KR101354523B1 - Recycling apparatus for recycling 1-piperazineethanol from waste high boiling point photoresist stripper - Google Patents

Abstract

The present invention relates to a recycling apparatus for recycling 1-piperazineethanol (HEP) from a waste high boiling point photoresist stripper, wherein the recycling yield of HEP is above 50%, thereby reducing costs and enabling the production of a high-quality recycled solvent. The present invention controls the moisture content of a waste high boiling point photoresist before being input to a recycling process to a level of inhibiting the generation of pyrolysis byproduct to inhibit the generation of the byproduct of HEP pyrolysis which is generated in a step for removing low boiling point foreign materials by first distilling the waste high boiling point photoresis stripper generated in the manufacturing process of an LED display or a semiconductor device. And the present invention additionally increases the recycling yield of HEP by minimizing the pyrolysis of HEP generated in a recycling process in the process of removing low boiling point foreign materials by first distillation with a reboiler at a temperature of 65°C. Also the present invention provides a device for controlling the moisture content of the waste high boiling point stripper supplied to a fist distilling device and a connected raw material supply tank.

Description

Recycling apparatus for recycling 1-Piperazineethanol from waste high boiling point photoresist stripper}

The present invention is an apparatus for improving the recovery yield of HEP recovered in the process of regenerating high-boiling 1-piperazineethanol (hereinafter referred to as HEP), which is a high boiling point peeling solvent, from a photoresist high boiling point peeling waste liquid. More particularly, the present invention relates to an apparatus for improving the recovery yield of HEP, a high boiling point peeling solvent, from a photoresist high boiling point peeling waste liquid generated in a liquid crystal display device or a semiconductor device manufacturing process to a high recovery rate of 50% or more. .

In general, the demand for semiconductors and liquid crystal displays (LCDs) is continuously increasing due to the rapid development of the information communication industry since the 1990s.

As a result, the demand for photoresist, which is a key to forming a fine circuit pattern, and expensive separating liquid used for diluting with the photoresist increases sharply, necessitating the recycling of the pulp removal liquid.

The stripper waste liquid generated during the manufacturing process of an electronic component such as a semiconductor wafer or a liquid crystal display glass substrate contains impurities such as moisture and heavy metals together with a photoresist resin in addition to a stripper solvent.

Most of these stripper wastes are removed through incineration or landfilling after simple pretreatment. In order to improve the environmental problems and disposal costs of the wastewater generation process and to enhance the competitiveness of the IT industry, Demand for recycling through renewal has been strengthened.

The development of IT technology is rapidly progressing beyond our expectations, and the kinds and roles of thinner and peeling liquid that are consumed are diversifying.

Currently, the major exfoliant solvents used during electronic parts manufacturing processes such as LCDs are recovered, refined and reused after being used in the manufacturing process.

Particularly, in the LCD field, demand for reduction of the process cost is increasing as the substrate becomes larger and the panel price drops.

Due to the recent rise in oil prices, the need to secure cost competitiveness due to rising raw material prices for thinner and exfoliation liquid has led to the recycling of raw materials through the refining process of pulp removal liquids, thereby reducing raw material consumption, There is a need for improvement.

On the other hand, in recent economic, environmental, and efficiency aspects, recycling technology of stripping process waste liquid is extensively studied.

Korean Patent No. 0901001 and Japanese Patent Application Laid-Open No. 2005-288329 propose a regenerating technology of a stripper solvent by removing a low-boiling substance such as moisture and a high-boiling substance such as a photoresist resin from a stripper waste solution have.

In addition to the above-mentioned distillation method, Korean Patent No. 0899777 discloses a high recovery recovery method that minimizes the loss in the regeneration process.

In recent years, with the rapid development of the LCD and semiconductor materials industries, such as the necessity of a photosensitive resin having a new structure due to the development of a new memory semiconductor, a high-performance stripper organic solvent capable of dissolving and peeling these resins in the peeling process is required The use amount of high-boiling point peeling solvents excellent in peelability and solubility is increasing.

However, in the case of the regeneration process employing the above-mentioned prior arts, high-boiling-off organic solvents are poorly separated and refined from heavy photoresist resins and metallic components due to high boiling point characteristics such as high viscosity, thermal decomposition and chromaticity change, By remaining excess in terms of prevention of process trouble, most of the high boiling point impurities are left in recycle residue and then discarded.

In addition, the quality of high-boiling separation solvents recovered by the above-mentioned prior art technologies, which are difficult to secure economical significance at around 15% at the recovery rate, is inferior in recycling value in purity and chromaticity. Thus, The demand for the development of the recovery technology has been booming in the related industry, but until now there have been no alternative replacement technologies in Korea and abroad.

Accordingly, in recent Korean Patents 1330653 and 1330654, not only general peeling organic solvent in photoresist stripper waste liquid but also expensive high-boiling peeling organic solvents are regenerated and recovered from photoresist residues which are being disposed of And a high level of regeneration process technology.

In this way, it will be effective not only in terms of efficient energy management but also in enhancing competitiveness of IT related companies.

However, the high recovery rate of high-boiling separation solvents such as HEP, which is an expensive oil resource imported from overseas, can be recovered at a high recovery rate, resulting in a 50% The recovery rate has not been reached.

Accordingly, an object of the present invention is to provide high-quality regeneration high boiling point from regeneration residues such as photoresist high boiling point stripping waste liquid or high boiling point impurity, in order to increase the economical low recovery yield of high boiling point stripping solvent, especially HEP, which is the limitation of the conventional regeneration method as described above. By recovering HEP as a point peeling solvent with an improved regeneration yield, by suppressing the production of by-products that induce HEP pyrolysis, which is caused by first distilling the high boiling point stripping waste to remove low boiling point impurities, By minimizing the thermal decomposition degree of the HEP to provide a device for further easily enhance or improve the recovery yield of the high boiling point peeling solvent HEP 50% or more.

In order to achieve the above object, an apparatus for recovering HEP from the photoresist high boiling point peeling waste liquid provided in the present invention has the following characteristics.

The apparatus for recovering HEP from the photoresist high boiling point separation waste liquid is a primary distillation apparatus for primary distillation of photoresist high boiling point separation waste liquid containing HEP which is a high boiling point separation solvent to remove low boiling point impurities, To the raw material supply tank for supplying the photoresist high boiling point stripping waste liquid with the moisture content ratio adjusted.

In addition, the process waste fluid moisture control apparatus of the device for recovering the HEP from the photoresist high boiling point peeling waste liquid is an isopropyl alcohol supply tank for supplying isopropyl alcohol (IPA) and received from the isopropyl alcohol supply tank A stirred mixing tank for mixing isopropyl alcohol and photoresist high boiling point stripping waste liquid discharged from the manufacturing facilities of LCD and semiconductor device with a stirrer, a line between the isopropyl alcohol supply tank and the stirring mixing tank for isopropyl alcohol supply; A flow control valve and a transfer pump respectively installed in a line between the stirred mixing tank and the raw material supply tank, a water content measuring instrument for measuring the water content of the high-resistance stripping waste liquid discharged from the stirring mixing tank, and the water content measuring instrument The flow control valve and the transfer pump may be It comprises a controller.

Particularly, in the apparatus for recovering HEP from the photoresist high boiling point stripping waste liquid, when the moisture content in the photoresist high boiling point stripping waste liquid measured by the moisture content measuring apparatus reaches 9.7 to 10.3% by weight or 14.8 to 15.2% by weight, And the stripping waste liquid is transferred from the agitation mixing tank to the raw material supply tank. The primary distillation apparatus is characterized in that the temperature and pressure of re-boiling are set to 62 to 67 ° C and 75 to 85 torr, respectively.

Here, when the water content in the photoresist high boiling point stripping waste liquid measured by the moisture content measuring device reaches 10 wt% or 15 wt%, the photoresist high boiling point stripping waste liquid is transferred from the agitation mixing tank to the raw material supply tank, The primary distillation apparatus can be operated by setting the temperature and pressure of the re-boiling to 65 ° C and 80 torr.

The isopropyl alcohol feed tank is comprised of an isopropyl alcohol feed tank for storing isopropyl alcohol and two isopropyl alcohol feed tanks comprised of a recycle isopropyl alcohol feed tank fed from a primary distillation unit, So that propyl alcohol can be fed into the stirred tank from the propyl alcohol feed tank.

The lower end and the upper end of the stirring and mixing tank are connected to each other through a circulation line having a flow valve and a transfer pump, and the photoresist high boiling point stripping waste liquid exiting from the lower end of the stirring tank is passed through the circulation line to the upper end So that it can be introduced again.

On the other hand, a method of recovering HEP from the photoresist high boiling point stripping waste liquid includes a first step of distilling a photoresist high boiling point stripping waste liquid containing HEP which is a high boiling point stripping solvent to remove low boiling point impurities, Subjecting the photoresist high boiling point waste liquid to secondary distillation at a temperature of 120 to 160 DEG C to remove high boiling point residues containing high boiling point impurities and regenerating the stripper solvent composition; Is subjected to tertiary distillation under the condition of re-boiling at a temperature of 80 to 120 DEG C to remove fine water content to ultimately regenerate a regenerated stripper solvent containing a part of regenerated high boiling point stripping solvent from the photoresist high boiling point stripping liquid As a method for recovering HEP, a photoresist high boiling point stripping waste solution containing HEP, which is a high boiling point stripping solvent, In order to inhibit the generation of HEP pyrolysis-inducing by-products generated in the step of removing low boiling point impurities by distillation, the photoresist high boiling point stripping waste liquid is transferred to a raw material supply tank, The water content in the stripping waste liquid is adjusted to 9.7 to 10.3 wt% or 14.8 to 15.2 wt%, and the temperature and pressure of the re-boiling at the first distillation are adjusted to 62 to 67 ° C and 75 to 85 torr, And distilling to remove low boiling point impurities.

Here, it is preferable that the water content in the photoresist high boiling point separation waste liquid is adjusted to 10% by weight or 15% by weight before the photoresist high boiling point separation waste liquid is transferred to the raw material supply tank and charged. The temperature and pressure of the re-boiling are preferably adjusted to 65 ° C and 80 torr.

In addition, the method of recovering the HEP from the photoresist high boiling point stripping waste liquid is the secondary by-product waste liquid discharged from the distillation residue after the second distillation is subjected to the fourth distillation under the conditions of the reboiler temperature of 120 ~ 160 ℃ high boiling impurities It may further include an additional regeneration step of additionally regenerating the high boiling point peeling solvent while removing the.

By using the method of easily promoting or improving the recovery yield of HEP which is a high boiling point separation solvent from the photoresist high boiling point separation waste liquid according to the present invention at a high recovery rate of 50% or more, HEP Of the high-boiling point separation solvent at a high recovery rate, thereby achieving a significant cost reduction. In addition to being able to produce at low cost with high-quality regenerating solvent, it is possible to increase the competitiveness of IT related companies The effect will be doubled, and a more substantial environmental improvement effect can be expected.

1 is a schematic view showing an apparatus for regenerating HEP from a photoresist high boiling point separation waste liquid according to an embodiment of the present invention

The waste liquid is transferred to a raw material supply tank in order to suppress the generation of HEP pyrolysis-inducing by-products generated in the step of first distilling the photoresist high boiling point stripping waste liquid containing HEP which is a high boiling point stripping solvent and removing low boiling point impurities Adjusting the ratio of the moisture content in the photoresist high boiling point stripping waste liquid prior to charging and removing the low boiling point impurities by a primary distillation at a temperature of 62 to 67 ° C (primary removal step) The photoresist high boiling point stripping waste liquid from which the low boiling point impurities have been removed is subjected to secondary distillation at a temperature of 120 to 160 DEG C to remove high boiling point residues containing high boiling point impurities, (Total regenerator recycling) and regenerating the stripper solvent composition at a temperature of 80 to 120 ° C. Distilling to remove fine water to regenerate the high purity regenerated stripper solvent containing a part of the regenerated high boiling point stripping solvent (secondary removal), and separately from the secondary by-product waste liquid discharged from the distillation residue after the second distillation. Under the conditions of 120-160 ° C., the temperature of the silver reboiler is controlled to the highest degree of high viscosity of the high boiling point peeling solvent contained in the high boiling point residue to optimally delay the deposition of the photoresist resin. A photoresist stripper regeneration device including an additional regeneration step (secondary regeneration: additional stripper recycling) for distilling to remove high-boiling impurities and additionally regenerating high-purity high-boiling stripping solvent.

As a result, the recycling yield of HEP, which is a high-boiling peeling solvent recovered, is improved to a recovery rate of 50% or more, and a high-quality high-purity electronic grade with greatly improved pyrolysis phenomenon and chromaticity change is economically and efficiently The number of times of regeneration becomes possible.

In particular, in the present invention, the regenerated stripper solvent recovered is a mixed organic solvent containing a protonic solvent, an aprotic solvent and a water-soluble organic amine solvent, and the organic amine solvent is monoisopropanolamine (hereinafter referred to as "MIPA " Or HEP which is a representative recycling solvent of high boiling point release solvent.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

First, a photoresist stripper waste solution containing HEP which is a high boiling point peeling solvent according to the present invention will be described.

In the photoresist high boiling point stripping waste liquid according to the present invention, the content of HEP which is a representative oil-rich resource of the high boiling point stripping solvent as the water soluble organic amine solvent is 15 to 40% by weight based on 100% by weight of the photoresist high boiling point stripping waste liquid .

These organic amine solvents penetrate into the polymer structure of the photoresist, which is denatured or crosslinked in various processes such as etching, painting, and ion implantation in the peeling process, and breaks the intramolecular or intermolecular attraction to dissolve the photoresist, So that it can be easily removed.

Particularly, HEP which is a high boiling point separation solvent has a high hygroscopicity and is difficult to purify to a level of moisture content of 0.1 wt% or less. Further, since the high temperature sensitivity due to high boiling point characteristic is high, the moisture content in the whole waste solution coexist at 3-5 wt% At 85 ° C or higher and at a temperature of 200 ° C or higher at a HEP content of 10-15 wt% or lower and a temperature of 160 ° C or higher at a temperature of 10-15 wt% or higher irrespective of the moisture content, A change phenomenon appears.

On the other hand, when the high viscosity, which is another high boiling point characteristic of the high boiling peeling solvent HEP, becomes higher than a certain weight ratio depending on the relative weight ratio of the waste solution to the photoresist resin, the viscosity gradually increases and the solidification of the photoresist resin And the precipitation time is advanced, thereby causing a regeneration process trouble. Thus, a large amount of HEP in the waste solution is removed and disposed of as residues together with high boiling point impurities.

In addition, the phenomenon of high viscosity is rapidly accelerated especially at a temperature of 160 ° C or higher.

In the present invention, the protic solvent (protonic glycol ether compound) may be a diethylene glycol monomethyl ether (hereinafter referred to as MDG) or diethylene glycol monobutyl ether (hereinafter referred to as BDG) or diethylene glycol mono Ethyl ether (hereinafter referred to as EDG), and MDG, BDG or EDG are used singly or in combination.

These protonic solvents are compounds having a high vapor pressure, so that the loss due to heating or evaporation is small and the hydroxide ions generated from the alkali compound effectively penetrate, dissolve and exfoliate in the space between the photoresist and the glass substrate in the peeling process The solubility in the photoresist is increased, and the photoresist separated by the alkali compound is dissolved.

In addition, the wettability is maximized due to the low interfacial tension, thereby preventing the re-adhesion of the photoresist mainly occurring in the cleaning process and maximizing the peeling efficiency.

In the present invention, the aprotic solvent (aprotic polyprotein) may be prepared by reacting dimethylacetamide (hereinafter referred to as DMAc) or N-methylpyrrolidone (hereinafter referred to as NMP) or N-methyl (Hereinafter referred to as MMF) or dimethylsulfoxide (hereinafter referred to as DMSO), and DMAc or NMP, MMF or DMSO are used singly or in combination.

These non-protonic solvents have high solubility in photoresist in the peeling step, so that the photoresist peeled off by the amine compound is dissolved to maximize the effect of preventing photoresist reattachment and cleaning effect, which are mainly generated in the cleaning process.

In the present invention, the low boiling point impurity is an impurity having a lower boiling point than the individual stripper solvent contained in the photoresist high boiling point stripping waste liquid, and isopropyl alcohol (IPA) and water or waste solvent, which are usually wastewater for cleaning, and The same amount of organic solvent.

In the present invention, the high boiling point impurity is an impurity having a boiling point higher than that of the individual stripper solvent contained in the photoresist high boiling point stripping waste solution, preferably an impurity having a boiling point of 235 DEG C or higher. Typically, Lt; RTI ID = 0.0 > photoresist < / RTI >

The high purity electromagnetic grade stripper solvent in the present invention means a solvent in which the purity of the individual stripper solvent is 99.5% or more, the water content is 0.1% by weight or less, the heavy metal or the total metal content is in the ppb level, The lower limit of the water content is not particularly limited but is generally about 0.001 wt%, the total metal content is preferably not more than 500 ppb, and the lower limit is not particularly limited, but it is about 1 ppb .

The high boiling point releasing solvent used in the present invention is an individual stripper solvent having a boiling point of 10 占 폚 or more higher than the boiling point of ordinary stripper solvent contained in the photoresist high boiling point stripping waste liquid, The above is a photoresist stripper solvent used in the peeling process, typically HEP solvent which is excellent in peelability and solubility as an organic amine solvent.

The photoresist high boiling point peeling waste solvent HEP regeneration apparatus of the present invention is a primary distillation apparatus for removing low-boiling impurities, while removing high-boiling residues containing high-boiling impurities while simultaneously recovering the stripper solvent composition in a mixture form. Secondary distillation apparatus, a third distillation apparatus for regenerating high-purity electronic grade regeneration stripper solvent containing a part of the regeneration high boiling point stripping solvent by removing the fine water, apart from the column after the first regeneration of the second distillation apparatus And a fourth distillation apparatus which removes high-boiling impurities from high-boiling residues including high-boiling impurities, which are secondary by-product wastes remaining in the reboiler, and additionally regenerates high-purity electronic grade high-boiling stripping solvents.

Alternatively, the high boiling point residue may be selectively removed through the secondary distillation apparatus, and the stripper solvent composition may be removed from the recovered stripper solvent composition while removing fine water content, The high boiling point releasing solvent and a small amount of ordinary stripper solvent are removed from the high purity high boiling point peeling solvent recovered through the quaternary distillation apparatus sequentially with a high purity electron A fifth-order distillation unit which sequentially separates and recovers the individual stripper regeneration solvent at a high level can be continuously and selectively operated.

The five-stage distillation apparatus may or may not be arbitrarily performed in accordance with the requirements of the application or use of the regenerated stripper solvent recovered therefrom in consideration of the conditions of the regeneration recovery process.

However, the process and apparatus for raising the regeneration yield of HEP to 50% or more include a primary distillation apparatus for removing the low boiling point impurities, and a stirring mixer with an impeller added to the raw material supply tank connected to the primary distillation apparatus And a process waste fluid regulating device including a tank.

The regeneration yield of HEP recovered as a high-quality regenerated high boiling point stripping solvent from the regenerated residues such as photoresist high boiling point stripping liquid or high boiling point impurities recovered through the regenerating process can be improved and an additional regeneration yield apparatus The regeneration yield of HEP is further increased to a level of 50% or more by the process and the process, so that HEP which is a high boiling point separation solvent which is a valuable oil resource can be recovered more economically and efficiently.

First, a regeneration process and apparatus for recovering HEP as a high boiling point separation solvent from photoresist high boiling point separation waste liquid will be described as follows.

The primary distillation apparatus is a multi-stage distillation column or a charge type distillation column. The number of stages of the separation and purification of the column is in the range of 15 to 25 stages, preferably about 20 stages. When the temperature of the reboiler is operated at a temperature of 62 to 67 ° C A photoresist stripper waste liquid or a process of removing low boiling point impurities such as moisture from a stripper waste liquid which has been pretreated by neutralization, precipitation, filtration or the like (primary removal process).

The second distillation apparatus is a multi-stage distillation column or a chargeable distillation column. The number of stages of separation and purification of the column is in the range of 7 to 15 stages, preferably 10 stages. The temperature of the re- Removing a high boiling point residue containing a high boiling point impurity such as a photoresist resin from a stripper waste liquid from which low boiling point impurities have been removed through the primary distillation apparatus, and simultaneously recovering the stripper solvent composition in the form of a mixture (Primary regeneration process: total stripper recycling).

Also, in the above-mentioned third distillation apparatus, the number of theoretical separation stages of the tower as the multi-stage distillation tower or the chargeable distillation tower is in the range of 25 to 35 stages, preferably 30 stages, and the temperature of the re- (Second removal step) of regenerating the regenerated stripper solvent having a high purity level of the electronic grade containing a part of the regenerated high boiling point exfoliating solvent is carried out by removing fine moisture from the stripper solvent composition recovered through the secondary distillation apparatus do.

Meanwhile, in the above-mentioned quaternary distillation apparatus, the number of separation theoretical stages of the tower as the multi-stage distillation tower or the chargeable distillation tower is 8 to 12 stages, preferably 10 stages or less, and the temperature of the re- A viscometer capable of measuring the viscosity of the residue so as to optimally control the progression level of the high viscosity of the high boiling point removing solvent contained in the high boiling point residue to delay the precipitation of the photoresist resin as much as possible, A high boiling point impurity containing a high boiling point impurity which is a waste solution of the secondary by-products remaining in the column after the first regeneration and the reboiler of the secondary distillation apparatus, while being operated under conditions including a flow meter for controlling the flow rate and a controller for controlling them integrally A step of removing high boiling point impurities and further recovering a high boiling point exfoliation solvent having a high purity level (secondary regeneration process: Additio nal stripper recycling.

On the other hand, the fifth distillation apparatus may be selectively operated and may or may not be performed arbitrarily according to the requirements of application or use of the recovered regenerant solvent to be recovered.

The fifth distillation apparatus is a spiral spinning band distillation column which optionally removes high boiling point residues through the secondary distillation apparatus and removes the stripper solvent composition further from the recovered stripper solvent composition, The high-purity high-boiling-point solvent and the high-purity high-boiling-point solvent separately from the high-purity high-boiling-point separating solvent, Separate stripper recycling is carried out by sequential separation and recovery of a small amount of ordinary stripper solvent into individual stripper regeneration solvents of high purity level according to the boiling point of each solvent.

The spinning band type distillation column is capable of rapidly rotating a spiral agitated column device made of metal or a Teflon material inside the column to maximize the contact surface area between the volatile vapor component in the column and the condensed liquid component, Liquid-liquid equilibration is performed so that high-resolution purification efficiency can be obtained.

The separation efficiency of the distillation column can be appropriately adjusted by varying the rotation speed of the spiral type stirring column device in the spinning band type distillation column, and the rotation speed of the stirring column device is preferably 1,500 to 2,500 rpm.

Next, the step of increasing the regeneration yield at a high recovery rate of 50% or more of the present invention will be described.

The photoresist high boiling point separation waste liquid is collected and mixed in a separate waste liquid storage tank, and then sent to a pretreatment process. The neutralization, precipitation, and filtration steps are carried out to remove solid components, insoluble modified photoresist components and organic acid components Removed.

The photoresist high boiling point stripping waste solution or the photoresist high boiling point stripping waste solution which does not require the pretreatment is then transferred to a series of regeneration processing steps in which the continuous distillation purification process is performed to remove the water contained in the photoresist high boiling point stripping waste liquid, Impurities such as a resist are sequentially removed and finally recovered and recovered with a high-boiling stripping solvent such as an electron-grade stripper solvent and HEP.

The high-boiling peeling solvent, such as HEP, which is recovered, is poorly separated and purified from heavy photoresist resins and metallic components contained in photoresist high boiling point peeling waste solution due to high boiling point characteristics such as high viscosity, thermal decomposition and chromaticity change, (Total regenerating process: total stripper recycling) and 4 (residual regenerating process). In the case of the above-mentioned process, Although the recovery of HEP was significantly improved through the primary and secondary regeneration process through the secondary stripping process (secondary stripping process), the recovery rate of HEP was 50% Or more.

 Meanwhile, the secondary and quaternary distillation apparatuses are operated in the process of re-boiling at a temperature of 160 ° C or less, and the pyrolysis phenomenon of HEP which may occur during the primary and secondary regeneration processes, that is, In the case of 10 to 15% by weight or less, a phenomenon in which the physicochemical properties such as thermal decomposition or deformation due to heat at a high temperature is changed at a temperature higher than 200 ° C and higher than 10-15% by weight at a temperature higher than 160 ° C However, in reality, such thermal damage does not completely solve the problem of thermal decomposition of HEP due to the tendency to start gradually from 120 ° C or more.

Further, in order to minimize the loss amount of HEP, in order to operate the re-boiling temperature of the second and fourth distillation apparatuses below 120 ° C, the recovery process pressure must be adjusted to a considerably low level. The productivity of the recovery process is reduced as well as the operation of the process is difficult. In addition, since a high back pressure is formed in the distillation column, the possibility of occurrence of process troubles such as flooding in the regeneration process becomes very difficult .

Accordingly, in order to solve the above problems, the present invention provides a method of removing low boiling point impurities from a photoresist high boiling point stripping waste liquid containing HEP which is a high boiling point stripping solvent by a primary distillation apparatus, A method of removing low boiling point impurities by primary distillation at a temperature of 62 to 67 ° C and a method of controlling and controlling the ratio of the moisture content of the high boiling point waste liquid supplied to the raw material supply tank connected to the primary distillation column, Which is capable of suppressing thermal decomposition of HEP that occurs during the primary and secondary regeneration processes by the process waste water regulator and enhancing the regeneration yield of HEP to a level of 50% Reproducing method.

The present invention is characterized in that, in the step of primary distillation from a photoresist high boiling point stripping liquid containing HEP which is a high boiling point stripping solvent to remove low boiling point impurities, an aprotic solvent (NMP, MMF, etc.) contained in the above- As the temperature of the device re-boiling rises, the amount of pyrolysis increases, and the pyrolysis rate of HEP that occurs during the primary and secondary regeneration processes increases or decreases according to the increase or decrease of the thermal decomposition degree of the non- .

Accordingly, by appropriately controlling the temperature of the reboiler connected to the primary distillation apparatus in order to prevent the increase in thermal decomposition of the aprotic solvent and to suppress the generation of HEP pyrolysis induction by-products, the primary and secondary regeneration processes The pyrolysis of HEP that occurs during the production of HEP is also decreased, thereby improving the regeneration recovery rate of HEP.

On the other hand, the non-magnetic solvent (NMP, MMF, etc.) has an amide group (-CO-NH-) in the molecule, and gradually reacts with water in the waste solution at a temperature of 40 ° C or higher, And the produced by-products are reacted with the photoresist resin (novolac resin, etc.) or the photosensitive agent in the waste solution including the high-boiling peeling solvent HEP at a temperature of 120 ° C or higher in the primary and secondary regeneration processes , And as a result, a part of the HEP is thermally decomposed, resulting in a decrease in the regeneration yield of HEP.

Referring to Table 1 and Table 2 regarding the method for increasing the recovery rate of HEP, the temperature of the boiling point of the high boiling point separation effluent of Examples I and II connected to the primary distillation apparatus was set at 75 deg. C As a result of the primary removal process, which removes low boiling point impurities at 65 ℃ and 50 ℃, the pyrolysis degree of NMP and MMF, which are nonpolar solvents, decreases greatly with temperature reduction, thereby suppressing the generation of HEP pyrolysis induction byproduct At the same time, the trend of the degree of thermal decomposition of HEP generated during the primary and secondary regeneration processes in the secondary and quaternary distillation apparatuses is also reduced in proportion to the relationship. , It is necessary to set the pressure to 50 torr. As a result, there is a high possibility of problems such as difficulty in process operation and lowering of process productivity, so that the temperature and pressure of the reboiler connected to the primary distillation device 62 ~ 67 ℃ and 75 ~ 85torr, it is most preferable to operate preferably set to 65 ℃ and 80torr.

In order to sufficiently improve and enhance the regeneration yield of HEP at a high recovery rate of 50% or more, another method of improving the recovery recovery rate according to the present invention is to use a pyrolysis of the aprotic solvent in the primary distillation apparatus It was confirmed that the degree of thermal decomposition of the aprotic solvent was remarkably reduced and the generation of HEP pyrolysis-inducing by-products was suppressed by appropriately adjusting the ratio of the amount of water contained in the high boiling point stripping liquid directly involved in the reaction, The degree of thermal decomposition of HEP that occurs during the primary and secondary regeneration processes also decreases proportionally, thereby enhancing the regeneration recovery rate of HEP.

To this end, isopropyl alcohol is supplementarily added to the waste solution for the purpose of a diluting solvent for controlling the water content ratio in the waste liquid, and the controlled moisture content ratio is measured by a moisture content meter, for example, a known Karl Fischer It is necessary to perform quantitative analysis by a moisture content meter.

First, for the high boiling point waste liquid fed to the raw material feed tank connected to the distillation column of the primary distillation apparatus, an isopropyl alcohol feed tank and a recycled isopropyl alcohol feed tank connected to each other in a separate stirring tank and isopropyl alcohol And the mixture is thoroughly mixed by using an agitator equipped with an impeller so that the whole of the high boiling point stripping liquid becomes a homogeneous state so that an appropriate level of the moisture content ratio capable of suppressing the generation of the HEP pyrolysis- And the high boiling point stripping waste liquid having the moisture content rate newly adjusted is supplied to the primary distillation apparatus through the raw material supply tank, the degree of thermal decomposition reaction of the aprotic solvent secondary to the primary stripping process And the HEP pyrolysis inducing portion The water generated is much more suppressed, and are thereby at the same time the primary and secondary playback also thermal decomposition of the HEP is generated in the process also decreases proportionally more can enhance easily the additional reproduction recovery of HEP.

Separately from the isopropyl alcohol additionally supplied in addition to the stirring tank for mixing, the isopropyl alcohol which is removed as a low boiling point impurity by an elimination step of the primary distillation apparatus from an economical viewpoint is not refluxed into the distillation column, If the content of propyl alcohol is relatively large, it may be used as recycled isopropyl alcohol for diluting solvent which is further fed to the stirring tank.

Next, referring to Table 3 and Table 4 regarding the method of increasing the HEP recovery rate by controlling the moisture content of the high boiling point stripping liquid, the high boiling point stripping waste solution of Examples I and II was subjected to the above- When each waste liquid in which the water content ratio is newly controlled and controlled by the process waste water regulator is used as a raw material for the recovery process for increasing the recovery rate, the temperature of the boiler period connected to the primary distillation apparatus is set at the conventional regeneration process temperature As a result of performing a primary removal process in which low boiling point impurities are removed at 75 DEG C under the conditions and at 65 DEG C under which the degree of thermal decomposition of the aprotic solvent is greatly reduced, the high boiling point waste solution of Examples I and II The smaller the ratio of the controlled content to the initial moisture content, the more the degree of thermal degradation of NMP and MMF It is, the same time also the thermal decomposition of HEP that occur during the primary and secondary regeneration step in the second and the fourth distillation unit was confirmed that at the same time showing a further reduction in proportional relationship trend.

In each case of the high boiling point waste liquid of Example I wherein the moisture content ratio is controlled and controlled by the process waste water control device including the stirring tank with the impeller, The additional reduction of the thermal decomposition degree of the NMP and MMF as the apical solvents is relatively large under the condition that the temperature of the freezing is set at 65 DEG C and 80 torr, and isopropyl alcohol used for controlling the moisture content ratio is newly supplemented It is most preferable that the moisture content ratio adjusted to a level satisfying both the economical aspect that minimizes the supply amount is 9.7 to 10.3% by weight, preferably 10% by weight.

If the water content ratio is less than 9.7 wt%, it is economically disadvantageous to supply a relatively large amount of isopropyl alcohol in order to reduce thermal decomposition of the non-quantitative solvent or HEP. On the other hand, if the water content ratio exceeds 10.3 wt% Although a relatively small amount of isopropyl alcohol is advantageous in terms of economy, it is disadvantageous in that the reduction width of the thermal decomposition of the non-quantitative solvent or HEP is so small that it is impossible to achieve a recovery rate of 50% or more with respect to HEP.

Similarly, in each case of the high boiling point waste liquid of Example II, in which the moisture content ratio is regulated by the process waste water control apparatus including the stirring tank with the impeller, the newly adjusted moisture content ratio And most preferably 14.8 to 15.2% by weight, preferably 15% by weight.

If the water content ratio is less than 14.8 wt%, it is economically disadvantageous to supply a relatively large amount of isopropyl alcohol in order to reduce thermal decomposition of the non-quantitative solvent or HEP. If the water content ratio exceeds 15.2 wt% Although a relatively small amount of isopropyl alcohol is advantageous in terms of economy, it is disadvantageous in that the reduction width of the thermal decomposition of the non-quantitative solvent or HEP is so small that it is impossible to achieve a recovery rate of 50% or more with respect to HEP.

Next, the present invention will be described in detail with reference to Fig. 1 and Tables 1 to 5 of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing an embodiment of a regenerating apparatus of the present invention used for HEP regeneration, which is a high-boiling point exfoliation solvent at a high recovery rate of 50% or more from the photoresist high boiling point separation waste liquid according to the present invention.

As shown in Fig. 1, an agitation mixing tank M8 for mixing photoresist high boiling point separation waste liquid and isopropyl alcohol for waste liquid dilution is provided, and the line extending from the lower end of the agitation mixing tank M8 is 2 One line in which the second flow control valve M10 and the third transfer pump M7 are installed is connected to the raw material supply tank T-1 and the first flow rate valve M9 and the first The other one line in which the transfer pump M6 is installed is connected to the upper end of the agitation mixing tank M8 as a circulation line.

Here, the first flow rate valve M9 and the first transfer pump M6 are connected to each other through a circulation line connected from the lower end to the upper end of the agitating and mixing tank M8, The circulation process in which the photoresist high boiling point stripping waste liquid flows in again through the upper end of the agitation mixing tank M8 can be performed.

Then, an isopropyl alcohol supply tank (M1) for storing isopropyl alcohol and a recycle isopropyl alcohol supply tank (M3) for storing isopropyl alcohol sent from the primary distillation apparatus side are provided, and the isopropyl alcohol supply is provided. Each line extending from the lower end of the tank M1 and the recirculating isopropyl alcohol supply tank M3 connects the third flow control valve M2, the fourth flow control valve M4, and the second transfer pump M5. It is connected to the upper end of the stirring mixing tank (M8).

Accordingly, isopropyl alcohol can be supplied from the isopropyl alcohol supply tank M1 and the recycle isopropyl alcohol supply tank M3 to the stirring mixing tank M8.

On the line extending from the lower end of the agitating and mixing tank M8, that is, on the line before branching into two, a moisture content meter M11 is provided. The moisture content meter M11 at this time is connected to the agitation mixing tank M8, And the water content of the waste liquid discharged from the waste water is measured.

The first flow rate valve M9, the second flow rate valve M10, the third flow rate valve M2, the fourth flow rate valve M4, the first feed pump M6, the second feed pump M5, The third transfer pump M7, and the moisture content measuring device M11, the controller M11a is provided.

1, the regeneration yield of HEP according to the present invention employing the process waste water control device 100 including the stirring / mixing tank M8 with the impeller attached thereto and the primary distillation apparatus is set at 50% The recovery method will be described below.

Referring to FIG. 1, the photoresist high boiling point waste liquid discharged from the manufacturing plants of the LCD and the semiconductor device is collected and mixed in a separate waste liquid storage tank, and then neutralized and immersed The photoresist high boiling point stripping waste liquid which has undergone a pretreatment process such as filtration or the photoresist high boiling point stripping waste liquid which does not require a pretreatment is fed to the raw material supply tank T-1 for a series of regeneration processing steps in which a continuous distillation purification process is performed Before being supplied, the photoresist is transferred to an agitating and mixing tank M8 equipped with an impeller so as to control and control the ratio of the amount of water contained in the photoresist high boiling point separation waste liquid containing HEP which is a high boiling point separation solvent.

Next, the first flow control valve M9 is opened while the agitator attached to the agitating and mixing tank M8 and having the impeller attached thereto is operated at a speed of 100 to 150 rpm for 1 hour or more so that the high boiling point waste liquid is in a uniform state. 1 transfer pump M6 is operated to circulate the upper portion of the agitation mixing tank M8 and then a part of the high boiling point waste liquid is introduced into the moisture content meter M11 to analyze the water content in the waste liquid.

Referring to Table 1, the water contents in the waste liquids of Examples I and II are 12 wt% and 17 wt%, respectively.

That is, in the present invention, two types of waste liquids each having a water content of 12 wt% and 17 wt% are applied.

After the water content contained in the high boiling point stripping liquid is determined in the above-described uniform state, the pyrolysis reaction of the aprotic solvent secondary to the primary removal process in the distillation column (D-1) of the primary distillation apparatus (The waste liquids of Examples I and II are levels of 10 wt% and 15 wt%, respectively, as shown in Tables 3 and 4) of the high boiling point stripping liquid, (M11a) calculates an isopropyl alcohol supplement supply amount necessary for the dilution of the waste liquid, then issues an output signal to open the third flow control valve (M2) and operate the second transfer pump (M5) to supply the isopropyl alcohol supply tank M1 to the mixing tank M8 for replenishment.

At the same time, a portion of the high-boiling stripping waste liquid in which the moisture content ratio is newly adjusted while the agitator equipped with the impeller is continuously operated at a speed of 200 to 300 rpm is introduced into the moisture content meter M11 to measure the changed moisture content in the waste liquid If the measured moisture content ratios do not meet the target levels (10% and 15% by weight respectively for the waste solutions of Examples I and II, see Table 3 and Table 4), the controller M11a, The first flow control valve M9 is opened by operating the first transfer pump M6 to circulate the upper portion of the agitation mixing tank M8 so that the waste liquid can be controlled in a uniform state .

Separately, there is provided a recycle isopropyl alcohol feed tank M3 which is connected in line with the primary distillation apparatus side so that it is removed from the distillation column (D-1) of the primary distillation apparatus as low boiling point impurities, The isopropyl alcohol is stored in the recycle isopropyl alcohol feed tank M3 via the fourth flow control valve M4 and the second feed pump M5 by the controller M11a, (M8) to be used as a diluting solvent.

That is, the process waste fluid control device 100 of the present invention includes two isopropyl alcohol supply tanks composed of isopropyl alcohol supply tank (M1) and recycled isopropyl alcohol supply tank (M3), and thus isopropyl It is possible to supply isopropyl alcohol from the alcohol supply tank M1 and the recycle isopropyl alcohol supply tank M3.

Subsequently, when it is determined from the moisture content meter M11 that the newly adjusted moisture content ratio of the high boiling point stripping liquid has reached the target level, that is, when the moisture content in the total high boiling point stripping liquid is 9.7 to 10.3 wt% , Preferably 10 wt.% Or 14.8-15.2 wt.%, Preferably 15 wt.%, The controller M11a issues an output signal to close the first and third or fourth flow control valves , The operation of the first and second transfer pumps is stopped, then the second flow control valve M10 is opened, and the third transfer pump M7 is operated so that the water content ratio is increased to the target level The stripping waste liquid is transferred from the agitating tank M8 to the raw material feed tank T-1.

Next, for the purpose of a series of regeneration processing steps in which the continuous distillation purification process is carried out, the high-boiling separation waste liquid is discharged from the raw material supply tank (T-1) by operating the fourth transfer pump (F- To the distillation column (D-1).

Subsequently, the waste liquid transferred to the primary distillation apparatus is heated above the boiling point of water to enable evaporation of low boiling point impurities such as moisture, and the stripper solvent component contained in the stripper waste liquid is decomposed or deformed by high temperature due to prolonged exposure to high temperature. It is necessary to prevent the physical and chemical properties from changing, and especially HEP, a high boiling point peeling solvent, has high thermal sensitivity due to high boiling point characteristics and at the same time coexists with moisture content of 3 to 5% by weight or more. Since thermal decomposition is promoted by thermal damage at a temperature of 85 ° C. or higher, a pressure reduction pump (not shown) connected to a distillation column may be operated to reduce the pressure in the tower to reduce pressure.

In addition, as the temperature of the reboiler (1-1) connected to the distillation column increases, the amount of pyrolysis of the aprotic solvent (NMP, MMF, etc.) contained in the waste liquid increases, and the thermal decomposition of such aprotic solvent also increases. Hence, HEP pyrolysis-induced by-products are inhibited by blocking the pyrolysis reaction of the aprotic solvent, since the effects on the thermal decomposition of HEP generated during the first and second regeneration processes are proportionally increased. Referring to Table 1 and Table 2 to further improve the recovery recovery of HEP through further reduction of the thermal decomposition degree of the immersion apparatus connected to the primary distillation apparatus for the high-boiling stripping waste liquid of Examples I and II. 1) The temperature and pressure in the 62 ~ 67 ℃ and 75 ~ 85torr, preferably the temperature is 65 ℃ level, the pressure distillation operation pressure is best set to 80torr level.

Distillation and extraction of low boiling point impurities such as water and isopropyl alcohol into the upper portion of the distillation tower are carried out while maintaining the purification conditions. These are condensed in the condenser 1-2 and recovered to the temporary storage tank 1-3, The pump 1-4 is operated to partially reflux to the top of the distillation column so that the vapor-liquid equilibrium inside the column can be optimally maintained on the basis of the material resin, or when the IAP content is relatively large, the recycle isopropyl alcohol supply And the other remainder is transported to a separate impurity collection tank (T-2) and then discarded.

Thereafter, when the water content level of the photoresist high boiling point stripping waste liquid from which low-boiling point impurities such as moisture has been removed reaches a range of 1 to 3 wt%, the water is returned to the sixth feed pump 1 -5) is fed to the distillation column (D-2) of the second distillation apparatus.

The photoresist high boiling point stripping waste liquid from which the low boiling point impurities are removed is subjected to secondary distillation at a temperature of 120 to 160 DEG C to remove the high boiling point residue (secondary waste by-product waste) containing high boiling point impurities At the same time, rapidly heated to a temperature equal to or higher than the boiling point of the component having the highest boiling point among the solvent components constituting the stripper, so that the entire stripper solvent composition constituting the stripper is distilled, extracted and regenerated at the same time ), The secondary waste by-product, which is a mixture of a high boiling point impurity and a high-boiling point HEP, is mixed with a fourth distillation pump (2-2) To the distillation column (D-4) of the apparatus.

On the other hand, the entire stripper solvent composition is distilled at once to remove the minute moisture remaining in the stripper solvent composition due to hygroscopicity of the stripper solvent component from the stripper solvent composition that has been subjected to total stripper recycling (primary regeneration process) The pump 2-1 is operated and transferred to the distillation column D-3 of the tertiary distillation apparatus.

Next, the third distillation apparatus removes fine moisture remaining from the recovered stripper solvent composition through the secondary distillation apparatus, thereby obtaining a high purity electronic grade level The volatile components including the moisture to be removed are recycled to the primary distillation unit and distilled, whereby the moisture is separated into a separate impurity collection tank (T- 2) and discarded, and some of the stripper solvents contained in the volatile components are sent back to the secondary distillation apparatus and recovered without loss.

In addition, the stripper solvent, which is volatilized and recovered to the column top and satisfies the quality standards (purity: 99.5% or more, moisture content: 0.1 wt% or less, total metal content: 100 ppb or less) of the high purity electronic grade, is applied to the tower bottom and the reboiler connected thereto. After operating the eighth transfer pump 3-1 and the ninth transfer pump 3-2 together with the remaining stripper composition solvent, the high quality electronic grade quality standard is passed through the microfilter 5. Recovered to meet the regenerated stripper composition solvent to be met and immediately transferred to the regenerated stripper solvent storage tank (T-4) and stored.

On the other hand, the stripper solvent composition recovered through the secondary distillation apparatus operates the seventh transfer pump 2-1 so that a spiral agitated column device made of metal or a teflon material as a spinning band type distillation column has a maximum of 2,500 (D-5) of the 5th distillation unit, which exhibits high separation efficiency by increasing the number of theoretical stages of the column while rapidly rotating at the speed of 5 rpm, and separating the fine particles separately or separating the mixture having a narrow non- Each of the individual stripper solvents recovered immediately after the microfilter 5 is subjected to a separate stripper recycling process is supplied to each of the regenerated stripper solvent storage tanks T-5, T- 6, T-7, T-8).

Subsequently, the secondary by-product waste liquid in which a considerable amount of HEP, which is a high boiling point peeling solvent, transferred to the fourth distillation apparatus is mixed as described above is distilled under a condition of 120 to 160 ° C. to remove high boiling impurities. While removing it, transfer it to a separate impurity collection tank (T-3) and discard it, and at the same time, the quality standard (purity: 99.5% or more, water content: 0.1 wt% or less, total metal content: 100 ppb or less) of high purity After the additional regeneration recovery process (Secondary regeneration process: Additional stripper recycling) for additionally regenerating HEP, which is a high boiling point peeling solvent, was performed, the HEP solvent satisfying the above specification was recovered by operating the eleventh transfer pump (4). After that, the microfilter 5 is recovered as a regeneration high boiling point peeling solvent that satisfies the high purity electronic grade quality standards, and is immediately transferred to a regeneration stripper solvent storage tank T-4 and stored therein.

On the other hand, the HEP solvent as the high-boiling-point peeling solvent recovered through the above-mentioned fourth-order distillation apparatus operates the eleventh feed pump 4 so that the high-purity separation is separately performed for the mixture having a narrow non- The individual stripper solvent recovered immediately after passing through the microfilter 5 after being carried to the distillation column (D-5) of the fifth distillation apparatus and performing the third reclamation process (Separate stripper recycling) Can be transported and stored in solvent storage tanks (T-5, T-6, T-7, T-8).

Referring to the results of the total regeneration recovery of HEP after the primary and secondary regeneration processes of Table 5 for the regeneration method of promoting the regeneration yield of the high-boiling peeling solvent HEPO at a high recovery rate of 50% or more, As a result of the present invention, the regeneration recovery rate of HEP was further increased by 13% compared with the conventional process, and the final total recovery reached 58%, thereby achieving high-quality regeneration It was confirmed that a recovery rate of 50% or more, which is a level that can be produced inexpensively with a solvent, can be achieved.

Also, in the results of the present invention for the photoresist high boiling point separation waste solution of Example II, the regeneration recovery rate of HEP was further increased by 10% in comparison with the existing process, and the final total recovery rate reached 52% The recovery rate of 50% or more was achieved.

Hereinafter, the present invention will be described in detail with reference to Examples, but the scope of the present invention is not limited by the Examples.

The regeneration method of the present invention was applied to the photoresist high boiling point separation waste liquid generated in the LCD manufacturing process and the composition of the waste solution used in this process is shown in Table 1.

Stripper Solvent Content (wt%) Content of impurity component (% by weight) MIPA DMAc MMF NMP MDG HEP Photoresist resin moisture IPA Etc Example I 12 - 15 - 33 21 3.0 12 3 1.0 Example II - 14 - 10 17 31 4.5 17 5 1.5

[0064] While performing the regeneration process according to the present invention for recovering the regeneration yield of HEP which is a high boiling point separation solvent from the high boiling point stripping liquid in the above Table 1 at a high recovery rate of 50% or more, The degree of pyrolysis of the aprotic solvent contained in the waste solution according to the distillation conditions in the process and the degree of pyrolysis of HEP after the primary and secondary regeneration processes are shown in Table 2.

Primary Removal Process (Primary Distillation Unit) Operating Conditions 75 [deg.] C and 110 torr 65 ° C and 80 torr 50 ° C and 50 torr Example I MMF thermal decomposition (%),
After the primary removal process 20.8 12.7 5.3 HEP thermal decomposition (%),
After the primary and secondary regeneration processes 17.6 11.9 4.9 Example II NMP thermal decomposition (%),
After the primary removal process 17.3 10.5 3.3 HEP thermal decomposition (%),
After the primary and secondary regeneration processes 14.2 9.4 2.7

While performing the regeneration treatment process according to the present invention for recovering the regeneration yield of HEP which is a high boiling point separation solvent from the high boiling point stripping liquid in Table 1 at a high recovery rate of 50% or more, the pyrolysis degree The results are shown in Table 1. The results are shown in Table 1. The results are shown in Table 1. The results are shown in Table 1. The results are shown in Table 1. The results are shown in Table 1. 3, and the waste solution of Example II is shown in Table 4.

The water content (wt.%) Ratio of the waste liquid (Example I) 5 8 9 10 12 15 75 [deg.] C and 10 torr
(Primary removal process operation condition) MMF thermal decomposition (%),
After the primary removal process 4.6 10.3 18.8 19.6 20.8 22.1 HEP thermal decomposition (%),
After the primary and secondary regeneration processes 3.5 8.0 14.3 15.8 17.6 19.1 65 ° C and 80 torr
(Primary removal process operation condition) MMF thermal decomposition (%),
After the primary removal process 2.6 3.8 4.5 7.1 12.7 13.6 HEP thermal decomposition (%),
After the primary and secondary regeneration processes 1.8 2.7 3.1 5.9 11.9 12.2

Water content (wt.%) Ratio of waste solution (Example II) 5 11 13 14 15 17 20 75 [deg.] C and 110 torr
(Primary removal process operation condition) NMP thermal decomposition (%),
After the primary removal process 3.5 5.4 11.8 13.9 15.6 17.3 18.3 HEP thermal decomposition (%),
After the primary and secondary regeneration processes 2.4 4.7 10.1 12.2 13.0 14.2 15.9 65 ° C and 80 torr
(Primary removal process operation condition) NMP thermal decomposition (%),
After the primary removal process 1.5 2.3 3.2 3.8 4.3 10.5 11.2 HEP thermal decomposition (%),
After the primary and secondary regeneration processes 0.9 1.8 2.5 2.9 3.3 9.4 10.0

Further, while carrying out the regeneration treatment process according to the present invention for recovering the regeneration yield of HEP which is a high boiling point separation solvent from the high boiling point stripping liquid in the above Table 1 at a high recovery rate of 50% or more, (65 ° C., 80 torr) and the change in the moisture content ratio of the waste solution (10% in each of Examples I and II, respectively), the distillation condition change (65 ° C., 80 torr) , 15%) were simultaneously performed. Table 5 shows the results obtained by comparing the total recovery after the primary and secondary regeneration processes of the HEP solvent in each case with the recovery rate according to the conventional process.

HEP total recovery (%, wt.) - after the 1st and 2nd regeneration processes Existing process Primary removal process change (65 ° C and 80 torr) Change in water content ratio of waste water
(10% by weight, 15% by weight in Examples I and II, respectively) and
Primary removal process change (65 ° C and 80 torr) Example I 45 50 58 Example II 42 45 52

M1, M3: Isopropyl alcohol supply tank
M2, M4, M9, M10: Flow control valve
M5, M6, M7, F-1,1-4,1-5,2-1,2-2,3-1,3-2,4: Feed pump
M11: Moisture content meter
M11a:
M8: Mixing tank
T-1: Feed tank
T-2, T-3: Impurity collection tank
T-4, T-5, T-6, T-7 and T-8:
D-1, D-2, D-3, D-4:
1-1: Rebuilding
1-2: Condenser
1-3: Temporary storage tank
5: Micro filter

Claims (5)

The primary distillation apparatus removes low boiling point impurities by first distilling the photoresist high boiling point peeling waste solution containing 1-piperazine ethanol, a high boiling point peeling solvent, to provide a water content ratio to a raw material supply tank for supplying the photoresist high boiling point peeling waste solution. It includes a process waste fluid moisture control device for transferring the adjusted photoresist high boiling point peeling waste liquid,
The process waste fluid moisture control device is an isopropyl alcohol supply tank for supplying isopropyl alcohol, isopropyl alcohol and the photoresist high boiling point peeling waste liquid discharged from the manufacturing plants of the LCD and semiconductor device supplied from the isopropyl alcohol supply tank And a flow control valve and a transfer pump respectively installed in the line between the isopropyl alcohol supply tank and the stirred mixing tank and the line between the stirred mixing tank and the raw material supply tank for isopropyl alcohol supply. And a moisture content measuring device for measuring the moisture content of the photoresist high boiling point peeling waste liquid discharged from the stirring mixing tank, and a controller for controlling the operation of the flow control valve and the transfer pump according to the moisture content measured by the water content measuring device. under,
When the water content in the photoresist high boiling point peeling waste measured by the moisture content measuring instrument reaches 9.7 to 10.3% by weight or 14.8 to 15.2% by weight, the photoresist high boiling point peeling waste is transferred from the stirred mixing tank to the raw material supply tank. The first distillation apparatus is a device for recovering 1-piperazine ethanol from the photoresist high boiling point peeling waste liquid, characterized in that to operate by setting the temperature and pressure of the reboiler to 62 ~ 67 ℃ and 75 ~ 85torr.
The method according to claim 1,
When the water content in the photoresist high boiling point peeling waste liquid measured by the water content measuring instrument reaches 10% by weight or 15% by weight, the photoresist high boiling point peeling waste liquid is transferred from the stirred mixing tank to the raw material supply tank, characterized in that Apparatus for recovering 1-piperazineethanol from photoresist high boiling point stripping waste liquid.
The method according to claim 1,
The primary distillation apparatus is a device for recovering 1-piperazine ethanol from the photoresist high boiling point stripping waste liquid, characterized in that to operate by setting the temperature and pressure of the reboiler to 65 ℃ and 80 torr.
The method according to claim 1,
The isopropyl alcohol supply tank is composed of two isopropyl alcohol supply tanks consisting of an isopropyl alcohol supply tank for storing isopropyl alcohol and a recirculating isopropyl alcohol supply tank sent from a primary distillation apparatus. Apparatus for recovering 1-piperazine ethanol from the photoresist high boiling point stripping waste liquid characterized in that the isopropyl alcohol from the supply tank can be supplied to the stirred mixing tank
The method according to claim 1,
The lower end and the upper end of the stirring mixing tank are connected to a circulation line having a flow valve and a transfer pump, and the photoresist high boiling point peeling waste liquid exiting the lower end of the stirring mixing tank is introduced again into the upper end of the stirring mixing tank through the circulation line. Apparatus for recovering 1-piperazine ethanol from the photoresist high boiling point stripping waste liquid, characterized in that it can be.

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