KR20190052871A - Polyester resin with excellent optic properties comprising 1,3-cyclohexanedimethanol and preparation method thereof - Google Patents

Abstract

The present invention relates to: a method for manufacturing a polyester resin comprising a step of conducting an esterification reaction and condensation polymerization reaction of a dicarboxylic acid compound composed of a terephthalic acid with a diol compound composed of ethylene glycol, tetrahydrofuran diol, and cyclohexane dimethanol; and the polyester resin manufactured by the same. According to the present invention, the polyester resin has an improved heat resistance in comparison with an existing polyester resin.

Description

TECHNICAL FIELD [0001] The present invention relates to a 1,3-cyclohexanedimethanol-containing polyester resin having excellent optical properties and a process for producing the same. BACKGROUND ART [0002]

More particularly, the present invention relates to a polyester resin containing terephthalic acid and ethylene glycol, tetrahydropyranediol, cyclohexanedimethanol, and a process for producing the same.

Conventionally known polyester resins are synthesized by a step of mixing a dicarboxylic acid compound and a diol compound to be esterified, and a step of polycondensation using a polycondensation catalyst. In order to suppress the crystallization due to the chemical structure of such a resin and to impart transparency, 1,4-cyclohexanedimethanol is copolymerized to synthesize an amorphous polyester resin. However, this technology has a problem that the production cost is high and the melting temperature is high because the relatively high 1,4-cyclohexane dimethanol is used in a large amount, resulting in poor processing efficiency in injection molding.

The present inventors have conducted research on a method for producing a polyester resin by using a second or a third alcohol compound other than ethylene glycol and ethylene glycol as a diol compound and found that when a specific diol compound is used, It is possible to produce a polyester resin having high heat resistance, high transparency and the like through experiments, and completed the invention.

The present invention relates to a polyester resin which can be produced at a low cost and which is excellent in processing efficiency and which is superior in transparency and heat resistance, and a method for producing the polyester resin, which is produced by using a dicarboxylic acid compound and a diol compound or a polycondensation catalyst About

In order to achieve the above object,

In the presence of a catalyst, a dicarboxylic acid component comprising terephthalic acid; And

The present invention provides a process for producing a polyester resin comprising esterifying and condensation polymerization of a diol component comprising ethylene glycol, 1,3-cyclohexanedimethanol and tetrahydrofuran diol.

The present invention also relates to a dicarboxylic acid component comprising a) a repeating unit derived from terephthalic acid; And

As a diol component, b) a repeating unit derived from ethylene glycol, c) a repeating unit derived from 1,3-cyclohexanedimethanol, and d) a repeating unit derived from tetrahydrofuran diol,

C) 50 to 90 mol% of repeating units derived from ethylene glycol, c) 5 to 50 mol% of repeating units derived from 1,3-cyclohexanedimethanol, and d) tetra And 5-10 mol% of recurring units derived from hydrolytic dianhydride.

According to the present invention, by adding diol comonomer such as tetrahydrofuran diol and cyclohexanedimethanol to the polyester resin in addition to ethylene glycol, it has improved heat resistance in comparison with conventional polyester resins. Also, the low melting temperature increases the flowability during injection molding, thereby further increasing the processing efficiency and increasing the transparency.

The present invention relates to a process for producing a dicarboxylic acid component comprising, in the presence of a catalyst, a dicarboxylic acid component comprising terephthalic acid; And a step of subjecting a diol component comprising ethylene glycol, 1,3-cyclohexanedimethanol and tetrahydrofuran diol to an esterification reaction and a condensation polymerization reaction.

Conventionally known polyester resins are synthesized by a step of mixing a dicarboxylic acid compound called terephthalic acid and a diol compound called ethylene glycol, followed by esterification and polycondensation using a polycondensation catalyst. In order to suppress the crystallization due to the chemical structure of such a resin and to impart transparency, 1,4-cyclohexanedimethanol is copolymerized to synthesize an amorphous polyester resin. However, this technology has a problem that the production cost is high and the melting temperature is high because the relatively high 1,4-cyclohexane dimethanol is used in a large amount, resulting in poor processing efficiency in injection molding.

However, in the present invention, instead of relatively expensive 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol and tetrahydropyranidiol are copolymerized as a diol compound to prepare a polyester resin, The present invention aims at solving the problem of lowering the production cost of the polyester resin by using a smaller amount of a less expensive compound compared to the diol compound and lowering the melting point without causing crystallization and thus lowering the processing efficiency at the time of injection molding.

In one embodiment of the present invention, it is preferable that the molar ratio of the dicarboxylic acid component to the diol component is in the range of 1: 1.1 to 1: 1.3.

In another embodiment of the present invention, 50 to 90 mol% of ethylene glycol, 5 to 50 mol% of 1,3-cyclohexane dimethanol, 5 to 10 mol% of tetrahydropyranediol, Mol% is preferably used.

In the production of the polyester resin according to the present invention, it is preferable that the esterification reaction is carried out at a temperature of 250-270 ° C, the condensation polymerization reaction is reduced to less than 1.0 torr, and the reaction proceeds at a temperature of 270-280 ° C.

The polyester resin can be produced by using a Ti-based catalyst.

The Ti precursor in the Ti-based catalyst is preferably 1-100 ppm (based on the amount of Ti element), preferably 5-50 ppm, more preferably 10-40 ppm, based on the weight of the polyester resin finally produced. If the content of the catalyst is excessively low, the reaction may be slow or inefficient, and the degree of polymerization may be low. If the content of the catalyst is excessive, the color of the polyester resin may not be good.

Examples of such Ti-based catalysts include tetraethyl titanate, acetyl tripropyl titanate, tetrapropyl titanate, tetrabutyl titanate, polybutyl titanate, 2-ethylhexyl titanate, octylen glycol titanate, Amine titanate, acetylacetonate titanate, thioacetoacetic ester titanate, isostearyl titanate, titanium dioxide, titanium dioxide and silicon dioxide complex oxide, and titanium dioxide and zirconium dioxide complex oxide may be used.

The method for producing a polyester resin according to the present invention may be based on a method commonly used in the technical field to which the present invention belongs, and the method thereof is not particularly limited.

The present invention also relates to a dicarboxylic acid component comprising a) a repeating unit derived from terephthalic acid; And b) a repeating unit derived from ethylene glycol, c) a repeating unit derived from 1,3-cyclohexanedimethanol, and d) a repeating unit derived from tetrahydrofuran diol as the diol component.

In one embodiment, the polyester resin according to the present invention comprises: a) from 50 to 90 mol% of repeating units derived from ethylene glycol, based on 100 mol% of repeating units derived from terephthalic acid, c) repeating from 1,3-cyclohexanedimethanol 5-50 mol% of units, and d) 5-10 mol% of repeating units derived from tetrahydropyranidiol.

The polyester resin according to the present invention contains a small amount of 1,3-cyclohexanedimethanol and tetrahydropyranediol, so that such a polyester resin can be obtained by using a conventional polyester resin such as 1,4-cyclohexanedimethanol-containing polyester resin And has improved heat resistance. Also, the low melting temperature increases the flowability during injection molding, thereby further increasing the processing efficiency and increasing the transparency. That is, the present invention has an advantage in that a small amount of cyclohexane dimethanol, which is relatively expensive, is contained, thereby improving the properties such as heat resistance, workability and transparency of the resin while lowering the production cost of the polyester

In one embodiment, the polyester resin according to the present invention may be amorphous.

In one embodiment, the glass transition temperature of the polyester resin according to the present invention may be 80-85 ° C.

In one embodiment, the transmittance of the polyester resin according to the present invention may be at least 90%.

In one embodiment, the haze of the polyester resin according to the present invention may be 3.5-4.0.

In one embodiment, the polyester resin according to the present invention has a glass transition temperature of 80-85 ° C, a transmittance of 90% or more and a haze of 3.5 to 4.0% according to ASTM D 1003 standard.

The polyester resin according to the present invention may further contain a heat stabilizer, a coloring agent, a color improver, an antioxidant, a flame retardant, a surfactant and the like, if necessary.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. However, the present invention can be embodied in various forms and is not limited to the embodiments described herein.

≪ Example 1: Production of polyester resin >

A batch polymerization reactor consisting of an esterification reactor and condensation polymerization reactor was used for the production of polyester resin. First, for the esterification reaction, a dicarboxylic acid compound consisting of 100 mole% of terephthalic acid (input amount: 2.072 g), which is a main raw material in the esterification reactor, was added with ethylene glycol 90 mole% (charging amount: 777.49 g) and 1,3-cyclohexane (Dicarboxylic acid compound: diol compound) in a molar ratio of 5 mol% (charged amount: 91.83 g) of dimethanol and 5 mol% (amount: 93.03 g) of tetrahydropyranidiol was charged, 0.750 g of a catalyst (Ti638UP, CPL Co., UK) was dissolved in ethylene glycol, stirred, and esterified at 260 DEG C for 3-4 hours. After the esterification reaction, the mixture was transferred to a condensation polymerization reactor, and 0.293 g of TEP (triethylphosphate) was added as a heat stabilizer, and the temperature was raised to 285 캜 while reducing the pressure so that the final degree of vacuum was 1.0 torr or less.

≪ Comparative Example 1 &

A polyester resin was prepared in the same manner as in Example 1, except that a diol compound consisting of 100 mol% of ethylene glycol was used for the dicarboxylic acid compound composed of 100 mol% of terephthalic acid in Example 1.

≪ Comparative Example 2 &

The procedure of Example 1 was repeated except for using a diol compound composed of 90 mol% of ethylene glycol and 10 mol% of tetrahydrofuran diol relative to 100 mol% of terephthalic acid in Example 1 to obtain poly To prepare an ester resin.

≪ Comparative Example 3 &

Example 1 was repeated except that a diol compound consisting of 95 mol% of ethylene glycol and 5 mol% of 1,4-cyclohexanedimethanol was used for the dicarboxylic acid compound composed of 100 mol% of terephthalic acid in Example 1. A polyester resin was prepared in the same manner.

≪ Comparative Example 4 &

Example 1 was repeated except that a diol compound consisting of 95 mol% of ethylene glycol and 5 mol% of 1,3-cyclohexanedimethanol was used for the dicarboxylic acid compound containing 100 mol% of terephthalic acid in Example 1. A polyester resin was prepared in the same manner.

≪ Comparative Example 5 &

Example 1 was repeated except that a diol compound consisting of 90 mol% of ethylene glycol and 10 mol% of 1,3-cyclohexanedimethanol was used for the dicarboxylic acid compound composed of 100 mol% of terephthalic acid in Example 1. A polyester resin was prepared in the same manner.

≪ Comparative Example 6 >

Example 1 was repeated except that the diol compound consisting of 85 mol% of ethylene glycol and 15 mol% of 1,3-cyclohexanedimethanol was used for the dicarboxylic acid compound containing 100 mol% of terephthalic acid in Example 1. A polyester resin was prepared in the same manner.

≪ Comparative Example 7 &

Example 1 was repeated except that the diol compound consisting of 80 mol% of ethylene glycol and 20 mol% of 1,3-cyclohexanedimethanol was used for the dicarboxylic acid compound containing 100 mol% of terephthalic acid in Example 1. A polyester resin was prepared in the same manner.

≪ Comparative Example 8 >

Example 1 was repeated except that the diol compound consisting of 70 mol% of ethylene glycol and 30 mol% of 1,3-cyclohexanedimethanol was used for the dicarboxylic acid compound comprising 100 mol% of terephthalic acid in Example 1. A polyester resin was prepared in the same manner.

≪ Comparative Example 9 &

Example 1 was repeated except that the diol compound consisting of 50 mol% of ethylene glycol and 50 mol% of 1,3-cyclohexanedimethanol was used for the dicarboxylic acid compound containing 100 mol% of terephthalic acid in Example 1. A polyester resin was prepared in the same manner.

Experimental Example 1

The glass transition temperature, melting point, heat of fusion and permeability of the final polyester resin obtained in Example 1 and Comparative Examples 1 to 9 were analyzed by the following methods, and the results are summarized in Table 1 below.

[Analysis method]

(1) glass transition temperature, melting point and heat of fusion

The glass transition temperature, melting point and heat of fusion of the polyester resin were analyzed using a differential scanning calorimeter. After raising the temperature from room temperature to 300 캜 at 20 캜 / min, the glass transition temperature, melting point and heat of fusion were confirmed while repeating quenching twice.

(2) Transmittance

Transmittance and haze transmittance of polyester resin was analyzed based on plastic product test method ASTM D 1003 using haze meter (NDH-5000) with white LED light source.

PTA: terephthalic acid

EG: ethylene glycol (ethylene glycol)

DEG: diethylene glycol (diethylene glycol)

THPDO: tetrahydropyran diol

CHDM: cyclohexanedimethanol

Tg: glass transition temperature

Tm: melting temperature

Tc: crystallization temperature

As shown in the above table, in Example 1 in which 5 mol% of each of 1,3-cyclohexanedimethanol and tetrahydrofuran diol was used as a diol compound, the resulting polyester resin had a glass transition temperature (Tg) of 84 DEG C, It was confirmed that the glass transition temperature was higher, the melting temperature was lower, and the permeability was better than that of Comparative Example 1 where the temperature (Tm) was 221 ° C and ethylene glycol alone was used as the diol compound. It can be confirmed that the heat resistance and permeability are superior to those of Comparative Examples 3 and 4 in which only ethylene glycol and cyclohexane dimethanol were used as diol compounds. Further, in Comparative Examples 5, 6, 7, 8 and 9 in which the content of 1,3-cyclohexane dimethanol was increased relative to ethylene glycol, the content of 1,3-cyclohexane dimethanol was increased, And the permeability was improved.

By adding 5 mol% of each of 1,3-cyclohexane dimethanol and tetrahydrofuran diol as diol compounds, it is possible to increase the economical efficiency with low production cost, to increase the heat resistance at a high glass transition temperature, to lower the melting temperature, It is possible to provide a polyester resin which is superior in optical characteristics such as the above.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will appreciate that such specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereby. something to do. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (8)

In the presence of a catalyst, a dicarboxylic acid component comprising terephthalic acid; And
Comprising a step of subjecting a diol component comprising ethylene glycol, 1,3-cyclohexanedimethanol and tetrahydrofuran diol to an esterification reaction and a condensation polymerization reaction. The process for producing a polyester resin according to claim 1, wherein the molar ratio of the dicarboxylic acid component to the diol component is from 1: 1.1 to 1: 1.3. The positive photosensitive resin composition according to claim 1, which comprises, based on 100 mol% of the dicarboxylic acid component, 50 to 90 mol% of ethylene glycol: 1,3-cyclohexanedimethanol: tetrahydropyranidiol; 5-50 mol%; To 5-10 mol% of the polyester resin. The process for producing a polyester resin according to claim 1, wherein the esterification reaction is carried out at a temperature of 250 to 270 ° C, the condensation polymerization reaction is reduced to less than 1.0 torr, and the reaction is carried out at a temperature of 270 to 280 ° C. The method for producing a polyester resin according to claim 1, wherein the catalyst comprises a titanium-based compound. A) a terephthalic acid-derived repeating unit as a dicarboxylic acid component; And
As a diol component, b) a repeating unit derived from ethylene glycol, c) a repeating unit derived from 1,3-cyclohexanedimethanol, and d) a repeating unit derived from tetrahydrofuran diol,
C) 50 to 90 mol% of repeating units derived from ethylene glycol, c) 5 to 50 mol% of repeating units derived from 1,3-cyclohexanedimethanol, and d) tetra And 5-10 mol% of repeating units derived from hydrolytic dianhydride. The amorphous polyester resin according to claim 6, which is amorphous. 7. The process according to claim 6, wherein the glass transition temperature is 80-85 DEG C,
According to ASTM D 1003 standard A polyester resin having a transmittance of 90% or more and haze of 3.5-4.0%.