KR20170077905A - Semi-continuous method of preparing biodegradable polyester resin - Google Patents

Abstract

(I) at least one dicarboxylic acid selected from the group consisting of an aliphatic dicarboxylic acid and an aromatic dicarboxylic acid; At least one diol in an aliphatic diol; And a step of introducing the catalyst into a first batch reactor to esterify the dicarboxylic acid and the diol, (ii) transferring the esterification reaction product obtained from step (i) to a second batch reactor, (Iii) transferring and storing the polycondensation product in a molten state obtained in the step (ii) to a buffer tank, and (iv) transferring the polycondensation reaction product and the chain extender in the buffer tank to a continuous- To provide a semi-continuous production method of the biodegradable polyester resin. The method for producing a biodegradable polyester resin of the present invention uses a semi-continuous production method in which a batch polymerization process and a continuous chain extension reaction process are used in combination, so that problems caused when each process is used alone can be solved have.

Description

[0001] The present invention relates to a semi-continuous method for preparing a biodegradable polyester resin,

The present invention relates to a semi-continuous method for producing a biodegradable polyester resin, and more particularly to a semi-continuous method for producing a biodegradable polyester resin using a batch polymerization process and a continuous chain extension reaction process together .

Due to its high functionality and durability, plastics are useful in real life. However, the conventional plastic has a problem such that the decomposition rate by microorganisms at the time of landfilling is low, and the noxious gas is released at the time of incineration, thereby causing environmental pollution, and development of biodegradable plastics has progressed.

Of these biodegradable plastics, polyester resins having biodegradability are attracting attention. Biodegradable polyester resin refers to a polymer that can be decomposed into water, carbon dioxide, or water and methane gas by microorganisms present in nature, such as bacteria, algae and fungi. Such a biodegradable polyester resin is proposed as a powerful solution for preventing environmental pollution caused by landfill or incineration.

Generally, a long residence time in a high-temperature reactor is required to obtain a polyester resin product having a high viscosity capable of satisfying commercial properties. At this time, as a result of the reversible reaction, the decomposition reaction is increased along with the increase of the viscosity, which adversely affects the physical properties.

As a method for obtaining a polyester resin having a high viscosity, conventionally, a polyester prepolymer having a low viscosity is produced through an esterification reaction and a polycondensation reaction using a batch process, and then the polyester prepolymer is pelletized and solidified and dried, A method has been used in which a high viscosity is obtained by reacting dried pellets in a separate reactor with a chain extender while remelting them. However, according to this method, a lot of energy is consumed in the solidification, drying and remelting process, and consequently, property deterioration may occur.

As a method for solving such a problem, Patent Document 1 (Korean Patent Laid-Open Publication No. 10-2012-0101387) discloses a continuous production method of a polyester mixture in which an esterification step, a condensation polymerization step and a chain extension step are continuously carried out .

According to the Patent Document 1, since the polyester polymer in the molten state after the polycondensation step can be made into a highly viscous state by reacting with the chain extender in a molten state without pelletizing and solidifying the molten polyester polymer, , Problems of high energy consumption and deterioration of physical properties in drying and remelting processes can be solved. However, in the case of the process for producing a biodegradable polyester resin using a continuous process, there has been a problem that it is difficult to carry out an operation such as a reactor cleaning when changing a production item.

Therefore, there is a need for a new biodegradable polyester resin production method capable of solving the problems of the batch process and the continuous process.

KR 1020120101387 A

The present invention relates to a semi-continuous process of biodegradable polyester resin capable of solving the problems according to each process by introducing a semi-continuous type manufacturing method using a batch type polymerization process and a continuous chain extension reaction process in combination And to provide a method for preparing a food.

Disclosure of the Invention In order to solve the above problems, the present invention provides a dicarboxylic acid composition comprising (i) at least one dicarboxylic acid selected from aliphatic dicarboxylic acid and aromatic dicarboxylic acid; At least one diol in an aliphatic diol; And a step of introducing the catalyst into a first batch reactor to esterify the dicarboxylic acid and the diol, (ii) transferring the esterification reaction product obtained from step (i) to a second batch reactor, (Iii) transferring and storing the polycondensation product in a molten state obtained in the step (ii) to a buffer tank, and (iv) transferring the polycondensation reaction product and the chain extender in the buffer tank to a continuous- To provide a semi-continuous production method of the biodegradable polyester resin.

After the completion of the esterification reaction in the step (i), the stabilizer is preferably added to the first batch reactor in a range of 0.01 to 0.5 mmol based on 1 mol of the dicarboxylic acid. The stabilizer is preferably selected from the group consisting of phosphorous acid, at least one phosphorus compound selected from the group consisting of phosphonous acid, trimethyl phosphite, triethyl phosphite, tripropyl phosphite, triphenyl phosphite, sodium phosphite and sodium hypophosphite.

The melt index (MI) of the polycondensation reaction product obtained from the step (ii) may be 30 to 100 g / 10 min.

The step (iii) is preferably carried out under a nitrogen blanket, and in the step (iii), the condensation polymerization product may be cooled to a temperature of 180 ° C to 200 ° C.

It is preferable that a stabilizer is added to the polycondensation reaction product between the step (iii) and the step (iv) in a range of 0.05 to 2.0 mmol based on 1 mol of the dicarboxylic acid. Thus, in the step (iv) The extension reaction can be carried out by introducing the stabilizer-introduced condensation polymerization product and the chain extender into the continuous reactor.

The step (iv) is preferably carried out at 190 to 200 ° C for 20 to 50 minutes. The continuous reactor used in the step (iv) is selected from the group consisting of an extruder, a list reactor and a static mixer It can be one.

The content of the chain extender is preferably 0.01 to 5 parts by weight based on 100 parts by weight of the polycondensation product.

According to the biodegradable polyester resin production method of the present invention, since the reaction product after the polycondensation reaction is not solidified, dried and remelted, energy consumption and physical property lowering due to the above processes do not occur. Therefore, the biodegradable polyester resin produced according to the present invention exhibits excellent chromaticity and acid value, and the mechanical properties of a final product such as a film made from the polyester resin or monosaccharide can be improved.

In addition, since the biodegradable polyester resin manufacturing method according to the present invention uses a semi-continuous manufacturing method using a batch process and a continuous process in combination, compared with the conventional continuous process alone, The ease of operation for the operation and the like can be ensured.

Fig. 1 schematically shows a semi-continuous production process of a biodegradable polyester resin according to an embodiment of the present invention.

The present invention relates to a semi-continuous method for producing a biodegradable polyester resin.

Referring to FIG. 1, a semi-continuous method for producing a biodegradable polyester resin according to the present invention is characterized in that (i) at least one dicarboxylic acid selected from among aliphatic dicarboxylic acid and aromatic dicarboxylic acid mountain; At least one diol in an aliphatic diol; And (ii) introducing the esterification reaction product obtained in the step (i) into a second batch reactor (2) into a first batch reactor (1) to thereby esterify the dicarboxylic acid and the diol; (Iii) transferring and storing the polycondensation product in a molten state obtained from the step (ii) to the buffer tank 3 and storing the product; and (iv) And feeding the condensation polymerization product and the chain extender into a continuous reactor (4, 5) to effect chain extension reaction.

Hereinafter, a semi-continuous production method of a biodegradable polyester resin according to an embodiment of the present invention will be described step by step with reference to the accompanying drawings.

(I) esterification step

In this step, a dicarboxylic acid, a diol and a catalyst are put into a first batch reactor (1) to esterify the dicarboxylic acid and the diol.

The dicarboxylic acid used in the present invention may be at least one of a substituted or unsubstituted C ₄ -C ₁₀ aliphatic dicarboxylic acid and a substituted or unsubstituted C ₈ -C ₂₀ aromatic dicarboxylic acid. And may include a carboxylic acid. The dicarboxylic acid may be selected from, for example, malonic acid, succinic acid, glutaric acid, 2-methylglutaric acid, 3-methylglutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, undecanedic acid, Aliphatic dicarboxylic acids including succinic acid, succinic acid, succinic acid, succinic acid, succinic acid, succinic acid, maleic acid, itaconic acid, or a combination thereof; And an aromatic dicarboxylic acid comprising terephthalic acid, isophthalic acid, 2,6-naphthoic acid, 1,5-naphthoic acid, or a combination thereof.

The diol may include at least one diol of a substituted or unsubstituted C ₂ -C ₁₀ aliphatic diol. The diol may be, for example, ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, 1,5-pentanediol, Ethyl-2-ethyl-1,3-hexanediol, 2,2-dimethyl-1,3-propanediol, -Isobutyl-1,3-propanediol, 2,2,4-trimethyl-1,6-hexanediol, or a combination thereof.

The content of the diol may be 1 to 2 moles relative to 1 mole of the dicarboxylic acid. The dicarboxylic acid and the diol may be reacted at a molar ratio of 1: 1 when the biodegradable polyester resin is reacted at a stoichiometric ratio during polymerization for semi-continuous production. That is, the amount of the diol to be used and the amount of the dicarboxylic acid to be used may be 1: 1 (mole ratio), but the amount of the diol to be used may be excessive relative to the amount of the dicarboxylic acid used to promote the reaction and increase the yield. have.

The catalyst serves to promote the esterification reaction and the condensation polymerization reaction, and the amount of the catalyst is preferably 0.1 to 0.4 mmol based on 1 mol of the dicarboxylic acid. If the content of the catalyst is within the above range, the polymerization reaction can be carried out with excellent reaction efficiency, and the degradation of physical properties such as chromaticity of the produced biodegradable polyester resin can be prevented.

The catalyst may be selected from the group consisting of titanium (Ti), tin (Sn), antimony (Sb), cerium (Ce), germanium (Ge), zinc (Zn), cobalt (Co), manganese And a metal compound containing at least one metal selected from the group consisting of Al, Mg, Ca, and Sr. The catalyst may be selected from, for example, calcium acetate, manganese acetate, magnesium acetate, zinc acetate, monobutyltin oxide, dibutyltin oxide, dibutyltin dibromide, monobutylhydroxy tin oxide, octyltin, tetrabutyltin, (2-ethylhexyl) titanate, tetra (2-ethylhexyl) titanate, tetraisopropyl titanate, tetra And may include at least one selected metal compound.

The esterification reaction may further include at least one branching agent selected from the group consisting of glycerol, pentaerythritol, and trimethylolpropane. The content of the branching agent may be 0.001 to 0.05 mol based on 1 mol of the dicarboxylic acid. When the content of the branching agent is within the above range, a polyester resin having a desired degree of polymerization can be obtained while preventing gelation of the polyester resin have.

After the esterification reaction is completed in the esterification step, a stabilizer may be added to the first batch reactor (1) in a range of 0.01 to 0.5 mmol based on 1 mol of the dicarboxylic acid. The stabilizer serves to reduce the activity of the catalyst, and not only prevents the reverse reaction or side reaction that may be caused by the catalyst, but also improves the high-temperature storage stability of the product obtained from the polycondensation step .

The stabilizer may include a phosphorus compound containing phosphorus (P), for example, phosphorous acid, phosphonous acid, trimethylphosphite, triethylphosphite, tripropylphosphite, triphenylphosphite, At least one phosphorus compound selected from the group consisting of sodium phosphite and sodium hypophosphite.

The esterification reaction may be carried out at 160 to 240 ° C for 60 to 300 minutes. The end point of the esterification reaction can be determined by measuring the amount of water or alcohol as a by-product in the reaction. For example, when 0.6 mol and 0.4 mol of adipic acid and dimethyl terephthalate are used as the dicarboxylic acid, respectively, and 1.3 mol of 1,4-butanediol is used as the diol, adipic acid and dimethyl terephthalate Assuming that all of the phthalate reacts with 1,4-butanediol, if a maximum of the by-productable water of 1.2 mol and 95% or more of the maximum by-productable methanol of 0.8 mol, i.e., 1.14 mol of water and 0.76 mol of methanol or more are produced, The esterification reaction can be terminated.

In order to increase the reaction rate by moving the chemical equilibrium in the esterification reaction, the by-produced water, the alcohol and / or the unreacted diol may be discharged outside the reaction system by evaporation or distillation.

An esterification reaction product (oligomer) having an ester bond is produced by such an esterification reaction.

(Ii) condensation polymerization step

In this step, the esterification reaction product (oligomer) is transferred to the second batch reactor (2) to carry out a condensation polymerization reaction.

The polycondensation reaction can be carried out at a pressure of 2 torr or less for 40 to 300 minutes at 220 to 260 ° C. By proceeding the condensation polymerization under vacuum in this way, a condensation polymerization product of high molecular weight can be obtained while removing unreacted raw materials (unreacted monomers and oligomers) and by-produced water / butanediol.

The melting point (MI) of the condensation polymerization product obtained from this step may be 30 to 100 g / 10 min. If the melt index is less than 30 g / 10 min, gelation may occur during the chain extension reaction, resulting in poor workability. If the melt index exceeds 100 g / 10 min, extension of the retention time, increase in reaction temperature, Additional measures may be required. In the present invention, the melt index indicates the weight (g) of the polymer to be forced through the extruded viscometer orifice (diameter 0.0825 inch) when applied to a load of 2160 g for 10 minutes at 190 占 폚 in the polymer and measured according to ASTM D1238.

(Iii)

This step is a step in which the polycondensation product in the molten state obtained from the polycondensation step is transferred to and stored in the buffer tank 3, and the polycondensation step using the batch type process and the chain extension step using the continuous type process are connected It is an intermediate step for.

The batch polymerization method means a method in which all reactants are initially added to a reactor, and the finished polymer is recovered as a final product after polymerization is completed. That is, in the esterification step of the present invention, all of the esterification reactants are initially charged into the first batch reactor (1), and the reaction product is recovered as the final product after the esterification reaction is completed. In the condensation polymerization step, Is initially charged into the second batch reactor (2) and the reaction product is recovered as a final product at the end of the condensation polymerization reaction.

Conventionally, the final product obtained from the polycondensation step is solidified in the form of pellets or the like, followed by drying, and the dried pellet is re-melted in the chain extension step to prepare a biodegradable polyester resin having a desired viscosity . However, according to such a conventional method, much energy is consumed for solidification, drying and re-melting of the pellets, and physical properties are also generated.

Accordingly, in the present invention, the molten reaction product obtained through the esterification step and the polycondensation step in a batch manner is conveyed to the continuous type reactors (4,5) for chain extension reaction through the buffer tank 3 without solidification .

Specifically, the buffer tank 3 is a space in which the condensation polymerization product discharged from the second batch type reactor 2 at a time is stored before being introduced into the continuous type reactors (4,5) for the chain extension reaction , The condensation polymerization reaction product in the buffer tank 3 is continuously supplied to the continuous type reactors (4,5). In order to facilitate this continuous production, the reaction product in the buffer tank 3 is introduced into the continuous reactor (4,5) before the next batch polymerization reaction in the second batch reactor 2 is completed .

The storage step of such a condensation polymerization product can be carried out under a nitrogen blanket, and in this case, deterioration of physical properties of the condensation polymerization product due to contact with oxygen and moisture in the atmosphere can be suppressed.

 In the storing step, the condensation polymerization product may be cooled to a temperature of 180 to 200 ° C. When the condensation polymerization reaction product is cooled to the temperature range, it is possible to maximize the effect of the stabilizer introduced into the condensation polymerization reaction product after being discharged from the buffer tank 3. Examples of the effect of the stabilizer include suppressing side reactions such as pyrolysis reaction, oxidation reaction and hydrolysis reaction in a post-process which may occur due to the residual catalyst present in the polycondensation reaction product, And improving the thermal stability of the product to ensure high-temperature storage stability.

The stabilizer may be further added to the condensation polymerization product between the storage step (iii) and the chain extension step (iv) to be described later, and a preferable amount of the stabilizer may be 0.05 to 2.0 mmol based on 1 mol of the dicarboxylic acid . Specifically, the condensation polymerization reaction product is discharged from the buffer tank 3 and then passed through a high-pressure piston pump 31, a gear pump 32 and a high-pressure piston pump 33 as shown in FIG. 1, The stabilizer may be introduced into the condensation polymerization product through the high pressure piston pump 31 located at the front end of the gear pump 32. [

(Iv) chain extension step

In this step, the condensation polymerization reaction product in the buffer tank 3 and the chain extender are fed into the continuous type reactors (4,5) to perform the chain extension reaction.

As described above, the condensation polymerization reaction product in the buffer tank 3 can be introduced into the continuous type reactors (4,5) through the addition of the stabilizer. Therefore, in the chain extension reaction according to the present invention, The introduced condensation polymerization product and the chain extender may be introduced into the continuous reactor (4). Specifically, as shown in FIG. 1, a chain extender may be introduced into the condensation polymerization reaction product through a high-pressure piston pump 33 located at a downstream end of the gear pump 32, have.

Also, since the chain extender can be reacted simultaneously with the condensation polymerization reaction product in the continuous reactor (4), the chain extender injection timing can be appropriately controlled depending on the case.

The content of the chain extender is preferably 0.01 to 5 parts by weight based on 100 parts by weight of the polycondensation product. However, when the content of the stabilizer is increased, the content of the chain extender can be increased accordingly. As the chain extender, a polyisocyanate compound may be used. Examples of the polyvalent isocyanate compound include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, 1,5-naphthylene diisocyanate, hexamethylene diisocyanate And triphenylmethane triisocyanate can be used.

The chain extension step is preferably performed at 190 to 200 ° C for 20 to 50 minutes. When the chain extension reaction is performed in the temperature and time ranges, a biodegradable polyester resin having a desired viscosity satisfying commercial properties is prepared It is preferable.

The continuous reactor used in this chain extension step may be any one selected from the group consisting of an extruder, a list reactor, and a static mixer.

As described above, in the present invention, by introducing a semi-continuous type production method that uses a batch type polymerization process and a continuous chain extension reaction process in combination, biodegradation without the solidification and remelting process as required in the conventional batch type process It is possible to remarkably reduce the energy consumption due to the solidification, drying and re-melting process, and to solve the problem of property deterioration such as chromaticity and acid value due to this.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these embodiments.

Example 1

≪ Esterification reaction step &

(117.06 mol) of 1,4-butanediol, 17.68 kg (120.98 mol) of adipic acid and 5.5 g (0.016 mol) of tetra n-butyl titanate were charged into the first batch reactor (1) After 4,300 ml of water is drained, the internal temperature is increased to 215 캜. As a result, an esterification reaction product, Bis Hydroxybutyl Adipate (BHBA), was obtained. Subsequently, 18.29 kg (202.95 mol) of 1,4-butanediol, 19.22 kg (98.97 mol) of dimethyl terephthalate, 55.5 g (0.60 mol) of glycerol as a branching agent, polymerization (0.016 mol) of tetra-n-butyl titanate as a catalyst was added thereto, and the temperature was raised while stirring to remove 8,000 ml of methanol, and then the internal temperature of the reactor was increased to 215 ° C. As a result, a final esterification reaction product was obtained.

Then, 3.0 g (0.037 mol) of phosphorous acid as a stabilizer was added to the esterification reaction product in the first batch reactor (1) and stirred for 10 minutes to prepare a reaction solution. Then, The reaction liquid was transferred to the second batch reactor (2).

<Concentration polymerization step>

The reaction liquid transferred to the second batch type reactor (2) is stirred with a double helical ribbon blade, and when the internal temperature reaches 220 캜, a reduced pressure is applied for 30 minutes to reach a pressure of 5 torr. Subsequently, while the reaction solution was stirred at a temperature of 225 ° C, the pressure in the second batch reactor (2) was reduced for 20 minutes to reach a final pressure of 2 torr. After the temperature was raised to 240 ° C, Lt; / RTI &gt; As a result, a condensation polymerization reaction product (hereinafter referred to as "Base-PBAT") was obtained.

Subsequently, the reduced pressure inside the second batch type reactor (2) was released, and the condensation polymerization reaction product was transferred to the buffer tank (high temperature storage tank) (3) by pressurization with nitrogen.

&Lt; Storage step and chain extension step >

The condensation polymerization reaction product transferred to the buffer tank 3 in a molten state is rapidly cooled to 190 DEG C and stored. The condensation polymerization product in the buffer tank 3 is then continuously fed through the gear pump 32 to the static mixer 2 before the next batch condensation reaction in the second batch reactor 2 is finished for continuous production, (SMX and Helical type combination) (4,5) at a rate of 6.6 kg / hr.

At this time, phosphorus acid as a stabilizer is introduced into the condensation polymerization reaction product at a rate of 1 g / hr through a high-pressure piston pump 31 located at the front end of the gear pump 32, Hexamethylene diisocyanate (HDI), which is a chain extender, was fed into the reaction product through a high-pressure piston pump 33 located at the rear end of the gear pump 32 at a rate of 60 g / hr, and then subjected to a condensation polymerization reaction The product is fed to the static mixer (4, 5).

The static mixer consisted of a pre-mixer 4 and a main mixer 5, and the condensation polymerization product and the chain extender were premixed at 190 ° C. for 1.5 minutes in a pre-mixer 4, ) At &lt; RTI ID = 0.0 &gt; 195 C &lt; / RTI &gt; for 25 minutes. As a result, a polybutylene adipate-co-terephthalate (PBAT) resin (hereinafter referred to as "Final-PBAT") was finally obtained.

Then, Final-PBAT discharged from the static mixer was cooled in water and then pelletized with a strand cutter to prepare a final-PBAT chip.

Example 2

&Lt; Esterification reaction step &

20.93 mol (230.0.2 mol) of 1,4-butanediol, 23.62 kg (200.17 mol) of succinic acid and 20 g (0.22 mol) of glycerol as a branching agent were charged into the first batch reactor (1) After draining, increase the internal temperature to 205 ° C. Subsequently, 16 g (0.047 mol) of tetra-n-butyl titanate as a polymerization catalyst and 6.0 g (0.073 mol) of phosphorous acid as a stabilizer were added to the first batch reactor 1 and stirred for 10 minutes to prepare a reaction liquid Respectively. Then, the reaction liquid in the first batch reactor (1) was transferred to the second batch reactor (2).

<Concentration polymerization step>

The polycondensation step of the reaction solution transferred to the second batch type reactor 2 proceeds in the same manner as in the first embodiment. As a result, a condensation polymerization reaction product (hereinafter referred to as "Base-PBS") was obtained and transferred to the buffer tank 3 in the same manner as in Example 1.

&Lt; Storage step and chain extension step >

The "storage step and chain extension step" of the condensation polymerization reaction product transferred to the buffer tank 3 proceeds in the same manner as in the first embodiment. As a result, finally, a poly (butylene succinate) (PBS) resin (hereinafter referred to as "Final-PBS") and a Final-PBS chip were prepared.

Comparative Example 1

&Lt; Esterification reaction step &

A reaction solution was prepared in the first batch reactor (1) in the same manner as in the "esterification reaction step" of Example 1, and the reaction solution was transferred to the second batch reactor (2).

<Concentration polymerization step>

The polycondensation step of the reaction liquid transferred to the second batch type reactor (2) was carried out in the same manner as in Example 1, except that the temperature was raised to 240 캜 and after 4 hours elapsed, The temperature was raised, and the condensation polymerization reaction was terminated after 5 hours. As a result, a condensation polymerization reaction product (hereinafter referred to as "Base-PBAT") was obtained.

After completion of the condensation polymerization, Base-PBAT discharged from the second batch reactor (2) through nitrogen pressurization was cooled in water and then pelletized with a strand cutter to prepare a Base-PBAT chip .

The Base-PBAT chip was dried to a water content of 100 ppm or less through a dehumidifying dryer (Hyundai Electric Machinery Co., Ltd., HDD-050).

<Chain extension step>

10 kg of the Base-PBAT chip, 0.01 kg of hexamethylene diisocyanate (HDI) and 0.002 kg of phosphorous acid, which had undergone the drying process, were mixed in a super mixer for 1 minute and then melt kneaded by a twin- screw extruder (L / D: 36/1, 24.2 mm) at 150 캜, followed by cooling in water, and then pelletizing with a strand cutter to prepare a chip. As a result, Final-PBAT chips were finally obtained.

Comparative Example 2

&Lt; Esterification reaction step &

A reaction solution was prepared in the first batch reactor (1) in the same manner as in the "esterification reaction step" of Example 2, and the reaction solution was transferred to the second batch reactor (2).

<Concentration polymerization step>

The polycondensation step of the reaction liquid transferred to the second batch type reactor (2) proceeds in the same manner as in Comparative Example 1. As a result, a condensation polymerization reaction product (hereinafter referred to as "Base-PBS") was obtained.

After completion of the condensation polymerization, Base-PBAT discharged from the second batch reactor (2) through nitrogen pressurization was cooled in water and then pelletized with a strand cutter to prepare a Base-PBAT chip .

The Base-PBS chip was dried at a moisture content of 100 ppm or less through a dehumidifying dryer (Hyundai Electric Machinery Co., Ltd., HDD-050).

<Chain extension step>

10 kg of the Base-PBS chip subjected to the drying process, 0.025 kg of hexamethylene diisocyanate (HDI) and 0.002 kg of phosphorous acid were mixed in a super mixer for 1 minute, and the mixture was extruded by a twin screw extruder (L / D: 36/1, 24.2 mm) at 150 캜, followed by cooling in water, and then pelletizing with a strand cutter to prepare a chip. As a result, Final-PBS chips were finally obtained.

Assessment Methods

(MI) and chromaticity values of the Base-PBAT chip and the Final-PBAT chip prepared according to Example 1 and Comparative Example 1, the Base-PBS chip and the Final-PBS chip prepared according to Example 2 and Comparative Example 2, And acid value were measured by the following methods, and the results are shown in Table 1 below. The Base-PBAT chip of Example 1 was prepared by pelletizing Base-PBAT, which is a condensation polymerization product, with a strand cutter after being cooled in water, and the Base-PBS chip of Example 2 was prepared by condensation polymerization The reaction product, Base-PBS, was prepared by pelletizing in the same manner. Each of the above chips was dried to a moisture of 100 ppm or less through a dehumidifying dryer (Hyundai Electric Machinery Co., Ltd., HDD-050).

In the following Table 1, the bases of Example 1 and Comparative Example 1 represent the Base-PBAT chip and the Final represents the Final-PBAT chip. In Example 2 and Comparative Example 2, Base represents the Base-PBS chip, Final-PBS chip.

1. Melt Index (MI)

According to ASTM D1238, the weight (g) of the polymer to be forced through the extruded viscometer orifice (diameter 0.0825 inches) when applied to a load of 2160 g for 10 minutes at 190 캜 was measured on the polymer, Respectively.

2. Chromaticity measurement

L *, a * and b * were measured in a CIE-L * a * b * (CIE 1976) colorimetric system using a Konica Minolta colorimeter. The "L *" value, the "a *" value and the "b *" value are indexes of color tones displayed in the CIE-L * a * b * (CIE 1976) color space. The "L *" value indicates the brightness, and the larger the value, the brighter. The "a *" value indicates the degree of redness, and the higher the value, the higher the degree of redness. The "b *" value indicates the degree of yellow color, and the higher the value, the higher the degree of yellowness. At this time, the higher the L * value, the brighter the color, and the lower the b * value, the closer the color to white.

3. Acid value measurement

Approximately 0.5 g of the Base-PBAT chip, the Final-PBAT chip, the Base-PBS chip and the Final-PBS chip was dissolved in 30 ml of chloroform at 25 ^° C., and then 20 ml of ethyl alcohol was further added to prepare a solution , And 0.1N KOH ethyl alcohol solution to measure the acid value of each resin.

4. Crystallization temperature (Tc)

The temperature was measured at a heating rate of 10 캜 / min using a differential scanning calorimeter (DSC) (TA Instrument, Q2000).

Example 1 Example 2 Comparative Example 1 Comparative Example 2 MI
(g / 10 min) Base 60 62 5.0 4.5 Final 3.5 3.0 2.7 2.8 Chromaticity
(L * / a * / b *) Base 83.1 / 12.8 / 16.4 87.3 / -0.9 / 1.8 79.8 / 5.1 / 14.2 82.4 / -1.2 / 3.0 Final 88.9 / -3.4 / 7.4 88.0 / -1.0 / 3.2 84.8 / -1.1 / 13.2 85.4 / -1.8 / 3.5 Acid value
(mgKOH / g) Base 0.7 1.5 1.12 2.7 Final 0.9 2.2 1.26 3.1 Tc (占 폚) Final 41 78 88 90

The Final-PBAT chip prepared according to Example 1 was superior in color and acid value to the Final-PBAT chip prepared according to Comparative Example 1, and the Final-PBS chip prepared according to Example 2 was superior to the Final- It can be confirmed that the chromaticity and acid value are superior to the Final-PBS chip prepared according to Comparative Example 2. In addition, the biodegradable polyester resin produced according to Examples 1 and 2 exhibits a lower crystallization temperature (Tc) than the biodegradable polyester resin produced according to Comparative Examples 1 and 2. In this case, slow crystallization (MD) and lateral (TD) physical properties of the film can be improved.

5. Evaluation of film properties

Each of the Final-PBAT chips prepared in Example 1 and Comparative Example 1 was fed into a uniaxial blown film extruder (Dairen Machine, L / D: 28: 1, die diameter: 45 mm, barrel temperature: . As a result, a film having a thickness of 30 mu m was obtained.

The tensile strength in the longitudinal direction (MD) and the transverse direction (TD) of each film was measured using a universal tensile tester (Instron, UTM-4484) by the method of ASTM D-638, Elmendorf tear strength was measured using a tear tester (Thwing-Albert Instrument Co., ProTear ^TM ) by the method of ASTM D-1922.

Tensile strength (kgf / cm2) Elmendorf (gf / 탆) MD TD MD Example 1 473 601 3.85 Comparative Example 1 417 529 0.90

As shown in Table 2, it was confirmed that the film prepared using the Final-PBAT of Example 1 exhibited a higher tensile strength and tear strength than the film produced using the Final-PBAT of Comparative Example 1 have.

6. Monosan property evaluation

The final-PBS chips prepared according to Example 2 and Comparative Example 2 were each made of monosaccharide using a melt spinning apparatus (J-S, JSM-65). At this time, the stretching ratio was set to 6.8 times. Twenty specimens were produced from the monosarpha obtained in this manner, and the diameter of each specimen was 0.404 mm.

The tensile strength (kgf) of each of the mono-sheets was measured according to the method of ASTM D-2256, and the tensile strength and elongation were measured using a universal tensile tester (Instron, UTM-4484) by the method of ASTM D-638. In this case, the tensile load represents a maximum load before the mono yarn is broken in a longitudinal direction, and does not compensate for the thickness.

The tensile load, the tensile strength and the elongation shown in the following Table 3 were obtained by averaging the measured values of the 20 mono-sided specimens. The gap between the grips was 400 mm, the test speed was 300 mm / min .

In the following Table 3, "difference" represents a value obtained by subtracting the length of the mono yarn that has been minimally stretched from the length of the mono yarn maximally stretched at the time of breaking, among the twenty mono yarns.

Tensile load (kgf) Tensile strength (kgf / cm2) Elongation (%) Difference (mm) Example 2 6.35 4,960 26 Δ13 Comparative Example 2 5.80 4,500 28 Δ30

As shown in Table 3, it was confirmed that the mono yarn prepared using the Final-PBS chip of Example 2 exhibited a higher tensile load and tensile strength than the mono yarn prepared using the Final-PBS of Comparative Example 2 And it can be confirmed that it exhibits a low elongation. In addition, in the case of monosaccharide produced using the Final-PBS chip of Example 2, the "difference" value was small, and it was found that the degree of elongation before fracture was uniform.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Should be construed as being included in the scope of the present invention.

1: first batch reactor 2: second batch reactor
3: buffer tank 32, 33: high pressure piston pump
32: Gear pump 4: Pre-mixer
5: main mixer
PI: Pressure Indicator
TI: Temperature Indicator

Claims (11)

(I) at least one dicarboxylic acid selected from aliphatic dicarboxylic acids and aromatic dicarboxylic acids; At least one diol in an aliphatic diol; And a catalyst in a first batch reactor to esterify the dicarboxylic acid and the diol,
(Ii) transferring the esterification reaction product obtained from the step (i) to a second batch reactor to carry out a condensation polymerization reaction,
(Iii) transferring and storing the polycondensation product in the molten state obtained in the step (ii) to a buffer tank, and
(Iv) feeding a condensation polymerization reaction product and a chain extender in the buffer tank to a continuous reactor to effect a chain extension reaction, thereby producing a semi-continuous preparation of a biodegradable polyester resin. The method according to claim 1,
Wherein a stabilizer is added to the first batch reactor in an amount of 0.01 to 0.5 mmol based on 1 mol of the dicarboxylic acid after completion of the esterification reaction in the step (i) Method of making a formula. 3. The method of claim 2,
The stabilizer is at least one member selected from the group consisting of phosphorous acid, phosphonous acid, trimethyl phosphite, triethyl phosphite, tripropyl phosphite, triphenyl phosphite, sodium phosphite and sodium hypophosphite A method for semi-continuous production of a biodegradable polyester resin characterized by comprising a compound. The method according to claim 1,
Wherein the polycondensation reaction product obtained from the step (ii) has a melt index (MI) of 30 to 100 g / 10 min. The method according to claim 1,
Wherein the step (iii) is carried out under a nitrogen blanket. The method according to claim 1,
Wherein the polycondensation reaction product is cooled to a temperature of 180 ° C to 200 ° C in the step (iii). The method according to claim 1,
Wherein a stabilizer is added to the polycondensation reaction product in a range of 0.05 to 2.0 mmol based on 1 mol of the dicarboxylic acid between the step (iii) and the step (iv) Gt; 8. The method of claim 7,
In the step (iv), the chain extension reaction is performed by continuously introducing the stabilization agent-introduced condensation polymerization product and the chain extender into the continuous reactor. The semi-continuous production method of the biodegradable polyester resin . The method according to claim 1,
Wherein the step (iv) is performed at 190 to 200 ° C for 20 to 50 minutes. The method according to claim 1,
Wherein the continuous reactor is any one selected from the group consisting of an extruder, a list reactor, and a static mixer. The method according to claim 1,
Wherein the content of the chain extender is 0.01 to 5 parts by weight based on 100 parts by weight of the polycondensation product.

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