KR20060035384A - Polyester resin composition which has good transparency and flexibility - Google Patents

Abstract

The present invention relates to a biodegradable polyester resin composition having excellent flexibility and transparency, comprising 99.9 to 90.0 parts by weight of polylactic acid (PLA) and 0.1 to 10.0 parts by weight of aliphatic polyester and / or aromatic-aliphatic polyester. .

Polylactic acid, polyester

Description

Biodegradable polyester resin composition excellent in flexibility and transparency

The present invention relates to a biodegradable polyester resin composition, and more particularly to a biodegradable polyester resin composition excellent in flexibility and transparency.

Synthetic plastics are used for various purposes all over the world because of their excellent properties and cheap and light properties. However, due to the problem of poor decomposition, which is the advantage and disadvantage of synthetic plastics, many countries have recently been interested in finding a solution. In the meantime, landfilling, incineration and regeneration have been mainly used, but these methods cannot completely solve the environmental pollution problem. Therefore, attention is focused on the development of so-called degradable plastics, which enables the used plastics to decompose themselves. The subdivision of technology related to degradable plastics is divided into biodegradation technology, photodegradation technology and bio-photodegradation technology combining these two technologies. Biodegradable plastics include microorganism-producing polymers such as polyhydroxybutylate, macromolecules-based biochemicals, synthetic polymers, chemically synthesized aliphatic polyesters, and chitin. There are many forms, including plastics with added polymers and starches. However, these plastics are inferior in mechanical properties compared to conventional plastics, and because of the high price, cheaper starch and the like must be mixed, which causes problems of deterioration in transparency and mechanical properties.

In recent years, polylactic acid (PLA) has been produced in large quantities and cheaply by developing fermentation methods of L-lactic acid, and has excellent characteristics such as fast decomposition rate in composting conditions, resistance to mold, and odor resistance to food. The scope of its use is expanding. However, polylactic acid has a brittle characteristic and is therefore not suitable as a resin suitable for applications requiring flexibility such as films and sheets. Therefore, in order to use the polylactic acid suitably, it is required to modify physical properties by using materials other than the polylactic acid. In general, techniques for soft-nitrifying resins include plasticizer addition, copolymerization, blending of soft polymers, and the like.

Although the plasticizer and the copolymer method can fully impart flexibility, there is a problem to lower the glass transition temperature of the resin composition and put it into practical use for reasons such as bleeding of the plasticizer. On the other hand, the blending method is suitable for its simplicity in practical use and does not significantly impair the properties of the polylactic acid. As the blend resin suitable for polylactic acid, aliphatic polyester or aromatic-aliphatic polyester is suitable if biodegradability is considered. Conventional techniques according to the blend application thereof include PLA and polybutylene succinate (PBS) of Mitsui, Japan. ), Starch, plasticizer composition patent (Sun 1999-241008), Mitsubishi Japan PLA and aliphatic polyester composition patent (Sun 1999-124495), Japan Unitika's PLA and aromatic-aliphatic polyester, plasticizer, etc. Film patent (Japan 2002-327107), container patent (Japan 2001-039426) consisting of PLA and PBS of Shiseido, Japan, composition patent (KR0428687) consisting of PLA and aliphatic polyesters, aromatic-aliphatic polyesters since And patent consisting of aliphatic polyester (KR 2001-0045677), PLA and aliphatic polyester from NOVAMONT, Europe, aromatic-aliphatic Composition patents (EP1227129) consisting of polyester and composition patents (EP 1227130) consisting of PLA and aliphatic polyester, polycaprolactone (PCL), and the like. In addition to simply blending PLA with aliphatic polyesters and aromatic-aliphatic polyesters, these techniques have mixed other plasticizers, inorganic fillers, starches, etc. to reinforce poor properties, in some cases aliphatic polyesters and aromatics rather than PLA contents. -Due to the higher content of aliphatic polyester, there is a problem that it is difficult to maintain the intrinsic properties of PLA, in particular transparency. In addition, when molding with polylactic acid alone, the molded body breaks easily due to the fragile nature of polylactic acid, and problems such as sheet breaking during sheet transfer and cutting even during thermoforming through the sheet occur. .

Accordingly, it is an object of the present invention to provide a biodegradable polyester resin composition which improves the fragile properties of polylactic acid while maintaining transparency, which is an inherent property of polylactic acid.                         

It is another object of the present invention to provide a biodegradable polyester film, sheet, filament, nonwoven fabric and various injection molded articles excellent in flexibility and transparency.

The present invention relates to a biodegradable polyester resin composition having excellent flexibility and transparency, comprising from 99.9 to 90.0 parts by weight of polylactic acid (PLA) and 0.1 to 10.0 parts by weight of aliphatic polyester and / or aromatic-aliphatic polyester.

The polylactic acid used consists of L-lactic acid, D-lactic acid or L, D-lactic acid and has a molecular weight of 10,000 or more. These polylactic acids may be used alone or in combination.

Aliphatic polyesters with aliphatic dicarboxylic acid or a derivative thereof is _{ROOC (CH 2) nCOOR '(} R, R' is hydrogen or an alkyl group, n is 2 to 14) succinic acid having the structure, glutaric acid, malonic acid, oxalic acid, At least one selected from the group consisting of adipic acid, sebacic acid, azelaic acid, nonanedicarboxylic acid and alkyl or aryl ester derivatives thereof, and glycols are HO- (CH ₂ ) n-OH (n is 2 Ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol or propylene glycol, 1,4-cyclohexanediol, hexamethylene glycol, 1 which is an aliphatic dihydric alcohol capable of forming a branched structure represented by the group consisting of alkylene glycol or polyalkylene glycol composed of polyethylene glycol, triethylene glycol, neopentyl glycol, tetramethylene glycol, or polyalkylene glycol or the general formula (1). , 2-propanediol, 1,2-butanediol, 1,3-butanediol, 1,2-pentane Ol, 1,3-pentanediol, 1,4-pentanediol, 1,2-hexanediol, 1,3-hexanediol, 1,4-hexanediol, 1,5-hexanediol, 1,2-octane Groups consisting of diols, 1,3-octanediol, 1,4-octanediol, 1,5-octanediol, 1,6-octanediol and the like can be used.

General formula (1)

In said general formula (1), R <_1> is a C2-C8 alkylene group and R <_2> is a C2-C8 alkyl group.

Aromatic-aliphatic polyesters are dicarboxylic acids or derivatives of ROOC-Ar-COOR '(R, R' is hydrogen or an alkyl group, Ar is an aromatic ring) structure as an aromatic component, terephthalic acid, phthalic acid, isophthalic acid, naphthalene 2, 6-dicarboxylic acid, diphenylsulfonic acid dicarboxylic acid, diphenylmethanedicarboxylic acid, diphenyletherdicarboxylic acid, diphenoxyethanedicarboxylic acid, cyclohexanedicarboxylic acid, or these Succinic acid having at least one member selected from the group consisting of alkylene esters and aliphatic dicarboxylic acid or derivative thereof having a structure of ROOC (CH ₂ ) nCOOR '(R, R' is hydrogen or alkyl group, n is 2-14) , Glutaric acid, malonic acid, oxalic acid, adipic acid, sebacic acid, azelaic acid, nonanedicarboxylic acid and alkyl or aryl ester derivatives thereof, and at least one member selected from glycols. ₂₎ n-OH (n is an ethylenically article having two or more) structure Cole, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol or propylene glycol, 1,4-cyclohexanediol, hexamethylene glycol, polyethylene glycol, tri 1,2-propane, an aliphatic dihydric alcohol capable of forming a branched structure represented by the group consisting of alkylene glycols or polyalkylene glycols composed of ethylene glycol, neopentyl glycol, tetramethylene glycol, or polyalkylene glycols Diol, 1,2-butanediol, 1,3-butanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,2-hexanediol, 1,3-hexanediol, 1 , 4-hexanediol, 1,5-hexanediol, 1,2-octanediol, 1,3-octanediol, 1,4-octanediol, 1,5-octanediol, 1,6-octanediol and the like Groups can be used.

The biodegradable polyester resin composition comprising the polylactic acid and aliphatic polyester and / or aromatic-aliphatic polyester is prepared by a mixed melt blend of each component, and the content of polylactic acid is 99.9 to 90.0 parts by weight of the total composition. It should be adjusted, and preferably 99.0 to 95.0 parts by weight is the best. It is not possible to improve the fragile characteristics of the polylactic acid when the content of the polylactic acid is 99.9 parts by weight or more, and when it is 90.0 parts by weight or less, the transparency of the polylactic acid cannot be maintained due to the influence of the polyester component. Aliphatic polyesters and aromatic-aliphatic polyesters may be used alone or in combination, and have the same effect regardless of their mixing ratio. However, in the case of aromatic-aliphatic polyester, the aromatic component should be adjusted to 10 to 50 mol%, preferably 30 mol% is the best. If the aromatic content is 10 mol% or less, the rubbery properties required in the present resin composition are weakened, and the elastic modulus is lowered.

The fragile nature of polylactic acid is inherent in polylactic acid, which causes a problem that is easily broken when the final product is manufactured. In order to solve this problem, physical properties can be enhanced to increase the molecular weight of the polylactic acid, and a polymer having flexibility such as aliphatic polyester and / or aromatic-aliphatic polyester can be mixed to compensate for the properties of the polylactic acid. In the present invention, polylactic acid and aliphatic polyester and / or aromatic-aliphatic polyester are melt blended at an appropriate ratio to minimize thermal decomposition of polylactic acid during melt blending to maximize physical property improvement. The mixing ratio of the polylactic acid and the aliphatic polyester and / or the aromatic-aliphatic polyester is higher in the blending amount of the aliphatic polyester and / or the aromatic-aliphatic polyester, but the flexibility of the resin composition is increased, but the aliphatic polyester and / or the aromatic- If the content of aliphatic polyester exceeds a certain level, it will damage transparency, which is an advantage of polylactic acid. In the present invention, a resin composition provided with flexibility was secured within a range that does not damage the transparency of the resin composition, wherein the appropriate mixing ratio of polylactic acid in the resin composition was found to be 99.9 to 90.0 parts by weight. This confirms that even the mixing of a small amount of aliphatic polyester and / or aromatic-aliphatic polyester enhances the flexibility of the whole composition. The compatibility of polylactic acid with aliphatic polyesters and / or aromatic-aliphatic polyesters is relatively good. When these are mixed, the degree of dispersion of the polymer varies depending on the degree of dispersion of the polylactic acid, but the transparency decreases sharply at 90.0 parts by weight or less, and the content of the aliphatic polyester and / or the aromatic-aliphatic polyester is greater than 90.0 parts by weight. More transparency is damaged than ever before. Transparency of the film or sheet depends on its use, but it is preferably 30% or less in terms of opacity (haze%), which is the degree of scattered light with respect to combat light when transmitted through light of 400 to 700 nm. Depending on the thickness, it is difficult to have an opacity of less than 30% (haze%) when the content of aliphatic polyester and / or aromatic-aliphatic polyester is 10.0 parts by weight or more. In addition, even if the content of the aliphatic polyester and / or the aromatic-aliphatic polyester is 5.0 parts by weight or more, it will have a haze% of 30% or more when the dispersion in mixing with the polylactic acid is not sufficient. In order to solve this problem, when mixing polylactic acid and aliphatic polyester and / or aromatic-aliphatic polyester, proper mixing conditions should be given to achieve the best dispersion. That is, the aliphatic polyester and / or the aromatic-aliphatic polyester is dispersed in the polylactic acid, which is a matrix resin, in a dispersed phase, so that the domain size of the aliphatic polyester and / or the aromatic-aliphatic polyester is appropriately adjusted. Light scattering in the visible range should be minimized.

In addition, during melt blending of polylactic acid and aliphatic polyester and / or aromatic-aliphatic polyester, extrusion was performed at an appropriate temperature level using a conventional general twin extruder, wherein polylactic acid and aliphatic polyester and / or aromatic-aliphatic The moisture content of the polyester resin was kept to a minimum, and preferably, the moisture content of 300 ppm or less is maintained. Two vacuum vents were placed in the extruder to remove as much moisture as the resin melted. The most important thing in this melt blend is the temperature condition and it is preferable to process at a temperature range of 180 to 250 ° C, preferably 200 to 230 ° C. This has the effect of doubling the flexibility of the resin composition by minimizing the thermal decomposition of the resin composition, and increasing the transparency of the resin composition by increasing the dispersibility of the aliphatic polyester and / or aromatic-aliphatic polyester resin by maintaining a sufficient melting temperature Giving effect.

The composition is prepared by mixing a predetermined amount of the polylactic acid and aliphatic polyester and / or aromatic-aliphatic polyester in the form of pellets by melt kneading in a conventional twin screw kneading extruder and melted again to form a film, sheet, filament, nonwoven fabric, It may be made into a molded article such as an injection molded article, and may be produced directly into a film, a sheet, a filament, a nonwoven fabric, or an injection molded article by discharging the resin composition from an extruder. The selection of an appropriate processing temperature is very important in the conditions of the present composition and the production of films, sheets, filaments, nonwovens, injection molded articles. Polylactic acid should be processed at a certain temperature because thermal degradation is severe when excessive decomposition occurs. The suitable processing temperature range is suitably 180 ~ 250 ℃ level, preferably 200 ~ 230 ℃ to the temperature of the polymer discharged from the extruder. In the case of the film or sheet produced in this way, the transparency appears different depending on the thickness, but the tendency of changing the transparency according to the content of aliphatic polyester and / or aromatic-aliphatic polyester is similar regardless of the thickness of the sheet.

As described above, the present invention is directed to a resin composition and a film, sheet, filament, nonwoven fabric, and injection molded article which complement the fragile disadvantage of polylactic acid and maintain transparency, which is an advantage of polylactic acid. It has physical properties similar to that of plastics but is characterized by biodegradation under normal composting conditions after use.

The following examples and comparative examples illustrate the invention in more detail, but do not limit the scope of the invention. First, the measurement and evaluation methods necessary for the explanation of the present invention were performed under the following conditions.

(1) Mechanical Strength (Tensile Strength; ASTM D 882A)

Using a tensile tester, the measurement was performed at a tensile rate of 500 mm / min at a temperature of 20 ± 2 ° C. and a relative humidity of 65 ± 2%. In addition, MD and the width direction were shown for the longitudinal direction of the film by TD.

(2) Flexibility (elongation; ASTM D 882A)

Elongation until fracture of the film was determined under the same conditions as the tensile strength.

(3) Impact resistance (falling impact strength; ASTM D 1709)

The energy required to break the specimen was measured by dropping a ball or dart weight on the sheet or plate.

(4) Transparency (ASTM D 1003)

5cm wide and vertical specimens were fabricated to transmit light having a wavelength of 400 ~ 700nm using a transparency meter (Haze Meter (Nippon Denshoku)), and the opacity (Haze%) value measured for scattered light against battle light Indicated.

Example 1

Slip type after blending 99.9kg of PLA resin with polylactic acid and 0.1kg of polybutylene succinate (PBS) with aliphatic polyester and melt blending at 210 ~ 220 ℃ processing temperature through a twin screw extruder It was ejected through a die to prepare a 350 탆 thick sheet. Specimens were prepared from the prepared sheets to measure tensile strength, elongation, impact strength, and transparency, and the results are shown in Table 1.

Example 2

A 350 µm thick sheet was manufactured in the same manner as in Example 1, except that 99.0 kg of a PLA resin of PLAGIL and 1.0 kg of polybutylene succinate (PBS) were mixed with an aliphatic polyester. Specimen was prepared from the film to measure the tensile strength, elongation, impact strength, transparency, and the results are shown in Table 1.

Example 3

A 350 μm-thick sheet was manufactured in the same manner as in Example 1, except that 97.0 kg of Cargill Dow's PLA resin was mixed with polylactic acid and 3.0 kg of polybutylene succinate (PBS) was used with aliphatic polyester. Specimens were prepared from the films to measure tensile strength, elongation, impact strength, and transparency, and the results are shown in Tables 1 and 2.

Example 4

A 350 μm-thick sheet was manufactured in the same manner as in Example 1, except that 95.0 kg of Cargill Dow's PLA resin was used as a polylactic acid and 5.0 kg of polybutylene succinate (PBS) was used as an aliphatic polyester. Specimen was prepared from the film to measure the tensile strength, elongation, impact strength, transparency, and the results are shown in Table 1.

Example 5

A 350 μm thick sheet was manufactured in the same manner as in Example 1, except that 93.0 kg of Cargill Dow's PLA resin was used as a polylactic acid and 7.0 kg of polybutylene succinate (PBS) was used as an aliphatic polyester. Specimen was prepared from the film to measure the tensile strength, elongation, impact strength, transparency, and the results are shown in Table 1.

Example 6

A 350 μm thick sheet was manufactured in the same manner as in Example 1, except that 90.0 kg of Cargill Dow's PLA resin was used as a polylactic acid and 10.0 kg of polybutylene succinate (PBS) was used as an aliphatic polyester. Specimen was prepared from the film to measure the tensile strength, elongation, impact strength, transparency, and the results are shown in Table 1.

Example 7

The same method as in Example 1 was used except that 97.0 kg of PLA resin of Cargill Dausa and polybutylene adipate, terephthalate (PBAT) of 30 mole%, were used as the polylactic acid and the aromatic-aliphatic polyester was used. 350 μm thick sheets were prepared, and specimens were prepared from the prepared films to measure tensile strength, elongation, impact strength, and transparency, and the results are shown in Tables 1 and 2.

Example 8

The same method as in Example 1, except that 93.0 kg of PLA resin of Cargill Dowsa as polylactic acid and 7.0 kg of polybutylene adipate with terephthalate (PBAT) having an aromatic content of 30 mol% with aromatic-aliphatic polyester were used. 350 μm thick sheets were prepared, and the tensile strength, elongation, impact strength, and transparency were measured by fabricating specimens in the prepared film, and the results are shown in Table 1.

Example 9

Polybutylene adipate, terephthalate (PBAT) of 97.0 kg of PLA resin from Cargill Dow with polylactic acid, 1.5 kg of polybutylene succinate (PBS) from aliphatic polyester, and 30 mol% of aromatic content from aromatic-aliphatic polyester. ) 350kg thick sheet was prepared in the same manner as in Example 1, except that 1.5kg was mixed, and the tensile strength, elongation, impact strength, and transparency were measured by preparing specimens from the prepared film. 1 and Table 2.

Example 10

Polybutylene adipate (PBAT) with 93.0 kg of PLA resin from Cargill Dow with polylactic acid, 3.5 kg of polybutylene succinate (PBS) with aliphatic polyester, and 30 mol% aromatic content with aromatic-aliphatic polyester. ) 350kg thick sheets were prepared in the same manner as in Example 1, except that 3.5kg was used in the mixture. The specimens were fabricated from the prepared films to measure tensile strength, elongation, impact strength, and transparency. 1 is shown.

Comparative Example 1

A 350 μm thick sheet was prepared in the same manner as in Example 1, except that only 100 kg of Cargill Dow's PLA resin was used as polylactic acid, and a specimen was prepared from the prepared film to measure tensile strength, elongation, impact strength, and transparency. The results are shown in Table 1.

Comparative Example 2

A 350 μm-thick sheet was manufactured in the same manner as in Example 1, except that 87.0 kg of Cargill Dow's PLA resin as a polylactic acid and 13.0 kg of polybutylene succinate (PBS) were mixed with an aliphatic polyester. Specimen was prepared from the film to measure the tensile strength, elongation, impact strength, transparency, and the results are shown in Table 1.

Comparative Example 3

The same method as in Example 1 was used except that 87.0 kg of PLA resin of Cargill Dowsa as polylactic acid and 13.0 kg of polybutylene adipate (PBAT) having an aromatic content of 30 mol% with aromatic-aliphatic polyester were used. 350 μm thick sheet was prepared, and the tensile strength, elongation, impact strength, and transparency were measured by fabricating a specimen from the prepared film, and the results are shown in Table 1.

Comparative Example 4

Polybutylene adipate, terephthalate (PBAT) with 87.0 kg of PLA resin of polylactic acid, 6.5 kg of polybutylene succinate (PBS) with aliphatic polyester, and 30 mole% of aromatic content with aromatic-aliphatic polyester. ) 350kg thick sheet was prepared in the same manner as in Example 1, except that 6.5kg was used, and tensile strength, elongation, impact strength, and transparency were measured using the prepared films. 1 is shown.

Comparative Example 5

Except for blending 97.0 kg of Cargill Dow's PLA resin with polylactic acid and 3.0 kg of polybutylene succinate (PBS) with aliphatic polyester, melt blending was carried out at a processing temperature of 170 to 180 ° C. using a twin screw extruder. In the same manner, a 350 μm thick sheet was prepared, and a specimen was prepared from the prepared film to measure tensile strength, elongation, impact strength, and transparency, and the results are shown in Table 2.

Comparative Example 6

The polylactic acid was mixed with 97.0 kg of PLA resin of Cargill Dow and polybutylene adipate with 30 mole% of aromatic-aliphatic polyester, 3.0 kg of terephthalate (PBAT). Except that melt blended at the processing temperature, 350 ㎛ thick sheet was prepared in the same manner as in Example 1, and the tensile strength, elongation, impact strength, transparency was measured by preparing a specimen from the film prepared, and the results are shown in Table 2 Shown in

Comparative Example 7

Polybutylene adipate, terephthalate (PBAT) of 97.0 kg of PLA resin from Cargill Dow with polylactic acid, 1.5 kg of polybutylene succinate (PBS) from aliphatic polyester, and 30 mol% of aromatic content from aromatic-aliphatic polyester. ) 350kg thick sheet was prepared in the same manner as in Example 1 except that 1.5kg was mixed and melt-blended at a processing temperature of 170 to 180 ° C. through a twin screw extruder. Elongation, impact strength, and transparency were measured, and the results are shown in Table 2.

Comparative Example 8

Except for blending 97.0 kg of Cargill Dow's PLA resin with polylactic acid and 3.0 kg of polybutylene succinate (PBS) with aliphatic polyester, melt blending at a processing temperature of 250 to 260 ° C. using a twin screw extruder. A 350 μm thick sheet was prepared in the same manner as described above. A specimen was fabricated from the prepared film to measure tensile strength, elongation, impact strength, and transparency, and the results are shown in Table 2 below.

Comparative Example 9

The polylactic acid is mixed with 97.0 kg of PLA resin of Cargill Dow and polybutylene adipate with 30 mole% of aromatic-aliphatic polyester and 3.0 kg of terephthalate (PBAT). Except that melt blended at the processing temperature, 350 ㎛ thick sheet was prepared in the same manner as in Example 1, and the tensile strength, elongation, impact strength, transparency was measured by preparing a specimen from the film prepared, and the results are shown in Table 2 Shown in

Comparative Example 10

Polybutylene adipate, terephthalate (PBAT) of 97.0 kg of PLA resin from Cargill Dow with polylactic acid, 1.5 kg of polybutylene succinate (PBS) from aliphatic polyester, and 30 mol% of aromatic content from aromatic-aliphatic polyester. ) 350kg thick sheet was prepared in the same manner as in Example 1 except that 1.5kg was mixed and melt blended at a processing temperature of 250 to 260 ° C. through a twin screw extruder. Elongation, impact strength, and transparency were measured, and the results are shown in Table 2.

TABLE-1

division Furtherance Properties PLA (wt%) PBS (wt%) PBAT (wt%) Tensile Strength (㎏ / ㎠) Elongation (%) Impact Strength (J / m) Transparency (HAZE%) MD TD MD TD Example-1 99.9 0.1 - 6.8 6.9 7.5 7.7 30.9 2.5 Example-2 99.0 1.0 - 6.9 7.0 8.5 8.6 32.8 5.7 Example-3 97.0 3.0 - 7.1 6.9 8.9 9.0 35.1 15.5 Example-4 95.0 5.0 - 7.2 6.9 9.0 9.3 39.3 21.3 Example-5 93.0 7.0 - 7.3 6.9 9.6 9.7 44.5 24.3 Example-6 90.0 10.0 - 6.9 7.3 10.7 10.9 52.1 28.9 Example-7 97.0 - 3.0 7.0 6.9 9.2 9.3 36.6 18.5 Example-8 93.0 - 7.0 7.4 7.1 9.9 9.9 46.5 27.3 Example-9 97.0 1.5 1.5 6.8 6.9 9.0 8.9 35.6 17.0 Example-10 93.0 3.5 3.5 7.1 7.0 9.6 9.5 44.0 26.5 Comparative Example-1 100.0 - - 6.2 5.6 5.5 4.9 19.2 1.9 Comparative Example-2 87.0 13.0 - 8.2 8.9 18.3 17.9 82.0 68.3 Comparative Example-3 87.0 - 13.0 8.5 9.3 20.3 19.5 91.4 73.9 Comparative Example-4 87.0 6.5 6.5 8.2 9.1 20.1 19.5 89.4 70.0

TABLE-2

division Furtherance Processing condition Properties PLA (wt%) PBS (wt%) PBAT (wt%) Temperature (℃) Tensile Strength (㎏ / ㎠) Elongation (%) Impact strength (J / m) Transparency (HAZE%) MD TD MD TD Example-3 97.0 3.0 - 210-220 7.1 6.9 8.9 9.0 35.1 15.5 Example-7 97.0 - 3.0 210-220 7.0 6.9 9.2 9.3 36.6 18.5 Example-9 97.0 1.5 1.5 210-220 6.8 6.9 9.0 8.9 35.6 17.0 Comparative Example-5 97.0 3.0 - 170-180 7.6 6.9 9.1 9.1 38.2 53.9 Comparative Example-6 97.0 - 3.0 170-180 7.7 6.5 9.5 9.8 38.8 59.7 Comparative Example-7 97.0 1.5 1.5 170-180 7.0 6.9 9.9 9.3 39.9 58.5 Comparative Example-8 97.0 3.0 - 250-260 5.0 4.9 4.6 4.7 16.9 20.0 Comparative Example-9 97.0 - 3.0 250-260 4.4 4.2 4.1 4.3 14.3 20.9 Comparative Example-10 97.0 1.5 1.5 250-260 4.9 5.1 5.1 4.9 17.8 18.7

As can be seen from the results of the above embodiment, the present invention has made improvements in physical properties such as tensile strength, elongation and impact strength through the use of aliphatic polyesters and / or aromatic-aliphatic polyesters. It is a composition that maintains transparency, which is the advantage of lactic acid, and transparent sheet through it. High-value compositions and films, sheets, filaments, nonwovens, injection molded articles.

Claims (7)

Biodegradable polyester resin composition comprising 99.9 to 90.0 parts by weight of polylactic acid and 0.1 to 10.0 parts by weight of aliphatic polyester and / or aromatic-aliphatic polyester. The biodegradable polyester resin composition according to claim 1, wherein the polylactic acid is composed of L-lactic acid, D-lactic acid or L, D-lactic acid, and has a molecular weight of 10,000 or more, and these are used alone or in combination. The aliphatic polyester according to claim 1, wherein the aliphatic polyester is at least one selected from a dicarboxylic acid having a structure of ROOC- (CH2) _n- COOR '(R, R' is hydrogen or an alkyl group, n is 2 to 14) or a derivative thereof. , Glycols are selected from the group consisting of diols of HO- (CH ₂ ) n -OH (n is 2 or more) structure, polyalkylene glycols, and aliphatic dihydric alcohols of the structure represented by formula (1). Biodegradable polyester resin composition characterized by: General formula (1)

In said general formula (1), R <_1> is a C2-C8 alkylene group and R <_2> is a C2-C8 alkyl group. The method of claim 1, wherein the aromatic-aliphatic polyester is at least one selected from dicarboxylic acids or derivatives thereof of the structure ROOC-Ar-COOR '(R, R' is hydrogen or an alkyl group, Ar is an aromatic ring) as an aromatic component. And an aliphatic component is at least one selected from ROOC- (CH ₂ ) n-COOR '(R, R' is hydrogen or an alkyl group, n is 2-14) structure, dicarboxylic acid or derivatives thereof, Biodegradation, characterized in that it is selected from the group consisting of diols of the structure HO- (CH ₂ ) n-OH (n is two or more), polyalkylene glycol, and aliphatic dihydric alcohols represented by the general formula (1). Sex Polyester Resin Compositions:  General formula (1)

In said general formula (1), R <_1> is a C2-C8 alkylene group and R <_2> is a C2-C8 alkyl group. The biodegradable polyester resin composition according to claim 1, wherein the aliphatic polyester and the aromatic-aliphatic polyester are used alone or in combination. The biodegradable polyester resin composition according to claim 1, wherein the polylactic acid and the aliphatic polyester and / or the aromatic-aliphatic polyester are melt blended at a processing temperature range of 180 to 250 ° C. A film, sheet, filament, nonwoven or injection molded article made from the biodegradable polyester resin composition of claim 1.