KR20160047930A - Continuous Manufacturing method of polyalkylenecarbonate - Google Patents

Abstract

The present invention relates to a continuous manufacturing method of a resin composition comprising polyalkylene carbonate. More particularly, the continuous manufacturing method of a resin composition comprising polyalkylene carbonate removes byproducts before removing a solvent after polymerization of polyalkylene carbonate, and continuously removing elements having negative influence on physical properties of a product. Thus, the continuous manufacturing method of the present invention can continuously manufacture resin products which can embody improved physical properties.

Description

Continuous manufacturing method of polyalkylenecarbonate < RTI ID = 0.0 >

The present invention relates to a method for continuously producing a resin composition comprising a polyalkylene carbonate.

The polyalkylene carbonate is amorphous transparent resin, unlike an aromatic polycarbonate which is a similar type of engineering plastic, and mainly uses carbon dioxide, which is a main cause of global warming. In addition, the polyalkylene carbonate exhibits biodegradability and has the advantage that it is completely decomposed into carbon dioxide and water during burning, leaving no carbon residue.

However, the polyalkylene carbonate has excellent transparency, tensile strength, elasticity, and oxygen barrier properties. However, when processed into a pellet or a film, the polyalkylene carbonate exhibits a blocking phenomenon, which is not easy to handle and has poor dimensional stability .

Accordingly, attempts have been made to mix and use other kinds of resins capable of improving the physical properties of polyalkylene carbonate, for example, polylactide having biodegradability. Since polylactide (or polylactic acid or polylactic acid) resin is based on biomass unlike conventional crude oil-based resin, it can be used as a recycled material and is used as a global warming gas It has environmentally friendly properties such as low CO2 emission and biodegradation by water and microorganisms at the time of landfilling. At the same time, it is a material with appropriate mechanical strength similar to conventional crude oil based resin.

Such polylactide resins have been mainly used for disposable packaging / containers, coatings, foams, films / sheets and fibers. In recent years, polylactide resins have been mixed with existing resins such as ABS or polypropylene There has been an increasing effort to use it for semi-permanent use such as a mobile phone exterior material or automobile interior material. However, the application range of the polylactide resin is still limited due to the weakness of the polylactide itself due to the biodegradation of the polylactide itself due to factors such as the catalyst used in the production and the moisture in the air.

The resin composition comprising the polyalkylene carbonate and the polylactide exhibits the effect of offsetting the disadvantages of the polyalkylene carbonate as the content of the polylactide increases, and the physical properties are remarkably improved.

On the other hand, the production of the polyalkylene carbonate proceeds in the presence of a solvent, and various impurities are present in the polymerization product after polymerization.

The production process of the resin containing the polyalkylene carbonate is largely divided into a polymerization process and a post-treatment process. In the post-treatment process, the remaining monomers and impurities other than the polyalkylene carbonate are removed and a pelletization process is included.

The types of residual monomers and impurities to be removed in the post-treatment step are as follows.

The residual monomers are carbon dioxide and alkylene oxide, and the impurities are catalyst residues, by-products and solvents. The catalyst residues are zinc-based catalysts and byproducts are alkylene carbonates.

In the pelletizing step, a polylactide resin and additives are used to improve the physical properties, and a final product is produced.

However, catalyst residues, residual monomers, and impurities are not effectively removed during the removal of the impurities, which limits the improvement of the physical properties of the final product.

An object of the present invention is to provide a resin composition comprising a polyalkylene carbonate having improved properties through compounding with a polylactide resin by removing catalyst residues, residual monomers and impurities in a process for producing a polyalkylene carbonate- In a continuous manner.

The present invention relates to a process for the production of carbon nanotubes, comprising: a polymerization step in which carbon dioxide and an epoxide compound are used as raw materials in the presence of a zinc-based catalyst and a solvent;

Recovering the residual monomer from the reaction mixture comprising the polyalkylene carbonate obtained by the polymerization process, the catalyst residue, the unreacted residual monomer, the solvent and the by-product comprising the alkylene carbonate;

Removing the catalyst residue from the reaction mixture from which the residual monomer has been removed;

Removing byproducts from the reaction mixture from which the catalyst residue and the residual monomer have been removed;

Removing the solvent from the reaction mixture from which the catalyst residue, residual monomer and byproduct have been removed; And

(Meth) acrylate to a polyalkylene carbonate which has been removed to a solvent to form a polyalkylene carbonate resin composition,

The polymerization step or the resin composition forming step may be carried out continuously,

A method for continuously producing a polyalkylene carbonate resin composition is provided.

Further, the method of the present invention may further comprise the step of purifying the monomer before the polymerization step. Such purification of the monomer may include passing the monomer through a column filled with a molecular sieve to purify the water content of the monomer to less than 10 ppm.

The step of removing the catalyst residue may be carried out by passing the reaction mixture through a metal filter, or horizontally passing the reaction mixture through a metal filter and removing the catalyst by filtration.

Further, the step of recovering the residual monomer may include a method of removing unreacted carbon dioxide and an epoxide compound by venting.

The step of removing byproducts may comprise passing the reaction mixture and water in an extraction column to remove byproducts from the reaction mixture comprising the polyalkylene carbonate, the solvent and the byproduct.

In addition, the step of removing the solvent may be performed using a simple flash drum, a falling film evaporator, a thin film evaporator (Extrusion DV), a film stirrer, and a kneader Kneader) may be used in combination.

Wherein the step of forming the polyalkylene carbonate resin composition comprises, based on 100 parts by weight of the polyalkylene carbonate, 0.5 to 50 parts by weight of polylactide; And 0.5 to 35 parts by weight of a polyalkyl (meth) acrylate in an extruder to pelletize the resin composition.

Further, the method of the present invention may further comprise the step of forming the polyalkylene carbonate resin composition, and then recovering the polyalkylene carbonate resin composition.

The by-product may include an alkylene carbonate having 1 to 5 carbon atoms.

According to the process of the present invention, it may be at least 90 wt.% In the final resin composition, 5 wt.% Or less of the polylactide resin and 1 wt.% Or less of the polyalkyl (meth) acrylate, the catalyst content is less than 300 ppm, May be 1% by weight or less.

The carbon dioxide may be continuously or discontinuously added at a molar ratio of 1: 1 to 10: 1 relative to the epoxide compound.

The epoxide compound is an alkylene oxide having 2 to 20 carbon atoms which is substituted or unsubstituted with halogen or an alkyl group having 1 to 5 carbon atoms; A cycloalkylene oxide having 4 to 20 carbon atoms substituted or unsubstituted with halogen or an alkyl group having 1 to 5 carbon atoms; And styrene oxide having 8 to 20 carbon atoms substituted or unsubstituted with halogen or an alkyl group having 1 to 5 carbon atoms, and the solvent may be a chlorinated solvent. The monomer of the polyalkyl (meth) acrylate may be an ester of (meth) acrylic acid and an alkyl group having 1 to 20 carbon atoms.

The polymerization process can be carried out at 50 to 100 DEG C and 15 to 50 bar for 1 to 60 hours.

The present invention relates to a process for producing a polyalkylene carbonate resin composition which comprises removing the by-products before the removal of the solvent after the polymerization of the polyalkylene carbonate and continuously removing the components adversely affecting the physical properties of the product, It is possible to continuously produce an implementable resin product.

Hereinafter, the present invention will be described in more detail. The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and the inventor may appropriately define the concept of the term in order to best describe its invention It should be construed as meaning and concept consistent with the technical idea of the present invention.

Also, " comprising "as used herein should be interpreted as specifying the presence of particular features, integers, steps, operations, elements and / or components, It does not exclude the presence or addition of an ingredient.

Hereinafter, a method for continuously producing a resin composition comprising a polyalkylene carbonate according to a preferred embodiment of the present invention will be described in more detail.

According to one embodiment of the present invention, there is provided a process for producing a catalyst, comprising: a polymerization step in which carbon dioxide and an epoxide compound are used as raw materials in the presence of a zinc-based catalyst and a solvent; Recovering the residual monomer from the reaction mixture comprising the polyalkylene carbonate obtained by the polymerization process, the catalyst residue, the unreacted residual monomer, the solvent and the by-product comprising the alkylene carbonate; Removing the catalyst residue from the reaction mixture from which the residual monomer has been removed; Removing byproducts from the reaction mixture from which the catalyst residue and the residual monomer have been removed; Removing the solvent from the reaction mixture from which the catalyst residue, residual monomer and byproduct have been removed; And a step of forming a polyalkylene carbonate resin composition by mixing polylactide and polyalkyl (meth) acrylate with the polyalkylene carbonate which has been removed to the solvent, wherein the polymerization step to the resin composition forming step A continuous process for continuously producing a polyalkylene carbonate resin composition is provided.

Further, in the present invention, it is possible to further include a step of purifying the monomer before the polymerization step.

That is, the present invention relates to a continuous production method of a resin composition containing polyalkylene carbonate, including a step of removing ethylene carbonate as a by-product before a solvent removing step.

Further, the present invention can produce the resin composition continuously from the monomer introduction, and after the polymerization, the monomer can be recovered and reused to reduce the manufacturing cost. In addition, the present invention eliminates the elements that adversely affect the physical properties of the product after polymerization, thereby realizing improved physical properties.

Each step of the continuous production method of the resin composition of the present invention will be described in more detail.

Firstly, in the method of the present invention, it is possible to further include a step of purifying the monomer before the above-mentioned polymerization step of the monomer. This step is a step of preparing an epoxide compound for use in the reaction, carbon dioxide, a solvent, etc. by refining.

Specifically, according to the above method, the carbon dioxide, the alkylene oxide compound and the solvent used as raw materials are purified before polymerization to keep the water content of the monomer below 10 ppm. In addition, the raw material can be passed through a column filled with a molecular sieve. Thus, the step of purifying the monomer comprises passing the monomer through a column packed with molecular sieve to purify the water content of the monomer to less than 10 ppm.

In addition, the polymerization step performed following the above step is a step of putting the raw materials into a polymerization reactor and proceeding polymerization under a catalyst to produce a polyalkylene carbonate.

That is, the method for producing the polyalkylene carbonate of the present invention is not particularly limited, but can be obtained, for example, by copolymerizing the above-mentioned alkylene oxide with carbon dioxide. Or ring-opening polymerization of cyclic carbonates. The copolymerization of the alkylene oxide and carbon dioxide can be carried out in the presence of a metal complex compound such as zinc, aluminum or cobalt.

Accordingly, the polymerization step according to a preferred embodiment of the present invention is a step of supplying a catalyst, a solvent, an epoxide compound and carbon dioxide to a polymerization reactor, and then polymerizing a monomer containing an epoxide compound and carbon dioxide under a catalyst and a solvent . Such polymerization may also be continuous polymerization.

After the solution polymerization is complete, a reaction mixture is formed which comprises a polyalkylene carbonate, unreacted residual monomer, catalyst residue, solvent and byproduct. The unreacted residual monomer includes unreacted carbon dioxide and unreacted alkylene oxide. Further, after the solution polymerization, the solids content including the polyalkylene carbonate, the solvent and the by-product may be about 10 to 50% by weight.

The polymerization may be carried out at 50 to 100 DEG C and 15 to 50 bar for 1 to 60 hours. Further, it is more preferable that the polymerization process is carried out at about 70 to 90 DEG C and about 20 to 40 bar for about 3 to 40 hours. Most preferably, the polymerization process can be carried out at 70 to 90 占 폚 and 20 to 40 bar for 2 to 10 hours. In addition, since the epoxide compound, especially ethylene oxide, has a self-polymerization temperature of 90 ° C, it is more preferable to perform the solution polymerization at a temperature of 60 to 90 ° C in order to reduce the by-product content due to autopolymerization.

Next, the present invention performs the step of removing residual monomer and impurities from the reaction mixture. Therefore, the present invention sequentially carries out the steps of recovering the residual monomer, removing the catalyst, removing the by-product, and removing the solvent from the reaction mixture.

Carbon dioxide as the raw material and carbon dioxide in the alkylene oxide are stable, but alkylene oxide is unstable, so it is preferable to recover the residual monomer first.

In addition, since the catalyst accelerates depolymerization as well as polymerization, it is preferable to immediately remove the catalyst residue after the recovery of the residual monomer after the polymerization is completed. At this time, the residual monomer can be recovered after polymerization and reused to reduce the manufacturing cost. In addition, the residual monomer may have an adverse effect on the physical properties of the product after polymerization, and the present invention is capable of realizing improved physical properties by continuously removing these elements.

The step of recovering the residual monomer may include a step of venting the unreacted carbon dioxide and the epoxide compound.

As the method for removing the catalyst residue in the catalyst removing step, there are filtration method, centrifugal removal method, ion exchange method, and the like. However, since the ion exchange method involves a problem in the process, in the present invention, the catalyst is removed by a filtration method or a centrifugal separation method, and the catalyst is preferably removed by a filtration method. Two types of filtration methods can be used, and a metal filter can be used. Filter cleaning and catalyst recovery are also performed through periodic backwashing. Preferably, in the present invention, the step of removing the catalyst residue may be performed by passing the reaction mixture through a metal filter or passing the reaction mixture in a direction parallel to the metal filter and removing the catalyst by filtration.

On the other hand, in the solution polymerization, a by-product, alkylene carbonate, can be produced in the process of decomposing the polymer by back-biasing by the catalyst and heat and in the polymerization mechanism.

If the by-product remains in the resin, it will adversely affect the physical properties of the resin, such as lowering the glass transition temperature and lowering the elasticity. Therefore, it is preferable to remove the by-product in the polyalkylene carbonate production process. Such by-products may include an alkylene carbonate having 1 to 5 carbon atoms, for example, ethylene carbonate.

The step of removing byproducts may comprise passing the reaction mixture and water in an extraction column to remove byproducts from the reaction mixture comprising the polyalkylene carbonate, the solvent and the byproduct.

Finally, the solvent is removed from the reaction mixture. However, as the solvent is removed, the viscosity gradually increases and the volatilization efficiency may be drastically lowered. Accordingly, in the present invention, a process of sequentially removing the solvent is performed using different types of equipment according to the viscosity range of the reaction mixture.

Preferably, the step of removing the solvent includes a simple flash drum, a Falling Film Evaporator, a Thin Film Evaporator (Extrusion DV), a Filmtruder, And a kneader. At this time, since the solvent removing devices are well known in the art, a detailed description thereof will be omitted.

Next, the present invention proceeds with the compounding step.

The compounding step may include a molding process such as pelletization, and the molding may be performed by mixing one or more additional resins. That is, since the polyalkylene carbonate alone has a problem of difficult handling due to its low glass transition temperature, in the present invention, by developing the compounding resin, it is possible to continuously produce a compounding resin by optimizing the resin composition, May provide an easy effect. Therefore, the step of compounding in the present invention may be a step of forming the polyalkylene carbonate resin composition.

According to one embodiment of the present invention, the step of forming the polyalkylene carbonate resin composition comprises, based on 100 parts by weight of the polyalkylene carbonate, 0.5 to 50 parts by weight of polylactide; And 0.5 to 35 parts by weight of a polyalkyl (meth) acrylate, into an extruder and pelletizing the resin composition.

If the amount of the polylactide is less than about 0.5 parts by weight, the excellent physical and mechanical properties as obtained by including the polylactide may be deteriorated, and the dimensional stability and thermal stability may be deteriorated And the blocking phenomenon can be intensified. In addition, when the polylactide is contained in an amount exceeding about 50 parts by weight, gas barrier properties and elongation may be lowered, and transparency may be lowered. When the amount of the polyalkyl (meth) acrylate is less than about 0.5 parts by weight, the dimensional stability and thermal stability may be deteriorated, the blocking phenomenon may become worse, and the transparency may be lowered. In addition, when it is contained in an amount exceeding about 35 parts by weight, the gas barrier property and the impact strength may be lowered.

The polylactide may include a repeating unit represented by the following formula (1).

[Chemical Formula 1]

In Formula 2,

n is an integer of 10 to 1000;

The molecular structure of the polylactide may contain any monomers such as L-lactic acid or D-lactic acid. The polylactide may be prepared by ring-opening polymerization of a lactide monomer to form the following repeating unit, and the polymer after completion of the ring-opening polymerization and the process for forming the following repeating unit is reacted with the polylactide or polylactide Can be referred to as resin. At this time, all types of lactide may be included in the category of the lactide monomer as described above.

The category of the polymer that can be referred to as the "polylactide resin" includes polymers in all states after the ring-opening polymerization and the formation of the repeating unit are completed, for example, A polymer contained in a liquid or solid resin composition before product molding, or a polymer included in a plastic or fabric finished with product molding, or the like.

"Lactide monomer" can be defined as follows. Generally, lactide can be divided into L-lactide composed of L-lactic acid, D-lactide composed of D-lactic acid, and meso-lactide composed of one L-form and one D-form. Also, a mixture of L-lactide and D-lactide at 50:50 is referred to as D, L-lactide or rac-lactide. It is known that when the polymerization is carried out using only L-lactide or D-lactide having high optical purity among these lactides, L- or D-polylactide (PLLA or PDLA) having a very high stereoregularity is obtained, It is known that lactide has a higher crystallization rate and higher crystallinity than a polylactide having a lower optical purity. However, the term "lactide monomer" is defined herein to include all types of lactide, regardless of the difference in properties of the lactide according to each type and the property difference of the formed polylactide therefrom.

In the polylactide resin, the polymerization degree n of the repeating unit of the formula (2) may be 10 to 1000, preferably 50 to 500, and the polylactide resin containing the same may have a molecular weight of about 10,000 to about 1,000,000 g / mol, Lt; RTI ID = 0.0 > g / mol. ≪ / RTI > As the repeating unit and the polylactide resin have the polymerization degree and the weight average molecular weight in this range, the resin layer or the disposable resin molded article obtained therefrom can exhibit biodegradability with mechanical properties such as appropriate strength.

Further, the monomer of the polyalkyl (meth) acrylate may be an ester of (meth) acrylic acid and an alkyl group having 1 to 20 carbon atoms.

The alkyl group may be a linear or branched aliphatic alkyl group having 1 to 20 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms. Examples of the alkyl (meth) acrylate as the monomer include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (Meth) acrylate, n-octyl (meth) acrylate, n-decyl (meth) acrylate, n-dodecyl (Meth) acrylate, palmityl (meth) acrylate, and stearyl (meth) acrylate, and preferably methyl (meth) acrylate.

The production method of the polylactide resin and the polyalkyl (meth) acrylate is not particularly limited.

Various additives may be added to the resin composition depending on the application. (Carbon black, titanium oxide, talc, calcium carbonate, clay, etc.), and the like, but not limited thereto. As a modifying additive, dispersant. Lubricants, plasticizers, flame retardants, antioxidants, antistatic agents, light stabilizers, ultraviolet absorbers, crystallization accelerators and the like. The various additives may be added when the pellets are produced from the polyalkylene carbonate resin composition or when the pellets are molded to produce a molded article.

Examples of the article produced by the continuous production method of such a resin composition include a film, a sheet, a film laminate, a filament, a nonwoven fabric, a molded article and the like.

When the polyalkylene carbonate of the present invention is used, or when a resin other than polyalkylene carbonate is used, known molding methods can be used. Examples of the method for obtaining a homogeneous mixture include a method of mixing by a Hensel mixer, a ribbon blender, a blender, or the like. As the melt kneading method, a VAN Antonie Louis Barye mixer, a single-screw or twin-screw compressor, or the like can be used. The shape of the resin composition of the present invention is not particularly limited and may be, for example, a strand, a sheet, a flat plate, a pellet, or the like.

A method of obtaining a molded article by molding the resin composition of the present invention can be carried out by a known method such as injection molding, compression molding, injection compression molding, gas injection molding, foam injection molding, inflation, T die, A calendar method, a blow molding method, a vacuum forming method, and a pressure forming method.

In the present invention, pelletization is used by using extrusion molding. Such a pelletizing process includes a step of putting the reaction mixture into a twin screw extruder to make it into a pellet form. And, as described above, in the pelletizing step, it is preferable to produce a pellet having a size of 1 mm to 5 mm.

Meanwhile, the present invention may further include a step of recovering the polyalkylene carbonate resin composition after forming the polyalkylene carbonate resin composition. That is, in the present invention, after the compounding, the step of recovering the product pellets is carried out. The pellet may further include additional volatilization processes as needed prior to pellet recovery.

According to this method, the resin composition of the present invention may include polyalkylene carbonate, polylactide, and polyalkyl (meth) acrylate, which is referred to as CAM resin in the embodiment of the present invention.

In the final resin composition of the present invention, the polyalkylene carbonate may be 90 wt% or more, the polylactide resin may be 5 wt% or less, the polyalkyl (meth) acrylate may be 1 wt% or less, the catalyst content may be less than 300 ppm , And the by-product content may be 1% by weight or less. More preferably, according to the present invention, the final resin composition comprises 50 to 99% by weight of polyalkylene carbonate, 0.5 to 50% by weight of polylactide and 0.5 to 35% by weight of polyalkyl (meth) acrylate, The catalyst content is 1 to 300 ppm, and the content of the by-product alkylene carbonate is 0.01 to 1% by weight. At this time, it is preferable that the polyalkylene carbonate is polyethylene carbonate.

The materials used in the solution polymerization will be described in more detail as follows.

The epoxide compound is an alkylene oxide having 2 to 20 carbon atoms which is substituted or unsubstituted with halogen or an alkyl group having 1 to 5 carbon atoms; A cycloalkylene oxide having 4 to 20 carbon atoms substituted or unsubstituted with halogen or an alkyl group having 1 to 5 carbon atoms; And styrene oxide having 8 to 20 carbon atoms substituted or unsubstituted with halogen or an alkyl group having 1 to 5 carbon atoms. More preferably, the epoxide compound may include an alkylene oxide having 2 to 20 carbon atoms which is substituted or unsubstituted with halogen or an alkyl group having 1 to 5 carbon atoms.

Specific examples of the epoxide compound include ethylene oxide, propylene oxide, butene oxide, pentene oxide, hexene oxide, octene oxide, decene oxide, dodecene oxide, tetradecene oxide, hexadecene oxide, octadecene oxide, Epichlorohydrin, epibromohydrin, isopropyl glycidyl ether, butyl glycidyl ether, t-butyl glycidyl ether, 2-epoxy-7-octene, epifluorohydrin, epichlorohydrin, -Ethylhexyl glycidyl ether, allyl glycidyl ether, cyclopentene oxide, cyclohexene oxide, cyclooctene oxide, cyclododecene oxide, alpha-pinene oxide, 2,3-epoxy norbornene, limonene oxide, dieldrin , 2,3-epoxypropylbenzene, styrene oxide, phenylpropylene oxide, stilbene oxide, Propyl methoxy ether, chloropropyl methoxy ether, chloropropyl methoxy ether, chloropropyl methoxy ether, chlorostyrene benzoate, dichlorostilbene oxide, 1,2-epoxy-3-phenoxypropane, benzyloxymethyloxirane, glycidyl- Phenyl ether, biphenyl glycidyl ether, glycidyl naphthyl ether, and the like. Preferably, the epoxide compound uses ethylene oxide.

The carbon dioxide may be continuously or discontinuously introduced during the reaction but is preferably continuously introduced. In this case, the polymerization reactor may be a semi-batch type or a closed batch system good. If carbon dioxide is not continuously supplied, production of byproducts such as polyethylene glycol may increase separately from the carbonate copolymerization reaction aimed at in the present invention. The reaction pressure may be 5 to 50 bar, or 10 to 40 bar when carbon dioxide is continuously supplied in the polymerization.

The carbon dioxide may be added in a molar ratio of 1: 1 to 10: 1 based on the epoxide compound. More preferably, the carbon dioxide may be introduced in a molar ratio of 2: 1 to 5: 1 relative to the epoxide compound. If carbon dioxide is introduced at the above ratio, it is preferable to use a semi-batch type system as the polymerization reactor.

The catalyst used in the present invention can be carried out in the presence of a metal complex compound such as zinc, aluminum or cobalt, but a zinc-based catalyst is preferably used. The zinc-based catalyst is not limited in its kind and may include zinc complexes well known in the art.

The catalyst may be added in a molar ratio of 1:50 to 1: 1000, more preferably 1:70 to 1: 600, or 1:80 to 1: 300, based on the epoxide compound . If the ratio is less than 1:50, sufficient catalyst activity is not exhibited in the solution polymerization. If the ratio is more than 1: 1000, by using an excessive amount of catalyst, the by-product may not be produced efficiently, (back-biting), the molecular weight may decrease and the amount of cyclic carbonate produced may increase.

The solvent is preferably used in a weight ratio of 1: 0.1 to 1: 100 based on the epoxide compound, more preferably 1: 1 to 1:10. The solvent may be a chlorinated solvent, and preferred examples thereof include methylene chloride or ethylene dichloride.

Hereinafter, preferred embodiments of the present invention will be described in detail. It should be understood, however, that these examples are for illustrative purposes only and are not to be construed as limiting the scope of the present invention.

[Examples 1 and 2]

After a polymerization reactor, an extruder for pelletization, a water feed tank for removing by-products, a centrifugal dryer, and a pellet recovery device were connected to each other, a resin composition containing polyethylene carbonate was continuously produced.

First, a dry diethyl-zinc catalyst, a solvent (MC), ethylene oxide (EO) and carbon dioxide were fed into this reactor using an autoclave reactor equipped with a stirrer as a polymerization reactor. To prepare poly (ethylene carbonate) carbonate. At this time, ethylene oxide (EO), carbon dioxide, and solvent were purified before polymerization and kept at a water content of less than 10 ppm.

Example 1 Example 2 Cat.amt (g) 8 0.4 EO (g) 180 8.77 menstruum (g) 900 8.52 EO / cat. 99.8 97.3 CO ₂ (bar) 40 40 Temperature (° C) 70 70 time (h) 4 3 yield (g) 90.5 7.17 yield (g / g-cat) 11 18 activation (g / g-cat.hr) 2.83 5.98 EO conversion rate (%) 25 41 TOF (mol / mol-cat.hr) 6.28 13.26

After completion of solution polymerization under the above conditions, unreacted carbon dioxide and ethylene oxide were removed by venting, and the catalyst residue was removed using a metal filter.

The reaction mixture and water were then passed through an extraction column of the rotating disc contactor type to remove the by-product ethylene carbonate from the reaction mixture.

The solvent was then removed from the reaction mixture under reduced pressure in a flash drum. After the solvent was removed, the remaining polyethylene carbonate (94 g) was added to a twin screw extruder (BA-19, manufactured by BAUTECH). Then, 5 g of polylactide (PLA, weight average molecular weight: 230,000, manufactured by NatureWorks) and 1 g of polymethyl methacrylate (PMMA, weight average molecular weight: 86,000, manufactured by LG MMA) were further added to the extruder and mixed , And this mixture was prepared in the form of pellets (pellet size: 3 mm).

Thereafter, the pellet was moved to a centrifugal dryer and dried. Then, a final pellet sample (that is, a CAM resin composition including polyethylene carbonate, polylactide and PMMA) was obtained through a pellet recovery device. The recovered pellet specimens were identified by nuclear magnetic resonance spectroscopy and the weight average molecular weight as determined by GPC was 230,000 g / mol.

Also, the final product contained 94 wt% of polyethylene carbonate, 5 wt% of polylactide, 1 wt% of PMMA, the catalyst content was less than 300 ppm, and the byproduct content was 1 wt% or less.

[Comparative Example 1]

Pellets were prepared under the same conditions as in Example 1, but the step of removing ethylene carbonate as a by-product in the extraction column was not carried out.

[Comparative Example 2]

Pellets were prepared under the same conditions as in Example 1, but the solvent was not removed.

[Comparative Example 3]

Pellets were prepared under the same conditions as in Example 1, but the catalyst residue was not removed.

[Experimental Example]

Property evaluation test

The extrudability, the pellet state, and the sheet formability of the resin composition specimens prepared in the above Examples and Comparative Examples were evaluated according to a method described later, and tensile strength, elongation and haze were measured.

(1) Extrusion property: The extrusion process of the resin composition was visually observed in the above-mentioned sample preparation process and evaluated in four stages of excellent (⊚), excellent (◯), moderate (△) and poor (X).

(2) Pellet state: About 20 g of the pellets containing the respective resin compositions according to the examples and comparative examples were placed in a convection oven at about 40 ° C under a load of 200 g, Minute, the state of the pellet containing each resin composition, the degree of blocking, and the like were visually observed and evaluated in four stages of excellent (?), Excellent (?), Normal (?) And defective Respectively.

(3) Sheet processability: After preheating the sheet at a temperature of 170 DEG C for 1 minute using a hot press machine, each sheet was compressed for 2 minutes under a pressure of 300 bar to provide a sheet to test sheet formability. (Very good (⊚) and excellent (◯)) and bubbles were observed (normal (△) and poor (X)) in the sheet produced by observing the produced sheet with naked eyes .

(4) Haze (%): A specimen having a width of 5 cm and a thickness of 0.18 mm was prepared and measured using a Nippon Denshoku Haze Meter according to ASTM D 1003. The transmittance of light with a wavelength of 400 to 700 nm was measured, and the opacity (Haze,%) value obtained by measuring the scattered light with respect to the whole transmitted light was expressed.

At this time, when the sample was visually observed, it was judged as opaque when the turbidity was 20% or more and the light was not passed, and when the turbidity was less than 20% and the light was almost passed, it was judged as transparent.

The evaluation and measurement results are summarized in Table 2 below.

Extrudability Pellet state Sheet formability Hayes
(%) Example 1 Very good (◎) Very good (◎) Very good (◎) Transparency Example 2 Very good (◎) Very good (◎) Very good (◎) Transparency Comparative Example 1 Usually (△) Bad (X) Bad (X) Not measurable Comparative Example 2 Bad (X) Usually (△) Bad (X) Not measurable Comparative Example 3 Usually (△) Usually (△) Usually (△) Bad
(opacity)

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will appreciate that such specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereby. something to do. It is therefore intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

Claims (14)

A polymerization step of using carbon dioxide and an epoxide compound as raw materials in the presence of a zinc-based catalyst and a solvent;
Recovering the residual monomer from the reaction mixture comprising the polyalkylene carbonate obtained by the polymerization process, the catalyst residue, the unreacted residual monomer, the solvent and the by-product comprising the alkylene carbonate;
Removing the catalyst residue from the reaction mixture from which the residual monomer has been removed;
Removing byproducts from the reaction mixture from which the catalyst residue and the residual monomer have been removed;
Removing the solvent from the reaction mixture from which the catalyst residue, residual monomer and byproduct have been removed; And
(Meth) acrylate to a polyalkylene carbonate which has been removed to a solvent to form a polyalkylene carbonate resin composition,
The polymerization step or the resin composition forming step may be carried out continuously,
A method for continuously producing a polyalkylene carbonate resin composition.
The method for continuously manufacturing a polyalkylene carbonate resin composition according to claim 1, further comprising, prior to the polymerization step, a step of purifying the monomer.
The method of claim 2, wherein the step of purifying the monomer comprises passing the monomer through a column filled with a molecular sieve to purify the water content of the monomer to less than 10 ppm. A method for continuously producing a resin composition.
The method according to claim 1, wherein the step of removing the catalyst residue comprises passing the reaction mixture through a metal filter, or passing the reaction mixture in a direction parallel to the metal filter, A method for continuously producing a resin composition.
The method of claim 1, wherein the step of recovering the residual monomer comprises:
And removing the unreacted carbon dioxide and the epoxide compound by venting. The continuous method for producing a polyalkylene carbonate based resin composition according to claim 1,
2. The method of claim 1 wherein removing the byproduct comprises passing the reaction mixture and water in an extraction column to remove byproducts from the reaction mixture comprising polyalkylene carbonate, A method for continuously producing a resin composition comprising a polyalkylene carbonate.
The method of claim 1, wherein removing the solvent comprises:
At least one selected from the group consisting of Simple Flash Drum, Falling Film Evaporator, Thin Film Evaporator (Extrusion DV), Filmtruder, and Kneader Wherein the polyalkylene carbonate is produced by using a combination of the polyalkylene carbonate and the polyalkylene carbonate.
The method according to claim 1,
Wherein the step of forming the polyalkylene carbonate resin composition comprises, based on 100 parts by weight of the polyalkylene carbonate, 0.5 to 50 parts by weight of polylactide; And 0.5 to 35 parts by weight of a polyalkyl (meth) acrylate is pelletized by pouring the resin composition into an extruder to continuously produce a resin composition comprising the polyalkylene carbonate.
The method according to claim 1, further comprising, after the polyalkylene carbonate resin composition is formed, recovering the polyalkylene carbonate resin composition.
The method according to claim 1, wherein the by-product comprises a polyalkylene carbonate comprising an alkylene carbonate having 1 to 5 carbon atoms.
The composition according to claim 1, which can be at least 90 wt.% In the final resin composition, less than 5 wt.% Polylactide resin, less than 1 wt.% Polyalkyl (meth) acrylate, less than 300 ppm catalyst, Is not more than 1% by weight based on the total weight of the polyalkylene carbonate.
The method according to claim 1,
The epoxide compound is an alkylene oxide having 2 to 20 carbon atoms which is substituted or unsubstituted with halogen or an alkyl group having 1 to 5 carbon atoms; A cycloalkylene oxide having 4 to 20 carbon atoms substituted or unsubstituted with halogen or an alkyl group having 1 to 5 carbon atoms; And styrene oxide having 8 to 20 carbon atoms which is substituted or unsubstituted with halogen or an alkyl group having 1 to 5 carbon atoms,
The solvent may be a chlorinated solvent,
A method for continuously producing a resin composition comprising a polyalkylene carbonate.
The method according to claim 1, wherein the monomer of the polyalkyl (meth) acrylate is a polyalkylene carbonate which is an ester of (meth) acrylic acid and an alkyl group having 1 to 20 carbon atoms.
2. The method according to claim 1, wherein the polymerization process is carried out at 50 to 100 DEG C and 15 to 50 bar for 1 to 60 hours.