Quality control method for 1-chloro-2,3,3-trifluoro-1-propene used for cleaning articles, and method for suppressing acid generation from 1-chloro-2,3,3-trifluoro-1-propene used for cleaning articles

Abstract

To provide a quality control method that does not change the cleaning performance of 1-chloro-2,3,3-trifluoro-1-propene used for cleaning a machine component or the like.SOLUTION: A method of controlling the quality of 1-chloro-2,3,3-trifluoro-1-propene (HCFO-1233 yd) aerosolized by a jetted gas and made to contact an article to be cleaned to remove an oil-dirt component adhering to the article to be cleaned, is characterized by adjusting the storage temperature of the HCFO-1233 yd sealed in a storage container to keep the chemical in a state of being suppressed from generating an acid component.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This disclosure relates to a method for quality control of a cleaning agent that is aerosolized to remove oily and grease stains from machinery and parts. [Background technology]

[0002] Industrial degreasing agents are used to clean grease and oil adhering to the surfaces of industrial machinery, transportation equipment, electrical and electronic equipment, tools, building materials, and other items. Transportation equipment, particularly automobiles, trains, tractors, ships, aircraft, and forklifts, have grease and oil adhering to various parts of their drive and brake systems for lubrication and cooling. These greases can be scattered during operation or sliding, or contaminants from the surrounding environment can adhere to the surfaces, leading to contamination. In cleaning such contaminated parts of transportation equipment, cleaning agent compositions using fluorinated solvents, which are non-flammable and have low ozone depletion potential (ODP) and global warming potential (GWP), have been proposed from an environmental perspective. Recently, fluoroolefins have been proposed as fluorinated solvents.

[0003] For example, Patent Document 1 discloses a cleaning aerosol that has excellent cleaning properties and a drying speed that is not too fast, which is a cleaning component for contaminants, comprising (A) a hydrofluoroolefin having a boiling point of 30°C or more and less than 100°C, and (B) at least one of a perfluoropolyether having a boiling point of 100°C or more and a hydrofluoroolefin having a boiling point of 100°C or more. Furthermore, Patent Document 2 discloses a method of spraying a solvent composition containing stabilizers that suppress the decomposition of HCFOs such as Z-1-chloro-2,3,3-trifluoropropene (1233yd(Z)) and E-1-chloro-2,3,3-trifluoropropene (1233yd(E)) into an aerosol using a spray gas onto an object to be cleaned.

[0004] Furthermore, Patent Document 3 discloses a solvent composition containing 1-chloro-2,3,3-trifluoro-1-propene and 1-chloro-2,2,3,3-tetrafluoropropane, which is suitable for cleaning processing oils. Furthermore, Patent Document 4 discloses an aerosol composition for cleaning oil dissolving agents, oil coating agents, oily stains and / or oil-contaminated objects, containing a solvent composition comprising one or more solvents selected from the group consisting of (E)-1-chloro-2,3,3-trifluoropropene and (Z)-1-chloro-2,3,3-trifluoropropene, and one or more solvents selected from the group consisting of ethylcyclohexane and isononane, and a propellant gas. Furthermore, Patent Document 5 discloses a method for stably storing a composition containing 1-chloro-2,3,3-trifluoro-1-propene by adding water at a high concentration to suppress its decomposition. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Republished Gazette No. 2019-208019 [Patent Document 2] Japanese Patent Publication No. 2019-112507 [Patent Document 3] Japanese Patent Publication No. 2020-172657 [Patent Document 4] Japanese Patent Publication No. 2021-004354 [Patent Document 5] Japanese Patent Publication No. 2021-70655 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] Lubricating and cooling oils and greases adhere to various parts of mechanical components that make up the drive and brake sections of industrial and transportation equipment. A known method of cleaning these parts is to spray them with aerosols such as parts cleaners or brake cleaners. These mechanical components are often made of steel, copper or copper alloys, aluminum or aluminum alloys, and are composed of various materials such as resins and rubber. It is necessary to avoid corrosion and deterioration of these materials by the cleaning components that adhere to them after being sprayed. Furthermore, cleaning components require storage stability to suppress changes in their composition and cleaning performance stability. As disclosed in Patent Document 1, cleaning agents using fluoroolefins with low boiling points have problems when sprayed in high-temperature environments, as the drying rate is too fast, and the oily stains attached to the items to be cleaned are not sufficiently removed before drying. 1-Chloro-2,3,3-trifluoro-1-propene has a high boiling point and moderate drying properties, making it suitable for use as an aerosol. However, sufficient knowledge has not been obtained regarding the storage stability of this compound when stored for preservation and the cleaning performance stability when attached to items to be cleaned. [Means for solving the problem]

[0007] The inventors evaluated the storage stability of 1-chloro-2,3,3-trifluoro-1-propene under various conditions and found that it generates acid under certain conditions. They then found that this acid generation makes it difficult to maintain the cleaning performance stability of 1-chloro-2,3,3-trifluoro-1-propene, particularly during the summer months when high temperatures are frequent.

[0008] The means for solving the above problems include the following embodiments. [1] This is a quality control method for 1-chloro-2,3,3-trifluoro-1-propene (HCFO-1233yd), which is aerosolized by a propellant gas and comes into contact with an object to be cleaned that has oil stain components attached to it to clean the oil stain components. The aforementioned control method is characterized by maintaining a state in which acid generation is suppressed by adjusting the storage temperature of the sealed storage container containing the HCFO-1233yd. Quality control methods. [2] The quality control method according to claim 1, characterized in that the storage temperature is adjusted to be between -50°C and 50°C. [3] The aforementioned acid contains fluoride ions, chloride ions, and CHF2CO2 ― Characteristics of being an ion The quality control method according to claim 1 or 2. [4] The amount of acid generated is such that fluoride ions are 0.7 ppm by mass or less, chloride ions are 0.7 ppm by mass or less, and CHF2CO2 ― A quality control method according to any one of claims 1 to 3, characterized by suppressing ions to 5.0 ppm by mass or less. [5] The quality control method according to any one of claims 1 to 4, characterized in that instructions for adjusting the storage temperature are given by printing on the storage container, attaching a label to the storage container, or attaching an irreversible temperature-indicating material. [6] A method for cleaning oily stain components, characterized by aerosolizing HCFO-1233yd, which has been quality-controlled by the method described in any one of claims 1 to 5, with a propellant gas and bringing it into contact with an article to be cleaned to which oily stain components are attached. [Effects of the Invention]

[0009] According to one embodiment of the present disclosure, a quality control method can be provided for 1-chloro-2,3,3-trifluoro-1-propene, which is used for cleaning machine parts and the like using an aerosol, that does not cause fluctuations in cleaning performance. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments of the present disclosure will be described. However, the present disclosure can be implemented in various forms without departing from the gist thereof, and is not to be construed as being limited to the description of the embodiments exemplified below. Also, other effects different from those brought about by the aspects of the following embodiments, which are apparent from the description in this specification or can be easily predicted by those skilled in the art, are naturally considered to be brought about by the present disclosure.

[0011] In the present disclosure, for halogenated hydrocarbons, the abbreviation of the compound is indicated in parentheses after the compound name, and the abbreviation is used in place of the compound name as necessary. For compounds having a double bond in the molecule and having trans (E-form) and cis (Z-form) isomers, the E-form and Z-form are indicated by (E) and (Z) respectively at the end of the abbreviation of the compound. Note that those without the notations (E) and (Z) at the end of the abbreviation of the compound name indicate the E-form and / or Z-form.

[0012] 1-Chloro-2,3,3-trifluoro-1-propene (hereinafter also referred to as "HCFO-1233yd") is Z-1-chloro-2,3,3-trifluoropropene (cis-form, hereinafter also referred to as "HCFO-1233yd(Z)"), or E-1-chloro-2,3,3-trifluoropropene (trans-form, hereinafter also referred to as "HCFO-1233yd(E)").

[0013] The storage stability and cleaning performance stability for suppressing changes in the cleaning component can be evaluated using the fluoride ion concentration, chloride ion concentration, and CHF2CO2 ― ion concentration as indicators after storing HCFO-1233yd for a certain period. These ion concentrations are measured by ion chromatography.

[0014] [Outline of Quality Control Method] Hereinafter, a quality control method for a cleaning agent (hereinafter also referred to as "this quality control method") used for cleaning an article to be cleaned with an oil stain component attached according to the present embodiment will be described.

[0015] This quality control method involves adjusting the storage temperature of a sealed storage container containing 1-chloro-2,3,3-trifluoro-1-propene, which is used as a cleaning agent.

[0016] (Cleansing ingredients) The cleaning component, 1-chloro-2,3,3-trifluoro-1-propene, is a fluoroolefin with a double bond between carbon atoms, and therefore has a short lifetime in the atmosphere and a low ozone depletion potential (ODP) and global warming potential (GWP). In this disclosure, "ozone depletion potential" is a value used to compare the intensity of ozone depletion, calculated by dividing the total ozone depletion per kg of each compound by the total ozone depletion per kg of trichlorofluoromethane. "Global warming potential" is an index that expresses the effect of individual greenhouse gases on global warming relative to the effect of carbon dioxide, taking into account their duration.

[0017] Z-1-chloro-2,3,3-trifluoropropene has a boiling point of approximately 54°C, and E-1-chloro-2,3,3-trifluoropropene has a boiling point of approximately 48°C, both being substances with very fast drying rates. Furthermore, even when boiled and turned into vapor, they remain at a similar temperature, so they are less likely to adversely affect heat-sensitive components such as accompanying resin parts. In addition, 1-chloro-2,3,3-trifluoro-1-propene has no flash point, low surface tension and viscosity, and evaporates easily even at room temperature, giving it excellent properties as a cleaning solvent and coating solvent.

[0018] In this disclosure, the boiling point of a compound is the boiling point at atmospheric pressure unless otherwise specified. In this disclosure, atmospheric pressure means 101.325 kPa and room temperature means 25°C.

[0019] HCFO-1233yd can be synthesized by known methods. For example, as described in Patent Document 3, it can be synthesized by a dehydrofluoridation reaction at a temperature of 50-80°C using 1-chloro-2,2,3,3-tetrafluoropropane (hereinafter also referred to as "HCFC-244ca") as a starting material and potassium hydroxide or sodium hydroxide as a reactant. The HCFO-1233yd obtained by this reaction may have a higher proportion of HCFO-1233yd(Z) than HCFO-1233yd(E). Furthermore, the crude purified product of HCFO-1233yd obtained by this reaction may contain the starting material HCFC-244ca and the by-product 1-chloro-3,3-difluoro-1-propyne.

[0020] HCFO-1233yd may be obtained using HCFO-1233yd(Z) or HCFO-1233yd(E) alone or in combination. The mass ratio when used in combination is not particularly limited, and HCFO-1233yd(Z) / HCFO-1233yd(E) = 0.01 / 99.99 to 99.99 / 0.01 is also acceptable. Furthermore, since HCFO-1233yd obtained by the above method is often obtained with the cis isomer as the main component, from the viewpoint of suppressing the increase in manufacturing costs due to distillation separation of the cis and trans isomers of HCFO-1233yd, the ratio of HCFO-1233yd(Z) content to the total amount of HCFO-1233yd may be 70 to 100% by mass, and 90 to 100% by mass is preferred. However, from the viewpoint of suppressing the increase in manufacturing costs due to the distillation separation of the Z and E forms of HCFO-1233yd, the upper limit of the HCFO-1233yd content is more preferably around 99.9% by mass relative to the total amount of HCFO-1233yd.

[0021] The HCFO-1233yd used as the cleaning component in this disclosure may be a crude purified product of HCFO-1233yd, which contains HCFC-244ca and at least one of 1-chloro-3,3-difluoro-1-propyne together with HCFO-1233yd. Using a crude purified product of HCFO-1233yd is preferable because it reduces the costs associated with distillation separation, etc. From the viewpoint of stability and separation costs, the total content ratio of HCFC-244ca and 1-chloro-3,3-difluoro-1-propyne is preferably 0.0001 to 5% by mass, and more preferably 0.0001 to 3% by mass, relative to the total amount of HCFO-1233yd.

[0022] HCFO-1233yd can be replaced with a commercially available product that is known to be available. For example, AGC Inc.'s Amorea® AS-300 (boiling point: 54°C, KB value: 44) can be used.

[0023] (Injection gas) Liquefied gases and compressed gases can be used as the propellant gas, and examples include carbon dioxide, nitrogen, LPG, dimethyl ether, and isopentane. From the viewpoint of being able to treat the propellant gas as a non-flammable material, it is preferable to use carbon dioxide or nitrogen as the propellant gas in this disclosure.

[0024] (Other ingredients) Other components can be mixed with HCFO-1233yd, provided that the effects of HCFO-1233yd are not impaired. Examples include stabilizers, surfactants, UV absorbers, antioxidants, chelating agents, rust inhibitors, and fragrances. Other components may include raw materials used in the synthesis process of 1-chloro-2,3,3-trifluoro-1-propene, by-products of the synthesis, impurities, and water that inevitably accompanies the product.

[0025] A stabilizer refers to a substance that has the effect of suppressing the decomposition of HCFO-1233yd(Z) and HCFO-1233yd(E) in the presence of air (oxygen). In this disclosure, a stabilizer is not required to suppress acid generation, but its addition does not impair the temperature control effect.

[0026] The stabilizer content is preferably 1 ppm by mass or more, more preferably 5 ppm by mass or more, and particularly preferably 10 ppm by mass or more, relative to the total amount with HCFO-1233yd. Furthermore, the stabilizer content is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 1% by mass or less. When the stabilizer is within the above preferred range, it not only exhibits sufficient stability with respect to HCFO-1233yd, but is also particularly excellent because it does not impair the characteristics of HCFO-1233yd, such as its low surface tension, low viscosity, and good permeability.

[0027] Compounds that can stabilize HCFO-1233yd include at least one stabilizer selected from the group consisting of phenols, ethers, epoxides, amines, alcohols, and hydrocarbons (Republished in 2017-122803). It is believed that different types of stabilizers have different stabilizing effects. For example, phenols and hydrocarbons suppress the decomposition of HCFO-1233yd through their antioxidant properties. Epoxides are thought to suppress the accelerated decomposition of HCFO-1233yd by acidic substances by capturing the generated acids and chloride ions, and amines by neutralizing the acidic substances produced by the decomposition. Therefore, by including two or more types of stabilizers as needed, a synergistic effect of each stabilizer can be obtained.

[0028] Phenols refer to aromatic hydroxy compounds having one or more hydroxyl groups on an aromatic hydrocarbon core. Aromatic hydroxy compounds are preferably soluble in HCFO-1233yd. A benzene ring is preferred as the aromatic hydrocarbon core. The aromatic hydrocarbon core may have one or more substituents attached in addition to hydrogen atoms. Examples of substituents include hydrocarbon groups, alkoxy groups, acyl groups, and carbonyl groups. Furthermore, one or more hydrogen atoms attached to the aromatic hydrocarbon core may be substituted with halogen atoms. Examples of hydrocarbon groups include alkyl groups, alkenyl groups, aromatic hydrocarbon groups, and aralkyl groups.

[0029] The content of the above-mentioned phenols is preferably 1 ppm to 10% by mass, more preferably 5 ppm to 5% by mass, and even more preferably 10 ppm to 1% by mass, relative to the total amount with HCFO-1233yd. When the content of phenols is within the above preferred range, it is particularly excellent because it shows sufficient stability with respect to HCFO-1233yd and does not hinder the characteristics of HCFO-1233yd, such as its low surface tension and viscosity and good permeability.

[0030] Furthermore, ethers refer to chain ethers in which two hydrocarbon groups are bonded to an oxygen atom, and cyclic ethers having an oxygen atom as an atom constituting a ring (excluding epoxy rings, which are three-membered cyclic ethers). The number of etheric oxygen atoms in chain ethers and cyclic ethers may be two or more. The number of carbon atoms in ethers is preferably 12 or less. In addition, the carbon atoms of the hydrocarbon groups constituting the ether may have substituents such as halogen atoms or hydroxyl groups. However, ethers having an epoxy group are considered epoxides.

[0031] The content of the above-mentioned ethers is preferably 1 ppm to 10% by mass, more preferably 10 ppm to 7% by mass, and even more preferably 0.01% to 5% by mass, relative to the total amount with HCFO-1233yd. When the content of ethers is within the above preferred range, it is particularly excellent because it shows sufficient stability with respect to HCFO-1233yd and does not hinder the characteristics of HCFO-1233yd, such as its low surface tension and viscosity and good permeability.

[0032] Furthermore, epoxides are compounds having one or more epoxy groups, which are three-membered cyclic ethers. Epoxides may have two or more epoxy groups in a single molecule, and may also have substituents such as halogen atoms, etheric oxygen atoms, or hydroxyl groups. Epoxides preferably have 12 or fewer carbon atoms.

[0033] The content of the above epoxides is preferably 1 ppm to 10% by mass, more preferably 10 ppm to 7% by mass, and even more preferably 0.01% to 5% by mass, relative to the total amount with HCFO-1233yd. When the content of epoxides is within the above preferred range, it is particularly excellent because it shows sufficient stability with respect to HCFO-1233yd and does not hinder the characteristics of HCFO-1233yd, such as its low surface tension, low viscosity, and good permeability.

[0034] Furthermore, amines refer to compounds (primary to tertiary amines) that have one or more substituted or unsubstituted amino groups. Amines may be acyclic amines or cyclic amines (cyclic compounds in which the nitrogen atom of an amino acid constitutes the ring). Preferred groups bonded to the nitrogen atom of secondary and tertiary amines are alkyl groups or hydroxyalkyl groups having 6 or fewer carbon atoms. Examples of acyclic amines include aliphatic amines and aromatic amines. Examples of aliphatic amines include benzene ring-containing compounds having one or more substituted or unsubstituted amino groups. Examples of cyclic amines include 4-6 membered ring compounds with 1 to 3 nitrogen atoms constituting the ring. Furthermore, the number of carbon atoms in amines is preferably 16 or less, and more preferably 10 or less.

[0035] The content of the above amines is preferably 1 ppm to 10% by mass, more preferably 5 ppm to 5% by mass, even more preferably 10 ppm to 1% by mass, and most preferably 0.001 to 0.1% by mass, relative to the total amount with HCFO-1233yd. When the amine content is within the above preferred range, it is particularly excellent because it shows sufficient stability with respect to HCFO-1233yd and does not hinder the characteristics of HCFO-1233yd, such as its low surface tension and viscosity and good permeability.

[0036] Furthermore, because the above-mentioned amines have a buffering effect, they capture the acid produced when HCFO-1233yd decomposes, preventing an increase in acidity and suppressing further decomposition reactions. By capturing acid introduced from outside, the influence of external factors can be reduced.

[0037] Furthermore, alcohols refer to organic compounds in which a hydroxyl group is bonded to a hydrocarbon with a linear, branched, or cyclic structure. In this disclosure, alcohols with 1 to 3 carbon atoms are preferred because they are soluble in HCFO-1233yd, volatile, and volatilize together with HCFO-1233yd, making them less likely to remain on the surface of articles.

[0038] The alcohol content is preferably 1 ppm to 10% by mass, more preferably 5 ppm to 5% by mass, even more preferably 10 ppm to 1% by mass, and most preferably 0.001 to 0.1% by mass, relative to the total amount with HCFO-1233yd. When the alcohol content is within the above preferred range, it exhibits sufficient stability with respect to HCFO-1233yd, and is particularly excellent because it does not hinder the low surface tension, viscosity, and good permeability characteristics of HCFO-1233yd.

[0039] Furthermore, hydrocarbons are organic compounds having hydrocarbon molecules with a linear, branched, or cyclic structure. In this disclosure, hydrocarbons may be saturated hydrocarbons or unsaturated hydrocarbons in which at least one carbon-carbon bond is an unsaturated bond. In this disclosure, hydrocarbons are preferably linear or cyclic hydrocarbons having 5 to 9 carbon atoms, as they are soluble in HCFO-1233yd, volatile, and do not easily remain on the surface of articles as they volatilize together with HCFO-1233yd. Of the hydrocarbons listed above, unsaturated hydrocarbons are more preferable as stabilizers of HCFO-1233yd because their antioxidant effect through oxygen scavenging is higher than that of saturated hydrocarbons.

[0040] The content of the above hydrocarbons is preferably 1 ppm to 10% by mass, more preferably 5 ppm to 7% by mass, and even more preferably 10 ppm to 5% by mass, with 0.001 to 0.1% by mass being the most preferred range. When the hydrocarbon content is within the above preferred range, it is particularly excellent because it shows sufficient stability with respect to HCFO-1233yd and does not hinder the characteristics of HCFO-1233yd, such as its low surface tension and viscosity and good permeability.

[0041] If the aerosol of this embodiment comes into contact with copper or copper alloy parts, it may contain nitro compounds or triazoles to avoid corrosion of those metals. The content of the nitro compounds or triazoles is preferably 10 ppm to 1% by mass relative to the total amount with HCFO-1233yd.

[0042] The storage containers of this disclosure only need to have pressure resistance to withstand internal pressure and airtightness to prevent leakage of contents. Examples of materials include metals such as iron (tin) and aluminum, glass, improved nylon, mixtures of polyethylene terephthalate (PET) and polybutylene linylate (PBT), polycarbonate, polyphenylene oxide, polyacetal, polyethylene naphthalate, and other resins. In particular, when the container body is made of metal, the inner surface of the container may have a coating to protect against corrosion of the inner surface by the contents and to prevent changes in the contents due to contact between the metal and the contents. This coating provides the container with water resistance, alkali resistance, solvent resistance, yellowing resistance, hygiene, and corrosion resistance, thereby suppressing corrosion of the inner surface of the container and improving the storage stability of the contents, which are the composition. Examples of coatings for this coating include epoxy-amino, epoxy-phenol, and polyamide-imide coatings. It is desirable to select a material that is less susceptible to degradation by HCFO-1233yd or a mixture of HCFO-1233yd and other components as described herein.

[0043] The storage temperature of a storage container containing HCFO-1233yd or a mixture of HCFO-1233yd and other components and the spray gas component of this disclosure shall be 50°C or lower, preferably 40°C or lower, more preferably 30°C or lower, and even more preferably 20°C or lower, as this has a particularly high effect in suppressing acid generation. The lower limit is not particularly limited, but -50°C or higher is preferred, and 0°C or higher is more preferred, as this makes it less likely for the liquid in the container to solidify and allows the liquid to be sprayed stably. When the storage temperature of a sealed storage container containing HCFO-1233yd is within the above range, the generation of acid from HCFO-1233yd is suppressed, which contributes to maintaining the stability of the cleaning performance of HCFO-1233yd.

[0044] The acids of this disclosure include, for example, HF, HCl, and CHF2CO2H, which are generated by the decomposition of HCFO-1233yd. As a method for controlling these acids, the fluoride ion concentration (ppm by weight), chloride ion concentration (ppm by mass), and CHF2CO2H in HCFO-1233yd stored for a certain period (e.g., one week, one month, or three months) are measured. ― The ion concentration (mass ppm) is to be controlled. This ion concentration can also be used as an indicator of the stability of HCFO-1233yd. These ion concentrations are measured using an ion chromatograph. Depending on the type of item being cleaned, the ion concentrations should be 0.7 mass ppm or less for fluoride ions, 0.7 mass ppm or less for chloride ions, and CHF2CO2 ― By having an ion concentration of 5.0 ppm by mass or less, when used as an aerosol, it is less likely to cause rust formation due to corrosion of metals and other materials of the items being cleaned by the acid, as well as erosion and deterioration of accompanying resins and rubbers. The less acid contained in the liquid in the container, the more the impact on the items being cleaned can be suppressed.

[0045] In the quality control method of the present disclosure, for the method of adjusting the storage temperature of the storage container containing HCFO-1233yd, known and publicly available means can be used as long as it is a means capable of cooling the entire storage container containing HCFO-1233yd or cooling it partially. As cooling means, for example, refrigerators, mobile cooling means such as spot coolers, and means such as immersing the container in a refrigerant such as ice or ice water can be mentioned. Also, within a range that does not impair workability, by performing operations while attaching a so-called coolant pack filled with a cooled cloth or a gel-like or liquid coolant to the storage container containing HCFO-1233yd, it is possible to suppress the temperature rise of the storage container and HCFO-1233yd sealed in the storage container. The temperature of the place where HCFO-1233yd is stored may be set to the storage temperature. From the perspective of thermal conductivity, when the storage container includes a metal part, it is preferable to cool the metal part. Also, in the process of adjusting the temperature of the storage container containing HCFO-1233yd, from the perspective of making the temperature of HCFO-1233yd uniform and improving the cooling efficiency, it is preferable to shake the storage container containing HCFO-1233yd as necessary.

[0046] In the quality control method of the present disclosure, for the method of indicating a temperature not exceeding 50°C as the storage temperature of the storage container containing 1233yd, known and publicly available means can be used as long as it is a means capable of communicating the instruction to the person handling the container such as the user or transporter of the storage container containing 1233yd. For example, printing an instruction on the storage container, attaching a label describing the instruction to the storage container, or attaching an irreversible thermosensitive material such as Thermo Label (registered trademark) of Nichiyu Giken Kogyo Co., Ltd. to indicate the adjustment of the storage temperature can be mentioned.

[0047] <Temperature of HCFO-1233yd> The temperature of HCFO-1233yd is presumed to reach a temperature equivalent to the cooling temperature by cooling the sealed container of HCFO-1233yd for a sufficient amount of time using the aforementioned cooling means. Furthermore, the temperature can be indirectly measured by measuring the temperature near the nozzle using thermography or other means at the start of HCFO-1233yd discharge. It is also presumed that if HCFO-1233yd is continuously discharged, the temperature of HCFO-1233yd will decrease due to a drop in pressure within the container. The cooling time can be determined according to the cooling method, the material of the container, the shape of the container, the amount of HCFO-1233yd sealed inside, the ambient temperature in which the container containing the sealed HCFO-1233yd is placed, and the target cooling temperature.

[0048] <Articles to be cleaned> The articles to which the aerosol of this disclosure can be applied are not particularly limited as long as they are metal products such as machine parts, but examples include parts of various vehicles, vehicles, and transportation equipment such as automobiles, motorcycles, bicycles, construction machinery, agricultural machinery, aircraft, railway vehicles, and ships. Because it is an aerosol, it can penetrate into complex structures, and since 1-chloro-2,3,3-trifluoro-1-propene volatilizes after removing oil stains attached to the parts, it is well applicable to cleaning brake components with complex structures. Furthermore, these metal products may also have accompanying parts made of rubber, resin, etc. It is preferable that such rubber, resin, etc. parts are made of materials that are resistant to erosion or deterioration upon contact with HCFO-1233yd.

[0049] The surface temperature of the article to be cleaned to which the aerosol of this disclosure is applied is not particularly limited, but application in the shade is preferred so that the surface temperature does not rise easily. When the surface temperature of the article to be cleaned to which the aerosol is applied is within the above preferred range, it is possible to suppress the rise in temperature of the aerosol adhering to the article, thereby suppressing the decomposition of HCFO-1233yd.

[0050] <Cleaning method> The cleaning method of this disclosure involves aerosolizing HCFO-1233yd, which has been quality-controlled by the method of this disclosure described above, using a spray gas, and bringing it into contact with the item to be cleaned to which oily contaminants are attached. The contaminants dissolve in HCFO-1233yd, and the dissolving solution drips from the item to be cleaned. However, HCFO-1233yd dries quickly, and even if it dries while partially adhering to the metal or associated rubber or resin parts of the item to be cleaned, the generation of acid is suppressed by the quality control method of this disclosure, allowing for the safe use of the aerosol. The dissolving solution will be a solution in which the contaminants are completely or partially dissolved, or in which the contaminants are emulsified or dispersed.

[0051] <Oil stain components> In the cleaning method of this disclosure, the adhering substances to be cleaned include flux, processing oil, lubricating oil, machine oil, quenching oil, mold release agent, dust, etc., adhering to various machine parts and items to be cleaned around brakes. Processing oils include cutting oil, rolling oil, press oil, extrusion oil, punching oil, drawing oil, wire drawing oil, forging oil, assembly oil, etc.

[0052] The method for cleaning an object to be cleaned using the aerosol of the present disclosure is not particularly limited other than bringing the aerosol of the present disclosure into contact with the object to be cleaned. For example, one method is to spray clean the object to be cleaned using an aerosol spray in which the aerosol of the present disclosure is filled and sealed in a spray can. By spraying the aerosol of the present disclosure onto the object to be cleaned from the aerosol spray, the aerosol of the present disclosure and the object to be cleaned can be efficiently brought into contact. In one embodiment, the object to be cleaned may be spray cleaned using an aerosol spray in which the crude refined product of HCFO-1233yd, the stabilizer, and the propellant gas are filled and sealed in a spray can.

[0053] The propellant gas is preferably at least one selected from carbon dioxide, nitrogen, and compressed air. The capacity of each spray can is preferably 100 ml to 300 ml, as this offers advantages in terms of portability, size, and ease of monitoring usage. This contact can remove dirt adhering to the surface of the object to be cleaned. Cleaning conditions, such as contact time and frequency, can be determined as needed.

[0054] In one aspect of this disclosure, in quality control of 1-chloro-2,3,3-trifluoro-1-propene (HCFO-1233yd) used for cleaning machine parts and the like in this disclosure, a quality control method that does not cause fluctuations in cleaning performance includes a step of adjusting the storage temperature of a sealed storage container containing HCFO-1233yd in this disclosure to 50°C or below. [Examples]

[0055] The effects of adjusting the storage temperature of a sealed storage container for 1-chloro-2,3,3-trifluoro-1-propene as described herein will be explained in detail below with reference to examples, but this disclosure is not limited to these examples.

[0056] (Evaluation of acid generation) As an indicator of the amount of acid generated from HCFO-1233yd, the fluoride ion concentration (mass ppm), chloride ion concentration (mass ppm), and CHF2CO2 concentration in HCFO-1233yd stored for a certain period of time are used. ― Ion concentrations (mass ppm) were evaluated. These ion concentrations were measured using an ion chromatograph.

[0057] Ionic components were analyzed using ion chromatography (Thermo Fisher Scientific, Aquion, column: AS-22, eluent: carbonate-based eluent), and the component ratios were determined based on the area ratio of each ion in the chromatogram. Specifically, 4 g of 1233 yd was extracted with 4 g of ultrapure water, and this solution was analyzed by ion chromatography.

[0058] 1.1233 yd stability The results of the storage test for HCFO-1233yd are shown below. HCFO-1233yd was prepared using HCFO-1233yd (E / Z = 7 / 93) obtained by dehydrofluorination of HCFC-244ca. Here, HCFO-1233yd (E / Z = 7 / 93) is a mixture of the trans (E) and cis (Z) isomers, referring to a mixture with a molar ratio of HCFO-1233yd (E):1233yd (Z) = 7:93. In addition, this HCFO-1233yd (E / Z = 7 / 93) contains octene added during dehydrofluorination as an additive, and the total amount of octene contained in HCFO-1233yd (E / Z = 7 / 93) was 3.2 wt%. Although octene contains at least four types of isomers, the individual identified octene was not performed.

[0059] [Example 1] As a storage test using a container made of stainless steel (hereinafter sometimes referred to as SUS), HCFO-1233yd (E / Z = 7 / 93) was filled and sealed in an autoclave (manufactured by耐压硝子工業株式会社), and left standing at 30 °C for 39 days. Then, the autoclave was opened, and the fluoride ion concentration (mass ppm), chloride ion concentration (mass ppm), and CHF2CO2 ― ion concentration (mass ppm) of the sample were measured.

[0060] [Comparative Example 1] HCFO-1233yd (E / Z = 7 / 93) was filled and sealed in a SUS container in the same manner as in Example 1, and left standing at 55 °C for 25 days. Then, in the same manner as in Example 1, the fluoride ion concentration (mass ppm), chloride ion concentration (mass ppm), and CHF2CO2 ― ion concentration (mass ppm) of the sample were measured.

[0061] The results of measuring the fluoride ion concentration (mass ppm), chloride ion concentration (mass ppm), and CHF2CO2 ― ion concentration (mass ppm) of HCFO-1233yd (E / Z = 7 / 93) before heating, the samples of Example 1 and Comparative Example 1 are shown in Table 1. [Table 1]

[0062] Table 1 shows that the acid content in the sample hardly increases when stored at 30°C, but increases significantly in a shorter period of time when stored at 55°C compared to when stored at 30°C.

[0063] From the above, it can be seen that by adjusting the storage temperature of a sealed container containing HCFO-1233yd to an appropriate temperature, the generation of acid from HCFO-1233yd can be suppressed and maintained.

Claims

1. A quality control method for 1-chloro-2,3,3-trifluoro-1-propene (HCFO-1233yd), which is aerosolized with an injection gas and contacts an article to be cleaned with an oil stain component attached thereto to clean the oil stain component, The quality control method is characterized in that the generation of acid is maintained in a suppressed state by adjusting the storage temperature of a storage container in which the HCFO-1233yd is sealed.

2. A method for suppressing the generation of acid in 1-chloro-2,3,3-trifluoro-1-propene (HCFO-1233yd), which is aerosolized with an injection gas and contacts an article to be cleaned with an oil stain component attached thereto to clean the oil stain component, The method is characterized in that the generation of acid is suppressed by adjusting the storage temperature of a storage container in which the HCFO-1233yd is sealed, and the method for suppressing the generation of acid.

3. The method according to claim 1 or 2, characterized in that the storage temperature is adjusted to be -50°C or higher and 50°C or lower.

4. The acid is fluoride ion, chloride ion and CHF ２ CO ２ － The method according to claim 1 or 2, characterized in that it is an ion.

5. The generation amount of the acid is suppressed to 0.7 mass ppm or less of fluoride ions, 0.7 mass ppm or less of chloride ions, and 5.0 mass ppm or less of CHF ２ CO ２ － The method according to claim 1 or 2, characterized in that the generation amount of the acid is suppressed to 5.0 mass ppm or less of ions.

6. The method according to claim 1 or 2, characterized in that an instruction for adjusting the storage temperature is given by printing on the storage container, attaching a label to the storage container, or attaching an irreversible temperature indicating material.

7. The method according to claim 1 or 2, wherein the injection gas is at least one selected from carbon dioxide, nitrogen, and compressed air.

8. The method according to claim 1 or 2, wherein the HCFO-1233yd contains at least one stabilizer selected from the group consisting of phenols, ethers, epoxides, amines, alcohols, and hydrocarbons.

9. The method according to claim 8, wherein the hydrocarbon is octene.

10. A method for cleaning the oil stain component, characterized in that the HCFO-1233yd quality-controlled by the method according to claim 1 is aerosolized with an injection gas and contacted with an article to be cleaned with an oil stain component attached thereto.

11. A method for cleaning the oil stain component, characterized in that the HCFO-1233yd with the generation of acid suppressed by the method according to claim 2 is aerosolized with an injection gas and contacted with an article to be cleaned with an oil stain component attached thereto.