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Title:
FLUORINATED LIQUID REGENERATION METHOD AND REGENERATION APPARATUS USING SUCH METHOD
Document Type and Number:
WIPO Patent Application WO/2019/142113
Kind Code:
A1
Abstract:
The fluorinated liquid regeneration method of an embodiment of the present disclosure includes the steps of bringing a fluorinated liquid contaminated with a detergent into contact with water to make concentration of a detergent of an aqueous phase located on an upper layer be less than 80 mass%; and separating a mixed liquid obtained after the water contact into two liquids of an aqueous phase located on the upper layer and a fluorinated liquid located on a lower layer, and then removing the liquid of the upper layer and collecting the liquid of the lower layer; wherein the detergent is an aprotic polar solvent dissolving in the fluorinated liquid and the fluorinated liquid is a hydrofluoroether, a hydrofluoroolefin, or a mixture thereof.

Inventors:
KIMURA, Tamami (6-7-29 Kitashinagawa, Shinagawa-ku, Tokyo, 〒141-8684, JP)
SAITO, Yusuke (6-7-29 Kitashinagawa, Shinagawa-ku, Tokyo, 〒141-8684, JP)
Application Number:
IB2019/050343
Publication Date:
July 25, 2019
Filing Date:
January 16, 2019
Export Citation:
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Assignee:
3M INNOVATIVE PROPERTIES COMPANY (3M Center, Post Office Box 33427Saint Paul, Minnesota, 55133-3427, US)
International Classes:
C11D7/50; B08B3/04; C23C14/24; C23G1/36; H01L51/50
Foreign References:
JP2008163400A2008-07-17
US20050263173A12005-12-01
JP2006313753A2006-11-16
Attorney, Agent or Firm:
BRAMWELL, Adam M., et al. (3M Center, Office of Intellectual Property CounselPost Office Box 3342, Saint Paul Minnesota, 55133-3427, US)
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Claims:
What is claimed:

1. A fluorinated liquid regeneration method comprising the steps of:

bringing a fluorinated liquid contaminated with a detergent into contact with water to make concentration of a detergent of an aqueous phase located on an upper layer be less than 80 mass%; and

separating a mixed liquid, obtained after the water contact, into two liquids of an aqueous phase located on the upper layer and a fluorinated liquid located on a lower layer, and then removing the liquid of the upper layer and collecting the liquid of the lower layer; wherein

the detergent is an aprotic polar solvent dissolving in the fluorinated liquid and the fluorinated liquid is a hydrofluoroether, a hydrofluoroolefm, or a mixture thereof.

2. The regeneration method according to claim 1, wherein the aprotic polar solvent is a cyclic amide-based solvent, an amine-based solvent, a glycol ether-based solvent, acetone, dimethyl sulfoxide, dimethylformamide, or a mixed solvent thereof.

3. The regeneration method according to claim 1 or 2, wherein purity of a fluorinated liquid in the liquid of the lower layer collected is not less than 95%.

4. The regeneration method according to claim 1 or 2, further comprising a step of distilling the liquid of the lower layer subsequent to the step of collecting the liquid of the lower layer.

5. The regeneration method according to claim 4, wherein purity of a fluorinated liquid in the liquid of the lower layer collected by the distillation is not less than 99.0%.

6. A method of using the fluorinated liquid regenerated by using the regeneration method according to any one of claims 1 to 5, as a rinse liquid for a member, used in an organic EL display manufacturing apparatus.

7. The method according to claim 6, wherein the member is a metal mask or a deposition prevention sheet.

8. A fluorinated liquid regeneration apparatus comprising:

means for bringing a fluorinated liquid contaminated with a detergent into contact with water to make concentration of a detergent of an aqueous phase located on an upper layer be less than 80 mass%; and

means for separating a mixed liquid obtained after the water contact into two liquids of an aqueous phase located on the upper layer and a fluorinated liquid located on a lower layer, and then removing the liquid of the upper layer and collecting the liquid of the lower layer; wherein

the detergent is an aprotic polar solvent dissolving in the fluorinated liquid and the fluorinated liquid is a hydrofluoroether, a hydrofluoroolefm, or a mixture thereof.

9. The fluorinated liquid regeneration apparatus according to claim 8, further comprising means for distilling the liquid of the lower layer subsequent to the means for collecting the liquid of the lower layer.

Description:
FLUORINATED LIQUID REGENERATION METHOD AND

REGENERATION APPARATUS USING SUCH METHOD

TECHNICAL FIELD

The present disclosure relates to a fluorinated liquid regeneration method and a regeneration apparatus using such a method.

BACKGROUND ART

For example, a method of manufacturing an organic EL display (sometimes referred to as an“OLED” hereinafter) includes a step of vapor-depositing RGB tricolor pigments 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 through a step of washing with an N-methyl-2-pyrrolidone (sometimes referred to as“NMP” hereinafter) solution and then rinsing with a fluorinated liquid and a step of drying.

Patent Document 1 (JP 2006-313753 A) describes a washing method in which a metal mask used in the vacuum vapor deposition step in manufacturing a

low-molecular- weight organic EL element is washed by dipping or water jet using a washing liquid composition containing an aprotic polar solvent such as

N-methyl-2-pyrrolidone, and then rinsed with a hydrofluoroether.

Patent Document 2 (JP 07-076787 A) describes a metal detergent regeneration apparatus including: a washing apparatus using NMP as a metal detergent, and a regeneration apparatus configured to remove a contaminant from an NMP washing liquid obtained after washing and recirculate the NMP washing liquid to the washing apparatus; wherein a filter medium provided inside the regeneration apparatus is a granular filter medium containing at least polypropylene and is buoyant in NMP.

Patent Document 3 (JP 2008-163400 A) describes a washing system including: a washing tank configured to hold a washing liquid including as a main component one or more types selected from (la) hydrocarbons, (lb) glycol ethers, and (lc) esters, into which an article to be washed is dipped; a rinse liquid tank configured to hold a rinse liquid including as a main component one or more types selected from (2a) hydrofluorocarbons and (2b) hydrofluoroethers, into which an article to be washed is dipped; a vapor tank configured to hold the rinse liquid and produce vapor of the rinse liquid; and a regeneration unit including a distiller. PRIOR ART DOCUMENTS

Patent Document 1 : JP 2006-313753 A

Patent Document 2: JP 07-076787 A

Patent Document 3: JP 2008-163400 A

SUMMARY OF THE INVENTION

As the number of times a metal mask is washed and rinsed increases, a contamination ratio of a detergent in the rinsing tank increases. As a result, the rinsing tank ends up being contaminated with the detergent, and thus the rinse liquid has needed to be replaced periodically. However, since a fluorinated liquid used as the rinse liquid is also an expensive solvent, the fluorinated liquid has generally been recovered from the contaminated rinse liquid by using distillation means and then reused.

However, in the current state of the art, since a quantity of the fluorinated liquid that can be recovered by such distillation means is extremely low, a majority of the fluorinated liquid is discarded.

The present disclosure provides a fluorinated liquid regeneration method having excellent regeneration efficiency of a fluorinated liquid contaminated with a detergent, and a regeneration apparatus using such a method.

MEANS FOR SOLVING THE PROBLEM

According to an embodiment of the present disclosure, provided is a fluorinated liquid regeneration method including the steps of: bringing a fluorinated liquid contaminated with a detergent into contact with water to make concentration of a detergent of an aqueous phase located on an upper layer be less than approximately 80 mass%; and separating a mixed liquid, obtained after the water contact, into two liquids of an aqueous phase located on the upper layer and a fluorinated liquid located on a lower layer, and then removing the liquid of the upper layer and collecting the liquid of the lower layer; wherein the detergent is an aprotic polar solvent dissolving in the fluorinated liquid and the fluorinated liquid is a hydrofluoroether, a hydrofluoroolefin, or a mixture thereof.

According to another embodiment of the present disclosure, provided is a method of using the fluorinated liquid regenerated by using the above-described regeneration method as a rinse liquid for a member used in an organic EL display manufacturing apparatus. According to yet another embodiment of the present disclosure, provided is a fluorinated liquid regeneration apparatus including: means for bringing a fluorinated liquid contaminated with a detergent into contact with water to make concentration of a detergent of an aqueous phase located on an upper layer be less than approximately 80 mass%; and means for separating a mixed liquid obtained after the water contact into two liquids of an aqueous phase located on the upper layer and a fluorinated liquid located on a lower layer, and then removing the liquid of the upper layer and collecting the liquid of the lower layer; wherein the detergent is an aprotic polar solvent dissolving in the fluorinated liquid and the fluorinated liquid is a hydrofluoroether, a

hydrofluoroolefm, or a mixture thereof.

EFFECT OF THE INVENTION

The fluorinated liquid regeneration method and the regeneration apparatus of the present disclosure can improve regeneration efficiency of a fluorinated liquid contaminated with a detergent.

Further, in several examples of the present disclosure, an additional distillation step and a heating step can be eliminated by bringing about sufficient separation. In these examples, since the process is completed at room temperature, energy efficiency is higher and an additional operation becomes unnecessary.

The above description should not be construed as indicating that all embodiments of the present disclosure and all advantages related to the present disclosure have been disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. l is a graph showing a relationship between detergent concentration in water, and purity and an output in each of various fluorinated liquids in using NMP as a detergent and using a fluorinated liquid regeneration method according to an embodiment of the present disclosure.

FIG. 2 is a view illustrating a relationship of discarded quantities of fluorinated liquids obtained after regeneration, based on a fluorinated liquid regeneration method using distillation only and a fluorinated liquid regeneration method according to an embodiment of the present disclosure. DESCRIPTION OF THE PREFERRED EMBODIMENTS

A fluorinated liquid regeneration method in a first embodiment of the present disclosure includes the steps of: bringing a fluorinated liquid contaminated with a detergent into contact with water to make concentration of a detergent of an aqueous phase located on an upper layer be less than approximately 80 mass%; and separating a mixed liquid obtained after the water contact into two liquids of an aqueous phase located on the upper layer and a fluorinated liquid located on a lower layer, and then removing the liquid of the upper layer and collecting the liquid of the lower layer; wherein the detergent is an aprotic polar solvent dissolving in the fluorinated liquid and the fluorinated liquid is a hydrofluoroether, a hydrofluoroolefm, or a mixture thereof. The regeneration method of the present disclosure can regenerate a fluorinated liquid having high purity with a high output (yield) simply by bringing a prescribed quantity of water into contact with a mixed system containing a specific detergent and a specific fluorinated liquid.

The aprotic polar solvent in the fluorinated liquid regeneration method in the first embodiment may be a cyclic amide-based solvent, an amine-based solvent, a glycol ether-based solvent, acetone, dimethyl sulfoxide, dimethylformamide, or a mixed solvent thereof. A combination of such aprotic polar solvents can further improve fluorinated liquid regeneration efficiency. Among these, when the aprotic polar solvent in the fluorinated liquid regeneration method in the first embodiment is a cyclic amide-based solvent, the fluorinated liquid regeneration efficiency can further be improved. Here, the regeneration efficiency refers to efficiency determined from purity, an output, and the like of the fluorinated liquid regenerated. When the fluorinated liquid can be regenerated with high purity and a high output, the regeneration efficiency is said to be excellent.

In the fluorinated liquid regeneration method in the first embodiment, purity of the fluorinated liquid in the liquid of the lower layer collected can be not less than approximately 95%.

The fluorinated liquid regeneration method in the first embodiment can further include the step of distilling the liquid of the lower layer subsequent to the step of collecting the liquid of the lower layer. The distillation step is further applied and thus, a fluorinated liquid having higher purity can be regenerated. In the fluorinated liquid regeneration method in the first embodiment, when the distillation step is employed, purity of the fluorinated liquid in the liquid collected by the distillation can be not less than approximately 99.0%.

A method of use, as a rinse liquid for a member, used in an organic EL display manufacturing apparatus in a second embodiment of the present disclosure can use the fluorinated liquid regenerated by using the fluorinated liquid regeneration method in the first embodiment. Examples of the member can include a metal mask and a deposition prevention sheet. In the fluorinated liquid regeneration method in the first embodiment, since a quantity of the fluorinated liquid to be discarded can be reduced greatly as compared to a conventional regeneration method using distillation only, the method in the second embodiment using the fluorinated liquid obtained by the regeneration method of the first embodiment can further reduce a manufacturing cost of an organic EL display.

A fluorinated liquid regeneration apparatus in a third embodiment of the present disclosure includes means for bringing a fluorinated liquid contaminated with a detergent into contact with water to make concentration of a detergent of an aqueous phase located on an upper layer be less than approximately 80 mass%; and means for separating a mixed liquid obtained after the water contact into two liquids of an aqueous phase located on the upper layer and a fluorinated liquid located on a lower layer, and then removing the liquid of the upper layer and collecting the liquid of the lower layer; wherein the detergent is an aprotic polar solvent dissolving in the fluorinated liquid and the fluorinated liquid is a hydrofluoroether, a hydrofluoroolefm, or a mixture thereof. The regeneration apparatus of the present disclosure can regenerate a fluorinated liquid having high purity with a high output (yield) in a mixed system containing a specific detergent and a specific fluorinated liquid.

The fluorinated liquid regeneration apparatus in the third embodiment can further include means for distilling the liquid of the lower layer subsequent to the means for collecting the liquid of the lower layer. The distillation step is further applied and thus, a fluorinated liquid having higher purity can be regenerated.

Typical embodiments of the present disclosure will be described in further detail below for the purpose of exemplification, but the present disclosure is not limited to these embodiments. Fluorinated liquid regeneration method

The fluorinated liquid regeneration method of an embodiment of the present disclosure includes steps of: bringing a fluorinated liquid contaminated with a detergent into contact with water to make concentration of a detergent of an aqueous phase located on an upper layer be less than approximately 80 mass% (sometimes referred to as a“water contact step” hereinafter); and separating a mixed liquid obtained after the water contact into two liquids of an aqueous phase located on the upper layer and a fluorinated liquid located on a lower layer, and then removing the liquid of the upper layer and collecting the liquid of the lower layer (sometimes referred to as a“separation and collection step” hereinafter); wherein the detergent is an aprotic polar solvent dissolving in the fluorinated liquid and the fluorinated liquid is a hydrofluoroether, a hydrofluoroolefm, or a mixture thereof.

Detergent

The detergent that can be a contaminant in the fluorinated liquid regeneration method of the present disclosure is a detergent used in washing of various members. An example of the detergent includes a detergent used in washing various members such as a metal mask and a deposition prevention sheet in an organic EL display manufacturing apparatus. Such a detergent may be any detergent as long as the detergent is an aprotic polar solvent dissolving in the fluorinated liquid. Examples of the detergent include but are not limited to a cyclic amide-based solvent, an amine-based solvent, a glycol ether-based solvent, acetone, dimethyl sulfoxide, dimethylformamide or a mixture thereof. From the perspective of ability to wash a metal mask or a deposition prevention sheet, a cyclic amide-based solvent is preferably used, and among cyclic amide-based solvents, a solvent called an N-alkyl-pyrrolidone solvent or a g-lactam solvent such as N-methyl-2-pyrrolidone (NMP) and N-butyl-2-pyrrolidone (NBP) is more preferred. As the aprotic polar solvent, one of these solvents can be used alone or two or more of these solvents can be used in combination. As long as the above-described detergents are used, a fluorinated liquid can be regenerated efficiently by the regeneration method of the present disclosure. The detergent may include a detergent other than the above-described detergents within the range where such a detergent does not hinder regeneration efficiency of the fluorinated liquid, but from the perspective of regeneration efficiency and the like, the detergent preferably includes no other detergent. From the perspective of applying the distillation step described below and the like, a boiling point of the detergent is preferably not less than approximately 55°C, not less than approximately l00°C, not less than approximately l50°C, not less than approximately 200°C, or not less than approximately 250°C.

Fluorinated liquid

Examples of the fluorinated liquid that can be regenerated by the fluorinated liquid regeneration method of the present disclosure can include a hydrofluoroether (sometimes abbreviated as“HFE” hereinafter), a hydrofluoroolefm (sometimes abbreviated as“HFO” hereinafter), or a mixture thereof. The fluorinated liquid may also include a fluorinated liquid other than the above-described fluorinated liquids (for example, a hydrochlorofluorocarbon and a hydrofluorocarbon) within the range where such a fluorinated liquid does not hinder regeneration efficiency, but from the perspective of regeneration efficiency and the like, the fluorinated liquid preferably includes no other fluorinated liquid.

From the perspective of applying the distillation step described below and the like, a boiling point of the fluorinated liquid is preferably not less than approximately 30°C, not less than approximately 55°C, not less than approximately 60°C, or not less than approximately 75°C, and not greater than approximately l50°C, not greater than approximately l00°C, or not greater than approximately 80°C.

Hydrofluoroether

Among the above-described fluorinated liquids, a hydrofluoroether is preferably used from the perspective of regeneration efficiency and the like. A hydrofluoroether is a compound containing an ether-bonding oxygen atom between carbon atoms of a hydrofluorocarbon. The number of ether-bonding oxygen atoms present in one molecule of the hydrofluoroether may be 1 or may be 2 or more. From the perspective of a boiling point making it easy to use as a solvent and from the perspective of stability and the like, the number of ether-bonding oxygen atoms present in one molecule of the hydrofluoroether is preferably 1 or 2, and is more preferably 1. A molecular structure of the hydrofluoroether may be of a chain, and may be of a straight chain or a branched chain, but a straight chain is preferred from the perspective of regeneration efficiency and the like. Examples of the hydrofluoroether can include but are not limited to a segregated hydrofluoroether such as C4F9OCH3, C4F9OCH2CH3, C5F11OCH3, C5F11OCH2CH3, C6F13OCH3, C6F13OCH2CH3, C7F15OCH3,

C7F15OCH2CH3, C8F17OCH3, C8F17OCH2CH3, C9F19OCH3, C9F19OCH2CH3,

C10F21OCH3, and C10F21OCH2CH3; and a hydrofluoroether such as

CF3CH2OCF2CF2H, CF3CHFOCH2CF3, CF3CH2OCF2CFHCF3,

CHF2CF2CH2OCF2CF2H, C3F7OC3F6OCFHCF3, CF 3 CF(CF3)CF(OCH3)CF 2 CF3, CF3CF(CF3)CF(OC2H 5 )CF 2 CF3, CF2(0CH 2 CF3)CF 2 H, CF 2 (OCH 2 CF3)CFHCF3, CF 2 (OCH2CF2CF2H)CF 2 H, and CF 2 (OCH 2 CF 2 CF 2 H)CFHCF 3. Among these, since use of a segregated hydrofluoroether can achieve high purity of not less than approximately 97%, not less than approximately 98%, or not less than approximately 99% simply by bringing the segregated hydrofluoroether into contact with water, the segregated hydrofluoroether is a particularly preferred fluorinated liquid. Among these, a particularly preferred segregated hydrofluoroether is C4F9OCH3 and C4F9OCH2CH3. Here,“segregated” means a structure in which ether bonds sandwich an oxygen atom, wherein one ether bond is completely fluorinated and the other is constituted of carbon and hydrogen. As the hydrofluoroether, one of these hydrofluoroethers can be used alone or two or more of these hydrofluoroethers can be used in combination.

Hydrofluoroolefm

A hydrofluoroolefm means a compound in which one or two or more hydrogen atoms present in an olefin are substituted with a fluorine atom. The number of fluorine atoms present in the hydrofluoroolefm is not particularly limited, but can be not less than 1 or not less than 2 and not greater than 10 or not greater than 6. The

hydrofluoroolefm may be of any of an E type (trans type) and a Z type (cis type). The hydrofluoroolefm may be a hydrochlorofluoroolefm (HCFO). A

hydrochlorofluoroolefin means a compound in which one or two or more hydrogen atoms present in an olefin are substituted with a fluorine atom and one or two or more other hydrogen atoms present in the olefin are substituted with a chlorine atom. The number of chlorine atoms present in a hydrochlorofluoroolefm is not particularly limited, but can be not less than 1 and not greater than 5 or not greater than 3. Examples of a hydrofluoroolefm having no chlorine atom include CF3-CH=CH2, CF3-CF=CH2, 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 , CF 3- CH= CF-CH3, CF3-CF=CH-CH 3 , CF 3- CH=CH-CH 2 F, CHF 2- CF=CF-CH3, 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-CF3, 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,

CH 2 F-CHF-CF=CF 2 , CH 2 F-CH 2- CF=CF 2 , CH 3- CF 2- CF=CHF, and

CH 3- CF 2- CH=CF 2. Examples of a hydrofluoroolefm having a chlorine atom (that is, a hydrochlorofluoroolefm) include CF 3- CH=CHC1, CHF 2- CF=CHC1, CHF 2- CH =CFC1, CHF 2- CCl=CHF, CH 2 F-CCl=CF 2 , CHFC1-CF =CHF, CH 2 Cl-CF=CF 2 , and CF 3- CCl=CH 2. A particularly preferred hydrofluoroolefm having a chlorine atom is CF 3- CH=CHC1. AS the hydrofluoroolefm (here also including a

hydrochlorofluoroolefm), one of these hydrofluoroolefins can be used alone or two or more of these hydrofluoroolefins can be used in combination.

Water

The water in the fluorinated liquid regeneration method of the present disclosure may be any water. Examples of the water that can be used include but are not limited to tap water, distilled water, and ion-exchanged water.

Water contact step

The fluorinated liquid regeneration method of the present disclosure includes a step of bringing a fluorinated liquid contaminated with a detergent into contact with water to make concentration of a detergent of a aqueous phase located on an upper layer be less than approximately 80 mass% (water contact step). From the perspective of regeneration efficiency, the concentration of the detergent of the aqueous phase located on the upper layer in the water contact step can be in the range of less than

approximately 75 mass% or the range of less than approximately 70 mass%. A lower limit value of the concentration of the detergent is not particularly limited, but can be, for example, in the range of greater than approximately 10 mass%, the range of greater than approximately 15 mass%, or the range of greater than approximately 20 mass%. Here, the detergent concentration in the aqueous phase located on the upper layer can be measured by, for example, extracting a detergent component from a mixed liquid of the upper layer and analyzing by gas chromatography and a micro moisture measurement apparatus.

Examples of a method of bringing a fluorinated liquid contaminated with a detergent into contact with water include but are not limited to methods of (1) to (7) described below. One of these methods can be employed alone or two or more of these methods can be employed in combination, and portions of the methods of (1) to (7) can be carried out in combination as appropriate. For example, a physical agitation method using shaking, a stirring bar or the like, an agitation method using air, or an agitation method using ultrasound or the like described in (3), (6), or (7) may be applied to the method of (1) or (2).

(1) A method of dripping a fluorinated liquid contaminated with a detergent into a container containing water from above the container.

(2) A method of adding water to a container containing a fluorinated liquid contaminated with a detergent from below the container.

(3) A method of physically agitating a container containing a mixed liquid of a detergent, a fluorinated liquid, and water by using shaking or using a stirring bar or a stirring blade.

(4) A method of connecting, in a container containing a mixed liquid of a detergent, a fluorinated liquid, and water in a state where the mixed liquid has already been separated into two layers, an upper layer and a lower layer with a tube or the like, and transferring an upper layer liquid to the lower layer by gravity or a pump or the like.

(5) A method of connecting, in a container containing a mixed liquid of a detergent, a fluorinated liquid, and water in a state where the mixed liquid has already been separated into two layers, an upper layer and a lower layer with a tube or the like and transferring a lower layer liquid to the upper layer by gravity or a pump or the like.

(6) A method of bubbling, in a container containing a mixed liquid of a detergent, a fluorinated liquid, and water in a state where the mixed liquid has already been separated into two layers, a gas such as air into the container to mix the mixed liquid.

(7) A method of applying, in a container containing a mixed liquid of a detergent, a fluorinated liquid, and water in a state where the mixed liquid has already been separated into two layers, ultrasound into the container to mix the mixed liquid.

Temperature and time used in bringing a fluorinated liquid contaminated with a detergent into contact with water can vary according to needed performance such as purity of a fluorinated liquid regenerated, but examples of the temperature and time can include but are not limited to a temperature in the range of not less than approximately 20°C, not less than approximately 23°C, or not less than approximately 25°C, and not greater than approximately 40°C, not greater than approximately 35°C, or not greater than approximately 30°C.

Separation and collection step

The fluorinated liquid regeneration method of the present disclosure includes a step of separating a mixed liquid obtained after the water contact into two liquids of an aqueous phase located on the upper layer and a fluorinated liquid located on a lower layer, and then removing the liquid of the upper layer and collecting the liquid of the lower layer. The separation into the two liquids of the upper layer and the lower layer can be achieved through the above-described water contact step and subsequently a step of leaving the mixed liquid containing the detergent and the fluorinated liquid to stand.

The lower layer liquid may be collected by, for example, direct collection via a tube or the like from below the container containing the mixed liquid, or by collecting the upper layer liquid from above the container and then collecting the lower layer liquid, or by extending a tube or the like from above the container to near a bottom of the container and collecting the lower layer liquid by suction.

Purity of the lower layer liquid collected in this stage can vary depending on a combination of a detergent and a fluorinated liquid and the like, but generally, the purity of a fluorinated liquid of not greater than approximately 90% prior to the water contact step can be brought to not less than approximately 95%, not less than approximately 96%, or not less than approximately 97%.

Optional steps

In the fluorinated liquid regeneration method of the present disclosure, optionally, one of steps such as a distillation step (for example, a boiling distillation step, a reduced-pressure distillation step, or the like), a cooling and separation step, and the like can be applied alone, or two or more of these steps can be applied in combination as appropriate.

Among the optional steps, when higher purity of a fluorinated liquid regenerated is desired, it is preferable to collect the lower layer liquid and subsequently apply the distillation step to the lower layer liquid. Examples of a distillation temperature in the distillation step can include but are not limited to not less than approximately 70°C, not less than approximately 72°C, or not less than approximately 75°C, and not higher than approximately l00°C, not higher than approximately 95°C, or not higher than approximately 90°C. Purity of a fluorinated liquid in the liquid collected by the distillation can vary depending on a combination of a detergent and a fluorinated liquid, but generally, the purity of not less than approximately 99.0%, not less than approximately 99.2%, or not less than approximately 99.4% can be achieved.

Fluorinated liquid regeneration apparatus

A fluorinated liquid regeneration apparatus of an embodiment of the present disclosure includes means for bringing a fluorinated liquid contaminated with a detergent into contact with water to make concentration of a detergent of an aqueous phase located on an upper layer be less than 80 mass% (sometimes referred to as“water contact means” hereinafter); and means for separating a mixed liquid, obtained after the water contact, into two liquids of an aqueous phase located on the upper layer and a fluorinated liquid located on a lower layer, and then removing the liquid of the upper layer and collecting the liquid of the lower layer (sometimes referred to as“separation and collection means” hereinafter); wherein the detergent is an aprotic polar solvent dissolving in the fluorinated liquid and the fluorinated liquid is a hydrofluoroether, a hydrofluoroolefm, or a mixture thereof. The detergent, the fluorinated liquid, and the water used in the above-described regeneration apparatus are the same as those used in the above-described regeneration method.

Water contact means

As the water contact means in the fluorinated liquid regeneration apparatus of the present disclosure, any kind of means can be employed as long as such means can apply the water contact step in the above-described fluorinated liquid regeneration method. For example, materials, volume, shapes, quantities, disposition locations and the like of containers configured to hold the detergent, the fluorinated liquid, and the water (sometimes referred to as“tanks”) can be selected as appropriate according to usage application or a usage environment of the apparatus, and the like.

Separation and collection means

As the separation and collection means in the fluorinated liquid regeneration apparatus of the present disclosure, any kind of means can be employed as long as such means can apply the separation and collection step in the above fluorinated liquid regeneration method. For example, materials, volume, shapes, quantities, disposition locations and the like of containers configured to hold the separated liquids (sometimes referred to as“tanks”) can be selected as appropriate according to usage application or a usage environment of the apparatus, and the like.

Optional means

In the fluorinated liquid regeneration apparatus of the present disclosure, any kind of means can be employed as long as such means can apply the optional steps such as the distillation step (for example, a boiling distillation step, a reduced-pressure distillation step, or the like) and the cooling and separation step in the above-described fluorinated liquid regeneration method. For example, a material, volume, a shape, a quantity, a disposition location and the like of a container configured to store the lower layer liquid used at the distillation step and the like can be selected as appropriate according to usage application or a usage environment of the apparatus, and the like. One of the various kinds of means such as the distillation means and the cooling and separation means can be applied alone to the fluorinated liquid regeneration apparatus, or two or more of the various kinds of means can be applied in combination to the fluorinated liquid regeneration apparatus.

Among the optional means, when higher purity of a fluorinated liquid regenerated is desired, it is preferable to collect the lower layer liquid and subsequently add the distillation means for distilling the lower layer liquid. As the distillation means, a conventional apparatus including a distillation still configured to store and heat a lower layer liquid collected, and a cooler connected in communication to the distillation still and configured to condense vapor of the lower layer liquid can be used.

Usage application of fluorinated liquid regenerated

The fluorinated liquid regeneration method and the regeneration apparatus of the present disclosure can be used online or offline in, for example, an organic EL display manufacturing step. When the fluorinated liquid regeneration method and the regeneration apparatus of the present disclosure are used online, the fluorinated liquid regeneration method and the regeneration apparatus may be configured as appropriate to enable the fluorinated liquid regenerated to be input again to a washing step. When the fluorinated liquid regeneration method and the regeneration apparatus are used offline, the fluorinated liquid regenerated can be reused in the washing step of the organic EL display manufacturing step, while the fluorinated liquid regenerated can also be reused in application different from such an application, and for example, can be reused as a rinse liquid for a printed circuit board.

The fluorinated liquid regenerated and obtained by the fluorinated liquid regeneration method and the regeneration apparatus of the present disclosure can be used, but not limited to, for example, in an organic EL display manufacturing apparatus, and as a rinse liquid for each of various members such as a metal mask and a deposition prevention sheet exposed to washing and rinsing operations, and also as a rinse liquid for each of various electronic parts, precision parts, metal parts, printed circuit boards and the like. Here, the deposition prevention sheet refers to, for example, a member disposed on an inner side of a vacuum chamber of a vacuum vapor deposition apparatus used in manufacturing an organic EL display, and is a member that can be removed and washed to prevent contamination of the vacuum chamber by RGB tricolor pigments being evaporation sources. The use as a rinse liquid is not limited to direct use as a liquid for dipping an article to be washed to rinse off a detergent and the like attached, but also includes indirect use for evaporating the rinse liquid and attaching an evaporated gas to a surface of an article to be washed to rinse off a detergent and the like.

EXAMPLES

Examples 1 to 22 and Comparative Examples 1 to 3

Specific embodiments of the present disclosure are exemplified in examples described below, but the present disclosure is not limited to the embodiments.

Products and the like used in the present examples are shown in Table 1. Table 1

Evaluation method

Collected liquids were evaluated as described below. Purity evaluation

Purity of fluorinated liquids regenerated was evaluated by gas chromatography by using model 7890A available from Agilent Technologies, Inc. Measurement conditions of the gas chromatography are as follows.

Column type: HP-1301

Column length: 60 m

Column temperature: 260°C

Carrier gas type: Helium gas Carrier gas flow rate: 205 mL/minute

Sample injection quantity: 1 pL

Moisture content evaluation

Moisture contents in lower layer liquids collected after the water contact step were measured by using a micro moisture measurement apparatus available from Mitsubishi Chemical Corporation.

Test 1 : Purity of various fluorinated liquids obtained after water contact step

Example 1

100 g of NOVEC (trade name) 7100 (fluorinated liquid) and 10 g of NMP (detergent) were individually added to a sample bottle and shaken for 30 minutes. 40 g of distilled water was added to this mixed liquid and shaken for another 30 minutes. Then, the obtained mixed liquid was transferred to a separating funnel, and left to stand until the mixed liquid separated into two layers of an upper layer and a lower layer. A lower layer liquid of the liquid separated into the two layers was collected, and purity of NOVEC (trade name) 7100 being the fluorinated liquid in the lower layer liquid was measured. The results are shown in Table 2. Note that an aprotic polar solvent detergent transfers to the distilled water side more readily than a fluorinated liquid, but since a proportion of a quantity of the detergent relative to a total quantity of the distilled water and the detergent (sometimes referred to as“detergent concentration in water” hereinafter) is 20 mass%, concentration of the detergent of a aqueous phase located on the upper layer does not exceed 20 mass%.

Example 2

Purity was measured in the same manner as in Example 1 except that NOVEC (trade name) 7200 was used instead of NOVEC (trade name) 7100.

Example 3

Purity was measured in the same manner as in Example 1 except that 1233Z was used instead of NOVEC (trade name) 7100. Example 4

Purity was measured in the same manner as in Example 1 except that Asahiklin (trade name) AE-3000 was used instead of NOVEC (trade name) 7100.

Example 5

100 g of NOVEC (trade name) 7100 (fluorinated liquid) and 5 g of NBP (detergent) were individually added to a sample bottle and shaken for 30 minutes. 10 g of distilled water was added to this mixed liquid and shaken for another 30 minutes. Then, the obtained mixed liquid was transferred to a separating funnel, and left to stand until the mixed liquid separated into two layers of an upper layer and a lower layer. A lower layer liquid of the liquid separated into the two layers was collected, and purity of NOVEC (trade name) 7100 being the fluorinated liquid in the lower layer liquid was measured. The results are shown in Table 2. Note that since detergent concentration in water in a mode of the present example is 33.3 mass%, concentration of the detergent of an aqueous phase located on the upper layer does not exceed 33.3 mass%.

Example 6

Purity was measured in the same manner as in Example 5 except that NOVEC (trade name) 7200 was used instead of NOVEC (trade name) 7100.

Example 7

Purity was measured in the same manner as in Example 5 except that 1233Z was used instead of NOVEC (trade name) 7100.

Example 8

Purity was measured in the same manner as in Example 5 except that Asahiklin (trade name) AE-3000 was used instead of NOVEC (trade name) 7100.

Example 9

100 g of NOVEC (trade name) 7100 (fluorinated liquid) and 10 g of

TETRAGLYME (detergent) were individually added to a sample bottle and shaken for 30 minutes. 80 g of distilled water was added to this mixed liquid and shaken for another 30 minutes. Then, the obtained mixed liquid was transferred to a separating funnel, and left to stand until the mixed liquid separated into two layers of an upper layer and a lower layer. A lower layer liquid of the liquid separated into the two layers was collected, and purity of NOVEC (trade name) 7100 being the fluorinated liquid in the lower layer liquid was measured. The results are shown in Table 2. Note that since detergent concentration in water in a mode of the present example is 11.1 mass%, concentration of the detergent of an aqueous phase located on the upper layer does not exceed 11.1 mass%.

Example 10

Purity was measured in the same manner as in Example 9 except that NOVEC (trade name) 7200 was used instead of NOVEC (trade name) 7100.

Example 11

Purity was measured in the same manner as in Example 9 except that Asahiklin (trade name) AE-3000 was used instead of NOVEC (trade name) 7100.

Example 12

100 g of NOVEC (trade name) 7100 (fluorinated liquid) and 10 g of AC (detergent) were individually added to a sample bottle and shaken for 30 minutes. 80 g of distilled water was added to this mixed liquid and shaken for another 30 minutes. Then, the obtained mixed liquid was transferred to a separating funnel, and left to stand until the mixed liquid separated into two layers of an upper layer and a lower layer. A lower layer liquid of the liquid separated into the two layers was collected, and purity of NOVEC (trade name) 7100 being the fluorinated liquid in the lower layer liquid was measured. The results are shown in Table 2. Note that since detergent concentration in water in a mode of the present example is 11.1 mass%, concentration of the detergent of an aqueous phase located on the upper layer does not exceed 11.1 mass%.

Example 13

Purity was measured in the same manner as in Example 12 except that NOVEC (trade name) 7200 was used instead of NOVEC (trade name) 7100.

Example 14

100 g of 1233Z (fluorinated liquid) and 10 g of DMSO (detergent) were individually added to a sample bottle and shaken for 30 minutes. 10 g of distilled water was added to this mixed liquid and shaken for another 30 minutes. Then, the obtained mixed liquid was transferred to a separating funnel, and left to stand until the mixed liquid separated into two layers of an upper layer and a lower layer. A lower layer liquid of the liquid separated into the two layers was collected, and purity of 1233Z being the fluorinated liquid in the lower layer liquid was measured. The results are shown in Table 2. Note that since detergent concentration in water in a mode of the present example is 50 mass%, concentration of the detergent of an aqueous phase located on the upper layer does not exceed 50 mass%.

Example 15

Purity was measured in the same manner as in Example 14 except that Asahiklin (trade name) AE-3000 was used instead of 1233Z.

Example 16

100 g of NOVEC (trade name) 7100 (fluorinated liquid) and 10 g of DMF (detergent) were individually added to a sample bottle and shaken for 30 minutes. 10 g of distilled water was added to this mixed liquid and shaken for another 30 minutes. Then, the obtained mixed liquid was transferred to a separating funnel, and left to stand until the mixed liquid separated into two layers of an upper layer and a lower layer. A lower layer liquid of the liquid separated into the two layers was collected, and purity of NOVEC (trade name) 7100 being the fluorinated liquid in the lower layer liquid was measured. The results are shown in Table 2. Note that since detergent concentration in water in a mode of the example is 50 mass%, concentration of the detergent of an aqueous phase located on the upper layer does not exceed 50 mass%.

Example 17

Purity was measured in the same manner as in Example 16 except that NOVEC (trade name) 7200 was used instead of NOVEC (trade name) 7100.

Example 18

Purity was measured in the same manner as in Example 16 except that 1233Z was used instead of NOVEC (trade name) 7100. Example 19

100 g of Asahiklin (trade name) AE-3000 (fluorinated liquid) and 10 g of DMF (detergent) were individually added to a sample bottle and shaken for 30 minutes. 80 g of distilled water was added to this mixed liquid and shaken for another 30 minutes. Then, the obtained mixed liquid was transferred to a separating funnel, and left to stand until the mixed liquid separated into two layers of an upper layer and a lower layer. A lower layer liquid of the liquid separated into the two layers was collected, and purity of Asahiklin (trade name) AE-3000 being the fluorinated liquid in the lower layer liquid was measured. The results are shown in Table 2. Note that since detergent

concentration in water in a mode of the present example is 11.1 mass%, concentration of the detergent of an aqueous phase located on the upper layer does not exceed 11.1 mass%.

Table 2

Results

As is clear from the results in Table 2, it was able to confirm that when the fluorinated liquid regeneration method of the present disclosure is used, the fluorinated liquid can be regenerated at purity of not less than approximately 95% simply by bringing the fluorinated liquid into contact with water.

Test 2: Regeneration status of various fluorinated liquids obtained after water contact step

Example 20

Purity (%) was measured and an output (g) of each of lower layer liquids collected was further measured in the same manner as in Example 1 except that the water contact step was carried out with various added quantities of distilled water as follows: 2.5 g (detergent concentration in water: 80.0 mass%), 5 g (detergent concentration in water: 66.7 mass%), 10 g (detergent concentration in water: 50.0 mass%), 20 g (detergent concentration in water: 33.3 mass%), 40 g (detergent concentration in water: 20.0 mass%), 60 g (detergent concentration in water: 14.3 mass%), and 80 g (detergent concentration in water: 11.1 mass%). A graph based on a value obtained by multiplying the measured purity and the measured output

(sometimes referred to as a“regeneration value” hereinafter) and based on detergent concentration in water (mass%) is shown in FIG. 1. Here, in relation to FIG. 1, a higher regeneration value means a better fluorinated liquid regeneration status.

Example 21

Purity and an output were measured in the same manner as in Example 20 except that NOVEC (trade name) 7200 was used instead of NOVEC (trade name) 7100. A graph based on these results is shown in FIG. 1.

Comparative Example 1

Purity and an output were measured in the same manner as in Example 20 except that VERTREL (trade name) XF was used instead of NOVEC (trade name) 7100. A graph based on these results is shown in FIG. 1.

Comparative Example 2

Purity and an output were measured in the same manner as in Example 20 except that Asahiklin (trade name) AK-225 was used instead of NOVEC (trade name) 7100. A graph based on these results is shown in FIG. 1.

Results

As is clear from the results in FIG. 1, it was able to confirm that any of the modes of Examples 20 and 21 corresponding to the regeneration method of the present disclosure achieves a higher regeneration value than in the modes of Comparative Examples 1 and 2 using a hydrofluorocarbon and a hydrochlorofluorocarbon and thus, the regeneration through the water contact step has a significant action on a fluorinated liquid other than a hydrofluorocarbon and a hydrochlorofluorocarbon. In particular, it was able to confirm that in any of the modes of Examples 20 and 21, the regeneration value is excellent when the detergent concentration in water is from approximately 30.0 mass% to approximately 60.0 mass%. This corresponds to a case where the water contact was performed to make the concentration of the detergent of the aqueous phase located on the upper layer be generally greater than approximately 30.0 mass% and less than approximately 60.0 mass%.

Test 3: Combination of water contact step and distillation step

Example 22

100 g of Asahiklin (trade name) AE-3000 (HFE-347pc-f) and 10 g of NMP were individually added to a sample bottle and shaken for 30 minutes. 40 g of distilled water was added to this mixed liquid and shaken for another 30 minutes to produce a mixed liquid containing Asahiklin (trade name) AE-3000 (HFE-347pc-f), water, and NMP in a ratio of 100:40: 10. Then, the mixed liquid was transferred to a separating funnel, and left to stand until the mixed liquid separated into two layers of an upper layer and a lower layer. A lower layer liquid of the liquid separated into the two layers was collected and then transferred into a distillation flask of a general distiller used at an experimental level, and distillation was started at approximately 80°C. Assuming that a time point at which a temperature of a thermometer installed near an inlet of a Liebig condenser dropped was end timing, the lower layer liquid was separated into a fluorinated liquid regenerated and a residue to be discarded. A range of the flow and the results are illustrated on the right side of FIG. 2. Note that a total of a quantity of the fluorinated liquid regenerated and a quantity of the fluorinated liquid present in the residue of less than 100 g is considered to be an experimental error.

Comparative Example 3

80 g of Asahiklin (trade name) AE-3000 (HFE-347pc-f) and 20 g of NMP were individually added to a sample bottle and shaken for 30 minutes. This mixed liquid was distilled by using the same distillation apparatus and distillation conditions as in Example 22, and was separated into a fluorinated liquid regenerated and a residue to be discarded. A range of the flow and the results are illustrated on the left side of FIG. 2.

Results

It is deduced by using a calibration curve and the like that when the mixed liquid containing the fluorinated liquid and the detergent is distilled at approximately 80°C, the residue contains the detergent and the fluorinated liquid at a ratio of approximately 30% and approximately 70%. In Comparative Example 3 corresponding to a conventional fluorinated liquid regeneration method using distillation only, when the mixed liquid was distilled at approximately 80°C, only 33.3 g of the fluorinated liquid (HFE-347pc-f) was able to be regenerated and the remaining 46.7 g of the fluorinated liquid could not be separated from the detergent (NMP) and thus had to be discarded, as illustrated on the left side of FIG. 2. That is, the quantity of the fluorinated liquid that had to be discarded was 58.4% of the fluorinated liquid present in the mixed liquid obtained before the regeneration. On the other hand, in Example 22

corresponding to the fluorinated liquid regeneration method of the present disclosure employing the distillation step, a majority of the detergent had already been removed in the lower layer liquid collected through the water contact step and the separation and collection step and thus, when the lower layer liquid was distilled at approximately

80°C, 92.6 g of the fluorinated liquid was able to be regenerated and a quantity of the fluorinated liquid to be discarded was able to be held to a very small quantity of 5.8 g, as illustrated on the right side of FIG. 2. That is, the quantity of the fluorinated liquid that had to be discarded (this quantity includes an error of 1.6 g in addition to the 5.8 g of the fluorinated liquid in the residue) was only 7.4% of the fluorinated liquid present in the mixed liquid obtained before the regeneration. Thus, it was able to confirm that the fluorinated liquid regeneration method of the present disclosure employing the distillation step reduces the quantity of the fluorinated liquid to be discarded by 87.3% as compared to the conventional regeneration method using distillation only.

It is obvious to a person skilled in the art that the above-described embodiments and examples can be modified variously without deviating from the basic principles of the present invention. Furthermore, it is obvious to a person skilled in the art that various improvements and modifications of the present invention can be carried out without deviating from the spirit and scope of the present invention.




 
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