| US20100126934A1 | 2010-05-27 | |||
| JPH10290963A | 1998-11-04 | |||
| JP2006313753A | 2006-11-16 | |||
| JP2006313753A | 2006-11-16 | |||
| JPH0776787A | 1995-03-20 | |||
| JP2008163400A | 2008-07-17 |
| What is claimed is: 1. A method for purifying a fluorinated liquid, comprising performing an extraction step two or more times, the extraction step including a first step of bringing water into contact with a fluorinated liquid into which a cleaning agent is mixed and a second step of separating a mixed solution after water contact into two liquids, an aqueous phase located in an upper layer and a phase containing the fluorinated liquid located in a lower layer, and then collecting the liquid in the lower layer, wherein a total amount of water bought into contact until the final extraction step is about 30.0 mass% or less, wherein the cleaning agent is an aprotic polar solvent that is dissolved in the fluorinated liquid, and wherein the fluorinated liquid is hydrofluoroether, hydrofluoroolefm, or a mixture thereof. 2. The purification method according to claim 1, wherein the amount of water brought into contact in the first step firstly performed is 3.0 to 20.0 mass%. 3. The purification method according to claim 1 or 2, wherein the number of times of performing the extraction step is 5 times or less. 4. The purification method according to any one of claims 1 to 3, wherein the aprotic polar solvent is at least one selected from a cyclic amide-based solvent, an amine-based solvent, a glycol ether-based solvent, acetone, dimethyl sulfoxide, and dimethylformamide. 5. The purification method according to any one of claims 1 to 4, wherein a solubility of water in the fluorinated liquid is 500 ppm or less. 6. The purification method according to any one of claims 1 to 5, further comprising a step of distilling a lower layer liquid collected through a final extraction step. 7. The purification method according to any one of claims 1 to 6, wherein a purity of the fluorinated liquid purified through the purification method is 95.0% or greater. 8. A method for using a fluorinated liquid purified using the purification method described in any one of claims 1 to 7 as a rinse liquid for a member used in an organic EL display manufacturing apparatus. 9. The method according to claim 8, wherein the member is a metal mask or a deposition-proof plate. 10. A fluorinated liquid purification apparatus comprising an extraction means performing an extraction step two or more times, the extraction step including a first step of bringing water into contact with a fluorinated liquid into which a cleaning agent is mixed and a second step of separating a mixed solution after water contact into two liquids, an aqueous phase located in an upper layer and a phase containing the fluorinated liquid located in a lower layer, and then collecting a liquid in the lower layer, wherein a total amount of water bought into contact until the final extraction step is about 30.0 mass% or less, wherein the cleaning agent is an aprotic polar solvent that is dissolved in the fluorinated liquid, and wherein the fluorinated liquid is hydrofluoroether, hydrofluoroolefin, or a mixture thereof. 11. The purification apparatus according to claim 10, further comprising a means for distilling a liquid in the lower layer collected through the extraction means. |
APPARATUS USING SAME
Technical Field
The present disclosure relates to a method for purifying a fluorinated liquid and to a purification apparatus using the method.
Background
For example, a method for making an organic EL display includes a step of evaporating RGB three colors of dye on a substrate such as glass via a metal mask to form an organic light-emitting layer. Since the metal mask is an expensive member, the metal mask is reused after the metal mask is cleaned with a cleaning agent such as N-methyl-2- pyrrolidone, followed by a rinsing step using a fluorinated liquid and a drying step.
Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2006-313753) describes a cleaning method in which a metal mask used in the vacuum evaporation step when a low-molecular-weight organic EL element is manufactured is cleaned by immersion with a cleaning liquid composition containing an aprotic polar solvent such as N-methyl-2-pyrrolidinone or with a jet stream, and then rinsed with hydrofluoroether.
Patent Document 2 (Japanese Unexamined Patent Application Publication No. H07- 076787) describes a purification apparatus of a metal cleaning agent, including a cleaning apparatus that uses NMP as a metal cleaning agent, and a purification apparatus that removes contaminants from the NMP cleaning liquid after cleaning and circulates the resultant liquid to the cleaning apparatus, in which a filter material provided in the purification apparatus is a granular filter material containing at least polypropylene and having floatability to NMP.
Patent Document 3 (Japanese Unexamined Patent Application Publication No. 2008-163400) discloses a cleaning system including a cleaning tank in which a cleaning liquid containing one or more selected from (la) hydrocarbons, (lb) glycol ethers, and (lc) esters is stored and a material to be cleaned is immersed; a rinse liquid tank in which a rinse liquid containing one or more selected from (2a) hydrofluorocarbons and (2b) hydrofluoroethers as a main component is stored and the material to be cleaned is immersed; a vapor tank that stores the rinse liquid and generates steam of the rinse liquid; and a purification unit having a distiller.
Citation List
Patent Documents
[Patent Document 1]: JP 2006-313753 A
[Patent Document 2] JP H07-076787 A
[Patent Document 3]: JP 2008-163400 A
Summary
In general, increasing the number of cleaning and rinsing operations also increases the mixing rate of the cleaning agent into a rinse tank. As a result, the rinse tank becomes contaminated by the cleaning agent, and therefore, the rinse liquid needs to be replaced periodically. However, since a fluorinated liquid used as the rinse liquid is also an expensive solvent, techniques for efficiently collecting and reusing a fluorinated liquid from a contaminated rinse liquid have been desired.
In recent years, regulations such as reducing environmental load tend to be performed in each country, and for example, in various manufacturing lines, there has been a demand for measures against strict drainage regulations such as reducing waste water.
The present disclosure provides a method for purifying a fluorinated liquid that contributes to reducing environmental load and that has excellent purification efficiency on the fluorinated liquid into which a cleaning agent is mixed, and a purification apparatus using the method.
Solution to Problem
According to one embodiment of the present disclosure, there is provided a method for purifying a fluorinated liquid, the method including performing an extraction step two or more times, the extraction step including a first step of bringing water into contact with a fluorinated liquid in which a cleaning agent is mixed and a second step of separating a mixed solution after water contact into two liquids, an aqueous phase located in an upper layer and a phase containing the fluorinated liquid located in a lower layer, and then collecting the liquid in the lower layer, in which a total amount of water bought into contact until the final extraction step is about 30.0 mass% or less, the cleaning agent is an aprotic polar solvent that is dissolved in the fluorinated liquid, and the fluorinated liquid is hydrofluoroether, hydrofluoroolefin, or a mixture thereof.
According to another embodiment of the present disclosure, there is provided a method for using a fluorinated liquid purified by using the method for purifying a fluorinated liquid described above as a rinse liquid for a member used in an organic EL display manufacturing apparatus.
According to still another embodiment of the present disclosure, there is provided a fluorinated liquid purification apparatus including an extraction means for performing an extraction step two or more times, the extraction step including a first step of bringing water into contact with a fluorinated liquid in which a cleaning agent is mixed and a second step of separating a mixed solution after water contact into two liquids, an aqueous phase located in an upper layer and a phase containing the fluorinated liquid located in a lower layer, and then collecting the liquid in the lower layer, in which a total amount of water bought into contact until the final extraction step is about 30.0 mass% or less, the cleaning agent is an aprotic polar solvent that is dissolved in the fluorinated liquid, and the fluorinated liquid is hydrofluoroether, hydrofluoroolefin, or a mixture thereof.
Advantageous Effects of Invention
According to the present disclosure, it is possible to provide a method for purifying a fluorinated liquid that contributes to reducing environmental load and that has excellent purification efficiency on the fluorinated liquid into which a cleaning agent is mixed, and a purification apparatus using the method.
The above descriptions should not be construed as that all aspects of the present disclosure and all advantages of the present disclosure are disclosed.
Detailed Description
Hereinafter, a more detailed description is given for the purpose of illustrating representative embodiments of the present disclosure, but the present disclosure is not limited to these embodiments.
In a method for purifying a fluorinated liquid according to one embodiment of the present disclosure, an extraction step is performed two or more times, the extraction step including a first step of bringing water into contact with a fluorinated liquid in which a cleaning agent is mixed and a second step of separating a mixed solution after water contact into two liquids, an aqueous phase located an upper layer and a phase containing the fluorinated liquid located in a lower layer, and then collecting the liquid in the lower layer, a total amount of water bought into contact until the final extraction step is about 30.0 mass% or less, the cleaning agent used here is an aprotic polar solvent that is dissolved in the fluorinated liquid, and the fluorinated liquid is hydrofluoroether, hydrofluoroolefm, or a mixture thereof. According to the purification method of the present disclosure, even though the total amount of water bought into contact until the final extraction step is as low as about 30.0 mass% or less, the purification efficiency of the fluorinated liquid is excellent, and the amount of waste water is small, and thus it is possible to contribute to reducing or suppressing the environmental load.
The cleaning agent that can be mixed in the method for purifying a fluorinated liquid of the present disclosure is a cleaning agent that is used during cleaning of various members, and examples thereof include a cleaning agent used during cleaning of a metal mask, a deposition-proof plate, or the like in an organic EL display manufacturing apparatus. The cleaning agent is not particularly limited as long as it is an aprotic polar solvent that is dissolved in the fluorinated liquid. Examples thereof include at least one selected from a cyclic amide-based solvent, an amine-based solvent, a glycol ether-based solvent, acetone, dimethyl sulfoxide, and dimethylformamide. These cleaning agents have excellent cleaning action and are more soluble in water than in fluorinated liquids, and thus are suitable cleaning agents in the purification method of the present disclosure, which uses water to remove the cleaning agent from the fluorinated liquid. Among these, from the perspective of the cleaning properties of various members such as metal masks and deposition-proof plates, and balance of solubility in the fluorinated liquid and water, a cyclic amide-based solvent is preferable, and N-alkyl-pyrrolidone solvent such as N-methyl-2-pyrrolidone (NMP) and N-butyl-2-pyrrolidone (NBP) or a solvent referred to as a g-lactam solvent are more preferable, and N-methyl-2-pyrrolidone (NMP) is particularly preferable. Such aprotic polar solvents can be used alone or in combination of two or more thereof. If the cleaning agent described above is used, a fluorinated liquid can be efficiently purified by the purification method of the present disclosure. The cleaning agent may contain other cleaning agents in addition to the cleaning agent described above within a range that does not inhibit the purification efficiency of the fluorinated liquid; however, from the perspective of purification efficiency and the like, no other cleaning agent is preferably contained.
A boiling point of the cleaning agent is not particularly limited, but in consideration of, for example, application of a distillation step described below, it is preferably about 55°C or higher, about 100°C or higher, about 120°C or higher, about 150°C or higher, about 180°C or higher, about 200°C or higher, or about 250°C or higher. An upper limit of the boiling point of the cleaning agent is not particularly limited, and can be set to, for example, about 300°C or lower, about 280°C or lower, or about 260°C or lower.
Examples of the fluorinated liquid that may be purified by the method for purifying a fluorinated liquid of the present disclosure include hydrofluoroether, hydrofluoroolefm, or a mixture thereof. The fluorinated liquid may contain other fluorinated liquids (for example, hydrochlorofluorocarbons, hydrofluorocarbons, and the like) in addition to the fluorinated liquid described above within a range that does not inhibit the purification efficiency; however, from the perspective of the purification efficiency and the like, no other fluorinated liquid is preferably included.
The solubility of water in the fluorinated liquid is not particularly limited. For example, from the perspective of separation performance and purification efficiency between the aqueous phase and the phase containing the fluorinated liquid, the solubility of water at 25°C is advantageously about 500 ppm or less, about 300 ppm or less, about 200 ppm or less, or about 150 ppm or less. A lower limit value of the solubility is not particularly limited, and can be set to, for example, about 10 ppm or more, about 30 ppm or more, or about 50 ppm or more. A cleaning agent such as NMP is more easily dissolved in water than in the fluorinated liquid. Therefore, when the solubility of water in the fluorinated liquid is within this range, water is difficult to dissolve in the fluorinated liquid, and thus when brought into contact with water, the cleaning agent in the fluorinated liquid tends to become more easily incorporated into the water, and the percentage of the cleaning agent remaining in the fluorinated liquid can be further reduced. Here,“the solubility of water in the fluorinated liquid” refers to the mass ratio of water that can be maximally dissolved in the fluorinated liquid under an atmosphere of 25°C, and is an average value obtained by measuring at least five times using a micromoisture measuring apparatus (manufactured by Mitsubishi Chemical Analytech Co., Ltd.) in accordance with Karl Fischer Titration Method (coulometric titration method) defined by JIS K 0068: 2001. The boiling point of the fluorinated liquid is not particularly limited, but in consideration of, for example, application of a distillation step described below, it is preferably about 30°C or higher, about 55°C or higher, about 60°C or higher, or about 75°C or higher, and preferably about 150°C or lower, about 100°C or lower, or about 80°C or lower.
Among the fluorinated liquids described above, from the perspective of separation performance and purification efficiency of a phase containing a water phase and a fluorinated liquid, the use of hydrofluoroether is preferable. The hydrofluoroether is a compound containing an oxygen atom that is ether bondable between carbon atoms of hydrofluorocarbon. The number of ether bondable oxygen atoms contained in one molecule of hydrofluoroether may be one or two or more. From the perspective of the boiling point that is easy to use as a solvent, the stability, and the like, one or two are preferable, and one is more preferable. A molecular structure of the hydrofluoroether only needs to be a chain and may be a straight chain or a branched chain, but from the perspective of purification efficiency and the like, a straight chain is preferable.
Examples of the hydrofluoroether include segregate-type hydrofluoroether such as C4F9OCH3, C4F9OCH2CH3, C5F11OCH3, C5F11OCH2CH3, C6F13OCH3, C6F13OCH2CH3, C7F15OCH3, C7F15OCH2CH3, CuFnOCHs, C8F17OCH2CH3, C9F19OCH3, C9F19OCH2CH3, C10F21OCH3, and C10F21OCH2CH3; and hydrofluoroether such as CF3CH2OCF2CF2H, CF3CHFOCH2CF3, CF3CH2OCF2CFHCF3, CHF2CF2CH2OCF 2CF2H,
C3F7OC3F6OCFHCF3, CF 3 CF(CF3)CF(0CH3)CF 2 CF3, CF3CF(CF3)CF(0C2H 5 )CF 2 CF3, CF2(0CH 2 CF3)CF 2 H, CF 2 (OCH 2 CF3)CFHCF3, CF 2 (OCH2CF2CF2H)CF 2 H, and CF2(OCH2CF2CF2H)CFHCF3. Such hydrofluoroethers can be used alone or in combination of two or more thereof.
Among them, segregate-type hydrofluoroether has low solubility in water, and in a case of being brought into contact with water, the proportion dissolved in the aqueous phase can be reduced as compared with other hydrofluoroethers or hydrofluoroolefins, and thus it is easy to separate the aqueous phase from the phase containing the fluorinated liquid. As a result, the separated aqueous phase is less likely to be contaminated with the fluorinated liquid, and therefore, for example, it can deal with relatively strict drainage regulations. Among the segregate-type hydrofluoroethers, C4F9OCH3 or C4F9OCH2CH3 is more preferable. Here, the“segregate-type” refers to a structure in which one side is completely fluorinated and the other side is composed of carbon and hydrogen with an ether bond interposed therebetween.
The hydrofluoroolefm is intended to be a compound in which one or more hydrogen atoms in the olefin are substituted with a fluorine atom. The number of fluorine atoms contained in the hydrofluoroolefm is not particularly limited, and can be one or more or two or more, and ten or less or six or less. The hydrofluoroolefins may be either type E (trans type) and type Z (cis type). The hydrofluoroolefm may be hydrochlorofluoroolefin. The hydrochlorofluoroolefm is intended to be a compound in which one or two or more hydrogen atoms in the olefin are substituted with fluorine atoms, and one or two or more other hydrogen atoms in the olefin are substituted with chlorine atoms. The number of chlorine atoms in the hydrochlorofluoroolefm is not particularly limited, and can be one or more, and five or less or three or less.
Examples of hydrofluoroolefins having no chlorine atom include CF3-CH=CH2,
CF3-CF=CH 2 , CHF 2 -CH=CHF, CHF 2 -CF=CH 2 , CH 2 F-CH=CF 2 , CH 2 F-CF=CHF, CH 3 - CF=CF 2 , CF3-CH=CH-CF 3 , CF3-CH=CF-CH 3 , CF3-CF=CH-CH 3 , CF 3 -CH=CH-CH 2 F,
CHF 2 -CF=CF-CH 3 , CHF 2 -CF=CH-CH 2 F, CHF 2 -CH=CF-CH 2 F, CHF 2 -CH=CH-CHF 2 , CH 2 F-CF=CF-CH 2 F, CH 2 F-CH=CH-CF 3 , CH 2 F-CF=CH-CHF 2 , CF 3 -CH 2 -CF=CH 2 , CF 3 - CHF-CH=CH 2 , CF 3 -CH 2 -CH=CHF, CHF 2 -CF 2 -CH=CH 2 , CHF 2 -CHF-CF=CH 2 , CHF 2 - CHF-CH=CHF, CH 2 F-CF 2 -CF=CH 2 , CH 2 F-CF 2 -CH=CHF, CH 2 F-CHF-CF=CHF, CHZF- CHF-CF=CF 2 , CH 2 F-CH 2 -CF=CF 2 , CH 3 -CF 2 -CF=CHF, and CH3-CF 2 -CH=CF 2 . Examples of the hydrofluoroolefm (that is, hydrochlorofluoroolefm) having a chlorine atom include
CF 3 -CH=CHC1, CHF 2 -CF= CHCl, CHF 2 -CH=CFC1, CHF 2 -CCI= CHF, CH 2 F-CCI= CF 2 , CHFC1-CF= CHF, CH 2 C1-CF= CF 2 , and CF3-CC1= CH 2 . A particularly preferable hydrofluoroolefm having a chlorine atom is CF3-CH=CHC1. The hydrofluoroolefins (also including hydrochlorofluoroolefins) may be used alone or in combination of two or more thereof.
The water used in the method for purifying a fluorinated liquid of the present disclosure is not particularly limited, and for example, tap water, distilled water, ion exchanged water, and the like can be used.
In the method for purifying a fluorinated liquid of the present disclosure, an extraction step is performed two or more times, the extraction step includes a first step of bringing water into contact with a fluorinated liquid in which a cleaning agent is mixed and a second step of separating a mixed solution after water contact into two liquids, an aqueous phase located an upper layer and a phase containing the fluorinated liquid located in a lower layer, and then collecting the liquid in the lower layer. The upper limit of the number of times of performing the extraction step is not particularly limited, but from the perspective of simplifying the purification process, for example, it is advantageous to have 5 times or less, 4 times or less, or 3 times or less.
The method of contacting water with the fluorinated liquid in which the cleaning agent is mixed in the first step is not particularly limited, and for example, the method of (1) to (7) below can be employed alone or in combination of two or more thereof, and can be performed by combining some of the method of (1) to (7) as appropriate. For example, a physical stirring method using vibration, a stirrer, or the like, a stirring method using air, and a stirring method using ultrasonic waves, or the like, which are described in (3), (6), or (7), may be applied to the method (1) or (2).
(1) A method for dripping a fluorinated liquid into which a cleaning agent is mixed to a container containing water from above the container.
(2) A method for adding water to a container containing a fluorinated liquid into which a cleaning agent is mixed from below the container.
(3) A method for physically stirring a container containing a mixed solution of a cleaning agent, a fluorinated liquid, and water, by using a stirrer, stirring blade, or the like.
(4) A method in which an upper layer and a lower layer are connected to each other by a tube or the like, and an upper layer liquid is moved to the lower layer by gravity or a pump in a situation where a mixed solution has already been separated into two layers in a container containing the mixed solution of a cleaning agent, a fluorinated liquid and water.
(5) A method in which an upper layer and a lower layer are connected to each other by a tube or the like, and a lower layer liquid is moved to the upper layer by gravity or a pump in a situation where a mixed solution has already been separated into two layers in a container containing the mixed solution of a cleaning agent, a fluorinated liquid and water.
(6) A method in which a gas such as air is blown into the container and bubbled to mix a mixed solution, and a lower layer liquid is moved to the upper layer by gravity or a pump in a situation where the mixed solution has already been separated into two layers in the container containing the mixed solution of a cleaning agent, a fluorinated liquid and water. (7) A method in which ultrasonic waves are applied to a container to mix a mixed solution, and a lower layer liquid is moved to the upper layer by gravity or a pump in a situation where the mixed solution has already been separated into two layers in the container containing the mixed solution of a cleaning agent, a fluorinated liquid and water.
The amount of water brought into contact in the first step may be the same as or different from each other in each extraction step. For example, in a case of performing the extraction step three times, a total of 3.0 g of water may be added by 1.0 g to and contacted with the fluorinated liquid in which the cleaning agent is mixed, alternatively, 1.5 g of water may be added for the first time, 1.0 g for the second time, and 0.5 g for the third time.
According to the method for purifying a fluorinated liquid of the present disclosure, excellent purification efficiency can be achieved by performing the extraction steps two or more times even if the amount of water brought into contact in the first step firstly performed is low and the total amount of water contacted until the final extraction step is about 30.0 mass% or less. The amount of water brought into contact in the first step firstly performed can be about 20.0 mass% or less, about 19.0 mass% or less, or about 18.0 mass% or less, and may be about 3.0 mass% or more, about 4.0 mass% or more, or about 5.0 mass% or more. Here,“the amount of water brought into contact in the first step firstly performed” means the value calculated as a percentage of the mass of the added water relative to the mass of the cleaning agent contained in the fluorinated liquid in the first step firstly performed and the mass of the added water. In addition, the mass of the cleaning agent contained in the fluorinated liquid at the first time of the first step can be determined by a quantitative analysis method using a calibration curve indicating the correlation of the concentration of the cleaning agent in the fluorinated liquid that is previously produced by a gas chromatography analyzer.
The temperature and time when the water is contacted with the fluorinated liquid in which the cleaning agent is mixed is not particularly limited because it can vary depending on the required performance, scale size, contact method, and the like of the purified fluorinated liquid. For example, the temperature can be about 20°C or higher, about 23 °C or higher, or about 25°C or higher, and about 40°C or lower, about 35°C or lower, or about 30°C or lower, and the contact time may be set to be about 30 seconds or longer, about 1 minute or longer, or about 5 minutes or longer, and can be about 1 day or shorter, about 10 hours or shorter, about 1 hour or shorter, or about 30 minutes or shorter. The second step in the extraction step includes a step of separating a mixed solution after water contact into two liquids, an aqueous phase located an upper layer and a phase containing the fluorinated liquid located in a lower layer, and then collecting the liquid in the lower layer. The separation into two liquids of the upper layer and the lower layer can be achieved, for example, by passing through a step of resting a mixed solution containing the cleaning agent and the fluorinated liquid.
The lower layer liquid may be collected directly from below the container containing the upper layer liquid and the lower layer liquid, via a tube or the like, or the upper layer liquid may be collected from above the container, and then the lower layer liquid may be collected, or a tube or the like may be stretched and drawn from above the container to the vicinity of the bottom of the container.
The total amount of water contacted until the final extraction step is about 30.0 mass% or less, and when considering, for example, the reduction in the amount of waste water and the balance of purification efficiency, the total amount is advantageous to be about 29.0 mass% or less, about 28.0 mass% or less, or about 27.0 mass% or less, about 25.0 mass% or less, about 23.0 mass% or less, or about 20.0 mass% or less, and is advantageous to be about 5.0 mass% or more, about 7.0 mass% or more, or about 9.0 mass% or more. Here,“total amount of water contacted until the final extraction step” means the value calculated as a percentage of the total amount of the added water relative to the mass of the cleaning agent contained in the fluorinated liquid at the first time of the first step and the total amount of the added water.
The purity of the fluorinated liquid that is purified through the method for purifying a fluorinated liquid of the present disclosure can achieve about 95.0% or higher, about 96.0% or higher, about 97.0% or higher, or about 98.0% or higher. The upper limit of the purity of the fluorinated liquid is not particularly limited, and can be set to be, for example, less than about 100%, about 99.9% or less, or about 99.8% or less.
The method for purifying a fluorinated liquid of the present disclosure can be applied as appropriate by using one or two or more of a heating step, a distillation step (such as a boiling distillation step, a vacuum distillation step, or the like), a cooling separation step, and the like in combination.
If it is desired to increase the purity of the fluorinated liquid, the purification method of the present disclosure may further include a distillation step of distilling the lower layer liquid collected through the final extraction step. In the related art, distillation means have been commonly employed for purification of a fluorinated liquid, but in a case where the fluorinated liquid is purified by the distillation means alone, since the amount of the fluorinated liquid that can be recovered is extremely low, most of the fluorinated liquid has to be disposed substantially. On the other hand, in a case where the distillation step is combined with the method for purifying a fluorinated liquid of the present disclosure, the amount of recovery of the fluorinated liquid can be greatly improved compared to a purification method using the distillation means alone.
The distillation temperature in the distillation step is not limited to the following, and for example, it can be about 70°C or higher, about 72°C or higher, or about 75°C or higher, and can be about 100°C or lower, about 95°C or lower, or about 90°C or lower.
In some embodiments, the purification method of the present disclosure may not apply an additional distillation step or heating step. The purification method that does not include such steps is capable of completing the purification at room temperature, thereby increasing energy efficiency and eliminating the need for additional operations. Therefore, from the perspective of reducing the environmental load, it is advantageous not to employ a distillation step or a heating step.
The fluorinated liquid purification apparatus according to one embodiment of the present disclosure includes extraction means for performing an extraction step performed two or more times, and the extraction step includes a first step of bringing water into contact with a fluorinated liquid in which a cleaning agent is mixed and a second step of separating into two phases, an aqueous phase located an upper layer and a phase containing the fluorinated liquid located in a lower layer, and then collecting the liquid in the lower layer, in which a total amount of water bought into contact with the liquid until the final extraction step is about 30.0 mass% or less, the cleaning agent used here is an aprotic polar solvent that is dissolved in the fluorinated liquid, and the fluorinated liquid is hydrofluoroether, hydrofluoroolefm, or a mixture thereof. Examples of the cleaning agent, fluorinated liquid, and water that can be used in such a purification apparatus may be the same as those used in the purification method described above. In addition, such a purification apparatus can similarly exhibit the effects described in the purification method described above.
The extraction means in the fluorinated liquid purification apparatus of the present disclosure is not particularly limited as long as the extraction means may perform the extraction step including the first step and the second step in the method for purifying a fluorinated liquid described above. For example, the material, capacity, shape, quantity, location, or the like of a container (referred to as a“tank” or the like in some cases) for storing a mixed solution containing a cleaning agent, a fluorinated liquid, and water used in the extraction means can be selected appropriately depending on the use application or use environment of the apparatus.
The fluorinated liquid purification apparatus of the present disclosure can optionally apply means that may perform any step, such as a heating step, a distillation step (such as a boiling distillation step, a vacuum distillation step, or the like), a cooling separation step, and the like in the method for purifying a fluorinated liquid described above. For example, the material, capacity, shape, quantity, location, or the like of a container for storing a lower layer liquid used in the distillation step can be selected appropriately depending on the use application or use environment of the apparatus. Various means such as heating means, distillation means, cooling separation means, and the like can be applied to the fluorinated liquid purification apparatus alone or in combination of two or more thereof.
If it is desired to increase the purity of the fluorinated liquid, the purification apparatus of the present disclosure may further include distillation means for distilling the lower layer liquid collected via the extraction means. The distillation means can use a known apparatus including, for example, a distillation pot for storing and heating the collected lower layer liquid, and a chiller connected in communication with the distillation pot to condense and liquefy the vapor of the lower layer liquid.
In some embodiments, the purification apparatus of the present disclosure may not apply an additional distillation means or heating means. A purification apparatus that does not contain such means is capable of completing purification at ambient temperature, thus increasing energy efficiency and eliminating the need for additional operations. Therefore, from the perspective of reducing the environmental load, it is advantageous not to employ distillation means or heating means.
The method for purifying a fluorinated liquid and the purification apparatus of the present disclosure can be used as appropriate on-line or off-line in various manufacturing lines. In a case of the on-line, when the method for purifying a fluorinated liquid and the purification apparatus of the present disclosure are used, these may be appropriately configured so that the purified fluorinated liquid can be reused, for example, in a cleaning step or in a rinsing step. If these are used on the off-line, the fluorinated liquid that has been used in a manufacturing line such as a cleaning step or a rinsing step of an organic EL display is purified in another line, and can be used again in the manufacturing line of the organic EL display; on the other hand, the purified fluorinated liquid can be reused for another purpose other than the use, for example, for a cleaning liquid or a rinse liquid for a printed wiring board.
The fluorinated liquid purified using the method for purifying a fluorinated liquid and the purification apparatus of the present disclosure is not limited to the following, and for example, it is used in the organic EL display manufacturing apparatus, and can be used as a cleaning liquid or a rinse liquid for various electronic parts, precision parts, metal parts, printed wiring boards and the like, in addition to the rinse liquids for various members such as metal masks and deposition-proof plates exposed to cleaning and rinsing operations. Here, the“deposition-proof plate” refers to a member disposed inside a vacuum chamber of a vacuum evaporation apparatus used in the manufacture of an organic EL display, and is a member that can be removed and cleaned to prevent contamination of the vacuum chamber from the three colors of red (R), green (G), and blue (B), which are evaporation sources. The use of the rinse liquid is not limited to direct use as a liquid, for example, in which a cleaning agent or the like that is deposited is rinsed off by immersing a material to be rinsed and cleaned into the rinse liquid, but includes the use in which the rinse liquid is evaporated to adhere the vaporized gas on a surface to be rinsed and cleaned to rinse off the cleaning agent or the like.
Examples
Specific embodiments of the present invention will be exemplified in the following examples, but the present invention is not limited to these embodiments.
Products and the like used in the examples are shown in Table 1 below. [Table 1]
The purity of the fluorinated liquid was evaluated by gas chromatography using 7890 A manufactured by Agilent Technologies. The measurement conditions of the gas chromatography method are as follows:
Column Type: HP-1301
Column length: 60 m
Column Temperature: 260°C
Type of carrier gas: Helium gas
Flow rate of carrier gas: 205 mL/min
Sample injection volume: 1 pL
Example 1
100 g of NOVEC (TM) 7100 (fluorinated liquid) and 10 g of NMP (cleaning agent) were added to a plastic bottle. 0.2 g of distilled water was added to a mixed solution and shaken for 15 minutes in a mechanical shaker. The resulting mixed solution was then left to separate into two layers of an upper layer (aqueous phase) and a lower layer (phase containing a fluorinated liquid), the upper layer was removed from the plastic bottle by collecting the upper layer (aqueous phase) floating on the surface with a dropper (first extraction step). Samples for purity measurements were collected from the lower layer liquid using a microsyringe, and the purity of the NOVEC (TM) 7100 in the lower layer liquid was measured. A series of operations from addition of distilled water to the purity measurements were performed four times in total, and the results of which are shown in Table 2. Here, the addition of 0.2 g of distilled water after the second time was performed on the lower layer liquid obtained by removing the upper layer (aqueous phase). Furthermore, the“amount of water after water contact (mass%)” in Table 2 is a value calculated as a percentage of the total added amount of water relative to the total added amount of water and the initial blending amount (10 g) of the cleaning agent (NMP). <Examples 2 to 5 and Comparative Examples 1 and 2>
The purity of the fluorinated liquid was measured in the same manner as in Example 1 except that the added amount of distilled water was changed to the amount shown in Table 2. Note that since the amount of water after the water contact exceeded 30.0 mass%, the extraction step after the fourth time in Example 4 and the third or subsequent extraction step in Example 5 were not performed. Furthermore, in Comparative Example 1, in the second extraction step, the amount of water after water contact was already greater than 30.0 mass% in the first extraction step in Comparative Example 2, and the subsequent extraction step was not performed.
It will be apparent to those skilled in the art that various modifications can be made to the embodiments and the examples described above without departing from the basic principles of the present invention. In addition, it will be apparent to those skilled in the art that various improvements and modifications of the present invention can be carried out without departing from the spirit and the scope of the present invention.