TW200808862A - Method for manufacturing polyester using non-stibium catalyst - Google Patents

Abstract

The present invention relates to a method for manufacturing polyester using non-stibium catalyst, wherein esterification reaction is proceeded with at least a dicarboxylic acid and at least a binary alcohol, or transesterification is proceeded with at least a dicarboxylic acid ester and at least a binary alcohol, and in the presence of a zinc catalyst and phosphorous acid triethyl ester, as stabilizer, the polymerization is proceeded with the prepolymer formed in previous reaction to prepare the intended product, polyester.

Description

200808862 IX. Description of the invention: [Technical field to which the invention pertains] The present invention relates to a process for producing a polyester, and more particularly to a process for producing a polyester using a zinc catalyst in a polycondensation reaction stage. [Prior Art] Products of synthetic polyester have been widely used in everyday life, such as polyester-fiber, polyester bottles, polyester films, and the like. Common polyesters are polyethylene terephthalate (polyethylene terephthalate), poly terephthalate (PPT), polybutylene terephthalate g ( Polybutylene terephthalate (PBT), polyethylene naphthalate (PNT), etc., among 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 is a goal that polyester producers are striving 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 process of polyester can be divided into two stages, the first stage is esterification or ί|transesterification, and the second stage is poiycondensation. Taking PET as an example, due to the different reaction modes in the first stage, it 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. In the first stage, 5 200808862 transesterification reaction is carried out, usually with Lewis acid as catalyst. After the completion of the first-stage reaction, whether in the TPA or DMT process, the catalyst is added to the second stage of the polycondensation reaction, so the stage in which the catalyst is used in the polyester process is mainly the condensation polymerization. The catalysts used in the polycondensation reaction of the polyester process mainly include a lanthanide, a lanthanide, a titanium system, and an aluminum system f. Because of the bismuth-based catalysts such as antimony trioxide (Sb2〇3), the price is low, and the polycondensation reaction can be greatly promoted, and the degree of degradation reaction is small. 'Almost all kinds of poly- _ can be used 锑Catalysts for preparation 'Because' The commercial production of polyester in the past few decades has mostly been dominated by the use of combined catalysts. However, in recent years, research has been conducted to point out that metal recording will endanger human health. The latest European regulations have also begun to limit the bismuth content of textiles. Therefore, the enzymes that do not contain strontium and heavy metals have developed into a catalyst for future development. Its t, the catalyst is medium to high activity, although

The color of the 酉 粒 粒 亮 眚 眚 眚 眚 amp amp amp amp amp amp amp amp amp amp 极 极 极 极 极 极 极 极 极 极 极 极 极 极 极 极 极 极 极 极 极 极 极 极However, the titanium catalyst has higher activity, and it is easy to form titanium dioxide when it is exposed to water at high temperature (for example, during the polycondensation reaction process), and the yellowing of the vinegar grains (yell〇wish) is also better than that of the recording medium. Difficult to accept, there is a certain degree of difficulty in industrial application. In addition, although the price is low, the activity is low, and a high amount of addition is required, so that the cost is not good. In addition to the aforementioned catalyst for the mono-metal component, a combination of a plurality of metal compounds is used to form a combined catalyst, for example, a metal compound 6 200808862 of titanium, zinc, and antimony, in order to reduce the amount of each metal used. However, too many components of the catalyst will complicate process control and increase manufacturing costs, and such combined catalyst technology still has a certain degree of bismuth content and does not conform to the trend of environmental protection. From the above, it has been found 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 and the like have found through various studies and experiments that the zinc catalyst with a single metal component is a catalyst for the polymerization reaction, and the organic sub-(10)S is used as a stabilizer to effectively promote the rate of polycondensation reaction and avoid The problem of polyester yellowing. In the early stage, although zinc catalysts were used in the transesterification reaction stage, the mechanism of the transesterification reaction was the same as that of the polycondensation reaction. In the condensation reaction, the catalyst was used alone, and there was a s In the case of chemistry, if the anti-static agent such as phosphoric acid is used, the activity of the catalyst will be disturbed. If the addition of phosphoric acid exceeds 001 wt%, the activity of the catalyst will be reduced, so it has not been found in the process of poly-S. The polycondensation reaction stage is applied to industrial production using a zinc catalyst method alone. This fx Mingren et al. found that if the organic (tetra) acid _, especially the organic phosphite of the large group, is used as a stabilizer, the polycondensation can be effectively inhibited, so that the zinc catalyst can be polycondensed in the (four) process. In the reaction, it is used alone, 'again' because the catalyst is not toxic, the price is low, and it has the life of the phase! · The life of the month b is achieved by reducing the manufacturing cost, shortening the reaction time and ensuring the advantages; The combination of zinc catalyst synthesis has the following advantages: 7 200808862 Thermal stability' also has a low crystallization rate. Injecting blow molding, no need to add crystallization inhibitor, in addition to saving raw materials. The cost can also avoid the influence of additives on the heat resistance properties of the polyester.

The non-cable catalyst polyester of the present invention is prepared by esterifying at least one dicarboxylic acid with at least one diol or transesterifying at least one dicarboxylic acid ester with at least one diol. Thereafter, 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 to prepare a polyester of the target. The zinc catalyst suitable for use in the present invention may be selected from the group consisting of zinc oxides, zinc organic acid salts, zinc halides, and the like. Specific examples of the zinc oxide include zinc oxide, zinc oxide nanopowder, and zinc peroxide. The zinc organic acid salt may specifically be, for example, zinc acetate, zinc acrylate, zinc methacrylate, zinc 3,5-di-tert-butylhydrate (zinc 3, 5-di-tert-butylsalicylate), zinc oxalate, zinc stearate, and zinc lactate. Zinc halides are best treated with zinc chloride and zinc bromide. The sub-filler suitable for use in the present invention is preferably a large group of organic phthalic acid esters, and specific examples include triphenyl phosphite and trimethyl phosphite. , diphenyl alkyl phosphites, phenyl dialkyl phosphites, tris(nonylphenyl) phosphite ( 8 200808862

Tris(nonylphenyl) phosphite ), trilauryl phosphite, trioctadecyl phosphite, distearyl pentaerythritol double sulphite Ditearyl pentaerythritol diphosphite, tris(254-di-tert-buiylplienyl) phosphite, diisoindole neopentyl alcohol double sub-fill Diisodecyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, double (2, 6 bis(2,6-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, bisisodecyloxy neotetrapentanol bis(bis(2-tert-butyl-4-methylphenyl) pentaerythritol diphosphite) Diisodecyloxypentaerythritol diphosphite, bis(2,4-di-butyl-6-methylphenyl) pentaerythritol Diphospliite), bis(25,5-tris(tert-butylphenyl)) pen Taerythritol diphosphite), tristearyl sorbitol triphospliite, 6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-diphenyl [d,g][ 1,3,2]dioxan:^S^(6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenz [d,g][l,3,2]dioxaphosphocin ), bis(2,4-di-tert-butyl-6-methylphenyl) methyl phosphate, bis(2,4-di-tert-butyl-6-methylphenyl) methyl phosphate (2,4-di-tert-butyl-6-methylphenyl) ethyl phosphite, 6-fluoro-2,4,8, 10-tetra-tert-butyl_12H-methyl-diphenyl[d,g][l,3,2]dioxanone (6-fluoro-2,4,8,10-tetra-tert) -butyl· 12H-methyl- 9 200808862 dibenz [d,g][l,3,2]dioxaphosphocin),2,2',2"-nitrogen [triethyl bis(3,3',5,5' _tetra-tert-butylbiphenyl-2,2'-di-ortho)phosphite]( 2,2,,2"-nitril〇[triethyltris(3,3,,5,5Metra_tert-butyM,l,- biphenyl -2,2'_diyl) phosphite]), 2-ethylhexyl (3,3,5,5'-tetra-tert-butyl-1,1,biphenyl-2,2,- 2-ethylhexyl (3,3', 555'-tetra-tert-butyl-l, 1 '-biphenyl-2,2'-diyl) phosphite), 5-butyl-5-B 5-(2,4,6-tri-tert-butylphenoxy)-1,3,2-dioxalanylphosphine (5-butyl-5-ethyl-2-(2,4,6) -tri-tert-butylphenoxy)-l,3,2-(!ioxaphosphiraiie) and combinations thereof; among them, triphenyl phosphite, trimethyl phosphite, tris, 4, di-tert-butyl phosphite A combination of a phenyl) ester, a tridecyl phenyl 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 alcohol is usually used in the reactants, and the excess of the alcohol is adjusted according to the equipment of the reaction process, so that the standards of the reactants are inconsistent. Taking the manufacture of pET as an example, the molar ratio of ethyl alcohol/p-benzoic acid in the reactant is usually between 1 · 〇 5 and 1 · 25, depending on the process equipment, and the total amount of the polyester product is estimated to be The amount of phthalic 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 10 1000 ppm, preferably between % and 卯 (five), and more preferably between 100 and 350 ppm. The amount of the phosphite to be used in the present invention is between 〇〇1 and 重量%, and the car is preferably between 〇·〇15 and 〇5. The diacidic acid suitable for use in the present invention includes terephthalic acid (2008)

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 (l54- Cyclohexane dimethanol), diethylene glycol, hydroquinone, 1,3-butane diol, 1,5-pentanediol (1,5-pentaiie diol) 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. . The polyester prepared by the invention can be further subjected to solid state polymerization to increase the viscosity of the polyester, and can be supplied for different use requirements. For example, the polyester for bottle needs higher viscosity, which is obtained by solid state polymerization. . 11 200808862 [Embodiment] Hereinafter, the contents of the present invention will be described in more detail by way of embodiments. <Example 1> 519 g (3.12 mole) of terephthalic acid and 204 g (3.28 mol of e) of ethyl alcohol were poured into a 1 liter stainless steel autoclave, under pressure. In an environment of more than 4 kg/cm2, the temperature is continuously increased (the speed of the stirrer is 60 rpm), and the temperature is gradually raised to 250 ° C in 5 hours while the water produced by the reaction is distilled off through the distillation tube. After completion of the esterification reaction, 2. 4 grams of stearic acid catalyst (expressed metal concentration 4 丨〇 (5)) and 0_045 grams of tridecyl linoleate were added, and the temperature was gradually increased to 28 in about 3 hours. TC, while vacuuming to i t (10) in i hours, at the end of the reaction, when the stirring power of the mixer gradually increased from 70 W to 1 〇 5 W, the reaction was stopped. The recording condensation reaction time was 135 minutes. <Bei Shi Example 2~ 3 &Comparative Example 1 > Examples 2 to 3 are the reaction conditions of Example} but the hard fat

Examples 1 to 3 and Comparative Example 1 are listed together in the table, the large valley point, and the crystallization temperature at the time of cooling, and the analysis of the properties of the polyester is performed side by side, and J indicates that Hyun went to this, and the person owed n # , , , , _ condensation reaction time, and its preparation is shown in Table 1. Among them, the Tm and Tc points are measured by a differential scanning analyzer (12 200808862 DSC, manufactured by ΤΑ Instruments, Model DSC 2910 Modulate DSC); 5% wt loss refers to the temperature at 5% weight loss, ie The cracking temperature of the polyester is measured by a thermogravimetric analyzer (Temperature Analyzer T, TGA, manufactured by ΤΑ Instruments, Model TGA 2950). The test method is to make the polyester test piece under nitrogen atmosphere at an ambient temperature of 30°. C is raised to 600 ° C, the heating rate is 10 ° C / min, and the temperature at which the weight loss is 5% is measured; IV is the intrinsic viscosity, which is to dissolve 1 gram of the ester granules in 100 gram / four A mixed solvent of phenol/terachloroethane, in which _ / tetrachloroethylene :): the weight ratio of 1:1 is 1, and measured by a libelode-viscosimeter at 30. 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 effective amount of the zinc metal used in Example 3 was 155 ppm, compared with the amount of catalyst added. Comparison 13 200808862 The effective concentration of the ruthenium metal in Example 1 is 250 ppm, indicating that the catalytic activity of zinc metal is higher than that of ruthenium metal. The relationship between the concentration of the metal of Example 3 and the condensation reaction time was analyzed by regression analysis. It can be seen that the condensation reaction time is about 175 minutes when the metal concentration is 25 〇ppm, and the reaction time can be shortened compared with the same concentration of ruthenium catalyst. It is clearer that zinc metal has better catalytic activity. Moreover, the properties of the polyester obtained by using zinc metal as a catalyst are also comparable to those of the polyester obtained by the conventional catalyst. Comparing the example id, it can be seen that with the addition of the amount of the zinc catalyst, the time of the polycondensation reaction is effectively shortened. <Examples 4 to 8> The reaction conditions of Examples 4 to 8 were the same as those of Example ,, but other types of catalysts were used, the type of catalyst, the amount of addition, the polymerization reaction time, and the obtained polymerization. The intrinsic viscosity values of the esters are shown in Table 2. Table 2 Examples Zinc Catalyst Zinc Metal Concentration (ppm) Zinc Oxide Nanoparticles Powder Zinc Oxide Polycondensation Reaction Time (min) 345 IV (dL/g) 0.644 Zinc Catalyst Concentration (PPm) 285 193 435 265 270 0.652 0.661

Zinc acetate zinc methacrylate zinc tert-butyl salicylate can be seen from Table 1 and Table 2, the different zinc catalysts in the same state of effective zinc gold concentration 14 200808862, the activity of the metal is not The same, while observing the obtained polycondensation reaction time, a large group of organic acid zinc such as zinc stearate and zinc 3,5 di-tert-butyl salicylate showed a better catalytic effect. &lt;Example 9&gt; 38 to 9 kg of terephthalic acid and 15.2 kg of ethylene glycol were poured into a stainless steel reaction mixture having a volume of 150 liters, and the pressure was continued in an environment of not more than 3 kg/cm 2 . Warming and stirring (mixer rotation speed is 3 rpm), and gradually heating to 25 (rc) within 6 hours, while allowing the water produced by the reaction to be distilled from the rectification official. After the esterification reaction is completed, 67 5 g of stearic acid is added. Zinc catalyst (zinc metal concentration 155 ppm) and 6.8 g of tridecyl phosphite, and gradually increase the temperature to 280 within 3 hours. (:, simultaneously pumping vacuum to it〇r]r within 2 hours, the end of the reaction When the current meter of the mixer shows that it gradually rises from 2·3 A to 2.5 A, the reaction is stopped. The inherent viscosity (IV) of the obtained polyester is 0.643 〇 and then the polyester obtained by the above reaction is taken. 15 kg is poured into a solid-state polymerization reactor with a volume of 3 liters, and the temperature is 235. (:, the pressure does not exceed !torr, the solid state polymerization is carried out for 3.5 hours. The solid-polymerized ester particles are measured. The physical properties of the measurement results are shown in Table 3. 15 200808862 After the solid state polymerization Physical Properties of Ester Particles 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, which is 16% higher than that of the solid agglomerated crucible (IV=0.643). t1/2 indicates the crystallization half-life. La and Lb represent the hue of S particles. The larger the L 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 larger the value of Lb. The yellower the grain, the larger the negative value means that the I grain is blue, so the La and Lb values are preferably close to "〇". 1) The ugly 0 indicates the content of diethylene glycol, which is a by-product formed in the reaction. It will lower the glass transition temperature (Tg) and the melting point (Tm) of polyg. The higher the acid value, the incomplete reaction, or the formation of ester group breakage during the reaction. The general industrial application requires DEG to be less than 3 wt%. Preferably, the acid value is preferably less than 50 meq/kg. Free AA means S in acetaldehyde, and potential AA means the probability of forming a plate, when the container is used to make a container for beverages or food, Acetaldehyde content Too high will result in a bitter taste in the beverage or food contained. Therefore, the lower the acetaldehyde content, the better, preferably less than 2 〇ppm. &lt;Comparative Example 2 &gt; The reaction conditions of Comparative Example 2 are the same as in Example 9, The catalyst was changed to 13.5 grams of antimony trioxide (the concentration of rhodium metal was 250 ppm). When the polycondensation was completed 16 200808862, 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, the viscosity was increased by 16%, and the crystallization half-life (tW2) was 1.119 minutes.

The crystallization half-life of the ester particles after solid state polymerization in Example 9 and Comparative Example 2 was 1 _ 5 5 6 minutes and 1 · 119 minutes, respectively, indicating that the crystallization rate of the polyester prepared using the zinc catalyst was lower than that of the use. Polyester made from catalyst. Since the crystallization rate of the polyacetate is low when the polyglycol is prepared 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 additive for the polyester waste heat. The nature of the effect is beneficial to the application of 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 media does not affect the operating costs of subsequent solid state polymerization. The thermal degradation rate test knives were taken in Example 9 and Comparative Example 2 before the solid-state polymerization was carried out. The injection was carried out at 28 G °C: L for temperature test, and the inherent viscosity of the test was analyzed and before injection. The intrinsic viscosity of vinegar grains can be compared with the case of viscosity degradation after thermal processing (thermal degradation rate). Results: 2: 4. % Table 17 200808862

As can be seen from the above table, the thermal degradation rate of the polyester granules prepared in Example 9 was lower than that of the polyacetal granules prepared in Comparative Example 2, showing that the materials were compared with the conventional _catalyst The obtained "the thermal stability is better. In summary, the present invention uses a non-ruthenium-based polyester preparation method, and a zinc catalyst can be used alone in the polycondensation reaction stage, which is non-toxic and inexpensive, and is not a virgin. The agent can inhibit the yellowing of the ester particles without affecting the activity of the zinc catalyst, and can effectively promote the polycondensation reaction to shorten the reaction time, and further, the polyester which is synthesized by the conventional catalyst is used in the present invention. The zinc catalyst synthesized by the zinc catalyst has the thermal stability of the slave, and also has a low crystallization rate. When the injection molding process is performed, there is no need to add a crystallization inhibitor, in addition to the cost of raw materials. It is possible to avoid the influence of the additive on the heat-resistant property of the poly-S, and it is advantageous for application to the hot-filled poly-g-mail bottle, and it is indeed possible to achieve the object of the present invention. However, the above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, that is, the simple equivalent change of the application of the present invention and the description of the invention. And modifications are still within the scope of the invention patent. [Simple description of the diagram] Benefit η,, 18 200808862 [Description of main component symbols]

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Claims (1)

200808862 X. Patent Application Range: L A method for preparing a polyester using a non-ruthenium catalyst for esterifying at least one dicarboxylic acid with at least one diol or at least one bismuth dicarboxylate After the glycol is subjected to a transesterification reaction, the precursor polymer formed in each reaction is subjected to a polycondensation reaction under the action of a zinc catalyst and a phosphite used as a stabilizer to prepare a target product. Polyester, wherein the compound of the word 2. Process for the preparation of a polyester according to claim 1 of the patent application. The zinc catalyst is obtained from a combination of zinc oxides, organic acid salts, and the like. 3. The method according to the second aspect of the invention, wherein the zinc oxide comprises zinc oxide, zinc oxide nano powder and peroxide. 4. According to the method of preparation (4) of the patent application _ Item 2, wherein the organic acid salt of the word includes acetic acid, acrylic acid, zinc methacrylate: zinc 3,5 di-tert-butyl salicylate, zinc oxalate, Zinc stearate and zinc lactate. 5. The m $ zinc halides according to paragraph (4) of the scope of the patent application include the words of chlorination and bromination. 6. According to the A patent, Wtj RV 7 -BL tp linolenic acid S is selected from the group consisting of wollatriene, sub-light trimethyl phthalate, diphenylalkyl phthalate, phenyl dialkyl phosphite, Triterpene benzene phosphite vinegar, linalic acid tris (twelve yards), tris (octadecanoate), distearyl pentaerythritol diphosphite, yalitri-tert-butyl Phenyl) 3⁄4, isoindole neotetrapentanol bisphosphite, bis(2 t-butylphenyl) neotetrapentanol diphosphoric acid, bis (2,6-tert-butyl·4 20 200808862) Neotetrapentanol bisphosphite, bisisodecyloxy neotetrapentanol citrate, bis(M di-tert-butyl-6-methylphenyl) neotetrapentanol bismuth bis(2) , 4,6·di(tert-butylphenyl) neotetrapentanol bis-discate, distearyl sorbitan trisphosphate, 6-isooctyloxy-2,4,8, ι〇_four uncle ^butyl^^ This i_d'g][i,j,2]oxocyclohexanyl, bis-bis(κdi-tert-butyl-6-methylphenyl)decyl ester, bisphosphite (2,4_di-tert-butylmethylphenyl)ethyl ester, 6-fluoro-2,4,8,10-tetra-tert-butyl-12H-methyl-diphenyl 1 smelting][1,3,2] Dioxane Phosphorus, 2, 2, 2,, _Nichuan [triethyltris(3,3',5,5'-tetra-tert-butyl-U, ·biphenyl-2,2,-di-ortho) Phosphate], ethylhexyl (3,3,5,5,-tetra-tert-butyl-1,1,-biphenyl·2,2,-di- ortho) phosphite, 5-butyl-5 -ethyl-2-(2,4,6-tri-tert-butylphenoxy)- 1'3,2-oxoxalate squama and combinations thereof, etc. 7 according to the scope of patent application The method for producing a polyester according to the invention, wherein the sub-acid _ is selected from the group consisting of triphenyl phosphite, trimethyl phosphite, di(2, bis-tert-butylphenyl) phosphite, and phosphorous triphosphate A combination of (mercaptophenyl) ester and the like. The method according to claim 1, wherein the zinc catalyst is added in an amount of the total amount of the polyester produced. The zinc metal is 辰 度 丨 丨 丨 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. 9. The total amount of polyester is such that the zinc metal wave is between 50 and 5 〇〇ρρηι. 1 〇. According to the scope of claim 9 The method for preparing the zinc catalyst is based on the total amount of the polyester produced, so that the concentration of the zinc metal 21 200808862 is between 100 and 350 ppm. 11. According to the scope of claim 1 a method for producing a polyester, wherein the phthalic acid ester is added in an amount of from 0.01 to 2.0% by weight based on the total amount of the polyester produced. The method for preparing the strontium sulphate is from 0.015 to 0.5% by weight based on the total amount of the polyester produced. 13. The method according to claim 1, wherein the at least one dicarboxylic acid is esterified with at least one diol comprising terephthalic acid and isophthalic acid. , naphthalenedicarboxylic 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-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, diethyl Glycol, hydroquinone, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, triethylene glycol, resorcinol. 14. The process for producing a polyester according to claim 13, wherein the dicarboxylic acid is terephthalic acid and the glycol is ethylene glycol. twenty two