Acidic cleaning agent composition for CIP and CIP cleaning method

Abstract

The objective is to provide an acidic CIP cleaning agent composition and a CIP cleaning method using the same, which suppresses equipment blockage during CIP cleaning and exhibits good cleaning performance while suppressing the generation of chlorine gas even when a chlorine-based cleaning agent is used as an alkaline cleaning agent. [Solution] The present invention provides an acidic CIP cleaning agent composition comprising (A) one or more polycarboxylic acid type chelating agents selected from the group consisting of aminocarboxylic acid type chelating agents and hydroxycarboxylic acid type chelating agents, (B) one or more alkaline agents selected from the group consisting of sodium hydroxide, potassium hydroxide, monoethanolamine, diethanolamine, triethanolamine, and monoisopropanolamine, and (C) water, with a pH of 3.5 or higher and 6.0 or lower at 25°C, and a CIP cleaning method using the same.

Description

Technical Field

[0001] The present invention relates to a cleaning agent composition for acidic CIP and a CIP cleaning method using the composition.

Background Art

[0002] In recent years, in beverage factories, food factories, etc., due to the increase in the size of manufacturing equipment and the diversification of products, the cleaning frequency has increased, making it difficult to disassemble and clean the manufacturing equipment. Therefore, instead of disassembling and cleaning, a CIP cleaning (Cleaning in place) method is widely adopted, in which the inside of manufacturing equipment such as pipes, sterilizers, and filling machines is filled with a cleaning liquid and circulated, or the cleaning liquid is sprayed onto the manufacturing equipment to wash and remove residual dirt.

[0003] For this CIP cleaning, one or more cleaning agents selected from an alkaline cleaning agent, an acid cleaning agent, a bactericide, etc. are used. For example, generally, CIP cleaning is performed in the steps of 1. water washing, 2. alkaline washing, 3. water rinsing, 4. acid washing, 5. water rinsing, 6. sterilization, 7. water rinsing. However, depending on the compounding components of each cleaning agent, or the type and state of the dirt, some of the above steps may be omitted, the order of the above steps may be changed, or the same step may be repeatedly performed. Also, when the target dirt is mainly food residue, the food residue contains organic dirt such as protein, oil and fat, and carbohydrates, as well as inorganic dirt such as calcium carbonate, calcium phosphate, and calcium silicate. Among the above organic dirt, there are also strongly heat-denatured ones found in sterilizers and the like.

[0004] Several methods have been proposed to further improve the efficiency of CIP while removing the complex contaminants described above. In particular, the contaminants on equipment after dairy product manufacturing contain a large amount of inorganic substances, and for such contaminants, the override method (water washing → acid washing → alkaline washing → water rinsing), which involves performing alkaline washing without a rinsing step after acid washing, is effective. In recent years, distinctive override methods have also been proposed for contaminants that are difficult to remove with conventional CIP. For example, there are methods that use a solution containing hydrogen peroxide as the first wash and perform alkaline washing as the second wash (Patent Documents 1 and 2), and methods that use a solution containing carbonate as the first wash and perform acid washing as the second wash (Patent Document 3). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Special Publication No. 2009-513339 [Patent Document 2] Special Publication No. 2011-511864 [Patent Document 3] Special Publication No. 2011-514834 [Overview of the project] [Problems that the invention aims to solve]

[0006] The cleaning method described above is highly effective in removing dirt from the object being cleaned, but there is a risk that the removed dirt may clog equipment such as strainers. Furthermore, while chlorine-based alkaline cleaning is effective in dissolving organic dirt, the override method cannot be used due to the generation of chlorine gas. In this case, one method is to perform thorough rinsing after the acid cleaning process or to make the acid cleaning solution alkaline by adding a chlorine-free alkaline cleaning agent, and then add a chlorine-based cleaning agent for cleaning. However, this requires a large amount of water for rinsing, and there is a risk that the equipment may clog due to the removed dirt during the neutralization process of the acid cleaning solution. In addition, it involves the cumbersome process of checking the pH when adding the alkaline cleaning agent and then adding the chlorine-based cleaning agent after checking the pH. [Means for solving the problem]

[0007] To solve the above problems, the present inventors conducted diligent studies and found that when a composition containing (A) one or more polycarboxylic acids selected from the group consisting of aminocarboxylic acid-type chelating agents and hydroxycarboxylic acid-type chelating agents, (B) one or more alkaline agents selected from the group consisting of sodium hydroxide, potassium hydroxide, monoethanolamine, diethanolamine, triethanolamine, and monoisopropanolamine, and (C) water, with a pH of 3.5 or higher and 6.0 or lower at 25°C, is used in the acid washing step in the override method, it exhibits good cleaning performance while suppressing the generation of chlorine gas even when a chlorine-based cleaning agent is used as the alkaline cleaning agent, thus completing the present invention.

[0008] In other words, the present invention is (1) As component (A), one or more polycarboxylic acid type chelating agents selected from the group consisting of aminocarboxylic acid type chelating agents and hydroxycarboxylic acid type chelating agents, (B) Component: One or more alkaline agents selected from the group consisting of sodium hydroxide, potassium hydroxide, monoethanolamine, diethanolamine, triethanolamine, and monoisopropanolamine; (C) Component: A cleaning agent composition for acidic CIP containing water and having a pH of 3.5 or higher and 6.0 or lower at 25°C. (2) The acidic CIP cleaning agent composition of (1), comprising as component (A), one or more polycarboxylic acid type chelating agents selected from the group consisting of ethylenediaminetetraacetic acid, diethylenetriaminopentaacetic acid, 1,3-propanediaminetetraacetic acid, nitrilotriacetic acid, glutamic acid diacetic acid, methylglycine diacetic acid, hydroxyethylethylenediaminetriacetic acid, and hydroxyethyliminodiacetic acid. (3) The alkaline agent of component (B) is monoethanolamine, the acidic cleaning agent composition of (1), (4) The acidic CIP cleaning agent composition of (1) wherein the value of (A) / (B) is 1 or more and 5 or less. (5) An acidic CIP cleaning method comprising an acidic cleaning step using an acidic cleaning solution prepared by adjusting the acidic CIP cleaning agent composition of (1) above with water so that the concentration of component (A) is 0.001% by mass or more and 10% by mass or less. (6) A CIP cleaning method comprising: an acid cleaning step using an acid cleaning solution prepared by adjusting the acidic CIP cleaning agent composition of (1) above with water so that the concentration of component (A) is 0.001% by mass or more and 10% by mass or less; and an alkaline cleaning step using a chlorine-based alkaline cleaning agent, wherein the alkaline cleaning step is performed after the acid cleaning solution has been discharged and without rinsing with water. (7) A CIP cleaning method comprising: an acid cleaning step using an acidic cleaning solution prepared by adjusting the acidic CIP cleaning agent composition of (1) above with water to a concentration of component (A) of 0.001% by mass or more and 10% by mass or less; and an alkaline cleaning step using a chlorine-based alkaline cleaning solution, wherein the alkaline cleaning step is performed immediately following the acid cleaning step without discharging the acidic cleaning solution or rinsing with water. This is the gist of it. [Effects of the Invention]

[0009] The acidic CIP cleaning agent composition and the CIP cleaning method using the same of the present invention can be used in override methods using chlorine-based alkaline cleaning agents because they can suppress the generation of chlorine gas. Furthermore, by using the acidic CIP cleaning agent composition and chlorinated alkaline cleaning agent of the present invention, it is possible to remove mixed inorganic and organic contaminants without clogging the equipment with detached dirt, and it is possible to reduce the amount of rinse water used and shorten the cleaning time. [Modes for carrying out the invention]

[0010] The present invention is characterized by containing (A) one or more polycarboxylic acid type chelating agents selected from the group consisting of aminocarboxylic acid type chelating agents and hydroxycarboxylic acid type chelating agents, (B) one or more alkaline agents selected from the group consisting of sodium hydroxide, potassium hydroxide, monoethanolamine, diethanolamine, triethanolamine and monoisopropanolamine, and (C) water, with a pH of 3.5 or higher and 6.0 or lower at 25°C.

[0011] The acidic CIP cleaning agent composition of the present invention will be described in more detail below. In the following description, preferred numerical ranges of the present invention may be indicated as appropriate. In this case, preferred ranges, more preferred ranges, and particularly preferred ranges regarding the upper and lower limits of the numerical range can be determined from all combinations of the upper and lower limits.

[0012] (A) component The polycarboxylic acid chelating agent used in the present invention is selected from the group consisting of aminocarboxylic acid type chelating agents and hydroxycarboxylic acid type chelating agents. Examples of aminocarboxylic acid type chelating agents include ethylenediaminetetraacetic acid, nitrilotriacetic acid, diethylenetriaminopentaacetic acid, triethylenetetraaminehexaacetic acid, 1,3-propanediaminetetraacetic acid, glycol etherdiaminetetraacetic acid, (S,S)-ethylenediamine disuccinic acid, 1,2-cyclohexadiaminetetraacetic acid, glutamic acid diacetic acid, methylglycine diacetic acid, and the like. Examples of hydroxycarboxylic acid type chelating agents include hydroxyethylethylenediaminetriacetic acid, hydroxyiminodiacetic acid, 1,3-diamino-2-hydroxypropanetetraacetic acid, citric acid, and the like. Among these, from the viewpoint of scale cleaning ability, ethylenediaminetetraacetic acid, diethylenetriaminopentaacetic acid, 1,3-propanediaminetetraacetic acid, nitrilotriacetic acid, glutamic acid diacetic acid, methylglycine diacetic acid, hydroxyethylethylenediaminetriacetic acid, and hydroxyethyliminodiacetic acid are preferred, ethylenediaminetetraacetic acid, diethylenetriaminopentaacetic acid, 1,3-propanediaminetetraacetic acid, nitrilotriacetic acid, glutamic acid diacetic acid, and methylglycine diacetic acid are more preferred, and ethylenediaminetetraacetic acid is even more preferred. These polycarboxylic acids may be used individually or in combination of two or more types.

[0013] The content of component (A) used in the present invention in the acidic CIP cleaning agent composition is not particularly limited, but from the viewpoint of scale cleaning performance and storage stability, it is preferably 3% by mass or more and 30% by mass or less, more preferably 5% by mass or more and 25% by mass or less, even more preferably 7% by mass or more and 20% by mass or less, and even more preferably 7% by mass or more and 17% by mass or less. By having component (A) at 3% by mass or more, scale cleaning performance can be more reliably obtained, and by having it at 30% by mass or less, a decrease in storage stability can be more reliably prevented.

[0014] (B) Component Examples of alkali agents used in the present invention include alkali metal hydroxides and alkanolamines. Examples of alkali metal hydroxides include sodium hydroxide and potassium hydroxide. Examples of alkanolamines include monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, N-methylethanolamine, and N-methyldiethanolamine. In particular, from the viewpoint of scale cleaning ability, sodium hydroxide, potassium hydroxide, monoethanolamine, diethanolamine, triethanolamine, and monoisopropanolamine are preferred, monoethanolamine, diethanolamine, triethanolamine, and monoisopropanolamine are more preferred, and monoethanolamine is even more preferred. These alkaline agents may be used individually or in combination of two or more types.

[0015] The content of component (B) used in the present invention in the acidic CIP cleaning agent composition is not particularly limited, but from the viewpoint of scale cleaning performance and storage stability, it is preferably 1.2% by mass or more and 15% by mass or less, more preferably 2% by mass or more and 12.5% ​​by mass or less, and even more preferably 2.8% by mass or more and 8.5% by mass or less, relative to the acidic CIP cleaning agent composition of the present invention. By having component (B) at 1.2% by mass or more, scale cleaning performance can be more reliably obtained, and by having it at 15% by mass or less, a decrease in storage stability can be more reliably prevented.

[0016] In this invention, component (A) may be in the form of a salt, and examples include alkali metal salts such as sodium salts and potassium salts, and alkanolamines such as monoethanolamine and triethanolamine. When using the salt form of component (A), the present invention also includes cases in which the pH has been adjusted to a predetermined level with a pH adjusting agent such as an inorganic acid or an organic acid. Examples of inorganic acids include sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid. Examples of organic acids include acetic acid and succinic acid.

[0017] In the acidic CIP cleaning agent composition of the present invention, the value of the mass ratio (A) / (B) of the mass of component (A) to the mass of component (B) is not particularly limited, but for example, it can be 1 or more and 5 or less. It is preferable that this value is 1 or more and 5 or less, more preferably 1.5 or more and 4 or less, still more preferably 2 or more and 3 or less, even more preferably 2.0 or more and 2.7 or less, and most preferably 2.0 or more and 2.5 or less. By including this value within the above range, the generation of chlorine gas can be suppressed, and good scale cleaning performance and storage stability can be more surely and sufficiently achieved simultaneously.

[0018] (Component (C)) The sterilizing cleaning agent composition of the present invention contains water as component (C). As the water, tap water, softened water, pure water, RO water, ion-exchanged water, distilled water can be used. Examples of tap water include the tap water in Arakawa-ku, Tokyo (pH = 7.6, total alkalinity (in terms of calcium carbonate) 40.5 mg / L, German hardness 2.3 °DH (among which, calcium hardness 1.7 °DH, magnesium hardness 0.6 °DH), chloride ion 21.9 mg / L, sodium and its compounds 15 mg / L, nitrate nitrogen and nitrite nitrogen 1.2 mg / L, fluorine and its compounds 0.1 mg / L, boron and its compounds 0.04 mg / L, total trihalomethane 0.016 mg / L, residual chlorine 0.4 mg / L, organic matter (total organic carbon content) 0.7 mg / L). The water of component (C) of the present invention is the remainder with respect to the total amount of the above components (A) and (B), or the remainder with respect to the total amount of components (A), (B), and other optional components.

[0019] The pH of the acidic CIP cleaning agent composition of the present invention is 3.5 or more and 6.0 or less at 25 °C. It is preferable that the pH is 3.8 or more and less than 6.0, and more preferably 4.0 or more and 5.8 or less. By including this value within the above range, chlorine gas can be suppressed, and good scale cleaning performance and storage stability can be more surely and sufficiently obtained.

[0020] The acidic CIP cleaning agent composition of the present invention may further contain an aromatic sulfonic acid compound as component (D) if necessary. Component (D) includes, for example, methoxybenzenesulfonic acid, methoxybenzene disulfonic acid, dimethoxybenzenesulfonic acid, dimethoxybenzenesulfonic acid, ethoxybenzenesulfonic acid, ethoxybenzenesulfonic acid, diethoxybenzenesulfonic acid, diethoxybenzenesulfonic acid, propoxybenzenesulfonic acid, propoxybenzenesulfonic acid, butoxybenzenesulfonic acid, butoxybenzenesulfonic acid, methylmethoxybenzenesulfonic acid, methylmethoxybenzenesulfonic acid, methylmethoxybenzenesulfonic acid, methoxynaphthalenesulfonic acid, methoxynaphthalenesulfonic acid, dimethoxynaphthalenesulfonic acid, dimethoxynaphthalenesulfonic acid, methylmethoxynaphthalenesulfonic acid, methylmethoxynaphthalenesulfonic acid, ethoxynaphthalenesulfonic acid, ethoxynaphthalenesulfonic acid, ethoxynaphthalenesulfonic acid, toluenesulfonic acid, cumenesulfonic acid, xylenesulfonic acid, substituted or unsubstituted naphthalenesulfonic acid, and their sodium, potassium, lithium, and calcium salts. Toluene sulfonic acid, cumene sulfonic acid, and xylene sulfonic acid may each be in any of the three isomers: o-isomer, m-isomer, or p-isomer. These may be used individually or in combination of two or more. Among these, methoxybenzene sulfonic acid or its salt, cumene sulfonic acid or its salt, m-xylene sulfonic acid or its salt, and p-toluene sulfonic acid or its salt are preferred.

[0021] The high-concentration neutral liquid detergent composition of the present invention may optionally contain pH adjusters other than component (B), preservatives, food colorings, fragrances, metal corrosion inhibitors, natural extracts, etc.

[0022] Examples of pH adjusters other than component (B) include sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, glycolic acid, lactic acid, malic acid, gluconic acid, tartaric acid, oxalic acid, malonic acid, succinic acid, acetic acid, isethionic acid, adipic acid, etc.

[0023] Examples of preservatives include thiazolines, hydantoins, iodo-2-propynylbutylcarbamate, isopropylmethylphenol, hexachlorophene, irgasan, and triclosan. Examples of thiazolines include 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, isothiazolin-3-one, 1,2-benzisothiazolin-3-one, and Nn-butylbenzisothiazolin-3-one. Examples of hydantoins include 1,3-dimethylol-5,5-dimethylhydantoin, 1 or 3-monomethylol-5,5-dimethylhydantoin, dimethylhydantoin, 1,3-dichloro-5,5-dimethylhydantoin, and 1,3-dichloroethylmethylhydantoin. These may be used individually or in combination of two or more.

[0024] Examples of food colorings include Red No. 2 (amaranth), Red No. 3 (erythrosine), Red No. 40 (allura red AC), Red No. 102 (new coccine), Red No. 104 (phloxine), Red No. 105 (rose bengal), Red No. 106 (acid red), Yellow No. 4 (tartrazine), Yellow No. 5 (sunset yellow FCF), Blue No. 1 (brilliant blue FCF), and Blue No. 2 (indigo carmine).

[0025] Examples of metal corrosion inhibitors include polycarboxylic acids such as short-chain dicarboxylic acids or tricarboxylic acids, phosphate esters, triazoles such as benzotriazole, toltriazole, or mercaptobenzothiazole, phosphonic acids such as 1-hydroxyethylidene-1,1-diphosphonic acid, adipic acid, glutaric acid, or succinic acid.

[0026] Examples of natural extracts include plant-derived natural extracts from plants such as Cannabaceae, Rubiaceae, Brassicaceae, Poaceae, Ebenaceae, Asteraceae, Lamiaceae, Zingiberaceae, Camellia, Solanaceae, Cupressaceae, Myrtaceae, Vitaceae, Fabaceae, Rutaceae, and Liliaceae, as well as animal-derived natural extracts such as lysozyme and leucoma protein extract.

[0027] It is not necessary to use polymer dispersions such as polyacrylic acid, polymethacrylic acid, polymaleic acid, polyitaconic acid, acrylic acid-methacrylic acid copolymers, and acrylic acid-maleic acid copolymers, or organic phosphonic acids such as 1-hydroxyethylidene-1,1-diphosphonic acid and 2-phosphonobutane-1,2,4-tricarboxylic acid, or cationic surfactants, anionic surfactants, and nonionic surfactants. This is because, even without using such components, chlorine generation can be suppressed in the override method using chlorine-based alkaline cleaning agents, and excellent cleaning effects can be obtained.

[0028] The acidic CIP cleaning agent composition of the present invention can be used on any hard surface such as glass, plastic, and metal. Specific cleaning locations include kitchens, commercial kitchens, cooking utensils, bathrooms, and factory equipment. Among these, use by CIP (clean-in-place cleaning) on ​​factory equipment is preferred. When using the acidic CIP cleaning agent composition of the present invention, it can be adjusted (diluted) with water to any desired concentration according to the intended use. Preferably, the acidic CIP cleaning agent composition is 0.01% by mass or more and 50% by mass or less, more preferably 0.03% by mass or more and 30% by mass or less, still preferably 0.1% by mass or more and 10% by mass or less, and most preferably 0.5% by mass or more and 5% by mass or less. The water temperature at this time is not particularly limited, but it is preferably above room temperature and below 80°C. When using heated water (hot water), the temperature is preferably between 60°C and 80°C.

[0029] CIP typically involves a combination of steps such as rinsing with water, alkaline cleaning, acid cleaning, and sterilization to clean the object to be cleaned. The acidic CIP cleaning agent composition of the present invention is used in the acid cleaning step of CIP. The CIP cleaning method of the present invention is used by adjusting (diluting) the concentration of component (A) of the acidic CIP cleaning agent composition to 0.001% by mass or more and 10% by mass or less, preferably 0.01% by mass or more and 5.5% by mass or less, more preferably 0.02% by mass or more and 3% by mass or less, and even more preferably 0.03% by mass or more and 1.5% by mass or less, depending on the type of equipment to be cleaned and the degree of soiling. Water is used to adjust the concentration, and it is preferable to use an aqueous solution adjusted to a temperature of preferably above room temperature and below 80°C, more preferably above 60°C and below 80°C, for use in the acid cleaning step. The water used for adjusting the concentration (dilution) can be the same as the water used for component (C).

[0030] The first CIP cleaning method of the present invention includes 1) an acidic cleaning step using an acidic cleaning solution adjusted (diluted) so that the concentration of component (A) of the acidic CIP cleaning agent composition is 0.001 to 10% by mass, and 2) an alkaline cleaning step using a chlorine-based alkaline cleaning agent without discharging the acidic cleaning solution and rinsing. Depending on the quality and amount of dirt, the 1) acidic cleaning step and the 2) alkaline cleaning step are usually performed for 10 minutes or more and 60 minutes or less, preferably 20 minutes or more and 40 minutes or less.

[0031] Furthermore, the second CIP cleaning method of the present invention includes 1) an acid cleaning step using an acidic cleaning solution adjusted (diluted) so that the concentration of component (A) of the acidic CIP cleaning agent composition is 0.001% by mass or more and 10% by mass or less, preferably 0.01% by mass or more and 5.5% by mass or less, more preferably 0.02% by mass or more and 3% by mass or less, and even more preferably 0.03% by mass or more and 1.5% by mass or less, and 2) an alkaline cleaning step using a chlorine-based alkaline cleaning solution without discharging the acidic cleaning solution and rinsing with water. In this second CIP cleaning method, it is preferable that the 2) alkaline cleaning step is carried out by adding a chlorine-based alkaline cleaning agent to the acid cleaning solution used in the 1) acid cleaning step. Similar to the first CIP cleaning method of the present invention described above, the 1) acid cleaning step and the 2) alkaline cleaning step are usually carried out for 10 minutes or more and 60 minutes or less, preferably 20 minutes or more and 40 minutes or less, depending on the quality and amount of dirt.

[0032] In the CIP cleaning method of the present invention, the rinsing step between 1) the acid cleaning step and 2) the alkaline cleaning step can be omitted. Generally, if a rinsing step with water is performed between the acid cleaning step and the alkaline cleaning step, it requires water usage, heat energy, and rinsing time. In conventional methods, adding a chlorine-based oxidizing agent to an acidic solution generates chlorine gas, which is dangerous. However, in the cleaning method of the present invention, even if a chlorine-based alkaline cleaning agent is added directly to the acidic cleaning solution and the alkaline cleaning step is performed without 1) draining the acidic cleaning solution or rinsing with water after the acidic cleaning step, no chlorine gas is generated.

[0033] Furthermore, in the CIP cleaning method of the present invention, after the 2) alkaline cleaning step, rinsing with water may be performed, and then, if necessary, various treatments such as sterilization, sodium hypochlorite treatment, peracetic acid treatment, iodine treatment, and hot water treatment may be performed.

[0034] In the CIP cleaning method of the present invention described above, the chlorine-based alkaline cleaning agent used in step 2) alkaline cleaning step is a powdered chlorine-based alkaline cleaning agent or a liquid chlorine-based alkaline cleaning agent containing an alkali and a chlorine-based oxidizing agent. Commercially available powdered chlorine-based alkaline cleaning agents contain approximately 50% by mass or more of an alkaline agent such as sodium hydroxide or potassium hydroxide, and approximately 1 to 15% by mass of a chlorine-based oxidizing agent such as dichloroisocyanurate as an effective chlorine concentration, further blended with carbonates, silicates, condensed phosphates, nonionic surfactants, polymer dispersants, etc. Commercially available liquid chlorine-based alkaline cleaning agents contain approximately 15% by mass or less of an alkali such as potassium hydroxide or sodium hydroxide, and approximately 1 to 15% by mass of a chlorine-based oxidizing agent such as sodium hypochlorite or potassium hypochlorite as an effective chlorine concentration, further blended with silicates, polymer dispersants, etc.

[0035] In the CIP cleaning method of the present invention described above, in step 2) alkaline cleaning, the commercially available chlorine-based oxidizing agent described above is preferably used as a diluted cleaning solution, which is usually diluted to an effective chlorine concentration of about 0.01 to 0.2% by mass. [Examples]

[0036] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. The components of the acidic CIP cleaning agent compositions used in the acidic CIP cleaning agent compositions of the examples and comparative examples are shown in Tables 1 to 6 below. The numerical values ​​for the amounts of each component shown in Tables 1 to 6 below represent the percentage (mass) of the pure content of each component relative to the acidic CIP cleaning agent composition, and "residue" indicating the water content represents the amount of each component adjusted so that the total amount of the final prepared acidic CIP cleaning agent composition is 100% by mass. The acidic CIP cleaning agent compositions were used to perform the measurements and evaluations described later. The measurement results and evaluation results are also shown in Tables 1 to 6 below.

[0037] (A) component A-1: Ethylenediaminetetraacetic acid A-2: Diethylenetriaminopentaacetic acid A-3: 1,3-propanediaminetetraacetic acid A-4: Nitrilotriacetic acid A-5: Hydroxyethylethylenediaminetriacetic acid A-6: Hydroxyethyliminodiacetic acid

[0038] (B) Component B-1: Sodium hydroxide B-2: Potassium hydroxide B-3: Monoethanolamine B-4: Monoisopropanolamine B-5: Diethanolamine B-6: Triethanolamine

[0039] (C) Component C-1: Ion-exchanged water

[0040] D-1: Sodium methoxybenzenesulfonate D-2: Sodium m-xylenesulfonate

[0041] The compositions of each example were prepared by adding water (component C) to a mixing tank so that the total composition amounted to 100% by mass, then adding components (A), (B), (C), and optionally (D) to the mixing tank, and thoroughly mixing and stirring.

[0042] Examples 1-44, Comparative Examples 1-3 Acidic cleaning agent compositions for CIP (Clean-in-Place) treatment were prepared as shown in Tables 1-6. Each acidic cleaning agent composition was used to measure its cleaning performance, chlorine gas generation prevention, scale removal performance, precipitate formation prevention during the alkaline cleaning process, storage stability, rubber gasket compatibility, and metal corrosion prevention. Tables 1-5 show the results for Examples 1-44, and Table 6 shows the results for Comparative Examples 1-3.

[0043] *1: pH measurement method A pH measuring composite electrode (Standard ToupH electrode 9615S-10D, manufactured by Horiba, Ltd.) was connected to a pH meter (pH / ion meter F-72, manufactured by Horiba, Ltd.), and the power was turned on. A saturated potassium chloride aqueous solution (3.33 mol / L) was used as the internal solution for the pH electrode. Next, 100 mL beakers were filled with pH 4.01 standard solution (phthalate standard solution), pH 6.86 (neutral phosphate standard solution), and pH 9.18 standard solution (borate standard solution), and the beakers were immersed in a 25°C constant temperature bath for 30 minutes. The pH measuring electrode was immersed in the standard solutions adjusted to constant temperature for 3 minutes, and calibration was performed in the order of pH 6.86 → pH 9.18 → pH 4.01. Each disinfectant composition was filled into a 100 mL beaker and adjusted to 25°C in a constant temperature bath. A pH measuring electrode was immersed in the temperature-adjusted sample for 3 minutes to measure the pH of the composition.

[0044] *2: Chlorine gas generation prevention test Using the apparatus described in the chlorine gas generation test (acidic type) for "quadrivalent synthetic detergents, laundry or kitchen soaps, and cleaning agents for homes or furniture" under the Household Goods Quality Labeling Act's Quality Labeling Regulations for Miscellaneous Industrial Products, 3 mL of acidic CIP cleaning agent composition was placed in a 10 mL beaker at the bottom of a 20 L synthetic resin container of the apparatus. 3 mL of 5% sodium hypochlorite aqueous solution was added to this, the container was immediately covered, and stirred with a magnetic stirrer. Air was also blown downwards using the apparatus's fan (approximately 2500 rpm at 50 Hz). After 5 minutes, 100 mL of gas was drawn from the container using a gas sampler equipped with a chlorine gas detection tube, and the chlorine gas concentration was measured according to the following formula (1).

[0045] [Calculation formula] Chlorine gas concentration (ppm) = Measured chlorine gas concentration (ppm) / 3 × Capacity of synthetic resin container (L) / 20

[0046] <Evaluation Criteria> ○: Chlorine gas concentration is less than 0.5 ppm. △: Chlorine gas concentration is 0.5 ppm or higher, but less than 1 ppm. ×: Chlorine gas concentration is 1 ppm or higher. Items with a △ or ○ rating were judged to be practical.

[0047] *3: Scale removal test A SUS304 stainless steel panel (2cm x 7cm) was coated with calcium phosphate to a dry weight of approximately 50mg and dried at 100°C for 1 hour to prepare a test panel. The weight of the stainless steel piece before applying calcium phosphate (W1) and the weight of the stainless steel piece after applying the model stain (W2) were measured. 100mL of a 3% by mass aqueous solution of the acidic CIP cleaning agent composition was prepared in a 200mL beaker, and the test piece was immersed therein for 20 minutes. The scale cleaning performance was evaluated according to the following criteria. After that, the sample was rinsed with deionized water for 15 seconds, air-dried, and the weight of the sample (W3) was measured. The cleaning rate of calcium phosphate was calculated from the weight change of the test piece before and after cleaning using the following formula (1), and evaluated according to the following evaluation criteria. Cleaning rate (%) = [(W2-W1)-(W3-W1)]÷(W2-W1)×100(1)

[0048] <Evaluation Criteria> ◎: Cleaning rate of 80% or more ○: Cleaning rate 60% or more, less than 80% △: Cleaning rate 40% or more, less than 60% ×: Cleaning rate less than 40% In the evaluation described above, △, ○, and ◎ were judged to be practical.

[0049] *4: Storage stability test Each tested acidic CIP cleaning agent composition was placed in a transparent polypropylene container at a rate of 100g and stored in constant temperature baths set to -5°C, 25°C, and 40°C. After one month, the appearance was observed and evaluated according to the following criteria.

[0050] <Evaluation Criteria> ○: No precipitates or turbidity are observed, indicating stability. △: Some precipitates and turbidity are visible. ×: Precipitates or turbidity become prominent, and separation is observed. Items with a △ or ○ rating were judged to be practical.

[0051] *5: Rubber gasket suitability test 50 mL of a 10% by mass aqueous solution of each tested acidic CIP cleaning agent composition was placed in a 100 mL polyethylene container with a cap. An EPDM rubber panel (manufactured by Irumagawa Rubber Co., Ltd., length x width x thickness = 50 mm x 25 mm x 2 mm (volume 2500 cubic millimeters)) and an NBR rubber panel (manufactured by Irumagawa Rubber Co., Ltd., length x width x thickness = 50 mm x 25 mm x 2 mm) were placed in separate polyethylene containers so that they were completely submerged, and the caps were closed. After raising the temperature to 80°C, the containers were kept at the same temperature for 24 hours, after which the rubber panels were removed and washed with running water. After drying at 105°C for 3 hours, the changes in appearance were visually judged and evaluated according to the following criteria.

[0052] <Evaluation Criteria> ○: No external changes such as hardening, cracking, or swelling are observed. △: Some changes in appearance such as hardening, cracking, and swelling are observed. ×: Changes in appearance such as hardening, cracking, and swelling are observed. Items with a △ or ○ rating were judged to be practical.

[0053] *6: Metal corrosion test 50 mL of a 10% by mass aqueous solution of each tested acidic CIP cleaning agent composition was placed in a 100 mL polyethylene container with a cap. SUS304 panels and SUS316 panels were then placed in separate polyethylene containers, each partially submerged, and the caps were applied. After raising the temperature to 80°C and maintaining it at that temperature for 24 hours, the SUS panels were removed, washed with running water, and then visually inspected for corrosion in the immersed portion of the SUS panel (the part submerged in the aqueous solution), the waterline portion at the boundary between the aqueous solution and air, and the gas phase portion exposed to air. The metal corrosiveness was then evaluated according to the following criteria.

[0054] <Evaluation Criteria> ○: No changes were observed in the immersed portion, the waterline portion, or the gas phase portion. △: Some corrosion is observed in the immersed area, waterline area, or gas phase area. ×: Corrosion is observed in one or more locations: the immersed area, the waterline, or the gas phase area. Items with a △ or ○ rating were judged to be practical.

[0055] *7: Washing process conditions A SUS304 stainless steel panel (2cm x 7cm) was coated with milk to a dry weight of approximately 50mg and heated at 130°C for 30 minutes. A cleaning test was then conducted using one of the cleaning methods I to III, which combined the following cleaning steps. Conditions for the cleaning process a) Rinse: Wash with room temperature water for 5 minutes, then drain the rinse solution. b-1) Acid cleaning α: After cleaning with a 3% by mass aqueous solution of each tested acidic CIP cleaning agent composition at 80°C for 20 minutes, the acid cleaning solution is discharged. b-2) Acid cleaning β: After cleaning with a 3% by mass aqueous solution of each tested acidic CIP cleaning agent composition at 80°C for 20 minutes, the acid cleaning solution is not discharged. c) Chlorinated alkaline cleaning: Using ADEKA Cycle SNP (manufactured by ADEKA Clean Aid, containing 15% potassium hydroxide by mass and 3% effective chlorine by mass), add the cleaning solution so that the PP alkalinity of the cleaning solution is 0.45% by mass in terms of potassium hydroxide. After cleaning at 80°C for 20 minutes, drain the chlorinated alkaline cleaning solution. d) Sterilization: Sterilize with hot water at 90°C or higher for 20 minutes, then drain the hot water.

[0056] Cleaning method I: a) Rinse cleaning, b-1) Acid cleaning α, a) Rinse cleaning, c) Chlorinated alkaline cleaning, a) Rinse cleaning, d) Sterilization Cleaning Method II: a) Rinse cleaning, b-1) Acid cleaning α, c) Chlorinated alkaline cleaning, a) Rinse cleaning, d) Sterilization Cleaning method III: a) Rinse cleaning, b-2) Acid cleaning β, c) Chlorinated alkaline cleaning, a) Rinse cleaning, d) Sterilization

[0057] The cleaning performance of the stainless steel panel surface was evaluated by comparing it to the surface before cleaning. Furthermore, the state of contamination in the cleaning solution during chlorinated alkaline cleaning or alkaline cleaning was evaluated.

[0058] *7-1: Cleaning performance evaluation criteria ○: There is almost no residue of dirt. △: A small amount of residual dirt is visible. ×: Some stains remain. -: The test cannot be conducted because it generates chlorine gas, which is dangerous. Based on this, items with a rating of △ or ○ were judged to be practical.

[0059] *7-2: Criteria for evaluating the solubility of dirt in cleaning solution ○: The dirt is dissolved uniformly. ×: Debris is floating around. -: The test cannot be conducted because it generates chlorine gas, which is dangerous. Based on this, a rating of ○ was determined to indicate practicality.

[0060] [Table 1]

[0061] [Table 2]

[0062] [Table 3]

[0063] [Table 4]

[0064] [Table 5]

[0065] [Table 6]

[0066] This specification discloses the following inventions. (1) As component (A), one or more polycarboxylic acid type chelating agents selected from the group consisting of aminocarboxylic acid type chelating agents and hydroxycarboxylic acid type chelating agents, (B) Component: One or more alkaline agents selected from the group consisting of sodium hydroxide, potassium hydroxide, monoethanolamine, diethanolamine, triethanolamine, and monoisopropanolamine. (C) A cleaning agent composition for acidic CIP, containing water as component, with a pH of 3.5 or higher and 6.0 or lower at 25°C. (2) The acidic CIP cleaning agent composition of (1), comprising as component (A), one or more polycarboxylic acid type chelating agents selected from the group consisting of ethylenediaminetetraacetic acid, diethylenetriaminopentaacetic acid, 1,3-propanediaminetetraacetic acid, nitrilotriacetic acid, glutamic acid diacetic acid, methylglycine diacetic acid, hydroxyethylethylenediaminetriacetic acid, and hydroxyethyliminodiacetic acid. (3) The alkaline agent of component (B) is monoethanolamine, the acidic CIP cleaning agent composition of (1) or (2), (4) An acidic CIP cleaning agent composition according to any of (1) to (3), wherein the value of (A) / (B) is 1 or more and 5 or less. (5) An acidic CIP cleaning method comprising an acidic cleaning step using an acidic cleaning solution prepared by adjusting the acidic CIP cleaning agent composition described in any of (1) to (4) above with water so that the concentration of component (A) is 0.001% by mass or more and 10% by mass or less. (6) A CIP cleaning method comprising: an acid cleaning step using an acidic cleaning solution prepared by adjusting the acidic CIP cleaning agent composition described in any of (1) to (4) above with water to a concentration of component (A) of 0.001% by mass or more and 10% by mass or less; and an alkaline cleaning step using a chlorine-based alkaline cleaning agent, wherein the alkaline cleaning step is performed after the acid cleaning solution has been discharged and without rinsing with water. (7) A CIP cleaning method comprising: an acid cleaning step using an acidic cleaning solution prepared by adjusting the acidic CIP cleaning agent composition described in any of (1) to (4) above with water to a concentration of component (A) of 0.001% by mass or more and 10% by mass or less; and an alkaline cleaning step using a chlorine-based alkaline cleaning solution, wherein the alkaline cleaning step is performed following the acid cleaning step without discharging the acidic cleaning solution or rinsing with water.

Claims

1. (A) One or more polycarboxylic acid type chelating agents selected from the group consisting of aminocarboxylic acid type chelating agents and hydroxycarboxylic acid type chelating agents, (B) Component: One or more alkaline agents selected from the group consisting of sodium hydroxide, potassium hydroxide, monoethanolamine, diethanolamine, triethanolamine, and monoisopropanolamine. (C) Contains water as an ingredient, An acidic cleaning agent composition for CIP (Clean-in-Place) treatment, having a pH of 3.5 or higher and 6.0 or lower at 25°C.

2. The acidic CIP cleaning agent composition according to claim 1, comprising as component (A) one or more polycarboxylic acid chelating agents selected from the group consisting of ethylenediaminetetraacetic acid, diethylenetriaminopentaacetic acid, 1,3-propanediaminetetraacetic acid, nitrilotriacetic acid, glutamic acid diacetic acid, methylglycine diacetic acid, hydroxyethylethylenediaminetriacetic acid, and hydroxyethyliminodiacetic acid.

3. The acidic CIP cleaning agent composition according to claim 1, wherein the alkaline agent of component (B) is monoethanolamine.

4. The acidic CIP cleaning agent composition according to claim 1, wherein the mass ratio (A) / (B) of component (A) to component (B) is 1 or more and 5 or less.

5. An acidic CIP cleaning method comprising an acidic cleaning step using an acidic cleaning solution prepared by adjusting the acidic CIP cleaning agent composition described in claim 1 with water so that the concentration of component (A) is 0.001% by mass or more and 10% by mass or less.

6. An acid cleaning step using an acidic cleaning solution prepared by adjusting the acidic cleaning agent composition for CIP described in claim 1 with water so that the concentration of component (A) is 0.001% by mass or more and 10% by mass or less, and An alkaline cleaning process using a chlorine-based alkaline cleaning agent, wherein the alkaline cleaning process is carried out without rinsing with water after the acidic cleaning solution has been discharged. A CIP cleaning method including the following.

7. An acid cleaning step using an acidic cleaning solution prepared by adjusting the acidic cleaning agent composition for CIP described in claim 1 with water so that the concentration of component (A) is 0.001% by mass or more and 10% by mass or less, and An alkaline cleaning process using a chlorine-based alkaline cleaning solution, wherein the alkaline cleaning process is performed following an acid cleaning process without discharging an acidic cleaning solution or rinsing with water. A CIP cleaning method including the following.

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