KR20230120960A - Processing of preparing recycled styrene resin and regeneration system of waste styrene resin - Google Patents

Abstract

The present specification includes the steps of crushing the waste styrene-based resin (S1); preparing a waste styrene-based resin solution by dissolving the pulverized waste styrene-based resin in a solvent (S2); Filtering the waste styrene-based resin solution with a filter (S3); and obtaining a regenerated styrene-based resin (S4), wherein the filter relates to a manufacturing process of a regenerated styrene-based resin having a pore size of 20 µm to 450 µm.

Description

Manufacturing process of recycled styrene-based resin and waste styrene-based resin recycling system

The present specification relates to a manufacturing process of recycled styrene-based resin and a system for recycling waste styrene-based resin.

Plastics can be molded into various shapes by heat or pressure, and as the quality of materials is gradually improving, plastics are used to replace objects in everyday life, or new products using them are being developed.

Since these plastics are convenient and easy to use, demand for products made of plastics such as plastic bags, PET bottles, disposable products, packaging products, and electronic products is gradually increasing worldwide.

Plastic used and discarded in this way is incinerated or landfilled. In the case of incineration, a lot of pollutants harmful to the human body are discharged, so the discarded plastic is landfilled rather than incinerated.

However, most plastics take a long time to decompose naturally after disposal, and since the amount of plastic that is landfilled is considerable, interest in plastic recycling is increasing.

Among plastics, styrene-based resins, and furthermore, acrylonitrile butadiene styrene copolymers (ABS) are widely used in battery/electronic products and automobile parts. Various methods for recycling ABS from waste containing ABS and materials that can minimize damage to mankind and the environment during the recycling process must be sought.

In the conventional styrene-based resin recycling process, waste styrene-based resin is physically pulverized to remove various foreign substances through a difference in specific gravity, and used as a raw material for recycling. However, when polyurethane foamed on the surface of the waste styrene-based resin and foreign matter attached to metal are pulverized into small pieces, the foreign matter pulverized in the existing recycling process is not detected. It is a major cause of quality deterioration. Therefore, research on effective removal of foreign substances in the waste styrene-based resin recycling process is required.

Korean Patent Publication No. 10-1996-0010197

The present specification provides a manufacturing process of recycled styrene-based resin and a system for recycling waste styrene-based resin.

An exemplary embodiment of the present specification includes crushing waste styrene-based resin (S1); preparing a waste styrene-based resin solution by dissolving the pulverized waste styrene-based resin in a solvent (S2); Filtering the waste styrene-based resin solution with a filter (S3); and obtaining a regenerated styrene-based resin (S4), wherein the filter provides a manufacturing process for a regenerated styrene-based resin having a pore size of 20 µm to 450 µm.

Another exemplary embodiment of the present specification is a crushing unit for crushing waste styrene-based resin; a dissolving unit for preparing a waste styrene-based resin solution by dissolving the pulverized waste styrene-based resin; and a filtering unit for separating the waste styrene-based resin-foreign material mixture, wherein the filtering unit includes a filter, and the filter has a pore size of 20 µm to 450 µm.

By manufacturing the regenerated styrene-based resin according to an exemplary embodiment of the present specification, foreign substances can be effectively removed, and the purity of the regenerated styrene-based resin can be increased.

By producing a regenerated styrene-based resin according to an exemplary embodiment of the present specification, it is possible to efficiently select polymers having different molecular weights, so that each molecular weight can be applied to each application field.

High-purity recycled styrene-based resin can be obtained by using the waste styrene-based resin regeneration system according to an exemplary embodiment of the present specification.

1 is a diagram schematically showing a manufacturing process of a regenerated styrene-based resin according to the present invention.

Hereinafter, this specification will be described in more detail.

In this specification, "include" means that other components may be further included without excluding other components unless otherwise stated.

In this specification, "waste styrene-based resin" means waste generated after using styrene-based resin, and the waste may be industrial, commercial, or household waste, and not only when styrene-based resin is used once , it can mean a state in which it can no longer be used after its use for its intended purpose is over.

In the present specification, "regenerated styrene-based resin" includes styrene-based resin that is separated or extracted from waste styrene-based resin and reused, and may be a main raw material of styrene-based resin.

In the present specification, the styrene-based resin may be a polymer using only a styrene monomer or a copolymer using styrene as a monomer, and specifically may be polystyrene or ABS resin (Acrylonitrile Butadiene Styrene copolymer).

An exemplary embodiment of the present specification includes crushing waste styrene-based resin (S1); preparing a waste styrene-based resin solution by dissolving the pulverized waste styrene-based resin in a solvent (S2); Filtering the waste styrene-based resin solution with a filter (S3); and obtaining a regenerated styrene-based resin (S4), wherein the filter provides a manufacturing process for a regenerated styrene-based resin having a pore size of 20 µm to 450 µm.

In the conventional process of recycling waste styrene-based resin, a simple physical method of pulverizing and sorting waste styrene-based resin according to specific gravity has been used. However, there is a limit to separating only the pure recycled styrene-based resin raw material from the waste styrene-based resin due to the difference in specific gravity. Specifically, when the foreign substances attached or bonded to the surface of the waste styrene-based resin are pulverized into small pieces, these foreign substances are not detected in the separation step of the styrene-based resin and the foreign matter, and are included in the recycled styrene-based resin raw material, thereby reducing the quality of the raw material. a big cause

The present inventors prepared a waste styrene-based resin solution by dissolving the waste styrene-based resin in order to effectively remove foreign substances from the waste styrene-based resin, and using an appropriate filter to filter out the waste styrene-based resin-foreign substance mixture, A manufacturing process capable of obtaining recycled styrene-based resins of pure purity was developed.

The filter used in the present invention has a pore size of 20 μm to 450 μm, and when a filter having a pore size within the above range is used, the yield of regenerated styrene-based resin from waste styrene-based resin can be increased, The purity of the recycled styrene-based resin has the effect of increasing. When a filter having a pore size smaller than the above range is used, the filter is quickly clogged and there is a problem in that the yield of the regenerated styrene-based resin decreases due to difficulty in filtering the regenerated styrene-based resin. In addition, when a filter having a larger pore size than the above range is used, there is a problem in that the purity of the regenerated styrene-based resin is lowered because even the waste styrene-based resin-foreign material mixture passes through the filter.

Grinding waste styrene-based resin (S1)

The manufacturing process of the regenerated styrene-based resin according to an exemplary embodiment of the present specification includes crushing the waste styrene-based resin (S1).

In one embodiment of the present specification, the waste styrene-based resin includes a styrene-based resin and a foreign material.

In one embodiment of the present specification, the foreign material means a material other than the styrene-based resin attached to the surface of the styrene-based resin, and metal particles, copper wires, PVC, PU foam, PP, PE, PET, metal Plating (aluminum, gold, copper, etc.), rubber etc. may be included, but is not limited thereto.

In one embodiment of the present specification, the crushing of the waste styrene-based resin (S1) may use a crushing device.

In one embodiment of the present specification, the crushing device may use a plastic sherader, mixer, grinder, etc., but is not limited thereto.

In one embodiment of the present specification, the particle size of the waste styrene-based resin pulverized through the grinding step is 200 μm to 20 mm, preferably 300 μm to 10 mm, more preferably 500 μm to 5 mm can be When the particle size is within the above range, the solubility in the solvent is good in the step of preparing the waste styrene-based resin solution, and it is easy to selectively classify only the styrene-based resin in the step of filtering.

Preparing a waste styrene-based resin solution (S2)

The manufacturing process of regenerated styrene-based resin according to an exemplary embodiment of the present specification includes dissolving the pulverized waste styrene-based resin in a solvent to prepare a waste styrene-based resin solution (S2).

In one embodiment of the present specification, the waste styrene-based resin solution includes a styrene-based resin and a waste styrene-based resin-foreign material mixture.

In one embodiment of the present specification, the waste styrene-based resin-foreign material mixture refers to waste styrene-based resin to which foreign materials are physically or chemically attached to the surface. For example, the waste styrene-based resin-foreign material mixture is not separated from the waste styrene-based resin even by external stimuli such as grinding or stirring.

In one embodiment of the present specification, the styrene-based resin in the waste styrene-based resin solution, that is, the styrene-based resin to which foreign substances are not adhered is all dissolved in the solvent.

In one embodiment of the present specification, the waste styrene-based resin-foreign substance mixture in the waste styrene-based resin solution is not dissolved in the solvent and exists as a precipitate or a suspended substance.

In one embodiment of the present specification, the particle size of the waste styrene-based resin-foreign material mixture may be 500 μm to 20 mm, or 500 μm to 5 mm.

In one embodiment of the present specification, the solvent is dichloromethane, dimethylsulfoxide, chloroform, oxalylchloride, 1,1,2,2-tetrachloroethane (1 ,1,2,2-tetrachloroethane, cyclopentanone, acetylchloride, ethylacetate, 2-cyclohexen-1-one, cyclohexanone (cyclohexanone), 3-methyl-2-butanone, 4-methylpyridine, 2-pentanone, acetic anhydride, 3- 3-picoline, 2,3-pentanedione, morpholine, isopropylacetate, pyrrole, 2-methylcyclopentanone ), 2-methylpyridine, 3,5-dimethylpyridine, 2-methylpyrazine, cycloheptanone, acetylacetone, 2 ,5-dimethylpyrazine, 1-methylimidazol, propionic anhydride, 1,1-ethanedioldiacetate, propionyl Chloride (propionylchloride), ethyl chloroformate (carbonochloridicacid, ethylester), 1,1-dichloroethane (1,1-dichloroethane), 3,6-dioxaoctane (3,6-dioxaoctane), 3,3-dimethyl- It may contain at least one selected from 2-butanone (3,3-dimethyl-2-butanone) and 3-methylcyclohexanone, but is limited to those that can dissolve styrene-based resins. It doesn't work.

In one embodiment of the present specification, the solvent may be used in an amount of 50 parts by weight to 5000 parts by weight based on 100 parts by weight of the pulverized waste styrene-based resin. Preferably 100 parts by weight to 5000 parts by weight, more preferably 1000 parts by weight to 5000 parts by weight. When the solvent is used within the above range, the waste styrene-based resin can be recycled as much as possible by sufficiently dissolving the styrene-based resin among the waste styrene-based resins.

In one embodiment of the present specification, the step (S2) of preparing the waste styrene-based resin solution may be performed at 10 °C to 100 °C, or room temperature, for example, 10 °C to 30 °C.

Stirring the waste styrene-based resin solution (S2-1)

The manufacturing process of the regenerated styrene-based resin according to an exemplary embodiment of the present specification may further include stirring the waste styrene-based resin solution (S2-1).

Through the step of stirring the waste styrene-based resin solution, the styrene-based resin in the waste styrene-based resin solution is dispersed in the solvent so that it can be sufficiently dissolved.

In one embodiment of the present specification, the stirring of the waste styrene-based resin solution (S2-1) may be performed at a speed of 50 rpm to 500 rpm.

In one embodiment of the present specification, the stirring of the waste styrene-based resin solution (S2-1) may be performed for 10 minutes to 180 minutes.

In one embodiment of the present specification, in the step (S2-1) of stirring the waste styrene-based resin solution, a stirring device may be used.

In one embodiment of the present specification, the stirring device may use a propeller mixer, a magnetic stirring device, etc., but is not limited thereto.

Filtering the waste styrene-based resin solution (S3)

The manufacturing process of the regenerated styrene-based resin according to an exemplary embodiment of the present specification includes filtering the waste styrene-based resin solution with a filter (S3).

In one embodiment of the present specification, the waste styrene-based resin solution includes a waste styrene-based resin-foreign substance mixture, and the waste styrene-based resin is extracted from the waste styrene-based resin solution through the filtering step (S3). Separates the counting paper-foreign mixture.

In one embodiment of the present specification, the filter has a pore size of 20 μm to 450 μm.

In one embodiment of the present specification, the pore size of the filter may be 20 μm to 450 μm, preferably 20 μm to 300 μm, or 20 μm to 200 μm, more preferably 20 μm to 100 μm. By using a filter having a pore size within the above range, only the styrene-based resin in the waste styrene-based resin can be selectively filtered, and a mixture of waste styrene-based resin and foreign substances can be filtered out.

In one embodiment of the present specification, it includes the filter, and the filter may be a mesh net, filter paper, or a test net (sieve), but is not limited thereto, and has a pore size of 20 μm to 450 μm Anything can be used.

In one embodiment of the present specification, the filter may be a mesh network of 40 mesh to 500 mesh, preferably a mesh network of 200 mesh to 500 mesh.

In one embodiment of the present specification, the filtering step (S3) may be performed twice or more. At this time, the pore size of the filter may be the same or different.

In one embodiment of the present specification, the filtering step (S3) may use one or more filters. That is, one or more types of filters may be used among filters having a pore size of 20 μm to 450 μm. For example, the waste styrene-based resin solution may be filtered through a filter having a pore size of 400 μm and then filtered once more through a filter having a pore size of 25 μm. In this way, when the waste styrene-based resin solution is filtered using two or more types of filters having different pore sizes, the purity of the regenerated styrene-based resin can be increased by more effectively separating the waste styrene-based resin-foreign substance mixture.

In one embodiment of the present specification, the filtered solution, that is, the solution that has passed through the filter, contains a regenerated styrene-based resin, and preferably does not contain a waste styrene-based resin-foreign substance mixture.

Obtaining Regenerated Styrene-based Resin (S4)

The manufacturing process of the regenerated styrene-based resin according to an exemplary embodiment of the present specification includes a step (S4) of obtaining the regenerated styrene-based resin.

In one embodiment of the present specification, the step of obtaining the regenerated styrene-based resin (S4) includes precipitating the regenerated styrene-based resin in the filtered solution (S4-1); filtering the precipitated regenerated styrene-based resin (S4-2); and drying the filtered regenerated styrene-based resin (S4-3).

Step of precipitating the regenerated styrene-based resin (S4-1)

In one embodiment of the present specification, in the step (S4-1) of precipitating the regenerated styrene-based resin in the filtered solution, a non-solvent may be used.

The manufacturing process of the regenerated styrene-based resin according to an exemplary embodiment of the present specification may further include precipitating the regenerated styrene-based resin in the filtered solution using a non-solvent (S4-1).

In one embodiment of the present specification, the non-solvent is a solvent in which the styrene-based resin is not dissolved, and 2-methylfuran, 1-methyl-1H-pyrrole, thiophene (thiophene), diethylene glycol monobutyl ether, 2-butoxyethanol, methanol, ethanol, isopropyl alcohol, and formamide It may include one or more that are, but is not limited thereto as long as the styrene-based resin is not dissolved.

In one embodiment of the present specification, the non-solvent may be used in an amount of 50 parts by weight to 5000 parts by weight based on 100 parts by weight of the filtered solution. Preferably 100 parts by weight to 5000 parts by weight, more preferably 500 parts by weight to 3000 parts by weight may be used. When using a non-solvent within the above range, the regenerated styrene-based resin dissolved in the filtered solution can be maximally precipitated and precipitated.

In one embodiment of the present specification, in the step (S4-1) of precipitating the regenerated styrene-based resin in the filtered solution, stirring may be performed simultaneously.

In one embodiment of the present specification, the step of precipitating the regenerated styrene-based resin in the filtered solution (S4-1) may further include stirring for 1 hour to 5 hours.

Filtering the precipitated regenerated styrene-based resin (S4-2)

In one embodiment of the present specification, the filter used in the step of filtering the precipitated regenerated styrene-based resin may be appropriately employed in the art and is not particularly limited. For example, a filter having a pore size of 25 μm to 2 mm, preferably 25 μm to 500 μm, and more preferably 25 μm to 100 μm may be used as the filter.

Step of drying the filtered regenerated styrene-based resin (S4-3)

In one embodiment of the present specification, drying conditions in the step of drying the filtered regenerated styrene-based resin (S4-3) are not particularly limited, and conditions used in the art may be appropriately employed.

In one embodiment of the present specification, a vacuum oven may be used as a drying device in the step (S4-3) of drying the filtered regenerated styrene-based resin.

In one embodiment of the present specification, the drying time in the step of drying the filtered regenerated styrene-based resin (S4-3) may be 1 hour to 60 hours, preferably 10 hours to 30 hours.

In one embodiment of the present specification, the yield of the regenerated styrene-based resin may be 70% or more, and the upper limit is not limited, but may be 100% or less.

The yield can be calculated from the formula "(yield of regenerated styrene-based resin/amount of waste styrene-based resin injected) x 100".

The yield may vary depending on the pore size of the filter used in the filtering step (S3). For example, the wider the pore size of the filter, the higher yield can be obtained, and the narrower the pore size of the filter, the lower the yield. However, when the pore size of the filter exceeds 450 μm, the waste styrene-based resin-foreign substance mixture passes through the filter and the purity of the regenerated styrene-based resin may be lowered. There may be a problem that the len-gye resin does not pass through the filter.

1 schematically shows the manufacturing process of the regenerated styrene-based resin according to the present invention.

In one embodiment of the present specification, the purity of the regenerated styrene-based resin may be 80% or more, preferably 90% or more, and more preferably 93% or more.

The purity of the regenerated styrene-based resin means the content of pure styrene-based resin in the obtained regenerated styrene-based resin, and the purity is "(content of pure styrene-based resin / yield of regenerated styrene) × 100" can be calculated from Eq.

In one embodiment of the present specification, the purity of the regenerated styrene-based resin is determined by loading 5 ± 1 mg of the regenerated styrene-based resin into a sampler and using TGA (Thermogravimetric analysis, thermogravimetric analysis) equipment at a N ₂ flow of 50ml/min. After setting the zero point, measure while raising the temperature from 25℃ to 1000℃ at 10℃/min. Then, with respect to the results obtained from the measurement, the weight change rate in the characteristic temperature reduction section of the styrene-based resin was analyzed, and the weight change rate in each section was measured to analyze the SAN and butadiene contents, and the total input amount in the regenerated styrene-based resin. The purity is calculated by measuring the styrene-based resin content.

When the regenerated styrene-based resin is a regenerated ABS resin, the characteristic temperature reduction range of the ABS is ~160 ° C, 280 ° C ~ 410 ° C, and 510 ° C ~ 610 ° C, specifically, 160 ° C or less is included in the regenerated ABS resin. 280 ℃ ~ 410 ℃ is the SAN weight change period in the regenerated ABS resin, and 510 ℃ ~ 610 ℃ is the butadiene weight change period in the regenerated ABS resin. That is, the changed weight in the temperature range of 280 ℃ ~ 410 ℃ is the weight of SAN, the changed weight in the temperature range of 510 ℃ ~ 610 ℃ is the weight of butadiene, and the sum of the weight of SAN and butadiene is pure ABS resin. By calculating the content of, it is possible to calculate the purity of the weight of the waste plastic containing ABS.

When the regenerated styrene-based resin is a regenerated PS resin, the characteristic temperature reduction range of the PS is ~ 160 ° C and 280 ° C ~ 410 ° C, specifically, the residual solvent content contained in the regenerated PS resin can be confirmed below 160 ° C 280 ℃ ~ 410 ℃ is the styrene weight change range in the recycled PS resin. That is, the changed weight in the temperature range of 280 ℃ ~ 410 ℃ is the weight of styrene, and the content of pure PS resin is calculated by the weight of styrene in the recycled PS resin, and the purity of the weight of the waste plastic containing PS can be calculated.

In one embodiment of the present specification, the yield of the regenerated styrene-based resin may be 70% or more, and the purity of the regenerated styrene-based resin may be 90% or more.

In one embodiment of the present specification, the final yield of the regenerated styrene-based resin may be 60% or more. Here, the final yield of regenerated styrene-based resin means the yield of pure styrene-based resin in waste styrene-based resin, and is a yield considering the purity of the regenerated styrene-based resin.

The final yield may be calculated by the formula "(content of pure styrene-based resin/amount of waste styrene-based resin input) × 100", or "(yield of regenerated styrene-based resin/amount of waste styrene-based resin input) × 100 × purity”.

Another exemplary embodiment of the present specification is a crushing unit for crushing waste styrene-based resin; a dissolving unit for preparing a waste styrene-based resin solution by dissolving the pulverized waste styrene-based resin; and a filtering unit for separating the waste styrene-based resin-foreign material mixture, wherein the filtering unit includes a filter, and the filter has a pore size of 20 µm to 450 µm.

crushing part

In one embodiment of the present specification, the crushing unit may include a crushing device or may be a crushing device itself, and the description of the crushing device is as described above.

In one embodiment of the present specification, the crushing unit is connected to the dissolving unit, and the waste styrene-based resin pulverized in the crushing unit moves to the dissolving unit.

dissolving part

In one embodiment of the present specification, the dissolving unit may include a solvent inlet. A solvent may be introduced through the solvent inlet to prepare a waste styrene-based resin solution, and the description of the solvent is as described above.

In one embodiment of the present specification, the melting unit may further include a stirring unit.

In one embodiment of the present specification, the dissolving unit may further include a stirring device, and a description of the stirring device is as described above.

In one embodiment of the present specification, the dissolving unit may be located between the crushing unit and the filtering unit.

In one embodiment of the present specification, the dissolving unit is connected to the filtering unit, and the waste styrene-based resin solution prepared in the dissolving unit moves to the filtering unit.

filtering part

In one embodiment of the present specification, the filtering unit may be a first filtering unit.

In one embodiment of the present specification, the filtering unit includes a filter.

In one embodiment of the present specification, the filtering unit may include a filter device or may be a filter device itself, and the filter device is described as described above.

In one embodiment of the present specification, the filter device includes a filter.

In one embodiment of the present specification, the filtering unit is divided into an upper part and a lower part based on the filter.

In one embodiment of the present specification, a waste styrene-based resin-foreign substance mixture filtered by the filter is present in the upper portion of the filtering unit.

In one embodiment of the present specification, a solution that has passed through the filter is present in the lower portion of the filtering unit, and the solution contains a regenerated styrene-based resin.

In one embodiment of the present specification, a non-solvent inlet may be provided at a lower portion of the filtering unit. The non-solvent is introduced through the non-solvent inlet to precipitate and precipitate the regenerated styrene-based resin in the filtration unit, and the description of the non-solvent is as described above.

sedimentation

The waste styrene-based resin regeneration system according to one embodiment of the present specification may further include a settling unit.

In one embodiment of the present specification, the settling unit is connected to the filtering unit, and the filtered solution may move to the settling unit.

In one embodiment of the present specification, the precipitation unit may include a non-solvent inlet. A non-solvent may be introduced through the non-solvent inlet to precipitate and precipitate the regenerated styrene-based resin, and the description of the non-solvent is as described above.

In one embodiment of the present specification, the settling unit may further include a stirring device, and any stirring device used in the settling unit may be used as long as it is used for stirring a solution in the art.

2nd filtration unit

The waste styrene-based resin recycling system according to one embodiment of the present specification may further include a second filtering unit.

In one embodiment of the present specification, the second filtering unit is connected to the settling unit, and a solution in which the regenerated styrene-based resin is precipitated may move from the settling unit to the second filtering unit.

In one embodiment of the present specification, the second filtering unit may include a filter unit or may be a filter unit itself, and the filter unit used in the second filtering unit is a device used for filtering precipitates in the art. Any ramen can be used. For example, the filter device may be a mesh net, filter paper, or a test sieve.

In one embodiment of the present specification, the second filtering unit includes a filter.

In one embodiment of the present specification, the second filtering part is divided into an upper part and a lower part based on the filter.

In one embodiment of the present specification, the upper portion of the second filtering unit has a regenerated styrene-based resin filtered by a filter device.

In one embodiment of the present specification, the solution that has passed through the filter device is present in the lower portion of the second filtering unit.

drying part

The waste styrene-based resin recycling system according to one embodiment of the present specification may further include a drying unit.

In one embodiment of the present specification, the drying unit is connected to an upper portion of the second filtering unit, and the regenerated styrene-based resin filtered by the second filtering unit moves to the drying unit.

In one embodiment of the present specification, the drying unit may include a drying device or may be a drying device itself, and any drying device used in the drying unit may be any device used for drying in the art. For example, the drying device may be a vacuum oven.

In one embodiment of the present specification, the drying unit may include a temperature control device.

The waste styrene-based resin regeneration system according to one embodiment of the present specification may further include additional components as needed.

Hereinafter, examples will be described in detail in order to specifically describe the present specification. However, embodiments according to the present specification may be modified in many different forms, and the scope of the present specification is not construed as being limited to the embodiments detailed below. The embodiments herein are provided to more completely explain the present specification to those skilled in the art.

Production Example 1. Production of Regenerated Styrene-based Resin

Example 1.

20g of waste plastic containing ABS was pulverized to a size of 500μm to 5mm, dissolved in 400mL of chloroform by stirring for 1 hour, and then the solution in which the waste plastic was dissolved was pulverized into a 200 mesh mesh (pore size of about 75 μm). Filtered using . The solution that passed through the filter was added dropwise to 4L of thiophene solution using a dropper while stirring was performed. After stirring at room temperature for 3 hours, the precipitate was collected through vacuum filteration, and the collected sample was dried in a vacuum oven for 48 hours. Thus, 14.8 g of regenerated styrene-based resin was obtained. (Yield: 74%)

Comparative Example 1.

20 g of waste plastic containing ABS was pulverized to a size of 500 μm to 5 mm, stirred and dissolved in 400 mL of chloroform for 1 hour, and then the dissolved waste plastic was dissolved through a 20 mesh mesh network (pore size about 850 μm) Filtered using . The solution that passed through the filter was added dropwise to 4L of thiophene solution using a dropper while stirring was performed. After stirring at room temperature for 3 hours, the precipitate was collected through vacuum filteration, and the collected sample was dried in a vacuum oven for 48 hours. Thus, 17.4 g of regenerated styrene-based resin was obtained. (Yield: 87%)

Comparative Example 2.

20 g of waste plastic containing ABS was pulverized to a size of 500 μm to 5 mm, stirred and dissolved in 400 mL of chloroform for 1 hour, and then filtered using a filter having a pore size of 3 μm with the solution in which the waste plastic was dissolved. did The solution that passed through the filter was added dropwise to 4L of thiophene solution using a dropper while stirring was performed. After stirring at room temperature for 3 hours, the precipitate was recovered through vacuum filteration, and the collected sample was dried in a vacuum oven for 48 hours. Thus, 1.8 g of regenerated styrene-based resin was obtained. (Yield: 9%)

Experimental Example 1. Measurement of purity and yield of regenerated styrene-based resin

5 ± 1 mg of the regenerated styrene-based resin prepared in Preparation Example 1 was loaded into the sampler, respectively, and the TGA (Thermogravimetric analysis, thermogravimetric analysis) equipment was set to N ₂ flow 50ml/min, and after zero point adjustment, at 25 ° C. The temperature was raised at 10 °C/min to 1000 °C and measured.

With respect to the results obtained from the measurement, the weight change rate in the characteristic temperature decrease section of ABS described in Table 1 below was analyzed.

~ 160℃ Residual solvent content contained in recycled styrene-based resin 280℃ ~ 410℃ SAN weight change section in recycled styrene-based resin (onset: polymer content analysis at 395°C) 510℃ ~ 610℃ Weight change range of butadiene among regenerated styrene-based resins (onset: polymer content analysis at 540°C)

SAN and butadiene contents were analyzed by measuring the weight change rate in each section, and the purity was calculated by measuring the ABS content in the recycled styrene-based resin relative to the total input amount. Specifically, the changed weight in the temperature range of 280 ℃ ~ 410 ℃ is the weight of SAN, the weight changed in the temperature range of 510 ° C to 610 ° C is the weight of butadiene, and the content of pure styrene-based resin is calculated by adding the weight of SAN and butadiene to the weight of regenerated styrene-based resin Purity was calculated.

The purity calculated as described above and the final yield of the regenerated styrene-based resin calculated based on this are shown in Table 2 below. The final yield means the ratio of the pure styrene-based resin obtained from the waste styrene-based resin, and was calculated by the formula "Each yield of Preparation Example 1 × Purity × 100".

water final yield Example 1 93.2% 69.0% Comparative Example 1 52.7% 45.8% Comparative Example 2 94.5% 8.5%

Looking at the results of Table 2, in the case of Example 1 using a filter within the pore size range of the present invention, with a yield of 74% and a high purity of 93.2%, pure styrene coefficient from waste styrene-based resin On the other hand, the final yield of Comparative Examples 1 and 2 using filters not satisfying the pore size range of the present invention was less than 50%. Specifically, in the case of Comparative Example 1 using a mesh network of 20 mesh, more regenerated styrene-based resins were obtained than in Example 1 by having a wider pore size than the filter of the present invention, but waste in the obtained regenerated styrene-based resin Styrene-based resin-foreign material mixture was also included, resulting in low purity. In addition, Comparative Example 2 had a narrower pore size than the filter of the present invention, so it was higher than Example 1 in terms of purity, but a large amount of waste styrene-based resin did not pass through the filter during the production of regenerated styrene-based resin, resulting in a yield of 9% , and it can be confirmed that it has a final yield of 8.5%.

Therefore, when the regenerated styrene-based resin is produced through the step of filtering the waste styrene-based resin using the filter having the pore size of the present invention, it is known that the high-purity regenerated styrene-based resin can be produced while increasing the yield. can

Production Example 2. Production of Regenerated PS Resin

Example 2.

20g of waste plastic containing PS is pulverized to a size of 500 μm to 5 mm, stirred and dissolved in 400 mL of chloroform for 1 hour, and then the dissolved solution of waste plastic is 200 mesh mesh (pore size is about 75 μm) Filtered using . The solution that passed through the filter was added dropwise to 4L of thiophene solution using a dropper while stirring was performed. After stirring at room temperature for 3 hours, the precipitate was collected through vacuum filteration, and the collected sample was dried in a vacuum oven for 48 hours. 17.0 g of regenerated PS resin was obtained. (Yield: 85%)

Comparative Example 3

20 g of waste plastic containing PS was pulverized to a size of 500 μm to 5 mm, stirred and dissolved in 400 mL of chloroform for 1 hour, and then filtered using a filter having a 3 μm pore size with the solution in which the waste plastic was dissolved. did The solution that passed through the filter was added dropwise to 4L of thiophene solution using a dropper while stirring was performed. After stirring at room temperature for 3 hours, the precipitate was collected through vacuum filteration, and the collected sample was dried in a vacuum oven for 48 hours. Thus, 6.4 g of recycled PS resin was obtained. (Yield rate: 32%)

experimental example. Measurement of purity and yield of recycled PS resin

5 ± 1 mg of the regenerated PS resin prepared in Preparation Example 2 was loaded into the sampler, respectively, and the TGA (Thermogravimetric analysis, thermogravimetric analysis) equipment was set to N ₂ flow 50ml / min, and after zero point adjustment, 25 ℃ to 1000 ℃ The temperature was raised at 10°C/min until the temperature was measured.

For the results obtained from the measurement, the weight change rate in the characteristic temperature decrease section of PS described in Table 3 below was analyzed.

~ 160℃ Residual solvent content contained in recycled PS resin 280℃ ~ 410℃ Styrene weight change section in recycled PS resin (onset: analysis of polymer content at 395°C)

Styrene content was analyzed by measuring the weight change rate in each section, and purity was calculated by measuring the PS content in the recycled PS resin compared to the total input amount. Specifically, the changed weight in the temperature range of 280 ℃ ~ 410 ℃ is the weight of Styrene. , and the purity of the recycled PS resin was calculated by calculating the content of pure PS resin by the weight of Styrene.

The purity calculated as described above and the final yield of the recycled PS resin calculated based on this are shown in Table 4 below. The final yield means the ratio of the pure PS resin obtained from the waste PS resin, and was calculated by the formula of "yield in Preparation Example 2 × purity × 100".

water final yield Example 2 94.7% 80.5% Comparative Example 3 95.0% 30%

Looking at the results of Table 4, in the case of Example 2 using a filter within the pore size range of the present invention, with a yield of 85% and a high purity of 94.7%, pure styrene coefficient from waste styrene-based resin On the other hand, in Comparative Example 3 using a filter that does not satisfy the pore size range of the present invention, the final yield was less than 50%. Specifically, Comparative Example 3 had a narrower pore size than the filter of the present invention, so it was higher than Example 1 in terms of purity, but a large amount of waste styrene-based resin did not pass through the filter during the manufacture of regenerated styrene-based resin, resulting in 32% The yield was shown, and it can be confirmed that the final yield was 30%.

Therefore, when the regenerated styrene-based resin is produced through the step of filtering the waste styrene-based resin using the filter having the pore size of the present invention, it is known that the high-purity regenerated styrene-based resin can be produced while increasing the yield. can

Claims (16)

Grinding the waste styrene-based resin (S1);
preparing a waste styrene-based resin solution by dissolving the pulverized waste styrene-based resin in a solvent (S2);
Filtering the waste styrene-based resin solution with a filter (S3); and
Including the step (S4) of obtaining a regenerated styrene-based resin,
The filter is a manufacturing process of a regenerated styrene-based resin having a pore size of 20 μm to 450 μm. The method according to claim 1, wherein the particle size of the pulverized waste styrene-based resin is 200 μm to 20 mm, the manufacturing process of the regenerated styrene-based resin is larger than the pore size of the filter. The method according to claim 1, wherein the solvent is dichloromethane, dimethyl sulfoxide, chloroform, oxalyl chloride, 1,1,2,2-tetrachloroethane, cyclopentanone, acetyl chloride, ethyl acetate, 2-cyclohexane-1- one, cyclohexanone, 3-methyl-2-butanone, 4-methylpyridine, 2-pentanone, acetic anhydride, 3-picoline, 2,3-pentanedione, morpholine, isopropylacetate, pyrrole, 2 -Methylcyclopentanone, 2-methylpyridine, 3,5-dimethylpyridine, 2-methylpyrazine, cycloheptanone, acetylacetone, 2,5-dimethylpyrazine, 1-methylimidazole, propionic anhydride, 1,1 -Selected from ethanediol diacetate, propionyl chloride, ethyl chloroformate, 1,1-dichloroethane, 3,6-dioxaoctane, 3,3-dimethyl-2-butanone, and 3-methylcyclohexanone Process for producing a regenerated styrene-based resin comprising at least one of which is. The manufacturing process of regenerated styrene-based resin according to claim 1, wherein the step (S2) of preparing the waste styrene-based resin solution is performed at 10 ° C to 100 ° C. The manufacturing process of regenerated styrene-based resin according to claim 1, further comprising the step (S2-1) of stirring the waste styrene-based resin solution. The method according to claim 1, wherein the waste styrene-based resin solution includes a waste styrene-based resin-foreign material mixture, and the waste styrene-based resin-foreign material is extracted from the waste styrene-based resin solution through the filtering step (S3). A process for producing a regenerated styrene-based resin, wherein the mixture is separated. The method according to claim 6, wherein the waste styrene-based resin-foreign substance mixture has a particle size of 500 μm to 20 mm. The method according to claim 1, wherein the filter is a 40 mesh to 500 mesh of the mesh network of the regenerated styrene-based resin manufacturing process. The manufacturing process of the regenerated styrene-based resin of claim 1, wherein the purity of the regenerated styrene-based resin is 80% or more. The manufacturing process of claim 1, wherein the yield of the regenerated styrene-based resin is 70% or more. The manufacturing process of regenerated styrene-based resin according to claim 1, further comprising the step (S4-1) of precipitating the regenerated styrene-based resin in the filtered solution using a non-solvent. The method according to claim 11, wherein the non-solvent is selected from 2-methylfuran, 1-methyl-1H-pyrrole, thiophene, diethylene glycol monobutyl ether, 2-butoxyethanol, methanol, ethanol, isopropyl alcohol, and formamide Process for producing a regenerated styrene-based resin comprising at least one of which is. A crushing unit for crushing waste styrene-based resin;
a dissolving unit for preparing a waste styrene-based resin solution by dissolving the pulverized waste styrene-based resin; and
A filter unit for separating the waste styrene-based resin-foreign substance mixture,
The filter unit includes a filter,
The filter is a waste styrene-based resin regeneration system having a pore size of 20 μm to 450 μm. The waste styrene-based resin regeneration system according to claim 13, wherein the melting part is maintained at a temperature of 10 °C to 100 °C. The waste styrene-based resin regeneration system according to claim 13, wherein the melting unit further comprises an agitator. The waste styrene-based resin regeneration system according to claim 13, further comprising a settling unit for precipitating the regenerated styrene-based resin.