Cleaning solvent composition

Abstract

To provide a cleaning method including a step of bringing vapor of a solvent composition for cleaning into contact with a cleaned object using an azeotropic solvent composition for cleaning that is repeatedly usable without preventing composition balance even when circulated, and cleans a cleaned object attached with various oily contaminant and oil.SOLUTION: A method for cleaning a cleaned object using a solvent composition for cleaning contains (A) cis-1-chloro-3,3,3-trifluoropropene and (B) hydrofluoroether indicating pseudo azeotropic properties when mixed with the component (A), in which when the total of the component (A) and the component (B) is 100 pts.wt., the component (A) is 8 pts.wt. or more and less than 30 pts.wt., and the method includes a step of bringing vapor of the solvent composition for cleaning into contact with the cleaned object.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a cleaning solvent composition. [Background technology]

[0002] Hydrofluoroolefins and hydrofluoroethers are expected to be substitutes for HCFC-225, which has been used in a variety of cleaning fields (oil and grease cleaning, flux cleaning, dust cleaning, moisture removal solvent, dry cleaning solvent, reaction solvent, dilution solvent for lubricants, etc.). Both hydrofluoroolefins and hydrofluoroethers have no flash point and are non-flammable. Patent Document 1 describes a cleaning agent composition containing hydrofluoroolefins and hydrofluoroethers and an aerosol composition thereof. Patent Document 2 describes that a cleaning agent composition containing hydrofluoroolefins and hydrofluoroethers has little effect on resins and has excellent solubility in oils and fats. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-200989 A [Patent Document 2] JP 2017-043742 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, Patent Documents 1 and 2 do not disclose any knowledge about how the liquid balance of a mixture of a hydrofluoroolefin and a hydrofluoroether changes when the mixture is circulated in a cleaning machine. In particular, in cleaning methods including a step of contacting an object to be cleaned with the vapor of a cleaning solvent composition, such as steam cleaning, steam rinsing, and steam drying, there have been cases where the liquid balance of the mixture changes significantly when the mixture is circulated in a cleaning machine, which has been a problem.

[0005] Therefore, an object of the present invention is to provide a cleaning method using a cleaning solvent composition which is unlikely to lose its compositional balance even when recycled, can be used repeatedly, and is for cleaning objects having various oily stains and oils attached thereto, the method including a step of contacting an object to be cleaned with vapor of the cleaning solvent composition.

[0006] The present invention has the following configuration. [1] (A) cis-1-chloro-3,3,3-trifluoropropene, (B) A hydrofluoroether that exhibits pseudoazeotropy when mixed with component (A). wherein, when the total of the components (A) and (B) is 100 parts by weight, the amount of the component (A) is 8 parts by weight or more and less than 30 parts by weight, said cleaning method including a step of contacting the object to be cleaned with vapor of the cleaning solvent composition. [2] The cleaning method according to [1], wherein the component (B) is 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether. [3] The cleaning method according to [1] or [2], wherein the difference between the liquid temperature and the vapor temperature of the cleaning solvent composition is less than 2.5°C. [4] The cleaning method according to any one of [1] to [3] for cleaning an object having one or more types of dirt selected from the group consisting of oily dirt and oil adhering to a substrate. [5] The cleaning method according to any one of [1] to [4], wherein the liquid temperature in the steam tank in the steam contact step is 38 to 60°C. [6] The cleaning method according to any one of [1] to [5], wherein the base material of the object to be cleaned comprises at least one material selected from the group consisting of plastic and rubber. [7] A steam contact tank or steam contact area for any of the cleaning methods described in [1] to [6]. [8] A steam generating tank for any of the cleaning methods described in [1] to [6]. Effect of the Invention

[0007] The present invention provides a cleaning method using an azeotropic cleaning solvent composition which is unlikely to lose its compositional balance even when recycled and can be used repeatedly, and which is used to clean objects having various oily stains and oils attached thereto, the method including a step of contacting an object to be cleaned with vapor of the cleaning solvent composition. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing an outline of a cleaning system 1. As shown in FIG. [Diagram 2] FIG. 2 is a diagram showing an outline of the cleaning system 2. As shown in FIG. [Diagram 3] FIG. 3 is a diagram showing an outline of the cleaning system 3. As shown in FIG. [Figure 4] FIG. 4 is a diagram showing an outline of the cleaning system 4. As shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (Definition of terms) "(A) cis-1-chloro-3,3,3-trifluoropropene" may be referred to as "(A)" or "(A) component." The same applies to other components. With regard to numerical ranges, "to" means that both ends of the range are included. That is, "8 to 28 parts" means "8 parts by weight or more and 28 parts by weight or less." Additionally, "or less" means "the same as or less than," and "or more" means "the same as or greater than."

[0010] [Cleaning method] The cleaning method is a method for cleaning an object to be cleaned using a cleaning solvent composition containing (A) cis-1-chloro-3,3,3-trifluoropropene and (B) a hydrofluoroether that exhibits pseudo-azeotropy when mixed with component (A), in which the amount of component (A) is 8 parts by weight or more and less than 30 parts by weight when the total amount of components (A) and (B) is 100 parts by weight, and includes a steam contacting step of contacting the object to be cleaned with steam of the cleaning solvent composition.

[0011] [Cleaning solvent composition] The cleaning solvent composition (hereinafter also simply referred to as "solvent composition") contains (A) cis-1-chloro-3,3,3-trifluoropropene and (B) a hydrofluoroether that exhibits pseudo-azeotropy when mixed with component (A), in which (A) is 8 parts by weight or more and less than 30 parts by weight when the total of components (A) and (B) is 100 parts by weight.

[0012] The present inventors have discovered that in a combination of a specific hydrofluoroolefin and a hydrofluoroether, by using component (B) which is in a pseudo-azeotropic state with component (A), it is possible to clean objects having various oils or oily stains thereon with little change in composition even when the component (A) is recycled.

[0013] Here, "hydrofluoroether exhibiting pseudo-azeotropy when mixed with component (A)" means that the difference between the liquid temperature and the vapor temperature of the cleaning solvent composition is less than 2.5°C. Here, the cleaning solvent composition whose liquid temperature and vapor temperature are measured is in a state that does not contain dirt such as oil. Specifically, the liquid temperature and vapor temperature of the cleaning solvent composition can be measured in a vapor tank of a cleaning device. Therefore, the difference between the liquid temperature and the vapor temperature of a cleaning solvent composition applied to a cleaning method and containing oily dirt or the like can be different. From the viewpoint of less change in composition even when used in a circulating manner, it is preferable that the difference between the liquid temperature and the vapor temperature of the cleaning solvent composition is within 2°C.

[0014] <(A) cis-1-chloro-3,3,3-trifluoropropene> Component (A) has a boiling point of 39° C. and is the main component of the cleaning solvent composition. Commercially available products of component (A) include CELEFIN (registered trademark) 1233Z (HCFO-1233zd(Z), HFO-1233zd(Z)) (manufactured by Central Glass Co., Ltd.).

[0015] <(B) Hydrofluoroether that exhibits pseudoazeotropy when mixed with component (A)> The component (B) is not particularly limited as long as it is a hydrofluoroether that exhibits pseudoazeotropy when mixed with the component (A). Hydrofluoroethers (HFEs) are compounds that contain carbon atoms, fluorine atoms, hydrogen atoms, and ether bonds (-O-). The component (B) can be 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether. 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether has a boiling point of 56°C and is also called 1,1,2,2-tetrafluoro-1-(2,2,2-trifluoroethoxy)ethane, HFE-347pc-f. Although the boiling point of 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether is about 17°C away from the boiling point of the component (A), it has been found that when combined with the component (A) in a specific composition, the difference between the liquid temperature and the vapor temperature of the cleaning solvent composition can be less than 2.5°C. In addition, it is particularly preferable that the (B) component is 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, since when combined with the (A) component in a specific composition, the cleaning ability of objects having oily stains and oil attached thereto is further improved.

[0016] <Ingredients other than (A) and (B)> The cleaning solvent composition may contain (C) a further component other than the components (A) and (B) and (D) an additive, as long as the effects of the present invention are not impaired.

[0017] <<(C) Further Ingredients>> (C) Additional components include (c1) nitro compounds, (c2) ethers, (c3) esters (excluding (c2) ethers), (c4) alcohols (excluding (c2) ethers), (c5) amide compounds, (c6) chloroolefins, (c7) hydrofluoroolefins, (c8) hydrobromocarbons, (c9) hydrofluorocarbons, (c10) hydrofluoroethers (excluding (B) components), (c11) hydrocarbons and (c12) chlorinated hydrocarbons (excluding (c6) chloroolefins and (c11) hydrocarbons).

[0018] <(c1) Nitro compounds> The (c1) nitro compound is not particularly limited as long as it has one or more nitro groups in the molecule. Examples of the (c1) component include nitroalkanes such as nitromethane, nitroethane, 1-nitropropane, and 2-nitropropane.

[0019] ≪(c2) Ether≫ The (c2) ether is an ether-based solvent that contains carbon atoms, hydrogen atoms, and an ether bond (-O-), and may be linear or branched, and may be cyclic or acyclic. The (c2) component includes glycols. Specific examples of the component (c2) include dipropyl ether, diisopropyl ether, tetrahydrofuran, methyltetrahydrofuran, 4-methyltetrahydropyran, 1,4-dioxane, 1,3-dioxolane, diethyl ether, diisobutyl ether, dibutyl ether, methyl tertiary butyl ether, methyl cellosolve, ethyl cellosolve, isopropyl cellosolve, 1,2-butylene oxide, epichlorohydrin, propylene oxide, cyclohexene oxide, cyclopentene oxide, pentene oxide, heptene oxide, octene oxide, alkyl glycidyl ether, alkyl glycidyl ester, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, monoethylene glycol monopropyl ether, diethylene glycol monopropyl ether, triethylene glycol monopropyl ether, and ethylene glycol mono butyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, monopropylene glycol monoethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monoethyl ether, monopropylene glycol monopropyl ether, dipropylene glycol monopropyl ether, tripropylene glycol monopropyl ether, monopropylene glycol monobutyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether, propylene glycol, ethylene glycol, dipropylene glycol, diethylene glycol, tripropylene glycol, diethylene glycol monobutyl ether, monoethylene glycol dimethyl ether (monoglyme), diethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol diethyl ether,Examples of the ethyl alcohol include triethylene glycol dimethyl ether, diethylene glycol dibutyl ether, dimethoxytetraethylene glycol, dipropylene glycol dimethyl ether, monopropylene glycol monomethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethylene glycol monophenyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, 3-methoxy-3-methyl-1-butanol, diethylene glycol monohexyl ether, diethylene glycol ethyl methyl ether, and dipropylene glycol ethyl methyl ether.

[0020] <(c3) Esters (excluding (c2) ethers)> Examples of (c3) esters (excluding (c2) ethers) include monoester solvents, ester solvents having two carbonyl groups, carbonate ester solvents, and cyclic ester solvents. Specific examples of the (c3) component include methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, butyl acetate, sec-butyl acetate, methoxybutyl acetate, amyl acetate, soybean fatty acid methyl esters, methyl lactate, ethyl lactate, propyl lactate, dibasic acid esters (DBE), ethyl acetoacetate, γ-butyrolactone, dimethyl carbonate, diethyl carbonate, dimethyl oxalate, and diethyl oxalate.

[0021] <(c4) Alcohols (excluding (c2) ethers)> Examples of (c4) alcohols (excluding (c2) ethers) include monoalcohol-based solvents. Specific examples of the (c4) component include ethanol, methanol, 1-propanol, isopropyl alcohol, 1-butanol, isobutyl alcohol, tertiary butanol, secondary butyl alcohol, benzyl alcohol, diacetone alcohol, 2-propyn-1-ol, and 2-ethylhexanol.

[0022] <(c5) Amide compound> (c5) Amide compound is a cyclic or acyclic compound having an amide bond. Examples of the (c5) component include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 2-pyrrolidone, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, dimethylformamide, dimethylacetamide, and dimethylacetoacetamide.

[0023] <(c6) Chloroolefin> (c6) Chloroolefin is an olefin compound containing carbon and chlorine atoms and may contain hydrogen and / or fluorine atoms. Examples of (c6) component include trans-1,2-dichloroethylene and trichloroethylene, which are hydrochloroolefins containing hydrogen atoms, tetrachloroethylene (perchloroethylene), 1,1-dichloro-2,3,3,3-tetrafluoropropene (CFO-1214ya), 1,1,2-trichloro-3,3,3-trifluoropropene (CFO-1213xa), and the like, which do not contain hydrogen atoms.

[0024] <(c7) Hydrofluoroolefin> (c7) Hydrofluoroolefin is a halogenated fluoroolefin compound which may contain one or more atoms selected from the group consisting of chlorine atoms and bromine atoms. Examples of the (c7) component include (E)-1-chloro-2,3,3-trifluoropropene ((E)-1-chloro-2,3,3-trifluoro-1-propene, HCFO-1233yd(E)), (Z)-1-chloro-2,3,3-trifluoropropene ((Z)-1-chloro-2,3,3-trifluoro-1-propene, HCFO-1233yd(Z)), 2-bromo-3,3,3-trifluoro-1-propene, 1,1-dichloro-3,3,3-trifluoropropene (HCFO-1223za), (Z)-1,2-dichloro-3,3,3-trifluoropropene ( HCFO-1223xd(Z)), (E)-1,2-dichloro-3,3,3-trifluoropropene (HCFO-1223xd(E)), 1-chloro-1,3,3-trifluoropropene, (Z)-1-chloro-2,3,3,4,4,5,5-heptafluoro-1-pentene (HCFO-1437dycc(Z)), (E)-1-chloro-2,3,3,4,4,5,5-heptafluoro-1-pentene (HCFO-1437dycc(E)), (Z)-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz(Z)), and the like. The hydrofluoroolefin is preferably (E)-1-chloro-2,3,3-trifluoropropene ((E)-1-chloro-2,3,3-trifluoro-1-propene, HCFO-1233yd(E)) or (Z)-1-chloro-2,3,3-trifluoropropene ((Z)-1-chloro-2,3,3-trifluoro-1-propene, HCFO-1233yd(Z)). Commercially available hydrofluoroolefins include AMOLEA (registered trademark) AS-300 (manufactured by AGC Corporation) (a mixture of (E)-1-chloro-2,3,3-trifluoropropene (HCFO-1233yd(E)), (Z)-1-chloro-2,3,3-trifluoropropene (HCFO-1233yd(Z)) and a stabilizer)).

[0025] ≪(c8) Hydrobromocarbon≫ (c8) Hydrobromocarbon is a compound consisting of only carbon, bromine and hydrogen atoms. Examples of the (c8) component include normal propyl bromide (1-bromopropane) and isobutyl bromide.

[0026] ≪(c9) Hydrofluorocarbon≫ (c9) Hydrofluorocarbon (HFC) is a compound consisting of only carbon, fluorine and hydrogen atoms and does not have a carbon-carbon double bond. (c9) component includes, for example, 1,1,1,3,3-pentafluorobutane (HFC-365mfc), 1,1,2,2,3,3,4-heptafluorocyclopentane (HFC-c447ef), 1,1,1,2,2,3,3,4,4,5,5,6,6-tridecafluorooctane, and 1,1,1,2,2,3,4,5,5,5-decafluoropentane (HFC-43-10mee). Commercially available products of the component (c1) include Solkane (registered trademark) 365mfc (manufactured by Nippon Solvay Co., Ltd.) for 1,1,1,3,3-pentafluorobutane, and Zeorora (registered trademark) H (manufactured by Nippon Zeon Co., Ltd.) for 1,1,2,2,3,3,4-heptafluorocyclopentane.

[0027] <(c10) Hydrofluoroether (excluding component (B))> (c10) Hydrofluoroether (HFE) is a compound containing carbon atoms, fluorine atoms, hydrogen atoms and an ether bond (-O-), other than component (B). Examples of component (c10) include methyl nonafluorobutyl ether, methyl nonafluoroisobutyl ether, ethyl nonafluorobutyl ether, ethyl nonafluoroisobutyl ether, 1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-(trifluoromethyl)pentane, 1,1,1,2,3,3-hexafluoro-4-(1,1,2,3,3,3-hexafluoropropoxy)pentane, 1,1,1,2,3,4,4,4-octafluoro-2-methoxy-3-(trifluoromethyl)butane, and methyl perfluoropropyl ether.

[0028] <(C11) Hydrocarbons> (c11) Hydrocarbon is a hydrocarbon-based solvent consisting of only carbon and hydrogen, which may be linear or branched, cyclic or noncyclic, and may have a carbon-carbon double bond. (c11) component includes hexane, isohexane, cyclohexane, normal heptane, isoheptane, cycloheptane, normal octane, isooctane, nonane, isononane, decane, methylcyclohexane, ethylcyclohexane, limonene, 2-methyl-2-butene, 2-methyl-1-pentene, 2-methyl-2-pentene, 3-ethyl-2-butene, 2,3-dimethyl-2-butene, 2,4,4-trimethyl-1-pentene, 2,4,4-trimethyl-2-pentene, 2,2,4,6,6-pentamethylheptane, isododecane, isoparaffins, naphthenes, aromatic hydrocarbons, etc. Hydrocarbon-based solvents may be synthetic.

[0029] <<(c12) Chlorinated hydrocarbons (excluding (c6) chloroolefins, (c7) hydrofluoroolefins, and (c11) hydrocarbons)>> (c12) Chlorinated hydrocarbons (excluding (c6) chloroolefins, (c7) hydrofluoroolefins, and (c11) hydrocarbons) are hydrocarbon solvents that contain chlorine atoms and carbon atoms and may contain hydrogen atoms. Examples of the (c12) component include methylene chloride.

[0030] (C) Each of the additional components may be one type or a combination of two or more types.

[0031] <<(D) Additives>> The (D) additive is not particularly limited as long as it is a component other than the (C) component and is a component commonly used in the field of cleaning solvent compositions. The (D) additive may be one or more selected from the group consisting of water, ultraviolet absorbers, antioxidants, rust inhibitors, antifoaming agents, surfactants, chelating agents, etc. The (C) component that acts as the (D) component is included in the (D) component.

[0032] The ultraviolet absorber and the antioxidant are components that improve the stability of the cleaning solvent composition during long-term storage, etc. Examples of the ultraviolet absorber include benzotriazole-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, and hindered amine-based ultraviolet absorbers. Examples of the antioxidant include phenol-based antioxidants, amine-based antioxidants, sulfur-based antioxidants, and phosphorus-based antioxidants.

[0033] Phenolic antioxidants include 2,6-di-t-butyl-4-methylphenol, triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-1,3,5-triazine, pentaerythrityl-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,2-thio- Diethylene bis[3-(3,5-di-t-butyl-hydroxyphenyl)propionate], octadodecyl-3-[3,5-di-t-butyl-4-hydroxyphenyl]propionate], N,N-hexamethylene bis(3,5-di-t-butyl-4-hydroxy-hydrocinnamide), 3,5-di-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, 2,4-bis[(octylthio)methyl]-o-cresol, and the like.

[0034] Examples of the amine-based antioxidant include alkylated diphenylamine, tris-(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanurate, N,N-di-sec-butyl-p-phenylenediamine, p-phenylenediamine derivatives, and 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethyl)isocyanurate. Examples of sulfur-based antioxidants include 2,4-bis[(octylthio)methyl]-o-cresol, dilauryl-3,3-thiodipropionate, dimyristyl-3,3-didipropionate, distearyl-3,3-thiodipropionate, pentaerythrityl tetrakis(3-laurylthiopropionate), ditridecyl-3,3-thiodipropionate, 2-mercaptobenzimidazole, bis[2-methyl-4-(3-n-alkylthiopropionyloxy)-5-t-butylphenyl]sulfide, etc. Examples of phosphorus-based antioxidants include tris-nonylphenyl phosphite, triphenyl phosphite, tris(2,4-di-t-butylphenyl)phosphite, tris(isodecyl)phosphite, etc.

[0035] The chelating agent may be an aminocarboxylic acid-based chelating agent, and preferred are hydroxyethylaminoacetic acid, hydroxyethyliminodiacetic acid, ethylenediaminetetraacetic acid, and salts thereof.

[0036] Examples of the rust inhibitor include cyclohexylamine, dicyclohexylamine, and N,N-bis(2-hydroxyethyl)-N-cyclohexylamine. Examples of the surfactant include nonionic surfactants, and preferred are higher alcohol ethylene oxide adducts, alkylphenol ethylene oxide adducts, fatty acid ethylene oxide adducts, higher alkylamine ethylene oxide adducts, fatty acid esters of sorbitol and sorbitan, sucrose fatty acid esters, silicone surfactants, and fluorine-based surfactants.

[0037] The additives other than the above-mentioned components are not particularly limited as long as they are components commonly used in the field of cleaning solvent compositions, and can be used as appropriate. Each of the (D) additives may be one type or a combination of two or more types.

[0038] <Composition of cleaning solvent composition> In the cleaning solvent composition, when the total of the (A) and (B) components is 100 parts by weight, the (A) component is 8 parts by weight or more and less than 30 parts by weight. When the (A) component is less than 8 parts by weight when the total of the (A) and (B) components is 100 parts by weight, the cleaning property tends to be poor. When the (A) component is 30 parts by weight or more when the total of the (A) and (B) components is 100 parts by weight, damage to the substrate may occur. From the viewpoint of reducing damage to the substrate and cleaning property, the (A) component is preferably 8 to 28 parts by weight, particularly preferably 10 to 28 parts by weight, when the total of the (A) and (B) components is 100 parts by weight. In addition, the (A) component may be 8 to 18 parts by weight, 9 to 17 parts by weight, or 9 to 14 parts by weight when the total of the (A) and (B) components is 100 parts by weight.

[0039] From the viewpoint of achieving a more excellent effect as a cleaning solvent composition, when the total amount of the cleaning solvent composition is taken as 100 parts by weight, the total amount of the (A) component and the (B) component is preferably 80 parts by weight or more, more preferably 85 parts by weight or more, and particularly preferably 90 parts by weight or more.

[0040] [Method of producing cleaning solvent composition] The cleaning solvent composition can be produced by any method. The raw material components contained in the cleaning solvent composition can be produced by appropriately selecting a known method, for example, by carrying out one or more means selected from the group consisting of stirring, mixing, dissolving, and dispersing.

[0041] [Uses of cleaning solvent composition] The cleaning solvent composition has excellent solubility for oil, flux, and / or uncured resin, and can therefore be used as a cleaning agent for cleaning an object to be cleaned having one or more selected from the group consisting of oily dirt, oil, flux, and uncured resin attached thereto. The cleaning method is particularly preferably a cleaning method for cleaning an object to be cleaned having one or more selected from the group consisting of oily dirt and oil attached thereto.

[0042] <<Oil>> Examples of oils include mineral oils, vegetable oils, animal oils, heavy oils, waxes, silicone oils, and fluorinated oils, etc. These oils may be used, for example, as cutting oils, press oils, drawing oils, heat treatment oils, rust-preventive oils, lubricating oils, metal processing oils, greases, asphalts, and water-soluble oils.

[0043] The mineral oil is not particularly limited, and a commercially available product is Pulley SF Oil (manufactured by Idemitsu Kosan Co., Ltd.). Examples of vegetable oils include olive oil, linseed oil, tung oil, sesame oil, safflower oil, soybean oil, castor oil, cottonseed oil, coconut oil, corn oil, and dehydrated castor oil. Fatty acids constituting vegetable oils are saturated or unsaturated fatty acids of C12 to C18, and specific examples include lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, and eleostearic acid. Examples of animal oils include fish oil, whale oil, lard, and beef tallow. Examples of heavy oils include asphaltene. Examples of resins include pitch and rosin. Examples of waxes include vegetable, animal, petroleum, and synthetic hydrocarbons.

[0044] Silicone oil is a linear polymer of siloxane bond, and may be mainly dimethyl silicone oil or methylphenyl silicone oil with other organic groups such as carboxyl group, amino group, polyether group or epoxy group introduced into the side chain or end.Specific examples of such silicone oil include dimethyl polysiloxane, methylphenyl polysiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, polyoxyethylene-methyl polysiloxane, etc.Commercially available products of such silicone oil include KF-96L-2CS and KF-6012 manufactured by Shin-Etsu Chemical Co., Ltd.

[0045] Fluorine oil is a substance in which some or all of the hydrogen atoms in a polyalkyl ether compound are replaced with fluorine, and may contain further atoms such as halogens such as chlorine and bromine, phosphorus, sulfur, and nitrogen. Commercially available fluorine oils include, for example, Fomblin Y-LVAC, Y-HVAC, Y04, and YR manufactured by Solvay Solexis Co., Ltd.; BARRIERTA J100 fluid, BARRIERTA J25 fluid, BARRIERTA J400 fluid, BARRIERTA J25V, BARRIERTA SJ07, BARRIERTA SJ15, and BARRIERTA SJ30 manufactured by NOK Kluber Co., Ltd.; Krytox 1506, Krytox 1514, and Krytox 1525 manufactured by DuPont Co., Ltd.; and Demnum S-20 manufactured by Daikin Industries, Ltd.

[0046] Water-soluble oils are broadly classified into emulsion type, soluble type, and solution type. Emulsion type oils are mainly composed of water-insoluble oils such as mineral oil and fatty oil, and surfactants, and form a milky emulsion when diluted with water. Soluble type oils also contain water-insoluble oils and surfactants, but become transparent to translucent when diluted with water. Solution type oils are mainly composed of water-soluble inorganic salts, and become transparent when diluted with water. There is also emulsion type silicone oil, which is a mixture of silicone oil, surfactant, and water.

[0047] <<Flux>> Examples of the flux include rosin-based fluxes. Examples of the rosin-based flux include non-activated rosin fluxes mainly composed of rosins such as rosin (resin acid mainly composed of abietic acid) and modified rosin; and activated rosin fluxes mainly composed of the rosins and one or more activators selected from the group consisting of inorganic acid salts of amine compounds (e.g., hydrochloride, sulfate) and organic acids. Examples of inorganic acid salts of amine compounds include triethanolamine hydrochloride, triethylenetetraamine hydrochloride, cyclohexylamine hydrochloride, aniline hydrochloride, etc. Examples of the organic acid include carboxylic acids (including dicarboxylic acids) such as succinic acid, adipic acid, glutaric acid, sebacic acid, and maleic acid; and oxyacids (hydroxycarboxylic acids).

[0048] The flux may be provided in the form of cream solder in which the soldering metal and rosin flux are integrated. The cream solder is a composition containing a solder alloy powder, a resin, an activator, an antioxidant, a thixotropic agent, and a solvent, and is composed of so-called metal powder and flux components.

[0049] <<Resin>> The resin in the uncured resin is not particularly limited, and examples thereof include urethane resin, epoxy resin, acrylic resin, styrene resin, silicone resin, polyvinyl chloride resin, polycarbonate resin, and acrylonitrile-butadiene-styrene resin.

[0050] Examples of urethane resins include reaction products of diisocyanates such as tolylene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI) with polyols such as polypropylene glycol. When the urethane resin is in a foam form, it may be any of soft foam, semi-rigid foam, and rigid foam. Examples of additives to be mixed with the urethane resin include curing agents, curing accelerators, emulsifiers, foaming agents, stabilizers, plasticizers, flame retardants, antistatic agents, colorants, sliding modifiers, and impact modifiers. Cured products of urethane resins are used as heat insulating materials, coating agents for electronic substrates, and the like.

[0051] Examples of epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AD ​​type epoxy resins, polyglycidyl ethers of polyhydric alcohols, polyglycidyl esters of polybasic acids, 3,4-epoxycyclohexyl-3',4'-epoxycyclohexane carboxylate, vinylcyclohexene diepoxide, cresol novolac type epoxy resins, and epoxy resins having a hydantoin ring.Additives that are mixed into the epoxy resins include curing agents, curing accelerators, fillers, stabilizers, plasticizers, lubricants, flame retardants, flame retardant assistants, antistatic agents, colorants, charge imparting agents, sliding property improvers, impact resistance improvers, and reactive diluents.

[0052] The curing agent for the epoxy resin may be any one that is commonly used as a curing agent for the epoxy resin, such as novolacs such as phenol novolac, biphenol novolac, and bisphenol A novolac, acid anhydrides such as phthalic anhydride, pyromellitic anhydride, and benzophenone tetracarboxylic anhydride, amines such as diaminodiphenylmethane, diaminodiphenylsulfone, metaphenylenediamine, and hexamethylenetetramine, and amide resins such as polyamidoamine. The curing accelerator may be, for example, a tertiary amine or an organic phosphorus compound. The cured product of the epoxy resin is used as an adhesive or a potting agent for electronic substrates.

[0053] Examples of the acrylic resin include compounds having an acryloyl group and / or a methacryloyl group, and specifically, methyl (meth)acrylate and 2-hydroxyethyl (meth)acrylate. Here, (meth)acrylate means at least one of acrylate and methacrylate. The acrylic resin preferably does not have a fluorine atom, and particularly preferably does not have a halogen atom. Examples of additives that are mixed with the acrylic resin include a curing agent, a curing accelerator, a filler, a stabilizer, a plasticizer, a lubricant, a flame retardant, a flame retardant assistant, an antistatic agent, a colorant, an electrostatic charge imparting agent, a sliding property improver, an impact resistance improver, and a reactive diluent. Since the acrylic resin has good processability and excellent transparency, the cured product of the acrylic resin is used for windshield glass, windows of aircraft, ships, automobiles, etc., aquariums, lenses, lighting equipment, displays, signs, etc.

[0054] Styrene resin is a polymer with styrene as a monomer, and its cured product is also called polystyrene. When the styrene resin is in a foam form, the cured foam of the styrene resin is also called expanded styrene. Additives to be mixed with the styrene resin include foaming agents, curing agents, curing accelerators, fillers, stabilizers, plasticizers, lubricants, flame retardants, flame retardant assistants, antistatic agents, colorants, charge imparting agents, sliding improvers, impact resistance improvers, and reactive diluents. The cured product of the styrene resin is used for automobile lamp lenses and covers.

[0055] Silicone resin is a high condensation product of an organic silicon compound, and has a repeating structure of dimethylsiloxane or methylphenylsiloxane.Additives that are mixed into silicone resin include curing agents, curing accelerators, fillers, stabilizers, plasticizers, lubricants, flame retardants, flame retardant assistants, antistatic agents, colorants, charge imparting agents, sliding improvers, impact resistance improvers, and reactive diluents.Cured products of silicone resins are used in adhesives, coating agents, etc.

[0056] Polyvinyl chloride resin is a homopolymer of vinyl chloride or a copolymer of vinyl chloride and another vinyl monomer.Additives that are mixed into polyvinyl chloride resin include curing agents, curing accelerators, fillers, stabilizers, plasticizers, lubricants, flame retardants, flame retardant assistants, antistatic agents, colorants, chargeability imparting agents, sliding property improvers, impact resistance improvers, and reactive diluents.Cured products of polyvinyl chloride resin are used in building materials such as pipes and flooring materials.

[0057] Polycarbonate resin is a type of thermoplastic. The junctions between monomer units are composed of carbonate groups (-O-(C=O)-O-). Additives that are mixed into polycarbonate resin include curing agents, curing accelerators, fillers, stabilizers, plasticizers, lubricants, flame retardants, flame retardant assistants, antistatic agents, colorants, electrostatic charge imparting agents, sliding property improvers, impact resistance improvers, and reactive diluents. Cured polycarbonate resins are widely used in components for automobiles, etc., and are used in roofs, headlamp lenses, etc.

[0058] Acrylonitrile-butadiene-styrene resin is an acrylonitrile-styrene copolymer, which is a copolymer of acrylonitrile and styrene with polybutadiene, a rubbery polymer, dispersed therein, and is mainly composed of three components: acrylonitrile, butadiene, and styrene. Additives that are mixed into acrylonitrile-butadiene-styrene resin include curing agents, curing accelerators, fillers, stabilizers, plasticizers, lubricants, flame retardants, flame retardant assistants, antistatic agents, colorants, electrostatic charge imparting agents, sliding improvers, impact resistance improvers, and reactive diluents. Cured products of acrylonitrile-butadiene-styrene resin are widely used in interior and exterior parts of automobiles, etc., and are used in wheel caps, wheel covers, dashboards, etc.

[0059] <<Oily stains>> The oily stains include oil stains, flux stains, and uncured resin stains. The oil, flux, and uncured resin that are the raw materials for the oily stains are as described above. The oily stains may contain dust. The oily stains include non-polar oily stains, oily stains due to polar components, and oily stains due to multiple components with different polarities, depending on the polarity of the oil. The flux stains include rosin, which is a flux component, an inorganic acid salt of an amine compound, an organic acid, and a component that is partially altered or carbonized by reflow at high temperatures. The cream solder stains include the flux component stains and metal powder. The resin stains include non-polar resin stains, oily stains due to polar components, and oily stains due to multiple components with different polarities, depending on the polarity of the resin component and the components used in combination. The oily stains are preferably oil stains.

[0060] <Cleaning method> The cleaning method using the cleaning solvent composition (i.e., the method of using the cleaning solvent composition) includes a steam contacting step of contacting the object to be cleaned with the steam of the cleaning solvent composition. The object to be cleaned has oily dirt and / or oil adhering to the substrate. The steam contacting step removes the oily dirt and / or oil adhering to the substrate from the substrate. In addition, when the oily dirt includes solid dirt such as dust, the solid dirt can be removed simultaneously with the removal of the oily dirt.

[0061] <Base material> The material of the substrate is not particularly limited, and examples thereof include metals, fibers, glass, ceramics, rubber, and plastics. Examples of metals include silver, zinc, nickel, iron, aluminum, copper, manganese, magnesium, stainless steel, and aluminum alloys (alloys of aluminum and one or more metals consisting of copper, manganese, silicon, magnesium, zinc, and nickel). Examples of rubbers include nitrile rubber, butyl rubber, natural rubber, styrene-butadiene rubber, isoprene rubber, butadiene rubber, chloroprene rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber, urethane rubber, silicone rubber, and thermoplastic elastomers (styrene-based, olefin-based, and vinyl chloride-based). Examples of plastics include polycarbonate resin, PET resin (polyethylene terephthalate resin), epoxy resin, acrylic resin, silicone resin, ABS resin (acrylonitrile-butadiene-styrene resin), polyolefin resin (polypropylene, polyethylene, etc.), and urethane resin. The substrate may be plastic as long as the above-mentioned oily dirt, oil, flux, uncured resin, etc. are removed from the substrate. The substrate of the object to be cleaned preferably contains plastic and / or rubber, and more preferably consists of only plastic and / or rubber.

[0062] Specific examples of the substrate include devices and parts thereof for obtaining a cured product of the resin, metal processed products, electric and electronic parts, optical parts, automobile parts, machine parts, semiconductor parts, and display parts.

[0063] Examples of electric and electronic parts include wiring boards such as printed circuit boards and ceramic substrates. Examples of optical parts include optical lenses (e.g., camera lenses) and parts for optical lenses (e.g., camera housings). Examples of automobile parts include metal parts used for automobile shafts, frame parts, exterior parts, etc. Examples of machine parts include bearings for vacuum pumps, semiconductor manufacturing equipment, cleaning equipment, motors, fans, etc., bearings for precision machine parts such as watches, and parts such as rollers for printing machines. Examples of semiconductor-related parts include electronic parts such as IC chips and resistors. Examples of display parts include liquid crystal substrates, organic EL substrates, inorganic EL substrates, etc. The shapes of these parts are not limited to plate-shaped members, but may be pipe-shaped members or long members with circular or rectangular cross sections, or members with other complex shapes.

[0064] The object to be cleaned may be an object for daily maintenance, that is, cleaned once or twice a day, or an object for overhaul, that is, cleaned once every six months to a year, for example.

[0065] <Steam contact process> The vapor contact step is not particularly limited as long as it includes a method of generating vapor of the solvent composition from the solvent composition and contacting the generated vapor with the object to be cleaned. Examples of the vapor contact step include vapor cleaning, vapor rinsing, vapor drying, or a combination thereof, and can be appropriately selected depending on the purpose.

[0066] In the steam contact step, the liquid temperature in the steam tank can be appropriately set according to the boiling point of the solvent composition, but is preferably 38 to 60°C, more preferably 40 to 58°C, even more preferably 45 to 56°C, and particularly preferably equal to or higher than the boiling point of the solvent composition. By setting the temperature at such a level, the vapor of the solvent composition can be efficiently generated. The liquid temperature in the steam tank is preferably the liquid temperature in the steam tank when the liquid does not contain dirt such as oil.

[0067] <Additional cleaning methods> The cleaning method may further include a step of immersion cleaning, shower cleaning, ultrasonic cleaning, wiping cleaning, barrel cleaning, spray cleaning, splash cleaning, or a combination of these steps. Here, the conditions for the further steps such as shower cleaning and ultrasonic cleaning can be appropriately set. The cleaning method preferably includes an immersion step of immersing an article in a solvent composition and the steam contact step.

[0068] In the immersion step, the liquid temperature of the solvent composition when it does not contain dirt such as oil can be appropriately set depending on the boiling point of the solvent composition, but is preferably 15 to 60° C., and particularly preferably 20 to 54° C. In addition, when the next step is a steam contact step, the temperature of the solvent composition in the immersion step is preferably 5° C. or more lower than the liquid temperature in the steam contact step. By setting the temperature in this range, dirt can be efficiently removed from the object to be washed.

[0069] The cleaning time corresponding to the contact time of the cleaning solvent composition and the object to be cleaned is not particularly limited as long as it is a time that can remove oily dirt and / or oil from the substrate. For example, the cleaning time may be 1 second or more and 2 hours or less. The same applies to the steam contact step, but the contact step may be 1 second or more and 2 hours or less, and may simply involve passing the generated steam.

[0070] [Cleaning system used in the cleaning method] The cleaning system (cleaning device) used in the cleaning method is not particularly limited, and examples thereof include cleaning devices having a cleaning tank that contains a cleaning agent and in which the object to be cleaned is immersed, and a steam tank that generates steam of the cleaning agent, as disclosed in JP 2008-163400 A and JP 2015-217319 A. In addition, examples of preferred cleaning systems used in the cleaning method will be described.

[0071] (1) Cleaning System 1 The cleaning system 1 is a single-tank cleaning machine. The cleaning system includes a boiling tank that contains a cleaning solvent composition containing components (A) and (B) and in which an object to be cleaned is immersed and generates steam of the cleaning solvent composition, a recovery section that liquefies and recovers the steam of the cleaning solvent composition generated by the boiling tank, and a water separator that separates water from the liquid recovered by the recovery section to extract the cleaning solvent composition.

[0072] The outline of the cleaning system 1 is shown in Fig. 1. The cleaning system 1 preferably includes a boiling tank (11 in Fig. 1) in which a cleaning solvent composition (1 in Fig. 1) containing components (A) and (B) is accommodated, a recovery section (e.g., 21 and 22 in Fig. 1) that liquefies and recovers the vapor of the cleaning solvent composition (2 in Fig. 1) generated from the boiling tank, and a water separator (23 in Fig. 1) that separates water from the liquid recovered by the recovery section to extract the cleaning solvent composition and supplies the extracted cleaning solvent composition to the boiling tank. In Fig. 1, the solid arrow indicates the flow of the cleaning solvent composition.

[0073] The boiling tank is a tank for boiling and cleaning the object to be cleaned. The boiling tank may be called a vapor tank or steam tank. The boiling tank is equipped with a heater (24 in FIG. 1) for maintaining the temperature at or above the temperature at which the cleaning solvent composition generates steam (preferably at or above the boiling point of the cleaning solvent composition). The boiling tank may have an ultrasonic vibrator that applies ultrasonic vibration to the cleaning liquid.

[0074] In the washing system 1, a pump and a filter circuit can be installed in the boiling tank. By providing the washing system 1 with a pump and a filter circuit, if the dirt to be removed from the object to be washed is solid, accumulation of the dirt in the boiling tank tends to be avoided.

[0075] A recovery section is provided at the top of the boiling tank to liquefy and recover the vapor of the cleaning solvent composition generated in the boiling tank. The recovery section is not particularly limited as long as it is provided with a means for liquefying the vapor of the cleaning solvent composition and a means for supplying the liquefied component to the water separator.

[0076] The means for liquefying the vapor of the cleaning solvent composition is not particularly limited, but a cooling pipe (21 in FIG. 1) is preferable. The cooling pipe is a means for lowering the temperature of the vapor of the cleaning solvent composition to liquefy it. By providing the cleaning system with a cooling pipe, the release of the cleaning solvent composition from the cleaning system to the outside is further reduced. The number of turns of the cooling pipe is preferably 3 or more, more preferably 4 or more, even more preferably 5 or more, and particularly preferably 6 or more.

[0077] The means for supplying the liquefied cleaning solvent composition to the water separator is not particularly limited, but a gutter (22 in FIG. 1) is preferred. The gutter is provided to supply the cleaning solvent composition liquefied by a cooling pipe or the like to the water separator. Here, the liquid of the cleaning solvent composition liquefied by the means for liquefying the vapor of the cleaning solvent composition and supplied to the water separator is called a recovered liquid.

[0078] The cleaning solvent composition is then extracted by a water separator, which will be described later, and reused as a regenerated liquid.

[0079] The water separator is provided to separate water from the recovered liquid, extract the cleaning solvent composition, and return it to the boiling tank. The means for separating water by the water separator is not particularly limited as long as it can separate water from the recovered liquid and extract the cleaning solvent composition, and examples of the means include gravity separation and membrane separation. The water separator preferably extracts the cleaning solvent composition by gravity separation.

[0080] In the case where the recovery section includes a cooling pipe and a gutter, and the means of water separation by the water separator is gravity separation, An example of the structure of the water separator is disclosed in JP 2015-217319 A.

[0081] Although not shown, the cleaning system 1 may have a supply means for shower-washing with a cleaning solvent composition. The cleaning effect tends to be improved by shower-washing with the composition after boiling and / or steam-washing the object to be cleaned and colliding the composition with the surface of the object to be cleaned.

[0082] <Cleaning method using cleaning system 1> A cleaning method using the cleaning system 1 includes the following steps: (1A) immersing the object to be cleaned in a boiling tank and boiling cleaning it, and (1B) placing the object to be cleaned in an area of ​​steam generated from the boiling tank and steam cleaning it.

[0083] Step (1A) is a step of immersing the object to be cleaned in a boiling tank and cleaning it by boiling. In FIG. 1, the object to be cleaned (S in FIG. 1) is moved from position S1 at the start of cleaning to position S2 and immersed in the cleaning solvent composition. In step (1A), the object to be cleaned comes into contact with the liquid of the composition. In the boiling tank, the cleaning solvent composition is brought to a boiling state, that is, in boiling cleaning, the cleaning solvent composition is heated by a heating means such as a heater.

[0084] In boiling cleaning, in order to enhance the cleaning effect, it is preferable to combine immersion with a means such as stirring, shaking, ultrasonic vibration, or air bubbling, and it is more preferable to combine a means using ultrasonic vibration.

[0085] In step (1B), the object to be cleaned is placed in the steam area generated from the boiling tank and steam cleaned. In FIG. 1, the object to be cleaned is moved from position S2 to position S4, which is the upper part of the boiling tank, and placed in the steam area. The steam area is made of steam of the cleaning solvent composition. In step (1B), steam cleaning is performed by bringing the object to be cleaned into contact with the steam generated from the boiling tank. This replaces the dirt components attached to the object to be cleaned with the cleaning solvent composition in the steam area. In addition, since the object to be cleaned comes into contact with the cleaning solvent composition in step (1B), rinsing (steam rinsing) is performed by the steam cleaning step. Thereafter, the object to be cleaned is moved to position S5, where cleaning is completed, and cleaning is completed.

[0086] (2) Cleaning System 2 The cleaning system 2 is a two-tank cleaning machine that includes an ultrasonic cleaning tank that contains a cleaning solvent composition containing the components (A) and (B) and in which an object to be cleaned is immersed for cleaning, a steam tank that generates steam of the cleaning solvent composition, a recovery section that liquefies and recovers the steam of the cleaning solvent composition generated by the steam tank, and a water separator that separates water from the liquid recovered by the recovery section to extract the cleaning solvent composition.

[0087] The outline of the cleaning system 2 is shown in FIG. 2. The cleaning system 2 preferably includes an ultrasonic cleaning tank (12 in FIG. 2) in which a cleaning solvent composition set (1 in FIG. 2) is accommodated, a steam tank (13 in FIG. 2) in which a cleaning solvent composition (3 in FIG. 2) is accommodated, a recovery section (e.g., 21 and 22 in FIG. 2) that liquefies and recovers the steam of the cleaning solvent composition (2 in FIG. 2) generated from the steam tank, and a water separator (23 in FIG. 2) that separates water from the recovery liquid recovered by the recovery section to extract the cleaning solvent composition and supplies the extracted cleaning solvent composition to the ultrasonic cleaning tank. The cleaning system 2 corresponds to the cleaning system 1 further including an ultrasonic cleaning tank, except that the cleaning solvent composition is returned from the water separator to the ultrasonic cleaning tank. In FIG. 2, the solid arrow indicates the flow of the cleaning solvent composition.

[0088] The steam tank in the cleaning system 2, including the preferred one, is the same as that in the cleaning system 1. As stated above. The ultrasonic cleaning tank is preferably equipped with an ultrasonic vibrator (25 in FIG. 2) that applies ultrasonic vibrations. Although not shown, the ultrasonic cleaning tank may also be equipped with a heater for adjusting the temperature of the composition. In the cleaning system 2, when the dirt to be removed from the object to be cleaned is solid, a pump and filter circuit may be installed in the ultrasonic cleaning tank to prevent the accumulation of dirt.

[0089] In the cleaning system 2, the cleaning solvent composition extracted by the water separator is supplied to an ultrasonic cleaning tank. The liquid level in the ultrasonic cleaning tank is higher than the liquid level in the steam tank, so that the cleaning liquid overflows from the ultrasonic cleaning tank to the steam tank.

[0090] <Cleaning method using cleaning system 2> A cleaning method using cleaning system 2 includes the following steps: (2A) immersing the object to be cleaned in an ultrasonic cleaning tank and ultrasonically cleaning it, and (2B) placing the object to be cleaned in a steam area generated from a steam tank and steam cleaning it.

[0091] In step (2A), an object to be cleaned (S in FIG. 2) is immersed in an ultrasonic cleaning tank and ultrasonically cleaned. The frequency of the ultrasonic waves is not particularly limited and can be set appropriately.

[0092] In step (2B), the object to be cleaned is placed in the steam area generated from the steam tank and cleaned with steam. In FIG. 2, the object to be cleaned is moved from position S2 to position S4, which is the upper part of the steam tank, and placed in the steam area. The object to be cleaned is then brought into contact with the steam generated from the boiling tank, thereby performing steam cleaning. The conditions in step (2B), including the preferred conditions, are as described above for step (1B). Thereafter, the object to be cleaned is moved to position S5, where cleaning is completed, and cleaning is completed.

[0093] (3) Cleaning System 3 The cleaning system 3 is a three-tank cleaning machine that includes an ultrasonic cleaning tank that contains a cleaning solvent composition containing the (A) component and the (B) component and in which an object to be cleaned is immersed for cleaning, a rinsing tank that contains the cleaning solvent composition and in which an object to be cleaned is immersed for rinsing, a steam tank that generates steam of the cleaning solvent composition, a recovery section that liquefies and recovers the steam of the cleaning solvent composition generated from the steam tank, and a water separator that separates water from the recovery liquid recovered by the recovery section to extract the cleaning solvent composition and return it to the rinsing tank.

[0094] The outline of the cleaning system 3 is shown in FIG. 3. The cleaning system 3 preferably includes an ultrasonic cleaning tank (12 in FIG. 3) in which a cleaning solvent composition (1 in FIG. 3) is accommodated, a rinse tank (14 in FIG. 3) in which a rinse liquid (4 in FIG. 3) is accommodated, a steam tank (13 in FIG. 3) in which a cleaning solvent composition (3 in FIG. 3) is accommodated, a recovery section (e.g., 21 and 22 in FIG. 3) that liquefies and recovers the steam of the cleaning solvent composition (2 in FIG. 3) generated from the steam tank, and a water separator (23 in FIG. 3) that separates water from the recovery liquid recovered by the recovery section to extract the cleaning solvent composition and supplies the extracted cleaning solvent composition to a rinse tank. The cleaning system 3 corresponds to the cleaning system 2 further equipped with a rinse tank. In FIG. 3, the solid arrow indicates the flow of the cleaning solvent composition.

[0095] The ultrasonic cleaning tank and the steam tank in the cleaning system 3 are as described above for the cleaning system 1 and the cleaning system 2. The rinse tank is a tank for rinsing the object to be cleaned. The rinse liquid is a cleaning solvent composition. Although not shown, the rinse tank may be equipped with an ultrasonic vibrator and may be equipped with a heater for adjusting the temperature of the rinse liquid. In order to prevent the amount of the rinse liquid from decreasing due to the generation of steam, the temperature of the rinse liquid in the rinse tank is preferably lower than the boiling point of the rinse liquid. When the dirt to be removed from the object to be cleaned is solid, a pump and a filter circuit may be installed in the rinse tank in order to prevent the accumulation of the dirt.

[0096] In one embodiment of the cleaning system 3, the cleaning solvent composition extracted by the water separator flows into a rinsing tank. The liquid level in the rinsing tank is higher than the liquid level in the ultrasonic cleaning tank, so that the rinsing liquid overflows from the rinsing liquid tank into the ultrasonic cleaning tank. The liquid level in the ultrasonic cleaning tank is higher than the liquid level in the steam tank, so that the cleaning liquid overflows from the ultrasonic cleaning tank into the steam tank.

[0097] <Cleaning method using cleaning system 3> A cleaning method using the cleaning system 3 includes the following steps: (3A) immersing the object to be cleaned in an ultrasonic cleaning tank and ultrasonically cleaning it, (3B) immersing the object to be cleaned in a rinsing tank and rinsing it, and (3C) placing the object to be cleaned in a steam area generated from a steam tank and steam cleaning it.

[0098] In step (3A), the object to be cleaned is immersed in an ultrasonic cleaning tank and ultrasonically cleaned. The conditions in step (3A), including the preferred conditions, are as described above for step (2A).

[0099] Step (3B) is a step of immersing the object to be cleaned in a rinse tank and rinsing it. In FIG. 3, the object to be cleaned is moved from position S2 to position S3 and immersed in the rinse liquid. The time for immersion in the rinse tank, i.e., the rinse time corresponding to the contact time between the rinse liquid and the object to be cleaned, is not particularly limited, and is preferably 1 second to 60 minutes, and more preferably 10 seconds to 30 minutes. Step (3B) replaces the cleaning agent composition and dirt components slightly adhering to the object to be cleaned with the rinse liquid.

[0100] In step (3C), the object is placed in the steam area generated from the steam tank and is steam cleaned. In FIG. 3, the object is moved from position S3 to position S4, which is the upper part of the steam tank. Then, the object is brought into contact with the steam generated from the steam tank, thereby performing steam cleaning. The conditions for steam cleaning are as described above in step (1B).

[0101] (4) Cleaning System 4 The cleaning system 4 is a one-cycle type cleaning machine, and includes an ultrasonic cleaning tank that contains a cleaning solvent composition containing the (A) component and the (B) component and in which an object to be cleaned is immersed and cleaned, a steam tank that generates steam of the cleaning solvent composition, a recovery section that liquefies and recovers the steam of the cleaning solvent composition generated by the steam tank, and a water separator that separates water from the liquid recovered by the recovery section to extract the cleaning solvent composition.

[0102] The outline of the cleaning system 4 is shown in FIG. 4. The cleaning system 4 preferably includes an ultrasonic cleaning tank (12 in FIG. 4) in which a cleaning solvent composition set (1 in FIG. 4) is accommodated, a steam tank (13 in FIG. 4) in which a cleaning solvent composition (3 in FIG. 4) is accommodated, a recovery section (e.g., 21 and 22 in FIG. 4) that recovers and liquefies the steam of the cleaning solvent composition (2 in FIG. 4) generated from the steam tank, and a water separator (23 in FIG. 4) that separates water from the recovery liquid recovered by the recovery section to extract the cleaning solvent composition and supplies the extracted cleaning solvent composition to the ultrasonic cleaning tank. The cleaning system 4 corresponds to the cleaning system 1 further including an ultrasonic cleaning tank, except that the cleaning solvent composition is returned from the water separator to the ultrasonic cleaning tank and is cleaned in the ultrasonic cleaning tank. In FIG. 4, the solid arrow indicates the flow of the cleaning solvent composition.

[0103] The ultrasonic cleaning tank and steam tank in cleaning system 4 are as described above for cleaning systems 1 to 3, including the preferred ones.

[0104] In the cleaning system 4, the cleaning solvent composition extracted by the water separator is supplied to an ultrasonic cleaning tank. The liquid level in the ultrasonic cleaning tank is higher than the liquid level in the steam tank, so that the cleaning liquid overflows from the ultrasonic cleaning tank to the steam tank.

[0105] <Cleaning method using cleaning system 4> A cleaning method using cleaning system 4 includes the following steps: (4A) immersing the object to be cleaned in an ultrasonic cleaning tank and ultrasonically cleaning it, and (4B) placing the object to be cleaned in a steam area generated from a steam tank and steam cleaning it.

[0106] Step (4A) is a step of immersing an object to be cleaned (S in FIG. 4) in an ultrasonic cleaning tank and cleaning it ultrasonically. The conditions in step (4A), including the preferred conditions, are as described above for step (2A).

[0107] Step (4B) is a step in which the object to be cleaned is placed in the steam area generated from the steam tank and cleaned with steam. In FIG. 4, the object to be cleaned is moved from position S2 to position S4, which is the upper part of the ultrasonic cleaning tank, and placed in the steam area. Then, the object to be cleaned is brought into contact with the steam generated from the steam tank, thereby performing steam cleaning. The conditions in step (4B), including the preferred conditions, are as described above in step (2B). Thereafter, the object to be cleaned is moved to position S5, where cleaning is completed, and cleaning is completed.

[0108] Each cleaning system may be equipped with a distillation and recycling device.

[0109] [Steam generation chamber, steam contact chamber or steam contact area for cleaning process] A further aspect of the present invention is a mixture of (A) cis-1-chloro-3,3,3-trifluoropropene and (B) a hydrofluoroether that exhibits pseudoazeotropy when mixed with component (A). The present invention relates to a method for cleaning an object to be cleaned using a cleaning solvent composition comprising the steps of: when the total amount of the components (A) and (B) is 100 parts by weight, the amount of the component (A) is 8 parts by weight or more and less than 30 parts by weight; and the cleaning method includes a steam contacting step of contacting the object to be cleaned with the steam of the cleaning solvent composition (hereinafter simply referred to as a "steam generating tank for the cleaning method", etc.).

[0110] The steam generating tank for the cleaning method is not particularly limited as long as it is a tank that can accommodate the cleaning solvent composition and generate steam of the cleaning solvent composition, and examples of the steam generating tank include the boiling tank of the cleaning system 1 and the steam tanks of the cleaning systems 2 to 4. The steam generating tank for the cleaning method may be a cleaning device equipped with an additional tank (for example, a rinsing tank of the cleaning system 3, an ultrasonic cleaning tank of the cleaning system 4, etc.).

[0111] The steam contact tank for the cleaning method is not particularly limited as long as it is a tank having an area where the object to be cleaned can come into contact with the steam of the cleaning solvent composition in the cleaning method, and is a tank in which a steam contact step is performed in which oily dirt and / or oil adhering to a substrate is removed from the substrate, and examples of the steam contact tank include the boiling tank of the cleaning system 1, the steam tanks of the cleaning systems 2 to 4, and the ultrasonic cleaning tank of the cleaning system 4. The steam generation tank for the cleaning method may be a cleaning device equipped with an additional tank.

[0112] The steam contact area for the cleaning method is an area where the object to be cleaned can come into contact with the steam of the cleaning solvent composition in the cleaning method. That is, the steam contact area for the cleaning method is provided in a steam contact tank for the cleaning method. Examples of the steam contact area include the steam area above the boiling tank of the cleaning system 1, the steam area above the steam tank of the cleaning systems 2 to 3, and the steam area above the ultrasonic cleaning of the cleaning system 4. Therefore, the steam contact area for the cleaning method is preferably the steam area used in the cleaning method using the cleaning systems 1 to 4. EXAMPLES

[0113] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. Unless otherwise specified, parts are parts by weight.

[0114] (Products used) The components used in the examples are as follows: The compositions of the examples and comparative examples were prepared according to the compositions (wt %) in the table by using the following solvents as they were or by mixing the solvents.

[0115] 1. Component (A) a-1: 1233Z; cis-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(Z), manufactured by Central Glass Co., Ltd.) 2.(B) Component b-1: HFE-347pc-f: 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether (AGC Corporation, Asahiklin AE-3000)

[0116] 3. Ingredients other than (A) and (B) a'-1: AS-300; AMOLEA (registered trademark) AS-300 (manufactured by AGC Corporation) (mixture of (E)-1-chloro-2,3,3-trifluoropropene (HCFO-1233yd(E)), (Z)-1-chloro-2,3,3-trifluoropropene (HCFO-1233yd(Z)) and a stabilizer) b'-1: Novec 7100; 3M (trademark) Novec 7100 high-performance liquid (manufactured by 3M Japan Ltd.) (a mixture of 20 to 80 parts by weight of methyl nonafluorobutyl ether and 20 to 80 parts by weight of methyl nonafluoroisobutyl ether)

[0117] 4.Oil etc. (1) Mineral oil: Pulley SF Oil (manufactured by Ozawa Kogyo Co., Ltd.) (mineral oil 90% by mass or more but less than 100% by mass, lubricating oil additives less than 10% by mass, 2,6-di-tertiary-4-cresol less than 1% by mass) (2) Fluorine oil: Fomblin Y25 (manufactured by Solvay Japan Co., Ltd.) (3) Silicone oil: Dimethyl silicone oil 1000CS (Shin-Etsu Chemical Co., Ltd., KF96-1000CS-1, viscosity 1000cSt)

[0118] 5. Resin and rubber pieces, etc. (1) PC: Polycarbonate resin plate (Hikari Corporation, 200mm x 300mm x 0.5mm) (2) ABS: ABS resin plate (manufactured by Takachi Electric Industry Co., Ltd., 200 mm x 300 mm x 1.0 mm) (3) PP: Polypropylene plate (As One Corporation, 495 mm x 495 mm x 1.0 mm) (4) PE: Polyethylene plate (As One Corporation, 495mm x 495mm x 1.0mm) (5) PET: Partition plate, transparent PET (MonotaRO Co., Ltd., 50mm x 100mm x 380mm x 1.0mm) (6) PU: urethane foam sheet (manufactured by Inoac Corporation, 1000mm x 1000mm x 10mm) (7) NR: Natural rubber sheet (Wake Sangyo Co., Ltd., 100mm x 100mm x 1.0mm) (8) CR: Chloroprene rubber sheet (no brand, MonotaRO order code 35844207, 100mm x 100mm x 1.0mm) (9) EPDM: Ethylene-propylene rubber sheet (no brand, MonotaRO order code 35841985, 100mm x 100mm x 1.0mm)

[0119] 6. Test Example The following Test Examples 1 to 7 were carried out.

[0120] Test example 1: Reflux test The temperatures of the gas phase and liquid phase were measured according to a method in accordance with JIS K2333. 60 ml of the solvent composition of each Example and Comparative Example was placed in a 300 ml three-neck flask, a cooling tube was attached to the top, and the mixture was heated to reflux on a hot plate. The cooling water passing through the cooling tube was kept below 15°C with a temperature difference of ±2°C, and the stable gas phase and liquid phase temperatures after 3 hours were recorded. The scale was read down to 0.5°C. ○: The temperature difference between the gas phase and the liquid phase is less than 2.5°C. ×: The temperature difference between the gas phase and the liquid phase is 2.5°C or more.

[0121] Test example 2: Cleaning test <Preparation of the object to be cleaned> 1 mg of mineral oil, fluorine oil or silicone oil was dropped onto the surface of a SUS304 plate (manufactured by Iwata Seisakusho Co., Ltd., 10 mm x 10 mm x 0.1 mm) and left for 1 hour to obtain a cleaning test sample (object to be cleaned) with each oil attached. <Test Method> (1) Cleaning method 1 500 ml of the solvent composition of each Example was placed in a 3 L beaker fitted with a SUS cooling coil (number of turns: 9, outer diameter of the tube: 6 mm, cooling water passing through the cooling tube was at room temperature (approximately 20°C)) on top, and the mixture was boiled to the boiling point using a silicone oil bath, and the cleaning test sample was immersed in the mixture for 60 seconds for immersion cleaning. The test sample was then exposed to the generated steam for 60 seconds, and then removed. The device used in this test method corresponds to the cleaning system 1 described above. (2) Cleaning method 2 65L of the solvent composition of each Example was placed in the ultrasonic cleaning tank (liquid volume 65L) in a two-tank manual cleaning device (manufactured by Muramatsu Corporation), and 48L of the solvent composition of each Example was placed in the steam tank (liquid volume 48L). A cleaning test sample was immersed in the ultrasonic cleaning tank and ultrasonic waves (600W, 40kHz) were applied for 60 seconds to perform immersion cleaning (the liquid temperature was the normal temperature, which was 5 to 20°C lower than the liquid temperature in the steam tank). Next, the steam tank was boiled to about the boiling point using a heater, and the test sample was exposed to the generated steam for 60 seconds, and then removed. The device used in this test method corresponds to the cleaning system 2 described above. (3) Cleaning method 3 10 ml of the solvent composition of each Example was placed in a 100 ml beaker, and the cleaning test sample was immersed in the liquid at room temperature (20°C), and ultrasonic waves (60 W, 40 kHz) were applied for 60 seconds to perform immersion cleaning. Then, 10 ml of the solvent composition of each Example was placed in a 100 ml beaker, and the cleaning sample was immersed in the liquid at room temperature (20°C), and immersion cleaning was performed for 60 seconds. Then, 500 ml of the solvent composition of each Example was placed in a 3 L beaker equipped with a SUS cooling coil (number of turns 9, outer diameter of the tube 6 mm, cooling water passing through the cooling tube was at room temperature (about 20°C)) on the top, and boiled to about the boiling point using a silicone oil bath, and the test sample was exposed to the generated steam for 60 seconds, and then removed. The device used in this test method corresponds to the cleaning system 3 described above. (4) Cleaning method 4 10 ml of the solvent composition of each Example and Comparative Example was placed in a 100 ml beaker, and the cleaning test sample was immersed in the liquid at room temperature (20°C), and ultrasonic waves (60 W, 40 kHz) were applied for 60 seconds to perform immersion cleaning. Then, 500 ml of the solvent composition of each Example was placed in a 3 L beaker equipped with a SUS cooling coil (number of turns: 9, outer diameter of the tube: 6 mm, cooling water passing through the cooling tube was at room temperature (about 20°C)) on the top, and boiled to about the boiling point using a silicone oil bath, and the test sample was exposed to the generated steam for 60 seconds, and then removed and the test sample surface was observed with the naked eye or using a HDMI digital stereo microscope STZ-161-TLED1080M (manufactured by Shimadzu Rika Co., Ltd.). The device used in this test method corresponds to the cleaning system 4 described above.

[0122] <Evaluation of cleaning ability> After the test samples were allowed to dry naturally, the surfaces of the test samples were observed with the naked eye or using a HDMI digital stereo microscope STZ-161-TLED1080M (manufactured by Shimadzu Rika Co., Ltd.). ◎: No residual oil was observed with the naked eye or under a microscope. ○: No remaining oil was observed with the naked eye. Microscopic observation revealed a very small amount of remaining oil, but this did not pose a problem in practical use. ●: A very small amount of remaining oil was visible to the naked eye. ×: Oil residue was clearly observed with the naked eye.

[0123] Test example 3: Resin impact test 60 ml of each Example and Comparative Example was placed in a 300 ml three-neck flask, and one test sample (50 mm x 5 mm x 0.5 mm) was placed in the gas phase and liquid phase. A cooling tube was attached to the top and the mixture was heated to reflux using a mantle heater. The cooling water passing through the cooling tube was below 15°C, with a temperature difference of ±2°C. After 30 minutes, the test sample was removed and naturally dried, and then evaluated as follows. (1)PC resin ◯: The resin surface had not lost its luster or transparency, and there was no damage to its appearance. ×: Some damage was observed in appearance. The resin surface changed or collapsed. (2) ABS resin A: The weight change rate was less than 1%. ×: The weight change rate was 1% or more.

[0124] Test example 4: Resin and rubber impact test 60 ml of each Example and Comparative Example was placed in a 300 ml three-neck flask, and one test sample each (50 mm x 5 mm x 0.5 mm, urethane foam resin piece only 50 mm x 5 mm x 5 mm) was placed in the gas phase and liquid phase parts, and a cooling tube was attached to the top and heated to reflux using a mantle heater. The cooling water passing through the cooling tube was below 15°C, with a temperature difference within ±2°C. After 1 hour, the test sample was removed and naturally dried, and then the sample was evaluated as follows. ⊚: The weight change rate was less than 1%. ◯: The weight change rate was 1% or more and less than 3%. △: The weight change rate was 3% or more and less than 10%. ×: The weight change rate was 10% or more.

[0125] Test Example 5: Comparison of cleaning performance with each cleaning method For each Example, a cleaning test was carried out using each of cleaning methods A to C, and the cleaning properties were compared. <Preparation of the object to be cleaned> A SUS304 plate (manufactured by Iwata Seisakusho Co., Ltd., 10 mm x 10 mm x 0.1 mm) was completely immersed in either mineral oil, fluorine oil or silicone oil, and then pulled out to prepare a cleaning sample.

[0126] <Cleaning method A> 10 ml of the solvent composition of each Example was placed in a 100 ml beaker, and the cleaning test sample was immersed in the liquid at room temperature (20°C), and ultrasonic waves (60 W, 40 kHz) were applied for 120 seconds to perform immersion cleaning. After that, 500 ml of the solvent composition of each Example was placed in a 3 L beaker equipped with a SUS cooling coil (number of turns 9, outer diameter of the tube 6 mm, cooling water passing through the cooling tube was at room temperature (about 20°C)) on the top, and the mixture was boiled to about the boiling point using a silicone oil bath, and the test sample was exposed to the generated steam for 120 seconds. The device used in cleaning method A corresponds to the cleaning system 4 described above.

[0127] <Cleaning method B> 10 ml of the solvent composition of each Example was placed in a 100 ml beaker, and a cleaning test sample was immersed in the liquid at room temperature (20° C.), and ultrasonic waves (60 W, 40 kHz) were applied for 120 seconds to perform immersion cleaning. Then, 10 ml of the solvent composition of each Example was placed in another 100 ml beaker, and a cleaning test sample was immersed in the liquid at room temperature (20° C.), and immersion cleaning was performed for 120 seconds.

[0128] <Cleaning method C> A set of two-ply tissue paper (manufactured by Oji Nepia Co., Ltd.) was cut to a size of 65 mm long and 72 mm wide, folded in four, soaked in the cleaning composition of each Example, and squeezed once between the thumb and index finger. The tissue paper soaked in each solvent composition was brought into contact with the surface of the test sample and wiped by rubbing with the hand. This cleaning was continued for 4 minutes. When the tissue paper dried, another tissue paper was soaked in the solvent composition of each Example and used.

[0129] <Evaluation of cleaning ability> After the test samples were allowed to dry naturally, the surfaces of the test samples were observed with the naked eye or using a HDMI digital stereo microscope STZ-161-TLED1080M (manufactured by Shimadzu Rika Co., Ltd.). ◎: No residual oil was observed with the naked eye or under a microscope. ○: No remaining oil was observed with the naked eye. Microscopic observation revealed a very small amount of remaining oil, but this did not pose a problem in practical use. ●: A very small amount of remaining oil was visible to the naked eye. ×: Oil residue was clearly observed with the naked eye.

[0130] Test Example 6: Comparison test of liquid temperature in steam tank <Preparation of the object to be cleaned> 1 mg of mineral oil was dropped onto the surface of a SUS304 plate (manufactured by Iwata Seisakusho Co., Ltd., 10 mm x 10 mm x 0.1 mm) and left for 1 hour to obtain cleaning test samples (objects to be cleaned) with each oil attached.

[0131] <Cleaning method> 10 ml of the solvent composition of each Example was placed in a 100 ml beaker, and the cleaning test sample was immersed in the liquid at room temperature (20°C), and ultrasonic waves (60 W, 40 kHz) were applied for 60 seconds to perform immersion cleaning. After that, 500 ml of the solvent composition of each Example was placed in a 3 L beaker equipped with a SUS cooling coil (number of turns 9, outer diameter of the tube 6 mm, cooling water passing through the cooling tube was at room temperature (about 20°C)) on the top, and heated using a silicone oil bath so that the liquid temperature was as shown in Table 5, and the test sample was exposed to the generated steam for 60 seconds. The device used in this cleaning method corresponds to the cleaning system 4 described above.

[0132] <Evaluation of cleaning ability> After the test samples were allowed to dry naturally, the surfaces of the test samples were observed with the naked eye or using a HDMI digital stereo microscope STZ-161-TLED1080M (manufactured by Shimadzu Rika Co., Ltd.). ◎: No residual oil was observed with the naked eye or under a microscope. ○: No remaining oil was observed with the naked eye. Microscopic observation revealed a very small amount of remaining oil, but this did not pose a problem in practical use. ●: A very small amount of remaining oil was visible to the naked eye. ×: Oil residue was clearly observed with the naked eye.

[0133] Test Example 7: Washing test for resin and rubber <Preparation of the object to be cleaned> 1 mg of mineral oil or silicone oil was dropped onto the surface of each resin or rubber piece (50 mm x 5 mm x 0.5 mm, except for the urethane foam resin piece, which was 50 mm x 5 mm x 5 mm) to obtain a cleaning test sample (item to be cleaned) with each oil attached.

[0134] <Cleaning method> 65L of the solvent composition of each Example was placed in the ultrasonic cleaning tank (liquid volume 65L) in a two-tank manual cleaning device (manufactured by Muramatsu Corporation), and 48L of the solvent composition of each Example was placed in the steam tank (liquid volume 48L). A cleaning test sample was immersed in the ultrasonic cleaning tank and ultrasonic waves (600W, 40kHz) were applied for 60 seconds to perform immersion cleaning (the liquid temperature was the normal temperature, which was 5 to 20°C lower than the liquid temperature in the steam tank). Next, the steam tank was boiled to about the boiling point using a heater, and the test sample was exposed to the generated steam for 60 seconds, and then removed. The device used in this test method corresponds to the cleaning system 2 described above.

[0135] <Evaluation of cleaning and damage resistance> After the test samples were allowed to dry naturally for 1 hour, the surfaces of the test samples were observed with the naked eye or using a HDMI digital stereo microscope STZ-161-TLED1080M (manufactured by Shimadzu Rika Co., Ltd.). ⊚: No visible change in the appearance of the sample, and the weight change rate was less than 3% (less than 1% for ABS). No remaining oil was observed with the naked eye or under a microscope. ○: There was no visible change in the appearance of the sample, and the weight change rate was less than 3% (less than 1% for ABS). No remaining oil was observed with the naked eye. Microscopic observation revealed a very small amount of remaining oil, but this did not pose a problem in practical use. ●: There was no visible change in the appearance of the sample, and the weight change rate was less than 3% (less than 1% for ABS). A very small amount of remaining oil was visible to the naked eye. ×: The appearance of the sample was visually changed, and / or the weight change rate was 3% or more (1% or more for ABS), or residual oil was clearly observed with the naked eye.

[0136] The results are summarized in the table below.

[0137] [Table 1]

[0138] The following can be seen from Table 1: The cleaning solvent compositions of Examples 1 to 6 had a difference between the liquid temperature and the vapor temperature of less than 2.5°C, and the component b-1 was a hydrofluoroether that exhibited pseudo-azeotropic properties when mixed with the component (A). In addition, since the cleaning solvent compositions of Examples 1 to 6 had excellent pseudo-azeotropic properties, the composition balance was not easily disturbed even when they were recycled, and it can be said that they can be used repeatedly. In addition, the results of Test Example 2 showed that Examples 1 to 6 had excellent cleaning properties for various oils, particularly fluorine oil, mineral oil, and silicone oil. In addition, the results of Test Example 3 showed that Examples 1 to 6 had reduced damage to substrates. Furthermore, a comparison between Examples 1 to 6 and Comparative Examples 1 to 4 showed that when the total of the components (A) and (B) was 100 parts by weight, the cleaning properties were excellent when the amount of the component (A) was 8 parts by weight or more and less than 30 parts by weight.

[0139] Comparative Examples 5 to 14 are examples using compositions containing component (A) and an HFE-based solvent other than component (B), and the temperature difference between the gas phase and the liquid phase is 2.5°C or more, the pseudo-azeotropic property is poor, and even when recycled, the composition balance is easily lost, so it cannot be said that it can be used repeatedly. Furthermore, by comparing Examples 1 and 2 with Comparative Examples 11 and 12, the solvent compositions of the comparative examples using hydrofluoroether other than component (B) caused damage to the substrate. In particular, in Comparative Examples 11 and 12, damage to PC was suppressed in the liquid phase, but damage occurred in the gas phase. This is presumably because the compositions of Comparative Examples 11 and 12 are poor in pseudo-azeotropic property, and therefore the compositions of the liquid phase and the gas phase are significantly different. On the other hand, in Examples 1 and 2, the compositions of the liquid phase and the gas phase are close due to the excellent pseudo-azeotropic property, so damage to PC was suppressed in both the liquid phase and the gas phase. In Comparative Example 14, the cleaning properties of mineral oil and silicone oil were poor.

[0140] Comparative Examples 15 and 16 are examples in which an HFO-based solvent other than component (A) or an HFE-based solvent other than component (B) was used. In Comparative Examples 15 and 16, the cleaning properties of any of fluorine oil, mineral oil, and silicone oil were poor. In Comparative Example 16, damage to the substrate occurred. Comparative Examples 17 to 33 are examples in which an HFO-based solvent other than component (A) was used. In Comparative Examples 17 to 25, the temperature difference between the gas phase and the liquid phase was 4°C, the pseudo-azeotropic property was poor, and even when recycled, the composition balance was easily lost, so it cannot be said that the solvents can be used repeatedly. Comparative Example 33 is an example in which the HFE-based solvent in Comparative Example 25 was changed. In Comparative Examples 25 and 33, the cleaning properties for mineral oil and silicone oil were poor. Furthermore, in Comparative Examples 17 to 33, damage to the substrate occurred.

[0141] [Table 2]

[0142] [Table 3]

[0143] The following can be seen from Tables 2 and 3. According to Examples 7 to 12, when the total amount of the components (A) and (B) was 100 parts by weight, the damage to various substrates was further reduced when a cleaning solvent composition containing 8 to 28 parts by weight of the component (A) was used. Comparing Examples 13 to 15 with Examples 16 to 18, when the total of the components (A) and (B) was 100 parts by weight, damage to various substrates was further reduced when a cleaning solvent composition containing 8 to 15 parts by weight of the component (A) was used. On the other hand, in Comparative Example 34, only the component (A) was used, which caused damage to the substrate. In Comparative Example 35, a cleaning solvent composition was used in which the component (A) was 30 parts by weight when the total of the components (A) and (B) was 100 parts by weight, which sometimes caused damage to the substrate.

[0144] [Table 4]

[0145] The following can be seen from Table 4. According to Examples 19 to 23, when the cleaning method includes a steam contact step, the cleaning ability of various oils was excellent. Even if oil is contained in the liquid of the cleaning solvent composition for generating steam in the steam contact step, the oil is generally not likely to be contained in the steam because the oil has a high boiling point. Therefore, precise cleaning was possible with the cleaning method including the steam contact step. On the other hand, according to Comparative Examples 36 to 40, when the cleaning method is immersion cleaning without a steam contact step, if oil is contained in the liquid of the cleaning solvent composition, the solvent composition containing the oil is naturally dried while still adhering to a certain extent, so that a very small amount of oil was observed to remain.

[0146] [Table 5]

[0147] The following can be seen from Table 5. Comparing Examples 24-25 with Example 26, comparing Examples 27-28 with Example 29, comparing Examples 30-31 with Example 32, and comparing Examples 33-34 with Example 35, it was found that when the temperature of the steam bath was 45°C or higher, the cleaning ability for mineral oil was superior.

[0148] [Table 6]

[0149] The following can be seen from Table 6. According to Examples 36 to 41, even when the substrate was resin or rubber, the cleaning properties of various oils, especially mineral oil and silicone oil, were excellent. In addition, damage to various substrates was further suppressed. [Explanation of symbols]

[0150] 1 cleaning solvent composition, 2 cleaning solvent composition vapor, 3 cleaning solvent composition, 4 rinsing liquid, 11 boiling tank, 12 ultrasonic cleaning tank, 13 steam tank, 14 rinsing tank, 21 cooling pipe, 22 gutter, 23 water separator, 24 heater, 25 ultrasonic vibrator, S object to be cleaned, S1~S5 object to be cleaned

Claims

1. (A) cis-1-chloro-3,3,3-trifluoropropene, (B) a hydrofluoroether that exhibits pseudoazeotropy when mixed with component (A); A method for cleaning an object to be cleaned using a cleaning solvent composition comprising the above-mentioned, wherein, when the total amount of the components (A) and (B) is 100 parts by weight, the amount of the component (A) is 8 to 28 parts by weight and the component (B) is 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, the cleaning method includes a steam contacting step of contacting the object to be cleaned with steam of the cleaning solvent composition, and the substrate of the object to be cleaned comprises one or more types selected from the group consisting of plastics and rubbers.

2. 2. The cleaning method according to claim 1, wherein the difference between the liquid temperature and the vapor temperature of the cleaning solvent composition is less than 2.5°C.

3. The cleaning method according to claim 1 or 2, for cleaning an object having at least one selected from the group consisting of oily stains and oil adhering to its substrate.

4. The cleaning method according to any one of claims 1 to 3, wherein the liquid temperature in the steam tank in the steam contact step is 38 to 60°C.

5. A steam contact tank or steam contact area for the cleaning method according to any one of claims 1 to 4.

6. A steam generating tank for the cleaning method according to any one of claims 1 to 4.

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