JP4159237B2 - Production method of polyester resin - Google Patents

Description

【００５６】
【発明の効果】
本発明によれば、色調に優れ、副生成物の少ない固相重縮合樹脂を、粘着や過度の結晶化等がなく生産性よく製造することができるポリエステル樹脂の製造方法を提供することができる。[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a method for producing a polyethylene terephthalate-based polyester resin, and more particularly to a method for producing a polyester resin capable of producing a solid phase polycondensation resin having excellent color tone and few by-products with high productivity.
[0002]
[Prior art]
  Conventionally, for example, polyester resins such as polyethylene terephthalate are excellent in mechanical strength, chemical stability, gas barrier properties, hygiene, etc., and are relatively inexpensive and lightweight. Widely used for packaging materials or fibers.
[0003]
  For example, a polyethylene terephthalate-based polyester resin generally undergoes an esterification reaction between a dicarboxylic acid component mainly composed of terephthalic acid and a diol component mainly composed of ethylene glycol, and then in the presence of a polycondensation catalyst. A melt polycondensation reaction is performed to obtain a melt polycondensation resin having an intrinsic viscosity of usually 0.1 to 0.7 dl / g. Subsequently, the granules of the melt polycondensation resin are further increased in polymerization degree, In order to reduce the content of oligomers such as acetaldehyde and cyclic trimer by-produced during melt polycondensation, a solid phase polycondensation reaction is performed in a solid state at a temperature below the melting point, and the intrinsic viscosity is usually 0.5. It is manufactured by forming a solid phase polycondensation resin of ˜1.5 dl / g.
[0004]
  However, since the solid-phase polycondensation reaction performed in a solid state below the melting point is performed at a low temperature, the polymerization rate is low. Phase polycondensation takes up to several tens of hours, and its low productivity and deterioration in color tone are problems. On the other hand, increasing the solid-phase polycondensation reaction temperature can cause adhesion between resin particles and thermal decomposition. As a result of problems such as increased by-products such as diethylene glycol, deterioration of color tone, and deterioration of moldability due to excessive crystallization, it cannot be adopted as a solution, and its solution is strongly desired. Currently.
[0005]
[Problems to be solved by the invention]
  The present invention has been made in view of the above-described present state of the prior art described above, and is capable of producing a solid phase polycondensation resin having excellent color tone and few by-products with high productivity without adhesion or excessive crystallization. It aims at providing the manufacturing method of the polyester resin which can be manufactured.
[0006]
[Means for Solving the Problems]
  As a result of intensive studies in view of the above situation, the present inventors have found that when the melt polycondensation resin is subjected to a solid phase polycondensation reaction, the Arrhenius equation in chemical kinetics, k = A exp (−ΔE / RT) [Where k is the rate constant, A is the frequency factor, ΔE is the activation energy, R is the gas constant, and T is the absolute temperature. The rate constant k can be increased by subjecting the melt polycondensation resin having a specific relationship between the activation energy ΔE and the frequency factor A to a solid phase polycondensation reaction, and the above object can be achieved. That is, in the present invention, a dicarboxylic acid component mainly composed of terephthalic acid and a diol component mainly composed of ethylene glycol are esterified and then subjected to a melt polycondensation reaction in the presence of a polycondensation catalyst. In the case of producing a polyester resin by subsequent solid-phase polycondensation reaction, as a polycondensation catalyst, titanium having an amount of 0.002 to 0.2 mmol as a content of titanium atoms per kg of the theoretical yield of the polyester resin Germanium with a compound and a metal atom content of 0.02 to 2 mmol eachCompound and magnesiumCompoundThings andUsingAlternatively, the amount of titanium compound is 0.002 to 0.2 mmol as the content of titanium atoms per kg of the theoretical yield of the polyester resin, and the amount is 0.02 to 2 mmol as the content of metal atoms. And a germanium compoundAs an aid for polycondensation catalyst,phosphorusCompoundThingsThe theoretical yield of polyester resin was used in an amount of 0.02 to 4 mmol as the content of atoms per kg, and the intrinsic viscosity was 0.1 to 0.7 dl / g, which was subjected to a solid phase polycondensation reaction. Polyester obtained by subjecting a melt polycondensation resin having an activation energy ΔE and a frequency factor A satisfying the following formula to a solid phase polycondensation reaction to form a solid phase polycondensation resin having an intrinsic viscosity of 0.5 to 1.5 dl / g The gist of the resin production method.
[0007]
    lnA / ΔE ≧ 0.80 [mol / (kcal · time)]
[0008]
DETAILED DESCRIPTION OF THE INVENTION
  The method for producing a polyester resin according to the present invention is such that other dicarboxylic acids and / or other diols using a dicarboxylic acid component containing terephthalic acid as a main component and a diol component containing ethylene glycol as a main component as needed. A copolymer slurry such as a catalyst, an auxiliary agent and the like are put into a slurry tank and mixed with stirring to prepare a raw material slurry.
[0009]
  Here, as dicarboxylic acid other than terephthalic acid as the dicarboxylic acid component, specifically, for example, phthalic acid, isophthalic acid, dibromoisophthalic acid, sodium sulfoisophthalate, phenylenedioxydicarboxylic acid, 4,4′- Diphenyldicarboxylic acid, 4,4′-diphenylether dicarboxylic acid, 4,4′-diphenylketone dicarboxylic acid, 4,4′-diphenoxyethanedicarboxylic acid, 4,4′-diphenylsulfonedicarboxylic acid, 2,6-naphthalenedicarboxylic acid Aromatic dicarboxylic acids such as acids, cycloaliphatic dicarboxylic acids such as hexahydroterephthalic acid and hexahydroisophthalic acid, and succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undeca Fats such as dicarboxylic acid and dodecadicarboxylic acid Dicarboxylic acid, and dimethyl terephthalate, dimethyl 2,6-naphthalenedicarboxylate, etc., these aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and alkyl esters having about 1 to 4 carbon atoms of aliphatic dicarboxylic acids, or halogens And derivatives thereof.
[0010]
  Examples of the diol other than ethylene glycol as the diol component include trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, octamethylene glycol, decamethylene glycol, neopentyl glycol, 2-ethyl-2- Aliphatic diols such as butyl-1,3-propanediol, diethylene glycol, polyethylene glycol, polytetramethylene ether glycol, 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,4 -Cycloaliphatic diols such as cyclohexanedimethanol, 2,5-norbornanedimethanol, xylylene glycol, 4,4'-dihydroxybiphenyl, 2,2-bis ( Aromatic diols such as' -hydroxyphenyl) propane, 2,2-bis (4'-β-hydroxyethoxyphenyl) propane, bis (4-hydroxyphenyl) sulfone, bis (4-β-hydroxyethoxyphenyl) sulfonic acid And 2,2-bis (4′-hydroxyphenyl) propane ethylene oxide adduct or propylene oxide adduct.
[0011]
  Further, in addition to the dicarboxylic acid component and the diol component, hydroxycarboxylic acids such as glycolic acid, p-hydroxybenzoic acid, p-β-hydroxyethoxybenzoic acid, and alkoxycarboxylic acids are used without departing from the effects of the present invention. Acids and monofunctional components such as stearyl alcohol, benzyl alcohol, stearic acid, benzoic acid, t-butylbenzoic acid, benzoylbenzoic acid, tricarballylic acid, trimellitic acid, trimesic acid, pyromellitic acid, gallic acid, trimethyl Trifunctional or more polyfunctional components such as methylolethane, trimethylolpropane, glycerol, pentaerythritol, tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, One or more of these are used as copolymerization components It may be.
[0012]
  In the method for producing a polyester resin of the present invention, the proportion of terephthalic acid in the total dicarboxylic acid component is preferably 95 mol% or more, more preferably 98 mol%, and 99 mol% or more. Particularly preferred. The proportion of ethylene glycol in the total diol component is preferably 95 mol% or more, more preferably 98 mol% or more, and particularly preferably 99 mol% or more.
[0013]
  Subsequently, the prepared raw material slurry is transferred to an esterification reaction tank, and is usually at a temperature of 240 to 280 ° C. and a relative pressure of 3 × 10 to normal pressure to atmospheric pressure.^FiveA polyester low molecular weight product is obtained by an esterification reaction with stirring under pressure of Pa for 1 to 10 hours.
[0014]
  Here, the esterification rate of the low molecular weight polyester (ratio of the total carboxyl group or carboxylic acid derivative group of the raw material dicarboxylic acid component that is esterified by reacting with the diol component) is a resin obtained by a polycondensation reaction described later. From the viewpoints of color tone and reduction of by-product content, it is 75% or more, preferably 90% or more, and particularly preferably 95% or more. The number average degree of polymerization of the low molecular weight material is 3.0 to 10.0 from the viewpoints of the stability and productivity of the reaction in the melt polycondensation described later, the color tone of the obtained resin, and the like. 9.0 is preferable, and 5.0 to 8.0 is particularly preferable.
[0015]
  Subsequently, the obtained esterification reaction product is transferred to a polycondensation reaction tank, and in the presence of a polycondensation catalyst or the like, usually at a temperature of 250 to 290 ° C. and gradually reduced from normal pressure to an absolute pressure of 1333 to A melt polycondensation resin is obtained by performing a melt polycondensation reaction under stirring at 13.3 Pa for 1 to 20 hours with stirring.
[0016]
  Here, as the polycondensation catalyst, titanium, germanium, alkali metal, alkaline earth metal, aluminum can be used because the requirements of the present invention in solid phase polycondensation described later can be satisfied and the effects of the present invention can be remarkably exhibited. Two or more different metal compounds selected from the group consisting of zinc, tin, antimony, zirconium, and hafniumForNoThe
[0017]
  Specific examples of the titanium compound include tetra-n-propyl titanate, tetra-i-propyl titanate, tetra-n-butyl titanate, tetra-n-butyl titanate tetramer, tetra-t-butyl titanate, tetra Cyclohexyl titanate, tetraphenyl titanate, tetrabenzyl titanate, titanium acetate, titanium oxalate, titanium potassium oxalate, sodium titanium oxalate, potassium titanate, sodium titanate, titanate-aluminum hydroxide mixture, titanium chloride, titanium chloride-aluminum chloride mixture , Titanium bromide, titanium fluoride, potassium hexafluorotitanate, cobalt hexafluorotitanate, manganese hexafluorotitanate, ammonium hexafluorotitanate, titanium acetylacetonate, etc. -n- propyl titanate, tetra -i- propyl titanate, tetra -n- butyl titanate, titanium oxalate, titanium oxalate potassium are preferred.
[0018]
  Specific examples of the germanium compound include germanium dioxide, germanium tetroxide, germanium hydroxide, germanium oxalate, germanium tetraethoxide, germanium tetra-n-butoxide, and the like. Is preferred.
[0019]
  Specific examples of the alkali metal compound include lithium acetate, sodium acetate, and potassium acetate. Specific examples of the alkaline earth metal compound include magnesium oxide, Examples thereof include magnesium hydroxide, magnesium alkoxide, magnesium acetate, magnesium carbonate, calcium oxide, calcium hydroxide, calcium acetate, and calcium carbonate.
[0020]
  Examples of the aluminum, zinc, tin, antimony, zirconium, and hafnium compounds include oxides, hydroxides, alkoxides, carbonates, phosphates, carboxylates, and halides of these metals.
[0021]
  Among the polycondensation catalysts described above, in the present invention, the titanium compound in an amount of 0.002 to 0.2 mmol as the content of titanium atoms per kg of the theoretical yield of the polyester resin, and also the content of metal atoms Using one or more of the above compounds of germanium, alkali metal, alkaline earth metal, aluminum, zinc, tin, antimony, zirconium, or hafnium each in an amount of 0.02 to 2 millimolarThe
[0022]
  Furthermore, in the method for producing a polyester resin of the present invention, polycondensation reactivity, thermal stability during melting, reduction of by-products such as acetaldehyde and cyclic trimer, and transparency and color tone of the resulting resin are obtained. In view of the above, one or more phosphorus compounds or silicon compounds selected from the group consisting of phosphorus and silicon are used as auxiliary agents for the polycondensation catalyst, and the content of atoms per kg of the theoretical yield of the polyester resin is 0. Used in an amount of 02 to 4 mmolThe
[0023]
  Here, specific examples of the phosphorus compound include orthophosphoric acid, polyphosphoric acid, and trimethyl phosphate, triethyl phosphate, tri-n-butyl phosphate, trioctyl phosphate, triphenyl phosphate, tricresyl phosphate, Trivalent (triethylene glycol) phosphate, ethyl diethyl phosphonoacetate, methyl acid phosphate, ethyl acid phosphate, isopropyl acid phosphate, butyl acid phosphate, monobutyl phosphate, dibutyl phosphate, dioctyl phosphate, triethylene glycol acid phosphate, etc. Phosphorus compound, phosphorous acid, hypophosphorous acid, and diethyl phosphite, trisdodecyl phosphite, trisnonyl decyl phosphite, And trivalent phosphorus compounds such as rephenyl phosphite. Among them, orthophosphoric acid, tris (triethylene glycol) phosphate, ethyl diethylphosphonoacetate, ethyl acid phosphate, triethylene glycol acid phosphate, phosphorous acid are preferable. , Tris (triethylene glycol) phosphate, ethyl diethyl phosphonoacetate, ethyl acid phosphate, triethylene glycol acid phosphate are particularly preferred.
[0024]
  Specific examples of the silicon compound include silica, clay, talc, mica, zeolite, and the like.
[0025]
  The polycondensation catalyst and the compound as an auxiliary agent may be added directly into the reaction system individually or in advance by reacting with each other, for example, as a solution such as ethylene glycol. It may be added inside.
[0026]
  In the production method of the present invention, the intrinsic viscosity of the melt polycondensation resin obtained through the esterification reaction and the melt polycondensation reaction is usually 0.1 to 0.7 dl / g, and 0.45 to 0.4. It is preferably 65 dl / g, particularly preferably 0.5 to 0.6 dl / g. If the intrinsic viscosity is less than the above range, the drawability from the polycondensation reaction tank when the molten polycondensation resin is made into granules is inferior, whereas if it exceeds the above range, the color tone of the melt polycondensation resin deteriorates or is a by-product. Problems such as an increase in the content of products will occur.
[0027]
  The color tone of the melt polycondensation resin is preferably such that the color coordinate b value in Hunter's color difference formula is −10 to 3, more preferably −5 to 2, and −3 to 2. Particularly preferred.
[0028]
  The molten polycondensation resin is usually extracted in the form of a strand from an extraction port provided at the bottom of the polycondensation reaction tank, and is granulated in pellets, chips, etc. while being cooled with water or after water cooling and cutting with a cutter, etc. As obtained. In that case, the average weight per one granule is from the viewpoint of handling properties such as aerodynamic transfer between processes, fusing properties between granulates, crystallization characteristics, bite into the screw during molding, etc. Preferably it is 15-30 mg, Most preferably, it is 20-25 mg.
[0029]
  In the production method of the present invention, when the molten polycondensation resin granule is subjected to a solid phase polycondensation reaction described later, the Arrhenius equation in chemical reaction kinetics, k = A exp (−ΔE / RT) [where , K is the rate constant, A is the frequency factor, ΔE is the activation energy, R is the gas constant, and T is the absolute temperature. It is essential that the activation energy ΔE and the frequency factor A satisfy the following formula. If the following formula is not satisfied, the object of the present invention cannot be achieved.
[0030]
    lnA / ΔE ≧ 0.80 [mol / (kcal · time)]
[0031]
  Moreover, it is preferable that the activation energy ΔE and the frequency factor A when the melt polycondensation resin granules are subjected to solid phase polycondensation satisfy the following formula.
[0032]
    1.0 ≧ lnA / ΔE ≧ 0.90 [mol / (kcal · time)]
[0033]
  Here, the activation energy ΔE is preferably 10 to 100 kcal / mol, and the frequency factor A is 1 × 10⁶~ 1x10^Ten/ Hour is preferred. In both cases where the activation energy ΔE is less than the above range and over the above range, the color tone of the solid phase polycondensation resin is inferior, and the heat stability at the time of molding tends to decrease. On the other hand, if the frequency factor A is less than the above range, a sufficient solid phase polycondensation reaction rate tends to be difficult to obtain. On the other hand, if the frequency factor A exceeds the above range, the color tone of the solid phase polycondensation resin is inferior. Stability tends to decrease.
[0034]
  Here, the activation energy ΔE and the frequency factor A are the intrinsic viscosities with respect to the melt polycondensation resin when the melt polycondensation resin granules are subjected to solid phase polycondensation reaction at 210 ° C. and 220 ° C. for 10 hours, respectively. It is calculated based on the amount of change.
[0035]
  In the production method of the present invention, the melt polycondensation resin obtained above is further increased in degree of polymerization, and the content of oligomers such as acetaldehyde and cyclic trimer by-produced during melt polycondensation is reduced. For this purpose, the granule is subjected to solid phase polycondensation reaction in a solid state at a temperature below the melting point.
[0036]
  In the solid phase polycondensation reaction, the molten polycondensation resin granules obtained above are usually in an inert gas atmosphere such as nitrogen, carbon dioxide, argon, etc., in a steam atmosphere, or in a steam-containing inert gas atmosphere. Then, after the resin granule surface is crystallized by heating at a temperature of 60 to 180 ° C., immediately below the adhesive temperature of the resin in an inert gas atmosphere or / and under a reduced pressure of 13333 to 13.3 Pa absolute pressure The solid phase polycondensation resin is obtained by heating at a temperature of -80 ° C. while rolling or flowing so that the granular materials do not stick together.
[0037]
  The reaction temperature for solid phase polycondensation is preferably from 210 to 240 ° C, particularly preferably from 220 to 230 ° C. If the solid-phase polycondensation reaction temperature is less than the above range, a sufficient polycondensation rate tends not to be obtained. On the other hand, if it exceeds the above range, adhesion between granular resins, deterioration of color tone, and moldability due to excessive crystallization. It tends to cause problems such as lowering.
[0038]
  In the production method of the present invention, the solid phase polycondensation resin obtained through the solid phase polycondensation reaction preferably has an intrinsic viscosity of 0.6 to 1.5 dl / g, more preferably 0.65 to 0.9 dl. / G, particularly preferably 0.7 to 0.8 dl / g.
[0039]
  The color tone is the color coordinate b value in Hunter's color difference formula, preferably −10 to 3, more preferably −5 to 2, particularly preferably −3 to 2, and the acetaldehyde content is preferably 5 ppm or less, more preferably 3 ppm or less, particularly preferably 2 ppm or less, and the cyclic trimer content is preferably 0.50% by weight or less, more preferably 0.40% by weight or less, particularly preferably 0. .35% by weight or less.
[0040]
  The polyester resin obtained by the production method of the present invention is, for example, formed into a preform by injection molding and then stretch blow molded, or by blow molding a parison molded by extrusion molding, a bottle or the like After being formed into a sheet by extrusion molding, it is molded into a tray or a container by thermoforming, or the sheet is biaxially stretched to form a film or the like, with mechanical strength and color tone. Since it is excellent and has few by-products, it is particularly useful in the food and beverage packaging field. Among them, it is suitable for forming a bottle by a blow molding method in which a preform obtained by injection molding is biaxially stretched. For example, liquid seasonings such as carbonated beverages, alcoholic beverages, soy sauce, sauces, mirin, and dressings Furthermore, it is suitably used as a container that requires heat resistance, such as a fruit juice drink, a drink such as tea or mineral water, etc.
[0041]
【Example】
  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example, unless the summary is exceeded.
[0042]
  ComparisonExample4
  A slurry prepared by stirring 43 parts by weight of terephthalic acid and 19 parts by weight of ethylene glycol in a slurry tank under nitrogen gas was previously charged with 50 parts by weight of an esterification reaction product, and the temperature was 250 ° C. and the pressure was a relative pressure to atmospheric pressure. 1.2 × 10^FiveThe esterification reaction tank held under pressure of Pa was supplied over 4 hours, and after completion of the supply, the esterification reaction was carried out over another 1 hour, and 50 parts by weight of this esterification reaction product was added to nitrogen gas. Then, it was transferred to a polycondensation reaction tank maintained at a temperature of 250 ° C. and normal pressure.
[0043]
  Subsequently, to the polycondensation reaction tank to which the esterification reaction product was transferred, ethyl acid phosphate, magnesium acetate, and tetra-n-butoxytitanium were each made into an ethylene glycol solution from the piping, and the theoretical yield of polyester resin was 1 kg. In order to achieve a content of 0.581 mmol as a phosphorus atom (P), 0.617 mmol as a magnesium atom (Mg), and 0.209 mmol as a titanium atom (Ti), it was sequentially added at intervals of 5 minutes. Thereafter, the temperature in the system is raised from 250 ° C. to 280 ° C. over 2 hours and 30 minutes, and the same temperature is maintained, and the pressure is reduced from normal pressure to 400 Pa in 1 hour while maintaining the same pressure. Extraction provided at the bottom of the polycondensation reaction tank is allowed to undergo a melt polycondensation reaction for a time when the intrinsic viscosity of the resin is around 0.55 dl / g. Withdrawn from the mouth into strands, cooled with water, by a chip-shaped with a cutter, average weight per grain was produced a melt polycondensation polyethylene terephthalate resin granules of 24 mg.
[0044]
  About the obtained melt polycondensed polyethylene terephthalate resin granules, the metal atom content, intrinsic viscosity, and color coordinate b value of P, Mg, and Ti are measured by the following method, and further, solid phase polycondensation reaction The activation energy and the frequency factor were calculated, and the results are shown in Table 1.
[0045]
Metal atom content
  A resin granule sample (2.5 g) was ashed and completely decomposed in a conventional manner in the presence of sulfuric acid, and then fixed to 50 ml with distilled water, and quantified by plasma emission spectrometry.
[0046]
Intrinsic viscosity
  110 ° C. with 0.50 g of the freeze-pulverized resin granule sample in a mixed solvent of phenol / 1,1,2,2-tetrachloroethane (weight ratio 1/1) and a concentration (c) of 1.0 g / dl For 20 minutes, and then using a Ubbelohde capillary viscosity tube at 30 ° C., the relative viscosity (η_rel) And the relative viscosity (η_rel) -1 specific viscosity (η_sp) And concentration (c) (η_sp/ C), and when the concentration (c) is 0.5 g / dl, 0.2 g / dl, and 0.1 g / dl, the ratio (η_sp/ C), and from these values, the ratio (η) when the concentration (c) is extrapolated to 0_sp/ C) was determined as intrinsic viscosity [η] (dl / g).
[0047]
Color coordinate b value
  The resin granular material sample is filled into a cylindrical powder colorimetry cell having an inner diameter of 36 mm and a depth of 15 mm, and JISZ8730 is used with a colorimetric color difference meter (“ND-300A” manufactured by Nippon Denshoku Industries Co., Ltd.). The color coordinate b in the Hunter's color difference formula defined in Reference 1 was obtained as a simple average value of values measured at four locations by rotating the cell 90 degrees by the reflection method.
[0048]
Activation energy, frequency factor
  After 2 g of molten polycondensation resin granule sample (particle weight 15 to 25 mg) was dried in an inert oven (“IPHH-201 type” manufactured by ESPEC) for 2 hours at 160 ° C. under a nitrogen gas flow of 40 l / min. The solid phase polycondensation resin sample obtained by heating at 210 ° C. and 220 ° C. for 10 hours to obtain the intrinsic viscosity [η]₂₁₀And [η]₂₂₀And its intrinsic viscosity [η]₂₁₀And [η]₂₂₀
From each of the number average molecular weights M according to the following formula (1)_n210And M_n220And the number average molecular weight M_n210And M_n220From the following formula (2), the number of molecular ends N_s210And N_s220On the other hand, the number average molecular weight M according to the formula (1) for the melt polycondensation resin_nAnd the number N of molecular ends is calculated from the calculated value according to equation (2)_mWas calculated. On the other hand, since the molecular weight is inversely proportional to the number of molecular ends, and the solid-phase polycondensation rate can be expressed as the rate of decrease of the number of molecular ends,₂₁₀And k₂₂₀Was calculated. And the speed constant k₂₁₀And k₂₂₀From this, the activation energy ΔE was calculated according to the following equation (4). The frequency factor A is the rate constant k obtained above when the solid-phase polycondensation temperature is 220 ° C.₂₂₀And the activation energy ΔE was substituted into the Arrhenius equation.
[0049]
(1) Number average molecular weight M_n210Or M_n220= ([Η]₂₁₀Or [η]₂₂₀/0.000736)^{1 / 0.685}
(2) Number of molecular ends N_s210Or N_s220(Mole / ton of polymer) = (1000000 / M_n210Or M_n220) × 2
(3) Speed constant k₂₁₀Or k₂₂₀(/ Hour) =-(lnN_s210Or N_s220-LnN_m) / 10≈- [ln (N_s210Or N_s220/ N_m)] / 10
(4) Activation energy ΔE (kcal / mol) = − ln (k₂₂₀/ K₂₁₀) / [{1 / (220 + 273)}-{1 / (210 + 273)}] × R / 1000
[0050]
  Subsequently, the molten polycondensed polyethylene terephthalate resin granules obtained above were dried in an inert oven (“IPHH-201 type” manufactured by ESPEC) at 160 ° C. for 2 hours under a nitrogen gas stream of 40 l / min. Thereafter, a solid phase polycondensation polyethylene terephthalate resin was produced by heating at 220 ° C. for a time such that the intrinsic viscosity of the obtained resin was around 0.75 dl / g to cause a solid phase polycondensation reaction.
[0051]
  About the obtained solid phase polycondensed polyethylene terephthalate resin granules, a rate constant is calculated based on the above formula, and the intrinsic viscosity and the color coordinate b value are calculated by the same method as described above, and by the method shown below. The acetaldehyde content and the cyclic trimer content were measured, and the results are shown in Table 1.
[0052]
Acetaldehyde content
  Weigh accurately 5.0 g of the resin granular material sample, enclose it in a 50 mL internal volume cylinder with 10 mL of pure water under a nitrogen seal, perform heat extraction at 160 ° C. for 2 hours, and determine the amount of acetaldehyde in the extract, It was quantified by gas chromatography (“GC-14A” manufactured by Shimadzu Corporation) using isobutyl alcohol as an internal standard.
[0053]
Cyclic trimer content
  4.0 mg of a resin particle sample is precisely weighed and dissolved in 2 ml of a mixed solvent of chloroform / hexafluoroisopropanol (volume ratio 3/2), further diluted with 20 ml of chloroform, and 10 ml of methanol is added thereto. The filtrate obtained by precipitation and subsequent filtration was evaporated to dryness and then dissolved in 25 ml of dimethylformamide, and the amount of cyclic trimer (cyclotriethylene terephthalate) in the solution was measured by liquid chromatography (“LC” manufactured by Shimadzu Corporation). -10A ").
[0054]
Example1~3Comparative Examples 1 to 3
  The polycondensation catalyst was changed as shown in Table 1 (however, germanium dioxide was used as the metal atom Ge compound),Comparative Example 4In the same manner as in the above, a melt polycondensation resin granule is produced, the metal atom content, the intrinsic viscosity, and the color coordinate b value are measured, and the activation energy when subjected to a solid phase polycondensation reaction, and The frequency factor was calculated and the results are shown in Table 1. Then,Comparative Example 4The solid phase polycondensation resin granule was produced in the same manner as described above, the rate constant was calculated, the intrinsic viscosity, the color coordinate b value, the acetaldehyde content, and the cyclic trimer content were measured. It is shown in Table 1.
[0055]
[Table 1]

[0056]
【The invention's effect】
  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the polyester resin which can manufacture the solid phase polycondensation resin which is excellent in color tone, and there are few by-products without adhesiveness, excessive crystallization, etc. with sufficient productivity can be provided. .

Claims (5)

An esterification reaction between a dicarboxylic acid component containing terephthalic acid as the main component and a diol component containing ethylene glycol as the main component is followed by a melt polycondensation reaction in the presence of a polycondensation catalyst, followed by a solid-phase polycondensation reaction. In producing a polyester resin,
As a polycondensation catalyst,
The theoretical yield of polyester resin The titanium compound in an amount of 0.002 to 0.2 mmol as the content of titanium atoms per kg, and the germanium compound in the same amount of 0.02 to 2 mmol as the content of metal atoms and Luke using a magnesium compound,
Or
The amount of titanium compound in the amount of 0.002 to 0.2 mmol as the content of titanium atoms per kg of the theoretical yield of the polyester resin, and the germanium compound in the amount of 0.02 to 2 mmol as the content of metal atoms Use
As an auxiliary agent for the polycondensation catalyst , a phosphorus compound is used in an amount of 0.02 to 4 mmol as the content of atoms per kg of the theoretical yield of the polyester resin,
Solid state polycondensation is performed on a melt polycondensation resin having an intrinsic viscosity of 0.1 to 0.7 dl / g and an activation energy ΔE and a frequency factor A satisfying the following formula when subjected to a solid phase polycondensation reaction: A method for producing a polyester resin, characterized by reacting to form a solid phase polycondensation resin having an intrinsic viscosity of 0.5 to 1.5 dl / g.
lnA / ΔE ≧ 0.80 [mol / (kcal · time)]   The method for producing a polyester resin according to claim 1, wherein the activation energy ΔE when the melt polycondensation resin is subjected to solid phase polycondensation is 10 to 100 kcal / mol.   The method for producing a polyester resin according to claim 1 or 2, wherein the melt polycondensation resin is a granule having an average weight of 15 to 30 mg per grain.   The method for producing a polyester resin according to any one of claims 1 to 3, wherein the solid phase polycondensation reaction temperature is 210 to 240 ° C.   The method for producing a polyester resin according to any one of claims 1 to 4, wherein the proportion of terephthalic acid in all dicarboxylic acid components is 95 mol% or more and the proportion of ethylene glycol in all diol components is 95 mol% or more.