Tablet detergent for automatic dishwasher

Abstract

To provide a detergent in tablet form to be used in an automatic dishwasher, and a method of washing tableware using the detergent in the automatic dishwasher.SOLUTION: A tablet detergent for an automatic dishwasher includes (A) an alkali agent, (B) a nonionic surfactant, (C) an aminocarboxylic acid-based chelating agent, (D) a polycarboxylic acid-based polymer, and (E) sodium chloride. When 0.5 g of the tablet detergent for an automatic dishwasher is dissolved in 1 L of water, the pH at 20°C is 8 or more and 12 or less, and the electric conductivity at 60°C is 1.4 mS / cm or more.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a tablet-shaped cleaning agent for use in an automatic dishwashing machine. The present invention also relates to a method for washing tableware using the cleaning agent in an automatic dishwashing machine.

Background Art

[0002] In recent years, automatic dishwashing machines have been widely used for washing tableware. Also in hotels, restaurants, catering companies, hospitals, company cafeterias, etc., in order to efficiently wash the used tableware, and also due to the recent improvement in hygiene awareness, industrial automatic dishwashing machines are widely used.

[0003] When washing tableware using an automatic dishwashing machine, particularly an industrial automatic dishwashing machine, after preparing a cleaning liquid at a predetermined concentration and heating and holding it in a cleaning liquid tank, the heated cleaning liquid is sprayed in a certain amount from a nozzle into a washing chamber containing the tableware to wash the tableware. Then, a rinsing liquid is sprayed in a certain amount from the nozzle onto the tableware in the washing chamber for rinsing, and drying is performed through such steps to carry out the washing. As cleaning agents for automatic dishwashing machines, conventionally, liquid, granular, powdered, and tablet-shaped ones have been used. While the liquid ones are easy to supply by a pump or the like, there are problems with costs such as transportation and storage because of their large volume. On the other hand, the powdered, granular, and tablet-shaped ones have the advantage that they can be in a high concentration and have a small volume. However, it is difficult to homogenize multiple components in the powdered ones, and there is a problem of undissolved residues in the cleaning liquid tank for the solid-shaped ones such as granular and tablet-shaped ones.

[0004] As a solid automatic dishwasher detergent composition, Patent Document 1 describes a molten solid type dishwasher detergent composition characterized in that it contains, as component (A), 40% by mass or more and 50% by mass or less of an alkali metal hydroxide, as component (B), 25% by mass or more and 45% by mass or less of an aminocarboxylic acid-based chelating agent, as component (C), 0.1% by mass or more and 10% by mass or less of a polymer, and as component (D), water, and (A) / {(A)+(D)} is 0.58 or more and 0.75 or less in terms of mass ratio. By forming it into a solid form having the above composition, it is compact, has good storage stability, has no risk of deliquescence during product storage, has good dissolution stability, does not dissolve excessively or cause poor dissolution, and can be stably supplied at a low concentration. Patent Document 2 also describes a solid detergent containing 20 to 60% by weight of an alkali metal hydroxide salt and a metal ion sequestering agent such as an aminocarboxylate, with a part of the alkali metal hydroxide salt being dispersed in the state of an anhydrous alkali metal hydroxide; and Patent Document 3 describes a solid type detergent containing about 2 to 15% by weight of an alkali source at least part of which is sodium or the like and about 20 to 40% by weight of an aminocarboxylic acid type metal ion sequestering agent at least part of which is a potassium salt.

[0005] Conventionally, dishwasher detergents for automatic dishwashers have used detergent compositions containing nonionic surfactants with low foaming properties. For example, Patent Document 4 discloses a dishwasher detergent composition comprising a nonionic surfactant, a cleaning builder, and an emulsifier composed of a carboxyvinyl polymer. Patent Document 5 also discloses a dishwasher detergent composition comprising a nonionic surfactant, a cleaning builder, and a linear aliphatic carboxylic acid having 6 to 10 carbon atoms.

[0006] In addition, Patent Document 6 describes a solid detergent composition for cleaning an object to be cleaned by using a dishwasher equipped with a control mechanism that monitors the electrical conductivity of the cleaning liquid to determine the necessity of supplying the detergent composition in order to facilitate the concentration control of the detergent composition in the dishwasher. Specifically, a detergent composition is described that contains (A) a nonionic surfactant, (B) a polyelectrolyte, (C) an alkaline agent, and (D) a chelating agent, and has an electrical conductivity of 1.2 mS / cm or more at 60 °C when 0.5 g of the detergent composition is dissolved in 1 L of water.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Summary of the Invention

Problems to be Solved by the Invention

[0008] An object of the present invention is to provide a tablet-shaped dishwasher detergent that has good tableting properties and hardness while being excellent in solubility in water. Another object of the present invention is to provide a tablet dishwasher detergent that has excellent detergency and anti-redeposition properties of dirt at a low concentration of 0.03 to 0.05% by mass. Furthermore, an object of the present invention is to provide a tablet dishwasher detergent that has high biodegradability.

Means for Solving the Problems

[0009] As a result of intensive studies to solve the above problems, the inventors of the present invention have found that when 0.5 g of the automatic dishwasher tablet detergent containing (A) an alkaline agent, (B) a nonionic surfactant, (C) an aminocarboxylic acid type chelating agent, (D) a polycarboxylic acid type polymer, and (E) sodium chloride is dissolved in 1 L of water, the pH of the aqueous solution at 20°C is 8 or more and 12 or less, and the electric conductivity at 60°C is 1.4 mS / cm or more. The tablet detergent obtained by tableting the detergent composition has excellent solubility in water while having good tableting properties and hardness, and it has been confirmed that even when it is put into an automatic dishwasher and used, the undissolved residue is significantly suppressed. Furthermore, it has been confirmed that the above tablet detergent exhibits excellent detergency and anti-redeposition properties of dirt when it is put into an automatic dishwasher and used at a low concentration of 0.03 to 0.05% by mass. In addition, it has been confirmed that the tablet detergent for automatic dishwashers containing trisodium methylglycinediacetate as a chelating agent has high biodegradability.

[0010] The present invention has been completed based on these findings and has the following embodiments. (I) Tablet detergent for automatic dishwashers (I-1) A tablet detergent for automatic dishwashers containing (A) an alkaline agent, (B) a nonionic surfactant, (C) an aminocarboxylic acid type chelating agent, (D) a polycarboxylic acid type polymer, and (E) sodium chloride, wherein the pH of the aqueous solution at 20°C is 8 or more and 12 or less, and the electric conductivity at 60°C is 1.4 mS / cm or more when 0.5 g of the tablet detergent for automatic dishwashers is dissolved in 1 L of water, Tablet detergent for automatic dishwashers. (I-2) The tablet detergent for automatic dishwashers according to (I-1), further containing (F) sucrose fatty acid ester. (I-3) The tablet detergent for automatic dishwashers according to (I-1) or (I-2), wherein the pH of the aqueous solution at 20°C is 8 or more and 12 or less, and the electric conductivity at 60°C is 1.0 mS / cm or more when 0.3 g of the tablet detergent for automatic dishwashers is dissolved in 1 L of water. (I-4)(A) An alkaline agent is contained in a proportion of 20 to 60% by mass, (B) a nonionic surfactant is contained in a proportion of 0.7 to 5% by mass, (C) an aminocarboxylic acid type chelating agent is contained in a proportion of 20 to 60% by mass, (D) a polycarboxylic acid type polymer is contained in a proportion of 0.1 to 20% by mass, and (E) sodium chloride is contained in a proportion of 10 to 55% by mass, which is the tablet detergent for automatic dishwashers described in any one of (I-1) to (I-3). (I-5) The (A) alkaline agent is at least one selected from the group consisting of sodium carbonate, sodium metasilicate, and hydrates thereof, and the total content in 100% by mass of the tablet detergent for automatic dishwashers is 20 to 40% by mass, which is the tablet detergent for automatic dishwashers described in any one of (I-1) to (I-4). (I-6) The (B) nonionic surfactant is at least one selected from the group consisting of aliphatic alcohol alkoxylates and synthetic alcohol alkoxylates, and the total content in 100% by mass of the tablet detergent for automatic dishwashers is 0.8 to 3% by mass, which is the tablet detergent for automatic dishwashers described in any one of (I-1) to (I-5). (I-7) The (C) aminocarboxylic acid type chelating agent is at least one selected from the group consisting of trisodium methylglycinediacetate, tetrasodium ethylenediaminetetraacetate, sodium nitrilotriacetate, and tetrasodium glutamate diacetate, and the total content in 100% by mass of the tablet detergent for automatic dishwashers is 20 to 50% by mass, which is the tablet detergent for automatic dishwashers described in any one of (I-1) to (I-6). (I-8) The (D) polycarboxylic acid type polymer is at least one selected from the group consisting of polyacrylic acid, olefin-maleic acid copolymers, and salts thereof, and the total content in 100% by mass of the tablet detergent for automatic dishwashers is 0.5 to 15% by mass, which is the tablet detergent for automatic dishwashers described in any one of (I-1) to (I-7). (I-9) The content of (E) sodium chloride in 100% by mass of the tablet detergent for automatic dishwashers is 10 to 45% by mass, which is the tablet detergent for automatic dishwashers described in any one of (I-1) to (I-8). (I-10) A tablet detergent for automatic dishwashers as described in any one of (I-1) to (I-9), which does not contain starch and modified starch. (I-11) A tablet detergent for automatic dishwashers as described in any one of (I-1) to (I-10), wherein the (B) aminocarboxylic acid type chelating agent is trisodium methylglycinediacetate.

[0011] (II) Method for producing tablet detergent for automatic dishwashers (II-1) Installing the tablet detergent for automatic dishwashers as described in any one of (I-1) to (I-11) in an elution hopper having a discharge port at the lower end portion, supplying water from a water supply nozzle to dissolve the tablet detergent for automatic dishwashers in the hopper in water, and heating and holding in a cleaning liquid tank of an automatic dishwasher a cleaning liquid adjusted to a concentration of 0.03 to 0.05% by mass of the tablet detergent for automatic dishwashers in the aqueous solution; A step of spraying the cleaning liquid in the cleaning liquid tank into the dishwasher compartment to clean the tableware, and A step of rinsing with a rinsing liquid after cleaning, A method for cleaning tableware by an automatic dishwasher, characterized by comprising the above steps.

Advantages of the Invention

[0012] The tablet detergent for automatic dishwashers of the present invention has excellent solubility in water while having good tableting properties and hardness, and can significantly suppress undissolved residues even when it is put into an automatic dishwasher at a ratio of at least 0.3 g to 0.5 g per 1 L of water and used. In addition, the tablet detergent for automatic dishwashers of the present invention can exhibit excellent detergency and anti-redeposition properties of dirt when it is put into an automatic dishwasher and used at a low concentration of 0.03 to 0.05% by mass. Furthermore, the tablet detergent for automatic dishwashers of the present invention using trisodium methylglycinediacetate as a chelating agent has high biodegradability. Therefore, according to the method for cleaning tableware by the automatic dishwasher of the present invention using the tablet detergent for automatic dishwashers of the present invention, excellent detergency and prevention of redeposition of dirt can be exhibited while using the tablet detergent for automatic dishwashers at a low concentration of 0.03 to 0.05% by mass, and the problem of undissolved residue of the tablet detergent for automatic dishwashers can also be solved.

Embodiments for Carrying Out the Invention

[0013] (I) Tablet detergent for automatic dishwashers The tablet detergent for automatic dishwashers of the present invention (hereinafter simply referred to as "this detergent") contains (A) an alkali agent, (B) a nonionic surfactant, (C) an aminocarboxylic acid type chelating agent, (D) a polycarboxylic acid type polymer, and (E) sodium chloride. These components will be described below.

[0014] (A) Alkaline agent (hereinafter also referred to as "Component A") In this detergent, as the component A, an alkali metal salt or an alkaline earth metal salt can be used. The type thereof is not particularly limited, but examples include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; alkali metal carbonates such as sodium carbonate and potassium carbonate; alkali metal hydrogen carbonates such as sodium hydrogen carbonate and potassium hydrogen carbonate; and alkali metal silicates such as sodium metasilicate, sodium sesquisilicate, sodium orthosilicate, potassium metasilicate, potassium sesquisilicate, and potassium orthosilicate. These compounds may be anhydrides or hydrates. Preferably, they are alkali metal carbonates, alkali metal hydrogen carbonates, and alkali metal silicates, and more preferably sodium salts as the alkali metal salts. Particularly preferably, they are sodium carbonate, sodium metasilicate, and hydrates thereof. These alkali agents can be used alone or in any combination of two or more.

[0015] These alkaline agents supply alkali metal ions when dissolved in water. Therefore, by dissolving a cleaning agent containing these alkaline agents in water, a cleaning solution with a high pH and high electrical conductivity can be obtained.

[0016] The content of component A in 100% by mass of this cleaning agent may be adjusted so that when 0.5 g of this cleaning agent is dissolved in 1 L of water, the pH of the resulting aqueous solution at 20°C is 8 or more and 12 or less, and the electrical conductivity at 60°C is 1.4 mS / cm or more. Although not particularly limited as long as it is within that range, for example, it can be selected from the range of 20 to 60% by mass. Preferably it is 20 to 50% by mass, more preferably 20 to 40% by mass. Although not limited, preferably it is adjusted so that when 0.3 g of this cleaning agent is dissolved in 1 L of water, the pH of the resulting aqueous solution at 20°C is 8 or more and 12 or less, and the electrical conductivity at 60°C is 1.0 mS / cm or more. In the present invention, the upper limit of the electrical conductivity is not limited as long as the effects of the present invention are achieved, but in any of the above cases, it can be 3000 mS / cm or less. In addition, when component A is at least one selected from the group consisting of sodium carbonate, sodium metasilicate, and hydrates thereof, the total content of these in 100% by mass of this cleaning agent can preferably be adjusted in the range of 20 to 40% by mass. When the content of component A is within the above range, the pH can be made sufficiently high, and also, a cleaning agent with a high electrical conductivity and high detergency against oil stains can be obtained.

[0017] (B) Nonionic surfactant (hereinafter also referred to as "Component B") In this detergent, as component B, examples thereof include aliphatic alcohol alkoxylates such as polyoxyethylene polyoxypropylene alkyl ether and polyoxyethylene polyoxybutylene alkyl ether (ethylene oxide, propylene oxide, and butylene oxide may be either random or block); synthetic alcohol alkoxylates such as polyoxyethylene polyoxypropylene secondary alcohol ether (ethylene oxide and propylene oxide may be either random or block); polyoxyalkylene alkenyl ethers such as polyoxyethylene alkenyl ether and polyoxyethylene polyoxypropylene alkenyl ether (ethylene oxide and propylene oxide may be either random or block); polyethylene glycol propylene oxide adduct, polypropylene glycol ethylene oxide adduct, glycerin fatty acid ester or its ethylene oxide adduct, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, alkyl polyglucoside, fatty acid monoethanolamide or its ethylene oxide adduct, fatty acid-N-methylmonoethanolamide or its ethylene oxide adduct, fatty acid diethanolamide or its ethylene oxide adduct, sucrose fatty acid ester, alkyl(poly)glycerin ether, polyglycerin fatty acid ester, polyethylene glycol fatty acid ester, fatty acid methyl ester ethoxylate, N-long chain alkyldimethylamine oxide, etc. These nonionic surfactants can be used alone or in any combination of two or more. Although not limited, in terms of low foaming property, aliphatic alcohol alkoxylates and synthetic alcohol alkoxylates are preferably used as nonionic surfactants. More preferably, from the viewpoints of low foaming property, tableting property during the production of this detergent, and stability of the preparation, polyoxyethylene polyoxypropylene secondary alcohol ether is used.

[0018] The content of component B in 100% by mass of this detergent may be in a proportion such that it does not prevent the pH of the aqueous solution at 20 °C when 0.5 g of this detergent is dissolved in 1 L of water from being 8 or more and 12 or less, and the electrical conductivity at 60 °C from being 1.4 mS / cm or more, and the foam generated during the use of the detergent does not become an obstacle during washing. Although not particularly limited as long as it is within that range, for example, it can be selected from the range of 0.7 to 5% by mass. Preferably it is 0.7 to 4% by mass, more preferably 0.8 to 3% by mass. Preferably, it can be adjusted so that the pH of the aqueous solution obtained when 0.3 g of this detergent is dissolved in 1 L of water is 8 or more and 12 or less at 20 °C, and the electrical conductivity at 60 °C is 1.0 mS / cm or more. When the content of component B is within the above range, it is possible to prevent good detergency and redeposition of dirt while suppressing foaming properties. In addition, when component B is at least one selected from the group consisting of aliphatic alcohol alkoxylates and synthetic alcohol alkoxylates, the total content of these in 100% by mass of this detergent can preferably be adjusted in the range of 0.8 to 3% by mass.

[0019] (C) Amino carboxylic acid type chelating agent (hereinafter also referred to as "Component C") In this detergent, as component C, although not limited, examples thereof include methylglycine diacetic acid or its salt, nitrilotriacetic acid or its salt, ethylenediaminetetraacetic acid or its salt, glutamic acid diacetic acid or its salt, diethylenetriaminepentaacetic acid or its salt, hydroxyethylethylenediaminetriacetic acid or its salt, triethylenetetraminehexaacetic acid or its salt, etc. Among these aminocarboxylic acid type chelating agents, because of their good washing effects, methylglycine diacetic acid or its salt, nitrilotriacetic acid or its salt, ethylenediaminetetraacetic acid or its salt, and glutamic acid diacetic acid or its salt are preferred, and more preferably methylglycine diacetic acid or its salt because it has high biodegradability and high chelating ability. Here, as the salt, alkali metal salts such as sodium or potassium can be preferably cited. More preferably, it is the sodium salt. These aminocarboxylic acid type chelating agents can be used alone or in any combination of two or more kinds.

[0020] The content of component C in 100% by mass of this detergent may be in a proportion that can exhibit a high chelating ability without preventing the pH of the aqueous solution at 20 °C from being 8 or more and 12 or less, and the electrical conductivity at 60 °C from being 1.4 mS / cm or more when 0.5 g of this detergent is dissolved in 1 L of water. Although not particularly limited as long as it is within that range, for example, it can be selected from the range of 20 to 60% by mass. Preferably it is 20 to 55% by mass, more preferably 20 to 50% by mass. Preferably, it can be adjusted so that the pH of the aqueous solution obtained when 0.3 g of this detergent is dissolved in 1 L of water is 8 or more and 12 or less at 20 °C, and the electrical conductivity at 60 °C is 1.0 mS / cm or more. When the content of component C is within the above range, a high chelating ability can be exhibited even when using this detergent at a low concentration such as 0.03 to 0.05% by mass. In addition, when component C is at least one selected from the group consisting of trisodium methylglycinediacetate, tetrasodium ethylenediaminetetraacetate, sodium nitrilotriacetate, and tetrasodium glutamate diacetate, the total content of these in 100% by mass of this detergent can be adjusted within the range of 20 to 50% by mass.

[0021] (D) Polycarboxylic acid type polymer or its salt (hereinafter also referred to as "Component D") In this detergent, although the component D is not limited, examples thereof include polyacrylic acid, polymethacrylic acid, polymaleic acid, polyitaconic acid, acrylic acid-methacrylic acid copolymer, acrylic acid-maleic acid copolymer, olefin-maleic acid copolymer, acrylic acid-sulfonic acid copolymer, maleic anhydride-styrene copolymer, maleic anhydride-ethylene copolymer, maleic anhydride-vinyl acetate copolymer, maleic anhydride-acrylic ester copolymer, and salts thereof. Preferably, polyacrylic acid or its salt, polymaleic acid or its salt, acrylic acid-methacrylic acid copolymer, acrylic acid-maleic acid copolymer, olefin-maleic acid copolymer, acrylic acid-sulfonic acid copolymer. More preferably, polyacrylic acid or its salt, olefin-maleic acid copolymer or its salt. Here, as the salt, alkali metal salts such as sodium or potassium can be preferably mentioned. These polycarboxylic acid type polymers or their salts may be used alone or in combination of two or more.

[0022] The weight average molecular weight of polyacrylic acid is preferably 500 to 20000, more preferably 1500 to 15000, and still more preferably 3000 to 10000. If the weight average molecular weight is less than 500, it is not preferable in terms of scale adhesion inhibition, and if it exceeds 20000, it is not preferable in terms of storage stability.

[0023] The content of the component D in 100% by mass of this detergent may be in a proportion such that the pH of the aqueous solution at 20 ° C. when 0.5 g of this detergent is dissolved in 1 L of water is 8 or more and 12 or less, and the electrical conductivity at 60 ° C. is 1.4 mS / cm or more, and a high chelating ability can be exhibited in the same manner as the component C. Although not particularly limited as long as it is within that range, for example, it can be selected from the range of 0.1 to 20% by mass. Preferably 0.5 to 20% by mass, more preferably 0.5 to 15% by mass. Still more preferably, it is 0.5 to 5% by mass. Preferably, it can be adjusted so that the pH of the aqueous solution obtained when 0.3 g of this detergent is dissolved in 1 L of water is 8 or more and 12 or less at 20 ° C., and the electrical conductivity at 60 ° C. is 1.0 mS / cm or more. When the content of component D is less than 0.1% by mass, the scale adhesion inhibitory property in the rinsing machine rinsed with diluted water becomes poor, and when it exceeds 20% by mass, a tendency of poor high-temperature storage stability is recognized. In addition, when component D is at least one selected from the group consisting of polyacrylic acid, olefin-maleic acid copolymer, and salts thereof, the total content of these in 100% by mass of this cleaning agent can preferably be adjusted in the range of 0.5 to 15% by mass, more preferably 0.5 to 5% by mass.

[0024] (E) Sodium chloride (hereinafter also referred to as "Component E") The content of component E in 100% by mass of this cleaning agent is not particularly limited as long as it can lower the hardness of the tablet cleaning agent and the electric conductivity of the aqueous solution at 60 °C when 0.5 g of this cleaning agent is dissolved in 1 L of water is 1.4 mS / cm or more. Preferably, in addition, it is a ratio such that the electric conductivity of the aqueous solution at 60 °C when 0.3 g of this cleaning agent is dissolved in 1 L of water is 1.0 mS / cm or more, and for example, it can be selected from the range of 10 to 55% by mass. Preferably it is 10 to 50% by mass, more preferably 10 to 45% by mass. By blending component E in the above range in this cleaning agent, a tablet cleaning agent with high hardness can be compression-molded, and a tablet preparation with high electric conductivity can be produced.

[0025] (F) Other components (hereinafter also referred to as "Component F") In addition to the above components A to E, this cleaning agent can be appropriately blended with other components (component F) such as sodium sulfate (Glauber's salt); alcohols such as ethanol; lubricants such as sucrose fatty acid ester and polyethylene glycol; antifoaming agents such as silicon; deodorants; antistatic agents, etc., within a range that does not interfere with the effects of the present invention (tableting property, hardness, solubility of the cleaning agent, detergency and anti-redeposition property of the cleaning agent, biodegradability, etc.). As component F, a lubricant is preferable, and among them, it is preferable to blend sucrose fatty acid ester. By blending a lubricant, particularly sucrose fatty acid ester, into this cleaning agent, it becomes possible to improve the slipperiness during compression molding and prevent tableting obstacles such as sticking. When formulating a sucrose fatty acid ester, its content in 100% by mass of this detergent may be within a range where the above object can be achieved. Although not particularly limited as long as it is within that range, for example, it can be selected from the range of 0.1 to 5% by mass. Preferably it is 0.3 to 3% by mass, more preferably 0.5 to 2% by mass.

[0026] In addition, this detergent is characterized in that it has good solubility in water and has little undissolved residue when put into an automatic dishwashing machine. For this reason, it is preferably free of components that cause undissolved residue. Components that reduce solubility in water and cause undissolved residue include starch and modified starch. Therefore, although it depends on the blending amount, it is preferably substantially free of starch and modified starch in this detergent.

[0027] This detergent is a solid detergent having a tablet shape. When 0.5 g of this detergent is dissolved in 1 L of water, the electrical conductivity of the aqueous solution at 60 °C is 1.4 mS / cm or more. Preferably it is 1.5 mS / cm or more, more preferably 1.6 mS / cm or more. As the upper limit of the electrical conductivity at 60 °C, it is 7 mS / cm or less, preferably 3.5 mS / cm or less. The electrical conductivity can be measured using a portable electrical conductivity meter (CM-31P) manufactured by Toa DKK Corporation, etc. The pH of the aqueous solution at 20 °C is 8 or more and 12 or less. Preferably it is pH 9 or more and 12 or less, more preferably pH 9 or more and 11 or less. The pH of the aqueous solution can be measured using a commercially available pH meter such as Horiba, Ltd.

[0028] In addition, when 0.3 g of this detergent is dissolved in 1 L of water, the electrical conductivity of the aqueous solution at 60 °C is 1.0 mS / cm or more. Preferably it is 1.05 mS / cm or more, more preferably 1.1 mS / cm or more. As the upper limit of the electrical conductivity at 60 °C, it is 6 mS / cm or less, preferably 3 mS / cm or less. Also, the pH of the aqueous solution at 20 °C is 8 or more and 12 or less. Preferably it is pH 9 or more and 12 or less, more preferably pH 9 or more and 11 or less.

[0029] When using this detergent, it is preferably supplied and used in an automatic dishwashing machine such that the concentration of this detergent in the cleaning liquid in the automatic dishwashing machine is 0.03% by mass or more at an electrical conductivity of 1.0 mS / cm or more at 60°C. More preferably, the concentration of this detergent in the cleaning liquid in the automatic dishwashing machine is 0.03 to 0.05% by mass.

[0030] The method for producing this detergent is not particularly limited. For example, a method can be exemplified in which the above components A to E (and other component F as necessary) are mixed, granulated as necessary, and then tabletted to form a tablet shape. Granulation can be arbitrarily carried out by a known method. The tabletting process can be carried out by applying a certain tabletting pressure using various tabletting machines such as a single-shot tabletting machine or a rotary tabletting machine. The tabletting pressure may be within a range that ensures the characteristics (hardness and solubility) of this detergent. For example, it can be appropriately set within the range of 5 to 80 kN.

[0031] The thus-prepared detergent can be produced with good tabletting properties. Further, its hardness is 50 N or more, and during distribution after packaging, it is less likely to crack or break. On the other hand, it has good solubility in water and has the characteristic that even when it is put into an automatic dishwashing machine and used at a concentration of 0.03 to 0.05% by mass, undissolved residues are less likely to occur. The evaluation methods and evaluation criteria for the tabletting properties, hardness, and solubility of this detergent will be described in the column of Examples described later.

[0032] As a method for washing tableware with an automatic dishwashing machine using this detergent, a method is included in which this detergent is dissolved in water in the cleaning liquid tank of the automatic dishwashing machine, a cleaning liquid with the detergent concentration adjusted to 0.03 to 0.05% by mass is heated and held in the cleaning liquid tank, the cleaning liquid in the cleaning liquid tank is sprayed into the cleaning cabinet containing the tableware to wash the tableware, and the step of rinsing with a rinsing liquid is continuously carried out after washing.

[0033] As a method for supplying this detergent to an automatic dishwashing machine, there is a method of using an elution hopper filled with this detergent in a container, dissolving the required amount of this detergent in the hopper with water, and sending the prepared cleaning solution through a supply pipe to the dishwashing machine. The cleaning solution diluted and prepared so that the concentration of this detergent becomes 0.03 to 0.05% by mass is usually held at 40°C to 70°C in the cleaning solution tank. The cleaning solution is sprayed onto the tableware in the dishwasher for about 30 seconds to 120 seconds.

[0034] After the cleaning step using the above cleaning solution, a rinsing step can be carried out to wash away the detergent adhering to the tableware. Usually, water is used as the rinsing solution in the rinsing step. In addition, a surfactant (also referred to as a rinse agent) having an action of promoting the water repellency effect on the tableware by reducing the surface tension of water and shortening the drying time can be added to the rinsing solution. However, from the perspective of cost and the like, the rinse agent may not be used. The rinsing solution is preferably 1 L to 3 L per 2500 cm 2 of the tableware installation plane area of the dishwasher. Also, the temperature of the rinsing solution is preferably 40°C to 95°C, more preferably 60°C to 90°C.

[0035] As the dilution water of this detergent or the water for the rinsing solution, tap water may be used (for example, tap water in Tokyo (pH = 7.6, total alkalinity (in terms of calcium carbonate) 40.5 mg / L, German hardness 2.7°DH (of which, calcium hardness 2.0°DH, magnesium hardness 0.7°DH), chloride ion 21.9 mg / L, sodium and its compounds 15 mg / L, nitrate nitrogen and nitrite nitrogen 1.2 mg / L, fluorine and its compounds 0.1 mg / L, boron and its compounds 0.04 mg / L, total trihalomethane 0.016 mg / L, residual chlorine 0.4 mg / L, organic matter (total organic carbon content) 0.7 mg / L).

[0036] As used herein, the terms "comprising" and "containing" include the meanings of "consisting of" and "substantially consisting of".

Example

[0037] Hereinafter, in order to assist the understanding of the configuration and effects of the present invention, the present invention will be described using experimental examples. However, the present invention is not limited by these experimental examples in any way. The following experiments were carried out under room temperature (25 ± 5 °C) and atmospheric pressure conditions unless otherwise specified. Unless otherwise specified, “%” described below means “mass %” and “part” means “part by mass”.

[0038] The materials used in the following examples and comparative examples are as follows. · Sodium metasilicate: Trade name granular anhydrous sodium metasilicate (Supplier: Nippon Chemical Industry) · Anhydrous sodium carbonate (light): Soda ash light (Supplier: Tokuyama) · Anhydrous sodium carbonate (dense): Soda ash dense (Supplier: Tokuyama) · Sodium carbonate monohydrate: Sodium carbonate monohydrate (Supplier: Takasugi Pharmaceutical) · Polyoxyethylene polyoxypropylene secondary alcohol ether: Trade name Fine Surf 7045 (EO 7 mol, PO 4.5 mol) (Supplier: Aoki Yushi Industry) · Aliphatic alcohol alkoxylate: Trade name Plurafac LF 224 (Supplier: BASF) · Trisodium methylglycine diacetate: Trilon M Max BioBased Gran (Supplier: BASF) · Tetrasodium ethylenediaminetetraacetate: Trilon BX (Supplier: BASF) · Trisodium nitrilotriacetate: Trade name Trilon A92R (Supplier: BASF) · Sodium polyacrylate: Trade name Sokalan PA25CL Granular (average molecular weight 4500) (Supplier: BASF) · Olefin-maleic acid copolymer, sodium salt: Trade name Sokalan CP9 Powder (average molecular weight 12000) (Supplier: BASF) · Sucrose fatty acid ester: Trade name Ryoto Sugar Ester S-370F (Supplier: Mitsubishi Chemical Foods) · Sodium sulfate: Trade name Neutral Anhydrous Glauber's Salt (Supplier: Shikoku Kasei Kogyo Co., Ltd.) · Ethylene bisstearamide: Trade name Alflo H50-T (Supplier: NOF Corporation) · Polyethylene glycol: Trade name PEG#6000P (average molecular weight 6000) (Supplier: NOF Corporation) · Glyceryl distearate: Trade name NIKKOL DGS-80 (Supplier: Nikko Chemicals Co., Ltd.) · Gelatinized waxy starch: Trade name Waxy α D-6 (Supplier: Nippon Shokuhin Kako Co., Ltd.)

[0039] Examples 1 to 5, Comparative Examples 1 to 11 A tablet-shaped detergent composed of the components described in Table 1 was formulated. Specifically, each material shown in Table 1 was mixed, and the prepared mixture was tabletted at a tabletting pressure of 30 kN using a single-shot tabletting machine (AUTO Tab-200) manufactured by Ichibashi Seiki Co., Ltd. to produce a tablet-shaped detergent with a thickness of 1.2 mm, a weight of 3.4 g, and a diameter of 15φ (hereinafter simply referred to as "detergent") (Examples 1 to 5, Comparative Examples 1 to 11).

[0040] For each of the manufactured detergents (Examples 1 to 5, Comparative Examples 1 to 11), the tabletting property, hardness, solubility, chelating property, electrical conductivity, pH of the dissolved aqueous solution, and detergency were evaluated by the following methods. Among these evaluations, the hardness was measured for 10 tablets randomly selected from each of the manufactured detergents, and the evaluation was based on the average value of the 10 tablets.

[0041] (1) Tableting property [Focus point] Can it be stably tabletted as a tablet using a single-shot tabletting machine (tabletting pressure: 3000 kgF)? [Test method] Using a single-shot tabletting machine (AUTO Tab-200) manufactured by Ichibashi Seiki Co., Ltd., 300 tablets of the tablet-shaped detergent were continuously tabletted. After tabletting 300 tablets, it was determined whether the detergent composition adhered to the surface of the punch after tabletting (whether sticking occurred). [Evaluation criteria] ○: No sticking occurred even after continuous tabletting of 300 tablets. ×: After continuous tableting of 300 tablets, sticking occurred, or before the number of continuous tableting reached 300 times, tableting failure occurred due to sticking, so continuous tableting was aborted halfway.

[0042] (2) Hardness [Focus point] Is the hardness of the detergent obtained by tableting 50 N or more? In addition, when the hardness of the detergent is 50 N / mm 2 or more, it is possible to avoid cracking and breakage when transporting in a product form where multiple tablets are put into a pouch together and packed. [Test method] The hardness of the detergent was measured with a digital hardness tester (KHT-40N manufactured by Fujiwara Seisakusho: pressurized diameter φ5 mm, sample table diameter φ25 mm). The sample (detergent) was placed on the test bench with the front and back surfaces of the tablet facing up and down, and measured by applying pressure from above and below. [Evaluation criteria] 〇: The hardness is 50 N or more and can withstand impacts such as transportation. ×: The hardness is less than 50 N and there is a risk of disintegration and wear.

[0043] (3) Solubility [Focus point] Undissolved residue when the detergent is put into the detergent supply device and dissolved in water [Test method] 1.0 kg of detergent was put into a Wellco detergent supply device (SER-020), and tap water at 40 °C was continuously ejected from the bottom of the supply device for 2 hours. Then, the presence or absence of undissolved residue of the detergent in the supply device was visually confirmed. [Evaluation criteria] 〇: No undissolved residue of the detergent is confirmed in the supply device. ×: Undissolved residue of the detergent is confirmed in the sharing device.

[0044] (4) Chelating property [Focus point] Presence or absence of carbonate scale derived from water [Test method] Assuming the use of tap water with a hardness of 150 ppm (mg / L), 1.5 mL of Solution A and 4 mL of Solution B shown below were mixed and made up to 1000 mL with distilled water to prepare artificial hard water with a hardness of 150 ppm. Solution A: Dissolve 6.775 g of magnesium chloride hexahydrate and 7.399 g of calcium chloride in distilled water to prepare a 1000 mL solution. Solution B: Dissolve 5.603 g of sodium hydrogen carbonate in distilled water to prepare a 1000 mL solution. Each detergent was dissolved in the artificial hard water prepared by the above method to a concentration of 0.05% by mass to obtain a test solution. 100 mL of each test solution was placed in a 200 mL polypropylene container, and a 5 cm × 3 cm stainless steel test piece (SUS430) was immersed. After leaving it at 60 °C for 24 hours, the test piece was taken out, rinsed with distilled water and dried, and the presence or absence of scale formation on the test piece was visually confirmed. [Evaluation Criteria] 〇: No scale formation was observed. △: Slight scale adhered. ×: A large amount of scale adhered.

[0045] (5) pH of dissolved aqueous solution [Test Method] The detergent was dissolved in tap water (hardness 80 ppm (mg / L)) so that the concentrations of the detergent were 0.03% by mass and 0.05% by mass, and this was used as a test solution. The pH of the test solution at 20 °C was measured with a pH meter manufactured by Horiba, Ltd.

[0046] (6) Electrical conductivity [Focus] Ensuring high electrical conductivity even at low concentrations of 0.03 - 0.05% by mass [Test Method] The detergent was dissolved in tap water (hardness 80 ppm (mg / L)) so that the concentrations of the detergent were 0.03% by mass and 0.05% by mass, and this was used as a test solution. The electrical conductivity of the test solution was measured at a liquid temperature of 60 °C using a portable electrical conductivity meter (CM-31P) manufactured by TOA-DKK Corporation. [Evaluation Criteria] (A) In the case of 0.05% by mass 〇: The electrical conductivity of a 0.05 mass% aqueous solution is 1.4 mS / cm or more ×: The electrical conductivity of a 0.05 mass% aqueous solution is less than 1.4 mS / cm (B) In the case of 0.03 mass% 〇: The electrical conductivity of a 0.03 mass% aqueous solution is 1.0 mS / cm or more ×: The electrical conductivity of a 0.03 mass% aqueous solution is less than 1.0 mS / cm

[0047] (7) Detergency and redeposition property [Focus point] Dishes with food stains were washed in an automatic dishwashing machine, and visual inspection and evaluation of stickiness were performed [Test method] As the automatic dishwashing machine, a HOBART BOX type washing machine (AM15) was used. As the washing conditions, the washing time was 38 seconds, the washing temperature (water temperature) was 60 °C, the rinsing time was 10 seconds, and the rinsing temperature (water temperature) was 80 °C. Both washing and rinsing were performed only once. Tap water (hardness 80 mg / L) was used as the washing water In the washing process, each detergent was added to make a washing solution so that the concentration of the detergent was 0.03 mass% with respect to the amount of water in the automatic dishwashing machine. The object to be washed (a white polypropylene dish coated with 1.5 g of curry liquid (24 g of curry roux / 100 g of water) and left for 30 minutes) was washed using the automatic dishwashing machine, and the appearance (presence or absence of coloring) of the dish after washing was visually inspected to evaluate the detergency in terms of the presence or absence of stains. Also, the presence or absence of stickiness on the surface of the dish was confirmed by touching and rubbing the dish after washing to evaluate the redeposition property [Evaluation criteria] 〇: No stain adhesion is observed, and no stickiness is felt on the dish after washing ×: Stain adhesion is observed, or although no stain adhesion is observed, stickiness is felt on the dish after washing

[0048] The results are shown in Table 1

[0049]

Table 1

[0050] As described in Table 1, all of the cleaning agents produced in Examples 1 to 5 had the desired tableting properties, hardness, solubility, chelating property, electrical conductivity, and detergency. On the other hand, it was confirmed that the cleaning agents of Comparative Examples 1 to 5 that did not contain a nonionic surfactant had stickiness on the dishes after washing, and had low detergency and anti-redeposition effect. Also, the cleaning agent of Comparative Example 6 was found to have stickiness on the dishes after washing, similar to Comparative Examples 1 to 5, and the amount of the nonionic surfactant blended was not sufficient to exhibit the desired detergency. Furthermore, it was confirmed that the cleaning agent of Comparative Example 10 that did not contain a nonionic surfactant and an alkaline agent had dirt adhesion on the dishes after washing and had low detergency. Also, it was confirmed that the cleaning agent of Comparative Example 9 that did not contain a chelating agent had low chelating property and could not prevent the generation and adhesion of scale derived from the tap water used for washing. The cleaning agents of Comparative Examples 1 to 3 also had low chelating property, similar to Comparative Example 9, and could not prevent the desired scale generation and adhesion. As a reason, it is conceivable that the amount of the alkaline agent blended was large, thus reducing the chelating ability of the chelating agent. The cleaning agent of Comparative Example 11 that did not contain sodium chloride did not reach the desired value for the electrical conductivity of the 0.03 to 0.05 mass% aqueous solution. From this, it was confirmed that in addition to the alkaline agent, sodium chloride is necessary to bring the electrical conductivity within the desired numerical range. The cleaning agents of Comparative Examples 1, 3 to 7, and 9 containing α-waxy starch commonly had low solubility, and undissolved tablets were observed in the apparatus.

Claims

1. A tablet detergent for automatic dishwashers, containing (A) an alkali agent, (B) a nonionic surfactant, (C) an aminocarboxylic acid type chelating agent, (D) a polycarboxylic acid type polymer, and (E) sodium chloride, wherein when 0.5 g of the tablet detergent for automatic dishwashers is dissolved in 1 L of water, the pH of the aqueous solution at 20°C is 8 or more and 12 or less, and the electrical conductivity at 60°C is 1.4 mS / cm or more. A tablet detergent for automatic dishwashers.

2. The tablet detergent for automatic dishwashers according to claim 1, further containing (F) a sucrose fatty acid ester.

3. wherein when 0.3 g of the tablet detergent for automatic dishwashers is dissolved in 1 L of water, the pH of the aqueous solution at 20°C is 8 or more and 12 or less, and the electrical conductivity at 60°C is 1.0 mS / cm or more. The tablet detergent for automatic dishwashers according to claim 1 or 2.

4. The tablet detergent for automatic dishwashers according to claim 1, containing (A) an alkali agent in a proportion of 20 to 60% by mass, (B) a nonionic surfactant in a proportion of 0.7 to 5% by mass, (C) an aminocarboxylic acid type chelating agent in a proportion of 20 to 60% by mass, (D) a polycarboxylic acid type polymer in a proportion of 0.1 to 20% by mass, and (E) sodium chloride in a proportion of 10 to 55% by mass.

5. The (A) alkali agent is at least one selected from the group consisting of sodium carbonate, sodium metasilicate, and hydrates thereof, and the total content in 100% by mass of the tablet detergent for automatic dishwashers is 20 to 40% by mass. The tablet detergent for automatic dishwashers according to claim 1, 2, or 4.

6. The (B) nonionic surfactant is at least one selected from the group consisting of aliphatic alcohol alkoxylates and synthetic alcohol alkoxylates, and the total content in 100% by mass of the tablet detergent for automatic dishwashers is 0.8 to 3% by mass. The tablet detergent for automatic dishwashers according to claim 1, 2, or 4.

7. The (C) aminocarboxylic acid type chelating agent is at least one selected from the group consisting of trisodium methylglycinediacetate, tetrasodium ethylenediaminetetraacetate, trisodium nitrilotriacetate, and tetrasodium glutamate diacetate, and the total content in 100% by mass of the tablet detergent for automatic dishwashers is 20 to 50% by mass. The tablet detergent for automatic dishwashers according to claim 1, 2 or 4.

8. The (D) polycarboxylic acid type polymer is at least one selected from the group consisting of polyacrylic acid, olefin-maleic acid copolymer, and salts thereof, The tablet detergent for automatic dishwashers according to claim 1, 2 or 4, wherein the total content in 100% by mass of the tablet detergent for automatic dishwashers is 0.5 to 15% by mass.

9. The tablet detergent for automatic dishwashers according to claim 1, 2 or 4, wherein the content of (E) sodium chloride in 100% by mass of the tablet detergent for automatic dishwashers is 10 to 45% by mass.

10. The tablet detergent for automatic dishwashers according to claim 1, 2 or 4, which does not contain starch and chemical starch.

11. The tablet detergent for automatic dishwashers according to any one of claims 1 to 10 is installed in an elution hopper having a discharge port at the lower end portion, water is supplied from a water supply nozzle to dissolve the tablet detergent for automatic dishwashers in the hopper in water, and the concentration of the tablet detergent for automatic dishwashers in the aqueous solution is adjusted to 0.03 to 0.05% by mass, and the cleaning liquid is heated and held in the cleaning liquid tank of the automatic dishwasher, A step of spraying the cleaning liquid in the cleaning liquid tank into the dishwasher compartment to clean the tableware, and A step of rinsing with the rinsing liquid after cleaning, A method for cleaning tableware by an automatic dishwasher, characterized by comprising the above steps.

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