JP2022011412A - Solvent composition and method for cleaning article using the same - Google Patents

Abstract

To provide a solvent composition that prevents rust from occurring in a cleaning object or a cleaning device and contains 1-chloro-2,3,3-trifluoro-1-propene.SOLUTION: A solvent composition contains 1-chloro-2,3,3-trifluoro-1-propene and nitromethane, and the content of the nitromethane is 0.6-3 mass% relative to the total mass of the solvent composition.SELECTED DRAWING: None

Description

The present invention relates to a solvent composition, a method for cleaning an article using the solvent composition, and a cleaning solvent combination product containing the solvent composition.

In the manufacturing process, assembly process, final finishing process, etc. of articles such as precision metal processed parts, optical parts, electronic parts, semiconductor manufacturing equipment, and plated parts, dirt such as oil and dust adhering to the articles is organic. It is removed by washing with a solvent. As the organic solvent used for such cleaning, fluoroolefin-based organic solvents that are nonflammable, have little effect on the human body, and have a low global warming potential and ozone depletion potential are used (Patent Documents 1 to 1). 4). Fluoroolefin-based organic solvents are known to be easily decomposed, although they have little impact on the global environment. For example, in Patent Documents 1 to 3, 1-chloro-2,3,3-trifluoro-1-propene (hereinafter, also referred to as “HCFO-1233yd”), which is one of the fluoroolefin-based organic solvents, is used. Additives that can be stabilized are described.

In addition, since fluoroolefin-based organic solvents are expensive, for example, when cleaning articles with a cleaning device equipped with a steam tank, the organic solvent vaporized in the steam tank is cooled and recovered for reuse. ing. On the other hand, if moisture in the air is mixed during cooling, there is a problem that rust is generated on the object to be cleaned or the cleaning device. However, Patent Document 4 describes 1-chloro-3, which is one of the fluoroolefin-based organic solvents. , 3,3-Trifluoro-1-Propen is described as an additive that can suppress the generation of rust even when water is mixed in the cleaning liquid.

International Publication No. 2017/122801 International Publication No. 2017/12802 International Publication No. 2017/122803 Japanese Unexamined Patent Publication No. 2018-9113

Although 1-chloro-3,3,3-trifluoro-1-propene has advantages such as a small impact on the global environment, it has a low boiling point of 39 ° C for Z isomer and 21 ° C for E isomer. The steam cleaning temperature cannot be set high, and in order to obtain an efficient cleaning effect in steam cleaning, the use of a fluoroolefin-based organic solvent having a higher boiling point is required. HCFO-1233yd has a high boiling point of 48 to 54 ° C., and when steam cleaning is performed, the cleaning effect is high because it can be cleaned at a higher temperature. It will be important. However, since the physical properties of fluoroolefin-based organic solvents differ depending on the type, no additive that can suppress the generation of rust in the object to be cleaned has not been known regardless of which fluoroolefin-based organic solvent is used. Therefore, an object of the present invention is to provide a solvent composition containing HCFO-1233yd in which the generation of rust in the object to be cleaned or the cleaning device is suppressed.

As a result of diligent studies to solve the above problems, the present inventors have found that the addition of nitromethane to a solvent composition containing HCFO-1233yd suppresses the generation of rust, and completed the present invention. That is, the present invention provides a solvent composition shown below, a method for cleaning an article using the same, and a solvent combination product for cleaning containing the solvent composition.
[1] A solvent composition containing 1-chloro-2,3,3-trifluoro-1-propene and nitromethane.
A solvent composition in which the content of the nitromethane is 0.6 to 3% by mass with respect to the total mass of the solvent composition.
[2] The solvent composition according to the above [1] for cleaning articles.
[3] The article comprises at least one metal selected from the group consisting of iron, copper, aluminum and alloys thereof, and / or ceramics of oxides, nitrides or carbides [2]. ] The solvent composition according to.
[4] A method of cleaning articles.
A step of preparing a solvent composition containing 1-chloro-2,3,3-trifluoro-1-propene and nitromethane, and
Including the step of immersing the article in the solvent composition in a washing tank.
The method in which the content of the nitromethane is 0.6 to 3% by mass with respect to the total mass of the solvent composition.
[5] The washing tank includes a hot tub and a cold tub, and the dipping step is a step of immersing the article in the solvent composition in the hot tub, and then immersing the article in the cold tub. The method according to the above [4], which comprises a step of immersing in a solvent composition.
[6] The above-mentioned [6] further comprising the step of generating the vapor of the 1-chloro-2,3,3-trifluoro-1-propene from the solvent composition and exposing the article to the vapor after the dipping step. 4] or the method according to [5].
[7] The step of cooling the steam to recover the 1-chloro-2,3,3-trifluoro-1-propene and the recovered 1-chloro-2,3,3-trifluoro-1-propene. The method according to the above [6], further comprising a step of separating and removing the water mixed in the water, if any.
[8] The article comprises at least one metal selected from the group consisting of iron, copper, aluminum, and alloys thereof, and / or ceramics of oxides, nitrides, or carbides. ] To the method according to any one of [7].
[9] The item according to any one of [4] to [8] above, further comprising a step of replenishing the washing tank with a supplement solution containing 1-chloro-2,3,3-trifluoro-1-propene. The method described.
[10] For cleaning, which comprises the solvent composition according to any one of the above [1] to [3] and a supplement containing 1-chloro-2,3,3-trifluoro-1-propene. Solvent combination product.

According to the present invention, by adding nitromethane to the solvent composition containing HCFO-1233yd, it is possible to suppress the generation of rust in the object to be cleaned or the cleaning device even if water is mixed in the solvent composition. can. Therefore, the vaporized HCFO-1233yd can be safely cooled and recovered without worrying about rusting on the object to be cleaned or the cleaning device. In particular, the material to be cleaned of iron-based materials is more likely to rust due to the moisture contained in the cleaning agent than other metal materials, so the above solvent composition is particularly effective in preventing rust on iron-based materials. be.

Hereinafter, the present invention will be described in more detail.
As used herein, the term "solvent composition" refers to a composition containing a solvent and additives. The solvent composition of the present invention contains HCFO-1233yd and nitromethane. The use of the solvent composition is not particularly limited, but for example, the solvent composition can be used as a cleaning agent for cleaning articles.

The HCFO-1233yd is one of the fluoroolefin-based organic solvents, and the positional isomers include Z isomer (hereinafter, also referred to as “HCFO-1233yd (Z)”) and E isomer (hereinafter, “HCFO-1233yd (Z)”). It may also be referred to as "HCFO-1233yd (E)"). The boiling point of HCFO-1233yd (Z) is about 54 ° C, and the boiling point of HCFO-1233yd (E) is about 48 ° C. As the solvent composition of the present invention, any of HCFO-1233yd (Z), HCFO-1233yd (E), and a mixture thereof may be adopted. For example, when the solvent composition is used as a cleaning agent, if HCFO-1233yd (Z) having a high boiling point is used, the steam cleaning temperature can be raised, and it is expected that the cleaning effect of oil and the like will be enhanced. Ru. Therefore, it is preferable to use HCFO-1233yd (Z), which has a high boiling point, as the main component of the cleaning agent.

The content of the HCFO-1233yd is not particularly limited, but may be, for example, about 97% by mass or more, preferably about 98% by mass or more, based on the total mass of the solvent composition. The content of HCFO-1233yd may be, for example, about 99.4% by mass or less, preferably about 99.3% by mass or less, based on the total mass of the solvent composition.

The nitromethane is one of the nitroalkanes that can be used as a solvent additive. When the nitromethane is added to the solvent composition containing the HCFO-1233yd, the effect of suppressing the generation of rust in the object to be cleaned or the cleaning device is exhibited even if water is mixed in the solvent composition. Will be done. Such an advantageous effect is not exhibited in any combination of the solvent and the additive, and is particularly remarkable in the relationship between the HCFO-1233yd and the nitromethane. The content of the nitromethane is not particularly limited as long as the effect of suppressing the generation of rust is exhibited, but may be, for example, about 0.6% by mass or more with respect to the total mass of the solvent composition, and is preferably about 0. It is 7.7% by mass or more. Further, the content of the nitromethane may be, for example, about 3% by mass or less, preferably about 2% by mass or less, based on the total mass of the solvent composition. The nitromethane is known to be flammable or explosive. Further, when the solvent composition of the present invention is used as a cleaning agent for steam cleaning, in many cases, a part of the HCFO-1233yd evaporates during the steam cleaning, and the nitromethane concentration increases. It has been confirmed by experiments that the increase is about 1% by mass. In particular, in the steam tank of the horizontal three-tank type cleaning device, it has been specifically confirmed that the concentration of nitromethane in the steam tank increases due to the evaporation loss of HCFO-1233yd. By adjusting the content of nitromethane, it is possible to maintain safety while effectively suppressing the generation of rust due to the water mixed in the cleaning agent.

In some embodiments, the solvent composition of the present invention is used for cleaning articles. The article to be cleaned (that is, the object to be cleaned) is not particularly limited, and is, for example, at least one metal selected from the group consisting of iron, copper, aluminum, and alloys thereof, and / or an oxide. , Nitride, or carbide ceramic may be included. Since a material mainly containing iron (iron-based material) is more vulnerable to rust due to water than a metal material mainly containing other metals, the solvent composition of the present invention is particularly used for cleaning articles formed of iron-based materials. The effect of suppressing the generation of rust caused by objects is particularly useful. Further, the surface of the cleaning tank of the cleaning device may also contain a metal, which is usually an iron-based material. For example, a corrosion-resistant metal such as stainless steel is usually used for a cleaning device, but since it is used continuously for a long period of time, rust may occur due to water. By using the solvent composition of the present invention, even if the object to be cleaned or the cleaning device contains a metal of an iron-based material, the cleaning operation can be performed without worrying about the occurrence of rust.

The solvent composition of the present invention can also be used in co-solvent cleaning. In co-solvent cleaning, a strong solvent for cleaning specific contaminants such as hydrocarbons, glycol ethers, and higher alcohols is used in the cleaning process, but these solvents have poor drying properties and stain the surface. Substances may remain. If such a solvent is mixed with the solvent composition of the present invention and used in the cleaning step, residual contaminants can be suppressed. That is, in one embodiment, the solvent composition of the present invention further contains an additional cleaning component, and the additional cleaning component is not particularly limited, but is, for example, hydrocarbon-based, glycol ether-based, and higher alcohol-based. It may be at least one selected from the group consisting of such as. Further, the solvent composition of the present invention can also be used in the rinsing step of co-solvent washing. For example, by performing steam cleaning using the solvent composition of the present invention, it is possible to cope with fields where high cleanliness is required.

The solvent composition of the present invention may further contain any additive or stabilizer commonly used in the art, as long as the object of the present invention is not impaired. As the stabilizer, those usually used in the art can be adopted without particular limitation, and for example, the stabilizer may be ethers (tert-butylmethyl ether, dioxane, etc.), nitro. At least one selected from the group consisting of alkanes (nitroethane, etc.), ketones (methylethylketone), epoxy compounds, phenols, imidazoles, amines, phosphorus compounds, sulfur compounds, hydrocarbons, alcohol compounds, etc. It may be a seed. Although not bound by a specific theory, it is speculated that, for example, phenols and hydrocarbons suppress the decomposition of HCFO-1233yd by their antioxidant action. Then, the epoxy compound captures the acidic substances and chlorine ions generated by the decomposition of a part of HCFO-1233yd, and the amines neutralize the acidic substances, respectively, so that the HCFO-1233yd due to the acidic substances is obtained. It is presumed to suppress further decomposition of. From these facts, it is expected that a synergistic stabilizing effect can be obtained by each stabilizer by using two or more kinds of stabilizers as needed. The content of the stabilizer is not particularly limited, but may be, for example, about 0.5% by mass or less with respect to the total mass of the solvent composition. By adding a small amount, for example, the effect of suppressing decomposition of HCFO-1233yd is exhibited without deteriorating the cleaning effect.

In another aspect, the invention also relates to a method of cleaning an article, which cleaning method.
A step of preparing a solvent composition containing HCFO-1233yd and nitromethane, and
It includes a step of immersing the article in the solvent composition in a washing tank. In some embodiments, the washing tank comprises a hot tub and a cold tub, and the dipping step is a step of immersing the article in the hot tub (eg, about 30 to about 50 ° C.) and then the solvent composition. May include a step of immersing the article in the solvent composition in the cold bath (eg, about 20 to about 30 ° C.). In the hot tub, the cleaning efficiency may be improved by, for example, applying ultrasonic waves to the article. Immersion in the cold bath includes a rinsing role other than cooling the article.

In some embodiments, it further comprises the step of generating the vapor of HCFO-1233yd from the solvent composition and exposing the article to the vapor after the dipping step. This step is so-called steam cleaning, and is performed in a steam atmosphere vaporized in a steam tank. Since the article has a temperature equal to or lower than the boiling point of the HCFO-1233yd as a result of undergoing the dipping step, when exposed to the steam, the HCFO-1233yd condenses and flows down on the surface of the article. In this way, the article is washed.

The method for cleaning an article of the present invention may further include any cleaning step or drying step commonly used in the art, as long as the object of the present invention is not impaired. For example, when a large amount of oil stains are attached to the article (object to be cleaned), the method of the present invention may include a step of rough cleaning the article with a hydrocarbon solvent as a pretreatment. Further, when it is difficult to dry the object to be cleaned because the structure of the object to be cleaned is complicated, the method of the present invention may include a step of subjecting the object to be cleaned to hot air drying or vacuum drying as a post-treatment. good.

The cleaning device to which the method for cleaning the solvent composition of the present invention and the article of the present invention is applied is not particularly limited, but for example, a vertical two-tank type cleaning utilizing the space above the cleaning tank as the steam tank. It may be an apparatus, or it may be a horizontal three-tank type cleaning apparatus including the hot bath (sometimes referred to as an immersion tank), the cold bath, and the steam tank. Generally, in order to prevent the steam generated in the steam tank from leaking out of the steam tank, a pipe through which cooling water flows is installed at the opening thereof. When the vapor of HCFO-1233yd tries to pass through the opening, it is cooled by cooling water and condensed, so that HCFO-1233yd is recovered as a liquid. The recovered HCFO-1233yd can be returned to the washing tank and reused after passing through the water separator. At this time, moisture in the air may be mixed in the cooled HCFO-1233yd, but not all the moisture can be removed by the water separator. Even in such a case, since the solvent composition of the present invention contains the nitromethane, it is possible to suppress the generation of rust in the object to be cleaned or the cleaning device. The horizontal three-tank cleaning device may have a structure in which when the solvent composition overflows from the cold bathtub, it flows into the hot bathtub (immersion tank) and the steam tank. In such a case, by returning the recovered HCFO-1233yd to the cold bath, the clean solvent can be efficiently reused.

In yet another aspect, the invention also relates to a cleaning solvent combination product, which comprises a solvent composition comprising HCFO-1233yd and nitromethane and a replenishing solution comprising HCFO-1233yd. .. When cleaning with the solvent composition using a cleaning device provided with a steam tank, it is difficult to completely recover the HCFO-1233yd vaporized in the steam tank. Further, the boiling point (100 to 103 ° C.) of the nitromethane is higher than the boiling point of the HCFO-1233yd, and since it does not azeotrope at the temperature at the time of steam cleaning, the cleaning that is accumulated in a liquid state in the lower part of the steam tank. In the agent, the concentration of the nitromethane tends to increase. In many cases, the nitromethane concentration increases by about 1% by mass, but after that, it often becomes a steady state, but it is dangerous if the nitromethane concentration becomes too high. Therefore, when the concentration of the nitromethane rises more than necessary, the concentration of the nitromethane can be kept in an appropriate range by the supplement solution.

In addition, the replenisher is periodically used to keep the amount of the solvent composition evaporated by steam washing in an appropriate amount. The composition of the supplement solution is the same as that of the solvent composition, only HCFO-1233yd without nitromethane, and somewhere in between (containing nitromethane but less than nitromethane in the solvent composition). ) And can be. That is, the supplement liquid may further contain the nitromethane, and the content thereof may be the same as or lower than the content in the solvent composition. It is desirable to decide what kind of replenisher to use after experimenting with the cleaning work with an actual cleaning device.

The method of using the replenisher is not particularly limited, and for example, the replenisher may be added to the washing tank (cooling tank if present) or to the steam generation site of the steam tank. good.

Hereinafter, the present invention will be specifically described with reference to Examples, but the scope of the present invention is not limited to these Examples.

[Test Example 1]
As a pretreatment for the test, SPCC cold-rolled steel sheet (15 mm x 50 mm) is dipped in an alkaline degreasing agent (manufactured by Dipsol, degreasing agent LC-34), brushed and washed, then washed with water and dried well to remove moisture. It was in a state where there was no dirt such as oil. This was used as a sample plate for subsequent tests.

HCFO-1233yd (AMOLEA ^(R) AS-300, manufactured by AGC) and various additives were placed in a hermetically sealed container at the concentrations shown in Table 1 or Table 2 below. The lid of this container was tightly closed, and the mixture was mixed well by inversion 100 rotations (rotation 180 degrees) at a rate of 2 times per second to prepare a test solution (solvent composition).

A screw tube bottle (screw cap bottle; No. 7, 100 mL) was prepared as a test container. 40 mL of the prepared test solution was added thereto, and 5 g of ion-exchanged water was further added. The lid of this test container was closed tightly, and the mixture was mixed 100 times and mixed well.

The test container containing the test solution and ion-exchanged water was allowed to stand, and after the test solution and water were completely separated, the sample plate was placed in the test container. The separated water was collected in the upper part (about 10% of the height of the whole solution in the test container), but the sample plate was completely immersed in the test solution. Ultrasonic waves were applied here for 1 minute to defoam, and the surface of the test plate was sufficiently wetted with the test solution. The sample plate in the immersed state was left in a constant temperature bath at 20 ° C., and the presence or absence of rust generated over time on the surface of the sample plate was visually observed and judged as follows. The results are shown in Tables 1 and 2.
○: No rust △: Test solution discolored ×: Rusted

When the sample plate is washed with HCFO-1233yd alone, rust is generated due to the influence of the water mixed in the test solution (Comparative Example 1). On the other hand, when nitromethane is blended in combination with HCFO-1233yd, rust does not occur even if water is mixed in the test solution (Examples 1 to 7). Such an advantageous effect was not confirmed in the test solution containing other additives (Comparative Examples 4 to 15).

[Test Example 2]
In the same manner as in Test Example 1 except that the solvent compositions of Examples 8 to 11 containing the stabilizer (Table 3) were used as the test solution, the presence or absence of rust generated on the surface of the sample plate over time was observed. , Visually observed. The results are shown in Table 3.

Rust did not occur even when the solvent compositions of Examples 8 to 11 additionally containing various stabilizers were used. Generally, when HCFO-1233yd is stored at a temperature lower than the boiling point, it may be decomposed to generate halogen ions such as chloride ions. However, since the solvent compositions of these examples contain stabilizers, the halogen ions may be generated. It is possible to suppress the generation of such halogen ions. Since the halogen ion can generate an acid and cause corrosion of the metal, the solvent compositions of Examples 8 to 11 have an additional effect of suppressing not only the generation of rust but also the corrosion of the metal.

From the above, it was found that by adding nitromethane to the solvent composition containing HCFO-1233yd, even if water is mixed in the solvent composition, the generation of rust in the object to be cleaned or the cleaning device can be suppressed. Therefore, the vaporized HCFO-1233yd can be safely cooled and recovered without worrying about rusting on the object to be cleaned or the cleaning device.

Claims (10)

A solvent composition containing 1-chloro-2,3,3-trifluoro-1-propene and nitromethane.
A solvent composition in which the content of the nitromethane is 0.6 to 3% by mass with respect to the total mass of the solvent composition. The solvent composition according to claim 1, for cleaning articles. 2. The article according to claim 2, wherein the article comprises at least one metal selected from the group consisting of iron, copper, aluminum, and alloys thereof, and / or ceramics of oxides, nitrides, or carbides. Solvent composition. A method of cleaning articles
A step of preparing a solvent composition containing 1-chloro-2,3,3-trifluoro-1-propene and nitromethane, and
Including the step of immersing the article in the solvent composition in a washing tank.
The method in which the content of the nitromethane is 0.6 to 3% by mass with respect to the total mass of the solvent composition. The washing tank includes a hot tub and a cold tub, and the dipping step is a step of immersing the article in the solvent composition in the hot tub, and then immersing the article in the cold tub. The method according to claim 4, which comprises a step of immersing in a bathtub. 4. The method described in. The step of cooling the steam to recover the 1-chloro-2,3,3-trifluoro-1-propene and mixing the recovered 1-chloro-2,3,3-trifluoro-1-propene with the recovered 1-chloro-2,3,3-trifluoro-1-propene. The method according to claim 6, further comprising a step of separating and removing the water, if any. 4. 7. The article comprises at least one metal selected from the group consisting of iron, copper, aluminum, and alloys thereof, and / or ceramics of oxides, nitrides, or carbides. The method described in any one of the items. The method according to any one of claims 4 to 8, further comprising a step of replenishing the washing tank with a supplement solution containing 1-chloro-2,3,3-trifluoro-1-propene. A cleaning solvent combination product comprising the solvent composition according to any one of claims 1 to 3 and a replenisher containing 1-chloro-2,3,3-trifluoro-1-propene.