KR101222791B1 - Extruded Articles Using Copolyester Resin - Google Patents

Abstract

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

According to the present invention, in the preparation of polyester resin copolymerized with 1,4-cyclohexanedimethanol, copolymerization is performed by adding polyfunctional monomer and polypropylene glycol bisphenol-A to obtain excellent melt viscosity, high melt strength, and low melt pressure. It is possible to produce a copolyester resin having excellent moldability while reducing moldability and reducing colorant usage. 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.

1,4-cyclohexanedimethanol, polypropylene glycol bisphenol-A, ethylene glycol, terephthalic acid, extrusion blow molding, release extrusion molding

Description

Extruded Articles Using Copolyester Resin

1 is a graph showing a change in viscosity value according to the shear rate of a copolyester resin to which a multifunctional monomer according to the prior art is added.

The present invention relates to a copolyester resin and a molded article using the same, and more particularly, to copolymerization based on terephthalic acid, ethylene glycol, 1,4-cyclohexanedimethanol, polypropylene glycol bisphenol-A, and a polyfunctional monomer. 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 a raw material, and adding a stabilizer and a catalyst to perform an esterification reaction and a polycondensation reaction.

However, these general polyester resins are suitable for injection molding and sheet forming using calender rolls, but profile extrusion and large capacity have a constant cross-sectional area and do not use calender rolls. 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. In more detail, 0.05-0.5 mol% of polyfunctional monomers, such as trimellitic acid and pentaerythritol, are added to the co-polyester resin which has other diols, such as ethylene glycol and 1, 4- cyclohexane dimethanol, with respect to terephthalic acid, It is a method of improving melt viscosity. In this case, the molecular weight is increased 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 copolymerized polyester resin 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 is a general copolymerization It shows higher value than polyester resin. 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 can be further improved by lowering the molding temperature. The disadvantage was the inability to obtain good results.

Meanwhile, Korean Laid-Open Patent Publication No. 2005-304 adds a multifunctional monomer and polyethylene glycol bisphenol-A when preparing a polyester resin copolymerized with 1,4-cyclohexanedimethanol to have high melt viscosity and low melt pressure. Disclosed are a copolyester resin excellent in aspect and a molded article using the same. However, in the case of the copolyester resin, a colorant is added to improve color, and there is a disadvantage in that deterioration is caused by increasing the colorant content to obtain a desired color.

Accordingly, the present invention solves the problems described above and studies 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 Copolymerization of a polyfunctional monomer and polypropylene glycol bisphenol-A by the addition of the copolymerization in preparation, not only has excellent moldability, but also excellent color, which reduces the amount of colorant used, and prevents deterioration. The present invention was completed based on this.

Accordingly, an object of the present invention is to provide a copolyester resin having excellent moldability, color, and thermal stability.

Another object of the present invention 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.

Copolyester resin according to the present invention for achieving the above object is a dicarboxylic acid containing terephthalic acid; 1.2 to 3 moles of diol relative to the dicarboxylic acid, wherein the diol contains 20 to 80 mole% of 1,4-cyclohexanedimethanol and 20 to 80 mole% of ethylene glycol; 0.05-0.5 mol% of a polyfunctional monomer with respect to the said dicarboxylic acid; And a polypropylene glycol bisphenol-A monomer represented by the following Chemical Formula 1 of 0.5 to 20 mol% with respect to the dicarboxylic acid, and having a col-b value of 3 or less and a thermal stability of 6 or less (delta col- b) at the same time.

[Formula 1]

In this formula, m + n is an integer of 2-12.

Extruded blow molded article according to the present invention for achieving the above another object is by extrusion blow molding the copolyester resin.

Release molded article according to the present invention for achieving the above another object is to perform the extrusion 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, copolymerization using a polyfunctional monomer and polypropylene glycol bisphenol-A is performed. Co-polyester resin having high melt viscosity and melt strength for producing a molded extruded molded article, low melt pressure during molding and low col-b value of 3 or less and delta col-b of 6 or less, and A molded product using the same is provided.

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, first, a dicarboxylic acid containing terephthalic acid and a glycol containing ethylene glycol and 1,4-cyclohexanedimethanol are reacted, followed by addition of a polyfunctional monomer and polypropylene glycol bisphenol-A. Let's do it.

In this case, the content of glycol is added to the terephthalic acid so that the content of glycol is 1.2 to 3.0, and the esterification reaction is preferably performed under the conditions of 230 to 260 ° C and 1.0 to 3.0 kg / cm 2, but is not limited thereto. Preferably, the said esterification temperature is 240-260 degreeC, More preferably, it is 245-255 degreeC. In addition, the esterification time is usually 100 ~ 300 minutes, which may be appropriately changed depending on the reaction temperature, pressure and the molar ratio of glycol to dicarboxylic acid used.

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

The glycol compound used to improve the moldability or other physical properties of the homopolymer based only on terephthalic acid and ethylene glycol is 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 glycol compound used for improving the 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, 20 to 80 mol% of the total glycol component is preferable.

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.

In this case, the amount of the polyfunctional monomer is preferably 0.05 to 0.5 mol% with respect to the dicarboxylic acid, if the amount is less than 0.05 mol% does not reach the melt strength (melt strength) useful for extrusion blow molding In addition, when the content exceeds 0.5 mol%, transparency is lowered due to active crosslinking, and thus a desired molded product cannot be obtained.

Polypropylene glycol bisphenol-A used in the present invention is a component having the advantage of improving the moldability of the copolymer resin of the conventional polyethylene glycol bisphenol-A, while at the same time the effect of lowering the col-b value compared to the same amount It is represented by the following formula (1):

[Formula 1]

In this formula, m + n is an integer of 2-12.

In this case, the amount of the polypropylene glycol bisphenol-A is preferably 0.5 to 20 mol% with respect to the dicarboxylic acid, and when the amount is less than 0.5 mol%, the physical property improvement effect according to the addition of the polypropylene glycol bisphenol-A is confirmed. It is difficult to do it, and if it exceeds 20 mol% there is a problem that the reactivity is inferior.

When the polypropylene glycol bisphenol-A is added to the copolyester resin containing a polyfunctional monomer, a high melt strength value increased by 20% or more when a diameter below 100 millimeters (mm) is measured from the die of the extrusion blow molding machine. And a low melt pressure value of 90 bar or less upon molding. 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 molding has a low melt 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.

In addition, it is possible to make a product with a lower col-b value than when adding the polyethylene glycol bisphenol-A, in the case of the present invention 3 or less compared to the same amount of polyethylene glycol bisphenol-A, preferably A product with a relatively low col-b value of 1 to 3 can be obtained. In the case of a transparent product such as the reactant, when a yellow product having a high col-b is produced, it has a feeling of deterioration and a feeling of deterioration of quality. Thus, at the same level, the col-b has a low transparent and blue color. That is, the polyester resin in which polypropylene glycol bisphenol-A is added may be said to have a product having such an advantage.

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-based catalyst is generally used as a polycondensation catalyst of a polyester resin copolymerized with 1,4-cyclohexanedimethanol by 15% or more by weight of terephthalic acid, and even when a small amount is used in comparison with an antimony-based catalyst It is possible and also has the advantage of lower cost than 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 the 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 is good and 10 ppm or less is preferable based on a silicon element amount. At this time, if the amount of titanium element is less than 1ppm can not reach the desired degree of polymerization, if it exceeds 100ppm the color of the final polymer is yellow and the desired color cannot be obtained.

Moreover, stabilizers, coloring agents, etc. are used. Stabilizers usable in the present invention typically include phosphoric acid, trimethyl phosphate, triethyl phosphate, triethyl phosphonoacetate, and the like. The amount of the stabilizer is preferably 10 to 100 ppm relative to the weight of the final polymer based on the small amount of the phosphorus. At this time, if the addition amount of the stabilizer is less than 10ppm it is difficult to obtain the desired bright color, if it exceeds 100ppm there is a problem that does not reach the desired high polymerization degree.

In addition, examples of the colorant that can be used in the present invention include conventional colorants such as cobalt acetate and cobalt propionate, and the addition amount thereof is preferably 0 to 90 ppm relative to the final polymer weight. In the present invention, if the content of the colorant exceeds 90ppm it is difficult to ensure thermal stability. 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 ~ 290 ° C, preferably 260 ~ 280 ° C, more preferably 265 ~ 275 ° C. In addition, a polycondensation reaction is performed under reduced pressure of 400-0.1 mmHg in order to remove the glycol by-product and obtains the polyester resin copolymerized with 1, 4- cyclohexane dimethanol.

As described above, the copolyester resin according to the present invention has improved melt viscosity and melt strength and has excellent moldability due to low melt pressure during molding processing. In addition, since the color is superior to the case of using the same amount of polyethylene glycol bisphenol-A, the amount of colorant need not be increased, and deterioration due to the colorant can be prevented, so that the col-b value of 3 or less is excellent. It has a color and at the same time ensures a thermal stability (delta col-b) of 6 or less. 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 diameter of the die is 30 millimeters, the temperature of the extruder 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:

×100

× 100

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 type of sample 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.

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

◎ Thermal stability: After placing 30g of chip on an aluminum plate and placing it at a temperature of 200 degrees Celsius for 30 minutes, the amount of chip col-b increase is measured.

Example 1

1.8 g of trimellitic acid was added to a polyester resin copolymerized with 277 g of 1,4-cyclohexanedimethanol and 466 g of ethylene glycol based on 6 moles of terephthalic acid, and m + n = 2 in Formula 1 The reaction is carried out while gradually raising the temperature to 255 ° C. while mixing 58 g of A in a 3 L reactor equipped with a stirrer and an outlet condenser.

At this time, the generated water is discharged out of the system to ester reaction, and when the generation of water, the outflow is finished, the contents are transferred to a 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, reacted under high vacuum until desired intrinsic viscosity, discharged, and cut into chips.

The glass transition temperature and color were measured by the above-described method of the 1,4-cyclohexanedimethanol copolymerized polyester resin thus prepared, and the glass transition temperature, transparency, intrinsic viscosity, melt viscosity, melt pressure, melt strength and thermal stability And col-b values are shown in Table 1 below.

Example 2

Except that 190g of polypropylene glycol bisphenol-A was carried out in the same manner as in Example 1, glass transition temperature, transparency, intrinsic viscosity, melt viscosity, melting pressure, melt strength, thermal stability and col-b value It is shown in Table 1 below.

Example 3

Except for adding 0.4g of cobalt acetate was carried out in the same manner as in Example 2, the glass transition temperature, transparency, intrinsic viscosity, melt viscosity, melting pressure, melt strength, thermal stability and col-b values are shown in Table 1 Shown in

Comparative Example 1

Except for adding polyethylene glycol bisphenol-A instead of polypropylene glycol bisphenol A was carried out in the same manner as in Example 2, glass transition temperature, transparency, intrinsic viscosity, melt viscosity, melt pressure, melt strength, thermal stability and The col-b values are shown in Table 1 below.

Comparative Example 2

Except not adding polypropylene glycol bisphenol-A was carried out in the same manner as in Example 3, glass transition temperature, transparency, intrinsic viscosity, melt viscosity, melting pressure, melt strength, thermal stability and col-b value It is shown in Table 1 below.

Comparative Example 3

Except that 0.7g of cobalt acetate was added, the same process as in Example 1 was carried out. The glass transition temperature, transparency, intrinsic viscosity, melt viscosity, melt pressure, melt strength, thermal stability, and col-b values are shown in the following table. 1 is shown.

Comparative Example 4

Except not adding polypropylene glycol bisphenol-A and trimellitic acid was carried out in the same manner as in Example 1, glass transition temperature, transparency, intrinsic viscosity, melt viscosity, melt pressure, melt strength, thermal stability and The col-b values are shown in Table 1 below.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Colorant Content (g) 0.5 0.5 0.4 0.6 0.5 0.7 0.5 Glass transition temperature
(℃) 81.2 81.0 81.1 82.2 79.4 79.0 79.0 Intrinsic viscosity (Ⅳ)
(dl / g) 0.78 0.77 0.78 0.77 0.77 0.78 0.78 Transparency (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 1.0 or less Melt pressure (bar) 87 ㅁ 4 75 Wh 4 75.4 75 Wh 4 105 W 4 94 ㅁ 4 94 ㅁ 4 Melt viscosity (Pa.s)
(275 ℃) 2210 2720 2700 2730 2100 2090 1090 Melt strength (%) 24.8 21.9 21.5 22.0 19 18.5 10.5 Col-b 2.0 1.8 2.9 4.0 5.3 3.1 4.1 Thermal stability
(delta col-b) 6 6 4 6 6 8 6

As can be seen from the above examples and comparative examples, in the present invention, the melt viscosity and the melt strength are similar to those of the copolymerized polyester prepared by the conventional method by adding polypropylene glycol bisphenol-A together with the multifunctional monomer. Not only improves the moldability but also reduces the col-b to obtain excellent color, which reduces the content of colorant and prevents deterioration. Molded products and release extrusion molding are possible.

Claims (5)

Dicarboxylic acids, including terephthalic acid, 1.2 to 3 moles of diol relative to the dicarboxylic acid, wherein the diol contains 20 to 80 mole% of 1,4-cyclohexanedimethanol and 20 to 80 mole% of ethylene glycol, 0.05-0.5 mol% of a polyfunctional monomer with respect to the said dicarboxylic acid, and Preparing a copolymerized polyester resin by reacting 0.5 to 20 mol% of a polypropylene glycol bisphenol-A monomer represented by Formula 1 with respect to the dicarboxylic acid; And Preparing the copolyester resin into an extrusion molded product through extrusion blow molding or release extrusion molding; / RTI > Wherein the copolyester resin satisfies a col-b value of 3 or less, a thermal stability of 6 or less (delta col-b), a melt strength of 20 or more and a melt pressure of 90 bar or less simultaneously. Manufacturing method of the product: Formula 1

In this formula, m + n is an integer of 2-12. delete 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, A process for producing an extruded article, characterized in that it is selected from the group consisting of trimethylolethane, glycerin and pentaerythritol. delete delete

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