KR20160047220A - Method for preparing poly(butylene carbonate-co-terephthalate) resin - Google Patents

Abstract

The present invention relates to a preparation method of poly(butylene carbonate-co-terephthalate) resin. According to the preparation method of the present invention, poly(butylene-co-terephthalate) resin can be manufactured using terephthalic acid as a monomer. Also, as the amount of ester residue existing in resin increases, melting point and glass transition temperature of the poly(butylene carbonate-co-terephthalate) resin increase. By adjusting molar ratio of the ester residue, the preparation method of the present invention can adjust physical properties of the resin to have desired properties. The preparation method of poly(butylene-co-terephthalate) resin comprises the steps of: a) performing an esterification reaction of terephthalic acid and 1,4-butanediol; b) performing a transesterification reaction of dimethyl carbonate and 1,4-butanediol; and c) performing a polycondensation reaction by mixing the reaction products obtained from step a) and reaction products obtained from step b).

Description

[0001] The present invention relates to a method for preparing poly (butylene carbonate-co-terephthalate) resin,

The present invention relates to a method for producing a poly (butylene carbonate-co-terephthalate) resin. More particularly, the present invention relates to a method for producing a poly (butylene carbonate-co-terephthalate) resin which can obtain a resin exhibiting a high melting point and a glass transition temperature using terephthalic acid as a dicarboxylic acid monomer.

Aliphatic polycarbonates containing aromatic ester moieties are environmentally friendly, biodegradable polymers, and have recently become highly useful.

As a conventional method for producing an aliphatic polycarbonate containing an aromatic ester moiety, there are a method of alternately copolymerizing with an epoxide using carbon dioxide as a monomer, a method of producing a cyclic compound by ring-opening polymerization, a method of producing a cyclic carbonate by reacting dimethyl carbonate or diethyl carbonate A condensation reaction of a diol, and the like are known.

Korean Patent No. 1326916 discloses a method for producing an aliphatic polycarbonate copolymer containing an aromatic ester moiety by a condensation reaction using a base catalyst using 1,4-butanediol, dimethyl carbonate and dimethyl terephthalic acid.

However, dimethyl terephthalic acid, which is used as a monomer in the above method, is expensive as compared with terephthalic acid, which causes a rise in production unit cost, and the method is disadvantageous in that it can not be applied to terephthalic acid monomers. This is because when the acid terephthalic acid is added together with the base catalyst, the activity of the catalyst as a catalyst is lost due to the base catalyst being bonded with terephthalic acid, and the polymerization can not proceed. In order to participate in the reaction, terephthalic acid is required to have a reaction temperature of 250 ° C or higher. At this reaction temperature, the other monomer, dimethyl carbonate, is volatilized.

In order to solve the above problems, the present invention provides a method for producing a poly (butylene carbonate-co-terephthalate) resin using terephthalic acid as a dicarboxylic acid monomer.

To achieve these and other advantages and in accordance with the purpose of the present invention,

a) performing an esterification reaction on terephthalic acid represented by the following formula (2) and 1,4-butanediol represented by the following formula (4);

b) carrying out a trans esterification reaction on dimethyl carbonate of formula (3) and 1,4-butanediol of formula (4); And

c) mixing the reaction product of the a) esterification reaction and the reaction product of the b) transesterification reaction to perform a polycondensation reaction.

There is provided a process for preparing a poly (butylene carbonate-co-terephthalate) resin of formula 1:

[Chemical Formula 1]

(2)

(3)

[Chemical Formula 4]

In Formula 1,

x and y are the number of moles of each repeating unit.

According to the production method of the present invention, poly (butylene carbonate-co-terephthalate) resin can be efficiently produced using terephthalic acid. Therefore, by using terephthalic acid which is inexpensive and easy to obtain instead of dimethyl terephthalic acid, the manufacturing cost can be reduced and the efficiency of the process can be increased.

Further, it is possible to produce a poly (butylene carbonate-co-terephthalate) resin in which the proportion of ester residues in the resin is more than 50 mol%, which is difficult to produce in the conventional method, and as the ratio of the ester residue increases, It is possible to easily adjust the physical properties of the resin by controlling the molar ratio of the ester residue to the melting point and the glass transition temperature of the resin.

1 is a graph showing a ¹ H-NMR measurement of a poly (butylene carbonate-co-terephthalate) resin according to Example 1 of the present invention.
2 is a graph showing the ¹ H-NMR measurement of the poly (butylene carbonate-co-terephthalate) resin according to Example 2 of the present invention.

Hereinafter, a method for producing the poly (butylene carbonate-co-terephthalate) resin of the present invention will be described in more detail.

The method for producing the poly (butylene carbonate-co-terephthalate) resin of the present invention comprises:

a) performing an esterification reaction on terephthalic acid represented by the following formula (2) and 1,4-butanediol represented by the following formula (4);

b) carrying out a trans esterification reaction on dimethyl carbonate of formula (3) and 1,4-butanediol of formula (4); And

c) mixing the reaction product of the a) esterification reaction and the reaction product of the b) transesterification reaction to perform a polycondensation reaction;

[Chemical Formula 1]

(2)

(3)

[Chemical Formula 4]

In Formula 1,

x and y are the number of moles of each repeating unit.

According to the method for producing the poly (butylene carbonate-co-terephthalate) resin of the present invention, in the production of the poly (butylene carbonate-co-terephthalate) resin, terephthalic acid, dimethyl carbonate and 1,4- Lt; / RTI >

In a conventional method, a condensation reaction of a mixture of 1,4-butanediol, dimethyl carbonate and dimethyl terephthalic acid is carried out under a base catalyst, and a condensation reaction of a mixture of 1,4-butanediol, dimethyl carbonate and dimethyl terephthalic acid, (Butylenecarbonate-co-terephthalate) resin is known as a method for producing a poly (butylene carbonate-co-terephthalate) resin.

However, the amount of dimethyl terephthalic acid used as the dicarboxylic acid monomer in the above method is higher than that of terephthalic acid, which causes an increase in production cost. When terephthalic acid is used instead of dimethyl terephthalic acid according to the above method, the poly (butylene carbonate- Terephthalate) resin can not be obtained. Therefore, there is a need to develop a technique for replacing dimethyl terephthalic acid, which is expensive in cost, in production of poly (butylene carbonate-co-terephthalate) resin with terephthalic acid.

On the other hand, terephthalic acid has a higher reaction temperature than dimethyl terephthalic acid, so that there is a problem in setting the reaction temperature during the reaction with dimethyl carbonate, which is another monomer, and the reaction between dimethyl terephthalic acid and diol, and the reaction between dimethyl carbonate and diol, The reaction between terephthalic acid and diol is an esterification reaction in which water is produced. When the reaction is carried out simultaneously in a reactor, another problem arises that water and methanol are produced at the same time. In addition, when the base catalyst used in the reaction is in contact with acidic terephthalic acid in one reactor, the base and the acid are met, which causes various problems such as the loss of activity of the base catalyst.

The present inventors have found that the use of terephthalic acid which is not dimethyl terephthalic acid enables the transesterification reaction and the esterification reaction to be carried out independently and then the reaction products are mixed and polycondensed in one reactor to produce a polymer, Butylene carbonate-co-terephthalate) resin can be produced.

According to the present invention, it is possible to produce a poly (butylene carbonate-co-terephthalate) resin having a molar ratio of ester moieties of more than 50 mol%, which is difficult to produce in the conventional method, - co-terephthalate) resin, the melting point and the glass transition temperature increased with increasing molar ratio of ester moieties in the resin.

Hereinafter, a method for producing a poly (butylene carbonate-co-terephthalate) resin according to a specific embodiment of the present invention will be described in detail.

According to a method for producing a poly (butylene carbonate-co-terephthalate) resin of the present invention, there is provided a process for producing a poly (butylene carbonate-co-terephthalate) resin comprising the steps of: a) performing an esterification reaction on terephthalic acid represented by the following general formula 2 and 1,4- ) Performing a transesterification reaction on the dimethyl carbonate of the formula (3) and the 1,4-butanediol of the formula (4) are carried out in separate reactors, respectively.

In this case, the a) esterification reaction and b) transesterification reaction are not necessarily performed sequentially in time, but are performed in separate physically separated reactors.

(2)

(3)

[Chemical Formula 4]

First, in the first reactor, the esterification reaction of terephthalic acid and 1,4-butanediol is carried out. The reaction temperature may range from about 210 to about 280 캜, preferably from about 220 to about 260 캜. If the reaction temperature is too low, terephthalic acid does not dissolve and reaction does not occur. If the reaction temperature is too high, 1,4-butanediol having a boiling point of about 235 ° C may not be able to participate in the reaction and may be evaporated, or the deformation rate may be increased to tetrahydrofuran as a by- From this point of view, the temperature range is preferable.

Water and tetrahydrofuran are produced as by-products of the esterification reaction, and the reaction can proceed while distilling off water and some tetrahydrofuran at normal pressure.

In the esterification reaction of terephthalic acid with 1,4-butanediol, the catalyst may be omitted. If a base catalyst is used, the base catalyst reacts with terephthalic acid in an acid-base reaction, and the catalytic activity is lost, so that the esterification reaction itself does not occur. Further, if an antimony (Sb) catalyst or a titanium (Ti) catalyst, which is conventionally known as a polymerization catalyst such as polyethylene terephthalate, is used, the reaction rate is accelerated but the reaction products are combined to perform a polycondensation reaction It is preferable not to use a catalyst because it may hinder the polymerization of halos.

The total amount of terephthalic acid and 1,4-butanediol charged into the esterification reaction is based on terephthalic acid. The molar ratio of the ester moiety of the poly (butylene carbonate-co-terephthalate) resin to be produced, 1 " y / (x + y).

The mole fraction (y / (x + y)) of y is not particularly limited, and can be controlled depending on the use and physical properties of the required resin. On the other hand, as the ratio of the ester residue increases, the melting point and the glass transition temperature of the poly (butylene carbonate-co-terephthalate) resin increase, and thus the resin having the necessary physical properties is obtained by controlling the molar ratio of the ester residue can do. According to one embodiment of the present invention, the molar fraction y (y / (x + y)) may be more than 0 mol% to less than 100 mol%, or more than 50 mol% to less than 100 mol%.

Also, according to one embodiment of the present invention, terephthalic acid and 1,4-butanediol can be used in an excess amount of 1,4-butanediol. For example, the molar ratio of terephthalic acid to 1,4-butanediol may be from about 1: 1.1 to about 1: 4.0.

When the esterification reaction is carried out using excess 1,4-butanediol as described above, an oligomer having a structure represented by the following general formula (5) in which most or all of the terminal groups are substituted with hydroxy groups can be produced in the esterification reaction product .

[Chemical Formula 5]

In Formula 5, n is the number of moles of the repeating unit, and may be 2 to 10.

According to the production process of the present invention, the oligomer compound having the structure of Formula 5 is separately prepared by the esterification reaction, and the oligomer compound and the reaction product of the transesterification reaction described later are mixed to perform the polycondensation reaction The problem that the activity of the base catalyst is lowered due to the terminal group of terephthalic acid can be prevented.

Next, a transesterification reaction of 1,4-butanediol and dimethyl carbonate is carried out in a separate second reactor. The reaction temperature may range from about 80 to about 150 캜, preferably from about 80 to about 130 캜. If the reaction temperature is too low, the transesterification reaction does not occur, If it is too high, dimethyl carbonate having a boiling point of about 90 ° C may not evaporate and evaporate, and from this viewpoint, the above temperature range is preferable.

Methanol is produced as a by-product of the transesterification reaction, and the reaction can proceed while distilling off methanol and some dimethyl carbonate at normal pressure.

The transesterification reaction of 1,4-butanediol and dimethyl carbonate can be carried out under a base catalyst.

As the base catalyst, at least one selected from the group consisting of the following formulas (7a) to (7d) can be used. In addition, the amount to be used may be about 0.1 to about 1 mol% based on 100 mol% of 1,4-butanediol charged in the transesterification reaction.

[Formula 7a]

MOR

[Formula 7b]

MOH

[Formula 7c]

MH

[Formula 7d]

[R ₄ N] ⁺ [OH] ^-

In the above formulas (7a) to (7d)

M is an alkali metal, and R is a straight or branched alkyl group having 1 to 10 carbon atoms.

The R may preferably be one selected from the group consisting of methyl, ethyl, propyl, primary butyl, and tertiary butyl.

The total amount of the dimethyl carbonate and 1,4-butanediol charged into the transesterification reaction is based on 1,4-butanediol, and the molar amount of the ester moiety of the poly (butylene carbonate-co-terephthalate) , That is, y / (x + y) in the above formula (1).

Also, according to one embodiment of the present invention, dimethyl carbonate and 1,4-butanediol can be used so that dimethyl carbonate is excessive. For example, the molar ratio of dimethyl carbonate to 1,4-butanediol may be about 1.1: 1 to about 4.0: 1.

When the transesterification reaction is carried out using an excessive amount of dimethyl carbonate as described above, a compound having a structure represented by the following formula (6) in which most or all of the terminal groups are substituted with a methoxy group can be produced in the transesterification reaction product .

[Chemical Formula 6]

The poly (butylene carbonate-co-terephthalate) resin represented by the following formula (1) can be obtained by carrying out the polycondensation reaction by mixing the reaction products of the transesterification reaction and the esterification reaction, .

[Chemical Formula 1]

In Formula 1,

x and y are the number of moles of each repeating unit.

According to one embodiment of the present invention, the reaction product is mixed at a temperature of about 190 ° C or higher, for example, about 190 ° C to about 230 ° C, to a temperature of about 210 to about 290 ° C, more preferably about 230 to about 260 ° C The polycondensation reaction can be carried out at a temperature of from about 760 to about 0.3 mm Hg at atmospheric pressure and reduced pressure. If the reaction temperature is too low, the reaction products harden and the reaction does not occur. If the reaction temperature is too high, the polymerization may not occur and the reactants may be evaporated.

Since the reaction proceeds rapidly as soon as the two reaction products are mixed, methanol, which is a reaction byproduct produced first, can be removed by distillation at atmospheric pressure, and then the reaction can be performed by gradually reducing the pressure. During the reaction, the melt viscosity of the polymer produced by the polycondensation reaction is gradually increased. After completion of the reaction, the base catalyst may be neutralized with phthaloyl chloride or the like.

In the polycondensation reaction, in order to induce the substance to be distilled and depressurized to be removed in the polycondensation reaction to become methanol, a reaction product of a methoxydar group derived from the reaction product of the transesterification reaction before the polycondensation reaction and a reaction product of the esterification reaction And the molar ratio of the resulting hydroxy end groups is from about 0.1: 1 to about 2.0: 1.

In the polycondensation reaction, the reaction product of the transesterification reaction of the formula (6) is an aliphatic oligomer, which has a low boiling point and is partially lost during the condensation reaction. Therefore, the ratio of x of the target poly (butylene carbonate-co-terephthalate) It is preferable to add about 1.1 to 1.5 times as much as the above.

By the polycondensation reaction, the poly (butylene carbonate-co-terephthalate) resin of Formula 1 can be obtained.

In the polycondensation reaction, the ratio of the reaction product of a) the esterification reaction and the reaction product of b) the transesterification reaction, the reaction temperature and the reaction time are changed so that the poly (butylene carbonate- -Terephthalate) resin, the molar ratio of the ester moiety, that is, the molar ratio (y / (x + y)) of y can be adjusted.

The poly (butylene carbonate-co-terephthalate) resin obtained according to the production method of the present invention increases the melting point and the glass transition temperature as the molar ratio of y increases, It is possible to easily control the physical properties of the resin. According to one embodiment of the present invention, the molar fraction y (y / (x + y)) may be more than 0 mol% to less than 100 mol%, or more than 50 mol% to less than 100 mol%.

The poly (butylene carbonate-co-terephthalate) resin obtained according to the process of the present invention has a weight average molecular weight of about 20,000 to about 200,000 g / mol, or about 20,000 to about 100,000 g / mol .

The poly (butylene carbonate-co-terephthalate) resin obtained according to the preparation method of the present invention has a melting point (Tm) of about 40 캜 or higher, for example about 40 to about 250 캜, or about 100 to 210 캜 And a resin having desired physical properties can be produced according to the molar ratio of the ester residue.

More specifically, for example, when the molar ratio of the ester residue is 1 mole%, the melting point (Tm) is about 48 ° C and the glass transition temperature (Tg) is about -32 ° C. When the molar ratio of the ester residue is about 40 mol%, the melting point (Tm) is about 130 캜, the glass transition temperature (Tg) is about -2 캜, and the molar ratio of the ester moiety When the ratio exceeds 50 mol%, it shows a high melting point (Tm) of about 150 to about 250 ° C.

Hereinafter, the present invention will be described in more detail with reference to examples according to the present invention. It is to be understood, however, that these embodiments are merely illustrative of the invention and are not intended to limit the scope of the invention.

< Example >

Poly (butylene Carbonate -nose- Terephthalate )

Example  One

<Esterification reaction>

Terephthalic acid (70 g, 421 mmol) and 1,4-butanediol (114 g, 1264 mmol) were added to the first reactor and stirred in a slurry state, and the inside of the reactor was replaced with nitrogen for 30 minutes. After the stirrer and the cooling condenser were connected to the reactor, the temperature of the reactor was gradually raised to 260 ° C, and the esterification reaction was performed for a total of 7 hours. At this time, considering the amount of tetrahydrofuran produced by the side reaction of 1,4-butanediol at 200 ° C or more, the amount of 1,4-butanediol was 3 times or more.

Water and tetrahydrofuran generated during the esterification reaction were distilled off at normal pressure and the reaction was allowed to proceed, and the reaction was terminated at the end of the spill.

&Lt; Transesterification reaction >

To the second reactor were added 1,4-butanediol (38 g, 421 mmol), NaOMe (45 mg, 0.1 mol% based on the total resin, dissolved and dissolved in methanol), base catalyst and dimethyl carbonate (114 g, 1263 mmole) And the inside of the reactor was replaced with nitrogen for 30 minutes. After the stirrer and the cooling condenser were connected to the reactor, the temperature of the reactor was gradually increased from 90 ° C to 120 ° C for 2 hours to perform the transesterification reaction. At this time, considering the amount of the partially lost dimethyl carbonate in the reaction, dimethyl carbonate was added in excess of 3 times as much as 1,4-butanediol.

Methanol produced during the reaction was distilled off at normal pressure, the temperature was raised to 130 ° C, and the remaining dimethyl carbonate was completely removed and the reaction was terminated.

<Polycondensation reaction>

The temperature of the reaction product of the second reactor was lowered to 210 DEG C, and the two reactants were mixed. As soon as the two reactants were mixed, the reaction proceeded rapidly, and the methanol produced first was distilled off at normal pressure for 30 minutes. After confirming that no more effluent was coming out, the cooling condenser connected to the reactor was replaced with a vacuum system. The reaction was continued at 210 ° C for 2 hours under a reduced pressure of 570 mmHg to 0.3 mmHg while the pressure was reduced to 0.3 mmHg. The temperature of the reactor was increased from 210 ° C to 240 ° C and methanol was removed for 4 hours And a polycondensation reaction was carried out. During the course of the reaction, the melt viscosity of the reactant gradually increased, confirming that the torque value of the stirrer was 20 or more, and the reaction was terminated.

After the completion of the reaction, the temperature was lowered to 100 ° C, and 1/2 part of phthaloyl chloride (added after dissolving in tetrahydrofuran) of the charged base catalyst was added thereto, followed by stirring at 160 ° C and normal pressure for 1 hour to neutralize Respectively. The resulting polymer was allowed to solidify at room temperature.

As a result of the analysis, it was confirmed that a poly (butylene carbonate-co-terephthalate) resin having an ester residue of 54 mol%, a weight average molecular weight of 32,370 g / mol and a melting point of 150 ° C was produced.

The resulting resin was dissolved in a chloroform (CDCl ₃ ) solvent for NMR (Nuclear Magnetic Resonance) and a small amount was taken, and its structure was confirmed by 500 MHz NMR and shown in FIG.

Example  2

The reaction was carried out in the same manner as in Example 1 except that the temperature of the reactor was raised to 260 ° C under a reduced pressure of 0.3 mmHg in the polycondensation reaction.

As a result of the analysis, it was confirmed that a poly (butylene carbonate-co-terephthalate) resin having an ester residue of 69 mol%, a weight average molecular weight of 28,460 g / mol and a melting point of 180 ° C was produced.

The resulting resin was dissolved in a chloroform (CDCl ₃ ) solvent for NMR (Nuclear Magnetic Resonance) and a small amount was taken, and its structure was confirmed by 500 MHz NMR and shown in FIG.

Example  3

The reaction was carried out in the same manner as in Example 1, except that the reaction time was increased by 2 times in the state of reduced pressure of 0.3 mmHg in the polycondensation reaction for 8 hours.

As a result of the analysis, it was confirmed that a poly (butylene carbonate-co-terephthalate) resin containing 58 mole% of an ester residue and having a weight average molecular weight of 41,290 g / mol and a melting point of 157 ° C was produced.

Example  4

In the transesterification reaction, 1,4-butanediol (24 g, 270 mmole), NaOMe (33 mg, 0.1 mol% of the total resin, dissolved in methanol) and a base catalyst and dimethyl carbonate (49 g, 540 mmole) The reaction was carried out.

In order to produce a resin having an ester residue of 70 mol% or more of the total resin in the polycondensation reaction, the amount of the reactant to be added to the transesterification reaction was 30 mol% based on the total resin. 1.3 times of the reaction product was added to the calculated value in consideration of the loss of the transesterification reaction product in the polycondensation reaction.

Experiments were carried out in the same manner as in Example 1 except for the above.

As a result of the analysis, it was confirmed that a poly (butylene carbonate-co-terephthalate) resin having an ester residue of 73 mol%, a weight average molecular weight of 35,720 g / mol and a melting point of 183 DEG C was produced.

Example  5

In a transesterification reaction, 1,4-butanediol (14 g, 158 mmole), NaOMe (28 mg, 0.1 mol% of the total resin, dissolved in methanol) and a base catalyst and dimethyl carbonate (42 g, 474 mmole) The reaction was carried out.

In order to produce a resin having an ester residue of 80 mol% or more of the total resin in the polycondensation reaction, the amount of the reactant to be added to the transesterification reaction was 20 mol% based on the total resin. In consideration of the loss of the transesterification reaction product in the polycondensation reaction, 1.5 times the amount of the reaction product was added to the calculated value.

Experiments were carried out in the same manner as in Example 1 except for the above.

As a result of the analysis, it was confirmed that a poly (butylene carbonate-co-terephthalate) resin having an ester residue of 85 mol% and a weight average molecular weight of 27,960 g / mol and a melting point of 204 ° C was produced.

Example  6

In a transesterification reaction, 1,4-butanediol (55 g, 606 mmole), NaOMe (55 mg, 0.1 mol% of the total resin, dissolved in methanol) and a base catalyst and dimethyl carbonate (164 g, 1819 mmole) The reaction was carried out.

Further, in order to produce a resin having an ester residue of 40 mol% or more of the total resin in the polycondensation reaction, the amount of the reactant to be added to the transesterification reaction was 60 mol% based on the total resin. In consideration of the loss of the transesterification reaction product in the polycondensation reaction, 1.2 times the amount of the reaction product was added to the calculated value.

Experiments were carried out in the same manner as in Example 1 except for the above.

As a result of the analysis, it was confirmed that a poly (butylene carbonate-co-terephthalate) resin having an ester residue of 46 mol%, a weight average molecular weight of 51,221 g / mol and a melting point of 133 ° C was produced.

Comparative Example  One

The order of the base catalyst, dimethyl carbonate (74 g, 816 mmole) and terephthalic acid (65 g, 389 mmol) was added to the reactor with 1,4-butanediol (70 g, 777 mmol), NaOMe (42 mg, 0.1 mol% And the mixture was stirred in a slurry state, and the interior of the reactor was replaced with nitrogen for 30 minutes. After the stirrer and the cooling condenser were connected to the reactor, the temperature of the reactor was gradually increased from 90 ° C to 120 ° C for 2 hours to proceed the reaction. Since there was no substance to be removed through the condenser, the temperature gradually increased to 120 ° C. or more. After the temperature exceeded 140 ° C., the material inside the reactor rapidly started to flow out. As a result of the 1H-NMR analysis, the effluent was found to be dimethyl carbonate.

The remaining reactants were continuously heated up to 210 ° C to attempt polymerization, but the reaction was terminated because the terephthalic acid did not dissolve. The remaining material in the reactor was analyzed by &lt; 1 &gt; H-NMR, indicating that all of the dimethyl carbonate had been distilled off.

< Experimental Example >

The mole ratio, molecular weight, melting point, and glass transition temperature of the ester residue and the carbonate residue in the resins obtained in Examples and Comparative Examples were measured according to the following methods and shown in Table 1 below.

(1) molar ratio (mol%) of ester residue

The resulting resin was dissolved in a chloroform (CDCl ₃ ) solvent for NMR (Nuclear Magnetic Resonance), and a small amount was taken. The structure of the final product was confirmed by 500 MHz NMR and the molarity of the ester moiety .

(2) Molecular weight (Mn, Mw)

Was measured at 40 캜 using a tetrahydrofuran (THF) solvent by gel permeation chromatography (GPC), and polystyrene was used as a standard.

(3) Melting point and glass transition temperature (Tg, Tm: 占 폚)

(DSC), and the temperature was gradually increased from -50 to 200 ° C at a rate of 10 ° C / min, then gradually cooled to 10 ° C / min and then the temperature was again measured.

Resin composition
(Ester: carbonate residue, mol%) Mw Mw / Mn Tm / Tg (占 폚) Example 1 54:46 57,230 1.97 150 / -4 Example 2 69:31 42,350 1.84 180/15 Example 3 58:42 62,780 1.93 157 / -2 Example 4 73:27 48,630 2.01 183/17 Example 5 85:25 39,510 1.98 204/29 Example 6 46:54 51,221 1.80 133 / -2 Comparative Example 1 Polymer not produced - - -

Referring to Table 1, in the method of Comparative Example 1 in which a mixture of 1,4-butanediol, dimethyl carbonate and terephthalic acid is condensed as a monomer under a base catalyst, a poly (butylene carbonate-co-terephthalate) I did.

In Examples 1 to 6, the poly (butylene carbonate-co-terephthalate) resin was successfully polymerized according to the production method of the present invention, and as the molar ratio of the ester residue in the resin was increased, It can be seen that the temperature rises.

Claims (13)

a) performing an esterification reaction on terephthalic acid represented by the following formula (2) and 1,4-butanediol represented by the following formula (4);
b) carrying out a trans esterification reaction on dimethyl carbonate of formula (3) and 1,4-butanediol of formula (4); And
c) mixing the reaction product of the a) esterification reaction and the reaction product of the b) transesterification reaction to perform a polycondensation reaction.
A method for producing a poly (butylene carbonate-co-terephthalate) resin represented by the following formula 1:
[Chemical Formula 1]

(2)

(3)

[Chemical Formula 4]

In Formula 1,
x and y are the number of moles of each repeating unit.
The method of claim 1, wherein the step a) is carried out at a temperature of 210 to 280 ° C.
The method for producing a poly (butylene carbonate-co-terephthalate) resin according to claim 1, wherein the a) esterification reaction is carried out while distilling off water and tetrahydrofuran as reaction by-
2. The method of claim 1, wherein the molar ratio of terephthalic acid to 1,4-butanediol used in the step a) is 1: 1.1 to 1: 4.0. 3. The poly (butylene carbonate- A method for producing a resin.
The method for producing a poly (butylene carbonate-co-terephthalate) resin according to claim 1, wherein the step (b) of carrying out the transesterification reaction is carried out at a temperature of 80 to 150 ° C.
The method for producing a poly (butylene carbonate-co-terephthalate) resin according to claim 1, wherein the step b) of carrying out the transesterification reaction is carried out while distilling off methanol and a part of dimethyl carbonate as reaction by-
2. The process according to claim 1, wherein the molar ratio of dimethyl carbonate to 1,4-butanediol used in the step b) is 1.1: 1 to 4.0: 1, and wherein the poly (butylene carbonate- Phthalate) resin:
The method for producing a poly (butylene carbonate-co-terephthalate) according to claim 1, wherein the step b) of carrying out the transesterification reaction is carried out under at least one base catalyst selected from the group consisting of the following formulas (7a) Method of producing resin:
[Formula 7a]
MOR
[Formula 7b]
MOH
[Formula 7c]
MH
[Formula 7d]
[R ₄ N] ⁺ [OH] ^-
In the above formulas (7a) to (7d)
M is an alkali metal, and R is a straight or branched alkyl group having 1 to 10 carbon atoms.
The process according to claim 1, wherein the step c) of carrying out the polycondensation reaction comprises the steps of: a) mixing the reaction product of the esterification reaction and b) the transesterification reaction product at 190 ° C or higher, And a pressure of 760 to 0.3 mmHg. The method of producing a poly (butylene carbonate-co-terephthalate)
The method according to claim 1, wherein the step c) of carrying out the polycondensation reaction comprises the steps of: b) reacting a methoxyal end group derived from the reaction product of the transesterification reaction with a) a hydroxy end derived from the reaction product of the esterification reaction Wherein the molar ratio of the poly (butylene carbonate-co-terephthalate) to the short-chain is from 0.1: 1 to 2.0: 1.
The method for producing a poly (butylene carbonate-co-terephthalate) resin according to claim 1, wherein the poly (butylene carbonate-co-terephthalate) resin has a weight average molecular weight of 20,000 to 200,000 g / mol.
The method for producing a poly (butylene carbonate-co-terephthalate) resin according to claim 1, wherein the poly (butylene carbonate-co-terephthalate) resin has a melting point (Tm) of 40 to 250 ° C.
The method of producing a poly (butylene carbonate-co-terephthalate) resin according to claim 1, wherein the molar fraction (y / (x + y)) of y is more than 50 mol% to less than 100 mol%.

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