JP6181425B2 - Catalyst for producing polyester and method for producing the catalyst for producing polyester - Google Patents

Description

  The present invention relates to a catalyst for producing a polyester having good stability over time, good polymerizability, and good polyester hue, diethylene glycol content, and terminal carboxy concentration, and a method for producing the same.

  Aromatic polyesters, especially polyethylene terephthalate (hereinafter abbreviated as PET), are widely used after being formed into fibers, films, industrial resins, bottles, cups, trays, etc. due to their excellent mechanical and chemical properties. ing.

  Usually, an aromatic polyester is produced using a dicarboxylic acid such as terephthalic acid and an aliphatic diol such as ethylene glycol as raw materials. Specifically, first, a low-order condensate (ester low polymer) is formed by an esterification reaction of an aromatic dicarboxylic acid and an aliphatic diol, and then this low-order condensate is formed in the presence of a polycondensation catalyst. It is deglycolized (liquid phase polycondensation) to increase the molecular weight. In some cases, solid state polycondensation is performed to further increase the molecular weight.

  Among the polyesters produced as described above, a bottle obtained by biaxially stretching a saturated polyester such as polyethylene terephthalate is excellent in transparency, mechanical strength, heat resistance and gas barrier properties, juice, soft drink, It is widely used as a beverage filling container (PET bottle) such as carbonated beverages.

  In such a polyester production method, an antimony compound, a germanium compound or the like is conventionally used as a polycondensation catalyst. However, polyethylene terephthalate produced using an antimony compound as a catalyst is inferior to polyethylene terephthalate produced using a germanium compound as a catalyst in terms of transparency and heat resistance. It is also desired to reduce the acetaldehyde content in the resulting polyester. However, since the germanium compound is quite expensive, there is a problem that the production cost of the polyester becomes high.

  By the way, it is known that titanium is an element having an action of promoting a polycondensation reaction of an ester. In addition, it is inexpensive because of the abundance of elements on the earth. Furthermore, it is known for its high safety, such as being used as a filling or covering in dental caries treatment. Many studies have been made to use titanium having such excellent characteristics as a polycondensation catalyst, and titanium alkoxide, titanium tetrachloride, titanyl oxalate, orthotitanic acid and the like are known.

  However, when a conventional titanium-based catalyst is used as a polycondensation catalyst, there is a problem that the obtained polyester is remarkably colored in yellow although it is more active than antimony compounds and germanium compounds. In order to solve the above-mentioned coloring problem, it is generally performed to add a cobalt compound to polyester to suppress yellowing. Certainly, the hue (b value) of the polyester can be improved by adding a cobalt compound, but the problem that the melting heat stability of the polyester is lowered and the polymer is easily decomposed by adding the cobalt compound. There is. Moreover, there are some knowledge as a catalyst for polyester production comprising a titanium compound, a phosphorus compound and a solvent (see Patent Documents 1 to 4).

International Publication No. 2003/008479 Pamphlet JP 2006-070165 A JP 2007-224106 A JP 2008-013594 A

  An object of the present invention is to provide a catalyst for producing polyester and a method for producing the same which have good stability over time, good polymerizability, and good hue, diethylene glycol content and terminal carboxy concentration of the resulting polyester.

  By using a solvent that has not been used in the past, the production method is simple and can be produced with equipment installed in a normal polyester plant. The catalyst after production is also easy to handle, and the catalytic activity and polymer quality are excellent. We succeeded in obtaining a good catalyst for polyester production.

That is, the present invention is chloroform, at least one solvent selected from the group consisting of ethyl acetate Contact and toluene, by mixing a titanium compound having a tetraalkoxy group of the phosphorus compound and the total carbon number of 4 to 24 Polyester Catalyst for production. Another present invention is obtained chloroform, at least one titanium compound solution was added to the titanium compound having a tetraalkoxy group total carbon number of 4 to 24 in a solvent selected from the group consisting of ethyl acetate Contact and toluene Furthermore, the present invention is a method for producing a catalyst for producing a polyester, wherein a phosphorus compound solution obtained by adding a phosphorus compound to the at least one solvent is mixed in an atmosphere of inert gas at room temperature.

  The polyester production catalyst obtained by the present invention has good stability over time and good polymerizability. Moreover, it is favorable also about the hue of the polyester obtained, diethylene glycol content, and terminal carboxy density | concentration.

Hereinafter, the present invention will be described in detail.
1) in a solvent according to the invention which constitutes a catalyst, the organic solvent used in the catalyst preparation, chloroform, at least one solvent selected from the group consisting of ethyl acetate and toluene is preferable from the viewpoint of stability of the catalyst. At this time, these solvents may be used alone or in combination of two or more, and can be arbitrarily selected depending on the purpose. In addition, when these solvents are used, other solvents can be used in combination as long as they do not affect the properties of the catalyst for polyester production. Examples of solvents that can be used in combination in this way include propanol, butanol, hexanol, octanol, ethylbenzene, hexane, acetonitrile, acetone, methyl ethyl ketone, tetrahydrofuran, dioxane, and ethylene glycol. As these solvents, commercially available solvents having grade purity can be used. If a stabilizer or the like is added in a large amount for some purpose, the object of the present invention may not be achieved.

2) Phosphorus compound As the phosphorus compound, phosphoric acids, phosphonic acids, and phosphinic acids are desirable. Specifically, phosphoric acids include orthophosphoric acid, phosphorous acid, polyphosphoric acid and phosphoric acid ester, trimethyl phosphate, triethyl phosphate, trinormal propyl phosphate, triisopropyl phosphate, tri-n-butyl phosphate, Tri-sec-butyl phosphate, tri-t-butyl phosphate, tripentyl phosphate, trihexyl phosphate, trioctyl phosphate, trinonyl phosphate, tridecyl phosphate, tridodecyl phosphate, tris (tridecyl) phosphate, tris (tetradecyl) phosphate , Tris (pentadecyl) phosphate, tris (dohexadecyl) phosphate, tris (heptadecyl) phosphate, tris (octadecyl) phosphate, trie Cosyl phosphate, triphenyl phosphate, tris (methylphenyl) phosphate, tris (ethylphenyl) phosphate, tris (propylphenyl) phosphate, tris (butylphenyl) phosphate, tris (pentylphenyl) phosphate, tris (hexylphenyl) phosphate, Tris (octylphenyl) phosphate, tris (nonylphenyl) phosphate, tri (decylphenyl) phosphate, tri (dodecylphenyl) phosphate, tribenzyl phosphate, triphenethyl phosphate, tricresyl phosphate, trixylyl phosphate, tribiphenyl phosphate, tri Naphthyl phosphate, trianthryl phosphate, triphenanthryl phosphate, dimethyl phosphate Phosphate, diethyl phosphate, dinormal propyl phosphate, diisopropyl phosphate, di-n-butyl phosphate, di-sec-butyl phosphate, di-t-butyl phosphate, dipentyl phosphate, dihexyl phosphate, diheptyl phosphate, dioctyl phosphate, di- Decyl phosphate, didodecyl phosphate, ditridecyl phosphate, ditetradecyl phosphate, dipentadecyl phosphate, didohexadecyl phosphate, diheptadecyl phosphate, dioctadecyl phosphate, dieicosyl phosphate, diphenyl phosphate, di (methylphenyl) phosphate, Di (ethylphenyl) phosphate, di (propylphenyl) phosphate, di (butylphenyl) phosphate Fate, di (pentylphenyl) phosphate, di (hexylphenyl) phosphate, di (octylphenyl) phosphate, di (nonylphenyl) phosphate, di (decylphenyl) phosphate, di (dodecylphenyl) phosphate, dibenzyl phosphate, diphenethyl Phosphate, dicresyl phosphate, dixylyl phosphate, dibiphenyl phosphate, dinaphthyl phosphate, dianthryl phosphate, diphenanthryl phosphate, monomethyl phosphate (methyl acid phosphate), monoethyl phosphate (ethyl acid phosphate), mononormal propyl phosphate, Monoisopropyl phosphate, mono-n-butyl phosphate (n-butyl acid phosphate), mono sec-butyl phosphate, mono-t-butyl phosphate, monopentyl phosphate, monohexyl phosphate, monoheptyl phosphate, monooctyl phosphate, monodecyl phosphate, monododecyl phosphate, monotridecyl phosphate, monotetradecyl phosphate, monopentadecyl Phosphate, monodohexadecyl phosphate, monoheptadecyl phosphate, monooctadecyl phosphate, monoeicosyl phosphate, monophenyl phosphate, mono (methylphenyl) phosphate, mono (ethylphenyl) phosphate, mono (propylphenyl) phosphate, mono (butyl) Phenyl) phosphate, mono (pentylphenyl) phosphate, mono (hexylphenyl) phosphate , Mono (octylphenyl) phosphate, mono (nonylphenyl) phosphate, mono (decylphenyl) phosphate, mono (dodecylphenyl) phosphate, monobenzyl phosphate, monophenethyl phosphate, monocresyl phosphate, monoxylyl phosphate, monobiphenyl phosphate And mononaphthyl phosphate, monoanthryl phosphate, or triphenanthryl phosphate. Further, as phosphites, trimethyl phosphite, triethyl phosphite, trinormal propyl phosphite, triisopropyl phosphite, tri-n-butyl phosphite, trihexyl phosphite, trioctyl phosphite, tridecyl phosphite , Tridodecyl phosphite, triphenyl phosphite, trinonylphenyl phosphite and tricresyl phosphite. One or more of these compounds can be appropriately selected and mixed for use.

  Phosphonic acids, phosphinic acids include phosphonic acid, phosphinic acid, phosphinic acid, phosphonous acid, methylphosphonic acid, ethylphosphonic acid, propylphosphonic acid, butylphosphonic acid, hexylphosphonic acid, octylphosphonic acid, decylphosphonic acid, dodecyl Phosphonic acid, phenylphosphonic acid, 4-methylphenylphosphonic acid, 1-naphthylphosphonic acid, 2-naphthylphosphonic acid, monomethylphosphinic acid, monoethylphosphinic acid, monopropylphosphinic acid, monobutylphosphinic acid, monohexylphosphinic acid, Monooctylphosphinic acid, monodecylphosphinic acid, monododecylphosphinic acid, monophenylphosphinic acid, mono-4-methylphenylphosphinic acid, mono-1-naphthylphosphinic acid, mono-2-naphthylphosphite Acid, dimethylphosphinic acid, diethylphosphinic acid, dipropylphosphinic acid, dibutylphosphinic acid, dihexylphosphinic acid, dioctylphosphinic acid, didecylphosphinic acid, didodecylphosphinic acid, diphenylphosphinic acid, di-4-methylphenylphosphinic acid, Di-1-naphthylphosphinic acid, di-2-naphthylphosphinic acid, carbomethoxymethanephosphonic acid, carboethoxymethanephosphonic acid, carbopropoxymethanephosphonic acid, carbopropoxymethanephosphonic acid, carbomethoxy-phosphono-phenylacetic acid, carboethoxy -Dimethyl esters, diethyl esters, dipropyl esters of phosphono-phenylacetic acid, carboprotoxy-phosphono-phenylacetic acid and carbobutoxy-phosphono-phenylacetic acid And the like, and dibutyl esters. These 1 type, or 2 or more types of compounds can be selected suitably, and can be used.

3) Titanium compound As the titanium compound, a titanium compound having a tetraalkoxy group having 4 to 24 carbon atoms in total is used. Examples of the titanium compound having a tetraalkoxy group having 4 to 24 carbon atoms include tetramethoxy titanium, tetraethoxy titanium, tetra-n-propoxy titanium, tetra-iso-propoxy titanium, tetra-n-butoxy titanium, tetra-iso- Examples include butoxytitanium, tetra-sec-butoxytitanium, tetra-tert-butoxytitanium, tetrapentyloxytitanium, and tetrahexyloxytitanium. These compounds may be used alone or in combination of two or more. . Moreover, another titanium compound can be used within the range which does not inhibit the effect of the catalyst for polyester manufacture by the titanium compound which has a tetraalkoxy group with 4-24 carbon atoms. Such a titanium compound is not particularly limited as long as it has a functional group capable of reacting with a phosphorus compound. Among these, an organic titanium compound, more preferably an organic phosphorus complex compound is preferable. Specifically, titanium acetate, titanium propionate, titanium benzoate, titanium tetramethoxide condensate, titanium tetraethoxide condensate, titanium tetra Normal propoxide condensate, titanium tetrabutoxide (tetrabutoxytitanium) condensate, titanium tetraisopropoxide condensate, titanium tetrakis acetylacetonate complex, titanium tetrakis (2,4-hexanedionate) complex, titanium tetrakis (3,5-heptanedionato) complex, titanium dimethoxybisacetylacetonate complex, titanium diethoxybisacetylacetonate complex, titanium diisopropoxybisacetylacetonate complex, titanium dinormalpropoxybisacetylacetonate Body, titanium dibutoxybisacetylacetonate complex, titanium dihydroxybisglycolate, titanium dihydroxybislactate, titanium dihydroxybis (2-hydroxypropionate), titanium lactate, titanium octanediolate, titanium dimethoxybistriethanolamate, titanium Diethoxybistriethanolamate, titanium dibutoxybistriethanolamate, hexamethyldititanate, hexaethyldititanate, hexapropyldititanate, hexabutyldititanate, hexaphenyldititanate, octamethyltrititanate, octaethyltrititanate, Octapropyl trititanate, octabutyl trititanate, octaphenyl trititanate, hexaalkoxy dititanate, oct Such as alkyltrimethylammonium titanate. These 1 type, or 2 or more types of compounds can be selected suitably, and can be used.

4) Production conditions for catalyst for producing polyester In the catalyst for producing polyester according to the present invention, at least one solvent as described above and tetra-n-butoxytitanium which is a typical titanium compound among the above phosphorus compounds. And a phosphorus compound can be mixed and dissolved or dispersed in a solvent. Hereinafter, the titanium compound having a tetraalkoxy group having 4 to 24 carbon atoms will be described using tetra-n-butoxytitanium, which is a typical compound. In general, a) a method of adding the phosphorus compound to a toluene solution in which the titanium compound is dissolved, a) a method of adding the titanium compound to a toluene solution in which the phosphorus compound is dissolved, and c) toluene in which the titanium compound is dissolved. Either a method of adding a phosphorus compound diluted with toluene in a solution or a method of adding a titanium compound diluted with toluene into a toluene solution in which the phosphorus compound is dissolved can be employed.

  One aspect of a preferred production method is as follows. That is, the production temperature after mixing the phosphorus compound tetra-n-butoxytitanium and the titanium compound may be performed from room temperature to the boiling point of each solvent minus 20 ° C. in a nitrogen atmosphere while stirring. Preferably, it is in the range of 20 ° C. to the boiling point of each solvent minus 20 ° C. In addition, as described later, in order to accurately set the content ratio of titanium element and phosphorus element within a specific numerical range, 1) a step of obtaining a titanium compound solution by adding tetra-n-butoxytitanium to the solvent described above 2) A step of obtaining a phosphorus compound solution by adding a phosphorus compound to the above-mentioned solvent, and 3) a step of mixing the titanium compound solution and the phosphorus compound solution with stirring while maintaining the above temperature. . Further, in the step 3), the phosphorus compound solution is preferably added to the titanium compound solution at room temperature with stirring. After completion of the dropping, the reaction system is usually only stirred and mixed, or further stirred at a temperature of 20 ° C. to 60 ° C., preferably room temperature (25 ° C.) to 50 ° C. for 1 minute to 4 hours, preferably 30 minutes to 2 hours. Is done by doing. In this reaction, the reaction pressure is not particularly limited, and may be under pressure (0.1 to 0.5 MPa), normal pressure, or reduced pressure (0.001 to 0.1 MPa). Usually performed under normal pressure. At this time, by stirring at the above temperature, a reaction product between a titanium compound, a phosphorus compound, or the like is generated regardless of whether or not heating is performed, and an aspect of such a reaction product is also included in this embodiment. It is one preferable aspect of the catalyst for polyester production of the invention.

  In the case of a highly volatile solvent, it can be carried out under an inert gas stream, but is preferably carried out under an inert gas atmosphere. Here, nitrogen, helium, neon, argon, krypton, and xenon can be listed as the inert gas, and it is preferable to use nitrogen because it can be obtained at low cost and is easy to use. The production time varies depending on the production temperature and the catalyst concentration, but the standard is 3 to 180 minutes. If it is less than 3 minutes, the production of the catalyst will not be completed sufficiently, and the polymerization reaction and the quality of the resulting polymer may become unstable when the polymer is polymerized. If the production reaction is carried out for more than 180 minutes, the resulting catalyst may be in the form of particles, gel or sol, which is not desirable. In addition, when manufacturing at room temperature or a temperature close to it, it is possible to keep stirring at the same temperature after 180 minutes. When storing for a long time, it is necessary to take measures to suppress volatilization of the organic solvent.

  As another method, as a representative example of a method for more efficiently producing the catalyst for producing a polyester of the present invention, first, tetra-n-butoxytitanium, which is a titanium compound as a catalyst component, and a phosphorus compound are used in the above solvent. Then, the solvent is distilled off from the solution and concentrated to such an extent that the fluidity of the solution can be maintained, and then the concentrated solution is a solvent having a higher boiling point in the above-mentioned category of the solvent. And / or a method of removing and removing residual low-boiling solvent and low-boiling components after selecting and mixing glycol-based solvents. This method is particularly effective when a catalyst for producing a polyester using glycol as a constituent component of a polyester such as ethylene glycol, propanediol, or butanediol as a glycol solvent is used.

  A mixed product or reaction product of a titanium compound and a phosphorus compound is separated from the reaction system by means such as centrifugal sedimentation or filtration, and then used as a catalyst for polyester production without purification. May be. Alternatively, if a reaction concentrated product is formed, the separated reaction product is purified by recrystallization from a recrystallization agent such as acetone, methyl alcohol and / or water, and thereby obtained. The purified product may be used as a catalyst. Moreover, you may use the reaction product containing reaction mixture as a catalyst containing mixture as it is, without isolate | separating the said reaction product from the reaction system.

5) P / Ti molar ratio The molar ratio of the phosphorus compound and the titanium compound in producing the polyester production catalyst of the present invention is the ratio of phosphorus atom and titanium atom contained in the obtained polyester production catalyst (P / As Ti), P / Ti may be 0.5 to 3.0. More preferably, it is 1.0-2.5, More preferably, it is 1.5-2.3. If it is less than 0.5, the catalytic activity after production is too strong and the subsequent polymerization reaction is good, but it is not desirable because the quality of the polyester obtained, in particular, the hue such as the b value is often deteriorated. On the other hand, when the ratio is larger than 3.0, the activity of the catalyst after the production of the catalyst becomes weak, the polymerization reaction becomes slow, and the production cost is likely to increase. As described above, when the solution is dissolved in at least one of the titanium compound and the phosphorus compound, or both of the above-mentioned solvents, the molar amount of the titanium compound and the molar amount of the phosphorus compound at the time of catalyst production can be grasped more accurately. It becomes easy to make the molar ratio (P / Ti) of phosphorus atoms and titanium atoms contained in the obtained catalyst for producing polyester to 0.5 to 3.0.
The polyester production catalyst produced above can be used in the same manner as conventional polyester production catalysts. Further, the polyester production catalyst thus obtained is preferable because the stability of the catalyst solution with time is good.

6) Polyester Production Method Hereinafter, a polyester production method that can be produced using this production catalyst will be described.

<Glycol component>
Examples of the glycol component used in the invention of the polyester production method include alkylene glycol, and specifically, ethylene glycol, trimethylene glycol, 1,2-propanediol, 1,4-butanediol (tetramethylene glycol). , Neopentylene glycol, and hexamethylene glycol. At this time, for example, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, hexamethylene glycol, decamethylene glycol, cyclohexanedimethanol, diethylene glycol, triethylene glycol, poly (oxy) ethylene glycol, polytetramethylene One kind or two or more kinds of alkylene glycols such as glycol and polymethylene glycol may be mixed and used, and can be arbitrarily selected depending on the purpose. Further, a trifunctional or higher polyfunctional compound such as glycerin, trimethylolpropane, pentaerythritol and the like may be copolymerized within a range in which the polymer chain constituting the copolymerized aromatic polyester is substantially linear. Moreover, you may use a monofunctional compound, for example, decyl alcohol, dodecyl alcohol, 2-phenylethanol etc. as needed.

<Dicarboxylic acid component>
Examples of the dicarboxylic acid component used in the invention of the method for producing polyester include aromatic dicarboxylic acids, and specifically, terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid. And aromatic dicarboxylic acids such as diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid, and diphenyl sulfone dicarboxylic acid. At this time, for example, aromatic dicarboxylic acid such as 2,6-naphthalenedicarboxylic acid, isophthalic acid, diphenyldicarboxylic acid, diphenyl ether dicarboxylic acid, diphenylsulfone dicarboxylic acid; alicyclic dicarboxylic acid such as hexahydroterephthalic acid; adipic acid, One kind or two or more kinds of dicarboxylic acid components represented by aliphatic dicarboxylic acids such as sebacic acid, azelaic acid, decanedicarboxylic acid and the like may be used in combination, and can be arbitrarily selected according to the purpose. Further, a polyfunctional compound having a valence of 3 or more, such as trimellitic acid, trimesic acid, pyromellitic acid, tricarballylic acid or gallic acid, within the range in which the polymer chain constituting the copolymerized aromatic polyester is substantially linear. May be copolymerized. Moreover, you may use a monofunctional compound, for example, benzoic acid, toluic acid, 1-naphthoic acid, 2-naphthoic acid, о-benzoyl benzoic acid etc. as needed. In addition, a small amount of hydroxycarboxylic acid such as lactic acid, glycolic acid, hydroxybenzoic acid or an alkyl ester thereof may be used.

<Third component>
As copolymerization components, aromatic dicarboxylic acids such as diphenoxyethanedicarboxylic acid and diphenyl ether dicarboxylic acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; fatty acid dicarboxylic acids such as adipic acid and sebacic acid; diethylene glycol and triethylene glycol Aliphatic diols such as tetramethylene glycol and hexamethylene glycol; alicyclic diols such as cyclohexanediol and cyclohexanedimethanol; aromatic diols such as naphthalenediol, bisphenol A and resorcin; p-oxybenzoic acid, m-oxybenzoic acid Examples thereof include oxycarboxylic acids such as acid, salicylic acid, mandelic acid, hydroacrylic acid, glycolic acid, 3-oxypropionic acid, asiatic acid, and quinobaic acid. One kind of trifunctional or more polyfunctional components such as tricarballylic acid, trimellitic acid, trimesic acid, pyromellitic acid, naphthalenetetracarboxylic acid, gallic acid, trimethylolethane, trimethylolpropane, glycerol, pentaerythritol, etc. Or 2 or more types may be used as a copolymerization component.

<Production method of polyester>
What is necessary is just to manufacture the said aromatic polyester using a conventionally well-known manufacturing method. For example, an aromatic dicarboxylic acid or a lower alkyl ester or lower aryl ester of an aromatic dicarboxylic acid and a glycol are used for esterification or transesterification, and the resulting reaction product is further heated under high temperature, high vacuum, and melting. This is a production method in which polycondensation proceeds. More specifically, the following embodiments can be exemplified.
In the present invention, the dicarboxylic acid component containing terephthalic acid or an ester-forming derivative thereof as a main component, the diol component containing ethylene glycol as a main component, and the copolymerization component used as necessary are esterified. In the reaction or transesterification, these components are usually 1.01, preferably 1.02, more preferably 1.05, and usually 2. as the upper limit, with the molar ratio of the diol component to the dicarboxylic acid component being the lower limit. Generally, it is used in the range of 00, preferably 1.70, more preferably 1.60.

  In the case of a transesterification reaction, it is generally necessary to use a transesterification catalyst, and since it is necessary to use a large amount of the catalyst, the generation of foreign matters due to the catalyst is likely to occur. As a method, a method for producing a dicarboxylic acid as a raw material through an esterification reaction is preferable to the transesterification reaction. Examples of transesterification catalysts include compounds containing alkali metal elements such as lithium, sodium, potassium and rubidium, compounds containing alkaline earth metal elements such as magnesium and calcium, transition metal elements such as titanium, manganese, cobalt, nickel and zinc. The compound containing can be mentioned.

  In the esterification reaction, for example, terephthalic acid and ethylene glycol are mixed in the above molar ratio to form a slurry, and this slurry is a single esterification reaction tank or a multi-stage where a plurality of esterification reaction tanks are connected in series. While refluxing ethylene glycol, using a reaction apparatus, while removing water generated in the reaction and excess ethylene glycol out of the system, the esterification rate (reacted with the diol component of all the carboxyl groups of the raw dicarboxylic acid component) The ratio of the esterified product is usually 90% or more, preferably 93% or more. Moreover, it is preferable that the number average molecular weights of the polyester low molecular weight body as an esterification reaction product obtained are 500-5,000.

As an example of the reaction conditions in the esterification reaction, when a single esterification reaction vessel is used, the temperature is usually about 200 to 280 ° C. and the relative pressure to atmospheric pressure is usually 0 to 400 kPaG (0 to 4 kg / cm ² G). (Where G represents a relative pressure with respect to atmospheric pressure) and a reaction time of about 1 to 10 hours with stirring is common. When a plurality of esterification reaction tanks are used, the lower limit of the reaction temperature in the first stage esterification reaction tank is usually 240 ° C, preferably 245 ° C, the upper limit is usually 270 ° C, preferably 265 ° C, and the pressure is The lower limit is usually 5 kPaG (0.05 kg / cm ² G), preferably 10 kPaG (0.1 kg / cm ² G), and the upper limit is usually 300 kPaG (3 kg / cm ² G), preferably 200 kPaG (2 kg / cm ² G). The lower limit of the reaction temperature in the final stage is usually 250 ° C., preferably 255 ° C., the upper limit is usually 280 ° C., preferably 275 ° C., and the pressure is usually 0-150 kPaG (0-1.5 kg / cm ² G), preferably A method of 0 to 130 kPaG (0 to 1.3 kg / cm ² G) is usually used.

  In the esterification reaction, for example, a tertiary amine such as triethylamine, tri-n-butylamine, benzyldimethylamine, tetraethylammonium hydroxide, tetra-n-butylammonium hydroxide, trimethylbenzyl hydroxide is included in the reaction system. By adding a small amount of basic compounds such as quaternary ammonium hydroxide such as ammonium, lithium carbonate, sodium carbonate, potassium carbonate, lithium acetate, sodium acetate, potassium acetate, etc., by-product of diethylene glycol from ethylene glycol Can be suppressed.

  As a melt polycondensation method of the low molecular weight polyester thus obtained, a single melt polycondensation tank or a plurality of melt polycondensation tanks were connected in series, for example, the first stage was equipped with a stirring blade Using a multi-stage reactor consisting of a fully mixed reactor, a horizontal plug flow reactor in which the second and third stages are equipped with stirring blades, the ethylene glycol produced is removed from the system under reduced pressure. A method of performing distillation is generally used.

  As an example of the reaction conditions in the melt polycondensation, when a single polycondensation tank is used in the production example of polyethylene terephthalate, the reaction temperature is usually about 240 to 300 ° C., preferably 260 to 290 ° C., from normal pressure. As the gradual pressure reduction, a method is generally adopted in which the absolute pressure is usually about 1.3 to 0.013 kPa (10 to 0.1 Torr) and the reaction time is about 1 to 20 hours with stirring. Moreover, as an example in the case of using a plurality of polycondensation tanks, the reaction temperature in the first stage polycondensation tank is 240 to 290 ° C., preferably 250 to 285 ° C., and the reaction pressure is 1.3 kPa in absolute pressure. It is preferable to employ a condition of (10 Torr) to 65 kPa (500 Torr), preferably 2 kPa (15 Torr) to 26 kPa (200 Torr). Further, the reaction temperature in the final stage of the polycondensation tank is 265 to 300 ° C., preferably 270 to 295 ° C., and the reaction pressure is 0.013 kPa (0.1 Torr) to 1.3 kPa (10 Torr), preferably 0 in absolute pressure. It is preferable to adopt a condition of 0.065 kPa (0.5 Torr) to 0.65 kPa (5 Torr).

  If necessary, the degree of crystallinity is increased by making the polyester obtained above granular or powdery, and heating or bringing it into contact with water or an organic solvent. Then, a solid state polymerization reaction is carried out to increase the degree of polymerization in a vacuum or in an inert gas stream at a temperature below the melting point with the crystallinity increased.

<Post-processing manufacturing method after polycondensation reaction in manufacturing method: water treatment>
In the invention of the method for producing polyester, the polyester obtained by solid phase polycondensation as described above may be subjected to water treatment or steam treatment as necessary. The water treatment of the polyester is performed by bringing the polyester into contact with water. The contact between the polyester and water is preferably carried out by immersing the polyester in water at room temperature to 150 ° C., preferably 70 to 110 ° C., for 1 minute to 20 hours, preferably 5 minutes to 10 hours. More specifically, it is carried out by immersing in water at 50 to 150 ° C. for 1 minute to 10 hours, preferably in water at 70 to 110 ° C. for 3 minutes to 5 hours. When such a water treatment process is performed, mold contamination during injection molding is extremely reduced. This is because the polycondensation catalyst contained in the polyester is deactivated by bringing the polyester and water into contact with each other. Therefore, the decomposition reaction or the transesterification reaction hardly proceeds due to heating during molding. It is considered that the amount of oligomers such as a monomer is reduced and the amount of mold contamination is reduced.

  The water vapor treatment of polyester is performed by bringing polyester and water vapor into contact with each other. The polyester used here is preferably granular (pellet shape). The contact between the polyester and water vapor is to contact the polyester (b) with water vapor at room temperature to 230 ° C, preferably 70 to 150 ° C, more preferably 90 to 140 ° C for 1 minute to 20 hours, preferably 5 minutes to 10 hours. It is preferable to be performed. More specifically, it is brought into contact with water vapor at 50 to 230 ° C. for 1 minute to 10 hours, preferably with water vapor at 70 to 150 ° C. for 3 minutes to 5 hours, preferably with water vapor at 90 to 140 ° C. for 3 minutes to 5 hours. Is done. When such a steam treatment process is performed, mold contamination during injection molding is extremely reduced. This is because the polycondensation catalyst contained in the polyester is deactivated by bringing the polyester and water vapor into contact with each other, so that the decomposition reaction or transesterification reaction hardly proceeds due to heating during molding, and thus the cyclic three-fold produced. It is considered that the amount of oligomers such as a monomer is reduced and the amount of mold contamination is reduced.

  The polyester obtained by water treatment or steam treatment as described above is dried. In the drying step, the polyester is heated at a temperature of 120 to 180 ° C, preferably 140 to 170 ° C for 2 to 24 hours, preferably 2 to 12 hours, more preferably 2 to 6 hours. The polyester is dried in air or in an inert gas atmosphere similar to the above, but is preferably performed in an inert gas atmosphere, and preferably in an inert gas atmosphere having an oxygen concentration of 20 ppm or less. More preferred. The polyester polycondensation reaction hardly proceeds in this drying step, and the intrinsic viscosity of the polyester obtained through the drying step is almost the same as the intrinsic viscosity of the polyester obtained in the solid phase polycondensation step.

<About aqueous solution treatment of alkali metals and alkaline earth metals>
In the present invention, the polyester obtained by the above method can be contacted with an aqueous solution of an alkali metal salt and / or an alkaline earth metal salt.

  The alkali metal salt used in the present invention is not particularly limited as long as it is water-soluble. Specifically, potassium chloride, potassium alum, potassium formate, tripotassium citrate, dipotassium hydrogen citrate, Potassium dihydrogen citrate, potassium gluconate, potassium succinate, potassium butyrate, dipotassium oxalate, potassium hydrogen oxalate, potassium stearate, potassium phthalate, potassium hydrogen phthalate, potassium metaphosphate, potassium malate, phosphoric acid Tripotassium, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, potassium nitrite, potassium benzoate, potassium hydrogen tartrate, potassium bioxalate, potassium biphthalate, potassium bitartrate, potassium bisulfate, potassium nitrate, potassium acetate, carbonic acid Potassium, potassium carbonate, charcoal Potassium hydrogen, potassium lactate, potassium sulfate, potassium hydrogen sulfate, sodium chloride, sodium formate, trisodium citrate, disodium hydrogen citrate, sodium dihydrogen citrate, sodium gluconate, sodium succinate, sodium butyrate, dioxalate Sodium, Sodium hydrogen oxalate, Sodium stearate, Sodium phthalate, Sodium hydrogen phthalate, Sodium metaphosphate, Sodium malate, Trisodium phosphate, Disodium hydrogen phosphate, Sodium dihydrogen phosphate, Sodium nitrite, Benzo Sodium tartrate, sodium hydrogen tartrate, sodium bioxalate, sodium biphthalate, sodium bitartrate, sodium bisulfate, sodium nitrate, sodium acetate, sodium carbonate, sodium bicarbonate, sodium lactate Lithium, sodium sulfate, sodium hydrogen sulfate, lithium chloride, lithium formate, trilithium citrate, dilithium hydrogencitrate, lithium dihydrogencitrate, lithium gluconate, lithium succinate, lithium butyrate, dilithium oxalate, oxalic acid Lithium hydrogen, lithium stearate, lithium phthalate, lithium hydrogen phthalate, lithium metaphosphate, lithium malate, trilithium phosphate, dilithium hydrogen phosphate, lithium dihydrogen phosphate, lithium nitrite, lithium benzoate, tartaric acid Examples include lithium hydrogen, lithium bioxalate, lithium biphthalate, lithium bitartrate, lithium bisulfate, lithium nitrate, lithium acetate, lithium carbonate, lithium hydrogen carbonate, lithium lactate, lithium sulfate, or lithium hydrogen sulfate. . These may be a single type of compound or a combination of a plurality of types of compounds. Among them, sodium acetate, potassium acetate, dipotassium carbonate, potassium bicarbonate, disodium carbonate, sodium bicarbonate, potassium sodium carbonate, lithium acetate, dilithium carbonate or lithium bicarbonate can be preferably used, preferably lithium. It is to use a salt, sodium salt or potassium salt, more preferably a sodium salt or potassium salt, particularly preferably a potassium salt. On the other hand, when viewed from the anion species side, among these, acetates and / or carbonates are preferred.

The alkaline earth metal salt used in the present invention is not particularly limited as long as it is water-soluble. Specifically, calcium chloride, calcium formate, calcium succinate, calcium butyrate, calcium oxalate, calcium phosphate, Examples include calcium nitrate, calcium acetate, calcium lactate, magnesium chloride, magnesium formate, magnesium succinate, magnesium butyrate, magnesium oxalate, magnesium phosphate, magnesium nitrate, magnesium acetate, magnesium lactate, and magnesium sulfate. These may be a single type of compound or a combination of a plurality of types of compounds. Among these, it is preferable to use magnesium acetate or calcium acetate. Preferably, a calcium salt or a magnesium salt is used, and more preferably, a calcium salt is used. On the other hand, when viewed from the anion species side, among these, acetates and / or carbonates are preferred. Further, an alkali metal salt and an alkaline earth metal salt may be used in combination.
The alkali metal / alkaline earth metal aqueous solution described above needs to be in a concentration range of 1 ppm to 10 wt%. If the concentration is 1 ppm, the effect of reducing white powder during molding is insufficient, and if it exceeds 10 wt%, the cost increases. A preferable range of the concentration is 10 ppm to 5 wt%, and more preferably 100 ppm to 2 wt%.

<High-speed crystallization agent: component of crystallization agent>
In the present invention, a crystallization accelerator can be blended with the polyester obtained by the above method. As the crystallization accelerator, various polymers such as vinyl chloride, polystyrene, and Teflon (registered trademark) can be used. However, from the viewpoint of ensuring hygiene and transparency, a compound having a similar composition, specifically a modified polyester, is particularly preferred when applied to food containers.

  In producing this modified polyester, examples of the glycol component include ethylene glycol, trimethylene glycol, 1,2-propanediol, 1,4-butanediol (tetramethylene glycol), 1,3-propylene glycol, neo One or more of alkylene glycols such as pentyl glycol, hexamethylene glycol, decamethylene glycol, cyclohexanedimethanol, diethylene glycol, triethylene glycol, poly (oxy) ethylene glycol, polytetramethylene glycol, polymethylene glycol, etc. They may be mixed and used, and can be arbitrarily selected depending on the purpose. Further, a trifunctional or higher polyfunctional compound such as glycerin, trimethylolpropane, or pentaerythritol may be copolymerized. Moreover, you may use a monofunctional compound, for example, decyl alcohol, dodecyl alcohol, 2-phenylethanol etc. as needed. Among these, a linear glycol compound having 2 to 10 carbon atoms is preferably the main component.

  Examples of the dicarboxylic acid component include aromatic dicarboxylic acids. Specifically, terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenylether dicarboxylic acid, Aromatic dicarboxylic acids such as diphenylsulfone dicarboxylic acid; alicyclic dicarboxylic acids such as hexahydroterephthalic acid; dicarboxylic acid components such as aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, decanedicarboxylic acid, etc. These may be used alone or in combination of two or more, and can be arbitrarily selected depending on the purpose. Furthermore, trifunctional or higher polyfunctional compounds such as trimellitic acid, trimesic acid, pyromellitic acid, tricarballylic acid or gallic acid may be copolymerized. Moreover, you may use a monofunctional compound, for example, benzoic acid, toluic acid, 1-naphthoic acid, 2-naphthoic acid, о-benzoyl benzoic acid etc. as needed. In addition, hydroxycarboxylic acids such as lactic acid, glycolic acid, and hydroxybenzoic acid, or alkyl esters thereof can be used. Among these, terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid are preferably the main dicarboxylic acid components.

Furthermore, in order to obtain solubility in a solvent, the above polyester contains 1 to 10 mol% of an isophthalic acid component having a sulfonic acid metal base as a copolymerization component, and further 3 to 5 mol% per total dicarboxylic acid component. Is preferred. Specifically, 5-lithium sulfoisophthalic acid, 5-sodium sulfoisophthalic acid, and 5-potassium sulfoisophthalic acid can be exemplified.
The above-mentioned modified polyester is blended in a ratio of 1 to 100 ppm, preferably 1 to 50 ppm, more preferably 5 to 50 ppm based on the raw material such as polyester with respect to the raw material such as polyester. If it is less than 1 ppm, there is no effect of improving crystallinity, and if it exceeds 100 ppm, fusion of the chips occurs when the chips are dried, or chip drop failure occurs during molding, and the stability of molding is hindered.

<High-speed crystallization agent: blending method of crystallization agent>
The modified polyester is preferably blended by attaching an aqueous dispersion containing the polyester at a concentration of 0.05 wt% to 2.0 wt% to the polyester chip. When the modified polyester is not blended in the state of an aqueous dispersion, for example, by blending with a powder blend, it becomes ununiform blending, and it is difficult to stably obtain the crystallization promoting effect, which is not preferable.
The concentration of the modified polyester aqueous dispersion is usually 0.05 to 2.0 wt%, preferably 0.1 to 1.0 wt%. If it is less than 0.1 wt%, it is difficult to attach an appropriate amount to the polyester chip, and the intrinsic viscosity may be greatly reduced by drying after treatment, which is not preferable. When it exceeds 2.0 wt%, it is difficult to uniformly adhere the solution to the polyester chip, which is not preferable. However, the preferable range can be dealt with by equipment and is not necessarily limited to the above range.

<About additives>
If necessary, using other additives such as color adjusting agents, antioxidants, ultraviolet absorbers, antistatic agents, flame retardants, alkali metals or alkaline earth metals and compounds thereof. Also good.

  The alkali metal compound used in the present invention is not limited to the following, but specifically, potassium chloride, potassium alum, potassium formate, tripotassium citrate, dipotassium hydrogen citrate, dicitrate dicitrate. Potassium hydrogen, potassium gluconate, potassium succinate, potassium butyrate, dipotassium oxalate, potassium hydrogen oxalate, potassium stearate, potassium phthalate, potassium hydrogen phthalate, potassium metaphosphate, potassium malate, tripotassium phosphate, Dipotassium hydrogen phosphate, potassium dihydrogen phosphate, potassium nitrite, potassium benzoate, potassium hydrogen tartrate, potassium bioxalate, potassium biphthalate, potassium bitartrate, potassium bisulfate, potassium nitrate, potassium acetate, potassium carbonate, carbonic acid Potassium sodium, hydrogen carbonate Lithium, potassium lactate, potassium sulfate, potassium hydrogen sulfate, potassium hydroxide, sodium hydroxide, sodium chloride, sodium formate, trisodium citrate, disodium hydrogen citrate, sodium dihydrogen citrate, sodium gluconate, sodium succinate , Sodium butyrate, disodium oxalate, sodium hydrogen oxalate, sodium stearate, sodium phthalate, sodium hydrogen phthalate, sodium metaphosphate, sodium malate, trisodium phosphate, disodium hydrogen phosphate, dihydrogen phosphate Sodium, sodium nitrite, sodium benzoate, sodium hydrogen tartrate, sodium bioxalate, sodium biphthalate, sodium bitartrate, sodium bisulfate, sodium nitrate, sodium acetate, sodium carbonate Sodium bicarbonate, sodium lactate, sodium sulfate, sodium hydrogen sulfate, lithium hydroxide, lithium chloride, lithium formate, trilithium citrate, dilithium hydrogen citrate, lithium dihydrogen citrate, lithium gluconate, lithium succinate, butyric acid Lithium, dilithium oxalate, lithium hydrogen oxalate, lithium stearate, lithium phthalate, lithium hydrogen phthalate, lithium metaphosphate, lithium malate, trilithium phosphate, dilithium hydrogen phosphate, lithium dihydrogen phosphate, Lithium nitrite, lithium benzoate, lithium hydrogen tartrate, lithium deuterate, lithium biphthalate, lithium bitartrate, lithium bisulfate, lithium nitrate, lithium acetate, lithium carbonate, lithium bicarbonate, lithium lactate, lithium sulfate or sulfuric acid water Elemental lithium and the like can be exemplified. These may be a single type of compound or a combination of a plurality of types of compounds. Among them, sodium acetate, potassium acetate, dipotassium carbonate, potassium bicarbonate, disodium carbonate, sodium bicarbonate, potassium sodium carbonate, lithium acetate, dilithium carbonate or lithium bicarbonate can be preferably used, preferably lithium. It is to use a salt, sodium salt or potassium salt, more preferably a sodium salt or potassium salt, particularly preferably a potassium salt. On the other hand, from the viewpoint of the anion species, among these, acetate, carbonate or hydroxide is preferred.

  The alkaline earth metal compound used in the present invention is not limited to the following, but specifically, calcium chloride, calcium formate, calcium succinate, calcium butyrate, calcium oxalate, calcium phosphate, calcium nitrate, Examples include calcium acetate, calcium lactate, magnesium chloride, magnesium formate, magnesium succinate, magnesium butyrate, magnesium oxalate, magnesium phosphate, magnesium nitrate, magnesium acetate, magnesium lactate, and magnesium sulfate. These may be a single type of compound or a combination of a plurality of types of compounds. Among these, it is preferable to use magnesium acetate or calcium acetate. Preferably, a calcium salt or a magnesium salt is used, and more preferably, a calcium salt is used. On the other hand, from the viewpoint of the anion species, among these, acetate, carbonate or hydroxide is preferred. Further, an alkali metal salt and an alkaline earth metal salt may be used in combination.

  Regarding the color adjusting agent, the polyester obtained by the production method of the present invention may contain 0.1 to 10 mass ppm of the color adjusting agent based on the total mass. The color adjusting agent represents an organic polyaromatic ring dye or pigment, and is preferably an anthraquinone dye, specifically, a blue color adjusting dye, a purple color adjusting dye, a red color dye. Examples thereof include color adjusting dyes and orange color adjusting dyes. These may be used singly or in combination of a plurality of types, but a blue color adjusting dye and a purple color adjusting dye may be used in a mass ratio of 90:10 to 40:60. preferable. Here, the blue color-modifying dye is generally indicated as “Blue” among commercially available color-adjusting dyes, and specifically, the maximum absorption in the visible light absorption spectrum in the solution. The wavelength is about 580 to 620 nm. Similarly, the purple color-modifying dye is the one described as “Violet” among commercially available color-adjusting dyes. Specifically, the maximum absorption wavelength in the visible light absorption spectrum in the solution is The thing in about 560-580 nm is shown. As these color adjusting dyes, oil-soluble dyes are particularly preferable. As specific examples, blue color adjusting dyes include C.I. I. Solvent Blue 11, C.I. I. Solvent Blue 25, C.I. I. Solvent Blue 35, C.I. I. Solvent Blue 36, C.I. I. Solvent Blue 45 (Polysynthren Blue), C.I. I. Solvent Blue 55, C.I. I. Solvent Blue 63, C.I. I. Solvent Blue 78, C.I. I. Solvent Blue 83, C.I. I. Solvent Blue 87, C.I. I. Solvent Blue 94 and the like. Examples of purple color adjusting pigments include C.I. I. Solvent Violet 8, C.I. I. Solvent Violet 13, C.I. I. Solvent Violet 14, C.I. I. Solvent Violet 21, C.I. I. Solvent Violet 27, C.I. I. Solvent Violet 28, C.I. I. Solvent Violet 36 etc. are mentioned.

  Here, when the blue color adjusting dye and the purple color adjusting dye are used in combination, when the mass ratio of the blue color adjusting dye is larger than the mass ratio 90:10, the color a * value of the obtained polyester composition Is small and exhibits a green color, and when the mass ratio of the blue color adjusting dye is smaller than 40:60, the color a * value increases and a red color is exhibited, which is not preferable. The color adjusting dye is more preferably a blue color adjusting dye and a purple color adjusting dye used in a mass ratio of 80:20 to 50:50.

<About polyester molding methods>
The polyester that has undergone the drying step is formed into various molded articles by an injection molding method. In injection molding, granular polyester contained in a hopper is usually supplied from a supply port to one end of a heating cylinder, melted in the heating cylinder, and melted from a nozzle provided on the side opposite to the supply port. A molded product is formed by injecting the polyester into a mold. At the time of injection molding, it is preferable to melt the polyester in the heating cylinder in an inert gas atmosphere. Examples of the inert gas include nitrogen gas, argon gas, and carbon dioxide gas, and nitrogen gas is particularly preferable. The oxygen concentration in the inert gas is 1% or less, preferably 0.1% or less, more preferably 0.01% or less. In the present invention, the inside of the hopper is also preferably an inert gas atmosphere, and the oxygen concentration in the inert gas is 1.0% or less, preferably 0.1% or less, more preferably 0.01% or less. Preferably there is.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention does not receive limitation at all by this. In addition, each physical property value in an Example was calculated | required with the following method. In Examples and Comparative Examples, “parts” represents parts by weight.

(Analysis method)
(1) Intrinsic viscosity (IV)
The intrinsic viscosity is measured by weighing a certain amount of a sample cut out from the top of the tip or preform bottle mouth (synonymous with the mouthpiece), and 0.012 g / ml in o-chlorophenol. Then, the solution was once cooled, and the solution was calculated from the solution viscosity measured at 35 ° C. using an Ubbelohde viscometer.

(2) Col. -L, a, b (hue)
The amorphous polymer was heat treated in a drier in a nitrogen atmosphere at 160 ° C. for 1 hour, crystallized, and then measured with a CM-7500 type color machine manufactured by Color Machine. The crystallized polymer was measured with a CM-7500 type color machine manufactured by Color Machine.

(3) Evaluation of catalyst stability The stability of the produced catalyst was evaluated visually with reference to Comparative Example 4 produced with ethylene glycol, and evaluated in three stages of x, o, and ◎. In the case of 長時間, precipitation did not occur and phase separation of the liquid catalyst solution did not occur even after a long time had elapsed after the catalyst preparation. ○ indicates that a slight amount of precipitate was observed after a long period of time after catalyst preparation. In x, formation of a precipitate was observed without much time after the preparation of the catalyst.

(4) Oligomer amount After pulverizing the sample with a pulverizer, a certain amount was weighed, once dissolved with a small amount of hexafluoroisopropanol / chloroform mixture, and then diluted to a constant concentration (50 g / L) with chloroform. This sample was subjected to gel-permission chromatography (GPC, Waters ALC / GPC 244 type) to detect a low molecular weight region and its peak, and a calibration obtained from a standard sample of cyclic trimer (cy-3). Based on the line, cy-3 in the polymer was quantified.

(5) Terminal carboxyl group concentration (CV)
The polymer sample was pulverized, dissolved in benzyl alcohol, and determined by neutralization titration with potassium hydroxide.

(6) Diethylene glycol (DEG) content The diethylene glycol content was measured by gas chromatography using Agilent Technologies, after the sample was decomposed with hydrazine.

(7) Analysis of metal content concentration in polyester The catalyst metal concentration in the polymer was determined by heating and melting a granular sample on an aluminum plate, and then forming a flat molded body with a compression press machine. Quantitative analysis was carried out using an electric industry 3270E type).

[Reference Example 1]
1) Polyester polymerization step 96.1 parts of oligomer was taken in the reactor from oligomers obtained from terephthalic acid and ethylene glycol prepared in advance, 1.55 parts of ethylene glycol was added, and nitrogen atmosphere was 250 ° C. And dissolved with stirring. After confirming that it was completely dissolved and became transparent, it was kept for 15 minutes. Thereafter, the temperature was raised to 285 ° C. In each of the catalysts produced in the examples, 4.0 mol% of Ti element was added to the terephthalic acid component, and the polymerization reaction was carried out while reducing the pressure from normal pressure to a high vacuum of 50 Pa. After reaching a high vacuum state, the polymerization reaction was terminated in 60 minutes. The molten polymer was removed from the reactor and cut into pellets. The production method of the catalyst is described in each of the following examples.

[Example 1]
In a reactor equipped with a stirrer, 100 parts by weight of chloroform and 0.74 parts by weight of tetra-n-butoxytitanium were gradually added under a nitrogen atmosphere, and then stirred and held for 30 minutes to obtain a chloroform solution A1 of a transparent titanium compound. Similarly, monobutyl phosphate was diluted with chloroform in a reactor equipped with a stirrer under a nitrogen atmosphere to obtain a 14.7 wt% chloroform solution B1. Thereafter, 4.53 parts by weight of the chloroform solution B1 was added to the chloroform solution A1 with stirring, and the mixture was stirred for 1 hour. The compounding ratio of the titanium compound and phosphorus compound at this time was P / Ti = 2.0.

[Examples 2 and 5, Reference Examples 3 and 4 ]
This was prepared in the same manner as in Example 1 except that the solvent was changed as shown in Table 1.

[Comparative Examples 1-3]
This was prepared in the same manner as in Example 1 except that the solvent was changed as shown in Table 1.

[Comparative Example 4]
In a reactor equipped with a stirrer, 100 parts by weight of ethylene glycol and 0.74 parts by weight of tetra-n-butoxytitanium are gradually added in a nitrogen atmosphere, and then stirred and held for 30 minutes to obtain an ethylene glycol solution A4 of a transparent titanium compound. It was. Similarly, in a reactor equipped with a stirrer, monobutyl phosphate (hereinafter sometimes abbreviated as MBP) was diluted with ethylene glycol in a nitrogen atmosphere to obtain a 14.7 wt% solution B4. Thereafter, 4.53 parts by weight of the ethylene glycol solution B4 was added to the ethylene glycol solution A4 under stirring, and the mixture was stirred and held at 130 ° C. for 1 hour. The compounding ratio of the titanium compound and phosphorus compound at this time was P / Ti = 2.0. In these Examples and Comparative Examples, the compounds used for preparing the polyester production catalyst, the amounts used, etc. are shown in Table 1.

  Table 2 shows the results of producing polyethylene terephthalate by the method described in Reference Example 1 using the catalysts produced in Examples 1, 2, 5 and Comparative Example 4.

  The polyester production catalyst obtained by the present invention has good stability over time and good polymerizability. Moreover, it is favorable also about the hue of the polyester obtained, diethylene glycol content, and terminal carboxy density | concentration.

Claims (2)

Chloroform, at least one solvent selected from the group consisting of ethyl acetate Contact and toluene, phosphorus compound and the total carbon number of 4 to 24 tetraalkoxy group catalyst for polyester production obtained by mixing a titanium compound having. Chloroform, was added titanium compound having at least one solvent to the total carbon number of 4 to 24 tetraalkoxy group selected from the group consisting of ethyl acetate Contact and toluene to give the titanium compound solution, further the titanium at room temperature A method for producing a catalyst for producing a polyester, wherein a phosphorus compound solution obtained by adding a phosphorus compound to at least one solvent is mixed in a compound solution under an inert gas atmosphere.