KR20150029367A - Polyalkylene carbonate resin molded article comprising polylactide particles - Google Patents

Abstract

The present invention relates to a molded article of polyalkylene carbonate resins including polylactide resin particles and, more specifically, a molded article of polyalkylene carbonate resins, which has an outstanding biodegradable and mechanical property while reducing a blocking situation in a processing step wherein the molded article has various forms such as various films, pellets and seats because the molded article has less blocking situations compared with an existing molded article, thereby being widely used in different industries like portable products, electronic products and built-in materials used in vehicles.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a polyalkylene carbonate resin molded article comprising a polylactide resin particle,

The present invention relates to a polyalkylene carbonate resin molded article comprising polylactide resin particles, and more particularly, to a polyalkylene carbonate resin molded article comprising a polylactide resin particle as an antiblocking agent and exhibiting excellent biodegradability and mechanical properties, blocking phenomenon of a polyalkylene carbonate resin can be reduced. The molded article of the present invention can be used in various applications such as various films, sheets, molded articles, disposable articles, electronic products, and automobile interior materials.

Many synthetic polymers, particularly synthetic resins, are made in a variety of commercial products, such as particulate or particulate forms, such as pellets, granules, briquettes or cubes. In general, the particle morphology of such polymers is either artificially formed for a particular purpose or formed naturally by the results of various processes in the production of polymers.

However, many commonly used polymer particles, especially synthetic resins, exhibit a blocking phenomenon in which their particles agglomerate or are undesirably fused. This blocking phenomenon can be caused by external conditions such as temperature, pressure and the like during the storage of the polymer particles. In particular, the blocking phenomenon can easily occur during the lamination and heating process of the polymer during the processing. If a blocking phenomenon occurs, a process may generally be required to partially or completely separate the aggregate, resulting in additional labor, costs, and further contamination or damage of the polymer in further processing have.

Thus, methods have been attempted that include particles such as dusting agents, such as carbon black, talc, chalk, silica, etc., in order to prevent blocking of the polymer particles, but in this case, It may affect the intrinsic properties, and the fine powder of the dusting agent may cause environmental problems, which is undesirable.

An olefin resin such as high density polyethylene (HDPE) or low density polyethylene (LDPE) may be used as an anti-blocking agent. However, since these resins are hydrophobic, It is difficult to serve as an antiblocking agent due to low compatibility with resins having polarity. In particular, carbon dioxide-based hydrophilic plastic resins such as polyalkylene carbonate have very low compatibility with olefinic resins, and conventional olefinic antiblocking agents having a size of about 30 to about 40 탆 have little effect.

Therefore, it is necessary to develop an antiblocking agent capable of maintaining the inherent physical properties of a synthetic resin and making a product having excellent workability and storage property by improving the blocking phenomenon without deteriorating transparency.

An object of the present invention is to provide a polyalkylene carbonate resin molded article comprising an antiblocking agent capable of improving storage, processing and blocking phenomena appearing in the 탆 square while maintaining the inherent mechanical and thermal properties of the synthetic resin.

The present invention provides a polyalkylene carbonate resin molded article comprising a polyalkylene carbonate resin and a polylactide resin particle having a particle size of 0.1 to 350 占 퐉 as an antiblocking agent.

The polyalkylene carbonate resin molded article of the present invention is excellent in workability and storage in the process of processing since blocking phenomenon is prevented, in particular, blocking phenomenon is prevented even at a high temperature of 70 캜 or more.

The polyalkylene carbonate resin molded article of the present invention contains a polyalkylene carbonate resin and a polylactide resin particle having a particle size of 0.1 to 350 mu m as an antiblocking agent.

The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprising," "comprising," or "having ", and the like are intended to specify the presence of stated features, But do not preclude the presence or addition of one or more other features, integers, steps, components, or combinations thereof.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Throughout this specification, the term "blocking phenomenon" refers to a phenomenon in which self-particles or molded articles are agglomerated or undesirably adhered to each other in the course of storage or processing of polymer particles, particularly synthetic resins or molded articles produced therefrom .

The anti-blocking agent means a material capable of preventing the blocking phenomenon that may occur during storage or processing of polymer particles, synthetic resin, or molded articles produced therefrom.

Hereinafter, the molded article of the polyalkylene carbonate resin of the present invention will be described in detail.

The polyalkylene carbonate resin molded article according to one aspect of the present invention comprises a polyalkylene carbonate resin and polylactide resin particles having a particle size of about 0.1 to about 350 mu m as an antiblocking agent.

Since polylactide resin is based on biomass unlike existing crude oil-based resin, it can be used as a renewable resource. In production, less carbon dioxide, which is a global warming gas, It has environment-friendly properties such as biodegradation by moisture and microorganisms, and is a material with appropriate mechanical strength similar to conventional crude oil-based resin.

The antiblocking agent contained in the molded article of the polyalkylene carbonate resin according to one embodiment of the present invention is a polylactide resin in the form of particles, the particle size of the polylactide resin may be about 0.1 to about 350 mu m, Preferably from about 0.1 to about 150 mu m.

The polylactide resin particles are uniformly dispersed on the surface of a polyalkylene carbonate resin molded article molded into various forms such as a film, a pellet, a sheet, etc., and the blocking phenomenon As an anti-blocking agent.

Although such a polylactide resin particle is larger in size than other resin particles that can be used as an antiblocking agent, the polylactide resin particle can be used as an antiblocking agent even with a small amount because it is effective as an antiblocking agent. In addition, since such polylactide resin particles are excellent in compatibility with polyalkylene carbonate resin as a polar resin as compared with conventional antiblocking agents such as olefinic anti-blocking agents, the polyalkylene carbonate resin molded article Even when subjected to processing such as molding, the physical properties inherent to the polyalkylene carbonate resin, such as transparency, tensile strength, elasticity, and oxygen barrier properties, hardly deteriorate.

The molecular structure of the polylactide may be one which is polymerized by one or more monomers of L-lactic acid and D-lactic acid. The polylactide resin may be prepared by the step of ring-opening polymerization of a lactide monomer to form the following repeating unit. The polymer after completion of the ring-opening polymerization and the formation of the repeating unit is referred to as the polylactide resin . At this time, all types of lactide may be included in the category of the lactide monomer as described above.

For example, the polylactide resin may include a repeating unit represented by the following formula (1).

[Chemical Formula 1]

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.

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.

As a method for producing a polylactide resin, there is known a method of directly condensing lactic acid or ring opening polymerization of the lactide monomer under an organometallic catalyst. Among them, in the direct condensation polymerization method, the viscosity increases sharply as the condensation polymerization progresses, and it becomes very difficult to effectively remove moisture as a reaction by-product. Therefore, it is difficult to obtain a polymer having a high molecular weight of 100,000 or more as a weight average molecular weight, and therefore it is difficult to sufficiently secure the physical and mechanical properties of the polylactide resin. On the other hand, the ring-opening polymerization method of lactide monomers requires a lactide monomer to be prepared first in lactic acid. Therefore, the production process is complicated and requires a higher unit cost than the condensation polymerization. However, lactide ring- Can be relatively easily obtained and the polymerization rate can be controlled in a favorable manner.

According to one embodiment of the present invention, the polylactide resin may have a weight average molecular weight of about 100,000 to about 1,000,000 g / mol. When the polylactide has a weight average molecular weight in the above range, it can sufficiently function as an antiblocking agent.

According to one embodiment of the present invention, the particle size of the polylactide resin may be about 0.1 to about 350 mu m, and preferably about 0.1 to about 150 mu m. When the particle size of the polylactide resin is in the above range, the polyalkylene carbonate resin molded product processed in the form of pellets, films, sheets and the like becomes more effective as an antiblocking agent.

The polylactide resin particle includes a polylactide polymer resin and means a solid powder, powder, pellet or the like having a diameter or a length of one side of the particle having a size in the above-mentioned range, But may be in the form of small particles made of, for example, spherical, cylindrical, prismatic or the like.

The polylactide resin particles having the above-described size can be produced by a general method used in the technical field, for example, emulsification, premix membrane emulsification, spray (RESS, GAS, ASES, SEDS, PGSS) using a supercritical fluid, as well as milling, drying, and milling.

According to one embodiment of the present invention, a sieve may be used to separate the polylactide resin particles produced by the above method according to their sizes. The type of sieve can be varied depending on the required size of the polylactide particles. For example, the polylactide resin particles having a desired size can be filtered using 30 mesh or 50 mesh size.

The polyalkylene carbonate resin included in the polyalkylene carbonate resin molded article according to one embodiment of the present invention may be represented by the following formula (2).

(2)

In Formula 2, R ¹ to R ⁴ each independently represent hydrogen, a linear or branched alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or a cycloalkyl group having 3 to 20 carbon atoms Alkyl group; At least any two of R ¹ to R ⁴ may be connected to each other to form a cycloalkyl group having 3 to 10 carbon atoms, and m is an integer of 10 to 1,000.

The polyalkylene carbonate resin can be obtained through copolymerization using an epoxide-based compound and carbon dioxide as a monomer in the presence of an organometallic catalyst. The epoxide compound may be at least one compound selected from the group consisting of ethylene oxide, propylene oxide, 1-butene oxide, 2-butene oxide, isobutylene oxide, 1-pentene oxide, 2-pentene oxide, 1-hexene oxide, Pentene oxide, cyclohexene oxide, styrene oxide or butadiene monoxide, and the like, or a combination of two or more different epoxy compounds selected from the foregoing.

Such a polyalkylene carbonate resin may be a homopolymer containing a repeating unit represented by the above formula (2); Or a copolymer comprising two or more kinds of repeating units belonging to the general formula (2), or a copolymer comprising an alkylene oxide repeating unit and the like together with the repeating unit represented by the general formula (2).

At this time, R ¹ to R ⁴ may be selected as appropriate functional groups in consideration of the mechanical properties or biodegradability of the polyalkylene carbonate resin to be finally obtained. For example, when the functional group is hydrogen or a functional group having a relatively small number of carbon atoms, it may be more advantageous in terms of biodegradability, and in the case of a functional group having a relatively large number of carbon atoms, it may be advantageous in terms of mechanical properties such as strength of the resin. As a specific example, it has been reported that polyethylene carbonate is biodegraded more rapidly than polypropylene carbonate (Inoue et al. Chem. Pharm. Bull, Jpn, 1983, 31, 1400; Ree et al. , 288-294).

In the polyalkylene carbonate resin, the polymerization degree m of the repeating unit represented by the above formula (2) may be 10-1,000, preferably 50-500. The polyalkylene carbonate containing the repeating unit may have a weight average molecular weight of about 10,000 to about 1,000,000, preferably about 50,000 to about 500,000. As the polyalkylene carbonate has the degree of polymerization and the weight average molecular weight, the molded article obtained from the polyalkylene carbonate can exhibit biodegradability along with mechanical properties such as appropriate strength.

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

According to one embodiment of the present invention, the polyalkylene carbonate resin is selected from the group consisting of polyethylene carbonate, polypropylene carbonate, polypentene carbonate, polyhexene carbonate, polyoctenecarbonate, polycyclohexene carbonate and copolymers thereof. It can be more than a species.

The form of the polyalkylene carbonate resin molded article of the present invention which can be produced using such a polyalkylene carbonate is not particularly limited, and for example, the molded article may be processed into a film, a pellet, a sheet or the like.

The method of processing the polyalkylene carbonate resin into a molded product can be a method generally used in the technical field of the present invention without any particular limitation. For example, a resin composition may be prepared by using one type of polyalkylene carbonate resin or by mixing one or more polyalkylene carbonate resins, and then molding the resin composition by a method such as injection molding, extrusion molding, extrusion blow molding, It can be processed into a molded article such as the above-mentioned film, pellet, sheet or the like.

The polyalkylene carbonate resin is an amorphous transparent resin, unlike an aromatic polycarbonate which is a similar synthetic resin, exhibits biodegradability and is thermally decomposable at a low temperature as well as completely decomposed into carbon dioxide and water to be free from carbon residues It has advantages.

In addition, although it has excellent transparency, tensile strength, elasticity, and oxygen barrier property, when it is processed into a film, a pellet, or a sheet form, there is a blocking phenomenon, which is not easy to handle and has poor dimensional stability.

Particularly, when a molded product such as a film of polyethylene terephthalate resin or a sheet is produced and processed into an air-inflatable product, the blocking phenomenon between the film and the sheet is very serious, and the workability and product storage property are greatly deteriorated .

At this time, although hydrophobic resin particles can be used as the antiblocking agent, such a hydrophobic antiblocking agent has poor compatibility with the polar resin as compared with the hydrophilic antiblocking agent. In particular, conventional olefinic anti-blocking agents of about 30 to about 40 microns in size have little blocking effect against polar resins such as polyalkylene carbonates.

On the contrary, the polyalkylene carbonate resin molded article of the present invention has a particle size of the polylactide resin dispersed on the surface of about 0.1 to about 350 μm, and has high compatibility with polyalkylene carbonate And the effect as an antiblocking agent is good. Therefore, even a small amount can serve as an antiblocking agent, and blocking phenomenon can be prevented without deteriorating physical properties inherent to the base resin, such as transparency, tensile strength, elasticity, oxygen barrier properties, and the like.

According to one embodiment of the present invention, the polyalkylene carbonate resin molded article may contain the polylactide resin particles in an amount of about 0.1 to about 5 parts by weight based on 100 parts by weight of the polyalkylene carbonate resin, , And about 0.5 to about 3 parts by weight. When the amount of the polylactide resin particles is less than about 0.1 parts by weight, the polylactide resin particles may not sufficiently serve as an antiblocking agent. When the amount of the polylactide resin particles is more than about 5% by weight, So that transparency, tensile strength, elasticity, oxygen barrier properties and the like may be lowered.

According to one embodiment of the present invention, the polyalkylene carbonate resin molded article may further include various additives depending on the use. (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. Various additives may be added when preparing the pellets from the polyalkylene carbonate resin or when molding the pellets to produce the processed product.

Best Mode for Carrying Out the Invention Hereinafter, the function and effect of the present invention will be described in more detail through specific examples of the present invention. It is to be understood, however, that these embodiments are merely illustrative of the invention and are not intended to limit the scope of the invention.

< Example >

Polyethylene Carbonate Pellet  Ready

<Preparation Example 1>

A polyethylene carbonate resin was prepared by copolymerizing ethylene oxide with carbon dioxide using a diethyl-zinc catalyst in the following manner (Journal of Polymer Science B 1969, 7, 287; Journal of Controlled release 1997, 49, 263).

A dry diethyl-zinc catalyst (1 g) and 10 mL of dioxane solvent were placed in an autoclave reactor equipped with a stirrer, and 0.1 g of dilute purified water was added to 5 mL of dioxane solvent while stirring slowly. Carbon dioxide was charged at a pressure of about 10 atm and then stirred at 120 DEG C for 1 hour. Thereafter, purified ethylene oxide (10 g) was charged, carbon dioxide was filled again at about 50 atm, and the temperature was adjusted to 60 ° C, and the reaction was carried out for about 48 hours. After the reaction, unreacted ethylene oxide was removed under reduced pressure and dissolved in a dichloromethane solvent. Washed with an aqueous hydrochloric acid solution (0.1 M) and precipitated in a methanol solvent to obtain a polyethylene carbonate resin. The recovered resin was about 15 g, and its formation was confirmed by nuclear magnetic resonance spectrum, and the weight average molecular weight analyzed by GPC was 230,000.

The polyalkylene carbonate resin was molded into a pellet using a twin screw extruder (BA-19, manufactured by BAUTECH).

Polylactide  Preparation of resin particles

<Preparation Example 2>

Polylactide resin particles having a particle size of 350 μm or less (manufactured by MIZUNE CHEMICAL INDUSTRIES, LTD., Weight average molecular weight: 230,000 g / mol) were separated using a 50 mesh sieve to prepare an antiblocking agent.

<Preparation Example 3>

The polylactic acid was dissolved in chloroform at a weight ratio of 1: 3. While stirring the mixture at 3,000 rpm, 10 times methanol was added slowly to the weight of the polylactic acid. The latex precipitate mixed with methanol was washed with methanol. Methanol was separated through filtration and the resulting precipitate was dried in a vacuum at 40 &lt; 0 &gt; C. After confirming that the particle size of the polylactide resin obtained after drying was 150 탆 or less, it was prepared as an antiblocking agent. (Weight average molecular weight: 230,000 g / mol)

Including antiblocking agent Polyalkylene Carbonate  Manufacture of Resin Molded Products

&Lt; Example 1 >

20 g of the polyethylene carbonate pellets prepared in Preparation Example 1 and 0.1 g of the polylactide particles prepared in Preparation Example 2 were mixed. (0.5 parts by weight, 50 mesh)

&Lt; Example 2 >

20 g of the polyethylene carbonate pellets prepared in Preparation Example 1 and 0.1 g of the polylactide particles prepared in Preparation Example 3 were mixed. (0.5 parts by weight, grade A)

&Lt; Comparative Example 1 &

20 g of the polyethylene carbonate pellet prepared in Preparation Example 1 was used without being mixed with an additional anti-blocking agent.

&Lt; Comparative Example 2 &

20 g of the polyethylene carbonate pellets prepared in Preparation Example 1 and 0.1 g of HDPE were mixed. (0.5 parts by weight, HDPE)

The HDPE used was a product of Copolymer Corp. and the particle size was 40 탆.

The compositions used in Examples 1 to 4 and Comparative Examples 1 to 3 are summarized in Table 1 below.

Remarks Suzy Anti-blocking agent Content (parts by weight) Example 1 PEC PLA 50mesh 0.5 Example 2 PEC PLAYA grade 0.5 Comparative Example 1 PEC - - Comparative Example 2 PEC HDPE 0.5

<Experimental Example 1>

About 20 g of the pellets according to Examples 1 and 2 and Comparative Examples 1 and 2 were heat treated in a convection oven at about 40 ° C. for about 30 minutes under a load of 200 g, The state of the pellets and the degree of blocking were visually observed and evaluated in four stages of very good (⊚), excellent (◯), normal (△) and poor (X).

<Experimental Example 2>

About 20 g of the pellets according to Examples 1 and 2 and Comparative Examples 1 and 2 were placed in a convection oven at about 50 ° C to about 60 ° C under a load of 200 g each for about 30 minutes After the heat treatment, the state of the pellet and the degree of blocking were visually observed and evaluated in four stages of excellent (?), Excellent (?), Normal (?) And poor (X).

<Experimental Example 3>

About 20 g of the pellets according to Examples 1 and 2 and Comparative Examples 1 and 2 were heated in a convection oven at about 70 ° C. for about 90 minutes under a load of 200 g, The state of the pellets and the degree of blocking were visually observed and evaluated in four stages of very good (⊚), excellent (◯), normal (△) and poor (X).

The results of the above experiments are summarized in Table 2 below.

Remarks Anti-blocking agent content
(Parts by weight) Temperature (℃) Time (min) Pellet state Example 1 PLA 50mesh 0.5 40 30 ◎ Example 2 PLAYA grade 0.5 40 30 ◎ Comparative Example 1 - - 40 30 X Comparative Example 2 HDPE 0.5 40 30 △ Example 1 PLA 50mesh 0.5 50-60 30 ○ Example 2 PLAYA grade 0.5 50-60 30 ◎ Comparative Example 1 - - 50-60 30 X Comparative Example 2 HDPE 0.5 50-60 30 △ Example 1 PLA 50mesh 0.5 70 30 △ Example 2 PLAYA grade 0.5 70 30 △ Comparative Example 1 - - 70 30 X Comparative Example 2 HDPE 0.5 70 30 X

Referring to Table 2, it was confirmed that the polyalkylene carbonate pellets according to the present invention had better inhibition of blocking phenomenon than when no anti-blocking agent was added or when HDPE was added as an anti-blocking agent, Particularly, when the particle size of the polylactide resin used as the antiblocking agent was 150 탆 or less, it was confirmed that it was more effective in inhibiting the blocking phenomenon.

Claims (10)

Polyalkylene carbonate resins; And
A polyalkylene carbonate resin molded article comprising a polylactide resin particle having a particle size of 0.1 to 350 占 퐉 as an antiblocking agent.
The polyalkylene carbonate resin molded article according to claim 1, wherein the polylactide resin of the polylactide resin particle has a weight average molecular weight of 100,000 to 1,000,000 g / mol.
The molded article of polyalkylene carbonate resin according to claim 1, wherein the polylactide resin particle is polymerized from L-lactic acid, D-lactic acid or L, D-lactic acid.
The polyalkylene carbonate resin molded article according to claim 1, wherein the polylactide resin particles are contained in an amount of 0.1 to 5% by weight based on 100 parts by weight of the polyalkylene carbonate resin.
The polyalkylene carbonate resin molded article according to claim 1, wherein the polylactide resin particles have a size of 0.1 to 150 탆.
The polyalkylene carbonate resin according to claim 1, wherein the polyalkylene carbonate resin A molded article of a polyalkylene carbonate resin represented by the following formula (2)
(2)

In Formula 2,
R ¹ to R ⁴ are each independently hydrogen, a linear or branched alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or a cycloalkyl group having 3 to 20 carbon atoms; At least any two of R ¹ to R ⁴ may be connected to each other to form a cycloalkyl group having 3 to 10 carbon atoms;
and m is an integer of 10 to 1,000.
The polyalkylene carbonate resin molded product according to claim 1, wherein the polyalkylene carbonate resin has a weight average molecular weight of 10,000 to 1,000,000 g / mol.
The polyalkylene carbonate resin according to claim 1, wherein the polyalkylene carbonate resin is at least one selected from the group consisting of polyethylene carbonate, polypropylene carbonate, polypentene carbonate, polyhexene carbonate, polyoctene carbonate, polycyclohexene carbonate, Alkylene Carbonate Resin Molded Products.
The polyalkylene carbonate resin molded article according to claim 1, wherein the molded article is in the form of a film, a pellet, or a sheet.
The method of claim 1, wherein the pigment, the dye, the carbon black, the titanium oxide, the talc, the calcium carbonate, the clay, and the dispersant. A polyalkylene carbonate resin molded article further comprising at least one additive selected from the group consisting of a lubricant, a plasticizer, a flame retardant, an antioxidant, an antistatic agent, a light stabilizer, an ultraviolet absorber, and a crystallization promoter.