KR100547347B1 - Copolyester resin and articles using the same - Google Patents

Abstract

The present invention relates to a copolyester resin and a molded article using the same, and more particularly, to a copolyester based on terephthalic acid, ethylene glycol, 1,4-cyclohexanedimethanol, polyethylene glycol bisphenol-A, and a polyfunctional monomer. It relates to an ester resin and a molded article using the same. According to the present invention, in the preparation of a polyester resin copolymerized with 1,4-cyclohexanedimethanol, copolymerization is performed by adding a polyfunctional monomer and polyethylene glycol bisphenol-A to have excellent transparency, high melt viscosity and melt strength, whereas Copolymerized polyester resins having excellent moldability due to low melting pressure can be prepared. In addition, extruded blow molded products such as tubes and bottles, release extruded molded products, and the like can be obtained using the copolyester resin having excellent physical properties.

Polyethyleneglycol bisphenol-A, 1,4-cyclohexanedimethanol, ethylene glycol, terephthalic acid, polyfunctional monomer

Description

Copolyester resin and molded products using same {Copolyester resin and articles using the same}

1 is a polyester resin (A) copolymerized with 1,4-cyclohexanedimethanol, a copolyester resin (B) in which a multifunctional monomer is added to A, and polyethylene glycol bisphenol-A is added to B. It is a graph which shows the change of the viscosity value according to the shear rate of co-polyester resin (C).

The present invention relates to a copolymerized polyester resin and a molded article using the same, and more particularly, to copolymerization based on terephthalic acid, ethylene glycol, 1,4-cyclohexanedimethanol, polyethylene glycol bisphenol-A and polyfunctional monomers. It relates to a polyester resin and a molded article using the same.

Recently, co-polyester resins copolymerized with 1,4-cyclohexanedimethanol have become commercial polyesters used as important materials in the fields of packaging materials, molded articles, films, and the like.

As one such example, US Pat. No. 5,340,907 and US Pat. No. 5,681,918 disclose the use of copolyester resins copolymerized with 1,4-cyclohexanedimethanol and methods for their preparation.

In general, a method of preparing a copolyester resin comprises terephthalic acid, ethylene glycol, and 1,4-cyclohexanedimethanol as raw materials to add a stabilizer and a catalyst to perform an esterification reaction and a polycondensation reaction.

However, the melt viscosity of such a general polyester resin is suitable for injection molding and sheet forming using calender rolls, but profile extrusion and large capacity having a constant cross-sectional area and no calender rolls are used. It is relatively low for use in extrusion blow molding of bottles.

In this regard, US Pat. Nos. 4,217,440 and 4,983,711 disclose methods for increasing melt viscosity by adding additives having multifunctional groups, such as trifunctional groups, in extrusion blow molding. More specifically, when preparing copolyester resins such as terephthalic acid, ethylene glycol and 1,4-cyclohexanedimethanol, 0.05 to 0.5 mol% of polyfunctional monomers such as trimellitic acid and pentaerythritol are added to melt viscosity. How to improve. In this case, the molecular weight is raised by branching (melting) to increase the melt viscosity, but this causes the melt pressure to increase during molding.

Referring to FIG. 1, in the case of the copolyester resin (B) to which the polyfunctional monomer is added, the viscosity value in the region where the molecular weight is increased and the shear rate is low due to the aforementioned branching effect, that is, the melt viscosity value The value higher than this general copolyester resin (A) is shown. However, due to this, even in the shear rate range similar to the internal conditions of the extrusion blow molding machine, the viscosity value is higher than that of the general copolymer polyester resin, which has a higher melt pressure than the general copolymer polyester resin during molding. If the melt pressure is high, the efficiency of shortening the cycle time by increasing the RPM for productivity improvement and shortening the working time cannot be expected, and since the margin of the molding temperature range is small, the melt temperature and strength are further improved by lowering the molding temperature. The disadvantage is that it does not yield good results.

Therefore, the present invention solves the problems described above and studied to prepare a polyester resin having properties superior to the copolymerized polyester resin according to the prior art, as a result, 1,4-cyclohexane dimethanol copolymerized polyester resin In the preparation of the copolymer, copolymerization of a polyfunctional monomer and polyethylene glycol bisphenol-A was performed to obtain a copolymerized polyester resin having excellent moldability due to an increase in melt viscosity, an increase in melt strength, and a low melt pressure. Completed on this basis.

Accordingly, it is an object of the present invention to provide a copolyester resin having improved moldability than conventional copolyester resins.

Another object of the present invention is to provide an extrusion blow molded product using the copolymerized polyester resin.

Still another object of the present invention is to provide a release extrusion molded product using the copolymerized polyester resin.

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상기 식에서, m+n은 2∼12의 정수이다.
상기 다른 목적을 달성하기 위한 본 발명에 따른 압출 중공 성형제품은 상기 공중합 폴리에스테르 수지를 압출 중공 성형하여 제조된다.
상기 또 다른 목적을 달성하기 위한 본 발명에 따른 이형 압출 성형제품은 상기 공중합 폴리에스테르 수지를 이형 압출 성형하여 제조된다.
이하, 본 발명을 좀 더 구체적으로 설명하면 다음과 같다.Co-polyester resin according to the present invention for achieving the above object is a dicarboxylic acid component containing terephthalic acid; 10 to 80 mol% of 1,4-cyclohexanedimethanol, 0.1 to 20 mol% of polyethylene glycol bisphenol-A monomer represented by the following formula (1), and the rest of which includes ethylene glycol so that the sum of all diol components is 100 mol% A diol component; And 0.05 to 0.5 mol% of multifunctional monomers.

Wherein m + n is an integer of 2-12.
Extruded blow molded article according to the present invention for achieving the above another object is manufactured by extrusion blow molding the copolymer polyester resin.
Release extrusion molded product according to the present invention for achieving the above another object is manufactured by release extrusion molding the copolymer polyester resin.
Hereinafter, the present invention will be described in more detail.

As described above, in the present invention, in the preparation of the polyester resin copolymerized with 1,4-cyclohexanedimethanol, the bottle and the mold release molded product are extruded through the extrusion hollow by adding and copolymerizing a polyfunctional monomer and polyethylene glycol bisphenol-A. Provided are co-polyester resins excellent in moldability, and molded articles using the same, which obtain high melt viscosity and melt strength which can be produced, and which also have low melt pressure during molding.

Copolyester resin according to the present invention is prepared through the first step of the esterification reaction and the second step of the polycondensation reaction.

The first step, the esterification reaction may be carried out in a batch or continuous manner, and each raw material may be separately added, but it is most preferable to add terephthalic acid in the form of a slurry to glycol.

More specifically, a dicarboxylic acid component containing terephthalic acid, a diol component containing 1,4-cyclohexanedimethanol, polyethylene glycol bisphenol-A and ethylene glycol, and a polyfunctional monomer are placed in a reactor and mixed under elevated temperature. And react.

At this time, the content of the diol component relative to the dicarboxylic acid component is added in a molar ratio of 1.2 to 3.0, it is preferable to perform the esterification under the conditions of 230 to 260 ℃ and 1.0 to 3.0 kg / ㎠, but is not limited thereto. It doesn't happen. Preferably, the said esterification temperature is 240-260 degreeC, More preferably, it is 245-255 degreeC. In addition, the esterification time is usually about 100 to 300 minutes, which may be appropriately changed depending on the reaction temperature, pressure and the molar ratio of the diol component to the dicarboxylic acid component used.

In addition to the terephthalic acid, the dicarboxylic acid component used for the purpose of improving the physical properties in the present invention includes isophthalic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanoic acid dicarboxylic acid, succinic acid and gluta. Lactic acid, adipic acid, sebacic acid, 2,6-naphthalenedicarboxylic acid, and the like, but are not particularly limited thereto.

Examples of the diol compounds used to improve moldability or other physical properties of the homopolymers based only on terephthalic acid and ethylene glycol are 1,4-cyclohexanedimethanol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol And 1,3-cyclohexanedimethanol. In particular, 1,4-cyclohexanedimethanol is preferable as the diol compound used for improving physical properties of the homopolymer.

The 1,4-cyclohexanedimethanol used in the present invention may be cis-, trans-, or a mixture of two isomers, and the amount of the 1,4-cyclohexanedimethanol is used in an amount close to the desired mole percent of the final polymer, preferably crystallization. In order to prevent moldability defects according to the present invention, it is preferably 10 to 80 mol% of all the diol components. In addition, the amount of ethylene glycol used as one of the diol components of the present invention is added so that the sum of all the diol components is 100 mol% in consideration of the amounts of 1,4-cyclohexanedimethanol and polyethylene glycol bisphenol-A.

The esterification reaction does not require a catalyst, but may be optionally added to reduce the reaction time.

The multifunctional monomer used in the present invention is a crosslinking agent component for improving extruded blow moldability and release extrudability such as a tube, and includes trimellitic acid, trimellitic anhydride, hemimeltic acid, and hemimelly anhydride. Tic acid, trimesic acid, tricavalic acid, trimethylolpropane, trimethylolethane, glycerin, pentaerythritol, and the like.

At this time, it is preferable that the usage-amount of the said polyfunctional monomer is 0.05-0.5 mol% with respect to the said dicarboxylic acid component. Within this range, it is possible to reach a melt strength useful for extrusion blow molding, and to prevent a decrease in transparency due to active crosslinking.

Polyethylene glycol bisphenol-A used in the present invention is represented by the following general formula (1) as a component for improving the moldability of the copolymer resin:

Formula 1

Wherein m + n is an integer of 2-12.

At this time, it is preferable that the usage-amount of the said polyethyleneglycol bisphenol-A is 0.1-20 mol%. Within this range, it is easy to confirm the physical property improvement effect of the addition of polyethylene glycol bisphenol-A, the reactivity is not degraded.

Addition of polyethyleneglycol bisphenol-A in the preparation of copolyester resins containing polyfunctional monomers resulted in high melt strength values increased by more than 20% when the diameter below 100 millimeters (mm) was measured from the die of the extrusion blow molding machine. Low molding pressure values of 90 bar or less can be expected when forming. If the percent melt strength is 20 or more, it is possible to produce a large-capacity bottle through the production of release extruded products and extrusion blow molding. In addition, when the molding has a low melting pressure of 90bar or less, the RPM of the molding machine is increased to shorten the cycle time, thereby improving productivity. In addition, since there is a margin in the molding temperature range, it is possible to obtain excellent results that can further improve the melt viscosity and strength by lowering the molding temperature.

After the first step of the above-mentioned esterification reaction is completed, the second step of the polycondensation reaction is carried out. The polycondensation catalyst, stabilizer and colorant are generally used in the polycondensation reaction of the resin of the polyester. May optionally be used.

Polycondensation catalysts usable in the present invention include, but are not limited to, titanium, germanium and antimony compounds.

The titanium catalyst is generally used as a polycondensation catalyst of a polyester resin in which 1,4-cyclohexanedimethanol is copolymerized with 15% or more of terephthalic acid by weight, and can be reacted even when a small amount is used in comparison with an antimony catalyst. In addition, it has the advantage of lower cost than the germanium-based catalyst.

Titanium-based catalysts usable in the present invention include tetraethyl titanate, acetyltripropyl titanate, tetrapropyl titanate, tetrabutyl titanate, tetrabutyl titanate, polybutyl titanate, 2-ethylhexyl titanate, octylene Glycol titanate, lactate titanate, triethanolamine titanate, acetylacetonate titanate, ethyl acetoacetic ester titanate, isostearyl titanate, titanium dioxide, titanium dioxide and silicon dioxide co-precipitates, titanium dioxide and zirconium dioxide And coprecipitates.

In this case, since the amount of the polycondensation catalyst affects the color of the final polymer, the amount of polycondensation catalyst may vary depending on the desired color and the stabilizer and colorant used. Preferably, the amount of polycondensation catalyst is 1 to 100 ppm based on the amount of titanium based on the weight of the final polymer. More preferably, 1-50 ppm and 10 ppm or less are preferable based on the amount of silicon elements. The desired degree of polymerization can be reached within this range, and the color of the final polymer is prevented from becoming yellow.

In addition, stabilizers and coloring agents and the like can be used as other additives.

Stabilizers usable in the present invention typically include phosphoric acid, trimethyl phosphate, triethyl phosphate, triethyl phosphonoacetate, and the like, and the amount of the stabilizer is preferably 10 to 100 ppm based on the small amount of the human polymer relative to the weight of the final polymer. It is easy to obtain the desired bright color within the said range, and the desired high polymerization degree can be reached.

In addition, the colorants usable in order to improve the color in the present invention include conventional colorants such as cobalt acetate and cobalt propionate, and the amount of addition is preferably 0 to 100 ppm relative to the final polymer weight.

In addition to the colorant, conventionally known organic compounds may be used as the colorant.

On the other hand, the second condensation reaction is carried out after the addition of these components is preferably carried out under reduced pressure conditions of 260 ~ 290 ℃ and 400 ~ 0.1mmHg, but is not limited thereto.

The polycondensation step is carried out for the required time until the desired intrinsic viscosity is reached. The reaction temperature is generally 260 to 290 ° C, preferably 260 to 280 ° C, more preferably 265 to 275 ° C.

In addition, polycondensation reaction is performed under reduced pressure of 400-0.1 mmHg in order to remove the glycol by-product.

As described above, the copolyester resin according to the present invention has an improved melt viscosity and melt strength and has excellent moldability due to low melt pressure during molding processing. Accordingly, such a copolyester resin may be molded through an extrusion hollow or a release extrusion process to obtain an extruded blow molded product and a release extruded product having excellent moldability.

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

The physical properties shown in the following Examples and Comparative Examples were measured in the following manner:

◎ Glass Transition Temperature (Tg): Using Differential Scanning Calorimetry from TA Instrument

◎ Transparency: Measured using Haze-meter from Nippon Denshoku, Japan

◎ Melt Viscosity: Measured by parallel plate type at shear rate (1 / s) = 1 area using Physica Rheometer of Physica, USA

◎ Melt strength: Measured by Extrusion Blow Molding of Bekum, Germany. The RPM of the machine is set to 20, the cycle time is 17 seconds, the die diameter is 30 millimeters, the extruder temperature and the die temperature are 195 ~ 220 ℃ and 190 ~ 205 ℃ for each section. Measure the diameter of the 100 mm bottom from

The melt strength (%) is calculated using the following equation:

Where X is the diameter after 10 centimeter extrusion from the die and D is the diameter of the die. Thus, if X is less than D, the percent melt strength is negative; if greater than D, it is positive.

◎ Melting pressure: measured by Extrusion Blow Molding of Bekum, Germany. After about 20 kg of the sample of the type to be measured is put into the molding machine, after 20 minutes of stabilization time, the difference between the setting internal temperature and the actual internal temperature of the molding machine is less than ± 1 ° C. Measure the average value below 4 bar.

Example 1

2 L of 1,4-cyclohexanedimethanol, 466 g of ethylene glycol, 10 g of polyethyleneglycol bisphenol-A having m + n = 2 in Formula 1, and 1.8 g of trimellitic acid per 6 moles of terephthalic acid were equipped with a stirrer and an outlet condenser. After administration to the reaction while slowly raising the temperature to 255 ℃ while mixing.

At this time, the generated water is discharged out of the system to esterify the reaction and when the generation of water, the outflow is finished, the contents are transferred to the polycondensation reactor equipped with a stirrer, a cooling condenser and a vacuum system.

Add 0.5 g of tetrabutyl titanate to the esterification reaction, add 0.4 g of triethylphosphate, add 0.5 g of cobalt acetate, and increase the internal pressure from 240 ° C to 275 ° C. After 40 minutes of low vacuum reaction from atmospheric pressure to 50mmHg, ethylene glycol was removed, and then gradually decompressed to 0.1mmHg until the desired intrinsic viscosity under high vacuum was discharged and cut into chips.

The glass transition temperature and color of the copolyester resin thus prepared were measured, and the glass transition temperature, transparency, intrinsic viscosity, melt viscosity, melt pressure, and melt strength together with the reaction conditions are shown in Table 1 below.

Example 2

Except that 57g of polyethylene glycol bisphenol-A was added, the same process as in Example 1 was carried out, and the glass transition temperature, transparency, intrinsic viscosity, melt viscosity, melt pressure, and melt strength together with the reaction conditions are shown in Table 1 below. Shown in

Example 3

Except that the addition of 190g polyethylene glycol bisphenol-A was carried out in the same manner as in Example 1, and the glass transition temperature, transparency, intrinsic viscosity, melt viscosity, melt pressure and melt strength together with the reaction conditions Table 1 Shown in

Example 4

The procedure was carried out in the same manner as in Example 2, except that 1.2 g of trimethylolpropane was added instead of the trimellitic acid used as the polyfunctional monomer, and the glass transition temperature, transparency, intrinsic viscosity, melting viscosity, and melting were performed together with the reaction conditions. Pressure and melt strength are shown in Table 1 below.

Comparative Example 1

Except not adding polyethylene glycol bisphenol-A was carried out in the same manner as in Example 1, and the glass transition temperature, transparency, intrinsic viscosity, melt viscosity, melt pressure and melt strength together with the reaction conditions Table 1 Shown in

Comparative Example 2

Except not adding polyethylene glycol bisphenol-A and trimellitic acid as a trifunctional monomer was carried out in the same manner as in Example 1, with the reaction conditions, glass transition temperature, transparency, intrinsic viscosity, melt viscosity, melting Pressure and melt strength are shown in Table 1 below.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 additive Polyethylene glycol bisphenol-A 10g + trimellitic acid 1.8g Polyethylene glycol bisphenol-A 57 g + trimellitic acid 1.8 g Polyethylene glycol bisphenol-A 190 g + trimellitic acid 1.8 g Polyethyleneglycol bisphenol-A 57g + trimethylol propane 1.2g 1.8 g of trimellitic acid - Glass transition temperature (℃) 80.2 81.2 82.2 80.4 79.4 79.0 Intrinsic Viscosity (IV) (dl / g) 0.77 0.76 0.77 0.77 0.77 0.78 Haze 1.0 or less 1.0 or less 1.0 or less 1.0 or less 1.0 or less 1.0 or less Melt pressure (bar) 89 ± 4 87 ± 4 75 ± 4 86 ± 4 105 ± 4 94 ± 4 Melt viscosity (Pa.s) (275 ℃) 2150 2210 2730 2300 2100 1090 Melt strength (%) 21.0 24.8 22.0 25.1 19 10.5

As can be seen from the above examples and comparative examples, in the present invention, by adding polyethylene glycol bisphenol-A to terephthalic acid, ethylene glycol, 1,4-cyclohexanedimethanol, trimellitic acid (or trimethylolpropane), Melt viscosity and melt strength are improved compared to the copolyester resin prepared by the conventional method, so that it is possible to manufacture extruded blow molded articles and release extrusion molding for the production of large-capacity bottles, and to mold the copolyester resin containing only polyfunctional monomers. Since the melt pressure is reduced, it is possible to improve productivity by increasing the RPM to shorten the cycle time. Also, since there is a margin in the molding temperature range, it is possible to obtain excellent results by further improving the melt viscosity and strength by lowering the molding temperature. I can make it.

Claims (5)

Dicarboxylic acid components including terephthalic acid; 10 to 80 mol% of 1,4-cyclohexanedimethanol, 0.1 to 20 mol% of polyethyleneglycol bisphenol-A monomer represented by the following formula (1), and the rest of which includes ethylene glycol so that the sum of all diol components is 100 mol% A diol component; And 0.05 to 0.5 mol% of a multifunctional monomer with respect to the dicarboxylic acid component; Copolymerized polyester resin comprising: Formula 1

Wherein m + n is an integer of 2-12. The method of claim 1, wherein the multifunctional monomer is trimellitic acid (trimellitic acid), trimellitic anhydride (hemimellitic acid), hemimelic acid anhydride, trimesic acid, tricavalic acid, trimethylolpropane, Copolymer polyester resin, characterized in that one selected from the group consisting of trimethylol ethane, glycerin and pentaerythritol. The copolyester resin according to claim 1, wherein the copolyester resin has a melt strength (%) of 20 or more and a melt pressure of 90 bar or less. An extruded blow molded article formed by extrusion blow molding the copolyester resin according to any one of claims 1 to 3. A release extrusion molded product formed by release extrusion molding the copolyester resin according to any one of claims 1 to 3.

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