Metal cleaning methods
A water-based cleaning method using a rheological modifier with specific properties and water flow velocity efficiently removes adherent water-insoluble hydraulic compositions from metal surfaces, addressing the challenge of high viscosity and labor-intensive cleaning.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- KAO CORP
- Filing Date
- 2022-02-01
- Publication Date
- 2026-07-29
AI Technical Summary
Water-insoluble hydraulic compositions, such as water-insoluble concrete and mortar, adhere to surfaces and are difficult to clean due to their high viscosity, requiring labor-intensive methods and generating waste.
A method involving a water-based cleaning process using a rheological modifier with specific relaxation times and a water flow velocity of 1.2 m/s or more to wash away the adherent slurry from metal surfaces.
The method effectively removes the adherent slurry with water, simplifying the cleaning process and reducing waste by leveraging the viscoelastic properties of the rheological modifier under defined water flow conditions.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a method for cleaning a metal to which a water-insoluble slurry composition adheres.
Background Art
[0002] Hydraulic compositions such as concrete and mortar are slurries containing inorganic powders such as hydraulic powders and are used in various fields such as civil engineering and construction. For example, hydraulic compositions are used in the production of underground water cutoff walls, underground piles, and the like.
[0003] In general, various chemical admixtures such as AE agents, water reducers, AE water reducers, high-performance water reducers, high-performance AE water reducers, fluidizing agents, and setting retarders are used in hydraulic compositions to adjust their workability, fluidity, strength, setting time, hardening time, and the like. Patent Document 1 discloses a rheology modifier containing two or more specific amine oxides having different structures. Patent Document 2 discloses a self-compacting concrete composition in which, in a concrete composition containing an alkylamine oxide having an alkyl group with 8 to 22 carbon atoms and a high-performance water reducer, the slump flow value (spread measured according to JIS-A 1101) of the concrete is 50 cm or more.
[0004] Among hydraulic compositions, water-insoluble slurries such as water-insoluble concrete and water-insoluble mortar, in which material separation in water hardly occurs, are known. In order to suppress the outflow of the cement paste part due to underwater drop or exposure to flowing water during underwater construction, they tend to increase their viscosity by adding a rheology modifier, a thickener, or the like. Due to their high viscosity, water-insoluble slurries tend to adhere to pipes, storage tanks, etc., and require labor for cleaning. Patent Document 3 discloses a method for cleaning an adherent of a hydraulic composition, which includes a step of bringing clay into contact with a hydraulic composition containing a combination of a compound selected from cationic surfactants and a compound selected from anionic aromatic compounds, water, and a hydraulic powder adhered to an object to be cleaned. [Prior art documents] [Patent Documents]
[0005] [Patent Document 1] Japanese Patent Publication No. 2020-76022 [Patent Document 2] Japanese Patent Application Publication No. 8-133805 [Patent Document 3] Japanese Patent Publication No. 2007-203607 [Overview of the Initiative] [Problems that the invention aims to solve]
[0006] The technology described in Patent Document 3 involves adding clay during a water-based washing operation to adsorb cationic surfactants, which form higher-order structures and exhibit viscosity, onto the clay. This suppresses the formation of higher-order structures, reduces the viscosity of the attached hydraulic composition, and facilitates washing with water. If hydraulic compositions can be easily washed with water alone, it would be a more desirable technology in this industry from the standpoint of simplifying the washing operation and reducing waste after washing.
[0007] The present invention provides a method for cleaning metals in which a water-non-separable slurry adhering to the metal can be easily washed away with water. [Means for solving the problem]
[0008] The present invention relates to a method for cleaning metal, comprising applying a stream of water to a water-based non-separable slurry composition containing an inorganic powder including cement, a rheological modifier, and water, which is adhering to a metal, in order to wash the composition away from the metal. The rheological modifier has a maximum relaxation time τ of 0.1 s to 10,000 s in an aqueous solution, as measured by the following method. The water flow velocity is 1.2 m / s or more. Regarding methods for cleaning metal. <Method for measuring the longest relaxation time τ> An aqueous solution of the rheological modifier is prepared by adding 1.0% by mass of the rheological modifier to water with a pH of 13 obtained by mixing deionized water and sodium hydroxide. The longest relaxation time τ is measured by frequency dispersion measurement of this aqueous solution at 20°C with a strain of 5% using a cone plate (diameter 50 mm, angle 0.0398 rad, GAP 0.097 mm). [Effects of the Invention]
[0009] The present invention provides a method for cleaning metal to which a water-non-separable slurry, which is generally considered difficult to wash away due to its high viscosity, can be easily washed away with water. [Modes for carrying out the invention]
[0010] In this invention, when cleaning metal to which a non-separable slurry composition containing cement-containing inorganic powder, a rheological modifier, and water has adhered is performed with water, the cleaning effect is dramatically improved by using a rheological modifier that satisfies predetermined physical properties and by precisely defining the application conditions of the water flow. The reason for this is presumed to be as follows: By using a rheological modifier with a predetermined relaxation time, it becomes possible to impart viscoelasticity to the non-separable slurry composition in water. Furthermore, a longer relaxation time makes it more elastic against short-term deformation, making it easier to peel off from the metal surface. In addition, by applying a water flow of a predetermined velocity, it is presumed that cleaning becomes easier. In contrast, a slurry composition prepared using a rheological modifier that does not satisfy the relaxation time of the present invention becomes more viscous, more likely to remain on the metal surface, and its cleaning performance deteriorates. It should be noted that the mechanism by which the effects of the present invention are manifested is not limited to this. Hereinafter, when referring to water flow, unless otherwise specified, it refers to water flow with a flow velocity of 1.2 m / s or more.
[0011] First, the water-non-separating slurry composition according to the present invention will be described. Examples of water-non-separating slurry compositions include slurry compositions that are less likely to cause material separation in water and are less likely to pollute water quality. The slurry composition according to the present invention may be a water-non-separating hydraulic slurry composition.
[0012] Examples of inorganic powders, though not particularly limited, include the following: (1) Cement, gypsum and other hydraulic powders (2) Potential hydraulic powders such as coal ash, blast furnace slag, and diatomaceous earth (3) Powders with pozzolanic properties such as fly ash, silica fume, volcanic ash, and silicic acid clay. (4) Silicates such as kaolin, aluminum silicate, clay, talc, mica, calcium silicate, sericite, and bentonite (5) Carbonates such as calcium carbonate, magnesium carbonate, barium carbonate, and basic lead carbonate (6) Sulfates such as calcium sulfate and barium sulfate (7) Chromates such as strontium chromate and pigment yellow (8) Molybdates such as zinc molybdate, calcium zinc molybdate, and magnesium molybdate (9) Metal oxides such as alumina, antimony oxide, titanium oxide, cobalt oxide, triiron tetroxide, diiron trioxide, trilead tetroxide, lead monoxide, chromium green oxide, tungsten trioxide, and yttrium oxide. (10) Metal hydroxides such as aluminum hydroxide, magnesium hydroxide, calcium hydroxide, iron hydroxide, and metatitanic acid (11) Metal carbides such as silicon carbide, tungsten carbide, boron carbide, and titanium carbide (12) Other inorganic powders not classified in (1) to (11) above, such as aluminum nitride, silicon nitride, boron nitride, zirconia, barium titanate, satin white, carbon black, graphite, chrome yellow, mercury sulfide, ultramarine, Paris blue, titanium yellow, chrome vermilion, lithopone, copper acetoarsenite, nickel, silver, palladium, lead zirconate titanate, etc.
[0013] The underwater non-separating slurry composition according to the present invention contains cement as an inorganic powder. Examples of cement include ordinary Portland cement, rapid-hardening Portland cement, ultra-rapid-hardening Portland cement, blast furnace cement, sulfate-resistant Portland cement, low-heat Portland cement, white Portland cement, and eco-cement (e.g., JIS R5214). Among these, cement selected from blast furnace cement, rapid-hardening Portland cement, ordinary Portland cement, sulfate-resistant Portland cement, and white Portland cement is preferred, and cement selected from blast furnace cement, rapid-hardening Portland cement, and ordinary Portland cement is more preferred.
[0014] Two or more types of inorganic powders can be used. The cement may also contain other inorganic powders, such as latent hydraulic powders or powders with possolane properties.
[0015] The rheological modifier according to the present invention has a maximum relaxation time τ of an aqueous solution of 0.1 s or more, preferably 0.5 s or more, more preferably 1 s or more, and 10,000 s or less, preferably 5,000 s or less, and more preferably 1,000 s or less, as measured by the following method, from the viewpoint of the washing effect by water flow under predetermined conditions. The maximum relaxation time τ is one of the indicators of viscoelasticity for the properties of an aqueous non-separable slurry composition, and the larger the maximum relaxation time τ, the more elastic the viscoelasticity of the aqueous non-separable slurry composition becomes. The maximum relaxation time τ for a rheological modifier can be positioned as one of the indicators of viscoelasticity of an aqueous non-separable slurry composition obtained using the rheological modifier. <Method for measuring the longest relaxation time τ> An aqueous solution of a rheology modifier is prepared by adding 1.0% by mass of a rheology modifier to water with a pH of 13 obtained by mixing ion-exchanged water and sodium hydroxide. For the aqueous solution, frequency dispersion measurement is performed at a strain of 5% at 20 °C using a cone plate (diameter 50 mm, angle 0.0398 rad, GAP 0.097 mm), and the longest relaxation time τ is measured.
[0016] Examples of the rheology modifier include amine oxide surfactants. The rheology modifier preferably contains an amine oxide surfactant [hereinafter referred to as component (A)].
[0017] The amine oxide surfactant of component (A) may be a surfactant having an amine oxide group. Examples of the amine oxide surfactant include amine oxides having one hydrocarbon group with 8 or more, further 14 or more, and 22 or less carbon atoms. Examples of component (A) include compounds represented by the following general formula (1).
[0018]
Chemical formula
[0019] [In the formula, X is a group represented by R p , 2 , , 2 , 3 , or R 1b -[CONH-CH2CH2CH2] n -. R 1a is an alkyl group having 14 or more and 22 or less carbon atoms or an alkenyl group having 14 or more and 22 or less carbon atoms. R 1b is an alkyl group having 13 or more and 21 or less carbon atoms or an alkenyl group having 13 or more and 21 or less carbon atoms. n is an integer of 1 or more and 3 or less. R 2 and R 3 are each independently an alkyl group having 1 or more and 4 or less carbon atoms or a group represented by -(C2H4O) p H. p is the average number of added moles, and R 2 and R3 The sum of the numbers is between 0 and 5 (inclusive). That is the case.
[0020] In the present invention, component (A) is two or more compounds represented by the general formula (1) above [hereinafter also referred to as compound (1)], The two or more compounds mentioned above differ in X in general formula (1), Of the two or more compounds mentioned above, at least one is R of X in general formula (1) 1a or R 1b It is a compound of an alkenyl group. This is preferable. This embodiment will be described below.
[0021] Regarding compound (1), if X in general formula (1) is different, consider the case where there are two types of compound (1) as an example, and include the following embodiments. Note that in the following embodiments, of the two types of compound (1), at least one of compound (1) has R 1a or R 1b This is an alkenyl group. (i) R 1a or R 1b R is an alkyl group, and the other R 1a or R 1b This is an alkenyl group. (ii) R 1a or R 1b The number of carbon atoms in the other R 1a or R 1b The number of carbon atoms is different. (iii) If one X is R 1a And the other X is R 1b -[CONH-CH2CH2CH2] n - is (iv) X is both R 1b -[CONH-CH2CH2CH2] n - and one n is different from the other n. (v) A combination of (i) to (iv) above.
[0022] In general formula (1), X is R 1a or R 1b-[CONH-CH2CH2CH2] n It is a base represented by -. R 1a This is an alkyl group having 14 to 22 carbon atoms or an alkenyl group having 14 to 22 carbon atoms. R 1a When the group is an alkenyl group, the number of carbon atoms is preferably 18 or more, and preferably 22 or less. R 1a When it is an alkyl group, the number of carbon atoms is preferably 16 or more, and preferably 22 or less. R 1b This is an alkyl group having 13 to 21 carbon atoms or an alkenyl group having 13 to 21 carbon atoms. R 1b When the group is an alkenyl group, the number of carbon atoms is preferably 17 or more, and preferably 21 or less. R 1b When it is an alkyl group, the number of carbon atoms is preferably 15 or more, and preferably 21 or less. n is an integer between 1 and 3, inclusive. Preferably, n is 0 or 1. R 2 and R 3 Each is independently preferably an alkyl group having 1 to 2 carbon atoms or (C2H4O) p It is a group represented by H. p is preferably a number between 0 and 3.
[0023] In this invention, two or more compounds (1) with different X in general formula (1) are used, preferably five or fewer, and more preferably two. At least one of the two or more compounds (1) used in this invention has R in general formula (1) 1a or R 1b A compound having an alkenyl group with 14 to 22 carbon atoms, that is, R in X in general formula (1) 1a as an alkenyl group having 14 to 22 carbon atoms or R 1b It is a compound containing an alkenyl group with 13 to 21 carbon atoms.
[0024] In this invention, there are two types of compound (1), and of the two types of compound (1), including (i) to (v) above, one of them is such that X in general formula (1) is R 1a Preferably, the compound is an alkenyl group having 14 to 22 carbon atoms. That is, component (A) is two types of compounds represented by the general formula (1), the two types of compounds differ in X in the general formula (1), and of the two types of compounds, one of which has X in the general formula (1) as R 1a And R 1a It is preferable that the compound is an alkenyl group.
[0025] (A) As a component, X in general formula (1) is R 1a or R 1b -[CONH-CH2CH2CH2] n - represents a group (where R 1a R is an alkenyl group having 14 to 22 carbon atoms. 1b Examples include a compound (1a) in which ( is an alkenyl group having 13 to 21 carbon atoms) and a compound (1b) in which X in general formula (1) is different from compound (1a). (A) Specifically, the components include a combination of compound (1a) represented by the following general formula (1a) and compound (1b) represented by the following general formula (1b).
[0026] [ka]
[0027] [During the ceremony, n1 and n2 are independent integers between 0 and 3 (inclusive). R 11a When n1 is 0, it is an alkenyl group with 14 to 22 carbon atoms, and when n1 is 1 to 3, it is an alkenyl group with 13 to 21 carbon atoms. R 11b When n2 is 0, it is an alkyl group having 14 to 22 carbon atoms or an alkenyl group having 14 to 22 carbon atoms; when n2 is 1 to 3, it is an alkyl group having 13 to 21 carbon atoms or an alkenyl group having 13 to 21 carbon atoms. However, if n1 and n2 are the same number, R 11b The alkenyl group is R 11a It is a different alkenyl group. R 2 and R 3 Each of these is independently an alkyl group having 1 to 4 carbon atoms or -(C2H4O) p It is a group represented by H. p is the average number of moles added, and R 2 and R 3 The sum of the numbers is between 0 and 5 (inclusive). That is the case.
[0028] In general formula (1a), R 11a The number of carbon atoms is preferably 17 or more, and preferably 22 or less. In general formula (1a), n1 is preferably 0 or 1, more preferably 0.
[0029] In general formula (1b), when n² is 0, R 11b If R is an alkyl group, 11b The number of carbon atoms is preferably 16 or more, and preferably 22 or less. In general formula (1b), when n² is 0, R 11b If R is an alkenyl group, 11b The number of carbon atoms is preferably 18 or more, and preferably 22 or less. In general formula (1b), n² is 1 to 3 and R 11b If R is an alkyl group, 11b The number of carbon atoms is preferably 15 or more, and preferably 21 or less. In general formula (1b), n² is 1 to 3 and R 11b If R is an alkenyl group, 11b The number of carbon atoms is preferably 17 or more, and preferably 21 or less. In general formula (1b), R 11b Alkyl alkyl groups are preferred. In general formula (1b), n2 is preferably 0 or 1.
[0030] In general formula (1a) or (1b), R 2 and R 3Each is independently preferably a C1 or C2 alkyl group or -(C2H4O) p The group is represented by H, and more preferably by an alkyl group having 1 or 2 carbon atoms. In general formula (1a) or (1b), p is preferably a number between 0 and 3. If n1 and n2 are the same number, R 11b The alkenyl group is R 11a It is a different alkenyl group.
[0031] The (A) component of the present invention includes a combination of compound (11a) represented by the following general formula (11a) and compound (1b) represented by the following general formula (1b).
[0032] [ka]
[0033] [During the ceremony, n2 is an integer between 0 and 3 (inclusive). R 11a This is an alkenyl group having 14 to 22 carbon atoms. R 11b When n2 is 0, it is an alkyl group having 14 to 22 carbon atoms or an alkenyl group having 14 to 22 carbon atoms; when n2 is 1 to 3, it is an alkyl group having 13 to 21 carbon atoms or an alkenyl group having 13 to 21 carbon atoms. However, if n2 is 0, R 11b The alkenyl group is R 11a It is a different alkenyl group. R 2 and R 3 Each of these is independently an alkyl group having 1 to 4 carbon atoms or -(C2H4O) p It is a group represented by H. p is the average number of moles added, and R 2 and R 3 The sum of the numbers is between 0 and 5 (inclusive). That is the case.
[0034] Compound (11a) represented by general formula (11a) corresponds to the compound in general formula (1a) where n1 is 0. 11a , R 2 and R 3 The preferred embodiment of compound (1b) is the same as that of general formula (1a). In this combination as well, the preferred embodiment of compound (1b) is the same as described above.
[0035] In the present invention, the mass ratio of compound (1b) / compound (1a) is preferably 5 / 95 or more, more preferably 25 / 75 or more, even more preferably 30 / 70 or more, even more preferably 40 / 60 or more, and preferably 95 / 5 or less, more preferably 90 / 10 or less, and even more preferably 85 / 15 or less.
[0036] When component (A) of the present invention is a combination of compound (11a) represented by the general formula (11a) and compound (1b) represented by the general formula (1b), the mass ratio of compound (1b) / compound (11a) is preferably 5 / 95 or more, more preferably 25 / 75 or more, even more preferably 30 / 70 or more, even more preferably 40 / 60 or more, and preferably 95 / 5 or less, more preferably 90 / 10 or less, and even more preferably 85 / 15 or less.
[0037] The rheological modifier may contain component (A) in amounts of, for example, 15% by mass or more, further 30% by mass or more, further 40% by mass or more, and 100% by mass or less, or it may contain 100% by mass of component (A), that is, it may consist of component (A).
[0038] Furthermore, from the viewpoint of improving non-separability in water, the rheological modifier is preferably further containing (B) anionic aromatic compound [hereinafter referred to as (B) component]. Examples of (B) component include one or more compounds selected from sulfonic acid having an aromatic ring, carboxylic acid having an aromatic ring, phosphonic acid having an aromatic ring, or salts thereof. The anionic aromatic compound is preferably an acid type compound with a total carbon number of 6 to 12. Specific examples of anionic aromatic compounds include salicylic acid, p-toluenesulfonic acid, sulfosalicylic acid, benzoic acid, m-sulfobenzoic acid, p-sulfobenzoic acid, 4-sulfophthalic acid, 5-sulfisophthalic acid, p-phenolsulfonic acid, m-xylene-4-sulfonic acid, cumenesulfonic acid, methylsalicylic acid, styrenesulfonic acid, chlorobenzoic acid, alkyl (e.g., carbon number 1 to 6) naphthalenesulfonic acid, etc. These may also form salts. Two or more anionic aromatic compounds may be used. The anionic aromatic compounds are preferably one or more compounds selected from sulfonic acids having an aromatic ring, carboxylic acids having an aromatic ring, and salts thereof. Examples of the salt of component (B) include alkali metal salts such as sodium salts. The rheological modifier according to the present invention preferably contains alkyl (e.g., having 1 to 6 carbon atoms) naphthalene sulfonic acid or a salt thereof as component (B).
[0039] If the rheological modifier contains component (B), the rheological modifier may contain component (B) in amounts of, for example, 85% by mass or less, further 70% by mass or less, and further 60% by mass or less. Furthermore, the total content of component (A) and component (B) in the rheological modifier may be 100% by mass.
[0040] When component (B) is used, the mass ratio of component (A) to component (B), and further the mass ratio of compound (1) to component (B), is preferably 70 / 30 or more, more preferably 80 / 20 or more, even more preferably 85 / 15 or more, and preferably 99.9 / 0.1 or less, and more preferably 95 / 5 or less.
[0041] The water used in the non-separating slurry composition can be tap water, river water, lake water, etc.
[0042] The water-non-separable slurry composition according to the present invention may have a water-to-inorganic powder mass ratio (W / P) of, for example, 25% or more, more precisely 30% by mass or more, more precisely 35% by mass or more, and 300% or less, more precisely 200% by mass or less, and more precisely 150% by mass or less. Here, W / P is the mass percentage (mass%) of water in the water-non-separable slurry composition to inorganic powder such as cement, and is calculated as (water content) / (inorganic powder content) × 100.
[0043] The non-separable slurry composition in water according to the present invention may contain a rheological modifier in an amount of, for example, 0.25% by mass or more, further 0.5% by mass or more, further 0.75% by mass or more, and 10% by mass or less, further 5% by mass or less, further 4% by mass or less, further 3% by mass or less, further 2.5% by mass or less, further 2% by mass or less, and further 1.5% by mass or less, relative to water.
[0044] When the rheological modifier contains compound (1) as component (A), the water-non-separable slurry composition according to the present invention may contain compound (1) in an amount of, for example, 0.001% by mass or more, further 0.01% by mass or more, further 0.05% by mass or more, further 0.1% by mass or more, and 10% by mass or less, further 5% by mass or less, further 4% by mass or less, further 3% by mass or less, further 2.5% by mass or less, further 2% by mass or less, and further 1.5% by mass or less, relative to water.
[0045] The water-non-separable slurry composition according to the present invention may contain any components other than inorganic powder, rheological modifier, and water.
[0046] The non-separating slurry composition in water according to the present invention may contain (C) an antifoaming agent [hereinafter referred to as component (C)]. Component (C) is preferably one or more compounds selected from polysiloxane, polyoxyethylene polyoxypropylene, polypropylene oxide and its derivatives (polyoxypropylene, polyoxypropylene glyceryl ether, etc.), acetylene glycol and its derivatives (acetylene glycol, alkylene oxide adduct of acetylene glycol, etc.), polyoxyalkylene fatty acid ester, polyoxyalkylene alkyl ether, polyoxyalkylene alkylamide, trialkyl phosphate, and alcohol. More preferably these compounds are compounds that are insoluble in water.
[0047] If the non-separable slurry composition in water according to the present invention contains component (C), the non-separable slurry composition in water contains component (C) in a ratio of preferably 0.001% by mass or more, more preferably 0.01% by mass or more, even more preferably 0.1% by mass or more, preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, relative to the rheological modifier and component (A).
[0048] The non-separable slurry composition in water according to the present invention may further contain other components besides those mentioned above, to the extent that it does not affect the effects of the present invention. Examples include sand, gravel, dispersants, air-entraining agents, retarders, foaming agents, thickeners, foaming agents, waterproofing agents, fluidizing agents, etc. (excluding inorganic powders and components (A) to (C)).
[0049] Next, the cleaning method of the present invention will be described. In this invention, a water-based non-separable slurry composition containing an inorganic powder including cement, a rheological modifier, and water, which is attached to a metal, is washed away from the metal by applying a water flow with a flow rate of 1.2 m / s or more.
[0050] In the cleaning method of the present invention, the water flow velocity is 1.2 m / s or more, preferably 2.0 m / s or more, preferably 30 m / s or less, and more preferably 20 m / s or less.
[0051] In the present invention, it is preferable that the entire amount of water applied to the non-separating slurry composition in water is applied to the composition as a water flow with a flow velocity of 1.2 m / s or more.
[0052] In the present invention, it is preferable to apply the water flow to the water-non-separable slurry composition using a hose or the like. Furthermore, in the present invention, the water flow may be applied to the water-non-separable slurry composition from any direction, such as from above, below, or to the side of the metal in the water-non-separable slurry composition.
[0053] In this invention, the water flow can be applied to different parts of the non-separable slurry composition in water. For example, the water flow can be applied to different parts of the non-separable slurry composition in water while moving it. Furthermore, in this invention, multiple water flows may be applied to the non-separable slurry composition in water.
[0054] In the present invention, the mass ratio (I) / (II) of the amount of water-non-separable slurry composition attached to the metal (II) to the total amount of water applied (I) may be, for example, 0.10 or more, further 1.0 or more, further 10.0 or more, and 2000 or less, further 1500 or less, and further 1000 or less. Applying water in this amount is preferable from the viewpoint of exhibiting the cleaning effect by water flow under the conditions of the present invention.
[0055] The water-non-separating slurry composition comes into contact with various metal components from manufacturing to use (e.g., construction). In this invention, examples of metals include stainless steel, aluminum, tinplate, and iron. The metal may be one or more metals selected from stainless steel, aluminum, tinplate, and iron, or further, one or more metals selected from stainless steel and tinplate. The metal may be a metal product having a predetermined use. Examples of metal products include pipes, storage tanks, storage containers, shovels, trowels, stirring wheels, pan-type mixers, dicross mixers, forced twin-shaft mixers, tilting mixers, air meters, tamping rods, and flow plates. [Examples]
[0056] [Ingredients used] (1)Water Tap water (2) Cement Blast furnace type B cement (Sumitomo Osaka Cement Co., Ltd.) (3) Components of rheological modifiers (3-1) Component (A) Oleyldimethylamine oxide Oleamide propyl dimethylamine oxide (3-2)(B) component Sodium m-xylenesulfonate Sodium butylnaphthalene sulfonate (3-3) Other ingredients Commercially available thickener 1: Asukaclean, manufactured by Shin-Etsu Chemical Co., Ltd. Commercially available thickener 2: Ocean SP-12, manufactured by Ando Hazama Industries Co., Ltd.
[0057] [Rheological modifier] Formulations 1-6: Rheological modifiers combining component (A) and component (B) as shown in Table 1 (percentages in Table 1 are by mass).
[0058] [Table 1]
[0059] <Example 1 and Comparative Example 1> A predetermined amount of cement was mixed with a predetermined amount of water for 30 seconds using a hand mixer. A predetermined amount of rheology modifier was then added and mixed for another 60 seconds using a hand mixer to prepare cement milk. The cement milk is a water-non-separating slurry composition, and the amounts of cement and water were adjusted so that the W / P ratio was as shown in Table 2. 50 g of the prepared cement milk was applied to a metal plate (Table 2) placed horizontally. 500 g of water was poured into the center of the cement milk from a predetermined height (5 cm, 10 cm, or 25 cm) using a funnel (with a 20 mm diameter outlet) at the predetermined flow rate shown in the table. After all the water had been poured, the amount of cement milk remaining on the surface of the metal plate (g) was measured, and the remaining rate was calculated using the following formula. A smaller remaining rate indicates better cleaning effect. The results are shown in Table 2. The flow rate is the free-falling velocity of water from a predetermined height [(2 × gravitational acceleration × height)]. 1 / 2 The calculation was performed without considering air resistance. Remaining percentage (%) = 100 × (Amount of cement grout remaining / 50)
[0060] [Table 2]
Claims
1. A method for cleaning metal, comprising applying a stream of water consisting only of water to a slurry composition adhering to the metal, which contains an inorganic powder including cement, a rheological modifier, and water, and is less likely to cause material separation in water and less likely to pollute the water, thereby washing the composition off the metal. The slurry composition has a water-to-inorganic powder ratio (W / P) of 35% by mass or more and 300% by mass or less, and a rheological modifier content of 0.25% by mass or more and 2.5% by mass or less relative to water. The rheological modifier is a rheological modifier that contains an amine oxide type surfactant represented by the following general formula (1), and whose maximum relaxation time τ of an aqueous solution of the rheological modifier, as measured by the following measurement method, is 1 s or more and 1000 s or less. The water flow velocity is 1.2 m / s or more. Methods for cleaning metal. 【Chemistry 1】 [During the ceremony, X is a group represented by R 1a or R 1b - [CONH-CH 2 CH 2 CH 2]n -, R1a is an alkyl group having 14 to 22 carbon atoms or an alkenyl group having 14 to 22 carbon atoms. R1b is an alkyl group having 13 to 21 carbon atoms or an alkenyl group having 13 to 21 carbon atoms. n is an integer between 1 and 3, R2 and R3 are each independently an alkyl group having 1 to 4 carbon atoms or a group represented by -(C2H4O)pH. p is the average number of added moles, and the sum of R2 and R3 is between 0 and 5. <Method for measuring the longest relaxation time τ> An aqueous solution of the rheological modifier is prepared by adding 1.0% by mass of the rheological modifier to water with a pH of 13 obtained by mixing deionized water and sodium hydroxide. The longest relaxation time τ is measured by performing frequency dispersion measurements on this aqueous solution at 20°C and a strain of 5% using a cone plate (diameter 50 mm, angle 0.0398 rad, GAP 0.097 mm).
2. The method for cleaning a metal according to claim 1, wherein the metal is one or more metals selected from stainless steel, aluminum, and tinplate.
3. A method for cleaning metal according to claim 1 or 2, wherein the mass ratio (I) / (II) of the amount of water-non-separable slurry composition attached to the metal (II) to the total amount of water applied (I) is 0.10 or more and 2000 or less.
4. The method for cleaning metal according to any one of claims 1 to 3, wherein the rheological modifier further contains an anionic aromatic compound.
5. The method for cleaning metal according to any one of claims 1 to 4, wherein the rheological modifier contains two amine oxide type surfactants represented by the general formula (1), and the two amine oxide type surfactants differ in that X is represented by the general formula (1).
6. The method for cleaning metal according to claim 5, wherein at least one of the two amine oxide-type surfactants is R1a in general formula (1), and R1a is an alkenyl group.