JP2023121851A - Liquid detergent composition for dishwasher, and method for cleaning tableware using the same - Google Patents

Abstract

To provide a liquid detergent composition for a dishwasher having low concentration and excellent detergency, and a method for cleaning tableware using the same.SOLUTION: A liquid detergent composition for a dishwasher contains the following components (A) to (E), where an alkali agent of the component (A) is at least one selected from the group consisting of an alkali metal hydroxide, silicate and carbonate, a ratio [(A)/(D)] of the component (A) to the component (D) is within a range of 0.25 to 3, a pH at 25°C of 0.05 mass% aqueous solution is 10.5 or more, and alkalinity of the liquid detergent composition for the dishwasher when pH of 8.2 is defined as an end point is 13 mass% or more in terms of potassium hydroxide. (A) Alkali agent: 5-20 mass%, (B) chelate agent: 15-40 mass%, (C) scale inhibitor: 0.5-10 mass%, (D) alkanol amine: 3-20 mass%, and (E) water.SELECTED DRAWING: None

Description

The present invention has excellent detergency at a low concentration, and even when washed with a water-saving dishwasher, it is excellent in preventing re-adhesion of stains on tableware and in rinsability, and leaves no detergent residue on tableware. without, moreover,
The present invention relates to a compact and highly workable liquid detergent composition for dishwashing machines, which produces little silica scale even when used at a low concentration, and a method for washing tableware using the same.

Conventionally, as a liquid detergent composition for dishwashers, as shown in Patent Document 1, high-concentration sodium hydroxide or potassium hydroxide and polyacrylate are blended, and the conductivity is 0.1.
It is known to be prepared with submicrosiemens water. This product is excellent in solubilizing and removing greasy stains by hydrolysis by blending a strong alkali, and by blending a polyacrylate and preparing it with water having a low electrical conductivity. is said to have high storage stability.

However, when used in a dishwasher without a water softener,
Since the chelating action is insufficient, it is not possible to obtain a satisfactory detergency against greasy stains, and there is a problem that the stains tend to re-adhere to the tableware. In addition, there is also the problem of adhesion of scale to the dishwasher.

On the other hand, there has also been proposed a liquid detergent composition for dishwashing machines that enhances the detergency against various stains and prevents scale from adhering to dishwashing machines (see Patent Document 2). However, this is not sufficient to solve the hygienic problem caused by silica scale generated in the dishwasher and in the water pipes and the problem of poor washing caused by nozzle clogging due to silica scale.

Further, as a liquid detergent composition for dishwashers, the one shown in Patent Document 3 has been proposed. This product is said to be able to prevent discoloration caused by tea stains, and to improve detergency against tea stains and other stains by blending a low-molecular chelating agent, a copolymer of acrylic acid and maleic acid, and an alkanolamine compound. there is However, if the stock solution pH is 8-11
Since the alkaline agent is only alkanolamine, when the liquid detergent composition for dishwashers is used as a low-concentration cleaning liquid, it may not be possible to obtain sufficient detergency against oil stains and protein stains. have.

Furthermore, in recent years, among commercial dishwashers, water-saving dishwashers that use less than half the rinsing water of conventional dishwashers have become popular. In the case of commercial dishwashers, generally, cleaning is performed by circulating the cleaning liquid in the cleaning tank, and all or part of the rinse water is allowed to flow into the cleaning tank, causing the dirt accumulated in the cleaning tank to overflow. It is designed to be discharged. However, since water-saving dishwashers also save water for rinsing,
Dirt overflows and becomes difficult to discharge, and there is a tendency for dirt to accumulate in the cleaning tank. For this reason, cleaning is performed using the cleaning liquid with the dirt still remaining, which poses problems of a decrease in cleanability and redeposition of the dirt on the tableware. In addition, since the amount of rinsing water is small, residual alkaline detergent on dishes due to poor rinsing is also a problem, and conventional liquid detergent compositions for dishwashers are insufficient to solve these problems. is. In addition, as the price of crude oil rises, transportation costs such as the cost of gasoline are rising, and compact concentrated liquid detergent compositions for dishwashers are desired in order to reduce transportation costs.

JP-A-4-15299 JP-A-2002-363596 JP 2008-163079 A

The present invention has been made in view of such circumstances, and has excellent detergency at a low concentration, prevents re-adhesion of stains to dishes even when washed with a water-saving dishwasher, and , The liquid detergent composition for dishwashing machines does not remain on the dishes due to its excellent rinsability, and even when used at a low concentration, it produces little silica scale, and is compact and excellent in transportation costs. It is an object of the present invention to provide a liquid detergent composition for Another object of the present invention is to provide a method for washing tableware with a dishwasher using this liquid detergent composition for a dishwasher.

The present invention has been made in view of such circumstances, and provides a liquid detergent composition for dishwashers containing the following components (A) to (E), wherein the component (A) is an alkaline agent. At least one selected from the group consisting of alkali metal hydroxides, silicates and carbonates, and the above (A
) to (D) components are contained in the following proportions with respect to the entire dishwashing liquid detergent composition, and the above (
The ratio [(A)/(D)] of component A to component (D) is in the range of 0.25 to 3,
The pH of the 0.05% by mass aqueous solution at 25° C. is 10.5 or more, and the alkalinity of the liquid detergent composition for dishwashers is 13 in terms of potassium hydroxide when the pH is 8.2 as the end point.
A first gist is a liquid detergent composition for dishwashers, which is at least % by mass.
(A) Alkaline agent: 5 to 20% by mass.
(B) chelating agent: 15 to 40% by mass;
(C) Scale inhibitor: 0.5 to 10% by mass.
(D) Alkanolamine: 3 to 20% by mass.
(E) water.

Further, according to the present invention, the alkanolamine of component (D) of the liquid detergent composition for dishwashers according to the first aspect is at least one selected from the group consisting of monoethanolamine, diethanolamine and triethanolamine. As a second aspect, the scale inhibitor of the component (C) of the dishwashing machine liquid detergent composition of the first aspect is an organic phosphorus scale inhibitor, a polymer electrolyte, and a glycine scale inhibitor. The third gist is at least one selected from the group consisting of Further, the present invention provides a cleaning solution containing 0.03 to 0.15% by mass of the liquid detergent composition for dishwashers according to the first to third gists, and the cleaning solution is used in the washing process of the dishwasher. A method for washing tableware is the fourth gist.

That is, the present inventors have made intensive studies to obtain a liquid detergent composition for dishwashing machines that has excellent detergency even when washed in a water-saving dishwashing machine. As a result, the above (A)
A liquid detergent composition for dishwashers containing component (E), wherein the alkaline agent of component (A) is at least one selected from the group consisting of alkali metal hydroxides, silicates and carbonates. and contains the above components (A) to (D) in the following ratios with respect to the entire dishwashing liquid detergent composition, and the ratio of the above component (A) to the component (D) [(A)/ (D)] is 0.25
to 3, the pH of the 0.05% by mass aqueous solution at 25° C. is 10.5 or more, and the alkalinity of the liquid detergent composition for dishwashers when the pH is 8.2 as the end point is 13% by mass or more in terms of potassium hydroxide, even when washed with a water-saving dishwasher, stains are prevented from re-adhering to the dishes, and the dishes have excellent rinsability. The inventors have found that the liquid detergent composition for washing machine does not remain, and arrived at the present invention.

As described above, the liquid detergent composition for dishwashers of the present invention includes (A) an alkaline agent that is at least one selected from the group consisting of alkali metal hydroxides, silicates and carbonates;
) a chelating agent, (C) a scale inhibitor, (D) an alkanolamine, and (E) water as essential components, of which components (A) to (D) are added to the entire dishwashing liquid detergent composition On the other hand, each is blended in a specific ratio, and the ratio (A / D) of the component (A) and the component (D)
is set in the range of 0.25-3. By blending components (A) and (D) in the above proportions, the alkaline buffering properties at low concentrations are optimized, and these are further combined with (B) a chelating agent blended in a specific proportion. , and the detergency against oil is enhanced. Moreover, since (B) the chelating agent and (C) the scale inhibitor are blended in a specific ratio, the generation of silica scale is effectively suppressed. Moreover, the liquid detergent composition for dishwashers of the present invention has a pH of 10.5 or more at 25° C. in a 0.05% by mass aqueous solution, and is for dishwashers when the end point is pH 8.2. Since the alkalinity of the liquid detergent composition is set to be 13% by mass or more in terms of potassium hydroxide, even at a low concentration, it has sufficient detergency against oil stains and protein stains compared to conventional detergents. It is compact and excellent in workability and economy.

Among the liquid detergent compositions for dishwashers of the present invention, when the alkanolamine of component (D) is at least one selected from the group consisting of monoethanolamine, diethanolamine and triethanolamine, It becomes more excellent in detergency and storage stability.

Further, when the scale inhibitor of the component (C) is at least one selected from the group consisting of organic phosphorus scale inhibitors, polymer electrolytes and glycine scale inhibitors, reattachment of dirt is more likely to occur. Since it is effectively prevented, the detergency can be improved, and the ability to prevent the generation of calcium carbonate scale, silica scale, and the like can be improved.

Then, the liquid detergent composition for dishwashers of the present invention is diluted with water to prepare a washing liquid containing 0.03 to 0.15% by mass of the liquid detergent composition for dishwashers, and the washing liquid is According to the washing method of tableware used in the washing process of the dishwasher, even a water-saving type dishwasher:
It has an excellent balance between cleaning effect and rinsability, and can be washed repeatedly in a short time. Therefore, less rinsing water is required, reducing water bills and reducing the temperature of typical rinsing water to 8
Energy costs for heating to 0° C. can be reduced. In addition, it is economically superior because it exerts a sufficient detergency even at a low concentration.

Next, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

First, the liquid detergent composition for dishwashers of the present invention (hereinafter referred to as "detergent composition") is (
A) an alkali agent, (B) a chelating agent, (C) a scale inhibitor, (D) an alkanolamine and (E) water, and the above components (A) to (D) are added to the entire cleaning composition. It is set to contain in a specific ratio, the ratio of (A) component to (D) component [(A) / (
D)] is in the range of 0.25 to 3, and the pH of the 0.05% by mass aqueous solution at 25 ° C. is 1
0.5 or more, and the alkalinity of the cleaning composition is set to be 13% by mass or more in terms of potassium hydroxide when pH 8.2 is the end point.

The alkali agent, which is the component (A) used in the cleaning composition, is at least one selected from the group consisting of alkali metal hydroxides, silicates and carbonates. Examples thereof include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, silicates such as sodium silicate and potassium silicate, and carbonates such as sodium carbonate and potassium carbonate. These can be used alone or in combination of two or more.

The content of the alkaline agent, component (A), is 5 to 20% by mass, more preferably 7 to 15% by mass, based on the total detergent composition. (A) If the blending amount of the component is too small,
There is a possibility that the desired cleaning performance cannot be exhibited, and conversely, if the amount of component (A) is too large, the rinsability when used in a dishwasher will deteriorate, and each performance of the detergent composition will be affected. This is because the balance deteriorates, and in particular, the synergistic effect with other components tends to saturate the cleaning performance, and the storage stability tends to decrease.

As the chelating agent, which is the component (B) used in the cleaning composition, both phosphorus-based and non-phosphorus-based chelating agents can be used. Examples of the phosphorus-based chelating agent include alkali metal phosphates, and examples of the phosphoric acid include orthophosphoric acid, polyphosphoric acid, pyrophosphoric acid, metaphosphoric acid, and hexametaphosphoric acid. Alkali metals to be combined with phosphoric acid include sodium and potassium. In particular, sodium tripolyphosphate is suitable among the above alkali metal phosphates. Examples of the non-phosphorus chelating agents include ethylenediaminetetraacetic acid, nitrilotriacetic acid, iminodiacetic acid, diethylenetriaminepentaacetic acid, N-hydroxyethylethylenediamineacetic acid, ethylenediaminetetrapropionacetic acid, methylglycinediacetic acid (MGDA), and triethylenetetramine. Hexaacetic acid, ethylene glycol dietherdiaminetetraacetic acid, hydroxyethyliminodiacetic acid, cyclohexane-1,2-diaminetetraacetic acid, diencolic acid, dicarboxymethylglutaric acid, hydroxyethylethylenediaminetriacetic acid, ethylenediaminedisuccinic acid (EDDS)
), L-glutamic diacetic acid (GLDA), 3-hydroxy-2,2′-iminodisuccinic acid (HIDS), L-aspartic acid-N,N-diacetic acid (ASDA), heptogluconic acid (GH-NA), taurine -N,N-diacetic acid, gluconic acid, citric acid, water-soluble alkali metal salts such as sodium salts and potassium salts thereof, ethanolamine salts, ammonium salts and the like. Among the above non-phosphorus chelating agents, ethylenediaminetetraacetic acid, nitrilotriacetic acid, L-glutamic acid diacetic acid, methylglycine diacetic acid, water-soluble alkali metal salts such as sodium salts and potassium salts thereof, and ethanolamine salts , ammonium salts are preferred, and sodium salts are particularly preferred in terms of detergency and cost. These may be used alone or in combination of two or more.

The content of the chelating agent, component (B), is 15 to 40% by mass, preferably 18 to 35% by mass, and more preferably 20 to 30% by mass, based on the total detergent composition.
If the amount of component (B) is too small, the balance with other ingredients will not only result in poor cleaning performance for greasy stains, but also cause scale formation. Conversely, if the amount of component (B) is too large, This is because not only is the storage stability lowered, but also the cost is disadvantageous.

As the (C) component scale inhibitor used in the cleaning composition, an organic phosphorus scale inhibitor, a polymer electrolyte and a glycine scale inhibitor are preferably used. These can be used alone or in combination of two or more.

The organophosphorus scale inhibitors include, for example, ethane-1,1-diphosphonate, ethane-1,1,2-triphosphonate, ethane-1-hydroxy-1,1-diphosphonate and derivatives thereof, Phosphonic acid compounds such as ethanehydroxy-1,1,2-triphosphonic acid, ethane-1,2-dicarboxy-1,2-diphosphonic acid, methanehydroxyphosphonic acid, or alkali metal salts and alkaline earth metal salts thereof , ammonium salt, or ethanolamine salt, 2-phosphonobutane-1,2-dicarboxylic acid, 1-phosphonobutane-2
, 3,4-tricarboxylic acid, phosphonocarboxylic acid compounds such as α-methylphosphonosuccinic acid, aminotrimethylphosphonic acid, or alkali metal salts and alkaline earth metal salts thereof,
Ammonium salts or ethanolamine salts can be mentioned. Among them, alkali metal salts are preferred. These can be used alone or in combination of two or more.

Examples of the polymer electrolyte include acrylic acid polymer and its salt, maleic acid polymer and its salt, acrylic acid-maleic acid copolymer and its salt, poly-α-hydroxyacrylic acid and its salt, acrylic acid- Examples include maleic acid-polyethylene glycol copolymers and salts thereof, olefin-maleic acid copolymers and salts thereof, and acrylic acid-sulfonic acid copolymers and salts thereof. Examples of salts thereof include sodium salts, potassium salts, ammonium salts and ethanolamine salts, with sodium salts and potassium salts being preferred. These can be used alone or in combination of two or more.

The polymer electrolyte may be a commercially available product. For example, when sodium polymaleate is used, sodium hydroxide is added (neutralization reaction) to polymaleic acid in advance to prepare sodium polymaleate. can be used. Similarly, in the above neutralization reaction,
Sodium hydroxide and potassium hydroxide can be used in place of sodium hydroxide, as this gives a mixture containing sodium polymaleate and potassium polymaleate in any ratio.

In the above polymer electrolyte, the average molecular weight of the maleic acid polymer, acrylic acid polymer and salt thereof of the polymer electrolyte is preferably 600 to 15,000, particularly preferably 1,000 to 15,000. are used. The average molecular weight of the copolymer of maleic acid and acrylic acid and the salt thereof is preferably 1,000 to 100,000, particularly preferably 3,000 to 80,000. . Further, the average molecular weight of the copolymer of sulfonic acid and acrylic acid and its salt is 1,000 to 100,0
00 is preferably used, particularly preferably 1,500 to 60,000. The salts of the above polymers and copolymers may be fully neutralized salts or partially neutralized salts.

Examples of the glycine-based scale inhibitor include iminodiacetic acid, dihydroxyethylglycine and salts thereof. In addition, these salts include sodium salts, potassium salts,
Among them, ammonium salts and ethanolamine salts are mentioned, and among them, the sodium salt of dihydroxyethylglycine is preferable. These can be used alone or in combination of two or more.

As such an anti-scaling agent for component (C), specifically, 1-hydroxyethylidene-1,1
-diphosphonic acid, ethane-1-hydroxy-1,1-diphosphonic acid sodium salt, phosphonobutanetricarboxylic acid, 1-phosphonobutane-2,3,4-tricarboxylic acid sodium salt, sodium polymaleate, polyacrylic acid, polyacrylic acid sodium salt, acrylic acid-maleic acid copolymer, sodium salt of acrylic acid-maleic acid copolymer, poly-
Sodium α-hydroxyacrylate, acrylic acid-maleic acid-polyethylene glycol copolymer, olefin-maleic acid copolymer sodium salt, acrylic acid-sulfonic acid copolymer sodium salt, dihydroxyethylglycine sodium salt It is preferably used.

The amount of the scale inhibitor, which is the component (C), is 0.5 to 0.5 with respect to the entire cleaning composition.
10% by mass, more preferably 1 to 7% by mass. That is, if the blending amount of component (C) is too small, there is a tendency that performance such as scale prevention, effect of reducing spots remaining on tableware, and stain dispersibility cannot be sufficiently obtained. If the blending amount of the ingredients is too large, the balance of each performance of the detergent composition may be deteriorated, the storage stability is lowered, and synergistic effects with other ingredients tend to be no longer obtained. is.

A compound having a hydroxyl group and an amino group in the alkane skeleton can be used as the alkanolamine, which is the component (D) used in the cleaning composition. Examples of such compounds include monoethanolamine, diethanolamine, triethanolamine, monopropanolamine, dipropanolamine, tripropanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, N-ethyldiethanolamine, N- ethylethanolamine, N-methyldiethanolamine, N-
Methylethanolamine may be mentioned. Among them, triethanolamine, diethanolamine, monoethanolamine, monoisopropanolamine, N-ethyldiethanolamine, N-methyldiethanolamine and N-methylethanolamine are preferably used. More preferred are triethanolamine, diethanolamine and monoethanolamine. These can be used alone or in combination of two or more.

The amount of the alkanolamine, which is the component (D), is 3 to
20% by mass, more preferably 5 to 15% by mass. If the amount of component (D) is too small, the cleaning performance for protein stains tends to be poor, and if the amount of component (D) is too large, rinsability deteriorates when used in a dishwasher. In addition, the balance of each performance of the detergent composition deteriorates, and not only is it difficult to obtain a synergistic effect with other components, but also there is a tendency to be disadvantageous in terms of cost.

The alkanolamine, which is the component (D), and the specific alkaline agent, which is the component (A), are blended so that the mass ratio of (A)/(D) is in the range of 0.25 to 3. , more preferably in the range of 0.35 to 2.5. That is, if the mass ratio is too high, there is a high possibility that the washed tableware will remain alkaline, and the inflow of contaminants will reduce the buffering performance of the washing solution. On the other hand, if the mass ratio is too low, it will be insufficient to obtain the desired detergency, and there will be a tendency to be disadvantageous in terms of cost.

Water, which is the component (E) used in the cleaning composition, includes, for example, tap water, soft water,
Ion-exchanged water, pure water, and purified water can be mentioned, and soft water, ion-exchanged water, and pure water are preferred. These can be used alone or in combination of two or more. The above "water" is the sum of the water of crystallization derived from each component constituting the liquid detergent composition, the water contained in the form of an aqueous solution, and the water added from the outside. % by mass.

In the detergent composition of the present invention, optional components may be used together with the above components (A) to (E). Examples of such optional components include scale inhibitors, neutralizers, pH adjusters, dye,
Perfumes, metal corrosion inhibitors, bactericides, deodorants, antistatic agents, and the like.

Examples of the scale inhibitor neutralizer include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, silicates such as sodium silicate and potassium silicate, and carbonates such as sodium carbonate and potassium carbonate. Among them, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide are preferably used in terms of storage stability and cost.

The cleaning composition of the present invention has a pH of 10.5 or higher, more preferably 10.8 or higher, at 25° C. as a 0.05 mass % aqueous solution. That is, the higher the pH, the higher the detergency can be expected, and the lower the pH, the lower the detergency and the sanitary environment in the dishwasher tends to be adversely affected. In addition, in the present invention, 0.0
The pH of a 5% by mass aqueous solution at 25° C. is a value measured according to JIS (Z-8802 “pH measurement method”).

The detergent composition of the present invention needs to have an alkalinity of 13% by mass or more, preferably 15% by mass, in terms of potassium hydroxide when pH 8.2 is the end point. That's it. That is, the higher the alkalinity, the higher the alkaline buffering property of the cleaning liquid when used in a dishwasher, and even when acidic stains such as oil stains are mixed, it is possible to maintain high detergency against protein stains and oil stains. . Further, the detergent composition of the present invention is added in an amount of 0.03 to 0.1
Even when diluted to a low concentration of 5% by mass and used as a cleaning liquid, a high alkalinity can be maintained and a desired detergency can be obtained.

Here, the alkalinity in the present invention is measured by neutralization titration with 0.1 mol/L hydrochloric acid normal solution using a phenolphthalein indicator against the detergent composition. It is a value calculated by the following general formula (1) with the disappearing point as the end point.
Alkalinity (as KOH) = 0.1 x F x X x 56.1/mass of sample (g) x 10 (1)
X = titration volume (mL) of 0.1 mol / L hydrochloric acid normal solution
F = factor of 0.1 mol/L hydrochloric acid normal solution

Therefore, the detergent composition of the present invention is suitable for cleaning tableware having hard surfaces such as glass, ceramics, metals and plastics. In the present invention, the term "tableware" refers to any object having a degree of hardness that allows itself to maintain a predetermined shape and that can be used to serve food and drink. It does not include products, but is intended to include elastic resin surfaces.

Moreover, the detergent composition of the present invention can be used not only for tableware, but also for automatic cleaning applications for cleaning utensils and containers in various manufacturing plants and processing plant buildings, plastic containers used for distribution, and the like. Furthermore, it can be preferably used for cleaning hard surfaces such as tiles and floors in food factories and food processing factories, cleaning containers such as glass bottles used for serving beverages, and cleaning metal surfaces. In particular, it is suitable for use in dishwashers in hotels, restaurants, schools, hospitals, restaurants, catering companies, company cafeterias, and the like. That is, the "tableware" in the present invention
In addition to the literal "tableware", cleaning objects related to various food manufacturing and food processing as described above are included.

The concentration of the cleaning liquid obtained by diluting the cleaning composition with water is
It preferably contains 0.03 to 0.15% by mass of the detergent composition, more preferably 0.04 to 0.13% by mass. That is, if the content of the detergent composition is too low, the desired effect tends to be difficult to obtain, and if it is too high, the rinsability is reduced.

A "dishwasher" is a machine that automatically washes dishes and the like, and includes door type, under counter type, rack conveyor type, flight conveyor type, and the like. The detergent composition of the present invention can be suitably used in a water-saving dishwasher that rinses dishes and the like with half the amount of rinsing water used conventionally. The amount of rinsing water in such a water-saving type dishwasher is, for example, 1 to 3 L of rinsing water per rinsing in the case of a door-type dishwasher. Also,
In the case of a rack conveyor type dishwasher, 1 rinse water per 1 rack rinse
~3L.

Next, examples will be described together with comparative examples, but the present invention is not limited by these.

[Examples 1 to 24, Comparative Examples 1 to 13]
Detergent compositions having the compositions shown in Tables 1 to 5 below (units of numerical values in each table are % by mass) were prepared, and detergency 1 (dishwasher detergency) and detergency 2 (dishwashing durability of cleaning agent in washing machines), rinsability (residual alkalinity on dishes in dishwashers), finish after washing, scale prevention 1 (inhibition of scale formation using artificial hard water), scale prevention 2
Nine items of (silica scale dispersibility), storage stability, pH and alkalinity were evaluated. The results are also shown in Tables 1 to 5 below. The test method and evaluation method for each item are as shown below.

[Washability 1: Washability with a dishwasher]
- Test method A cleaning liquid was prepared by diluting the prepared cleaning composition with deionized water so that the concentration of the cleaning agent was as follows. Set this washing liquid in the washing tank of a commercial dishwasher (SD104GS, Nippon Washing Machine Co., Ltd.), wash a set of 10 porcelain dishes or bowls to be washed under the following operating conditions, and wash them. Performance was evaluated according to the following criteria. As stains, two kinds of stains, oil (beef tallow) stains and protein (egg yolk) stains, were prepared, and cleaning evaluation was performed for each of the stains.
*Operating conditions Detergent concentration: 0.05% by mass
Washing temperature: 60°C
Rinsing temperature: 80°C
Rinse water volume: 2.2L
Washing course: Standard washing cycle (washing: 50 seconds, rinsing: 10 seconds)
Tap water hardness: 60 mg/L (as _CaCO3 )
Grease stain: A porcelain dish with a diameter of 25 cm was used, on which 4 g/pan of refined beef tallow was adhered.
Protein stain: A 25 cm diameter porcelain dish is coated with 4 g/plate of chicken egg yolk,
It was dried at room temperature (about 23±2° C.) for 1 hour and immersed in hot water at 40° C. for 30 minutes just before washing.
-Evaluation Criteria Oil red liquid was applied to the washed porcelain dish for greasy stains, and for protein stains, the degree of stain removal was determined visually as follows. The oil red liquid contains an azo dye, which dyes the oil red.
A: Very good (90% or more stain removal).
◯: Good (stain removal of 70% or more and less than 90%).
Δ: Good (50% or more and less than 70% dirt removal).
x: Poor (less than 50% stain removal).

[Detergency 2: Durability of cleaning performance of detergent in dishwasher]
- Test method As for the washing method, the test of washability 1 was repeated 10 times. At that time, the cleaning liquid in the cleaning tank was adjusted to a concentration of 0.05 by adding a cleaning agent to the amount that the concentration of the cleaning agent was diluted by the inflow of rinsing water.
It was kept at mass % and was not replaced after every wash. On the other hand, the porcelain dishes or bowls to be washed were replaced each time washing was repeated, and the objects to which the stains were adhered were used at the start of each washing. Therefore, as washing is repeated, the dirt separated from the tableware accumulates in the washing tank, and the amount of accumulated dirt in the washing liquid increases.
Evaluation Criteria After the 10th wash, washing evaluation was performed according to the same evaluation criteria as for washability 1.

[Rinsability: Remaining alkalinity on dishes in a dishwasher]
- Test method A cleaning liquid was prepared by diluting the prepared cleaning composition with deionized water so that the concentration of the cleaning agent was as follows. This washing solution is set in the washing tank of a commercial dishwasher (SD104GS, Nippon Washing Machine Co., Ltd.), and the object to be washed is placed on the washing rack with the spout facing down under the following operating conditions. A set of 10 glasses (7-ounce tumbler, Toyo Sasaki Glass Co., Ltd.) was washed and its rinsing performance was evaluated according to the following criteria.
*Operating conditions Detergent concentration: 0.15% by mass
Washing temperature: 60°C
Rinsing temperature: 80°C
Rinse water volume: 2.2L
Washing course: Standard washing cycle (washing: 50 seconds, rinsing: 10 seconds)
Tap water hardness: 60 mg/L (as _CaCO3 )
・Evaluation criteria Phenolphthalein solution is added dropwise to the water remaining at the bottom of the glass after washing and rinsing,
Coloring reaction due to residual alkaline agent was visually observed, and the rinsability was determined as follows.
⊚: Very good (no coloring reaction observed at all).
◯: Good (almost no coloring reaction was observed).
x: Poor (marked coloring reaction observed).

[Finishing after washing]
- Test method A cleaning liquid was prepared by diluting the prepared cleaning composition with deionized water so that the concentration of the cleaning agent was as follows. This washing solution is set in the washing tank of a commercial dishwasher (SD104GS, Nippon Washing Machine Co., Ltd.), and the object to be washed is placed on the washing rack with the spout facing down under the following operating conditions. A set of 10 glasses (7-ounce tumbler, Toyo Sasaki Glass Co., Ltd.) was washed, and its finish performance was evaluated according to the following criteria. Milk stains were prepared as stains.
*Operating conditions Detergent concentration: 0.05% by mass
Washing temperature: 60°C
Rinsing temperature: 80°C
Rinse water volume: 2.2L
Washing course: Standard washing cycle (washing: 50 seconds, rinsing 10 seconds)
Water hardness used: 60mg/L (as _CaCO3 )
Milk stain: After milk was poured into the glass, it was left for 5 minutes. Then, after discarding the milk, it was air-dried for 30 minutes without rinsing with water.
Evaluation Criteria ⊚: Very good (no water spots observed at all).
◯: Good (1 to 2 water spots are observed).
Δ: Acceptable (3 to 5 water spots are observed).
x: Bad (6 or more water spots are observed).

[Scale prevention property 1: Suppression of scale generation using artificial hard water]
Test method A test solution was prepared by diluting the detergent composition to 0.05% by mass with artificial hard water (total hardness: 150 mg/L). Pour 50 mL of this test solution into a colorimetric tube with a capacity of 100 mL, hold it at 60 ° C. for 4 hours in an incubator (IS800, Yamato Scientific Co., Ltd.), and then visually observe the test solution and the colorimetric tube according to the following criteria. Suppression of scale formation was evaluated. There are scales that float in the test solution and those that adhere to the bottom and sides of the colorimetric tube.
Both were evaluated.
·Evaluation Criteria ⊚: Very good (no scale was generated).
◯: Good (almost no scale was generated).
Δ: Acceptable (scale was generated).
x: Poor (remarkable scale adhesion).

[Scale prevention property 2: dispersibility of silica scale]
・Test method Fumed silica (average particle size 20 μm, PQ Corporation) 0.3 as a silica scale in a test tube (diameter 23 mm, height 200 mm, IWAKI GLASS)
ammonium chloride-ammonia pH buffer solution, artificial hard water (total hardness: 150 mg/L), and a detergent composition were added in order to make a total of 30 g including fumed silica. A dispersibility test solution containing 100 mg/L of the substance was prepared. After capping and sealing, the test tube was shaken to evenly disperse the fumed silica in the dispersibility test liquid. After that, the test tube was allowed to stand at room temperature (approximately 23±2° C.) for 1 hour. After 1 hour, 5 mL of the dispersibility test liquid was sampled from the top, and the 1 cm cell absorbance (Abs) at UV wavelength 380 nm was measured.
*Evaluation method The absorbance of the dispersibility test solution immediately after shaking the test tube to uniformly disperse the fumed silica (Abs before standing) and the absorbance of the dispersibility test solution after standing for 1 hour measured above ( Abs after standing)
was applied to the following general formula (2) to calculate the dispersibility (%) of silica scale. Good silica scale dispersibility (%) indicates that deposition and growth of silica scale are suppressed.
Dispersibility of silica scale (%) = (Abs after standing) / (Abs before standing) x 100 (2)
·Evaluation Criteria A: Very good (dispersibility was 75% or more).
◯: Good (dispersibility was 50% or more and less than 75%).
Δ: Acceptable (dispersibility was 25% or more and less than 50%).
x: Poor (dispersibility was less than 25%).

[Storage stability]
・Test method Put the prepared detergent composition as an undiluted solution in a 100 mL glass bottle,
4S, Sunaka Rika Kogyo Co., Ltd.) and stored in an atmosphere of 40° C. for one month. In the same way, the prepared detergent composition was placed in a 100 mL glass bottle as an undiluted solution, placed in an incubator (MTH-2400, SANYO) under a program-controlled atmosphere of -5°C to 5°C, and placed in the atmosphere. was stored for 1 month. The appearances of these samples were visually observed and evaluated according to the following evaluation criteria.
Evaluation Criteria ⊚: Very good (after 1 month, there was no change in appearance such as turbidity, separation, or precipitation).
◯: Good (after one month, slight changes in appearance such as turbidity, separation, and precipitation were observed).
Δ: Acceptable (after 2 weeks, a slight change in appearance such as turbidity, separation, or precipitation was observed).
x: Poor (appearance change such as turbidity, separation or precipitation occurred immediately after blending).

[pH]
・Measurement method Using a pH meter (pH METER F-12, Horiba Ltd.), JIS Z-8
802:1984, the pH value at 25° C. of a 0.05% by mass aqueous solution of the detergent composition prepared was measured and evaluated based on the following evaluation criteria.
・Evaluation criteria ◎: Good (pH value is 10.5 or more)
×: bad (pH value is less than 10.5)

[Alkalinity]
Test method Pure water was added to 0.2 g of the detergent composition to make 100 g, 3 drops of phenolphthalein indicator was added, and neutralization titration was performed with a 0.1 mol/L hydrochloric acid normal solution. The point at which the pink color of the phenolphthalein indicator disappeared (pH 8.2) was defined as the end point, and the alkalinity of the detergent composition was calculated based on the following general formula (1). A 0.1 mol/L hydrochloric acid normal solution was a commercial product that had already been evaluated.
Alkalinity (as KOH) = 0.1 x F x X x 56.1/mass of detergent composition (g) x 10 (1)
X = titration volume (mL) of 0.1 mol / L hydrochloric acid normal solution
F = factor of 0.1 mol/L hydrochloric acid normal solution

In Tables 1 to 5 below, the details of the components used and their effective pure content (%) are as follows, and the numerical values in the tables indicate the pure content of each component. In addition, ion-exchanged water is used as water.

[(A) Component]
Alkali metal hydroxide salt 1: sodium hydroxide (pure content 48%) [liquid caustic soda 48%,
Asahi Glass Company].
Alkali metal hydroxide salt 2: Potassium hydroxide (pure content 48%) [48% liquid caustic potash, Asahi Glass Co., Ltd.]
Silicate 1: Sodium metasilicate pentahydrate (pure content 57%) [Metaace 5, Sambo Kagaku Kogyo Co., Ltd.]
.
Silicate 2: Sodium orthosilicate (pure content 65%) [Ortho 65, Toyo Sodium Silicate Co., Ltd.].
Carbonate 1: sodium carbonate (99% pure) [light soda ash, Tokuyama Soda Co.].
Carbonate 2: Potassium carbonate (pure content 99%) [potassium carbonate powder, Asahi Glass].

[(B) component]
Chelating agent 1: sodium tripolyphosphate [pure content 58% ( _{P2O5 )} ], [sodium tripolyphosphate, Nippon Kagaku Co., Ltd.].
Chelating agent 2: Tetrasodium ethylenediaminetetraacetic acid (pure content 87%) [Trilon BPo
Wder, BASF].
Chelating agent 3: trisodium nitrilotriacetic acid (purity 92%) [Trilon A92R, BA
SF Company].
Chelating agent 4: tetrasodium glutamate diacetate (pure content 80%) [Disolvin GL-
PD-S, Akzo Nobel].
Chelating agent 5: Trisodium methylglycine diacetate (purity 76%) [Trilon MSG,
BASF Corp.].

[(C) component]
Scale inhibitor 1: 1-hydroxyethylidene-1,1-diphosphonic acid (60% pure)
[DEQUEST 2016, Italmatch Japan].
Scale inhibitor 2: Phosphonobutane tricarboxylic acid (pure content 50%) [BAYHIB
IT AM, Lanxess].
Scale inhibitor 3: polyacrylic acid [average molecular weight = 4,500 (pure content 48%)], [A
cusol 445, Rohm and Haas].
Scale inhibitor 4: acrylic acid-maleic acid copolymer (average molecular weight = 70,000) [
Sokaran CP-5G, BASF Corp.].
Scale inhibitor 5: sodium salt of olefin-maleic acid copolymer [average molecular weight = 1
2,000 (pure content 25%)], [Sokalan CP-9, BASF].
Scale inhibitor 6: sodium salt of acrylic acid-sulfonic acid copolymer [average molecular weight =
5,000 (47% pure)], [Acusol 500, Rohm and Haas].
Scale inhibitor 7: Sodium dihydroxyethylglycinate (pure content 50%) [Chelest
G-50, Cherest Corp.].

[(D) component]
Alkanolamine 1: Triethanolamine (99% pure) [Triethanolamine S, Nippon Shokubai Co.].
Alkanolamine 2: Monoethanolamine (90% pure) [Monoethanolamine 90%, Nippon Shokubai Co.].

[Scale inhibitor neutralizer]
Sodium hydroxide (pure content 48%) [caustic soda 48%, Asahi Glass].

Thus, it can be seen that the detergent composition of the present invention has excellent detergency even when diluted to a low concentration. In addition, even when washed with a water-saving dishwasher, dirt does not adhere to the tableware again, and the rinsability is excellent, and the generation of silica scale is effectively suppressed. In addition, it can be seen that the storage stability is excellent, the compact size is excellent in workability, and the economy is excellent. Furthermore, although not shown in the above tables, it was found that the same results as those of monoethanolamine and triethanolamine were obtained when diethanolamine was used as the component (D).

Since the detergent composition of the present invention has excellent detergency and rinsability at a low concentration, it is suitable for use as a detergent for water-saving dishwashers.

Claims (4)

A liquid detergent composition for dishwashers containing the following components (A) to (E), wherein the above (
The alkaline agent of component A) is at least one selected from the group consisting of alkali metal hydroxides, silicates and carbonates, and components (A) to (D) are used in a liquid detergent composition for dishwashers. Contained in the following ratio to the whole, the ratio of the above component (A) to the component (D) [(A) / (D
)] is in the range of 0.25 to 3, and the pH of the 0.05% by mass aqueous solution at 25 ° C. is 10
. 5 or more, and the alkalinity of the liquid detergent composition for dishwashing machines when pH is 8.2 as an end point is 13% by mass or more in terms of potassium hydroxide. cleaning composition.
(A) Alkaline agent: 5 to 20% by mass.
(B) chelating agent: 15 to 40% by mass;
(C) Scale inhibitor: 0.5 to 10% by mass.
(D) Alkanolamine: 3 to 20% by mass.
(E) water. 2. The liquid detergent composition for dishwashers according to claim 1, wherein the alkanolamine of component (D) is at least one selected from the group consisting of monoethanolamine, diethanolamine and triethanolamine. 3. The dishwashing machine according to claim 1 or 2, wherein the antiscaling agent of component (C) is at least one selected from the group consisting of organic phosphorus antiscaling agents, polymer electrolytes and glycine antiscaling agents. Liquid detergent composition. Diluting the liquid detergent composition for dishwashers according to any one of claims 1 to 3 with water,
A method for washing tableware, comprising preparing a washing liquid containing 0.03 to 0.15% by mass of a liquid detergent composition for a dishwasher, and using the washing liquid in a washing process of the dishwasher.