TWI321574B - - Google Patents

Description

[Technical Field] The present invention relates to a process for producing a polyester, and particularly to a process for producing a polyester using a zinc catalyst in a polycondensation reaction stage. [Prior Art] Products for synthesizing polyester have been widely used in everyday life such as polyester fibers, polyester bottles, polyester films and the like. Common polyesters are polyethylene terephthalate (PET), polypropylene terephthalate (PPT), polybutylene terephthalate (PBT). ), polyethylene naphthalate (PNT), etc., of which PET is most common. In order to cope with the increasing demand in the market, how to shorten the reaction time of the polyester process has been the goal of polyester producers to improve. Since the action of the catalyst can increase the reaction rate, it is an important role in shortening the reaction time in the process. The polyester process can be divided into two stages, the first stage being esterification or transesterification, and the second stage being polycondensation. Taking PET as an example, the first stage reaction method can be divided into direct esterification method (known as TPA process) and transesterification method (known as DMT process). The TPA process uses terephthalic acid and ethylene glycol as raw materials to carry out the esterification reaction in the first stage. At this stage, it is usually unnecessary to add a catalyst, and the DMT process is terephthalic acid. Dimethyl terethphalate and ethylene glycol are used as raw materials, and the ο * ν · 3曰 exchange reaction in the first stage is usually made by Lewis. Stuffed with Gan Bish 3 for a long time as a catalyst. After the first stage reaction of Yuancheng, whether it is ΤΡΑ or DMT1胄#, y· #. I privately in the second stage of the polycondensation reaction will add catalyst, so the purpose is to shrink polymerization. The catalyst is used in the polyester process. The catalysts used in the polycondensation process are mainly recorded, lanthanide, titanium, and (4). Due to the recording of catalysts, such as the third oxidation (

Sb203) 'The price is cheap, and it can greatly promote the polycondensation reaction, and it affects the extent of the degradation reaction. Almost all grades (4) can be prepared by using the catalyst. Because of &, the past few decades have gathered (4) Commercial production is mostly based on the use of recorded touches. In recent years, research has pointed out that base metals will endanger human health. The latest European regulations have also begun to limit the bismuth content of textiles. Therefore, the brewing contains no bismuth and heavy metals. A trend towards future development. The wrong system, the Chin system and the Shaoxing catalyst are the catalysts that have recently developed in response to the demand of non-recording media. Among them, the 锗 catalyst is medium to high activity, although the 8 曰 color husk white produced is excellent, but it is expensive, and it is only suitable for producing special grade polyester. However, in addition to the high activity of the titanium catalyst, the yellowing of the ester particles caused by the failure of water to form titanium dioxide at high temperatures (for example, during the polycondensation reaction process) is also more difficult than that of the catalyst. Therefore, there is a certain degree of difficulty in industrial application. In addition, although the aluminum catalyst is inexpensive, but the activity is low, it requires a high amount of addition, so the cost is not good. In addition to the catalyst of a single metal component, a combination of a plurality of metal compounds is used to form a combined catalyst, for example, a metal compound composed of titanium, lanthanum or cerium, in order to reduce the amount of each metal used. However, too many components of the catalyst will complicate process control, which also increases manufacturing costs, and such combined catalyst technology still has a certain degree of bismuth content, which is in line with the trend of underwriting. From the above, it is known that there is still a demand for a catalyst which is inexpensive, non-toxic, simple in composition, and highly active in the polycondensation reaction stage. SUMMARY OF THE INVENTION In order to solve the above problems, the inventors have conducted research and experiments through various experiments, and found that a zinc catalyst having a single metal component is a catalyst for polycondensation reaction, and an organic phosphite is used as a stabilizer to effectively promote shrinkage. The polymerization rate avoids the problem of polyester yellowing. Although the zinc catalyst was used in the early stage of the transesterification reaction, the mechanism of the transesterification reaction is not the same as that of the polycondensation reaction. If the zinc catalyst is used alone in the polycondensation reaction, the ester particles may be yellowed. However, if it is used with a conventional stabilizer such as phosphoric acid, the activity of the catalyst will be disturbed. For example, if the addition of more than 001 wt% of phosphoric acid will reduce the activity of the zinc catalyst, it has not been found in the polymerization of the ester of the ester. The phase-independent (four) medium production method is applied to industrial production. The present inventors have found that if an organic phosphite, especially a large group of organic phosphites, is used as a stabilizer, the yellowing of the polyester can be effectively inhibited, so that the zinc catalyst can be polycondensed in the polyester process. In the reaction, it is used alone; in addition, since the zinc catalyst is not toxic, inexpensive, and has considerable activity, it can achieve the advantages of reducing the manufacturing cost, shortening the reaction time, and being environmentally friendly; in addition, the present invention uses zinc catalyst. The synthesized polyester has better thermal stability' and also has a lower crystallization rate. In the injection blow molding process (zero (10)n blow 〜~), there is no need to add crystallization inhibitor, in addition to saving raw material cost' It is also possible to avoid the influence of the additive on the properties of the polyether. The invention relates to a method for preparing a non-ruthenium-terminated polyester by subjecting at least one di- tacrotic acid to at least one diol, or vine exchange of at least one bis to at least one diol. Then, the precursor polymer formed in each of the reactions is subjected to a polycondensation reaction under the action of sulphite as a stabilizer for the precursor polymer produced in the reaction, thereby preparing a polyacetate of the object. The zinc catalyst of the present invention may be selected from the group consisting of an oxide of zinc, an organic acid salt of zinc, a halide of zinc, and the like. The oxide of zinc may specifically be, for example, zinc oxide or oxidized sodium powder ( _ ohde nanopowder) and zinc perzide (zinc per〇xide), etc. The zinc organic acid salt may specifically be, for example, zinc acetate, acrylate, zinc methacrylate, 3, 5 Zinc 3,5-di-tert-butylsalicylate, zinc oxalate, zinc stearate and zinc lactate (1) Mail 1 (10) coffee. Zinc halides With zinc chloride (zinc chi〇ride) and zinc bromide (zinc bromide) Preferably, the phosphite suitable for use in the present invention is preferably a large group of organic sub-sodium hydrates, and specific examples include triphenyl ph〇Sphite and arylene acid. Trimethyl phosphite, diphenyl alkyl phosphites, phenyl dialkyl phosphites, tris-phenyl benzoate ( 1321574)

Tris(nonylphenyl) phosphite ), trilauryl phosphite, trioctadecyl phosphite, distearyl pentaerythritol double sub-fill Ditearyl pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphite, diisoindole neopentyl alcohol Diisodecyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, double (2) ,6-tert-butyl-4-methylphenyl pentaerythritol diphosphite, bis(isobutyloxy) neotetrapentanol Diisodecyloxypentaerythritol diphosphite, bis(2,4-di-butyl-6-methylphenyl) pentaerythritol diphosphite Bis(2,4,6-tris(tert-butylphenyl) neotetrapentanol bisphosphite (bis(2,4,6-tris(tert-butylphenyl)) pentaerythri Tol diphosphite), tristearyl sorbitol triphosphite, 6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-diphenyl [d,g][l ,3,2]dioxane hexyl structure (6 〇〇(^丫1〇\7-2,4,8,10-16匕3-161^-1)111}^1-1214- (1) 61^[(1,§][1,3,2](1丨〇\3卩11〇5卩11〇(^11), sub-filled acid (2,4-di-tert-butyl- Bis(2,4-di-tert-butyl-6-methylphenyl) methyl phosphate, bis(2,4-di-tert-butyl-6-nonylphenyl) ) bis(2,4-di-tert-butyl-6-methylphenyl) ethyl phosphite) 6-fluoro-2,4,8,10-tetra-tert-butyl-12H-indenyl-diphenyl [ d,g][l,3,2]dioxanone (6-fluoro-2,4,8510-tetra-tert-butyl- 12H-methyl-

9 1321574 dibenz [d,g][l,3,2]dioxaphosphocin),2,2',2"-qichuan [triethyl bis(3,3',5,5'-tetra-tert-butyl-1 , Γ-biphenyl-2,2,-di-ortho)phosphite]( 2,2',2"-nitrilo[triethyltris(3,3',5,5,-tetra-tert-butyl-l, L'-biphenyl-2,2,-diyl) phosphite]), 2-ethylhexyl (3,3',5,5'-tetra-tert-butyl-1,1'-biphenyl-2,2,- 2-ethylhexyl (3,3 ',5,5 '-tetra-tert-butyl-1,1 '-biphenyl-2,2'-diyl) phosphite), 5-butyl- 5-ethyl-2-(2,4,6-tri-tert-butylphenoxy)-l,3,2-oxohedoyl (5-butyl-5-ethyl-2-(2) , 4,6-tri-tert-butylphenoxy)-l,3,2-dioxaphosphirane) and combinations thereof; among them, triphenyl linoleate, trimethyl sulfite, sub-acid three (2, A combination of 4-di-tert-butylphenyl) ester, tridecylphenyl phosphite, and the like is preferred. The zinc catalyst and phosphite used in the present invention are added in an amount based on the total amount of the polyester product. If the total amount of the reactants is used, the excess amount of the alcohol is usually used in the reactants, and the excess of the alcohol is adjusted according to the apparatus of the reaction process, so that the standards of the reactants are inconsistent. For example, in the manufacture of PET, the molar ratio of ethylene glycol to stearic acid in the reactant is usually between 1 〇 5 and 1 Μ, depending on the process equipment, and the total amount of the polyester product is estimated to be benzene. The amount of dicarboxylic acid can be divided by 0.8646. The amount of the zinc catalyst to be used in the present invention is based on the zinc metal concentration of ίο~1〇〇〇 ppm, preferably between 5 〇 and 5 〇〇 ppm, and more preferably between 100 and 350 ppm. The phosphite to be used in the present invention is added in an amount of from 1 to 15% by weight, preferably from 〇.〇15 to 〇·5 by weight. Ditoxaic acid suitable for use in the present invention includes terephthalic acid (10 1321574)

Acid ), isophthalic acid, naphthalene dicarboxylic acids, p-hydroxybenzoic acid, hydroxynaphthoic acids, cyclohexane dicarboxylic acid Acids, succinic acid, glutaric acid, adipic acid, sebacic acid, l12-dodecane dioic acid and Itaconic acid, etc., is particularly suitable for terephthalic acid. The dicarboxylic acid esters suitable for use in the present invention include the esterified derivatives of the foregoing dicarboxylic acids.

Diols suitable for use in the present invention include ethylene glycol, 1,3-propane diol, naphthylene glycol, 1,2-propanediol (1,2-propane) Diol ), 1,2-cyclohexane dimethanol, 1,3-cyclohexane dimethanol, 1,4-cyclohexanedimethanol (l,4- Cyclohexane dimethanol), diethylene glycol, hydroquinone, 1,3-butane diol, 1,5-decanediol (1,5-pentane) Ethylene glycol, 1,6-hexanediol, triethylene glycol, and resorcinol are particularly suitable for ethylene glycol. The diol may also be a long chain diols and a polyol formed by reacting a plurality of diols or polyols having alkylene oxides (p〇). Iy〇is ). The polyester prepared by the invention can be further subjected to solid state polymerization to increase the viscosity of the polyester for different use requirements. For example, the polyester for the bottle needs higher viscosity, which is obtained by solid state polymerization. . 11 1321574 [Embodiment] Hereinafter, the contents of the present invention will be described in more detail by way of embodiments. &lt;Example 1&gt; 519 g (3·12 mole) of terephthalic acid and 204 g (3.28 mole) of ethylene glycol were poured into a stainless steel autoclave having a volume of 丨 liter at a pressure. In an environment of no more than 4 kg/cm2, the temperature is continuously increased (the speed of the batcher is 60 rpm) and the temperature is gradually increased to 250 °C within 5 hours while the water produced by the reaction is distilled off through the distillation tube. After completion of the esterification reaction, '2.4 g of zinc stearate catalyst (zinc metal concentration 41 〇 ppm) and 0.045 g of trimethyl linalate were added, and the temperature was gradually increased to 280 ° C in about 3 hours while Vacuum is applied to 丨t〇rr within 1 hour. At the end of the reaction, the reaction is stopped when the stirring power of the mixer is gradually increased from 70 W to 1 〇 5 w. The condensation reaction time was recorded to be 135 minutes. <Examples 2 to 3 &amp; Comparative Example 1 &gt; Examples 2 to 3 are the conditions of the reaction of Example 1, but the addition amount of the zinc stearate catalyst was changed to 0.6 g (zinc metal concentration: 100 ppm). And 0.9 g (zinc metal concentration 155 ppm). The reaction conditions in the comparative examples were the same as those of the implementers, but the catalyst was changed from zinc stearate to antimony trioxide (2〇3), and the amount added was gram (recording metal concentration was 250 ppm, which was PET). The standard level of the process). The condensation reaction time of the shell examples 1 to 3 and the comparative example i, and the properties of the polyester obtained therefrom, were combined and not listed in Table 1. Among them, Tm and Tc respectively indicate the melting point and the glistening at the time of cooling: Tian 疳 θ ^ t ... day / dish degree, 疋 by the thermal difference scanning analyzer ( 12 1321574

DSC, manufactured by ΤΑ Instruments, model DSC 2910 Modulate DSC); 5% wt loss is the temperature at 5% weight loss, ie the cracking temperature of the polyester, measured by a thermogravimetric analyzer ( Thermo gravimetric) Analyzer, referred to as TGA, manufactured by ΤΑ Instruments, model TGA 2950), is tested in a nitrogen atmosphere with an ambient temperature of 30 ° C to 600 ° C and a heating rate of 10 ° C / min. The temperature at which the weight loss is 5%; IV is the intrinsic viscosity, which is a mixture of 1 gram of S particles dissolved in 100 grams of a phenol/terachloroethane mixed solvent, wherein The weight ratio of the chlorine broth was 1:1 and was measured at 30 ° C using a libelode-viscosimeter. Table 1 Metal concentration (ppm) Condensation reaction time (min) Tm (°C) Tc (°C) 5% wt loss (°C) IV (dL/g) Example zinc metal 1 410 130 249.22 193.27 390.97 0.653 2 100 245 251.74 195.02 396.37 0.672 3 155 205 251.45 196.93 404.24 0.659 Comparative Example Metal 1 250 200 253.51 198.17 403.78 0.644

According to Table 1, the reaction time of Example 3 and Comparative Example 1 was comparable under the same operating conditions of the polycondensation reaction, but the amount of catalyst added was compared, and the effective metality of the zinc metal of Example 3 was 155 ppm. Comparing the effective concentration of the ruthenium metal in 13 cases was 25 〇ppm, indicating that the catalytic activity of zinc metal is higher than that of ruthenium metal. The relationship between the zinc metal concentration of Example 丨3 and the condensation reaction time was analyzed by regression analysis, and it was found that the concentration of zinc metal was 25 〇.

The condensation reaction time at PPm, about 175 minutes, can shorten the reaction time compared to the same concentration of the recording medium. It is clear that the zinc metal has a better catalytic activity. Moreover, the nature of the polyester obtained by using zinc metal as a catalyst is also equivalent to the nature of the polyester obtained by the conventional recording medium. Compare Example W

It can be seen that as the amount of zinc catalyst added increases, it takes time. <Examples 4 to 8 &gt; The polymerization conditions of Examples 4 to 8 which can be effectively shortened are the same as those of Example i, but other kinds of zinc catalysts are used, and the catalyst species are turned over, and the crystals are turned, The enthalpy of addition, the polymerization time, and the inherent viscosity values of the obtained polyester are shown in Table 2.

Table 2 Example -------- Zinc Catalyst (ppm) _ 285 ----- Zinc Metal Concentration••(PPm) ^ 150 Polycondensation _8^Between (min') IV (dL /g) 4 zinc oxide nano rotifer 644 5 __ Zn 193 1 C Λ 6 zinc acetate 1 D u _265 0.652 435 150 ------- 7 —_ zinc methacrylate 270 0.661 558 150 ——___ 300 0.648 8 Zinc salicylate 1337 1 &lt;〇1 J VJ 215 0.643 It can be seen from Table 1 and Table 2 that different zinc catalysts are in effective zinc metal concentration.

14 1321574 In the same state, the activity of zinc metal is not the same, and the large group of organic acid zinc, such as zinc stearate and 3,5 di-tert-butyl water, is observed from the obtained polycondensation reaction time. Zinc salicylate shows a better catalytic effect. &lt;Example 9&gt; 38.9 kg of terephthalic acid and 15 2 kg of ethylene glycol were poured into a stainless steel reaction vessel having a volume of 150 liters, and the temperature was continuously raised under a pressure of not more than 3 kg/cm2. Stirring (mixer rotation speed of 3 rpm), and gradually raising the temperature to 25 Torr in 6 hours while allowing the water produced by the reaction to be distilled off from the distillation tube. After completion of the esterification reaction, 67.5 g of stearic acid catalyst (zinc metal concentration 155 ppm) and 6.8 g of trimethyl phosphite were added, and the temperature was gradually increased to 28 (TC) within 3 hours while within 2 hours. Vacuuming until around t〇rr, at the end of the reaction, the reaction was stopped when the ammeter of the mixer showed a gradual increase from 2·3 A to 2.5 A. The inherent viscosity (IV) of the obtained polyester was measured to be 0.643. 15 kg of the polyester granules obtained by the foregoing reaction were poured into a solid-state polymerization reactor having a volume of 3 liters, and solid-state polymerization was carried out for 35 hours at a temperature of 235 Torr: and a pressure of not more than 1 Torr. The physical properties of the granulated particles after solid state polymerization are shown in Table 3. 15 1321574 Table 3 Physical properties of solid particles after solid state polymerization 皙IV (dL/g) tl/2 (min) L La Lb DEG ( %) Acid value (meq/kg) Free AA (ppm) Potential AA (ppm) 0.746 1.556 83 -3.1 -0.5 2.42 38.3 1.4 16.9 In Table 3, the intrinsic viscosity of the ester particles after solid state polymerization is 〇746 dL/g, The viscosity before the solid state polymerization (IV=0.643) is increased by 16%. tl/2 means the crystallization half-life, L, La, Lb The hue of the grain, the higher the j^ value, the higher the whiteness. The larger the positive value of La, the more red the ester particles. The larger the negative value, the greener the ester particles. The larger the positive value of Lb, the yellower the ester particles. The larger the value, the bluer the ester particles; therefore, the La and Lb values are preferably close to "0". DEG indicates the content of diethylene glycol, which is a by-product formed in the reaction, which lowers the glass transition temperature of the polyester ( ). And the melting point (Tm). The higher the acid value, the incomplete reaction, or the formation of ester group cleavage during the reaction. The general industrial application requires DEG to be less than 3 wt%, and the acid to be less than 50 meq/ Km is better. Free AA means the age of the age, and potential AA means the probability of forming acetaldehyde. When the polyester is made into a barn containing beverages or foods, 'if the acetic acid content is too high, the beverage or food will be contained. Bitter taste. Therefore, the lower the acetic acid content, the better, less than 2 〇 ppm. <Comparative Example 2 &gt; The reaction conditions of Comparative Example 2 are the same as in Example 9, except that the catalyst is changed to 13.5 g of antimony trioxide. (锑 metal concentration 25〇ppm). When the polycondensation is completed

16 1321574 After the reaction, the intrinsic viscosity (IV) of the polyester ester particles was measured to be 0.662 dL/g. After completion of the solid state polymerization, the intrinsic viscosity (IV) of the ester particles was measured to be 0.767 dL/g, and the viscosity increased by 16%, while the crystallization half-life (t1/2) was 1.119 minutes. In Example 9 and Comparative Example 2, the crystallization half-life of the ester particles after the solid state polymerization was 1.556 minutes and Μ 19 minutes, respectively, indicating that the crystallization rate of the polyester prepared using the catalyst was lower than that of the catalyst. Made of polyester. Since the polyester has a low crystallization rate when preparing the polyester by the zinc catalyst, it is not necessary to add a crystallization inhibitor during the injection blow molding process, in addition to saving the raw material cost, and also avoiding the heat resistance of the additive to the polyester. The effect is beneficial to the application in hot-filled polyester bottles. Further, in Example 9 and Comparative Example 2, after the solid state polymerization, the degree of change in the viscosity of the ester particles was comparable, and the polyester obtained by using the zinc catalyst in the polycondensation reaction showed a solidification rate comparable to that of the polyester using the catalyst. That is, the use of zinc catalyst does not affect the operating cost of subsequent solid state polymerization. Thermal degradation rate test The ester particles before the solid state polymerization were carried out in Example 9 and Comparative Example 2, respectively. After the test piece was shot at an operating temperature of 28 〇t, the intrinsic viscosity of the test piece was analyzed, and before the injection. The intrinsic viscosity of vinegar granules can be compared to the case of viscosity degradation after injection processing (thermal degradation rate. The results are shown in Table 4 〇17 1321574 Table 4

Example 9 IV CdL/g before injection IV ------- Thermal degradation rate f % 1 0.643 0.571 ------ 11 Comparative Example 2 0.662 0.563 15 -~----丨· ------L

As can be seen from the above table, the thermal degradation rate of the polyester granules prepared in Example 9 is lower than that of the granules prepared by comparing 爿2, which is compared with the conventional ruthenium catalyst. The thermal stability of the polyester obtained by the catalyst is better. '· In summary, the present invention uses a non-recording medium for the production of polyester, which can be used alone in the polycondensation reaction stage. It is non-toxic and inexpensive, and can inhibit the granular yellow with the Weiwei Sl as a stabilizer. It does not affect the activity of the zinc catalyst, and can effectively promote the polycondensation reaction to shorten the reaction time. Furthermore, the polyacetate synthesized by the zinc catalyst in the present invention is better than the conventional polyester synthesized by the catalyst. The thermal stability, as well as the low crystallization rate, does not require the addition of crystallization inhibitors during the injection blow molding process, in addition to saving the cost of raw materials, and also avoiding the influence of additives on the thermal properties of the polystyrene. It is applied to a hot-filled vinegar bottle, and it is indeed possible to achieve the present invention. The above is only a preferred embodiment of the present invention, and does not limit the scope of the practice of the present invention, that is, according to the present invention. The simple equivalent changes and modifications made by the patent and the contents of the invention are still within the scope of the invention. [Simple description of the diagram] M. ί»*ν 18 1321574 [Description of main component symbols]

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Claims (1)

1321574 Climbing 129045_^jg_Patent p case application replacement Taixuan called view) X. Patent application scope: Less amendment 1. - Use __ to make at least H acid esterification reaction with at least one diol, or at least Dicarboxylic acid After transesterification of at least one of the hydrazines, the precursor polymer formed in each of the reactions is subjected to a polycondensation reaction under the action of a zinc catalyst and a phosphite as a stabilizer. a polyester of a target product, wherein the phosphite is selected from the group consisting of triphenyl phosphite, trimethyl phosphite, diphenylalkyl phosphite, stearyl dialkyl phosphite, phosphorous acid Tris(壬基笨) ester, tris(dodecyl)phosphite, dioctadecyl phosphite, distearyl pentaerythritol diphosphite, bisphosphite di(2,4 -di-tert-butylphenyl)ester, diisoindolyl neopentyl bisphosphite, bis(2,4-di-tert-butylphenyl)netetramethylene bis-discate, bis (2,6 Tert-butyl 4-methylphenyl) neotetrapentanol bisphosphite, bisisodecyloxy neotetrapentyl bisphosphite, bis(2,4-di-tert-butyl-6methylphenyl) Tetrakiol bisphosphite, bis(2,4,6-tris(tert-butylphenyl) neotetrapentyl bisphosphite, tristearate sorbite, 6-isooctyloxy _ 2 , 4'8,10-tetra-tert-butyl_12H-two [d,g][l,3,2]dioxanylphosphine, bis(2,4-di-tert-butyl-6-methylphenyl)methyl phosphite, bisphosphite (2, 4·di-tert-butyl-6-mercaptophenyl)ethyl ester, 6-fluoro-2,4,8,1〇·tetra-tert-butyl-121-methyl-diphenyl[^][1,3,2 Dioxanylphosphine, 2,2',2''-nitrogen [triethyltris(3,3,5,5,-tetra-tert-butyl-hydrazine, _ _ _ _ 2, 2'-di-ortho)phosphite], 2-ethylhexyl (3,3,5,5,-tetra-tert-butyl-1, fluorene-biphenyl-2,2'-di-ortho) Phosphate, 5-butyl-5·ethyl 2_(2,4,6-tri-tert-butylphenoxy)-1,3,2-dioxalanyl fluorene and its 20 ^ ° And the phosphite is added in an amount of 0.01 to 2.0% by weight based on the total amount of the polyester produced. 2. The method according to the first aspect of the patent application, wherein the zinc The catalyst is selected from the group consisting of an oxide of zinc, an organic acid salt of zinc, a dentate of zinc, and the like, and a method for preparing the polyester according to claim 2, wherein the oxide of the word includes Zinc oxide, zinc oxide nano powder and zinc peroxide. Please refer to the method for preparing the brewed wine according to item 2 of the patent scope. In the first, the organic acid salt of the formula includes the acetic acid word 'zinc zinc acrylate, zinc methacrylate: 3'5-tert-butyl zinc salicylate, oxalic acid Zinc, stearic acid and zinc lactate. According to the method for preparing polyester according to claim 2, wherein the iS compound of the word includes chlorinated and zinc bromide. The method according to the fifth aspect, wherein the phosphite is selected from the group consisting of triphenyl phosphite, tris = ^ η Λ 1 g phosphorous acid-(, tert-butylphenyl) ester, and phosphorous acid tris ( Nonyl phenyl) ester and its 21 2121574 indifference ranged from 100 to 350 ppm. 10. The method for producing a polyester according to claim 1, wherein the arsenic acid is added in an amount of from 0.01 to 0.5% by weight based on the total amount of the polycondensate produced. . 11. The method according to claim 1, wherein the at least one dicarboxylic acid is esterified with at least one diol, and the dicarboxylic acid comprises terephthalic acid, isophthalic acid, Naphthoic acid, p-hydroxybenzoic acid, hydroxynaphthoic acid, cyclohexanedicarboxylic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedioic acid, itaconic acid; the diol Including ethylene glycol, 1,3-propanediol, naphthalenediol, 1,2-propanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedhenol, 1,4-cyclohexanedimethanol, two Ethylene glycol, hydroquinone, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, triethylene glycol, and isophthalic acid. 12. The process for producing a polyester according to claim 11, wherein the dicarboxylic acid is terephthalic acid and the glycol is ethylene glycol. twenty two