KR100701622B1 - Biodegradable aliphatic/aromatic copolyester polymer and preparation thereof - Google Patents

Abstract

The present invention relates to an aliphatic / aromatic copolyester polymer having excellent biodegradation properties and mechanical properties, and a method of preparing the same, and more particularly, to an aromatic / aliphatic copolyester containing an aromatic component added to improve tear strength. In the present invention, the biodegradable weakness caused by the component can be molded by obtaining a high molecular weight aliphatic / aromatic copolyester without degrading biodegradability through the change of the molecular structure of the existing biodegradable aliphatic / aromatic copolyester. The range of conditions is considerably wide, and the products obtained by using the same are also concerned with high molecular weight aliphatic / aromatic copolyester polymers having excellent mechanical properties and methods for their preparation.

  Biodegradable, aliphatic / aromatic copolyester

Description

Biodegradable aliphatic / aromatic copolyester polymer and its preparation method {BIODEGRADABLE ALIPHATIC / AROMATIC COPOLYESTER POLYMER AND PREPARATION THEREOF}

The present invention relates to biodegradable aliphatic / aromatic copolyester polymers and methods for their preparation.

Plastic is an indispensable product in the modern industrial society, and its use is increasing gradually. However, recently, environmental pollution caused by plastic products that have been used and discarded has become a big issue in the world, and as a way to reduce such wastes, the reuse of plastic products, incineration, and development of biodegradable plastics have emerged. Among them, biodegradable plastics are in the spotlight as environmentally friendly products that solve environmental pollution, and in the present invention, biodegradable aliphatic / aromatic copolyesters used as raw materials of such biodegradable plastics are synthesized to prevent environmental pollution due to waste plastics. Its purpose is to prevent it.

There are many types 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 their limitations in application to products or poor moldability and productability.

It is well known that aliphatic / aromatic copolyesters are biodegradable in the proper molecular structure [Journal of Environmental polymer Degradation, Vol. 5, No. 2, 1997], these biodegradable materials are mainly applied to medical, agricultural, fishing materials, packaging materials, etc., and their applications are gradually being expanded.

However, the existing aliphatic / aromatic copolyesters have low thermal stability during melting and are easy to thermally decompose, so the range of working conditions is quite narrow, so it is difficult to set the working conditions, so that the defective rate of the product is high, and the melt flow index is high. Due to the very low cooling rate, the resin alone is not easy to form and process, and there is a problem in that its use is limited due to weak tensile strength.Also, the synthesis of aliphatic / aromatic noses depends on the amount of aromatic compounds in the molecule and the length of the aromatic chain. The biodegradability of polyesters is greatly affected [Journal of applied polymer science, 26, 441, 1981].

As a method for practical use of such aliphatic / aromatic copolyester, a method of synthesizing a high molecular weight aliphatic polyester resin by appropriately adjusting the reaction temperature, vacuum degree and catalyst conditions is disclosed in Korean Patent Application No. 2000-0042622. Is disclosed. However, the aliphatic / aromatic copolyester resin produced by this method has lower tensile strength than general purpose polyethylene, and the esterification step is one step, and the molecular structure is considerably random. Poor workability

As another conventional example, Korean Patent Application Nos. 97-7003252 and 97-7003253 describe polyfunctional monomers capable of forming sulfonate compounds and ester linking groups in the range of 3 to 10 in addition to the existing aliphatic and aromatic monomers. And a method for producing a high molecular weight aliphatic / aromatic copolyester by adding an isocyanate monomer in the preparation of a copolyester. 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 aliphatic / aromatic copolyester is rapidly increased and the physical properties such as tensile strength are lowered, it is difficult to be practically used, and there is a problem of gelation, which makes it difficult to control the reactivity. The aliphatic / aromatic copolyester resins obtained by the above-mentioned method have a problem in that isocyanate, which is a coupling agent used to increase the molecular weight, is extremely harmful to the human body and requires attention in operation. In addition, biodegradation of copolyester can cause secondary pollution of the soil by isocyanates.

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

Accordingly, the present invention is to solve the problems of the conventional aliphatic / aromatic copolyester as described above, unlike the conventional biodegradable aliphatic polyester, as a compound having a new structure and properties, while having sufficient biodegradability for practical use Its purpose is to obtain biodegradable aliphatic / aromatic copolyester resins having excellent mechanical properties and processability comparable to those of general-purpose resins.

In order to achieve the above object, the present inventors directly prepared and used aliphatic / aromatic polydiol in order to change molecular structure and improve reactivity, and introduced a multi-step reaction in aliphatic / aromatic copolyester reaction process. The aliphatic / aromatic polydiol compound used in the present invention has a molecular weight of 500-150 which extends the chain by reacting 3- (4-hydroxyphenyl) propionic acid (or a derivative thereof) with an aliphatic polydiol having a molecular weight of 200-1,000. As an aliphatic / aromatic polydiol which is 10,000, it can be added and reacted during the esterification reaction between aliphatic dicarboxylic acid and aliphatic glycol during the aliphatic / aromatic copolyester synthesis step to yield a high molecular weight aliphatic / aromatic copolyester. That is, the aliphatic / aromatic polydiol is added to the esterification and transesterification reaction between aliphatic dicarboxylic acid and aliphatic glycol in the aliphatic / aromatic copolyester multistage synthesis process to further increase the length of the polymer chain in the aliphatic / aromatic copolyester polymerization. It is possible to obtain an aliphatic / aromatic copolyester having a higher molecular weight than the aliphatic / aromatic copolyester synthesized by the conventional technique.

In one aspect, the present invention is a method for producing a biodegradable aliphatic / aromatic copolyester polymer,

(i) High molecular weight aliphatic / aromatic polydiols having a molecular weight of 500 to 10,000 in which a chain is extended by reacting 3- (4-hydroxyphenyl) propionic acid (or a derivative thereof) with an aliphatic polydiol having a molecular weight of 200 to 1,000. Preparing a;

(ii) reacting the aromatic dicarboxylic acid (or its acid anhydride) with an aliphatic (or cycloaliphatic) glycol to obtain a primary esterification and transesterification product;

(iii) with the aliphatic (or cycloaliphatic) dicarboxylic acid (or acid anhydride thereof) in the presence of the primary reaction product of step (ii) and in the presence of the aliphatic / aromatic polydiol of step (i) Reacting an aliphatic (or cycloaliphatic) glycol to obtain a secondary esterification and transesterification product; And

(iv) a method of preparing an aliphatic / aromatic copolyester polymer comprising condensation polymerization of the reaction product of step (iii).

In a preferred embodiment of this embodiment, the aliphatic polydiol has a molecular weight ranging from 200 to 1000, and is a single component or mixed component selected from polyethylene glycol, polypropylene glycol and polybutanediol, and 3- (4-hydroxyphenyl The molar ratio of propionic acid (or derivative thereof) is in the range of 1: 1.0 to 1: 2.0.

In another preferred embodiment, in the preparation of aliphatic / aromatic polydiols, the reaction temperature ranges from 160 to 180 ° C. and tin-based metal catalysts can be used.

In another preferred embodiment, the molar ratio of aromatic dicarboxylic acid (or acid anhydride thereof) and aliphatic (including cyclic aliphatic) glycol used in the primary esterification and transesterification is in the range of 1: 1.15 to 1: 2.0. will be.

In another preferred embodiment, specific examples of the aromatic dicarboxylic acid (or acid anhydride thereof) include terephthalic acid, phthalic acid, phthalic anhydride, isophthalic acid, 4-methylphthalic acid, 4-methylphthalic anhydride, dimethyl terephthalate and dimethylphthalate. However, it is not limited thereto. Such aromatic dicarboxylic acids (or acid anhydrides) thereof may be used alone or as a mixture of two or more thereof.

In another preferred embodiment, the aliphatic (including cycloaliphatic) glycols used in the esterification and transesterification reactions include ethylene glycol, diethyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, 1, 3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentylglycol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,2-octanediol, 1 , 6-octanediol, 1,9-nonanediol, 1,2-decanediol, 1,10-decanediol and decamethyleneglycol. Such aliphatic (including cyclic aliphatic) glycols may be used alone or as a mixture of two or more thereof.

In another preferred embodiment, the temperature range in which the primary esterification and transesterification reactions are carried out is preferably maintained at 180 to 220 ° C., which is the active temperature of the aromatic component.

In another preferred embodiment, aliphatic (including cycloaliphatic) dicarboxylic acids (or acid anhydrides) include succinic acid, glutaric acid, adipic acid, pimeric acid, subberic acid, azelaic acid, sebacic acid, 1,9 Nonandicarboxylic acids, 1,10-decanedicarboxylic acids and acid anhydrides thereof, including but not limited to. These aliphatic (including cyclic aliphatic) dicarboxylic acids (or their acid anhydrides) may be used alone or as mixtures of two or more thereof.

In another preferred embodiment, the temperature range in which the secondary esterification and transesterification reactions are carried out is suitably in the range from 150 to 180 ° C.

In another preferred embodiment, the aromatic dicarboxylic acid (or acid anhydride thereof) and aliphatic dicarboxylic acid (or acid anhydride thereof) used in the process for preparing the aliphatic / aromatic copolyester polymer of the present invention are from 0.3: 0.7 to It is preferable that it is molar ratio of 0.7: 0.3.

In another preferred embodiment, the content of aliphatic / aromatic polydiol present in the secondary esterification and transesterification is preferably in the range of 5-30 wt% of the theoretical amount of the aliphatic / aromatic copolyester polymer as the final product.

In another preferred embodiment, the final condensation polymerization reaction is preferably carried out for 180 to 240 minutes under a vacuum degree of 0.005 to 2.0 torr in the 220 to 260 ℃ temperature range.

In another preferred embodiment, further catalysts may be added at the beginning or end of the esterification, transesterification and polycondensation reactions. Such catalysts may be used in the range of 0.02% to 2.0% by weight, based on the total reactant weight. Specific examples of such a catalyst include any one or two or more mixed catalysts selected from metal compounds including Ti, Ge, Zn, Fe, Mn, Co, Zr, etc., preferably titanate, tin oxide, antimonate Is an organometallic compound containing, in particular, one or two or more kinds selected from the group consisting of tetrabutyl titanate, calcium acetate, antimony trioxide, monobutyl tin oxide, zinc acetate, antimoniacetate, and tetrapropyl titanate. desirable.

In another preferred embodiment, further stabilizers may be added at the beginning or end of the esterification, transesterification and polycondensation reactions. Such stabilizers are suitably used in the range of 0.02 to 2.0% by weight, based on the total reactant weight. Such stabilizers include, but are not limited to, trimethylphosphate, phosphoric acid and triphenylphosphate. These stabilizers can be used alone or in mixture of two or more.

In another aspect, the present invention is prepared according to the production method described in the above-described aspect, wherein the number average molecular weight of 40,000, wherein the aromatic dicarboxylic acid component is continuously present at 10 or less in the dicarboxylic acid position of the polymer chain An aliphatic / aromatic nose having excellent mechanical properties, processability and biodegradability, having a range of -80,000, a weight average molecular weight of 100,000-250,000, a melting point of 70-150 ° C., and a melt flow index of 0.1-50 (190 ° C., 2160 g). It provides a polyester polymer.

Referring to the present invention in more detail as follows.

In the present invention, the aliphatic / aromatic copolyester resin is a biodegradable resin composition, which will be described. First, it is necessary to prepare a high molecular weight aliphatic / aromatic polydiol for raising the aliphatic / aromatic copolyester to a high molecular weight. In the following description, 3- (4-hydroxyphenyl) propionic acid (or a derivative thereof) is added to a reactor equipped with a reflux tower and a stirrer, and aliphatic polydiol is added to 3- (4-hydroxyphenyl) propionic acid (or Derivatives) 1 mole to 2 moles per mole, and then the water generated as a by-product of the reaction by distilling the reactant under 160 to 180 ℃ tin-based metal catalyst conditions to produce aliphatic / aromatic polydiol and representative The product is shown in Scheme 1.

Where n and m are integers where n is 4-16 and m is 1-12.

The molecular weight of the aliphatic polydiol used in the production of the aliphatic / aromatic polydiol is in the range of 200 to 1,000, and if the molecular weight is 200 or less, biodegradation due to the short distance between the aromatic components in the molecular structure of the aliphatic / aromatic polydiol. It may lead to degradation, and if it is more than 1,000, the production of aliphatic / aromatic polydiol is difficult due to the long chain of aliphatic polydiol, and the reaction rate of the resin may be reduced and the slow cooling rate may be caused in the later production of aliphatic / aromatic copolyester. It may cause difficulty in molding. As the aliphatic polydiol, a single or mixed component containing any one or more selected from polyethylene glycol, polypropylene glycol, and polybutanediol may be used, and preferably, polyethylene glycol or polybutanediol is a single component.

The aliphatic / aromatic polydiol thus synthesized is added to the second step of the following aliphatic / aromatic copolyester multistage synthesis to be used as a diol component. When added in step 1, the block of aromatic components is lengthened, affecting the degradability.

Specifically, the first step of the aliphatic / aromatic copolyester synthesis is the aromatic dicarboxylic acid (or its acid anhydride) containing aromatics in molecular structures such as dimethyl terephthalate and terephthalic acid, and 1,4-butanediol and ethylene glycol. It is carried out by reacting an aliphatic (including cyclic aliphatic) glycol containing any one or more selected. Specifically describing possible reactant combinations in this step are:

(1) Dimethyl terephthalate (including terephthalic acid) sole component: ethylene glycol sole component or mixed component of ethylene glycol and other glycols (glycol having an alkylene group having 3 to 10 carbon atoms (including cyclic alkylene group)),

(2) Dimethyl terephthalate (including terephthalic acid) Single component: 1,4-butanediol single component or 1,4-butanediol and other glycols (glycols having 2 to 3, 5 to 10 alkylene groups (including cyclic alkylene groups)) Of mixed ingredients,

③ dimethyl terephthalate (including terephthalic acid) single component or mixed component of dimethyl terephthalate (including terephthalic acid) and other aromatic dicarboxylic acid (or acid anhydride thereof): ethylene glycol single component,

④ Dimethyl terephthalate (including terephthalic acid) single component or mixed component of dimethyl terephthalate (including terephthalic acid) and other aromatic dicarboxylic acid (or acid anhydride thereof): 1,4-butanediol single component,

(5) Dimethyl terephthalate (including terephthalic acid) alone or mixed component of dimethyl terephthalate (including terephthalic acid) and other aromatic dicarboxylic acids (or acid anhydrides thereof): Ethylene glycol alone or ethylene glycol and other glycols A mixed component of an alkylene group of 10 (including a glycol having a cyclic alkylene group),

⑥Dimethyl terephthalate (including terephthalic acid) single component or mixed component of dimethyl terephthalate (including terephthalic acid) and other aromatic dicarboxylic acid (or acid anhydride thereof): 1,4-butanediol single component or 1,4-butanediol A mixed component of other glycols (glycols having 2 to 3, 5 to 10 alkylene groups (including cyclic alkylene groups)).

Any one reaction combination selected from these reaction components is introduced into the reactor, and water or methanol is completely discharged through the esterification reaction and the transesterification reaction while maintaining at an active temperature of 180-220 ° C. of the aromatic component. The molar ratio of aromatic dicarboxylic acid (or acid anhydride thereof) and aliphatic (including cyclic aliphatic) glycol added in the one-step reaction is preferably 1: 1.15 to 1: 2.0, more preferably 1: 1.3 to 1 :: Add at a rate of 1.5.

In a two-step reaction, an aliphatic (saturated aliphatic) containing succinic acid is added to the aliphatic / aromatic polydiol synthesized above at 5 to 30% by weight of the theoretical amount of the resulting aliphatic / aromatic copolyester. After the addition of dicarboxylic acid (or its acid anhydride), aliphatic (including cyclic aliphatic) glycol is added, and then esterification reaction and transesterification reaction to completely drain the water to react the reaction product. Get If the added aliphatic / aromatic polydiol is less than 5% by weight of the theoretical aliphatic / aromatic copolyester, the effect is difficult to expect. If the aliphatic / aromatic polydiol is more than 30%, the processability and degradability are reduced due to the decrease in the crystallinity of the resin and the increase in the aromatic component. Can fall. Aliphatic (including cyclic aliphatic) glycol added in this step is added in a molar ratio of 1: 1.35 to 1: 1.45 to aliphatic (including cyclic aliphatic) dicarboxylic acids (or acid anhydrides thereof), more preferably 1: The reaction temperature is 1.38 to 1: 1.42, and in this step, the reaction is carried out at a temperature of 150 to 180 ° C. in order to lower the activity of the aromatic dicarboxylic acid (or its acid anhydride). If the reaction temperature is less than 150 ℃ water is difficult to flow out, if more than 180 ℃ is the component of the aromatic dicarboxylic acid (or its acid anhydride) that was unreacted in the first step is activated to affect the biodegradability of the final resin obtained. In particular, since the aliphatic / aromatic polydiol contains aromatic components, the effect may be more biodegradable.

Finally, in the three-step reaction, the polymer resin obtained in the two-step reaction introduced is condensation-polymerized for 180 to 240 minutes at a temperature of 220 to 260 ° C. and a vacuum of 0.005 to 2.0 torr for a high molecular weight aliphatic / aromatic copolyester resin. Create At this time, the produced copolyester has a number average molecular weight of 40,000 to 80,000 weight average molecular weight 100,000 to 250,000.

On the other hand, in the present invention, the catalyst may be added at the beginning or the end of the esterification, transesterification or condensation polymerization in one to three stages, the addition amount is 0.02 to 2.0% by weight relative to the total weight of the composition. If the amount of the catalyst used is less than 0.02% by weight, the theoretical amount of the theoretical amount of water and the methanol unreacted glycol is impossible or time-consuming, whereas if the amount of the catalyst added exceeds 2.0% by weight, the theoretical amount of the methanol, water and the unreacted Glycol spills are easy but may affect color and properties. In this case, any catalyst selected from metal compounds containing Ti, Ge, Zn, Fe, Mn, Co, Zr, etc., or two or more mixed catalysts may be used. Preferably, titanate, tin oxide, and antimonate are used. An organometallic compound containing a compound is used, and more preferably any one or two or more mixed catalysts selected from tetrabutyl titanate, calcium acetate, antimony trioxide, monobutyl tin oxide, zinc acetate, antimony acetate, and tetrapropyl titanate Is used.

In addition, a stabilizer may be added at the beginning or end of the esterification, transesterification, or condensation polymerization of the first step to the third step, the amount of which is 0.02 to 2.0% by weight based on the total weight of the composition. If it is less than 0.02% by weight, the effect as a stabilizer cannot be obtained, and color becomes poor. On the other hand, if the amount of the stabilizer is added in excess of 2% by weight, the reaction rate becomes long and it is difficult to obtain a high molecular weight polyester. Therefore, the preferred amount of the stabilizer is 0.22% by weight, and as the stabilizer, any one or two or more mixed stabilizers selected from phosphate-based stabilizers such as trimethylphosphate, phosphoric acid, triphenylphosphate, and the like are used.

In short, the polyester resin of the present invention is a high-molecular weighted polymer by synthesizing an aliphatic / aromatic polydiol and then adding it to a two-step reaction and including the same, and a number average molecular weight of 40,000 to 80,000, weight Aliphatic / aromatic copolyesters having an average molecular weight of 100,000 to 250,000. Melting point is 70-150 degreeC, and melt flow index is 0.1-50 (190 degreeC, 2160g).

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the Examples and should be construed to include various modifications within the scope of the present invention.

Melting point was measured using a Perkin Elmer differential scanning calorimeter at a temperature rise rate of 10 ℃ per minute, flow flow index was measured with a load of 2160g at 190 ℃ in accordance with ASTM D1238. In addition, the molecular weight was measured by gel chromatography method, and the tensile strength and elongation were measured by ASTM D882 method after molding each resin with a hot press of 50㎛ thickness.

In addition, the biodegradable copolyester polymer was molded into a film having a thickness of 35 μm using a blown film molding machine, and then cut into 20 cm in width and length, respectively, and then No.18 mesh having a body hole of 1 mm to prevent loss. (mesh) was inserted between the two, embedded in a depth of 30cm in the soil and taken out after 3 months to determine the weight loss by measuring the biodegradation. Each film was measured 3 pieces per sample and the average value was taken.

Example

Comparative Example 1

Substitute 100 liters of reactor with nitrogen, 28.62 kg of basic ester (21% by weight of dimethyl succinate, 16% by weight of dimethyl adipate, 62% by weight of dimethylglutalate, 1% by weight), 116.4kg of dimethyl terephthalate, 1, 40.56 kg of 4-butanediol was added, 40 g of antimony trioxide, 40 g of zinc acetate, and 16 g of isopropyltriisostearoyl titanate were added. 40 g of trimethyl phosphate was added thereto, followed by condensation polymerization under a high vacuum of 1 torr for 2 hours 30 minutes to obtain an aliphatic / aromatic copolyester.

The number average molecular weight of the sample obtained at this time was 18,000, and the weight average molecular weight was 62,000. Melting point was 119 degreeC. After 3 months, the weight loss was 16%.

Comparative Example 2

The 100 L reactor was replaced with nitrogen, and then 4.672 kg of 1,4-butanediol, 7.000 kg of adipic acid and 50 g of tin dioctoate were added and then reacted at a temperature in the range of 230 to 240 ° C. to completely remove the theoretical water runoff. . After taking 1.81 kg of the obtained polymer, 1.17 kg of dimethyl terephthalate and 1.7 kg of 1,4-butanediol were added thereto, and methanol generated while heating to 180 ° C. with gentle stirring was removed. In this process, 4.7 g of tetrabutyl ortho titanate, 6.6 g of pyromellitic dianhydride, and 1.9 g of 50% aqueous phosphite solution are added, and the polycondensation reaction is carried out at a temperature of 230 to 240 ° C. and a high vacuum of less than 1 torr for about 2 hours. After proceeding, the melt was cooled to 200 ° C., 15 g of hexamethylene diisocyanate was added over 15 minutes, and then the mixture was stirred. The polyester was granulated and processed into a film.

Melting | fusing point of resin obtained at this time was 98 degreeC, the number average molecular weight was 14,320, and the weight average molecular weight was 98,350. After 3 months, the weight loss was 32%.

Comparative Example 3

The 100 L reactor was replaced with nitrogen, and then 4.672 kg of 1,4-butanediol, 7.000 kg of adipic acid and 50 g of tin dioctoate were added and then reacted at a temperature in the range of 230 to 240 ° C. to completely remove the theoretical water runoff. . After taking 16.52 kg of the obtained polymer, 13.1 kg of dimethyl terephthalate and 17 kg of 1,4-butanediol were added, and methanol generated while heating to 180 ° C. with gentle stirring was removed. In this process, 47 g of tetrabutyl ortho titanate, 16.5 g of pyromellitic dianhydride, and 19 g of 50% aqueous phosphite solution were added, and the polycondensation reaction was carried out at a temperature of 230 to 240 ° C. and a high vacuum of less than 1 torr for about 2 hours. The melt was cooled to 200 ° C. and 290 g of hexamethylene diisocyanate was added over 15 minutes, then the mixture was stirred. The polyester was granulated and processed into a film.

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. After 3 months, the weight loss was 28%.

Example 1

Substitute 100 L reactor with nitrogen, add 16.618 kg of 3- (4-hydroxyphenyl) propionic acid, 36 kg of polyethylene glycol with a molecular weight of 300, add 10 g of monobutyl tin oxide as a catalyst, and gradually increase the temperature. The reaction was carried out at a reaction temperature of 170 ° C. to flow out water. When the theoretical amount of water generated was released, the reaction was terminated to obtain an aliphatic / aromatic polydiol having a molecular weight of about 500.

Subsequently, the 100 L reactor was replaced with nitrogen, 15.54 kg of dimethyl terephthalate, 11 kg of 1,4-butanediol, and 20 g of tetrabutyl titanate as a catalyst were added thereto, reacted in a nitrogen stream for 2 hours, and the theoretical amount of methanol was distilled out. At this time, the methanol was completely discharged while maintaining the temperature at 205 DEG C, and then 2.86 kg of the above-mentioned aliphatic / aromatic polydiol, 12.98 kg of 1,4-butanediol, 7.1 kg of succinic acid and 8.77 kg of adipic acid, were reacted. The temperature was fixed at 180 ° C. and water was let off. At this time, 10 g of antimony acetate, 20 g of thibutyltin oxide, 7 g of tetrabutyl titanate, and 20 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 temperature was subjected to a condensation polymerization reaction at 190 ° C. under a reduced pressure of 0.1 Torr for 190 minutes.

At this time, the sample collected was the number average molecular weight 48,366 and the weight average molecular weight 160,915, and melting | fusing point measured by the DSC method was 80 degreeC. After 3 months, the weight loss was 84%.

Example 2

Substitute 100 L reactor with nitrogen, add 16.618 kg of 3- (4-hydroxyphenyl) propionic acid, 36 kg of polyethylene glycol with a molecular weight of 300, add 10 g of monobutyl tin oxide as a catalyst, and gradually increase the temperature. The reaction proceeded at a reaction temperature of 170 ° C., and water was discharged. When the theoretical amount of water generated was discharged, the reaction was terminated to obtain an aliphatic / aromatic polydiol having a molecular weight of about 900.

Subsequently, the 100L reactor was replaced with nitrogen, 21.68 kg of dimethyl terephthalate, 15.14 kg of 1,4-butanediol, and 20 g of tetrabutyl titanate as a catalyst were added thereto, reacted for 2 hours in a nitrogen stream, and the theoretical amount of methanol was distilled out. At this time, the methanol was completely discharged while maintaining the temperature at 205 ° C., and the reaction temperature of 4.8 kg, 1,4-butanediol 9.5 kg and 10.39 kg succinic acid was fixed at 180 ° C. in the reactor. Water was spilled. At this time, 10 g of antimony acetate, 20 g of thibutyltin oxide, 7 g of tetrabutyl titanate, and 20 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 temperature was subjected to a condensation polymerization reaction at 220 ° C. under a reduced pressure of 0.1 Torr.

At this time, the collected sample had a number average molecular weight of 52,364 and a weight average molecular weight of 182,365, and the melting point measured by the DSC method was 123 ° C. After 3 months, the weight loss was 52%.

Example 3

Substitute 100 L reactor with nitrogen, add 16.618 kg of 3- (4-hydroxyphenyl) propionic acid, 36 kg of polyethylene glycol with a molecular weight of 500, add 10 g of monobutyl tin oxide as a catalyst, and slowly raise the temperature. The reaction proceeded at a reaction temperature of 170 ° C., and water was discharged. When the theoretical amount of water generated was released, the reaction was terminated to obtain an aliphatic / aromatic polydiol having a molecular weight of about 1200.

Subsequently, the 100L reactor was replaced with nitrogen, 18.63 kg of dimethyl terephthalate, 12.11 kg of 1,4-butanediol, and 20 g of tetrabutyl titanate as a catalyst were added and reacted in a nitrogen stream for 2 hours to release the theoretical methanol. At this time, methanol was completely discharged while maintaining the temperature at 205 ° C., and 8.08 kg of the above-mentioned aliphatic / aromatic polydiol, 12.18 kg of 1,4-butanediol, 15.2 kg of adipic acid, and the reaction temperature were 180 ° C. And fixed with water. At this time, 10 g of antimony acetate, 20 g of thibutyltin oxide, 7 g of tetrabutyl titanate, and 20 g of trimethyl phosphate were added as a stabilizer. After the theoretical amount of water had flowed out, the temperature was subsequently raised and the polycondensation reaction was carried out for 210 minutes at 245 ° C. under a reduced pressure of 0.1 Torr.

At this time, the sample collected was the number average molecular weight 72,358, the weight average molecular weight 248,320, and the melting point measured by the DSC method was 121 ° C. After 3 months, the weight loss was 69%.

Example Comparative example One 2 3 One 2 3 Tensile Strength (kgf / cm ² ) 249 281 265 212 234 214 Tear strength (kgf / cm) 223 248 239 186 208 197 Melt Index (190 ℃, 2160g) 2.3g / 10 minutes 2.5g / 10 minutes 2.1g / 10 minutes 12g / 10 minutes 18g / 10 minutes 12g / 10 minutes Melting Point (℃) 80 123 121 119 98 108.3 Number average molecular weight 48,366 52,364 72,358 18,000 14,320 17,589 Weight average molecular weight 160,915 182,365 248,320 62,000 98,350 113,550 Biodegradability (%) 84 52 69 16 32 28

According to the present invention, in the synthesis of aliphatic / aromatic copolyesters, a low chain produced by using conventional polyfunctional monomers is obtained by synthesizing long-chain aliphatic / aromatic polydiols as a kind of chain extension and adding them to the reaction to obtain a product. It is possible to solve the problem of rapid increase of molecular weight polyester and gelation as well as to obtain aliphatic / aromatic copolyester of higher molecular weight than existing aliphatic / aromatic copolyester, so that it is easy to process at a wide working temperature. Easy resin can be obtained. In addition, the mechanical properties of the resulting aliphatic / aromatic copolyesters are superior to the aliphatic / aromatic copolyesters according to the prior art, and their biodegradability also has properties similar to those of conventional biodegradable aliphatic polyesters. It can lead to an increase in the use of copolyesters, which can lead to a reduction of environmental pollution by waste plastics.

Claims (19)

As a method for producing a biodegradable aliphatic / aromatic copolyester polymer, (i) High molecular weight aliphatic / aromatic polydiols having a molecular weight of 500 to 10,000 in which a chain is extended by reacting 3- (4-hydroxyphenyl) propionic acid (or a derivative thereof) with an aliphatic polydiol having a molecular weight of 200 to 1,000. Preparing a; (ii) reacting the aromatic dicarboxylic acid (or its acid anhydride) with an aliphatic (or cycloaliphatic) glycol to obtain a primary esterification and transesterification product; (iii) with the aliphatic (or cycloaliphatic) dicarboxylic acid (or acid anhydride thereof) in the presence of the primary reaction product of step (ii) and in the presence of the aliphatic / aromatic polydiol of step (i) Reacting an aliphatic (or cycloaliphatic) glycol to obtain a secondary esterification and transesterification product; And (iv) polycondensation reaction of the reaction product of step (iii). The method according to claim 1, wherein the aliphatic polydiol has a molecular weight in the range of 200 to 1000, and is a single component or a mixed component selected from polyethylene glycol, polypropylene glycol and polybutanediol, and 3- (4-hydroxyphenyl) propy. A method for producing an aliphatic / aromatic copolyester polymer, characterized in that the molar ratio of onyx acid (or a derivative thereof) is from 1: 1.0 to 1: 2.0. The process for preparing aliphatic / aromatic copolyester polymers according to claim 1, wherein in the preparation of aliphatic / aromatic polydiols, the reaction temperature is in the range from 160 to 180 ° C. and tin-based metal catalysts are used. The method of claim 1, wherein the molar ratio of aromatic dicarboxylic acid (or acid anhydride thereof) and aliphatic (including cyclic aliphatic) glycol is in the range of 1: 1.15 to 1: 2.0. . The method of claim 1, wherein the aromatic dicarboxylic acid (or acid anhydride thereof) is selected from the group consisting of terephthalic acid, phthalic acid, phthalic anhydride, isophthalic acid, 4-methylphthalic acid, 4-methyl phthalic anhydride, dimethyl terephthalate and dimethylphthalate. A method for producing an aliphatic / aromatic copolyester polymer, characterized in that one or a mixture of two or more. The method of claim 1, wherein the aliphatic (including cyclic aliphatic) glycol is ethylene glycol, diethyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentylglycol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,2-octanediol, 1,6-octanediol, 1,9-nonane A method for producing an aliphatic / aromatic copolyester polymer, characterized in that one or two or more mixtures selected from the group consisting of diols, 1,2-decanediol, 1,10-decanediol and decamethylene glycol. The process for preparing aliphatic / aromatic copolyester polymers according to claim 1, characterized in that the primary esterification and transesterification are carried out in the range of 180 to 220 ° C. The aliphatic (including cycloaliphatic) dicarboxylic acid (or acid anhydride) of claim 1, wherein the succinic acid, glutaric acid, adipic acid, pimeric acid, subberic acid, azelaic acid, sebacic acid, 1,9 -A process for producing an aliphatic / aromatic copolyester polymer characterized in that it is one or a mixture of two or more selected from the group consisting of nonanedicarboxylic acid, 1,10-decanedicarboxylic acid and acid anhydrides thereof. The process for preparing aliphatic / aromatic copolyester polymers according to claim 1, wherein the secondary esterification reaction and the transesterification reaction are carried out in the range of 150 to 180 ° C. The aliphatic / aromatic copolyester of claim 1 wherein aromatic dicarboxylic acid (or acid anhydride thereof) and aliphatic dicarboxylic acid (or acid anhydride thereof) are used in a molar ratio of 0.3: 0.7 to 0.7: 0.3. Process for preparing ester polymer. The aliphatic according to claim 1, characterized in that the content of aliphatic / aromatic polydiol present in the secondary esterification and transesterification ranges from 5 to 30 wt% of the theoretical amount of the aliphatic / aromatic copolyester polymer which is the final product. Process for the preparation of aromatic copolyester polymers. The method of claim 1, wherein the polycondensation reaction is carried out for 180 to 240 minutes under a vacuum degree of 0.005 to 2.0 torr in the temperature range of 220 to 260 ℃. The process for producing aliphatic / aromatic copolyester polymers according to claim 1, characterized in that a catalyst is additionally added at the beginning or end of the esterification, transesterification and polycondensation. The process of claim 13, wherein the catalyst is used in the range of 0.02 to 2.0% by weight based on the total reactant weight. The method according to claim 13, wherein the catalyst is one or a mixture of two or more selected from the group consisting of tetrabutyl titanate, calcium acetate, antimony trioxide, monobutyl tin oxide, zinc acetate, antimoniacetate, and tetrapropyl titanate. A process for preparing an aliphatic / aromatic copolyester polymer characterized by the above. The method of claim 1, wherein a stabilizer is added at the beginning or end of the esterification, transesterification and polycondensation reactions. The method of claim 16, wherein the stabilizer is used in the range of 0.02 to 2.0% by weight based on the total reactant weight. 17. The process of claim 16, wherein the stabilizer is selected from the group consisting of trimethylphosphate, phosphoric acid and triphenylphosphate. (delete)