KR20090086814A - Polylactide foam and use of foam-molding product thereby - Google Patents

Abstract

A polylactide foam is provided to improve expansion molding property of a polylactide-based resin, to increase molecular weight of the polylactide-based resin, to secure melt viscosity, crystallinity and uniform foamed cell. A polylactide foam is manufactured by extruding a foam composition. The foam composition comprises an organic peroxide-based cross-linking agent 0.05-4 parts by weight, a plasticizer 0.001-1 parts by weight and talc 0.1-5 parts by weight based on a polylactide-containing base resin 100.0 parts by weight. The polylactide-containing base resin comprises crystalline polylactide or crystalline polylactide 60-90 weight% and non-crystalline polylactide 10-40 weight%.

Description

POLYLACTIDE FOAM AND USE OF FOAM-MOLDING PRODUCT THEREBY}

The present invention relates to the use of polylactide foams and foamed articles using the same, and more particularly, to optimize physical properties of polylactide-containing base resins, and to optimize crosslinking agents, plasticizers and talc in the polylactide-containing base resins. The present invention relates to a polylactide foam obtained by mixing and extrusion-molding by molding to ensure flatness and uniformity of a foam cell, and a food packaging container and an industrial packaging material formed by molding the polylactide foam.

As awareness of the global environment has recently increased, biodegradable resins that are degraded by hydrolysis or microorganisms have been attracting attention if they are buried in soil after use. To date, various biodegradable resins have been developed and expanded to develop fibers, films, and other molding materials using the same.

Most biodegradable resins still depend on fossil raw materials, but polylactide (PLA) is a biodegradable resin material found in corn and sweet potatoes. Is in the spotlight. Such polylactide biodegradable resin is an environmentally friendly material that is completely decomposed into water and carbon dioxide when disposed.

The scope of application of such biodegradable resins is expanding day by day, and typically, the movement to replace plastic bags made of fossil raw materials is actively applied to food packaging containers, takeout containers, and garbage bags.

However, polylactide is low in heat resistance, and when storing or transporting a polylactide-based resin sheet and a molded article thereof, a high temperature is often reached when the inside of a warehouse, a truck in transport, or a ship is in summer. For this reason, problems such as deformation and fusion may occur. As such, the polylactide-based polymer is vulnerable to thermal stability, and thus it is difficult to use the polymer produced as it is. In addition, since the crystallization speed is high and the melt index is high, the molding conditions are large, and thus there is a problem in that productivity is decreased during foam molding.

Therefore, when the crystallized polylactide resin is formed into a foam sheet, when crystallization occurs at the nozzle portion of the extruder, the foaming is no longer performed. Therefore, a special molding machine and a molding technique for increasing the expansion ratio are required. In addition, the amount of energy required for molding is not small, and since high temperature is used when molding the foam sheet, non-uniform shrinkage may occur in the obtained foam molding porous body, and irregularities may occur on the surface thereof.

As a conventional technique for solving such a problem, a method of crosslinking by adding a (meth) acrylic acid ester compound or a polyvalent isocyanate compound to a biodegradable polyester resin in order to improve heat resistance and productivity [Japanese Patent Laid-Open No. 2003- 128901] or a method using a biodegradable polyester and layered silicate in combination (Japanese Patent Laid-Open No. 2003-147182) has been proposed.

On the other hand, Japanese Patent Laid-Open No. 2001-261797 discloses a technique for improving heat resistance and hydrolysis resistance by blocking the carboxyl terminal of polylactic acid with a specific carbodiimide compound. However, although the heat resistance and moldability of the polylactide resin are improved by crosslinking and addition of layered silicate, the physical properties are not maintained by hydrolysis of the resin during long-term storage or when used under severe moist heat. do. Therefore, simply blocking the end of a polylactide resin with a carbodiimide compound is not preferable as a molded article such as injection, extrusion, foaming or blow.

In addition, Japanese Patent Application Laid-Open No. 8-73628 discloses a blister sheet and a molded article excellent in transparency, impact resistance, and heat resistance by stretching a polylactide-based sheet biaxially and performing a predetermined orientation. I have reported. Since the crystallization of the polylactide resin is required to perform a predetermined orientation in the present invention, it is well known to those skilled in the art that the crystallization is not exhibited unless the composition occupies most of the D or L forms. At this time, polylactide having a D / L ratio of 4 to 5/96 to 95 is used.

However, in the case of producing a thermoformed product using the polylactide disclosed in the present invention, in order to exhibit sufficient impact resistance or heat resistance, it is necessary to increase the thickness of the molded article, and thus to form the polylactide having a sufficient thickness. When the thermoforming is performed using the sheet, impact resistance and heat resistance are maintained, but the pressurization pressure in the thermoforming is greater, resulting in problems in molding processability.

Thus, the present inventors have made efforts to improve the physical properties of the conventional polylactide and to increase its utilization, to optimize the physical properties of the base resin containing the polylactide, to ensure the flatness and uniformity of the foam cell in the base resin In order to improve the foamability of the polylactide-based resin by mixing a specific crosslinking agent, a plasticizer, and talc under optimum conditions, and to increase the molecular weight of the polylactide-based resin to secure an appropriate melt viscosity, to increase the crystallinity, and to foam cells The present invention was completed by providing this uniform polylactide foam.

It is an object of the present invention to provide a polylactide foam with improved physical properties of polylactide.

Another object of the present invention is to provide an environmentally friendly food packaging container and an industrial packaging material manufactured using polylactide foam.

In order to achieve the above object, the present invention is extrusion foamed composition comprising 0.05 to 4 parts by weight of organic peroxide crosslinking agent, 0.001 to 1 part by weight of plasticizer and 0.1 to 5 parts by weight of talc with respect to 100 parts by weight of polylactide-containing base resin Provided are molded polylactide foams.

The polylactide-containing base resin of the present invention is crystalline polylactide alone; Resin consisting of 60 to 90% by weight of crystalline polylactide and 10 to 40% by weight of amorphous polylactide; Resin containing 0.5-5 weight part of polycaprolactone further with respect to 100 weight part of crystalline polylactide; And a resin further containing 0.5 to 5 parts by weight of polycaprolactone with respect to 100 parts by weight of the base resin consisting of 60 to 90% by weight of crystalline polylactide and 10 to 40% by weight of amorphous polylactide. It is either one.

The crosslinking agent of the present invention preferably uses an organic peroxide compound, and more preferably, a mixed form of the organic peroxide compound and the epoxy compound. As the organic peroxide crosslinking agent, benzoyl peroxide, lauryl peroxide, dicumyl peroxide, dihexyl peroxide, butyl cumyl peroxide, dibutyl peroxide, p-methane hydroperoxide, diisopropylbenzene hydroperoxide , Tetramethylbutyl peroxide, cumene hydroperoxide, 2,5-dimethyl-2,5-dibutylperoxyhexine-3, 2,3-dimethyl-2,3-diphenylbutane, 1,1-di ( t-hexylperoxy) cyclohexane, 1,1-di (t-butylperoxy) cyclohexane, 2,2-di (4,4-di- (t-butylperoxy) cyclohexyl) propane, di ( 2-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-dibutylperoxyhexane, hexyl peroxy isopropyl carbonate, butyl peroxy 2-ethylhexyl carbonate, diisopropyl peroxy dicarbonate, butyl Peroxy Isopropyl Carbonate, Butyl Peroxy Maleic Acid, Butyl Peroxy-3,5,5-trimethylhexanoate, Butyl Peroxy Laurate, butyl peroxy benzoate, hexyl peroxy benzoate, butyl peroxy acetate, n-butyl 4,4-di-butyl peroxy valerate, 2,2-di-butyl peroxy butane It is to use any one selected.

The plasticizer used in the present invention uses an organic acid or an alcohol compound metal compound or a citric acid compound.

In addition, the particle size of the talc used in the present invention is preferably 0.5 to 7㎛.

The present invention provides a food packaging container and an industrial packaging material produced by molding the polylactide foam.

The present invention provides a composition optimized to optimize the physical properties of the polylactide-containing base resin, to increase the crystallinity of the polylactide resin, to ensure the appropriate melt viscosity, and to have a uniform foam cell structure when foaming And, it provides an extruded polylactide foam, by using the polylactide foam with improved physical properties can provide environmentally friendly food packaging containers and industrial packaging materials such as trays, cups, cup noodle containers, lunch boxes. have.

Hereinafter, the present invention will be described in detail.

The present invention relates to a polylactide foam in which a composition consisting of 0.05 to 4 parts by weight of an organic peroxide crosslinking agent, 0.001 to 1 part by weight of plasticizer and 0.1 to 5 parts by weight of talc is extrusion-molded based on 100 parts by weight of a polylactide-containing base resin. to provide.

The polylactide foam of the present invention optimizes the polylactide-containing base resin to meet the requirements for ensuring flatness and uniformity of the foam cells.

That is, in order for the polylactide foam to have an excellent quality having excellent flatness, in particular, uniformity of the foaming cell, it is preferable to use a polylactide-containing base resin composed of crystalline polylactide alone.

Lactic acid, a raw material of polylactide, has an optically active carbon atom array in its molecule, and thus has optical isomers of L-lactic acid and D-lactic acid. Furthermore, poly L-lactic acid (hereinafter referred to as "PLLA") and poly D-lactic acid (hereinafter referred to as "PDLA") are present.

Thus, in the present invention, the crystalline polylactide is a case in which the ratio of L-lactic acid in PLLA and D-lactic acid in PDLA is high in polylactide, that is, when the optical purity is high. This is excellent. On the other hand, amorphous polylactide is a copolymer having a relatively high ratio of L-lactic acid in PDLA or D-lactic acid in PLLA, and has low crystallinity and thermal stability and low mechanical properties.

As the polylactide-containing base resin of the present invention, more preferably, a polylactide-containing base resin composed of 60 to 90% by weight of crystalline polylactide and 10 to 40% by weight of amorphous polylactide is used. At this time, impact resistance and heat resistance are preserved from the crystalline polylactide, and flexibility is imparted by the amorphous polylactide polymer, thereby improving the foamability of the polylactide resin. In this case, the content of the amorphous polylactide is used in 10 to 40% by weight, by mixing less than the crystalline polylactide, thereby improving the flex resistance and minimizing the shape change of the molded article by heat, molding stability This is improved.

A further preferred form for the polylactide-containing base resin of the present invention to have excellent flatness and uniformity of the foaming cell is that it further contains 0.5 to 5 parts by weight of polycaprolactone based on 100 parts by weight of the crystalline polylactide. And, most preferably, 0.5 to 5 parts by weight of polycaprolactone, based on 100 parts by weight of polylactide-containing base resin consisting of 60 to 90% by weight of crystalline polylactide and 10 to 40% by weight of amorphous polylactide. It is to contain.

At this time, the polycaprolactone is excellent in miscibility with the polylactide resin and serves to improve the flexural strength and impact strength of the polylactide resin. When the content exceeds 5 parts by weight, the foaming agent increases more than necessary for flexibility, and thus the shape stability of the molding is poor. Thus, the embodiment of the present invention will be described with reference to the polylactide-containing base resin of the most preferred form.

The molecular weight (Mw) of a general polylactide resin is about 200,000 to 250,000, and the melt viscosity is low to produce a sheet by extrusion foam molding. Thus, by adding a crosslinking agent in the extrusion foaming process, the polymer chain is partially crosslinked at the melting temperature of the resin in the extruder to make the apparent molecular weight 300,000 or more, thereby increasing the melt viscosity.

The crosslinking agent used in the present invention is preferably an organic peroxide compound, preferably benzoyl peroxide, lauryl peroxide, dicumyl peroxide, dihexyl peroxide, butyl cumyl peroxide, dibutyl peroxide, p-methane hydroper Oxide, diisopropylbenzenehydroperoxide, tetramethylbutylperoxide, cumene hydroperoxide, 2,5-dimethyl-2,5-dibutylperoxyhexine-3, 2,3-dimethyl-2,3-di Phenylbutane, 1,1-di (t-hexylperoxy) cyclohexane, 1,1-di (t-butylperoxy) cyclohexane, 2,2-di (4,4-di- (t-butylper Oxy) cyclohexyl) propane, di (2-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-dibutylperoxyhexane, hexyl peroxy isopropyl carbonate, butyl peroxy 2-ethylhexyl carbonate , Diisopropyl peroxydicarbonate, butyl peroxy isopropyl carbonate, butyl peroxy maleic acid, butyl peroxy-3,5 , 5-trimethylhexanoate, butyl peroxylaurate, butyl peroxy benzoate, hexyl peroxy benzoate, butyl peroxy acetate, n-butyl 4,4-di-butyl peroxy valerate, 2,2- Any one selected from the group consisting of di-butylperoxybutane and the like is used.

The crosslinking agent of the present invention is more preferably used by mixing an organic peroxide compound with an epoxy compound used as a conventional crosslinking agent.

The epoxy compound conventionally used is any one selected from the group consisting of bisphenol A diglycidyl ether, terephthalic acid diglycidyl ether, trimethylolpropane diglycidyl ether, and 1,6-hexanediol diglycidyl ether. By using, there is an expensive disadvantage. Thus, the crosslinking agent of the mixed form of the present invention can provide an equivalent effect while reducing the content of the conventional expensive epoxy-based crosslinking agent, it is possible to increase the melt viscosity by partially crosslinking the polymer chain. At this time, if the mixing ratio of the conventional epoxy compound is used in 1 to 2%, 0.5 to 1% of the epoxy compound is mixed with 0.1 to 1% of the organic peroxide compound to crosslinking reaction.

It is preferable to use 0.05-4 weight part of crosslinking agents of this invention with respect to 100 weight part of polylactide containing base resins. At this time, if the content of the crosslinking agent is less than 0.05 parts by weight, the apparent molecular weight increase effect is insufficient. If the content of the crosslinking agent is more than 4 parts by weight, crosslinking occurs too much and the viscosity of the molten resin increases rapidly or the foaming extruder may be blocked. Brings about.

Even if the polylactide foam obtains an appropriate melt viscosity, it is not preferable at the time of foaming, if the foaming ratio is low since the moldability is poor and additional costs such as introduction of a special molding machine for enhancing moldability are added.

Therefore, the polylactide foam of the present invention improves the expansion ratio by adding a suitable low molecular weight plasticizer. Preferred plasticizers used in the present invention should basically be compatible with the resin, and the following compounds may be selected or used in combination. Examples of the compound include aluminum stearate, magnesium stearate, zinc stearate, calcium stearate, aluminum oleate, zinc oleate, calcium oleate, aluminum palmitate, magnesium palmitate, zinc palmitate, zinc citrate, butyl gutate, acetyl gutate In addition to triethyl, acetyl tributyl citrate, aliphatic polyhydric carbon ester, aliphatic polyhydric alcohol ester, aliphatic polyhydric alcohol ether, and the like, for example, dimethyl adipate, 2-ethylhexyl adipate, diisobutyl adipate, Dibutyl adipate, diisodecyl adipate, dibutyl sebacate, 2-ethylhexyl sebacate, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol ethyl ether, diethylene glycol diethyl ether, Diethylene glycol butyl ether, diethylene glycol di Butyl ether, diethylene glycol ethylhexyl ether, polyoxyethylene dimethyl ether, polyoxypropylene dimethyl ether, citric acid and sodium dicarbonate mixture, calcium gluconate and the like.

The preferred amount of plasticizer is 0.001 to 1 part by weight, more preferably 0.005 to 0.5 part by weight based on 100 parts by weight of the polylactide-containing base resin. At this time, when the plasticizer is used at less than 0.001 parts by weight, the plasticity improvement of the molten resin and the foaming magnification improvement effect of the foamed molded article are insufficient. On the other hand, if it exceeds 1 part by weight, there is a disadvantage in that the foamed molded article and the molded article are too flexible, resulting in poor shape stability.

In addition, if the cell wall thickness of the foam is thin in the foam extrusion process or the size and thickness of the foam cell are uneven, the tensile elongation is low, so the wall is easily broken.

Therefore, the polylactide foam of the present invention contains 0.1 to 5 parts by weight of talc having a particle size of 0.5 to 7 μm with respect to 100 parts by weight of the polylactide-containing base resin, thereby adjusting the cell thickness to prevent foams that are not easily broken. You can get it.

At this time, if the talc is used in less than 0.1 parts by weight, it can be improved to 6 to 10 times the desired foaming ratio, but because the size of one foam cell is too large, such as 0.5mm, the quality of the sheet product falls. On the other hand, when talc is used in excess of 5 parts by weight, the size of the foam cell becomes too small, or the wall of the foam cell is broken to obtain the desired foam drainage.

In addition, in the present invention, the talc used for the purpose of improving foamability is preferably used in the particle size of 0.5 to 7㎛, when using larger particles than the particle size, since the membrane itself of the foam cell is destroyed, commercially available talc Within the particle range, the finer particles are more preferable, and the size and wall thickness of the desired foam cell cannot be adjusted if the particle size exceeds 7 μm.

The present invention provides a food packaging container and an industrial packaging material manufactured by molding the polylactide foam.

The polylactide foam of the present invention increases the molecular weight of the polylactide-based resin in the foam extrusion process to secure proper melt viscosity, improve crystallinity, improve foamability, and obtain a uniform foaming cell, thereby forming it. One foamed molded article is preferable as a food packaging container such as a tray, a cup, a cup noodles container, a lunch box, or an industrial packaging material.

That is, the conventional polylactide foam is not uniform in size and thickness of the foam cell, when applied as a container, the edge of the container is thick and the bottom is thin, not only the quality of the product, but also can not guarantee the functionality, the present invention Since the polylactide foam is obtained with excellent foaming properties and uniform foaming cells, food packaging containers and industrial packaging materials using the same can solve the conventional problems.

Hereinafter, the present invention will be described in detail by way of examples.

The following examples are merely illustrative of the present invention, but the scope of the present invention is not limited to the following examples.

<Example 1>

15 wt% of amorphous polylactide (manufactured by NatureWorks, trade name: PLA 6302D) was mixed with 85 wt% of crystalline polylactide to prepare a polylactide-containing base resin, and based on 100 parts by weight of the base resin, 2 parts by weight of polycaprolactone was added to prepare a polylactide-based polymer composition.

2 parts by weight of dicumyl peroxide as a crosslinking agent, 0.05 parts by weight of diisodecyl adipate as a plasticizer and 5 μm in the composition Mix 2 parts by weight of talc of particle size well using a general mixer such as a tumbling mixer, and then use a tandem extruder connected to a first extruder having an internal diameter of 90 mm and a second extruder having an internal diameter of 120 mm to form a foam sheet as follows. Prepared. The heat melting temperature was maintained at 170 to 230 ° C based on the resin temperature, and then slightly decreased in the temperature of the melt mixed reactant in the second extruder connected with the first extruder to bring the resin temperature to about 150 ° C. Thereafter, the sheet was extruded from an annular die having a cylindrical slit having a diameter of 110 mm and a slit interval of 0.5 mm, and then foamed into a cylindrical shape.

<Examples 2-15>

A foam sheet was prepared in the same manner as in Example 1, except that 1 part by weight of bisphenol A diglycidyl ether and 0.5 part by weight of organic peroxide-based were used as a crosslinking agent.

Comparative Example 1

Except not using a crosslinking agent, it was carried out in the same manner as in Example 1, to prepare a foam sheet. The molecular weight was selected from the weight average molecular weight based on the polystyrene polymer using GPC, and the expansion ratio was calculated by measuring the specific gravity of the extruded foam sheet.

< Example  16-23>

Except for using 0.05 parts by weight and 0.5 parts by weight of citric acid-based compounds in magnesium palmitate, calcium oleate, zinc stearate, calcium stearate, magnesium stearate, dibutyl adipate, diethylene glycol ethylhexyl ether, the same as in Example 1 Performed by the method, a foam sheet was prepared.

Comparative Example 2

Except not using a plasticizer, it was carried out in the same manner as in Example 1, to prepare a foam sheet.

Comparative Example 3

0.05 parts by weight of calcium stearate was used as a plasticizer, except that talc was not used, and was carried out in the same manner as in Example 1 to prepare a foam sheet.

<Comparative Example 4>

0.05 parts by weight of diethylene glycol ethylhexyl ether and 0.5 parts by weight of citric acid-based compound were used as a plasticizer, except that talc was not used, and a foam sheet was prepared in the same manner as in Example 1.

As shown in Examples 16 to 23, when the extrusion of the organic acid or alcohol-based compound and the citric acid-based compound in parallel, it can be seen that the size distribution of the foaming cell is uniform, and the thickness of the extrusion sheet is increased to foam The effect of increasing magnification was confirmed.

On the other hand, as shown in Comparative Example 2, when only talc is added, the size distribution of the foaming cells is somewhat uniform, but the foaming ratio does not increase. In addition, as shown in Comparative Examples 3 and 4, if the plasticizer is added without the addition of talc, it can be seen that the expansion ratio is increased, but the size of the foam cell is increased and the size distribution of the foam cell is widened.

<Example 24>

As a polylactide-containing base resin, except that 100% by weight of crystalline polylactide was used, the same procedure as in Example 1 was carried out to prepare a foam sheet.

<Example 25>

As the polylactide-containing base resin, the above-mentioned implementation was carried out except that a resin containing 3 parts by weight of polycaprolactone (manufactured by Aldrich) was used as the polylactide-containing base resin composed of 100% by weight of crystalline polylactide. In the same manner as in Example 1, a foam sheet was prepared.

Example 26

As the polylactide-containing base resin, 15 wt% of amorphous polylactide (manufactured by NatureWorks, trade name: PLA 6302D) is mixed with 85 wt% of crystalline polylactide, and polycaprolactone is added to the polylactide-containing base resin. (Manufactured by Aldrich) A foam sheet was prepared in the same manner as in Example 1, except that resin containing 3 parts by weight was used.

As shown in Example 24, even if the polycaprolactone is not added, the size of the foam cell is small and the distribution is relatively uniform. At this time, the thickness of the foam sheet was about 9 mm.

In the case of Example 25, when 3 parts by weight of polycaprolactone is further added, the size distribution of the foaming cell becomes more uniform, and the thickness of the foam sheet is increased to 10 mm, which is more preferable in effect on extrusion foaming. This is interpreted as a characteristic of the polymer blend in which the polycaprolactone polymer chain acts as a kind of polymer plasticizer. This property is most preferable in the case of the base resin of Example 26, which further contains polycaprolactone in the base resin mixed with 85% of crystalline polylactide and 15% of amorphous polylactide.

Comparative Example 5

Except for using a talc having a particle size of 8㎛, it was carried out in the same manner as in Example 1, the size of the foam cell is 0.03 ~ 0.3mm, to prepare a foam sheet of 5mm thickness. At this time, the membrane of the foam cell is broken, so that the thickness of the foam sheet is greatly reduced, and the size of the foam cell is also reduced.

As described above, the present invention optimizes the physical properties of the polylactide-containing base resin, and mixes specific crosslinking agents, plasticizers and talc to the polylactide-containing base resin under optimum conditions, thereby providing flatness and uniformity of the foam cell. This secured polylactide foam was provided.

In addition, since the polylactide foam of the present invention increases the molecular weight of the polylactide-based resin during the foam extrusion process, it obtains an appropriate melt viscosity, increases crystallinity, improves foamability, and obtains a uniform foam cell. It can be molded and used as food packaging containers and industrial packaging materials such as trays, cups, cup noodles containers, lunch boxes and the like.

While the invention has been described in detail only with respect to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the scope of the invention, and such modifications and variations belong to the appended claims.

Claims (10)

Polylactide foam, characterized in that the composition consisting of 0.05 to 4 parts by weight of organic peroxide crosslinking agent, 0.001 to 1 part by weight of plasticizer and 0.1 to 5 parts by weight of talc is extrusion-molded based on 100 parts by weight of polylactide-containing base resin. . The polylactide foam according to claim 1, wherein the polylactide-containing base resin consists of crystalline polylactide alone. The polylactide foam according to claim 1, wherein the polylactide-containing base resin comprises 60 to 90 wt% of crystalline polylactide and 10 to 40 wt% of amorphous polylactide. The polylactide foam according to claim 1, wherein the polylactide-containing base resin further contains 0.5 to 5 parts by weight of polycaprolactone based on 100 parts by weight of the crystalline polylactide. The polycaprolactone of claim 1, wherein the polylactide-containing base resin is based on 100 parts by weight of the base resin consisting of 60 to 90% by weight of crystalline polylactide and 10 to 40% by weight of amorphous polylactide. Said polylactide foam further comprises 5 parts by weight. The polylactide foam according to claim 1, wherein the crosslinking agent is a mixed form of the organic peroxide crosslinking agent and the epoxy crosslinking agent. The method of claim 1, wherein the organic peroxide crosslinking agent is benzoyl peroxide, lauryl peroxide, dicumyl peroxide, dihexyl peroxide, butyl cumyl peroxide, dibutyl peroxide, p-methane hydroperoxide, diisopropylbenzene Hydroperoxide, tetramethylbutylperoxide, cumene hydroperoxide, 2,5-dimethyl-2,5-dibutylperoxyhexine-3, 2,3-dimethyl-2,3-diphenylbutane, 1,1 -Di (t-hexylperoxy) cyclohexane, 1,1-di (t-butylperoxy) cyclohexane, 2,2-di (4,4-di- (t-butylperoxy) cyclohexyl) propane , Di (2-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-dibutylperoxyhexane, hexyl peroxy isopropyl carbonate, butyl peroxy 2-ethylhexyl carbonate, diisopropyl peroxydi Carbonate, butyl peroxy isopropyl carbonate, butyl peroxy maleic acid, butyl peroxy-3,5,5-trimethylhexanoate, butyl peroxy Selected from the group consisting of laurate, butylperoxybenzoate, hexylperoxybenzoate, butylperoxyacetate, n-butyl 4,4-di-butylperoxyvalerate and 2,2-di-butylperoxybutane The polylactide foam, characterized in that any one. The polylactide foam according to claim 1, wherein the plasticizer is a single or mixed form selected from organic acid or alcohol compound metal compound or citric acid compound. The polylactide foam according to claim 1, wherein the talc has a particle size of 0.5 to 7 mu m. A food packaging container and an industrial packaging material, characterized in that the polylactide foam of claim 1 is molded.