POLYESTER MOLDED BODY AND METHOD FOR MANUFACTURING SAME

Abstract

The present invention relates to a polyester molded body and a method for manufacturing the same, the polyester molded body including polyester obtained by polymerization in the presence of an inorganic tin compound catalyst, wherein the polyester molded body containing an inorganic tin compound of the present invention may overcome problems caused by a residual antimony-based catalyst, and may be used as an eco-friendly container which does not affect taste and aroma when used as a food storage container due to reduced amounts of acetaldehyde and formaldehyde and which is not toxic to the human body.

Claims

1. A polyester molded body molded with polyester prepared using an inorganic tin compound as a polymerization catalyst.

2. The polyester molded body of claim 1, wherein the inorganic tin compound is an inorganic tin first compound (stannous tin compound) or an inorganic tin second compound (stannic tin compound).

3. The polyester molded body of claim 2, wherein the inorganic tin first compound is selected from the group consisting of stannous oxide, stannous pyrophosphoric acid, stannous phosphoric acid, stannous tartaric acid, stannous acetic acid, stannous oxalic acid, stannous stearic acid, stannous oleic acid, stannous gluconic acid, stannous citric acid, stannous 2-ethylhexanonic acid, stannous ethoxide, stannous acetylacetonate, and stannous glycolic acid.

4. The polyester molded body of claim 2, wherein the inorganic tin second compound is selected from the group consisting of stannic oxide, stannic pyrophosphoric acid, stannic phosphoric acid, stannic tartaric acid, stannic acetic acid, stannic oxalic acid, stannic stearic acid, stannic oleic acid, stannic gluconic acid, stannic citric acid, stannic 2-ethylhexanonic acid, stannic ethoxide, stannic acetylacetonate, and stannic glycolic acid.

5. The polyester molded body of claim 1, wherein the polyester molded body comprises 10 ppm to 200 ppm of a residue of the inorganic tin compound.

6. The polyester molded body of claim 1, wherein the polyester is one or more selected from the group consisting of polyethylene terephthalate, polytrimethylene terephthalate and polytetramethylene terephthalate.

7. A method for manufacturing a polyester molded body, the method comprising: melting and molding a polyester resin composition composed of polyester prepared using an inorganic tin compound as a polymerization catalyst.

8. The method of claim 7, wherein the method comprises: melting a polyester resin composition; filling the melted polyester resin composition in a mold; and cooling and releasing the polyester resin composition filled in the mold.

9. The method of claim 7, wherein, when polymerizing polyester, 10 ppm to 200 ppm of an inorganic tin compound catalyst is added to the polyester.

10. The method of claim 7, wherein the molding is performed by compression molding, transfer molding, lamination molding, injection molding, extrusion molding, blow molding, calendar molding, gas molding, insert molding, or vacuum molding.

Description

EXAMPLES

Example 1

Preparation of Catalyst Solution

[0061] 5 g of an inorganic tin compound catalyst shown in Table 2 below was diluted in ethylene glycol to a total weight of 2 kg, and stirred at a stirring speed of 400 rpm to prepare an inorganic tin compound catalyst at a concentration of 0.25% in ethylene glycol. Thereafter, the inorganic tin compound catalyst was reacted in a refluxable reactor at a reaction temperature of 160° C. to 180° C. for 2 hours to prepare an inorganic tin compound catalyst solution.

[0062]

Preparation of Polyester Resin

[0063] 7.8 kg of terephthalic acid (TPA) and 3.3 kg of ethylene glycol (EG) were prepared as a slurry (EG/TPA molar ratio=1.13) and introduced into an esterification reactor in a semi-batch manner to be reacted until the reaction temperature reached 265° C. in an atmospheric pressure reaction under a nitrogen atmosphere so as to prepare a polyester oligomer. At this time, the esterification reaction temperature, a temperature at which the slurry was introduced, was 253° C., and the final esterification reaction end temperature was 265° C., and the reaction time was about 3 hours and 30 minutes. The PET oligomer prepared in the esterification reactor was transferred to a polycondensation reactor, and 200 ppm of a tin oxide catalyst based on the finally obtained PET was added thereto, and a polycondensation reaction was performed thereon under high-vacuum reduced pressure for about 2 hours and 30 minutes until the reaction temperature reached 288° C. to produce a raw chip. Thereafter, the raw chip was solid-phase polymerized to have an intrinsic viscosity of 0.76 dl/g at a temperature of about 250° C. and under vacuum.

[0064]

Manufacturing of Polyester Molded Body

[0065] Using a bottle manufacturing machine (model: Erontier), a prepared preform was put into the machine in which the temperature applied to the preform was fixed at 70° C. to 80° C., and the pressure applied thereto was fixed at a certain level of nitrogen pressure (5 to 8 kgf/cm.sup.2), and the preform was automatically rotated along a lane to be heated. At this time, the preform was rotated at a speed of 8.4 seconds, and three stages of air pressure (first: 11 kgf/cm.sup.2, second: 40 kgf/cm.sup.2, third: 7 kgf/cm.sup.2) was applied to the preform in a mold. In the mold, a bottle was manufactured by determining the thickness of the bottom of the bottle by the pressure applied to the preform, and by determining the thickness of the entire surface of the bottle by the intensity of air simultaneously blown.

Examples 2 to 50

[0066] A polyester molded body was manufactured in the same manner as in Example 1, except that a polyester chip produced using the inorganic tin compound shown in Table 2 below as a catalyst was used.

[0067]

Comparative Example 1

[0068] A polyester molded body was manufactured in the same manner as in Example 1, except that a catalyst was not used.

[0069]

Comparative Example 2

[0070] 40 g of antimony was dissolved in ethylene glycol to a total weight of 2 kg, and stirred at 400 rpm to prepare a catalyst solution. In a refluxable reactor, the catalyst solution was reacted at a reaction temperature of 180° C. to 190° C. for 2 hours to prepare an antimony glycolate solution. A polyester molded body was manufactured in the same manner as in Example 1, except that polyester polymerized using the obtained antimony catalyst solution was used.

[0071]

Comparative Examples 2 to 9

[0072] A polyester molded body was manufactured in the same manner as in Example 1, except that a polyester polymer prepared using the antimony catalyst shown in Table 1 below as a catalyst was used.

[0073]

Comparative Example 10

[0074] 40 g of a titanium compound was dissolved in ethylene glycol to a total weight of 2 kg, and stirred at 400 rpm to prepare a catalyst solution. In a refluxable reactor, the catalyst solution was reacted at a reaction temperature of 180° C. to 190° C. for 2 hours to prepare an titanium glycolate solution. A polyester molded body was manufactured in the same manner as in Example 1, except that polyester polymerized using the obtained titanium catalyst solution was used.

[0075]

Comparative Examples 11 to 17

[0076] A polyester molded body was manufactured in the same manner as in Example 1, except that a polyester polymer prepared using the titanium compound catalyst shown in Table 1 below as a catalyst was used.

[0077]

Comparative Examples 18 to 47

[0078] A polyester molded body was manufactured in the same manner as in Example 1, except that a polyester polymer, which was prepared using 1 ppm, 8 ppm, or 500 ppm of each of the inorganic tin compounds shown in Table 2 below as a catalyst, was used.

[0079]

Test Example

[0080] Physical properties of each of the polyester molded body manufactured according to Examples 1 to 50 and Comparative Examples 1 to 47 were evaluated by the following method, and the results are shown in Table 1 and Table 2 below.

[0081]

[0082] (1) Intrinsic Viscosity

[0083] In accordance with ASTM D 4603, 0.1 g of a sample was dissolved for 90 minutes in a reagent (Raw Chip 90° C., SSP 130° C.), in which phenol and 1,1,2,2-tetrachloroethane were mixed in a weight ratio of 6:4, until the concentration reached 0.4 g/100 , and then transferred into a Ubbelohde viscometer and remained in a thermostat of 30° C. for 10 minutes, and the number of drop seconds of the solution was obtained using the viscometer and an aspirator. The number of drop seconds of the solvent were obtained in the same manner, and then the R.V. (relative viscosity) value and I.V. (intrinsic viscosity) value were calculated by Equations 1 and 2.

R.V.=Number of drop seconds of sample/number of drop seconds of solvent  <Equation 1>

I.V.=¼×[(R.V.−1)/C]+¾×(lnR.V./C)  <Equation 2>

[0084] In Equation above, C represents the concentration (g/100 ) of the sample in the solution.

[0085]

[0086] (2) Concentration of Carboxyl Terminal Group (CEG)

[0087] In accordance with ASTM D 7409, the sample was dissolved using O-cresol and then analyzed using acid-base neutralization titration. Specifically, about 0.2 g of a sample was taken and 10 of benzyl alcohol was added thereto. The mixture was dissolved by being heated for 10 minutes in a heating block of 200° C., and then cooled in a water bath for 1 minute. Then, 10 of chloroform, phenol red, and a few drops of phenolphthalein indicator are added thereto, and the mixture was titrated using 0.02 N KOH (or NaOH). Using an appropriate amount thereof, the concentration of a carboxyl terminal group (CEG) was calculated by Equation 3. The number of carboxyl groups is represented by milliequivalents of carboxyl groups/kg of polymer (meq/kg).

CEG=(A−B)×0.02×1000/W  <Equation 3>

[0088] A: consumed in sample, B: blank, W: weight of sample

[0089]

[0090] (3) Acetaldehyde (A.A.) Content (ppm) of Polymer

[0091] In accordance with ASTM F 2013, a frozen-crushed polyester sample was put into a headspace sampler vial, sealed, and then heat-extracted at 160° C. for 2 hours to be analyzed by gas chromatography GC (Agilent 7890).

[0092]

[0093] (4) Color Measurement (Color L)

[0094] Using a colorimeter (Color view-9000, a product of BYK Gardner), the Color L value was measured under the condition of D65 light source and 10°. The L value measured by a spectrophotometer is a colorimetric value calculated from the CIE 1976 CIE Lab chrominance equation after measuring the reflectance of the sample.

[0095]

[0096] (5) Analysis of Acetaldehyde (A.A) Content (ppb) of Bottled Water in Molded Body

[0097] Drinking water was put into a polyester molded article to be measured, and a trace amount (ppb level) content of acetaldehyde in the drinking water was analyzed using HPLC/UV-VIS through 2,4-dinitrophenyl hydrazine (DNPH) derivatization.

[0098] A DNPH derivatization solution was prepared with 0.2 g of 2,4-dinitrophenyl hydrazine/100 of acetonitrile, and the derivatization reaction procedure was performed by taking 2 of a sample of a solution to be measured in 4 of a vial, and then adding 100 μL of the DNPH derivatization solution thereto, followed by stirring. After the measurement sample was stirred, 100 μL of 45% H.sub.3PO.sub.4 was added thereto, followed by applying ultrasonication for 30 minutes to derivatize the sample. The derivatized sample solution was analyzed and evaluated using HPLC/UV-VIS (Waters LC Module 1 plus). A column used for the analysis was Kromasil KR100-10C18 (25 cm*4.6 mm), and the solvent condition for using the instrument was CH3CN/Water=2/1.

[0099] A UV-VIS detection wavelength was evaluated at 356 nm to measure the acetaldehyde content of the measurement target.

TABLE-US-00002 TABLE 1 A.A. in A.A. of drinking water Content IV CEG Color polymer in container Catalyst category (ppm) (dl/g) (meq/kg) L (ppm) (ppb) Catalyst not used Comparative 0 0.389 40 80.2 10.1 1033.5 Example 1 Antimony Antimony Comparative 500 0.771 20 87.1 1.9 10.8 compound triglycolate Example 2 (P) Comparative 200 0.767 16 88.3 0.6 1.5 Example 3 Comparative 100 0.715 29 88.1 1.9 3.8 Example 4 Comparative 40 0.687 29 89.4 5.6 35.1 Example 5 Comparative 20 0.599 35 87.5 9.9 594.7 Example 6 Comparative 10 0.601 35 85.6 8.6 429.5 Example 7 Comparative 8 0.458 28 81.5 8.4 892.0 Example 8 Comparative 1 0.378 39 81.1 6.6 955.6 Example 9 Titanium Titanium Comparative 500 0.765 29 81.5 11.5 986.3 compound butoxide Example 10 (L) Comparative 200 0.761 28 83.6 10.6 812.4 Example 11 Comparative 100 0.763 29 87.9 6.1 315.6 Example 12 Comparative 40 0.750 25 89.4 2.9 114.5 Example 13 Comparative 20 0.760 25 90.1 1.8 84.3 Example 14 Comparative 10 0.759 25 90.9 0.6 21.4 Example 15 Comparative 8 0.759 24 88.7 0.9 18.7 Example 16 Comparative 1 0.509 33 82.6 4.3 264.4 Example 17

TABLE-US-00003 TABLE 2 A.A. of A.A. of IV CEG Color polymer solution Catalyst category Content (dl/g) (meq/kg) L (ppm) (ppb) Inorganic Tin oxide Comparative 500 0.760 22 88.1 9.7 789.1 tin first (P) Example 18 compound Example 1 200 0.760 21 88.6 2.9 97.4 (stannous Example 2 100 0.763 22 89.3 1.8 32.1 tin Example 3 40 0.764 18 92.1 0.4 1.0 compound) Example 4 20 0.759 17 91.9 0.5 0.6 Example 5 10 0.759 18 92.5 0.4 0.9 Comparative 8 0.760 20 91.0 3.1 35.4 Example 19 Comparative 1 0.516 30 81.5 10.5 876.3 Example 20 Tin acetate Comparative 500 0.765 21 88.7 8.4 687.4 (P) Example 21 Example 6 200 0.760 22 88.6 2.1 84.5 Example 7 100 0.755 21 89.6 1.7 22.1 Example 8 40 0.760 18 91.1 0.6 0.9 Example 9 20 0.762 17 92.3 0.9 0.5 Example 10 10 0.757 19 92.0 0.4 0.6 Comparative 8 0.754 21 89.1 3.6 25.4 Example 22 Comparative 1 0.521 33 82.5 9.4 676.3 Example 23 Tin oxalate Comparative 500 0.760 22 86.7 8.4 512.4 (P) Example 24 Example 11 200 0.762 20 88.1 2.8 51.5 Example 12 100 0.763 22 89.2 1.4 11.1 Example 13 40 0.766 19 91.9 0.3 0.3 Example 14 20 0.764 19 92.6 0.4 0.5 Example 15 10 0.757 18 92.6 0.3 0.4 Comparative 8 0.752 22 89.1 3.0 25.4 Example 25 Comparative 1 0.545 35 83.5 7.4 456.3 Example 26 Tin stearate Comparative 500 0.759 23 87.7 11.4 997.4 (P) Example 27 Example 16 200 0.766 25 88.1 3.0 362.5 Example 17 100 0.760 22 89.2 1.4 12.1 Example 18 40 0.763 19 90.9 0.7 1.5 Example 19 20 0.760 20 91.8 1.2 1.0 Example 20 10 0.759 20 92.5 0.6 0.4 Comparative 8 0.752 22 89.0 3.0 129.9 Example 28 Comparative 1 0.549 35 84.9 6.7 608.3 Example 29 Tin glycolate Comparative 500 0.760 20 88.7 8.3 768.4 (P, L) Example 30 Example 21 200 0.760 20 89.9 2.4 124.5 Example 22 100 0.764 19 90.6 0.9 3.1 Example 23 40 0.760 19 91.9 0.4 1.1 Example 24 20 0.762 18 92.5 0.5 1.9 Example 25 10 0.762 18 92.9 0.3 0.6 Comparative 8 0.760 20 89.7 3.1 229.9 Example 31 Comparative 1 0.561 34 85.9 5.1 708.3 Example 32 Inorganic Tin oxide Comparative 500 0.755 24 89.1 14.1 1156.9 tin second (P) Example 33 compound Example 26 200 0.759 26 88.4 3.0 125.4 (stannic Example 27 100 0.760 23 89.3 2.0 11.2 tin Example 28 40 0.764 21 90.1 1.1 4.5 compound) Example 29 20 0.761 22 90.7 1.2 2.1 Example 30 10 0.758 23 91.5 1.0 1.1 Comparative 8 0.759 22 91.4 3.4 65.4 Example 34 Comparative 1 0.511 34 84.5 9.4 900.3 Example 35 Tin acetate Comparative 500 0.761 23 88.4 10.1 756.9 (P) Example 36 Example 31 200 0.766 22 89.1 2.4 96.4 Example 32 100 0.761 22 90.3 2.0 20.2 Example 33 40 0.765 20 90.7 1.3 11.5 Example 34 20 0.765 21 90.8 0.9 1.1 Example 35 10 0.761 23 91.2 0.9 0.9 Comparative 8 0.759 23 91.0 3.3 155.4 Example 37 Comparative 1 0.487 37 83.5 4.8 300.3 Example 38 Tin oxalate Comparative 500 0.761 32 85.7 10.0 1112.4 (P) Example 39 Example 36 200 0.760 24 89.1 2.6 41.5 Example 37 100 0.759 24 89.4 1.3 10.1 Example 38 40 0.757 22 90.9 0.5 1.9 Example 39 20 0.763 21 91.6 0.5 1.6 Example 40 10 0.760 23 91.9 0.8 2.1 Comparative 8 0.760 22 90.1 3.4 175.5 Example 40 Comparative 1 0.459 35 81.5 8.6 861.3 Example 41 Tin stearate Comparative 500 0.766 33 88.7 9.4 699.4 (P) Example 42 Example 41 200 0.761 35 88.9 2.8 198.5 Example 42 100 0.760 32 89.3 1.9 11.1 Example 43 40 0.763 29 90.2 1.1 4.5 Example 44 20 0.759 25 91.0 0.5 0.9 Example 45 10 0.761 24 92.1 0.4 1.1 Comparative 8 0.755 26 89.9 3.1 331.1 Example 43 Comparative 1 0.449 35 82.3 5.9 612.3 Example 44 Tin glycolate Comparative 500 0.761 30 87.7 7.3 568.4 (P, L) Example 45 Example 46 200 0.762 25 88.9 2.8 224.5 Example 47 100 0.759 23 90.1 0.9 5.1 Example 48 40 0.763 22 91.0 0.6 1.9 Example 49 20 0.765 24 92.1 0.8 1.4 Example 50 10 0.760 22 91.9 0.5 0.9 Comparative 8 0.758 24 90.0 3.4 209.6 Example 46 Comparative 1 0.501 34 84.4 6.4 654.1 Example 47

[0100] Referring to Table 1 and Table 2 above, it can be confirmed that the polyester containers manufactured in Examples 1 to 50 have physical properties which are equal to or greater than those of Comparative Examples 2 to 7 in which a polyester resin using an antimony catalyst was used. In addition, in the case of the polyester containers manufactured in Examples 1 to 50, it was confirmed that the content of acetaldehyde in the drinking water contained in the containers was significantly reduced, and the color was good. Accordingly, it can be confirmed that it is possible to manufacture an eco-friendly container which does not affect the taste and aroma of a beverage and which is not toxic to the human body since the polyester resin molded bodies of Examples contain a trace amount of acetaldehyde. In contrast, in the bottles of Comparative Examples 1 to 47, a relatively large amount of acetaldehyde was detected in the drinking water contained in the containers, so that the use of the bottle as a food storage container would be harmful to both the environment and the human body, and it was confirmed that the color was bad.

[0101] Although the present invention has been described above with reference to limited embodiments, the present invention is not limited thereto, and various modifications and variations may be made to the technical spirit of the present invention by those skilled in the art to which the present invention belongs. Therefore, the true scope of protection of the present invention should be determined by the claims described below and the scope equivalent thereto.