Patent Description:
Imaging modules are used in applications such as video cameras, cell phones equipped with video capabilities, TV phones or camera-equipped intercoms. In recent years, optical systems used in these imaging modules are especially required to be compact. Reducing the size of optical systems results in the serious problem of chromatic aberration of the system. Therefore, chromatic aberration is known to be able to be corrected by combining an optical lens material having a high refractive index for the optical lens and high dispersion by reducing the Abbe number with an optical lens material having a low refractive index and low dispersion by increasing the Abbe number.

Although the glass conventionally used as materials of optical systems is able to realize various required optical properties as well as having superior environmental resistance, it has the problem of poor processability. In contrast, resins that are inexpensive and have superior processability in comparison with glass materials are used in optical components. In particular, resins having a fluorene skeleton or binaphthalene skeleton are used for reasons such as high refractive index. For example, a polycarbonate is described in PTL1 that uses <NUM>,<NUM>'-bis(<NUM>-hydroxyethoxy)-<NUM>,<NUM>'-binaphthalene. PTL2 describes a thermoplastic resin that uses <NUM>,<NUM>-bis[<NUM>-(<NUM>-hydroxyethoxy)-<NUM>-phenylphenyl]fluorene. PTL3 describes a resin that uses <NUM>,<NUM>-bis[<NUM>-(<NUM>-hydroxyethoxy)-<NUM>-phenylphenyl]fluorene and <NUM>,<NUM>'-bis(<NUM>-hydroxyethoxy)-<NUM>,<NUM>'-binaphthalene. The refractive indices of these resins range from <NUM> to <NUM>, still having room for improvement. PTL4 describes a polyester resin that uses <NUM>,<NUM>'-bis(ethoxycarbonylmethoxy)-<NUM>,<NUM>'- binaphthyl and <NUM>,<NUM>-bis[<NUM>-(<NUM>-hydroxyethoxy)-<NUM>-phenylphenyl]fluorene, PTL5 and PTL6 describe a polycarbonate that uses <NUM>,<NUM>-bis[<NUM>-(<NUM>-hydroxyethoxy)-<NUM>-naphthyl]fluorene and indicate a resin having a refractive index of <NUM>-<NUM>. PTL7 describes a polycarbonate that uses <NUM>,<NUM>-bis[<NUM>-(<NUM>- hydroxyethoxy)phenyl]-<NUM>,<NUM>-benzofluorene. The contents of this literature are incorporated in the present description by reference. However, although these resins have a high refractive index, they have room for improvement with respect to birefringence and inadequate balance between heat resistance and formability. <CIT> aims to provide a novel production method of a poly(ester)carbonate and describes a production method of a poly(ester)carbonate, including subjecting a diol and a carbonate ester to a transesterification reaction in the presence of a catalyst, wherein the catalyst comprises aluminum or a compound thereof, and a phosphorus compound. <CIT> relates to the problem to obtain a resin composition having excellent transparency, low optical anisotropy, high refractive index and low hygroscopicity, useful for high-performance optical plastic lens, especially an aspherical lens by making the composition include a resin containing a specific biaryl compound as a monomer component. As a solution to the problem, the document describes a composition which comprises a resin containing a biaryl compound as a monomer component which is bonded with a bond axis to be provided with an inner rotation anisotropy and has the number of π electrons of at least one aryl group of 4n+<NUM> (n is a natural number) based on the bond axis. <CIT> relates to the problem to provide a resin excellent in optical properties such as high refractive index and low birefringence and having high thermostability, particularly a thermoplastic resin having high thermostability and excellent in optical properties. As a solution to the problem, the document describes a thermoplastic resin which contains a repeating unit represented by formula (<NUM>) of <NUM> mol% or more in all the units. <CHM><CIT>
relates to the problem to provide a thermoplastic resin which has high refractive index, low birefringence and high heat resistance, especially a thermoplastic resin which has excellent optical characteristics. As a solution to the problem, the document describes a thermoplastic resin which contains <NUM> mol% or more of repeating units represented by the above general formula (<NUM>) or the following general formula (<NUM>) in all units.

In formula (<NUM>), each of R<NUM> and R<NUM> independently represents a hydrocarbon group which may contain an aromatic group having <NUM>-<NUM> carbon atoms; each of n and m independently represents an integer of <NUM> or more; each of R<NUM>-R<NUM> independently represents a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom or a hydrocarbon group which may contain an aromatic group having <NUM>-<NUM> carbon atoms; each of R<NUM> and R<NUM> independently represents a hydrocarbon group which may contain an aromatic group having <NUM>-<NUM> carbon atoms; each of o and p independently represents an integer of <NUM> or more; and each of R<NUM> and R<NUM> independently represents a hydrogen atom or a hydrocarbon group which may contain an aromatic group having <NUM>-<NUM> carbon atoms. In formula (<NUM>), each of R<NUM> and R<NUM> independently represents a hydrocarbon group which may contain an aromatic group having <NUM>-<NUM> carbon atoms; each of n and m independently represents an integer of <NUM> or more; each of R<NUM>-R<NUM> independently represents a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom or a hydrocarbon group which may contain an aromatic group having <NUM>-<NUM> carbon atoms; each of R<NUM> and R<NUM> independently represents a hydrocarbon group which may contain an aromatic group having <NUM>-<NUM> carbon atoms; each of o and p independently represents an integer of <NUM> or more; and each of R<NUM>-R<NUM> independently represents a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom or a hydrocarbon group which may contain an aromatic group having <NUM>-<NUM> carbon atoms.

Therefore, an object of the present invention is to provide a polyester resin or polyester carbonate resin that has a high refractive index, low birefringence and superior balance between heat resistance and formability.

As a result of conducting extensive research to solve this object, the inventors of the present invention found that a polyester resin or polyester carbonate resin having a fluorene skeleton containing a specific aromatic group and binaphthalene skeleton has a high refractive index, low birefringence and superior balance between heat resistance and formability, thereby leading to completion of the present invention.

Namely, the present invention is as indicated below.

The industrial effects demonstrated by the polyester resin or polyester carbonate resin of the present invention are extraordinary since it has a high refractive index, low birefringence and a superior balance between heat resistance and formability.

<FIG> indicates the <NUM>H-NMR spectrum of a polyester carbonate resin obtained in Example <NUM>.

The following provides a more detailed explanation of the present invention.

The polyester resin or polyester carbonate resin of the present invention contains the repeating units represented by the following formulas (<NUM>) and (<NUM>), wherein the ratio between the repeating unit represented by formula (<NUM>) and the repeating unit represented by formula (<NUM>) is <NUM>:<NUM> to <NUM>:<NUM>:
<CHM>
(wherein,.

In a preferable aspect of the polyester resin or polyester carbonate resin of the present invention, examples of the polycyclic aromatic hydrocarbon groups represented by rings Z<NUM> and Z<NUM> in formula (<NUM>) preferably include condensed polycyclic aromatic groups having at least <NUM> to <NUM> carbon atoms and more preferably include those having a benzene ring skeleton, and condensed bicyclic hydrocarbon groups or condensed tricyclic hydrocarbon group and the like are preferable. Examples of condensed bicyclic hydrocarbon groups preferably include aromatic hydrocarbon groups having <NUM> to <NUM> carbon atoms such as an indene ring or naphthalene ring, and more preferably include condensed bicyclic hydrocarbon groups having <NUM> to <NUM> carbon atoms. In addition, examples of condensed tricyclic hydrocarbon groups preferably include an anthracene ring and phenanthrene ring. These polycyclic aromatic hydrocarbon groups may have substituents.

In a preferable aspect of the polyester resin or polyester carbonate resin of the present invention, Z<NUM> and Z<NUM> of formula (<NUM>) represent naphthalene-diyl groups.

Examples of polycyclic aromatic hydrocarbon groups represented by rings Z<NUM> and Z<NUM> in formula (<NUM>) preferably include naphthalene-<NUM>,<NUM>-diyl groups and naphthalene-<NUM>,<NUM>-diyl groups, and more preferably include naphthalene-<NUM>,<NUM>-diyl groups.

In a preferable aspect of the polyester resin or polyester carbonate resin of the present invention, formula (<NUM>) is composed of units represented by the following formula (<NUM>):
<CHM>
(wherein,
R<NUM>, R<NUM>, R<NUM> and R<NUM> respectively and independently represent a hydrocarbon group that may contain an aromatic group having <NUM> to <NUM> carbon atoms, R<NUM>-R<NUM> and R<NUM>-R<NUM> represent hydrogen atoms or aliphatic or aromatic substituents, j, k, r and s respectively and independently represent an integer of <NUM> or more, and m, n, p and q respectively and independently represent <NUM> or <NUM>).

Examples of R<NUM>-R<NUM> and R<NUM>-R<NUM> in formula (<NUM>) more preferably include hydrogen atoms, halogen atoms, alkyl groups, cycloalkyl groups, alkoxy groups and cycloalkyloxy groups, and even more preferably include hydrogen atoms.

In a preferable aspect of the polyester resin or polyester carbonate resin of the present invention, R<NUM>, R<NUM>, R<NUM>, R<NUM>, R<NUM> and R<NUM> respectively and independently represent a hydrocarbon group having <NUM> to <NUM> carbon atoms that may contain an aromatic group, and preferable examples thereof include an alkylene group such as a methylene group, ethylene group, propylene group or butylene group, and an arylene group such as a phenylene group or naphthalene-diyl group. Among these, a methylene group or ethylene group is more preferable. In particular, R<NUM>, R<NUM>, R<NUM> and R<NUM> preferably represent ethylene groups. In addition, R<NUM> and R<NUM> preferably represent methylene groups.

In a preferable aspect of the polyester resin or polyester carbonate resin of the present invention, R<NUM>-R<NUM> in formulas (<NUM>) and (<NUM>) preferably represent hydrogen atoms, halogen atoms, alkyl groups, cycloalkyl groups, alkoxy groups and cycloalkyloxy groups, and among these, hydrogen atoms are more preferable.

In a preferable aspect of the polyester resin or polyester carbonate resin of the present invention, R<NUM>-R<NUM>, R<NUM>-R<NUM> and R<NUM>-R<NUM> in formulas (<NUM>) and (<NUM>) represent hydrogen atoms or substituents, hydrogen atoms are preferable, and specific examples of substituents preferably include halogen atoms, alkyl groups, cycloalkyl groups, aryl groups, aralkyl groups, alkoxy groups, cycloalkyloxy groups, aryloxy groups and aralkyloxy groups.

Preferable examples of halogen atoms include fluorine atoms, chlorine atoms and bromine atoms.

Specific examples of alkyl groups preferably include methyl groups, ethyl groups, propyl groups, isopropyl groups, butyl groups and t-butyl groups, more preferably include alkyl groups having <NUM> to <NUM> carbon atoms, and even more preferably include methyl groups or ethyl groups.

Specific examples of cycloalkyl groups preferably include cyclopentyl groups, cyclohexyl groups, cycloheptyl groups, cyclooctyl groups, cyclodecanyl groups, cyclododecanyl groups and <NUM>-tert-butylcyclohexyl groups, and more preferably include cyclohexyl groups.

Specific examples of aryl groups preferably include phenyl groups, alkylphenyl groups (mono- and dimethylphenyl groups such as tolyl groups, <NUM>-methylphenyl groups or xylyl groups) and naphthyl groups, more preferably include phenyl groups and naphthyl groups, and even more preferably include phenyl groups.

Specific examples of aralkyl groups preferably include benzyl groups and phenethyl groups, and more preferably include benzyl groups.

Specific examples of alkoxy groups preferably include methoxy groups, ethoxy groups, propoxy groups, isopropoxy groups and butoxy groups, more preferably include alkoxy groups having <NUM> to <NUM> carbon atoms, and even more preferably include methoxy groups and ethoxy groups.

Specific examples of cycloalkyloxy groups preferably include cyclopentyloxy groups, cyclohexyloxy groups, cycloheptyloxy groups and cyclooctyloxy groups, and more preferably include cyclohexyloxy groups.

Specific examples of aryloxy groups preferably include phenoxy groups, alkylphenoxy groups (mono- or dimethylphenoxy groups) and naphthyloxy groups, more preferably include phenoxy groups and naphthyloxy groups, and even more preferably include phenoxy groups.

Specific examples of aralkyloxy groups preferably include benzyloxy groups and phenethyloxy groups, and more preferably include benzyloxy groups.

It is known that the refractive index of a substance can be increased by increasing the electron density of the molecule and reducing molecular volume based on the relational expression between molecular structure and refractive index conventionally known as the Lorentz-Lorenz formula. The resins having a fluorene skeleton and binaphthalene skeleton indicated in PTL1-<NUM> demonstrate an increase in refractive index by comprising a large number of aromatic groups within the molecule based on this theory. However, although these resins demonstrate high refractive indices, birefringence and the balance between heat resistance and formability are inadequate.

The specific ester structure represented by formula (<NUM>) of the present invention demonstrates a high refractive index, low birefringence and contributes to high heat resistance, while the specific ester structure represented by formula (<NUM>) demonstrates a high refractive index, although lower than formula (<NUM>), low birefringence, and contributes to formability as a result of lowering the glass transition temperature of the resin. Accordingly, the polyester resin or polyester carbonate resin comprising the repeating units represented by formulas (<NUM>) and (<NUM>) have a high refractive index, low birefringence and balance between heat resistance and formability.

The component ratio of the resin in the present invention indicates the molar ratio of the monomer structure introduced into the resin based on the number of moles of all monomer units. Furthermore, all monomer units referred to here do not include the carbonic acid unit used to produce the polyester carbonate resin.

A repeating unit in the present invention refers to the minimum unit that makes a connection with ester bonds and/or carbonate bonds. The repeating unit of ester bonds refers to a structural unit formed from diol components and dicarboxylic acid units, while the repeating unit of carbonate bonds refers to the structural unit formed from a diol derivative and carbonic acid component.

The molar ratio between the repeating unit represented by formula (<NUM>) and the repeating unit represented by formula (<NUM>) of the polyester resin or polyester carbonate resin of the present invention is <NUM>:<NUM> to <NUM>:<NUM>.

The molar ratio between the repeating unit represented by formula (<NUM>) and the repeating unit represented by formula (<NUM>) is preferably <NUM>:<NUM> to <NUM>:<NUM> and more preferably <NUM>:<NUM> to <NUM>:<NUM>. There is a superior balance between high refractive index and birefringence if within the aforementioned ranges.

In the resin of the present invention, the repeating units represented by formulas (<NUM>) and (<NUM>) may each be present at <NUM> mol% or more, <NUM> mol% or more, <NUM> mol% or more, <NUM> mol% or more or <NUM> mol% or more, and may be present at <NUM> mol% or less, <NUM> mol% or less, <NUM> mol% or less, <NUM> mol% or less, <NUM> mol% or less or <NUM> mol% or less. For example, these repeating units may each be present in the resin at <NUM> mol% to <NUM> mol% or <NUM> mol% to <NUM> mol%.

In the case the resin of the present invention is a polyester carbonate resin in particular, a repeating unit comprised of carbonate bonds is contained in addition to the repeating unit represented by formula (<NUM>) and the repeating unit represented by formula (<NUM>). The repeating unit comprised of carbonate bonds may be a repeating unit in which a portion of the ester bonds of the repeating units represented by formulas (<NUM>) to (<NUM>) have simply been changed to carbonate bonds. The repeating units comprised of carbonate bonds in the polyester carbonate resin of the present invention may be present at <NUM> mol% or more, <NUM> mol% or more, <NUM> mol% or more or <NUM> mol% or more, and may be present at <NUM> mol% or less, <NUM> mol% or less, <NUM> mol% or less, <NUM> mol% or less or <NUM> mol% or less. For example, the repeating unit may be present at <NUM> mol% to <NUM> mol% or <NUM> mol% to <NUM> mol% in the resin.

In addition, repeating units other than the repeating unit of formula (<NUM>), the repeating unit of formula (<NUM>) and repeating unit in which a portion of the ester bonds thereof have been changed to carbonate bonds may not be present, or may be present at <NUM> mol% or more, <NUM> mol% or more, <NUM> mol% or more or <NUM>% or more or may be present at <NUM> mol% or less, <NUM> mol% or less, <NUM> mol% or less, <NUM> mol% or less or <NUM> mol% or less.

In a preferable aspect of the polyester resin or polyester carbonate resin of the present invention, specific viscosity is preferably <NUM> to <NUM>, more preferably <NUM> to <NUM>, and even more preferably <NUM> to <NUM>. Furthermore, specific viscosity is preferably within the aforementioned ranges since this results in superior balance between formability and mechanical strength. Furthermore, specific viscosity is the specific viscosity (ηsp) obtained by measuring at <NUM> using solution obtained by dissolving <NUM>% by weight in methylene chloride (solution obtained by dissolving <NUM> of resin in <NUM> of methylene chloride).

In a preferable aspect of the polyester resin or polyester carbonate resin of the present invention, refractive index at a wavelength of <NUM> measured at <NUM> (abbreviated as nD) is preferably <NUM>-<NUM>, more preferably <NUM>-<NUM>, even more preferably <NUM>,<NUM>-<NUM>, still more preferably <NUM>-<NUM> and most preferably <NUM>-<NUM>. In the case the refractive index is equal to or greater than the lower limit, spherical aberration of the lens can be reduced and focal distance of the lens can be shortened.

Although the polyester resin or polyester carbonate resin of the present invention has a high refractive index, it also preferably has a low Abbe number. The Abbe number (v) is preferably <NUM>-<NUM>, more preferably <NUM>-<NUM> and even more preferably <NUM>-<NUM>. The Abbe number is calculated using the following formula from the refractive indices at wavelengths of <NUM>, <NUM> and <NUM> measured at <NUM>:<MAT>.

In a preferable aspect of the polyester resin or polyester carbonate resin of the present invention, the glass transition temperature (Tg) is preferably <NUM> to <NUM>, more preferably <NUM> to <NUM> and even more preferably <NUM> to <NUM>. If the glass transition temperature is within the aforementioned ranges, the balance between heat resistance and formability is superior, thereby making this preferable.

In a preferable aspect of the polyester resin or polyester carbonate resin of the present invention, the absolute value of orientation birefringence (|Δn|)is preferably within the range of <NUM> × <NUM>-<NUM> to <NUM> × <NUM>-<NUM>, more preferably <NUM> × <NUM>-<NUM> to <NUM> × <NUM>-<NUM>, and even more preferably <NUM> × <NUM>-<NUM> to <NUM> × <NUM>-<NUM>.

|Δn| is determined according to the following formula by stretching a <NUM> film obtained from the polyester resin or polyester carbonate resin of the present invention two-times at a temperature <NUM> higher than Tg and measuring the retardation at a wavelength of <NUM>. If |Δn is within the aforementioned ranges, optical distortion of the lens is reduced thereby making this preferable.

In a preferable aspect of the polyester resin or polyester carbonate resin of the present invention, the total light transmittance for a thickness of <NUM> is preferably <NUM>% or more, more preferably <NUM>% or more and even more preferably <NUM>% or more. If total light transmittance is within the aforementioned ranges, the resin is suitable as an optical member. Furthermore, total light transmittance is measured for a molded piece having a thickness of <NUM> using the NDH-300A manufactured by Nippon Denshoku Industries Co.

In a preferable aspect of the polyester resin or polyester carbonate resin of the present invention, the degree of coloring, and particularly yellowish coloring, is preferably low. More specifically, the b* value of the CIE1976 (L* a* b*) color system is preferably <NUM> or less, <NUM> or less, <NUM> or less or <NUM> or less. The b* value is more preferably <NUM> or less and even more preferably <NUM> or less. This b* value is the value of the CIE1976 (L* a* b*) color system measured with a spectrophotometer for a solution obtained by dissolving <NUM> in <NUM> of methylene chloride (solution obtained by dissolving in methylene chloride to <NUM>% by weight).

In a preferable aspect of the polyester resin or polyester carbonate resin of the present invention, water absorption after immersing for <NUM> hours at <NUM> is preferably <NUM>% by weight or less and more preferably <NUM>% by weight or less. If water absorption is within the aforementioned ranges, changes in optical properties caused by absorption of water are small, thereby making this preferable.

In a preferable aspect of the polyester resin or polyester carbonate resin of the present invention, the amount of terminal carboxylic acid may be <NUM> equivalents/ton or less, <NUM> equivalents/ton or less, <NUM> equivalents/ton or less or <NUM> equivalents/ton or less, and preferably <NUM> equivalent/ton or less. If the amount of terminal carboxylic acid is greater than <NUM> equivalents/ton, the carboxylic acid acts as a catalyst of hydrolysis of ester bonds, which may exacerbate wet heat resistance. If the amount of terminal carboxylic acid is <NUM> equivalents/ton or less, wet heat resistance is superior, thereby making this preferable. The amount of terminal carboxylic acid can be measured by titration after having dissolved <NUM> of resin in <NUM> of benzyl alcohol at <NUM> in a nitrogen atmosphere.

In a preferable aspect of the polyester resin or polyester carbonate resin of the present invention, wet heat resistance can be evaluated by treating in an environment at a temperature of <NUM> and relative humidity of <NUM>% for a prescribed amount of time followed by comparing specific viscosity of the resin before and after treatment. More specifically, wet heat resistance can be calculated with the formula below.

Wet heat resistance after treating for <NUM> hours is preferably <NUM>% or more, more preferably <NUM>% or more, and even more preferably <NUM>% or more.

The following provides an explanation of specific raw materials used in the polyester resin or polyester carbonate resin of the present invention.

The diol component serving as a raw material of formula (<NUM>) of the present invention is a mainly a diol component represented by the following formula (a) and may be used alone or two or more types thereof may be used in combination.

In formula (a), Z<NUM>, Z<NUM>, R<NUM>-R<NUM>, j, k, m, n, p and q are the same as defined in formula (<NUM>).

Although the following indicates typical specific examples of the diol component represented by formula (a), the raw material used in formula (<NUM>) of the present invention is not limited thereto.

More specifically, preferable examples include <NUM>,<NUM>-bis(<NUM>-(<NUM>-hydroxyethoxy)-<NUM>-naphthyl) fluorene, <NUM>,<NUM>-bis(<NUM>-(<NUM>-hydroxypropoxy)-<NUM>-naphthyl) fluorene, <NUM>,<NUM>-bis(<NUM>-(<NUM>-hydroxyethoxy)-<NUM>-naphthyl) fluorene, <NUM>,<NUM>-bis(<NUM>-(<NUM>-hydroxypropoxy)-<NUM>-naphthyl) fluorene, <NUM>,<NUM>-bis(<NUM>-hydroxy-<NUM>-naphthyl) fluorene and <NUM>,<NUM>-bis(<NUM>-hydroxy-<NUM>-naphthyl) fluorene. Among these, <NUM>,<NUM>-bis(<NUM>-(<NUM>-hydroxyethoxy)-<NUM>-naphthyl) fluorene, <NUM>,<NUM>-bis(<NUM>-(<NUM>-hydroxyethoxy)-<NUM>-naphthyl) fluorene, <NUM>,<NUM>-bis(<NUM>-hydroxy-<NUM>-naphthyl) fluorene and <NUM>,<NUM>-bis(<NUM>-hydroxy-<NUM>-naphthyl) fluorene are more preferable, and <NUM>,<NUM>-bis(<NUM>-(<NUM>-hydroxyethoxy)-<NUM>-naphthyl) fluorene and <NUM>,<NUM>-bis(<NUM>-(<NUM>-hydroxyethoxy)-<NUM>-naphthyl) fluorene are even more preferable.

These may be used alone or two or more types may be used in combination.

The diol component serving as a raw material of formula (<NUM>) of the present invention is mainly a diol component represented by the following formula (b), and may be used alone or two or more types may be used in combination.

In formula (b), R<NUM>-R<NUM>, t and u are the same as defined in formula (<NUM>).

Although the following indicates typical specific examples of the diol component represented by formula (b), the raw material used in formula (<NUM>) of the present invention is not limited thereto.

More specifically, preferable examples include <NUM>,<NUM>'-bis(<NUM>-hydroxyethoxy)-<NUM>,<NUM>'-binaphthyl, <NUM>,<NUM>'-bis(<NUM>-hydroxyethoxy)-<NUM>,<NUM>'-diphenyl-<NUM>,<NUM>'-binaphthyl, <NUM>,<NUM>'-bis(<NUM>-hydroxyethoxy)-<NUM>,<NUM>'-diphenyl-<NUM>,<NUM>'-binaphthyl, <NUM>,<NUM>'-bis(<NUM>-hydroxyethoxy)-<NUM>,<NUM>'-diphenyl-<NUM>,<NUM>'-binaphthyl, <NUM>,<NUM>'-bis(<NUM>-hydroxyethoxy)-<NUM>,<NUM>'-dimethyl-<NUM>,<NUM>'-binaphthyl, <NUM>,<NUM>'-bis(<NUM>-hydroxyethoxy)-<NUM>,<NUM>'-dimethyl-<NUM>,<NUM>'-binaphthyl, <NUM>,<NUM>'-bis(<NUM>-hydroxyethoxy)-<NUM>,<NUM>'-dimethyl-<NUM>,<NUM>'-binaphthyl, <NUM>,<NUM>'-bi-<NUM>-naphthol, <NUM>,<NUM>'-dihydroxy-<NUM>,<NUM>'-diphenyl-<NUM>,<NUM>'-binaphthyl, <NUM>,<NUM>'-dihydroxy-<NUM>,<NUM>'-diphenyl-<NUM>,<NUM>'-binaphthyl and <NUM>,<NUM>'-dihydroxy-<NUM>,<NUM>'-diphenyl-<NUM>,<NUM>'-binaphthyl. Among these, <NUM>,<NUM>'-bis(<NUM>-hydroxyethoxy)-<NUM>,<NUM>'-binaphthyl and <NUM>,<NUM>'-bi-<NUM>-naphthol are more preferable, and <NUM>,<NUM>'-bis(<NUM>-hydroxyethoxy)-<NUM>,<NUM>'-binaphthyl is even more preferable.

The polyester resin or polyester carbonate resin of the present invention may also have other diol components copolymerized to a degree that does not impair the characteristics of the present invention. Other diol components are preferable present at less than <NUM> mol% in all repeating units.

Diol components known in the art can be used as other diol components able to be used in the polyester resin or polyester carbonate resin of the present invention, and in addition to the diols described in paragraph [<NUM>] of PTL7, examples thereof include <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl) fluorene, <NUM>,<NUM>-bis(<NUM>-hydroxy-<NUM>-methylphenyl) fluorene, <NUM>,<NUM>-bis(<NUM>-hydroxy-<NUM>-cyclohexylphenyl) fluorene, <NUM>,<NUM>-bis(<NUM>-hydroxy-<NUM>-phenylphenyl) fluorene, <NUM>,<NUM>-bis(<NUM>-(<NUM>-hydroxyethoxy)phenyl) fluorene, <NUM>,<NUM>-bis(<NUM>-(<NUM>-hydroxyethoxy)-<NUM>-methylphenyl) fluorene, <NUM>,<NUM>-bis(<NUM>-(<NUM>-hydroxyethoxy)-<NUM>-cyclohexylphenyl) fluorene, <NUM>,<NUM>-bis(<NUM>-(<NUM>-hydroxyethoxy)-<NUM>-phenylphenyl) fluorene and <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl) anthrone, and these may be used alone or two or more types may be used in combination.

Dicarboxylic acids represented by the following formula (c) or ester-forming derivatives thereof are preferably used as dicarboxylic acid components used in the units represented by formula (<NUM>) and formula (<NUM>) of the polyester resin or polyester carbonate resin of the present invention.

In formula (c), R<NUM>-R<NUM>, r and s are the same as defined in formula (<NUM>).

Although the following indicates typical specific examples of dicarboxylic acids represented by formula (c) or ester-forming derivatives thereof, the raw material used in formula (c) of the present invention is not limited thereto.

More specifically, preferable examples include <NUM>,<NUM>'-biphenyl dicarboxylic acid, <NUM>,<NUM>'-bis(carboxymethoxy)-<NUM>,<NUM>'-binaphthyl, <NUM>,<NUM>'-bis(<NUM>-carboxyethoxy)-<NUM>,<NUM>'-binaphthyl, <NUM>,<NUM>'-bis(<NUM>-carboxypropoxy)-<NUM>,<NUM>'-binaphthyl, <NUM>,<NUM>'-bis(<NUM>-carboxy-<NUM>-methylpropoxy)-<NUM>,<NUM>'-binaphthyl and <NUM>,<NUM>'-bis(<NUM>-carboxyphenylmethoxy)-<NUM>,<NUM>'-binaphthyl, and <NUM>,<NUM>'-bis(carboxymethoxy)-<NUM>,<NUM>'-binaphthyl is more preferable.

These may be used alone or two or more types may be used in combination. In addition, acid chlorides, methyl esters, ethyl esters, phenyl esters and other esters may be used as ester-forming derivatives.

Other dicarboxylic acid components may be copolymerized to a degree that does not impair the characteristics of the present invention for use as dicarboxylic acid components in the polyester resin or polyester carbonate resin of the present invention. These other dicarboxylic acid components are preferably present at less than <NUM> mol% in all repeating units.

Carboxylic acid components known in the art can be used as other dicarboxylic acid components used in the polyester resin or polyester carbonate resin of the present invention, and for example, carboxylic acid components as described in paragraph [<NUM>] of PTL7 can be used.

A production method known in the art can be used for the production method of the polyester resin of the present invention, and for example, the production method described in paragraphs [<NUM>] to [<NUM>] of PTL7 can be used.

The polyester carbonate resin of the present invention can be obtained by reacting a diol component and dicarboxylic acid component or ester-forming derivative thereof with a carboxylic acid-forming derivative such as phosgene or carbonate diester by interfacial polymerization or melt polymerization, and a catalyst, terminal stopping agent or antioxidant and the like may also be used.

In the case of using interfacial polymerization, a solution obtained by dissolving dicarboxylic acid chloride in an organic solvent incompatible with water (organic phase) with an aqueous alkaline solution containing an aromatic diol and polymerization catalyst (aqueous phase) followed by reacting with phosgene. The reaction temperature is <NUM> to <NUM> and preferably <NUM> or lower, and the polymerization reaction is preferably carried out for <NUM>-<NUM> hours while stirring.

A solvent that is incompatible with water and dissolves the polyester resin of the present invention is preferable for the solvent used for the organic phase. Preferable examples of such solvents include methylene chloride, <NUM>,<NUM>-dichloroethane, chloroform, chlorobenzene and other chlorine-based solvents and toluene, benzene, xylene and other aromatic hydrocarbon-based solvents, and methylene chloride is more preferable in terms of being easy to use during production.

Preferable examples of aqueous alkaline solutions used in the aqueous phase included aqueous solutions of sodium hydroxide, potassium hydroxide or sodium carbonate.

Catalysts in the manner of tertiary amines, quaternary ammonium compounds or quaternary phosphonium compounds such as trimethylamine, tetra-n-butyl ammonium bromide or tetra-n-butyl phosphonium bromide can be used to accelerate the reaction.

The reaction using melt polymerization is normally a transesterification reaction between the diol component, dicarboxylic acid or ester-forming derivative thereof and a carbonate-forming derivative, and is carried out by mixing the diol component and dicarboxylic acid or ester-forming derivative thereof with the carbonate-forming derivative while heating in the presence of an inert gas followed by distilling off the water formed during the reaction along with hydroxyl compounds such as alcohols or phenol.

The reaction preferably proceeds as indicated below in the case of polymerization using a dicarboxylic acid component and carbonate-forming derivative as raw material monomers in particular. In the first stage of the reaction, an ester condensation reaction between the diol component and dicarboxylic acid component is allowed to proceed. In this reaction, water is produced as a by-product and the reaction is able to proceed even in the absence of a catalyst. After having removed water outside the system, in the second stage of condensation polymerization, a transesterification reaction is allowed to proceed with the carbonate-forming derivative, a polyester carbonate is preferably formed while hydroxyl compounds such as alcohols and phenol are produced as by-products, and this reaction preferably proceeds in the presence of a catalyst to be subsequently described.

Although varying according to the diol component used, the reaction temperature is preferably <NUM> to <NUM>, more preferably <NUM> to <NUM> and even more preferably <NUM> to <NUM>. The degree of vacuum is changed in steps and is ultimately made to be <NUM> kPa or less to distill off water formed and hydroxyl compounds such as alcohols and phenol outside the system. The reaction time is normally preferably about <NUM> hour to <NUM> hours.

Preferable examples of the carbonate-forming derivative include esters of optionally substituted aryl groups or aralkyl groups having <NUM> to <NUM> carbon atoms and alkyl groups having <NUM> to <NUM> carbon atoms. More specifically, preferable examples include diphenyl carbonate, ditolyl carbonate, bis(chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, bis(biphenyl) carbonate, dimethyl carbonate, diethyl carbonate and dibutyl carbonate, and among these, diphenyl carbonate is more preferable.

In addition, a catalyst can be used to increase the degree of polymerization in the case of melt polymerization. Examples of catalysts that can be used preferably include catalysts normally used in esterification reactions and transesterification reactions such as alkaline metal compounds such as lithium acetate, sodium hydroxide, potassium hydroxide and sodium and potassium salts of divalent phenols, alkaline earth metal compounds such as calcium hydroxide, barium hydroxide or magnesium hydroxide, nitrogen-containing basic compounds such as tetramethyl ammonium hydroxide, tetraethyl ammonium hydroxide, trimethylamine or triethylamine, alkoxides of alkaline metals and alkaline earth metals, organic acid salts of alkaline metals and alkaline earth metals, zinc compounds, boron compounds, aluminum compounds, silicon compounds, germanium compounds, organic tin compounds, lead compounds, osmium compounds, antimony compounds, manganese compounds, magnesium compounds, titanium compounds, cobalt compounds and zirconium compounds. Among these, aluminum, tin, titanium and germanium compounds are more preferable from the viewpoints of resin melt stability and hue, while aluminum compounds are even more preferable.

The catalyst may be used alone or two or more types may be used in combination, and another compound may be used in combination as a co-catalyst. The amount of these polymerization catalysts used is preferably within the range of <NUM> × <NUM>-<NUM> to <NUM> × <NUM>-<NUM> moles based on a total of <NUM> mole for the total amount of all monomer units.

The aluminum or compound thereof preferably used as a catalyst has activity as a catalyst for polymerizing the polyester carbonate resin by an esterification reaction. The aluminum or aluminum compound acts as a catalyst of a carbonate formation reaction during polymerization that uses the diol component, dicarboxylic acid component and carbonate-forming derivative as monomer raw materials in particular.

Preferable examples of this aluminum or aluminum compound include aluminum metal, aluminum salts, aluminum chelate compounds, organic aluminum compounds and inorganic aluminum compounds.

Preferable examples of aluminum salts include organic acid salts and inorganic acid salts of aluminum. Examples of organic acid salts of aluminum include aluminum carboxylic acid salts, and specific preferable examples thereof include aluminum formate, aluminum acetate, aluminum propionate, aluminum oxalate, aluminum acrylate, aluminum laurate, aluminum stearate, aluminum benzoate, aluminum trichloroacetate, aluminum lactate, aluminum citrate and aluminum salicylate. Preferable examples of inorganic acid salts of aluminum include aluminum chloride, aluminum hydroxide, aluminum carbonate, aluminum phosphate and aluminum phosphonate.

Preferable examples of aluminum chelate compounds include aluminum acetyl acetonate, aluminum acetyl acetate, aluminum ethyl acetoacetate and aluminum ethyl acetoacetate di-isopropoxide.

Preferable examples of organic aluminum compounds include aluminum alkoxides such as trialkylaluminum, dialkylaluminum alkoxides, alkylaluminum dialkoxides, aluminum trialkoxides and hydrolysates thereof, and more specifically, preferable examples include aluminum methoxide, aluminum ethoxide, aluminum n-propoxide, aluminum isopropoxide, aluminum n-butoxide, aluminum tert-butoxide and other aluminum alkoxides, trimethyl aluminum, triethyl aluminum and hydrolysates thereof. Preferable examples of inorganic aluminum compounds include aluminum oxide.

In particular, carboxylic acid salts, inorganic acid salts and chelate compounds of aluminum are preferable, and among these, aluminum acetate, aluminum chloride, aluminum hydroxide, aluminum hydroxychloride and aluminum acetyl acetonate are more preferable.

Other compounds may be used in combination with these aluminum compounds as cocatalysts, and phosphorous compounds in particular improve the catalytic activity of aluminum or compounds thereof in a polymerization reaction of the polyester carbonate resin.

Examples of such phosphate compounds include phosphonic acid-based compounds, phosphinic acid-based compounds, phosphine oxide-based compounds, phosphonous acid-based compounds, phosphinous acid-based compounds and phosphine-based compounds. Among these, preferable examples include phosphonic acid-based compounds, phosphinic acid-based compounds and phosphine oxide-based compounds, while more preferable examples include phosphonic acid-based compounds.

Preferable examples of phosphonic acid-based compounds include dimethyl methylphosphonate, diethyl methylphosphonate, dihexyl methylphosphonate, dioctyl methylphosphonate, diphenyl methylphosphonate, dimethyl phenylphosphonate, diethyl phenylphosphonate, dihexyl phenylphosphonate, dioctyl phenylphosphonate, diphenyl phenylphosphonate, dimethyl benzylphosphonate, diethyl benzylphosphonate, dihexyl benzylphosphonate, dioctyl benzylphosphonate, diphenyl benzylphosphonate, dimethyl p-methylbenzylphosphonate, diethyl p-methylbenzylphosphonate, dihexyl p-methylbenzylphosphonate, dioctyl p-methylbenzylphosphonate, diphenyl p-methylbenzylphosphonate, dimethyl <NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxybenzylphosphonate, diethyl <NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxybenzylphosphonate, dihexyl <NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxybenzylphosphonate, dioctyl <NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxybenzylphosphonate and diphenyl <NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxybenzylphosphonate, while more preferable examples include dimethyl <NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxybenzylphosphonate, diethyl <NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxybenzylphosphonate, dihexyl <NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxybenzylphosphonate, dioctyl <NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxybenzylphosphonate and diphenyl <NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxybenzylphosphonate.

The molar ratio of the amount of phosphorous compound used to the amount of aluminum or compound thereof used is preferably within the range of <NUM> to <NUM>, more preferably within the range of <NUM> to <NUM>, and even more preferably within the range of <NUM> to <NUM>.

There are no particular limitations on the form when adding catalyst, and the catalyst in the form of a powder and the like may be added to the monomer or the catalyst in the form of dispersion or solution in a solvent may be added to the monomer. In addition, a mixture obtained by mixing the aluminum or compound thereof with the phosphorous compound in advance may also be added, or the aluminum or compound thereof and the phosphorous compound may be added separately.

The polyester carbonate resin of the present invention may use a monofunctional hydroxyl compound normally used as a terminal stopping agent in the polymerization reaction thereof. In the case of using phosgene as a carbonate precursor in particular, monofunctional phenols are typically used as terminal stopping agents in order to adjust molecular weight, and since the terminals of the obtained resin are blocked by groups based on monofunctional phenols, thermal stability is superior in comparison with those which are not blocked. Preferable examples of other terminal stopping agents include epoxy compounds, oxazoline compounds, isocyanate compounds, carbodiimide compounds and ketene imine compounds.

The polyester carbonate resin of the present invention may contain a copolymerized component of a diol component other than the diol component, dicarboxylic acid or ester-forming derivative thereof.

The content of residual phenol of the polyester carbonate resin of the present invention is preferably <NUM>-<NUM> ppm, more preferably <NUM>-<NUM> ppm and even more preferably <NUM>-<NUM> ppm.

The phenol content is preferably adjusted according to the reaction time at a pressure of <NUM> kPa or less. In the case of not carrying out the reaction at a degree of vacuum of <NUM> kPa or less, phenol content increases. In addition, if the reaction time is excessively long, an excess amount ends up distilling off from within the resin.

In addition, phenol content may also be adjusted after having obtained the polyester carbonate resin of the present invention. For example, a method consisting of dissolving the polyester carbonate resin of the present invention in an organic solvent followed by washing the organic solvent layer with water, or a method consisting of removing by devolatilization at a pressure of <NUM>-<NUM> Pa and temperature of <NUM> to <NUM> using a commonly used kneading apparatus such as a single-screw or twin-screw extruder or various types of kneaders.

The content of residual phenol in the polyester carbonate resin of the present invention makes it possible to improve molding fluidity without impairing heat resistance. However, if the amount of residual phenol exceeds <NUM> ppm, thermal stability during heating and melting is lacking and mold contamination during resin injection molding becomes severe, thereby making this undesirable. Moreover, phenol has the property of becoming colored when oxidized, thereby exacerbating the hue of the polyester carbonate resin. In addition, if the amount of residual phenol is less than <NUM> ppm, molding fluidity becomes inferior, thereby making this undesirable.

The residual fluorenone content of the polyester resin or polyester carbonate resin of the present invention is <NUM>-<NUM> ppm, preferably <NUM>-<NUM> ppm, more preferably <NUM>-<NUM> ppm and particularly preferably <NUM>-<NUM> ppm or <NUM>-<NUM> ppm.

If the residual fluorenone content in the polyester resin or polyester carbonate resin of the present invention is greater than <NUM> ppm, the resin becomes extremely colored, thereby making this undesirable.

Additives such as mold release agents, heat stabilizers, ultraviolet absorbers, bluing agents, antistatic agents, flame retardants, plasticizers or fillers can be suitably added and used in the polyester resin or polyester carbonate resin of the present invention. Additives known in the art can be added according to a known method such as by referring to the method described in paragraphs [<NUM>] to [<NUM>] of PTL7.

The polyester resin or polyester carbonate resin of the present invention is preferable for an optical member and particularly an optical lens. A known usage method can be used for the method for using the resin of the present invention in an optical member and optical lens in particular, such as by referring to the method described in paragraphs [<NUM>] to [<NUM>] of PTL7.

Although the following further provides an explanation of the present invention by listing examples thereof, the present invention is not limited thereto.

The residual amounts of fluorenone and phenol in the resin were analyzed by HPLC with a gradient program at a column temperature of <NUM> and detector wavelengths of <NUM> and <NUM> using an acetonitrile eluent and a mixture of <NUM>% aqueous acetic acid and acetonitrile with the Develosil ODS-<NUM> column manufactured by Nomura Chemical Co. A calibration curve was prepared and quantified using fluorenone and phenol standards. Measurement was carried out by dissolving <NUM> of resin in <NUM> of methylene chloride followed by adding <NUM> of acetonitrile and stirring, concentrating with an evaporator, passing through a <NUM> filter and injection of <NUM>µl of this acetonitrile solution.

<NUM> parts by weight of <NUM>,<NUM>'-bis(carboxymethoxy)-<NUM>,<NUM>'-binaphthyl (abbreviated as BCMB), <NUM> parts by weight of <NUM>,<NUM>-bis[<NUM>-(<NUM>-hydroxyethoxy)-<NUM>-naphthyl]fluorene (abbreviated as BNEF), <NUM> parts by weight of <NUM>,<NUM>'-bis(<NUM>-hydroxyethoxy)-<NUM>,<NUM>'-binaphthyl (abbreviated as BHEB) and <NUM> × <NUM>-<NUM> parts by weight of tetrabutoxytitanium (IV) were placed in a reaction tank equipped with a stirrer and distiller and nitrogen substitution was carried out three times followed by heating the jacket to <NUM> to melt the raw materials. , After melting completely, the pressure was reduced to <NUM> kPa over the course of <NUM> minutes. Subsequently, the jacket was heated to <NUM> at the rate of <NUM>/hr to carry out an esterification reaction. Subsequently, pressure was reduced to <NUM> kPa over the course of <NUM> minutes while holding the jacket at <NUM> and a polymerization reaction was carried out until a prescribed stirring torque was reached under conditions of <NUM> and <NUM> kPa. Following completion of the reaction, the formed resin was taken out while pelletizing to obtain pellets of polyester resin.

The obtained polyester resin was analyzed by <NUM>H-NMR and the BCMB component was confirmed to have been comprised at <NUM> mol%, the BNEF component at <NUM> mol% and the BHEB component at <NUM> mol% based on all monomer units. The specific viscosity of the obtained polyester resin was <NUM>, the amount of terminal carboxylic acid was <NUM> equivalents/ton, Tg was <NUM>, refractive index was <NUM>, Abbe number was <NUM>, the absolute value of orientation birefringence was <NUM> × <NUM>-<NUM>, b* was <NUM>, wet heat resistance was <NUM>% and formability was A. Residual fluorenone content was <NUM> ppm.

Pellets of polyester resin were obtained by carrying out the same method as Example <NUM> by placing <NUM> parts by weight of BCMB, <NUM> parts by weight of BNEF, <NUM> parts by weight of BHEB, <NUM> parts by weight of ethylene glycol (abbreviated as EG) and <NUM> × <NUM>-<NUM> parts by weight of tetrabutoxytitanium (IV) in a reaction tank equipped with a stirrer and distiller. The obtained polyester resin was confirmed to have the BCMB component at <NUM> mol%, the BNEF component at <NUM> mol%, the BHEB component at <NUM> mol% and the EG component at <NUM> mol%. The specific viscosity of the obtained polyester resin was <NUM>, the amount of terminal carboxylic acid was <NUM> equivalents/ton, Tg was <NUM>, refractive index was <NUM>, Abbe number was <NUM>, the absolute value of orientation birefringence was <NUM> × <NUM>-<NUM>, b* was <NUM>, wet heat resistance was <NUM>% and formability was A.

Polyester resin pellets were obtained using the same method as Example <NUM> with the exception of using <NUM> parts by weight of BCMB of Example <NUM>, <NUM> parts by weight of BNEF, <NUM> parts by weight of BHEB and <NUM> × <NUM>-<NUM> parts by weight of tetrabutoxytitanium (IV). The obtained polyester resin was confirmed to have been comprised of the BCMB component at <NUM> mol%, the BNEF component at <NUM> mol% and the BHEB component at <NUM> mol%. The specific viscosity of the obtained polyester resin was <NUM>, the amount of terminal carboxylic acid was <NUM> equivalents/ton, Tg was <NUM>, refractive index was <NUM>, Abbe number was <NUM>, the absolute value of orientation birefringence was <NUM> × <NUM>-<NUM>, b* was <NUM>, wet heat resistance was <NUM>% and formability was A.

<NUM> parts by weight of BCMB, <NUM> parts by weight of BNEF, <NUM> parts by weight of BHEB and <NUM> parts by weight of diphenyl carbonate (abbreviated as DPC) were placed in a reaction tank equipped with a stirrer and distiller and nitrogen substitution was carried out three times followed by heating the jacket to <NUM> and melting the raw materials. After melting completely, the pressure was reduced to <NUM> kPa over the course of <NUM> minutes. After heating the jacket to <NUM> at the rate of <NUM>/hr, pressure was reduced to <NUM> kPa over the course of <NUM> minutes while holding the jacket at <NUM>. Subsequently, <NUM> × <NUM>-<NUM> parts by weight of aluminum acetyl acetonate (abbreviated as Al(acac)<NUM>) and <NUM> × <NUM>-<NUM> parts by weight of diethyl <NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxybenzyl phosphonate (abbreviated as DEBHBP) were added to the reaction tank. Subsequently, the pressure was reduced to <NUM> kPa over the course of <NUM> minutes while holding the jacket at <NUM> and a polymerization reaction was carried out until a prescribed stirring torque was reached under conditions of <NUM> and <NUM> kPa or lower. Following completion of the reaction, the formed pellets were taken out while pelletizing to obtain pellets of polyester carbonate resin. The obtained polyester carbonate resin was confirmed to have been comprised of the BCMB component at <NUM> mol%, the BNEF component at <NUM> mol% and the BHEB component at <NUM> mol%. The specific viscosity of the obtained polyester resin was <NUM>, the amount of terminal carboxylic acid was <NUM> equivalent/ton, Tg was <NUM>, refractive index was <NUM>, Abbe number was <NUM>, the absolute value of orientation birefringence was <NUM> × <NUM>-<NUM>, b* was <NUM>,<NUM>, wet heat resistance was <NUM>% and formability was A. The residual fluorenone content was <NUM> ppm and the residual phenol content was <NUM> ppm.

Polyester carbonate resin pellets were obtained using the same method as Example <NUM> with the exception of using <NUM> parts by weight of BCMB of Example <NUM>, <NUM> parts by weight of BNEF, <NUM> parts by weight of BHEB, <NUM> parts by weight of DPC, <NUM> × <NUM>-<NUM> parts by weight of Al(acac)<NUM> and <NUM> × <NUM>-<NUM> parts by weight of DEBHBP. The obtained polyester carbonate resin was confirmed to have been comprised of the BCMB component at <NUM> mol%, the BNEF component at <NUM> mol% and the BHEB component at <NUM> mol%. The specific viscosity of the obtained polyester carbonate resin was <NUM>, the amount of terminal carboxylic acid was <NUM> equivalent/ton, Tg was <NUM>, refractive index was <NUM>, Abbe number was <NUM>, the absolute value of orientation birefringence was <NUM> × <NUM>-<NUM>, b* was <NUM>, wet heat resistance was <NUM>% and formability was A. The residual fluorenone content was <NUM> ppm and the residual phenol content was <NUM> ppm.

Polyester carbonate resin pellets were obtained using the same method as Example <NUM> with the exception of using <NUM> parts by weight of BCMB of Example <NUM>, <NUM> parts by weight of BNEF, <NUM> parts by weight of BHEB, <NUM> parts by weight of DPC, <NUM> × <NUM>-<NUM> parts by weight of Al(acac)<NUM> and <NUM> × <NUM>-<NUM> parts by weight of DEBHBP. The obtained polyester carbonate resin was confirmed to have been comprised of the BCMB component at <NUM> mol%, the BNEF component at <NUM> mol% and the BHEB component at <NUM> mol%. The specific viscosity of the obtained polyester carbonate resin was <NUM>, the amount of terminal carboxylic acid was <NUM> equivalents/ton, Tg was <NUM>, refractive index was <NUM>, Abbe number was <NUM>, the absolute value of orientation birefringence was <NUM> × <NUM>-<NUM>, b* was <NUM>, wet heat resistance was <NUM>% and formability was A. The residual fluorenone content was <NUM> ppm and the residual phenol content was <NUM> ppm.

Polyester carbonate resin pellets were obtained using the same method as Example <NUM> with the exception of using <NUM> parts by weight of BCMB of Example <NUM>, <NUM> parts by weight of BNEF, <NUM> parts by weight of BHEB, <NUM> parts by weight of DPC, <NUM> × <NUM>-<NUM> parts by weight of Al(acac)<NUM> and <NUM> × <NUM>-<NUM> parts by weight of DEBHBP. The obtained polyester carbonate resin was confirmed to have been comprised of the BCMB component at <NUM> mol%, the BNEF component at <NUM> mol% and the BHEB component at <NUM> mol%. The specific viscosity of the obtained polyester carbonate resin was <NUM>, the amount of terminal carboxylic acid was <NUM> equivalents/ton, Tg was <NUM>, refractive index was <NUM>, Abbe number was <NUM>, the absolute value of orientation birefringence was <NUM> × <NUM>-<NUM>, b* was <NUM>, wet heat resistance was <NUM>% and formability was A.

Polyester resin pellets were obtained using the same method as Example <NUM> with the exception of using <NUM> parts by weight of BCMB of Example <NUM>, <NUM> parts by weight of BHEB, <NUM> parts by weight of BNEF and <NUM> × <NUM>-<NUM> parts by weight of tetrabutoxytitanium (IV). The specific viscosity of the obtained polyester resin was <NUM>, the amount of terminal carboxylic acid was <NUM> equivalents/ton, Tg was <NUM>, refractive index was <NUM>, Abbe number was <NUM>, the absolute value of orientation birefringence was <NUM> × <NUM>-<NUM>, b* was <NUM> and wet heat resistance was <NUM>%.

Polyester resin pellets were obtained using the same method as Comparative Example <NUM> with the exception of using <NUM> parts by weight of BCMB of Comparative Example <NUM>, <NUM> parts by weight of <NUM>,<NUM>-bis[<NUM>-(<NUM>-hydroxyethoxy)phenyl] fluorene (abbreviated as BPEF) instead of BHEB and <NUM> × <NUM>-<NUM> parts by weight of tetrabutoxytitanium (IV). The specific viscosity of the obtained polyester resin was <NUM>, the amount of terminal carboxylic acid was <NUM> equivalents/ton, Tg was <NUM>, refractive index was <NUM>, Abbe number was <NUM>, the absolute value of orientation birefringence was <NUM> × <NUM>-<NUM>, b* was <NUM> and wet heat resistance was <NUM>%. The residual fluorenone content was <NUM> ppm.

Polyester carbonate resin pellets were obtained using the same method as Example <NUM> with the exception of using <NUM> parts by weight of BCMB of Example <NUM>, <NUM> parts by weight of BHEB, <NUM> parts by weight of BPEF instead of BNEF, <NUM> parts by weight of DPC, <NUM> × <NUM>-<NUM> parts by weight of Al(acac)<NUM> and <NUM> × <NUM>-<NUM> parts by weight of DEBHBP. The specific viscosity of the obtained polyester carbonate resin was <NUM>, the amount of terminal carboxylic acid was <NUM> equivalents/ton, Tg was <NUM>, refractive index was <NUM>, Abbe number was <NUM>, the absolute value of orientation birefringence was <NUM> × <NUM>-<NUM>, b* was <NUM> and wet heat resistance was <NUM>%. The residual fluorenone content was <NUM> ppm.

Polyester carbonate resin pellets were obtained using the same method as Comparative Example <NUM> with the exception of using <NUM> parts by weight of BCMB of Comparative Example <NUM>, <NUM> parts by weight of BHEB, <NUM> parts by weight of <NUM>,<NUM>-bis[<NUM>-(<NUM>-hydroxyethoxy)-<NUM>- phenylphenyl] fluorene instead of BPEF, <NUM> parts by weight of DPC, <NUM> × <NUM>-<NUM> parts by weight of Al(acac)<NUM> and <NUM> × <NUM>-<NUM> parts by weight of DEBHBP. The specific viscosity of the obtained polyester carbonate resin was <NUM>, the amount of terminal carboxylic acid was <NUM> equivalents/ton, Tg was <NUM>, refractive index was <NUM>, Abbe number was <NUM>, the absolute value of orientation birefringence was <NUM> × <NUM>-<NUM>, b* was <NUM> and wet heat resistance was <NUM>%.

<NUM> parts by weight of BNEF, <NUM> parts by weight of BHEB, <NUM> parts by weight of DPC and <NUM> × <NUM>-<NUM> parts by weight of tetrabutoxytitanium (IV) were placed in a reaction tank equipped with a stirrer and distiller and nitrogen substitution was carried out three times followed by heating the jacket to <NUM> and melting the raw materials. After melting completely, the pressure was reduced to <NUM> kPa over the course of <NUM> minutes. After heating the jacket to <NUM> at the rate of <NUM>/hr, pressure was reduced to <NUM> kPa over the course of <NUM> minutes while holding the jacket at <NUM>. Subsequently, the pressure was reduced to <NUM> kPa over the course of <NUM> minutes and a polymerization reaction was carried out until a prescribed stirring torque was reached under conditions of <NUM> and <NUM> kPa or lower. Following completion of the reaction, the formed resin was taken out while pelletizing to obtain pellets of polycarbonate resin. The obtained polycarbonate resin was confirmed to have been comprised of the BNEF component at <NUM> mol% and the BHEB component at <NUM> mol%. The specific viscosity of the obtained polycarbonate resin was <NUM>, Tg was <NUM>, refractive index was <NUM>, Abbe number was <NUM>, the absolute value of orientation birefringence was <NUM> × <NUM>-<NUM>, b* was <NUM>, wet heat resistance was <NUM>% and formability was C.

The polyester resins or polyester carbonate resins obtained in Examples <NUM>-<NUM> demonstrated high refractive indices, low Abbe numbers, a superior balance between heat resistance and formability, and low birefringence for use as optical lenses. In contrast, the polyester resins or polyester carbonate resins of Comparative Examples <NUM>-<NUM> demonstrated low refractive indices and high Abbe numbers. Although the refractive index and heat resistance of the polycarbonate resin of Comparative Example <NUM> were high, formability was inferior.

Claim 1:
A polyester resin or polyester carbonate resin comprising repeating units represented by the following formulas (<NUM>) and (<NUM>), wherein the ratio of the repeating unit represented by the following formula (<NUM>) and repeating unit represented by the following formula (<NUM>) is <NUM>:<NUM> to <NUM>:<NUM>, wherein the amount of fluorenone contained therein, determined by HPLC as specified in the description, is <NUM> to <NUM> ppm or less:
<CHM>
wherein,
rings Z<NUM> and Z<NUM> respectively represent a polycyclic aromatic hydrocarbon group having <NUM> to <NUM> carbon atoms, R<NUM>, R<NUM>, R<NUM> and R<NUM> respectively and independently represent a hydrocarbon group that may contain an aromatic group having <NUM> to <NUM> carbon atoms, R<NUM>-R<NUM> and R<NUM>-R<NUM> represent hydrogen atoms or aliphatic or aromatic substituents, j, k, r and s respectively and independently represent an integer of <NUM> or more, and m, n, p and q respectively and independently represent <NUM> or <NUM>; and
<CHM>
wherein,
R<NUM>, R<NUM>, R<NUM> and R<NUM> respectively and independently represent a hydrocarbon group that may contain an aromatic group having <NUM> to <NUM> carbon atoms, R<NUM>-R<NUM> and R<NUM>-R<NUM> represent hydrogen atoms or aliphatic or aromatic substituents, and r, s, t and u respectively and independently represent an integer of <NUM> or more.