KR101255826B1 - Biodegradable aliphatic/aromatic copolyester resin composition with high transparency - Google Patents

Abstract

The present invention has a transparency having one melting point composed of aliphatic (including cycloaliphatic) dicarboxylic acid, aromatic dicarboxylic acid, polylactide having a weight average molecular weight of 3,000 to 300,000, and aliphatic (including cycloaliphatic) glycol in its molecular structure. The present invention relates to an excellent aliphatic / aromatic copolyester resin composition, and in particular, it solves problems of physical properties, transparency, processability, reaction rate, and water fragility of conventional biodegradable resins, thereby making it possible to manufacture all molded products such as extrusion and injection. It relates to an aliphatic / aromatic copolyester resin composition having excellent transparency having one melting point.

Description

Biodegradable aliphatic / aromatic copolyester resin composition with excellent transparency {BIODEGRADABLE ALIPHATIC / AROMATIC COPOLYESTER RESIN COMPOSITION WITH HIGH TRANSPARENCY}

The present invention provides a polylactide, aliphatic (including cyclic aliphatic) dicarboxylic acid having a weight average molecular weight of 3,000 to 300,000 in order to improve the weak mechanical properties and transparency, which are problems in the production of conventional biodegradable resins. Transparency that solves the above problems by producing an excellent aliphatic / aromatic copolyester resin having one melting point containing anhydrides, aromatic dicarboxylic acids (or anhydrides thereof) and aliphatic (including cyclic aliphatic) glycols It is related with this excellent aliphatic polyester resin composition. 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.

Aliphatic / aromatic copolyester resins have been known for several decades and their compositions and manufacturing methods, and are still being studied for use expansion, processability, and mechanical properties.

For example, U.S. Pat.Nos. 4094721 (June 13. 1978) and 4966959 (Oct. 30. 1996) show that the aromatic acid component is at least 40 mol% or more in the copolyester molecular structure, and the remaining acid component is aliphatic acid. An aliphatic / aromatic copolyester resin composition prepared by using a component comprising a total acid component of 100 mol% and reacting with the mixed component of 1,4-butanediol and other diols was prepared. Its melting point and its properties are explained.

In the above-mentioned conventional techniques, the range of the composition of components, such as aliphatic acid components and aromatic acid components, in which aliphatic / aromatic copolyesters prepared in the aliphatic / aromatic copolyester resin composition may exhibit biodegradability, is presented in detail. In addition, the various characteristics such as melting point, intrinsic viscosity, etc. according to the composition of the components are described in detail.

All plastics can be used as adhesives for their purpose by using the property of melting after cooling by heat melting, and the aliphatic / aromatic copolyester can also be used as a hot melt adhesive. (US Patent No. 4,401,805) Aug. 30. 1983, and 4,328,059 May 4. 1982).

Aliphatic / aromatic copolyesters exhibit tackiness depending on the type and number of constituents thereof, and US Pat. No. 4,966,959 (1990, Cox. A. Heyer. MF) has tackiness in preparing aliphatic / aromatic copolyesters. The glycol component used for this purpose states that it must contain two dialcohol components.

In Korean Patent Application No. 10-1993-0701622, the adhesiveness of the aliphatic / aromatic copolyester in the conventional technology is used to prepare aliphatic / aromatic copolyester to solve this problem because of problems in molding plastic products. It was suggested that the glycol component was overcome by using a single component rather than a mixed component. However, this is a well known fact that the adhesive can be removed by controlling the number and type of aliphatic / aromatic copolyester components in the art, and US Pat. No. 4,328,059 also uses aliphatic aliphatic alcohols. Processes for the production of aromatic copolyesters are known.

In addition to patents, the Journal of Macromolecule, SCI-Chem A-23 (3), 1986, P393-409, describes the presence of biodegradability when aliphatic acid components are present in more than a certain component in aliphatic / aromatic copolyester compositions. have.

However, the aliphatic / aromatic copolyester prepared by the above method is still poor in processability and mechanical properties compared to general-purpose resins such as polyethylene, polypropylene, polystyrene, etc. Research to solve the problem is actively in progress.

For example, in the case of Korean Patent Application No. 10-1999-7002353, in the preparation of aliphatic / aromatic copolyester, diisocyanate, a chain extender, is prepared by oligomerizing hexamethylene diisonate to control NCO content, which is a chain extension functional group. To disclose a method for producing the same. It uses polyfunctional and isocyanate in order to secure high processability and mechanical properties by high molecular weight of copolyester to be manufactured.In this case, it is safe to natural environment and human body during worker's safety and biodegradation of copolyester during isocyanate. Hazards may occur and are economically vulnerable due to increased work processes.

Korean Patent Application No. 10-1997-2703252 discloses a method of using a sulfonate compound or a compound having three or more ester-forming functional groups to prepare an aliphatic / aromatic copolyester resin. However, this method can shorten the reaction time and increase the average molecular weight, but the molecular weight distribution of the resulting aliphatic / aromatic copolyester composition is widened, so that a large amount of low molecular weight copolyester is present. This causes easy pyrolysis in the processing process and weakens the durability of the manufactured product which is vulnerable to moisture in the atmosphere.

In the case of Korea Patent Application No. 10-1997-0703253, a dihydroxy compound containing an ether functional group was used to prepare an aliphatic / aromatic copolyester resin. Aromatic copolyester resins are prepared, which are easily blown away by lactic acid heat and easily blown in low vacuum, making them extremely difficult to polycondensate, and yields poor economical fit. In addition, in this patent, oligomer and high molecular weight polylactide do not react with each other after the preparation of aliphatic / aromatic copolyester resins. There will be limits to using it apart.

Accordingly, the inventors of the present invention to solve the above problems, polylactide having a weight average molecular weight of 3,000 to 300,000, aliphatic (including cyclic aliphatic) dicarboxylic acid (or including anhydride thereof), aromatic dicarboxylic acid (or anhydride thereof) It is characterized by an excellent aliphatic / aromatic copolyester resin having one melting point made of hyperaliphatic (including cyclic aliphatic) glycol, and also suitable composition ratio of raw material composition suitable for the preparation of sugar composition and its reaction conditions. The study of optimization has led to the completion of the present invention.

The aliphatic / aromatic copolyester resin composition of the present invention comprises, as a main component, an acid component of an aliphatic dicarboxylic acid or its anhydride and a mixture composed of polylactide having a weight average molecular weight of 3,000 to 300,000 and an aromatic dicarboxylic acid; And an aliphatic ratio of 1.1 to 1.5 moles per 1 mole of the sum of the acid component of the aromatic dicarboxylic acid or its anhydride, the aliphatic dicarboxylic acid or its anhydride and the polylactide having a weight average molecular weight of 3,000 to 300,000. After the glycol is mixed, it is prepared through esterification, transesterification and condensation polymerization in the presence of a catalyst and a stabilizer.

According to the present invention, by adding a polylactide having a weight average molecular weight of 3,000 to 300,000 in the molecular structure to provide an aliphatic / aromatic copolyester resin composition excellent in transparency having one melting point rather than the blend concept, conventional biodegradability All molded products, such as extrusion and injection molding, can be manufactured while solving problems of resin properties, processability, reaction speed, and moisture weakness.

In the present invention, (1) aromatic dicarboxylic acid (or anhydride thereof), (2) aliphatic (including cyclic aliphatic) dicarboxylic acid (or anhydride thereof) and (3) a polyamide having a weight average molecular weight of 3,000 to 300,000 In the presence of aliphatic (including cyclic aliphatic) glycols as an acid component composed of a mixture of lactide, and a condensation polymerization reaction having undergone at least one reaction selected from esterification, transesterification, and condensation polymerization, A biodegradable aliphatic / aromatic copolyester resin composition excellent in transparency is provided.

The fully biodegradable aliphatic / aromatic copolyester resin composition comprising lactic acid according to the present invention will be described in detail as follows.

The aromatic dicarboxylic acid (or acid anhydride thereof) used in the present name is terephthalic acid, isophthalic acid, 2,6-naphthoic acid and ester-forming derivatives thereof. Terephthalic acid (or its ester forming derivatives) is particularly useful, and the components can be used alone or in combination.

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 arox. 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, polylactide having a weight average molecular weight of 3,000 to 300,000 is used in the present composition. In the case of polymers prepared using lactic acid, D-form, L-form, and D, L-form exist as optical isomers. Polylactide having a weight average molecular weight of 3,000 to 300,000 used in the present invention It can be used without being restricted by the composition ratio of each component.

The molar ratio of the aliphatic dicarboxylic acid (or its acid anhydride) and the polylactide having a weight average molecular weight of 3,000 to 300,000 and the aromatic dicarboxylic acid in the acid component used in the present invention is 70 mol%: 30 mol%-30 mol%: 70 mol%, More preferably, they are 60 mol%: 40 mol%-40 mol%: 60 mol%.

If the aliphatic acid is less than 30 mol% and the aromatic dicarboxylic acid is more than 70 mol% with respect to the composition of the total acid component, the resulting resin composition does not show biodegradability and thus loses the meaning of the present invention, and the aliphatic is more than 70 mol%, If the aromatic dicarboxylic acid is less than 30 mol%, the resulting composition has a low melting point, resulting in a low moldability.

When the molar sum of aliphatic dicarboxylic acid and polylactide used in the present invention is based on 100 mol%, the composition of the polylactide having a weight average molecular weight of 3,000 to 300,000 is 99.99 mol%: 0.01 mol It consists of a molar ratio of% to 50 mol%: 50 mol%. 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, and the amount of aliphatic glycol used is based on 1 mole of the acid composition consisting of aromatic dicarboxylic acid, aliphatic dicarboxylic acid and polylactide having a weight average molecular weight of 3,000 to 300,000. In molar ratios of from 1: 1.1 to 1: 1.5.

If the input amount is less than 1.1 molar ratio, the reaction is slow and color discoloration is caused. If the molar ratio exceeds 1.5 molar ratio, the economic cost increases and the effect of the invention is reduced.

Preferably, the present invention provides a biodegradable aliphatic / aromatic copolyester resin composition having excellent transparency, which comprises (i) esterification and transesterification products of aromatic dicarboxylic acid and aliphatic glycol in the presence of a catalyst and a stabilizer. step; (ii) esterifying and transesterifying the aliphatic dicarboxylic acid and the polylactide having a weight average molecular weight of 3,000 to 300,000 in the presence of the reaction product of step (i) in the presence of a catalyst and a stabilizer; And (iii) condensation polymerization of the reaction product of step (ii) at a reaction temperature of 240 ° C.-260 ° C., wherein the aliphatic glycol is an aliphatic dicarboxylic acid or anhydride thereof, and a weight average molecular weight of 3,000˜. It is added in an amount of 1.1 to 1.5 moles per 1 mole of the sum of the acid components of the polylactide and the aromatic dicarboxylic acid of 300,000, in the esterification reaction and the transesterification reaction in the steps (i) and (ii), Each of the catalyst and the stabilizer is based on 100 parts by weight of the total weight of the aromatic component and acid anhydride thereof, aliphatic dicarboxylic acid or anhydride thereof, and the acid component of the polylactide having a weight average molecular weight of 3,000 to 300,000 and aliphatic glycol. To each, it is added in an amount of 0.0001 to 1 parts by weight, and in the polycondensation reaction in the step (iii), 0.3 to 1.5 parts by weight of the polycondensation reaction catalyst and 0.0001 to 0.5 parts by weight of stabilizer is added, It provides an excellent reputation biodegradable Castle aliphatic / aromatic co-polyester resin composition.

Also preferably, in the biodegradable aliphatic / aromatic copolyester resin composition having excellent transparency of the present invention, the aromatic dicarboxylic acid may be terephthalic acid, isophthalic acid, 2,6-naphthoic acid and ester forming derivatives thereof, and their Aliphatic dicarboxylic acids are succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid and two or more thereof Aliphatic glycols are ethylene glycol, 1,2-propanediol, 1,2-butanediol, 1,4-butanediol, 1,6-hexanediol, 1,2-cyclohexanedimethanol and these Selected from the group consisting of two or more mixtures of 2,2-bis- (2-oxazoline), N, N'-hexamethylene-bis- (2-carbamoyl-, in esterification or transesterification reaction. 2-oxazoline), 2,2'-methylene-ratio -(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, the total weight of the acid component and aliphatic glycol 100 parts by weight As a reference, it is further used in an amount of 10 parts by weight or less.

The present invention also provides a product injection or extrusion molded from a biodegradable aliphatic / aromatic copolyester resin composition having excellent transparency according to the present invention.

In addition, the present invention provides a composition or a molded article formed by adding starch, calcium carbonate, or talc mineral to the biodegradable aliphatic / aromatic copolyester resin composition having excellent transparency according to the present invention.

In the process of (i), (ii) in the present invention, the esterification reaction or transesterification temperature is suitably about 170 to 230 ° C., and a catalyst and a stabilizer may be added at the initial stage of the esterification reaction or transesterification. have. 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 amount of the catalyst and the stabilizer is appropriately 0.0001 to 1 parts by weight based on 100 parts by weight of the total weight of the acid component and the aliphatic glycol, respectively, and when the amount of the catalyst is less than 0.0001 parts by weight, the rate of transesterification is slowed, whereas 1 part by weight If exceeded, the reaction rate is high 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 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 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 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 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 weight of the acid component and aliphatic glycol It is 0-10 weight part with respect to 100 weight part.

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, 93.2 g of dimethyl terephthalate and 121.6 g of 1,4-butanediol were added thereto, 0.1 g of tetramethyl titanate was added, and the esterification reaction was carried out at 200 ° C. for 2 hours to obtain a theoretical amount. After distilling off methanol, 68.7 g of adipic acid and 4.5 g of polylactide having a weight average molecular weight of 150,000 were 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 150 minutes under reduced pressure of 2.0 Torr or less at 255 ° C. The resin thus obtained had a melting point of 110 ° C. of number average molecular weight of 33,800 and a weight average molecular weight of 74.300.

Example 2

A 500 ml round bottom flask was replaced with nitrogen, 93.2 g of dimethyl terephthalate and 121.6 g of 1,4-butanediol were added thereto, 0.1 g of tetramethyl titanate was added, and the esterification reaction was carried out at 200 ° C. for 2 hours to obtain a theoretical amount. After distilling out methanol, 62 g of adipic acid and 9.08 g of polylactide having a weight average molecular weight were added thereto, and then 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 150 minutes under reduced pressure of 2.0 Torr or less at 255 ° C. The resin thus obtained had a melting point of 115 ° C. of number average molecular weight of 38,300 and a weight average molecular weight of 80,600.

Example 3

A 500 ml round bottom flask was replaced with nitrogen, 93.2 g of dimethyl terephthalate and 121.6 g of 1,4-butanediol were added thereto, 0.1 g of tetramethyl titanate was added, and the esterification reaction was carried out at 200 ° C. for 2 hours to obtain a theoretical amount. After distilling off methanol, 62 g of adipic acid was added thereto, and the reaction temperature was fixed at 200 ° C., and water was distilled out. Thereafter, 20 g of polylactide having a molecular weight of 110,000, 0.1 g of antimony acetate, 0.1 g of thibutyltin oxide, 0.1 g of tetrabutyl titanate, and 0.2 g of trimethylphosphate 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 thus obtained had a melting point of 100 ° C. of number average molecular weight of 35,300 and a weight average molecular weight of 75,200.

Example 4

A 500 ml round bottom flask was replaced with nitrogen, 93.2 g of dimethyl terephthalate and 121.6 g of 1,4-butanediol were added thereto, 0.1 g of tetramethyl titanate was added, and the esterification reaction was carried out at 200 ° C. for 2 hours to obtain a theoretical amount. After distilling off methanol, 20 g of polylactide having a molecular weight of 110,000 and 62 g of adipic acid were added thereto, and the reaction temperature was fixed at 200 ° C., and water was distilled off. 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 100 minutes under a reduced pressure of 2.0 Torr or less at 250 ° C. 10 g of 1,6-hexamethylene diisocyanate was added to the resin thus obtained to form a compound. Melting | fusing point was 100 degreeC, the number average molecular weight was 47,000, and the weight average molecular weight was 97,000.

Comparative Example 1

A 500 ml round bottom flask was replaced with nitrogen, 93.2 g of dimethyl terephthalate and 121.6 g of 1,4-butanediol were added thereto, 0.1 g of tetramethyl titanate was added, and the esterification reaction was carried out at 200 ° C. for 2 hours to obtain a theoretical amount. After distilling off methanol, 76 g of adipic acid was added thereto, 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 is fixed at 205 ° C.

After completely flowing out the theoretical amount of water to produce 34.4 g of an "aliphatic low molecular weight polymer" having a molecular weight of about 600, 77.5 g of dimethyl terephthalate, 135.2 g of 1,4-butanediol and tetrabutyl tita as a catalyst were added to the Erlenmeyer flask. 0.2g of nate is added to raise the temperature slowly, and methanol is 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 melting point of the resin obtained at this time was 108.3 ° C., the number average molecular weight was 17,589 and the weight average molecular weight was 113,550.

Comparative Example 4

A 500 ml round bottom flask was replaced with nitrogen, 93.2 g of dimethyl terephthalate and 121.6 g of 1,4-butanediol were added thereto, 0.1 g of tetramethyl titanate was added, and the esterification reaction was carried out at 200 ° C. for 2 hours to obtain a theoretical amount. After distilling 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. 25 g of polylactide was added to the resin obtained at the time of nitrogen stream, and it stirred after 20 minutes, and reaction was complete | finished. The resin thus obtained had two melting points of 120 ° C and 173 ° C, and the number average molecular weight was 27,000 weight average molecular weight of 47,000.

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 (14)

As a biodegradable aliphatic / aromatic copolyester resin composition excellent in transparency,
(i) esterifying the aromatic dicarboxylic acid and the aliphatic glycol in the presence of a catalyst and a stabilizer and a transesterification product;
(ii) obtaining an esterification and transesterification product of an aliphatic dicarboxylic acid and a polylactide having a weight average molecular weight of 3,000 to 300,000 in the presence of the reaction product of (i) in the presence of a catalyst and a stabilizer; And
(iii) a condensation polymerization reaction of the reaction product of (ii) at a reaction temperature of 240 ° C.-260 ° C.,
Here, aliphatic glycol is added in the amount of 1.1-1.5 mol with respect to 1 mol of sum total of the acid component of aliphatic dicarboxylic acid or its anhydride, polylactide whose weight average molecular weight is 3,000-300,000, and aromatic dicarboxylic acid,
In the esterification reaction and the transesterification reaction in (i) and (ii), each of the catalyst and the stabilizer is an aromatic dicarboxylic acid or an acid anhydride thereof, an aliphatic dicarboxylic acid or an anhydride thereof, and a weight average molecular weight of 3,000. It is added in an amount of 0.0001 to 1 part by weight, based on 100 parts by weight of the total weight of the acid component and aliphatic glycol of polylactide of ˜300,000,
In the polycondensation reaction in the above (iii), 0.3 to 1.5 parts by weight of the polycondensation reaction catalyst and 0.0001 to 0.5 parts by weight of the stabilizer is added,
A biodegradable aliphatic / aromatic copolyester resin composition having a number average molecular weight of 30,000 to 70,000, a weight average molecular weight of 50,000 to 300,000, a melting point of 80 to 150 ° C, and excellent transparency. The molar ratio of the sum of the aliphatic dicarboxylic acid or anhydride thereof and the polylactide having a weight average molecular weight of 3,000 to 300,000 and the aromatic dicarboxylic acid is 70 mol%: 30 mol% to 30 mol. A biodegradable aliphatic / aromatic copolyester resin composition having excellent transparency, characterized in that%: 70 mol%. 2. The transparency according to claim 1, wherein the molar ratio of the aliphatic dicarboxylic acid or its anhydride and the polylactide having a weight average molecular weight of 3,000 to 300,000 is 99.99 mol%: 0.01 mol% to 50 mol%: 50 mol%. This excellent biodegradable aliphatic / aromatic copolyester resin composition. The biodegradable aliphatic having excellent transparency according to 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. / Aromatic copolyester resin composition. 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 / aromatic copolyester 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 / aromatic copolyester resin composition excellent in transparency, characterized in that it is selected from the group consisting of the above mixture. The 2,2-bis- (2-oxazoline), N, N'-hexamethylene-bis- (2-carbamoyl-2-oxazoline) according to claim 1, in the esterification reaction and the transesterification reaction. , 2,2'-methylene-bis- (2-oxazoline), 2,2'-ethylene-bis- (2-oxazoline), 2,2'-propylene-bis- (2-oxazoline), 1 The oxazoline compound selected from the group consisting of, 3-phenylene-bis- (2-oxazoline), 2,2-P-phenylene-bis- (2-oxazoline) and mixtures of two or more thereof is an acid component. 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 of the total weight of the aliphatic glycol. The method of claim 1, wherein in the esterification reaction and the transesterification reaction, 1,3-dicyclohexylcarbodiimide, HMV-8CA, HMV-10B, bis- (2,6-diisopropyl-phenyline-2 Carbodiimide compounds selected from the group consisting of, 4-carbodiimide), poly- (1,3,5-triisopropyl-phenylri-2,4-carbodiimide), and mixtures of two or more thereof, 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 of the total weight of the component and aliphatic glycol. The method according to any one of claims 1 to 8, wherein in the esterification reaction and the transesterification reaction, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-diphenylmethane as a chain extender. The isocyanate compound selected from the group consisting of diisocyanate, 2,2'-diphenylmethane diisocyanate and mixtures of two or more thereof is contained in an amount of 5 parts by weight or less based on 100 parts by weight of the total weight of the acid component and the aliphatic glycol. A biodegradable aliphatic / aromatic copolyester resin composition excellent in transparency, which is further used. delete The biodegradable aliphatic / aromatic copolyester of claim 1, wherein the polyfunctional acid or the polyfunctional glycol is further added in an amount of 10 parts by weight or less based on 100 parts by weight of the total weight of the acid component and the aliphatic glycol. Resin composition. The aromatic dicarboxylic acid 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, wherein the aliphatic dicarboxylic acid is succinic acid, glue Taruic acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid and mixtures of two or more thereof, and aliphatic glycols are ethylene glycol, 1,2- Selected from the group consisting of propanediol, 1,2-butanediol, 1,4-butanediol, 1,6-hexanediol, 1,2-cyclohexanedimethanol and mixtures of two or more thereof, and esterification or transesterification 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- An oxazoline compound selected from the group consisting of (2-oxazoline), 2,2-P-phenylene-bis- (2-oxazoline) and mixtures of two or more thereof, has a total weight of 100 parts by weight of an acid component and an aliphatic glycol. A biodegradable aliphatic / aromatic copolyester resin composition having excellent transparency, characterized in that it is further used in an amount of 10 parts by weight or less based on parts. An article injected or extruded from the biodegradable aliphatic / aromatic copolyester resin composition having excellent transparency. A compound or a product molded therefrom by adding starch, calcium carbonate, or talc mineral to the biodegradable aliphatic / aromatic copolyester resin composition having excellent transparency.