JP2019094426A - Cleaning liquid - Google Patents

Abstract

To provide a cleaning liquid that shows a remarkably good cleaning effect in comparison to conventional cleaning liquids.SOLUTION: A cleaning liquid contains: a static liquid 21 that contains a first microbubble group 15a; and a dynamic liquid 22 that contains a second microbubble group 15b having an average bubble diameter equal to an average bubble diameter of the first microbubble group 15a, has a temperature higher than a room temperature, and is blown to an object to be cleaned W held in the static liquid 21.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cleaning solution containing fine bubbles in a liquid.

  Patent Document 1 discloses a cleaning solution. The cleaning solution contains nano-sized air bubbles dissolved in a liquid at a saturation dissolution concentration. Patent Document 1 focuses on the distance of hydrogen bonds of liquid molecules in order to improve the cleaning effect.

JP, 2011-88979, A

  Patent Document 1 also focuses on an external force that collapses a bubble. Such external forces include pressure changes, temperature changes, shock waves, ultrasonic waves, infrared rays, and vibrations. It is thought that bubble collapse contributes to the improvement of detergency.

  An object of the present invention is to provide a cleaning solution which exhibits a dramatically better cleaning effect than before.

  According to a first aspect of the present invention, a static liquid including a first group of fine bubbles and a second group of fine bubbles having an average cell diameter equal to the average cell diameter of the first group of fine bubbles are included. There is provided a cleaning liquid having a high temperature and a dynamic liquid sprayed towards an object held in said static liquid.

  According to the first aspect, when the dynamic liquid collides with the object, a second microbubble is formed at the boundary (the outline of the interface) between the substance (for example, the contaminant) adhering to the surface of the object (the object) and the surface of the object. The group acts. Since the dynamic liquid has higher energy than at room temperature, the second microbubbles effectively cause exfoliation at the interface. As the exfoliation progresses, gas intrudes inward from the contour. Thus, the substance separates from the surface of the object. The substance is separated from the object. Since the dynamic liquid is ejected in the state of containing the second group of micro bubbles, the dynamic liquid is more reliable than the case of blowing the micro bubbles toward the flow of the dynamic liquid created in the static liquid. The second microbubbles group can be contained in a specified amount. The cleaning solution exhibits a dramatically better cleaning effect than before.

It is a conceptual diagram which shows the whole image of the washing | cleaning-liquid manufacturing apparatus which concerns on one Embodiment of this invention. It is a graph which shows distribution. It is a graph which shows the relationship between a temperature condition and an average bubble diameter, and the weight of the chip | tip which remains. It is a graph which shows the relationship between temperature conditions and an average bubble diameter, and the density | concentration of the oil collect | recovered in the solvent.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

(1) Cleaning Device FIG. 1 shows an overall image of the cleaning device 11 according to the embodiment. The cleaning device 11 includes a first liquid tank 12a and a second liquid tank 12b. The first preliminary cleaning liquid 13a is contained in the first liquid tank 12a. The second preliminary cleaning liquid 13b is contained in the second liquid tank 12b. A mixing tank 12c is commonly connected to the first liquid tank 12a and the second liquid tank 12b. The static liquid 21 is contained in the mixing tank 12c. The static liquid 21 is a mixture of a first preliminary cleaning solution 13a introduced from the first liquid tank 12a and a second preliminary cleaning solution 13b introduced from the second liquid tank 12b.

A first bubble generator 14 is connected to the first liquid tank 12a. The first bubble generator 14 has a supply port 14a that opens into the liquid. As the liquid, in addition to pure water, a liquid in which water or an organic solvent is used as a solvent, an electrolyte, a surfactant, a gas or the like is dissolved can be used. The first bubble generator 14 blows fine bubbles into the liquid from the supply port 14a. Microbubbles include microbubbles and nanobubbles (= ultrafine bubbles). The microbubbles may be a collection of bubbles having an average diameter smaller than a specified value. The diameter of the air bubbles can be set based on the diameter of the micro holes provided in the supply port 14a. The diameter of the pores is set to less than 100 nm. Preferably, the diameter of the air bubble is 50 nm or less. Here, the first bubble generation device 14 blows out the first micro bubble group 15 a which is formed of gas at the first temperature and has an average bubble diameter of less than 100 nm. It is desirable that the bubble concentration less than 100 nm in diameter is 1 × 10 ⁶ or more per milliliter. The first micro bubble group 15 a flows into the mixing tank 12 c to form a second micro bubble group 15 b in the static liquid 21.

  A gas source 16 a is connected to the first bubble generator 14. The gas source 16 a supplies a gas to the first bubble generator 14. The gas is not limited to air, nitrogen, hydrogen and the like, and may be any kind of gas. The first temperature control device 17a is connected to the gas source 16a. The first temperature adjusting device 17a adjusts the temperature of the gas of the gas source 16a. In the temperature adjustment, thermal energy is added to (or deprived of) the gas from the first temperature adjustment device 17a. Thermal energy (plus or minus) may be transferred to the gas in any way. Here, the gas of the first temperature is supplied from the gas source 16 a to the first bubble generator 14.

  At this time, a temperature control device may be connected to the first liquid tank 12a. The thermal energy is equilibrated between the first fine bubble group 15a and the liquid in the first preliminary cleaning solution 13a. The temperature of the gas contained in each fine bubble is considered to be equal to the temperature measured as the first preliminary cleaning solution 13a. The temperature of the first micro-bubble group 15a can be set by adjusting the temperature of the first preliminary cleaning liquid 13a. Thus, the temperature of the first preliminary cleaning solution 13a may be maintained at the first temperature by the operation of the temperature control device.

Similarly, a second bubble generator 18 is connected to the second liquid tank 12b. The second bubble generator 18 has a supply port 18a that opens into the liquid. As the liquid, a liquid in which water or an organic solvent is used as a solvent, an electrolyte, a surfactant, a gas or the like is dissolved can be used. The second bubble generator 18 blows fine bubbles into the liquid from the supply port 18a. Microbubbles include microbubbles and nanobubbles. The microbubbles may be a collection of bubbles having an average diameter smaller than a specified value. The diameter of the air bubbles can be set based on the diameter of the micro holes provided in the supply port 18a. The diameter of the micropores is set to 100 nm or more and 50 μm or less. Preferably, the diameter of the air bubble is 1000 nm (= 1 μm) or less. Here, the second bubble generator 18 blows out the third micro bubble group 15 c formed of the gas at the first temperature. The bubble concentration of 100 nm or more and 50 μm or less in diameter is desirably 1 × 10 ⁶ or more per 1 ml. The third micro bubble group 15 c flows into the mixing tank 12 c to form a fourth micro bubble group 15 d in the static liquid 21.

  A gas source 16 b is connected to the second bubble generator 18. The gas source 16 b supplies a gas to the second bubble generator 18. The gas is not limited to air, nitrogen, hydrogen and the like, and may be any kind of gas. The type of gas may be the same as or different from that of the first bubble generator 14. The second temperature control device 17b is connected to the gas source 16b. The second temperature adjusting device 17b adjusts the temperature of the gas of the gas source 16b. In the temperature adjustment, thermal energy is added to (or deprived of) the gas from the second temperature control device 17b. Thermal energy (plus or minus) may be transferred to the gas in any way. Here, the gas of the first temperature is supplied from the gas source 16 b to the second bubble generator 18.

  At this time, a temperature control device may be connected to the second liquid tank 12b. Thermal energy is equilibrated between the third group of micro bubbles 15c and the liquid in the second preliminary cleaning liquid 13b. The temperature of the gas contained in each microbubble is considered to be equal to the temperature measured as the second preliminary cleaning liquid 13b. The temperature of the third micro bubble group 15c can be set by adjusting the temperature of the second preliminary cleaning liquid 13b. Thus, the temperature of the second preliminary cleaning liquid 13b may be maintained at the first temperature by the operation of the temperature control device.

  A liquid flow generator 19 is connected to the mixing tank 12c. The liquid flow generating device 19 has a supply port 19a opened in a liquid (hereinafter referred to as "static liquid") 21 in the mixing tank 12c. The liquid flow generating device 19 flows the liquid into the static liquid 21 from the supply port 19a. The flow rate (flow rate) is set to 3.0 to 30.0 L / min. Thus, a liquid flow (hereinafter referred to as "dynamic liquid") 22 is generated in the static liquid 21. The dynamic liquid 22 comprises a liquid which forcibly produces relative movement with the static liquid 21. Such forced relative movement may be achieved in the form of an impeller jet.

  A liquid source 23 is connected to the liquid flow generator 19. The liquid source 23 supplies the liquid flow generator 19 with the liquid. The liquid may be the same liquid as the static liquid 21. That is, the liquid source 23 may circulate the static liquid 21 in the mixing tank 12 c. The third temperature control device 17 c is connected to the liquid source 23. The third temperature adjusting device 17 c adjusts the temperature of the liquid of the liquid source 23. In the temperature adjustment, thermal energy is added to the liquid from the third temperature control device 17c. Thermal energy may be transferred to the liquid in any manner. Thus, the temperature of the dynamic liquid 22 is set to a temperature higher than room temperature. Here, the temperature of the dynamic liquid 22 is set to a second temperature higher than the temperature of the static liquid 21 by the operation of the third temperature adjustment device 17 c.

  The cleaning device 11 has a holder 24 for holding the object to be cleaned W. For example, a basket is used for the holder 24. The holder 24 is immersed in the static liquid 21. The object to be cleaned W is fixed to the tip of the holder 24. The object to be cleaned W is held in the static liquid 21. The supply port 19 a of the fluid flow generating device 19 is directed to the object to be cleaned W on the holder 24. Thus, a liquid flow is generated toward the object to be cleaned W.

  The positioning mechanism 25 may be connected to the holder 24. The positioning mechanism 25 exerts a driving force that generates the movement of the holder 24 along, for example, a horizontal surface. In response to the movement of the holder 24, the dynamic liquid 22 can be directed to the target position on the object W to be cleaned. Cleaning of the cleaning surface can be realized over a wide range. In addition, instead of driving the holder 24, the mixing tank 12c may be moved relative to the holder 24 to be fixed. Alternatively, the orientation of the supply port 19a may be changed with respect to the holder 24 and the mixing tank 12c to be fixed.

  When the cleaning device 11 operates, the first preliminary cleaning solution 13a containing the first fine bubble group 15a formed of the gas of the first temperature is generated in the first liquid tank 12a, and the second liquid tank 12b generates the second preliminary cleaning liquid 13a. A second preliminary cleaning solution 13b is generated which contains a third group of microbubbles 15c formed of a gas at a temperature. As a result of mixing the first preliminary cleaning solution 13a and the second preliminary cleaning solution 13b in the mixing tank 12c, a second fine bubble group 15b formed of gas of an average bubble diameter of the first diameter in a single liquid; A cleaning liquid is produced which contains the fourth microbubble group 15d formed of a gas having an average cell diameter of two diameters. The ratio between the second micro bubble group 15b and the fourth micro bubble group 15d can be set according to the flow rate of the first preliminary cleaning solution 13a and the second preliminary cleaning solution 13b flowing into the mixing tank 12c.

  A temperature control device may be connected to the mixing tank 12c. The temperature of the static liquid 21 can be adjusted by the operation of the temperature control device. The thermal energy is equilibrated between the second micro bubble group 15 b and the fourth micro bubble group 15 d in the static liquid 21 and the liquid. The temperature of the gas contained in each microbubble is considered to be equal to the temperature measured as static liquid 21. Thus, the temperatures of the second micro bubble group 15 b and the fourth micro bubble group 15 d can be set in the mixing tank 12 c.

  As shown in FIG. 2, the first micro bubble group 15a and the second micro bubble group 15b have an average cell diameter of the first diameter D1 (= less than 100 nm). The first bubble generation device 14 ejects fine bubbles of the first diameter D1 at the maximum number [pieces]. As the bubble diameter increases or decreases from the first diameter D1, the number of bubbles decreases. That is, the quantity distribution shows a peak at the first diameter D1 (= 80 nm). On the other hand, the third micro bubble group 15 c and the fourth micro bubble group 15 d have an average cell diameter of the second diameter D 2 (= 100 nm or more and 50 μm or less). The second bubble generator 18 ejects fine bubbles of the second diameter D2 at the maximum number. As the bubble diameter increases or decreases from the second diameter D2, the number of bubbles decreases. That is, the quantity distribution shows a peak at the second diameter D2 (= 200 nm). The number of bubbles of the second micro bubble group 15b per unit volume is 50% or more of the total number of bubbles. The number of bubbles in the fourth micro bubble group 15 d per unit volume is 50% or less of the total number of bubbles.

  When the liquid flow generator 19 operates, a dynamic liquid 22 is formed from the supply port 19 a toward the object to be cleaned W. The dynamic liquid 22 contains the second microbubbles 15 b and the fourth microbubbles 15 d in the static liquid 21. The second micro bubble group 15 b and the fourth micro bubble group 15 d collide with the object to be cleaned W. The second micro-bubbles group 15b and the fourth micro-bubbles group 15d are in contact with the boundary between the surface of the object to be cleaned W and the contamination (the contour of the interface). Since the dynamic liquid 22 has higher energy than at room temperature, the second micro bubble group 15 b and the fourth micro bubble group 15 d effectively cause peeling at the interface. As the peeling progresses, fine bubbles inward from the contour. Thus, the contaminants are peeled off from the surface of the object to be cleaned W. Contaminants are separated from the object to be cleaned W. The dynamic liquid 22 is ejected from the supply port 19 a of the liquid flow generating device 19 in the state of containing the second micro bubble group 15 b and the fourth micro bubble group 15 d, and thus the dynamic produced in the static liquid 21. The dynamic liquid 22 can reliably contain a predetermined amount of the second micro bubble group 15 b and the fourth micro bubble group 15 d as compared to the case where the micro bubbles are blown into the liquid flow. The cleaning solution exhibits a dramatically better cleaning effect than before. In particular, since the temperature of the dynamic liquid 22 is higher than the temperature of the static liquid 21, the microbubbles with different temperatures act on the contour of the interface one after another to repeat the temperature change in the contour of the interface (the vibration of the temperature ) Occurs. Temperature oscillations promote the exfoliation of the contaminants. Moreover, since the average cell diameter of the second micro cell group 15b and the average cell diameter of the fourth micro cell group 15d are different, the fourth average cell diameter is large from the difference in the amount of heat energy contained in each cell. The fine bubble group 15d produces a gradual temperature change at the interface between the object to be cleaned W and the contaminant, and the second fine bubble group 15b having a small average bubble diameter has a rapid temperature change at the interface between the object to be cleaned W and the contaminant Produce The rapid temperature change causes a rapid expansion of the object to be cleaned W or a rapid contraction of the object to be cleaned W, which promotes the separation of the contaminants. It has been confirmed that the cleaning effect is further enhanced. The smaller the microbubbles, the easier it is to enter the boundary between the surface of the object to be cleaned W and the contaminants, and promote the separation, but if the bubble diameter of the microbubbles having a temperature difference is different, further improvement of the cleaning effect is realized. Conceivable.

  The temperature of the liquid in the first liquid tank 12 a and the liquid in the second liquid tank 12 b may be set to the first temperature. When the liquid is, for example, pure water or an aqueous solution, it is desirable that the temperature of the liquid be set to 80 ° C. or less. When the temperature of the pure water or the aqueous solution exceeds 80 ° C., the bubbles can not stably maintain a high number density.

(2) Verification The present inventors conducted verification in accordance with the cleaning device 11. In the verification, the influence of the temperature condition of the dynamic liquid 22 was observed. The first preliminary cleaning liquid 13a is generated in the first liquid tank 12a. Pure water was used as the liquid of the first preliminary cleaning solution 13a. The atmosphere (air) was supplied to the first bubble generator 14 from the gas source 16a. The temperature of the air (first temperature T1) was adjusted. The amount of fine bubbles was set to about 1 × 10 ⁶ per milliliter. The temperature of the pure water was set to the first temperature T1.

The second preliminary cleaning liquid 13b is generated in the second liquid tank 12b. Pure water was used as the liquid of the second preliminary cleaning liquid 13b. The atmosphere (air) was supplied to the second bubble generator 18 from the gas source 16 b. The temperature of the air (first temperature T1) was adjusted. The amount of fine bubbles was set to about 1 × 10 ⁶ per milliliter. The temperature of the pure water was set to the first temperature T1.

  The first preliminary washing solution 13a and the second preliminary washing solution 13b were poured into the mixing tank 12c. The static liquid 21 was formed in the mixing tank 12c. The temperature TL of the static liquid 21 was adjusted. The temperature TL of the static liquid 21 reflects the first temperature T1 of the first preliminary cleaning solution 13a and the second preliminary cleaning solution. The temperature of the second microbubble group 15b and the fourth microbubble group 15d in the static liquid 21 was assumed to be equal to the temperature TL of the static liquid 21.

  A basket was used for the holder 24. The machine parts were mounted on the basket as the article W to be cleaned. On the surface of the machine parts, chips at the time of cutting were attached together with the oil. After 10 minutes of cleaning, the amount of chips and oil remaining on the surface of the machine parts was measured. The machine parts after cleaning were subjected to high pressure cleaning to measure the amount of chips. The chips thus washed off were collected with filter paper. The weight [milligram] of the collected chips was measured using an electronic balance. On the other hand, the machine parts after washing were immersed in the solvent to measure the amount of oil. The concentration [ppm] of the oil dissolved in the solvent was measured.

条件１では動的液体２２の液体温度ＴＤおよび静的液体２１の液体温度ＴＬは等しく室温よりも高い温度に設定された。第１微細気泡群１５ａの温度および第２微細気泡群１５ｂの温度は等しく液体温度ＴＬに設定された。条件２では、動的液体２２の液体温度ＴＤは室温よりも高い温度に設定され、静的液体２１の液体温度ＴＬは室温から徐々に上昇した。静的液体２１の液体温度ＴＬは変動した。第１微細気泡群１５ａの温度および第２微細気泡群１５ｂの温度は等しく液体温度ＴＬに設定された。条件３、条件４および条件５では、動的液体２２の液体温度ＴＤは室温よりも高い温度に設定され、静的液体２１の液体温度ＴＬは室温に設定された。こうして液体温度ＴＤと液体温度ＴＬとの間に温度差が設定された。第１微細気泡群１５ａの温度および第２微細気泡群１５ｂの温度は等しく液体温度ＴＬに設定された。 Three conditions were set up as follows in observing the temperature conditions.

Under condition 1, the liquid temperature TD of the dynamic liquid 22 and the liquid temperature TL of the static liquid 21 were set to temperatures equal to or higher than room temperature. The temperature of the first micro bubble group 15a and the temperature of the second micro bubble group 15b were set equal to the liquid temperature TL. In condition 2, the liquid temperature TD of the dynamic liquid 22 was set to a temperature higher than room temperature, and the liquid temperature TL of the static liquid 21 gradually rose from room temperature. The liquid temperature TL of the static liquid 21 fluctuated. The temperature of the first micro bubble group 15a and the temperature of the second micro bubble group 15b were set equal to the liquid temperature TL. In conditions 3, 4 and 5, the liquid temperature TD of the dynamic liquid 22 was set to a temperature higher than room temperature, and the liquid temperature TL of the static liquid 21 was set to room temperature. Thus, a temperature difference was set between the liquid temperature TD and the liquid temperature TL. The temperature of the first micro bubble group 15a and the temperature of the second micro bubble group 15b were set equal to the liquid temperature TL.

The inventors set comparative conditions for observing the temperature conditions. Under the comparison conditions, the liquid temperature TD of the dynamic liquid 22 and the liquid temperature TL of the static liquid 21 were equally set to room temperature.

At the same time, the inventor observed the relationship between the bubble diameter of the second micro bubble group 15 b and the fourth micro bubble group 15 d and the cleaning effect. The effect of bubble diameter was observed under conditions 3, 4 and 5 under equal temperature conditions. That is, under condition 3, the average bubble diameter of the second micro bubble group 15b and the average bubble diameter of the fourth micro bubble group 15d were set equal. Under the condition 4, the average cell diameter of the second micro bubble group 15b is set smaller than the average cell diameter of the fourth micro bubble group 15d. The amount of air bubbles in the second micro air bubble group 15 b and the fourth micro air bubble group 15 d was set equal. Under condition 5, the average cell diameter of the second micro bubble group 15b is set smaller than the average cell diameter of the fourth micro bubble group 15d. The bubble amount of the second micro bubble group 15 b is set to be larger than the bubble amount of the fourth micro bubble group 15 d. Condition 1 and 2 and the average bubble diameter and bubble volume of comparison conditions were set equal to condition 3.

  As a result of observation, as shown in FIG. 3, it was confirmed that the removal of chips was promoted under the conditions 1 to 5 as compared with the comparison condition. It has been found that chip removal is effectively realized when the temperature of the dynamic liquid 22 is set higher than room temperature. In particular, as apparent from the comparison between the condition 1 and the comparison condition, when the liquid temperature TD of the dynamic liquid 22 and the liquid temperature TL of the static liquid 21 are set higher than room temperature, the chip cleaning effect is enhanced That was confirmed. Further, as apparent from the condition 3, when the temperature difference is set between the liquid temperature TD of the dynamic liquid 22 and the liquid temperature TL of the static liquid 21, it has been confirmed that the chip cleaning effect is enhanced. . Further, as apparent from the comparison of the conditions 3 to 5, when the difference in cell diameter is set between the second micro bubble group 15b and the fourth micro bubble group 15d, the washing effect of the chips is further enhanced. That was confirmed. In particular, as apparent from the condition 5, it was confirmed that the chip cleaning effect is enhanced as the proportion of the second micro-bubble group 15b having a small average diameter increases beyond 50%.

  As shown in FIG. 4, it was confirmed that the removal of oil was promoted under the conditions 1 to 5 as compared with the comparison condition. It has been found that oil removal is effectively realized when the temperature of the dynamic liquid 22 is set higher than room temperature. In particular, oil removal is promoted when the liquid temperature TD of the dynamic liquid 22 and the liquid temperature TL of the static liquid 21 are set higher than room temperature, as is apparent from the comparison between the condition 1 and the comparison condition. That was confirmed. Further, as apparent from the condition 3, it was confirmed that the oil removal is promoted when the temperature difference is set between the liquid temperature TD of the dynamic liquid 22 and the liquid temperature TL of the static liquid 21. . In addition, as apparent from the comparison of conditions 3 to 5, when the difference in cell diameter is set between the second micro bubble group 15b and the fourth micro bubble group 15d, the removal of oil is significantly promoted. That was confirmed. In particular, as apparent from the condition 5, it was confirmed that the removal of oil is promoted as the proportion of the first micro-bubble group 15a having a small average diameter increases to more than 50%.

  15a: first microbubble group 15b: second microbubble group 15c: third microbubble group 15d: fourth microbubble group 21: static liquid 22: dynamic liquid D1: first diameter D2: second diameter, W: object (object to be cleaned).

Claims (5)

A static liquid comprising a first group of fine bubbles,
The second microbubbles group having an average cell diameter equal to the average cell diameter of the first microbubbles group, having a temperature higher than room temperature, and squirting toward the object held in the static liquid Dynamic liquid to be dispensed,
A cleaning solution characterized by having:   The cleaning liquid according to claim 1, wherein the temperature of the dynamic liquid is higher than the temperature of the static liquid. In the cleaning liquid according to claim 2,
The static liquid further includes a third microbubble group having an average cell diameter different from an average cell diameter of the first microbubble group,
The cleaning liquid, wherein the dynamic liquid further includes a fourth microbubbles group having an average cell diameter equal to an average cell diameter of the third microbubbles group.   4. The cleaning liquid according to claim 3, wherein an average cell diameter of the first microbubbles group and the second microbubbles group is less than 100 nm, and an average cell diameter of the third microbubbles group and the fourth microbubbles group. Is 100 nm or more and 50 μm or less.   5. The cleaning solution according to claim 4, wherein the number of bubbles in the second micro bubble group per unit volume in the dynamic liquid is 50% or more of the total number of bubbles.

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