WO2025022675A1 - Detergent composition for hard surfaces - Google Patents

Abstract

The present invention relates to a detergent composition for hard surfaces, the detergent composition containing a fluoride, and provides: a detergent composition for hard surfaces, the composition achieving both corrosion prevention of a hard surface and water stain removal performance under mild conditions in a weak acidic to neutral region; and a method for cleaning a hard surface using the detergent composition for hard surfaces.　Disclosed is a detergent composition for hard surfaces, the detergent composition containing (a) a fluoride (hereinafter referred to as a component (a)) and (b) an organic acid or a salt thereof. The content of the component (a) is 4 mM to 240 mM inclusive in terms of fluorine atoms, and the pH at 25°C is 4.0 to 6.5 inclusive. The hydrogen fluoride concentration [HF] in the detergent composition for hard surfaces calculated from (formula 1) is 0.25 mM to 0.9 mM inclusive.　(Formula 1) 7.08 × 10^-4 = [F^-][H⁺]/[HF] [F^-]: the ionized fluorine content (mM) in the component (a) contained in the detergent composition for hard surfaces [H⁺]: the hydrogen ion concentration (mM) calculated from the pH of the detergent composition for hard surfaces at 25°C 7.08 × 10^-4: the acid ionization constant of hydrogen fluoride at 25°C

Description

Cleaning composition for hard surfaces

The present invention relates to a cleaning composition for hard surfaces and a method for cleaning hard surfaces.

2. Background Art Various hard surfaces made of materials such as tiles, plastics, and metals exist in the living environment facilities surrounding us, and these hard surfaces are exposed to environments where various stains adhere in daily life. In particular, hard surfaces used in bathrooms, kitchens, etc. are surfaces that people come into contact with on a daily basis, so many stains tend to remain and accumulate, and are difficult to clean and remove. Generally, cleaning agents used in bathrooms, such as bathtubs, bathroom walls, and floors, contain surfactants, solvents, sequestering agents, etc. to remove metal soap stains, especially calcium salts of fatty acids. In addition, in bathrooms and kitchens, silicic acid contained in water polymerizes and accumulates on hard surfaces, depositing in a scaly pattern to become limescale stains. This limescale stain is also known to be a stain that is very difficult to remove.

China Patent Publication No. 106190617 discloses a glass scale cleaner containing 0.5 to 10 parts of a surfactant, 0.5 to 15 parts of a fluoride, 10 to 30 parts of a weak acid, 1 to 3 parts of an acrylic acid homopolymer sodium salt, 1 to 10 parts of borax, 5 to 20 parts of a solvent, and 40 to 70 parts of demineralized water.
China Patent Publication No. 111979054 discloses a neutral, environmentally friendly bathroom cleaner containing 0.3%-5% cleaning promoter, 10%-25% organic acid, 5%-15% neutralizer, 0.1%-0.5% corrosion inhibitor, 1%-5% chelating dispersant, 1%-5% surfactant, and the balance deionized water.

Summary of the Invention Conventionally, strong acid detergent compositions have been used to clean limescale stains on hard surfaces used in bathrooms, kitchens, etc., and hypochlorous acid detergent compositions have been used to clean black mold stains on the hard surfaces. For example, when a strong acid detergent composition and a hypochlorous acid detergent composition are used simultaneously to clean hard surfaces such as bathrooms, there is a risk that the two detergent compositions will be mixed by mistake, resulting in the generation of harmful chlorine, which is very dangerous. Therefore, there is a demand for a detergent composition that is excellent in cleaning limescale stains on hard surfaces under mild conditions with a pH close to neutral.
Also, as in Patent Document 1, a cleaning composition for hard surfaces containing a fluoride under strongly acidic conditions is disclosed. However, although such a cleaning composition can remove limescale stains, it corrodes hard surfaces such as glass and aluminum, and therefore it is necessary to incorporate a corrosion inhibitor such as borax. Therefore, there is a demand for a cleaning composition for hard surfaces containing a fluoride that can achieve both limescale stain removal performance and corrosion prevention properties under mild conditions in the weak acid to neutral range.

The present invention relates to a fluoride-containing cleaning composition for hard surfaces, and provides a cleaning composition for hard surfaces that combines water stain removal performance and corrosion prevention for hard surfaces under mild conditions in the weak acidic to neutral range, and a method for cleaning hard surfaces using the same.

The present invention relates to a cleaning composition for hard surfaces, which contains (a) a fluoride (hereinafter referred to as component (a)), and (b) an organic acid or a salt thereof (hereinafter referred to as component (b)), in which the content of component (a) is 4 mM or more and 240 mM or less in terms of fluorine atoms, the pH at 25° C. is 4.0 or more and 6.5 or less, and the hydrogen fluoride concentration [HF] in the cleaning composition for hard surfaces, calculated by the following (Equation 1), is 0.25 mM or more and 0.9 mM or less.
7.08×10 ⁻⁴ = [F ⁻ ][H ⁺ ]/[HF] (Formula 1)
[F- ^] : the content (mM) of ionized fluorine in the component (a) contained in the hard surface cleaning composition
[H ⁺ ]: hydrogen ion concentration (mM) calculated from the pH of the hard surface cleaning composition at 25° C.
7.08×10 ⁻⁴ : Acid ionization constant of hydrogen fluoride at 25°C

The present invention also relates to a method for cleaning a hard surface, which comprises contacting the hard surface with a cleaning composition for hard surfaces for a predetermined period of time, and then rinsing the hard surface with water.

According to the present invention, there is provided a fluoride-containing cleaning composition for hard surfaces that achieves both water stain removal performance and corrosion prevention for hard surfaces under mild conditions in the weak acidic to neutral range, and a cleaning method for hard surfaces using the same.
In one embodiment of the cleaning composition for hard surfaces of the present invention, it is possible to achieve both water stain removal performance and corrosion prevention for hard surfaces without containing a corrosion inhibitor for hard surfaces.

Modes for Carrying Out the Invention The reason why the cleaning composition for hard surfaces of the present invention is able to achieve both water stain removal performance and corrosion prevention for hard surfaces under mild conditions in the weak acidic to neutral range is not entirely clear, but is presumed to be as follows.
Limescale is formed by repeated deposition of calcium carbonate or silicic acid dissolved in water on a hard surface. The fluoride, which is the component (a) contained in the hard surface cleaning composition of the present invention, is partially converted into hydrogen fluoride (HF) depending on the pH of the cleaning composition, and it is believed that this hydrogen fluoride acts on silicic acid deposits to exhibit the removal performance. The lower the pH, the higher the hydrogen fluoride concentration, and the higher the limescale stain removal performance. On the other hand, glass hard surfaces also have silicic acid as a structural unit, and there is a trade-off between limescale removal performance and corrosion prevention of hard surfaces such as glass. The present inventors have found that by strictly controlling the amount of fluoride contained in the hard surface cleaning composition of the present invention, the pH, and the hydrogen fluoride concentration in the cleaning composition, and by containing an organic acid or a salt thereof, which is the component (b), it is possible to achieve both limescale stain removal performance and corrosion prevention of hard surfaces even under mild conditions in the weak acid to neutral range, and have arrived at the present invention.

[Cleaning composition for hard surfaces]
<Component (a)>
The cleaning composition for hard surfaces of the present invention contains a fluoride as component (a).
Examples of the fluoride of component (a) include one or more selected from hydrogen fluoride, sodium fluoride, potassium fluoride, zinc fluoride, lithium fluoride, ammonium fluoride, sodium hydrogen fluoride, ammonium hydrogen fluoride, hexafluorosilicic acid, sodium hexafluorosilicate, and ammonium hexafluorosilicate.
From the viewpoints of availability and economy, the component (a) is preferably one or more selected from hydrogen fluoride, sodium fluoride, potassium fluoride, lithium fluoride, ammonium fluoride, sodium hydrogen fluoride, and ammonium hydrogen fluoride, more preferably one or more selected from sodium fluoride, ammonium fluoride, and sodium hydrogen fluoride, and even more preferably sodium fluoride.

<Component (b)>
The cleaning composition for hard surfaces of the present invention contains an organic acid or a salt thereof as component (b). Component (b) has a synergistic effect with component (a) to enhance the ability to remove water stains.
From the viewpoint of limescale stain removal performance, the acid dissociation constant (hereinafter referred to as pKa) of component (b) is preferably 4.6 or more, more preferably 5.0 or more, even more preferably 6.0 or more, and preferably 7.0 or less. The above-mentioned range of the acid dissociation constant may include any one of the first acid dissociation constant (hereinafter referred to as pKa1), the second acid dissociation constant (hereinafter referred to as pKa2), and the third acid dissociation constant (hereinafter referred to as pKa3) of component (b).

From the viewpoint of ease of incorporation into the cleaning composition for hard surfaces, the component (b) is preferably a water-soluble organic acid or a salt thereof that can dissolve 5 g or more in 100 g of water at 20° C., and is preferably one or more selected from monocarboxylic acids, dicarboxylic acids, tricarboxylic acids, and salts thereof.
Examples of the organic acid salt of component (b) include alkali metal salts such as sodium and potassium, and alkaline earth metal salts such as calcium.
Examples of monocarboxylic acids include propanoic acid (pKa: 4.87), lactic acid (pKa: 3.86), and butyric acid (pKa: 4.82).
Examples of dicarboxylic acids include malic acid (pKa1: 3.46, pKa2: 5.10), tartaric acid (pKa1: 2.98, pKa2: 4.34), succinic acid (pKa1: 4.19, pKa2: 5.60), maleic acid (pKa1: 1.90, pKa2: 6.07), and malonic acid (pKa1: 2.83, pKa2: 5.29).
An example of the tricarboxylic acid is citric acid (pKa1: 3.09, pKa2: 4.76, pKa3: 6.40).

From the viewpoint of the limescale cleaning performance and corrosion prevention performance of the hard surface cleaning composition, component (b) is preferably one or more selected from citric acid, propanoic acid, lactic acid, malic acid, tartaric acid, succinic acid, and salts thereof, more preferably one or more selected from citric acid, propanoic acid, malic acid, and salts thereof, and even more preferably citric acid or a salt thereof.

<Composition, etc.>
In the hard surface cleaning composition of the present invention, the content of component (a) is, in terms of fluorine atoms, from the viewpoint of ensuring sufficient removal performance even against severe water scale stains, 4 mM or more, preferably 6 mM or more, more preferably 7 mM or more, even more preferably 8 mM or more, still more preferably 10 mM or more, still more preferably 35 mM or more, and from the viewpoint of corrosion prevention, 240 mM or less, preferably 200 mM or less, more preferably 150 mM or less, even more preferably 125 mM or less, and from the viewpoint of corrosion prevention and from the viewpoint of ensuring sufficient removal performance even against severe water scale stains, still more preferably 100 mM or less, still more preferably 75 mM or less.

In the hard surface cleaning composition of the present invention, the content of component (b) is preferably 1 mass % or more, more preferably 2 mass % or more, and even more preferably 3 mass % or more from the viewpoint of limescale stain removal performance, and from the viewpoint of corrosion prevention, it is preferably 15 mass % or less, more preferably 12 mass % or less, even more preferably 11 mass % or less, still more preferably 9 mass % or less, and even more preferably 7 mass % or less.
In the present invention, the mass of the component (b) is expressed as an acid-equivalent value.

The hydrogen fluoride concentration in the hard surface cleaning composition of the present invention is, from the viewpoint of water stain removal performance, 0.25 mM or more, preferably 0.30 mM or more, more preferably 0.40 mM or more, and from the viewpoint of corrosion prevention, 0.9 mM or less, preferably 0.80 mM or less, more preferably 0.70 mM or less.
The hydrogen fluoride concentration [HF] in the hard surface cleaning composition of the present invention is calculated by the following (Equation 1).
7.08×10 ⁻⁴ = [F ⁻ ][H ⁺ ]/[HF] (Formula 1)
[F- ^] : the ionized fluorine content (mM) in the component (a) contained in the hard surface cleaning composition
[H ⁺ ]: hydrogen ion concentration (mM) calculated from the pH of the hard surface cleaning composition at 25° C.
7.08×10 ⁻⁴ : The acid ionization constant [HF] of hydrogen fluoride at 25° C. is calculated by the following procedure when, for example, component (a) is sodium fluoride.
1. If the total amount of sodium fluoride blended in the hard surface cleaning composition is C mM, then C = [F ^- ] + [HF]
2. Introducing C=[F ^- ]+[HF] into (Equation 1), 7.08 x ^10-4 =[F ^- ][H ⁺ ]/[HF]=(C-[HF])[H ⁺ ]/[HF]
3. When [HF] is rearranged, [HF] = C / (7.08 × 10 ^-4 / [H ⁺ ] + 1)
4. Substitute the respective values for C and [H ⁺ ] to calculate [HF].

From the viewpoints of water stain removing performance and ease of incorporation into the hard surface cleaning composition, the hard surface cleaning composition of the present invention may further contain, as component (c), one or more polymers selected from (c1) a carboxylic acid-based polymer containing a structural unit having a carboxyl group or a salt thereof (hereinafter referred to as component (c1)), and (c2) a sulfonic acid-based polymer containing a structural unit having a sulfonic acid group or a salt thereof (hereinafter referred to as component (c2)).
Of the component (c), from the viewpoints of water stain removing performance and ease of incorporation into a cleaning composition for hard surfaces, the component (c1) is more preferred.

The carboxylic acid polymer of component (c1) is preferably one or more selected from polyacrylic acid, polymaleic acid, acrylic acid-maleic acid copolymer, and salts thereof, from the viewpoint of further improving the limescale removal performance and corrosion prevention performance, and more preferably one or more selected from polyacrylic acid, acrylic acid-maleic acid copolymer, and salts thereof. The salt may be a partial or complete salt, and is preferably an alkali metal salt, more preferably a sodium salt or potassium salt.

The weight average molecular weight of the carboxylic acid polymer of component (c1) is preferably 500 or more, more preferably 1000 or more, even more preferably 1500 or more, and preferably 300,000 or less, more preferably 200,000 or less, even more preferably 100,000 or less, and even more preferably 60,000 or less, from the viewpoints of limescale removal performance and easy-to-use liquid properties. The weight average molecular weight of the carboxylic acid polymer is measured by gel permeation chromatography (GPC) using polyethylene glycol of known molecular weight as a standard substance.

Examples of the sulfonic acid polymer of component (c2) include aromatic formalin condensates or salts thereof containing aromatic sulfonic acids or salts thereof. Among these, examples of aromatic sulfonic acids include petroleum sulfonic acid, naphthalene sulfonic acid, lignin sulfonic acid, creosote oil sulfonic acid, and cresol alkylene sulfonic acid.
Specific examples of sulfonic acid polymers include meta-cresol methylene sulfonic acid-Schaeffer acid formalin condensate salts (such as "Demol SSL" (registered trademark) manufactured by Kao Corporation), meta-cresol methylene sulfonic acid formalin condensate salts (such as "Demol SC30" (registered trademark) manufactured by Kao Corporation), creosote oil sulfonic acid formalin condensate salts (such as "Demol C" (registered trademark) manufactured by Kao Corporation), naphthalene sulfonic acid formalin condensate salts (such as "Demol NL" (registered trademark) manufactured by Kao Corporation), lignin sulfonic acid formalin condensate salts, melamine sulfonic acid formalin condensate salts, and sodium styrene sulfonate polymer salts.
From the viewpoint of water stain removing performance, the sulfonic acid polymer is preferably a naphthalenesulfonic acid-formalin condensate or a salt thereof.

The weight average molecular weight of the sulfonic acid polymer of component (c2) is preferably 500 or more, more preferably 1000 or more, even more preferably 1500 or more, and preferably 300,000 or less, more preferably 200,000 or less, even more preferably 100,000 or less, and even more preferably 60,000 or less, from the viewpoints of removal performance and easy-to-use liquid properties. The weight average molecular weight of the sulfonic acid polymer is measured by gel permeation chromatography (GPC) using polyethylene glycol of known molecular weight as a standard substance.

When the hard surface cleaning composition of the present invention contains component (c), the content of component (c) in the hard surface cleaning composition of the present invention is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more, from the viewpoint of water stain removal performance, and is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less, from the viewpoint of obtaining suitable liquid properties, for example, suitable liquid properties required when spraying or applying to an object using a spray means.

The hard surface cleaning composition of the present invention may further contain a surfactant as component (d) from the viewpoint of further enhancing the performance of removing water stains.
The surfactant of the component (d) may be one or more selected from (d1) anionic surfactants (hereinafter also referred to as component (d1)), (d2) nonionic surfactants (hereinafter also referred to as component (d2)), (d3) amphoteric surfactants (hereinafter also referred to as component (d3)), and (d4) cationic surfactants (hereinafter also referred to as component (d4)). From the viewpoint of ease of incorporation into the cleaning composition for hard surfaces, one or more selected from anionic surfactants, nonionic surfactants, and amphoteric surfactants are preferred, and amphoteric surfactants are more preferred.

Examples of the anionic surfactant of component (d1) include one or more selected from alkylbenzenesulfonates, polyoxyalkylene alkyl or alkenyl ether sulfate salts, alkyl or alkenyl sulfate salts, olefinsulfonates, alkanesulfonates, saturated or unsaturated fatty acid salts, alkyl or alkenyl ether carboxylate salts, α-sulfofatty acid salts, N-acylamino acids, mono- or di-phosphate esters, and sulfosuccinate esters.
The carbon number of the alkyl group or alkenyl group of the anionic surfactant is, for example, 8 to 22 carbon atoms, preferably 10 to 16 carbon atoms, and more preferably 12 to 14 carbon atoms. In the polyoxyalkylene group of the anionic surfactant, the oxyalkylene group is preferably one or more groups selected from an oxyethylene group and an oxypropylene group, and is preferably an oxyethylene group. In the polyoxyalkylene group, the average number of moles of the oxyalkylene group added is, for example, 0 to 10, and preferably 1 to 3.
Examples of counter ions of the anionic groups of these anionic surfactants include alkali metal ions such as sodium ion and potassium ion; alkaline earth metal ions such as calcium ion and magnesium ion; ammonium ion; and alkanolamines having 1 to 3 alkanol groups having 2 or 3 carbon atoms (for example, monoethanolamine, diethanolamine, triethanolamine, triisopropanolamine, etc.).

From the viewpoint of economic efficiency, the anionic surfactant of component (d1) is preferably one or more selected from alkylbenzenesulfonates, alkyl or alkenyl ether sulfates, and alkyl or alkenyl sulfates, and from the viewpoint of limescale stain removal performance, more preferably alkyl or alkenyl ether sulfates.
From the viewpoint of ease of incorporation into the hard surface cleaning composition, the number of carbon atoms in the alkyl group of the alkylbenzenesulfonate is 10 or more, preferably 12 or more, and 18 or less, preferably 14 or less, and the alkyl group is preferably linear.
The alkyl or alkenyl ether sulfate is preferably a polyoxyalkylene alkyl or alkenyl ether sulfate. From the viewpoint of ease of incorporation into a hard surface cleaner composition, the polyoxyalkylene alkyl or alkenyl ether sulfate has an alkyl or alkenyl group having 8 or more, preferably 10 or more, and 18 or less, preferably 14 or less carbon atoms. The polyoxyalkylene alkyl or alkenyl ether sulfate has an oxyalkylene group having preferably 2 or 3, more preferably 2, and an average addition molar number of the oxyalkylene group being 0.5 or more, preferably 1.0 or more, and 4.0 or less, preferably 3.0 or less.
From the viewpoint of ease of incorporation into the hard surface cleaning composition, the number of carbon atoms in the alkyl or alkenyl group of the alkyl or alkenyl sulfate ester salt is 10 or more, preferably 12 or more, and 18 or less, preferably 14 or less.

The nonionic surfactant of component (d2) may be one or more selected from polyoxyalkylene alkyl ethers, polyoxyalkylene alkenyl ethers, polyoxyalkylene sorbitan fatty acid esters, alkyl glycosides, alkyl polyglycosides, sucrose fatty acid esters, and alkyl polyglyceryl ethers. The number of carbon atoms in the alkyl or alkenyl group of these nonionic surfactants is preferably 6 or more, more preferably 8 or more, and preferably 22 or less, more preferably 18 or less. The alkylene oxide of the polyoxyalkylene alkyl ether, polyoxyalkylene alkenyl ether, and polyoxyalkylene sorbitan fatty acid ester preferably contains an alkylene oxide selected from ethylene oxide and propylene oxide, and the average number of moles of alkylene oxide added is preferably 2 or more, and preferably 25 or less.

From the viewpoint of water stain removal performance, the component (d2) is preferably a nonionic surfactant represented by the following general formula (d2).
R ^21d (CO) _m O-(A ^21d O) _n -R ^22d (d2)
[In the formula, R ^21d is an aliphatic hydrocarbon group having 8 to 18 carbon atoms, and R ^22d is a hydrogen atom or a methyl group. CO is a carbonyl group, and m is a number of 0 or 1. ^{A 21d} group is an alkyleneoxy group having 2 to 4 carbon atoms and including an ethyleneoxy group. n is the average number of moles added, which is a number of 1 to 30.]

In general formula (d2), the number of carbon atoms in R ^21d is 8 or more, preferably 10 or more, more preferably 12 or more, and 18 or less, preferably 16 or less, more preferably 14 or less, from the viewpoint of ease of incorporation into the cleaning composition for hard surfaces.
R ^21d is an aliphatic hydrocarbon group, and is preferably a group selected from an alkyl group and an alkenyl group.

In the general formula (d2), the A ^21d O group is an alkyleneoxy group containing an ethyleneoxy group and having 2 to 4 carbon atoms, preferably an alkyleneoxy group containing an ethyleneoxy group and having 2 to 3 carbon atoms, more preferably an ethyleneoxy group. The A ^21d O group may be an alkyleneoxy group containing an ethyleneoxy group and another alkyleneoxy group, for example a propyleneoxy group. The other alkyleneoxy group is preferably a propyleneoxy group. When the A ^21d O group contains an ethyleneoxy group and a propyleneoxy group, the ethyleneoxy group and the propyleneoxy group may be a block bond or a random bond.

In general formula (d2), n is the average number of moles of ^A21dO groups added, and is a number from 1 to 30. In general formula (d2), n is 1 or more, preferably 6 or more, more preferably 10 or more, and is 30 or less, preferably 25 or less, more preferably 20 or less, from the viewpoint of ease of incorporation into a cleaning composition for hard surfaces.

The amphoteric surfactant of component (d3) may be one or more selected from alkyl dimethylamine oxide, alkyl dimethylaminoacetic acid betaine, alkyl hydroxysulfobetaine, alkyl amidopropyl betaine, and alkyl carboxymethyl hydroxyethyl imidazolium betaine.

As the amphoteric surfactant of component (d3), from the viewpoint of obtaining good water stain removing performance and favorable foam characteristics when sprayed or applied to an object using a spray means, a compound of the following general formula (d3) is preferred.

[In the formula, R ^31d is an alkyl or alkenyl group having 7 to 18 carbon atoms, and R ^32d is an alkylene group having 1 to 6 carbon atoms. A is a group selected from -COO-, -CONH-, -OCO-, -NHCO-, and -O-, and r is the number 0 or 1. ^{R 33d} and R ^34d are alkyl or hydroxyalkyl groups having 1 to 3 carbon atoms, and R ^35d is an alkylene group having 1 to 5 carbon atoms which may be substituted with a hydroxy group. B is -SO ₃ ^- , -OSO ₃ ^- , or -COO-. ^]

In general formula (d3), from the viewpoint of ease of incorporation into a cleaning composition for hard surfaces, R ^31d is an alkyl group or alkenyl group, preferably an alkyl group, having 7 or more, preferably 10 or more, and 18 or less, preferably 14 or less, more preferably 12 or less carbon atoms.
A is preferably --COO-- or --CONH--, and more preferably --CONH--.
R ^32d preferably has 2 or 3 carbon atoms.
r is preferably 0.
R ^33d and R ^34d are preferably methyl groups.
R ^35d is preferably a hydroxyalkyl group having 3 carbon atoms.
B is preferably —SO ₃ ^— .

The cationic surfactant of component (d4) may be one or more selected from alkyltrimethylammonium salts in which the alkyl group has 8 to 22 carbon atoms, dialkyldimethylammonium salts in which the alkyl group has 8 to 22 carbon atoms, alkyldimethylbenzylammonium salts in which the alkyl group has 8 to 22 carbon atoms, and benzethonium salts. Examples of salts include halogen salts and alkyl sulfates in which the carbon number is 1 to 3.

When the hard surface cleaning composition of the present invention contains component (d), the content of component (d) in the hard surface cleaning composition of the present invention is preferably 0.3 mass% or more, more preferably 0.6 mass% or more, even more preferably 1 mass% or more, and preferably 7 mass% or less, more preferably 5 mass% or less, even more preferably 3 mass% or less, from the viewpoints of economy, stability over time of the composition, water stain removal performance, and ease of incorporation into the composition. In the present invention, when component (d1) is included as component (d), the mass of component (d1) is converted to the sodium salt. Furthermore, when component (d4) is included as component (d), the mass of component (d4) is converted to the chlorine salt.

The hard surface cleaning composition of the present invention may further contain a water-soluble solvent as component (e) from the viewpoint of further improving the performance of removing water stains. With respect to component (e), "water-soluble" means that 5 g or more of the component dissolves in 100 g of water at 20°C.

Examples of the water-soluble solvent of component (e) include one or more water-soluble solvents selected from ethanol, isopropyl alcohol, 2-methyl-2-propanol, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, propylene glycol monoethyl ether (methylpropylene glycol), propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol monohexyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, triethylene glycol monobutyl ether, 3-methyl-3-methoxybutanol, and dibutylene diglycol.
From the viewpoint of further improving the limescale stain removing performance, the component (e) is more preferably one or more water-soluble solvents selected from diethylene glycol monobutyl ether, diethylene glycol monopropyl ether, and propylene glycol monohexyl ether.

When the hard surface cleaning composition of the present invention contains component (e), the content of component (e) in the hard surface cleaning composition of the present invention is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, from the viewpoint of water stain removal performance, and is preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 7% by mass or less, from the viewpoint of economy.

The hard surface cleaning composition of the present invention may optionally contain chelating agents, fragrances, colorants, preservatives, enzymes, pH adjusters, antioxidants, etc., in order to increase the added value of the product (excluding the above-mentioned components (a) to (e)).

The hard surface cleaning composition of the present invention can achieve both water stain removal performance and corrosion prevention for hard surfaces without containing a corrosion inhibitor.
The corrosion inhibitor may include one or more selected from aluminates, gluconates, aluminum salts, borax, and zinc salts.
In the cleaning composition for hard surfaces of the present invention, the content of the corrosion inhibitor is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less, from the viewpoints of economic efficiency and stability over time of the composition.
The hard surface cleaning composition of the present invention may not contain a corrosion inhibitor.

The hard surface cleaning composition of the present invention contains water. That is, the remainder other than the components (a) to (b) and optional components is water. The hard surface cleaning composition of the present invention contains water in an amount of preferably 60% by mass or more, more preferably 65% by mass or more, even more preferably 70% by mass or more, and preferably 97% by mass or less, more preferably 95% by mass or less, even more preferably 93% by mass or less. It is preferable to use ion-exchanged water, sterilized ion-exchanged water, etc. as the water.

The pH of the hard surface cleaning composition of the present invention at 25°C is 4.0 or more, preferably 4.5 or more, more preferably 4.8 or more, and 6.5 or less, preferably 6.0 or less, more preferably 5.5 or less, from the viewpoints of water stain removal performance and corrosion prevention. The pH is measured by the glass electrode method. The pH of the hard surface cleaning composition of the present invention at 25°C is specifically measured by the pH measurement method described below.

<pH Measurement Method>
A composite electrode for pH measurement (glass-ground sleeve type, manufactured by HORIBA) is connected to a pH meter (pH/ion meter F-23, manufactured by HORIBA) and the power is turned on. A saturated aqueous potassium chloride solution (3.33 mol/L) is used as the internal solution of the pH electrode. Next, a pH 6.86 standard solution (neutral phosphate standard solution), a pH 9.18 standard solution (borate standard solution), and a pH 12.0 standard solution (saturated calcium hydroxide standard solution) are filled into 100 mL beakers and immersed in a thermostatic bath at 25°C for 30 minutes. The pH measurement electrode is immersed in the thermostatically adjusted standard solution for 3 minutes, and a calibration operation is performed in the order of pH 6.86 → pH 9.18 → pH 12.0. The sample to be measured (the cleaning agent composition for hard surfaces of the present invention) is adjusted to 25°C, the electrode of the pH meter is immersed in the sample, and the pH is measured after 1 minute.

The hard surface to be treated with the hard surface cleaner composition of the present invention may be a hard surface made of tile, glass, metal (stainless steel, aluminum alloy, etc.), plastic, or ceramic.
The hard surface cleaner composition of the present invention is suitable for cleaning hard surfaces such as bathrooms, bathtubs, washbasins, tiles, restrooms, washstands, mirrors, kitchen sinks, countertops, and areas around water supplies. It is suitable for use in bathrooms. Here, the term "for use in bathrooms" refers not only to bathrooms, but also to other items having hard surfaces present in the bathroom, such as bathtubs and washbasins. The present invention is preferably intended for hard surfaces with limescale stains.

The hard surface cleaning composition of the present invention is preferably used by spraying or applying it in the form of droplets or foam and contacting it with a hard surface. A spray means can be used for spraying or applying. The present invention provides a hard surface cleaning product in a spray container, which is prepared by filling the hard surface cleaning composition of the present invention into a container equipped with a sprayer.

The container equipped with a sprayer that fills the hard surface cleaning composition of the present invention in the spray-contained hard surface cleaning article of the present invention can be a trigger-type spray container, a manual spray device that does not use a propellant such as a pump-type spray container, or an aerosol that uses a propellant. The container equipped with the sprayer is preferably a trigger-type spray that can spray or apply the contents in droplets or foam form, and more preferably a trigger-type spray equipped with a mechanism for spraying the contents in droplets or a mechanism for forming foam (foam-forming mechanism).

In the case where a trigger-type spray having a mechanism for spraying the hard surface cleaner composition of the present invention in the form of droplets is used in the spray-container-packed hard surface cleaner article of the present invention, the nozzle diameter of the spray container containing the composition is preferably 0.1 mm or more, more preferably 0.3 mm or more, and preferably 2 mm or less, more preferably 1 mm or less, in order to facilitate spraying, to ensure that the sprayed droplets are not rough, that they are not sprayed in a straight line, and that the area that can be sprayed is not extremely narrow.
When using a trigger-type spray equipped with a mechanism for spraying in the form of droplets, the spray-containerized hard surface antifungal agent article of the present invention sprays preferably 0.1 mL or more, more preferably 0.3 mL or more, and preferably 5 mL or less, more preferably 2 mL or less of the composition in one operation.

Furthermore, in the case where a trigger-type spray equipped with a foam-forming mechanism is used in the spray-contained hard surface cleaning article of the present invention, it is preferable to use one having a spin element and a liquid passage plate with several rod-shaped protrusions installed in a circular space with a diameter of 4 to 8 mm. Here, the spin element is a mechanism that gives a spin to the flow of liquid through the spin element and finally sprays it from the nozzle, and for detailed structure, reference can be made to JP-A-8-332422, FIG. 4(b) of JP-A-8-108102, FIG. 1 of JP-A-2002-68265, etc.

When using a trigger-type sprayer equipped with a foam-forming mechanism, the spray-contained hard surface cleaner article of the present invention sprays, in one operation, preferably 0.5 mL or more, more preferably 1 mL or more, and preferably 30 mL or less, more preferably 15 mL or less, and even more preferably 5 mL or less of the composition.

The liquid passage plate, another component of the foam-forming mechanism, has preferably 3 to 8 rod-shaped protrusions installed in a circular space with a diameter of 5 to 7 mm, and when the plate is viewed in plan, the rod-shaped protrusions are preferably rectangular with a width of 0.8 to 1.2 mm and a length of 2 to 4 mm. Furthermore, the area occupied by the rod-shaped protrusions in relation to the space excluding the rod-shaped protrusions is preferably 30 area% or more, more preferably 40 area% or more, and preferably 90 area% or less, more preferably 80 area% or less, and even more preferably 70 area% or less. By installing such a liquid passage plate, the adhesion and retention of bubbles on the vertical surface is improved.

The container of the spray-contained hard surface cleaner article of the present invention can be a commonly used container. For example, it can be obtained from raw materials such as polyethylene, polypropylene, or polyethylene terephthalate, and can be manufactured by blow molding or the like. The thickness of the container may differ between the bottom and sides, and is preferably 0.01 to 2 mm, and the container capacity is preferably 100 to 1000 mL. For ease of handling, the amount of hard surface cleaner composition filled into the container is preferably 200 to 500 mL. Furthermore, the liquid is filled while leaving a reasonable amount of space.

[Method of cleaning hard surfaces]
According to the present invention, there is provided a method for cleaning a hard surface, which comprises contacting the hard surface with the cleaning composition for hard surfaces of the present invention for a predetermined period of time, and then rinsing the hard surface with water.
Furthermore, the present invention provides a method for removing water stains, which comprises contacting the hard surface with the cleaning composition for hard surfaces of the present invention for a predetermined period of time and then rinsing the hard surface with water. That is, the method for removing water stains on a hard surface comprises contacting the hard surface cleaning composition for hard surfaces of the present invention for a predetermined period of time and then rinsing the hard surface with water.
The matters described in the description of the hard surface cleaning composition of the present invention can be appropriately applied to these methods. The preferred embodiments of the composition are also the same as those of the hard surface cleaning composition of the present invention described above.
The hard surfaces to be treated are the same as those described in the hard surface cleaning composition of the present invention.

In the method for cleaning a hard surface of the present invention, the above-mentioned cleaning composition for hard surfaces is brought into contact with the hard surface.
Specifically, the cleaning method includes contacting the hard surface cleaning composition in an undiluted form with the hard surface, or contacting the hard surface cleaning composition in an undiluted form with the hard surface, i.e., contacting the hard surface cleaning composition without dilution with the hard surface.
The phrase "contacting the hard surface cleaning composition with a hard surface without dilution" means that the hard surface cleaning composition is not contacted with a hard surface after intentionally diluting it with water, etc. For example, when the hard surface cleaning composition is contacted with a hard surface having water droplets or the like attached thereto, or when water droplets are attached to the hard surface after the hard surface cleaning composition is contacted with the hard surface, it can be understood that the hard surface cleaning composition is contacted with the hard surface without dilution.
In the present invention, it is preferable to contact the undiluted solution of the hard surface cleaning composition with the hard surface as it is, that is, without changing the composition. For example, the hard surface cleaning composition is contacted with the hard surface without being attached to a water-absorbed sponge. After contacting with the hard surface, the composition of the hard surface cleaning composition may change. That is, after contacting with the hard surface, the composition of the hard surface cleaning composition may be diluted or concentrated.

The method of contacting the hard surface cleaning composition with the hard surface is preferably spraying or coating, and more preferably spraying in droplet form or coating in foam form. The method for cleaning hard surfaces of the present invention preferably uses the above-mentioned spray-contained hard surface cleaning product of the present invention.

In the method for cleaning a hard surface of the present invention, the cleaning composition for hard surfaces is contacted in an amount of preferably 0.1 g or more, more preferably 0.3 g or more, even more preferably 0.4 g or more, and preferably 5 g or less, more preferably 3 g or less, even more preferably 2 g or less, per 100 ^cm2 of the area of the hard surface to be cleaned.

The time for which the hard surface cleaning composition of the present invention is left to stand after contacting the hard surface is, from the viewpoint of cleaning power, preferably 1 minute or more, preferably 2 minutes or more, more preferably 3 minutes or more, even more preferably more than 3 minutes, even more preferably 4 minutes or more, even more preferably 5 minutes or more, and from the viewpoint of efficient cleaning, preferably 60 minutes or less, more preferably 30 minutes or less, even more preferably 15 minutes or less, even more preferably 10 minutes or less. In this case, the time when the composition first comes into contact with the hard surface may be regarded as the start of the leaving period. The temperature during leaving may be room temperature, for example, 10°C or more and 30°C or less.

Furthermore, in the present invention, hard surfaces can be cleaned using a cleaning article having a base impregnated with the hard surface cleaner composition of the present invention.
As an example, a method for cleaning a hard surface is provided, in which the cleaning composition for hard surfaces of the present invention is applied to the hard surface, left for a predetermined time, and then wiped off. For wiping off, it is preferable to use a cloth, dustcloth, nonwoven fabric, etc. to remove the composition applied to the hard surface from the hard surface.

The substrate used in the cleaning article impregnated with the hard surface cleaning composition is flexible, can be impregnated with the hard surface cleaning composition, has sufficient strength during use, and does not generate debris. It is preferable to use a substrate that can be impregnated with the hard surface cleaning composition in the amount described below under no load.

Such substrates include fiber structures made of fibrous materials, such as various types of paper, nonwoven fabrics, woven fabrics, or knitted fabrics. Examples of the fibrous materials that make up these fiber structures include cellulose-based fibers, modified cellulose-based fibers, synthetic fibers, and mixtures of two or more of these. In addition, porous structures (e.g., sponge-like structures) obtained by dispersing air bubbles in a resin can also be used as the substrate.

The cleaning method of wiping a hard surface with a cleaning article impregnated with the hard surface cleaning composition of the present invention is preferable for light cleaning of hard surfaces from the viewpoint of the workability of the cleaning work. The cleaning article impregnated with the hard surface cleaning composition may be one in which the substrate is impregnated with the cleaning composition in advance, or one in which the dry substrate is impregnated with the hard surface cleaning composition immediately before use. The cleaning article impregnated with the hard surface cleaning composition may be attached to a mop-shaped cleaning tool or may be held directly by hand and used for wiping.

In the present invention, the cleaning composition for hard surfaces of the present invention is brought into contact with a hard surface and left for a predetermined period of time, and then, after further cleaning as necessary, the hard surface is rinsed with water. When rinsing, an external force (physical force) such as hand washing may be applied, or the surface may simply be rinsed with a water stream.

Examples The components used in the examples and comparative examples are shown below.
<Component (a)>
NaF: sodium fluoride, manufactured by Sunlit Fluo & Chemical Co., Ltd. NH ₄ F: ammonium fluoride, manufactured by GIN JOB ENTEPRISECo., Ltd./CHINAG MAU Co., Ltd. NaHF ₂ : sodium hydrogen fluoride, manufactured by GIN JOB ENTEPRISECo., Ltd./CHINAG MAU Co., Ltd. <Component (b)>
・Citric acid: Citric acid, manufactured by SunlitFluo & Chemical Co., Ltd. ・Propanoic acid: Propanoic acid, manufactured by Tokyo Chemical Industry Co., Ltd. ・Lactic acid: Lactic acid, manufactured by Corbion ・Malic acid: Malic acid, manufactured by FusoChemical Co., Ltd. ・Tartanic acid: Tartaric acid, manufactured by Combi-Blocks ・Succinic acid: Succinic acid, manufactured by Tokyo Chemical Industry Co., Ltd.

<Component (c)>
Acusol 445N: Polyacrylic acid sodium salt, weight average molecular weight 4500, component (c1), manufactured by Dow Chemical Company DEMOL N: Naphthalenesulfonic acid formalin condensate sodium salt, weight average molecular weight 5000, component (c2), manufactured by Kao Corporation FK-6H: Diallyldimethylammonium chloride-maleic acid-sulfur dioxide copolymer, weight average molecular weight 23000, component (c1), manufactured by Nittobo Medical Co., Ltd. Sokalan CP88: Acrylic acid-maleic acid copolymer sodium salt, weight average molecular weight 3000, component (c1), manufactured by BASF Co., Ltd. Sokalan CP7: Acrylic acid-maleic acid copolymer sodium salt, weight average molecular weight 50000, component (c1), manufactured by BASF Co., Ltd. Acusol 469N: acrylic acid-maleic acid copolymer, weight average molecular weight 45,000, component (c1), manufactured by Dow Chemical Company; OLIGOMER KDS: sodium salt of acrylic acid-maleic acid copolymer, weight average molecular weight 2,000, component (c1), manufactured by Kao Corporation

<Component (d)>
Amphitol 20AB: lauric acid amidopropyl betaine, component (d3), manufactured by Kao Corporation; AS: ammonium lauryl sulfate, "EMAL AD-25", component (d1), manufactured by Kao Taiwan Co., Ltd.; AES (EO2): polyoxyethylene (2) sodium lauryl ether sulfate (the number in parentheses is the average number of moles of oxyethylene groups added), "EMAL 227HP", component (d1), manufactured by Kao Corporation; LAS: sodium alkylbenzene sulfonate, "NEOPELEX S-N", component (d1), manufactured by Kao Taiwan Co., Ltd.; AEO (EO10): polyoxyethylene adduct of natural alcohol (the average number of moles of oxyethylene groups added is 10 moles), "Pannox 710", component (d2), manufactured by PAN ASIA CHEMICAL Co., Ltd.; Amphitol 20HD: Lauryl hydroxysulfobetaine, component (d3), manufactured by Kao Corporation (component (e))
BDG: Diethylene glycol monobutyl ether, manufactured by BASF Co., Ltd.

[Preparation of cleaning composition for hard surfaces]
Using the components shown in Tables 1 to 5, hard surface cleaning compositions having the compositions shown in Tables 1 to 5 were prepared by the method described below. To obtain the hard surface cleaning compositions shown in Tables 1 to 5, first, components (a) to (e) were added to ion-exchanged water in the amounts shown in Tables 1 to 5, and dissolved at room temperature (25° C.). After blending, hydrochloric acid and/or sodium hydroxide were added as a pH adjuster to adjust the pH to the value shown in Tables 1 to 5. The pH was measured by a glass electrode method.
The contents of the various components in Tables 1 to 5 are all effective amounts. The contents of component (a) are also shown in the tables in terms of fluorine atoms.

[Hydrogen fluoride concentration in hard surface cleaning composition]
The hydrogen fluoride concentration [HF] in each hard surface cleaning composition was calculated using the following formula 1. The results are shown in Tables 1 to 5.
7.08×10 ⁻⁴ = [F ⁻ ][H ⁺ ]/[HF] (Formula 1)
[F- ^] : the content (mM) of ionized fluorine in the component (a) contained in the hard surface cleaning composition
[H ⁺ ]: hydrogen ion concentration (mM) calculated from the pH of the hard surface cleaning composition at 25° C.
7.08×10 ⁻⁴ : The acid ionization constant [HF] of hydrogen fluoride at 25° C. is calculated by the following procedure when, for example, component (a) is sodium fluoride.
1. If the total amount of sodium fluoride blended in the hard surface cleaning composition is C mM, then C = [F ^- ] + [HF]
2. Introducing C=[F ^- ]+[HF] into (Equation 1), 7.08 x ^10-4 =[F ^- ][H ⁺ ]/[HF]=(C-[HF])[H ⁺ ]/[HF]
3. When [HF] is rearranged, [HF] = C / (7.08 × 10 ^-4 / [H ⁺ ] + 1)
4. Substitute the values of C and [H ⁺ ] to calculate [HF].

[Evaluation of water stain cleaning ability]
Preparation of Glass Plate Adhering Water Scale Stain for Evaluation A glass plate adhering water scale stain for evaluation was prepared by the following procedure.
1. 1000 ml of tap water from Hsinchu City, Taiwan was placed in a beaker and concentrated to a volume of 250 ml while heating it with a panel heater, and then cooled at room temperature.
2. 0.5 ml of the solution prepared in 1 was dropped onto a 2 x 10 cm soda lime glass plate (microscope slide CAT. NO. 7101, SAIL BRAND), and then the water was evaporated while being heated with a heater.
3. Step 2 was repeated 8 times, and then the plate was left for 3 days to prepare a glass plate with water stains.

Method for Evaluating Water Scale Cleaning Ability The water scale cleaning ability was evaluated according to the following procedure.
1. First, a cellulose fiber (2.5 x 2.0 cm, product name: Laune Facial Puff, KNH Enterprise Co., LTD.) was placed on a glass plate with water stains to prevent dripping, and 200 μl of each of the hard surface cleaning compositions shown in Tables 1 to 5 was dropped onto the cellulose fiber.
After leaving it for a few minutes, the cellulose fibers were removed.
3. Next, as a scrubbing step, a paper towel with a 250 g weight placed on it was passed back and forth across the surface three times.
4. The glass plate before the stains were attached and the glass plate with the stains attached before and after cleaning were scanned with a printer (IMC2500, Ricoh Co., Ltd.), the gray value was measured, and the cleaning rate of the stains was calculated from the following formula using the image processing software "Image J". The results are shown in Tables 1 to 5.
Cleaning power (%) = (Ga-Gb)/(G-Gb) x 100
Gb: Average gray value of glass plate with water stains before cleaning Ga: Average gray value of glass plate with water stains after cleaning G: Average gray value of glass plate before water stains

[Corrosion test]
The same cellulose fiber (2.5×2.0 cm, product name: Laune Facial Puff, KNH Enterprise Co., Ltd.) as above was placed on an evaluation plate made of a soda lime glass plate (microscope slide CAT. NO. 7101, SAIL BRAND) and an aluminum alloy plate (supplied by a hardware store in Taiwan), and 500 μl of each of the hard surface cleaning compositions shown in Tables 1 to 5 was dropped thereon. After waiting for 24 hours, the surface of the evaluation plate was visually observed and evaluated according to the following criteria. The results are shown in Tables 1 to 5.
For the evaluation criteria other than evaluation criterion 1, the evaluation result of the composition in Example 1 was assigned an evaluation criterion of 4, the evaluation result of the composition in Comparative Example 2 was assigned an evaluation criterion of 2, and the results were visually judged on a 5-point scale between the evaluation criterion.
(Evaluation Criteria)
4: No change on the surface of the evaluation plate.
3 to 4: The surface of the evaluation plate is slightly faded.
3: The surface of the evaluation plate is slightly faded.
2 to 3: The surface of the evaluation plate is slightly faded.
2: The surface of the evaluation plate is faded.
1: The surface of the evaluation board is uneven.

Claims (13)

A cleaning composition for hard surfaces, comprising (a) a fluoride (hereinafter referred to as component (a)), and (b) an organic acid or a salt thereof (hereinafter referred to as component (b)), the content of component (a) being 4 mM or more and 240 mM or less in terms of fluorine atoms, the pH at 25°C being 4.0 or more and 6.5 or less, and the hydrogen fluoride concentration [HF] in the cleaning composition for hard surfaces, calculated by the following (Equation 1), being 0.25 mM or more and 0.9 mM or less.
7.08×10 ⁻⁴ = [F ⁻ ][H ⁺ ]/[HF] (Formula 1)
[F- ^] : the content (mM) of ionized fluorine in the component (a) contained in the hard surface cleaning composition
[H ⁺ ]: hydrogen ion concentration (mM) calculated from the pH of the hard surface cleaning composition at 25° C.
7.08×10 ⁻⁴ : Acid ionization constant of hydrogen fluoride at 25°C The cleaning composition for hard surfaces according to claim 1, wherein component (a) is one or more selected from hydrogen fluoride, sodium fluoride, potassium fluoride, lithium fluoride, ammonium fluoride, sodium hydrogen fluoride, and ammonium hydrogen fluoride. The cleaning composition for hard surfaces according to claim 1 or 2, wherein component (b) is an organic acid having a carboxy group. The cleaning composition for hard surfaces according to any one of claims 1 to 3, wherein component (b) is one or more selected from citric acid, propanoic acid, lactic acid, malic acid, tartaric acid, and succinic acid. The cleaning composition for hard surfaces according to any one of claims 1 to 4, wherein the content of component (b) is 1% by mass or more and 15% by mass or less. The cleaning composition for hard surfaces according to any one of claims 1 to 5 further contains, as component (c), one or more polymers selected from (c1) a carboxylic acid-based polymer containing a structural unit having a carboxyl group or a salt thereof (hereinafter referred to as component (c1)), and (c2) a sulfonic acid-based polymer containing a structural unit having a sulfonic acid group or a salt thereof (hereinafter referred to as component (c2)). The cleaning composition for hard surfaces according to claim 6, wherein component (c) is component (c1). The cleaning composition for hard surfaces according to claim 6 or 7, wherein the content of component (c) is 0.1% by mass or more and 10% by mass or less. The cleaning composition for hard surfaces according to any one of claims 1 to 8 further contains a surfactant as component (d). The cleaning composition for hard surfaces according to claim 9, wherein component (d) is at least one selected from anionic surfactants, nonionic surfactants, and amphoteric surfactants. A method for cleaning a hard surface, comprising contacting the hard surface with the cleaning composition for hard surfaces described in any one of claims 1 to 10 for a predetermined period of time, and then rinsing the hard surface with water. The method for cleaning hard surfaces according to claim 11, wherein the predetermined time is 1 minute or more. The method for cleaning a hard surface according to claim 11 or 12, wherein the hard surface is a hard surface having water stains.