KR101441031B1 - A recylcing method of polyolefin and liquid paraffin contained in polymeric membrane of secondary battery - Google Patents

Abstract

The present invention relates to a method for reproducing polyolefin and paraffin from a secondary battery waste separation membrane. More specifically, the method comprises the steps of: i) partially separating only liquid paraffin by heating a second battery waste separation membrane including polyolefin and liquid paraffin; ii) dissolving and dispersing liquid paraffin in a stripping liquor by mixing the stripping liquor with the secondary battery waste separation membrane from which the liquid paraffin is partially removed; and iii) respectively separating and obtaining a solid polyolefin, a stripping liquor, and a liquid paraffin mixture through solid-liquid separation. The present provides an economical, efficient, and environmentally friendly step by which liquid paraffin and polyolefin components can be respectively separated at high purity from separation membrane scraps and defective separation membranes that are generated during the manufacture of secondary batteries.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a method of recycling polyolefins and paraffins from a secondary battery pulmonary separation membrane. BACKGROUND ART < RTI ID = 0.0 >

The present invention relates to a method for regenerating a polyolefin and a paraffin from a secondary battery pulmonary separation membrane, and more particularly, to a method for recovering a polyolefin and a paraffin from a secondary battery pulmonary separation membrane. Ii) dissolving and dispersing the liquid paraffin in the exfoliating liquid by mixing the secondary battery pulmonary separation membrane from which the liquid paraffin has been partially removed and the exfoliating liquid; And iii) separating the solid phase polyolefin, liquid phase exfoliating liquid and liquid paraffin through solid-liquid separation to obtain a polyolefin and a paraffin from the secondary battery pulmonary separation membrane, respectively.

The secondary battery is a chemical battery which can be used semi-permanently by continuously repeating charging and discharging through oxidation-reduction reaction, and it can be a lead battery, a nickel cadmium battery, a nickel hydrogen battery, a lithium ion battery and a lithium polymer battery. In the past, such secondary batteries were mainly used as lead acid batteries in automobile batteries and uninterruptible power supply devices. Recently, however, lithium ion batteries, which have high energy density, are being used in mobile phones, notebook computers, tablet PCs and the like. Lithium ion batteries usually use a porous separator for separating the positive and negative electrodes while moving charge. In the method of making a microporous membrane, a wet process in which a polyolefin is kneaded with a diluent at a high temperature to make a single phase, a polyolefin and a diluent are separated in a cooling process, and a diluent is extracted to form a void in the polyolefin, And is excellent in strength and transparency, and uniform in pore quality and excellent in quality stability, and is widely used in high capacity / high output lithium ion secondary batteries. As the diluent, liquid paraffin is usually used. Korean Patent No. 1354708 discloses a process for preparing a multi-component separator for a lithium secondary battery comprising ultra-high molecular weight polyethylene, which comprises a compatibilizer for easily kneading a vinylidene fluoride-based polymer, ultrahigh molecular weight polyethylene and a high density polyolefin And mixing the mixture with liquid paraffin; and extruding and extruding the melted mixture to prepare a sheet of ultra-high molecular weight polyethylene-high density polyolefin-vinylidene fluoride-based polymer type Casting the biaxially stretched diatomaceous membrane with a volatile solvent to remove liquid paraffin in the biaxially stretched diverted membrane; Biaxially stretched membrane Opening is characterized in that it comprises a determining step, it is disclosed a multi-component membrane for a lithium secondary battery comprising the ultra high molecular weight polyethylene. As shown in the above document, the parylene content of the polylactic component in the separator film to be produced is reduced to less than 5% by the washing process, but the scrap or the pulverized membrane is discarded with 30 to 80% paraffin contained therein.

Scrap or pulmonary separation membranes are inevitably generated in the process of manufacturing the secondary battery or in the recycling process after collection of the waste secondary batteries. Such scrap or pulmonary separation membranes can not be regenerated, and waste disposal It is treated in an improper way by the law, which causes problems such as resource waste and environmental pollution. Therefore, efforts have been made to scrap the secondary battery separation membrane and regenerate the pulmonary separation membrane. Korean Patent No. 1300652 discloses a process for producing a porous secondary battery separator comprising a waste secondary battery separator made of polyethylene impregnated with paraffin oil, the separator comprising platinum (Pt), palladium (Pd), iridium (Ir) A paraffin oil extracting step of separating the paraffin oil from the waste secondary battery separator by reacting with at least one of noble metals of osmium (Os), rhodium (Rh) or ruthenium (Ru) And removing the paraffin oil remaining on the surface of the secondary battery separator by spraying distilled water to the secondary battery separator in which the paraffin oil is separated in the paraffin oil extraction step. Is decomposed into paraffin oil and polyethylene.

However, since the process disclosed in the above document includes a catalytic reaction, a catalyst separation reaction, and a reaction using a solvent, the process is complicated and the cost is excessive, and the cleaning liquid becomes a secondary waste again, there is a problem.

Korean Patent No. 1354708 Korean Patent No. 1300652

Accordingly, it is an object of the present invention to provide an economical, efficient, and environmentally friendly process for separating liquid paraffin and polyolefin components from separator scrap and defective waste separator, which are generated during the manufacturing process of a secondary battery, with high purity.

In order to accomplish the above object, the present invention provides a method of manufacturing a semiconductor device, comprising the steps of: (i) separating only liquid paraffin by heating a secondary battery pulmonary separation membrane containing polyolefin and liquid paraffin (S020); Ii) dissolving and dispersing the liquid paraffin in the exfoliating liquid by mixing the secondary battery pulp separation membrane from which the liquid paraffin is partially removed and the exfoliating liquid (S030); (Iii) a step (S040) of separating solid phase polyolefin, liquid phase exfoliating liquid and liquid paraffin through solid-liquid separation, respectively, to recover polyolefin and paraffin from the secondary battery pulmonary separation membrane.

The present invention also provides a method for regenerating a polyolefin and a paraffin from a secondary battery pulmonary separation membrane, which further comprises the step (S010) of breaking the secondary battery pulmonary separation membrane before step (i).

The present invention also relates to a process for producing a toner according to the present invention, wherein the exfoliating liquid is at least one selected from the group consisting of dichloropropane, water, trichlorethylene, methylene chloride, tetrachloroethylene, toluene, xylene, It is preferable to use at least two kinds selected from the group consisting of methyl ethyl ketone, ethyl acetate, methyl acetate and 1-bromopropane, The present invention also provides a method for regenerating polyolefins and paraffins from a secondary battery pulmonary separation membrane.

The present invention also provides a method for regenerating a polyolefin and a paraffin from a secondary battery pulmonary separation membrane, wherein the liquid phase and the solid phase are separated by centrifugation or filtration in the step (iii).

The present invention also relates to a method for recovering a polyolefin and a paraffin from a secondary battery pulmonary separation membrane, further comprising a step (iv) of separating the liquid phase separation liquid and the liquid paraffin mixture separated by the solid-liquid separation step (S050) . ≪ / RTI >

Also, the present invention provides a method for regenerating a polyolefin and a paraffin from a secondary battery pulmonary separation membrane, wherein the heating in step (i) is performed at a temperature ranging from 70 to 90 ° C.

The method of recovering polyolefin and paraffin from the secondary battery pulmonary separation membrane of the present invention is an economical, efficient and environmentally friendly method of separating the liquid paraffin and the polyolefin component from the separation membrane scrap and the poor pulmonary separation membrane generated during the manufacturing process of the secondary battery, Process.

Brief Description of the Drawings Fig. 1 is a process flow chart of one embodiment of a method for regenerating polyolefin and paraffin from a secondary battery pulmonary separation membrane of the present invention

Hereinafter, the present invention will be described in detail.

The term 'pulmonary separation membrane' as used herein refers to both defective products and scrap that accompany the secondary battery membrane production process, and refers to a portion having a high liquid paraffin content because it is not cleaned during the production of the separation membrane, and is generally referred to as an Oily Sheet. In this specification, the term 'liquid paraffin' refers to paraffin used as a diluent in the manufacture of the secondary battery separator, and the term 'separator' refers to the solubility of the polyolefin, which is a main component of the secondary battery separator, Of not more than 1% and solubility in liquid paraffin of not less than 95% to dissolve only the liquid paraffin component adhered to the polyolefin into the peeling liquid.

1 is a process flow diagram of one embodiment of a method for regenerating a polyolefin and a paraffin from a secondary battery pulmonary separation membrane of the present invention. As shown in FIG. 1, the method for recovering polyolefin and paraffin from the secondary battery pulmonary separation membrane of the present invention comprises the steps of (i) heating a secondary battery pulmonary separation membrane containing polyolefin and liquid paraffin to partially separate only liquid paraffin (S020) ,; Ii) dissolving and dispersing the liquid paraffin in the exfoliating liquid by mixing the secondary battery pulp separation membrane from which the liquid paraffin is partially removed and the exfoliating liquid (S030); Iii) separating the solid phase polyolefin, the liquid phase exfoliating liquid and the liquid paraffin mixed liquid through solid-liquid separation, respectively (S040).

The present invention comprises i) heating a secondary battery pulmonary separation membrane containing a polyolefin and liquid paraffin to partially separate only liquid paraffin (S020). 20 to 40% by weight of the liquid paraffin content of the pulmonary separation membrane, that is, about 10 to 20% by weight based on the total weight of the pulmonary separation membrane can be isolated depending on the temperature and the heating time of the heating process. The step i) should be carried out at a temperature lower than the melting point (Tm) of the polyolefin in the components of the pulverized separation membrane, and below the temperature at which the paraffin component is not carbonized. The higher the heating temperature, the higher the acid value due to the paraffin carbonization and the higher quality liquid paraffin can not be obtained. Generally, the melting point of the polyolefin is 110 ° C or higher, and the carbonization of the paraffin occurs at a temperature of about 100 ° C. Therefore, the heating is preferably performed at 90 ° C or lower, and at a temperature in the range of 70 to 90 ° C Is more preferable.

The method of regenerating the polyolefin and the paraffin from the secondary battery pulmonary separation membrane of the present invention may further comprise a step (S010) of pulverizing the secondary battery pulmonary separation membrane before the step (i). The secondary battery pulmonary separation membrane is in the form of a sheet, and if it is maintained in this form, the specific surface area is not wide, so that the efficiency of separation and removal of liquid paraffin in the heating step of step i) or the liquid paraffin separation step of step ii) . Accordingly, the surface area of the pulmonary separation membrane is widened before the above-described process, thereby increasing the efficiency of separating the liquid paraffin from the solid polyolefin.

The present invention includes (ii) a step (S030) of dissolving and dispersing liquid paraffin in a stripping liquid by mixing a secondary battery pulmonary separation membrane from which a part of the liquid paraffin has been removed and a stripping liquid. The peeling liquid is not particularly limited as long as it has the properties as defined in the present specification. Preferable examples of the peeling solution include dichloroprene, water, trichlorethylene, methylene chloride, tetrachloroethylene, toluene, xylene, methyl ethyl But is not limited to, at least one selected from the group consisting of methyl ethyl ketone, ethyl acetate, methyl acetate and 1-bromopropane, . Dichloropropane has a relatively low solubility in polyolefins compared to other solvents, has good ability to separate liquid paraffins from polyolefins, has low toxicity to humans, and has high separation efficiency during liquid-liquid separation due to fractional distillation with liquid paraffin Most preferred.

The method for regenerating the polyolefin and the paraffin from the secondary battery pulmonary separation membrane of the present invention includes: (iii) separating the solid phase polyolefin, the liquid phase exfoliating liquid and the liquid paraffin mixed liquid through solid-liquid separation, respectively (S040). The solid-liquid separation step is not particularly limited, and any known solid-liquid separation step such as centrifugation or filtration can be used. The solid phase polyolefin having been subjected to the solid-liquid separation step has a residual liquid paraffin content of only 3% by weight or less, which is sufficient for re-pellet workability and merchantability. The solid polyolefin can be produced in the form of pellets after extrusion process after being subjected to a solid-liquid separation process (S040) and, if necessary, in addition, or can be commercialized through an injection machine.

 The method for regenerating the polyolefin and the paraffin from the secondary battery pulmonary separation membrane of the present invention comprises the steps of (iv) separating the liquid phase separation liquid and the liquid paraffin mixture separated after the solid-liquid separation step (S050) . When the fractional distillation (S050) is completed, the polyolefin and the liquid paraffin can be obtained in a very high purity from the pulmonary separation membrane, and the polyolefin and the liquid paraffin and the liquid paraffin can be obtained with high purity. Reusable. The specific conditions of the fractional distillation may be adjusted by those skilled in the art depending on the composition and characteristics of the exfoliating liquid and the liquid paraffin, so that the description of the present invention will not be further described herein.

Hereinafter, the present invention will be described in more detail by way of examples which are preferred examples of the present invention. However, the following examples are for the purpose of understanding the present invention and the scope of the present invention is not limited to the following examples.

Example

100 kg of separation membrane scrap was charged into a crushing process and passed through a heating pipe at 70 to 90 ° C. for 60 seconds to obtain 25 kg of paraffin. Then, a stripping liquid obtained by mixing dichloropropane and water at a ratio of 90:10 (vol.%) And the mixture was stirred for 20 seconds, followed by solid-liquid separation in a dehydration tank. The polyolefin obtained after the solid-liquid separation was dried, and the weight of polyolefin after drying was 57 kg. The amount of residual paraffin was measured by Energy Dispersive X-Ray Fluorescence (ED-XRF) Respectively. On the other hand, the remover solution and the paraffin mixed solution recovered through solid-liquid separation are re-pumped 2 to 3 times and recycled as the exfoliation solution, then drained through a sieve, stored and then fractionally distilled. Fractional distillation was carried out by setting the distiller temperature to 130 ~ 140 ℃ and heating. The peeling solution with 95 ~ 99% purity was recovered and the remaining paraffin was classified by filtering. The liquid paraffin obtained after fractional distillation has a purity of 95 to 99% and can be reused for suitable use depending on its acid value.

The embodiments of the present invention described above should not be construed as limiting the technical idea of the present invention. The scope of protection of the present invention is limited only by the matters described in the claims, and those skilled in the art will be able to modify the technical idea of the present invention in various forms. Accordingly, such improvements and modifications will fall within the scope of the present invention as long as they are obvious to those skilled in the art.

Claims (6)

I) a step (S020) of separating only liquid paraffin by heating a secondary battery pulmonary membrane containing polyolefin and liquid paraffin;
(Ii) a secondary battery pulmonary separation membrane in which a part of the liquid paraffin has been removed, and at least one of dichloropropane, water, trichlorethylene, methylene chloride, tetrachloroethylene, toluene, At least one selected from the group consisting of Xylene, Methyl Ethyl Ketone, Ethyl Acetate, Methyl Acetate and 1-Bromopropane, (S030) of dissolving and dispersing the liquid paraffin in the exfoliating liquid by mixing the exfoliating liquid necessarily containing dichlorparopane;
Iii) separating the solid phase polyolefin, the liquid phase exfoliating liquid and the liquid phase paraffin through solid-liquid separation to obtain a step (S040), respectively, wherein the polyolefin and paraffin are recovered from the secondary battery pulmonary separation membrane. The method according to claim 1,
The method for regenerating polyolefin and paraffin from a secondary battery pulmonary separation membrane including the step (S010) of crushing the secondary battery pulmonary separation membrane before the step (i). delete The method according to claim 1,
Wherein the solid-liquid separation in step (iii) comprises separating the liquid phase from the solid phase by centrifugal separation or filtration, and recycling the polyolefin and the paraffin from the secondary battery pulmonary separation membrane. The method according to claim 1,
(Iv) a step (S050) of performing liquid-liquid separation through fractional distillation of the separated liquid phase separation liquid and the liquid paraffin mixed liquid after the solid-liquid separation step, and regenerating polyolefin and paraffin from the secondary battery pulmonary separation membrane. The method according to claim 1,
Wherein the heating in step (i) is performed at a temperature in the range of 70 to 90 占 폚.

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