JP4761293B2 - Cleaning composition and cleaning method - Google Patents

Description

  The present invention is a cleaning for cleaning dirt, such as flux, wax, processing oil, etc. adhering to parts such as electric / electronic parts, optical parts, automobile parts, precision machine parts, etc. The present invention relates to an agent composition and a cleaning method.

  Conventionally, fluorocarbon solvents such as trifluorotrichloroethane or chlorinated solvents such as 1,1,1-trichloroethane, trichloroethylene, and methylene chloride are used for cleaning precision parts with flux, wax, processing oil, vegetable oil, etc. Has been used as. However, the production of trifluorotrichloroethane and 1,1,1-trichloroethane was prohibited at the end of 1995 as substances that destroy the ozone layer. In addition, trichlorethylene and methylene chloride are highly toxic and, when released, cause air and water pollution, so the laws and regulations are severe.

  In addition, the use of water-based detergents containing surfactants and inorganic alkalis, and water-soluble detergents such as phosphates is also considered, but it is economical because it has poor detergency and requires a large space for wastewater treatment facilities. It is not preferable from the viewpoint of sex. Therefore, a relatively safe hydrocarbon-based cleaning agent that has no ozone depletion, high degreasing power, low toxicity, and no flammability at room temperature has been reviewed. Unlike chlorofluorocarbon and chlorinated solvents, flammable Because of this liquid, there are restrictions on the number of dangerous goods specified by the Fire Service Act.

  Hydrocarbons classified as dangerous oil third petroleums of the Fire Service Act have few restrictions on the designated quantity of dangerous goods, but have a problem that it takes time to dry after washing because of the slow evaporation rate. Hydrofluorocarbon or hydrofluoroether (HFC / E) is used as a rinsing agent or a steam cleaning agent after cleaning with a hydrocarbon cleaner, but the hydrocarbon cleaner is hardly soluble in HFC / E. The hydrocarbon cleaning agent is not sufficiently replaced with HFC / E on the surface of the object to be cleaned, and a part of the hydrocarbon cleaning agent including the soil component remains on the surface of the object to be cleaned, resulting in poor cleaning. There was a risk of waking up.

  There has been proposed a cleaning method comprising a cleaning step using a warm bath of a mixture of an organic compound such as glycol ether or ester compatible with HFC / E and HFC / E and a rinsing step using the HFC / E alone. (See Patent Document 1). In addition, after washing the object to be cleaned with a uniform cleaning agent composed of HFC / E and organic compounds (glycol ethers, glycol ether acetates, hydroxycarboxylic acid esters, etc.), the HFC / E is contaminated in the rinsing process. There has also been proposed a method of separating the contaminated dirt component and / or cleaning agent component by allowing the rinsing agent to stand, and reusing the cleaning agent and the rinsing agent (see Patent Document 2). However, the glycol ethers described in these documents do not necessarily have a high detergency for mineral oil as compared with hydrocarbons.

In addition, a cleaning apparatus (see Patent Document 3) for cleaning an object to be cleaned with a primary cleaning liquid mainly composed of a hydrocarbon solvent and then rinsing with a secondary cleaning liquid mainly composed of HFC, or HFC / E An organic compound such as a hardly soluble hydrocarbon and HFC / E are separated into two layers in a washing tank and filled, and the object to be washed is washed mainly with an upper liquid containing the organic compound, and then this mainly contains the HFC / E. There has been proposed a cleaning method comprising shower cleaning with a lower layer liquid, then rinsing with the HFC / E, and further steam cleaning with a saturated vapor of the HFC / E (see Patent Document 4). Furthermore, a cleaning apparatus has been proposed in which an object to be cleaned is cleaned with a hydrocarbon solvent and then rinsed with HFC / E (see Patent Document 5). Here, it is mentioned as a feature that the hydrocarbon solvent and HFC / E are not compatible with each other so that both can be easily separated by specific gravity. These patents are characterized in that a solvent that is hardly soluble in HFC / E is used. In the rinsing process by HFC / E, the solvent remains on the surface of the object to be cleaned, and the soil component dissolved in the solvent is covered. There is a risk of causing stains on the surface of the cleaning object, resulting in poor cleaning.
JP 10-36894 A JP 2001-334104 A JP-A-6-328052 Japanese Patent Laid-Open No. 10-192797 JP-A-10-202209

  The present invention does not cause poor cleaning as described above, has no environmental problems such as ozone layer destruction, has few restrictions on the designated quantity of dangerous materials, has little loss due to volatilization, can be heated and cleaned, and is sufficient It is an object of the present invention to provide a cleaning composition and a cleaning method that have a drying performance, are easy to recover, and have sufficient cleaning properties against dirt adhered by combining flux, wax, processing oil, and the like.

  As a result of extensive research, the present inventors have found that a mixture of a saturated hydrocarbon and an acetate ester is suitable for cleaning various types of dirt, and has a characteristic solubility characteristic with hydrofluorocarbon or hydrofluoroether, The present invention has been reached.

  That is, the cleaning composition of the present invention contains 60 to 20% by weight of saturated hydrocarbon having a boiling point of 200 to 350 ° C. and 40 to 80% by weight of acetate. Moreover, it is preferable that carbon number of a saturated hydrocarbon is 12-19, an acetic ester is 3-methyl-3-methoxybutyl acetate, and the flash point of a cleaning composition is 70 degreeC or more. When the flash point is less than 70 ° C., the generation of flammable vapor is usually increased in the temperature range used for cleaning, and the safety risk increases. Therefore, the flash point is preferably 70 ° C. or higher.

Further, after the object to be cleaned is immersed and cleaned using this cleaning agent, various cleanings can be sufficiently cleaned by a cleaning method in which the object is rinsed by being immersed in hydrofluorocarbon or hydrofluoroether.
Further, after performing the above-described cleaning method, the cleaning is performed by bringing the hydrofluorocarbon or hydrofluoroether vapor into contact with the object to be cleaned, followed by steam cleaning, and then drying the object to be cleaned. In addition, the cleaning composition and the hydrofluorocarbon or hydrofluoroether are compatible with each other, so that the cleaning composition on the surface of the object to be cleaned and the hydrofluorocarbon or hydrofluoroether are replaced, and rinsing or steam cleaning is performed. Each can be easily recovered by separating the two layers by cooling the hydrofluorocarbon or hydrofluoroether containing the subsequent cleaning composition. The boiling point of the hydrofluorocarbon or hydrofluoroether at this time is preferably 30 to 150 ° C.

  The cleaning composition according to the present invention has no environmental problems such as ozone layer destruction, and since it belongs to the third petroleum, there are few restrictions on the designated quantity of dangerous goods, and because of its high boiling point, there is little loss due to volatilization. It can be cleaned by heating, and has sufficient cleaning properties against dirt adhered by a combination of flux, wax, processing oil, and the like. And, by the cleaning method utilizing the characteristics of the cleaning composition of the present invention, which is compatible in the vicinity of the boiling point temperature of HFC / E, and the solubility greatly decreases as the temperature becomes lower, the object to be cleaned by the HFC / E A rinsing soundness, a fast evaporation rate of an object to be cleaned, and an easy separation and recovery method of a cleaning agent and a steam cleaning agent are provided.

The cleaning composition of the present invention contains 60 to 20% by weight of a saturated hydrocarbon having a boiling point in the range of 200 to 350 ° C. The saturated hydrocarbon may be linear, branched, or cyclic, and these may be used alone or in combination. Saturated aliphatic hydrocarbons are preferred, and straight chain saturated aliphatic hydrocarbons are particularly preferred. Saturated hydrocarbons having a boiling point of less than 200 ° C. are not preferable for safety because they belong to the second petroleum or the first petroleum, which is a dangerous material of the Fire Service Act. On the other hand, if the boiling point exceeds 350 ° C., the saturated hydrocarbon has a high viscosity, which is not preferable because the cleaning efficiency is reduced and drying after cleaning becomes difficult. The saturated hydrocarbon preferably has 12 to 19 carbon atoms, particularly 12 carbon atoms, and particularly normal decane.
The cleaning composition of the present invention contains 60 to 20% by weight of the saturated hydrocarbon, and preferably 40 to 30% by weight. If the saturated hydrocarbon content is less than 20% by weight, the cleaning performance for mineral oil is lowered, which is not preferable. On the other hand, if it exceeds 60% by weight, the compatibility with HFC / E becomes low, so that it is difficult to replace the cleaning agent when rinsing or steam cleaning with HFC / E.

The cleaning composition of the present invention contains 40 to 80% by weight of acetate and preferably 60 to 70% by weight. As the acetate ester, an aliphatic hydrocarbon derivative having a hydroxyl group and an ester of acetic acid, particularly an ester of alcohol and acetic acid obtained by substituting one of the hydrogen elements of a dialkyl ether with a hydroxyl group is preferably used. The number of carbon atoms of the acetate ester is preferably 5 to 10, particularly 6 to 8.
If the acetic acid ester is less than 40% by weight, the cleaning performance with respect to dirt containing polar substances such as flux and wax decreases, and the solubility with HFC / E decreases. When performing, it is not preferable because the cleaning agent is hardly replaced. On the other hand, if it exceeds 80% by weight, it is not preferable because the detergency to mineral oil is lowered.

  Acetic acid esters include ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol diacetate, Butylene glycol monoethyl ether acetate, butylene glycol monopropyl ether acetate, butylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monomethyl ether acetate, dipropylene glycol Monoethyl ether acetate, dipropylene glycol monomethyl ether acetate, triethylene glycol monoethyl ether acetate, triethylene glycol monomethyl ether acetate. In view of availability and high flash point, 3-methyl-3-methoxybutyl acetate, which is a kind of butylene glycol monomethyl ether acetate, is preferably used.

  The cleaning composition of the present invention includes other components such as hydrocarbons, esters, alcohols, ketones, lactams, surfactants, antioxidants and the like as long as the object of the present invention is not impaired. Conventional additives such as UV absorbers and rust inhibitors can be included. The total content of these components is preferably less than 10% by weight, particularly less than 2% by weight. Moreover, it is preferable that water is not normally mix | blended.

  The surfactant is preferably a nonionic surfactant. For example, higher alcohol ethylene oxide adduct, alkylphenol ethylene oxide adduct, fatty acid ethylene oxide adduct, higher alkylamine ethylene oxide adduct, sorbitol and sorbitan fatty acid ester, Any of sugar fatty acid ester, silicon type, fluorine type and the like can be used.

  In addition, UV absorbers and antioxidants help improve stability during long-term storage of cleaning liquids, and UV absorbers such as benzotriazoles, benzophenones, and hindered amines can be used. Any of those that dissolve in the cleaning composition of the present invention, such as phenol, amine, sulfur, and phosphorus, can be used. It is particularly preferable to add 50 to 1000 ppm of a phenolic antioxidant.

  Although the cleaning composition of the present invention has a high flash point, it has a problem that the evaporation rate is slow. Therefore, it is preferable to use steam cleaning using HFC / E as a steam cleaning agent in order to provide quick drying. That is, after rinsing and removing the cleaning agent adhering to the object to be cleaned in a rinsing tank filled with HFC / E, the evaporation rate is remarkably improved by leaving the object to be cleaned in the saturated vapor layer of the HFC / E. Is done. Here, the boiling point of HFC / E is in the range of 30 to 150 ° C. Considering the ease of handling, compatibility with the cleaning agent and the difference in boiling point with the cleaning agent, Fluoroether (HFE) is particularly preferably used. Examples of HFE include 1,2,2,2-tetrafluoroethyl-heptafluoropropyl ether (boiling point 40 ° C.), 1,1,1,2,3,3-hexafluoro-2-heptafluoropropyloxy- 3- (1,2,2,2-tetrafluoroethoxy) -propane (boiling point 104 ° C.), 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether (boiling point 56 ° C.) , Nonafluorobutyl methyl ether (boiling point 61 ° C.) and nonafluorobutyl ethyl ether (boiling point 76 ° C.).

  In general, in the case of steam cleaning, it is preferable that the cleaning agent and the steam cleaning agent are compatible in the vicinity of the boiling point of the steam cleaning agent. A mixture of normal dodecane and 3-methyl-3-methoxybutyl acetate, which is a cleaning composition of the present invention, and 1,1,2,2-tetrafluoroethyl-2,2 which is a kind of HFE as a steam cleaning agent , 2-trifluoroethyl ether (HFE-1) (Examples 1-5 and Comparative Examples 1-3) is shown in FIG. Since the cleaning composition of the present invention is compatible with HFE-1 at 50 ° C., good steam cleaning is achieved. Further, the solubility of the cleaning composition of the present invention in HFE-1 rapidly decreases as the temperature decreases. Accordingly, the mixture of the cleaning composition of the present invention and the steam cleaning agent that is uniform near the boiling point of the steam cleaning agent is separated into two layers when cooled, and each can be easily recovered and reused.

  In the cleaning method of the present invention, the method of bringing the article to be cleaned into contact with the cleaning composition is not particularly limited, and any known method can be used. For example, it is preferable to make contact by wiping with a sponge impregnated with the cleaning composition, immersion in the cleaning composition, spraying, or the like. In cleaning by dipping, it is more preferable to combine stirring, shaking, ultrasonic waves, air bubbling, etc. at the same time in order to enhance the cleaning effect. In this case, the use conditions of the ultrasonic waves are preferably, for example, an oscillation frequency of 20 to 100 kHz and an oscillation output of 10 to 200 W per 1 L of the cleaning agent. In air bubbling, dirt that does not dissolve in the cleaning composition can be raised and separated together with the bubbles by ventilating fine bubbles, preferably at a gas: cleaning agent volume ratio of 1: 1 to 5: 1. In the cleaning by spraying, the pressure is preferably 0.05 to 1 MPa, for example. In any case, the washing time is preferably 15 seconds to 2 hours, particularly 30 seconds to 20 minutes. If it is less than this range, the washing is insufficient and the dirt cannot be removed sufficiently. On the other hand, even if it exceeds this range, the cleaning effect is not improved significantly. The washing temperature is preferably 20 to 130 ° C, and the washing effect can be remarkably increased by heat treatment at 50 to 130 ° C.

  In the cleaning method of the present invention, the cleaning agent adhering to the object to be cleaned is removed by rinsing and steam cleaning using HFC / E. The method is not particularly limited, and any known method can be used. For example, after rinsing an object to which the cleaning agent is adhered in a rinsing tank filled with HFC / E, a clean article can be obtained by standing in a saturated vapor layer of the HFC / E and performing steam cleaning. The rinsing tank may be either a boiling bath or a cold bath, or both, and a stirrer or an ultrasonic generator may be attached to enhance the rinsing effect. It is most effective to rinse in a boiling bath and then in a cold bath with an ultrasonic generator. When the object to be cleaned is cooled to a temperature lower than the boiling point of HFC / E in the rinsing tank and then pulled up and introduced into the saturated vapor layer of HFC / E, the HFC / E is condensed on the surface of the object to be cleaned. -Liquefaction is replaced with a cleaning agent containing dirt that could not be removed in the rinsing tank, and rinsing is completed. At this time, if the compatibility between the HFC / E and the cleaning agent is low, the substitution may be insufficient, and the cleaning agent may remain on the surface of the cleaning agent, causing stains. Since the product is compatible with the HFC / E in the vicinity of the boiling point of the HFC / E, poor cleaning does not occur. Since the surface of the object to be cleaned that has been rinsed is wet only by the HFC / E, it is quickly dried.

  Distillation methods are often applied to separate detergent and soil components from steam cleaners. Even in the cleaning composition of the present invention, it is possible to use a distillation method for separation from the vapor cleaning agent, but the distillation method generally has a problem of requiring a great deal of time and cost. As shown in FIG. 1, the compatibility between the cleaning composition of the present invention and the steam cleaning agent has a remarkable temperature dependence. Therefore, in the cleaning method of the present invention, the rinsing tank or steam containing the cleaning agent is used. A separation method is also included in which the condensate of the cleaning agent is cooled and separated into two layers, and each is recovered and reused. Here, the cleaning agent containing the collected soil component is reused after being separated into the cleaning composition and the soil component by a distillation method or the like.

  Examples of the object to be cleaned include parts such as electronic / electrical parts, optical parts, precision machine parts, and automobile parts. Target electrical / electronic components include printed circuit boards, wiring boards such as ceramic wiring boards, semiconductor package members such as lead frames, contact members such as relays and connectors, display parts such as liquid crystals and plasma displays, and hard disk storage media. And magnetic storage parts such as magnetic heads, piezoelectric parts such as crystal oscillators, motor parts such as motors and solenoids, and sensor parts. Examples of the optical component include glasses, a lens for a camera, and a housing thereof. Examples of precision machine parts include parts such as precision bearings used in VTRs and the like.

  Examples of dirt adhering to the object to be cleaned include machine oils such as asphalt pitch, wax, pine oil, fats and oils, vegetable oils, greases, fluxes, photoresists, and adhesives. The cleaning composition of the present invention has an excellent cleaning power especially for fluxes and waxes.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is limited to an Example and is not interpreted.

Examples 1-5, Comparative Examples 1-10
[Preparation of detergent]
Formulation of Table 1 using normal undecane (n-C11) (boiling point 171 ° C.), normal dodecane (n-C12) (boiling point 209 ° C.) and 3-methoxy-3-methylbutyl acetate (MMBAC) (boiling point 188 ° C.) The cleaning agents of Examples 1 to 5 and Comparative Examples 1 to 10 were prepared by mixing in amounts.

[Flash point]
Table 1 also shows tag sealed flash points (JIS K2265) of the cleaning agents of Examples 1 to 5 and Comparative Examples 1 to 10. The cleaning agents in Examples 1 to 5 and Comparative Examples 1 to 4 are third petroleums (flash point 70 ° C. or higher and lower than 200 ° C.), and the cleaning agents in Comparative Examples 5 to 10 are second petroleums. (Flash point 21 ° C or higher and lower than 70 ° C).

[Solubility in steam cleaner]
For the cleaning agents of Examples 1 to 5 and Comparative Examples 1 to 4 classified as third petroleums, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether (HFE-1 ) Was measured. The results are shown in Table 2 and FIG. Here, the upper limit of the measurement of solubility was 100 g / 100 g HFE-1. The cleaning agents of Examples 1 to 5 were compatible with HFE-1 at 50 ° C., and the compatibility was greatly reduced as the cooling was performed. On the other hand, the cleaning agents of Comparative Examples 1 to 3 have low solubility in HFE-1 even at 50 ° C., and are not easily replaced with the cleaning agent remaining on the parts. Therefore, when steam cleaning is performed under the same conditions as in Examples 1 to 5, rinsing failure occurs. Moreover, since the cleaning agent of Comparative Example 4 is completely compatible with HFE-1 even at −10 ° C., it is not possible to separate the cleaning agent and the steam cleaning agent (HFE-1) while cooling and recover each of them. . The recovery rate at −10 ° C. of each cleaning agent (up to 100 g / 100 g HFE-1) dissolved in HFE-1 at 50 ° C. is shown in Table 2 as the separation recovery rate.

[Solid solubility]
For the cleaning agents of Examples 1 to 5 and Comparative Examples 1 to 4 classified as third petroleums, a solubility test of pine resin (Kanto Chemical) was conducted. 40% by weight of each cleaning agent and 60% by weight of pine resin were mixed, and ultrasonic irradiation (output 100 W, frequency 28 kHz) was performed at room temperature for 5 minutes, and the presence or absence of insoluble matter was visually observed. The completely compatible materials were evaluated as ◯, and even the slightly insoluble components were evaluated as ×, and are also shown in Table 2. From this result, it can be seen that the cleaning agents of Examples 1 to 5 exhibit high pine resin solubility. On the other hand, it turns out that the pine resin solubility of the cleaning agent of Comparative Examples 1-2 is inferior.

[Flux cleaning properties]
Evaluation of the flux cleaning property was carried out by applying 1 mg each of rosin-based flux-containing solder paste (Tamura Chemical Research, SQ-1030SZM-1) on a metal plate (copper plate 50 × 50 mm, thickness 0.03 mm), 250 What was reflowed at 30 ° C. for 30 seconds was washed. This object to be cleaned was subjected to ultrasonic irradiation (output: 100 W, frequency: 28 kHz) at a liquid temperature of 20 ° C. in a cleaning tank filled with 200 cm ³ of cleaning liquid and cleaned for 10 seconds. After cleaning, evaluation was made on the metal plate where no trace of the flux was observed, and evaluation was made on the case where the trace of the flux was slightly observed as x. From this result, it can be seen that the cleaning agents of Examples 1 to 5 exhibit high flux cleaning properties.

[Wax detergency]
Wax cleanability evaluation was performed by applying 100 mg of terpene phenol resin wax (Nikko Seiko, Alcowax 542M) on a metal plate (copper plate 50 × 50 mm, thickness 0.03 mm) and ultrasonically irradiating it at room temperature for 30 seconds. Washing was performed at an output of 100 W and a frequency of 28 kHz. In the evaluation, the residual ratio of wax (the ratio (%) of the residual wax weight to the initial coating amount) was obtained. From this result, it can be seen that the cleaning agents of Examples 1 to 5 exhibit high wax detergency.

[Vegetable oil washability]
Evaluation of the cleanability of vegetable oil was performed by attaching 300 to 400 mg of castor oil (Kanto Chemical) on a laminated mesh plate (SUS 30 mmφ, thickness 1.0 mm), and irradiating with ultrasonic waves (output 100 W, frequency 28 kHz) for 60 seconds at room temperature. And washed. In the evaluation, the residual ratio of vegetable oil (ratio (%) of the amount of residual vegetable oil with respect to the initial amount of adhesion) was determined. From this result, it can be seen that the detergents of Examples 1 to 5 exhibit high vegetable oil detergency.

  The cleaning composition of the present invention has no environmental problems such as ozone layer destruction, has few restrictions on the designated quantity of hazardous materials, has little loss due to volatilization, can be heated and cleaned, and has sufficient drying performance. In addition, since the cleaning composition and the cleaning method of the present invention are easy to collect, the flux, wax, processing oil, etc. attached to parts such as electric / electronic parts, optical parts, automobile parts, precision machine parts, etc. In particular, it is useful for cleaning soils in which these are combined and adhered.

It is a figure which shows the solubility of the cleaning composition of this invention with respect to 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether which is 1 type of HFE.

Claims (7)

  A detergent composition comprising 60 to 20% by weight of saturated hydrocarbon having a boiling point of 200 to 350 ° C. and 40 to 80% by weight of acetate.   The cleaning composition according to claim 1, wherein the saturated hydrocarbon has 12 to 19 carbon atoms.   The cleaning composition according to claim 1 or 2, wherein the acetate is 3-methyl-3-methoxybutyl acetate.   The cleaning composition according to any one of claims 1 to 3, wherein the cleaning composition has a flash point of 70 ° C or higher.   A cleaning method comprising rinsing by immersing an object to be cleaned in a hydrofluorocarbon or hydrofluoroether after immersion cleaning using the cleaning composition according to any one of claims 1 to 4.   A cleaning method for performing steam cleaning by bringing a hydrofluorocarbon or hydrofluoroether vapor into contact with an object to be cleaned after performing the cleaning method according to claim 5, and then drying the object to be cleaned. In this case, the cleaning composition and the hydrofluorocarbon or hydrofluoroether are compatible with each other, thereby replacing the cleaning composition on the surface of the object to be cleaned with the hydrofluorocarbon or hydrofluoroether, and rinsing or steam cleaning. A cleaning method, wherein the hydrofluorocarbon or hydrofluoroether containing the cleaning composition after the step is separated into two layers by cooling, and each is recovered.   The cleaning method according to claim 5 or 6, wherein the boiling point of the hydrofluorocarbon or hydrofluoroether is 30 to 150 ° C.

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