal containers, etc.) is preferable from the viewpoint of manifesting the effects of the present invention.

  The powder composition shown in Table 1 was mixed with water to a concentration of 1% by weight to obtain a liquid detergent composition. A stainless steel plate to which heat-denatured oil stains prepared as follows was immersed in a liquid detergent composition, and the state after being left for 30 minutes at a liquid temperature of 40 ° C. was observed. The power was evaluated. The results are shown in Table 1.

<Preparation of stainless steel plate with heat denatured oil stain>
Rapeseed oil was applied to a 0.1 g, 3 cm × 7 cm stainless steel plate (SUS304) and treated in a thermostatic bath at 200 ° C. for 2 hours to prepare a stainless steel plate to which heat-denatured oil stains adhered.

<Evaluation criteria for cleaning power>
A: Dirt is peeled off.
X: Dirt is not peeled off.
FIG. 1 shows the cleaning results of Example 1 and Comparative Example 3. From FIG. 1, it can be seen that in Example 1, dirt was peeled off from the immersed portion (the stainless steel plate was exposed), and the cleaning power was high. On the other hand, in Comparative Example 3, no dirt was peeled off at the immersed portion, indicating that the cleaning power was not sufficient.

  In the table, the sodium silicate granulated product contains 52.5% by weight of sodium silicate in the granulated product, so that the sodium silicate content in the powder composition is 8% by weight. Moreover, pH is pH at the liquid temperature at the time of immersion cleaning.

In the table, the concentration of hydrogen peroxide is determined by the following formula. This formula calculates the hydrogen peroxide concentration by multiplying the amount of hydrogen peroxide obtained from sodium percarbonate at the concentration used by the concentration used (1 wt% concentration) of sodium percarbonate.
Hydrogen peroxide concentration (wt%) = sodium percarbonate concentration (wt%) x 51/157 x 0.01

The figure which shows the immersion cleaning result of Example 1 and Comparative Example 3

Claims (5)

Hydrogen peroxide (a), one or more compounds (b) selected from ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), hydroxyethylenediaminetriacetic acid (HEDTA), and alkali metal salts thereof, and alkali A liquid detergent composition containing a metal silicate (c) and having a weight ratio of (a) and (b) of (a) / (b) = 0.5 to 15 and having a pH of 10 to 11 A method for immersing and cleaning metal products, in which metal products with heat-denatured oil stains are immersed and cleaned. The method for immersion cleaning of metal products according to claim 1, wherein the content of hydrogen peroxide (a) in the liquid cleaning composition is 0.1 to 1% by weight. The metal product immersion cleaning method according to claim 1 or 2, wherein the metal product is a metal product made of stainless steel and / or aluminum. The metal product immersion cleaning method according to claim 1, wherein the metal product is a kitchen metal product. The compound (b) is one or more compounds selected from ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), and alkali metal salts thereof. Method.