Conductive hydrocarbon-based detergent composition

Abstract

In order to provide a conductive hydrocarbon-based detergent composition having high electrical conductivity, a conductive hydrocarbon-based detergent composition according to the present invention comprises 20-80 mass% of a hydrocarbon-based solvent (A) and 20-80 mass% of a polar solvent (B), and has a conductivity of not less than 1×10-11 S / m.

Description

Conductive hydrocarbon-based cleaning agent composition

[0001] The present invention relates to a conductive hydrocarbon-based cleaning agent composition used for cleaning processed products and the like.

[0002] Conventionally, in the manufacturing and processing processes of various industrial fields such as automobile and vehicle-related parts, machine parts, electrical and electronic components, and optical instrument parts, cleaning agent compositions mainly composed of liquid hydrocarbons are sometimes used for the purpose of removing dirt after parts processing. Such cleaning agent compositions are clarified by distillation and regeneration in a cleaning device and repeatedly used for cleaning parts.

[0003] During distillation and regeneration, the cleaning agent composition is transported and circulated within the piping of the cleaning equipment. However, during this process, the cleaning agent composition may become electrically charged due to friction with the inner walls of the piping (flow charging phenomenon). If the cleaning agent composition becomes electrically charged, it could ignite due to electrostatic discharge, potentially causing a fire. Therefore, it is desirable to suppress this phenomenon as much as possible. Thus, cleaning agent compositions with high conductivity are required, but the conductivity of liquid hydrocarbons used as base oils is 10. -14 The conductivity was quite low, around S / m, and there was a need for measures to improve the conductivity of the cleaning agent composition.

[0004] Patent Document 1 (Japanese Unexamined Patent Publication No. 6-128776) proposes a technology to suppress the generation of static electricity due to triboelectric charging and avoid the risk of ignition and explosion by incorporating a detergent mainly composed of a surfactant and a dry solvent (organic solvent) into a petroleum-based hydrocarbon solvent. Non-Patent Document 1 proposes and sells a cleaning agent that boasts antistatic properties, claiming to enhance fire safety by suppressing fluid charging in the cleaning tank through the incorporation of a cleaning modifier. Japanese Unexamined Patent Publication No. 6-128776, Idemitsu Kosan Co., Ltd. Daphne Cleaner NM / NH Catalog

[0005] In the aforementioned Patent Document 1, by adding 0.3 to 1.0 volume percent of a detergent containing a surfactant and a trace amount of water to 100 volume percent of a petroleum-based hydrocarbon solvent with a flash point of 40 to 70°C, the volume resistivity of the cleaning solution is increased to approximately 10 9 ~about 10 10 Ω・cm or less (conductivity approximately 10 -8 ~10-7 It is said that by setting the conductivity to S / m or higher, the conductivity increases and the generation of static electricity due to triboelectric charging can be greatly suppressed. Furthermore, in Non-Patent Document 1, it is stated that by effectively blending a naphthenic hydrocarbon solvent with a cleaning modifier (CB agent: CLEANING BOOSTER), good solubility with metalworking oil is achieved, exhibiting excellent cleaning performance, and the blending of the cleaning modifier suppresses fluid charging in the cleaning tank, thereby improving fire safety.

[0006] However, in the example of Patent Document 1, although the conductivity of the cleaning solution is relatively high, it has the drawback that it cannot be reused by distillation because it uses a surfactant. Also, in Non-Patent Document 1, although it claims to have antistatic properties, the conductivity calculated from the volume resistivity listed in the catalog is 5 × 10⁻⁶. -12 Because the S / m ratio is relatively low and a cleaning and modifying agent is included, it has the disadvantage of not being able to be reused by distillation and regeneration, similar to Patent Document 1.

[0007] While it might be possible to calculate the conductivity of a detergent composition by assuming additivity from the conductivity values ​​of each individual compound, this invention has shown that additivity of the conductivity of each individual compound is not always true, and that it exhibits unique characteristics that cannot be predicted from calculated additivity values. Therefore, it has become clear that the conductivity of a mixed composition needs to be confirmed by actual measurement. For this reason, it is important to determine the conductivity of a detergent composition by actual measurement after mixing and to optimize the formulation conditions based on this.

[0008] Based on the above findings, the inventors conducted studies to solve the problem and found that a cleaning agent composition obtained by combining a specific hydrocarbon solvent and a specific polar solvent exhibits appropriate conductivity and is easily regenerated by distillation, thus completing the present invention.

[0009] One aspect of the present invention is as follows, for example.

[0010] [1] A hydrocarbon solvent (A) comprising 20% ​​by mass or more and 80% by mass or less, and a polar solvent (B) comprising 20% ​​by mass or more and 80% by mass or less, wherein the conductivity is 1 × 10 -11A conductive hydrocarbon-based cleaning agent composition having a conductivity of S / m or higher.

[0011] [2] The conductive hydrocarbon cleaning agent composition according to [1], wherein the polar solvent (B) is one or more selected from the group consisting of alcohol-based solvents, ketone-based solvents, and ester-based solvents that dissolve in the hydrocarbon-based solvent (A).

[0012] [3] The conductive hydrocarbon-based cleaning agent composition according to [1] or [2], wherein the boiling point of the polar solvent (B) is 130 to 350°C and is less than or equal to the boiling point of the hydrocarbon-based solvent (A) plus 40°C, and is greater than or equal to the boiling point of the hydrocarbon-based solvent (A) minus 50°C.

[0013] [4] The conductive hydrocarbon cleaning agent composition according to [1], [2], or [3], wherein the boiling point of the hydrocarbon solvent (A) is 130 to 350°C.

[0014] [5] The conductive hydrocarbon cleaning agent composition according to [1], [2], [3], or [4], wherein the flash point of each of the hydrocarbon solvent (A) and the polar solvent (B) is 40°C or higher.

[0015] [6] The conductive hydrocarbon cleaning agent composition according to [1] or [2], wherein the total of the hydrocarbon solvent (A) and the polar solvent (B) is 100% by mass, and water is contained in an amount of 0.01% by mass or more and 10% by mass or less.

[0016] The cleaning agent composition according to the present invention makes it possible to provide a cleaning agent composition with relatively high conductivity.

[0017] The present invention will be described in detail below.

[0018] The hydrocarbon solvent (A) used in the detergent composition according to the present invention is a solvent composed of compounds of carbon and hydrogen having 8 to 20 carbon atoms, and may include single compounds and mixtures of multiple single compounds.

[0019] The hydrocarbon solvent (A) is present in an amount of 20% to 80% by mass of the cleaning agent composition. Preferably, it is 25% to 75% by mass, more preferably 30% to 70% by mass, even more preferably 35% to 65% by mass, and particularly preferably 40% to 60% by mass. Polar solvents alone often affect materials such as resins and rubbers, but this effect is generally mitigated when mixed with a hydrocarbon solvent. If the hydrocarbon solvent (A) is less than 20% by mass, there is a concern that rubber materials such as O-rings used in the cleaning device may swell. On the other hand, if it exceeds 80% by mass, the conductivity decreases, increasing the risk of ignition due to flow charging.

[0020] The boiling point of the hydrocarbon solvent (A) is preferably 130 to 350°C. If the boiling point of the hydrocarbon solvent (A) is less than 130°C, the flash point is low and undesirable from a safety standpoint. Furthermore, if the boiling point of the hydrocarbon solvent (A) exceeds 350°C, its high viscosity makes it difficult for the cleaning agent to penetrate into the gaps of the object being cleaned, leading to a tendency for cleaning residue to occur, making it undesirable as a cleaning agent. Also, if the boiling point of the hydrocarbon solvent (A) exceeds 350°C, it becomes difficult to separate the organic components in the dirt components from the hydrocarbon solvent (A) during the distillation process of the cleaning agent composition described later, which is undesirable. The boiling point of the hydrocarbon solvent (A) is more preferably 150 to 330°C, and even more preferably 170 to 310°C.

[0021] Examples of hydrocarbon solvents (A) in the detergent composition of this embodiment include aliphatic saturated hydrocarbon solvents (paraffinic hydrocarbons), aliphatic unsaturated hydrocarbon solvents (olefinic hydrocarbons), alicyclic hydrocarbon solvents (naphthenic hydrocarbons), and aromatic hydrocarbon solvents. The aliphatic saturated hydrocarbon solvent (paraffinic hydrocarbon) may be a linear saturated hydrocarbon solvent (normal paraffinic hydrocarbon) or a branched saturated hydrocarbon solvent (isoparaffinic hydrocarbon).

[0022] Examples of hydrocarbon solvents (A) that can be suitably used in the present invention include normal paraffins having 9 to 20 carbon atoms, isoparaffins having 9 to 20 carbon atoms, and cycloparaffins having 9 to 20 carbon atoms. Particularly suitable hydrocarbon solvents (A) that can be suitably used in the present invention are one or more selected from the group consisting of n-decane (10 carbon atoms), n-undecane (11 carbon atoms), n-dodecane (12 carbon atoms), pentamethylheptane (12 carbon atoms), cisdecalin (10 carbon atoms), transdecalin (10 carbon atoms), and trimethylbenzene (9 carbon atoms).

[0023] The polar solvent (B) used in the detergent composition according to the present invention can be an oxygen-containing organic compound that is compatible with the hydrocarbon solvent (A).

[0024] The cleaning agent composition according to the present invention contains 20% by mass or more and 80% by mass or less of polar solvent (B). Preferably, it is 25% by mass or more and 75% by mass or less, more preferably 30% by mass or more and 70% by mass or less, even more preferably 35% by mass or more and 65% by mass or less, and particularly preferably 40% by mass or more and 60% by mass or less. The reason for including 20% ​​by mass or more and 80% by mass or less of polar solvent (B) is that if the amount of polar solvent (B) is less than 20% by mass, the conductivity becomes low, increasing the risk of ignition due to flow charging. On the other hand, if it exceeds 80% by mass, the effect of the polar solvent on the equipment components increases, resulting in adverse effects such as swelling of rubber materials such as O-rings used in the cleaning equipment.

[0025] Such polar solvents (B) can be one or more selected from the group consisting of alcohol-based solvents, ketone-based solvents, and ester-based solvents that dissolve in the hydrocarbon-based solvent (A) described above.

[0026] The alcohol-based solvent that can be used as the polar solvent (B) can be one or more selected from the group consisting of 4-methyl-2-pentanol, 2-ethylbutanol, 1-hexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 4-methylcyclohexanol, 2,6-dimethyl-4-heptanol, 2-ethyl-1-hexanol, 3,5,5-trimethyl-1-hexanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 1-nonanol, α-terpineol, 3-methyl-3-methoxybutanol, 2-(2-ethylhexyloxy)ethanol, 1-decanol, cyclohexanol, and the like.

[0027] Furthermore, one or more ketone-based solvents that can be used as polar solvents (B) can be selected from the group consisting of mesityl oxide, ethyl-n-butyl ketone, di-n-propyl ketone, methyl-n-amyl ketone, 2-methylcyclohexanone, 3-methylcyclohexanone, 4-methylcyclohexanone, methyl-n-hexyl ketone, 5-methyl-3-heptanone, phorone, acetophenone, isophorone, 3,3,5-trimethylcyclohexanone, 4-methyl-3-penten-2-one, 2-heptanone, 3-heptanone, 4-heptanone, cyclohexanone, 2-methylcyclohexanone, 3-methylcyclohexanone, 4-methylcyclohexanone, acetylacetone, and others.

[0028] Furthermore, the ester solvent that can be used as the polar solvent (B) can be one or more selected from the group consisting of ethyl isovalerate, isoamyl acetate, butyl propionate, amyl acetate, isoamyl propionate, butyl butyrate, cyclohexyl acetate, 3-methoxybutyl acetate, 3-methoxy-3-methylbutyl acetate, dimethyl malonate, isoamyl isovalerate, methyl benzoate, 2-ethylhexyl acetate, benzyl acetate, methyl salicylate, dibutyl oxalate, dimethyl phthalate, diethyl phthalate, dioctyl sebacate, dibutyl phthalate, butyl stearate, dibutyl sebacate, butyl lactate, etc.

[0029] Among the polar solvents (B) described above, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, 3-methyl-3-methoxybutanol, methyl n-hexyl ketone, 5-methyl-3-heptanone, 3-methoxybutyl acetate, methyl benzoate, isophorone, 3,3,5-trimethylcyclohexanone, and butyl lactate are particularly preferably used.

[0030] By providing a detergent composition containing a hydrocarbon solvent (A) and a polar solvent (B) compatible with the hydrocarbon solvent (A), the electrical conductivity is 1×10 -11 S / m or more can be achieved for the detergent composition. Preferably, the electrical conductivity is 1×10 -10 S / m or more, more preferably 1×10 -9 S / m or more, and particularly preferably 1×10 -8 S / m or more. By increasing the electrical conductivity of the detergent composition compared to that of the hydrocarbon solvent (A) alone, the risk of ignition due to flow electrification can be suppressed.

[0031] Further, in the detergent composition according to the present invention, the boiling point of the polar solvent (B) is preferably 130 to 350°C. The boiling point of the polar solvent (B) is preferably equivalent to that of the hydrocarbon solvent. In addition, since compounds with low boiling points tend to have low flash points, it is preferable to use those having a boiling point of 130°C or higher. Further, when the boiling point of the polar solvent (B) exceeds 350°C, due to the high viscosity, it is difficult for the detergent to penetrate into the gaps of the object to be cleaned, and cleaning residues are likely to occur, which is not preferable as a detergent. In addition, when the boiling point of the polar solvent (B) exceeds 350°C, it becomes difficult to separate the organic components in the dirt from the polar solvent (B) during the distillation step of the detergent composition described later, which is not preferable.

[0032] In addition, in the detergent composition according to the present invention, the boiling point of the polar solvent (B) is set to be 40°C or less above the boiling point of the hydrocarbon solvent (A) and 50°C or more below the boiling point of the hydrocarbon solvent (A). Preferably, it is 35°C or less above the boiling point of the hydrocarbon solvent (A) and 45°C or more below the boiling point of the hydrocarbon solvent (A). More preferably, it is 30°C or less above the boiling point of the hydrocarbon solvent (A) and 40°C or more below the boiling point of the hydrocarbon solvent (A). Particularly preferably, it is 25°C or less above the boiling point of the hydrocarbon solvent (A) and 35°C or more below the boiling point of the hydrocarbon solvent (A).

[0033] If the hydrocarbon solvent (A) has multiple boiling points or spans a predetermined range, the boiling point of the polar solvent (B) can be less than or equal to the highest boiling point of the hydrocarbon solvent (A) plus 40°C, and greater than or equal to the lowest boiling point of the hydrocarbon solvent (A) minus 50°C.

[0034] Furthermore, if there are multiple boiling points for the hydrocarbon solvent (A) or if they span a predetermined range, the boiling point of the polar solvent (B) is preferably 35°C or less above the highest boiling point of the hydrocarbon solvent (A) and 45°C or more above the lowest boiling point of the hydrocarbon solvent (A). More preferably, it is 30°C or less above the highest boiling point of the hydrocarbon solvent (A) and 40°C or more above the lowest boiling point of the hydrocarbon solvent (A). Particularly preferably, it is 25°C or less above the highest boiling point of the hydrocarbon solvent (A) and 35°C or more above the lowest boiling point of the hydrocarbon solvent (A).

[0035] The cleaning agent composition is distilled in the cleaning apparatus, but if the difference between the boiling point of the polar solvent (B) and the boiling point of the hydrocarbon solvent (A) deviates from the range described above, the ratio of each component constituting the cleaning agent composition may fall outside the range specified in this application, and therefore the desired performance may not be achieved.

[0036] As described above, by limiting the boiling point difference between the hydrocarbon solvent (A) and the polar solvent (B), a distillably renewable cleaning composition can be obtained.

[0037] Furthermore, in the present invention, by blending water (C) in addition to the hydrocarbon solvent (A) and the polar solvent (B), reliable retention of conductivity and further improvement of conductivity can be expected. Water does not dissolve with hydrocarbon solvents, but it dissolves due to the intervention of the polar solvent (B). In the present invention, the blending amount of water (C) is 0.01 to 10 parts by mass, preferably 0.03 to 5 parts by mass, relative to 100 parts by mass of the total amount of the hydrocarbon solvent (A) and the polar solvent (B). In this case, it is preferable to use water (C) within a range that does not cause precipitation from the cleaning composition. Precipitation can be found, for example, in forms such as turbidity, water accumulation, and water separation.

[0038] In addition, it is preferable that the residue of the cleaning composition according to the present invention after heating at 140°C for 30 minutes is less than 0.1%. The cleaning composition preferably does not contain high-boiling components such as additives, enabling repeated use through distillation regeneration.

[0039] In addition, the flash point of each individual compound constituting the cleaning composition according to the present invention is preferably 40°C or higher. This flash point is set because when the flash point is lower than 40°C, even if ignition due to flow electrification of the cleaning composition can be prevented, there is still a risk of ignition due to ordinary combustion.

[0040] In addition, the cleaning composition according to the present invention ensures a predetermined dissolving power for water-insoluble processing oils. The water-insoluble processing oil may not be compatible if only the polar solvent (B) is used, and the dissolving power for poorly soluble water-insoluble processing oil can be improved by forming a mixed composition with the hydrocarbon solvent (A).

[0041] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. (Examples 1 to 39, Comparative Examples 1 to 15, Reference Example 1) The respective components shown in Table 1 were selectively mixed to prepare the detergent compositions of respective examples shown in Tables 2 to 14. [Procedures for Performance and Evaluation of Electrical Conductivity] For measurement of the electrical conductivity of a detergent composition, a digital ultra-high resistance / micro ammeter 5451 and a liquid resistance sample chamber 12707 manufactured by ADC Corporation were used. Approximately 1 mL of the detergent composition sample of each example was measured into an electrode unit, a DC voltage of 50 V was applied to the sample at room temperature for 1 minute, and the electrical conductivity was determined as the reciprocal of the measured volume resistivity. [Procedures for Performance and Evaluation of Compatibility with Processing Oil] Reliapress RA150 (manufactured by ENEOS) was used as a processing oil (hereinafter referred to as "processing oil"). In a 20 mL sample bottle, the detergent composition of each example and the processing oil were weighed so that the mass ratio thereof was 50:50. Then, after shaking well by hand at room temperature (25°C) for 1 minute, the mixture was allowed to stand at room temperature (25°C) for 24 hours. The appearance of the detergent composition of each example with the processing oil added was visually observed immediately after shaking and after 24 hours of standing, and the compatibility between the processing oil and the detergent composition of each example was evaluated according to the following criteria.

[0042] ○: The detergent remained transparent from immediately after shaking until 24 hours after shaking △: The detergent became cloudy or separated between immediately after shaking and 24 hours after shaking ×: The detergent became cloudy or separated immediately after shaking

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[0057] Examples 1 to 75 all meet the criteria set forth in the present invention in terms of conductivity, compatibility with machining oils, and performance and evaluation of the boiling point difference between hydrocarbon solvent (A) and polar solvent (B). In contrast, Comparative Examples 1 to 8 and 29 to 39 do not meet the conductivity criteria, and Comparative Examples 9 to 28 do not meet the machining oil compatibility criteria. Furthermore, while Comparative Examples 43, 51, and 57 meet the specified conductivity requirements, they do not meet the set flash point and boiling point conditions.

[0058] Examples 76 to 82 shown in Table 9 were prepared by adding the amount of water (C) indicated in the table to a total of 100 parts by mass of hydrocarbon solvent (A) and polar solvent (B).

[0059] For reference, the conductivity of the mixture calculated using the proportions and conductivity of hydrocarbon solvent (A), polar solvent (B), and water (C) is listed. Comparing this to measured values ​​reveals that additivity does not hold true.

[0060] Although the present invention has been described above based on embodiments, the present invention is not limited to the above embodiments. Various modifications to the above embodiments or combinations of embodiments within the same and equivalent scope as the present invention are also included in the scope of the present invention. Industrial applicability

[0061] The cleaning agent composition is transported and circulated within the piping of the cleaning device, but during this process, the cleaning agent composition may become electrically charged due to friction with the inner wall of the piping (flow charging phenomenon). If the cleaning agent composition becomes electrically charged, it is possible that it may ignite due to electrostatic discharge and cause a fire, so it is desirable to suppress such a phenomenon as much as possible. In the prior art, cleaning agent compositions using surfactants have been proposed, although they have relatively high conductivity, but there was a problem that they could not be reused by distillation because they use surfactants. To solve this problem, the conductive hydrocarbon-based cleaning agent composition according to the present invention contains 20% to 80% by mass of a hydrocarbon solvent (A) and 20% to 80% by mass of a polar solvent (B), and has an conductivity of 1 × 10⁻⁶ -11 The S / m value is higher, which can suppress the occurrence of the aforementioned phenomenon, and thus has very high industrial applicability.

Claims

1. A hydrocarbon solvent (A) comprising 20% ​​to 80% by mass and a polar solvent (B) comprising 20% ​​to 80% by mass, wherein the conductivity is 1 × 10 -11 A conductive hydrocarbon-based cleaning agent composition having a conductivity of S / m or higher.

2. The conductive hydrocarbon-based cleaning agent composition according to claim 1, wherein the polar solvent (B) is one or more selected from the group consisting of alcohol-based solvents, ketone-based solvents, and ester-based solvents that dissolve in the hydrocarbon-based solvent (A).

3. The conductive hydrocarbon-based cleaning agent composition according to claim 1 or claim 2, wherein the boiling point of the polar solvent (B) is 130 to 350°C and is less than or equal to the boiling point of the hydrocarbon-based solvent (A) plus 40°C, and is greater than or equal to the boiling point of the hydrocarbon-based solvent (A) minus 50°C.

4. The conductive hydrocarbon-based cleaning agent composition according to claim 1 or claim 2, wherein the boiling point of the hydrocarbon solvent (A) is 130 to 350°C.

5. The conductive hydrocarbon-based cleaning agent composition according to claim 1 or claim 2, wherein the flash points of each of the hydrocarbon solvent (A) and the polar solvent (B) are 40°C or higher.

6. The conductive hydrocarbon-based cleaning agent composition according to claim 1 or claim 2, wherein the total of the hydrocarbon-based solvent (A) and the polar solvent (B) is 100% by mass, and water is contained in an amount of 0.01% by mass or more and 10% by mass or less.

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