KR101139130B1 - Blend of PET resin and transparent copolyester resin, preparing method thereof and articles using the same - Google Patents

Abstract

The present invention relates to a blend of a polyethylene terephthalate resin and a transparent copolyester resin, a method of manufacturing the same, and a molded product using the same, with respect to a polyethylene terephthalate resin having an intrinsic viscosity of 0.50 to 1.2 dl / g, and a dicarboxylic acid. It is characterized by blending 50-80 mol% copolymerized transparent co-polyester resin with 1,4-cyclohexanedimethanol.

According to the present invention, the content of 1,4-cyclohexanedimethanol can be adjusted as desired without a separate polymerization process, and the polyethylene terephthalate resin and the transparent co-polyester resin can be dried in one place, thereby simplifying work steps. By doing so, workability is improved, and as a result, cost reduction and production efficiency can be improved.

Polyethylene terephthalate, copolyester, blending, terephthalic acid, ethylene glycol, 1,4-cyclohexanedimethanol

Description

Blend of PET resin and transparent copolyester resin, preparing method etc. and articles using the same}

The present invention relates to a blend of a polyethylene terephthalate resin and a transparent copolyester resin, a preparation method thereof, and a molded product using the same. More specifically, blends of polyethylene terephthalate resin and transparent copolymer polyester resin which can be blended through an economical and efficient process by improving the compatibility of the polyethylene terephthalate resin and the transparent copolymer polyester resin and adjusting them to have similar crystallinity, It relates to a manufacturing method and a molded product using the same.

In general, in case of a product manufactured using polyethylene terephthalate resin (hereinafter referred to as 'PET resin') as a raw material, since the PET resin is a crystalline polymer, turbidity occurs due to crystallization during injection molding and blow molding, Transparency and physical property degradation occur. Moreover, since it is a crystalline polymer, the problem by shrinkage of a product after processing, such as injection, also arises.

In order to solve this problem, a method for producing a transparent polyester resin copolymerized with 1,4-cyclohexanedimethanol is known. For example, Korean Patent No. 378778 introduces a method for producing a transparent polyester resin copolymerized with 1,4-cyclohexanedimethanol. According to this method, crystallization is prevented by adding 1,4-cyclohexanedimethanol monomer, thereby solving the above problems. In this case, however, a large scale reactor is required because of the polymerization process, and a large investment in time and cost is required.

Another technique reported in the art is a technique of blending a PET resin and a transparent polyester resin copolymerized with 1,4-cyclohexanedimethanol. In this case, the transparent polyester resin used is a resin that is widely commercialized by copolymerizing 1,4-cyclohexanedimethanol to about 30 mol% of terephthalic acid, and may cause problems such as fusion of transparent polyester resin in a drying process. Work should be done below the glass transition temperature. Therefore, there is a disadvantage in that the PET resin must be dried through a separate process, and it must be dried for a long time because it is dried at a low temperature.

Meanwhile, US Pat. No. 4,874,809 solves the problem of PET resin turbidity by blending 100% by mol of a transparent polyester resin copolymerized with terephthalic acid to PET resin and 1,4-cyclohexanedimethanol. However, in this case, as the content of the transparent polyester resin increases, the processing temperature increases during blending, so that pyrolysis occurs, and thus, the physical properties decrease and the color changes to yellow, so that the blending operation is smooth without adding a separate heat stabilizer. A disadvantage arises that is not made.

Accordingly, the present inventors have solved the problems of the prior art, and researched to produce a polyester resin having properties superior to existing polyester resins, and as a result, blended a transparent polyester resin and a PET resin having specific physical properties in a specific composition ratio By easily adjusting the content of 1,4-cyclohexane dimethanol as desired, it was possible to obtain a blend of transparent polyester resin and PET resin through an economical and efficient method, the present invention was completed based on this.

Accordingly, an object of the present invention is to overcome the drawbacks of each of the transparent polyester resin and PET resin, to provide a blend of a PET resin and a transparent co-polyester resin having excellent physical properties, a manufacturing method and a molded product using the same. .

Another object of the present invention is to control the content of 1,4-cyclohexanedimethanol as desired without a separate polymerization process, PET resin and transparent that can be dried through a single process together with a PET resin and a transparent co-polyester resin The present invention provides a blend of a copolyester resin, a method of manufacturing the same, and a molded product using the same.

According to one aspect of the present invention for achieving the above and other objects:

1 to 99 mol% of PET resin having an intrinsic viscosity of 0.50 to 1.2 dl / g; And

1 to 99 mol% of a transparent copolymerized polyester resin copolymerized with 50 to 80 mol% of 1,4-cyclohexanedimethanol based on the dicarboxylic acid component;

A blend of a PET resin and a transparent copolyester resin is provided, which is obtained by blending.

According to another aspect of the present invention for achieving the above and other objects:

1 to 99 mol% of PET resin having an inherent viscosity of 0.50 to 1.2 dl / g, and 1 to 4-cyclohexanedimethanol copolymerized with 50 to 80 mol% of the dicarboxylic acid component, After blending 99 mol%, there is provided a method for producing a blend of a PET resin and a transparent copolyester resin, which is dried at a temperature of 120 to 160 ° C.

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

As described above, according to the present invention, the copolymerization by controlling the amount of 1,4-cyclohexanedimethanol monomer to form a crystal so that the compatibility is similar to the PET resin and to be dried in the same process as the PET resin Provided is a blend of a PET resin and a transparent co-polyester resin blended through an economical and efficient process by blending a polyester resin with the PET resin, a method of manufacturing the same, and a molded product using the same.

In general, polyester resins copolymerized with 1,4-cyclohexanedimethanol are known to prevent 1,4-cyclohexanedimethanol from causing crystallization by interfering regularity between structures in PET resin.

However, the inventors of the present invention have structural regularity when the 1,4-cyclohexanedimethanol monomer is added in a predetermined amount or more, and thus crystallization is performed even in the polyester resin copolymerized with 1,4-cyclohexanedimethanol. Was found to form. Thus, if the copolymerized polyester resin after crystallization and blended with the PET resin, it is possible to dry at a time without undergoing an unnecessary two-step drying process, and this makes it possible to easily prepare a blending resin. It is early.

Based on these findings, the blend according to the present invention is obtained by copolymerizing a PET resin having an intrinsic viscosity of 0.50 to 1.2 dl / g with 50 to 80 mol% of 1,4-cyclohexanedimethanol based on the dicarboxylic acid component. It is good to blend a transparent co-polyester resin.

PET resin used in the present invention is preferably intrinsic viscosity is 0.50 ~ 1.2dl / g, preferably 0.75 ~ 0.87dl / g. At this time, when the intrinsic viscosity of the PET resin is less than 0.50dl / g is expected to lower the mechanical properties due to the low molecular weight, when it exceeds 1.2dl / g, high pressure and temperature are required for blending and molding efficiency of Degradation occurs.

The PET resin is usually polymerized from dicarboxylic acids and diols, as known in the art. Dicarboxylic acids and derivatives thereof used in the polymerization of the PET resin are mainly terephthalic acid (TPA), isophthalic acid (IPA), naphthalene 2,6-dicarboxylic acid (2,6-naphthalenedicarboxylic acid; 2, 6-NDA), dimethyl terephthalic acid (DMT), dimethylisophthalate (DMI), dimethyl naphthalene 2,6-dicarboxylic acid (dimethyl 2,6-naphthalenedicarboxylate; 2,6-NDC), but are not limited thereto. It doesn't become

In addition, the diol used in the polymerization of the PET resin is EG, diethylene glycol (DEG), propylene glycol (PG), neopentyl glycol (NPG), cyclohexane dimethanol (cyclohexane dimethanol; CHDM) is not particularly limited, and all diols known in the art may be used in the manufacture of PET resin, but EG is preferable.

Looking at the polymerization process of the PET resin in more detail, the raw material dicarboxylic acid and diol are introduced into a reactor of a high temperature and high pressure, by adding a reaction catalyst, stabilizer and colorant as necessary to the oligomer (oligomer) made here The reaction is carried out in a high temperature vacuum state to polymerize a high molecular weight polyester resin, and the present invention is not particularly limited, and the PET resin can be polymerized as is known in the art.

The transparent copolyester resin copolymerized with 1,4-cyclohexanedimethanol used in the present invention has a dicarboxylic acid content of 1,4-cyclohexanedimethanol monomer content in the polyester resin so that crystallization is measured by differential scanning calorimetry. It should be adjusted to 50 to 80 mol% relative to the component to maximize the time and cost reduction effect in the process desired in the present invention.

The transparent copolyester resin 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 performed in a batch or continuous manner, and each raw material may be added separately, but it is most preferable to add terephthalic acid in the form of a slurry to glycol.

More specifically, first, a dicarboxylic acid component containing terephthalic acid and a glycol component containing 1,4-cyclohexanedimethanol are reacted. In this case, it is preferable to add the diol component to the dicarboxylic acid component so that the content of the diol component is 1.2 to 3.0, and to perform the esterification under the conditions of 230 to 260 ° C and 1.0 to 3.0 kg / cm 2, 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 ~ 300 minutes, which may be appropriately changed according to 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 isophthalic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, succinic acid, article Rutaric acid, adipic acid, sebacic acid, 2,6-naphthalenedicarboxylic acid, and the like, but are not particularly limited thereto.

1,4-cyclohexanedimethanol is used as another diol component other than ethylene glycol in order to improve the moldability or other physical properties of the homopolymer based only on terephthalic acid and ethylene glycol. As the 1,4-cyclohexanedimethanol, cis-, trans-, or a mixture of two isomers may be used, and the amount of the 1,4-cyclohexanedimethanol is added in an amount close to the desired mole percent of the final polymer, preferably with a PET resin. As described above, 50 to 80 mol% of the dicarboxylic acid may be used so as to allow drying and to prevent thermal decomposition due to high temperatures during processing.

In addition, the amount of ethylene glycol used as one of the diol components is added to 100 mol% of the total diol components compared to the dicarboxylic acid in consideration of the amount of 1,4-cyclohexanedimethanol.

In addition, other diol components usable in the copolymerization of the copolymerized polyester resin include 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, 1,3-cyclohexanedimethanol, and the like, but are not particularly limited thereto. no.

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

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, etc. are generally selected as components commonly used in the polycondensation reaction of the polyester resin. Can be used as

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.

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

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, polycondensation reaction is performed under reduced pressure of 400-0.1 mmHg in order to remove the glycol by-product, and the polyester resin copolymerized with 1, 4- cyclohexane dimethanol is obtained.

On the other hand, the blending amount of the PET resin and the transparent co-polyester resin prepared as described above is 1 to 99 mol%, respectively, to adjust the content of 1,4-cyclohexanedimethanol monomer in the polymer after the total blending as desired Although the mixing ratio can be adjusted in various ways, preferably, the mixing ratio must be adjusted so that the content of 1,4-cyclohexanedimethanol monomer in the total blending is 5 mol% or more of the dicarboxylic acid component. Can overcome them.

However, according to the conventional method, the PET resin chip and the transparent polyester resin chip may be used directly by mixing the PET resin chip and the transparent polyester resin chip at a mixing ratio set during the blending process of the PET resin and the transparent co-polyester resin, but the drying temperature is a PET resin and the transparent poly Since the ester resins are different, the chips of each polymer must be dried separately.

On the other hand, in the present invention, since the composition is composed of specific physical properties and components as described above so that crystallization occurs in the two kinds of polymers, the two chips are mixed in advance at a predetermined mixing ratio, without undergoing a separate two-step drying process, and then in a dryer. This is done by drying.

Here, the drying process is most preferably carried out at 120 to 160 ℃ in terms of efficiency compared to the economy.

The blend of the PET resin of the present invention prepared as described above and the copolyester resin may be molded through a conventional molding process known in the art, and may be manufactured into a molded article having a suitable shape as needed.

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

Example 1

PET resin chips with an intrinsic viscosity of 0.80 dl / g and transparent polyester resin chips with an intrinsic viscosity of 0.75 dl / g and a content of 1,4-cyclohexanedimethanol monomer in the polymer of 60 mol% compared to terephthalic acid are used as raw materials It was. The PET resin and the transparent polyester resin were mixed in a 5: 5 ratio in a rotary stirrer, dried at 160 ° C. for 5 hours in a dehumidifying dryer, and then introduced into an injection machine hopper. The molding machine manufactured a 200 ml cylindrical container using a Nissei Injection Blow Machine which is blow molded simultaneously with injection stretching. The parison is designed to have a mass of 45 g when the entire amount of PET resin is used, and the cylindrical container manufactured is designed to have an elongation ratio of 1.2 times on the axis and 1.5 times on the side with respect to the parison. The barrel temperature of the injection molding machine was set at 255 ° C, and injection and cooling were performed for 11 seconds each.

[Example 2]

A PET resin and a transparent polyester resin used in Example 1 were prepared in the same manner as in Example 1 except for blending in a 7: 3 ratio.

Example 3

A PET resin and a transparent polyester resin used in Example 1 were prepared in the same manner as in Example 1 except for blending in a 9: 1 ratio.

Comparative Example 1

Except for blending the transparent polyester resin used in Example 1 with a PET resin in a 6: 4 ratio by using a 1, 4- cyclohexane dimethanol monomer 30 mol% compared to terephthalic acid in Example 1 Produced in the same way as.

Comparative Example 2

Except that blended in Example 1 using only the PET resin was produced in the same manner as in Example 1 above.

Comparative Example 3

The same method as in Example 1, except that the 1,4-cyclohexanedimethanol monomer 100% by mole of the terephthalic acid in the copolymerized polyester resin and PET resin blended 3: 7 Was produced.

As described above, according to the present invention, it is possible to blend the PET resin and the transparent co-polyester resin without going through a two-step drying process, and as a result, it is possible to easily compensate for the problems that the PET resin has, as desired within the resin. Since the 4-cyclohexanedimethanol monomer content can be controlled, it has the advantage of time and economy.

In addition, as can be seen in Comparative Example 1, due to the risk of fusion of the transparent copolyester resin during molding in blending with a transparent copolyester polyester resin containing 30 mol% of 1,4-cyclohexanedimethanol monomer compared to terephthalic acid The temperature of the feeding zone of the injection molding machine should be lowered, and therefore, the temperature of the rear zone should be set relatively high. In contrast, the present invention has the additional advantage of having a much wider processing temperature range because there is no risk of fusion of chips in the front wheels.

Claims (4)

1 to 99 mol% of polyethylene terephthalate resin having an intrinsic viscosity of 0.50 to 1.2 dl / g; And 1 to 99 mol% of a transparent copolymerized polyester resin copolymerized with 50 to 80 mol% of 1,4-cyclohexanedimethanol based on the dicarboxylic acid component; A blend of a polyethylene terephthalate resin and a transparent copolyester resin, characterized by blending. The blend of polyethylene terephthalate resin and transparent co-polyester resin according to claim 1, wherein the intrinsic viscosity of the polyethylene terephthalate resin is 0.75 to 0.87 dl / g. 1 to 99 mol% polyethylene terephthalate resin having an intrinsic viscosity of 0.50 to 1.2 dl / g, and 50 to 80 mol% of 1,4-cyclohexanedimethanol copolymerized with respect to the dicarboxylic acid component. After blending 1 to 99 mol%, drying is carried out at a temperature of 120 to 160 ℃ a method for producing a blend of polyethylene terephthalate resin and transparent co-polyester resin. A molded article formed by molding a blend of the polyethylene terephthalate resin and the transparent co-polyester resin according to claim 1.