JPH09169997A - Cleaning agent and method for recovering the same - Google Patents

Abstract

(57) [Summary] [Objective] To provide a cleaning agent in which the composition does not change before and after distillation recovery and in which impurities are less mixed, and a recovery method thereof. [Structure] One type of hydrocarbon having 5 to 20 carbon atoms or a mixture of two types of hydrocarbon having 1 to 5 carbon atoms and 5 to 20 carbon atoms is used, and as the organic compound having a polar group, A detergent containing one or more of those having a boiling point within ± 25 ° C. of the 50% distillation temperature of the hydrocarbon solvent at atmospheric pressure is used. Distillation recovery is performed within ± 25 ° C of the 50% distillation temperature of the cleaning agent at atmospheric pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to oils and fats, machine oils, etc. used for processing and assembling electric and electronic parts and machine parts.
The present invention relates to a cleaning agent that has excellent removability of grease, flux, and the like, and excellent distillability and recovery.

[0002]

2. Description of the Related Art Conventionally, a chlorine-based or CFC-based cleaning agent which is flame-retardant and supplied at a low cost has been used as a disposable material for removing dirt adhering to the surfaces of electric and electronic parts, mechanical parts and the like. However, these substances will be restricted in the future as causative substances of ozone layer depletion. For this reason, many water-based or solvent-based cleaning agents have been proposed as cleaning agents in place of chlorine-based or freon-based solvents. On the other hand, in recent years, an example of using terpenes such as limonene, pinene, dibenten, etc. as a cleaning agent with little environmental pollution and high safety is described in US Pat. No. 4,511,488 and Japanese Patent Publication No. 63-501.
908 (US Pat. Nos. 4,640,719 and 4,740,247) and the like. In addition to these, there are also water-based detergents in which a surfactant and a builder are mixed with sodium orthosilicate and caustic soda.

Further, when a hydrocarbon type cleaning agent is used alone, it has a low environmental pollution property, but has a problem in flux removability. Therefore, the hydrocarbon solvent is alcohol,
A cleaning agent in which a polar substance such as ether or ketone is added to improve the flux removing property and the component cleaning property is disclosed in JP-A-3-146.
597 and Japanese Patent Application Laid-Open No. 7-503032.

Such hydrocarbon-based detergents are usually distilled and recovered for repeated use in order to reduce the cost and the impact on the environment. However, the polar substance may be decomposed or oxidized during the distillation recovery or the washing, and the detergent may be deteriorated or explosive peroxide may be generated. In order to prevent this, an example in which an antioxidant is added is disclosed in JP-A-7-268.
It is disclosed in Japanese Patent No. 391.

[0005]

However, none of these detergents satisfies all the conditions required for detergents such as dirt oil removability and low toxicity. That is, terpenes typified by limonene are not only expensive because they are derived from natural products and have a limited supply amount, but also have a problem in durability during use. In addition, the cleaning power of water-based cleaning agents is poor,
It also causes rusting and is more difficult to recycle, requiring specialized waste liquid treatment equipment.

Hydrocarbon-based detergents containing polar substances are
Usually, the boiling point range is wide because a petroleum fraction having a specific boiling point range is used as a solvent. Therefore, when the impurities are removed by distillation and recovery, there is a problem that the composition is largely changed before and after the recovery and the cleaning performance is changed. In addition, there is a problem that impurities tend to be mixed in when the recovery rate is increased.

[0007] The present invention provides a cleaning agent which is improved in the above-mentioned drawbacks of the prior art and is excellent in cleaning property and safety, and is excellent in distillation recovery property in order to reduce environmental pollution and supply at low cost. The purpose is.

[0008]

[Means for Solving the Problems] As a result of intensive studies for solving the above problems, as a result, in the case of a mixed composition having a difference in boiling point, the composition and It was found that the detergency hardly changed.

As a result of further studies, it was found that the cleaning agents comprising the following (A) and (B) have excellent distillation recovery properties.

(A) One of hydrocarbons having the same carbon number of 5 to 20 or a mixture of isomers thereof, or a carbon number of 1 different from each other and a carbon number of 5 to 20 different from each other 2 Hydrocarbon solvent consisting of a mixture of seeds (B) ± 50% of 50% distillation temperature of the above hydrocarbon solvent at atmospheric pressure
An organic compound having one or two or more polar groups having a boiling point within 25 ° C. Then, by adopting a method in which the distillation recovery is carried out within 50% distillation temperature ± 25 ° C. of the detergent at atmospheric pressure, The present invention has been completed because it is possible to provide a distillation and recovery method in which not only changes in composition and cleaning properties before and after distillation recovery are extremely small, but also impurities are less mixed.

That is, the present invention is a cleaning composition for cleaning and removing oils and fats, machine oil, grease, flux, etc. adhering to electric and electronic parts, mechanical parts, etc., which has a boiling point close to that of the above-mentioned hydrocarbons. It is intended to provide a cleaning composition which can suppress the composition change due to distillation recovery and the inclusion of impurities at the time of distillation recovery by mixing and adding a polar substance and can be stably used for a long time, and a recovery method thereof.

The hydrocarbon solvent used in the present invention is one of hydrocarbons having 5 to 20 carbon atoms having the same carbon number, a mixture of isomers thereof, or a carbon solvent having different carbon numbers from each other among commercially available solvent systems. A mixture of two kinds having different carbon numbers of 5 to 20 can be used, and there is no particular limitation, but it is desirable to select one having less environmental pollution. Examples of such a detergent include a normal paraffin solvent having 5 to 15 carbon atoms and an isoparaffin synthetic solvent having 6 to 20 carbon atoms obtained by polymerizing an olefin having 3 or 4 carbon atoms.

Normal paraffin has 5 to 1 carbon atoms.
5, preferably having 7 to 14 carbon atoms, and particularly preferably having 9 to 13 carbon atoms. If the number of carbon atoms is less than 5, there is a danger of fire or explosion during the cleaning work and there is a safety problem. Further, if it exceeds 15, not only the flux removability is deteriorated, but also the boiling point is too high to make it difficult to recover by distillation, and there are some which do not become a solution state unless heated. The isoparaffin synthesis solvent has 6 carbon atoms.
-20, preferably 8-16, particularly preferably 8-12
However, it is usually practical to select an appropriate number from the carbon number of 6, 8, 9, 12, and 16 for ease of synthesis. In this case,
When mixed with a solvent having one different carbon number, a combination of 8 and 9 is used or a combination with normal paraffin is used.

In order to improve the detergency against flux and the like, an organic compound having a polar group is added to the above hydrocarbon solvent. Examples of the organic compound having such a polar group include alcohols, ketones, ethers and esters, and the compounding ratio thereof is 3 to 50%, preferably 5 to 30.
%, Particularly preferably about 10 to 25%. In order to ensure the recoverability by distillation, this organic compound has a boiling point within ± 25 ° C, preferably within ± 15 ° C, more preferably within ± 7 ° C of the 50% distillation temperature of the above hydrocarbon solvent. Select and use one. These organic compounds may be used alone or in combination of two or more.

The polar organic compound has 4 to 4 carbon atoms.
It must be 20. If the carbon number is 3 or less, there is a risk of fire and explosion during operation, and there is a safety problem.
If it exceeds 20, the detergency will decrease. Among them, those having 6 to 17 carbon atoms, particularly those having 7 to 15 carbon atoms are preferable.

When alcohol is used as the organic compound having a polar group, the alcohol has 1 or 2 hydroxyl groups.
Select ones. When the number of the hydroxyl groups is 3 or more, not only the polarity becomes too large and the detergency becomes insufficient, but also the solubility in hydrocarbon decreases, which is not preferable. Specific examples of alcohols include 2-ethylhexanol, 1-hexanol, 1-octanol,
2-octanol, lauryl alcohol, oleyl alcohol, 2-hepten-1-ol, 10-undecen-1-ol, Guerbet alcohol, 2-cyclo-2-propanol, cycloundecanol, 1,2-dodecanediol, 1 , 2-octadecanediol, 1,16-
Examples include synthetic or natural alcohols such as hexadecane diol and dipropylene glycol.

As the ether compound, the hydrogen atom of the hydroxyl group of the above alcohol is an alkyl group having 1 to 4 carbon atoms, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl. A group substituted with a t-butyl group, which can be obtained, for example, by reacting the above-mentioned alcohol with a corresponding halogenated hydrocarbon. Further, a cyclic ether having a 5-membered ring or more can also be used. In the ether compound, the number of hydroxyl groups is reduced by replacing the hydrogen atom with a hydrocarbon group. Therefore, when the ether compound has hydroxyl groups, the number of hydroxyl groups is 0.
~ 2 can be selected. Specific examples of the ether compound include dibutyl ether, propylene glycol monobutyl ether, 1,2-diethoxyethane, 1,8-cineol, diethylene glycol diethyl ether, diethylene glycol dibutyl ether,
Examples include propylene glycol methyl ether, anisole, dihexyl ether, dipentyl ether and the like.

As the ketone compound, an alkyl group having 1 to 4 carbon atoms such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t
-A butyl group and an alkyl group having 1 to 15 carbon atoms and having 4 to 20 carbon atoms in the molecule can be used. These can be synthesized by oxidation of the corresponding secondary alcohol or catalytic dehydrogenation reaction.

The ester compound is also an alkyl group having 1 to 4 carbon atoms, for example, methyl group, ethyl group, n-propyl group, i-
Those having a propyl group, an n-butyl group, an i-butyl group, a t-butyl group and an alkyl group having 1 to 15 carbon atoms and having 5 to 20 carbon atoms in the molecule can be used. These can be synthesized by a dehydration reaction of an organic acid and an alcohol. Specific examples of the ester compound include butyl acetate, isopentyl acetate, 3-methoxybutyl acetate, butyl propionate, butyl butyrate, isopentyl isovalerate, methyl benzoate, diethyl malonate and ethylene glycol monoacetate.

Although the cleaning agent is recovered by distillation, an appropriate method can be adopted as the distillation recovery condition depending on the cleaning agent. Usually, in order to prevent contamination with contaminants, the normal recovery is ± 25 ° C of the 50% distillation temperature of the cleaning agent at atmospheric pressure as described above.
Do within. However, when the boiling point of the dirt component is close to the atmospheric pressure conversion 50% distillation temperature of the cleaning agent, it is ± 15 ° C, especially ± 15 ° C.
It is preferably carried out within 7 ° C. In this case, it is necessary to select one having a boiling point close to that of the component constituting the detergent at normal pressure. In addition, depending on the combination of the hydrocarbon solvent and the organic compound having a polar group, it may be possible to recover at ± 5 ° C or ± 3 ° C of the 50% distillation temperature converted to atmospheric pressure. Such combinations are preferred. If the distillation recovery temperature range deviates from ± 25 ° C., which is the atmospheric pressure-converted 50% distillation temperature of the cleaning agent, it is not preferable because components other than the cleaning agent component will be recovered.

Further, since the composition of the cleaning agent of the present invention hardly changes due to the recovery by distillation, a method of removing a part of the distillate can be adopted for the purpose of preventing contamination of impurities. Specifically, a method of removing 0 to 3% or 0 to 5% of a low-boiling-point distilling portion, and a normal-pressure-equivalent boiling point of a low-boiling component contained in a detergent.
The inclusion of impurities can also be prevented by a method of removing a distillate at 1 ° C., preferably + 1 ° C. or less. On the other hand, 97 on the high boiling point side
-100% or 95-100% method of removing distillate, and boiling point of high-boiling components contained in the detergent at atmospheric pressure +1
The inclusion of impurities can also be prevented by a method of removing a distillate at a temperature of ℃, preferably -1 ℃ or more. It goes without saying that there is almost no change in the composition even after such removal, so that the change in cleaning properties is extremely small.

Further, as an additive, a rust preventive agent for metal surfaces such as electric and electronic parts and mechanical parts can be added, and a nitrogen-containing organic additive, an epoxy compound and the like can be added. As the nitrogen-containing organic additive, benzotriazole, tolyltriazole, a benzotriazole derivative having a hydrocarbon group having 2 to 10 carbon atoms, benzimidazole, an imidazole derivative having a hydrocarbon group having 2 to 20 carbon atoms, and 2 to 20 carbon atoms. The thiazole derivative having a hydrocarbon group can be used. On the other hand, as the epoxy compound, propylene oxide, 1,2-epoxybutane, 1,2
-Epoxy octane, 1,6-hexanediol glycidyl ether, and glycidyl ethers having 3 to 15 carbon atoms can be used. 0.1% of one or more selected from these nitrogen-containing organic additives and epoxy compounds,
It can be added to a detergent and used.

Further, a surfactant may be added as an additive in order to separate the water adhering from the surface of the electric / electronic parts, mechanical parts and the like. As the surfactant, any of anionic, cationic, amphoteric surfactants and the like can be used, but a nonionic surfactant is most preferable in that it has little effect on the cleaning surface. For example, polyoxyalkylene alkyl ether, polyoxyalkylene alkyl phenol ether, polyoxyalkylene alkyl fatty acid ester, polyoxyalkylene allyl phenol ether, polyoxyalkylene sorbitan fatty acid ester, polyoxyalkylene alkylamine, these polyoxyalkylenes, sorbitan fatty acid ester, etc. Can be preferably used.

The cleaning agent of the present invention can be used in various cleaning methods such as a dipping method, an ultrasonic cleaning method, a rocking method and a spraying method, and a preferable result can be obtained.

When the cleaning agent of the present invention is used in a cleaning process of machine parts, for example, ultrasonic cleaning is first performed in an ultrasonic cleaning tank containing the cleaning agent of the present invention, and then rinsed with the cleaning agent of the present invention and dried. By carrying out the method continuously, it is possible to efficiently wash.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

(Test Method) A simulated post-cleaning liquid was prepared by simulating the cleaning liquid after cleaning and mixing the cleaning agent and the processing oil in a ratio of 9: 1. The processing oil has an initial boiling point of 25 at normal pressure.
This is press oil at 0 ° C. Distillation recovery was carried out within the range of the distillation temperature of the cleaning agent which was examined in advance. Of this recovered liquid, 10
-30%, 31-60% and 61-90% of each fraction were analyzed by gas chromatography to analyze the hydrocarbon solvent,
Organic compounds having polar groups, measuring the content of processing oil,
The changes in composition were compared.

Further, the flux detergency was examined using the liquid after the distillation recovery. First, a printed wiring board having an IC chip mounted thereon was subjected to a flux treatment and then a solder treatment to obtain a test piece. This test piece was immersed in a cleaning solution kept at 80 ° C., and after cleaning for 5 minutes, the flux removability from the printed wiring board was visually evaluated. The evaluation results are classified into the following three levels.

◯: Almost no flux remained Δ: Flux remained slightly X: Flux remained considerably Although the cleaning liquid used in the following Examples and Comparative Examples, when a new product was used The detergency was good.

Example 1 80% of normal decane having a boiling point of 175 ° C. and a boiling point of 18
The distillation recovery liquid was tested in accordance with the above test method using a detergent containing 5% of 2-ethylhexanol at 20%. Also for this example, 0-9% and 91-100% fractions were tested. The results are shown in Table 1. No mixing of processing oil was observed in all the distillates, and the composition of the detergent was unchanged. No change was observed in the flux cleaning property.

[0031]

[Table 1]

Example 2 Tests were carried out in the same manner as in Example 1 except that normal decane was 87.5% and 2-ethylhexanol was 12.5%. The results are shown in Table 2 and were the same as in Example 1.

[0033]

[Table 2]

Example 3 A distillation recovery liquid was tested in accordance with the test method described above using a detergent composed of 80% normal decane and 20% 2-octanol having a boiling point of 179 ° C. The results are shown in Table 3. No mixing of processing oil was observed in the fractions of 10 to 30%, 31 to 60% and 61 to 90%, and the composition of the detergent was unchanged. No change was observed in the flux cleaning property. Although not shown in the table, no mixing of processing oil was observed in the 91 to 100% fraction.

[0035]

[Table 3]

Examples 4 to 6 Example 3 was repeated except that dioctyl ether (boiling point 187 ° C.), propylene glycol monobutyl ether (boiling point 170 ° C.) and butyl lactate (boiling point 187 ° C.) were used instead of 2-octanol in Example 3. And tested in the same manner. The results are shown in Tables 4 to 6, and are 10 to 30%, 31 to 60% and 61.
No mixing of processing oil was observed in the -90% fraction, and the composition of the detergent was unchanged. No change was observed in the flux cleaning property. Although not shown in the table, 91-
No mixing of processing oil was found in the 100% fraction.

[0037]

[Table 4]

[0038]

[Table 5]

[0039]

[Table 6]

Example 7 Normal decane of Example 3 was converted into iso-paraffin having 12 carbon atoms (mixture of isomers; 50% distillation temperature 193 ° C.), 2
-Tested as in Example 3, except that octanol was changed to normal ethyl hexanol. The results are shown in Table 7, and are 10 to 30%, 31 to 60% and 50 to 90%.
No mixing of processing oil was observed in the fraction, and the composition of the detergent was unchanged. No change was observed in the flux cleaning property. Although not shown in the table, 91 to 100%
No mixing of processing oil was found in the fraction.

[0041]

[Table 7]

Comparative Example 1 A test was conducted in the same manner as in Example 3 except that 2-octanol in Example 3 was changed to normal dodecyl alcohol (boiling point 231 ° C.). The results are shown in Table 8 and are 10 to 30.
%, 31-60% and 61-90% fractions have significantly changed their composition, resulting in poor flux cleanability.
Particularly, the 10 to 60% fraction contains almost no normaldodecyl alcohol, so that the flux detergency is extremely deteriorated. Further, the processing oil was mixed in the 61 to 90% fraction.

[0043]

[Table 8]

Comparative Example 2 Normal decane of Example 3 was added to the boiling point range of 175 to 194.
2-Octanol as 2-
The test was conducted in the same manner as in Example 3 except that ethylhexanol was used. The results are shown in Table 9, and 10 to 30%, 3
The composition of the 1-60% and 61-90% fractions has changed, so there is little 2-ethylhexanol component 31-90
The flux cleanability of the% fraction decreased.

[0045]

[Table 9]

Comparative Example 3 Normal decane of Example 3 was used in the boiling range of 175 to 194.
A test was conducted in the same manner as in Example 3 except that a hydrocarbon-based mixed solvent at 0 ° C. was used and 2-octanol was changed to normal dodecyl alcohol. The results are shown in Table 10.
%, 31% to 60% and 61 to 90% fractions have different compositions, and the content of normaldodecyl alcohol component is low.
The flux detergency of the 0 to 60% fraction decreased. Also,
Processing oil was mixed in the 31 to 90% fraction.

[0047]

[Table 10]

[0048]

EFFECT OF THE INVENTION The cleaning agent of the present invention has excellent detergency and has a very small change in composition during recovery by distillation. Further, by adopting the recovery method of the present invention, contamination of impurities is extremely small. Therefore, even if the distillation and recovery are repeated, the change in the cleaning property is extremely small, and stable use can be achieved for a long period of time. Further, since it can be easily recovered by distillation, it is less likely to cause environmental pollution, and can be advantageously used in a cleaning process for electric and electronic parts, mechanical parts and the like.

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[Procedure amendment]

[Submission date] January 31, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction contents]

[0002]

2. Description of the Related Art Conventionally, a chlorine-based or CFC-based cleaning agent which is flame-retardant and supplied at a low cost has been used as a disposable material for removing dirt adhering to the surfaces of electric and electronic parts, mechanical parts and the like. However, these substances will be restricted in the future as causative substances of ozone layer depletion. For this reason, many water-based or solvent-based cleaning agents have been proposed as cleaning agents in place of chlorine-based or freon-based solvents. Recently contrast, limonene as high cleaning agent having less safety environmental pollution, pinene, examples using terpenes such as di-pentene U.S. Pat. No. 4,511,488, JP-T Akira 63-501
908 (US Pat. Nos. 4,640,719 and 4,740,247) and the like. In addition to these, there are also water-based detergents in which a surfactant and a builder are mixed with sodium orthosilicate and caustic soda.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction contents]

Normal paraffin has 5 to 1 carbon atoms.
5, preferably having 7 to 14 carbon atoms, and particularly preferably having 9 to 13 carbon atoms. If the number of carbon atoms is less than 5, there is a danger of fire or explosion during the cleaning work and there is a safety problem. Further, if it exceeds 15, not only the flux removability is deteriorated, but also the boiling point is too high to make it difficult to collect by distillation, and there are some which do not become a solution state unless heated. The isoparaffin synthesis solvent has 6 carbon atoms.
-20, preferably 8-16, particularly preferably 8-12
However, in general, it is practical to select an appropriate carbon number from 6, 8, 9, 12 and 16 for ease of synthesis. In this case, when mixed with a solvent having a different carbon number of 1, the combination of 8 and 9 or the combination with normal paraffin is used.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction contents]

The polar organic compound has 4 to 4 carbon atoms.
It must be 20. Those having a carbon number of 3 or less has a problem in danger increases safety of operation on the fire or explosion,
If it exceeds 20, the detergency will decrease. Among them, those having 6 to 17 carbon atoms, particularly those having 7 to 15 carbon atoms are preferable.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0045

[Correction method] Change

[Correction contents]

[0045]

[Table 9]

Claims (5)

[Claims] 1. A cleaning agent comprising the following (A) and (B): (A) One hydrocarbon having the same carbon number of 5 to 20 carbon atoms, or a mixture of isomers thereof, or having 1 to each other.
Hydrocarbon solvent composed of a mixture of two different carbon atoms having different carbon numbers of 5 to 20 (B) ± 50% of atmospheric pressure conversion distillation temperature of the hydrocarbon solvent
Organic compound having one or more polar groups having a boiling point within 25 ° C 2. The cleaning agent according to claim 1, wherein the hydrocarbon is normal paraffin having 5 to 16 carbon atoms. 3. The cleaning agent according to claim 1, wherein the hydrocarbon is an isoparaffin or an alicyclic hydrocarbon having 6 to 20 carbon atoms. 4. The organic compound having a polar group is an alcohol, a ketone, an ether, or an ester having 4 to 20 carbon atoms, according to claim 1, 2 or 3. Cleaning agent. 5. The method according to claim 1, wherein the cleaning agent is distilled and recovered within a range of 50% distillation temperature at which the cleaning agent is converted into atmospheric pressure ± 25 ° C. A method for distilling and collecting the cleaning agent described.