JP2005314660A - Polyester composition and polyester film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester composition improving color tone and further oxidation degradation resistance and slightly containing foreign materials. <P>SOLUTION: The polyester composition comprises titanium element, an alkali metal element and a trivalent phosphorus compound. In the polyester composition, the content of the titanium element is 0.5-50 ppm expressed in terms of the weight of the titanium metal atom and the content of the alkali metal element is 1-30 ppm expressed in terms of the weight of the alkali metal atom. The content of the trivalent phosphorus compound is 1-100 ppm expressed in terms of the weight of the phosphorus metal atom and the content of antimony element is ≤30 ppm expressed in terms of the weight of the antimony metal atom. The content of germanium element is ≤30 ppm expressed in terms of the weight of the germanium metal atom. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a polyester composition and a polyester film that contain substantially no antimony compound, are excellent in color tone and heat resistance, have few foreign matters, and have high productivity.

  In general, polyethylene terephthalate is produced from terephthalic acid or an ester-forming derivative thereof and ethylene glycol. In a commercial process for producing a high molecular weight polymer, an antimony compound is widely used as a polycondensation catalyst. However, polymers containing antimony compounds have some undesirable properties as described below.

  For example, when an antimony compound is used as a polycondensation catalyst, if a polyester film is continuously formed over a long period of time, foreign matter adheres and accumulates around the base, and when the film is formed, the base streaks are generated or the film surface is There is a problem that precipitates and causes surface defects.

  Further, germanium compounds are known as catalysts, but germanium compounds are very expensive and difficult to use for general purposes.

Furthermore, it has been proposed to use a titanium compound such as titanium tetrabutoxide as a polycondensation catalyst other than the antimony compound. However, when such a titanium compound is used, there are problems such as the above-mentioned base streaks and film surface defects. However, there are problems that the obtained polyester itself is colored yellow, the heat stability of the melt becomes unstable, the film is torn, and the productivity is deteriorated. In order to solve the above-mentioned coloring problem, a cobalt compound is generally added to polyester to suppress yellowing, but the heat stability of melting is lowered, which also deteriorates productivity. As a method for improving the color tone and heat resistance problems in a titanium-based catalyst, for example, Patent Document 1 proposes a method using a composite oxide composed of titanium and silicon as a catalyst. When the obtained polyester is used for a film, there are problems such as frequent yarn breakage due to catalyst-derived foreign matters, and problems such as an increase in filtration pressure during polymer filtration cannot be solved sufficiently. Patent Document 2 proposes a titanium compound catalyst obtained by hydrolyzing a titanium halogen compound. For example, when a thick film is produced, the polyester itself has a large yellow tint, and the color tone adjusting agent itself produces a film. Has been insufficiently improved, for example, when the difference in color tone becomes a problem, such as in optical applications.
WO95 / 18839 pamphlet JP 2001-89557 A

  The object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a polyester composition and a polyester film which are substantially free of antimony compounds, have excellent color tone and heat resistance, have little foreign matter, and have high productivity. There is.

  In order to achieve the above object, the present invention includes a titanium element, an alkali metal element, and a trivalent phosphorus compound, and the titanium element content is 0.5 to 50 ppm as the titanium metal atomic weight, and the alkali metal element content. Is characterized by a polyester composition having an alkali metal atom weight of 1 to 30 ppm, and a trivalent phosphorus compound content of phosphorus atom weight of 1 to 100 ppm.

  According to the present invention, it is possible to provide a polyester composition and a polyester film having good color tone, good oxidative degradation resistance, and less foreign matter.

  The polyester composition of the present invention is not particularly limited as long as it is a polymer synthesized from a dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof.

  As such a polyester composition, you may contain the copolymerization component with respect to all the acid components. Specifically, aromatic dicarboxylic acids such as isophthalic acid, naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid or ester-forming derivatives thereof, aliphatic dicarboxylic acids such as adipic acid and sebacic acid, or ester-forming derivatives thereof And alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid or ester-forming derivatives thereof.

  Further, the polyester composition of the present invention may contain a copolymer component of a diol component. Specific examples include propanediol, butanediol, neopentyl glycol, hexamethylene glycol, polyethylene glycol, polypropylene glycol, cyclohexane dimethanol and the like, and ester-forming derivatives thereof.

The polyester composition of the present invention is
(1) Titanium element,
(2) alkali metal elements,
(3) Including a trivalent phosphorus compound, the titanium element content is 0.5 to 50 ppm as titanium metal atom weight, the alkali metal element content is 1 to 30 ppm as alkali metal atom weight, and the trivalent phosphorus compound is contained It is a polyester composition whose amount is 1 to 100 ppm in terms of phosphorus metal atomic weight. At this time, it is preferable that the content of the antimony element is 30 ppm or less as an antimony metal atomic weight, and the content of the germanium element is 30 ppm or less as a germanium metal atomic weight.

  These titanium element, alkali metal element, and trivalent phosphorus compound may react with each other to form one kind of compound.

  When the titanium element is contained in an amount of 0.5 ppm or more as the titanium element weight with respect to the polymer weight to be obtained, the polymerization activity is high, and the color tone and heat resistance of the polymer to be obtained are also preferable. When the amount exceeds 50 ppm, the heat resistance is deteriorated, and further, it tends to cause foreign matters due to the catalyst. As content, More preferably, it is 1-30 ppm, More preferably, it is 1-20 ppm. In order to contain a predetermined amount of these titanium elements in the polymer, a predetermined amount may be added when the compound containing these elements is added (the added amount is maintained in the polymer as it is).

  In addition, by setting the alkali metal element content to 1 to 30 ppm as the alkali metal atomic weight with respect to the polymer weight, the pH in the system at the time of polymerization can be increased, and hydrolysis of the titanium compound can be suppressed. . The content of the alkali metal element is preferably 1 to 15 ppm. When the content is less than 1 ppm, the effect of inhibiting hydrolysis is poor, and when the content is more than 30 ppm, foreign matter may be generated. The introduction of the alkali metal element can be realized, for example, by adding a predetermined amount of a compound such as sodium hydroxide, potassium hydroxide, sodium acetate or potassium acetate.

  The content of the trivalent phosphorus compound is preferably 1 to 100 ppm as the phosphorus element weight with respect to the polymer weight. More preferably, it is 5-30 ppm. If the content exceeds 100 ppm, the polymerization reactivity tends to deteriorate, and if the content is less than 1 ppm, it is difficult to maintain heat resistance. In addition, the reference | standard of content here is the phosphorus element amount of a trivalent phosphorus compound, and oxidation resistance is maintained by being a trivalent phosphorus compound.

  The content of the antimony compound and the germanium compound with respect to the polymer weight is preferably 30 ppm or less in terms of the weight of metal atoms. By setting it within this range, it is possible to obtain a polymer that is less likely to cause contamination of the die during molding and is relatively inexpensive. More preferably, the content of each compound as antimony and germanium in terms of the weight of metal atoms is 10 ppm or less, particularly preferably not substantially contained.

  When the polyester composition is used as a film, for example, the alkali metal element content is Ma (mol / g), the alkaline earth metal element content is Md (mol / g), and the phosphorus element content is Mp. It is preferable that Ma, Md, and Mp satisfy the following formula:

Ma + 2 × Md ≧ 3 × Mp
The above formula is synonymous with MP ≧ 0, preferably MP−0.5, where Ma + 2 × Md is M and 3 × Mp is P. When M−P <0, the electrostatic application castability becomes poor, and air easily enters between the film and the casting drum at the time of melt extrusion casting, so that the film forming speed tends to be reduced. Productivity will be degraded. The alkali metal element-containing compound or alkaline earth metal element-containing compound used for satisfying the above formula is not particularly limited, but specifically, for example, lithium acetate, sodium acetate, potassium acetate, magnesium acetate, calcium acetate, Potassium hydroxide, sodium hydroxide, magnesium hydroxide, calcium hydroxide, etc. can be used.

  The titanium compound of the present invention is preferably at least one compound selected from the group represented by the following general formula (1) or (2).

Ti (OR) ₄ (1)
Ti (OH) _m (OR) _4-m (2)
(R: an organic group having 2 to 10 carbon atoms (may be the same or different from each other)
m: integer from 0 to 4)
As such a titanium compound, a titanium chelate compound or a tetraalkoxytitanium compound is preferable. For example, titanium chelates such as titanium acetylacetonate, titanium tetraacetylacetonate, titanium octylene glycolate, titanium lactate, titanium ethyl acetoacetate, titanium citrate, titanium lactate, titanium peroxocitrate ammonium ammonium, tetraisopropyl titanate, tetrabutyl Examples thereof include alkyl titanates such as titanate, tetra (2-ethylhexyl) titanate, and tetramethyl titanate. Among them, titanium chelate and tetrabutyl titanate are preferably used.

  In the present invention, examples of the trivalent phosphorus compound include tris (2,4-di-tert-butylphenyl) phosphite, bis [2,4-bis (1,1-dimethylethyl) -6-methylphenyl] ethyl. Ester phosphorous acid, tetrakis (2,4-di-tert-butylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphonite, bis (2,4-di-tert-butylphenyl) Pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol di-phosphite, bis (2,4-dicumylphenyl) pentaerythritol diphosphite are used. In particular, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol-di-phos Aito, bis (2,4-dicumylphenyl) pentaerythritol - di - phosphite is preferred.

  Furthermore, the polyester resin of the present invention may contain a phosphorus compound in addition to the trivalent phosphorus compound. Examples of the phosphorus compound include at least one selected from the group consisting of phosphoric acid, phosphorous acid, phosphonic acid, phosphinic acid, phosphine oxide, phosphonous acid, phosphinic acid, phosphine, phosphate, phosphite, phosphonate and phosphinate. be able to. As specific compounds, phosphoric acid, trimethyl phosphoric acid, ethyl diethylphosphonoacetate, phenyldipropylphosphonate and the like are preferable. By containing these phosphorus compounds, the heat resistance of the titanium catalyst can be improved and the color tone b value can be improved without generating foreign matter.

  In addition, the polyester resin of the present invention preferably contains a hydroxy polyvalent carboxylic acid or a nitrogen-containing polyvalent carboxylic acid. As a method for adding such a compound, there are a method of mixing with a catalyst in advance, a method of reacting with a catalyst to produce a product, and a method of adding directly to a resin. Specific compounds include hydroxy polyvalent carboxylic acids such as lactic acid, malic acid, tartaric acid, salicylic acid and citric acid, polyvalent carboxylic acids such as phthalic acid, trimellitic acid, trimesic acid, hemimellitic acid and pyromellitic acid, ethylenediamine Examples thereof include nitrogen-containing polycarboxylic acids such as tetraacetic acid, nitrilotripropionic acid, carboxyiminodiacetic acid, carboxymethyliminodipropionic acid, and diethylenetriaminopentaacetic acid.

  The titanium compound as a polymerization catalyst of the present invention may be added as it is to the reaction system of polyethylene terephthalate, but the compound is mixed with a solvent containing a diol component that forms a polyester such as ethylene glycol in advance to obtain a solution or slurry. If necessary, it is preferable to remove the low-boiling components such as alcohol used at the time of synthesizing the compound and then add it to the reaction system because the generation of foreign matters in the polymer is further suppressed. As the esterification reaction catalyst and the transesterification reaction catalyst, there are a method of adding a catalyst immediately after the addition of the raw material and a method of adding the catalyst together with the raw material. Moreover, when adding as a polycondensation reaction catalyst, it should just be substantially before the polycondensation reaction start, and a polycondensation reaction catalyst may be added together with an esterification reaction catalyst or a transesterification reaction catalyst.

  In addition, fluorescent whitening agents such as those listed in “Plastics Additives Handbook”, Ed. R. Gacher and H. Muller, Hanser verlag, 3rd Ed., 1990 P775-789 ”are added. It is also possible to improve the color tone.

  Also, from one or more of organic blue pigments such as azo, triphenylmethane, quinoline, methine, dioxazine, quinacridone, anthraquinone, phthalocyanine, organic blue dyes and inorganic blue pigments, inorganic blue dyes Can be added.

  Next, the manufacturing method of the polyester composition of this invention is demonstrated.

  Polyethylene terephthalate can be manufactured, for example, by any of the following processes. (1) A process in which terephthalic acid and ethylene glycol are used as raw materials, a low polymer is obtained by direct esterification reaction, and a high molecular weight polymer is obtained by subsequent polycondensation reaction, and (2) dimethyl terephthalate and ethylene glycol are used as raw materials. In this process, a low polymer is obtained by a transesterification reaction, and a high molecular weight polymer is obtained by a subsequent polycondensation reaction. Although the esterification reaction proceeds even without a catalyst, the titanium compound of the present invention may be added as a catalyst. Further, in the transesterification reaction, for example, it proceeds using a compound having catalytic ability including an element such as manganese, calcium, magnesium, lithium or the titanium catalyst of the present invention, and after the transesterification reaction is substantially completed. In order to inactivate the catalyst used in the reaction, a phosphorus compound is added.

  In the present invention, titanium as a polycondensation catalyst is added to the low polymer obtained in any stage of the series of reactions (1) or (2), preferably in the first half of the series of reactions (1) or (2). A method of obtaining a high molecular weight polyethylene terephthalate by adding a compound and conducting a polycondensation reaction can be employed.

  Moreover, although said reaction is implemented by forms, such as a batch type, a semibatch type, or a continuous type, the manufacturing method of this invention can be applied to any of those forms.

  The above-described polyester composition can be suitably used as a film.

  Especially, it is preferable to set it as the laminated film which has a main layer and a sublayer. The laminated film can be produced by, for example, melting polyesters (A) and (B), respectively. In this case, the melting temperature is not particularly limited, and may be any temperature that does not hinder the extrusion of the polyesters (A) and (B) from the die. Next, both the melted polyesters (A) and (B) are laminated to form a laminated sheet. The lamination method is a method in which polyesters (A) and (B) are joined and laminated from the extruder to the die, or in the die, and are discharged from the die as a laminated sheet, so-called co-extrusion method, or different slit shapes The polyester (A) and (B) may each be discharged from the die of the sheet in the form of a sheet, and the both may be laminated, but the coextrusion method is preferred. In addition, although the polyester (A) and (B) should just be laminated | stacked at least as for the layer structure of a lamination sheet, (A) / (B) two-layer structure or (A) / (B) / (A) , (B) / (A) / (B). In particular, a three-layer structure is preferable. At this time, the polyester of the present invention may be formed alone, or the polyester composition of the present invention is mixed with 1% by weight or more of the other polyester composition to obtain a film having a changed metal concentration. From the viewpoint of improving the productivity and heat resistance of other varieties.

  As the coextrusion lamination method, a feed block, a static mixer, a multi-manifold die, or the like can be used. Examples of the static mixer include a pipe mixer and a square mixer. In the present invention, it is preferable to use a square mixer. Moreover, it is preferable from a foreign material viewpoint that the layer which consists of a polyester resin composition of this invention comprises at least one surface.

  The laminated sheet thus obtained is taken up by various moving cooling bodies, preferably a rotating drum, and an electrostatic charge is deposited on the sheet and cooled and solidified by the moving cooling body. Any method may be used for depositing an electrostatic charge on the sheet. For example, a method of applying a voltage between the wire electrode and the moving cooling body by providing a wire electrode in the vicinity between the base and the moving cooling body and on the sheet surface on the side where the sheet does not contact the moving cooling body Can be used. The cooled and solidified laminated sheet, that is, the unstretched sheet is then stretched uniaxially or biaxially by various stretching methods such as a roll stretching method or a tenter stretching method and wound up. The order of stretching may be either sequential or simultaneous.

  Here, stretching in the longitudinal direction refers to stretching for imparting a molecular orientation in the longitudinal direction to the film. For example, this stretching performed by the difference in the peripheral speed of the roll may be performed in one step, or a plurality of You may carry out in multiple steps using a roll pair. The stretching ratio is preferably 2 to 15 times, more preferably 2.5 to 7 times.

  Stretching in the transverse direction refers to stretching for giving the film an orientation in the width direction. For example, the film is stretched in the width direction by using a tenter while gripping both ends of the film with clips. The stretching ratio is preferably 2 to 10 times.

  In the case of simultaneous biaxial stretching, the film is stretched simultaneously in the longitudinal direction and the lateral direction while being conveyed while being gripped by clips in the tenter, and this method may be used.

  The biaxially stretched film is preferably subjected to a heat treatment at a temperature not lower than the stretching temperature and not higher than the melting point in the tenter in order to impart flatness and dimensional stability. After uniform cooling, the film is cooled to room temperature and wound. In the film of the present invention, the heat treatment temperature is preferably 120 to 240 ° C. from the viewpoints of flatness and dimensional stability.

  Although the thickness of the laminated polyester film of this invention is not specifically limited, Preferably it is 0.5-100 micrometers, Especially 1-80 micrometers is preferable.

  In addition, when forming an easy-adhesion layer, particle layer, etc., the coating components may be applied in-line before stretching or between longitudinal stretching and lateral stretching using a coating technique such as gravure coating or metering bar. It is also possible to perform off-line coating after stretching.

  The polyester composition and the polyester film of the present invention are particularly suitable as a base film for capacitors and a base film for electrical insulation. In addition, a base film for photography, a base film for vapor deposition, a base film for packaging, and a base film for adhesive tape. Also, it can be suitably used for a magnetic tape base film and an optical base film.

  Hereinafter, the present invention will be described in more detail with reference to examples. In addition, the physical-property value in an Example was measured by the method described below.

(1) Content of titanium element, antimony element, and germanium element in polyethylene terephthalate Obtained with a fluorescent X-ray element analyzer (manufactured by Horiba, Ltd., MESA-500W type) or ICP emission analyzer (manufactured by Seiko Instruments Inc., SPS1700). It was. In addition, in order to remove the influence of inorganic particles such as titanium oxide particles in the target polyethylene terephthalate as necessary, the following pretreatment was performed and then X-ray fluorescence or ICP emission analysis was performed. That is, polyethylene terephthalate is dissolved in orthochlorophenol, the viscosity of the polymer solution is adjusted with chloroform as necessary, and then the particles are precipitated with a centrifuge. Thereafter, only the supernatant liquid is collected by a gradient method, and the polymer is reprecipitated by adding acetone, filtered and washed to obtain a polymer from which particles are removed. The polymer obtained by removing the particles obtained by the above pretreatment was analyzed for the amount of titanium element, antimony element and germanium element.

(2) Intrinsic viscosity of polymer (η)
Measurement was performed at 25 ° C. using orthochlorophenol as a solvent. Hereinafter referred to as η.

(3) Melting point About 10 mg of a sample to be measured is precisely weighed and sealed using an aluminum open pan and pan cover, and 20 ° C. under a nitrogen stream using a differential scanning calorimeter (Perkin Elmer, DSC7 type). The temperature was raised at a rate of 16 ° C./min.

(4) Solution haze About 2 g of the sample to be measured was dissolved in 20 mL of orthochlorophenol, and analysis was performed by an integrating sphere photoelectric photometry method using a haze meter (manufactured by Suga Test Instruments Co., Ltd., HGM-2DP type). In addition, in order to remove the influence of inorganic particles such as titanium oxide particles in the target polyethylene terephthalate, the same pretreatment as described in the above (1) was performed to obtain a polymer.

  If the solution haze is less than 1%, the content of foreign matter is small, and it can be said that the polymer has excellent film forming properties.

(5) Color tone of polymer Using a color difference meter (SM color computer format SM-3) manufactured by Suga Test Instruments Co., Ltd., it was measured as a Hunter value (L, a, b value).

(6) Gelation rate of polymer (%)
About 2 g of polymer chips are frozen and ground with a freezer mill, sifted with # 42 (350 μm or less), dried under reduced pressure (100 ° C., 40 minutes, pressure 133 Pa), weighed (1.0 ± 0.01 g), and then heat treated (predetermined) Time, 300 ° C., in air) at a flow rate of 100 ml / min).

  After heat treatment, dissolve at 80 ° C x 0.5 hr (orthochlorophenol), filter through glass filter (3G3), wash with about 50-100 ml of dichloromethane, and dry under reduced pressure (110 ° C x 2.0 hr, pressure 133 Pa) Then, the filtered material on the filter was weighed, and the gelation rate (%) with respect to the weight of the treated polymer was calculated.

(7) Number of foreign objects The chip is ultrasonically cleaned with (concentrated hydrochloric acid: pure water = 1: 1) for 1 minute in a class 100 clean room, then ultrasonically cleaned with pure water for 1 minute, and then the cover on the hot plate A sample was prepared by melting on glass and placing a cover glass so that no air bubbles would enter. Using a digital microscope (VHZ-450) manufactured by Keyence Corporation, four fields were measured by the dark field method (450 times), and the average was obtained. Observed. A defect of 1 μm or more was judged as a foreign substance. Foreign matter in a chip having a visual field area of 0.0034 cm ² and a thickness of about 40 μm to 0.02 mg is measured.

(8) Number of coarse projections H1 and H2 of the film
After ^two measurement surfaces (100 cm ² ) are stacked and brought into close contact with each other by electrostatic force (applied voltage 5.4 kV), the height of the coarse protrusion from the Newton ring caused by the interference of the coarse protrusion light between the two films. The number of coarse protrusions of a single ring or more was H1, and the number of coarse protrusions of a double ring or more was H2. The light source was a halogen lamp with a 564 nm band pass filter.

However, when measurement is difficult with the measurement area, the measurement area may be changed as appropriate and converted to 100 cm ² . (For example, a measurement area of 1 cm ² is measured for 50 visual fields and converted to 100 cm ^2. )
In addition, when measurement by the above method is difficult, a three-dimensional roughness meter (SE-3AK manufactured by Kosaka Laboratory: scans in the film width direction under the following conditions and performs measurement 50 times. Radius of tip of stylus is 2 μm. Using a stylus load of 0.07 g, a measurement area width of 0.5 mm × length of 15 mm (pitch of 0.1 mm), and a cut-off value of 0.08 mm), the number of protrusions having a height of 0.28 μm or more and a height of 0. H1 and H2 may be obtained by measuring the number of protrusions of 56 μm or more and converting it to 100 cm ² . Furthermore, if necessary, various methods for measuring the number of protrusions on the surface of the film, such as an atomic force microscope (AFM) or a 4-detection type SEM, may be used in combination.

(9) Content of alkali metals such as lithium in polyester (atomic absorption method)
This was measured by atomic absorption spectrometry using a polarized Zeeman atomic absorption spectrophotometer model number 180-80 (frame: acetylene-air) manufactured by Hitachi, Ltd. A hollow cathode lamp was used with 8 g of polymer as a light source, atomized by a frame method, detected by a photometric unit, and converted into metal content using a calibration curve prepared in advance.

(10) Melting specific resistance An electrode having a copper plate of 22 cm ² and a copper plate interval of 9 mm is prepared by sandwiching a Teflon (registered trademark) spacer between ^two copper plates as an electrode. This electrode is immersed in a polymer melted at 290 ° C. The resistance value was calculated from the amount of current when a voltage of 5,000 V was applied between them.

(Method for synthesizing reaction product of titanium citrate chelate compound and trivalent phosphorus compound)
Citric acid monohydrate (532 g, 2.52 mol), trivalent phosphorus compound bis (2,4-dicumyl) in warm water (371 g) in a 3 L flask equipped with stirrer, condenser and thermometer Phenyl) pentaerythritol-diphosphite (85.6 g, 0.1 mol) was dissolved. To this stirred solution was slowly added titanium tetraisopropoxide (288 g, 1.00 mol) from the addition funnel. The mixture was heated to reflux for 1 hour to produce a cloudy solution from which the isopropanol / water mixture was distilled under reduced pressure. The product was cooled to a temperature below 70 ° C., and a 32 wt / wt% aqueous solution of NaOH (380 g, 3.04 mol) was slowly added via a dropping funnel to the stirred solution. The resulting product was filtered and then mixed with ethylene glycol (504 g, 80 mol) and heated under reduced pressure to remove isopropanol / water and a slightly cloudy light yellow product (Ti content 3 0.03 wt.%). {Catalyst i}
(Method for synthesizing titanium citrate chelate compound)
Citric acid monohydrate (532 g, 2.52 mol) was dissolved in warm water (371 g) in a 3 L flask equipped with stirrer, condenser and thermometer. To this stirred solution was slowly added titanium tetraisopropoxide (288 g, 1.00 mol) from the addition funnel. The mixture was heated to reflux for 1 hour to produce a cloudy solution from which the isopropanol / water mixture was distilled under reduced pressure. The product was cooled to a temperature below 70 ° C., and a 32 wt / wt% aqueous solution of NaOH (380 g, 3.04 mol) was slowly added via a dropping funnel to the stirred solution. The resulting product was filtered and then mixed with ethylene glycol (504 g, 80 mol) and heated under reduced pressure to remove isopropanol / water and a slightly cloudy light yellow product (Ti content 4 .15% by weight). {Catalyst ii}
(Method for synthesizing titanium alkoxide compound)
Ethylene glycol (217.85 g, 3.15 mol) was added from a dropping funnel to titanium tetrabutoxide (340 g, 1.00 mol) stirred in a 3 L flask equipped with a stirrer, condenser and thermometer. . The addition rate was adjusted so that the heat of reaction warmed the flask contents to about 50 ° C. The reaction mixture is stirred for 15 minutes, a 32 wt / wt% aqueous solution of NaOH (125 g, 1.00 mol) is slowly added to the stirred solution via a dropping funnel and heated under reduced pressure to remove the water. A clear yellow liquid was obtained. (Ti content 7.93 wt%) {Catalyst iii}
(Method for synthesizing reaction product of titanium alkoxide compound and trivalent phosphorus compound)
Titanium tetrabutoxide (340 g, 1.00 mol) stirred in a 3 L flask equipped with a stirrer, a condenser and a thermometer was added to the trivalent phosphorus compound bis (2,4-dicumylphenyl) pentaerythritol. -Diphosphite (85.6 g, 0.1 mol) was added and ethylene glycol (217.85 g, 3.15 mol) was added from the dropping funnel. The addition rate was adjusted so that the heat of reaction warmed the flask contents to about 50 ° C. The reaction mixture is stirred for 15 minutes, a 32 wt / wt% aqueous solution of NaOH (125 g, 1.00 mol) is slowly added to the stirred solution via a dropping funnel and heated under reduced pressure to remove the water. A clear yellow liquid was obtained. (Ti content 6.95% by weight) {Catalyst iv}
Example 1
Purified terephthalic acid (manufactured by Mitsui Chemicals, Inc.) 100 kg of ethylene glycol (manufactured by Nippon Shokubai Co., Ltd.) 45 kg slurry previously bis (hydroxyethyl) terephthalate about 123kg is charged, temperature 250 ° C., a pressure 1.2 × 10 ⁵ Pa The esterification reaction tank was sequentially supplied to the held esterification reaction tank over 4 hours, and after the completion of the supply, the esterification reaction was further performed over 1 hour, and 123 kg of this esterification reaction product was transferred to the polycondensation tank.

  Subsequently, the catalyst i was added to the polycondensation reaction vessel to which the esterification reaction product had been transferred so that the titanium atom weight was 5 ppm with respect to the resulting polymer, and then bis (2,4-dioxide). Milphenyl) pentaerythritol-diphosphite is added so that the phosphorus atomic weight is 10 ppm with respect to the polymer, and the magnesium acetate solution is added so that the magnesium atomic weight is 50 ppm, and then the low polymer is stirred at 30 rpm. While gradually raising the temperature of the reaction system from 250 ° C. to 285 ° C., the pressure was reduced to 40 Pa. The time to reach the final temperature and final pressure was both 60 minutes. When the predetermined stirring torque was reached, the reaction system was purged with nitrogen, returned to normal pressure, the polycondensation reaction was stopped, discharged into cold water in the form of a strand, and immediately cut to obtain a polymer pellet polyester composition (A). The time from the start of decompression to the arrival of the predetermined stirring torque was 3 hours.

  Η of the obtained polymer was 0.63, the melting point of the polymer was 259 ° C., and the solution haze was 0.3%. Moreover, it confirmed that content of the titanium atom derived from the titanium catalyst measured from the polymer was 5 ppm. The color tone was good, the oxidative degradation resistance was good, and there were few foreign substances. The results are shown in Table 1.

(Example 2)
Polymer pellets (polyester composition (B)) were obtained in the same manner as in Example 1 except that catalyst ii was used in place of catalyst i used in Example 1. The obtained polymer had η of 0.64, the melting point of the polymer was 260 ° C., and the solution haze was 0.3%. Although the color tone was slightly inferior to that of Example 1, it was relatively good, had good oxidative degradation resistance, and had less foreign matter. The results are shown in Table 1.

(Example 3)
Polymer pellets (polyester composition (C)) were obtained in the same manner as in Example 1 except that the catalyst iii was used instead of the catalyst i used in Example 1. The obtained polymer had η of 0.63, the melting point of the polymer was 260 ° C., and the solution haze was 0.5%. Although the color tone was slightly inferior to that of Example 1, it was relatively good, oxidation resistance was good, and there were few foreign matters. The results are shown in Table 1.

Example 4
Polymer pellets (polyester composition (D)) were obtained in the same manner as in Example 1 except that catalyst iv was used in place of catalyst i used in Example 1. The obtained polymer had η of 0.64, the melting point of the polymer was 260 ° C., and the solution haze was 0.5%. Although the color tone was slightly inferior to that of Example 1, it was relatively good, had good oxidative degradation resistance, and had less foreign matter. The results are shown in Table 1.

(Comparative Example 1)
Polymer pellets (polyester composition (E)) were obtained in the same manner as in Example 1 except that catalyst ii was used in place of catalyst i used in Example 1 and no phosphorus compound was added. The obtained polymer had η of 0.64, the melting point of the polymer was 260 ° C., and the solution haze was 0.5%. Although there were few foreign substances, the oxidation-degradation resistance was poor, and the color tone also deteriorated. The results are shown in Table 1.

(Comparative Example 2)
Polymer pellets (polyester composition (F)) in the same manner as in Example 1 except that antimony trioxide (manufactured by Sumitomo Metal Mining) was used as the antimony atomic weight in an amount of 200 ppm instead of the catalyst i used in Example 1. Got. The obtained polymer had η of 0.64, the melting point of the polymer was 262 ° C., and the solution haze was 1.3%. There were many foreign objects. The results are shown in Table 1.

(Comparative Example 3)
In place of catalyst i used in Example 1, tetrabutyl titanate (manufactured by Nippon Soda Co., Ltd., TBT-100) was added in an amount of 20 ppm as the amount of Ti metal, and in the same manner as Example 1, except that magnesium acetate was not added. Pellets (polyester composition (G)) were obtained. The obtained polymer had a η of 0.64, a melting point of the polymer of 260 ° C., a solution haze of 0.8%, and foreign matter was generated, and MP was low. The results are shown in Table 1.

(Example 5)
The polyester composition (A) obtained in Example 1 was dried at 180 ° C. for 3 hours under reduced pressure at 133 Pa and fed to an extruder A heated to 280 ° C., and then placed on a casting drum having a surface temperature of 25 ° C. After melt-extrusion, it was melted and rapidly cooled and solidified by applying electrostatic force on a cast drum to form a single-layer unstretched film, and this unstretched film was longitudinally stretched at 90 ° C. at 3.5 ° C. with a roll stretcher. Further, using a tenter, the film was stretched 3.5 times horizontally at 105 ° C., heat treated for 10 seconds at a temperature of 200 ° C. under a constant length, and then subjected to a relaxation treatment of 2% in the width direction. An axially oriented polyester film was obtained.

(Example 6)
Using two extruders, the polyester composition (A) obtained in Example 1 was dried under reduced pressure at 180 ° C. for 3 hours at 133 Pa and supplied to the main layer (A layer) extruder. Further, after drying the polyester composition (B) obtained in Example 2 under reduced pressure at 133 Pa for 3 hours at 180 ° C., the polyester composition (B) was supplied to a sub-layer (B layer) extruder and merged in a T-die. It is melt-extruded from a layer die onto a casting drum, fused onto a cast drum having a surface temperature of 25 ° C. while applying electrostatic force, and then rapidly cooled and solidified. A / B type (thickness ratio 6/1) two-layer unstretched A film was obtained. Next, this unstretched film was stretched 3.5 times vertically at 90 ° C. with a roll-type stretching machine, and further stretched 3.5 times horizontally at 105 ° C. using a tenter, and the temperature was 200 ° C. under constant length. After 10 seconds of heat treatment, a relaxation treatment of 2% in the width direction was performed to obtain a laminated polyester film having a thickness of 8 μm (layer B laminated thickness of 1.33 μm). The film forming property was good. The film thus obtained had few coarse protrusions and good color tone. The results are shown in Table 2.

(Comparative Example 4)
A polyester film was obtained in the same manner as in Example 5 except that the polyester composition (E) obtained in Comparative Example 1 was used. The film forming property was good. Although the film thus obtained had few coarse protrusions, the color tone was poor, the thermal stability was poor, and the productivity was deteriorated. The results are shown in Table 2.

(Comparative Example 5)
The polyester composition (E) obtained in Comparative Example 1 is supplied to the main layer (A layer) extruder, and the polyester composition (F) obtained in Comparative Example 2 is supplied to the sublayer (B layer) extruder. A laminated polyester film having a thickness of 8 μm was obtained in the same manner as in Example 6 except that the thickness of the layer B was 1.33 μm. The film forming property was. The film thus obtained had many coarse protrusions, poor color tone, poor thermal stability, and deteriorated productivity. The results are shown in Table 2.

(Comparative Example 6)
The polyester composition (G) obtained in Comparative Example 3 was dried at 180 ° C. for 3 hours under reduced pressure at 133 Pa, supplied to an extruder, melt-extruded on a casting drum having a surface temperature of 25 ° C., and statically placed on a cast drum. The film was melted and rapidly solidified by applying electric power to form a single-layer unstretched film, but the adhesion was weak and the film was uneven. The results are shown in Table 2.

Claims (8)

A titanium element, an alkali metal element, and a trivalent phosphorus compound, the titanium element content is 0.5 to 50 ppm in terms of titanium metal atomic weight, and the alkali metal element content is in the range of 1 to 30 ppm as alkali metal atomic weight; The polyester composition whose content of a valence phosphorus compound is 1-100 ppm as phosphorus atomic weight. The polyester composition according to claim 1, wherein the content of the antimony element is 30 ppm or less as an antimony metal atomic weight, and the content of the germanium element is 30 ppm or less as a germanium metal atomic weight. When the content of the alkali metal element is Ma (mol / g), the content of the alkaline earth metal element is Md (mol / g), and the content of the phosphorus element is Mp, Ma, Md and Mp are expressed by the following formulas: The polyester composition according to claim 1 or 2, which is satisfactory.
Ma + 2 × Md ≧ 3 × Mp The polyester composition according to any one of claims 1 to 3, wherein the titanium element is derived from at least one compound selected from the group represented by the following general formula (1) or (2).
Ti (OR) ₄ (1)
Ti (OH) _m (OR) _4-m (2)
(R: an organic group having 2 to 10 carbon atoms (may be the same or different)
m: integer from 0 to 4) Containing at least one phosphorus compound selected from the group consisting of phosphoric acid, phosphorous acid, phosphonic acid, phosphinic acid, phosphine oxide, phosphonous acid, phosphinic acid, phosphine, phosphate, phosphite, phosphonate and phosphinate The polyester composition according to any one of claims 1 to 4. The polyester composition according to claim 1, which contains a hydroxy polyvalent carboxylic acid or a nitrogen-containing polyvalent carboxylic acid. The polyester composition according to any one of claims 4 to 6, wherein the compound represented by the general formula (1) or (2) is a tetraalkoxytitanium compound or a titanium chelate compound. The polyester film containing the polyester composition in any one of Claims 1-7.