JP2008303271A - Method for producing polyester and film using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for efficiently producing polyester excellent in a low refractive index and thermal stability, and to provide a film as a multilayer film formed from the polyester, having a small photoelastic modulus and excellent light reflecting property. <P>SOLUTION: The method for producing polyester includes transesterification of an alicyclic dicarboxylic acid alkyl ester and an alicyclic diol and then polycondensation, wherein the transesterification is carried out by adding a compound containing an titanium element by 51 to 100 ppm and a compound containing metal elements of not more than 200 ppm other than a titanium element, and then the polycondensation is carried out by adding a compound containing titanium, antimony and germanium elements by 51 to 500 ppm and a compound containing a phosphorous element by 51 to 500 ppm. The obtained polyester satisfies the following characteristics: (1) the glass transition temperature is from 65 to 90°C; (2) the refractive index is from 1.500 to 1.570; (3) the gelation rate is not more than 60% in air and not more than 20% in nitrogen; and (4) the thermal reduction rate of not more than 2% in air and not more than 1% in nitrogen. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  In the copolymerization of the alicyclic component compound, the transesterification reaction is efficiently performed in the presence of a titanium compound and a metal compound other than the titanium compound, and a polyester obtained by adding a specific polymerization catalyst and a specific amount of phosphorus is used. It is a manufacturing method. Specifically, this is a method for producing a polyester in which the use of a titanium compound as a transesterification reaction catalyst allows the copolymerization component to sufficiently react in the polyester reaction step, thereby preventing scattering outside the reaction step. In addition, the polyester obtained by the production method can simultaneously provide an optical polyester film having excellent thermal stability (suppression of black foreign matter and gelation), and further excellent optical isotropy and light reflectivity. .

Polyester containing an alicyclic component has optical characteristics, crystallization characteristics, and mechanical characteristics different from aromatic polyesters such as polyethylene terephthalate (hereinafter referred to as PET). The polyester alone or the aromatic polyester Used in combination.

  For example, in Patent Document 1, in order to improve heat resistance, a dicarboxylic acid having a cyclic acetal skeleton, a production method in which a transesterification reaction is performed under high pressure when copolymerizing a diol, and the like, Patent Documents 2 and 3 describe a dicarboxylic acid. A method has been proposed in which a diol having a cyclic acetal skeleton is advanced to an ester obtained from diol and diol in the presence of a titanium compound, and is stably produced.

  However, in this production method, a diol having a cyclic acetal skeleton cannot be reacted efficiently, and problems such as scattering of a diol component having a cyclic acetal skeleton occur in a polycondensation reaction that is a polymerizing step, making stable production difficult. It is. Further, for example, it is exemplified that the glass transition point is increased by copolymerizing spiroglycol or the like having a rigid molecular chain. However, even when the resin composition is used in a multilayer laminated film, the Tg is higher than that of a normal polyethylene terephthalate resin composition, and thus the crystallinity is different when forming into a film. Inferior in workability. In addition, the refractive index cannot be lowered sufficiently with spiroglycol alone, and the light reflectance is lowered when a multilayer laminated film is formed.

  Patent Document 4 discloses a production method for obtaining a polyester resin in which a phosphorus-based antioxidant or the like is blended and kneaded with a polyester resin composition having a cyclic acetal skeleton. However, it cannot cope with the thermal deterioration during the production of the polyester resin, and the effect is insufficient.

Further, Patent Document 5 discloses a light-reflective film obtained by laminating a copolymerized polyester resin composition on a polyethylene naphthalate resin composition (hereinafter referred to as PEN), and Patent Document 6 discloses a nylon resin composition or an acrylic resin on a polyester resin composition. The light-reflective fiber in which the composition is laminated is a multilayer optical film in which PEN and a copolyester resin composition are laminated in Patent Document 7, and in PTL 8 is a photograph made of a PEN copolymer polyester resin composition having excellent transparency. Films have been proposed. However, the polyester resin compositions described in Patent Documents 5 and 7 are inferior in processability because the polyesters having different Tg are laminated, and the combination of Patent Document 6 is inferior in the adhesiveness between the polymers. The diversion is inappropriate, and the polyesters described in Patent Documents 5, 7, and 8 have a large photoelastic coefficient and cannot be used for liquid crystal displays and the like.
Japanese Patent Application Laid-Open No. 2004-67829 (Items 1 to 9) Japanese Patent Laying-Open No. 2005-314643 (1-14) JP 2006-225621 A (1st to 19th terms) JP 2004-67830 A (1st to 4th terms) JP 2000-141567 A WO98 / 46815 pamphlet (2-5) Japanese National Patent Publication No. 9-506837 (paragraphs 2-6) Japanese Patent Application Laid-Open No. 6-295014 (paragraph 2)

  An object of the present invention is to solve the above-described conventional problems, an alicyclic ring for obtaining characteristics excellent in thermal stability, a low photoelastic coefficient, and excellent in reflectivity when used as an optically isotropic laminated film. It is in providing the manufacturing method of polyester containing a group component, and the polyester film using the same.

The above-described problems of the present invention can be achieved by adopting the following configuration.
In the method for producing a polyester by subjecting at least an alicyclic dicarboxylic acid alkyl ester to a dicarboxylic acid structural unit and at least an alicyclic diol to a diol structural unit and undergoing a transesterification and then polycondensation, the alicyclic dicarboxylic acid alkyl A polyester containing an ester and an alicyclic diol is subjected to an ester exchange reaction by adding a titanium compound of 5 ppm or more and 100 ppm or less as a titanium element and a metal compound of 200 ppm or less as a metal element other than the titanium element, and then polycondensation. As a reaction catalyst, at least one of compounds in which the total of each element of titanium element, antimony element and germanium element is 5 ppm or more and 500 ppm or less is added, and further, a phosphorus compound of 50 ppm or more and 500 ppm or less is added as a phosphorus element. And method for producing a polyester, characterized in that a polyester satisfying the polycondensation reaction was the following characteristics (1) to (4).

Glass transition temperature by differential scanning calorimetry: 65 ° C. to 90 ° C. (1)
Refractive index at sodium D line: 1.500 or more and 1.570 or less (2)
Gelation rate: 60% or less under air, 20% or less under nitrogen (3)
Thermal loss rate by simultaneous differential heat and thermogravimetric measurement: 2% or less under air, 1% or less under nitrogen (4)
Moreover, the characteristic of light reflectance 90% or more is achieved by the laminated polyester film which laminates | stacks the polyester obtained by the manufacturing method of polyester of this invention alternately, and PET.

  According to the present invention, when a compound of an alicyclic component is copolymerized, a transesterification reaction is efficiently performed in the presence of a titanium compound and a metal compound other than titanium, and a specific polycondensation catalyst and a specific amount of a phosphorus compound are produced. By adding, it is possible to efficiently polycondense without scattering of low molecular weight substances during polycondensation, and it is possible to produce a polyester excellent in thermal stability (black foreign matter, suppression of gelation).

  The polyester obtained by the present invention has a low photoelastic coefficient suitable for a liquid crystal display, and a laminated polyester film excellent in light reflectivity can be obtained.

  The method for producing a polyester of the present invention is a method for producing a polyester by subjecting at least an alicyclic dicarboxylic acid alkyl ester to a dicarboxylic acid constituent unit and at least an alicyclic diol to a diol constituent unit and undergoing a transesterification and then polycondensation. In addition, to the polyester containing the alicyclic dicarboxylic acid alkyl ester and the alicyclic diol, 5 ppm or more and 100 ppm or less of a titanium compound as a titanium element, and 200 ppm or less of a metal compound as a metal element other than the titanium element are added. Then, at least one compound in which the total of each element of titanium element, antimony element and germanium element is 5 ppm or more and 500 ppm or less is added as a polycondensation reaction catalyst, and further 50 ppm or more as a phosphorus element Process for producing a polyester, characterized in that the addition of the following phosphorus compounds 500 ppm, and polyester satisfying the polycondensation reaction was the following characteristics (1) to (4).

Glass transition temperature by differential scanning calorimetry: 65 ° C. to 90 ° C. (1)
Refractive index at sodium D line: 1.500 or more and 1.570 or less (2)
Gelation rate: 60% or less under air, 20% or less under nitrogen (3)
Thermal loss rate by simultaneous differential heat and thermogravimetric measurement: 2% or less under air, 1% or less under nitrogen (4)
The polyester obtained by the method for producing a polyester of the present invention (hereinafter referred to as polyester A) needs to have a glass transition temperature (hereinafter referred to as Tg) in the range of 65 ° C to 90 ° C. When the Tg is less than 65 ° C., the heat resistance is insufficient, so the optical properties of the polyester or its molded body are likely to change with time, and there is a large difference in Tg between the laminated resins when the film is laminated with PET or the like. Therefore, stacking unevenness and the like occur, and film formation stability is impaired. In the case of a laminated film, it is preferable to match the Tg of the polyester A of the present invention with the Tg of the laminated polymer, and the difference between the Tg (Tg1) of the laminated polymer and the Tg (Tg2) of the polyester A of the present invention (| Tg1−Tg2). |) Is preferably within 10 ° C, more preferably within 5 ° C. On the other hand, when the Tg exceeds 90 ° C., the Tg difference becomes too large when laminating PET or the like, and as described above, laminating unevenness or the like occurs, film formation stability is impaired, and the refraction of the polyester film It becomes difficult to lower the rate. Therefore, the Tg of the polyester A resin of the present invention is preferably in the range of 70 to 87 ° C, more preferably in the range of 75 to 85 ° C.
The Tg in the present invention is measured with a differential scanning calorimeter (DSC7, manufactured by Perkin Elmer Co.), heated at a rate of 16 ° C./minute from 20 ° C. to 285 ° C. in a nitrogen atmosphere, and then liquid nitrogen. After rapid cooling, the temperature is increased again from 20 ° C. to 285 ° C. at a rate of 16 ° C./min in a nitrogen atmosphere. This refers to Tg in the second temperature raising process.

  The refractive index of the polyester A of the present invention needs to be in the range of 1.500 to 1.570. It is difficult for a polyester resin to have a refractive index of less than 1.500. When the refractive index exceeds 1.570, the difference in refractive index from the laminated polymer is small, so that the resulting film has low light reflectivity. Become. The refractive index of the polyester A of the present invention is preferably in the range of 1.510 to 1.560. In addition, the refractive index in this invention points out the refractive index measured using the sodium D line | wire on 23 degreeC conditions.

  In the method for producing a polyester of the present invention, in order to give the above-described properties, the polyester A needs to contain at least an alicyclic dicarboxylic acid alkyl ester in a dicarboxylic acid constituent unit and an alicyclic diol in a diol constituent unit. . The aromatic ring contained in polyester A has the effect of increasing Tg, but at the same time has the effect of increasing the refractive index and increasing the photoelastic coefficient. When the photoelastic coefficient is large, the phase difference changes greatly when a stress is applied to the film, so that it is not suitable for a film for use in a liquid crystal display.

  Therefore, the polyester A of the present invention has a refractive index and a photoelastic coefficient by substituting a part of the aromatic dicarboxylic acid component with an alicyclic dicarboxylic acid alkyl ester or a part of the diol component with an alicyclic diol. It is reduced.

  Examples of the alicyclic dicarboxylic acid alkyl ester in the present invention include dimethyl cyclohexane dicarboxylate and dimethyl decalin dicarboxylate. In particular, dimethyl cyclohexanedicarboxylate is preferable from the viewpoint of availability and polycondensation reactivity.

  The alicyclic component such as cyclohexanedicarboxylic acid alkyl ester has a cis isomer and a trans isomer as stereoisomers. In the present invention, the trans isomer ratio is preferably 40% or less. If the ratio of the transformer body is high, the photoelastic coefficient tends to increase, so that it tends to be inferior. In addition, since the trans isomer has a higher melting point than the cis isomer, if the trans isomer ratio is high, it easily coagulates and settles during storage at room temperature or during transportation, resulting in heterogeneity and reactivity. Not only is it worse, but workability is also worse in handling. Therefore, the trans isomer ratio is preferably 35% or less, and more preferably 30% or less.

  As the alicyclic diol in the present invention, spiroglycol and isosorbide are preferable, and spiroglycol is particularly preferable from the viewpoint of the color tone of the obtained polyester. Here, spiroglycol refers to 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane.

  In the present invention, for example, in the case of PET, Tg decreases when a terephthalic acid component (aromatic ring component) is substituted with a cyclohexanedicarboxylic acid alkyl ester or the like. On the other hand, by replacing the ethylene glycol component with an alicyclic diol such as spiroglycol or isosorbide, Tg increases, and as a result, it can be adjusted to the same Tg as that of normal PET used in the laminated film of the present invention. The effect of increasing Tg is remarkable in spiroglycol and isosorbide.

  In order to reduce the refractive index and the photoelastic coefficient of the polyester A of the present invention, the number of moles of aromatic rings contained in 1 kg of the polyester is preferably 4.8 moles or less. When it exceeds 4.8 mol, the refractive index and the photoelastic coefficient tend to increase, which is not preferable. The number of moles of aromatic rings in the present invention is based on the number of moles of benzene rings. The definition in the present invention will be described using PET and PEN as examples.

  In the case of PET, since the molecular weight of the basic repeating unit is 192, the number of basic repeating units per 1 kg of polyester is 5.2. Since 1 mol of the terephthalic acid component (corresponding to one benzene ring) is contained in the basic repeating unit, the number of moles of aromatic ring of PET is calculated to be 5.2. On the other hand, in the case of PEN, the molecular weight of the basic repeating unit is 242 and the number of basic repeating units per kg of polyester is 4.1. Although 1 mole of naphthalene dicarboxylic acid component is contained in the basic repeating unit, since the naphthalene ring corresponds to 2 benzene rings, the number of moles of aromatic ring of PEN is calculated as 8.2 moles.

  The polyester A of the present invention contains at least an alicyclic dicarboxylic acid alkyl ester and an alicyclic diol, and the other dicarboxylic acid component is selected from 2,6-naphthalenedicarboxylic acid component, terephthalic acid component, and isophthalic acid component. The It is preferable to add 20 to 95 mol% of at least one kind of dicarboxylic acid component with respect to the total dicarboxylic acid component. Moreover, about a glycol component, it is preferable to add 20-95 mol% of ethylene glycol components as a glycol component. When the above-mentioned aromatic dicarboxylic acid component is less than 20 mol%, it becomes difficult to make Tg 65 ° C. or higher, for example, when laminating with PET or PEN, the interlaminar adhesion with these resins deteriorates. come. Similarly, when the ethylene glycol component is less than 20 mol%, interlayer adhesion with these resins deteriorates when laminated with PET or PEN. On the other hand, when the aromatic dicarboxylic acid component exceeds 95 mol%, it is difficult to reduce the refractive index and the photoelastic coefficient. When the ethylene glycol component exceeds 95 mol%, the Tg may be 65 ° C. or higher. It becomes difficult.

  In the polyester A of the present invention, the addition amount of the alicyclic dicarboxylic acid alkyl ester and the alicyclic diol is preferably in the range of 5 to 80 mol%, more preferably 8 to 50 mol% from the above description.

  The polyester A of the present invention needs to have a gelation rate of 60% or less after heat treatment in the atmosphere, preferably 50% or less. Further, the gelation rate after heat treatment under nitrogen is required to be 20% or less, preferably 10% or less, more preferably 5% or less. The gelation rate is a ratio of the weight of insoluble matter when the polyester is dissolved in ortho-chlorophenol after heat treatment under air or nitrogen under conditions of 285 ° C. × 2.5 hr. In particular, polyesters copolymerized with spiroglycol are characterized by being decomposed and gelated by heat under acidic and moisture contents.

  Therefore, when the gelation rate after heat treatment in the atmosphere is 60% or more and the gelation rate after heat treatment under nitrogen is 20% or more, it means that the polyester is a polymer that is remarkably easily gelled. When discharging into strands, the shape becomes fussy and can no longer be cut with a cutter, or the filtration pressure increases abnormally due to a large amount of gel in the filter filtration process when forming a film, and the surface defects of the laminated film increase Or the thickness of the multilayer laminated film may vary.

        Further, the polyester A of the present invention needs to have a heat loss rate in the atmosphere of 2% or less, preferably 1.5% or less. Further, the heat loss rate under nitrogen is required to be 1% or less, and preferably 0.8% or less. The thermal weight loss rate is the value when the temperature is raised to 20 ° C. to 400 ° C. (temperature increase rate: 4 ° C./min) under the atmosphere and nitrogen using a differential heat / thermogravimetric simultaneous measurement device (hereinafter referred to as TG-DTA). It is the ratio with respect to the whole weight loss weight of polyester at 300 ° C.

  As described above, the polyester A of the present invention is a polyester obtained by copolymerization of an alicyclic dicarboxylic acid alkyl ester or an alicyclic diol, and therefore tends to be inferior in thermal stability. (Hereinafter referred to as black foreign matter). Therefore, when the thermal weight loss rate under the atmosphere exceeds 2% and the thermal weight loss rate under nitrogen exceeds 1%, the polyester is remarkably inferior in thermal stability, so that it is a polymer that tends to gel or black foreign matter. Meaning, for example, when discharging into a strand after polycondensation, the shape becomes fussy and can no longer be cut with a cutter, or the polyester adhering to the mouthpiece hole after leaving the discharge left becomes a black foreign substance and loses fluidity. Such as being blocked as a black foreign substance in the subsequent polyester. In addition, the filter filtration process during film formation may cause an abnormal increase in filtration pressure due to a large amount of gel or black foreign matter, generation of decomposition gas, lamination unevenness resulting in increased surface defects of the laminated film, and multilayer lamination. Problems such as fluctuations in the thickness of the laminated film may occur.

  In the method for producing a polyester of the present invention, transesterification is carried out in the presence of a titanium element compound having high reaction activity from the viewpoint of efficiently reacting an alicyclic component, particularly spiroglycol, and further suppressing gelation and black foreign matter. It is necessary to add 5 to 100 ppm of titanium element as a transesterification reaction catalyst to the polyester obtained by the polycondensation reaction from the transesterification reaction. When it exceeds 100 ppm, the amount of titanium element to be added increases, so that the thermal stability is inferior and gelation and black foreign matter tend to be promoted. On the other hand, in the case of less than 5 ppm, the transesterification reaction is not completely completed, the reaction time is delayed, the unreacted material is scattered in the vacuum circuit in the polycondensation reaction, and the target polyester cannot be obtained, It is not preferable because the gelation is promoted by mitigating the decrease in. Therefore, the amount of titanium element added is preferably 7 to 70 ppm, more preferably 10 to 50 ppm.

  In the production method of the present invention, a titanium compound in which the substituent of the titanium element compound as the transesterification reaction catalyst is at least one of an alkoxy group, a phenoxy group, an acylate group, an amino group, and a hydroxyl group is preferably used.

  Specific alkoxy groups include tetraethoxide, tetrapropoxide, tetraisopropoxide, tetrabutoxide, titanium tetraalkoxide such as tetra-2-ethylhexoxide, β-diketone functional groups such as acetylacetone, lactic acid, Examples include hydroxy polyvalent carboxylic acid functional groups such as malic acid, tartaric acid, salicylic acid, citric acid, and ketoester functional groups such as methyl acetoacetate and ethyl acetoacetate, with aliphatic alkoxy groups being particularly preferred. Examples of the phenoxy group include phenoxy and cresylate. The acylate groups include tetraacylate groups such as lactate and stearate, phthalic acid, trimellitic acid, trimesic acid, hemimellitic acid, pyromellitic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid , Functional groups of polycarboxylic acids such as sebacic acid, maleic acid, fumaric acid, cyclohexanedicarboxylic acid or their anhydrides, ethylenediaminetetraacetic acid, nitrilotripropionic acid, carboxyiminodiacetic acid, carboxymethyliminodipropionic acid, diethylenetria Nitrogenous polyvalent carboxylic acid functional groups such as minopentaacetic acid, triethylenetetraminohexaacetic acid, iminodiacetic acid, iminodipropionic acid, hydroxyethyliminodiacetic acid, hydroxyethyliminodipropionic acid, methoxyethyliminodiacetic acid Especially aliphatic asylum Group is preferred. Examples of the amino group include aniline, phenylamine, diphenylamine and the like. Further, diisopropoxybisacetylacetone and triethanolaminate isopropoxide containing two kinds of these substituents can be mentioned.

  In addition, since the titanium element compound is a high-temperature active catalyst in the transesterification reaction in the polyester production method of the present invention, a metal element other than titanium element is added as an auxiliary agent. As a result, low-temperature activity is generated and the transesterification reaction is promoted. In addition, since electrostatic applicability when forming a film is improved, the transesterification catalyst is used for the polyester obtained from the transesterification reaction through the polycondensation reaction. It is necessary to add 200 ppm or less of a metal element other than titanium element. If it exceeds 200 ppm, the amount of metal to be added increases, so that the heat resistance tends to be inferior, and gelation and black foreign matter are promoted. Therefore, the addition amount of the metal element other than the titanium element is preferably 150 ppm or less, more preferably 100 ppm or less.

  The metal element other than titanium preferably contains an element selected from alkaline earth metals, Zn, Co, and Mn. In the alkaline earth metal, Ca easily forms foreign matters, and Mg is preferable. Of Zn, Co, and Mn, Mn is preferable from the viewpoint of foreign matter and color tone. Among these, Mg and Mn are preferable from the viewpoint of the transparency of the resin, and Mn is particularly preferable.

  The above-described metal compound is preferably soluble in polyester, preferably a hydroxide, chloride or acetate, and particularly preferably acetate.

  As a method for producing the polyester of the present invention, from the viewpoint of gelation and black foreign matter suppression, each of each of titanium element, antimony element and germanium element as a polycondensation reaction catalyst with respect to the polyester obtained by the polycondensation reaction from the transesterification reaction It is necessary to add 5 to 500 ppm of the total of the elements. If it exceeds 500 ppm, the polycondensation activity is too high, so that gelation and black foreign matter are promoted, which is not preferable. On the other hand, when the concentration is less than 5 ppm, the polycondensation activity cannot be sufficiently obtained, so that the polycondensation time cannot be extended and a polymer having a sufficient degree of polymerization cannot be obtained. Therefore, the addition amount of titanium element and / or antimony element and / or germanium element is preferably 10 to 250 ppm, more preferably 10 to 100 ppm.

  In the production method of the present invention, a titanium compound in which the substituent of the titanium element compound as the polycondensation catalyst is at least one of an alkoxy group, a phenoxy group, an acylate group, an amino group, and a hydroxyl group is preferably used.

  Specific alkoxy groups include tetraethoxide, tetrapropoxide, tetraisopropoxide, tetrabutoxide, titanium tetraalkoxide such as tetra-2-ethylhexoxide, β-diketone functional groups such as acetylacetone, lactic acid, Examples include hydroxy polyvalent carboxylic acid functional groups such as malic acid, tartaric acid, salicylic acid, citric acid, and ketoester functional groups such as methyl acetoacetate and ethyl acetoacetate, with aliphatic alkoxy groups being particularly preferred. Examples of the phenoxy group include phenoxy and cresylate. The acylate groups include tetraacylate groups such as lactate and stearate, phthalic acid, trimellitic acid, trimesic acid, hemimellitic acid, pyromellitic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid , Functional groups of polycarboxylic acids such as sebacic acid, maleic acid, fumaric acid, cyclohexanedicarboxylic acid or their anhydrides, ethylenediaminetetraacetic acid, nitrilotripropionic acid, carboxyiminodiacetic acid, carboxymethyliminodipropionic acid, diethylenetria Nitrogenous polyvalent carboxylic acid functional groups such as minopentaacetic acid, triethylenetetraminohexaacetic acid, iminodiacetic acid, iminodipropionic acid, hydroxyethyliminodiacetic acid, hydroxyethyliminodipropionic acid, methoxyethyliminodiacetic acid Especially aliphatic asylum Group is preferred. Examples of the amino group include aniline, phenylamine, diphenylamine and the like. Further, diisopropoxybisacetylacetone and triethanolaminate isopropoxide containing two kinds of these substituents can be mentioned.

  In addition, examples of the antimony compound of antimony element and the germanium compound of germanium element include antimony trioxide, antimony pentoxide, and germanium dioxide. These may be used alone or in combination.

  In the polyester production method of the present invention, from the viewpoint of thermal stability for gelation and black foreign matter suppression, phosphorus element 50 to 500 ppm is added to the polyester obtained by the polycondensation reaction from the transesterification reaction before the polycondensation reaction. The amount of phosphorus element is the amount of phosphorus element in the phosphorus compound used as a deactivator of the transesterification catalyst used as an anti-coloring agent and the phosphorus element of the heat-resistant stabilizer of the phosphorus compound containing phosphorus element Including the amount. If it exceeds 500 ppm, the polycondensation reactivity is inferior, and a remarkable effect for suppressing gelation or black foreign matter cannot be obtained, which is economically useless. If it is less than 50 ppm, it is not preferable because an effect for suppressing gelation and black foreign matters cannot be obtained. The addition amount of phosphorus element is preferably 60 to 400 ppm, more preferably 70 to 300 ppm.

  The phosphorus compound is not particularly limited, but examples of the phosphorus compound include phosphoric acid-based, phosphorous acid-based, phosphonic acid-based, and phosphinic acid-based compounds. From the viewpoint of

  In addition, it is preferable to add a heat resistance stabilizer of a phosphorus compound containing a phosphorus element, because the effect on gelation and black foreign matter tends to be further obtained. In particular, a heat-resistant stabilizer containing trivalent phosphorus is preferable. As the heat-resistant stabilizer containing trivalent phosphorus described above, a commercially available heat-resistant stabilizer can be applied. Examples of such phosphorus compounds include phosphites, alkyl diarylphosphites, aryl diarylphosphites. , Aryl phosphonite dialkyl, aryl phosphonite diaryl, specifically, triphenyl phosphite, tris (4-monononylphenyl) phosphite, tri (monononyl / dinonyl phenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, monooctyl diphenyl phosphite, monodecyl diphenyl phosphite, bis [2,4- (bis 1,1-dimethylethyl) -6-methylphenyl] ethyl phosphite Fight, Tetrakis (2,4-Di-tert Butylphenyl) 4,4′-biphenylene diphosphite, tris (2,4-di-tert-butylphenyl) phosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol-di -Phosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol-di-phosphite, 3,9-bis (2,4-dicumylphenoxy) -2,4,8,10-tetraoxa- 3,9-diphosphaspiro [5.5] undecane, phenyl-neopentylene glycol-phosphite, 2,2-methylenebis (4,6-di-tert-butylphenyl) octyl phosphite, bis (2,4-dicyclo Milphenyl) pentaerythritol diphosphite, tetra (C12-C15 alkyl) -4,4'-i Can be exemplified propylidene diphenyl phosphite is not limited thereto.

  As the method for producing the polyester of the present invention, it is preferable to carry out the polycondensation temperature at a temperature as low as possible from 260 to 290 ° C. from the viewpoint of suppressing gelation and black foreign matter formation. The polycondensation temperature is usually the final constant temperature because the temperature is gradually raised from 230 to 240 ° C., and after reaching a certain target temperature, polycondensation is performed at a constant temperature. When the temperature is higher than 290 ° C., although polycondensation is promoted, it is not preferable because thermal deterioration is promoted, gelation is promoted, and the polyester adhering to the discharge nozzle hole is promoted. When the temperature is lower than 260 ° C., the polycondensation activity is lowered, and the polycondensation time is delayed. Therefore, the polycondensation temperature is preferably 270 to 288 ° C, more preferably 275 to 285 ° C. In consideration of scattering of the low polymer in the polycondensation, it is preferable to take 1 to 3 hours to reach the target temperature. The decompression speed is preferably 1 hour to 3 hours. Furthermore, the final polycondensation pressure reduction is preferably 133 Pa or less.

  The polyester A of the present invention thus obtained preferably has an intrinsic viscosity in the range of 0.60 to 1.0. When the intrinsic viscosity is less than 0.60, the polyester becomes brittle, which is not preferable. When the intrinsic viscosity exceeds 1.0, the melt viscosity becomes high, so that accurate lamination becomes difficult.

  The polyester A of the present invention is preferably amorphous, and is substantially amorphous within the above-mentioned copolymerization range. The term “amorphous” in the present invention means that the heat of fusion is 4 J / g or less in DSC measurement. Such an amorphous polyester resin composition is preferable because its optical properties hardly change during film production.

  Amorphous polyester A obtained by the production method of the present invention tends to be heat-sealed by drying and easily form a lump. Therefore, by including 5 to 50% by weight of crystalline polyester, lump formation due to drying can be suppressed. As such a crystalline polyester, it is preferable that the heat of crystal fusion in differential scanning calorimetry is 4 J / g or more.

  As a method of including the crystalline polyester, melt kneading by a vent type extruder is preferable. That is, it is a method of obtaining pellets by melting and kneading the crystalline polyester and the polyester A of the present invention with a vent type extruder. Examples of the crystalline polyester include PET, polybutylene terephthalate, PEN, and copolymers thereof, and PET is most preferable.

  The aromatic dicarboxylic acid component contained in the polyester A of the present invention is at least selected from the above-mentioned types, but a terephthalic acid component and an isophthalic acid component are preferable from the viewpoint of refractive index and photoelastic coefficient, and these are used at the same time. It doesn't matter. In particular, the terephthalic acid component is preferably used mainly from the viewpoint of adhesion to other polyesters. As other dicarboxylic acid components, conventionally known ones may be copolymerized as long as the characteristics allow, and the same applies to glycol components. Examples of such components include aliphatic dicarboxylic acids such as adipic acid and sebacic acid and esters thereof, aromatic dicarboxylic acids such as 4,4′-bisphenylenedicarboxylic acid, 5-sodiumsulfoisophthalic acid, diphenic acid, and the like. Examples thereof include glycol components such as esters, diethylene glycol, butanediol, propanediol, polyethylene glycol, and polytetramethylene glycol. Further, inorganic particles, organic particles, dyes, pigments, antistatic agents, antioxidants, waxes and the like may be contained.

  The polyester film of the present invention contains the above-described polyester A of the present invention, has a small photoelastic coefficient and refractive index, and can be suitably used for liquid crystal display applications and the like.

  The laminated polyester film of the present invention exhibits excellent light reflectivity by being laminated with polyester having different refractive indexes. The laminated polyester film of the present invention is a polyester film containing at least one layer of the polyester A of the present invention. In order to obtain excellent light reflectivity, the polyester A of the present invention and a PET resin are alternately laminated. Is preferred. Since the refractive index of the polyester A of the present invention is lower than that of the PET resin and is amorphous, the refractive index hardly changes even when the film is stretched. Therefore, light is efficiently reflected at the interface between the polyester A of the present invention and the PET layer.

  Of course, a higher light reflectance is preferable, but 90% or more is preferable as a light reflective film. In order to obtain excellent light reflectivity, the total number of laminated layers is preferably 250 or more.

  The method for obtaining such a laminated film is realized by feeding the polymers fed from different flow paths into a multilayer laminating apparatus using two or more extruders. Examples of the multilayer laminating apparatus include a multi-manifold die, a feed block, a static mixer, and the like. In particular, it is preferable to use a multi-manifold die or a feed block in view of the accuracy of the laminated thickness. The polyester laminated in this manner is extruded into a sheet form from the die and cooled by a cooling drum or the like, so that an unstretched sheet can be obtained. In order to obtain an unstretched sheet having excellent thickness unevenness and surface condition, it is preferable to use an electrostatic application method.

  The resulting unstretched sheet can then be uniaxially or biaxially stretched. In biaxial stretching, simultaneous biaxial stretching and sequential biaxial stretching can be performed.

  Next, the manufacturing method of the polyester of this invention and the manufacturing method of a film are demonstrated in detail.

  Polyester A of the present invention uses a method of synthesizing a low polymer by transesterifying a dicarboxylic acid alkyl ester and a diol because spiroglycol is easily decomposed by an acid, and then polycondensing it.

  As raw materials, for example, dimethyl terephthalate, dimethyl cyclohexanedicarboxylate, ethylene glycol, and spiroglycol are charged into a reactor so as to have a predetermined polyester composition. In this case, the reactivity of the glycol component is improved by adding 1.6 to 2.5 moles to the total dicarboxylic acid component. A titanium compound such as titanium citrate chelate or tetrabutyl titanate containing titanium element in the raw material, and a metal element-containing metal compound such as manganese acetate / tetrahydrate are added as a transesterification reaction catalyst, and as a polycondensation reaction catalyst. By adding an antimony compound such as antimony trioxide, the monomer component becomes a uniform molten liquid at about 150 ° C. Next, methanol is distilled while gradually raising the temperature in the reaction vessel to 235 ° C. over 4 hours, and a transesterification reaction is performed. In this manner, the transesterification reaction is completed, and a phosphorus compound such as trimethyl phosphoric acid or a phosphorus element-containing heat stabilizer is added as a transesterification catalyst deactivator. Next, after distilling off excess ethylene glycol, polycondensation reaction catalyst of titanium compound such as titanium citrate chelate and tetrabutyl titanate and / or antimony compound such as antimony trioxide and / or germanium compound such as germanium dioxide Added. Thereafter, the reaction product is charged into a polycondensation reaction apparatus at 235 ° C., and the temperature inside the can is gradually raised to 285 ° C. over 1.5 hours. At the same time as the temperature rise, the pressure inside the can is increased from normal pressure to 133 Pa or less for 2 hours. And depressurize. As the polycondensation reaction proceeds, the viscosity of the reaction product increases. For the predetermined polyester viscosity, the polycondensation reaction is terminated using the stirring torque as a guide, and the polyester is discharged into the water tank from the polycondensation device outlet hole. The discharged polyester is quenched in a water tank and made into chips with a cutter.

  Polyester A can be obtained by such a polyester production method, but the above is an example, and the monomer, catalyst and polycondensation conditions are not limited thereto.

  Next, film formation of a polyester film will be described.

  As the film forming method, a T-die method with favorable thickness unevenness can be preferably used.

  Polyester A obtained by the polyester production method is vacuum dried. For the melt extrusion, an extruder type melt extrusion apparatus equipped with a single screw or twin screw can be used. A laminated film can be produced by using two or more extruders, laminating a molten polyester with a multi-manifold die or a feed block, and extruding the laminated polyester.

  Casting method is to measure the melted polyester with a gear pump and then discharge it from a T-die die. Then, on a cooled drum, electrostatic application method, air chamber method, air knife method, press roll, which is a well-known close contact means. It is preferable that an unstretched film is obtained by tightly cooling and solidifying to a cooling medium such as a drum by a method or the like and rapidly cooling to room temperature. In particular, in order to obtain flatness and uniform thickness, an electrostatic application method is preferably used.

  The obtained unstretched film can be further uniaxially or biaxially stretched.

  The biaxial stretching method is not particularly limited, and methods such as a sequential biaxial stretching method and a simultaneous biaxial stretching method can be used.

  In the case of stretching by sequential biaxial stretching, the obtained unstretched film is contact-heated on a roll group heated to (glass transition temperature Tg-30 ° C.) or more and (glass transition temperature Tg + 50 ° C.) or less of polyester. The film is stretched 1.1 to 4.0 times in the longitudinal direction, and once cooled, the end of the film is bitten into a tenter clip, and the width of the polyester (glass transition temperature Tg + 5 ° C.) or more ( Glass transition temperature Tg + 50 ° C.) In a temperature atmosphere below, the polyester film is stretched 1.1 to 4.0 times to obtain a biaxially oriented polyester film.

  When the biaxially oriented film after stretching is further heat-treated at a temperature in the range of Tg + 50 ° C. to Tg + 150 ° C., the dimensional stability is improved.

  The polyester film thus obtained has a low photoelastic coefficient and is suitable as a liquid crystal display film. Moreover, the film which laminated | stacked PET etc. alternately is excellent in light reflectivity, and is suitable for a reflector use.

  The present invention will be described more specifically with reference to the following examples.

In addition, the measuring method of a physical property and the evaluation method of an effect were performed in accordance with the following method.
(1) Thermal properties of polyester (glass transition point, heat of crystal melting)
About 10 mg of the sample to be measured was weighed, sealed with an aluminum pan and pan cover, and measured with a differential scanning calorimeter (DSC7 model, manufactured by Perkin Elmer). In the measurement, the temperature was raised from 20 ° C. to 285 ° C. at a rate of 16 ° C./min in a nitrogen atmosphere, then rapidly cooled with liquid nitrogen, and again from 20 ° C. to 285 ° C. at a rate of 16 ° C./min. Raise the temperature. The glass transition point was measured in the second temperature raising process.

The amount of heat of crystal melting was calculated from the area of the crystal melting peak appearing in the second temperature raising process.
(2) Refractive index of polyester A 100-micrometer-thick unstretched sheet is obtained by melt-extruding polyester. Next, the refractive index was measured with an “Abbe refractometer NAR-4T” manufactured by Atago Co., Ltd. under a temperature condition of 23 ° C. using sodium D line as a light source.
(3) Intrinsic viscosity Intrinsic viscosity was measured at 25 ° C using orthochlorophenol as a solvent.
(4) Content of metal element in polyester resin composition Using a fluorescent X-ray apparatus (model number MESA-500W) manufactured by Horiba, Ltd., the intensity of fluorescent X-ray of polyester was measured. In addition, the value was converted into metal content using the analytical curve which created the sample of known content beforehand.
(5) Gelation rate A polyester sample to be measured is freeze-pulverized to form a powder having a diameter of 300 μm or less and vacuum-dried. 1 g of this sample is heat-treated in an oven at 285 ° C. for 2.5 hours under air or nitrogen. This is dissolved in 50 ml of orthochlorophenol (OCP) at a temperature of 160 ° C. for 40 minutes. Subsequently, it is filtered through a Buchner type glass filter (maximum pore size 20-30 μm), washed and vacuum dried. The weight of the OCP insoluble matter remaining on the filter was calculated from the increase in the weight of the filter before and after the filtration, and the weight fraction of the OCP insoluble matter with respect to the polyester weight (1 g) was determined to obtain the gelation rate (%).
(6) Thermal loss rate of polyester About 10 mg of a sample to be measured was weighed, put in an aluminum pan, vacuum-dried at 60 ° C. for 24 hours, and then the sample weight was measured again. Using an aluminum pan, differential heat / heat It measured with the simultaneous weight measuring device (Seiko Instruments TG / DTA6200 type | mold). In the measurement, the ratio of the weight loss at 300 ° C. when the temperature was raised from 20 ° C. to 400 ° C. at a rate of 10 ° C./min in the air or nitrogen was determined as the heat loss rate (%).
(7) Cis and trans isomer ratios of cyclohexanedicarboxylic acid A sample was diluted 5 to 6 times with methanol, and 0.4 μl of the diluted solution was measured by liquid chromatography under the following conditions.
Device: Shimadzu LC-10ADvp
Column: Capillary column DB-17 manufactured by Agilent Technologies (length 30 m, inner diameter 0.32 mm, film thickness 0.25 μm)
Temperature rising conditions: initial temperature 110 ° C., initial time 25 minutes, temperature rising rate 6 ° C./min, final temperature 200 ° C.
(8) Photoelastic coefficient (× 10 ⁻¹² Pa ⁻¹ )
A sample having a short side of 1 cm and a long side of 7 cm was cut out. The thickness of this sample is d (μm). Using this sample, TRANSDUCER U3C1-5K manufactured by Shimadzu Corporation, the checker was placed 1 cm above and below, and a tension (F) of 1 kg / mm ² (9.81 × 10 ⁶ Pa) was applied in the long side direction. . In this state, the phase difference R (nm) was measured using a polarizing microscope 5892 manufactured by Nikon Corporation. Sodium D line (589 nm) was used as a light source. These numerical values were applied to photoelastic coefficient = R / (d × F) to calculate the photoelastic coefficient.

The case where the photoelastic coefficient was less than 100 × 10 ⁻¹² Pa ⁻¹ was regarded as acceptable.
(9) Reflectance A spectrophotometer (U-3410 Spectrophotometer) manufactured by Hitachi, Ltd. was fitted with a φ60 integrating sphere 130-0632 (Hitachi Ltd.) and a 10 ° inclined spacer, and the peak value of the reflectance was measured. The band parameter was set to 2 / servo, the gain was set to 3, and the range from 187 nm to 2600 nm was set to 120 nm / min. Measured at a detection speed of. In order to standardize the reflectance, an attached BaSO ₄ plate was used as a standard reflecting plate. In this evaluation method, since the relative reflectance is obtained, the reflectance may be 100% or more.
(10) Peelability The test was conducted according to JIS K5600 (2002). The film was regarded as a hard substrate, and 25 lattice patterns were cut at intervals of 2 mm. Further, a tape cut to a length of about 75 mm was adhered to the lattice portion, and the tape was peeled off at an angle close to 60 ° in a time of 0.5 to 1.0 seconds. Here, Sekisui's cello tape (registered trademark) no. 252 (width 18 mm) was used. The evaluation result was expressed by the number of lattices in which one lattice was completely separated. When the thickness of the test film was less than 100 μm, a sample in which the test film was firmly bonded to the biaxially stretched PET film (Toray “Lumirror” T60) having a thickness of 100 μm with an adhesive was used for the peel test. . At this time, a test was performed by cutting a grid in the surface of the test sample so as not to penetrate the test sample. The number of peeling was 4 or less.
(11) Black foreign matter Polyester of the same level was continuously batch-condensed twice, and the second batch of gut-like polymer was discharged into a water tank and cut into a cutting chip. The number of black foreign matters having a size of 1 mm or more contained in the chip is visually counted. Note that the size of the black foreign object is the length of the shortest side of the smallest rectangle surrounding the foreign object.

When black foreign matter is 0-3 / kg (polymer) or less
When black foreign matter is 4-9 / kg (polymer) ... △
When the number of black foreign objects is 10 / kg (polymer) or more
In addition, if a black foreign substance having a size of 5 mm or more was observed, it was evaluated as x regardless of the number of foreign substances.
The method for synthesizing the catalyst is described below.

  The method for synthesizing the catalyst is described below.

Reference Example 1 (Titanium Catalyst A. Synthesis Method of Citric Acid Chelate Titanium Compound)
Citric acid monohydrate (532 g, 2.52 mol) was dissolved in warm water (371 g) in a 3 L flask equipped with a stirrer, condenser and thermometer. To this stirred solution was slowly added titanium tetraisopropoxide (284 g, 1.0 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 and distilled under reduced pressure. The product was cooled to a temperature below 70 ° C., and 380 g of a 32 wt% aqueous solution of NaOH was slowly added via a dropping funnel while stirring the solution. The resulting product was filtered and then mixed with ethylene glycol (504 g, 8.1 mol) and heated under vacuum to remove isopropanol / water and a slightly cloudy, pale yellow product (Ti-containing) Amount 3.85% by weight).

Reference Example 2 (Titanium Catalyst B. Lactate Chelate Titanium Compound Synthesis Method)
Ethylene glycol (218 g, 3.51 mol) was added from a dropping funnel to titanium tetraisopropoxide (285 g, 1.0 mol) stirred in a 2 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 was stirred for 15 minutes and 252 g of an 85 wt% aqueous solution of ammonium lactate was added to the reaction flask to give a clear, light yellow product (Ti content 6.54 wt%).

Reference Example 3 (Titanium Catalyst C. Synthesis Method of Titanium Alkoxide Compound)
Ethylene glycol (496 g, 8.0 mol) was added from a dropping funnel to titanium tetraisopropoxide (285 g, 1.0 mol) stirred in a 2 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. To the reaction flask, 125 g of a 32 wt% aqueous solution of NaOH was slowly added by a dropping funnel to obtain a clear yellow liquid (Ti content 5.2 wt%).

Example 1
(Synthesis of polyester)
67.6 parts by weight of dimethyl terephthalate (hereinafter referred to as DMT), 17.4 parts by weight of dimethyl cyclohexanedicarboxylate (hereinafter referred to as CHDC) having a cis / trans ratio of 75/25, and ethylene glycol (hereinafter referred to as EG). 54 parts by weight and 20 parts by weight of spiroglycol (hereinafter referred to as SPG) were charged into a transesterification reaction apparatus. Titanium catalyst A as the transesterification reaction catalyst was 20 ppm as the titanium element and antimony trioxide (hereinafter referred to as trioxide) as the polycondensation reaction catalyst. Sb) EG slurry containing 0.008 part by weight was added, and the contents were dissolved at 150 ° C. and stirred.

  While stirring, methanol was distilled while slowly raising the temperature of the reaction contents to 235 ° C. over 4 hours. After distilling a predetermined amount of methanol, an EG solution containing 0.01 part by weight of trimethyl phosphoric acid (hereinafter referred to as TMPA) and bis (2,6-di-tert-butyl-4-) manufactured by Asahi Denka Kogyo Co., Ltd. EG slurry containing 0.15 parts by weight of methylphenyl) pentaerythritol-di-phosphite (hereinafter PEP36) was added. After adding TMPA or the like, excess EG was distilled with stirring for 30 minutes, and then excess EG was distilled with stirring for 10 minutes to complete the transesterification reaction.

  Thereafter, the transesterification product was transferred to a polycondensation reaction apparatus. Subsequently, the transesterification reaction of the second batch was advanced in the same manner as the first batch.

  Subsequently, the polycondensation reaction apparatus was stirred and the pressure was reduced and the temperature was increased, and a polycondensation reaction was performed while distilling EG. Note that the pressure was reduced from normal pressure to 133 Pa or less over 120 minutes, and the temperature was raised from 235 ° C. to 285 ° C. over 90 minutes. During the polycondensation reaction, no vacuum circuit failure occurred, the stirring torque reached a predetermined value in the polycondensation reaction time 185 minutes, the inside of the polycondensation reactor was returned to normal pressure with nitrogen gas, The valve was opened and the gut polymer was discharged into the water tank. The polyester gut cooled in the water tank was cut with a cutter to form chips. After the polycondensation reaction of the first batch is completed, the temperature of the polycondensation reaction device is returned to the initial state, and after chip formation, the remaining polymer in the polycondensation reaction device is allowed to flow for about 30 minutes, and then the bottom of the polycondensation reaction device And the second batch of polycondensation reaction was carried out. The two batches of polymer obtained were mixed evenly. Moreover, when the decompression circuit of the polycondensation reaction apparatus was disassembled, no droplet deposits were observed on the circuit.

  The composition and properties of the polyester A thus obtained, and the film properties are shown in Tables 1 to 4. In addition, the characteristic of obtained polyester is a characteristic of 1st batch.

(Formation of single-layer biaxially stretched film)
The polyester A chip was vacuum-dried, but a lump was observed in a part thereof, and this was broken before being supplied to the extruder. Polyester A supplied to the extruder was melted at 280 ° C., filtered through a metal nonwoven fabric filter, and then extruded from a T die as a molten sheet. The molten sheet was cooled and solidified on a specular drum whose surface temperature was controlled at 25 ° C. by an electrostatic application method (electrodes used a tungsten wire having a diameter of 0.15 mm) to form an unstretched sheet. Using the unstretched sheet, the refractive index and the photoelastic coefficient were measured.

The refractive index was 1.552 and the photoelastic coefficient was 85 × 10 ⁻¹² Pa ⁻¹ .

(Formation of laminated polyester film)
The polyester A and the PET resin were each vacuum dried and then supplied to two extruders.

  Polyester A and PET resin were each melted at 280 ° C. by an extruder, passed through a gear pump and a filter, and then joined by a 101-layer feed block. At this time, both surface layers of the laminated film were made to be PET resin layers, and the laminated thickness was alternately laminated so that the polyester A layer / PET resin layer was ½. That is, the polyester A layer was laminated alternately so that 50 layers and the PET layer were 51 layers.

  The 101-layer laminate thus obtained was supplied to a die, extruded into a sheet, and rapidly cooled and solidified on a casting drum maintained at a surface temperature of 25 ° C. by electrostatic application (DC voltage 8 kV). .

The obtained cast film was led to a roll type longitudinal stretching machine, heated by a group of rolls heated to 90 ° C., and stretched 3 times in the longitudinal direction between rolls having different peripheral speeds. The film that had been stretched in the machine direction was then led to a tenter-type transverse stretcher. The film was preheated with hot air at 100 ° C. in a tenter and stretched 3.3 times in the transverse direction. The stretched film was directly heat treated with hot air at 200 ° C. in a tenter. In this way, a film having a thickness of 50 μm could be obtained. Table 4 shows the properties of the obtained film. Polyester A of the present invention has a photoelastic coefficient of less than 100 ⁻¹² Pa ⁻¹ . When a laminated film is formed, there is no problem in peelability and the light reflectance is excellent at 100%.

Examples 2-3
Example 2 is an EG solution containing 0.04 parts by weight of manganese acetate tetrahydrate (hereinafter referred to as Mn acetate), as a metal compound other than titanium in titanium catalyst A which is a transesterification catalyst of Example 1, In Example 3, a transesterification reaction and a polycondensation reaction were performed in the same manner as in Example 1 except that an EG solution containing 0.06 part by weight of magnesium acetate / tetrahydrate (hereinafter referred to as Mg acetate) was added. And a film was obtained. The characteristics are shown in Tables 1-4.

Examples 4-15
Example 1 except that the titanium catalyst species / addition amount, the polycondensation catalyst species / addition amount, the phosphorus compound species / amount, and the polycondensation temperature as the transesterification catalyst of Example 1 were changed as shown in Table 2. Polyester A and a film were obtained. The characteristics are shown in Tables 1-4. The addition timing of titanium catalyst A and germanium dioxide (hereinafter referred to as Ge dioxide), which are polycondensation catalysts, was added after TMPA or the like was added, after excessive EG was distilled while stirring for excess EG 30 minutes. The reaction was terminated after stirring for a minute. Further, as Ge dioxide, 1 part by weight of Ge dioxide was completely dissolved with 3.75 parts by weight of tetraethylammonium hydroxide 20% aqueous solution manufactured by Sanyo Chemical Industries, Ltd., and then an EG solution to which EG was added was used.

Examples 16-19
A polyester A and a film were obtained in the same manner as in Example 1 except that the amount ratio of DMT, CHDC, EG, and SPG in Example 1 was changed. In Examples 16 and 17, since Tg was different from PET by about 10 ° C., some unevenness occurred when biaxially stretching the laminated film, but it was within the scope of the present invention. In Example 18, the photoelastic modulus slightly increased due to the large number of moles of aromatic rings. In Example 19, since the number of moles of the aromatic ring was small, the refractive index was decreased and excellent light reflectivity was exhibited. However, since the amount of the copolymerization component was increased, the compatibility with PET was slightly decreased and the delamination property was weak. became. The characteristics are shown in Tables 1-4.

Examples 20-21
In Examples 20 to 21, the intrinsic viscosity of Example 1 was changed. In Example 20, the intrinsic viscosity was 0.65, and some unevenness was observed in the lamination property during film formation, and the refractive index was changed. The reflectivity was not great. In Example 21, since the intrinsic viscosity was as high as 0.95, some unevenness was observed in the lamination property during film formation, and the reflectance was not large for the refractive index. The characteristics are shown in Tables 1-4.

Example 22
A polyester film was obtained in the same manner as in Example 1 except that CHDC having a cis / trans ratio of CHDC of Example 1 of 60/40 was used. Since the transformer ratio of CHDC was higher than that in Example 1, the photoelastic coefficient was higher than that in Example 1. The characteristics are shown in Tables 1-4.

Example 23
A film was obtained in the same manner as in Example 1 except that the total number of layers 101 in Example 1 was changed to 251 in the total number of layers. The thickness of the obtained laminated polyester film was 50 μm, and the number of light reflecting layers was increased by increasing the number of layers, and excellent light reflectivity was exhibited. The characteristics are shown in Tables 1-4.

Comparative Example 1
A polyester and a film were obtained in the same manner as in Example 1 except that the SPG of Example 1 was not included, and 15 mol% of dimethyl isophthalate (hereinafter, DMI) was copolymerized in place of the CHDC component. Since neither an alicyclic dicarboxylic acid component nor an alicyclic diol component was contained, the refractive index and photoelastic coefficient were large, and the reflectance of the laminated film was also small. The characteristics are shown in Tables 5-8.

Comparative Example 2
A polyester and a film were obtained in the same manner as in Example 1 except that CHDC of Example 1 was not included, and 30 mol% of 1,4-cyclohexanedimethanol (CHDM) was copolymerized in place of the SPG component. Although the refractive index was lowered, the photoelastic coefficient was slightly large, and the reflectance of the laminated film was slightly inferior. The characteristics are shown in Tables 5-8.

Comparative Example 3
A polyester and a film were obtained in the same manner as in Example 1 except that the CHDC of Example 1 was not included and the amount of the SPG component was changed to 45 mol%. The Tg, gelation rate, and heat loss rate were very high, and the peelability of the laminated film was poor. The characteristics are shown in Tables 5-8.

Comparative Example 4
A polyester and a film were obtained in the same manner as in Example 1 except that the SPG of Example 1 was not included and the amount of the CHDC component was changed to 25 mol%. Although the refractive index was within the target range, Tg was lowered, the peelability of the laminated film was poor, and the reflectance was small. The characteristics are shown in Tables 5-8.

Comparative Example 5
The transesterification was carried out in the same manner as in Example 1 except that the titanium catalyst A as the transesterification catalyst in Example 1 was changed to 0.06 part by weight of Mn acetate, and the polycondensation reaction proceeded. Canceled. When the vacuum circuit was disassembled, a large amount of SPG adhered to the circuit. For this reason, the target polyester could not be obtained. Tables 5 and 6 show.

Comparative Examples 6, 7, 8, 9
In Comparative Example 6, when the amount of the titanium catalyst A, which is the transesterification reaction catalyst of Example 1, was changed to 3 ppm, the reaction was stopped because a predetermined amount of methanol was not obtained in the transesterification reaction. In Comparative Example 7, the amount of the titanium catalyst A, which is the transesterification reaction catalyst of Example 2, was reduced to 3 ppm and the polycondensation reaction was advanced. When the vacuum circuit was disassembled, a large amount of SPG adhered to the circuit. In Comparative Example 8, when the production of the polyester was advanced in the same manner as in Example 1 except that the amount of the titanium catalyst A that was the transesterification reaction catalyst of Example 1 was changed to 130 ppm, the polyester was slightly gutted when discharged into the water tank. Thickness was generated, the coloring of the polyester was large, and the gelation rate and heat loss rate were high. In addition, large black foreign matter was observed in the subsequent batch of polyester. Furthermore, the film surface and lamination | stacking thickness nonuniformity were recognized, and it was inferior to peelability and a reflectance. In Comparative Example 9, production of polyester proceeded in the same manner as in Example 1, except that the amount of Mn acetate, which was the transesterification catalyst of Example 2, was changed to 0.11 part by weight. When the polyester was discharged into the water tank, a slight thickness was generated in the gut, a large black foreign substance was observed in the polymer in the subsequent batch, and the gelation rate and heat loss rate were high. Moreover, the film surface and lamination | stacking thickness nonuniformity were recognized, and it was inferior to peelability and a reflectance. The characteristics are shown in Tables 5-8.

Comparative Examples 10, 11, 12, 13
In Comparative Example 10, when the titanium element amount of the titanium catalyst A of the polycondensation catalyst of Example 4 was changed to 3 ppm, the TMPA amount was changed to 0.005 parts by weight, and the PEP36 amount was changed to 0.05 parts by weight, the polycondensation reaction did not proceed. Therefore, the reaction was stopped. In Comparative Example 11, the production of the polyester was advanced in the same manner as in Example 1 except that Sb trioxide of the polycondensation catalyst of Example 1 was changed to 0.07 parts by weight. Thickness was generated, large black foreign matter was observed in the polymer of the subsequent batch, and the gelation rate and heat loss rate were high. Moreover, the film surface and lamination | stacking thickness nonuniformity were recognized, and it was inferior to peelability and a reflectance. In Comparative Example 12, polyester production proceeded in the same manner as in Example 1 except that the amount of TMPA in Example 1 was changed to 0.005 parts by weight and the amount of PEP36 was changed to 0.035 parts by weight. Large black foreign matter was observed in the subsequent batch of polymer, and the gelation rate and heat loss rate were high. Moreover, the film surface and lamination | stacking thickness nonuniformity were recognized, and it was inferior to peelability and a reflectance. In Comparative Example 13, when the amount of PEP36 in Example 1 was changed to 0.6 weight, the ingot reaction in which the polycondensation reaction did not proceed was stopped. The characteristics are shown in Tables 5-8.

Claims (12)

In the method for producing a polyester by subjecting at least an alicyclic dicarboxylic acid alkyl ester to a dicarboxylic acid structural unit and at least an alicyclic diol to a diol structural unit and undergoing a transesterification and then polycondensation, the alicyclic dicarboxylic acid alkyl A polyester containing an ester and an alicyclic diol is subjected to an ester exchange reaction by adding a titanium compound of 5 ppm or more and 100 ppm or less as a titanium element and a metal compound of 200 ppm or less as a metal element other than the titanium element, and then polycondensation. As a reaction catalyst, at least one of compounds in which the total of each element of titanium element, antimony element and germanium element is 5 ppm or more and 500 ppm or less is added, and further, a phosphorus compound of 50 ppm or more and 500 ppm or less is added as a phosphorus element. And method for producing a polyester, characterized in that a polyester satisfying the polycondensation reaction was the following characteristics (1) to (4).
Glass transition temperature by differential scanning calorimetry: 65 ° C. to 90 ° C. (1)
Refractive index at sodium D line: 1.500 or more and 1.570 or less (2)
Gelation rate: 60% or less under air, 20% or less under nitrogen (3)
Thermal loss rate by simultaneous differential heat and thermogravimetric measurement: 2% or less under air, 1% or less under nitrogen (4)   The method for producing a polyester according to claim 1, wherein the titanium compound has at least one substituent selected from the group consisting of an alkoxy group, a phenoxy group, an acylate group, an amino group and a hydroxyl group.   The alkoxy group of the titanium compound is at least one functional group selected from the group consisting of a β-diketone functional group, a hydroxycarboxylic acid functional group, and a ketoester functional group. A method for producing polyester.   The metal element other than titanium element is a metal compound containing at least one metal element selected from the group consisting of alkaline earth metals, Zn, Co or Mn. The manufacturing method of polyester of description.   The polyester production method according to any one of claims 1 to 4, wherein a trivalent phosphorus compound is added as a phosphorus compound in an amount of 0.005 to 1.0% by weight.   The method for producing a polyester according to any one of claims 1 to 5, wherein the alicyclic dicarboxylic acid alkyl ester component is dimethyl cyclohexanedicarboxylate, and is added in an amount of 5 to 80 mol% in the total dicarboxylic acid component.   The production of a polyester according to any one of claims 1 to 6, comprising cis and trans isomers of stereoisomers as dimethyl cyclohexanedicarboxylate, wherein the trans isomer content is 40% or less. Method. The method for producing a polyester according to any one of claims 1 to 7, wherein the alicyclic diol component is spiroglycol and is 5 to 80 mol% in the total diol component.   The method for producing a polyester according to any one of claims 1 to 8, wherein the molar number of aromatic rings contained in the polyester repeating unit is 4.8 mol or less in terms of 1 kg of the polyester resin.   The method for producing a polyester according to any one of claims 1 to 9, wherein a polycondensation temperature is 260 to 290 ° C during the polycondensation reaction. The laminated polyester film which laminated | stacked the polyester and polyethylene terephthalate which were obtained with the manufacturing method of the polyester of any one of Claims 1-10 alternately.   The laminated polyester film according to claim 11, wherein the light reflectance is 90% or more.