KR100276105B1 - Preparation method of polytrimethylene terephthalate having good thermal stability and colorability - Google Patents

Abstract

The present invention is a method for condensation polymerization of a product obtained by esterification or transesterification of a bifunctional carboxylic acid with 1,3-propanediol to prepare a polytrimethylene terephthalate, wherein a tetraalkyl titanate compound is used as a reaction catalyst. 0.01 to 0.5 parts by weight based on 100 parts by weight of carboxylic acid are added at the beginning of the esterification reaction or the transesterification reaction and the condensation polymerization reaction, respectively, and the titanium compound is stabilized at the end of the esterification or transesterification reaction or at the beginning of the condensation polymerization reaction. It relates to a method for producing polytrimethylene terephthalate having excellent thermal stability and color by adding 0.01 to 0.5 parts by weight with respect to 100 parts by weight of carboxylic acid.

Description

Method for producing polytrimethylene terephthalate with excellent thermal stability and color

The present invention relates to a method for producing polytrimethylene terephthalate, and more particularly, the production of polytrimethylene terephthalate (hereinafter referred to as PTT) having low -COOH end group content and excellent thermal stability and color. It is about a method.

In general, PTT obtained by condensation polymerization of a product obtained by esterification or transesterification of 1,3-propanediol, terephthalic acid, which is a bifunctional carboxylic acid, and terephthalic acid and dimethylterephthalate in the presence of a catalyst It has excellent molding processability, chemical resistance, mechanical properties, electrical properties, and elasticity, so it is applied to applications such as textiles for apparel, industrial textiles, and engineering plastics.

However, in the case of using PTT as a molded product or a fiber material, excellent heat resistance is essential because it requires a molding process such as extrusion, injection, or spinning, and therefore it is important to keep the COOH end group content as low as possible. The COOH end group inhibits the thermal stability of PTT, makes the color poor, and makes it difficult to obtain a polymer having a high degree of polymerization of a certain molecular weight or more during the condensation polymerization reaction.

In order to solve such a problem, Japanese Laid-Open Patent Publication No. 53-35795 discloses lithium; Although the color of the polymer has been improved by adding a metal compound such as sodium, in this case, there is a problem that the remaining metal compound acts as a foreign material during processing of the polymer, which may cause a process and a poor quality. -24695, Japanese Patent Laid-Open No. 51-163945 Hindered phenolic heat stabilizer was added to improve thermal stability, but the stabilizer is likely to scatter during the reaction, and may act as a terminal inhibitor depending on the type of stabilizer, Problems such as causing coloring were exposed.

Accordingly, the present inventors conducted a variety of studies by appropriately combining the type, amount, and soaking time of the catalyst and stabilizer to produce PTT having a low COOH end group content and excellent thermal stability and color, and the present invention was completed based on this. .

Accordingly, it is an object of the present invention to provide a method for producing PTT having excellent thermal stability and color.

The method of the present invention for achieving the above object is a method for condensation polymerization of a product obtained by esterification or transesterification of a bifunctional carboxylic acid and 1,3-propanediol to produce PTT, and tetraalkyl as a reaction catalyst. The titanate compound is added at 0.01 to 0.5 parts by weight based on 100 parts by weight of the bifunctional carboxylic acid at the beginning of the esterification reaction or the transesterification reaction and the condensation polymerization reaction, respectively, and the titanium compound is esterified or transesterified as a stabilizer. It consists of adding 0.01 to 0.5 parts by weight based on 100 parts by weight of the difunctional carboxylic acid at the end of the reaction or at the beginning of the condensation polymerization.

Hereinafter, the present invention will be described in more detail.

Examples of the difunctional carboxylic acid used in the present invention include terephthalic acid and dimethyl terephthalate. Examples of the difunctional carboxylic acid include isophthalic acid, naphthalene dicarboxylic acid, adipic acid, 5-sodium sulfodimethyl isophthalate and the like can be copolymerized in the range of 40 mol% or less of the total acid component.

Copolymer diol components other than 1,3-propanediol used in the present invention include ethylene glycol, 1-4 butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-dicyclohexane dimethanol, and the like. The component of can be copolymerized and used in 40 mol% or less of a total diol component.

Tetraalkyl titanate compounds which are catalysts used in the present invention include tetramethyl titanate, tetraethyl titanate, tetraisopropyl titanate, tetrabutyl titanate, tetrapentyl titanate and tetra (2-ethylhexyl) titanate. It is selected from the group consisting of, the amount is preferably 0.01 to 0.5 parts by weight based on 100 parts by weight of the difunctional carboxylic acid. If the addition amount of the catalyst is less than 0.01 part by weight, the effect as an esterification reaction or transesterification and condensation polymerization catalyst is insufficient, the reaction rate is significantly lowered, it is difficult to obtain a polymer having a sufficient degree of polymerization, the addition amount is 0.5 parts by weight If exceeded, depolymerization occurs at the end of the condensation polymerization reaction due to the excessive input of the catalyst, thereby lowering the molecular weight and deteriorating the color of the polymer.

The catalyst should be added at the beginning of the esterification reaction or the transesterification reaction and at the beginning of the condensation polymerization reaction, preferably within 10 minutes after the start of each reaction, in terms of process and reaction efficiency.

As the titanium compound, which is a stabilizer used in the present invention, phosphate or aminoalkyl type is suitable, and in particular, neopentyl (diaryl) oxytri (dioctyl) phosphato titanate, neopentyl (diaryl) oxytri ( Dioctyl) pyrophosphatotitanate, neopentyl (diaryl) oxytri (N-ethylenediamino) ethyltitanate and neopentyl (diaryl) oxytri (m-amino) phenyl titanate As for the usage-amount, 0.01-0.5 weight part is preferable with respect to 100 weight part of difunctional carboxylic acid. If the amount of the stabilizer is less than 0.01 parts by weight, the effect as a stabilizer is insufficient, the polymer is thermally decomposed, and the overall physical properties are significantly reduced. If the amount is more than 0.5 parts by weight, the color of the polymer is deteriorated and the strength is lowered. There is a problem.

The stabilizer is preferably added at the end of the esterification reaction or the transesterification reaction or at the beginning of the polycondensation reaction in view of increasing the reaction efficiency and the charging effect.

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

Example 1

1000 g of dimethyl terephthalate and 783 g of 1,3-propanediol were added to the reactor, stirred, and melted. Then, 1.5 g of tetrabutyl titanate was added, and a transesterification reaction was carried out at 220 ° C. At the time when 95% of the theoretical methanol was discharged, 1.0 g of neopentyl (diaryl) oxytri (dioctyl) phosphatotitanate was added to complete the transesterification reaction, and then the transesterification product was transferred to the condensation polymerization reactor. Then, 1.5 g of tetrabutyl titanate was added to maintain the vacuum at 0.1 Torr or lower while gradually reducing the pressure, and the reaction was performed at 260 ° C. for 240 minutes to obtain a final product. Physical properties of the final product are shown in Table 1 below.

Example 2

1000 g of dimethyl terephthalate and 783 g of 1,3-propanediol were added to the reactor, stirred, and melted. Then, 1.5 g of tetrabutyl titanate was added, and a transesterification reaction was carried out at 220 ° C. At the time when 95% of the theoretical methanol was distilled off, 3.0 g of neopentyl (diaryl) oxytri (dioctyl) pyrophosphatotitanate was added to complete the transesterification reaction, and then the product of the transesterification reaction was condensation polymerization reactor. After transferring to, and 1.5 g of tetrabutyl titanate was added, the vacuum degree was maintained at 0.1 Torr or less while gradually reducing the pressure, and the reaction was performed at 260 ° C. for 240 minutes to obtain a final product. Physical properties of the final product are shown in Table 1 below.

Example 3

1000 g of dimethyl terephthalate and 783 g of 1,3-propanediol were added to the reactor, stirred, and melted. Then, 1.5 g of tetrabutyl titanate was added, and a transesterification reaction was carried out at 220 ° C. After completion of the transesterification reaction, the product of transesterification reaction was transferred to a condensation polymerization reactor, and 1.0 g of neopentyl (diaryl) oxytri (dioctyl) phosphato titanate and 1.5 g of tetrabutyl titanate were slowly added thereto. The vacuum degree was maintained at 0.1 Torr or less under reduced pressure, and the reaction was performed at 260 ° C. for 240 minutes to obtain a final product. Physical properties of the final product are shown in Table 1 below.

Example 4

1000 g of dimethyl terephthalate and 783 g of 1,3-propanediol were added to the reactor, stirred, and melted. Then, 1.5 g of tetraisopropyl titanate was added thereto, and a transesterification reaction was performed at 220 ° C. When methanol was released at 95% of theory, 1.0 g of neopentyl (diaryl) oxytri (dioctyl) phosphatotitanate was added to complete the transesterification reaction, and then the transesterification product was transferred to the condensation polymerization reactor. Then, 1.5 g of tetraisopropyl titanate was added to keep the vacuum at 0.1 Torr or lower while gradually reducing the pressure, and the reaction was performed at 260 ° C. for 240 minutes to obtain a final product. Physical properties of the final product are shown in Table 1 below.

Example 5

1000 g of dimethyl terephthalate and 783 g of 1,3-propanediol were added to the reactor, stirred, and melted. Then, 1.5 g of tetrabutyl titanate was added, and a transesterification reaction was carried out at 220 ° C. When methanol was released at 95% of theory, 1.Og of neopentyl (diaryl) oxytri (N-ethylenediamino) ethyl titanate was added to complete the transesterification reaction, and then condensation polymerization of the transesterification product. After transferring to the reactor, 1.5 g of tetrabutyl titanate was added and the vacuum degree was kept to 0.1 Torr or less while gradually depressurizing, reaction was performed at 260 degreeC for 240 minutes, and the final product was obtained. Physical properties of the final product are shown in Table 1 below.

Comparative Example 1

1000 g of dimethyl terephthalate and 783 g of 1,3-propanediol were added to the reactor, stirred, and melted. Then, 1.5 g of tetrabutyl titanate was added, and a transesterification reaction was carried out at 220 ° C. When methanol was distilled 95% of the theoretical value, 1.Og of diphenyldecylphosphite and 0.5 g of Irganox 1010, a trade name of Shivagaigi Co., Ltd., were added. The resulting product was transferred to a condensation polymerization reactor, 1.5 g of tetrabutyl titanate was added thereto, and the vacuum degree was maintained at 0.1 Torr or lower while gradually reducing the pressure. The reaction was performed at 260 ° C. for 240 minutes to obtain a final product. Physical properties of the final product are shown in Table 1 below.

Comparative Example 2

1000 g of dimethyl terephthalate and 783 g of 1,3-propanediol were added to the reactor, stirred, and melted. Then, 1.5 g of tetrabutyl titanate was added thereto, and a transesterification reaction was performed at 220 ° C. When methanol was distilled at 95% of the theoretical value, 1.0 g of diphenyldecylphosphite was added to complete the transesterification reaction, and then the product of transesterification reaction was transferred to a condensation polymerization reactor, and 1.5 g of tetrabutyl titanate was added slowly. The vacuum was maintained at 0.1 Torr or lower under reduced pressure, and the reaction was carried out at 260 ° C. for 240 minutes to obtain a final product. Physical properties of the final product are shown in Table 1 below.

Comparative Example 3

1000 g of dimethyl terephthalate and 783 g of 1,3-propanediol were added to the reactor, stirred, and melted. Then, 1.5 g of tetrabutyl titanate was added thereto, and a transesterification reaction was performed at 220 ° C. When methanol was distilled 95% of the theoretical value, 1.0 g of triphenylphosphite was added to complete the transesterification reaction, and then the product of transesterification reaction was transferred to a condensation polymerization reactor, and 1.5 g of tetrabutyl titanate was added slowly. The vacuum degree was maintained at 0.1 Torr or less under reduced pressure, and the reaction was performed at 260 ° C. for 240 minutes to obtain a final product. Physical properties of the final product are shown in Table 1 below.

[Comparative Example 4]

1000 g of dimethyl terephthalate and 783 g of 1,3-propanediol were added to the reactor, stirred, and melted. Then, 50 g of tetrabutyl titanate was added thereto, and a transesterification reaction was performed at 220 ° C. At the time when 95% of the theoretical methanol was discharged, 1.0 g of neopentyl (diaryl) oxytri (dioctyl) phosphatotitanate was added to complete the transesterification reaction, and then the transesterification product was transferred to the condensation polymerization reactor. Then, 50 g of tetrabutyl titanate was added to keep the vacuum at 0.1 Torr or lower while gradually reducing the pressure, and the reaction was performed at 260 ° C. for 240 minutes to obtain a final product. Physical properties of the final product are shown in Table 1 below.

[Comparative Example 5]

1000 g of dimethyl terephthalate and 783 g of 1,3-propanediol were added to the reactor, stirred, and melted. Then, 1.5 g of tetrabutyl titanate was added thereto, and a transesterification reaction was performed at 220 ° C. At the time when 95% of the theoretical methanol was discharged, 1.0 g of neopentyl (diaryl) oxytri (dioctyl) phosphatotitanate was added to complete the transesterification reaction, and then the transesterification product was transferred to the condensation polymerization reactor. After maintaining the vacuum degree at 0.1 Torr or less while gradually reducing the pressure, the reaction was carried out at 260 ° C. for 240 minutes to obtain a final product. Physical properties of the final product are shown in Table 1 below.

Comparative Example 6

1000 g of dimethyl terephthalate and 783 g of 1,3-propanediol were added to the reactor, stirred, and melted. Then, 1.5 g of tetrabutyl titanate was added thereto, and a transesterification reaction was performed at 220 ° C. At the time when 95% of the theoretical methanol was discharged, 1.0 g of neopentyl (diaryl) oxytri (dioctyl) phosphatotitanate was added to complete the transesterification reaction, and then the transesterification product was transferred to the condensation polymerization reactor. After maintaining the vacuum degree at 0.1 Torr or lower while gradually reducing the pressure, the reaction was performed at 260 ° C. for 240 minutes, 1.5 g of tetrabutyl titanate was added thereto, followed by stirring for 5 minutes to obtain a final product. Physical properties of the final product are shown in Table 1 below.

Comparative Example 7

1000 g of dimethyl terephthalate and 783 g of 1,3-propanediol were added to the reactor, stirred, and melted. Then, 1.5 g of tetrabutyl titanate was added thereto, and a transesterification reaction was performed at 220 ° C. After the completion of the transesterification reaction, the product of transesterification reaction was transferred to the condensation polymerization reactor and 1.5 g of tetrabutyl titanate was added to keep the vacuum at 0.1 Torr or less while gradually depressurizing, and the reaction was performed at 260 ° C. for 240 minutes. After quenching, 1.0 g of neopentyl (diaryl) oxytri (dioctyl) phosphato titanate was added and stirred for 5 minutes to obtain a final product. The final product was obtained. Physical properties of the final product are shown in Table 1 below.

Comparative Example 8

1000 g of dimethyl terephthalate and 783 g of 1,3-propanediol were added to the reactor, stirred, and melted. Then, 1.5 g of calcium acetate was added thereto and subjected to a transesterification reaction at 220 ° C. At the time when 95% of the theoretical methanol was discharged, 1.0 g of neopentyl (diaryl) oxytri (dioctyl) phosphatotitanate was added to complete the transesterification reaction, and then the transesterification product was transferred to the condensation polymerization reactor. Then, 1.5 g of calcium acetate was added to keep the vacuum at 0.1 Torr or lower while gradually reducing the pressure, and the reaction was performed at 260 ° C. for 240 minutes to obtain a final product. The final product was obtained. Physical properties of the final product are shown in Table 1 below.

TABLE 1

The intrinsic viscosity is a specific value at 35 ℃ as an orthochlorophenol solvent. The COOH end group content was obtained by dissolving the sample in benzyl alcohol and titrating with NaOH. Heat resistance was evaluated by the rate of change of the intrinsic viscosity after drying the sample for 4 hours at 180 ℃ hot air dryer. Color was measured using a colorimeter at room temperature.

As described above, the PTT produced by the method of the present invention has a lower COOH end group content than the PTT prepared by the conventional method, and thus shows excellent thermal stability and color. Much more useful than

Claims (3)

A method of condensation polymerization of a product obtained by esterification or transesterification of a bifunctional carboxylic acid with 1,3-propanediol to produce a polytrimethylene terephthalate, wherein the tetraalkyl titanate compound is esterified by a group or 0.01 to 0.5 parts by weight based on 100 parts by weight of the bifunctional carboxylic acid are added at the beginning of the transesterification reaction and the condensation polymerization reaction, respectively, and the titanium compound is stabilized at the end of the esterification reaction or the transesterification reaction or at the beginning of the condensation polymerization reaction. It is prepared by adding 0.01 to 0.5 parts by weight based on 100 parts by weight of the bifunctional carboxylic acid, characterized in that the polytrimethylene terephthalate having excellent thermal stability and color. The method of claim 1, wherein the catalyst is selected from the group consisting of tetramethyl titanate, tetraethyl titanate, tetraisopropyl titanate, tetrabutyl titanate and tetra (2-ethylhexyl) titanate. The method of claim 1, wherein the stabilizer is neopentyl (diaryl) oxytri (dioctyl) phosphato titanate, neopentyl (diaryl) oxytryl (dioctyl) pyrophosphato titanate, neopentyl ( Diaryl) oxyfree (N-ethylenediamino) ethyl titanate and neopentyl (diaryl) oxytri (m-amino) phenyl titanate, selected from the group of phosphate-based or aminoalkyl-based titanium compounds Way.