JP2015196778A - Method for washing tablewares - Google Patents

Abstract

[PROBLEMS] To provide an excellent storage stability of a cleaning composition, and a cleaning solution diluted with the composition has sufficient cleaning performance and bleaching performance even at a low concentration. A dishwashing method using an automatic dishwasher with excellent quality is provided. SOLUTION: (A) Alkali metal hydroxide is 1.2 to 9.8% by mass, (B) Alkali metal hypochlorite is 1 to 10% by mass as effective chlorine, (C) Corrosion inhibitor. As a cleaning composition containing 1 to 7.5% by mass of at least one selected from organic phosphonic acid, polycarboxylic acid type polymer, sulfonic acid type polymer and salts thereof, and (D) water, At the time of use, the cleaning liquid is diluted with water or hot water so that the pH at 25 ° C. is 9.1 to 10.9 and used as a cleaning liquid for an automatic dishwasher. [Selection figure] None

Description

  The present invention relates to a method for diluting a cleaning composition for a concentrated automatic dishwasher and using it as a cleaning liquid for an automatic dishwasher to wash dishes. Specifically, even if it is used at a lower concentration than before, it has sufficient detergency and bleachability, is excellent in scale prevention, corrosion prevention, biofilm prevention in the washing machine, and storage stability of the stock solution Furthermore, the present invention provides a method for cleaning dishes using an excellent cleaning composition for a concentrated automatic dishwasher.

  In recent years, automatic dishwashers have been rapidly spreading, and liquid detergent type ones have been proposed as cleaning agents used for automatic dishwashers from the viewpoint of ease of use. In addition, the importance of developing and selling products that are friendly to the global environment is increasing, and there is a demand for products that are friendly to the global environment in the field of detergents. Under such circumstances, since the reduction of energy and the amount of waste in logistics are expected, miniaturization of containers for storing the cleaning composition is progressing.

  Conventional cleaning agents for automatic dishwashers, especially cleaning agents for commercial automatic dishwashers, have an alkaline agent as a main component, and their liquidity is strongly alkaline exceeding pH 11. For this reason, when it contacts a washing | cleaning liquid, irritation | stimulation to skin and mucous membrane was strong and there existed a problem in safety. Further, such washing waste water of strong alkaline washing liquid is not preferable because it has an adverse effect on the environment. Furthermore, there has been a problem of corrosion on objects to be washed (ceramics, glasses, wooden products, metals (aluminum, iron, copper, stainless steel, etc.) products, plastic products, etc.) (Patent Document 1). In addition, from the viewpoint of safety, environmental load reduction, corrosion, and the like, the liquidity during use is strongly required to be weakly alkaline or neutral. However, in the case of use in a neutral region, the cleaning power against oil stains is not satisfactory (Patent Document 2).

JP 2006-335908 A JP 2006-257352 A

  Accordingly, the present invention has been made to solve the above-mentioned problems of the prior art, and the object of the present invention is to provide sufficient cleanability and bleachability even when used at a low concentration, and the scale in the washing machine. Disclosed is a dishwashing method using a concentrated detergent composition for an automatic dishwashing machine that is excellent in prevention, corrosion prevention, biofilm prevention, and storage stability of a stock solution. .

  In order to solve the above-mentioned problems, the present inventors have intensively studied. As a result, (A) 1.2 to 9.8% by mass of alkali metal hydroxide, and (B) alkali metal hypochlorite is effective chlorine. 1 to 10% by mass as an amount, (C) 1 to 7.5% by mass of at least one selected from organic phosphonic acid, polycarboxylic acid type polymer, sulfonic acid type polymer and salts thereof as a corrosion inhibitor, And (D) at the time of use, the cleaning composition containing water is diluted with water or hot water so that the pH of the cleaning liquid at 25 ° C. is 9.1 to 10.9, and used as a cleaning liquid for an automatic dishwasher. It has been found that the above conventional problems can be solved by using it, and the present invention has been completed.

That is, the present invention
(1) (A) 1.2-9.8% by mass of alkali metal hydroxide, (B) 1-10% by mass of alkali metal hypochlorite as effective chlorine amount, (C) as corrosion inhibitor 1 to 7.5% by mass of at least one selected from organic phosphonic acid, polycarboxylic acid type polymer, sulfonic acid type polymer and salts thereof, and (D) a detergent composition containing water. A dishwashing method, characterized in that, at times, the washing liquid is diluted with water or hot water so that the pH at 25 ° C. is 9.1 to 10.9 and used as a washing liquid for an automatic dishwasher,
(2) The method for washing dishes according to (1) above, wherein the component (A) is sodium hydroxide or potassium hydroxide,
(3) In the above (1) or (2), the organic phosphonic acid and salt thereof as component (C) are at least one or more of phosphonic acids or salts thereof having no amino group Cleaning method of tableware,
(4) The organic phosphonic acid and the salt thereof as component (C) are 2-phosphonobutane-1,2,4-tricarboxylic acid or a salt thereof, bis (poly-2-carboxyethyl) phosphinic acid or a salt thereof, phosphinocarboxylic acid The method for washing dishes according to any one of (1) to (3) above, which is an acid copolymer or a salt thereof, bis (poly-2-carboxyethyl) phosphinic acid or a salt thereof,
(5) The polycarboxylic acid type polymer and the salt thereof as component (C) are polyacrylic acid or a salt thereof, polymaleic acid or a salt thereof, an acrylic acid-maleic acid copolymer or a salt thereof, and an olefin-maleic acid copolymer. Or at least one selected from the salts thereof, and the sulfonic acid type polymer and the salt thereof are at least one selected from an acrylic acid-sulfonic acid type monomer copolymer or a salt thereof. (1)-(4) any of the tableware cleaning methods,
(6) The cleaning composition comprises (A) component, (B) component + (C) component, (A) / [(B) + (C)] = 3/2 to 1/10 (mass ratio) ) The tableware cleaning method according to any one of the above (1) to (5),
(7) The method for cleaning dishes according to any one of (1) to (6) above, wherein the content of aminocarboxylic acid and its salt in the cleaning composition is less than 0.5% by mass,
(8) The content of carbonates, silicates, and phosphates in the cleaning composition is less than 0.5% by mass of the tableware according to any one of (1) to (7) above Cleaning method,
(9) The method for cleaning dishes according to any one of (1) to (8) above, wherein the content of the surfactant in the cleaning composition is less than 0.5% by mass,
(10) The method for cleaning dishes according to any one of (1) to (9) above, wherein the cleaning liquid diluted with the cleaning composition is heated to 20 ° C. to 80 ° C. and used.
(11) The concentration of the component (A) in the cleaning liquid in which the cleaning composition is diluted is 0.0002 to 0.005% by mass of the tableware according to any one of (1) to (10) above Cleaning method,
Is a summary.

  The cleaning method for tableware of the present invention is equivalent to a highly alkaline detergent having a pH of 11 or more, despite the fact that the pH of the washing liquid at 25 ° C. is a low pH (weak alkaline) of 9.1 to 10.9. In addition, it has excellent cleaning properties, scale prevention properties in the washing machine, corrosion prevention properties, biofilm prevention properties, and excellent storage stability of the stock solution before dilution.

  The concentrated detergent composition for an automatic dishwasher before dilution used for the cleaning liquid in the method of the present invention comprises (A) 1.2 to 9.8% by mass of alkali metal hydroxide, and (B) hypochlorous acid. 1 to 10% by mass of an alkali metal salt as an effective chlorine amount, (C) 1 to at least one selected from organic phosphonic acid, polycarboxylic acid type polymer, sulfonic acid type polymer and salts thereof as a corrosion inhibitor 7.5% by mass and (D) water.

  When (A) in the cleaning composition is less than 1.2% by mass, it is not preferable from the viewpoint of the cleaning property of the cleaning liquid obtained by diluting the cleaning composition to pH 9.1 to 10.9, and 9.8% by mass. Exceeding the range is not preferable in terms of scale prevention and storage stability during storage of the cleaning composition. When the component (B) in the cleaning composition is less than 1% by mass, it is not preferable in terms of cleaning properties, bleaching properties, and biofilm prevention properties with a cleaning solution prepared by diluting the cleaning composition, and exceeds 10% by mass. In view of the corrosive problem of the cleaning liquid and the effective chlorine stability in the cleaning composition, it is not preferable. Further, when the component (C) is less than 1% by mass, it is not preferable from the viewpoint of the corrosiveness of the cleaning liquid and the scale prevention property, and when it exceeds 7.5% by mass, it is not preferable from the viewpoint of effective chlorine stability. In the present invention, the cleaning composition preferably contains 1.5 to 8% by mass of the component (A), more preferably 2 to 5% by mass. Moreover, it is preferable to contain 2-8 mass% of (B) component, and it is more preferable to contain 3-6 mass%. Furthermore, it is preferable to contain 1.5-6 mass% of (C) component, and it is more preferable to contain 2-5 mass%.

  Examples of the alkali metal hydroxide as the component (A) include sodium hydroxide and potassium hydroxide, and these can be used alone or in combination. Among these, the stability and storage of effective chlorine. From the viewpoint of stability, it is preferable that the proportion of potassium hydroxide or potassium hydroxide is large.

  Examples of the alkali metal hypochlorite as the component (B) include sodium hypochlorite, calcium hypochlorite, potassium hypochlorite and the like. Specifically, sodium hypochlorite having an effective chlorine content of 12% by mass, sodium hypochlorite having an effective chlorine content of 6% by mass, etc. are used, and the salt concentration is 4% by mass or less. Of these, sodium hypochlorite is preferred.

  (C) The corrosion inhibitor includes at least one selected from organic phosphonic acid, polycarboxylic acid type polymer, sulfonic acid type polymer, and salts thereof. As the organic phosphonic acid, a phosphonic acid having no amino group is preferable, and a phosphonic acid having no hydroxyl group is more preferable. Specific examples include 2-phosphonobutane-1,2,4-tricarboxylic acid, bis (poly-2-carboxyethyl) phosphinic acid, phosphinocarboxylic acid copolymer, and the like. 1,4-tricarboxylic acid is preferred.

  The phosphinocarboxylic acid copolymer is a compound having one or more phosphino groups and two or more carboxyl groups in the molecule, specifically, bis-poly (2-carboxyethyl) phosphinic acid, bis-poly (1,2-dicarboxyethyl) phosphinic acid, poly (2-carboxyethyl) (1,2-dicarboxyethyl) phosphinic acid, bis-poly [2-carboxy- (2-carboxymethyl) ethyl] phosphinic acid, And a reaction product of acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid and hypophosphorous acid, and preferably poly (2-carboxyethyl) (1,2-dicarboxyethyl) phosphinic acid and bis- Poly [2-carboxy- (2-carboxymethyl) ethyl] phosphinic acid. The preparation of phosphinopolycarboxylic acid is usually carried out by heating hypophosphorous acid and monoethylenically unsaturated carboxylic acid in an aqueous solvent in the presence of a free radical initiator, for example, JP-B-54-29316. No. 5, JP-B-5-57992 and JP-B-6-47113. Further, phosphinopolycarboxylic acids are commercially available from BWA under trade names such as Belsperse 164 (registered trademark) and Belclene 400 (registered trademark).

  Examples of the polycarboxylic acid type polymer include polyacrylic acid, polymaleic acid, polymethacrylic acid, acrylic acid type copolymer, maleic acid type copolymer, and methacrylic acid type copolymer. An acid-maleic acid copolymer is more preferred. Moreover, as a copolymer such as an acrylic acid type copolymer, a maleic acid type copolymer, and a methacrylic acid type copolymer, those containing no amide bond are preferable. The weight average molecular weight of polyacrylic acid is preferably 1,000 to 20,000, and particularly preferably 2,000 to 15,000. When the weight average molecular weight is less than 1000, it is not preferable from the viewpoint of scale prevention, and when it exceeds 20000, it is not preferable from the viewpoint of storage stability.

  Examples of the sulfonic acid type polymer include acrylic acid-sulfonic acid type monomer copolymers, and the weight average molecular weight of the acrylic acid-sulfonic acid type monomer copolymer is preferably 1,000 to 20,000, particularly preferably 2. , 15,000 to 15,000. When the weight average molecular weight is less than 1000, it is not preferable from the viewpoint of scale prevention, and when it exceeds 20000, it is not preferable from the viewpoint of storage stability. As the salt of the organic phosphonic acid, polycarboxylic acid type polymer, and sulfonic acid type polymer used as the corrosion inhibitor, alkali metal salts such as sodium and potassium are preferable.

  (D) Water includes purified water, distilled water, ion exchange water, soft water, pure water, ultrapure water, tap water, and the like. These may be used alone or in combination of two or more. Among these, water from which hardness components such as calcium and magnesium and heavy metals such as iron, which are present in minute amounts in water are removed, is preferable, and ion-exchanged water is most preferable from the viewpoint of economy and storage stability. (D) Water is the balance of the cleaning composition containing the component (A), the component (B), the component (C) and other components.

  The ratio of the component (A) and the component (B) + (C) component in the cleaning composition used for preparing the cleaning liquid in the present invention is (A) / [(B) + (C)]. = 3/2 to 1/10 (mass ratio) is preferable, (A) / [(B) + (C)] = 6/5 to 1/8 (mass ratio) is more preferable, and (A) / [( B) + (C)] = 1/1 to 1/5 (mass ratio) is particularly preferable. When the component (A), the component (B), and the component (C) are contained at a ratio of (A) / [(B) + (C)] = 3/2 to 1/10 (mass ratio), a synergistic effect is obtained. Scale prevention effect, cleaning effect and corrosion prevention effect are enhanced. However, if the amount of component (B) + component (C) is too small relative to component (A), the storage stability and effective chlorine stability may decrease, and component (B) relative to component (A) When there are too many + (C) components, corrosion prevention property and effective chlorine stability may fall.

  The dishwashing method of the present invention is an automatic dishwashing using the above-mentioned detergent composition diluted with water or hot water so that the pH of the washing liquid at 25 ° C. is 9.1 to 10.9. It is a method of washing dishes with a machine. More preferably, the cleaning liquid to be used has a pH of 9.5 to 10.5, and particularly preferably a pH of 9.6 to 10.3. When the pH is less than 9.1, it is not preferable in terms of metal corrosion prevention and effective chlorine stability, and when the pH exceeds 10.9, it is preferable in terms of storage stability, scale precipitation, and effective chlorine stability. Absent.

  In addition to the components (A), (B), and (C), the cleaning composition used in the present invention includes aminocarboxylic acid and a salt thereof, carbonate, silicate, phosphate, It may contain a surfactant or the like. However, from the viewpoint of liquid stability and effective chlorine stability, the aminocarboxylic acid and its salt in the cleaning composition are preferably less than 0.5% by mass, more preferably 0.1% by mass or less. Further, it is more preferable not to contain an aminocarboxylic acid and / or a salt thereof.

  Examples of the aminocarboxylic acid and / or its salt include nitrilotriacetic acid and / or its salt (NTA), ethylenediaminetetraacetic acid and / or its salt (EDTA), glutamic acid diacetic acid and / or its salt (GLDA), methyl Glycine diacetic acid and / or its salt (MGDA), gluconic acid and / or its salt, hydroxyethylenediamine triacetic acid and / or its salt (HEDTA), diethylenetriaminopentaacetic acid and / or its salt (DTPA), triethylenetetraamine Hexaacetic acid and / or salt thereof (TTHA), hydroxyethyliminodiacetic acid and / or salt thereof (HIDA), dihydroxyethylglycine (DHEG), aspartic acid diacetic acid and / or salt thereof (ASDA), β-alanine diacetic acid And / or its salt (ADA), serine diacetic acid and / or its (SDA) and mixtures of two or more thereof. In addition, sodium, potassium, etc. are mentioned as a counter ion used as the salt of these chelating agents.

  Moreover, since it becomes a generation source of a scale, it is preferable that carbonate, a silicate, and a phosphate in a cleaning composition are less than 0.5 mass%, and it is more preferable that it is 0.1 mass% or less. More preferably, it does not contain carbonate, silicate or phosphate.

  Examples of the carbonate include sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate and the like. Examples of the silicate include sodium orthosilicate, potassium orthosilicate, sodium metasilicate, potassium metasilicate, No. 1 sodium silicate, No. 1 potassium silicate, No. 2 sodium silicate, No. 3 sodium silicate, and the like. As the phosphate, orthophosphoric acid, polyphosphoric acid, pyrophosphoric acid, metaphosphoric acid, hexametaphosphoric acid and alkali metal salts thereof are used. Examples of the alkali metal combined with these include sodium and potassium.

  Furthermore, from the viewpoint of effective chlorine stability, the surfactant in the detergent composition, for example, anionic surfactant, nonionic surfactant, amphoteric surfactant, and cationic surfactant should be less than 0.5% by mass. Is preferable, it is more preferable that it is 0.1 mass% or less, and it is more preferable not to contain surfactant further.

  The cleaning composition used in the present invention may contain components usually used in the technical field depending on the preparation form of the cleaning composition as long as the effects of the present invention are not impaired. Examples of such components include water-soluble solvents, chelating agents, bactericides, pH adjusters, antifoaming agents, thickeners, fragrances, and dyes.

  Examples of the water-soluble solvent include alcohol solvents, glycol ether solvents, etc., and alcohol solvents include ethyl alcohol, isopropanol, 3-methoxybutanol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol. , Dipropylene glycol, tripropylene glycol, polypropylene glycol, 1,3-butylene glycol, 1,4-butanediol, 1,5-pentanediol, hexylene glycol, glycerin and the like.

  Also, glycol ether solvents include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol. Dimethyl ether, diethylene glycol diethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, polyethylene glycol mono Chirueteru, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, 3-methyl-3-methoxybutanol and the like.

  Examples of the chelating agent include alkanolamine salts such as glycolic acid, lactic acid, citric acid, gluconic acid, tartaric acid, malic acid, and alkali metal salts, ammonium salts, monoethanolamine, triethanolamine, and monoisopropanolamine. Is mentioned. These may be used alone or in combination of two or more.

  Examples of the bactericides include thiazolines, hydantoins, iodo-2-propynylbutyl carbamate, isopropylmethylphenol, hexachlorophene, irgasan, triclosan, and the like. Thiazolines include 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, isothiazoline-3-one, 1,2-benzisothiazolin-3-one, Nn-butyl-benzisothiazolin-3-one and the like. Hydantoins include 1,3-dimethylol-5,5-dimethylhydantoin, 1 or 3-monomethylol-5,5-dimethylhydantoin, dimethylhydantoin, 1,3-dichloro-5,5-dimethylhydantoin, 1, Examples include 3-dichloroethylmethylhydantoin.

  Examples of the pH adjuster include acetic acid, hydrochloric acid, sulfuric acid, nitric acid, citric acid, phosphoric acid, sodium hydroxide, potassium hydroxide, sodium acetate, sodium carbonate, sodium citrate, sodium hydrogen citrate, sodium phosphate, Examples thereof include sodium hydrogen phosphate.

  Examples of the antifoaming agent include silicone-based antifoaming agents, polyoxyalkylene-based antifoaming agents, and mineral oil-based antifoaming agents.

  Examples of the thickener include sorbit, glycerin, propylene glycol, pentylene glycol, hexylene glycol, octylene glycol, xylitol, erythritol, polyethylene glycol having an average molecular weight of 200 to 6,000, ethylene glycol, 1,3- Polybutyl alcohol such as butylene glycol, reduced starch saccharified product, cellulose derivatives such as polyvinyl alcohol, polyvinyl pyrrolidone, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, alginic acid derivatives such as sodium alginate, fatty acid derivatives such as stearyl alcohol and mucopolysaccharides A certain hyaluronic acid derivative, a chondroitin sulfate derivative, etc. are mentioned.

  Examples of the fragrances include natural fragrances, synthetic fragrances, and blended fragrances thereof. Examples of the dye include natural dyes, synthetic dyes, and mixtures thereof.

  The tableware cleaning method of the present invention is a method of cleaning tableware with an automatic dishwasher using a cleaning solution diluted with water or hot water to a pH of 9.1 to 10.9 when using the above detergent composition. Yes, it is applied to the cleaning of dishes using automatic dishwashers such as household automatic dishwashers and commercial automatic dishwashers, but in particular, there are more restrictions on operating conditions compared to household automatic dishwashers When washing dishes with a commercial automatic dishwasher, a better cleaning effect is exhibited. The concentration of the component (A) is preferably 0.0002 to 0.005% by mass, and is preferably heated to 20 to 80 ° C. for the washing liquid used for washing with an automatic dishwasher. According to the tableware washing method of the present invention, an excellent washing effect can be obtained even when the washing time by the automatic dishwasher is 5 minutes or less, and even shorter is 1 minute or less. Furthermore, although excellent cleaning performance is always exhibited even when the cleaning temperature is in the range of 20 to 80 ° C, the cleaning temperature is preferably 35 to 75 ° C, and particularly preferably 45 to 70 ° C.

  The cleaning solution diluted with the cleaning composition used in the method of the present invention exhibits excellent cleaning performance against all kinds of dirt such as fats and oils, proteins, starch, etc., made of metal such as aluminum, stainless steel, silver, melamine Suitable for cleaning dishes such as glass, plastic, glass, porcelain, lacquerware and ceramics. In particular, it can be suitably used for automatic dishwashers in hotels, restaurants, schools, hospitals, restaurants, catering companies, company cafeterias and the like.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. Each component used for blending in Examples and Comparative Examples is shown below.

(A) Component A-1: Potassium hydroxide A-2: Sodium hydroxide

(B) Component B-1: Sodium hypochlorite B-2: Potassium hypochlorite

(C) Component C-1: Sodium polyacrylate (weight average molecular weight is 4,000)
C-2: Acrylic acid-maleic acid copolymer (weight average molecular weight is 10,000)
C-3: Olefin-maleic acid copolymer (weight average molecular weight is 12,000)
C-4: Acrylic acid-sulfonic acid type monomer polymer (weight average molecular weight is 5,000)
C-5: 2-phosphonobutane-1,2,4-tricarboxylic acid C-6: Bis (poly-2-carboxyethyl) phosphinic acid [Belsperse164 (registered trademark) (manufactured by BWA)]
C-7: Phosphinocarboxylic acid copolymer [Belclene400 (registered trademark) (manufactured by BWA)]

Examples 1-30, Comparative Examples 1-20
Based on the formulations shown in Tables 1 to 5, concentrated detergent compositions for automatic dishwashers were prepared. The pH of a cleaning solution obtained by diluting the cleaning composition to 0.07% by mass was measured. In addition, for each detergent composition or its dilution, detergency (starch stain, protein stain, oil stain), bleachability, scale prevention property, metal corrosion prevention property, biofilm prevention property, effective chlorine stability, storage stability Was measured by the method shown below. The results are shown in Tables 1 to 5. In addition, the numerical value of the mixing | blending of the Example in a table | surface and a comparative example represents the mass% of a pure part.

* 1: pH measurement method <calibration of pH meter>
Connect a pH measurement composite electrode (made by HORIBA; glass sliding sleeve type) to a pH meter (made by HORIBA; pH / ion meter F-23) and turn on the power. A saturated potassium chloride aqueous solution (3.33 mol / L) was used as the pH electrode internal solution. Next, pH 4.01 standard solution (phthalate standard solution), pH 6.86 standard solution (neutral phosphate standard solution), and pH 9.18 standard solution (borate standard solution) are filled in a 100 ml beaker. And immersed in a constant temperature bath at 25 ° C. for 30 minutes. The pH measurement electrode was immersed in a standard solution adjusted to a constant temperature for 3 minutes, and calibration operations were performed in the order of pH 6.86, pH 9.18, and pH 4.01.

<Measurement of pH of sample>
A sample (concentrated detergent composition for an automatic dishwasher) is filled into a 100 ml beaker, and is converted into calcium carbonate equivalent to 75 mg / L [German hardness 4.2 ° DH] in hard water to 0.07% by mass. After dilution, the temperature was adjusted to a constant temperature of 25 ° C. in a constant temperature bath at 25 ° C. The pH measurement electrode was immersed in a sample adjusted to a constant temperature for 3 minutes, and the pH was measured.

* 2: Detergency test (1) Detergency test (starch dirt)
<Cleaning conditions>
Washing machine used: Automatic dishwasher made by HOBART (model AM-14)
Washing temperature: 66 ° C
Cleaning time: 40 seconds Rinsing temperature: 82 ° C
Rinsing time: 9 seconds Cleaning solution: 0.07% by weight diluted solution of cleaning composition Water used: Hard water of 200 mg / L [German hardness 11.2 ° DH] in terms of calcium carbonate

<Adjustment of items to be washed>
A 3% by mass rice starch solution was stirred at 80 ° C. for 15 minutes to gelatinize. 1 g of this gelatinized starch was uniformly applied to a white porcelain dish (diameter: 12 cm) and dried at room temperature to obtain an object to be washed for a detergency test.

<Detergency evaluation method>
Ten contamination dishes prepared by the above method were placed in a washing rack, washed under the above washing conditions, rinsed, and dried at room temperature. After drying, 0.1% iodine solution was sprinkled over the entire dish, and the area (S ₁ ) of the colored portion colored with iodine was measured. From the initial contamination area (S ₀ ), the washing rate was determined by the following formula, and the average value of 10 dishes was adopted as a result.

Cleaning rate (%) = {(S ₀ −S ₁ ) / S ₀ } × 100

A: The cleaning rate is 80% or more.
○: The cleaning rate is 60% or more and less than 80%.
Δ: The cleaning rate is 40% or more and less than 60%.
X: The cleaning rate is less than 40%.
And Δ, ○, and ◎ were determined to be practical.

(2) Detergency test (oil stain)
<Cleaning conditions>
Washing machine used: Ishikawajima-Harima Heavy Industries Co., Ltd. automatic dishwasher (model JWD-6 type)
Washing temperature: 60 ° C
Washing time: 45 seconds Rinsing temperature: 80 ° C
Rinsing time: 12 seconds Cleaning solution: 0.07% by weight diluted solution of cleaning composition Water used: Hard water of 200 mg / L [German hardness 11.2 ° DH] in terms of calcium carbonate

<Adjustment of items to be washed>
5 g of rice starch was dissolved in 20 g of water and stirred at 80 ° C. for 3 minutes to gelatinize. 20 g of beef tallow dissolved in this was added and stirred well, cooled to 53 ° C., and then 10 g of egg yolk added and emulsified to make it dirty. The soil was uniformly applied to a 15 cm × 15 cm vinyl chloride black plate using a coating rod, and dried at room temperature to obtain a washing plate for washing power test.

<Evaluation method>
One washing plate prepared by the above method was placed in a washing rack, washed under the above washing conditions, and then lightly rinsed with running water. The remaining portion of the plate after washing and rinsing was sketched on a 5 mm square grid, the clean grids were counted, and the clean area ratio was defined as the cleaning rate. It can be said that the larger the value of the cleaning rate, the better the cleaning power.
A: The cleaning rate is 80% or more.
○: The cleaning rate is 60% or more and less than 80%.
Δ: The cleaning rate is 40% or more and less than 60%.
X: The cleaning rate is less than 40%.
And Δ, ○, and ◎ were determined to be practical.

(3) Detergency test (protein stain)
<Cleaning conditions>
Washing machine used: Automatic dishwasher made by HOBART (model AM-14)
Washing temperature: 66 ° C
Cleaning time: 40 seconds Rinsing temperature: 82 ° C
Rinsing time: 9 seconds Cleaning solution: 0.07% by weight diluted solution of cleaning composition Water used: Hard water of 200 mg / L [German hardness 11.2 ° DH] in terms of calcium carbonate

<Adjustment of items to be washed>
A 5% by mass egg yolk solution was uniformly applied to a white porcelain dish (12 cm in diameter), heated at 100 ° C. for 30 minutes, and denatured to obtain a washing object for detergency test.

<Evaluation method>
Ten contamination dishes prepared by the above method were placed in a washing rack, washed under the above washing conditions, rinsed, and dried at room temperature. After drying, a 0.1% amide black solution was sprinkled over the entire dish, and the area (S ₁ ) of the colored portion that was colored was measured. From the initial contaminated area (S ₀ ), the washing rate was determined by the following formula, and the average value of 10 dishes was adopted as a result.

Cleaning rate (%) = {(S ₀ −S ₁ ) / S ₀ } × 100

A: The cleaning rate is 80% or more.
○: The cleaning rate is 60% or more and less than 80%.
Δ: The cleaning rate is 40% or more and less than 60%.
X: The cleaning rate is less than 40%.
And Δ, ○, and ◎ were determined to be practical.

* 3: Bleachability test method:
<Cleaning conditions>
Washing machine used: Automatic dishwasher made by HOBART (model AM-14)
Washing temperature: 66 ° C
Cleaning time: 40 seconds Rinsing temperature: 82 ° C
Rinsing time: 9 seconds Cleaning solution: 0.07% by weight diluted solution of cleaning composition Water used: Hard water of 200 mg / L [German hardness 11.2 ° DH] in terms of calcium carbonate

<Adjustment of items to be washed>
A white porcelain dish (12 cm in diameter) was immersed in black tea at 80 ° C. for 5 minutes and then heated at 100 ° C. for 30 minutes to give a browned product for bleaching test.

<Evaluation method>
Ten contamination dishes prepared by the above method were placed in a washing rack, washed under the above washing conditions, rinsed, and dried at room temperature. Measure the reflectivity of 460 nm using a reflectometer (NF-333, manufactured by Nippon Denshoku Industries Co., Ltd.) before and after washing, determine the bleaching rate using the following formula, and adopt the average value of 10 plates as a result. did.

  Bleaching rate (%) = (reflectance after bleaching−reflectance of contaminated site before bleaching) / (reflectance of uncontaminated site−reflectance of contaminated site before bleaching) × 100

A: The bleaching rate is 80% or more.
○: The bleaching rate is 60% or more and less than 80%.
Δ: Bleaching rate is 40% or more and less than 60%.
X: The bleaching rate is less than 40%.
And Δ, ○, and ◎ were determined to be practical.

* 4: Scale prevention test method:
The slide glass was immersed in a diluted solution of each cleaning composition diluted to 0.07% by mass with hard water of 200 mg / L [German hardness 11.2 ° DH] in terms of calcium carbonate, and kept at a constant temperature of 80 ° C. The glass slide was rinsed with distilled water and dried, and the glossiness of the slide glass was measured with a glossmeter. The scale inhibition degree was calculated by the following formula and the scale inhibition property was evaluated.

  Scale suppression (%) = Glossiness of slide glass after immersion in cleaning solution / Glossiness of untreated slide glass × 100

Evaluation of scale inhibition ○: Scale inhibition is 96% or more (no scale adhesion)
Δ: Scale suppression is 75% or more and less than 96% (slightly adheres to scale)
X: Scale suppression is less than 75% (scale adhesion)
And Δ and ○ were determined to be practical.

* 5: Metal corrosion prevention test method:
The test piece [stainless steel (SUS430), gray cast iron (FC200)] is used after previously washed with a neutral detergent, treated with acetone and dried. Dilute each detergent composition to 0.07 mass% with hard water of 75 mg / L [German hardness 4.2 ° DH] in terms of calcium carbonate, put 60 ml into a 70 ml capacity glass bottle with a lid, and test it. The pieces were immersed and stored in a thermostat at 70 ° C. for 5 days. The test piece after storage was taken out, rinsed and dried with ion-exchanged water, the state of the test piece surface was visually observed, and corrosivity was determined according to the following criteria.

Metal corrosion prevention evaluation criteria:
◎: No corrosion ○: Almost no corrosion
Δ: Slightly corroded, but no problem in use ×: Corroded, and Δ, ○, and ◎ were judged as practical.

* 6: Biofilm prevention test test method:
Dissolve each detergent composition in 5 g using a sterilized Mueller Hinton medium (manufactured by Nippon Becton Dickinson Co., Ltd.) to make a total amount of 100 g, and prepare a 5% by weight conch solution of each detergent composition. did. This conc solution is further diluted with a sterilized Mueller Hinton medium so that the concentration of the cleaning composition is 0.07% by mass, and 2 mL each is added to a 24-well microplate (Asahi Techno Glass Co., Ltd.). It was.

  Using a LB medium (manufactured by Nippon Becton Dickinson Co., Ltd.) for each of Pseudomonas aeruginosa NBRC13275 and Klebsiella pneumoniae ATCC13883, the bacterial solution which had been pre-cultured for 18 hours at 37 ° C. Used to inoculate 100 μL of the test solution in the microplate. After culturing at 37 ° C. for 48 hours, the culture solution was discarded, and each well was washed 5 times with 2 mL of sterilized purified water. The biofilm adhered to the microplate wall was stained with 0.1% by mass crystal violet solution, rinsed with sterilized water, and the formation state of the biofilm was visually observed.

Evaluation criteria:
A: Biofilm covers 0 to less than 20% of plate wall surface ○: Biofilm covers 20% or more and less than 40% of plate wall surface Δ: Biofilm covers 40% or more and less than 60% of plate wall surface X: The biofilm covered 60% or more of the plate wall surface, and Δ, ○, and ◎ were judged as practical.

* 7: Effective chlorine stability test method:
Each cleaning composition was stored at 40 ° C. for 30 days, and the storage stability of hypochlorite at that time was evaluated from the effective chlorine residual rate according to the following criteria. In addition, the effective chlorine residual rate was calculated | required by the formula shown below based on JIS method JIS K-0101.

  Effective chlorine residual ratio (%) = effective chlorine concentration in the composition after storage) / (effective chlorine concentration in the composition before storage) × 100

Evaluation of storage stability of hypochlorite ◎: Effective chlorine residual ratio is 85% or more ○: Effective chlorine residual ratio is 70% or more and less than 85% Δ: Effective chlorine residual ratio is 50% or more and less than 70% ×: Effective chlorine residual ratio was less than 50%-: Measurement was impossible, and Δ, ○, and ◎ were determined to be practical.

* 8: Storage stability test method:
100 g of each cleaning composition was placed in a transparent glass bottle and allowed to stand at −5 ° C., 25 ° C., and 40 ° C. for 1 month, and then the appearance was observed.

Stability evaluation criteria:
○: No separation or turbidity is observed and stable Δ: There is no overall separation, but some turbidity is observed ×: Separation or turbidity is observed
And Δ and ○ were determined to be practical.

Claims (11)

(A) 1.2-9.8 mass% of alkali metal hydroxide,
(B) 1 to 10% by mass of an alkali metal hypochlorite as an effective chlorine amount,
(C) As a corrosion inhibitor, 1 to 7.5% by mass of at least one selected from organic phosphonic acid, polycarboxylic acid type polymer, sulfonic acid type polymer and salts thereof,
And (D) a detergent composition containing water,
A method for washing dishes, wherein the washing liquid is diluted with water or hot water so that the washing liquid has a pH of 9.1 to 10.9 at 25 ° C. and is used as a washing liquid for an automatic dishwashing machine.   (A) A component is sodium hydroxide and / or potassium hydroxide, The washing | cleaning method of the tableware of Claim 1 characterized by the above-mentioned.   (C) The organic phosphonic acid and its salt of a component are the phosphonic acids which do not have an amino group, or its salt, The washing | cleaning method of the tableware of Claim 1 or 2 characterized by the above-mentioned.   Component (C) is an organic phosphonic acid or a salt thereof, 2-phosphonobutane-1,2,4-tricarboxylic acid or a salt thereof, bis (poly-2-carboxyethyl) phosphinic acid or a salt thereof, or a phosphinocarboxylic acid copolymer. The method for cleaning tableware according to any one of claims 1 to 3, wherein the product is a product or a salt thereof, or bis (poly-2-carboxyethyl) phosphinic acid or a salt thereof. Component (C) is a polycarboxylic acid type polymer and a salt thereof, such as polyacrylic acid or a salt thereof, polymaleic acid or a salt thereof, an acrylic acid-maleic acid copolymer or a salt thereof, an olefin-maleic acid copolymer or a salt thereof. At least one selected from
The tableware according to any one of claims 1 to 4, wherein the sulfonic acid type polymer and a salt thereof are at least one selected from an acrylic acid-sulfonic acid type monomer copolymer or a salt thereof. Cleaning method.   The cleaning composition comprises (A) component, (B) component + (C) component, (A) / [(B) + (C)] = 3/2 to 1/10 (mass ratio). It contains by a ratio, The washing | cleaning method of the tableware of any one of Claims 1-5 characterized by the above-mentioned.   The cleaning method for tableware according to any one of claims 1 to 6, wherein the content of the aminocarboxylic acid and the salt thereof in the cleaning composition is less than 0.5% by mass.   The method for cleaning tableware according to any one of claims 1 to 7, wherein the content of carbonate, silicate and phosphate in the cleaning composition is less than 0.5% by mass. .   The tableware cleaning method according to any one of claims 1 to 8, wherein the content of the surfactant in the cleaning composition is less than 0.5% by mass.   The method for cleaning tableware according to any one of claims 1 to 9, wherein a cleaning liquid obtained by diluting the cleaning composition is heated to 20 ° C to 80 ° C and used.   The washing | cleaning method of the tableware of any one of Claims 1-10 whose (A) component density | concentration in the washing | cleaning liquid which diluted the cleaning composition is 0.0002-0.005 mass% .