KR101255823B1 - Biodegradable aliphatic polyester resin composition with high transparency - Google Patents

Abstract

The present invention relates to an aliphatic polyester resin composition having excellent transparency composed of lactic acid or a polymer thereof, aliphatic (including cyclic aliphatic) dicarboxylic acid and aliphatic (including cyclic aliphatic) in a molecular structure, and particularly, properties of conventional biodegradable resins. The present invention relates to an aliphatic polyester resin composition which can manufacture all molded products such as extrusion and injection by solving problems of processability, reaction speed and moisture fragility.

Description

Biodegradable aliphatic polyester resin composition with excellent transparency {BIODEGRADABLE ALIPHATIC POLYESTER RESIN COMPOSITION WITH HIGH TRANSPARENCY}

The present invention relates to lactic acid (Latic acid) or a polymer thereof, aliphatic (including cyclic aliphatic) dicarboxylic acid (or an acid anhydride thereof) in order to improve the weak mechanical properties and transparency, which is a problem caused in the production of conventional biodegradable resins The present invention relates to an aliphatic polyester resin composition having excellent transparency which solves the above problems through esterification, transesterification and condensation polymerization of an aliphatic (including cyclic aliphatic) glycol. The aliphatic polyester obtained at this time is characterized by a number average molecular weight of 30,000 to 70,000 weight average molecular weight of 50,000 to 300,000 and a melting point of 80 to 150 ° C.

There are many kinds of biodegradable resins known to date, but their biodegradable properties, molecular weights, and various physical properties are different from each other, and thus the use of the biodegradable resins is limited due to limitations in application to products or poor moldability or productability.

The fact that conventional aliphatic polyesters are biodegradable is already well known and described in Journal of Macromol. SCI-Chem., A-23 (3), 1986, p393-409], these biodegradable materials are mainly applied to medical, agricultural and fishery materials and packaging materials, and are gradually expanding their applications.

However, existing aliphatic polyesters are prone to thermal decomposition due to low thermal stability when melted, and the range of working conditions that can be formed is considerably narrow, product defect rate is high, and melt flow index is high, resulting in low workability and tensile strength. And mechanical properties such as tear strength is poor, there is a problem such as limited use.

As one method for solving this problem, a method for synthesizing a high molecular weight aliphatic polyester resin having a number average molecular weight of 30,000 or more by appropriately adjusting the reaction temperature, vacuum degree and catalyst conditions is disclosed in Korean Patent Application No. 93-0020638 It is. However, the aliphatic polyester resin produced by this method has a low weight average molecular weight, is extremely sensitive to heat, and is inferior in formability.

As another existing example, Korean Patent Application No. 97-0004788 discloses a method for producing a high molecular weight aliphatic polyester by adding a monomer of a trihydric or higher polyhydric alcohol or a trivalent or higher polyhydric carboxylic acid in polyester production. Is disclosed. According to this method, by introducing the monomer into the reaction system, the reaction time can be shortened, the molecular weight distribution can be diffused, and the moldability can be improved.

However, since the low molecular weight polyester is rapidly increased to decrease the physical properties such as tensile strength, it is not only practical to use, but also has a problem of high gelation, which makes it difficult to control the reactivity.

Another method for raising the number average molecular weight of aliphatic polyester is disclosed in Korean Patent Application Laid-Open No. 95-25072, which discloses (1) an aliphatic (including cyclic aliphatic) glycol, and (2) Presence or ratio of aliphatic (including cyclic aliphatic) dicarboxylic acids (or acid anhydrides) as a main component and a small amount of (3) trivalent or more polyhydric alcohols or trivalent or higher polyhydric carboxylic acid (or acid anhydride) monomers After obtaining an aliphatic polyester having a number average molecular weight of about 15,000-20,000 obtained by dehydration reaction and a deglycol reaction in the presence, an aliphatic polyester resin having a number average molecular weight of about 20,000-70,000 obtained by further reacting a polyisocyanate as a coupling agent is obtained. will be. However, according to this method, since the reaction time is long, productivity decreases, and polyisocyanate, a coupling agent used to increase the molecular weight, is extremely harmful to the human body.

As described above, in order to prepare a high molecular weight aliphatic polyester resin, a method of adding a polyisocyanate, which is a coupling agent, or a polyfunctional monomer such as a polyhydric alcohol or a polycarboxylic acid is used in the preparation of the aliphatic polyester. Has been. However, the aliphatic polyester thus prepared had problems with productivity, physical properties, moldability, and the like.

Accordingly, the present inventors are characterized in that to introduce the aliphatic (including cyclic aliphatic) dicarboxylic acid (including anhydride), aliphatic (cyclic aliphatic) glycol and lactic acid (Latic acid) or a polymer thereof to solve the above problems In addition, the present invention has been completed as a result of studying the optimum composition ratio of the raw material composition suitable for the preparation of the sugar composition and the optimization of the reaction conditions thereof.

The aliphatic polyester resin composition of the present invention is prepared by using lactic acid or a polymer thereof, aliphatic dicarboxylic acid (including cyclic aliphatic), aliphatic (including cyclic aliphatic) glycol as its main constituents.

According to the present invention, there is provided an aliphatic polyester resin composition having excellent transparency and mechanical properties in which lactic acid or a polymer thereof is introduced into a molecular structure, thereby solving problems of physical properties, processability, reaction rate, and moisture fragility of conventional biodegradable resins. While solving, all molded products such as extrusion and injection can be manufactured.

In the present invention, (1) aliphatic (including cyclic aliphatic) dicarboxylic acid (or anhydride thereof) and (2) lactic acid monomer or lactic acid polymer having a molecular weight of 90 to 300,000 (3) aliphatic (cyclic aliphatic) Provided is a biodegradable aliphatic polyester resin composition having excellent transparency and mechanical properties characterized by a condensation polymerization reaction of any one or two or more selected from esterification, transesterification, and condensation polymerization in the presence of glycol. .

Referring to the fully biodegradable aliphatic polyester resin composition comprising lactic acid according to the present invention in detail.

The aliphatic (including cyclic aliphatic) dicarboxylic acid (or acid anhydride thereof) used in the present invention preferably has 2 to 14 carbon atoms, and examples thereof include oxalic acid, malonic acid, succinic acid, glutaric acid, and hypochlorous acid. Any one or a mixture of two or more selected from diflic acid, pimelic acid, sebacic acid, azelaic acid, nonanedicarboxylic acid, dimethylsuccinate, dimethyladipate and anhydride derivatives thereof is used.

In addition, lactic acid or a polymer thereof is used in the composition, and when a lactic acid polymer is used, one having a molecular weight in the range of 90 to 300,000 is used. In the case of lactic acid and polymers thereof, D- and L-forms exist as optical isomers. The lactic acid and polymers used in the present invention can be used without being limited by the composition ratio of each component of the optical isomers.

When the molar sum of aliphatic dicarboxylic acid and lactic acid or a polymer thereof is 100 mol% in the present invention, the composition of the aliphatic dicarboxylic acid and lactic acid or a polymer thereof is composed of a molar ratio of 99.99: 0.01 to 50:50. If the lactic acid or polymers used is less than 0.01 mol%, the effect is not, and if it is 50 mol% or more, the color change of the resin and the rate of reaction are slow and there is no economic effect.

In addition, the aliphatic glycol preferably has 2 to 20 carbon atoms, and in the present invention, glycol having a hydroxyl group at the sock end may be used, and a glycol containing an ether group may be used together with the glycol. First, examples of the diol having hydroxyl groups at both terminals include ethylene glycol, 1,3-propanediol, neopentyl glycol, propylene glycol, 1,2-butanediol, 1,4-butanediol, and 1,6-hexanediol. Any one or two or more selected mixtures are used, wherein the amount of aliphatic glycol used is from 1: 1.2 to 1: 1.5 in molar ratio based on 1 mole of the composition consisting of aliphatic dicarboxylic acid and lactic acid or a polymer thereof. Used as

If the input amount is less than 1.2 molar ratio, the reaction is slow and color discoloration is caused, and if it exceeds 1.5 molar ratio, the economic cost increases and the effect of the invention is reduced.

The process for preparing a resin according to the present invention comprises the steps of (i) esterifying aliphatic (including cycloaliphatic) dicarboxylic acids, lactic acid or polymers thereof and aliphatic glycols in the presence of catalysts and stabilizers and obtaining transesterification products ;

(ii) optionally adding lactic acid or a polymer thereof to obtain an esterification and transesterification product;

(iii) It provides a method for producing an aliphatic polyester resin comprising the step of condensation polymerization of the reaction product of step (i) or (ii).

Preferably, the present invention is an aliphatic polyester resin composition having excellent transparency, comprising an aliphatic dicarboxylic acid or anhydride thereof and a polymer of lactic acid or lactic acid having a molecular weight of 90 to 300,000, wherein the composition between these two components is 99.99 mol. An acid component mixture composed of a molar ratio of%: 0.01 mol% to 50 mol%: 50 mol%; And aliphatic glycol in a ratio of 1.1 to 1.5 moles per 1 mole of the acid component mixture, and 0.0001 to 1 part by weight of the catalyst based on 100 parts by weight of the total weight of the acid component mixture and the aliphatic glycol, respectively. And a stabilizer were added to the esterification reaction or transesterification reaction, and 0.3 to 1.5 parts by weight of the polycondensation reaction catalyst and 0.0001 to 0.5 parts by weight based on 100 parts by weight of the total weight of the acid component mixture and aliphatic glycol were added to the reaction product. Provided is a biodegradable aliphatic polyester resin composition excellent in transparency prepared by adding a negative stabilizer to a polycondensation reaction.

Preferably, in preparing the biodegradable aliphatic polyester resin composition having excellent transparency of the present invention, the aromatic dicarboxylic acid is selected from terephthalic acid, isophthalic acid, 2,6-naphthoic acid and ester-forming derivatives thereof, and mixtures of two or more thereof. The aliphatic dicarboxylic acid is composed of succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid and mixtures of two or more thereof. Aliphatic glycols are selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,2-butanediol, 1,4-butanediol, 1,6-hexanediol, 1,2-cyclohexanedimethanol and two or more thereof 2,2-bis- (2-oxazoline), N, N'-hexamethylene-bis- (2-carbamoyl-2-oxazoline in the esterification or transesterification reaction ), 2,2'-methylene-bis- (2-oxazole Lin), 2,2'-ethylene-bis- (2-oxazoline), 2,2'-propylene-bis- (2-oxazoline), 1,3-phenylene-bis- (2-oxazoline) , Oxazoline compounds selected from the group consisting of 2,2-P-phenylene-bis- (2-oxazoline) and mixtures of two or more thereof, based on 100 parts by weight of the total weight of the acid component mixture and aliphatic glycol, It is further used in the amount below a weight part.

Also preferably, the present invention provides a product injection or extrusion molded from the biodegradable aliphatic polyester resin composition having excellent transparency of the present invention.

In addition, the present invention preferably provides a compound or a molded article formed by adding starch, calcium carbonate, or talc mineral to the biodegradable aliphatic polyester resin composition having excellent transparency of the present invention.

In the present invention, the esterification or transesterification temperature is suitably about 170 to 230 ° C., and a catalyst and a stabilizer may be added in the initial stage of esterification or transesterification. As the catalyst, dibutyl tin oxide and tetrabutyl titanate are used alone or as mixed catalysts, and as the stabilizer, triphenyl phosphate and trimethyl phosphate are used alone or as mixed stabilizers.

The addition amount of the catalyst and the stabilizer is appropriately 0.0001 to 1 part by weight based on 100 parts by weight of the total weight of the acid component mixture and the aliphatic glycol, respectively, when the addition amount of the catalyst is less than 0.0001 parts by weight, the rate of transesterification reaction is slow, while 1 weight If it exceeds the portion, the reaction rate is fast but the color is deteriorated.

In addition, when the addition amount of the stabilizer is less than 0.0001 parts by weight, the reaction product during the transesterification reaction does not prevent the factor that can be gas-decomposed, while when it exceeds 1 part by weight lowers the reaction rate.

In the initial stage of the polycondensation of the present invention, a catalyst for promoting the polycondensation reaction may be added. As the catalyst, any one or two or more mixed catalysts selected from magnesium acetate, tetrapropyl titanate, zinc acetate, tetrabutyl titanate, dibutyl tin oxide, tetrapropyl titanate, calcium acetate and tetraisopropyl titanate can be used. The addition amount is suitably 0.3 to 1.5 parts by weight based on 100 parts by weight of the total weight of the acid component mixture and aliphatic glycol. If the added amount is less than 0.3 parts by weight, there is a limit to increase the molecular weight by losing activity as a catalyst at any given time, and if the amount exceeds 1.5 parts by weight, the reaction rate increases but there is a concern that the color is lowered.

In addition, a stabilizer may be added in the polycondensation step, and as the stabilizer, any one or two or more mixed stabilizers selected from trimethyl phosphate, trimethyl phosphine, triphenyl phosphate, and phosphate may be used. 0.0001-0.5 weight part is preferable based on 100 weight part of total weight of an aliphatic glycol. At this time, if the amount of the stabilizer added is less than 0.0001 parts by weight, it does not play a role as a stabilizer, whereas if it exceeds 0.5 parts by weight, the reaction is delayed to increase the reaction time.

In the present invention, the polycondensation reaction temperature is preferably 230 to 260 ° C. When the polycondensation reaction temperature is less than 230 ° C, the polycondensation reaction time is long, while the polycondensation reaction temperature is higher than 260 ° C. In addition, the polycondensation reaction time is different depending on the amount of catalyst and stabilizer, but 150 minutes to 250 minutes is preferred.

In addition, in the case of the biodegradable aliphatic polyester resin prepared by the above composition, a chain extender, a hydrolysis agent, a reaction stabilizer may be used in the reaction process in order to improve its functionality.

As the chain extender that can be used in the above, an isocyanate compound may be used by adding 0 to 5 parts by weight based on 100 parts by weight of the total weight of the acid component mixture and aliphatic glycol. Examples include 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, and the like, and particularly 1,6-hexamethylene diisocyanate. Isocyanate shows the most excellent effect, and it is preferable to add 0.01-5 weight part.

As the hydrolysis agent that can be used in the above, a carbodiimide compound is used, 1,3-dicyclohexylcarbodiimide, HMV-8CA, HMV-10B, bis- (2,6) sold by Nisshinbo, Japan -Diisopropyl-phenyline-2,4-carbodiimide), poly- (1,3,5-triisopropyl-phenylri-2,4-carbodiimide), and the like. The amount is 0 to 10 parts by weight based on 100 parts by weight of the total weight of the acid component mixture and aliphatic glycol added.

An oxazoline compound may be used for the stability of the reaction in the reaction process, for example, 2,2-bis- (2-oxazoline), N, N'-hexamethylene-bis- (2-carbamoyl- 2-oxazoline), 2,2'-methylene-bis- (2-oxazoline), 2,2'-ethylene-bis- (2-oxazoline), 2,2'-propylene-bis- (2- Oxazoline), 1,3-phenylene-bis- (2-oxazoline), 2,2-P-phenylene-bis- (2-oxazoline), and the dosage is the total of the acid component mixture and the aliphatic glycol It is 0-10 weight part with respect to 100 weight part of weight.

Hereinafter, the present invention will be described in more detail with reference to examples.

Example 1

A 500 mL round bottom flask was replaced with nitrogen, and 106.2 g of succinic acid, 9 g of lactic acid, and 121.6 g of 1,4-butanediol were added thereto, followed by an esterification reaction at 200 ° C. for 2 hours to allow the theoretical amount of water to flow out. At this time, 0.1 g of antimony acetate, 0.1 g of thibutyltin oxide, 0.1 g of tetrabutyl titanate, and 0.2 g of trimethyl phosphate were added as a stabilizer. After the amount of theoretical water had flowed out, the temperature was continuously raised, and the polycondensation reaction was carried out for 150 minutes under a reduced pressure of 2.0 Torr or less at 250 ° C. The resin obtained at this time had a number average molecular weight of 33,400 and a weight average molecular weight of 72,100.

Example 2

A 500 ml round bottom flask was replaced with nitrogen, 94.47 g of succinic acid, 14.6 g of adipic acid, 9 g of lactic acid, 121.6 g of 1,4-butanediol, 0.1 g of tetramethyl titanate were added and esterified at 200 ° C. for 2 hours. The reaction was carried out and the theoretical amount of water was distilled out. At this time, 0.1 g of antimony acetate, 0.1 g of thibutyltin oxide, 0.1 g of tetrabutyl titanate, and 0.2 g of trimethyl phosphate were added as a stabilizer. After the amount of theoretical water had flowed out, the temperature was continuously raised, and the polycondensation reaction was carried out for 150 minutes under a reduced pressure of 2.0 Torr or less at 250 ° C. The resin obtained at this time had a number average molecular weight of 31,400 and a weight average molecular weight of 68,300.

Example 3

Replace the 500 ml round bottom flask with nitrogen, add 106 g of succinic acid, 20 g of polylactic acid having a molecular weight of 200, 121.6 g of 1,4-butanediol, add 0.1 g of tetramethyl titanate, and proceed with the esterification reaction at 200 ° C. for 2 hours. The reaction temperature was fixed at 200 ° C., and the theoretical amount of water was distilled out. At this time, 0.1 g of antimony acetate, 0.1 g of tetrabutyl titanate, and 0.2 g of trimethyl phosphate were added as a stabilizer. After the theoretical amount of water had flowed out, the temperature was continuously raised and the polycondensation reaction was carried out for 100 minutes under a reduced pressure of 2.0 Torr or less at 250 ° C. The resin obtained at this time had a number average molecular weight of 37,100 and a weight average molecular weight of 78,200.

Comparative Example 1

Substitute 500 ml of round bottom flask with nitrogen, add 93.2 g of dimethyl terephthalate, 121.6 g of 1,4-butanediol, add 0.1 g of tetramethyl titanate, and proceed with the esterification reaction at 200 ° C. for 2 hours. After distilling off methanol, 76 g of adipic acid was added thereto, and the reaction temperature was fixed at 200 ° C., and water was distilled out. At this time, 0.1 g of antimony acetate, 0.1 g of thibutyltin oxide, 0.1 g of tetrabutyl titanate, and 0.2 g of trimethyl phosphate were added as a stabilizer. After the theoretical amount of water had flowed out, the temperature was continuously raised and the polycondensation reaction was carried out for 320 minutes under a reduced pressure of 2.0 Torr or less at 255 ° C. The resin obtained at this time had a number average molecular weight of 23,000 and a weight average molecular weight of 51,000.

Comparative Example 2

After replacing the 500 ml Erlenmeyer flask with nitrogen, 23.6 g of succinic acid, 27 g of 1,4-butanediol, and 0.1 g of tetrabutyl titanate as a catalyst were added thereto, followed by esterification while raising the temperature in a stream of nitrogen to allow water to flow out. At this time, the temperature was fixed at 205 DEG C, and the theoretical amount of water was completely flowed out to produce 34.4 g of "aliphatic low molecular weight polymer" having a molecular weight of about 600, and then dimethyl terephthalate 77.7g, 1,4- in the Erlenmeyer flask. 135.2 g of butanediol and 0.2 g of tetrabutyl titanate were added as a catalyst to raise the temperature gradually, and methanol was discharged through a transesterification reaction. At this time, the methanol was completely discharged while maintaining the temperature at 205 ° C, and then 35.4 g of succinic acid and 43.8 g of adipic acid were added to the Erlenmeyer flask to carry out an esterification reaction. At this time, after fixing the temperature at 180 ° C. and completely distilling water, 0.1 g of antimony trioxide, 0.3 g of dibutyl tin oxide, 0.07 g of tetrabutyl titanate, and 0.1 g of trimethylphosphate were added as a stabilizer. Then, the temperature was raised and the polycondensation reaction was carried out for 180 minutes at 245 ° C. under a reduced pressure of 0.3 Torr. The number average molecular weight was 48,000 and the weight average molecular weight was 310,000.

Comparative Example 3

The 500 ml Erlenmeyer flask was replaced with nitrogen, and then 116.8 g of 1,4-butanediol, 35 g of adipic acid and 0.25 g of tindioctate were added and reacted at a temperature ranging from 230 to 240 ° C. to completely remove the theoretical water flow rate. did. After taking 82.6 g of the obtained polymer, 65.5 g of dimethyl terephthalate and 85 g of 1,4-butanediol were added, and then methanol was generated while heating to 180 ° C. while gradually stirring. In this process, 0.235 g of tetrabutyl ortho titanate, 0.0825 g of pyromellitic dianhydride, and 0.095 g of 50% phosphorous phosphate solution were added, and the polycondensation reaction was performed at a temperature of 230 to 240 ° C. and a high vacuum of less than 1 torr for about 120 minutes. After cooling, the melt was cooled to 200 ° C., 1.45 g of hexamethylene diisocyanate was added over 15 minutes, and then the mixture was stirred.

The resin obtained at this time was a number average molecular weight of 17,589 and a weight average molecular weight of 113,550.

Table 1 shows the properties of the resins obtained from the examples and the comparative examples.

The number average molecular weight and the weight average molecular weight were measured by gel chromatography using polystyrene as a base material, and biodegradation was collected three months after landfilling by 30 cm depth from soil index and measured by weight loss method. Transparency was measured by Haze,% haze value of 30㎛ film using a Haze meter.

Claims (11)

As an aliphatic polyester resin composition excellent in transparency,
It consists of aliphatic dicarboxylic acid or anhydrides thereof and polymers of lactic acid or lactic acid having a molecular weight of 90 to 300,000, and the composition between these two components is in a molar ratio of 99.99 mol%: 0.01 mol% to 50 mol%: 50 mol%. Acid component mixtures composed; And aliphatic glycol in a ratio of 1.1 to 1.5 moles per 1 mole of the acid component mixture,
To the resultant mixture, esterification or transesterification is performed by adding 0.0001 to 1 parts by weight of catalyst and stabilizer, respectively, based on 100 parts by weight of the total weight of the acid component mixture and aliphatic glycol,
Based on 100 parts by weight of the total weight of the acid component mixture and aliphatic glycol, the reaction product was prepared by polycondensation by adding 0.3 to 1.5 parts by weight of a polycondensation reaction catalyst and 0.0001 to 0.5 parts by weight of a stabilizer to obtain a number average molecular weight. The 30,000-70,000 weight average molecular weights are 50,000-300,000, melting | fusing point is 80-150 degreeC, The biodegradable aliphatic polyester resin composition excellent in transparency. The group of claim 1 wherein the aliphatic dicarboxylic acid consists of succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid and mixtures of two or more thereof. Biodegradable aliphatic polyester resin composition excellent in transparency, characterized in that it is selected from. The method of claim 1 wherein the aliphatic glycol is ethylene glycol, 1,2-propanediol, 1,2-butanediol, 1,4-butanediol, 1,6-hexanediol, 1,2-cyclohexanedimethanol and two of them Biodegradable aliphatic polyester resin composition excellent in transparency, characterized in that selected from the group consisting of the above mixture. 2,2-bis- (2-oxazoline), N, N'-hexamethylene-bis- (2-carbamoyl-2-, according to claim 1 during esterification or transesterification or during polycondensation. Oxazoline), 2,2'-methylene-bis- (2-oxazoline), 2,2'-ethylene-bis- (2-oxazoline), 2,2'-propylene-bis- (2-oxazoline ), 1,3-phenylene-bis- (2-oxazoline), 2,2-P-phenylene-bis- (2-oxazoline) and an oxazoline compound selected from the group consisting of two or more thereof Biodegradable aliphatic polyester resin composition having excellent transparency, characterized in that it is further used in an amount of 10 parts by weight or less, based on 100 parts by weight of the total weight of the acid component mixture and aliphatic glycol. The method of claim 1, wherein during the esterification or transesterification reaction or during condensation polymerization, 1,3-dicyclohexylcarbodiimide, HMV-8CA, HMV-10B, bis- (2,6-diisopropyl-phenyl Carbodiimide compounds selected from the group consisting of rin-2,4-carbodiimide), poly- (1,3,5-triisopropyl-phenylri-2,4-carbodiimide) and mixtures of two or more thereof Biodegradable aliphatic polyester resin composition having excellent transparency, characterized in that it is further used in an amount of 10 parts by weight or less based on 100 parts by weight of the total weight of the acid component mixture and aliphatic glycol. The method according to any one of claims 1 to 5, wherein, during esterification or transesterification or during polycondensation, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 4,4'- as a chain extender. Isocyanate compound selected from the group consisting of diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate and mixtures of two or more thereof, based on 100 parts by weight of the total weight of the acid component mixture and aliphatic glycol, by weight or less Biodegradable aliphatic polyester resin composition excellent in transparency, characterized in that it is further used in the amount of. The biodegradable aliphatic polyester resin composition having excellent transparency according to claim 1, which is further used in an amount of 10 parts by weight or less based on 100 parts by weight of the total weight of the acid component mixture and aliphatic glycol. The method of claim 1 wherein the aromatic dicarboxylic acid is selected from the group consisting of terephthalic acid, isophthalic acid, 2,6-naphthoic acid and ester forming derivatives thereof, and mixtures of two or more thereof,
Aliphatic dicarboxylic acid is selected from the group consisting of succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid and mixtures of two or more thereof,
Aliphatic glycol from the group consisting of ethylene glycol, 1,2-propanediol, 1,2-butanediol, 1,4-butanediol, 1,6-hexanediol, 1,2-cyclohexanedimethanol and mixtures of two or more thereof Selected,
2,2-bis- (2-oxazoline), N, N'-hexamethylene-bis- (2-carbamoyl-2-oxazoline), 2,2'- during esterification or transesterification Methylene-bis- (2-oxazoline), 2,2'-ethylene-bis- (2-oxazoline), 2,2'-propylene-bis- (2-oxazoline), 1,3-phenylene- An oxazoline compound selected from the group consisting of bis- (2-oxazoline), 2,2-P-phenylene-bis- (2-oxazoline) and mixtures of two or more thereof, may be used as a whole of the acid component mixture and aliphatic glycol. A biodegradable aliphatic / aromatic copolyester resin composition having excellent transparency, which is further used in an amount of 10 parts by weight or less based on 100 parts by weight. delete An article injected or extruded from a biodegradable aliphatic polyester resin composition having excellent transparency. A compound or a product molded therefrom by adding an inorganic substance of starch, calcium carbonate or talc to the biodegradable aliphatic polyester resin composition having excellent transparency.