KR930010563B1 - Producing method of polyester co-polymer - Google Patents

Abstract

No content.

Description

Polyester copolymer manufacturing method

The present invention relates to a method for producing a polyester copolymer, which is mainly used for heat fusion bonding, base film adhesion, paint and ink binder, coating, laminate and the like.

Aromatic polyesters, including polyethylene terephthalate, are widely used in textiles, base films, and plastic moldings because of their good mechanical, chemical, and electrical properties, but they have high crystallization and melting temperatures, and poor solubility in organic solvents. It is a limitation to use as. Accordingly, by adding an aliphatic dibasic acid or preparing a polyester copolymer using two or more alkylene glycols, the melting temperature is lowered, and the solubility in organic solvents is increased to improve the adhesion as a binder. Patents include U.S. Patent Nos. 3,795,784, 4,065,439, 4,201,859, JP 54-8376, JP 55-54375, 59-76480, 59-11383, 59-232119, and 61-281.

Compositions of polyester copolymers useful as binders include bifunctional ester forming compounds based on terephthalic acid and ethylene glycol or 1,4 butylene glycol, including phthalic acid, terephthalic acid, isophthalic acid and ester forming derivatives thereof. Among the glycols, it is known that carbon atoms including ethylene glycol and 1,4 butylene glycol have about 10 carbon atoms.

Polymerization of the polyester copolymer is generally carried out in two stages, and undergoes a polycondensation reaction after an esterification reaction or a transesterification reaction.

The catalysts mainly used in the transesterification reaction are zinc acetate, calcium acetate, magnesium compounds, titanium compounds and the like, and the polycondensation reaction catalysts mainly use antimony compounds and titanium compounds. Here, the titanium compound means that titanium, such as tetrabutyl titanate, isopropyl titanate, tetrafluorotitanium, is contained.

The polymerization of polyethylene terephthalate mainly uses antimony compounds, and the polymerization of polybutylene terephthalate uses titanium compounds. It is well known that titanium compounds are more effective than antimony compounds. A polymer having a high degree of polymerization can be obtained within a short time, but the polymer is colored by side reaction.

In the polymerization of terephthalic acid and ethylene glycol, a method of improving the coloration by using a titanium compound and a cobalt compound has been proposed (Japanese Patent Application No. 55-5531), but it is less effective as the content of aliphatic dibasic acid increases.

In the polymerization of the polyester copolymer, when the titanium compound is used depending on the composition of the copolymer, the coloring becomes severe, but the type of glycol and the content of aliphatic dibasic acid are greatly affected. In particular, the composition forming the polyester copolymer comprises an aromatic dibasic acid unit (a), an aliphatic dibasic acid unit (b), an ethylene glycol unit (c), and other glycon units having 4 to 10 carbon atoms (d). The copolymer produced when (b) / (a) = 0.1 or more, (c) / (d) = 0.8 or more and using a titanium compound as a catalyst has an intrinsic viscosity of at least 0.4 in orthochlorophenol solution at 25 ° C. And severe coloration.

The present inventors found that the main part reaction in the polymerization of polyester is affected by the concentration of terminal carboxylic acid as shown in formulas (I) and (II),

Although it is influenced by the type of glycol and the content of aliphatic dibasic acid, it is noted that the coloration is improved by adding a proper amount of dibasic monomer at a specific ratio when using a titanium compound. As a result of adding the dibasic acid monomer during the transesterification reaction, it was found that the reaction time was shortened and the amount of glycol used was saved.

That is, the present invention improves the reaction efficiency by using a titanium compound as a catalyst in the polymerization of a polyester copolymer having a composition of (b) / (a) = 0.1 or more and (c) / (d) = 0.8 or more as indicated above. An aliphatic dibasic acid monomer is added during the exchange reaction, and the reaction time is shortened by changing the concentration of glycol. The present invention relates to a method for producing a polyester copolymer having improved economic efficiency by using a lower concentration of glycol.

Hereinafter, the present invention will be described in detail, in the preparation of a polyester copolymer composed of at least four or more monomers having (b) / (a) = 0.1 or more and (c) / (d) = 0.8 or more, the composition of which The dibasic acid monomer is added to the compound undergoing the exchange reaction when the amount of the theoretical distillation methanol is 60% to 90%, and the reaction proceeds. The molar ratio of glycol and acid including the dibasic acid monomer added at that time is from 2.0 to 1.55.

At least one titanium compound and a dibasic acid monomer are added to the third compound having completed the transesterification reaction, the polycondensation reaction is carried out to some extent, and then the dibasic acid monomer is added under vacuum to continue the polycondensation reaction. do. The addition time and molar ratio of the dibasic acid monomer during the transesterification reaction is more economical at 65% to 80% and 1.55 to 1.75, especially at 70% to 75% and 1.60 to 1.70. The closer the molar ratio is to 2.0, the more economical the reaction time is, but in terms of raw materials, it is more economical.

The coloration degree of the copolymer was measured by L.a.b. color standard using the standard KSA 0066 object color measurement method. Represented by value. L value is lightness (larger value is brighter), a value is (+) red, (-) green, b value is (+) yellow, (-) blue, and the color tone of the polymer is higher L value, The closer to 0, the smaller the value of b is.

Hereinafter, the present invention will be described in detail with reference to Examples.

Example 1

162 g of dimethyl terephthalate, 162 g of dimethyl isophthalate, 130 g of ethylene glycol, 125 g of neopentyl glycol, 1.2 g of tetrabutyl titanate (10% ethylene glycol solution), and 0.09 g of zinc acetate dihydrate were added to a 1 L three-necked flask, and the temperature was increased. After proceeding to 75% of the theoretical ethanol effluent was discharged, 62g of dimethyl sebacate was added and the reaction was continued to proceed to 240 ℃ to complete the reaction.

0.075 g of trimethyl phosphate and 10 g of terephthalic acid were added thereto, and the reaction time was elapsed after the reaction time had elapsed after 80 minutes at 250 ° C. and 30 minutes, and then 2 g of sebacic acid was added under reduced pressure to carry out the reaction for 20 minutes. A copolymer having an inherent viscosity of 0.55 was obtained in a 25 ° C. orthochlorphenol solution. The conditions for obtaining a copolymer and the coloring degree of the obtained copolymer are shown in Table 1.

Comparative Example 1

162 g of dimethyl terephthalate, 162 g of dimethyl isophthalate, 62 g of dimethyl sebacate, 157 g of ethylene glycol, 151 g of neopentyl glycol, 1.2 g of tetrabutyl titanate (10% ethylene glycol solution), and 0.09 g of zinc acetate dihydrate were placed in a 1 L three-neck flask. The reaction was carried out by raising the temperature, and the theoretical methanol amount was flowed out near 240 ° C., and then the reaction was completed. Then, 0.075 g of trimethyl phosphate and 10 g of terephthalic acid were added thereto. After elapsed, 2 g of sebacic acid was added under reduced pressure, and the reaction proceeded for 20 minutes. A copolymer having an intrinsic viscosity of 0.54 in a 25 ° C. orthochlorophenol solution was obtained. The conditions for obtaining a copolymer and the coloring degree of the obtained copolymer are shown in Table 1.

[Comparative Examples 2 to 3]

Except that the addition time of the dibasic acid is the same as in Example 1 except that. The coloring degree of the obtained copolymer is shown in Table 1.

Example 2

162 g of dimethyl terephthalate, 162 g of dimethyl isophthalate, 123 g of ethylene glycol, 118 g of neopentyl glycol, 1.2 g of tetrabutyl titanate (10% ethylene glycol solution), and 0.09 g of zinc acetate dihydrate were added to a 1 L three-necked flask, and the temperature was increased. 75% of the theoretical effluent methanol was distilled off, and 62 g of dimethyl sebacate was added thereto, and the reaction was continued to 240 ° C. to complete the reaction. To this, 0.075 g of trimethyl phosphate and 10 g of terephthalic acid are added, and after 250 minutes at 1 mmHg for 100 minutes, 2 g of sebacic acid is added and the reaction proceeds for 30 minutes. A copolymer having an intrinsic viscosity of 0.63 in a 25 ° C. orthochlorophenol solution was obtained. The conditions for obtaining a copolymer and the coloring degree of the obtained copolymer are shown in Table 1.

[Comparative Examples 4, 5, 6]

It carried out similarly to Example 2 except having performed the addition time and molar ratio of dibasic acid as Table 1. The coloring degree of the obtained copolymer is shown in Table 1.

Comparative Example 7

162 g of dimethyl terephthalate, 162 g of dimethyl isophthalate, 62 g of dimethyl sebacate, 157 g of ethylene glycol, 151 g of neopentyl glycol, and 0.09 g of zinc acetate dihydrate were added to a 1 L three-necked flask and the reaction was carried out by increasing the temperature. After the amount was distilled off, the reaction was completed, and 0.075 g of trimethyl phosphate and 0.1 g of antimony trioxide were added thereto, and the reaction was performed at 250 ° C. and 1 mmHg for 150 minutes. A copolymer having an intrinsic viscosity of 0.63 in a 25 ° C. orthochlorophenol solution was obtained. The conditions for obtaining a copolymer and the coloring degree of the obtained copolymer are shown in Table 1.

TABLE 1

As can be seen in Table 1, Examples 1 and 2 have a molar ratio of 1.6 to 1.7, the reaction time is shorter than other conditions, and Comparative Examples 1 and 7 have a short reaction time but a large molar ratio, and Comparative Examples 2 to 6 The molar ratio and the timing of dosing were changed under the same conditions. The faster the dosing time is, the more favorable the effect of molar ratio is. The slower the dosing time, the slower the reaction time.

Claims (1)

Aromatic dibasic acid units (a), aliphatic dibasic acid units (b), ethylene glycol units (c), and other glycol units having 4 to 10 carbon atoms (d), wherein (b) / (a) = 0.1 or more In the preparation of polyester copolymer using (c) / (d) = 0.8 or more and a titanium compound as a reaction catalyst, dibasic acid monomer is added when the theoretical methanol effluent is 65-80% during transesterification reaction. Method for producing a polyester copolymer characterized in that the molar ratio of the total glycol and acid to 1.55 ~ 1.75.