JP2006290910A - Polyester manufacturing method, polyester and polyester molded item - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for continuously manufacturing a polyester in the presence of a polyester polycondensation catalyst comprising at least one selected from the group consisting of aluminum compounds and at least one selected from the group consisting of phosphorus compounds, where glycols and the phosphorus compounds distilled out in the manufacturing processes of the polyester can be circulated to be reused, and to provide an economical continuous manufacturing method of the polyester that allows the control of the temperature-rising crystallization temperature and gives a highly transparent molded item while retaining polycondensation catalyst activities. <P>SOLUTION: In the manufacturing method of the polyester, distillates (A) distilled out of a reaction tank, to which the phosphorus compound has been added, and subsequent reaction tanks are fractionally distilled into a low-boiling fraction mainly composed of water, a medium-boiling fraction mainly composed of ethylene glycol and a high-boiling fraction containing the phosphorus compound or the like, and the medium-boiling fraction is reused as a part of glycols for the esterification reaction while the high-boiling fraction is reused as a part or the whole of the phosphorus compound. The polyester manufactured by the manufacturing method and the molded item thereof are also provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a polyester production method using a novel polyester polycondensation catalyst that does not use germanium, antimony, and a titanium-based compound as a main component of the catalyst, and a polyester and a polyester molded body. The present invention relates to a method for producing a polyester capable of producing a high-quality polyester, and to a polyester obtained by the production method and a polyester molded body.

  Polyesters represented by polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), etc. are excellent in mechanical properties and chemical properties. For example, according to the properties of each polyester, clothing It is used in a wide range of fields such as fibers for industrial and industrial materials, films and sheets for packaging, magnetic tape, optics, bottles that are hollow molded products, casings for electrical and electronic parts, and other engineering plastic molded products. ing. In particular, bottles made of saturated polyesters such as PET are excellent in mechanical strength, heat resistance, transparency and gas barrier properties, so that they are used as containers for filling beverages such as juices, carbonated drinks and soft drinks, and containers for eye drops and cosmetics. Widely used.

  For example, in the case of PET, a polyester having aromatic dicarboxylic acid and alkylene glycol as main components as a typical polyester is bis ((ester) by esterification reaction or transesterification reaction between terephthalic acid or dimethyl terephthalate and ethylene glycol. An oligomer mixture such as 2-hydroxyethyl) terephthalate is produced, and this is produced by liquid phase polycondensation using a catalyst at high temperature under vacuum.

  Conventionally, antimony or germanium compounds have been widely used as the polyester polycondensation catalyst used in such polycondensation of polyester. Antimony trioxide is an inexpensive catalyst with excellent catalytic activity. However, if it is used in an amount of such a main component, that is, a practical polymerization rate, metal antimony is used during polycondensation. As a result of precipitation, darkening and foreign matter are generated in the polyester, which causes surface defects of the film. Further, when a raw material such as a hollow molded product is used, it is difficult to obtain a hollow molded product having excellent transparency. Under such circumstances, a polyester that does not contain antimony at all or does not contain antimony as a main catalyst component is desired.

  Germanium compounds have already been put to practical use as catalysts that give polyesters that have excellent catalytic activity other than antimony compounds and do not have the above problems, but the problem that this catalyst is very expensive, Since it is easy to distill out of the reaction system from the reaction system during the polymerization, there is a problem that the catalyst concentration in the reaction system changes and it becomes difficult to control the polymerization.

  Polycondensation catalysts to replace antimony or germanium catalysts have been studied, and titanium compounds typified by tetraalkoxy titanates have already been proposed. Polyesters produced using these compounds are subject to thermal degradation during melt molding. There is a problem that the polyester is easily colored and the polyester is remarkably colored.

  With the above circumstances, it is a polycondensation catalyst that uses metal components other than antimony, germanium, and titanium as the main metal components of the catalyst, and has excellent catalytic activity, excellent color and thermal stability, and transparency of molded products. There is a need for polycondensation catalysts that provide excellent polyesters.

As a novel polycondensation catalyst that meets the above requirements, a catalyst system comprising an aluminum compound and a phosphorus compound has been disclosed and attracted attention (for example, see Patent Documents 1 to 4).
JP 2001-131276 A JP 2001-163963 A JP 2001-163964 A JP 2002-220446 A

  Among these uses, in particular, beverages such as fruit juice beverages, mineral water, oolong tea, green tea, and black tea are required to be aseptically filled or sterilized at 85 ° C. or higher when filled into a polyester bottle. Generally, the latter is carried out, and heat resistance is required so as not to be deformed even when contacted with a soft drink or juice heated to 85 ° C. or higher. However, in the case of normal polyester bottles, the container shrinks and deforms during such a hot filling process, which becomes a problem. Therefore, as a method of improving the heat resistance of the polyester bottle, the preform or the bottle cap is heat treated. And a method of crystallizing the bottle (see Patent Document 5) or a method of heat-fixing the stretched and blown bottle (heat setting process) to increase the degree of crystallinity of the bottle body and the like (see Patent Document 6). ) Has been proposed.

  When the crystallization of the plug portion is insufficient or the variation in crystallinity is large, deformation due to insufficient heat resistance may occur, sealing performance with the cap may deteriorate, and leakage of contents may occur. Moreover, when the heat setting process of the bottle body is insufficient, the body may be deformed, which causes a problem.

In the method of improving heat resistance by heat-treating such plugs and barrels, the time and temperature of the crystallization treatment greatly affect the productivity, the treatment can be performed at a low temperature in a short time, and the crystallization speed is increased. A fast polyester resin is preferred. However, even if the crystallization rate is too fast, the shrinkage rate due to the plug portion crystallization treatment fluctuates, the plug portion size after crystallization deviates from the specified value, the sealing performance with the cap decreases, and the contents leak. Etc. may occur. In addition, glass-like transparency is required for parts other than the bottle cap, but if the crystallization rate of the polyester is too high, the preform will crystallize and stretch in the process of heating the preform to the stretching temperature. There may be a problem that the appearance of blow-molded bottles becomes cloudy.
Therefore, the crystallization rate of the polyester may cause a problem if it is too fast or too slow, and it is essential to control it within a certain range.

  Further, in order to improve the heat resistance of the bottle body, a method of heat-treating the stretch blow mold at a high temperature is employed. By such a method, many bottles are continuously formed using the same blow mold. And the bottle obtained with a long driving | operation will whiten, transparency will fall, and only a bottle with no commercial value will be obtained. In particular, in recent years, the molding speed has been increased along with the downsizing of the bottle, and shortening of the heating time for crystallization of the plug portion is required from the viewpoint of productivity.

  Various proposals have been made as methods for increasing the crystallization rate. For example, a method of copolymerizing polyethylene or the like with polyethylene terephthalate (see Patent Document 7), a method of bringing a polyethylene terephthalate resin into contact with a crystalline thermoplastic resin member such as polyethylene under flow conditions (see Patent Document 8), A method of blending a small amount of a crystalline thermoplastic resin member such as polyethylene (see Patent Document 9), a method of containing a trace amount of a polyolefin resin or a polyamide resin in a polyester composed of antimony and a titanium catalyst, and lowering the temperature rising crystallization temperature (Tc1) ( (See Patent Document 10). However, these methods have problems in terms of quality and productivity, such as variations in the dimensions of the plug portion after crystallization, transparency of the trunk portion, and an increase in the number of processes, and are not fully satisfactory. .

JP 55-79237 A Japanese Examined Patent Publication No.59-6216 JP-A-5-9275 JP-A-9-71639 JP-A-9-151308 JP 2002-294056 A

  For the reasons mentioned above, the stopper part is heated and crystallized in a short time, and also has excellent dimensional stability, high productivity during molding, and less transparency and coloring problems as the bottle part. A polyester resin and a method for producing the same are desired.

  Currently, polyesters as described above are used as oligomers in which glycol is condensed at both ends by esterification reaction or transesterification reaction by using glycol component in excess of acid component in order to increase reactivity. A deglycolization reaction by transesterification under reduced pressure, a so-called polycondensation reaction, is a two-stage reaction method for obtaining a high molecular weight polyester. In recent years, so-called direct esterification methods using aromatic dicarboxylic acids and glycols as raw materials have become mainstream due to low production costs. Separate reaction tanks are used, and these reaction apparatuses each have a plurality of reaction tanks in order to cause the esterification reaction and the polycondensation reaction to proceed uniformly and stepwise.

  In the direct esterification method, polyester is produced by preparing an aromatic dicarboxylic acid and glycol in a slurry preparation tank and supplying the slurry to an esterification reaction tank to carry out an esterification reaction. Since the aromatic dicarboxylic acid is solid and insoluble in glycol, these raw materials are supplied in a slurry form to the esterification reaction tank. In order to ensure the fluidity of this slurry, more than the theoretical amount of glycol is required. A method of supplying as a raw material and recovering an excess part is common. The esterified oligomer produces a polyester by deglycolization reaction in a polycondensation reaction tank. These excessively used glycols and glycols generated by the polycondensation reaction must be recovered and reused. Since methods for recovering and reusing these glycols greatly affect the production cost of polyester, various methods are disclosed.

A method in which the low-boiling fraction of the distillate in the esterification reaction tank is rectified and recycled to the slurry preparation tank (see Patent Document 11), and the low-boiling fraction of ethylene glycol discharged from the esterification reaction tank Rectified and removed and supplied to the ethylene glycol storage tank, and a part of this is used as a circulating liquid for the wet condenser provided in the polycondensation reaction tank to supply the condensate to the ethylene glycol storage tank and the ethylene retained in the ethylene glycol storage tank. A method of reusing glycol for slurry preparation (see Patent Document 12), distillate generated from a polycondensation reaction tank is condensed in a wet condenser, and sent to a distillation column provided in the esterification reaction tank. After removing the portion, a method of returning to the slurry preparation tank and reusing it (see Patent Document 13), the distillate generated in the polycondensation reaction tank is continuously simply distilled, A method in which the bottom extraction liquid of the continuous single distillation can is sent to a batch-type single distillation can for simple distillation, and the distilled liquid excluding the first distillation portion is used as a part of the polycondensation reaction gas condensation refrigerant liquid ( Patent Document 14), the esterification reaction tank distillate removes the low-boiling distillate, and the polycondensation reaction tank distillate removes the low-boiling distillate and the high-boiling distillate and circulates in the slurry preparation. A method of reusing (see Patent Document 15), a method of reusing the distillate discharged from the second stage of the esterification southern European reaction tank directly as a part or the whole of the raw material without distillation purification (Patent Document) 16), and a method of refining a distillate from a polycondensation reaction tank as a part of a raw material glycol by rectifying and removing a low-boiling fraction by flash distillation (see Patent Document 17).
Japanese Patent Laid-Open No. 53-126096 JP-A-55-56120 JP-A-60-163918 JP-A-8-325363 Japanese Patent No. 3424755 Japanese Patent Laid-Open No. 10-279777 WO01 / 088382

  On the other hand, in the production of polyester, blocking of a metal compound used for an esterification or transesterification reaction catalyst, so-called internal particle method in which fine particles are precipitated by reaction with a metal compound in a polyester production process, or electrostatic adhesion to a polyester. In many cases, a phosphorus compound is added to block the metal compound to be added or to improve electrostatic adhesion characteristics. A part of these phosphorus compounds is mixed in the distilled glycol. Since the phosphorus compound mixed in the distillate glycol affects the reaction when reused, it is necessary to prevent or control the contamination. However, in the technique disclosed in the above patent document, the glycol that is recycled and reused is used. No consideration is given to the inclusion of phosphorus compounds in the water.

In a method for producing polyethylene terephthalate by an internal particle method using a phosphorus compound having a specific structure, which is one of the methods for producing a polyester using a phosphorus compound, a part of the phosphorus compound is distilled out of the system together with ethylene glycol. When ethylene glycol is reused, there is a problem that a polyester that gives desired surface characteristics cannot be obtained with good reproducibility when a film is formed by changing the particle size or the amount of precipitated particles and the amount of precipitated particles. As a method for solving this problem, a method of using ethylene glycol distilled after heat-treating ethylene glycol distilled from the production process of polyester in the presence of an alkali compound (Patent Document 18), distilling ethylene glycol in the same volume or more The method of using ethylene glycol obtained by adding and heating water and distilling off the mixed phosphorus compound together with water (see Patent Document 19) and 0.2 to 10 wt% of water with respect to distilled ethylene glycol A method of using ethylene glycol recovered by distillation after adding and heat-treating is disclosed (see Patent Document 20).
JP 57-14619 A JP 57-14620 A JP 59-96124 A

  Although the above method is an effective method for preventing the phosphorus compound from being mixed into the recovered ethylene glycol, it has a problem that it is disadvantageous in terms of economy.

  In the method for producing a polyester in the presence of a catalyst system comprising an aluminum compound and a phosphorus compound, a part of the phosphorus compound added together with the distilled glycol is distilled. When recycled and reused, this distillate phosphorus compound is also circulated, which adversely affects polycondensation catalyst activity and polyester quality. Therefore, it is necessary to establish a method in which the glycol can be recycled and reused, for example, by removing the phosphorus compound mixed in the distillate glycol by an economical method.

In addition, a method for recovering and effectively using a polycondensation catalyst component contained in glycol distilled in the polyester production process is disclosed (for example, see Patent Documents 21 to 24). However, no technical disclosure has been made regarding the effective use of phosphorus compounds contained in the distillate glycol.
Japanese Patent Laid-Open No. 7-228677 JP 2000-34343 A JP 2002-332338 A JP 2003-183374 A

  The present invention has been made against the background of the problems of the prior art, and polyester in the presence of a polyester polycondensation catalyst comprising at least one selected from the group consisting of aluminum compounds and at least one selected from the group consisting of phosphorus compounds. In the method for continuously producing the above, a method is provided in which the glycol and phosphorus compounds distilled in the polyester production process can be recycled and reused in an economical manner. Further, the present invention provides a method for producing a polyester which can control a Tc1 in a wide temperature range while maintaining the polycondensation catalytic activity and obtain a molded article having high transparency.

In order to solve the above-mentioned problems, the present invention has finally been completed as a result of intensive studies. That is, the present invention provides a method for continuously producing polyester in the presence of a polyester polycondensation catalyst comprising at least one selected from the group consisting of aluminum compounds and at least one selected from the group consisting of phosphorus compounds. High boiling point containing distillate (A) distilling from the reaction tank to which the compound is added and the subsequent reaction tanks, including a low-boiling fraction mainly composed of water, a middle fraction mainly composed of ethylene glycol, and a phosphorus compound. Polyester production characterized by distilling into fractions, reusing middle distillate with part of glycol for esterification reaction, and reusing high boiling fraction as part or all of phosphorus compound Is the method.
In this case, it is preferable to control Tc1 of the obtained polyester by adjusting the reuse ratio of the high-boiling fraction.
In this case, it is preferable that the phosphorus compound contains a hindered phenol residue.
In this case, the distillate (A) may be subjected to fractional removal of the low-boiling fraction mainly composed of water, and then fractionated again to fractionate and remove the high-boiling fraction containing the phosphorus compound and the like. Is preferred.
Further, in this case, it is preferable to add the phosphorus compound to the second esterification reaction tank and / or thereafter.
In this case, the distillate (B) distilled from the reaction vessel before adding the phosphorus compound is subjected to fractional removal of the low-boiling fraction mainly composed of water, and the residue is glycol for esterification reaction. It is preferable to reuse as.
Moreover, this invention is the polyester manufactured with said polyester manufacturing method.
Furthermore, the present invention is a molded body made of the above polyester.

  The method for producing a polyester according to the present invention comprises a continuous polycondensation in the presence of a polycondensation catalyst comprising at least an aluminum compound and a phosphorus compound, which is a polycondensation catalyst having a metal component other than antimony, germanium and titanium as the main metal component of the catalyst. In the method of manufacturing the polyester, the glycol distilled in the polyester manufacturing process and the phosphorus compound mixed in the glycol are recycled in a highly economical manner, avoiding adverse effects on the polycondensation catalyst activity and quality of the polyester. Therefore, there is an advantage that reduction of operation cost and simplification of equipment can be achieved. Further, in the present invention, even when the above-mentioned circulation reuse is performed, it is possible to produce a polyester that maintains the high polycondensation catalytic activity of the polycondensation catalyst of the present invention and that can provide a molded article with high transparency. Has the advantage. Furthermore, in the present invention, when the phosphorus compound separated by the above method is recycled and reused, Tc1 of the polyester obtained by adjusting the reuse rate can be controlled. As a result, for example, in molding of a hollow molded body such as a bottle, the polyester resin molded body amorphous part or amorphized without increasing the number of steps such as contact or inclusion of a small amount of polyolefin resin or polyamide resin with the polyester resin. The temperature rise crystallization temperature of the molded product can be controlled in a wide range, and the crystallization characteristics of polyester such as polyester resin for bottles improved in terms of dimensional stability, transparency and productivity are regarded as important. It has the advantage that it can be used particularly suitably for certain fields.

Hereinafter, the present invention will be described in detail.
The polyester referred to in the present invention refers to a polyester comprising a dicarboxylic acid and / or an ester-forming derivative thereof and a diol and / or an ester-forming derivative thereof.

  Dicarboxylic acids include succinic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, dodecanedicarboxylic acid, tetradecanedicarboxylic acid, hexadecanedicarboxylic acid, 1,3 -For cyclobutanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2,5-norbornanedicarboxylic acid, dimer acid, etc. Saturated aliphatic dicarboxylic acids exemplified, or ester-forming derivatives thereof, unsaturated aliphatic dicarboxylic acids exemplified by fumaric acid, maleic acid, itaconic acid, etc., or ester-forming derivatives thereof, orthophthalic acid, isophthalic acid, terephthalic acid acid, -(Alkali metal) sulfoisophthalic acid, diphenic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid Acid, 4,4′-biphenyldicarboxylic acid, 4,4′-biphenylsulfonedicarboxylic acid, 4,4′-biphenyletherdicarboxylic acid, 1,2-bis (phenoxy) ethane-p, p′-dicarboxylic acid, pamoin Examples thereof include aromatic dicarboxylic acids exemplified by acids, anthracene dicarboxylic acids and the like, and ester-forming derivatives thereof.

  Of these dicarboxylic acids, terephthalic acid and naphthalenedicarboxylic acid, particularly 2,6-phthalenedicarboxylic acid, are preferred from the viewpoint of the physical properties of the resulting polyester, and other dicarboxylic acids are used as constituents if necessary.

In addition to these dicarboxylic acids, a polyvalent carboxylic acid may be used in combination if the amount is small. Examples of the polyvalent carboxylic acid include ethanetricarboxylic acid, propanetricarboxylic acid, butanetetracarboxylic acid, pyromellitic acid, trimellitic acid, trimesic acid, 3, 4, 3 ′, 4′-biphenyltetracarboxylic acid, and these Examples thereof include ester-forming derivatives.

  As glycol, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, diethylene glycol, triethylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 1,4 -Butylene glycol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,4-cyclohexanediethanol, 1,10-decamethylene glycol, 1,12-dodecanediol, polyethylene glycol, polytrimethyl Aliphatic glycols exemplified by tylene glycol and polytetramethylene glycol, hydroquinone, 4,4′-dihydroxybisphenol, 1,4-bis (β-hydroxyethoxy) benzene, 1,4-bis (β-hydroxyethoxyphenyl) ) Sulfone, bis (p-hydroxyphenyl) ether, bis (p-hydroxyphenyl) sulfone, bis (p-hydroxyphenyl) methane, 1,2-bis (p-hydroxyphenyl) ethane, bisphenol A, bisphenol C, 2 , 5-naphthalenediol, aromatic glycols exemplified by ethylene glycol added to these glycols, and the like.

  Of these glycols, ethylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, and 1,4-cyclohexanedimethanol are preferred.

  In addition to these glycols, polyhydric alcohols may be used in combination in small amounts. Examples of the polyhydric alcohol include trimethylolmethane, trimethylolethane, trimethylolpropane, pentaerythritol, glycerol, hexanetriol, and the like.

  Moreover, you may use together hydroxycarboxylic acid. Examples of the hydroxycarboxylic acid include lactic acid, citric acid, malic acid, tartaric acid, hydroxyacetic acid, 3-hydroxybutyric acid, p-hydroxybenzoic acid, p- (2-hydroxyethoxy) benzoic acid, 4-hydroxycyclohexanecarboxylic acid, or these And ester-forming derivatives thereof.

  Moreover, combined use of cyclic ester is also permitted. Examples of the cyclic ester include ε-caprolactone, β-propiolactone, β-methyl-β-propiolactone, δ-valerolactone, glycolide, and lactide.

  Examples of ester-forming derivatives of polyvalent carboxylic acids or hydroxycarboxylic acids include alkyl esters and hydroxylalkyl esters of these compounds.

  Examples of ester-forming derivatives of diols include esters of diols with lower aliphatic carboxylic acids such as acetic acid.

  As the polyester of the present invention, PET, PBT, polypropylene terephthalate, poly (1,4-cyclohexanedimethylene terephthalate), PEN, polybutylene naphthalate, polypropylene naphthalate and copolymers thereof are preferable, and among these, polyethylene terephthalate and This copolymer is particularly preferred. As a copolymer, what consists of 50 mol% or more of ethylene terephthalate units is preferable, and 70 mol% or more is more preferable. PET is particularly preferred.

  The aluminum compound constituting the polycondensation catalyst of the present invention is not limited as long as it dissolves in a solvent, but aluminum formate, aluminum acetate, aluminum propionate, aluminum oxalate, aluminum acrylate, aluminum laurate, aluminum stearate, Carboxylates such as aluminum benzoate, aluminum trichloroacetate, aluminum lactate, aluminum citrate, aluminum tartrate, aluminum salicylate, aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride, aluminum nitrate, aluminum sulfate, aluminum carbonate, aluminum phosphate , Inorganic acid salts such as aluminum phosphonate, aluminum methoxide, aluminum ethoxide, aluminum n-propoxide, aluminum Aluminum chelate such as muiso-propoxide, aluminum n-butoxide, aluminum t-butoxide, aluminum alkoxide, aluminum acetylacetonate, aluminum acetylacetate, aluminum ethylacetoacetate, aluminum ethylacetoacetate diiso-propoxide, trimethylaluminum , Organoaluminum compounds such as triethylaluminum and their partial hydrolysates, reaction products composed of aluminum alkoxides and aluminum chelate compounds and hydroxycarboxylic acids, aluminum oxide, ultrafine aluminum oxide, aluminum silicate, aluminum and titanium or silicon, Composite with zirconium, alkali metal, alkaline earth metal, etc. Product and the like. Of these, carboxylates, inorganic acid salts and chelate compounds are preferred, and among these, aluminum acetate, aluminum lactate, aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride and aluminum acetylacetonate are particularly preferred.

  Among these aluminum compounds, aluminum acetate, aluminum chloride, aluminum hydroxide, and aluminum hydroxide chloride having a high aluminum content are preferable, and aluminum acetate, aluminum chloride, and aluminum hydroxide chloride are more preferable from the viewpoint of solubility. Furthermore, the use of aluminum acetate is particularly preferred from the viewpoint of not corroding the device.

Here, aluminum hydroxide chloride is a general term for what is generally called polyaluminum chloride or basic aluminum chloride, and those used for water supply can be used. These are represented by, for example, the general structural formula [Al ₂ (OH) _n Cl _6-n ] _m (where 1 ≦ n ≦ 5). Among these, those having a low chlorine content are preferable from the viewpoint of not corroding the device.

  The above-mentioned aluminum acetate is a general term for those having a structure of an aluminum salt of acetic acid represented by basic aluminum acetate, aluminum triacetate, aluminum acetate solution, etc. Among these, from the viewpoint of solubility and solution stability The use of basic aluminum acetate is preferred. Of the basic aluminum acetates, aluminum monoacetate, aluminum diacetate, or those stabilized with boric acid are preferred. Examples of basic aluminum acetate stabilizers include urea and thiourea in addition to boric acid.

The above aluminum compound is preferably solubilized in a solvent such as water or glycol.
Solvents that can be used in the present invention are water and alkylene glycols. Examples of alkylene glycols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, trimethylene glycol, ditrimethylene glycol, tetramethylene glycol, ditetramethylene glycol, neopentyl glycol, and the like. . Preferably, they are ethylene glycol, trimethylene glycol, tetramethylene glycol, more preferably ethylene glycol. It is preferable to use those solubilized in water and / or ethylene glycol because the effects of the present invention can be remarkably exhibited.

In the present invention, it is preferable to use the above aluminum compound dissolved in ethylene glycol, and the integrated value of the peak appearing at -15 to 30 ppm in the ²⁷ Al-NMR spectrum determined by the following method is the integral of the reference peak. It is more preferable to use an ethylene glycol solution of an aluminum compound having a ratio to the value of 0.3 or more.
[Method of measuring NMR spectrum of aluminum compound ethylene glycol solution]
The NMR spectrum of an aluminum glycol solution of an aluminum compound is measured by the following method.
Sample: Ethylene glycol solution of aluminum compound (concentration: source of aluminum)
2.65g / l as a basic quantity)
Apparatus: Fourier transform nuclear magnetic resonance apparatus (AVANCE500 manufactured by BRUKER)
Measurement solution: 20 parts by volume of deuterated dimethylsulfoxy with respect to 80 parts by volume of the sample.
Add sid
²⁷ Al resonance frequency: 130.33 MHz
Detection pulse flip angle: 90 °
Data acquisition time: 1.0 seconds Delay time: 1.0 seconds Proton decoupling: not implemented Integration count: 500-1000 times Measurement temperature: room temperature On the other hand, aluminum chloride hexahydrate (AlCl ₃ .6H ₂ O) The peak integral value when measuring a 1.3 mmol / l heavy aqueous solution under the above conditions is 1.0 as a standard, and the peak integral appearing at −15 to 30 ppm of the ethylene glycol solution of the aluminum compound measured by the above method Display as a ratio of values.
The integral value ratio of the peak is more preferably 0.35 or more, further preferably 0.40 or more, and particularly preferably 0.50 or more. If the integral value ratio of the peak is less than 0.30, the amount of aluminum-based foreign matter insoluble in polyester described later increases, and it is not possible to secure 3500 ppm or less, which is not preferable.

The method for setting the integral value ratio of the peak to 0.3 or more is not limited, but it is a preferred embodiment that the temperature of the solution does not become 110 ° C. or higher when the aluminum compound is made into a solution. 105 ° C. or lower is more preferable, and 100 ° C. or lower is further preferable. As described above, the aluminum compound is preferably finally added to the reaction system as an ethylene glycol solution. The method for preparing the ethylene glycol solution is not limited, however, after the aluminum compound is once dissolved in water, ethylene glycol is added to the aqueous solution, and the resulting water / ethylene glycol mixed solvent is heated to remove water. It is a preferable embodiment to carry out by a liquid replacement method for distilling off.
Here, the solution formation includes all steps related to solution formation such as dissolution or liquid replacement. As a method for lowering the temperature in the liquid replacement, it is a preferred embodiment that the lowering is carried out under reduced pressure and both the lowering of the temperature and the shortening of time are performed. Considering the efficiency of liquid replacement, 55 to 105 ° C is preferable, and it is particularly preferable to perform at 60 to 100 ° C.

  In addition, the quality of the aluminum compound used for dissolution is also important as a method for setting the integral value ratio of the peak to 0.3 or less. It is also an effective method to select one with a low degree of association. The method for suppressing the association of the aluminum compound before dissolution is not limited. For example, when preparing an aluminum compound, an additive that suppresses association is added, the drying temperature when taking out the aluminum compound in the preparation step is lowered, or the degree of drying at the time of drying is reduced to include moisture. It is effective to make it a product in the state. It is also a preferred embodiment that the aluminum compound is obtained in the form of a solution such as an aqueous solution without isolation.

  As selection criteria for an aluminum compound having a low degree of association, for example, the amount of insoluble components when the aluminum compound is dissolved in water is specified, the crystallinity of the aluminum compound is specified, and the amount of water of crystallization of the aluminum compound is specified. And the like. It is also a preferred embodiment to use an additive that improves the solubility of the aluminum compound in a solvent such as water and a compound that improves the stability of the aluminum compound against hydrolysis and the like.

The method for dissolving the aluminum compound is exemplified below.
(1) Preparation example of aqueous solution of basic aluminum acetate Water is added to basic aluminum acetate and stirred at 50 ° C. or lower for 3 hours or longer. The stirring time is more preferably 6 hours or longer. Thereafter, stirring is performed at 60 ° C. or more for several hours or more. The temperature in this case is preferably in the range of 60 to 100 ° C. The stirring time is preferably 1 hour or longer. The concentration of the aqueous solution is preferably 10 g / l to 30 g / l, particularly preferably 15 g / l to 20 g / l.

(2) Preparation Example of Ethylene Glycol Solution of Basic Aluminum Acetate Ethylene glycol is added to the above aqueous solution. The amount of ethylene glycol added is preferably 0.5 to 5 times the volume ratio of the aqueous solution. More preferably, the amount is 1 to 3 times. The solution is stirred at room temperature for several hours to obtain a uniform water / ethylene glycol mixed solution. Thereafter, the solution is heated and water is distilled off to obtain an ethylene glycol solution. The temperature is preferably 50 ° C. or higher, and preferably 110 ° C. or lower. More preferably, the water is distilled off by stirring at 55 to 105 ° C. for several hours. It is particularly preferable to carry out at 60 to 100 ° C. It is preferred to reduce the system pressure during the distillation. By reducing the pressure, ethylene glycol can be rapidly distilled off at a lower temperature. In other words, the distillation can be performed at 80 ° C. or lower under reduced pressure, and the heat history applied to the system can be further reduced.

(3) Preparation example of aluminum glycol solution of aluminum lactate An aqueous solution of aluminum lactate is prepared. The preparation may be performed at room temperature or under heating, but is preferably performed at room temperature. The concentration of the aqueous solution is preferably 20 g / l to 100 g / l, particularly preferably 50 to 80 g / l. Ethylene glycol is added to the aqueous solution. The amount of ethylene glycol added is preferably 1 to 5 times the volume ratio of the aqueous solution. More preferably, the amount is 2-3 times. After stirring the solution at room temperature to obtain a uniform water / ethylene glycol mixed solution, the solution is heated and water is distilled off to obtain an ethylene glycol solution. The temperature is preferably 50 ° C. or higher, and preferably 110 ° C. or lower. More preferably, the water is distilled off by stirring at 55 to 105 ° C. for several hours. It is particularly preferable to carry out at 60 to 100 ° C. As in the case of basic aluminum acetate, it is preferable to perform liquid replacement with an ethylene glycol solution under reduced pressure.

In the present invention, removing the insoluble foreign matter such as contaminants present in the solution by a method such as filtration, centrifugation or ultracentrifugation of the aluminum compound solution obtained by the above method is a preferable implementation.

  When the polyester is produced according to the method of the present invention, the amount of the basic aluminum acetate used is based on the number of moles of all constituent units of the carboxylic acid component such as dicarboxylic acid or polycarboxylic acid of the obtained polyester. 0.001-0.05 mol% is preferable as an aluminum atom, More preferably, it is 0.005-0.02 mol%. If the amount used is less than 0.001 mol%, the catalytic activity may not be sufficiently exerted. If the amount used is more than 0.05 mol%, the thermal stability or thermal oxidation stability is lowered, resulting from aluminum. Occurrence of foreign matters or increased coloring may be a problem. Thus, even if the addition amount of the aluminum component is small, the polycondensation catalyst of the present invention has a great feature in that it exhibits sufficient catalytic activity. As a result, the thermal stability and thermal oxidation stability are excellent, and foreign matters and coloring caused by aluminum are reduced.

The phosphorus compound constituting the polycondensation catalyst of the present invention is not particularly limited, but phosphoric acid and phosphoric acid esters such as trimethyl phosphoric acid, triethyl phosphoric acid, phenyl phosphoric acid and triphenyl phosphoric acid, phosphorous acid and trimethyl. Phosphite, triethyl phosphite, triphenyl phosphite, tris (2,4-di-tert-butylphenyl) phosphite, tetrakis (2,4-di-tert-butylphenyl) 4,4′-biphenylene diphosphite And the like.

  More preferable phosphorus compound of the present invention is at least one phosphorus compound selected from the group consisting of phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phosphonous acid compounds, phosphinic acid compounds, and phosphine compounds. It is. By using these phosphorus compounds, an effect of improving the catalytic activity is seen, and an effect of improving physical properties such as thermal stability of the polyester is seen. Among these, use of a phosphonic acid compound is preferable because of its great effect of improving physical properties and improving catalytic activity. Among the above-described phosphorus compounds, the use of a compound having an aromatic ring structure is preferable because the physical property improving effect and the catalytic activity improving effect are great.

  The phosphonic acid-based compound, phosphinic acid-based compound, phosphine oxide-based compound, phosphonous acid-based compound, phosphinic acid-based compound, and phosphine-based compound referred to in the present invention are represented by the following formulas (Formula 1) to (Formula 6), respectively. It refers to a compound having the structure represented.

  Examples of the phosphonic acid compound of the present invention include dimethyl methylphosphonate, diphenyl methylphosphonate, dimethyl phenylphosphonate, diethyl phenylphosphonate, diphenyl phenylphosphonate, dimethyl benzylphosphonate, diethyl benzylphosphonate and the like. Examples of the phosphinic acid compound of the present invention include diphenylphosphinic acid, methyl diphenylphosphinate, phenyl diphenylphosphinate, phenylphosphinic acid, methyl phenylphosphinate, phenylphenylphosphinate and the like. Examples of the phosphine oxide compound of the present invention include diphenylphosphine oxide, methyldiphenylphosphine oxide, and triphenylphosphine oxide.

  Among the phosphinic acid compounds, phosphine oxide compounds, phosphonous acid compounds, phosphinic acid compounds, and phosphine compounds, the phosphorus compounds of the present invention are represented by the following formulas (Chemical Formula 7) to (Chemical Formula 12). Are preferred.

  Among the above-described phosphorus compounds, the use of a compound having an aromatic ring structure is preferable because the physical property improving effect and the catalytic activity improving effect are great.

  In addition, when the compounds represented by the following general formulas (Chemical Formula 13) to (Chemical Formula 15) are used as the phosphorus compound of the present invention, the physical property improving effect and the catalytic activity improving effect are particularly large and preferable.

Wherein R ¹ , R ⁴ , R ⁵ and R ⁶ are each independently hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group, a halogen group, an alkoxyl group or an amino group. Represents a hydrocarbon group having 1 to 50 carbon atoms including R ² and R ³ each independently represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydrocarbon group having 1 to 50 carbon atoms including a hydroxyl group or an alkoxyl group. However, the hydrocarbon group may contain an alicyclic structure such as cyclohexyl or an aromatic ring structure such as phenyl or naphthyl.)

The phosphorus compound of the present invention is particularly preferably a compound in which R ¹ , R ⁴ , R ⁵ , and R ⁶ are groups having an aromatic ring structure in the above formulas (Chemical Formula 13) to (Chemical Formula 15).

  Examples of the phosphorus compound of the present invention include dimethyl methylphosphonate, diphenyl methylphosphonate, dimethyl phenylphosphonate, diethyl phenylphosphonate, diphenyl phenylphosphonate, dimethyl benzylphosphonate, diethyl benzylphosphonate, diphenylphosphinic acid, diphenylphosphinic acid. Examples include methyl, phenyl diphenylphosphinate, phenylphosphinic acid, methyl phenylphosphinate, phenyl phenylphosphinate, diphenylphosphine oxide, methyldiphenylphosphine oxide, and triphenylphosphine oxide. Of these, dimethyl phenylphosphonate and diethyl benzylphosphonate are particularly preferred.

  Among the phosphorus compounds described above, a phosphorus metal salt compound is particularly preferable as the phosphorus compound in the present invention. The phosphorus metal salt compound is not particularly limited as long as it is a metal salt of a phosphorus compound. However, when a metal salt of a phosphonic acid compound is used, the physical properties improving effect and catalytic activity improving effect of the polyester, which are the problems of the present invention, are improved. Largely preferred. Examples of the metal salt of the phosphorus compound include a monometal salt, a dimetal salt, and a trimetal salt.

  Further, among the above-described phosphorus compounds, when the metal portion of the metal salt is selected from Li, Na, K, Be, Mg, Sr, Ba, Mn, Ni, Cu, and Zn, the catalytic activity is improved. Is preferable. Of these, Li, Na, and Mg are particularly preferable.

  As the phosphorus metal salt compound of the present invention, it is preferable to use at least one selected from the compounds represented by the following general formula (Chemical Formula 16) because the effect of improving the physical properties and the effect of improving the catalytic activity are large.

(In the formula (Formula 16), R ¹ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group, a halogen group, an alkoxyl group, or an amino group, and a hydrocarbon group having 1 to 50 carbon atoms. R ² represents , Hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group or an alkoxyl group, and a hydrocarbon group having 1 to 50 carbon atoms, R ³ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group or an alkoxyl group. A hydrocarbon group having 1 to 50 carbon atoms including a group or carbonyl, l is an integer of 1 or more, m is 0 or an integer of 1 or more, l + m is 4 or less, M is a (l + m) -valent metal Represents a cation, n represents an integer of 1 or more, and the hydrocarbon group may contain an alicyclic structure such as cyclohexyl, a branched structure, or an aromatic ring structure such as phenyl or naphthyl.)

Examples of R ¹ include phenyl, 1-naphthyl, 2-naphthyl, 9-anthryl, 4-biphenyl, 2-biphenyl, and the like. Examples of R ² include hydrogen, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, long-chain aliphatic group, phenyl group, naphthyl group, Examples thereof include a substituted phenyl group, a naphthyl group, and a group represented by —CH ₂ CH ₂ OH. Examples of R ³ O ⁻ include hydroxide ions, alcoholate ions, acetate ions, and acetylacetone ions.

  Among the compounds represented by the general formula (Chemical Formula 16), it is preferable to use at least one selected from the compounds represented by the following General Formula (Chemical Formula 17).

(In the formula (Chemical Formula 17), R ¹ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group, a halogen group, an alkoxyl group, or an amino group, and a hydrocarbon group having 1 to 50 carbon atoms. R ³ represents , Hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group or an alkoxyl group, or a hydrocarbon group having 1 to 50 carbon atoms including carbonyl, l is an integer of 1 or more, and m is 0 or an integer of 1 or more. , L + m is 4 or less, M represents a (l + m) -valent metal cation, and the hydrocarbon group may contain an alicyclic structure such as cyclohexyl or a branched structure, or an aromatic ring structure such as phenyl or naphthyl.

Examples of R ¹ include phenyl, 1-naphthyl, 2-naphthyl, 9-anthryl, 4-biphenyl, 2-biphenyl, and the like. Examples of R ³ O ⁻ include hydroxide ions, alcoholate ions, acetate ions, and acetylacetone ions.

  Among the above-described phosphorus compounds, the use of a compound having an aromatic ring structure is preferable because the physical property improving effect and the catalytic activity improving effect are great.

  Among the above formulas (Chemical Formula 17), when M is selected from Li, Na, K, Be, Mg, Sr, Ba, Mn, Ni, Cu, and Zn, the effect of improving the catalytic activity is large and preferable. Of these, Li, Na, and Mg are particularly preferable.

  Examples of the metal salt compound of phosphorus according to the present invention include lithium [ethyl (1-naphthyl) methylphosphonate], sodium [ethyl (1-naphthyl) methylphosphonate], magnesium bis [ethyl (1-naphthyl) methylphosphonate], potassium [ (2-naphthyl) methylphosphonate ethyl], magnesium bis [(2-naphthyl) methylphosphonate ethyl], lithium [benzylphosphonate ethyl], sodium [benzylphosphonate ethyl], magnesium bis [benzylphosphonate ethyl], beryllium bis [Ethyl benzylphosphonate], strontium bis [ethyl benzylphosphonate], manganese bis [ethyl benzylphosphonate], sodium benzylphosphonate, magnesium bis [benzylphosphonic acid], sodium [(9-anths L) ethyl methylphosphonate], magnesium bis [(9-anthryl) methylphosphonate ethyl], sodium [ethyl 4-hydroxybenzylphosphonate], magnesium bis [4-hydroxybenzylphosphonate ethyl], sodium [4-chlorobenzylphosphone] Acid phenyl], magnesium bis [4-chlorobenzylphosphonate ethyl], sodium [methyl 4-aminobenzylphosphonate], magnesium bis [4-aminobenzylphosphonate methyl], sodium phenylphosphonate, magnesium bis [phenylphosphonic acid] Ethyl], zinc bis [ethyl phenylphosphonate] and the like. Among these, lithium [ethyl (1-naphthyl) methylphosphonate], sodium [ethyl (1-naphthyl) methylphosphonate], magnesium bis [ethyl (1-naphthyl) methylphosphonate], lithium [ethyl benzylphosphonate], Sodium [ethyl benzylphosphonate], magnesium bis [ethyl benzylphosphonate], sodium benzylphosphonate and magnesium bis [benzylphosphonic acid] are particularly preferred.

Among the phosphorus compounds described above, in the present invention, a phosphorus compound having at least one P—OH bond is particularly preferable as the phosphorus compound. In addition to particularly enhancing the physical properties improving effect of the polyester by containing these phosphorus compounds, the catalytic activity is improved by using these phosphorus compounds in combination with the aluminum compound of the present invention at the time of polymerization of the polyester. Seen large.
The phosphorus compound having at least one P—OH bond is not particularly limited as long as it is a phosphorus compound having at least one P—OH in the molecule. Among these phosphorus compounds, the use of a phosphonic acid compound having at least one P—OH bond is preferred because of its great effect of improving the physical properties and improving the catalytic activity of the polyester.

  Among the above-described phosphorus compounds, the use of a compound having an aromatic ring structure is preferable because the physical property improving effect and the catalytic activity improving effect are great.

  As the phosphorus compound having at least one P—OH bond of the present invention, it is preferable to use at least one selected from the compounds represented by the following general formula (Chemical Formula 18) because the physical property improving effect and the catalytic activity improving effect are large. .

(In the formula (Chemical Formula 18), R ¹ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group, a halogen group, an alkoxyl group, or an amino group, and a hydrocarbon group having 1 to 50 carbon atoms. R ² represents , Hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydrocarbon group having 1 to 50 carbon atoms including a hydroxyl group or an alkoxyl group, n represents an integer of 1 or more, and the hydrocarbon group is an alicyclic structure such as cyclohexyl. And may contain an aromatic ring structure such as a branched structure or phenyl or naphthyl.)

Examples of R ¹ include phenyl, 1-naphthyl, 2-naphthyl, 9-anthryl, 4-biphenyl, 2-biphenyl, and the like. Examples of R2 include hydrogen, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, long-chain aliphatic group, phenyl group, naphthyl group, and substitution. And a phenyl group, a naphthyl group, a group represented by —CH ₂ CH ₂ OH, and the like.

  Among the above-described phosphorus compounds, the use of a compound having an aromatic ring structure is preferable because the physical property improving effect and the catalytic activity improving effect are great.

  Examples of the phosphorus compound having at least one P—OH bond of the present invention include (1-naphthyl) methylphosphonic acid ethyl, (1-naphthyl) methylphosphonic acid, (2-naphthyl) methylphosphonic acid ethyl, benzylphosphonic acid ethyl, benzylphosphonic acid. Acid, ethyl (9-anthryl) methylphosphonate, ethyl 4-hydroxybenzylphosphonate, ethyl 2-methylbenzylphosphonate, phenyl 4-chlorobenzylphosphonate, methyl 4-aminobenzylphosphonate, ethyl 4-methoxybenzylphosphonate Etc. Of these, ethyl (1-naphthyl) methylphosphonate and ethyl benzylphosphonate are particularly preferred.

  A preferable phosphorus compound of the present invention is a phosphorus compound represented by the chemical formula (Formula 19).

(In the formula (Chemical Formula 19), R ¹ represents a hydrocarbon group having ¹ to 49 carbon atoms, or a hydrocarbon group having ¹ to 49 carbon atoms including a hydroxyl group, a halogen group, an alkoxyl group, or an amino group, and R ² , R ³ each independently represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group or an alkoxyl group, which has an alicyclic structure, a branched structure or an aromatic ring structure. May be included.)

More preferably, at least one of R ¹ , R ² and R ^{3 in} the chemical formula (Chemical Formula 19) is a compound containing an aromatic ring structure.

  Specific examples of these phosphorus compounds are shown below.

  Moreover, since the phosphorus compound of the present invention has a large molecular weight, it is more effective because it is less likely to be distilled off during polymerization.

  The phosphorus compound of the present invention is preferably a phosphorus compound having a phenol moiety in the same molecule. In addition to enhancing the physical properties of polyester by containing a phosphorus compound having a phenol moiety in the same molecule, the effect of increasing catalytic activity by using a phosphorus compound having a phenol moiety in the same molecule during polyester polymerization Is larger, and therefore the polyester productivity is excellent.

  The phosphorus compound having a phenol moiety in the same molecule is not particularly limited as long as it is a phosphorus compound having a phenol structure, but a phosphonic acid compound, a phosphinic acid compound, a phosphine oxide compound having a phenol moiety in the same molecule. When one or more compounds selected from the group consisting of a compound, a phosphonous acid compound, a phosphinic acid compound, and a phosphine compound are used, the effect of improving the physical properties of the polyester and the effect of improving the catalytic activity are greatly preferred. Among these, when a phosphonic acid compound having one or two or more phenol moieties in the same molecule is used, the effect of improving the physical properties of the polyester and the effect of improving the catalytic activity are particularly large and preferable.

  As a phosphorus compound which has the phenol part of this invention in the same molecule | numerator, the compound represented by the following general formula (Formula 26)-(Formula 28) is preferable.

(In the formulas (Chemical Formula 26) to (Chemical Formula 28), R ¹ is a carbon having 1 to 50 carbon atoms including a phenol part, a substituent such as a hydroxyl group, a halogen group, an alkoxyl group, or an amino group, and a phenol part. Represents a hydrocarbon group having a number of 1 to 50. R ⁴ , R ⁵ and R ⁶ each independently represents a substituent such as hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group, a halogen group, an alkoxyl group or an amino group. Represents a hydrocarbon group having 1 to 50 carbon atoms, and R ² and R ³ are each independently hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group, or an alkoxyl group. Represents a hydrocarbon group, provided that the hydrocarbon group may contain a branched structure, an alicyclic structure such as cyclohexyl, or an aromatic ring structure such as phenyl or naphthyl, and the ends of R ² and R ⁴ are bonded to each other. Moyo Yes.)

  Examples of the phosphorus compound having the phenol moiety of the present invention in the same molecule include p-hydroxyphenylphosphonic acid, dimethyl p-hydroxyphenylphosphonate, diethyl p-hydroxyphenylphosphonate, diphenyl p-hydroxyphenylphosphonate, bis (P-hydroxyphenyl) phosphinic acid, methyl bis (p-hydroxyphenyl) phosphinate, phenyl bis (p-hydroxyphenyl) phosphinate, p-hydroxyphenylphenylphosphinic acid, methyl p-hydroxyphenylphenylphosphinate, p- Phenyl hydroxyphenylphenylphosphinate, p-hydroxyphenylphosphinic acid, methyl p-hydroxyphenylphosphinate, phenyl p-hydroxyphenylphosphinate, bis (p-hydroxyphenyl Yl) phosphine oxide, tris (p- hydroxyphenyl) phosphine oxide, bis (p- hydroxyphenyl) methyl phosphine oxide, and the following formula (Formula 29), and the like compounds represented by to (Formula 32). Among these, a compound represented by the following formula (Chemical Formula 31) and dimethyl p-hydroxyphenylphosphonate are particularly preferable.

As a compound represented by the above formula (Chemical Formula 31), SANKO-220 (manufactured by Sanko Co., Ltd.) can be used.

  Among the phosphorus compounds having the phenol moiety of the present invention in the same molecule, at least one selected from a metal salt compound of a specific phosphorus represented by the following general formula (Formula 33) is particularly preferable.

(In Formula (Chemical Formula 33), R ¹ and R ² each independently represent hydrogen and a hydrocarbon group having 1 to 30 carbon atoms. R ³ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group or R ⁴ represents a hydrocarbon group having 1 to 50 carbon atoms including an alkoxyl group, R ⁴ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group, an alkoxyl group, or a carbonyl group including carbonyl. Examples of R ⁴ O ⁻ include hydroxide ion, alcoholate ion, acetate ion, acetylacetone ion, etc. l is an integer of 1 or more, m is 0 or an integer of 1 or more, and l + m is 4 or less. M represents a (l + m) -valent metal cation, n represents an integer of 1 or more, and the hydrocarbon group includes an alicyclic structure such as cyclohexyl, a branched structure, and an aromatic ring structure such as phenyl or naphthyl. Moyo .)

  Among these, at least one selected from compounds represented by the following general formula (Formula 34) is preferable.

(In the formula (Chemical Formula 34), M ^{n +} represents an n-valent metal cation. N is 1, 2, 3, or 4)
Represents. )

  Among the above formulas (Chemical Formula 33) or (Chemical Formula 34), when M is selected from Li, Na, K, Be, Mg, Sr, Ba, Mn, Ni, Cu, Zn, the catalytic activity is improved. The effect is large and preferable. Of these, Li, Na, and Mg are particularly preferable.

  Specific phosphorus metal salt compounds of the present invention include lithium [3,5-di-tert-butyl-4-hydroxybenzylphosphonate], sodium [3,5-di-tert-butyl-4-hydroxybenzyl] Ethyl phosphonate], sodium [3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid], potassium [ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate], magnesium bis [3 , 5-di-tert-butyl-4-hydroxybenzylphosphonic acid ethyl], magnesium bis [3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid], beryllium bis [3,5-di-tert- Methyl butyl-4-hydroxybenzylphosphonate], strontium bis [3,5-di-te t-butyl-4-hydroxybenzylphosphonate ethyl], barium bis [3,5-di-tert-butyl-4-hydroxybenzylphosphonate phenyl], manganese bis [3,5-di-tert-butyl-4- Ethyl hydroxybenzylphosphonate], nickel bis [3,5-di-tert-butyl-4-hydroxybenzylphosphonate], copper bis [3,5-di-tert-butyl-4-hydroxybenzylphosphonate] Zinc bis [3,5-di-tert-butyl-4-hydroxybenzylphosphonate] and the like. Among these, lithium [ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate], sodium [ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate], magnesium bis [ Ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate] is particularly preferred.

  Among the phosphorus compounds having the phenol moiety of the present invention in the same molecule, at least one selected from specific phosphorus compounds having at least one P—OH bond represented by the following general formula (Formula 35) is particularly preferable.

(In formula (Chemical Formula 35), R ¹ and R ² each independently represent hydrogen and a hydrocarbon group having 1 to 30 carbon atoms. R ³ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group or A hydrocarbon group having 1 to 50 carbon atoms including an alkoxyl group is represented, and n represents an integer of 1 or more.
The hydrocarbon group may contain an alicyclic structure such as cyclohexyl, a branched structure, or an aromatic ring structure such as phenyl or naphthyl. )

  Among these, at least one selected from compounds represented by the following general formula (Formula 36) is preferable.

(In formula (Chemical Formula 36), R ³ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydrocarbon group having 1 to 50 carbon atoms including a hydroxyl group or an alkoxyl group. The hydrocarbon group is a fatty acid such as cyclohexyl. (It may contain a ring structure, a branched structure, or an aromatic ring structure such as phenyl or naphthyl.)

Examples of R ³ include hydrogen, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, long-chain aliphatic group, phenyl group, naphthyl group, Examples thereof include a substituted phenyl group, a naphthyl group, and a group represented by —CH ₂ CH ₂ OH.

  Specific phosphorus compounds having at least one P-OH bond of the present invention include ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, 3,5-di-tert-butyl-4-hydroxy Methyl benzylphosphonate, isopropyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, phenyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, 3,5-di-tert-butyl Examples include octadecyl-4-hydroxybenzylphosphonate, 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid, and the like. Of these, ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate and methyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate are particularly preferred.

  Among the phosphorus compounds having the phenol moiety of the present invention in the same molecule, at least one phosphorus compound selected from specific phosphorus compounds represented by the following general formula (Formula 37) is preferable.

(In the above formula (Chemical Formula 37), R ¹ and R ² each independently represent hydrogen and a hydrocarbon group having 1 to 30 carbon atoms. R ³ and R ⁴ are each independently hydrogen and carbon atoms having 1 to 50 carbon atoms. Represents a hydrocarbon group having 1 to 50 carbon atoms including a hydrogen group, a hydroxyl group or an alkoxyl group, n represents an integer of 1 or more, and the hydrocarbon group is an alicyclic structure such as cyclohexyl, a branched structure, or an aromatic such as phenyl or naphthyl. It may contain a ring structure.)

  Among the above general formulas (Chemical Formula 37), it is preferable to use at least one selected from the compounds represented by the following General Formula (Chemical Formula 38) because the effect of improving the physical properties of the polyester and the effect of improving the catalytic activity are high.

(In the above formula (Chemical Formula 38), R ³ and R ⁴ each independently represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydrocarbon group having 1 to 50 carbon atoms including a hydroxyl group or an alkoxyl group. The group may contain an alicyclic structure such as cyclohexyl, a branched structure, or an aromatic ring structure such as phenyl or naphthyl.)

Examples of R ³ and R ⁴ include short chain aliphatic groups such as hydrogen, methyl and butyl groups, long chain aliphatic groups such as octadecyl, phenyl groups, naphthyl groups, substituted phenyl groups and naphthyl groups. An aromatic group such as a group, a group represented by —CH ₂ CH ₂ OH, and the like.

  Specific phosphorus compounds of the present invention include diisopropyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, di-n-butyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, Examples include dioctadecyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate and diphenyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate. Of these, dioctadecyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate and diphenyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate are particularly preferred.

  Among the phosphorus compounds having the phenol moiety of the present invention in the same molecule, a particularly desirable compound in the present invention is at least one phosphorus compound selected from compounds represented by chemical formulas (Chemical Formula 39) and (Chemical Formula 40).

  As the compound represented by the above chemical formula (Chemical Formula 39), Irganox 1222 (manufactured by Ciba Specialty Chemicals) is commercially available, and as the compound represented by the chemical formula (Chemical Formula 40), Irganox 1425 (Ciba Specialty Chemical) is available. Chemicals) is commercially available and can be used.

  As the usage-amount of the phosphorus compound in this invention, 0.0001-0.1 mol% is preferable with respect to the number-of-moles of all the structural units of the carboxylic acid component of the polyester obtained, 0.005-0.05 mol% More preferably it is.

It is preferable that the polyester in this invention is 3500 ppm or less of the aluminum type foreign substance insoluble in the polyester quantified by the evaluation method shown below.
[Aluminum-based foreign substance evaluation method insoluble in polyester]
30 g of polyester pellets after melt polycondensation and 300 ml of parachlorophenol / tetrachloroethane (3/1: weight ratio) mixed solution are put into a round bottom flask with a stirrer, and the pellets are added to the mixed solution at 100 to 105 ° C. for 2 hours. Stir and dissolve. The solution was allowed to cool to room temperature, and a polytetrafluoroethylene membrane filter (Advantec PTFE membrane filter, product name: T100A047A) having a diameter of 47 mm / a pore size of 1.0 μm was used, and the total amount was under a pressure of 0.15 MPa. Use to filter out foreign objects. The effective filtration diameter was 37.5 mm. After completion of the filtration, the product is subsequently washed with 300 ml of chloroform, and then dried under reduced pressure at 30 ° C. for a whole day and night. The amount of aluminum element was quantified on the filtration surface of the membrane filter using a scanning X-ray fluorescence analyzer (manufactured by RIGAKU, ZSX100e, Rh tube 4.0 kW). The quantification is performed on a portion having a diameter of 30 mm at the center of the membrane filter. The calibration curve of the fluorescent X-ray analysis method is obtained using a polyethylene terephthalate resin having a known aluminum element content, and the apparent aluminum element amount is expressed in ppm. The measurement is carried out by measuring Al-Kα ray intensity under the conditions of PHA (wave height analyzer) 100-300, using pentaerythritol as a spectral crystal, PC (proportional counter) as a detector, with an X-ray output of 50 kV-70 mA. . The amount of aluminum element in the polyethylene terephthalate resin for the calibration curve is quantified by high frequency inductively coupled plasma emission spectrometry.

  The amount of aluminum-based foreign matter insoluble in polyester measured by the above evaluation method is more preferably 2500 ppm or less. 1500 ppm or less is more preferable. When the amount of aluminum-based foreign matter insoluble in polyester exceeds 3500 ppm, fine foreign matters that are insoluble in the polyester cause the haze of the molded product to deteriorate when molded as a molded product such as a film or bottle. Therefore, it is not preferable. Moreover, it leads to the subject that the filter clogging at the time of filtration of polyester in a polycondensation process or a molding process increases.

The amount of the aluminum-based foreign substance insoluble in the polyester measured by the above evaluation method is a converted value to the last, and the content relative to the total amount of the polyester used for the above evaluation becomes a very small amount of ppb level. The transparency of the molded product deteriorates due to the amount of this very small amount of foreign matter. The aluminum-based foreign matter that is insoluble in polyester measured by the above evaluation method has low affinity for polyester. It is presumed that a void is formed at the interface between the aluminum-based foreign material and light is scattered by the void and the transparency of the molded body is lowered.

  In order to satisfy the above characteristics, it is preferable to use an ethylene glycol solution of an aluminum compound having the above-described characteristics, but it is important to use a mixed solution obtained by mixing the solution and the above-described phosphorus compound solution. The correspondence stabilizes the polyester in which the amount of aluminum-based foreign matter insoluble in the polyester is within a preferable range even when the addition time, location, and characteristics of the added polyester oligomer of the polycondensation catalyst of the present invention are changed. Can be obtained. In this case, it is a preferred embodiment that the phosphorus compound contains a hydroxyl group. Accordingly, a structural compound having at least one hydroxyl group in one molecule of the phosphorus compound is preferable. For example, among the above phosphorus compounds, acid compounds and acid / ester mixed compounds of acids and esters are applicable. In the case of a fully esterified compound in which all the hydroxyl groups of the phosphorus compound are esterified, the phosphorus compound is pretreated with a water-containing solvent such as water or alkylene glycol, and the ester bond is hydrolyzed to partially convert the ester bond to a hydroxyl group. It is a preferred embodiment to use the converted one. The amount of conversion to hydroxyl groups in this case is not limited, but the amount of insoluble foreign matter to the polyester is very small, and the effect of reducing the amount of insoluble foreign matter to the polyester by introducing the hydroxyl group is manifested in a very small amount. Even an amount of about% is effective. Therefore, even if an ester type phosphorus compound in which all the hydroxyl groups in the phosphorus compound are esterified is used, the effect is also exhibited by the hydroxyl group formed when mixed with the aluminum compound solution. The use of is not excluded.

  As described above, the effect of the present invention can be expressed more efficiently by using one that has been previously heat-treated in at least one solvent selected from the group consisting of water and alkylene glycol. However, since the effect of improving the polycondensation catalyst activity is exhibited by the heat treatment, it is recommended as a particularly preferred embodiment.

  The solvent used when heat-treating the phosphorus compound in advance is not limited as long as it is at least one selected from the group consisting of water and alkylene glycol, but it is preferable to use a solvent that dissolves the phosphorus compound. As the alkylene glycol, it is preferable to use ethylene glycol. The heat treatment in the solvent is preferably performed after dissolving the phosphorus compound, but may not be completely dissolved. Further, it is not necessary that the compound retains the original structure after the heat treatment, and the solubility in the solvent may be improved by the modification by the heat treatment.

  Although the temperature of heat processing is not specifically limited, It is preferable that it is the range of 20-250 degreeC. More preferably, it is the range of 100-200 degreeC. The upper limit of the temperature is preferably around the boiling point of the solvent used. Although the heating time varies depending on conditions such as temperature, the heating temperature is preferably in the range of 1 minute to 50 hours, more preferably 30 minutes to 10 hours, and even more preferably 1 to 5 hours. Range. The pressure of the heat treatment system may be normal pressure, higher or lower, and is not particularly limited. The concentration of the solution is preferably 1 to 500 g / l as a phosphorus compound, more preferably 5 to 300 g / l, and still more preferably 10 to 100 g / l. The heat treatment is preferably performed in an atmosphere of an inert gas such as nitrogen. The storage temperature of the solution or slurry after heating is not particularly limited, but is preferably in the range of 0 ° C to 100 ° C, and more preferably in the range of 20 ° C to 60 ° C. It is preferable to store the solution in an atmosphere of an inert gas such as nitrogen.

  In the present invention, the NMR spectrum peak of the phosphorus atom to which the hydroxyl group is bonded in the mixed solution is shifted to a higher magnetic field side than the NMR spectrum peak of the phosphorus atom to which the hydroxyl group is bonded in the phosphorus compound single solution before mixing, and the peak is broadened. It is preferable to become. Furthermore, the integrated value of the NMR spectrum peak of the phosphorus atom to which the hydroxyl group of the mixed solution is bonded is 10% or more with respect to the integrated value of the NMR spectrum peak of the phosphorus atom to which the hydroxyl group of the phosphorus compound single solution before mixing is bonded. Is a preferred embodiment. 15% or more is more preferable, and 20% or more is more preferable. If it is less than 10%, the effect of suppressing the production of foreign substances insoluble in the polyester resulting from the aluminum polycondensation catalyst is reduced, and the content of foreign substances insoluble in the polyester is increased. For example, when molded as a molded body such as a film or bottle, This is not preferable because the haze of the molded body deteriorates. Moreover, it leads to the subject that the filter clogging at the time of filtration of polyester in a polycondensation process or a molding process increases. In addition, it is preferable that 90 mol% or more of the solvent of said mixed solution is ethylene glycol.

  The method of mixing the ethylene glycol solution and the phosphorus compound solution of the aluminum compound is not limited, but it is preferable to add the aluminum compound dropwise while stirring the phosphorus compound solution. The conditions at the time of addition are not limited. In the case of a phosphorus compound containing a hydroxyl group, room temperature mixing is preferred. On the other hand, in the case of an ester type phosphorus compound in which all the hydroxyl groups are esterified, it is necessary to cause the formation of hydroxyl groups, so that heating is required. Although the temperature of this heating is not limited, 50-200 degreeC is preferable. The mixing conditions are appropriately set depending on the structure of the phosphorus compound or aluminum compound used. It is a preferred embodiment that the conditions are set by following the change in the NMR spectrum when the two solutions are mixed and setting the mixing conditions that satisfy the above requirements. In the case of using a phosphorus compound that does not contain a hydroxyl group, it is preferable to use a phosphorus compound that has been heat-treated as an ethylene glycol solution to form a hydroxyl group before mixing with the ethylene glycol solution of the aluminum compound. A small amount of water may be added during the pretreatment to promote the formation of hydroxyl groups.

When mixing the ethylene glycol solution and the phosphorus compound solution of the above aluminum compound, the mixing ratio of the aluminum compound and the phosphorus compound is preferably such that the molar ratio of the aluminum atom and the phosphorus atom is represented by the formula (1). .
0.5 ≦ P / Al (molar ratio) ≦ 20 (1)
Exceeding the range of the above formula (1) is not preferable because the polycondensation catalyst activity is lowered and the effect of suppressing the formation of foreign matters insoluble in the polyester is lowered. P / Al (molar ratio) is preferably 0.8 to 10, more preferably 1.0 to 5.

  By mixing an ethylene glycol solution of the above aluminum compound and a phosphorus compound solution, the NMR spectrum peak of the phosphorus atom to which the hydroxyl group is bonded shifts to the high magnetic field side. This is because the hydroxyl group in the phosphorus compound is aligned with the aluminum atom in the aluminum compound. It is presumed that it is caused by the formation of a complex.

  The method for storing the mixed solution of the aluminum compound and the phosphorus compound is not particularly limited. For example, in order to omit the storage tank, it is preferable to mix the solution immediately before the supply to the polyester production process. Although the mixing method is not limited, for example, a predetermined amount of each solution is extruded with a metering pump and mixed while stirring with a stirring mixer, or mixing in a static mixer or piping can be mentioned.

  When mixing and supplying in advance, it is preferable to store the mixed solution at 10 to 45 ° C. 15-40 degreeC is more preferable. When stored at a temperature higher than the temperature range, gelation of the aluminum compound or a complex of the aluminum compound and the phosphorus compound occurs. On the low temperature side, the fluidity of the mixed solution decreases due to precipitation of the phosphorus compound, and the polycondensation reaction. This is not preferable because it leads to an undesirable situation such as a decrease in the quantitativeness of the supply to the system. Although the storage method is not particularly limited, a solution obtained by stirring and mixing an ethylene glycol solution of an aluminum compound and an ethylene glycol of a phosphorus compound for 30 minutes so as to have a predetermined mixing ratio is once taken out and is within the above preferable temperature range. The method of storing in such a thermostat or a constant temperature room is mentioned.

  In the present invention, the mechanism that the content of foreign matter insoluble in polyester is reduced by satisfying the above requirements has not been clarified, but the hydroxyl group in the phosphorus compound is coordinated to the aluminum atom of the aluminum compound, and the aluminum compound It is presumed that the formation of a complex of a phosphorus compound is caused by the formation of foreign matters insoluble in the polyester derived from the aluminum compound.

  In the present invention, a polycondensation catalytic activity having high practicality can be expressed by using the above-mentioned aluminum or its compound in combination with a phosphorus compound, but it can be selected from a smaller amount of alkali metal, alkaline earth metal and compound thereof. It is a preferred embodiment that at least one of these is allowed to coexist as the second metal-containing component. The coexistence of such a second metal-containing component in the catalyst system is effective in improving productivity by obtaining a catalyst component having an increased reaction rate in addition to an effect of suppressing the formation of diethylene glycol, and thus a higher reaction rate. .

  A technique of adding an alkali metal compound or an alkaline earth metal compound to an aluminum compound to obtain a catalyst having sufficient catalytic activity is known. When such a known catalyst is used, a polyester having excellent thermal stability can be obtained. However, a known catalyst used in combination with an alkali metal compound or an alkaline earth metal compound is added in an amount to obtain practical catalytic activity. However, when an alkali metal compound is used, the hydrolysis resistance of the resulting polyester is reduced and the amount of foreign matter resulting from the alkali metal compound is increased. Moreover, when used for a film, the film properties and the like deteriorate. In addition, when an alkaline earth metal compound is used in combination, the thermal stability of the obtained polyester is lowered when it is attempted to obtain practical activity, coloring due to heating is large, the amount of foreign matter generated is increased, and water resistance is increased. Degradability also decreases.

When adding an alkali metal, an alkaline earth metal and a compound thereof, the amount M (mol%) used is 1 × 10 ⁻⁶ or more and 0.1 or more relative to the number of moles of all polycarboxylic acid units constituting the polyester. It is preferably less than mol%, more preferably 5 × 10 ^{−6 to} 0.05 mol%, still more preferably 1 × 10 ^{−5 to} 0.03 mol%, and particularly preferably 1 × 10 10. ^{-5 to} 0.01 mol%. Since the addition amount of alkali metal and alkaline earth metal is small, it is possible to increase the reaction rate without causing problems such as deterioration of thermal stability, generation of foreign substances, coloring, deterioration of hydrolysis resistance, etc. is there. When the amount M of the alkali metal, alkaline earth metal, or compound thereof is 0.1 mol% or more, the thermal stability decreases, the generation of foreign matter and coloring, and the hydrolysis resistance become problems in product processing. A case occurs. When M is less than 1 × 10 ⁻⁶ , the effect is not clear even when added.

  In the present invention, the alkali metal or alkaline earth metal constituting the second metal-containing component preferably used in addition to aluminum or a compound thereof includes Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr. , Ba is preferable, and among these, at least one selected from Li, Na, Mg or a compound thereof is more preferable. Examples of the alkali metal and alkaline earth metal compounds include saturated aliphatic carboxylates such as formic acid, acetic acid, propionic acid, butyric acid, and succinic acid, and unsaturated aliphatic carboxylates such as acrylic acid and methacrylic acid. , Aromatic carboxylates such as benzoic acid, halogen-containing carboxylates such as trichloroacetic acid, hydroxycarboxylates such as lactic acid, citric acid and salicylic acid, carbonic acid, sulfuric acid, nitric acid, phosphoric acid, phosphonic acid, hydrogen carbonate, phosphorus Inorganic acid salts such as acid hydrogen, hydrogen sulfide, sulfurous acid, thiosulfuric acid, hydrochloric acid, hydrobromic acid, chloric acid and bromic acid, and organic sulfonates such as 1-propanesulfonic acid, 1-pentanesulfonic acid and naphthalenesulfonic acid , Organic sulfates such as lauryl sulfate, methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, tert-butyl Alkoxides such as alkoxy, chelate compounds and the like acetylacetonate, hydrides, oxides, and hydroxides and the like.

  Among these alkali metals, alkaline earth metals or their compounds, when using strongly alkaline ones such as hydroxides, these tend to be difficult to dissolve in diols such as ethylene glycol or organic solvents such as alcohols. However, it must be added to the polymerization system in an aqueous solution, which may cause a problem in the polymerization process. Furthermore, when a strongly alkaline material such as a hydroxide is used, the polyester is liable to undergo side reactions such as hydrolysis during the polymerization, and the polymerized polyester tends to be colored, and the hydrolysis resistance also decreases. Tend to. Accordingly, the alkali metal or their compounds or alkaline earth metals or their compounds suitable for the present invention are preferably saturated aliphatic carboxylates, unsaturated aliphatic carboxylates, aromatics of alkali metals or alkaline earth metals. Aromatic carboxylates, halogen-containing carboxylates, hydroxycarboxylates, sulfuric acid, nitric acid, phosphoric acid, phosphonic acid, hydrogen phosphate, hydrogen sulfide, sulfurous acid, thiosulfuric acid, hydrochloric acid, hydrobromic acid, chloric acid, bromic acid Selected inorganic acid salts, organic sulfonates, organic sulfates, chelate compounds, and oxides. Among these, from the viewpoint of ease of handling, availability, and the like, it is preferable to use an alkali metal or alkaline earth metal saturated aliphatic carboxylate, particularly acetate.

  The polycondensation catalyst of the present invention is a polycondensation catalyst such as an antimony compound, a germanium compound, or a titanium compound, and the addition of these components does not cause problems in the product such as the characteristics, processability, and color tone of the polyester. Coexistence within the range of the addition amount is effective and preferable in improving productivity by shortening the polymerization time.

  The antimony compound is preferably added in an amount of 50 ppm or less as an antimony atom to the polyester obtained by polymerization. A more preferable addition amount is 30 ppm or less. When the amount of antimony added is 50 ppm or more, metal antimony is precipitated, and darkening and foreign matter are generated in the polyester.

  The germanium compound is preferably added in an amount of 20 ppm or less as germanium atoms to the polyester obtained by polymerization. A more preferable addition amount is 10 ppm or less. If the amount of germanium added is 20 ppm or more, it is not preferable because it is disadvantageous in terms of cost.

  The titanium compound is preferably added in an amount of 5 ppm or less as a titanium atom to the polyester obtained by polymerization. A more preferable addition amount is 3 ppm or less, and further preferably 1 ppm or less. If the amount of titanium added is 5 ppm or more, the resulting polyester is markedly colored, and the thermal stability is significantly reduced, which is not preferable.

  Although it does not specifically limit as an antimony compound which can be used in this invention, An antimony trioxide, an antimony pentoxide, an antimony acetate, an antimony glycoxide etc. are mentioned as a suitable compound, Especially use of antimony trioxide is preferable. Further, the germanium compound is not particularly limited, and examples thereof include germanium dioxide and germanium tetrachloride. Germanium dioxide is particularly preferable. As germanium dioxide, both crystalline and amorphous materials can be used.

  The titanium compound that can be used in the present invention is not particularly limited, but tetra-n-propyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, tetraisobutyl titanate, tetra-tert-butyl titanate, tetracyclohexyl titanate, tetra Phenyl titanate, tetrabenzyl titanate, lithium oxalate titanate, potassium oxalate titanate, ammonium oxalate titanate, titanium oxide, composite oxide of titanium and silicon, zirconium, alkali metal, alkaline earth metal, etc., titanium orthoester or Condensed ortho ester, titanium ortho ester or reaction product of condensed ortho ester and hydroxycarboxylic acid, titanium ortho ester or condensed ortho ester and hydroxy carbonate A reaction product composed of an acid and a phosphorus compound, a titanium ortho ester or a condensed ortho ester and a polyhydric alcohol having at least two hydroxyl groups, a reaction product composed of a 2-hydroxycarboxylic acid and a base, etc. Of these, a composite oxide of titanium and silicon, a composite oxide of titanium and magnesium, a reaction product composed of titanium orthoester or condensed orthoester, hydroxycarboxylic acid and phosphorus compound is preferable.

  In addition, as tin compounds, dibutyltin oxide, methylphenyltin oxide, tetraethyltin, hexaethylditin oxide, triethyltin hydroxide, monobutylhydroxytin oxide, triisobutyltin acetate, diphenyltin dilaurate, monobutyltin trichloride, dibutyltin sulfide, Examples thereof include dibutylhydroxytin oxide, methylstannoic acid, and ethylstannic acid, and the use of monobutylhydroxytin oxide is particularly preferable.

  In the polyester of the present invention, it is preferable to add a cobalt compound as a cobalt atom in an amount of less than 10 ppm with respect to the polyester for the purpose of improving the color tone. More preferably, it is 5 ppm or less, More preferably, it is 3 ppm or less. The cobalt compound is not particularly limited, and specific examples include cobalt acetate, cobalt nitrate, cobalt chloride, cobalt acetylacetonate, cobalt naphthenate, and hydrates thereof. Of these, cobalt acetate tetrahydrate is particularly preferred.

  In order to improve the color tone of the polyester of the present invention, it is also a preferred embodiment to use a color tone improving agent other than the cobalt compound. The color tone improving agent refers to a substance that changes color tone when added. The color tone improving agent of the present invention is not particularly limited, but inorganic and organic pigments, dyes, fluorescent whitening agents and the like are preferable.

  When a pigment or a dye is used, when the amount used is increased, there arises a problem that the brightness of the polycondensate decreases as a result. This causes the problem of being unacceptable for many applications. Therefore, the total amount of pigments and dyes used is preferably 20 ppm or less, more preferably 10 ppm or less, still more preferably 5 ppm or less, based on the polyester obtained. In such a region, the coloring can be effectively eliminated without reducing the brightness of the polycondensate.

  Further, it is preferable to use a fluorescent brightening agent alone or in combination with another color tone improving agent because the color tone is improved and, for example, the amount of the pigment or dye used may be small. As the fluorescent brightening agent, one kind of generally used brightening agent may be used, or two or more kinds thereof may be used in combination. The amount added is preferably 50 ppm or less, more preferably 5 to 25 ppm, based on the polyester obtained.

  The inorganic pigment of the present invention is not particularly defined as long as it can change the color tone, for example, titanium dioxide, carbon black, iron black, nickel titanium yellow, yellow iron oxide, cadmium yellow, chrome lead, chrome titanium yellow, Examples include zinc ferrite pigments, dials, cadmium red, molybdenum red, chromium oxide, spinel green, chrome orange, cadmium orange, ultramarine blue, bitumen, and cobalt blue. Of these, chromium oxide, ultramarine blue, bitumen, and cobalt blue are preferable, and ultramarine blue and cobalt blue are more preferable. One or more of these inorganic pigments may be used in combination as necessary.

  The organic pigments and dyes of the present invention are not specified as long as they can change the color tone, but, for example, Pigment Red 5, 22, 23, 31, 38, 48: 1, 48: 2 displayed by a color index. , 48: 3, 48: 4, 52, 53: 1, 57: 1, 122, 123, 144, 146, 151, 166, 170, 177, 178, 179, 187, 202, 207, 209, 213, 214 , 220, 221, 247, 254, 255, 263, 272, Pigment Orange 13, 16, 31, 36, 43, 61, 64, 71, Pigment Brown 23, Pigment Yellow 1, 3, 12, 13, 14, 17 , 55, 73 , 74, 81, 83, 93, 94, 95, 97, 109, 110, 128, 130, 133, 136, 138, 147, 150, 151, 154, 180, 181, 183, 190, 191, 191: 1 , 199, Pigment Green 7, 36, Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15.4, 15: 6, 29, 60, 64, 68, Pigment Violet 19, 23, 37, 44, Solvent Red 52, 117, 135, 169, 176, Disperse Red 5, Solvent Orange 63, 67, 68, 72, 78, Solvent Yellow 98, 103, 105, 113, 116, Di perseYellow 54, 64, 160, Solvent Green 3, 20, 26, Solvent Blue 35, 45, 78, 90, 94, 95, 104, 122, 132, Solvent Violet 31, and the like. Other anthraquinone, phthalocyanine, quinacridone, isoindolinone, dioxazine, quinophthalone, perylene, perinone, benzimidazolone, diarylide, bat, indigo, quinophthalone, diketopyrrolo Examples include pyrrole and anthrapyrrolidone dyes / pigments.

  Of these, Pigment Red 187, 263, Pigment Blue 15: 1, 15: 3, 29, 60, Pigment Violet 19, Solvent Red 135, Solvent Blue 45, 90, 104, 122, and anthraquinone and phthalocyanine dyes / Pigments are preferred. Furthermore, anthraquinone and phthalocyanine dyes / pigments are particularly preferred.

  The selected pigments and / or dyes preferably satisfy the following conditions. First, the pigments and dyes must be non-extractable from the polycondensate for maximum safety. It is stable to sunlight and a wide range of temperature and humidity conditions. Furthermore, it does not cause sublimation or hue changes as a result of the extremely high temperatures encountered during the production of polyester. Furthermore, it is preferable that these pigments and dyes do not adversely affect the physical properties of the polyester polymer.

  A pigment and / or a dye satisfying these conditions is not particularly limited as long as it improves the color tone of the polyester. For example, in Japanese Translation of PCT International Publication No. 2000-511111, a certain blue 1,4-bis (2,6-dialkylanilino) is used. ) Color tone improvers that mainly use anthraquinone and combine red anthraquinone and anthrapyridone (3H-dibenzo [fi, j] isoquinoline-2,7-dione) compounds according to the hue are exemplified. be able to. These dyes have suitable color characteristics, are stable to heat, light, humidity and various environmental factors and can be included in the polyester polymer structure during polycondensation, and are known organic dyes. Overcome many of the problems you encounter. It is stable to UV light, high temperature and hydrolysis. Furthermore, the amount of the blue component and the red component can be changed as necessary so as to work effectively for polyesters having different degrees of coloring.

  As the optical brightener of the present invention, those generally used may be used alone or in combination. For example, benzoxazoline-based fluorescent brighteners, preferably UVITEX OB, UVITEX OB-P, UVITEX OB-ONE, CHIARI Specialty Chemicals, Ltd., HOTALUX KS, manufactured by Clariant, and those described in JP-A-10-1563 Can be preferably used.

  Since the above-described color tone improving agent achieves an achromatic hue, it can be used in any combination of types and addition ratios. Further, the color tone improving agent may be added at any stage of the polycondensation, after the polycondensation reaction, or at any stage from the end of the polycondensation reaction to the time of molding. . Further, the addition method is preferably added after dissolving in powder or one of polyester monomers during polycondensation. Furthermore, after completion of the polycondensation reaction, it is preferably added as a powder or a master batch.

  Moreover, when a problem arises in the dispersibility of pigments or the like, it may be preferable to use a dispersant as necessary. The dispersant is not particularly defined as long as it aids in dispersing the pigment. For example, N, N′-ethylenebismyristic acid amide, N, N′-ethylenebisstearic acid amide, N, N′-ethylenebisoleic acid N, N′-methylenebismyristic acid amide, N, N′-methylenebisstearic acid amide, N, N′-methylenebisoleic acid amide, and other N, N′-alkylenebisfatty acid amides. Of these, N, N'-methylenebisstearic acid amide is preferable. The amount added depends on the performance, but it is 10 to 200% by mass, preferably 40 to 150% by mass, based on the pigment.

The polyester of the present invention preferably has a haze value of a uniaxially stretched film evaluated by the following evaluation method of 1.2% or less.
[Haze value of uniaxially stretched film]
The polyester resin was dried under vacuum at 130 ° C. for 12 hours and 1000 ±±
Create a 100 μm sheet. The heat press temperature, pressure and time are 320 ° C., 100 kg / cm ² G and 3 seconds, respectively. After pressing, the sheet is put into water and rapidly cooled. The obtained sheet is uniaxially stretched 3.5 times with a batch type stretching machine (manufactured by TM LONG CO., INC, FILM STRETCHER) to obtain a uniaxially stretched film of 300 ± 20 μm. The stretching temperature is blow temperature 95 ° C / plate temperature 100 ° C. The stretching speed is 15,000% / min. The haze of the obtained uniaxially stretched film is measured according to JIS-K7136 using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., 300A). The measurement is performed 5 times and the average value is obtained. The haze value is displayed as a converted value of a film thickness of 300 μm.
1.0% or less is more preferable, and 0.8% or less is more preferable. When the haze value exceeds 1.2%, it is not preferable because a highly transparent molded body cannot be obtained for a molded body formed by molding involving stretching of a film or a bottle.

  In the present invention, the method for setting the haze value of the uniaxially stretched film to 1.2% or less is not limited. However, the haze value is greatly affected by the amount of aluminum-based foreign matter insoluble in polyester and Tc1, so that the characteristic value is determined. It is preferable to optimize to the aforementioned range.

  The polyester production method in the present invention needs to be a continuous polycondensation method. The continuous polycondensation method is advantageous in terms of quality uniformity and economy compared to the batch polycondensation method. The continuous polycondensation method in the present invention is a so-called transesterification method which is produced by a reaction between an ester-forming derivative of a dicarboxylic acid and a diol, even if it is a so-called direct esterification method which is produced by a reaction between a dicarboxylic acid and a diol. It does not matter which of Further, the number and size of the reactors in the esterification, transesterification and polycondensation steps, production conditions in each step, and the like can be appropriately selected without limitation. As described above, the direct esterification method is advantageous and preferable from the viewpoint of economy.

The production method by the direct esterification method is exemplified below.
A slurry containing 1.02 to 1.5 moles, preferably 1.03 to 1.4 moles of ethylene glycol per mole of terephthalic acid was prepared, and this was continuously added to the esterification reaction step. To supply.

  The esterification reaction is carried out using a multistage apparatus in which 1 to 3 esterification reaction tanks are connected in series while removing water generated by the reaction from the system with a rectification column. The temperature of the esterification reaction in the first stage is 240 to 270 ° C., preferably 245 to 265 ° C., and the pressure is normal pressure to 0.29 MPa, preferably 0.005 to 0.19 MPa. The temperature of the esterification reaction at the final stage is usually 250 to 290 ° C, preferably 255 to 275 ° C, and the pressure is usually 0 to 0.15 MPa, preferably 0 to 0.13 MPa. When carried out in three or more stages, the reaction conditions for the esterification reaction in the intermediate stage are conditions between the reaction conditions for the first stage and the reaction conditions for the final stage. The increase in the reaction rate of these esterification reactions is preferably distributed smoothly at each stage. Ultimately, it is desirable that the esterification reaction rate reaches 90% or more, preferably 93% or more. A low-order condensate having a molecular weight of about 500 to 2000 is obtained by these esterification reactions. Subsequently, it is transferred to a polycondensation reaction tank to carry out polycondensation. The number of reaction tanks in the polycondensation step is not limited. In general, a three-stage system of initial polycondensation, intermediate polycondensation and late polycondensation is employed. As for the polycondensation reaction conditions, the reaction temperature of the first stage polycondensation is 250 to 290 ° C., preferably 260 to 280 ° C., and the pressure is 0.065 to 0.0026 MPa, preferably 200 to 30 Torr. The temperature of the polycondensation reaction is 265 to 300 ° C., preferably 275 to 295 ° C., and the pressure is 0.0013 to 0.000013 MPa, preferably 0.00065 to 0.000065 MPa. When carried out in three or more stages, the reaction conditions for the intermediate stage polycondensation reaction are conditions between the reaction conditions for the first stage and the reaction conditions for the last stage. The degree of increase in intrinsic viscosity achieved in each of these polycondensation reaction steps is preferably distributed smoothly.

  In the case of the transesterification method, the transesterification reaction is performed by continuously supplying, for example, dimethyl terephthalate and ethylene glycol to the reactor using an apparatus in which one or two transesterification reactors are connected in series. The methanol produced by the reaction is removed from the system by a rectification column. The temperature of the first stage transesterification is 180 to 250 ° C, preferably 200 to 240 ° C. The temperature of the transesterification reaction at the final stage is usually 230 to 270 ° C, preferably 240 to 265 ° C. As the transesterification catalyst, it is preferable to use fatty acid salts such as Zn, Cd, Mg, Mn, Co, Ca, Ba, carbonates, and the like.

  In this invention, it is preferable to add the solution which mixed the above-mentioned aluminum compound and phosphorus compound after completion | finish of esterification reaction or transesterification. This suppresses the formation of aluminum-based foreign matters that are insoluble in the polyester. Further, since the polyester having a high Tc1 can be stably obtained when the separated and collected phosphorus compound is not recycled, the ratio of the reuse of the separated and collected phosphorus compound, which is one of the major features of the present invention, is adjusted. This leads to the stability of controlling Tc1 of the polyester in a wide range.

  As long as the mixed solution is added after completion of the esterification reaction or transesterification reaction, the addition location and addition method are not limited. For example, it may be added to the transfer pipe from the esterification reactor or transesterification reactor to the polycondensation reactor, or it may be added in the polycondensation step, but from the esterification reactor or transesterification reactor It is a preferred embodiment to add to an in-line mixer installed in the transfer tube to the polycondensation reactor. This method is preferable because the added phosphorus compound and the esterification reaction or transesterification product can be mixed uniformly, and the effects of the present invention can be expressed more efficiently. The structure of the in-line mixer used in this method is not limited as long as a uniform mixing effect can be exhibited. For example, an in-line mixer for the purpose of dispersing and mixing the slurry disclosed in JP-A-8-299771 is suitable.

  In the case of adding to the polycondensation reaction tank, in order to prevent the scattering of the additive, for example, a capsule addition method in which the mixed solution is enclosed in a container made of the same polyester as the production target and added is a preferred embodiment. .

  Moreover, since Tc1 of polyester tends to change depending on the temperature of the polycondensation step after adding the above mixed solution, it is better to increase the temperature control of the addition place, the subsequent transfer pipe and the polycondensation step.

  In the present invention, when polycondensation of polyester is carried out by the above method, it is distilled together with a distillate such as glycol from which a part of the phosphorus compound is distilled into the polycondensation reaction system. Therefore, when the distillate glycol is reused, it is necessary to prevent or control the mixing of the phosphorus compound in the recovered glycol. Also in the polycondensation catalyst system of the present invention, the amount of the phosphorus compound greatly affects the polycondensation catalyst activity. In addition, if the phosphorus compound is circulated in the initial stage of the reaction such as the esterification slurry, the production of aluminum-insoluble foreign matters that are insoluble in the polyester is increased, which leads to undesirable effects such as a decrease in transparency of the molded body. Further, when a compound containing a hindered phenol residue such as Chemical Formula 39 or Chemical Formula 40 is used as the phosphorus compound, the structural change of the distilling phosphorus compound occurs, and the modified phosphorus compound is mixed into the polyester. Then, the effect | action that Tc1 of polyester falls is expressed. The cause of this is unknown, but it is presumed that the elimination of the t-butyl group in the hindered phenol residue is involved. Therefore, when the phosphorus compound is recycled and reused without separating and removing, a polyester having a low Tc1 is obtained.

  The present invention is linked to a technique for controlling the Tc1 of the polyester in a wide range by utilizing the effect of lowering the Tc1 of the polyester by the phosphorus compound having a structural change distilled together with the glycol. That is, it occurs when the distilled phosphorus compound is separated and recovered, the recovered phosphorus compound is used as the phosphorus compound constituting the polycondensation catalyst, and the phosphorus compound is reused without being separated and recovered. Establishing technology to produce polyester with desired Tc1 by changing Tc1 by avoiding reduction of polycondensation catalytic activity and generation of aluminum-based foreign matters insoluble in polyester and changing the ratio of recovered phosphorus compound did.

That is, the distillate (A) distilled from the reaction tank to which the phosphorus compound is added and the subsequent reaction tanks is obtained by fractionating and removing the low-boiling fraction mainly composed of water and the high-boiling fraction containing the phosphorus compound and the like. The middle distillate is reused as part or all of the glycol for polyester production, and the high boiling fraction containing the phosphorus compound (hereinafter referred to as recovered phosphorus compound fraction) is used as part or all of the phosphorus compound. It is preferable to do.
In this case, the distillate (A) is subjected to fractional removal of a low-boiling fraction mainly composed of water, and the residue is reused as a part or all of the glycol for the esterification reaction. In the case of carrying out the method according to the method described in 1., it is not preferable because the phosphorus compound whose structure is changed is mixed into the recovered glycol and has the above-mentioned adverse effects.

  In this case, what is necessary is just to set suitably the usage-ratio as a polycondensation catalyst component of a collection | recovery phosphorus compound fraction so that it may become Tc1 requested | required as polyester manufactured. The range of Tc1 of the polyester controlled by this method varies depending on the polyester structure, the type of phosphorus compound used and the polycondensation catalyst conditions, etc., but the polyester is PET and contains a hindered phenol residue as the phosphorus compound. When used, the temperature is 140 to 167 ° C. If a phosphonic acid phosphorus compound that increases Tc1 is used in combination, a polyester having a higher Tc1 can be obtained.

  As described above, when the distillated phosphorus compound having a changed structure is circulated in the initial part of the polyester production process, the polycondensation catalyst activity decreases and the generation of aluminum-based foreign matters insoluble in the polyester increases. When the separation is carried out by a method in which the aluminum compound solution and the phosphorus compound solution, which is a preferred embodiment of the present invention, are mixed and added to the polycondensation step, the above adverse effects are suppressed.

  In the present invention, the distillate (A) may be obtained by fractionating a low-boiling fraction and a high-boiling fraction at the same time with one distillation column, or by dividing the distillation column into two groups, with water as the main component. After the low-boiling fraction is removed by fractional distillation, the high-boiling fraction containing a phosphorus compound or the like may be fractionally removed by fractional distillation again. The latter is preferred because it allows efficient distillation.

  On the other hand, since the phosphorus compound is not mixed in the distillate distilled from the reaction tank before the phosphorus compound is added, the distillate distilled from the reaction tank before the phosphorus compound is added and the reaction in which the phosphorus compound is added The distillate distilled from the tank and the subsequent reaction tanks is preferably treated separately. Processing the two separately has a great impact on the economy, that is, the reduction of operating costs and the simplification of equipment.

  The distillate (A) distilled from the reaction vessel before adding the phosphorus compound is obtained by fractionating and removing the low-boiling fraction mainly composed of water, and using the residue as part or all of the glycol for polyester production. It is preferable to reuse.

  When distillate (B) is reused as part or all of the glycol for esterification reaction, the distillate (B) is the same as distillate (A). Is not preferable because the treatment of the distillate (A) becomes excessive, leading to an increase in equipment and operating costs, which is economically disadvantageous. In general, since the amount of the distillate (B) is larger than that of the distillate (A), the economic effect of carrying out by separating both of the methods of the present invention is great.

  As described above, it is one of the major features of the present invention that the distillate (A) and the distillate (B) are separated and processed. Accordingly, it is a preferred embodiment that the phosphorus compound is added to the second esterification reactor and / or thereafter.

  In the present invention, it is preferable to continuously remove the low-boiling fraction of the distillate from the esterification reaction tank by the heat of the distillate itself. Therefore, it is preferable to carry out in-line. This can further reduce operating costs and simplify equipment. If necessary, auxiliary heating by heating or exchanging piping is not excluded. On the other hand, since the distillate from the polycondensation reaction tank is generally recovered by being cooled and condensed in a wet condenser, it is heated and supplied to the distillation column. Therefore, distillation of the distillate from the polycondensation reaction tank may be carried out batchwise.

  The performance of each distillation column for removing the low-boiling fraction and removing the high-boiling fraction is preferably 8 to 15 for the former and 20 to 30 for the latter. Either a bubble column or a packed column may be used. The reflux ratio is appropriately set depending on the performance of the distillation column and the required quality of the recovered glycol.

  In the present invention, when the recovered glycol is ethylene glycol, the low boiling point impurities are mainly those having a boiling point of 165 ° C. or less other than water, acetaldehyde, 2-methyl-1,3-dioxolane, methyl cellosolve or these compounds. It becomes a target.

The method for reusing the glycol recovered by the above method is not limited. After storage in a glycol storage tank, it is preferably reused as a glycol for polyester production. Distillate (A)
And the recovered glycol from (B) may be stored in separate storage tanks or in a lump. Moreover, you may use in the collect | recovered plant and may use it in another plant.

  There is no restriction | limiting in the usage rate of collection | recovery glycol, It can set and use suitably. Polyester may be produced using the entire amount of recovered glycol.

  In the direct esterification method, 90 to 95% of the amount of distillate distilled in the polyester production process is generated in the esterification process, although there are some fluctuations depending on the polyester production conditions. In the present invention, since the phosphorus compound is preferably added after the esterification reaction or transesterification reaction, the fraction containing no phosphorus compound in the distillate accounts for the overwhelming majority. In the present invention, for the fraction that occupies the overwhelming majority, it is only necessary to cut the low-boiling fraction, and since this distillation can be distilled by the amount of heat that the distillate itself has, the operating cost can be reduced and the equipment The effect on simplification is greatly expressed. Therefore, the economic effect is great.

  The esterification or transesterification reaction conditions, the characteristics of the low-order condensate of the product, and the polycondensation reaction conditions in the present invention may be appropriately set in consideration of the quality and productivity of the polyester.

  In the present invention, the use of recycled raw materials such as terephthalic acid, dimethyl terephthalate, or ethylene glycol obtained by the chemical decomposition recovery method for recovered PET bottles is a preferred embodiment because it helps save resources and protects the environment.

  The polyester obtained by the method of the present invention is heated under reduced pressure or under an inert gas stream to further proceed with polycondensation, an oligomer such as a cyclic trimer contained in the polyester resin, acetaldehyde, etc. There are no restrictions on taking measures such as removing the by-products. Further, for example, it is possible to incorporate a treatment such as purifying a polyester resin by an extraction method such as a supercritical pressure extraction method to remove impurities such as the by-products.

  The polyester of the present invention can contain organic, inorganic, and organometallic toners, and a fluorescent brightening agent. By containing one or more of these, the yellowness of the polyester, etc. Can be suppressed to an even better level. It also contains other optional polymers, antistatic agents, antifoaming agents, dyeability improvers, dyes, pigments, matting agents, fluorescent brighteners, stabilizers, antioxidants, and other additives. Also good. As antioxidants, aromatic amine-based and phenol-based antioxidants can be used, and as stabilizers, phosphoric acid and phosphate ester-based phosphorus-based, sulfur-based, amine-based stabilizers, etc. Can be used.

  These additives can be added at any stage during or after polymerization of the polyester, or at the time of molding the polyester. Which stage is suitable depends on the structure of the target polyester and the requirements of the resulting polyester. What is necessary is just to select suitably according to performance, respectively.

  The polyester obtained by the above method can produce fibers by a conventional melt spinning method, and a method of spinning and stretching in two steps and a method of performing in one step can be adopted. Furthermore, all known fiber manufacturing methods such as staple manufacturing methods and monofilaments with crimping, heat setting and cutting steps can be applied.

  The obtained fibers can be made into various fiber structures such as atypical cross-section yarns, hollow cross-section yarns, composite fibers, original yarns, etc., and well-known means such as blending, blending, etc. can also be used in yarn processing. Can do.

  Furthermore, the polyester fiber can be made into a fiber structure such as a woven or knitted fabric or a non-woven fabric.

  The above polyester fibers are used for interior and bedding fibers such as clothing fibers, curtains, carpets, futons, fiber fills, tensile cords such as tire cords and ropes, civil engineering and building materials, and vehicles such as airbags. It can be used for various fiber applications such as fibers for industrial materials represented by materials, various fabrics, various knitted fabrics, nets, short fiber nonwoven fabrics, and long fiber nonwoven fabrics.

  The polyester of the present invention is suitably used as a hollow molded body.

  Examples of the hollow molded body include mineral water, juice, beverage containers such as wine and whiskey, milk bottles, bottled food containers, containers for hairdressing products and cosmetics, housing and dishwashing detergent containers, and the like.

  Among these, polyester is particularly suitable for various beverages as a pressure-resistant container, a heat-resistant pressure-resistant container, and an alcohol-resistant container utilizing the hygiene and strength and solvent resistance of polyester. The hollow molded body is manufactured by a method in which a polyester chip obtained by melt polymerization or solid phase polymerization is dried by a vacuum drying method or the like, and then molded by a molding machine such as an extrusion molding machine or an injection molding machine, or melted after melt polymerization. A preform with a bottom is obtained by a direct molding method in which the body is introduced into a molding machine in a molten state and molded. Further, a final hollow molded body can be obtained by blow molding such as stretch blow molding, direct blow molding, and extrusion blow molding. Of course, a molded product obtained by a molding machine such as the above-described extrusion molding machine or injection molding machine can be used as a final hollow container.

  When manufacturing such a hollow molded body, waste resin generated in the manufacturing process or polyester resin recovered from the market can be mixed. Even with such a recycled resin, the polyester resin of the present invention is less deteriorated and a high-quality hollow molded product can be obtained.

  Further, such a container can have a multilayer structure in which an intermediate layer is provided with a gas barrier resin layer such as polyvinyl alcohol or polymetaxylylenediamine adipate, a light shielding resin layer or a recycled polyester layer. It is also possible to coat the inside and outside of the container with a metal such as aluminum or a layer of diamond-like carbon using a method such as vapor deposition or CVD (chemical vapor deposit).

  In addition, in order to raise crystallinity, such as a plug part of a hollow molded object, inorganic nucleating agents, such as other resin including polyethylene and talc, can also be added.

  Further, the polyester of the present invention can be extruded into a sheet-like material from an extruder to form a sheet. Such sheets are processed by vacuum forming, pressure forming, stamping, etc., and used as trays and containers for food and sundries, cups, blister packs, carrier tapes for electronic components, and electronic component delivery trays. The sheet can also be used as various cards.

  Even in the case of these sheets, it is also possible to take a multilayer structure in which a gas barrier resin layer, a light shielding resin layer, and a recycled polyester layer are provided on the intermediate layer as described above.

  Similarly, recycled resin can be mixed. Furthermore, for the purpose of forming a crystalline heat-resistant container, other resins such as polyethylene and inorganic nucleating agents such as talc can be added to enhance crystallinity.

  The polyester obtained by the polyester production method of the present invention can be used for a film. In this method, polyester is melt-extruded and formed into a sheet shape from a T-die on a cooling rotary roll to create an unstretched sheet. In this case, for example, by applying the technique described in Japanese Patent Publication No. 6-39521 and Japanese Patent Publication No. 6-45175, high-speed film formation is possible. Moreover, it is good also as a laminated | multilayer film by a coextrusion method by using a some extruder and sharing various functions in a core layer and a skin layer.

  The polyester obtained by the polyester production method of the present invention can be used for an oriented polyester Ttel film. The oriented polyester film can be obtained by stretching 1.1 to 6 times at least in the uniaxial direction at a temperature not less than the glass transition temperature of the polyester and less than the crystallization temperature using a known method.

  For example, in the case of producing a biaxially oriented polyester film, a sequential biaxial stretching method in which uniaxial stretching is performed in the longitudinal direction or the transverse direction and then stretching in the orthogonal direction, and a simultaneous biaxial stretching method in which stretching is performed in the longitudinal direction and the transverse direction simultaneously. In addition to using a linear motor as the driving method for simultaneous biaxial stretching, several times in the same direction, such as horizontal / longitudinal / longitudinal stretching, longitudinal / horizontal / longitudinal stretching, and longitudinal / vertical / horizontal stretching It is possible to adopt a multistage stretching method in which the stretching is performed separately.

  Furthermore, in order to reduce the thermal shrinkage rate of the film after stretching, a heat setting treatment is performed within 30 seconds, preferably within 10 seconds, at a temperature from (melting point−50 ° C.) to less than the melting point. % Longitudinal relaxation treatment, lateral relaxation treatment, etc. are preferably performed.

  The obtained oriented polyester film has a thickness of preferably 1 μm or more and 1000 μm or less, more preferably 5 μm or more and 500 μm or less, and more preferably 10 μm or more and 200 μm or less. If it is less than 1 μm, it is difficult to handle because there is no waist. Moreover, when it exceeds 1000 micrometers, it is too hard and handling is difficult.

  In addition, in order to provide various functions such as adhesion, releasability, antistatic properties, infrared absorption, antibacterial properties, scratch resistance, etc., the surface of the oriented polyester film may be coated with a polymer resin by a coating method. Good. Moreover, it is good also as a slippery highly transparent polyester film by making an inorganic and / or organic particle | grain contain only in a coating layer. Furthermore, an inorganic vapor deposition layer can be provided to provide various barrier functions such as oxygen, water, and oligomer, or a conductive layer can be provided by a sputtering method or the like to provide conductivity. In addition, inorganic and organic salt particles or heat-resistant polymer resin particles are added in the polyester polymerization process in order to improve the handling properties such as slipping property, running property, wear resistance, and winding property of the oriented polyester film. Then, irregularities may be formed on the film surface. These particles may be either inorganic / organic or hydrophilic / hydrophobic surface-treated or non-surface-treated particles. For example, particles that have been surface-treated for the purpose of improving dispersibility. There are cases where it is preferable to use.

  Inorganic particles include calcium carbonate, kaolin, talc, magnesium carbonate, barium carbonate, calcium sulfate, barium sulfate, lithium phosphate, calcium phosphate, magnesium phosphate, aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, lithium fluoride, Examples include sodium calcium aluminum silicate.

  Examples of the organic salt particles include terephthalate such as calcium oxalate, calcium, barium, zinc, manganese, and magnesium.

    Examples of the crosslinked polymer particles include homopolymers or copolymers of vinyl monomers of divinylbenzene, styrene, acrylic acid, methacrylic acid, acrylic acid or methacrylic acid. In addition, organic particles such as polytetrafluoroethylene, benzoguanamine resin, thermosetting epoxy resin, unsaturated polyester resin, thermosetting urea resin, and thermosetting phenol resin may be used.

    The method for incorporating the inert particles in the polyester that is the base film is not limited, but (a) the inert particles are dispersed in a slurry form in a diol that is a polyester component, A method of adding polyester to a polymerization reaction system, (b) a method of adding a water slurry of inert particles dispersed in a molten polyester resin by a vented twin screw extruder in a melt extrusion process of a polyester film, and (c) polyester Examples include a method of kneading a resin and inert particles in a molten state (d) a method of kneading a polyester resin and a master resin of inert particles in a molten state.

  In the case of the method of adding to the polymerization reaction system, it is preferable to add the diol slurry of inert particles to the reaction system having a low melt viscosity before the esterification reaction or transesterification reaction and before the start of the polycondensation reaction. Moreover, when preparing the diol slurry of inert particles, it is preferable to perform a physical dispersion treatment such as a high-pressure disperser, a bead mill, or ultrasonic dispersion. Furthermore, in order to stabilize the dispersion-treated slurry, it is preferable to use an appropriate chemical dispersion stabilization treatment according to the type of particles used.

  As the dispersion stabilization treatment, for example, in the case of inorganic oxide particles or crosslinked polymer particles having a carboxyl group on the particle surface, an alkali compound such as sodium hydroxide, potassium hydroxide or lithium hydroxide is added to the slurry. Further, reaggregation between particles can be suppressed by electrical repulsion. In the case of calcium carbonate particles, hydroxyapatite particles, etc., it is preferable to add sodium tripolyphosphate or potassium tripolyphosphate to the slurry.

  In addition, when adding the diol slurry of inert particles to the polyester polymerization reaction system, heat treatment of the slurry to near the boiling point of the diol can also be applied to heat shock (addition between the slurry and the polymerization reaction system). (Temperature difference) can be reduced, which is preferable in terms of dispersibility of the particles.

  The oriented polyester film of the present invention is preferably an antistatic film, an easily adhesive film, a card, a dummy can, an agricultural product, a building material, a cosmetic material, a wallpaper, an OHP film, a printing, and an inkjet recording. For sublimation transfer recording, laser beam printer recording, electrophotographic recording, thermal transfer recording, thermal transfer recording, printed circuit board wiring, membrane switch, plasma display, touch panel, masking film, photoengraving, For X-ray film, For photographic negative film, For retardation film, For polarizing film, For polarizing film protection (TAC), For protective film, For photosensitive resin film, For field of view expansion film, For diffusion sheet, For reflection film, Reflection For prevention film, conductive film, separator, UV protection, back glass It is used, for example, for Ndotepu.

  As the antistatic film, for example, the techniques described in Japanese Patent No. 2952677 and Japanese Patent Application Laid-Open No. 6-184337 can be used. Examples of the easy-adhesive film include JP-B-07-108563, JP-A-10-235820, and JP-A-11-323271, and examples of cards include those described in JP-A-10-171856 and JP-A-11-010815. The technique can be applied to the film of the present invention. For the dummy can, for example, instead of the sheet-like cylinder described in Japanese Patent Application Laid-Open No. 10-101103, a design obtained by printing a design on the film of the present invention to form a cylinder or a half cylinder can be used. As a building material, a decorative plate for building material, and a decorative material, for example, the film of the present invention is used as a base sheet described in JP-A No. 05-200927 and a transparent sheet described in JP-A No. 07-314630. it can. As the OHP (for overhead projector), the film of the present invention can be used as the transparent resin sheet described in JP-A-06-297831 and the transparent polymer synthetic resin film described in JP-A-08-305065. For inkjet recording, for example, the film of the present invention can be used as a transparent substrate described in JP-A No. 05-032037. For sublimation transfer recording, for example, the film of the present invention can be used as a transparent film described in JP-A No. 2000-025349. For laser beam printers and electrophotographic recording, for example, the film of the present invention can be used as a plastic film described in JP-A-05-088400. For thermal transfer recording, the film of the present invention can be used by the methods described in JP-A-07-032754, for thermal recording, and JP-A-11-034503, respectively. For printed circuit boards, for example, the film of the present invention can be used as a polyester film described in JP-A No. 06-326453. For the membrane switch, the film of the present invention can be used, for example, by the method described in JP-A No. 05-234459. As the optical filter (for heat ray filter and plasma display), for example, the film of the present invention can be used by the method described in JP-A-11-231126. For a transparent conductive film and a touch panel, the film of the present invention can be used, for example, by the method described in JP-A-11-224539. For the masking film, the film of the present invention can be used, for example, by the method described in JP-A No. 05-273737. For photoengraving, for example, the film of the present invention can be used by the method described in JP-A No. 05-057844. As a photographic negative film, for example, the film of the present invention can be used as a polyethylene terephthalate film described in paragraph No. (0123) of JP-A No. 06-167768. For a phase difference film, for example, the film of the present invention can be used as a film described in JP-A No. 2000-162419. For the separator, for example, the film of the present invention can be used as the film described in paragraph No. (0012) of JP-A No. 11-209711. For preventing ultraviolet rays, for example, the film of the present invention can be used as a polyester film described in JP-A-10-329291. An agricultural film can be obtained by applying the film of the present invention to a polyethylene terephthalate film described in JP-A-10-166534. The pressure-sensitive adhesive sheet can be obtained, for example, by applying the oriented polyester film of the present invention to a polyethylene terephthalate film described in JP-A-06-122856.

  Even in the case of these sheets, it is also possible to take a multilayer structure in which a gas barrier resin layer, a light shielding resin layer, and a recycled polyester layer are provided on the intermediate layer as described above.

  Similarly, recycled resin can be mixed. Furthermore, for the purpose of forming a crystalline heat-resistant container, other resins such as polyethylene and inorganic nucleating agents such as talc can be added to enhance crystallinity.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not restrict | limited to these Examples. In addition, the evaluation method was implemented with the following method.

1. Measurement of NMR spectrum of ethylene glycol solution of aluminum compound NMR spectrum of ethylene glycol solution of aluminum compound was measured by the following method.
Sample: Ethylene glycol solution of aluminum compound (concentration: source of aluminum)
2.65g / l as a basic quantity)
Apparatus: Fourier transform nuclear magnetic resonance apparatus (AVANCE500 manufactured by BRUKER)
Measurement solution: 20 parts by volume of deuterated dimethyl sulfoxide with respect to 80 parts by volume of the sample
Add
²⁷ Al resonance frequency: 130.33 MHz
Detection pulse flip angle: 90 °
Data acquisition time: 1.0 seconds Delay time: 1.0 seconds Proton decoupling: not implemented Integration count: 500-1000 times Measurement temperature: room temperature On the other hand, aluminum chloride hexahydrate (AlCl ₃ .6H ₂ O) The peak integral value when measuring a 1.3 mmol / l heavy aqueous solution under the above conditions is 1.0 as a standard, and the peak integral appearing at −15 to 30 ppm of the ethylene glycol solution of the aluminum compound measured by the above method Displayed as a ratio of values.

2. Method for measuring NMR spectrum of mixed solution of aluminum compound and phosphorus compound Apparatus: Fourier transform nuclear magnetic resonance apparatus (AVANCE500 manufactured by BRUKER)
Measurement solution: 20 parts by volume of deuterated dimethylsulfoxy with respect to 80 parts by volume of the sample
Added.
³¹ P resonance frequency: 202.47 MHz
Detection pulse flip angle: 45 °
Data acquisition time: 2.0 seconds Delay time: 0.5 seconds Proton decoupling: Proton complete decoupling Integration count: 2000 to 10000 times Measurement temperature: Room temperature

3. Measurement of intrinsic viscosity (IV) It measured at 30 degreeC using the phenol / tetrachloroethane (60:40, weight ratio) mixed solvent.

4. Measurement of Tc1 Measurement was performed using a DSC50 manufactured by Shimadzu Corporation. 10.0 mg of polyester is put into an aluminum pan, heated from room temperature to 300 ° C. at a heating rate of 20 ° C./min in a nitrogen atmosphere, held for 3 minutes after reaching 300 ° C., and immediately removed from the pan. Quenched in liquid nitrogen. The droplets adhering to the surface were removed by blowing air with an air nozzle. Thereafter, the aluminum pan containing the sample was again heated from 25 ° C. to 300 ° C. at a rate of temperature increase of 20 ° C./min, and the crystallization temperature (Tc1) at the time of temperature increase was determined. The temperature at the maximum part of the exothermic peak was defined as Tc1.

5. Color tone Using a polyester resin chip (length: about 3 mm, diameter: about 3 mm), a color difference meter (manufactured by Tokyo Denshoku Co., Ltd .: Model ND-1001DP) was used to measure the L value and b value of the hunter.

6. Evaluation method of aluminum insoluble matter insoluble in polyester 30g of polyester pellets after melt polycondensation and 300ml of parachlorophenol / tetrachloroethane (3/1: weight ratio) mixed solution are put into a screw-lens Erlenmeyer flask and the pellets are mixed The solution was stirred and dissolved in a sealed state at 60 to 80 ° C. for 2 hours. While maintaining the solution at 50 to 70 ° C., foreign matter was filtered off under reduced pressure using a membrane filter made of polytetrafluoroethylene having a diameter of 47 mm / pore size of 1.0 μm (PTFE membrane filter manufactured by Advantec, product name: T100A047A). . The effective filtration diameter was 37.5 mm. After completion of the filtration, the product was subsequently washed with 50 ml of chloroform, and then the filter was dried at 80 ° C. for 2 hours under normal pressure. The amount of aluminum element was quantified on the filtration surface of the membrane filter with a scanning fluorescent X-ray analyzer (manufactured by RIGAKU, ZSX100e, Rh tube 4.0 kW). The quantification was performed on a portion having a diameter of 30 mm at the center of the membrane filter. The calibration curve of the X-ray fluorescence analysis was determined using a polyethylene terephthalate resin having a known aluminum element content, and the apparent aluminum element amount was expressed in ppm. The measurement was carried out by measuring the intensity of Al-Kα rays under the conditions of PHA (wave height analyzer) 100-300 using X-ray output 50 kV-70 mA and using pentaerythritol as a spectroscopic crystal and PC (proportional counter) as a detector. . The amount of aluminum element in the polyethylene terephthalate resin for the calibration curve was determined by high frequency inductively coupled plasma optical emission spectrometry. 7. Haze value of uniaxially stretched film Polyester resin was dried at 130 ° C. for 12 hours under vacuum, and 1000 by heat press method. ±
Create a 100μm sheet. The heat press temperature, pressure and time were 320 ° C., 100 kg / cm ² G and 3 seconds, respectively. After pressing, the sheet was put into water and rapidly cooled. The obtained sheet was uniaxially stretched 3.5 times by a batch type stretching machine (manufactured by TM LONG CO., INC, FILM STRETCHER) to obtain a uniaxially stretched film of 300 ± 20 μm. The stretching temperature was blow temperature 95 ° C./plate temperature 100 ° C. The stretching speed was 15,000% / min. The haze of the obtained uniaxially stretched film was measured according to JIS-K7136 using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., 300A). In addition, the measurement was performed 5 times and the average value was calculated | required. The haze value was displayed as a converted value of a film thickness of 300 μm.

Example 1
(1) Preparation of polycondensation catalyst solution (Preparation of ethylene glycol solution of phosphorus compound)
After adding 2.0 liters of ethylene glycol to a flask equipped with a nitrogen introduction tube and a cooling tube at room temperature and normal pressure, while stirring at 200 rpm in a nitrogen atmosphere, Irganox 1222 (Ciba 39) represented by -200 g of Specialty Chemicals) was added. Further, 2.0 liters of ethylene glycol was added, the temperature was raised by changing the jacket temperature setting to 196 ° C., and the mixture was stirred under reflux for 60 minutes from the time when the internal temperature reached 185 ° C. or higher. Thereafter, the heating was stopped, the solution was immediately removed from the heat source, and the solution was cooled to 120 ° C. or less within 30 minutes while maintaining the nitrogen atmosphere. The mole fraction of Irganox 1222 in the obtained solution was 40%, and the mole fraction of the compound whose structure changed from Irganox 1222 was 60%.
(Preparation of aqueous solution of aluminum compound)
After adding 5.0 liters of pure water to a flask equipped with a cooling tube at room temperature and normal pressure, 200 g of basic aluminum acetate was added as a slurry with pure water while stirring at 200 rpm. Further, pure water was added so as to be 10.0 liters as a whole, and the mixture was stirred at room temperature and normal pressure for 12 hours. Thereafter, the jacket temperature was changed to 100.5 ° C., the temperature was raised, and the mixture was stirred under reflux for 3 hours from the time when the internal temperature reached 95 ° C. or higher. Stirring was stopped and the mixture was allowed to cool to room temperature to obtain an aqueous solution.
(Preparation of ethylene glycol mixed solution of aluminum compound)
After adding an equal volume of ethylene glycol to the aqueous aluminum compound solution obtained by the above method and stirring for 30 minutes at room temperature, the internal temperature is controlled to 80 to 90 ° C., and the pressure is gradually reduced to reach 27 hPa, while stirring for several hours. Water was distilled off from the system to obtain an ethylene glycol solution of an aluminum compound at 20 g / l. The peak integrated value ratio of ²⁷ Al-NMR spectrum of the obtained aluminum solution was 2.2.

(2) Esterification reaction and polycondensation A high-speed stirrer is provided in the transfer line from the second esterification reaction tank to the first polycondensation reaction tank, comprising two continuous esterification reaction tanks and three polycondensation reaction tanks. First-esterification by continuously supplying slurry prepared by mixing 0.45 parts by mass of ethylene glycol with 1 part by mass of high-purity terephthalic acid in a continuous polyester production apparatus equipped with an in-line mixer having The reaction time in the first and second esterification reaction tanks is adjusted at a reaction temperature of 250 ° C. and 0.1 MPa, the second esterification reaction tank is 250 ° C. and 0.1 MPa, and the second esterification reaction tank is used. Ethylene glycol was added to obtain a polyester oligomer. AVO and OHVo of the oligomer at the outlet of the first esterification reactor were 1600 eq / ton and 1400 eq / ton, respectively. The oligomers AVO and OHVo at the outlet of the second esterification reactor were 650 eq / ton and 1520 eq / ton, respectively, and OHV% was 70 mol%. The oligomer is continuously transferred to a continuous polycondensation apparatus comprising three reaction tanks, and the ethylene glycol solution of the aluminum compound and the ethylene glycol solution of the phosphorus compound prepared by the above method in an in-line mixer installed in the transfer line. (A solution obtained by mixing an ethylene glycol solution of a phosphorus compound prepared by the above method and a recovered phosphorus compound fraction obtained by the following method in a phosphorus element amount ratio of 97: 3 mass ratio) with respect to each acid component in the polyester Then, it is continuously added while stirring with a stirring mixer so as to be 0.015 mol% and 0.036 mol% as aluminum atoms and phosphorus atoms, and the initial polycondensation reactor is 265 ° C., 0.009 MPa, medium period The polycondensation reactor is 265-275 ° C., 0.0067 MPa, and the final polycondensation reactor is 270-2. Polycondensation was performed at 80 ° C. and 0.0000133 MPa to obtain PET with an IV of 0.62. The characteristic values of the obtained PET are shown in Table 2. The NMR spectrum of the mixed solution of the aluminum compound solution and the phosphorus compound solution at the outlet of the stirring mixer does not exist in the spectrum of the ethylene glycol solution of the phosphorus compound before mixing with the ethylene glycol solution of the aluminum compound. A broad peak (referred to as coordination peak) was observed in the range of. The integral value of the coordination peak is that of the NMR spectrum peak of the phosphorus atom bonded with a hydroxyl group observed in the vicinity of 25 to 27 ppm present in the NMR spectrum of the ethylene glycol solution of the phosphorus compound before mixing with the ethylene glycol solution of the aluminum compound. It was 46% with respect to the integrated value.

The flow of ethylene glycol in the polyester production process is shown in FIG.
Fresh ethylene glycol and recovered ethylene glycol supplied to the slurry preparation tank 2 are in a mass ratio of 0.4: 0.6.

  The distillate distilled from the first esterification reaction tank 3 and the second esterification reaction tank 4 is supplied to a bubble-bell type distillation column 10 having 15 stages to remove low boiling fractions mainly composed of water, It is supplied to the ethylene glycol reservoir 17. The ethylene glycol recovered here is about half of the ethylene glycol supplied to the slurry preparation tank. In this case, since the heat necessary for distillation is sufficient for the distillate itself, there is no need for heating.

The distillate distilled from the three polycondensation reaction tanks 7 to 9 is supplied to the distillation column 15 to remove the low-boiling fraction mainly from water and to the distillation column 16 for removing the high-boiling fraction. Then, it was fractionated into a recovered ethylene glycol fraction (column top fraction) mainly composed of ethylene glycol and a recovered phosphorus compound fraction (column bottom fraction). The number of stages of the distillation columns 15 and 16 is 15 and 30, respectively. However, since these distillates are generated in a reduced pressure system, they are condensed in the wet condensers 12 to 13 installed in the respective reaction tanks and supplied to the ethylene glycol condensate storage tanks 18 to 20 and then supplied to the distillation column 15. . For this purpose, the heat exchanger 24 supplies heat for distillation. At this time, in order to suppress an increase in the temperature of the ethylene glycol liquid sprayed on the wet condenser, it is cooled by the coolers 21 to 23 and supplied to the wet condenser. Although this condensate is carried out by self-circulation of the condensate itself condensed in each wet condenser, new ethylene glycol may be supplied as necessary.
Table 1 shows the component analysis results of ethylene glycol recovered in each distillation column. Moreover, phosphorus element content in the collection | recovery ethylene glycol which distilled the high boiling point fraction in the distillation column 16 was 1.3 ppm. The amount of phosphorus element in the recovered phosphorus compound fraction was 1.8% by mass.

Comparative Example 1
In the method of Example 1, the distillate distilled from the three polycondensation reaction tanks 7 to 9 is stopped from the two-stage distillation in the distillation column 15 and the distillation column 16 and supplied to the distillation column 10 to obtain a high boiling point. Polyester was obtained by performing polycondensation in the same manner as in Example 1 except that the fraction was changed so as to be supplied to the ethylene glycol storage tank 17 without performing the fraction removal treatment. The flow of ethylene glycol in the polyester production process in Comparative Example 1 is shown in FIG. The bottom fraction of the distillation column 10 contained 59 ppm of phosphorus element. Therefore, in this comparative example, the phosphorus compound is circulated to the polycondensation step without being removed. Further, although the details of the phosphorus compound are unknown, the structure is changed in the polycondensation step. For this reason, the polyester obtained in this comparative example increased the amount of aluminum-based foreign matter insoluble in the polyester, and the haze value of the uniaxially stretched film deteriorated. Moreover, compared with Example 1, the polycondensation catalyst activity fell and the intrinsic viscosity of polyester was as low as 0.60. The results are shown in Table 3.

Comparative Example 2
In the method of Comparative Example 1, the method of Comparative Example 2 was changed in the same manner as in Comparative Example 1, except that water was distilled off at the normal pressure from 140 to 160 ° C. during preparation of the ethylene glycol solution of the aluminum compound. PET was obtained. The integral ratio of peaks in the ²⁷ Al-NMR spectrum of the ethylene glycol solution of the aluminum compound obtained in this Comparative Example was 0.18. Further, the NMR spectrum of the polycondensation catalyst solution composed of a mixture of the above-mentioned aluminum compound ethylene glycol solution and phosphorus compound ethylene glycol solution obtained in this comparative example was observed in the polycondensation catalyst solution obtained in Example 1. Coordination peak was hardly detected, and the integrated value of the coordination peak was observed in the vicinity of 25 to 27 ppm present in the NMR spectrum of the phosphorus compound ethylene glycol solution before mixing with the aluminum compound ethylene glycol solution. It was 1% or less with respect to the integrated value of the NMR spectrum peak of the phosphorus atom to which the hydroxyl group was bonded. The properties of the obtained PET are shown in Table 3.

Examples 2-5
In the method of Example 1, the mixing ratio between the ethylene glycol solution of the novel phosphorus compound and the recovered phosphorus compound fraction was 30:70, 50:50, 75:25 and 0: 100 (mass ratio) in terms of the amount of phosphorus element. The PET of Examples 2 to 5 was obtained in the same manner as in Example 1 except that the change was made. The properties of the obtained PET are shown in Table 2.

Example 6
In the method of Example 1, PET of Example 2 was obtained in the same manner as in Example 1 except that the inner temperature was controlled to 95 to 105 ° C. when the aqueous solution of the aluminum compound was replaced with the ethylene glycol solution. The integrated value ratio of the ²⁷ Al-NMR spectrum peak of the aluminum solution obtained in this example was 0.85. Further, the integrated value of the coordination peak in the NMR spectrum of the polycondensation catalyst solution is the value of the phosphorus atom bonded to the hydroxyl group observed in the vicinity of 25 to 27 ppm present in the NMR spectrum of the ethylene glycol solution of the phosphorus compound before preparation of the polycondensation catalyst. It was 22% with respect to the integral value of the NMR spectrum peak. The properties of the obtained PET are shown in Table 2.

Example 7
PET was produced by the method according to Example 1 except that the esterification reaction tank was changed to three groups and the installation of the distillation tower was changed as shown in FIG. The difference from Example 1 in the recovery of ethylene glycol is that a distillation column 11 is added as the number of esterification reaction vessels increases, and the treatment in the distillation column 10 is performed only as a distillate from the first esterification reaction vessel. The distillate from the second and third esterification reactors is combined and treated in the distillation column 11. Others were processed according to the method of Example 1.
The properties of the obtained PET are shown in Table 2.

Comparative Example 3
In the method of Example 7, the distillate distilled from the three polycondensation reaction tanks 7 to 9 is stopped from the two-stage distillation in the distillation column 15 and the distillation column 16 and supplied to the distillation column 11 to have a high boiling point. Polyester was obtained by performing polycondensation in the same manner as in Example 7 except that the fraction was changed so as to be supplied to the ethylene glycol storage tank 17 without performing the fraction removal treatment. The flow of ethylene glycol in the polyester production process in Comparative Example 3 is shown in FIG. Since the polyester obtained in this comparative example contains a phosphorus compound in the collected ethylene glycol as in Comparative Example 1, the amount of aluminum-based foreign matter insoluble in the polyester is increased, and the haze value of the uniaxially stretched film is deteriorated. did. Moreover, compared with Example 7, the polycondensation catalyst activity fell and the intrinsic viscosity of polyester was as low as 0.60. The results are shown in Table 2.

Example 8
In the method of Example 7, PET was obtained by changing the mixing ratio of the ethylene glycol solution of the novel phosphorus compound and the recovered phosphorus compound fraction in the same manner as in Examples 2-5. As in Examples 2 to 5, the Tc1 of the polyester decreased as the ratio of the recovered phosphorus compound fraction increased.

The PET obtained in Examples 1 to 8 has high polycondensation productivity, produces a highly transparent molded body with little generation of insoluble aluminum-based foreign matter with respect to color tone and polyester, and is compatible with economy and quality. . The uniaxially stretched film obtained by using the PET obtained in these Examples had a low haze and an excellent transparency. Moreover, Tc1 of polyester was able to be controlled by changing the use ratio of the recovered phosphorus compound in the phosphorus compound used for the polycondensation catalyst.
On the other hand, in Comparative Examples 1 to 3, the polycondensation activity was decreased, and the amount of insoluble aluminum-based foreign matter with respect to the polyester was increased, and the transparency of the molded product was deteriorated. The polycondensation catalyst activity and quality deterioration in these comparative examples are caused by the structurally changed phosphorus compound being circulated in the polycondensation system. Further, the PET obtained in Comparative Example 2 is extremely inferior in transparency. In addition to the above-mentioned adverse effects, this was caused by taking into account that the amount of insoluble aluminum-based foreign matter with respect to the polyester was remarkably increased due to poor preparation of the aluminum compound solution.

  The method for producing a polyester according to the present invention comprises a continuous polycondensation in the presence of a polycondensation catalyst comprising at least an aluminum compound and a phosphorus compound, which is a polycondensation catalyst having a metal component other than antimony, germanium and titanium as the main metal component of the catalyst. In the method of manufacturing the polyester, the glycol distilled in the polyester manufacturing process and the phosphorus compound mixed in the glycol are recycled in a highly economical manner, avoiding adverse effects on the polycondensation catalyst activity and quality of the polyester. Therefore, there is an advantage that reduction of operation cost and simplification of equipment can be achieved. Further, in the present invention, even when the above-mentioned circulation reuse is performed, it is possible to produce a polyester that maintains the high polycondensation catalytic activity of the polycondensation catalyst of the present invention and that can provide a molded article with high transparency. Has the advantage. Furthermore, in the present invention, when the phosphorus compound separated by the above method is recycled and reused, Tc1 of the polyester obtained by adjusting the reuse rate can be controlled. As a result, for example, in molding of a hollow molded body such as a bottle, the polyester resin molded body amorphous part or amorphized without increasing the number of steps such as contacting the polyester resin with a polyolefin resin or polyamide resin or adding a trace amount. The temperature rise crystallization temperature of the molded product can be controlled in a wide range, and the crystallization characteristics of polyester such as polyester resin for bottles improved in terms of dimensional stability, transparency and productivity are regarded as important. It has the advantage that it can be used particularly favorably in certain fields, so it contributes greatly to the industry.

2 is a flow chart of ethylene glycol in a polyester production process in Examples 1 and 2. FIG. 2 is a flow chart of ethylene glycol in a polyester production process in Comparative Examples 1 and 2. FIG. 5 is a flowchart of ethylene glycol in a polyester production process in Example 3. 10 is a flowchart of ethylene glycol in a polyester production process in Comparative Example 3.

Explanation of symbols

1: Metering tank 2: Slurry preparation tank 3: First esterification reaction tank 4: Second esterification reaction tank 5: Third esterification reaction tank 6: In-line mixer 7: First polycondensation reaction tank 8: Second double Condensation reaction tank 9: Third polycondensation reaction tank 10, 11, 15, 16: Distillation tower 12-14: Wet condenser 17: Ethylene glycol storage tank 18-20: Ethylene glycol condensate storage tank 21-23: Cooler 24: Heat Exchanger 25-39: Pump

Claims (8)

  Reaction in which a phosphorus compound is added in a method for continuously producing a polyester in the presence of a polyester polycondensation catalyst comprising at least one selected from the group consisting of aluminum compounds and at least one selected from the group consisting of phosphorus compounds The distillate (A) distilled from the tank and the subsequent reaction tank is fractionated into a low boiling fraction mainly composed of water, a middle fraction mainly composed of ethylene glycol, and a high boiling fraction containing a phosphorus compound and the like. The middle distillate is reused as a part of the glycol for esterification reaction, and the high boiling fraction is reused as a part or all of the phosphorus compound constituting the polycondensation catalyst. Polyester manufacturing method.   The method for producing a polyester according to claim 1, wherein the crystallization temperature (Tc1) during temperature rise of the obtained polyester is controlled by adjusting the reuse ratio of the high-boiling fraction.   The method for producing a polyester according to claim 1 or 2, wherein the phosphorus compound comprises a hindered phenol residue.   The distillate (A) is obtained by fractionating and removing a low-boiling fraction mainly composed of water and then fractionating again to fractionate a high-boiling fraction containing a phosphorus compound and the like. 4. The method for producing a polyester according to any one of 3 above.   The polyester production method according to any one of claims 1 to 4, wherein the phosphorus compound is added to the second esterification reaction tank and / or thereafter.   The distillate (B) distilled from the reaction tank prior to the addition of the phosphorus compound can be removed by distilling off the low-boiling fraction mainly composed of water, and the residue can be reused as glycol for the esterification reaction. The method for producing a polyester according to any one of claims 1 to 6.   Polyester manufactured with the polyester manufacturing method in any one of Claims 1-6.   The molded object which consists of polyester described in Claim 7.

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