KR100797760B1 - Polyester composition having good reheating property and polyester bottle comprising the same - Google Patents

Abstract

A polyester composition, a method for preparing the polyester composition, an injection molded polyester preform comprising the composition, and a polyester container obtained by blow-molding the preform are provided to improve reheating velocity, thereby saving energy and enhancing productivity. A polyester composition comprises 10-500 ppm of a mixture comprising calcium, tin, iron oxide, carbon black, cobalt and antimony, wherein the content of calcium, tin, iron oxide, carbon black, cobalt and antimony is 0.5-1.5 parts by weight, 0.5-1.5 parts by weight, 4.5-5.5 parts by weight, 4.5-5.5 parts by weight, 4.5-5.5 parts by weight, and 9.5-10.5 parts by weight, respectively. Preferably the mixture comprises further 0.5-1.5 parts by weight of magnesium or 0.5-1.5 parts by weight of titanium.

Description

Polyester composition having good reheating property and polyester bottle comprising the same}

1 is a schematic diagram of a reheat performance evaluation equipment process of a thermoplastic polyester resin.

<Brief description of the symbols for the main parts of the drawings>

1 quartz lamp 2 controller 3 preform

4 controller sensor 5 preform holder 6 diffuse reflection insulation plate

7: support box 8: diffuse reflection insulation table

10 air exhaust 11 air intake

The present invention relates to a polyester composition, a method for preparing the same, a polyester preform and a polyester container including the composition. More specifically, the polyester composition according to the present invention includes calcium, tin, iron oxide, carbon black, 10 to 500 ppm of cobalt and an antimony-containing mixture (MAO compound), the reheating speed is high during the production of plastic containers for food and beverages, so that required energy can be saved and productivity can be improved.

In the conventional plastic molding container manufacturing method, the resin is extruded into pellets, injection molded to form a preform, and then reheated and blown with air to form the container in the form of a molding mold. It's a print out.

The injection molded preform is reheated to about 90-145 ° C. using infrared light and blown with air to prepare a container. In the blow-molding step, biaxial orientation occurs at least at the container wall and the container bottom to increase the strength of the container, to withstand deformation from internal pressure when the container is used, and to increase the storage period of the container contents to preserve the contents. Can be.

Currently, polyester resins, especially polyethylene terephthalate (PET), have properties such as stability and excellent strength, and thus replace conventional glass as a container material such as carbonated beverages, bottled water, or juice beverages. The demand is growing more than 10% every year.

Generally, polyester is mixed with 60 to 68% of terephthalic acid and 28 to 32 wt% of ethylene glycol as a raw material of the resin, and 250 to 350 ppm of antimony trioxide (Sb ₂ O ₃ ) and 150 to 250 ppm of phosphoric acid (H ₃ PO ₄ ) as additives. It was prepared by adding 1.0 ~ 2.5mole% / PET of high purity isophthalic acid as a secondary raw material, but a method of adding a large amount of inorganic particles in order to improve the reheating performance of the polyester in the process of reheating and preforming the polyester preform Has been proposed.

For example, US Pat. No. 4,408,004 discloses the use of additives comprising carbon black. However, the carbon black has a problem that it is easily lost even in the smallest process change due to the fine particle size. In addition, US Pat. No. 4,420,581 discloses a method for improving the infrared absorption rate of a PET resin containing a green pigment using red iron oxide. However, there is a problem that the red iron oxide ultraviolet absorber adversely affects the color of the transparent PET container.

Another method is disclosed in US Pat. No. 4,481,314, which uses a specific anthraquinone type of pigment to improve the reheat rate. However, these pigments additionally absorb light in the visible region, causing a change in the color of the polymer product. In addition, due to the relatively low light absorbency, a higher content should be added, and when this amount is added, the product becomes green in color, which is not suitable for the manufacture of transparent containers.

Therefore, there is a need for a resin composition that maintains transparency while improving productivity by increasing the reheating performance of the resin composition during reheating for blow molding.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a polyester resin composition having excellent reheating performance and transparency.

Another object of the present invention is to provide a method for producing the polyester resin composition.

Still another object of the present invention is to provide a polyester preform and a polyester container including the polyester resin composition.

The present invention relates to a polyester composition having excellent reheatability and transparency, including 10 to 500 ppm of a mixture containing calcium, tin, iron oxide, carbon black, cobalt, and antimony (hereinafter referred to as MAO compound).

The present inventors have found that the reheatability and transparency of the polyester can be increased when the MAO compound is used, thereby completing the present invention. Therefore, the present invention is characterized by adding 10 to 500 ppm of the MAO compound to the polyester composition. More preferable content of MAO compound is 200 to 400 ppm. If the content of the MAO compound is less than 10 ppm, the desired reheatability cannot be obtained, and if the content of the MAO compound is more than 500 ppm, the color of the resin becomes excessively black and the commerciality of the resin is low.

The MAO compound is calcium, tin, iron oxide, carbon black, cobalt, and antimony content of 0.5 to 1.5 parts by weight, 0.5 to 1.5 parts by weight, 4.5 to 5.5 parts by weight, 4.5 to 5.5 parts by weight, 4.5 to 5.5 parts by weight, respectively. And 9.5 to 10.5 parts by weight.

In addition, the MAO compound preferably further comprises 0.5 to 1.5 parts by weight of magnesium or 0.5 to 1.5 parts by weight of titanium as an optional component.

Preferred composition components of the MAO compound are shown in Table 1 below.

Furtherance magnesium calcium Remark Iron oxide titanium Carbon black cobalt antimony Weight ratio 0.5-1.5 0.5-1.5 0.5-1.5 4.5 ~ 5.5 0.5-1.5 4.5 ~ 5.5 4.5 ~ 5.5 9.5-10.5

In the MAO compound according to the present invention, calcium is added to improve the dispersibility and diactivity between the additives, the content is preferably 0.5 to 1.5 parts by weight. If the content is less than 0.5, the influence on dispersibility and diactivity is insignificant, and if it is more than 1.5, it is disadvantageous in slurry viscosity.

Tin is added to enhance the role of co-catalyst in the polycondensation reaction during the polymerization, the content is preferably 0.5 to 1.5 parts by weight. If the content is less than 0.5, the cocatalyst function is deteriorated, and if it is more than 1.5, the color of the resin becomes red.

Iron oxide is added to promote reheating performance, and the content thereof is preferably 4.5 to 5.5 parts by weight. If the content is less than 4.5, the reheating performance is weak. If the content is more than 5.5, the color of the resin becomes excessively black and the commercial value of the resin is lowered.

Carbon black is added to improve the reheating performance, the content is preferably 4.5 to 5.5 parts by weight. If the content is less than 4.5, the efficiency decreases, and if the content exceeds 5.5, the color of the resin becomes excessively black.

Cobalt is added to improve reheating performance and to prevent the color of the resin from becoming yellow, and the content thereof is preferably 4.5 to 5.5 parts by weight. If the content is less than 4.5, the reheating performance improvement effect is insufficient, and if the content exceeds 5.5, the color of the resin becomes blue.

Antimony is added to improve reheating performance and polymerization rate, and the content thereof is preferably 9.5 to 10.5 parts by weight. If the content is less than 9.5, the efficiency of reheating performance is inferior. If the content exceeds 10.5, the color of the resin becomes gray.

In addition, magnesium, which is an optional component of the MAO compound, is added to increase transparency and reheating performance as a material used as an electrostatic agent in PET film production, and the content thereof is preferably 0.5 to 1.5 parts by weight. If the content is less than 0.5, the efficiency of reheating performance is reduced. If the content exceeds 1.5, the color becomes dark yellow.

In addition, titanium as an optional component is added to enhance the activity of the intermediate product during polymerization to form a compound through rapid reaction between the additive and the product, the content is preferably 0.5 to 1.5 parts by weight. If the content is less than 0.5, the activity is reduced, and if the content is more than 1.5, the color of the resin becomes yellow.

In addition, the MAO compound according to the present invention has an average particle diameter of 10 ~ 2000nm, it is preferable to use a spherical carbon coated powder particles. If the average particle diameter is less than 10nm, the particle size is too small, workability is lowered, if it exceeds 2000nm, transparency may be lowered.

On the other hand, in the polyester composition according to the present invention, the polyester is polycyclohexanedimethanol terephthalate (copolymer of cyclohexane dimethanol and polyethylene terephthalate), polytrimethylene terephthalate (polymer of terephthalic acid and propanediol), polybutyl It includes lene terephthalate (polymer of terephthalic acid and butanediol), or polyethylene naphthalenedicarboxylate (polymer of naphthalenedicarboxylate and ethylene glycol), in particular, polyethylene terephthalate is free of environmental hormones and excellent gas barrier properties It is preferable as a food container in that the shelf life is superior to other resins and the tensile strength is high.

The present invention also provides a method for producing a polyester by reacting a dicarboxylic acid compound and a glycol compound,

It relates to a method for producing a polyester composition, characterized in that a mixture (MAO compound) containing calcium, tin, iron oxide, carbon black, cobalt, and antimony is added at 200 to 400 ppm relative to the total composition.

Generally, polyester can be synthesize | combined resin using a dicarboxylic acid compound and a glycol compound.

Dicarboxylic acid compounds that can be used in the present invention include terephthalic acid, isophthalic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, succinic acid, glutaric acid, adipic acid, seba Acid, 1,4-, 1,5-, 2,3-, 2,6-, or 2,7-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, or 4,4 ' Dibenzyldi carboxylic acid and the like, but not limited thereto, and preferred dicarboxylic acid compounds are terephthalic acid, isophthalic acid or mixtures thereof.

Glycol compounds include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-cyclohexanediol, 1, 2-, 1,3-, or 1,4-cyclohexanedimethanol, neopentyl glycol, or 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and the like, but are not limited thereto. The glycol compound is ethylene glycol, 1,4-cyclohexanedimethanol or mixtures thereof.

In the manufacturing method of the polyester composition which concerns on this invention, reaction conditions, such as reaction temperature and a pressure, can use a well-known method as it is. In addition, the MAO compound is preferably mixed with a glycol compound, and then polymerized, in view of preventing additive slurry dispersibility and additive precipitation, and maintaining additive intrinsic function. In addition, general additives used to prepare the polyester may include, for example, antimony trioxide (Sb ₂ O ₃ ), phosphoric acid (H ₃ PO ₄ ) and isophthalic acid and the like.

The invention also relates to an injection molded polyester preform comprising the polyester composition according to the invention. The preparation of the preform according to the invention can be produced by known injection molding methods.

For example, in the case of preform manufacturing using a Canadian injection molding machine, the injection temperature range is 280 ° C to 295 ° C, and the injection time is 7 to 10 seconds.

The present invention also relates to a polyester container blow molded of the preform described above. The method of manufacturing the said polyester container can also use a well-known method. In general, polyester containers can be reheated an injection molded preform and then use air to produce a container of the same shape as the mold. In this case, the quartz lamp used for reheating the preform is generally a quartz lamp having an emission spectrum of 500 to 1500 nm. The quartz lamp reheats the polyester preform to 105-145 ° C. to enable blow molding. Infrared rays are divided into near infrared rays (0.8-2.5 μm), medium infrared rays (2.5-50 μm), and far infrared rays (50-500 μm) with a wavelength of 0.8-500 μm. Under the assumption that there is no heating of the resin by conduction, heat is generated because infrared rays penetrate the inside of the resin and vibrate molecules. The polyester can be heated more quickly and more uniformly by infrared radiation than by conduction heating, but the polyester absorbs a portion of the infrared wavelengths of 5.9 μm and 8.7 to 9.1 μm.

In the case of the composition of the present invention, the MAO compound increased heat absorption in the 700 to 1200 nm range to improve reheating performance of the polyester resin.

Hereinafter, the present invention will be described in more detail based on the following examples, but the present invention is not limited to the following examples.

Examples 1-7

Referring to Figure 1 describes the performance evaluation equipment used in the experiment of the present invention. A quartz lamp 1 supported by the diffuse reflection plate 6 is installed on one side of the diffuse reflection insulation table 8, and a support box 7 is installed on the other side of the diffuse reflection insulation table 8. The preform holder 5 is installed on the support box 7, and the preform holder 5 is provided with a controller sensor 4 so that the controller 2 and the controller sensor 4 are electrically connected to each other. First, all of the preforms 3 prepared in the preform process step are kept at room temperature for 24 hours, and then set in the preform holder 5. Secondly, the controller 2 and the controller sensor 4 are connected, and the controller sensor 4 is installed in the preform 3. Third, the quartz lamp 1 for heating the preform 3 is fixed at a position 15 cm away from the preform holder 5 and irradiated to the preform 3. Fourth, after heating, the temperature of the preform 3 is measured by the controller 2.

The content of the MAO mixture [Magnesium, Calcium, Tin, Iron Oxide, Titanium, Carbon Black, Cobalt, and Antimony (1: 1: 1: 1: 5: 1: 10: 5: 10) by weight before the polymerization of polyethylene terephthalate The polymerization was carried out by adding 50 ppm, 100 ppm, 150 ppm, 200 ppm, 300 ppm, 400 ppm, and 500 ppm. The composition was injected into a preform and blow molded into a plastic bottle.

Blow molding conditions were optimized using existing resins (MAO-free resins).

RIV (Reheat Index Value) of the sample to which the MAO compound was added according to the content was measured. The preforms were placed in holders on a sample-by-sample basis, and heating was allowed to transmit for 15 seconds by emitting light at a temperature of 2000 ° C. (Max. 1100 nm wavelength) using a halogen lamp heater. The endothermic performance was recorded by measuring the temperature of the preform after permeation. At room temperature, the temperature of the preform was set to the initial temperature Ti and the temperature of the heating (Heating) was recorded as Tf. The temperature rise was recorded as ΔT (Tf-Ti), and the average value (ΔTavg) was calculated after calculating ΔT for each of the four preforms in order to control the temperature change due to the micro-difference of the preform thickness.

Where RIV (Reheat Index Value) = (△ Tavg _Comparative- △ Tavg _Example ) / ΔTavg _Comparative , and represents the degree of reheating performance.

In addition, to measure the color of the resin, using LOL (COLOR METER (Japan, GIGA, TC-1500SX)) to measure the L * [brightness of the resin color, the larger the brightness (0 ~ 100)], the comparative example and practice The color difference of the example, ΔL * [L * _Comparative -L * _Example ] was calculated. This is shown in Table 1 below.

Comparative Example 1

Except that no MAO compound was used, the container was prepared and tested in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 1 (Ref) Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 MAO addition amount (ppm) 0 50 100 150 200 300 400 500 Ti (℃) 25 25 25 25 25 25 25 25 Tf (℃) 78 78.8 80.0 81.5 83.4 85.7 90.7 94.8 △ Tavg (℃) 53 53.8 55 56.5 58.4 60.7 65.7 69.8 RIV (%) - 1.51 3.77 6.60 10.18 14.53 23.90 31.69 L * 84.71 83.34 78.62 75.50 73.12 71.20 69.10 67.10 △ L * 0.00 -1.37 -6.09 -9.21 -11.59 -13.51 -15.61 -17.61 RIV / △ L * - 1.10 0.62 0.71 0.87 1.07 1.53 1.80

The present invention improves the endothermic performance of the polyester resin by adding a MAO compound as an additive to the polyester resin, thereby minimizing the reheating time of the resin, thereby increasing the preform reheating process speed and increasing the productivity of the resin. It also has the effect of maintaining transparency.

Claims (9)

10 to 500 ppm of a mixture containing calcium, tin, iron oxide, carbon black, cobalt, and antimony, The calcium, tin, iron oxide, carbon black, cobalt, and antimony content of 0.5 to 1.5 parts by weight, 0.5 to 1.5 parts by weight, 4.5 to 5.5 parts by weight, 4.5 to 5.5 parts by weight, 4.5 to 5.5 parts by weight, and 9.5 Polyester composition, characterized in that ~ 10.5 parts by weight. delete The method of claim 1, Polyester composition, characterized in that the mixture further comprises 0.5 to 1.5 parts by weight of magnesium or 0.5 to 1.5 parts by weight of titanium. The method of claim 1, Polyester composition, characterized in that the mixture is carbon coated. The method of claim 1, Particle diameter of the mixture is a polyester composition, characterized in that 10 ~ 2000nm. The method of claim 1, Polyester is a polyester composition, characterized in that polyethylene terephthalate. In the method for producing a polyester by reacting a dicarboxylic acid compound and a glycol compound, A mixture containing calcium, tin, iron oxide, carbon black, cobalt and antimony was added at 10 to 500 ppm relative to the total composition and then polymerized, The calcium, tin, iron oxide, carbon black, cobalt, and antimony content of 0.5 to 1.5 parts by weight, 0.5 to 1.5 parts by weight, 4.5 to 5.5 parts by weight, 4.5 to 5.5 parts by weight, 4.5 to 5.5 parts by weight, and 9.5 A method for producing a polyester composition, characterized in that the polymerization was added to 10.5 parts by weight. An injection molded polyester preform comprising the polyester composition according to claim 1. A polyester container blow molded of the preform according to claim 8.

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