Method for regenerating filter cloth

Abstract

To provide a novel method for regenerating a filter cloth.SOLUTION: The present disclosure in one aspect relates to a method for regenerating a filter cloth, comprising removing iron stains from the filter cloth by bringing a detergent composition into contact with the filter cloth. The detergent composition comprises a detergent component for removing the iron stains. The detergent component is selected from the group consisting of a nonionic surfactant having a cloud point of lower than 80°C, a sulfonic acid-type anionic surfactant, a fatty acid amide alkyl betaine, and a halogenated dialkyl dimethyl ammonium, and combinations thereof.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to a method for regenerating a filter fabric and a cleaning composition used in the method. [Background technology]

[0002] Filter fabrics are used in various processes such as the paper pulp industry, chemical industry, various production processes for food and chemical products, water treatment for sludge treatment in drinking water and industrial water, and the papermaking process in paper manufacturing. For example, they are used in filter presses (pressure filters) used to filter sludge in paper pulp manufacturing processes, and in the press part (compression and water squeezing part) in the papermaking process. They are also used in humidification correction devices installed to adjust the moisture content of the paper surface in the papermaking process.

[0003] Methods for cleaning filter cloth include, for example, Patent Documents 1 to 3. Patent Document 1 discloses a method for cleaning the filter cloth of a sludge dewatering machine using a filter cloth cleaner formed by mixing a cleaning liquid mainly containing an alkali metal hydroxide with an organic thickener to form a gel. Patent Document 2 discloses a method for cleaning the filter cloth in a filter press using an acidic cleaning solution to which an inhibitor, a surfactant, and a reducing agent (stannous chloride or hydrazine) have been added. Patent Document 3 discloses a method for cleaning the filter cloth for dewatering sludge conditioned with an organic flocculant as an auxiliary, using an alkaline cleaner containing an iron ion chelating agent. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 05-034397 [Patent Document 2] Special Publication No. 56-025173 [Patent Document 3] Special Publication No. 01-042729 Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure provides a new method for regenerating filter cloth that focuses on iron stains on the filter cloth, and a cleaning composition used therein. [Means for solving the problem]

[0006] The present disclosure relates to, as one aspect, a method for regenerating a filter fabric, the method comprising removing iron stains from the filter fabric by contacting the filter fabric with a detergent composition, the detergent composition containing a detergent component for removing iron stains, the detergent component being selected from the group consisting of a nonionic surfactant having a cloud point of less than 80° C., a sulfonic acid-type anionic surfactant, a fatty acid amidoalkyl betaine, a dialkyldimethylammonium halide, and a combination thereof.

[0007] In another aspect, the present disclosure relates to a detergent composition for use in the method for regenerating a filter cloth of the present disclosure, the detergent composition containing a detergent component for removing iron stains, the detergent component being selected from the group consisting of a nonionic surfactant having a cloud point of less than 80°C, a sulfonic acid type anionic surfactant, a fatty acid amidoalkyl betaine, a dialkyldimethylammonium halide, and a combination thereof. Effect of the Invention

[0008] According to the present disclosure, it is possible to provide a new method for regenerating a filter cloth and a cleaning composition used therein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In the papermaking process of a paper mill, a humidification correction (moisture correction) device is arranged to control and adjust the moisture content of the paper produced. In this humidification correction (moisture correction) device, a filter cloth is arranged to remove dirt in the water used for humidification correction. When this filter cloth becomes dirty, it causes poor water permeability, so the dirty filter cloth is replaced with a new filter cloth. The dirty filter cloth is then discarded. In the course of research to reuse the discarded filter cloth, the present inventor identified the cause of the dirt on the filter cloth and found a cleaning method. Specifically, it was thought that the general dirt components in the papermaking process were derived from calcium carbonate, but it was found that the main cause of the dirt was derived from iron. Then, in the course of further research, it was found that a specific surfactant is extremely effective in cleaning iron dirt from the filter cloth, and that the regeneration effect of the filter cloth can be improved by cleaning the filter cloth with the surfactant. The present disclosure is based on these findings.

[0010] The "filter cloth" to be treated in the present disclosure may include not only filter cloth used to treat drain water used in a humidification correction device disposed in the papermaking process of a paper mill, but also filter cloth used to treat other drain water, water such as industrial water, clean water, drinking water, or chemicals, as well as papermaking felt (blanket) used in the papermaking process. In one or more embodiments, the material of the filter cloth may be cotton, wool, synthetic fiber, glass fiber, or the like. In one or more embodiments, the filter cloth may be a woven fabric or a nonwoven fabric.

[0011] In the present disclosure, "regenerating a filter cloth" refers to removing contaminants (dirt) adhering to the filter cloth. In one or more embodiments, "regenerating a filter cloth" may include removing contaminants (dirt) adhering to the filter cloth to restore the filtering ability of the filter cloth. In one or more embodiments, "regenerating a filter cloth" may include washing the filter cloth in order to reuse it. Furthermore, in one or more embodiments, "regenerating a filter cloth" may include washing iron contaminants from the filter cloth and reusing the washed filter cloth.

[0012] [How to regenerate filter cloth] In one aspect, the present disclosure relates to a method for regenerating a filter cloth, which comprises contacting the filter cloth with a detergent composition to remove iron stains from the filter cloth. The detergent composition used in the method of the present disclosure contains a detergent component for removing iron stains, and the detergent component is selected from the group consisting of nonionic surfactants having a cloud point of less than 80° C., sulfonic acid type anionic surfactants, fatty acid amidoalkyl betaines, and dialkyldimethylammonium halides, and combinations thereof. According to the method of the present disclosure, in one or more embodiments, the detergent composition containing the above-mentioned surfactant is used as the detergent component for removing iron stains, thereby efficiently removing iron stains from the filter cloth and making it reusable.

[0013] In one or more embodiments, "contacting the filter cloth with the detergent composition" in the method of the present disclosure may include spraying the detergent composition onto the filter cloth, immersing the filter cloth in the detergent composition, etc. The temperature of the detergent composition when contacting the filter cloth and the frequency of contacting the detergent composition with the filter cloth are not particularly limited and may be appropriately determined depending on the degree of dirt.

[0014] [Component (A): Cleaning agent component for removing iron stains] The cleaning composition used in the method of the present disclosure contains, as a cleaning component (component (A)) for removing iron stains, a nonionic surfactant having a cloud point of less than 80°C, a sulfonic acid type anionic surfactant, a fatty acid amidoalkyl betaine, or a dialkyldimethylammonium halide, or a combination thereof.

[0015] <Nonionic surfactant> The cloud point of the nonionic surfactant that may be contained as a cleaning agent component is less than 80°C. In one or more embodiments, the cloud point of the nonionic surfactant is preferably 15°C or higher, 20°C or higher, 25°C or higher, 30°C or higher, 35°C or higher, 40°C or higher, or 45°C or higher, from the viewpoint of improving the cleaning effect of iron soils. From the same viewpoint, the cloud point of the nonionic surfactant is 79°C or lower in one or more embodiments. In the present disclosure, the "cloud point" refers to the temperature at which the nonionic surfactant aqueous solution becomes cloudy and phase separation occurs when the temperature is increased, and can be measured, for example, by the measurement method described in ISO 1065 1991 (Nonionic surfactants derived from ethylene oxide and mixed nonionic surfactants - Determination of cloud point).

[0016] In one or more embodiments, the HLB of the nonionic surfactant is 10 to 19. In one or more embodiments, the HLB of the surfactant B is 10.5 or more, 11.5 or more, 12.5 or more, or 13.5 or more from the viewpoint of improving the cleaning effect of iron stains. In one or more embodiments, the HLB is 18.5 or less, 17.5 or less, or 16.5 or less from the same viewpoint. In one or more embodiments, the "HLB (hydrophilic lipophilic balance)" in the present disclosure can be calculated using the following Griffin formula. HLB = 20 x (sum of hydrophilic moieties formula weights / molecular weight)

[0017] In one or more embodiments, the nonionic surfactant having a cloud point of less than 80° C. may be polyoxyalkylene alkyl ether, polyoxyalkylene alkyl phenyl ether, fatty acid polyethylene glycol, polyoxyalkylene alkyl amine, or the like. In one or more embodiments, the polyoxyalkylene alkyl ether may be polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene alkyl ether, or the like. In one or more embodiments, the polyoxyalkylene alkyl phenyl ether may be polyoxyethylene alkyl phenyl ether, polyoxypropylene alkyl phenyl ether, polyoxyethylene polyoxypropylene alkyl phenyl ether, or the like. In one or more embodiments, the polyoxyalkylene alkyl amine may be polyoxyethylene alkyl amine, polyoxyethylene polyoxypropylene alkyl amine, or the like. As the nonionic surfactant having a cloud point of less than 80° C., in one or a plurality of embodiments, polyoxyethylene alkyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, fatty acid polyethylene glycols, polyoxyethylene alkyl amines, polyoxyethylene polyoxypropylene alkyl amines, and the like can be preferably used from the viewpoint of improving the cleaning effect for iron stains.

[0018] [Polyoxyalkylene alkyl ether] In one or more embodiments, examples of the polyoxyalkylene alkyl ether include polyoxyethylene decyl ether (decyl ether EO), polyoxyethylene isodecyl ether (isodecyl ether EO), polyoxyethylene polyoxypropylene isodecyl ether (isodecyl ether EO / PO), polyoxyethylene lauryl ether (lauryl ether EO), polyoxyethylene polyoxypropylene lauryl ether (lauryl ether EO / PO), polyoxyethylene tridecyl ether (tridecyl ether EO), polyoxyethylene isotridecyl ether (isotridecyl ether EO), polyoxyethylene polyoxypropylene tridecyl ether (tridecyl ether EO / PO), polyoxyethylene polyoxypropylene isotridecyl ether (isotridecyl ether EO / PO), polyoxyethylene secondary alkyl (C12-14) ether (polyoxyethylene secondary alkyl ether), and polyoxyethylene polyoxypropylene secondary alkyl (C12-14) ether (polyoxyethylene polyoxypropylene secondary alkyl ether).

[0019] In one or more embodiments, the polyoxyalkylene alkyl ether may be a polyoxyalkylene alkyl ether represented by the following formula (1): [ka] In formula (1), R 11 and R 12 are each independently a hydrogen atom or an alkyl group having 8 to 22 carbon atoms, and at least one of them is an alkyl group having 8 to 22 carbon atoms. AO is at least one of an oxyethylene group and an oxypropylene group, and n11 is the average number of moles of AO added and is 5 to 25.

[0020] In one or more embodiments of formula (1), R 11 and R 12 Both of R may be alkyl groups having 8 to 22 carbon atoms. 11 and R12 From the viewpoint of improving the cleaning effect on iron stains, in one or more embodiments, the number of carbon atoms in the alkyl group represented by the formula (I) is 10 or more or 11 or more, and preferably 12 or more. From the same viewpoint, in one or more embodiments, the number of carbon atoms in the alkyl group is 20 or less, and preferably 18 or less. In one or more embodiments, the alkyl group may be linear or branched.

[0021] In formula (1), in one or more embodiments, AO may consist of only an oxyethylene group (EO) as shown in the following formula (1'), or may consist of an oxyethylene group (EO) and an oxypropylene group (PO) as shown in the following formula (1''). In view of improving the cleaning effect on iron stains, in one or more embodiments, n11 is 6 or more, 7 or more, 8 or more, or 9 or more. In view of the same, in one or more embodiments, n11 is 20 or less, 19 or less, 18 or less, 17 or less, or 16 or less.

[0022] In one or more embodiments, the polyoxyalkylene alkyl ether represented by formula (1) may be a polyoxyethylene alkyl ether represented by the following formula (1') or a polyoxyethylene polypropylene alkyl ether represented by the following formula (1''). In formulas (1') and (1''), R 11 and R 12 is the same as equation (1). [ka] In formula (1'), n12 is the average number of moles of EO added, and is 5 to 25. From the viewpoint of improving the cleaning effect for iron stains, in one or more embodiments, n12 is 6 or more, 7 or more, 8 or more, or 9 or more. From the same viewpoint, in one or more embodiments, n12 is 20 or less, 19 or less, 18 or less, 17 or less, or 16 or less. In formula (1″), n13 is the average number of moles of EO added, and n14 is the average number of moles of PO added. n13+n14 is 5 to 25, and in one or more embodiments, from the viewpoint of improving the cleaning effect on iron stains, is 6 or more, 7 or more, 8 or more, or 9 or more. From the same viewpoint, it is 20 or less, 19 or less, 18 or less, 17 or less, or 16 or less. In formula (1″), the addition form of EO and PO is not particularly limited, and may be block or random. From the viewpoint of improving the cleaning effect on iron stains, PO and EO are preferably block-bonded in the order represented by the above formula (1″).

[0023] [Polyoxyalkylene alkyl phenyl ether] In one or more embodiments, polyoxyethylene alkylphenyl ether is preferably used as the polyoxyalkylene alkylphenyl ether. In one or more embodiments, polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene styrenated phenyl ether, etc. can be mentioned as the polyoxyethylene alkylphenyl ether. The number of moles of EO added in the polyoxyethylene alkylphenyl ether can be appropriately determined according to the number of carbon atoms of the alkyl group, and in one or more embodiments, it is 8 to 16. In one or more embodiments, the number of moles of EO added in the polyoxyethylene alkylphenyl ether is 16 or less, 14 or less, 12 or less, 11 or less, or 10 or less.

[0024] [Fatty acid polyethylene glycol] In one or a plurality of embodiments, the fatty acid polyethylene glycol may be, for example, fatty acid polyethylene glycol represented by the following formula (2). [ka] In formula (2), R 21is an alkyl group having 8 to 22 carbon atoms, EO is an oxyethylene group, and n21 is the average number of moles of EO added and is 5 to 25.

[0025] In formula (2), R 21 From the viewpoint of improving the cleaning effect on iron stains, the number of carbon atoms in the alkyl group represented by the formula (I) is, in one or more embodiments, 10 or more, 12 or more, 14 or more, or 16 or more. From the same viewpoint, the number of carbon atoms in the alkyl group is, in one or more embodiments, 20 or less. In one or more embodiments, the alkyl group may be linear or branched. In formula (2), in order to improve the cleaning effect on iron stains, in one or more embodiments, n21 is 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 11 or more, or 12 or more. In order to achieve the same result, in one or more embodiments, n21 is 20 or less, 19 or less, 18 or less, 17 or less, 16 or less, or 15 or less.

[0026] In one or a plurality of embodiments, examples of the fatty acid polyethylene glycol represented by formula (2) include polyethylene glycol oleate.

[0027] [Polyoxyalkylene alkylamine] In one or a plurality of embodiments, examples of the polyoxyalkylene alkylamine include polyoxyethylene cetylamine (cetylamine EO), polyoxyethylene polyoxypropylene cetylamine (cetylamine EO / PO), polyoxyethylene stearylamine (stearylamine EO), polyoxyethylene polyoxypropylene stearylamine (stearylamine EO / PO), polyoxyethylene oleylamine (oleylamine EO), and polyoxyethylene polyoxypropylene oleylamine (oleylamine EO / PO).

[0028] In one or more embodiments, the polyoxyalkylene alkylamine may be a polyoxyalkylene alkylamine represented by the following formula (3): [ka] In formula (3), R 31 represents an alkyl group having 8 to 22 carbon atoms, AO represents at least one of an oxyethylene group and an oxypropylene group, and n31 and n32 represent the average number of moles of AO added and are each independently 5 to 25.

[0029] In formula (3), R 31 From the viewpoint of improving the cleaning effect on iron stains, the number of carbon atoms in the alkyl group represented by the formula (I) is, in one or more embodiments, 10 or more, 12 or more, 14 or more, or 16 or more. From the same viewpoint, the number of carbon atoms in the alkyl group is, in one or more embodiments, 20 or less. In one or more embodiments, the alkyl group may be linear or branched. In one or more embodiments, AO in formula (3) may be composed of only an oxyethylene group (EO), or may be composed of an oxyethylene group (EO) and an oxypropylene group (PO). When composed of EO and PO, the addition form of EO and PO is not particularly limited and may be block or random. In one or more embodiments, n31 and n32 are, from the viewpoint of improving the cleaning effect of iron stains, 6 or more, 7 or more, 8 or more, or 9 or more. In the same viewpoint, in one or more embodiments, n31 and n32 are, from the viewpoint of improving the cleaning effect of iron stains, 20 or less, 19 or less, 18 or less, 17 or less, or 16 or less.

[0030] <Sulfonic acid type anionic surfactant> Examples of sulfonic acid type anionic surfactants that may be contained as cleaning agent components include, in one or more embodiments, dialkyl sulfosuccinates, alkanesulfonates, alpha olefin sulfonates, linear alkyl benzene sulfonates, alkyl (branched) benzene sulfonates, naphthalene sulfonate-formaldehyde condensates, alkyl naphthalene sulfonates, and N-methyl-N-acyltaurate salts. Examples of dialkyl sulfosuccinates include, in one or more embodiments, sodium dioctyl sulfosuccinate.

[0031] <Fatty acid amidoalkyl betaine> The cleaning composition used in the method of the present disclosure may contain a fatty acid amidoalkyl betaine, which is a neutral surfactant, as a cleaning agent component. In one or more embodiments, examples of the fatty acid amidoalkyl betaine that may be contained as a cleaning agent component include coconut oil fatty acid amidopropyl dimethylaminoacetic acid betaine (cocamidopropyl betaine) and cocamidopropyl hydroxysultaine.

[0032] <Dialkyldimethylammonium halide> The cleaning composition used in the method of the present disclosure may contain a cationic surfactant, dialkyldimethylammonium halide, as a cleaning agent component. In one or more embodiments, the dialkyldimethylammonium halide may be dicocoyl dimethylammonium chloride (coconut alkyldimethylammonium chloride dicocoyl).

[0033] In one or more embodiments, the content of the detergent component when the detergent composition is used is 0.05% by mass or more, 0.1% by mass or more, or 0.15% by mass or more. In one or more embodiments, the content of the detergent component is 5% by mass or less, 4% by mass or less, 3% by mass or less, 2% by mass or less, or 1% by mass or less. The detergent component (component (A)) may be one type or multiple types. The content of the detergent component (component (A)) may refer to the total content of the detergent components (component (A)).

[0034] [Component (B): Chelating agent] In order to further improve the cleaning effect on iron stains, the cleaning composition may further contain a chelating agent (component (B)) in one or a plurality of embodiments.

[0035] In one or more embodiments, examples of the chelating agent include ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), cyclohexanediaminetetraacetic acid (CyDTA), etidronic acid (1-hydroxyethane-1,1-diphosphonic acid, HEDP), ethylenediamine-N,N'-disuccinic acid (EDDS), ethylenediamine-N,N'-bis[2-(2-hydroxyphenyl)acetic acid (EDDHA), ethylenediaminesuccinic acid, gluconic acid, phosphonic acid, pentasodium aminotrimethylenephosphonate, ligninsulfonic acid, polyacrylic acid, polymaleic acid, copolymers of polyacrylic acid and polymaleic acid, hydroxyethylethylenediaminetriacetic acid (HEDTA), tetrasodium L-glutamate diacetate, glycol ether diaminetetraacetic acid, bipyridine, phenanthroline, porphyrin, crown ether, and 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC), as well as salts thereof.

[0036] In one or more embodiments, the content of the chelating agent when the cleaning composition is used is 0.05% by mass or more, 0.1% by mass or more, or 0.15% by mass or more. In one or more embodiments, the content of the chelating agent is 5% by mass or less, 4% by mass or less, 3% by mass or less, 2% by mass or less, or 1% by mass or less. The chelating agent (component (B)) may be one type or multiple types. The content of the chelating agent (component (B)) may refer to the total content of the chelating agent (component (B)).

[0037] [Component (C): Water] In one or more embodiments, the cleaning composition used in the method for regenerating a filter cloth of the present disclosure may contain water (component (C)). Examples of component (C) include ion-exchanged water, RO water (water treated with a reverse osmosis membrane), distilled water, pure water, and ultrapure water.

[0038] In one or more embodiments, the content of component (C) when the cleaning composition is used may be the remainder excluding component (A) which is a cleaning component, and optional component (B) and other optional components. In one or more embodiments, the content of component (C) is 1 mass% or more, 10 mass% or more, or 30 mass% or more. In one or more embodiments, the content of component (C) is 90 mass% or less, 80 mass% or less, 70 mass% or less, or 60 mass% or less.

[0039] In one or more embodiments, the cleaning agent composition used in the method for regenerating a filter cloth of the present disclosure may further contain other agents such as a bactericide and an antifungal agent. In one or more embodiments, examples of the bactericide include an isothiazolinone compound, a benzoisothiazoline compound, an aliphatic nitroalcohol compound, a cationic surfactant that can be used as a bactericide in the field, and an inorganic bactericide such as monochloramine.

[0040] In one or more embodiments, the cleaning agent composition used in the method for regenerating a filter cloth of the present disclosure may contain at least one of microbubbles and an organic acid, or may not contain at least one of them or both. In one or more embodiments, the method for regenerating a filter cloth according to the present disclosure may include forming microbubbles in a cleaning agent composition. In one or more embodiments, examples of the method for forming microbubbles include an ejector method, a cavitation method, a swirling flow method, a pressurized dissolution method, and an ultrasonic method.

[0041] In one or a plurality of embodiments, the contact of the filter cloth with the cleaning composition may be carried out before or during operation of the facility, or may be carried out while the production facility is stopped.

[0042] In one or more embodiments, the method for regenerating a filter cloth according to the present disclosure may include spraying shower water containing microbubbles onto the filter cloth in parallel with the contact with the cleaning composition. In one or more embodiments, the shower water may contain the cleaning composition according to the present disclosure.

[0043] The method for regenerating a filter cloth according to the present disclosure can also be said to be a method for cleaning iron stains on a filter cloth using the above-mentioned detergent composition. Thus, in another aspect, the present disclosure relates to a method for cleaning iron stains on a filter cloth using the above-mentioned detergent composition.

[0044] [Cleaning agent composition] In another aspect, the present disclosure relates to a detergent composition for use in the method for regenerating a filter cloth of the present disclosure. The detergent composition of the present disclosure contains a detergent component (component (A)) for removing iron stains, which is selected from the group consisting of nonionic surfactants having a cloud point of less than 80° C., sulfonic acid type anionic surfactants, fatty acid amidoalkyl betaines, and dialkyldimethyl ammonium halides, and combinations thereof. According to the detergent composition of the present disclosure, in one or more embodiments, the cleaning properties of the iron stains on the filter cloth are excellent, and the filter cloth can be efficiently regenerated. The component (A) in the detergent composition of the present disclosure is the same as that in the method for regenerating a filter cloth of the present disclosure.

[0045] In one or more embodiments, the cleaning composition of the present disclosure may further contain a chelating agent (component (B)) in order to improve the cleaning properties of the filter cloth against iron stains. The chelating agent is the same as that in the method for regenerating a filter cloth of the present disclosure.

[0046] In one or more embodiments, the cleaning composition of the present disclosure may further contain water (component (C)). Component (C) is the same as that in the method for regenerating a filter cloth of the present disclosure.

[0047] In one or more embodiments, the cleaning agent composition of the present disclosure may or may not further contain at least one of a bactericide, an antifungal agent, an organic acid, and microbubbles.

[0048] The present disclosure further relates to one or more of the following embodiments. [1] A method for regenerating a filter fabric, comprising the steps of: removing iron stains from the filter fabric by contacting the filter fabric with a cleaning composition; The cleaning composition contains a cleaning component for removing iron stains, The method according to claim 1, wherein the cleaning agent component is selected from the group consisting of nonionic surfactants having a cloud point of less than 80° C., sulfonic acid type anionic surfactants, fatty acid amidoalkyl betaines, and dialkyldimethylammonium halides, and combinations thereof. [2] The method according to [1], wherein the nonionic surfactant is selected from the group consisting of polyoxyethylene alkyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, fatty acid polyethylene glycols, polyoxyethylene alkylamines, and polyoxyethylene polyoxypropylene alkylamines. [3] The method according to [1] or [2], wherein the cleaning composition further comprises a chelating agent. [4] A cleaning agent composition for use in the method for regenerating a filter fabric according to any one of [1] to [3], The cleaning composition contains a cleaning component for removing iron stains, The cleaning agent composition, wherein the cleaning agent component is selected from the group consisting of a nonionic surfactant having a cloud point of less than 80° C., a sulfonic acid type anionic surfactant, a fatty acid amidoalkyl betaine, a dialkyldimethylammonium halide, and a combination thereof. [5] The cleaning composition according to [4], wherein the nonionic surfactant is selected from the group consisting of polyoxyethylene alkyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, fatty acid polyethylene glycols, polyoxyethylene alkylamines, and polyoxyethylene polyoxypropylene alkylamines. [6] The cleaning composition according to [4] or [5], further comprising a chelating agent.

[0049] The present disclosure will be described in more detail below with reference to examples, but these are merely illustrative and the present disclosure is not limited to these examples. EXAMPLES

[0050] In the following Examples, Comparative Examples and Reference Examples, the following drugs were used. [Drugs] <Nonionic surfactant> Polyethylene glycol oleate (EO14) (Daiichi Pharmaceutical Co., Ltd.) Stearylamine PO(2)EO(15) (Aoki Oil Industries Co., Ltd.) Polyethylene glycol stearate (EO23) (Daiichi Pharmaceutical Co., Ltd.) Tridecyl alcohol EOPO (EO8-9) (PO1-2) (ADEKA Corporation) Polyoxyalkylene decyl ether (Daiichi Pharmaceutical Co., Ltd.) Polyoxyalkylene lauryl ether (Daiichi Pharmaceutical Co., Ltd.) Polyoxyethylene stearylamine EO (15) (Aoki Oil Industry Co., Ltd.) Polyoxyethylene stearylamine EO (20) (Aoki Oil Industry Co., Ltd.) Polyoxyethylene secondary alcohol EO(12)PO(3) (Nippon Shokubai Co., Ltd.) Polyoxyethylene decyl ether EO(3) (Aoki Oil Industries Co., Ltd.) Polyoxyethylene tridecyl ether EO(3) (Aoki Oil Industries Co., Ltd.) Polyoxyethylene tridecyl ether EO(9) (Aoki Oil Industries Co., Ltd.) Polyoxyethylene polyoxypropylene tridecyl ether EO(70)PO(30) (Aoki Oil Industries Co., Ltd.) Polyoxyethylene polyoxypropylene tridecyl ether EO(75)PO(25) (Aoki Oil Industries Co., Ltd.) Polyoxyethylene polyoxypropylene tridecyl ether EO(80)PO(20) (Aoki Oil Industries Co., Ltd.) Polyoxyethylene polyoxypropylene lauryl ether EO(60)PO(40) (manufactured by Aoki Oil Industries Co., Ltd.) Fatty alcohol alkoxylates (BASF) <Anionic surfactant> Sodium dioctyl sulfosuccinate (Sanyo Chemical Industries, Ltd.) Polyoxyethylene (EO3) alkyl ether sulfate (Sanyo Chemical Industries, Ltd.) Polyoxyethylene (EO3) alkyl (lauryl) ether carboxylate (Sanyo Chemical Industries, Ltd.) <Cationic surfactant> Dicocoyl dimethyl ammonium chloride (Lion Corporation) Dipolyoxyethylene oleylmethylammonium chloride EO(2) (Lion Corporation) Benzalkonium chloride (Sanyo Chemical Industries, Ltd.) <Amphoteric surfactant> Coconut oil fatty acid amidopropyl dimethylaminoacetic acid betaine (cocamidopropyl betaine) (Kao Corporation) Lauryl Betaine (Kao Corporation) Lauryl hydroxysulfobetaine (Kao Corporation)

[0051] [Cloud point measurement] The cloud points of nonionic surfactants were measured by referring to the catalog values ​​of each company, and for those not listed, a 1% aqueous solution was prepared and measured in accordance with JIS K 2269. Furthermore, for those that were not soluble in a 1% aqueous solution, the measurements were made using an aqueous solution mixed with about 25% BDG.

[0052] [HLB measurement] The HLB was calculated using the following Griffin formula. HLB = 20 x (sum of hydrophilic moieties formula weights / molecular weight)

[0053] <Preliminary Examination> The humidity compensation device installed in the papermaking process is equipped with a filter (cylindrical type) and treats (filters) drain water, etc. In order to confirm the composition of the dirt on the filter cloth placed in the filter (cylindrical type) used to treat (filter) drain water, an ignition loss test and fluorescent X-ray analysis were performed.

[0054] [Burning weight loss test] A filter cloth (material: synthetic fiber) was removed from a cylindrical filter of a humidification correction device in the papermaking process of a certain paper mill, and test pieces (length: 5.0 cm x width: 3.0 cm x thickness: 0.8 cm) were cut from the surface (outside of the cylinder: outside of the filter cloth) and the inner layer (inside of the cylinder: inside of the filter cloth) of the filter cloth, which were then heated at 525°C for 3 hours or at 800°C for 1 hour, and the weight of the test pieces before and after heating was measured to determine the loss on ignition. Weight measurements were performed using a precision electronic balance. The results are shown in Table 1. As shown in Table 1, in the test piece cut from the outside of the filter cloth, the ash content (ignition loss) was greater when heated at 525°C than when heated at 800°C, and a difference in ash content was confirmed depending on the heating temperature. It was suggested that this difference was due to Ca scale contamination such as Ca carbonate.

[0055] [X-ray fluorescence analysis] The results of X-ray fluorescence analysis using samples (ash) obtained from the ignition loss test are shown below. As shown in Table 1 below, more than 95% of the ash was Fe2O3. Therefore, the main component of the dirt is thought to be iron. In addition, the results below suggest that dirt has accumulated inside the filter fabric. [Table 1]

[0056] [Cleaning effect confirmation test 1] A test piece (length: 5.0 cm x width: 3.0 cm x thickness: 0.8 cm) was cut from the surface of the filter fabric and placed in a wire mesh, and then immersed in a chemical solution containing 0.2% by weight of the surfactant shown in Tables 2 and 3. After immersion for 30 minutes, the ignition loss was measured in the same manner as in the above-mentioned ignition loss test, and the inorganic matter contained in the test piece (ash weight of the chemical treatment) was measured. In addition, a test piece (length: 5.0 cm x width: 3.0 cm x thickness: 0.8 cm) cut from the surface of the filter fabric as a blank was similarly measured for ignition loss without chemical treatment, and the inorganic matter contained in the test piece (ash weight of the untreated treatment) was measured. The ash removal rate was calculated from the obtained weight using the following formula. The obtained ash removal rate was evaluated according to the following criteria, and the results are shown in Tables 2 and 3 below. [Ash removal rate %] = (weight of untreated ash (g) - weight of ash treated with chemicals (g)) / weight of untreated ash (g) x 100 <Evaluation> ◎: Ash removal rate is 55% or more ○: Ash removal rate is 35% or more and less than 55% △: Ash removal rate is 15% or more but less than 35% ×: Ash removal rate is less than 15%

[0057] [Table 2]

[0058] As shown in Table 2, by using a nonionic surfactant with a cloud point of less than 80° C., iron stains on the filter cloth could be washed away.

[0059] [Table 3]

[0060] As shown in Table 3, iron stains on the filter fabric could be washed away by using a sulfonic acid type anionic surfactant, a dialkyldimethylammonium halide, and a fatty acid amidoalkylbetaine.

[0061] [Cleaning effect confirmation test 2] A cleaning effect confirmation test was conducted in the same manner as in Cleaning Effect Confirmation Test 1 using chelating agents (2Na EDTA, 4Na EDTA, 5Na DTPA, HEDP, 3Na EDDS, sodium gluconate, 5Na ATMP, sodium lignosulfonate, and ammonium polyacrylate). The content of the chelating agent in the chemical solution was 0.5% by weight. As a result, the ash removal rate for all chelating agents was less than 10%, and no effect on cleaning iron stains was confirmed.

[0062] [Cleaning effect confirmation test 3] A cleaning effect confirmation test was conducted in the same manner as in Cleaning Effect Confirmation Test 1, using a chemical solution containing a surfactant and a chelating agent as shown in Table 4 below. The results are shown in Table 4 below. Table 4 below shows the rate at which the ash removal rate increased by using a chelating agent in combination (removal improvement rate). The removal improvement rate (%) was calculated from the ash removal rate (%) when cleaning was performed using only the surfactant (ash removal rate A) and the ash removal rate (%) when cleaning was performed using a surfactant and a chelating agent in combination (ash removal rate B) according to the following formula. [Removal improvement rate %]=[[Ash removal rate B]-[Ash removal rate A]) / [Ash removal rate A]]×100 [Table 4]

[0063] As shown in Table 4, the iron stain cleaning effect was improved when any of the surfactants was used in combination with a chelating agent.

Claims

1. 1. A method for regenerating a filter fabric, comprising: removing iron stains from the filter fabric by contacting the filter fabric with a cleaning composition; The cleaning composition contains a cleaning component for removing iron stains, The method according to claim 1, wherein the cleaning agent component is selected from the group consisting of nonionic surfactants having a cloud point of less than 80° C., sulfonic acid type anionic surfactants, fatty acid amidoalkyl betaines, and dialkyldimethylammonium halides, and combinations thereof.

2. 2. The method of claim 1, wherein the nonionic surfactant is selected from the group consisting of polyoxyethylene alkyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, fatty acid polyethylene glycols, polyoxyethylene alkyl amines, and polyoxyethylene polyoxypropylene alkyl amines.

3. The method of claim 1 , wherein the cleaning composition further comprises a chelating agent.

4. A cleaning agent composition for use in the method for regenerating a filter fabric according to any one of claims 1 to 3, The cleaning composition contains a cleaning component for removing iron stains, The cleaning agent composition, wherein the cleaning agent component is selected from the group consisting of a nonionic surfactant having a cloud point of less than 80° C., a sulfonic acid type anionic surfactant, a fatty acid amidoalkyl betaine, a dialkyldimethylammonium halide, and a combination thereof.

5. 5. The cleaning composition according to claim 4, wherein the nonionic surfactant is selected from the group consisting of polyoxyethylene alkyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, fatty acid polyethylene glycols, polyoxyethylene alkyl amines, and polyoxyethylene polyoxypropylene alkyl amines.

6. The cleaning composition of claim 4, further comprising a chelating agent.

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