JP2008229408A - Liquid separation method and liquid separation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid separation method increased in interlaminar differential pressure and having a good permeation speed (high treatment speed). <P>SOLUTION: In the liquid separation method constituted so that a mixed liquid containing a resist is supplied to one side of a separation membrane so as to come into contact with the one side of the separation membrane and a component, of which the molecular weight is lower than that of the resist, is selectively permeated to the other side of the separation membrane while recovering the resist not having permeated through the separation membrane, the mixed liquid is supplied so as to pressurize the one side of the separation membrane and the other side of the separation membrane is reduced in pressure. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid separation method and a liquid separation system. More specifically, the present invention relates to a liquid separation method and a liquid separation system having a good permeation rate using the pervaporation separation method.

  Conventionally, when separating a dissolved component from a mixed liquid of a solvent and a dissolved component (specific component), an osmotic vapor separation method (pervaporation method) that separates by applying a boiling point difference between the solvent and the dissolved component has been used. It has been. In this pervaporation separation method, for example, a separation membrane having a predetermined pore diameter is used, a mixed liquid heated to a predetermined temperature is provided on one surface side (primary side) of the separation membrane, and the other surface side (2 This is a method of separating a specific component by reducing the pressure on the next side with a vacuum pump or the like. This pervaporation separation method can easily separate a mixed liquid that is difficult to separate by a distillation method, such as an azeotropic mixture or a mixed liquid having a boiling point close to each other.

  For example, using a separation membrane composed of a titania membrane having a predetermined pore diameter, a mixed liquid heated to a predetermined temperature is provided on one surface side (primary side) of the separation membrane, and the other surface side (secondary side) An osmotic vapor separation method is known in which a specific component is separated by reducing the pressure on the side) with a vacuum pump (Patent Document 1).

JP-A-62-2405

  However, in the pervaporation separation method described in Patent Document 1, because the separation side is a method in which the primary side of the separation membrane is atmospheric pressure and the secondary side (the other side (permeation side)) is depressurized, The transmembrane pressure difference (primary side and secondary side differential pressure) contributing to permeation was 0.1 MPa at the maximum. That is, there is a problem that the permeation rate is slow (the processing speed of the mixed liquid is slow) because the transmembrane pressure difference is not sufficiently obtained (the transmembrane pressure difference is small).

  The present invention has been made in view of such problems of the prior art, and the object of the present invention is to increase the transmembrane pressure difference and achieve a good permeation rate (fast). And a liquid separation system.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be achieved by pressurizing the primary side in addition to depressurizing the secondary side. It came to complete.

  That is, according to the present invention, the following liquid separation method and liquid separation system are provided.

[1] A mixed liquid containing a resist is supplied to one surface side of the separation membrane so that the mixed liquid is in contact with one surface of the separation membrane, and the resist is applied to the other surface side of the separation membrane. A liquid separation method for selectively permeating lower molecular weight components and recovering the resist that does not permeate the separation membrane so that one side of the separation membrane is pressurized with the mixed liquid A liquid separation method for supplying and depressurizing the other surface side of the separation membrane.

[2] The liquid separation method according to [1], wherein the mixed liquid is supplied under a pressure of 0.01 to 0.5 MPa.

[3] The liquid separation method according to [1] or [2], wherein the resist has a weight average molecular weight of 500 to 5,000.

[4] The liquid separation method according to any one of [1] to [3], wherein the material of the separation membrane is at least one selected from the group consisting of titania, silica, alumina, zeolite, and carbon.

[5] A separation membrane and a supply unit are provided, and a mixed liquid containing a resist is supplied to one surface of the separation membrane so that the mixed liquid is in contact with the one surface of the separation membrane. A liquid separation system that selectively transmits a component having a molecular weight lower than that of the resist to the other surface side of the membrane and collects the resist that does not pass through the separation membrane. A liquid separation system comprising supply means for supplying pressure so that one surface side of the separation membrane is pressurized, and further comprising pressure reducing means for decompressing the other surface side of the separation membrane.

[6] The liquid separation system according to [5], wherein the supply unit supplies the mixed liquid while being pressurized to a pressure of 0.01 to 0.5 MPa.

[7] The liquid separation system according to [5] or [6], wherein the separation membrane is made of a porous material, and an average pore diameter thereof is 0.1 to 5 nm.

[8] The liquid separation system according to any one of [5] to [7], wherein the material of the separation membrane is at least one selected from the group consisting of titania, silica, alumina, zeolite, and carbon.

  The liquid separation method of the present invention has an effect that the permeation rate is good because the transmembrane pressure difference is large.

  The liquid separation system of the present invention has an effect that the permeation rate is good because the transmembrane pressure difference is large.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be described below, but the present invention is not limited to the following embodiment, and is based on the ordinary knowledge of those skilled in the art without departing from the gist of the present invention. It should be understood that modifications and improvements as appropriate to the following embodiments also fall within the scope of the present invention.

[1] Liquid separation method:
In the liquid separation method of the present invention, a mixed liquid containing a resist is supplied to one surface side of the separation membrane so that the mixed liquid contacts one surface of the separation membrane, and the other surface side of the separation membrane A liquid separation method for selectively permeating components having a molecular weight lower than that of the resist and recovering the resist that does not permeate the separation membrane so that one surface side of the separation membrane is pressurized. Supply and depressurize the other side of the separation membrane.

  By such a method, there is a large difference between the pressure difference between the separation membranes, that is, the pressure applied to one surface where the mixed liquid is in contact with the pressure applied to the other surface through which a component having a lower molecular weight is selectively permeated than the resist. Therefore, the permeation speed of the component having a low molecular weight is better than that of the resist that selectively permeates.

  Hereinafter, the liquid separation method of the present invention will be specifically described based on the liquid separation system shown in FIG.

  A liquid separation system 100 shown in FIG. 1 includes a stock solution tank 11 into which a waste solution (mixed liquid containing a resist) is charged, a supply unit 12 that is connected to the stock solution tank 11 and sends the waste solution from the stock solution tank 11, and a supply unit. 12, a heater 13 for heating the waste liquid, a separator 15 connected to the heater 13 and provided with a separation membrane 15a, a cooling device connected to the separation device 15 and cooling components that have passed through the separation membrane 15a Means (not shown), a recovery tank 17 for recovering the above components cooled by the cooling means, a decompression means 18 connected to the recovery tank 17, and a liquid feed toward the separation device 15 from the heater 13 The piping branches, and the liquid feeding pressure meter 14 disposed at the branching portion and the liquid feeding piping from the recovery tank 17 to the pressure reducing means 18 are branched. And a permeate Pressure meter 16 disposed in the branch portion. Further, the separation device 15 further includes a recovery pipe for sending a resist that does not pass through the separation membrane 15 a, and this recovery pipe is connected to the stock solution tank 11. Therefore, the resist that does not pass through the separation membrane 15a can be collected in the stock solution tank 11. The recovery pipe can be connected to a resist recovery tank (not shown), and the stock solution tank 11 and the resist recovery tank are appropriately selected and connected.

  In the liquid separation system 100 shown in FIG. 1, first, the mixed liquid containing the resist supplied to the stock solution tank 11 in advance is sent to the heater 13 by the supply means 12. Thereafter, the mixed liquid sent to the heater is heated to a predetermined temperature by the heater 13. The heated mixed liquid is supplied so as to be in contact with one surface of the separation membrane 15. That is, the mixed liquid passes through the liquid feeding pipe from the heater 13 toward the separation membrane 15 and reaches the separation membrane 15 provided at the tip of the liquid feeding pipe. Be regulated. At this time, the other surface of the separation membrane 15 (the surface opposite to the surface in contact with the mixed liquid) is depressurized to a predetermined pressure by the depressurization means 18, so that a desired component (lower than the resist) is obtained. The molecular weight component) permeates to the other side of the separation membrane 15 while vaporizing. The supply unit 12 adjusts the supply amount so that one surface of the separation membrane 15 (the surface with which the mixed liquid is in contact) is pressurized by the mixed liquid at a predetermined pressure. Liquid.

  The mixed liquid pressure meter 14 measures the pressure on one side of the separation membrane 15, and the permeate pressure meter 16 measures the pressure on the other side of the separation membrane 15. The measured value of the mixed liquid pressure meter 14 is fed back, and a pressure control valve (not shown) provided on one surface side of the separation membrane 15 is opened and closed and / or the amount of liquid supplied by the supply means 12 is adjusted. Is called. The measured value of the permeate pressure meter 16 is fed back, and a pressure control valve (not shown) provided on the other surface side of the separation membrane 15 is opened and closed and / or the suction amount of the decompression means 18 is adjusted. .

  Subsequently, the component that has passed through the separation membrane 15 is cooled by the cooling means and is collected in the collection tank 17. On the other hand, the resist that does not pass through the separation membrane 15 is sent to the stock solution tank 11. The resist sent to the stock solution tank 11 is mixed with the mixed liquid and sent from the stock solution tank 11 again. Thereafter, when the resist has a desired concentration, it can be recovered in a resist recovery tank (not shown) separate from the stock solution tank 11. The liquid separation method may be a continuous method as described above, or may be a batch method in which a resist that does not pass through the separation membrane 15 is collected in a resist collection tank without being sent to the stock solution tank 11. Good.

  The stock solution tank, supply means, heater, separation membrane, cooling means, recovery tank, decompression means, mixed liquid pressure meter, and permeate pressure meter used in the liquid separation method of the present invention are the liquid of the present invention described later. The same stock solution tank, supply means, heater, separation membrane, cooling means, recovery tank, decompression means, mixed liquid pressure meter, and permeate pressure meter used in the separation system can be suitably used.

[2] Liquid separation system:
FIG. 1 is an explanatory view schematically showing one embodiment of the liquid separation system of the present invention. As shown in FIG. 1, the liquid separation system 100 of this embodiment includes a separation membrane 15 and a supply unit 12, and a mixed liquid containing a resist is provided on one surface of the separation membrane 15, and the mixed liquid is a separation membrane. 15 is supplied so as to be in contact with one surface of the separation membrane 15 and selectively transmits a component having a lower molecular weight than the resist to the other surface side of the separation membrane 15 and collects the resist that does not penetrate the separation membrane 15. The supply unit 12 is a supply unit that pressurizes and supplies the mixed liquid, and further includes a decompression unit 18 that decompresses the other surface side of the separation membrane 15. Furthermore, the undiluted | stock solution tank 11 installed in the upstream of the supply means 12, the heater 13 arrange | positioned downstream of the supply means 12, and the liquid supply pipe | tube arrange | positioned by branching the liquid feeding piping which goes to the separation membrane 15 from the heater 13 The pressure meter 14, the recovery tank 17 disposed downstream of the separation membrane 15, the cooling means (not shown) disposed between the recovery tank 17 and the separation membrane 15, and the recovery tank 17 toward the decompression means 18. A permeate pressure meter 16 is provided in which the liquid supply pipe is branched.

  With such a configuration, there is a large difference between the pressure difference between the separation membranes, that is, the pressure applied to one surface where the mixed liquid contacts and the pressure applied to the other surface through which a component having a lower molecular weight is selectively transmitted than the resist. Therefore, the permeation speed of the component having a low molecular weight is better than that of the resist that selectively permeates.

  Here, the “mixed liquid” in the present specification includes a resist, and further includes, for example, a stripping solution (resist stripping solution) for stripping the resist, a photosensitive agent, and a reaction product thereof. Specific examples include waste liquid when the resist is peeled off, a flat panel display, and thinner cleaning waste liquid in a semiconductor production process. The content of the resist in the mixed liquid is not particularly limited, but is preferably 0.01 to 20% by mass, more preferably 0.01 to 10% by mass with respect to the mixed liquid. It is especially preferable that it is 0.01-5 mass%.

  The “resist” means, for example, a high molecular weight organic component used in a manufacturing process of a semiconductor, liquid crystal glass, photomask, or the like. Specifically, the weight average molecular weight of the resist is preferably 500 to 5000, more preferably 1000 to 5000, and particularly preferably 2000 to 5000. There exists a possibility of permeate | transmitting to the secondary side as the said weight average molecular weight is less than 500. On the other hand, if it exceeds 5000, the resist captured by the separation membrane is easily gelled on the separation membrane, so that the permeation resistance of components that permeate the separation membrane increases and the processing speed of the mixed liquid may be significantly reduced. . The type of the resist is not particularly limited, and examples thereof include novolac resins and acrylic resins.

  The resist stripping solution is not particularly limited as long as it is a solution for stripping the resist, and usually has a lower molecular weight than that of the resist. Specifically, the weight average molecular weight is 200 to 400. Many things are used. Moreover, there is no restriction | limiting in the kind, For example, DMSO (dimethyl sulfoxide) -amine, MEA (monoethanolamine), NMP (N-methylpyrrolidone) etc. can be mentioned.

  In the conventional pressurized liquid separation system, a reaction product of the resist and the resist stripping solution, a compound whose molecular weight is close to the molecular weight of the resist stripping solution permeate to the secondary side (leak out to the secondary side). Therefore, it is difficult to pressurize and supply the mixed liquid containing the resist. On the other hand, the liquid separation system of the present invention has solved the problem of permeation to the secondary side (leakage to the secondary side) by applying the pervaporation separation method using the boiling point difference. There is an advantage that the mixed liquid can be fed and the processing speed of the mixed liquid is good.

[2-1] Separation membrane:
The separation membrane used in the liquid separation system of the present invention is for selectively permeating components having a lower molecular weight than the resist from the mixed liquid. By using such a separation membrane, the resist can be separated and recovered from the mixed liquid. The resist separated by the separation membrane can be collected in the stock solution tank 11, for example, as shown in FIG. After collecting the resist in this way, when the resist in the mixed liquid reaches a predetermined concentration, it can be collected as a resist having a desired concentration in a resist collection tank different from the stock solution tank.

  The separation membrane is composed of a porous body having a large number of fine pores that are three-dimensionally continuous, and the average pore diameter is preferably 0.1 to 5 nm, and preferably 0.5 to 2 nm. Is more preferable, and 0.5 to 1 nm is particularly preferable. If the average pore diameter of the separation membrane made of the porous material is less than 0.1 nm, the resist stripping solution to be permeated may not permeate. On the other hand, if it exceeds 5 nm, the resist component to be supplemented may not be transmitted to the secondary side. Here, “average pore diameter” in the present specification is a value measured using a nano palm porometer manufactured by Seika Sangyo Co., Ltd. Specifically, this value is obtained by measuring the permeation amount of nitrogen gas that permeates the separation membrane when the partial pressure of hexane gas, which is a condensable gas, is changed under nitrogen gas.

  The separation membrane can determine the weight average molecular weight of the resist to be separated and recovered by setting the average pore diameter. Specifically, when the average pore diameter of the separation membrane is 5 nm, the fractional molecular weight of the resist that can be separated and recovered is 9000. That is, since a resist having a weight average molecular weight of 9000 or more cannot permeate the separation membrane, the desired resist can be separated from the mixed liquid by collecting the remaining portion without permeating the separation membrane.

  When the separation membrane is composed of a porous body, the pore size distribution of the pores formed in the separation membrane is preferably 0.1 to 10 nm, and preferably 0.5 to 5 nm. Is more preferable, and 0.5 to 2 nm is particularly preferable. If the pore size distribution is less than 0.1 nm, the resist stripping solution may not permeate. On the other hand, if it exceeds 10 nm, the resist component to be supplemented may be transmitted to the secondary side. Here, in the present specification, when “pore size distribution” is used, a nano palm porometer manufactured by Seika Sangyo Co., Ltd. is used, and the partial pressure of hexane gas, which is a condensable gas, is changed under nitrogen gas. It is a value obtained by measuring the amount of permeation.

  Further, the porosity of the separation membrane is preferably 20 to 50%, more preferably 20 to 40%, and particularly preferably 30 to 40%. When the porosity is less than 20%, the permeation resistance applied to the separation membrane when the resist stripper permeates increases, and the processing speed of the mixed liquid may be significantly reduced. On the other hand, if it exceeds 50%, the pressure resistance of the separation membrane is lowered, and there is a risk of breakage during use. Here, the term “porosity” in the present specification is a value measured by injecting mercury using a mercury porosimeter manufactured by Shimadzu Corporation.

  The material of the separation membrane is preferably at least one selected from the group consisting of titania, silica, alumina, zeolite, and carbon. Among these, it is preferable that it is at least one selected from the group consisting of titania, silica, and zeolite from the viewpoint of having corrosion resistance and obtaining a uniform pore size distribution.

  Conventionally, an “organic membrane” is used as a separation membrane to separate an isopropanol mixed solution. However, when the mixed liquid containing the resist is separated, there is a problem in that the organic film dissolves because of the lack of corrosion resistance to the mixed liquid due to its material. On the other hand, the separation membrane used in the liquid separation system of the present invention is preferably an inorganic membrane made of the above material having corrosion resistance against highly corrosive liquids such as the above mixed liquid.

  Furthermore, the shape of the separation membrane is not particularly limited. For example, the shape of the separation membrane can be a flat plate shape, a bottomed cylindrical shape, a monolith shape, a honeycomb shape, or the like. In the case of a bottomed cylindrical separation membrane, the mixed liquid can be supplied so as to be in contact with the inside of the cylindrical separation membrane, or can be supplied so as to be in contact with the outside.

  The thickness of the separation membrane is not particularly limited, but is preferably 0.1 to 5 μm, more preferably 0.1 to 3 μm, and particularly preferably 0.5 to 1 μm. If the thickness of the separation membrane is less than 0.1 μm, the separation membrane may be peeled off by a solid contained in the treatment liquid. On the other hand, if it exceeds 5 μm, the permeation resistance applied to the separation membrane when the resist stripper permeates increases, and the processing speed of the mixed liquid may be significantly reduced.

  The separation membrane can be produced by a known method, and specifically can be produced by dip coating.

[2-2] Supply means:
The supply means used in the liquid separation system of the present invention is to supply a mixed liquid containing a resist to one surface of the separation membrane so that the mixed liquid contacts one surface of the separation membrane. In addition, the liquid mixture is supplied so that one surface side of the separation membrane is pressurized. Here, “so that one surface side of the separation membrane is pressurized” means that the closed space formed by the supply means, the liquid supply pipe, and the separation membrane is filled, and further, the supply means enters the space. This means that the liquid mixture to be sent is applying internal pressure to the supply means, the liquid feed pipe, and the separation membrane. It means receiving power toward other aspects. However, in the present specification, the internal pressure generated by normal liquid feeding from the supply means does not mean that one surface side of the separation membrane is pressurized.

  The supply means is not particularly limited as long as it can be supplied so that one surface side of the separation membrane is pressurized. For example, supply of a rotary pump, a diaphragm pump, a screw pump, a centrifugal pump, etc. A pump can be mentioned. A plurality of these can be used. Further, a check valve can be used in combination.

  It is preferable that the supply means pressurize and supply the mixed liquid to a pressure of 0.01 to 0.5 MPa, more preferably pressurize and supply the pressure to a pressure of 0.05 to 0.5 MPa. It is particularly preferable that the pressure is supplied at a pressure of 1 to 0.3 MPa. If the pressure is less than 0.01 MPa, the effect of improving the processing speed of the mixed liquid may not be obtained. On the other hand, if it exceeds 0.5 MPa, the resist component to be trapped may be transmitted to the secondary side.

[2-3] Pressure reducing means:
The decompression means decompresses the other surface side of the separation membrane. Here, “reducing the pressure on the other surface side of the separation membrane” means that the space on the other surface side of the separation membrane is set to a pressure equal to or lower than the atmospheric pressure. Examples of the decompression means include a vacuum pump.

  The decompression means preferably decompresses the mixed liquid at a vacuum degree of 10 to 500 Pa, more preferably 10 to 200 Pa, and particularly preferably 10 to 150 Pa. If the degree of vacuum is less than 10 Pa, the apparatus becomes complicated in order to achieve a high degree of vacuum, and the merit for cost may be reduced. On the other hand, if it exceeds 500 Pa, sufficient resist vaporization is not performed when the resist stripper permeates the separation membrane, which may reduce the resist recovery rate.

  The heater is preferably used for heating the mixed liquid and facilitating the permeation of the component that permeates the separation membrane. Examples of the heater include a heater by electric heating, a heater by steam heating, an indirect heater by a heat exchanger, and the like.

  In addition, although the heating temperature of the liquid mixture by a heater can be suitably selected according to the boiling point of the liquid mixture to process, it is preferable that it is 70-100 degreeC, It is more preferable that it is 70-90 degreeC, 80- A temperature of 90 ° C. is particularly preferable. If the heating temperature is less than 70 ° C., the resist stripping solution does not evaporate when permeated through the separation membrane, so that the permeation amount of the separation membrane decreases and the recovery rate may decrease. On the other hand, if it exceeds 100 ° C., the resist component to be trapped may be vaporized and transmitted to the secondary side.

  The pressure control valve can be arranged on one surface side and the other surface side of the separation membrane, and is preferably used for adjusting the pressure by opening and closing according to the measured value of the pressure meter. Examples of the pressure control valve include an automatic control valve and a back pressure valve.

  The cooling means is preferably used for recovering as a liquid the component which has been vaporized and permeated through the separation membrane. Examples of the cooling means include a tank with a cooling jacket and a heat exchanger capable of indirect cooling.

  FIG. 2 is an explanatory view schematically showing another embodiment of the liquid separation system of the present invention. The liquid separation system of the present embodiment is obtained by further adding a trap 19 downstream of the separation membrane 15 to the liquid separation system 100 shown in FIG. That is, in the liquid separation system 110 shown in FIG. 2, the supply unit 12, the heater 13, the separation membrane 15, the trap 19, the cooling unit (not shown), the recovery tank 17, and the decompression are sequentially arranged downstream of the stock solution tank 11. Means 18 is further provided, and the liquid supply piping from the heater 13 to the separation membrane 15 is branched, and the liquid supply piping from the mixed liquid pressure meter 14 and the recovery tank 17 to the pressure reducing means 18 is branched to transmit the permeate. Pressure meter 16. Examples of the trap include a tank with a cooling jacket.

  Such a liquid separation system 110 shown in FIG. 2 can further separate the components that have permeated through the separation membrane by the trap even if the mixed liquid contains a plurality of components in addition to the resist. . Specifically, when the component that has permeated through the separation membrane 15 (permeated component) is composed of a gas component and a liquid component, the trap 19 can separate and recover the liquid component from the permeated component. . The gaseous component that is not recovered by the trap 19 is cooled by a cooling means disposed downstream of the trap 19 and recovered in the recovery tank 17.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples.

Example 1
Liquid separation was performed using the liquid separation system shown in FIG. In this liquid separation system, a supply pump, a heater, and a monolithic separation membrane made of titania (average pore diameter of 5 nm, pore diameter distribution of 0.5 to 10 nm, porosity of 35 are sequentially provided downstream of a 20 L stock solution tank. %, Film thickness 1 μm), a cooling means, a recovery tank, and a vacuum pump as a decompression means. In liquid separation, first, a mixed liquid comprising 5% by mass of a novolak resist (weight average molecular weight 2500) and DMSO (dimethyl sulfoxide) -amine resist stripper (weight average molecular weight 300) is added to a 20 L stock solution tank. Was introduced.

  Thereafter, the mixed liquid was sent to a heater by a supply pump, and the mixed liquid was heated to 80 ° C. by the heater. After heating, the mixed liquid was supplied in contact with one surface of the separation membrane so that the pressure on one surface side of the separation membrane was 0.5 MPa. At this time, the other surface side of the separation membrane was decompressed to 133.3 Pa by a vacuum pump. The components that permeated through the separation membrane were cooled and then collected in a collection tank.

After performing liquid separation as described above, the concentration of the resist stripping solution recovered in the recovery tank was measured by liquid chromatography (manufactured by Shimadzu Corporation), and was 90% by mass. In addition, the flux (permeation flow rate) was measured and found to be 12 L / m ² h. Specifically, the flux measurement is performed by measuring the amount of the component (resist stripping solution) that is transmitted to the other side of the separation membrane and collected in the collection tank after a predetermined time (h) has elapsed from the start of the evaluation. (L) was weighed and calculated by the following formula.
Formula: Flux = Q / (A · t)
(In the above formula, Q: amount of component recovered in the recovery tank (L), A: area of the separation membrane (m ² ), t: predetermined time (h) from the start of evaluation)

(Examples 2 and 3)
Using the liquid separation system shown in FIG. 2, 5% by mass of a novolak resist (weight average molecular weight 2500), DMSO (dimethyl sulfoxide) -amine resist stripping solution (weight average molecular weight 300), and photosensitivity are used as a mixed liquid. Liquid separation was performed in the same manner as in Example 1 except that the liquid (weight average molecular weight 1000) was used and the conditions shown in Table 1 were used. The photosensitive solution was recovered by the trap, and the resist stripping solution was recovered in the recovery tank.

(Comparative Example 1)
Liquid separation was carried out in the same manner as in Example 1 except that the conditions shown in Table 1 were used, using the liquid separation system shown in FIG.

  As described above, in the liquid separation systems of Examples 1 to 3, the permeation rate of the components that permeate the separation membrane is better (the processing speed of the mixed liquid is faster) than the liquid separation system of Comparative Example 1. Was confirmed.

  In the liquid separation method of the present invention, for example, a resist and a component having a lower molecular weight than the resist are separated from a mixed liquid (waste liquid) containing the resist, which is produced in a manufacturing process of a semiconductor, liquid crystal glass, photomask, and the like. This is a recovery method, and is suitably used as a liquid separation method having a good permeation rate (a high processing speed).

  The liquid separation system of the present invention separates a resist and a component having a molecular weight lower than that of the resist from a mixed liquid (waste liquid) containing the resist, which is generated in a manufacturing process of a semiconductor, liquid crystal glass, a photomask, and the like. It is to be recovered and is suitably used as a liquid separation system having a good permeation rate (high processing speed).

It is explanatory drawing which shows typically one Embodiment of the liquid separation system of this invention. It is explanatory drawing which shows typically other embodiment of the liquid separation system of this invention.

Explanation of symbols

11: Stock solution tank, 12: Supply means, 13: Heater, 14: Pressure meter for mixed liquid, 15: Separation membrane, 16: Pressure meter for permeate, 17: Recovery tank, 18: Pressure reducing means, 19: Trap, 100, 110: Liquid separation system.

Claims (8)

A mixed liquid containing a resist is supplied to one surface side of the separation membrane so that the mixed liquid is in contact with one surface of the separation membrane,
While selectively allowing a component having a lower molecular weight than the resist to permeate to the other surface side of the separation membrane,
A liquid separation method for recovering the resist that does not pass through the separation membrane,
A liquid separation method in which the mixed liquid is supplied so that one surface side of the separation membrane is pressurized, and the other surface side of the separation membrane is decompressed.   The liquid separation method according to claim 1, wherein the mixed liquid is supplied under a pressure of 0.01 to 0.5 MPa.   The liquid separation method according to claim 1, wherein the resist has a weight average molecular weight of 500 to 5,000.   The liquid separation method according to any one of claims 1 to 3, wherein a material of the separation membrane is at least one selected from the group consisting of titania, silica, alumina, zeolite, and carbon. A separation membrane and a supply means, supplying a mixed liquid containing a resist to one surface of the separation membrane so that the mixed liquid is in contact with the one surface of the separation membrane; A liquid separation system for selectively permeating a component having a lower molecular weight than that of the resist to the surface side and recovering the resist that does not permeate the separation membrane,
The supply means is a supply means for supplying the mixed liquid so that one surface side of the separation membrane is pressurized, and further includes a decompression means for decompressing the other surface side of the separation membrane. .   The liquid separation system according to claim 5, wherein the supply unit supplies the mixed liquid while being pressurized to a pressure of 0.01 to 0.5 MPa.   The liquid separation system according to claim 5 or 6, wherein the separation membrane is composed of a porous body, and an average pore diameter thereof is 0.1 to 5 nm.   The liquid separation system according to any one of claims 5 to 7, wherein a material of the separation membrane is at least one selected from the group consisting of titania, silica, alumina, zeolite, and carbon.

Images