JP2010111815A - Method for producing optical polyester resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an optical polyester resin excellent in heat resistance and wavelength dispersibility and suitable for an optical base material, such as a retardation film, by which excess distillate during polycondensation is suppressed and which excels in production stability and quality stability. <P>SOLUTION: In the method of producing the polyester by charging all monomer components before transesterification reaction and performing polycondensation after performing the transesterification reaction, the polyester resin having high heat resistance and reverse dispersibility is produced by performing the transesterification reaction using a titanium compound as a catalyst. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is a method for producing an optical polyester resin that has physical properties such as moldability, heat resistance, and wavelength dispersibility suitable for an optical substrate such as a retardation film. Specifically, by using a titanium compound as a transesterification reaction catalyst, a low-reactivity copolymer component sufficiently reacts, so that scattering of unreacted substances during polymerization is suppressed, and desired characteristics can be obtained and crosslinking can be performed. Since side reactions such as reactions are unlikely to occur, a film excellent in wavelength dispersibility can be obtained when a retardation film is formed.

  As optical elements, glass having excellent transparency and small birefringence has been used for a long time. However, since it is inferior in moldability and difficult to reduce in weight, recently, polymer materials with excellent moldability, light weight, and easy property control have been used for disc substrates, lenses, cables, various display films, etc. according to their characteristics. Yes.

  Among them, functional optical films such as retardation films and prism sheets are composed of polymethyl methacrylate (hereinafter referred to as PMMA), polycarbonate (hereinafter referred to as PC), and cyclic polyolefin (hereinafter referred to as COC), and are used for liquid crystal displays and the like. However, in general, PMMA has a large dimensional change due to moisture absorption, and PC has a very high melt viscosity, so that molding is difficult, COC is expensive, and film molding is not easy.

  For example, the retardation film has birefringence, so that incident light having the same phase in both the X-axis direction and the Y-axis direction gives a phase shift to outgoing light in the X-axis direction and the Y-axis direction when passing through the retardation film. For example, in a liquid crystal display, a retardation film is used for applications such as viewing angle compensation, color compensation, conversion of linearly polarized light into circularly polarized light, and antireflection. In reflective and transmissive liquid crystal displays, a polarizing plate and a retardation film are combined and used as a circularly polarizing plate. The circularly polarizing plate has a function of converting incident non-polarized light into circularly polarized light. Here, the retardation film used for the circularly polarizing plate preferably has a retardation of a quarter of the wavelength for all wavelengths λ (nm), but it is difficult to obtain a film satisfying this with one sheet. there were.

  When COC is used, it is necessary to laminate one or more retardation films and a polarizing plate so that the slow axis of the retardation film and the absorption axis of the polarizing plate are at a specific angle (Patent Document 1). The component cost and the bonding cost are large, and there is a limit to reducing the thickness and weight of the display.

  In addition, a thermoplastic film is disclosed in which a monomer having a cardo group such as fluorene is copolymerized with PC and has a wide band in the visible light region and a phase difference close to ¼ wavelength can be obtained with a single sheet (Patent Document 2). ). However, since these resins have a high melt viscosity, it is necessary to form a film by a solution casting method, resulting in poor productivity and a problem that the solvent used adversely affects the environment.

  Therefore, a polyester film obtained by copolymerizing fluorene has been proposed as a polyester film having excellent melt film-forming properties (Patent Document 3). However, this method is insufficient to satisfy the properties such as heat resistance and low photoelastic coefficient, and it is necessary to introduce a rigid component such as alicyclic diol.

  However, as the polymerization characteristics of fluorene polyester, fluorene is bulky, so the polymerization reactivity is poor, and when copolymerizing high molecular weight monomers such as alicyclics with poor polymerization reactivity, those with sufficient molecular weight cannot be obtained. Problems such as coloring due to the longer time of formation and a large amount of unreacted distillate during polymerization become apparent. Here, when unreacted distillate is generated during the polymerization, the composition of the product is not stabilized, and the vacuum line of the polymerization apparatus is contaminated and clogged.

  In addition, if the catalytic activity is increased in order to react with a monomer having poor polymerization reactivity, side reactions such as a crosslinking reaction occur. However, as a result of our study, when retardation and wavelength dispersion are controlled by stretching orientation such as retardation film. It is known that if the resin has a cross-linked resin, the stretched orientation is hindered, the phase difference is lowered, and the reverse dispersibility is lost or reduced in terms of wavelength dispersibility.

  In the proposal regarding the production method of alicyclic polyester, as for the suppression of excess distillate, crosslinking and gelation suppression, in the direct polymerization method, after first producing an oligomer with a copolymer component other than the monomer having a cyclic acetal skeleton A method has been proposed in which a monomer having a cyclic acetal skeleton is added, transesterified under a titanium catalyst, and then polymerized (Patent Document 4). However, the production method cannot efficiently react with a diol having a cyclic acetal skeleton, causing problems such as scattering of a diol component having a cyclic acetal skeleton in a polycondensation reaction that is a polymerizing step, and stable production is difficult. It is. Also, it is not preferable in the process that the reaction is multistage.

Although the proposal about the suppression of excess distillate is also made about the manufacturing method of fluorene polyester (patent document 5), it is a proposal mainly regarding a polycondensation process, there is no proposal regarding transesterification, and it relates to transesterification of the present invention. Combined with the proposal, it is possible to further control the distillate.
JP-A-5-2108 JP-A-2005-156665 JP 2006-215064 A JP 2006-226521 A JP 2008-81656 A

  The present invention solves the above-mentioned problems of the prior art, and in the case of producing an optical polyester resin excellent in heat resistance and wavelength dispersion, particularly an optical polyester resin suitable for a retardation film, sublimation during polymerization. An object of the present invention is to provide a production method in which side products such as a crosslinking reaction are suppressed by suppressing the product.

In order to solve the above problems, the present invention has the following features.
(1) [Claim 1] In a method for preparing a polyester by charging all the monomer components including an alicyclic dicarboxylic acid or a derivative thereof into a transesterification reactor, followed by a transesterification reaction and polycondensating, 5 ppm as titanium element As described above, a titanium compound of 100 ppm or less and a metal compound of 200 ppm or less as a metal element other than the titanium compound are added to cause a transesterification reaction, and then a polycondensation reaction catalyst is selected from the group consisting of a titanium element, an antimony element, and a germanium element. In addition, an optical polyester resin satisfying the following characteristics (1) and (2) is produced by adding at least one metal compound to a total of 5 ppm to 500 ppm and performing a polycondensation reaction. A method for producing a polyester resin.
Glass transition temperature is 100 ° C or higher (1)
Wavelength dispersibility of phase difference is negative (2)
(2) The method for producing an optical polyester resin according to (1), which has a diol residue of a cyclic diol represented by the chemical formula (1) as a diol component which is a monomer component.

R ¹ is the same or different alkyl group having 1 to 4 carbon atoms, and m represents an integer of 0 to 3.
R ² represents the same or different alkyl group having 1 to 30 carbon atoms, cycloalkyl group, and aryl group, and n represents an integer of 0 to 4.
(3) The titanium compound containing a titanium element has at least one substituent selected from the group consisting of an alkoxy group, a phenoxy group, an acylate group, an amino group or a hydroxyl group (1) or ( 2) The manufacturing method of the polyester resin for optics of description.
(4) The optical polyester according to (3), wherein the alkoxy group 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. Manufacturing method of resin.
(5) The metal element other than the titanium compound is a metal compound containing at least one metal element selected from the group consisting of alkaline earth metals, Zn, Co, or Mn (1) to ( The method for producing an optical polyester resin according to any one of 4).
(6) The production of the optical polyester resin according to any one of (1) to (5), wherein a trivalent phosphorus compound is added before the polycondensation reaction of 0.005 to 1.0% by weight. Method.
(7) The alicyclic dicarboxylic acid or its derivative component is dimethyl 2,6-decahydronaphthalenedicarboxylate, and is added in an amount of 5 to 100 mol% in all dicarboxylic acid components (1) to (6) The manufacturing method of the polyester resin for optics of any one of these.
(8) The method for producing an optical polyester resin as described in any one of (1) to (7), wherein spiroglycol is added as a diol component in an amount of 5 to 80 mol% in all diol components.
(9) A polyester resin obtained by the method for producing an optical polyester resin according to any one of (1) to (8).

  INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a stable method for producing an optical polyester resin having excellent heat resistance, a small photoelastic coefficient, and exhibiting excellent wavelength dispersion when used as a retardation film. That is, the present invention provides a production method that has few sublimates during polymerization and is excellent in production stability and product quality stability.

  The present invention is described in detail below.

  The polyester production method of the present invention is a method produced from a transesterification reaction through a polycondensation reaction. In the transesterification reaction for the purpose of efficiently reacting spiroglycol and other high molecular weight alicyclic components and inhibiting the crosslinking reaction. The transesterification reaction is performed using a titanium catalyst having high reaction activity. In the present invention, it is necessary to add a titanium compound of 5 ppm or more and 100 ppm or less as a titanium element to the transesterification catalyst. If it exceeds 100 ppm, the thermal stability is inferior due to an increase in the amount of titanium element added, and gelation and black foreign matter tend to be promoted. On the other hand, when it is less than 5 ppm, the transesterification reaction is not completed sufficiently, the reaction time is delayed, or unreacted substances are scattered in the vacuum circuit in the polycondensation reaction, and the target polyester cannot be obtained. A preferable addition amount of titanium element is 7 to 70 ppm, more preferably 10 to 50 ppm. Titanium catalysts are also active in polycondensation reactions, but generally they are less acidic than polycondensation catalysts such as antimony catalysts and germanium catalysts, especially when monomers having a cyclic acetal skeleton are used. Side reactions such as ring-opening, polyfunctionalization, and cross-linking, which are conspicuous in the catalytic metal species, are unlikely to proceed. Here, by using a titanium element having activity as a polycondensation catalyst as a transesterification reaction catalyst, it is possible to reduce the concentration of the polycondensation catalyst composed of a metal element that induces a side reaction such as cross-linking in the subsequent step.

  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, it is also preferable to add a metal element compound other than the titanium element compound as an auxiliary agent, and the addition amount is 200 ppm or less. Preferably, it is 150 ppm or less, More preferably, it is 100 ppm or less. When it exceeds 200 ppm, the amount of metal to be added increases, so that the heat resistance tends to be inferior and gelation is promoted.

  The metal element other than titanium of the transesterification catalyst preferably contains an element selected from alkaline earth metals, Zn, Co, and Mn. In the alkaline earth metal element, Ca easily forms foreign matters, and Mg is preferable. Among 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.

  As a method for producing the polyester of the present invention, from the viewpoint of cross-linking suppression, the total of titanium element, antimony element and germanium element as a polycondensation catalyst is 5 ppm or more and 500 ppm as a polycondensation catalyst with respect to the polyester obtained by transcondensation reaction from transesterification reaction. It is necessary to add. When it exceeds 500 ppm, since the polycondensation activity is too high, crosslinking is promoted, which is not preferable. On the other hand, when the concentration is 5 ppm or less, 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. A preferable addition amount is 10 ppm or more and 250 ppm or less, more preferably 10 ppm or more and 100 ppm or less.

  The polyester obtained by the polyester production method of the present invention needs to have a glass transition temperature (hereinafter referred to as Tg) of 100 ° C. or higher. When Tg is less than 100 ° C., the heat resistance is insufficient, so that the optical properties of the polyester or its molded product are liable to change with time, which is not preferable. Preferably it is 110 degreeC or more. An upper limit of Tg is not particularly provided, but a temperature of 250 ° C. or higher is not preferable because the melting temperature is increased and the film forming and stretching costs are increased. In order to control Tg within this range, the copolymerization component includes a decalin structure, a tricyclodecene structure, a rigid alicyclic structure such as a norbornane structure, a benzene ring, a naphthalene ring, a fluorene ring, and 9,9-bisphenylfluorene. It is preferable to copolymerize aromatic structures such as structures at a high molar ratio.

  Further, the polyester resin of the present invention is characterized in that the wavelength dispersion of retardation is negative. Although the wavelength dispersion of the retardation will be described in detail later, when it is negative, when the retardation film is formed, it is possible to achieve high functionality such as thinning. In order to control the wavelength dispersion of the polyester resin to be negative, although it depends on other copolymerization components, a copolymer component having a cardo structure such as a fluorene ring is generally copolymerized more than a certain amount.

    Hereafter, the specific example of the manufacturing method of the polyester resin for optics of this invention is described.

  The polymerization method of the resin of the present invention relates to a transesterification method among a known polymerization method, a direct polymerization method using a dicarboxylic acid and a diol as a derivative, and a transesterification method using a dicarboxylic acid diester and a diol. Here, as long as the transesterification reaction is not inhibited, the dicarboxylic acid is contained in an amount of 30 mol% or less of the total dicarboxylic acid derivative component including the dicarboxylic acid diester, and the transesterification reaction of the dicarboxylic acid diester and the esterification reaction of the dicarboxylic acid are performed in the same reaction tank. The method carried out in the method can also be preferably applied.

  The glycol component of the polyester of the present invention preferably contains a fluorene derivative represented by the chemical formula (1) in the resin. Here, the fluorene derivative has an effect of improving the wavelength dispersibility in the case of using a resin as a retardation film in addition to imparting heat resistance. The retardation film is a film that causes a difference between the phase of the fast axis and the phase of the slow axis when light of a certain wavelength passes. In the present invention, the retardation film is, for example, a quarter wavelength. Λ / 4 phase difference film that gives a phase difference of λ / 2, λ / 2 phase difference film that gives a phase difference of ½ wavelength, a viewing angle widening film, an optical compensation film, and all other films that give a phase difference.

  Here, the fast axis is the in-plane direction through which light passes the earliest, and the slow axis is the in-plane direction orthogonal to this.

  For example, it is desirable that a quarter wavelength film has a phase difference of ¼ of each wavelength in the visible wavelength region. Here, the phase difference of the wavelength X (nm) is described as R (X) (nm). For example, R (450) and R (550) in the visible wavelength region will be briefly described. When used as a retardation film of a reflective liquid crystal display, all visible wavelengths are not formed by laminating a plurality of retardation films. In order to obtain a broadband retardation film in which the retardation of the wavelength in the region approaches the ideal value, it is preferable to satisfy the following formula (1).

R (450) / R (550) = (450/4) / (550/4) = 0.818 (1)
On the other hand, ordinary polycarbonate, cyclic polyolefin and the like are represented by the following formula (2). Regarding the wavelength dispersion of the phase difference, the state of the following expression (2) is called forward dispersion.

R (450) / R (550)> 1 (2)
On the other hand, the state of the following expression (3) that is close to ideal is called inverse dispersion.

R (450) / R (550) <1 (3)
There is a demand for a retardation film that satisfies the above equation (3) with a single sheet because of the reduction in constituent members and the reduction in bonding costs. In the present application, a film exhibiting reverse dispersion and having a close R (450) / R (550) = 0.818 is referred to as a film excellent in wavelength dispersion.

  The polyester resin of the present invention is characterized in that the wavelength dispersion of retardation is negative. In the present invention, a resin having a negative wavelength dispersion means that a non-oriented single layer film (thickness of 500 μm or less) made of the resin is 1% / second in an oven at Tg + 10 ° C. while holding both ends in the stretching direction. This means that the wavelength dispersibility when the film is uniaxially stretched at a stretching speed of 2 times or more is negative.

  As molecular design for obtaining reverse dispersion, the same effect as that obtained when a plurality of retardation films are superposed in the molecule may be used. In the present application, the polymer containing the chemical formula (1) having a cardo structure exhibits the same effect as two types of retardation films superimposed in the main chain direction and the direction orthogonal to the main chain, and reverse dispersion It becomes possible to show sex.

Here, R ¹ in the chemical formula (1) is the same and is preferably an ethyl group, and preferably m = 1. When the number of carbon atoms in the alkyl group is large, Tg may decrease, which is not preferable. When m = 0, polymerization reactivity is decreased and mechanical strength is decreased. R ² is an alkyl group, a cycloalkyl group, or an aryl group, and n may be n = 0-4, but preferably n = 0. When n ≧ 1, the polymerization reactivity is lowered and the mechanical strength is lowered, which is not preferable.

Examples of the derivative of the structural unit represented by the chemical formula (1) include 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3. -Methylphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3,5-dimethylphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3-ethylphenyl] Fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3,5-diethylphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3-propylphenyl] fluorene, 9, 9-bis [4- (2-hydroxyethoxy) -3,5-dipropylphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3-isopropyl Ruphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3,5-diisopropylphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3-n-butylphenyl] Fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3,5-di-n-butylphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3-isobutylphenyl] Fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3,5-diisobutylphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3- (1-methylpropyl) phenyl ] Fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3,5-bis (1-methylpropyl) phenyl] fluorene, 9,9-bis 4- (2-hydroxyethoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3,5-diphenylphenyl] fluorene, 9,9-bis [4- (2 -Hydroxyethoxy) -3-benzylphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy) -3,5-dibenzylphenyl] fluorene, 9,9-bis [4- (3-hydroxypropoxy) ) Phenyl] fluorene 9,9-bis [4- (4-hydroxybutoxy) phenyl] fluorene and the like. Among these, 9,9-bis (4- (2-Hydroxyethoxy) phenyl) fluorene is preferred. These components may be used alone or in combination of two or more. Further, the charging composition of these fluorene derivatives is not particularly limited, but is preferably 5 mol% or more and 40 mol% or less, more preferably 10 mol% or more and 35 mol% or less in the total copolymerization component including the diol component and the dicarboxylic acid derivative component. . If it is smaller than this range, it is insufficient to develop heat resistance and reverse dispersibility, and if it is larger than this range, the polymerization reactivity is lowered and the photoelastic coefficient is also increased. In terms of the expression of reverse dispersion, it is effective to increase the copolymerization ratio of monomers having no double bond atoms such as aromatic rings.
The diol component is not particularly limited except for the fluorene derivative, and various diols can be used. For example, aliphatic diols such as ethylene glycol, trimethylene glycol, 1,2-propanediol, 1,3-propanediol, butanediol, 2-methyl-1,3-propanediol, hexanediol, neopentyl glycol, Cyclohexanedimethanol, cyclohexanediethanol, decahydronaphthalene diethanol, decahydronaphthalene diethanol, norbornane dimethanol, norbornane diethanol, tricyclodecane dimethanol, tricyclodecane diethanol, tetracyclododecane dimethanol, tetracyclo Saturated alicyclic primary diol such as decanediethanol, decalin dimethanol, decalin diethanol, 2,6-dihydroxy-9-oxabicyclo [3,3, ] Nonane, 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane (spiroglycol), 5-methylol-5-ethyl- Saturated heterocyclic primary diol such as 2- (1,1-dimethyl-2-hydroxyethyl) -1,3-dioxane, other cyclohexanediol, bicyclohexyl-4,4′-diol, 2,2-bis (4 -Hydroxycyclohexylpropane), 2,2-bis (4- (2-hydroxyethoxy) cyclohexyl) propane, cyclopentanediol, 3-methyl-1,2-cyclopentanediol, 4-cyclopentene-1,3-diol, Various alicyclic diols such as isosorbide, bisphenol A, bisphenol S, styrene glycol, etc. Cyclic diols can be exemplified. In addition to diols, polyfunctional alcohols such as trimethylolpropane and pentaerythritol can also be used. However, it is not limited to the glycol component specifically exemplified.
Among these, a diol having a monomer unit molecular weight of 82 or more is preferable from the viewpoint of heat resistance. Aliphatic diols such as hexanediol, and alicyclic diols include cyclohexanedimethanol, cyclohexanediethanol, decahydronaphthalenediethanol, decahydronaphthalenediethanol. Saturated alicyclic primary diols such as norbornane dimethanol, norbornane dimethanol, tricyclodecane dimethanol, tricyclodecane dimethanol, tetracyclododecane dimethanol, tetracyclodecane diethanol, decalin dimethanol, decalin diethanol, 2,6- Dihydroxy-9-oxabicyclo [3,3,1] nonane, 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro 5,5] undecane (spiroglycol), saturated heterocyclic primary diols such as 5-methylol-5-ethyl-2- (1,1-dimethyl-2-hydroxyethyl) -1,3-dioxane, and other cyclohexanediols , Bicyclohexyl-4,4′-diol, 2,2-bis (4-hydroxycyclohexylpropane), 2,2-bis (4- (2-hydroxyethoxy) cyclohexyl) propane, cyclopentanediol, 3-methyl- Examples include various alicyclic diols such as 1,2-cyclopentanediol, 4-cyclopentene-1,3-diol, and isosorbide, and aromatic diols such as bisphenol A, bisphenol S, and styrene glycol. In addition to diols, polyfunctional alcohols such as trimethylolpropane and pentaerythritol are preferred, and among them, cyclic diols are preferred. Further, from the viewpoint of reducing the photoelastic coefficient and improving the wavelength dispersion (reducing the double bond atom concentration), for example, cyclohexanedimethanol, spiroglycol, tricyclodecanedimethanol, decalindimethanol and the like are preferable, and spiroglycol is particularly preferable. Two or more kinds can be combined within a range not impairing the object of the present invention. For example, heat resistance, photoelastic coefficient and stretchability can be adjusted by a combination of spiroglycol and ethylene glycol. In the present invention, a particularly preferable copolymer composition is one in which spiro glycol is copolymerized in an amount of 5 to 80 mol% in the total diol component. If it is less than 5 mol%, sufficient heat resistance cannot be imparted. If it exceeds 80 mol%, the polymerization reactivity is lowered and the time required for polymerization is prolonged, resulting in thermal deterioration of the produced polymer such as polymer coloring. .

Moreover, there is no restriction | limiting in particular as a dicarboxylic acid component of polyester of this invention, The raw material of a general polyester resin can be used. Examples thereof include ester-forming derivatives such as aromatic dicarboxylic acids, chain aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, and lower alkyl esters thereof. In the present invention, a lower alkyl ester of a carboxylic acid is particularly preferred because the transesterification method is applied. Aromatic dicarboxylic acids include phthalic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, diphenylether-4,4′-dicarboxylic acid, 4,4′-diphenylmethanedicarboxylic acid, benzylmalon An acid etc. are mentioned. Examples of chain aliphatic dicarboxylic acids include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, methylmalonic acid, ethylmalonic acid, 2,2-dimethylsuccinic acid, 2,3- Examples include dimethyl succinic acid, 2,3-dimethyl succinic acid, 3-methyl glutaric acid, and 3,3-dimethyl glutaric acid. Examples of the alicyclic dicarboxylic acid include 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, cyclopentanedicarboxylic acid, 2,6-decahydronaphthalenedicarboxylic acid, 1,5 -Decahydronaphthalenedicarboxylic acid, 1,6-decahydronaphthalenedicarboxylic acid, 2,7-decahydronaphthalenedicarboxylic acid, 2,3-decahydronaphthalenedicarboxylic acid, 2,3-norbornanedicarboxylic acid, bicyclo [2,2 , 1] saturated alicyclic dicarboxylic acid such as heptane-3,4-dicarboxylic acid, cis-5-norbornene-endo-2,3-dicarboxylic acid, methyl-5-norbornene-2,3-dicarboxylic acid, cis-1,2,3,6-tetrahydrophthalic acid, methyl tetrahydrophthal Acid, 3,4,5,6 unsaturated alicyclic dicarboxylic acids such as tetrahydrophthalic acid can be exemplified. In addition to dicarboxylic acid, polyfunctional carboxylic acid components such as trimellitic acid and pyromellitic acid can also be used as the polyfunctional component.
Among these, 2,6-decalin dicarboxylic acid and 1,4-cyclohexanedicarboxylic acid are preferably used from the viewpoint of improving heat resistance and reducing the photoelastic coefficient, and 2,6-decalin dicarboxylic acid is particularly preferable. In the range that does not impair the object of the present invention, it can be used alone or in combination of two or more. For example, by using terephthalic acid and 2,6-decalin dicarboxylic acid together, the photoelastic coefficient, heat resistance, and retardation are adjusted. can do. In the present invention, a particularly preferable copolymer composition is one in which dimethyl 2,6-decahydronaphthalenedicarboxylate is copolymerized in an amount of 5 to 100 mol% in all diol components. If it is less than 5 mol%, sufficient heat resistance cannot be imparted.

  Although it does not restrict | limit especially in a transesterification catalyst and a polycondensation catalyst, various catalysts can be used.

  For example, in a transesterification catalyst, metal compounds such as alkali metals, alkaline earth metals, Zn, Co, and Mn are preferably used in addition to titanium compounds, and Mn is particularly preferable because of its high activity and excellent transparency. Further, the metal compound is preferably soluble in polyester, and acetate is particularly preferable.

  It is preferable to use a Ti, Sb, Ge compound as a polymerization catalyst for the polycondensation catalyst of the optical polyester resin. These catalysts may be used properly according to the characteristics required for the polyester resin or may be used in combination.

  In the production method of the present invention, a titanium compound in which the substituent of the titanium element compound as the transesterification catalyst or 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.

  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 method for producing a polyester of the present invention, 0.005 to 1% by weight of a phosphorus compound is added to a polyester obtained by a polycondensation reaction from a transesterification reaction from the viewpoint of thermal stability for cross-linking and black foreign matter suppression. It is necessary to add it before the condensation reaction, and the amount of the phosphorus compound includes the phosphorus compound in the phosphorus compound used as a deactivator of the transesterification catalyst used as the anti-coloring agent and the phosphorus compound of the heat stabilizer. If it exceeds 1% by weight, the polycondensation reactivity is inferior, and a remarkable effect for suppressing gelation or black foreign matter cannot be obtained. If it is less than 0.005% by weight, an effect for suppressing gelation and black foreign matter formation cannot be obtained. The addition amount of the phosphorus compound is preferably 0.006 to 0.5% by weight, more preferably 0.7 to 0.3% by weight.

  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.

  Specifically, when the production method is used, in the transesterification method, for example, when using dimethyl 2,6-decalindicarboxylate, 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, spiroglycol, ethylene glycol, Dimethyl 2,6-decalindicarboxylate, 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, spiroglycol, and ethylene glycol are charged into a reaction vessel so as to have a predetermined polymer composition. At this time, the reactivity is improved by adding 1.7 to 2.3 moles of ethylene glycol to the total dicarboxylic acid component. After melting these at about 150 ° C., a citrate chelate titanium compound and manganese acetate are added as a catalyst and stirred. At 150 ° C., these monomer components become a homogeneous molten liquid. Subsequently, methanol is distilled while gradually raising the temperature to 235 ° C., and a transesterification reaction is performed. After completion of the ester reaction, trimethyl phosphoric acid is added and water is evaporated after stirring. Further, after adding the ethylene glycol solution of germanium dioxide, the reaction product is charged into the polymerization apparatus, and while the apparatus temperature is gradually raised to the polymerization temperature of 285 ° C., the apparatus pressure is reduced from normal pressure to 0.1 Torr or less. And ethylene glycol is distilled off. As the polymerization reaction proceeds, the viscosity of the reaction product increases. When the predetermined stirring torque is reached, the reaction is terminated, and the resin is discharged from the polymerization apparatus into a water tank in a strand shape. The discharged resin is rapidly cooled in a water tank, and after winding it is made into chips with a cutter. The obtained resin is put into a water tank filled with 95 ° C. warm water and subjected to water treatment for 5 hours. After water treatment, use a dehydrator to remove moisture from the resin and remove fines. Although the resin of the present invention can be obtained in this way, it is not limited to the above method.

  The polyester resin of the present invention is a surface-forming agent, processability improver, antioxidant, ultraviolet absorber, light stabilizer, antistatic agent, lubricant, antiblocking agent, nucleating agent, plasticizer for the purpose of improving film properties. Additives such as an agent, an antifogging agent, a colorant, a dispersant, and an infrared absorber can be added.

The additive may be colorless or colored, but is preferably colorless and transparent so as not to impair the characteristics of the optical film. Examples of additives for surface formation include inorganic particles such as SiO ₂ , TiO ₂ , Al ₂ O ₃ , CaSO ₄ , BaSO ₄ , CaCO ₃ , carbon black, carbon nanotubes, fullerene, zeolite, and other metal fine powders. Etc. Preferred organic particles include, for example, particles made of an organic polymer such as cross-linked polyvinylbenzene, cross-linked acryl, cross-linked polystyrene, polyester particles, polyimide particles, and fluororesin particles, or a treatment such as coating the surface with the above organic polymer. Inorganic particles subjected to.

In addition, the optical polyester resin of the present invention may be a laminated film with another light transmissive film when formed into a film. Besides using as a retardation film, a dichroic dye can be added to the film to form a polarizing plate.
The polyester resin obtained by the method of the present invention is also preferably used for a prism sheet or a lens sheet.

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

The physical properties were measured and the effects were evaluated according to the following methods.
(1) Glass transition temperature (Tg)
It measured using the following measuring device.

Apparatus: Differential scanning calorimeter DSC-7 (manufactured by Perkin Elmer)
Measurement conditions: Under nitrogen atmosphere Measurement range: 25-300 ° C
Heating rate: 20 ° C./min According to the method for determining the midpoint glass transition temperature in 9.3 of JIS-K7121 (Rule 1987), there is an equal distance from the extended straight line of each baseline of the measurement chart to the vertical axis The temperature was defined as the point at which the straight line and the curve of the step-like change portion of the glass unit intersect.
(2) Distillate weight X
After completion of the polycondensation reaction, the total distillate weight in the reaction system was calculated. Specifically, the total amount of the sublimated distillate adhering to the polymerization vessel wall, stirring rod, and vacuum line, and the liquid distillate weight in the vacuum trap, and the weight obtained by subtracting the excess component for transesterification calculated from the charged composition. X.
(3) Intrinsic viscosity of polymer Measured at 25 ° C. using orthochlorophenol as a solvent.
(4) Wavelength dispersion R (450) / R (550)
It measured using the following measuring device.

Apparatus: Automatic birefringence meter KOBRA-21ADH / DSP (manufactured by Oji Scientific Instruments)
Measurement diameter: φ5mm
Measurement wavelength: 400 to 800 nm
The phase difference at the wavelength x (nm) was described as R (x) (nm).

    The values of R (450) (nm) and R (550) (nm) were calculated using the following Cauchy equation. There are four wavelengths used for calculation of a to d in the equation: 480.4 nm, 548.3 nm, 628.2 nm, and 752.7 nm.

R (λ) = a + b / λ ² + c / λ ⁴ + d / λ ⁶
R (450) (nm) / R (550) (nm) was calculated from the calculated R (450) (nm) and R (550) (nm).

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
Methyl 2,6-decahydronaphthalenedicarboxylate (trans ratio 69%, hereinafter DDC) 46.4 parts by mass, spiroglycol (hereinafter SPG) 33.3 parts by mass, 9,9-bis (4- (2hydroxyethoxy) Phenyl) fluorene (hereinafter referred to as BPEF) 32.0 parts by mass, ethylene glycol (hereinafter referred to as EG) 22.6 parts by mass (2 mols of the dicarboxylic acid component), respectively, and a transesterification reaction equipped with a thermometer and a stirrer After charging the apparatus and melting the contents at 150 ° C., an ethylene glycol solution was added and stirred so that the titanium compound A prepared in the Reference Example as a catalyst was 50 ppm in terms of titanium metal element with respect to the amount of polymer produced.

    The temperature was raised to 205 ° C. over 30 minutes, and methanol was distilled while raising the temperature to 235 ° C. over 60 minutes. After distillation of a predetermined amount of methanol, trimethyl phosphoric acid (hereinafter referred to as TMPA) as a catalyst deactivator is 1.38 ppm relative to the product amount and bis (2,6-di-tert-butyl-) manufactured by Asahi Denka Kogyo Co., Ltd. An EG solution containing 4-ppm of 4-methylphenyl) pentaerythritol-di-phosphite) (hereinafter referred to as PEP36) relative to the product amount was added and stirred for 5 minutes to stop the transesterification reaction.

    After adding an ethylene glycol solution containing 139 ppm of germanium dioxide in terms of phosphorus relative to the amount of product, the reaction product was charged into a polymerization apparatus equipped with a thermometer, a stirrer, and a decompression device, and the temperature in the apparatus was changed from 235 ° C. to 285 over 90 minutes. While raising the temperature to 0 ° C., the pressure in the apparatus is reduced from normal pressure to vacuum over 90 minutes to distill ethylene glycol. The reaction is terminated when the viscosity of the reaction product increases with the progress of the polymerization reaction and reaches a predetermined stirring torque. At the end of the reaction, the inside of the polymerization apparatus was returned to room temperature with nitrogen gas, the valve at the bottom of the polymerization apparatus was opened, and gut-shaped polyester was discharged into the water tank. The discharged polyester resin was quenched in a water tank and then cut with a cutter to form a chip.

A polyester chip was thus obtained. The amount of distillate X obtained by subtracting 22.6 parts by mass of excess EG for transesterification at the time of monomer charging and EG used for catalyst dilution (also excess EG for transesterification) from the distillate recovered from the polymerization apparatus, trap, etc. is The amount was 2.0 parts by mass.
(Polyester water treatment)
The obtained polyester chip was put into a water tank filled with 95 ° C. ion exchange water and water-treated for 5 hours. The chip after the water treatment was separated from the water by a dehydrator.

Table 1 shows the results of the charging composition, resin Tg, intrinsic viscosity, and X.
(Polyester film production)
The obtained polyester resin chip was dried under reduced pressure, and then formed into a film using the following hot press method. A polyimide film was stacked on a metal plate, and a metal frame having an inner frame of 8 cm square was stacked on the polyimide film. A 3.5 g chip was placed in the center of the metal frame. Further, the polyimide film and the metal plate were overlapped, preheated at 270 ° C. for 2 minutes, and then pressed at a pressure of 10 kgf / cm ² for 10 seconds.

    After the press, the metal plate with the film sandwiched in water was cooled and solidified, and the film was cut out from the metal frame.

    Further, the cut film was cut into a rectangle, and both ends in the longitudinal direction were held, and uniaxial stretching was performed in a Tg + 10 ° C. oven at a stretching rate of 1% / second and a stretching ratio of 2.5 times. Table 1 shows the measurement results of wavelength dispersion.

  As a result, the amount of excess distillate during polymerization was small and the polyester resin was excellent in heat resistance, and the film after uniaxial stretching showed reverse dispersibility.

Example 2
The amount of titanium catalyst added as the transesterification catalyst of Example 1 and the type and amount of phosphorus compound were changed, and the same titanium compound A as the transesterification catalyst was added as a polycondensation catalyst after the addition of the phosphorus compound to increase the polymerization temperature. Except that the temperature was changed to 260 ° C., a transesterification reaction, a polycondensation reaction, and film formation were performed in the same manner as in Example 1 to obtain a polyester resin and film.

  As a result, the amount of excess distillate during polymerization was small and the polyester resin was excellent in heat resistance, and the film after uniaxial stretching showed reverse dispersibility.

Example 3
Titanium catalyst seed which is the transesterification catalyst of Example 1, titanium catalyst addition amount, and phosphorus compound species and addition amount were changed, and the same titanium compound B as the transesterification catalyst was additionally added as the polycondensation catalyst after the phosphorus compound addition. Except for changing the polymerization temperature to 260 ° C., a transesterification reaction, a polycondensation reaction, and a film formation were performed in the same manner as in Example 1 to obtain a polyester resin and a film.

  As a result, the amount of excess distillate during polymerization was small and the polyester resin was excellent in heat resistance, and the film after uniaxial stretching showed reverse dispersibility.

Example 4
A polyester resin and a film were obtained by carrying out a transesterification reaction, a polycondensation reaction, and a film formation in the same manner as in Example 3 except that the amount of the titanium catalyst added as the transesterification catalyst of Example 3 was changed.

  As a result, the amount of excess distillate during polymerization was small and the polyester resin was excellent in heat resistance, and the film after uniaxial stretching showed reverse dispersibility.

Example 5
The monomer composition of Example 1 is dimethyl cyclohexanedicarboxylate (trans ratio 30%, hereinafter CHDC) 50 mol%, BPEF 30 mol%, SPG 20 mol%, and is a transesterification catalyst titanium catalyst species, titanium catalyst addition amount, and phosphorus compound species, addition Except for changing the amount, polycondensation catalyst species, and addition amount, a transesterification reaction, a polycondensation reaction, and film formation were carried out in the same manner as in Example 1 to obtain a polyester resin and a film.

  As a result, the amount of excess distillate during polymerization was small and the polyester resin was excellent in heat resistance, and the film after uniaxial stretching showed reverse dispersibility.

Example 6
The monomer composition of Example 1 was DDC 40 mol%, cis-1,2,3,6-tetrahydrophthalic acid (hereinafter referred to as THPA) 10 mol%, BPEF 30 mol%, EG 20 mol%, and the amount of titanium catalyst added as a transesterification catalyst and the amount of titanium catalyst added. A polyester resin and a film were obtained by carrying out a transesterification reaction, a polycondensation reaction, and a film formation in the same manner as in Example 1 except that the phosphorus compound species, addition amount, polycondensation catalyst species, and addition amount were changed.

  As a result, the amount of excess distillate during polymerization was small and the polyester resin was excellent in heat resistance, and the film after uniaxial stretching showed reverse dispersibility.

Comparative Example 1
The transesterification catalyst of Example 1 was changed to manganese acetate tetrahydrate and KOH, both were added in EG slurry, and the same procedure as in Example 1 was carried out except that the phosphorus compound species, addition amount, polycondensation catalyst species, and addition amount were changed. Thus, a transesterification reaction, a polycondensation reaction, and film formation were performed to obtain a polyester resin and a film.

  As a result, since the catalytic activity was reduced, the amount of excess distillate during polymerization was larger than in Example 1, and the reverse dispersibility of the film after uniaxial stretching was lowered. Moreover, Tg also fell because the reaction rate of SPG and BPEF was low.

Comparative Example 2
A polyester resin was obtained in the same manner as in Example 1 except that the addition of KOH to the transesterification catalyst of Comparative Example 1 was stopped. The charged composition and results are shown in Table 1. Since the catalytic activity was reduced, the amount of excess distillate during polymerization was larger than in Example 1, and the film after uniaxial stretching was reversely dispersed and forward-dispersed.

Comparative Example 3
A polyester resin was obtained in the same manner as in Example 1 except that the polycondensation catalyst type, amount added, and polymerization temperature in Comparative Example 2 were changed. The charged composition and results are shown in Table 1. Since the catalytic activity was small, the amount of excess distillate during polymerization was larger than in Example 1, and the reverse dispersibility of the film after uniaxial stretching was lowered. Moreover, Tg also fell because the reaction rate of SPG and BPEF was low.

Comparative Example 4
The transesterification catalyst of Example 5 was changed to manganese acetate tetrahydrate and added as an EG slurry, and the transesterification reaction was carried out in the same manner as in Example 1 except that the phosphorus compound species, addition amount, polycondensation catalyst species, and addition amount were changed. Then, a polycondensation reaction and film formation were performed to obtain a polyester resin and a film.

  As a result, since the catalytic activity was reduced, the amount of excess distillate during polymerization was large, and the film after uniaxial stretching was reduced in reverse dispersibility as compared with Example 5.

Comparative Example 5
The transesterification catalyst of Example 6 was changed to manganese acetate tetrahydrate, added as an EG slurry, and the polycondensation catalyst species and the amount added were changed in the same manner as in Example 1 except for the transesterification reaction, polycondensation reaction, and film formation. To obtain a polyester resin and a film.

  As a result, since the catalytic activity was reduced, the amount of excess distillate at the time of polymerization was large, and the film after uniaxial stretching was reduced in reverse dispersibility as compared with Example 1 and was forward-dispersed.

Comparative Example 6
Except that the transesterification catalyst amount of Example 1 was changed, a transesterification reaction, a polycondensation reaction, and film formation were carried out in the same manner as in Example 1 to obtain a polyester resin and a film.

As a result, since the catalyst activity was too high and the resin was gelled, the film after uniaxial stretching did not progress in orientation, and the reverse dispersibility was lower than that in Example 1 and forward dispersion was achieved.
In addition, the symbol of the raw material used by the Example and the comparative example is as follows.
CHDC: Dimethyl 1,4-cyclohexanecarboxylate
(Cis isomer / trans isomer = 70/30)
DDC: Dimethyl 2,6-decalin dicarboxylate (trans isomer 69 mol% or more)
THPA: cis-1,2,3,6-tetrahydrophthalic acid BPEF: 9,9-bis (4- (2hydroxyethoxy) phenyl) fluorene
[In formula (1), R ¹ is an ethyl group, corresponding to m = 1, n = 0]
SPG: Spiroglycol EG: Ethylene glycol TEPA: Triethylphosphonoacetate TMPA: Trimethyl phosphate TBT: Tetra-n-butyl titanate X: Distillate weight excluding excess components for substantial transesterification during polymerization

Claims (9)

In a method of preparing a polyester by charging all the monomer components including an alicyclic dicarboxylic acid or a derivative thereof into an ester exchange reactor, and performing a polycondensation after the ester exchange reaction, a titanium compound having a titanium element content of 5 ppm or more and 100 ppm or less, And at least one metal compound selected from the group consisting of titanium element, antimony element, and germanium element as a polycondensation reaction catalyst. A method for producing a polyester resin, wherein an optical polyester resin satisfying the following characteristics (1) and (2) is produced by polycondensation reaction by adding a total of 5 ppm or more and 500 ppm or less of each element.
Glass transition temperature is 100 ° C or higher (1)
Wavelength dispersibility of phase difference is negative (2) 2. The method for producing an optical polyester resin according to claim 1, wherein the diol component as a monomer component has a diol residue of a cyclic diol represented by the chemical formula (1).

R ¹ is the same or different alkyl group having 1 to 4 carbon atoms, and m represents an integer of 0 to 3.
R ² represents the same or different alkyl group having 1 to 30 carbon atoms, cycloalkyl group, and aryl group, and n represents an integer of 0 to 4.   The optical system according to claim 1 or 2, wherein the titanium compound containing a titanium element 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. Of manufacturing polyester resin for use in a process.   4. The optical polyester resin according to claim 3, wherein the alkoxy group 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. Method.   The metal element other than the titanium compound is a metal compound containing at least one metal element selected from the group consisting of alkaline earth metals, Zn, Co, or Mn. A method for producing an optical polyester resin according to item 1.   The method for producing an optical polyester resin according to any one of claims 1 to 5, wherein a trivalent phosphorus compound is added before the polycondensation reaction of 0.005 to 1.0% by weight.   The alicyclic dicarboxylic acid or its derivative component is dimethyl 2,6-decahydronaphthalenedicarboxylate, and is added in an amount of 5 to 100 mol% in the total dicarboxylic acid component. The manufacturing method of the polyester resin for optics of description.   The method for producing an optical polyester resin according to any one of claims 1 to 7, wherein spiroglycol is added as a diol component in an amount of 5 to 80 mol% of all diol components.   The polyester resin obtained with the manufacturing method of the optical polyester resin of any one of Claims 1-8.