JPH09227898A - Detergency improver and cleaning method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a detergency improver which can remove not only dirt particles unremovable by conventional nonaq. detergents but also an aq. dirt by using a compsn. comprising a nonpolar nonaq. solvent, a surfactant, and water and having a specified pH. SOLUTION: This improver contains a nonpolar nonaq. solvent, a mixture of cationic and anionic surfactants, or a cationic surfactant alone pref. in a concn. of 0.2-20wt.%, and water pref. in a concn. of 0.1-10wt.% and has a pH of 6-8.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a cleaning performance improving tablet for use in industrial cleaning of metal processed parts, resin molded parts, glass molded parts, electric substrates, ceramic processed parts, etc. The cleaning method that was used.

[0002]

2. Description of the Related Art For cleaning metal processed parts, resin molded parts, glass molded parts, electric circuit boards, ceramic processed parts, etc.
Chlorine-containing organic solvents represented by CFCs and trichloroethane have been used because of their high chemical stability, flame retardancy, high detergency, and nontoxicity. However, environmental damage on the global scale has been pointed out now, and it has been decided to abolish the use of CFCs and trichloroethane.

Further, other chlorine-containing organic solvents as substitutes for these have similar effects to those of CFCs, so that their use is likely to be restricted. In addition, some chlorine-containing organic solvents are toxic to the human body. For these reasons, the conversion of cleaning agents to water-based / semi-water-based / non-aqueous cleaning agents that do not use CFCs or chlorine-containing organic solvents is progressing.

Among them, a non-aqueous cleaning agent has been developed which can achieve a cleaning cost equivalent to that of a CFC- and chlorine-containing organic solvent. Among these, Japanese Patent Publication No. Sho 64-3141 describes a hydrocarbon or oxygen-containing hydrocarbon-based detergent which is a petroleum-based detergent as an alternative detergent. Such non-aqueous cleaning agents do not require the addition of new equipment to conventional cleaning equipment that has been used with CFCs and chlorine-containing organic solvents.
Water that not only has the merit of being able to deal with a slight modification, but also causes problems in the cleaning process such as wastewater treatment and dry finishing that water-based and semi-water-based cleaning agents have, and causes metal rust and corrosion. This is because there is no problem in that it cannot be used for cleaning applications of materials that dislike contact with.

However, in contrast to the fact that the CFC- and chlorine-containing organic solvent was able to clean a wide range of objects to be cleaned and dirt, the non-aqueous cleaning agent does not have a cleaning power capable of facing these in terms of cleaning performance. In particular, among non-aqueous detergents, hydrocarbon-based detergents that are petroleum-based are mainly non-polar solvents, whereas stains are non-polar and polar, especially water-containing, and various stains such as particle stains. Yes, there is a problem that not all can be washed.

[0006]

By the way, after processing an actual metal processed part, resin molded part, glass molded part, electric substrate, ceramic processed part, etc.
Not only liquid stains such as cutting oil, machine oil, and rust preventive oil are attached, but also particle stains such as metal scraps, resin burr scraps, abrasive grains, solder scraps, and ceramic scraps generated in the processing process. It is contained in the liquid dirt of and forms sludge,
In this state, it adheres firmly to the surface of the object to be cleaned.

Even if the conventional non-aqueous detergent is sludge like this, most of the liquid stains such as processing oil, cutting oil, machine oil and rust preventive oil can be washed, but some of the particle stains. Often remains on the surface of the object to be cleaned without being cleaned. Ultrasonic waves as a physical force other than the detergency of the cleaning agent are used to separate these metal debris, resin debris, abrasive grains, solder debris, ceramic debris, and other particle contaminants from the surface of the various objects to be cleaned described above. , Submerged jet, cleaning agent shower,
The cleaning power is improved by applying a cleaning agent jet or the like during the cleaning process, but there are some that cannot be separated even if such physical force is used together. In particular, for fine particle dirt with a size of several tens of μm or less, improvement of the cleaning process alone
In many cases, it cannot be peeled off and eventually remains on the surface of the object to be cleaned. For this reason, it is necessary to manually scrape or wipe fine particles such as metal chips, resin chips, polishing particles, solder chips, and ceramic chips after the cleaning process. There is.

Furthermore, even liquid stains such as polar stains containing inorganic salts such as hand oil and water-based stains containing a trace amount of water cannot be removed by the above-mentioned washing, and remain as residues after washing.
For this reason, in the case of cleaning the parts where the appearance is important, a step of manually wiping off is required as in the case of particle contamination. The above requires a great deal of labor and man-hours when the required cleaning accuracy is high, the shape of the object to be cleaned is complicated, or the material of the object to be cleaned is easily damaged.

The present invention has been made in consideration of such conventional problems, and is based on a generally used non-aqueous cleaning agent, such as metal scraps, resin burr scraps, abrasive grains, Not only can particle dust such as solder dust and ceramic shavings be removed, but also polar stains containing inorganic salts such as hand oil and water-based stains containing a small amount of water can be removed. On the other hand, it is an object of the present invention to provide a cleaning performance improver and a cleaning method which have less attack and can improve the cleaning finish.

[0010]

In order to achieve the above object, the cleaning performance improver according to claim 1 contains a non-polar non-aqueous solvent, a cation and a surfactant composed of nonion or cation, and water. The hydrogen ion concentration is 6 to 8.

The detergency-improving agent according to claim 2 comprises 0.2 to 20% by weight of the surfactant of claim 1 and 0.1 to 10% by weight of water based on the entire composition. Is characterized by.

According to a third aspect of the present invention, there is provided a cleaning method for cleaning an object to be cleaned with a cleaning liquid obtained by diluting the cleaning performance improving agent according to the first or second aspect with the above-mentioned non-polar non-aqueous cleaning agent, and a normal paraffin organic material. A substitution step of substituting the cleaning liquid adhering to the object to be cleaned with a solvent, an isoparaffin-based organic solvent, a cycloparaffin-based organic solvent, a monocyclic aromatic-containing organic solvent or a silicone-based organic solvent, or a replacement liquid formed by arbitrarily mixing these. And a drying step of drying the replacement liquid adhering to the object to be cleaned in this replacement step.

Metal scraps, resin burrs scraps, abrasive grains, solder scraps, ceramic scraps, etc. adhering to the surface of the object to be cleaned such as metal processed parts, resin molded parts, glass molded parts, electric substrates, ceramic processed parts, etc. The particle dirt, especially the minute particle dirt having a size of several tens of μm or less, is attached very strongly by electrostatic adsorption in a liquid such as a non-aqueous cleaning agent. Therefore, a non-aqueous cleaning agent such as a hydrocarbon-based cleaning agent cannot provide a peeling force that overcomes this electrostatic adsorption.

On the other hand, in the cleaning performance improver of the present invention, the non-aqueous cleaning agent, the surfactant and water form an emulsion. In the cleaning process using this cleaning agent, the action of the cationic surfactant to reverse the surface potential of the particles and remove it from the cleaning object against the dirt of fine particles that are electrostatically adsorbed on the cleaning object Then, the nonionic surfactant takes the exfoliated particles into water.

The surfactant used in the present invention is composed of a cation and a nonion or a cation, and does not contain an anionic surfactant. This is because the anionic surfactant has a large attack property on the object to be cleaned and damages the object to be cleaned. Among the surfactants, the cation system has a positron, and this positron neutralizes the ζ potential of the fine particles. Therefore, when the cationic surfactant is included, it becomes easy to remove stains composed of fine particles from the object to be cleaned.

The cleaning performance improver of the present invention has a hydrogen ion concentration of 6 to 8 in the entire system including such a surfactant. When the pH is lower than 6, the acidity becomes strong and the iron-based metal tends to rust, while when the pH is higher than 8, the alkalinity becomes strong and the surface of aluminum or glass is easily corroded, which is not preferable. . Therefore, the composition of the surfactant determines the composition of the surfactant so that the pH is within the above range.

The cationic surfactant may be selected from primary to tertiary amine salts, quaternary ammonium salts, pyridinium compounds and the like. Nonionic surfactants include polyhydric alcohol fatty acid esters, ethylene oxide polymerization adducts,
An alkylol amide type surfactant or the like can be selected.

The mixing ratio of the above surfactants is 0.2 to 20% by weight with respect to 100% by weight of the cleaning performance improver.
If it is less than 0.2% by weight, the water added as a component of the cleaning performance improver cannot be held uniformly, and the cleaning performance improver becomes non-uniform. If it exceeds 20% by weight, the surfactant is a substance having a higher viscosity than water, so that the cleaning performance improver has a high viscosity. For this reason, the effectiveness of the viscosity-reducing effect due to the addition of the polar solvent described later also does not work. Furthermore, such a high-viscosity cleaning liquid is not preferable because it causes problems such as a large amount that is adhered to the surface of the object to be cleaned during cleaning and is carried out, and the cleaning property of fine gaps is deteriorated.

The cleaning performance improver of the present invention contains water. The mixing ratio of this water is 100% by weight of the cleaning performance improver.
On the other hand, it is 0.1 to 10% by weight. If it is less than 0.1, the absolute amount of water becomes small, and it becomes difficult to cover the surface of the fine particle with a layered structure, which lowers the particle detergency. If it exceeds 10% by weight, fine particles can be washed, but after washing, a large amount of water remains on the surface of the object to be washed to cause stains, or part of the water is not compatible and There is a problem in that the composition of the cleaning performance improver becomes non-uniform and the cleaning performance is not stable. The water used is preferably pure water or ion-exchanged water for precision cleaning, but tap water may be used for rough cleaning.

The cleaning performance improver of the present invention is based on a non-polar non-aqueous solvent for the above surfactant and water. As the non-aqueous solvent, a normal paraffin organic solvent, an isoparaffin organic solvent, a cycloparaffin organic solvent, a monocyclic aromatic-containing organic solvent, a silicone organic solvent, or a mixed system obtained by arbitrarily mixing these can be used. . These organic solvents are highly safe to the environment and the human body, are easily available, and can be stably supplied. Among them, the silicone-based organic solvent has the merit of having higher safety than other solvents.

The cleaning performance improver of the present invention contains a non-polar non-aqueous solvent, a surfactant and water as essential components, but a polar solvent may be added in addition to these essential components. The polar solvent acts on the surfactant that is present between the non-aqueous cleaning agent and water, and acts to reduce the viscosity of the cleaning performance improver. Further, the polar solvent has an action of improving the compatibility between the cleaning liquid using the cleaning performance improving agent of the present invention and the replacement liquid. Since such a polar solvent has a high polarity, the compounding of the polar solvent improves the cleaning property for polar stains, thereby exerting an effective action for improving the cleaning property of hand oil and the like.

The mixing ratio of the polar solvent is 100 for the cleaning performance improver.
It is effective that the content is 0.05 to 5% by weight with respect to the weight%. If it is less than 0.05% by weight, the amount is too small,
The effect of reducing the viscosity of the polar solvent cannot be obtained.
If it is more than 10% by weight, the polarity becomes strong and the composition of the cleaning performance improver becomes non-uniform, which is not preferable. It is desirable to use glycol ethers, alcohols or the like as the polar solvent. As glycol ethers, mono- or di- or tri-ethylene glycol alkyl ether,
Mono-, di- or tri-propylene glycol alkyl ether and 3-methoxy-3-methylbutanol can be selected, and alcohols having 6 or less carbon atoms can be selected.

In the cleaning method of the present invention, the non-aqueous cleaning agent can be mixed in a proportion of 0 to 50% by weight with respect to 1% by weight of the cleaning performance improver. That is, in the cleaning method of the present invention, the cleaning performance improver alone can be used for cleaning, and can be used even when diluted with a non-aqueous cleaning agent. This dilution ratio can be arbitrarily changed according to the degree of dirt on the object to be cleaned, the type of dirt, the required cleanliness, and the like. In this case, if the dilution is more than 50 times, the detergency of the fine particles is deteriorated and the required detergency cannot be obtained.

In the replacement step of the cleaning method of the present invention, the cleaning liquid remaining on the surface of the object to be cleaned is replaced, whereby the drying property in the next drying step is improved and the surfactant having low volatility is used. It is possible to prevent the residue due to the residue of the polar solvent on the surface of the object to be cleaned. Therefore, a clean object can be obtained by performing the drying step after the replacement step after the cleaning step.

Further, in the replacement step after the cleaning step, an oil / water separator, for example, one that separates by utilizing the difference in specific gravity is provided, so that water and surfactant in the cleaning solution brought into the replacement solution and the replacement solution can be separated from each other. It becomes possible to separate. As a result, it is possible to prevent stains on the surface of the object to be cleaned after drying when cleaning the lens or prism.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) In this embodiment, the polished surface of a buffed aluminum product was cleaned. In this cleaning, the buffing abrasive grains adhering to the polishing surface, and the chips and buffing abrasive grains remaining on the threaded portion become stains to be cleaned. The screw part is a female screw hole having a diameter (φ) of 3 mm and a depth of 6 mm. The washing conditions were as shown below. (Composition of cleaning performance improver) Non-aqueous cleaning agent (86 wt%) Naphthesol M (Cyclofoil-based organic solvent manufactured by Japan Petrochemical Co., Ltd.) Water (4 wt%) Pure water (resistance value: 1 MΩ or more) Cationic surface activity Agent (5 wt%) CA-3475 (manufactured by Nikko Chemicals Co., Ltd., distearyldimethylammonium chloride) Polar solvent (5 wt%) Diethylene glycol monoethyl ether (Wako Pure Chemical Industries, Ltd., glycol ether) Hydrogen ion concentration pH 6.5 (Cleaning liquid) 10 wt% of the above-mentioned cleaning performance improver and 90 wt% of naphthezol M, which is a non-aqueous cleaning agent, were mixed and agitated to be uniform. (Substitution liquid) Naphthesol L (manufactured by Nippon Petrochemical Co., Ltd.,
Cycloparaffinic organic solvent) was used. (Washing conditions) Washing tank, replacement tank volume: 25 liters Ultrasonic device: 25 kHz, 600 W Liquid temperature: 25 ± 1 ° C Cleaning time: 5 minutes Tank configuration: Two cleaning tanks and two replacement tanks. Abrasive grains: cerium oxide, average particle size 2 μm (drying method) 80 ° C. hot air was blown for 5 minutes to dry.

The cleaning performance improver used in this embodiment was uniform in appearance. Detergency was evaluated by putting 100 objects to be washed into the washing basket, washing, replacing and drying under the above washing conditions, and then observing with a binocular stereomicroscope (300 times magnification) when aluminium-unim was polished on the polished surface of aluminum. Those in which no abrasive grains remained and those in which no abrasive grains or chips remained on the screw part were judged as good products. As a comparative example, cleaning was carried out by using Naphthesol M alone, which is a non-aqueous cleaning agent, as a cleaning liquid, and using the same replacement liquid and the same drying method. Table 1 shows the cleaning results.

[0028]

[Table 1]

As shown in Table 1, in the cleaning line using only the non-aqueous cleaning agent of Comparative Example 1, defective cleaning products are generated. In this embodiment, the polishing abrasive grains and chips are completely cleaned. It was confirmed that the effect of adding the cationic surfactant, water and the polar solvent to the non-aqueous detergent which is the non-polar solvent was confirmed. Furthermore, in this embodiment, diethylene glycol monoethyl ether is added as a polar solvent, and by this addition, the uniformity is superior to that without the polar solvent, and the effect on the uniformity of the polar solvent was also confirmed. It was

(Embodiment 2) In this embodiment, B
The polishing surface of an optical lens made of a glass material of SM15 and having a diameter of 20 mm and a thickness of 1 mm was washed and evaluated. In this cleaning, the polishing abrasive particles attached to the polishing surface become stains to be cleaned. The washing conditions are as shown below. (Cleaning performance improver) Non-aqueous cleaning agent (85 wt%) Clean Sol G (Nippon Petrochemical Co., Ltd., alkylbenzene organic solvent) Water (4 wt%) Pure water (resistance value: 1 MΩ or more) Cationic surfactant ( 2wt%) CA-3475 (manufactured by Nikko Chemicals Co., Ltd., distearyldimethylammonium chloride) Nonionic surfactant (9wt%) BT-9 (manufactured by Nippon Chemicals Co., Ltd., polyoxyalkylene water-soluble surfactant) Hydrogen Ion concentration pH 7.1 (cleaning liquid) 10 wt% of the above-mentioned cleaning performance improver and 90 wt% of Clean Sol G were mixed and adjusted by uniformly stirring. (Substitution liquid) Kyowasol C900 (Kyowa Hakko Kogyo Co., Ltd., isoparaffin hydrocarbon) (Washing conditions) Washing tank, substitution tank volume: 25 liters Ultrasonic device: 25 kHz, 600 W Liquid temperature: 25 ± 1 ° C Washing tact time : 5 minutes Tank configuration: Two cleaning tanks and two replacement tanks. Abrasive grains: Cerium oxide, average particle size 2 μm (drying method) 80 ° C. warm air was blown for 2 minutes to dry.

The cleaning performance improver of this embodiment is uniform in appearance. For the evaluation of detergency, 5
After 0 pieces were installed, the pieces were washed, replaced and dried under the above-mentioned washing conditions, they were observed with a binocular stereomicroscope (300 times magnification), and those in which no polishing abrasive grains remained on the polished surface of the lens were judged as non-defective. As a comparative example, non-aqueous cleaning agent Clean Sol G
A single substance was used and washed with the same replacement liquid, washing conditions, and drying method. Table 2 shows the cleaning results.

[0032]

[Table 2]

As shown in Table 2, defective cleaning occurs in the cleaning line using only the non-aqueous cleaning agent of Comparative Example 2, but in this embodiment, the abrasive grains could be completely cleaned. . This confirmed the effect of adding a cationic surfactant and water to a non-aqueous detergent, which is a non-polar solvent, and a polar solvent. Furthermore, in this embodiment, BT-9 was added as a nonionic surfactant, and the uniformity was excellent as compared with the case where no nonionic surfactant was added. From this, it was also confirmed that the nonionic surfactant maintains the cleaning performance constant.

Further, under the same conditions as the above cleaning conditions, the cleaning property of fingerprints, which are hand grease adhering to the polished surface of the lens, was confirmed.
Hand grease was adhered after wiping the polished surface of the lens with a cloth impregnated with acetone, and was washed within 20 minutes after the adhesion. Detergency was evaluated by visually observing the prism surface under a fluorescent lamp, and the presence or absence of residue of fingerprints, which was hand oil, was evaluated. The results are shown in Table 3.

[0035]

[Table 3]

As shown in Table 3, in the cleaning line using only the non-aqueous cleaning agent of Comparative Example 2, a defective cleaning product occurs, but in this embodiment, fingerprints, which are hand oil, are completely cleaned. I was able to.

Further, in this embodiment, when the cationic surfactant was changed to DDP-2 (a phosphate ether type anionic oil-soluble surfactant manufactured by Nikko Chemicals Co., Ltd.) which is an anionic surfactant, the pH of the cleaning solution was changed. The value became 3 and the acidity became strong, and the lens was eroded white. On the other hand, when the cationic surfactant is used, the pH value is 6 to
It was confirmed that the lens had a neutrality of 8 and thus had a low attack property on the lens.

(Embodiment 3) Under the cleaning conditions of Embodiment 2, an oil-water separator (U-Tech TK-15, manufactured by Asahi Kasei Co., Ltd.) was connected to the substitution tank, and the effect of the oil-water separator was confirmed.

When a washing basket in which 50 lenses of the above-mentioned size are installed is continuously washed, and under the washing condition without an oil / water separator connected, if 5 baskets are continuously washed, water is separated in the replacement liquid. Initially, stains were visually confirmed under a fluorescent lamp on the lens surface after drying. On the other hand, when the oil / water separator was connected, water in the replacement liquid was separated from the replacement liquid by the oil / water separator even after continuous washing with 10 baskets, so that no stain was observed on the lens surface after drying.

From these results, it was confirmed that connecting the oil-water separator to the replacement tank was effective in preventing the generation of stains on the lens after drying, and it became possible to extend the life of the replacement liquid.

In this embodiment, the buffing abrasive grains and the chips are used as the dirt to be cleaned, but particle dirt such as resin burrs, solder scraps, and ceramic shavings, and an aqueous system containing a small amount of water. Dirt has a similar effect.

The cleaning performance improver and cleaning conditions in each of the above embodiments are merely examples, and the present invention is not limited to these.

From the above embodiments, the following additional items can be claimed in the present invention. (Additional Item 1) A cleaning performance, characterized by containing a non-polar non-aqueous solvent, a surfactant composed of a cation and nonion or a cation, water, and a polar solvent, and having a hydrogen ion concentration of 6 to 8. Improver. (Additional Item 2) The surfactant is 0.2 to 20% by weight, the water is 0.1 to 10% by weight, and the polar solvent is 0.05 to 5% by weight with respect to the entire composition. The cleaning performance improver according to Additional Item 1, characterized in that (Additional Item 3) A cleaning step of cleaning an object to be cleaned with a cleaning liquid obtained by diluting the cleaning performance improver according to Additional Item 1 or 2 with the non-polar non-aqueous cleaning agent, a normal paraffin organic solvent, an isoparaffin organic solvent. And a cycloparaffin organic solvent, a monocyclic aromatic-containing organic solvent or a silicone organic solvent, or a replacement liquid for replacing the cleaning liquid adhering to the object to be cleaned with a replacement liquid arbitrarily mixed, and this replacement process And a drying step of drying the replacement liquid adhering to the article to be cleaned.

[0044]

As described above, by using the cleaning performance improver and the cleaning method of the present invention, it adheres to the object to be cleaned such as metal processed parts, resin molded parts, glass molded parts, electric substrates and ceramic processed parts. Also clean metal dirt, resin debris, abrasive grits, solder scraps, ceramic shavings and other particle dirt, polar dirt containing inorganic salts such as hand oil, and water-based dirt containing a small amount of water. At the same time, by making the pH neutral, it is possible to reduce the attack on the object to be cleaned. Further, in the present invention, by providing the device for separating the replacement liquid and the water in the replacement step, the cleaning quality can be improved and the life of the liquid can be extended.

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Claims (3)

[Claims] 1. A cleaning performance improver comprising a non-polar non-aqueous solvent, a surfactant composed of a cation and a nonion or a cation, and water, and having a hydrogen ion concentration of 6 to 8. 2. Cleaning according to claim 1, characterized in that the surfactant is 0.2 to 20% by weight and the water is 0.1 to 10% by weight with respect to the total composition. Performance improver. 3. A cleaning step of cleaning an object to be cleaned with a cleaning liquid obtained by diluting the cleaning performance improver according to claim 1 or 2 with the non-polar non-aqueous cleaning agent, a normal paraffin organic solvent, an isoparaffin organic solvent. And a cycloparaffin-based organic solvent, a monocyclic aromatic-containing organic solvent or a silicone-based organic solvent, or a replacement liquid which replaces the cleaning liquid adhering to the object to be cleaned with a replacement liquid which is an arbitrary mixture thereof, and the replacement process And a drying step of drying the replacement liquid adhering to the article to be cleaned.