JP2018172659A - Polyester resin having fluorene skeleton, method for producing the same, and molded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel polyester resin that realizes both high refractive index and low birefringence.SOLUTION: The polyester resin comprises (A) a dicarboxylic acid unit and (B) a diol unit. The dicarboxylic acid unit (A) includes at least (A1) a first dicarboxylic acid unit represented by the following formula (A1) and the diol unit (B) includes at least (B1) a first diol unit represented by the following formula (B1). (In the formulae, Arepresents a hydrocarbon group or the like; Arepresents a direct bond or a hydrocarbon group; Arepresents an alkylene group; Z represents an arene ring; R, Rand Rrepresent a substituent; k and m represent an integer of 0 to 4; and n and p represent an integer of 0 or more.)SELECTED DRAWING: None

Description

  The present invention includes a novel polyester resin containing a dicarboxylic acid unit having a bis (fluoren-9-yl) skeleton and a diol unit having a 9,9-bisarylfluorene skeleton, a method for producing the same, and the polyester resin. It relates to a molded body.

  Polyester resins (thermoplastic polyester resins or saturated polyester resins) can form resins having various characteristics by appropriately combining a dicarboxylic acid component and a diol component, which are polymerization components, according to the application. Therefore, polyester resins are used as various products ranging from industrial products such as electric / electronic parts and automobile parts to daily necessities such as clothes and food containers.

  Since such a polyester resin is lighter and more flexible than an inorganic material such as glass, application development to an optical member such as an optical lens has been studied. Typically, a polyester resin formed from a polymerization component having a fluorene skeleton is known as a polyester resin excellent in optical characteristics such as a high refractive index.

  For example, JP-A-2006-069643 (Patent Document 1) discloses a diol component having a 9,9-bis (hydroxy (poly) alkoxy fused polycyclic aryl) fluorene skeleton, and a dicarboxylic acid component having a fluorene skeleton. It is disclosed that a polyester resin having a polymerization component can achieve both high refractive index and low birefringence, which are mutually contradictory characteristics. In the examples of this document, a diol component containing 9,9-bis (6- (2-hydroxyethoxy) -2-naphthyl) fluorene and a dicarboxylic acid containing 9,9-bis (2-methoxycarbonylethyl) fluorene Various polyester resins are prepared by polycondensation of components.

  The polyester resin of this document achieves a high refractive index and a low birefringence in a relatively balanced manner. However, in recent years, with the remarkable improvement in performance of optical devices, higher optical characteristics are required for the optical members to be mounted, and sufficient performance has not been obtained yet. Further, although the polyester resin of this document is excellent in moldability, it is not sufficient in heat resistance and may not be used for applications that are expected to be used in a high temperature environment.

  On the other hand, US Patent Application Publication No. 2012/0170118 (Patent Document 2) discloses a laminated optical film containing a negative birefringent polyester resin. In Examples 6 to 18 of this document, as polyester resins having negative birefringence, for example, various polyester resins formed with polymerization components having a fluorene skeleton such as a 9,9-bis (fluoren-9-yl) alkane skeleton are used. A polyester resin has been prepared.

  JP-A-2015-25111 (Patent Document 3) discloses a resin composition containing a polymer having divalent oligofluorene as a repeating unit. In Experimental Examples 12, 13 and 17 of this document, a polyester resin formed of a polymerization component having a 9,9-bis (fluoren-9-yl) methane skeleton as an oligofluorene skeleton is prepared.

  These polyester resins described in Patent Documents 2 and 3 are assumed to be optical members that require birefringence such as reflecting films such as reflectors and polarizers, retardation films, or the like. Highly compatible with birefringence. Moreover, the polyester resin of any literature has low heat resistance, and cannot be used in a high temperature environment.

JP 2006-069643 A US Patent Application Publication No. 2012/0170118 Japanese Patent Laying-Open No. 2015-25111

  Accordingly, an object of the present invention is to provide a novel polyester resin capable of achieving both a high refractive index and a low birefringence, a method for producing the same, and a molded body containing the polyester resin.

  Another object of the present invention is to provide a novel polyester resin capable of achieving both high heat resistance and high moldability, a method for producing the same, and a molded body containing the polyester resin.

  Still another object of the present invention is to provide a novel polyester resin having a low Abbe number, a method for producing the same, and a molded article containing the polyester resin.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors formed a combination of a dicarboxylic acid unit having a bis (fluoren-9-yl) skeleton and a diol unit having a 9,9-bisarylfluorene skeleton. It was found that the polyester resin can satisfy a high refractive index and a low birefringence in a more balanced manner, and the present invention has been completed.

  That is, the polyester resin of the present invention is a polyester resin having a dicarboxylic acid unit (A) and a diol unit (B), wherein the dicarboxylic acid unit (A) is represented by the following formula (A1). The dicarboxylic acid unit (A1) is included at least, and the diol unit (B) includes at least the first diol unit (B1) represented by the following formula (B1).

(In the formula, A ¹ is the same or different and is a divalent hydrocarbon group which may have a substituent, and A ² is a divalent hydrocarbon group which may have a direct bond or a substituent. , R ¹ is the same or different substituent, k is the same or different and represents an integer of 0 to 4).

(Wherein Z is the same or different and arene ring, R ² and R ³ are the same or different substituents, A ³ is the same or different and is a linear or branched alkylene group, m is the same or different and 0 An integer of -4, n is the same or different and is an integer of 0 or more, and p is the same or different and represents an integer of 0 or more).

In the formula (A1), A ¹ is a linear or branched C _2-4 alkylene group, A ² is a direct bond or a linear or branched C _1-4 alkylene group, and k is about 0 to 2. It may be an integer. In the formula (B1), Z is a C _6-10 arene ring, R ³ is a C _1-4 alkyl group or a C _6-10 aryl group, and A ³ is a linear or branched C _2-4 alkylene. Group, m may be an integer of about 0 to 2, n may be an integer of about 0 to 2, and p may be an integer of about 1 to 10.

  The proportion of the first dicarboxylic acid unit (A1) may be about 10 to 100 mol% with respect to the whole dicarboxylic acid unit (A), and the proportion of the first diol unit (B1) is About 50-100 mol% may be sufficient with respect to the whole diol unit (B). Moreover, the ratio of the 1st diol unit (B1) may be about 0.5-4 mol with respect to 1 mol of 1st dicarboxylic acid units (A1).

  The dicarboxylic acid unit (A) may further contain a second dicarboxylic acid unit (A2) represented by the following formula (A2).

(In the formula, Ar represents an arene ring, R ⁴ represents a substituent, and q represents an integer of 0 or more).

The ratio between the first dicarboxylic acid unit (A1) and the second dicarboxylic acid unit (A2) may be about the former / the latter (molar ratio) = 99/1 to 10/90. In the formula (A2), Ar may be a C _6-10 arene ring, R ⁴ may be a C _1-4 alkyl group or a C _6-10 aryl group, and q may be an integer of about 0-4.

  The dicarboxylic acid unit (A) may further contain a third dicarboxylic acid unit (A3) represented by the following formula (A3-1) or (A3-2).

(Wherein R ⁵ is the same or different and is a substituent, r and s are each an integer of 0 to ^4, and A ⁴ and A ⁵ are each a divalent hydrocarbon group which may have a substituent) .

The ratio of the first dicarboxylic acid unit (A1) and the third dicarboxylic acid unit (A3) may be about the former / the latter (molar ratio) = 90/10 to 20/80. The dicarboxylic acid unit (A) may contain at least a third dicarboxylic acid unit (A3) represented by the formula (A3-1). In the formula (A3-1), r may be an integer of about 0 to 2, and A ⁴ may be a linear or branched C _2-4 alkylene group.

  The diol unit (B) may further contain a second diol unit (B2) represented by the following formula (B2).

(In the formula, A ⁶ represents a linear or branched alkylene group, and t represents an integer of 1 or more).

The ratio of the first diol unit (B1) and the second diol unit (B2) may be about the former / the latter (molar ratio) = 99/1 to 50/50. In the formula (B2), A ⁶ may be a linear or branched C _2-4 alkylene group, and t may be an integer of about 1 to 3.

The diol unit (B) may further contain a third diol unit (B3) represented by the following formula (B3).

(Wherein X is a direct bond or alkylene group, R ⁶ and R ⁷ are the same or different substituents, A ⁷ is the same or different linear or branched alkylene group, u is the same or different and 0 to An integer of 4, v is the same or different and is an integer of 0 to 2, and w is the same or different and represents an integer of 0 or more).

The ratio of the first diol unit (B1) and the third diol unit (B3) may be about the former / the latter (molar ratio) = 90/10 to 10/90. In the formula (3), X is a direct bond, R ⁶ and R ⁷ are each a C _1-6 alkyl group or a C _6-12 aryl group, A ⁷ is a linear or branched C _2-6 alkylene group, u may be an integer of about 0 to 2, v may be 0 or 1, and w may be an integer of about 0 to 10.

The glass transition temperature Tg of the polyester resin may be about 120 to 250 ° C .; the refractive index at a temperature of 20 ° C. and a wavelength of 589 nm may be about 1.62 to 1.7; The absolute value of birefringence of a film stretched three times at a temperature 10 ° C. higher may be about 0.001 × 10 ⁻⁴ to 50 × 10 ⁻⁴ at a temperature of 20 ° C. and a wavelength of 600 nm.

  The present invention provides a dicarboxylic acid component (A) containing at least a first dicarboxylic acid component (A1) for forming a first dicarboxylic acid unit (A1) represented by the formula (A1), Also included is a method for producing the polyester resin by reacting with a diol component (B) containing at least a first diol component (B1) for forming the first diol unit (B1) represented by B1). To do.

  The present invention also includes a molded article containing the polyester resin, such as an optical film, an optical sheet, or an optical lens.

  In the present specification and claims, “dicarboxylic acid unit” or “structural unit derived from dicarboxylic acid component” is a unit obtained by removing OH (hydroxyl group) from two carboxyl groups of the corresponding dicarboxylic acid ( Or a “dicarboxylic acid component” (including compounds exemplified as the dicarboxylic acid component) may be used synonymously with the corresponding “dicarboxylic acid unit”. Similarly, the “diol unit” or “structural unit derived from the diol component” means a unit (or a divalent group) obtained by removing a hydrogen atom from two hydroxyl groups of the corresponding diol component, “Component” (including compounds exemplified as the diol component) may be used synonymously with the corresponding “diol unit”.

In addition, in the present specification and claims, the “dicarboxylic acid component” means, in addition to dicarboxylic acid, an ester-forming derivative thereof, such as dicarboxylic acid lower alkyl ester, dicarboxylic acid halide, dicarboxylic acid anhydride and the like. Used to include. Examples of the dicarboxylic acid lower alkyl ester include C _1-4 alkyl esters such as methyl ester, ethyl ester, and t-butyl ester. The “ester-forming derivative” may be a monoester (half ester) or a diester.

In the present specification and claims, the number of carbon atoms of the substituent may be indicated by C ₁ , C ₆ , C ₁₀ or the like. For example, an alkyl group having 1 carbon atom is represented by “C ₁ alkyl”, and an aryl group having 6 to 10 carbon atoms is represented by “C _6-10 aryl”.

  In the present invention, since the dicarboxylic acid unit having a bis (fluoren-9-yl) skeleton and the diol unit having a 9,9-bisarylfluorene skeleton are combined, the resulting new polyester resin has a high refractive index and a low Both birefringence can be achieved. Moreover, both high heat resistance and high moldability can be achieved. Furthermore, the polyester resin has a low Abbe number, and satisfies these characteristics at a higher level in a well-balanced manner.

  The polyester resin of the present invention has a dicarboxylic acid unit (A) containing at least the first dicarboxylic acid unit (A1) and a diol unit (B) containing at least the first diol unit (B1).

[First dicarboxylic acid unit (A1)]
The dicarboxylic acid unit (A) includes at least a first dicarboxylic acid unit (A1) represented by the following formula (A1).

(In the formula, A ¹ is the same or different divalent hydrocarbon group which may have a substituent, A ² is a divalent hydrocarbon group which may have a direct bond or a substituent, R ¹ is the same or different and is a substituent, and k is the same or different and represents an integer of 0 to 4.

In the formula (A1), examples of the substituent represented by R ¹ include a hydrocarbon group, a cyano group, and a halogen atom.

Examples of the hydrocarbon group include an alkyl group and an aryl group. Examples of the alkyl group include linear or branched C _1-6 alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, and a t-butyl group. As an aryl group, _C6-10 aryl groups, such as a phenyl group, etc. are mentioned, for example.

  Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.

Of these groups R ¹ , an alkyl group, a cyano group, and a halogen atom are preferable, and an alkyl group, particularly a linear or branched C _1-4 alkyl group such as a methyl group is preferable.

The substitution number k of the group R ¹ is, for example, an integer of about 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, especially 0. In the four different benzene rings constituting the two fluorene rings, the number of substitutions k may be the same or different from each other. The types of the groups R ¹ substituted on the different benzene rings may be different from each other and are usually the same in many cases. When k is 2 or more, the types of two or more groups R ¹ substituted on the same benzene ring may be the same or different from each other. The substitution position of the group R ¹ is not particularly limited, and may be, for example, the 2nd to 7th positions of the fluorene ring, for example, the 2nd, 3rd, 7th positions, and the like.

Examples of the divalent hydrocarbon group represented by A ¹ include a linear or branched alkylene group such as a methylene group, an ethylene group, a trimethylene group, a propylene group, a tetramethylene group, and 1,2-butanediyl. And a linear or branched C _1-8 alkylene group such as a 2-methylpropane-1,3-diyl group. Preferred hydrocarbon groups are linear or branched C _1-6 alkylene groups, more preferably linear chains such as methylene group, ethylene group, trimethylene group, propylene group, 2-methylpropane-1,3-diyl group. Or a branched C _1-4 alkylene group, in particular, a linear or branched C _1-3 alkylene group such as an ethylene group.

Examples of the substituent of the hydrocarbon group in the group A ¹ include an aryl group such as a phenyl group and a cycloalkyl group such as a cyclohexyl group. Examples of the hydrocarbon group A ¹ having a substituent include 1-phenylethylene group and 1-phenylpropane-1,2-diyl group.

The group A ¹ is usually a linear or branched C _2-4 alkylene group, for example, a linear or branched C _2-3 alkylene group such as an ethylene group _{or a} propylene group, particularly an ethylene group. There are many cases. The type of two groups A ¹ may be different from each other, usually the same.

Examples of the divalent hydrocarbon group represented by A ² include a linear or branched alkylene group and an alkylidene group exemplified as the divalent hydrocarbon group represented by the group A ¹ such as a methylene group. Etc. Examples of the alkylidene group include C _2-6 alkylidene groups such as an ethylidene group, a propylidene group, and an isopropylidene group (2,2-propanediyl group). Preferred alkylidene groups include C _2-4 alkylidene groups such as an ethylidene group.

Examples of the substituent of the hydrocarbon group in the group A ² include an aryl group such as a phenyl group and a cycloalkyl group such as a cyclohexyl group. Examples of the hydrocarbon group A ² having a substituent include a phenylmethylene group.

The group A ² is usually a divalent hydrocarbon group which may have a substituent, and in particular, a linear or branched C _1-6 alkylene group, more preferably a linear group. Jo or branched C _1-4 alkylene group, more preferably a straight-chain or branched-chain C _1-3 alkylene group such as methylene group, it is often particularly methylene group.

As the dicarboxylic acid unit (A1) represented by the formula (A1), typically, A ¹ is a linear or branched C _2-6 alkylene group, and A ² is a linear or branched C. Units that are _1-4 alkylene groups, specifically bis [9- (2-carboxyethyl) -fluoren-9-yl] methane, bis [9- (2-carboxypropyl) -fluoren-9-yl] Bis [9- (carboxy C _2-6 alkyl) -fluoren-9-yl] C _1-4 alkanes such as methane, 1,2-bis [9- (2-carboxyethyl) -fluoren-9-yl] ethane And structural units derived from the first dicarboxylic acid component (A1) such as these ester-forming derivatives. Especially, the structure derived from 1st dicarboxylic acid components (A1), such as bis [9- (carboxy _C2-4 alkyl) -fluoren-9-yl] _C1-3 alkane, and these ester-forming derivatives. Units are preferred.

These 1st dicarboxylic acid units (A1) can also be used individually or in combination of 2 or more types. Of these first dicarboxylic acid units (A1), bis [9- (carboxyC _2-3 alkyl) -fluorene-9 such as bis [9- (2-carboxyethyl) -fluoren-9-yl] methane -Il] _C1-2 alkanes and their ester-forming derivatives are particularly preferred.

  These first dicarboxylic acid components (A1) are prepared by a conventional method described in Patent Document 3, such as a mixture of fluorene and a metal alkoxide (such as sodium ethoxide) and an aldehyde (such as formaldehyde; paraffin). A step of preparing bis (fluoren-9-yl) methane by reacting with a formaldehyde multimer such as formaldehyde; formalin and the like; and the obtained bis (fluoren-9-yl) methane and an acrylic ester (acrylic acid) And a step of reacting with a phase transfer catalyst (such as benzyltrimethylammonium hydroxide) in the presence of a phase transfer catalyst.

  By including such a first dicarboxylic acid unit (A1), birefringence can be effectively reduced without lowering the high refractive index and heat resistance. The ratio of the first dicarboxylic acid unit (A1) can be selected, for example, from the range of about 1 to 100 mol% with respect to the entire dicarboxylic acid unit (A), and preferably 10 to 100 mol% stepwise below. 20 to 99 mol%, 30 to 97 mol%, 40 to 95 mol%, 50 to 93 mol%, more preferably 60 to 90 mol%, especially 70 to 85 mol%, especially 75 to 85 mol% %. If the proportion of the first dicarboxylic acid unit (A1) is too small, the heat resistance and refractive index may be reduced, and birefringence and Abbe number may not be reduced.

  [First diol unit (B1)]

(Wherein Z is the same or different and arene ring, R ² and R ³ are the same or different substituents, A ³ is the same or different and is a linear or branched alkylene group, m is the same or different and 0 An integer of -4, n is the same or different and is an integer of 0 or more, and p is the same or different and represents an integer of 1 or more).

  In the formula (B1), examples of the arene ring (aromatic hydrocarbon ring) represented by the ring Z include a monocyclic arene ring such as a benzene ring, a polycyclic arene ring, and the like. The arene ring includes a condensed polycyclic arene ring (condensed polycyclic aromatic hydrocarbon ring), a ring assembly arene ring (ring assembly aromatic hydrocarbon ring) and the like.

  Examples of the condensed polycyclic arene ring include condensed bicyclic to tetracyclic arene rings such as a condensed bicyclic arene ring and a condensed tricyclic arene ring.

Examples of the condensed bicyclic arene ring include condensed bicyclic C _10-16 arene rings such as a naphthalene ring and an indene ring. Examples of the condensed tricyclic arene ring include an anthracene ring and a phenanthrene ring.

Preferred ring-fused polycyclic arene rings include condensed polycyclic C _10-16 arene rings such as naphthalene ring and anthracene ring, more preferably fused polycyclic C _10-14 arene rings, and in particular naphthalene ring Is preferred.

  Examples of the ring assembly arene ring include a biarene ring and a teraarene ring.

Examples of the bialene ring include bi-C _6-12 arene rings such as biphenyl ring, binaphthyl ring, and phenylnaphthalene ring (1-phenylnaphthalene ring, 2-phenylnaphthalene ring, etc.). Examples of the telearene ring include a tel C _6-12 arene ring such as a terphenylene ring. A preferable ring assembly arene ring includes a bi-C _6-10 arene ring, and a biphenyl ring is particularly preferable.

The types of the two rings Z may be the same or different from each other, and are usually often the same. Among the rings Z, C _6-12 arene rings such as benzene ring, naphthalene ring and biphenyl ring are preferable, and among them, C _6-10 arene rings such as benzene ring and naphthalene ring are preferable. Particularly, the moldability is high. A benzene ring is preferable from the viewpoint of easily reducing birefringence, and a naphthalene ring is preferable from the viewpoint of improving the refractive index and glass transition temperature. In particular, a naphthalene ring is most preferable from the viewpoint of excellent balance of high refractive index, low birefringence, high heat resistance, high moldability, and a low Abbe number.

  In addition, the substitution position of the ring Z couple | bonded with 9th-position of a fluorene ring is not specifically limited. For example, when ring Z is a benzene ring, it may be in any position from 1 to 6 positions, and when ring Z is a naphthalene ring, it may be in either position 1 or 2; When Z is a biphenyl ring, it may be in any of the 2-position, 3-position, and 4-position.

The substituent represented by the group R ² includes the group R ¹ exemplified in the section of the first dicarboxylic acid unit (A1), and the substitution number m of the substituent represented by the group R ² is the first substituent. The substitution number k of the substituent represented by the group R ¹ exemplified in the section of the dicarboxylic acid unit (A1) may be the same as that including preferred embodiments. In the two benzene rings forming the fluorene ring, the type of the group R ² and the substitution number m may be the same or different from each other. When m is 2 or more, the types of the groups R ² substituted on the same benzene ring may be the same or different from each other.

Examples of the substituent represented by the group R ³ include a halogen atom, a hydrocarbon group, an alkoxy group, a cycloalkyloxy group, an aryloxy group, an aralkyloxy group, an alkylthio group, a cycloalkylthio group, an arylthio group, and an aralkylthio group. , Acyl group, nitro group, cyano group, substituted amino group and the like.

  Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

  Examples of the hydrocarbon group include an alkyl group; a cycloalkyl group; an aryl group; and an aralkyl group.

Examples of the alkyl group include linear or branched C _1-10 alkyl such as methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, and t-butyl group. Group and the like. The preferred alkyl group is a linear or branched C _1-6 alkyl group, and more preferably a linear or branched C _1-4 alkyl group.

Examples of the cycloalkyl group include C _5-10 cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group.

Examples of the aryl group include C _6-12 aryl groups such as a phenyl group, an alkylphenyl group, a biphenylyl group, and a naphthyl group. Examples of the alkylphenyl group include a methylphenyl group (tolyl group) and a dimethylphenyl group (xylyl group).

Examples of the aralkyl group include C _6-10 aryl-C _1-4 alkyl groups such as benzyl group and phenethyl group.

Examples of the alkoxy group include linear or branched C _1-10 alkoxy groups such as a methoxy group, an ethoxy group, a propoxy group, an n-butoxy group, an isobutoxy group, an s-butoxy group, and a t-butoxy group. Can be mentioned.

Examples of the cycloalkyloxy group include a C _5-10 cycloalkyloxy group such as a cyclohexyloxy group.

Examples of the aryloxy group include C _6-10 aryloxy groups such as a phenoxy group.

Examples of the aralkyloxy group include a C _6-10 aryl-C _1-4 alkyloxy group such as a benzyloxy group.

Examples of the alkylthio group include a C _1-10 alkylthio group such as a methylthio group, an ethylthio group, a propylthio group, an n-butylthio group, and a t-butylthio group.

Examples of the cycloalkylthio group include a C _5-10 cycloalkylthio group such as a cyclohexylthio group.

Examples of the arylthio group include C _6-10 arylthio groups such as a thiophenoxy group.

Examples of the aralkylthio group include a C _6-10 aryl-C _1-4 alkylthio group such as a benzylthio group.

Examples of the acyl group include a C _1-6 acyl group such as an acetyl group.

Examples of the substituted amino group include a dialkylamino group; a bis (alkylcarbonyl) amino group, and the like. Examples of the dialkylamino group include a _diC1-4 alkylamino group such as a dimethylamino group. Examples of the bis (alkylcarbonyl) amino group include a bis (C _1-4 alkyl-carbonyl) amino group such as a diacetylamino group.

Of these groups R ³ , typically, hydrocarbon groups such as halogen atoms, alkyl groups, cycloalkyl groups, aryl groups, aralkyl groups, alkoxy groups, acyl groups, nitro groups, cyano groups, substituted amino groups, etc. Is mentioned. When the substitution number n is 1 or more, preferred groups R ³ include an alkyl group, an aryl group, and an alkoxy group. The alkyl group is preferably a linear or branched C _1-6 alkyl group such as a methyl group, the aryl group is preferably a C _6-12 aryl group such as a phenyl group, and the alkoxy group is a methoxy group. A linear or branched C _1-4 alkoxy group such as is preferred. Among them, an alkyl group and an aryl group are preferable, a linear or branched C _1-4 alkyl group such as a methyl group, and a C _6-10 aryl group such as a phenyl group are more preferable, and a methyl group is more preferable. And a phenyl group, and a phenyl group is particularly preferable.

The substitution number n of the group R ³ can be appropriately selected according to the type of the ring Z, and may be an integer of about 0 to 8, for example, and preferably in the following stepwise, an integer of 0 to 4, 0 to 3 , An integer of 0 to 2, especially 0 or 1, particularly 0. In two different rings Z, the type of the group R ³ and the number of substitutions n may be the same or different from each other. When the number of substitutions n is 2 or more, the types of two or more groups R ³ substituted on the same ring Z may be the same or different from each other. The substitution position of the group R ³ is not particularly limited, and may be substituted at a position other than the bonding position between the ring Z and the 9-position of the group [—O— (A ³ O) _p —] and the fluorene ring. .

The linear or branched alkylene group represented by A ^3, for example, ethylene group, propylene group (1,2-propanediyl), trimethylene, 1,2-butanediyl group, a tetramethylene group Examples thereof include a linear or branched C _2-6 alkylene group. Preferred alkylene group A ³ is a linear or branched C _2-4 alkylene group, more preferably a linear or branched C _2-3 alkylene group such as an ethylene group or a propylene group, particularly an ethylene group. It is.

The number of repetitions (addition mole number) p of the oxyalkylene group (OA ³ ) may be an integer of 0 or more, and can be selected from, for example, an integer of about 0 to 15, preferably stepwise from 0 to 10 below. It is an integer, an integer of 0-8, an integer of 0-6, more preferably an integer of 0-4, especially an integer of 0-2, especially 0 or 1. When the repeating number p is 1 or more, p may be selected from an integer of about 1 to 10, for example, preferably an integer of 1 to 6, and more preferably an integer of 1 to 2. Especially, it is preferable that p is 1 from a viewpoint of polymerization reactivity. In the present specification and claims, the “number of repetitions (addition mole number) p” may be an average value (arithmetic average value, arithmetic average value) or an average addition mole number, and a preferred embodiment is as follows. May be the same as the preferred integer range. If the repetition number p is too large, the refractive index may decrease. The two repeating numbers p may be the same or different, and when p is 2 or more, the types of the two or more oxyalkylene groups (OA ³ ) may be different from each other, and are usually the same. There are many cases. Further, the types of oxyalkylene groups (OA ³ ) bonded to different rings Z via an ether bond (—O—) may be the same or different from each other.

The substitution position of the group [—O— (A ³ O) _p —] is not particularly limited as long as it is a position other than the bonding position between the ring Z and the fluorene ring. For example, when the ring Z is a benzene ring, Any position from the 2nd to 6th positions of the phenyl group bonded to the 9th position of the fluorene ring may be used. When ring Z is a naphthalene ring, the fluorene ring is usually substituted at any of positions 5 to 8 of the naphthyl group bonded at the 1-position or 2-position with respect to the 9-position of the fluorene ring. The 1- or 2-position of the naphthalene ring is substituted with respect to the 9-position of the ring (substituted by the relationship of 1-naphthyl or 2-naphthyl), and the 1,5-position, 2,6-position with respect to this substitution position In particular, it is preferable that the substitution is performed in a relationship such as 2,6 position. When ring Z is a biphenyl ring, it may be substituted at any of positions 2-6 and 2′-6 ′ of the biphenyl ring. For example, the 3-position or 4-position of the biphenyl ring is a fluorene ring. When the 3-position of the biphenyl ring is bonded to the 9-position of fluorene, the substitution position of the group [—O— (A ³ O) _p —] is, for example, 2 of the biphenyl ring. , 4th, 5th, 6th, 2 ′, 3 ′, 4 ′, preferably 6th, 4 ′, especially 6th Etc. may be substituted. When the 4-position of the biphenyl ring is bonded to the 9-position of the fluorene ring, the substitution position of the group [—O— (A ³ O) _p —] is the 2-position, 3-position, 2′-position, 3 of the biphenyl ring. It may be any position at the 'position, 4' position, and may preferably be substituted at any position of the 2nd position, 4 'position, particularly the 2nd position.

  The first diol unit (B1) is a structural unit derived from (or corresponding to) the first diol component (B1). As a representative first diol component (B1), for example, the formula (B1) ), A 9,9-bis [hydroxy (poly) alkoxyaryl] fluorene corresponding to a unit wherein p is 1 or more, specifically about 1 to 10, preferably 1 to 6, more preferably 1 to 3. And the like. In the present specification and claims, unless otherwise specified, “(poly) alkoxy” is used to mean including both an alkoxy group and a polyalkoxy group.

  Examples of 9,9-bis [hydroxy (poly) alkoxyaryl] fluorenes include (B1-1) 9,9-bis [hydroxy (poly) alkoxyphenyl] fluorene; (B1-2) 9,9-bis. [Hydroxy (poly) alkoxy-alkylphenyl] fluorene; (B1-3) 9,9-bis [hydroxy (poly) alkoxy-arylphenyl] fluorene; (B1-4) 9,9-bis [hydroxy (poly) alkoxy Naphthyl] fluorene and the like.

Examples of (B1-1) 9,9-bis [hydroxy (poly) alkoxyphenyl] fluorene include 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene and 9,9-bis [4- 9,9-bis [hydroxy (mono to deca) C _2-4 such as (2-hydroxypropoxy) phenyl] fluorene, 9,9-bis [4- (2- (2-hydroxyethoxy) ethoxy) phenyl] fluorene Alkoxy-phenyl] fluorene and the like.

(B1-2) 9,9-bis [hydroxy (poly) alkoxy-alkylphenyl] fluorene includes, for example, 9,9-bis [4- (2-hydroxyethoxy) -3-methylphenyl] fluorene, 9,9-bis [hydroxy (mono to deca) C _2-4alkoxy- (mono or di) C _1-4 such as 9-bis [4- (2-hydroxyethoxy) -3,5-dimethylphenyl] fluorene Alkyl-phenyl] fluorene and the like.

Examples of (B1-3) 9,9-bis [hydroxy (poly) alkoxy-arylphenyl] fluorene include 9 such as 9,9-bis (4- (2-hydroxyethoxy) -3-phenylphenyl) fluorene. , 9-bis [hydroxy (mono to deca) C _2-4alkoxy- C _6-10aryl- phenyl] fluorene.

Examples of (B1-4) 9,9-bis [hydroxy (poly) alkoxynaphthyl] fluorene include 9,9-bis [6- (2-hydroxyethoxy) -2-naphthyl] fluorene and 9,9-bis. 9,9-bis [hydroxy (mono to deca) C _2-4 alkoxy-naphthyl] fluorene such as [5- (2-hydroxyethoxy) -1-naphthyl] fluorene and the like.

These 1st diol units (B1) can also be used individually or in combination of 2 or more types. Of these the first diol units (B1), 9,9-bis [hydroxy (mono- to _{deca) C 2-4} alkoxy _{C 6-10} aryl] fluorene such as 9,9-bis [hydroxy (poly) alkoxy Preferred are structural units derived from aryl] fluorenes; (B1-1) 9,9-bis [hydroxy (poly) alkoxyphenyl] fluorene, (B1-4) 9,9-bis [hydroxy (poly) alkoxy naphthyl] fluorene are preferred; more preferably 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene such as 9,9-bis [hydroxy (mono- to _{hexa) C 2-4} alkoxyphenyl] fluorene, 9,9-bis [hydroxy (molybdenum) such as 9,9-bis [6- (2-hydroxyethoxy) -2-naphthyl] fluorene To _{hexa) C 2-4} alkoxy - naphthyl] fluorene; in particular, from the viewpoint easily increase the refractive index and heat resistance, 9,9-bis [6- (such as 2-hydroxyethoxy) -2-naphthyl] fluorene 9 , 9-bis [hydroxy (mono to tri) C _2-3 alkoxy-naphthyl] fluorene units are preferred.

  By including such a first diol unit (B1), the refractive index and heat resistance can be improved and the Abbe number can be reduced without greatly increasing the birefringence of the polyester resin. The ratio of the first diol unit (B1) can be selected, for example, from the range of about 10 to 100 mol%, preferably 30 to 100 mol%, 50, step by step with respect to the entire diol unit (B). It is -100 mol%, 60-99 mol%, 70-98 mol%, 75-97 mol%, More preferably, it is 80-95 mol%, Especially 85-95 mol%. If the proportion of the first diol unit (B1) is too small, the refractive index and heat resistance may be lowered, and the Abbe number may not be reduced.

  The polyester resin of the present invention has mutually conflicting characteristics such as high refractive index and low birefringence, high heat resistance and high moldability by appropriately combining the dicarboxylic acid unit (A1) and the diol unit (B1). Can be satisfied at a higher level. Therefore, the ratio of the 1st diol unit (B1) can be selected from the range of about 0.1-10 mol with respect to 1 mol of 1st dicarboxylic acid units (A1), Preferably, it is stepwise below. 0.3-5 mol, 0.5-4 mol, 0.7-3 mol, 0.8-2 mol, 0.9-1.5 mol, more preferably 1-1.3 mol, In particular, it is 1-1.2 mol.

  The polyester resin of the present invention may be formed by only the dicarboxylic acid unit (A1) and the diol unit (B1). However, from the viewpoint of improving (or improving) the polymerization reactivity and mechanical properties in a balanced manner, A structural unit (or polymerization component) may be included.

[Other structural units]
(Second dicarboxylic acid unit (A2))
The dicarboxylic acid unit (A) may further include a second dicarboxylic acid unit (A2) represented by the following formula (A2).

(In the formula, Ar represents an arene ring, R ⁴ represents a substituent, and q represents an integer of 0 or more).

In the formula (A2), as the arene ring (aromatic hydrocarbon ring) represented by the ring Ar, an arene ring similar to the arene ring exemplified for the ring Z in the first diol unit (B1) can be exemplified. . Preferable ring Ar includes, for example, a C _6-14 arene ring such as a benzene ring, a naphthalene ring, and a biphenyl ring, more preferably a C _6-12 arene ring, particularly C ₆ such as a benzene ring and a naphthalene ring. _-10 arene rings, in particular naphthalene rings.

Examples of the substituent represented by R ⁴ include the same substituents including the group R ³ described in the section of the first diol unit (B1) and preferred embodiments.

The number of substitutions q of the group R ⁴ can be selected according to the type of the ring Ar, and can be selected from, for example, an integer of about 0 to 6, preferably stepwise, an integer of 0 to 4, an integer of 0 to 2, More preferred is 0 or 1, especially 0. When q is 2 or more, the types of the two or more groups R ⁴ may be the same or different from each other. Further, the substitution position of the group R ⁴ is not particularly limited, and may be substituted at a position other than the bonding position between the two carbonyl groups [—C (═O) —] and the ring Ar.

  The substitution position of the two carbonyl groups [—C (═O) —] is not particularly limited. For example, when the ring Ar is a benzene ring, the two carbonyl groups [—C (═O) —] are o- Substituent, m-position or p-position may be substituted. Among them, substitution is preferably performed at the m-position or p-position, particularly p-position. In addition, when the ring Ar is a naphthalene ring, the two carbonyl groups [—C (═O) —] may be substituted at any of the 1 to 8 positions, but usually one of the carbonyl groups is In many cases, the other carbonyl group is substituted at the 5- to 8-position with respect to the naphthyl group substituted at the 1- or 2-position. For example, the positional relationship between the 1,5-position or 2,6-position, particularly the 2,6-position Is preferably substituted. When the ring Ar is a biphenyl ring, the two carbonyl groups [—C (═O) —] may be substituted in any positional relationship, but usually they are each substituted with different benzene rings, Substitution is preferably made in the positional relationship of the 2,2′-position, the 3,3′-position or the 4,4′-position, particularly the 4,4′-position.

  The second dicarboxylic acid unit (A2) is a structural unit corresponding to the second dicarboxylic acid component (A2), and typical second dicarboxylic acid component (A2) is, for example, in the formula (A2) Benzenedicarboxylic acids corresponding to units in which ring Ar is a benzene ring; polycyclic arenedicarboxylic acids corresponding to units in which ring Ar is a polycyclic arene ring; and ester-forming derivatives thereof.

Examples of benzenedicarboxylic acids include benzenedicarboxylic acid and alkylbenzenedicarboxylic acid. Examples of benzenedicarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid, and the like. Examples of the alkylbenzene dicarboxylic acid include C _1-4 alkyl-benzene dicarboxylic acid such as 5-methylisophthalic acid.

  Examples of the polycyclic arene dicarboxylic acids include condensed polycyclic arene dicarboxylic acids and ring-assembled arene dicarboxylic acids.

Examples of the condensed polycyclic arene dicarboxylic acid include naphthalene dicarboxylic acids such as 1,2-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, and 2,6-naphthalenedicarboxylic acid; anthracene Dicarboxylic acid; condensed polycyclic C _10-24 arene-dicarboxylic acid such as phenanthrene dicarboxylic acid. A preferred condensed polycyclic arene dicarboxylic acid is a condensed polycyclic C _10-14 arene dicarboxylic acid.

Examples of the ring assembly arene dicarboxylic acid include bi C _6-10 arene dicarboxylic acid such as 2,2′-biphenyldicarboxylic acid, 3,3′-biphenyldicarboxylic acid, 4,4′-biphenyldicarboxylic acid, and the like. It is done.

These second dicarboxylic acid units (A2) may be used alone or in combination of two or more. Of these second dicarboxylic acid units (A2), benzene dicarboxylic acids, for example, benzene dicarboxylic acids such as isophthalic acid and terephthalic acid; dicarboxylic acid units derived from condensed polycyclic arene dicarboxylic acids are preferred. Of these, condensed polycyclic C _10-14 arene-dicarboxylic acid, more preferably naphthalenedicarboxylic acid, particularly 2,6-naphthalenedicarboxylic acid, because it is easy to improve the refractive index and heat resistance and easily reduce the Abbe number. Dicarboxylic acid units derived from acids and their ester-forming derivatives are preferred.

  By including the second dicarboxylic acid unit (A2), the refractive index and heat resistance of the polyester resin are improved, and the Abbe number is easily reduced. When the second dicarboxylic acid unit (A2) is included, the ratio of the first dicarboxylic acid unit (A1) to the second dicarboxylic acid unit (A2) is, for example, the former / the latter (molar ratio) = 99.9. Can be selected from a wide range of about /0.1 to 1/99, and preferably 99/1 to 10/90, 98/2 to 20/80, 97/3 to 30/70, 95/5 in the following steps. -50/50, 93/7 to 60/40, more preferably 90/10 to 70/30, especially 85/15 to 75/25. When there are too many 2nd dicarboxylic acid units (A2), there exists a possibility that birefringence may increase.

(Third dicarboxylic acid unit (A3))
The dicarboxylic acid unit (A) may further include a third dicarboxylic acid unit (A3) represented by the following formula (A3-1) or (A3-2).

(Wherein R ⁵ is the same or different and is a substituent, r and s are each an integer of 0 to ^4, and A ⁴ and A ⁵ are each a divalent hydrocarbon group which may have a substituent) .

In the formula (A3-1) or (A3-2), the substituent R ⁵ includes the group R ¹ exemplified in the section of the first dicarboxylic acid unit (A1) and the substitution number r of the substituent R ⁵ as follows. The number of substitution k of the group R ¹ exemplified in the section of the first dicarboxylic acid unit (A1) may be the same as that including preferred embodiments. In the two benzene rings forming the fluorene ring, the type of the group R ⁵ and the number of substitutions r may be the same or different from each other. When r is 2 or more, the types of the groups R ⁵ substituted on the same benzene ring may be the same or different from each other.

Examples of the divalent hydrocarbon group which may have a substituent represented by the groups A ⁴ and A ⁵ are the same groups as the group A ¹ exemplified in the section of the first dicarboxylic acid unit (A1). Is mentioned. The group A ⁴ is often a linear or branched C _2-4 alkylene group, for example, a linear or branched C _2-3 alkylene group such as an ethylene group or a propylene group, particularly an ethylene group, A ⁵ is often a linear or branched C _1-3 alkylene group such as a methylene group or an ethylene group. The hydrocarbon groups A ⁴ and A ⁵ having a substituent may be, for example, a 1-phenylethylene group or a 1-phenylpropane-1,2-diyl group. The type of the two radicals A ⁴ may be different from each other, usually the same.

  In the formula (A3-2), the repeating number s of the methylene group can be selected from, for example, an integer of about 0 to 3, preferably an integer of 0 to 2, and more preferably 0 or 1.

As the dicarboxylic acid unit (A3) represented by the formula (A3-1), typically, for example, a unit in which A ⁴ is a linear or branched C _2-6 alkylene group, specifically, 9,9-bis (carboxy C _2-6 alkyl) fluorene such as 9,9-bis (2-carboxyethyl) fluorene, 9,9-bis (2-carboxypropyl) fluorene; and ester-forming derivatives thereof And a structural unit derived from the third dicarboxylic acid component (A3).

As the dicarboxylic acid unit (A3) represented by the formula (A3-2), typically, for example, s is 0, and the group A ⁵ is a linear or branched C _1-6 alkylene group. A unit, specifically 9- (1,2-dicarboxyethyl) fluorene; a compound in which s is 1 and the group A ⁵ is a linear or branched C _1-6 alkylene group, 9- (Dicarboxy C _2-8 alkyl) fluorene such as 9- (2,3-dicarboxypropyl) fluorene; and dicarboxylic acids derived from the third dicarboxylic acid component (A3) such as ester-forming derivatives thereof Examples include units.

These third dicarboxylic acid units (A3) may be used alone or in combination of two or more. Of these third dicarboxylic acid units (A3), the dicarboxylic acid unit represented by the formula (A3-1) is preferable from the viewpoint of easy reduction of birefringence, and among them, 9,9-bis (carboxyl). C _2-6 alkyl) fluorene, more preferably 9,9-bis (carboxy C _2-4 alkyl) fluorene, in particular 9,9-bis (2-carboxyethyl) fluorene, 9,9-bis (2-carboxy). propyl) fluorene such as 9,9-bis (carboxy _{C 2-3} alkyl) fluorene, among others, is 9,9-bis (2-carboxyethyl) fluorene, and the dicarboxylic acid units derived from ester-forming derivatives thereof preferable.

  By including the third dicarboxylic acid unit (A3), it is easy to improve the polymerization reactivity, moldability, and mechanical properties while reducing the birefringence of the polyester resin. Moreover, since the excessive raise of the glass transition temperature Tg can be suppressed by containing a 3rd dicarboxylic acid unit (A3) in a suitable ratio, adjusting the balance of heat resistance and a moldability in a still higher level. You can also. When the third dicarboxylic acid unit (A3) is included, the ratio of the first dicarboxylic acid unit (A1) to the third dicarboxylic acid unit (A3) is, for example, the former / the latter (molar ratio) = 99/1. Can be selected from a wide range of about 5/95, preferably stepwise 95/5 to 10/90, 90/10 to 20/80, 85/15 to 30/70, 80/20 to 40/60. 75/25 to 50/50, more preferably 70/30 to 55/45, particularly 65/35 to 60/40. When there are too many 3rd dicarboxylic acid units (A3), there exists a possibility that heat resistance and a refractive index may fall.

  When both the second dicarboxylic acid unit (A2) and the third dicarboxylic acid unit (A3) are included, the ratio of the second dicarboxylic acid unit (A2) to the third dicarboxylic acid unit (A3) is For example, the former / the latter (molar ratio) can be selected from a wide range of about 90/10 to 5/95, and preferably in the following steps, 80/20 to 10/90, 70/30 to 10/90, 65 / 35-15 / 85, 60 / 40-20 / 80, 55 / 45-25 / 75, more preferably 50 / 50-30 / 70, and especially 45 / 55-35 / 65.

(Fourth dicarboxylic acid unit (A4))
In addition, as long as the dicarboxylic acid unit (A) is a range that does not impair the effects of the present invention, the other dicarboxylic acid unit (fourth dicarboxylic acid unit that does not belong to the range of the first to third dicarboxylic acid units ( A4)) may be included. Examples of the fourth dicarboxylic acid unit (A4) include aromatic dicarboxylic acids (excluding the first to third dicarboxylic acid components); alicyclic dicarboxylic acids; aliphatic dicarboxylic acids; and ester formation thereof. And a dicarboxylic acid unit derived from the fourth dicarboxylic acid component (A4) such as a functional derivative.

Examples of the aromatic dicarboxylic acid (excluding the first to third dicarboxylic acid components) include diarylalkane dicarboxylic acid and diaryl ketone dicarboxylic acid. Examples of the diarylalkanedicarboxylic acid include diC _6-10 aryl C _1-6 alkane-dicarboxylic acid such as 4,4′-diphenylmethanedicarboxylic acid. Examples of the diaryl ketone dicarboxylic acid include di (C _6-10 aryl) ketone-dicarboxylic acid such as 4.4′-diphenyl ketone dicarboxylic acid.

Examples of the alicyclic dicarboxylic acid include cycloalkane dicarboxylic acid, bridged cyclic cycloalkane dicarboxylic acid, cycloalkene dicarboxylic acid, bridged cyclic cycloalkene dicarboxylic acid, and the like. Examples of the cycloalkanedicarboxylic acid include C _5-10 cycloalkane-dicarboxylic acid such as 1,4-cyclohexanedicarboxylic acid. Examples of the bridged cyclic cycloalkanedicarboxylic acid include di- or tricycloalkanedicarboxylic acid such as decalin dicarboxylic acid, norbornane dicarboxylic acid, adamantane dicarboxylic acid, and tricyclodecane dicarboxylic acid. Examples of the cycloalkene dicarboxylic acid include C _5-10 cycloalkene-dicarboxylic acid such as cyclohexene dicarboxylic acid. Examples of the bridged cyclic cycloalkene dicarboxylic acid include di- or tricycloalkene dicarboxylic acid such as norbornene dicarboxylic acid.

Examples of the aliphatic dicarboxylic acid include alkane dicarboxylic acid and unsaturated aliphatic dicarboxylic acid. Examples of the alkanedicarboxylic acid include C _2-12 alkane-dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and decanedicarboxylic acid. Examples of the unsaturated aliphatic dicarboxylic acid include C _2-10 alkene-dicarboxylic acid such as maleic acid, fumaric acid, and itaconic acid.

  These 4th dicarboxylic acid units (A4) can also be used individually or in combination of 2 or more types. The proportion of the fourth dicarboxylic acid unit (A4) may be, for example, 50 mol% or less, preferably 30 mol% or less, more preferably 10 mol% or less, based on the entire dicarboxylic acid unit (A). 5 mol% or less. When the fourth dicarboxylic acid unit (A4) is included, the proportion thereof may be, for example, about 0.1 to 50 mol% with respect to the entire dicarboxylic acid unit (A).

(Second diol unit (B2))
The diol unit (B) may contain a second diol unit (B2) represented by the following formula (B2) in addition to the first diol unit (A1).

(In the formula, A ⁶ represents a linear or branched alkylene group, and t represents an integer of 1 or more).

In the formula (B2), the alkylene group A ⁶ may be the same as the group A ³ described in the first diol unit (B1), including preferred embodiments.

The repeating number t of the oxyalkylene group (OA ⁶ ) may be an integer of 1 or more, for example, an integer of about 1 to 10, and is preferably an integer of 1 to 5, an integer of 1 to 3, 1 or 2, more preferably 1. If the number t of repetitions is too large, the refractive index and heat resistance may be reduced.

  Specific examples of the second diol unit (B2) include structural units derived from the second diol component (B2) such as alkane diol and polyalkylene glycol (or polyalkane diol).

Examples of the alkanediol include ethylene glycol, propylene glycol, trimethylene glycol, 1,2-butanediol, 1,3-butanediol, tetramethylene glycol (1,4-butanediol), 1,5-pentanediol, Examples thereof include linear or branched C _2-12 alkanediols such as neopentyl glycol, 1,6-hexanediol, 1,8-octanediol, and 1,10-decanediol.

Examples of the polyalkylene glycol (or polyalkane diol) include poly C _2-6 alkane diols such as polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol. Preferred polyalkylene glycols include di to tetra C _2-4 alkanediols such as diethylene glycol, triethylene glycol, and dipropylene glycol.

These 2nd diol units (B2) can also be utilized individually or in combination of 2 or more types. Of these second diol units (B2), linear or branched C _2-6 alkanediols such as ethylene glycol, propylene glycol and 1,4-butanediol are preferable, and linear chains are more preferable. In particular, units derived from linear or branched C _2-4 alkanediols, especially linear or branched C _2-3 alkanediols such as ethylene glycol and propylene glycol, particularly ethylene glycol are preferred.

  By including such a second diol unit (B2), it is possible to improve the polymerization reactivity and improve properties such as mechanical properties (for example, flexibility) and moldability of the polyester resin.

  The ratio of the total amount of the first diol unit (B1) and the second diol unit (B2) is, for example, not less than 10 mol%, specifically about 30 to 100 mol% with respect to the entire diol unit (B). Preferably, in the following stepwise, it is 50 mol% or more, 60 mol% or more, 70 mol% or more, 80 mol% or more, more preferably 90 mol% or more, especially 95 mol% or more. In particular, it may be substantially 100 mol%, ie only the first diol unit (B1) and / or the second diol unit (B2).

  When a unit other than the first and second diol units is included, the ratio of the total amount of the first diol unit (B1) and the second diol unit (B2) is, for example, relative to the entire diol unit (B), You may select from the range of about 60-99.9 mol%, Preferably it is 80-99 mol%, More preferably, it is 90-95 mol%. In addition, when the diol unit (B) includes a third diol unit (B3) described later, the ratio of the total amount of the first diol unit (B1) and the second diol unit (B2) is the diol unit. (B) You may select from the range of about 30-90 mol% with respect to the whole, for example, Preferably it is 40-80 mol% and 50-70 mol% in steps below, More preferably, it is 55 ~ 60 mol%.

  When the diol unit (B) includes the second diol unit (B2), the ratio of the first diol unit (B1) to the second diol unit (B2) is, for example, the former / the latter (molar ratio). Can be selected from a wide range of about 99.9 / 0.1 to 10/90, and preferably 99/1 to 30/70, 99/1 to 50/50, and 98/2 to 60/40 step by step. 97/3 to 70/30, 96/4 to 75/25, more preferably 95/5 to 80/20, and particularly 95/5 to 85/15.

(Third diol unit (B3))
The diol unit (B) may contain a third diol unit (B3) represented by the following formula (B3) in addition to the first diol unit (A1).

(Wherein X is a direct bond or alkylene group, R ⁶ and R ⁷ are the same or different substituents, A ⁷ is the same or different linear or branched alkylene group, u is the same or different and 0 to An integer of 4, v is the same or different and is an integer of 0 to 2, and w is the same or different and represents an integer of 0 or more).

In the formula (B3), the alkylene group represented by X is, for example, a linear or branched chain such as a methylene group, an ethylene group, a propylene group, a trimethylene group, a 1,2-butanediyl group, or a tetramethylene group. C _1-4 alkylene group and the like can be mentioned. Preferable X is, for example, a direct bond; a C _1-2 alkylene group such as a methylene group from the viewpoint of optical properties such as a high refractive index, a low Abbe number, and a low birefringence, and a direct bond is particularly preferable.

Examples of the substituents R ⁶ and R ⁷ include the same substituents as the substituent R ³ exemplified in the above formula (B1), and the same applies to preferable examples.

The substitution number u of the substituent R ⁶ can be selected from an integer of about 0 to 3, preferably 0 to 2, more preferably 0 or 1, particularly 0. The substitution number v of the substituent R ⁷ is, for example, 0 or 1, preferably 0.

In the two different naphthalene rings constituting the formula (B3), the number of substitutions u and the number of substitutions v may be the same or different from each other, and the types of the groups R ⁶ and R ⁷ are the number of substitutions u and Depending on v, they may be the same or different from each other. Further, when two or more groups R ⁶ and / or two groups R ⁷ are substituted on the same naphthalene ring (that is, when u is 2 or more and / or v is 2), two or more groups R ⁶ The type and / or type of the two groups R ⁷ may be the same or different from each other.

Further, the substitution position of the group R ⁶ is not particularly limited, and among the 5-position to 8-position (or 5′-position to 8′-position) with respect to the linking group X substituted at the 1,1′-position of the naphthalene ring, It may be substituted at any position. The substitution position of the group R ⁷ is not particularly limited as long as it is a position other than the substitution position of the linking group X and the oxyalkylene group (OA ⁷ ) -containing group.

The alkylene group represented by the group A ⁷ constituting the oxyalkylene group (OA ⁷ ) is, for example, the same as the alkylene group A ³ exemplified in the formula (B1), including preferred embodiments.

The repeating number w of the oxyalkylene group (OA ⁷ ) may be an integer of 0 or more, and can be selected, for example, from a range of about 0 to 15. A preferable range is 0 to 10, 0 to 3 stepwise below. 0 to 2, more preferably 0 or 1, high polymerization reactivity, excellent optical properties such as high refractive index, low Abbe number, and low birefringence, and heat resistance, and also suppresses coloring. In view of the possibility, the number of repetitions w is particularly preferably 1.

The substitution position of the oxyalkylene group (OA ⁷ ) -containing group forming the main chain of the polyester resin is the 2-position to the 4-position (or the 2′-position) with respect to the linking group X substituted at the 1,1′-position of the naphthalene ring. To the 4 ′ position), but the 2nd position (or the 2 ′ position) is particularly preferable from the viewpoint that birefringence can be reduced.

  A typical example of the third diol unit (B3) is a unit derived from (or corresponding to) a third diol component such as dihydroxy-1,1'-binaphthalene in which X is a direct bond. Examples of the dihydroxy-1,1′-binaphthalene include dihydroxy-1,1′-binaphthalene such as 2,2′-dihydroxy-1,1′-binaphthalene; bis [hydroxy (poly) alkoxy] -1,1. '-Binaphthalene etc. are mentioned.

Examples of bis [hydroxy (poly) alkoxy] -1,1′-binaphthalene include 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene and 2,2′-bis (2-hydroxy). 2,2′-bis [hydroxy (mono to deca) C such as propoxy) -1,1′-binaphthalene, 2,2′-bis [2- (2-hydroxyethoxy) ethoxy] -1,1′-binaphthalene _2-4 alkoxy] -1,1′-binaphthalene and the like.

These 3rd diol units (B3) can also be used individually or in combination of 2 or more types. Among these third diol units (B3), from the viewpoint of being excellent not only in polymerization reactivity but also in optical properties such as high refractive index, low Abbe number, low birefringence and heat resistance, and coloration can be suppressed. , 2'-bis [hydroxy (mono- to _{deca) C 2-4} alkoxy] -1,1'-binaphthalene, among others, 2,2'-bis [hydroxy (mono- to _{hexa) C 2-4} alkoxy] -1 , 1′-binaphthalene-derived units are preferred, especially 2,2′-bis [hydroxy (mono to tri) C ₂ such as 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene. _-3 alkoxy] -1,1′-binaphthalene derived units are preferred.

  By including the third diol unit (B3), it is easy to improve the optical properties, particularly the refractive index, of the obtained polycarbonate resin.

  When the third diol unit (B3) is included, the total amount (or the first to third diol units) of the first diol unit (B1), the second diol unit (B2) and the third diol unit (B3) The total amount of the diol unit (B) can be selected from the range of, for example, 10 mol% or more, specifically, about 30 to 100 mol%, preferably 50 mol% stepwise below. Or more, 60 mol% or more, 70 mol% or more, 80 mol% or more, more preferably 90 mol% or more, especially 95 mol% or more, in particular, substantially 100 mol%, that is, first to first. Only 3 diol units. When a unit other than the first to third diol units, for example, a fourth diol unit (B4) described later is included, the ratio of the total amount of the first to third diol units is based on the entire diol unit (B). For example, you may select from the range of about 60-99.9 mol%, Preferably it is 80-99 mol%, More preferably, it is 90-95 mol%.

  When the diol unit (B) includes the third diol unit (B3), the ratio of the first diol unit (B1) to the third diol unit (B3) is, for example, the former / the latter (molar ratio). Can be selected from a wide range of about 99/1 to 1/99, preferably 90/10 to 10/90, 80/20 to 20/80, and 70/30 to 30/70 in stages. 60/40 to 40/60 is preferable, and 55/45 to 45/55 is particularly preferable. If the proportion of the third diol unit (B3) is too small, the refractive index may not be improved, and if it is too large, the heat resistance may not be improved.

  When the diol unit (B) includes both the second diol unit (B2) and the third diol unit (B3), the ratio between the second diol unit (B2) and the third diol unit (B3) Can be selected from a wide range of, for example, the former / the latter (molar ratio) = 99/1 to 1/99, preferably 90/10 to 10/90, 85/15 to 30/70, stepwise below. 80/20 to 50/50, more preferably 75/25 to 55/45, particularly 70/30 to 60/40.

(Fourth diol unit (B4))
In addition, as long as a diol unit (B) is a range which does not impair the effect of this invention, it is another diol unit (4th diol unit (B4) which does not belong to the range of the 1st-3rd diol unit). May be included. Examples of the fourth diol unit (B4) include alicyclic diols, aromatic diols (excluding the first and third diol units), and C _2-4 alkylene oxides (or the diol components) (or Examples include units derived from the fourth diol component (B4) such as adducts of alkylene carbonate and haloalkanol.

  Examples of the alicyclic diol include cycloalkane diols such as cyclohexane diol; bis (hydroxyalkyl) cycloalkanes such as cyclohexane dimethanol; and hydrogenated aromatic diols such as hydrogenated bisphenol A described later. It is done.

  Examples of the aromatic diol (excluding the first and third diol units) include, for example, dihydroxyarenes such as hydroquinone and resorcinol; araliphatic diols such as benzenedimethanol; bisphenol A, bisphenol F, bisphenol AD, bisphenol Bisphenols such as C, bisphenol G, and bisphenol S; and biphenols such as p, p′-biphenol.

Examples of the C _2-4 alkylene oxide (or alkylene carbonate, haloalkanol) adduct of the diol component include adducts in which about 2 to 10 mol of ethylene oxide is added to 1 mol of the diol component such as bisphenol A. Is mentioned.

  These 4th diol units (B4) can also be used individually or in combination of 2 or more types. The proportion of the fourth diol unit (B4) may be, for example, 50 mol% or less, preferably 30 mol% or less, more preferably 10 mol% or less, particularly with respect to the entire diol unit (B). 5 mol% or less. When the fourth diol unit (B4) is included, the ratio thereof may be, for example, about 0.1 to 50 mol% with respect to the entire diol unit (B).

[Production method of polyester resin]
The method for producing a polyester resin of the present invention comprises reacting a dicarboxylic acid component (A) containing at least the first dicarboxylic acid component (A1) with a diol component (B) containing at least the first diol component (B1). It can be prepared by a conventional method, for example, a melt polymerization method such as a transesterification method or a direct polymerization method, a solution polymerization method or an interfacial polymerization method, and a melt polymerization method is preferred. The reaction may be performed in the presence or absence of a solvent depending on the polymerization method.

  The use ratio (or charge ratio) of the dicarboxylic acid component (A) and the diol component (B) is usually the former / the latter (molar ratio) = for example, 1 / 1.2 to 1 / 0.8, preferably 1. /1.1 to 1 / 0.9). In addition, in reaction, the usage-amount (use ratio) of each dicarboxylic acid component (A) and diol component (B) may be the same including the ratio and preferable aspect of each said dicarboxylic acid unit and diol unit, If necessary, each component or the like may be used in excess. For example, the second diol component (B2) such as ethylene glycol that can be distilled from the reaction system may be used in excess of the ratio (or introduction ratio) introduced into the polyester resin.

  The reaction may be performed in the presence of a catalyst. As the catalyst, a conventional esterification catalyst such as a metal catalyst can be used. Examples of metal catalysts include alkali metals (sodium, etc.); alkaline earth metals (magnesium, calcium, barium, etc.), transition metals (manganese, zinc, cadmium, lead, cobalt, titanium, etc.); periodic table group 13 metals (Aluminum etc.); Metal compounds containing Periodic Table Group 14 metals (Germanium etc.); Periodic Table Group 15 metals (antimony etc.) are used. The metal compound may be, for example, an alkoxide, an organic acid salt (acetate, propionate, etc.), an inorganic acid salt (borate, carbonate, etc.), a metal oxide, etc., and these hydrates. It may be. Typical metal compounds include, for example, germanium compounds (eg, germanium dioxide, germanium hydroxide, germanium oxalate, germanium tetraethoxide, germanium-n-butoxide, etc.); antimony compounds (eg, antimony trioxide, antimony acetate) Titanium compounds (eg, tetra-n-propyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, titanium oxalate, potassium potassium oxalate); manganese compounds (manganese acetate, 4 water) Examples thereof include calcium compounds (calcium acetate monohydrate, etc.).

These catalysts can be used alone or in combination of two or more. When using a plurality of catalysts, each catalyst can be added according to the progress of the reaction. Of these catalysts, manganese acetate tetrahydrate, calcium acetate monohydrate, germanium dioxide and the like are preferable. The amount of the catalyst used is, for example, 0.01 × 10 ^{−4 to} 100 × 10 ⁻⁴ mol, preferably 0.1 × 10 ⁻⁴ to 40 × 10 ^{−4 with} respect to 1 mol of the dicarboxylic acid component (A). Is a mole.

In addition, the reaction may be stabilized with a heat stabilizer (for example, a phosphorus compound such as trimethyl phosphate, triethyl phosphate, triphenyl phosphate, phosphorous acid, trimethyl phosphite, triethyl phosphite) or an antioxidant as necessary. You may carry out in presence of an agent. The amount of the stabilizer used is, for example, 0.01 × 10 ^{−4 to} 100 × 10 ⁻⁴ mol, preferably 0.1 × 10 ⁻⁴ to 40 × 10 ^{− with} respect to 1 mol of the dicarboxylic acid component (A). ⁴ moles.

The reaction may be performed in air, or may be generally performed in an inert gas atmosphere (for example, nitrogen; a rare gas such as helium or argon). The reaction can also be performed under reduced pressure (for example, about 1 × 10 ² to 1 × 10 ⁴ Pa). The reaction temperature can be selected according to the polymerization method. For example, the reaction temperature in the melt polymerization method is 150 to 300 ° C, preferably 180 to 290 ° C, more preferably 200 to 280 ° C.

[Characteristics of polyester resin]
Since the polyester resin of the present invention contains the first dicarboxylic acid unit (A1) and the first diol unit (B1), it has excellent optical properties (high refractive index, low birefringence, low Abbe number). In addition, both heat resistance and moldability can be achieved, and these characteristics can be satisfied in a highly balanced manner.

  The glass transition temperature Tg of the polyester resin can be selected from the range of, for example, about 100 to 250 ° C., and preferably 120 to 230 ° C., 130 to 220 ° C., 140 to 210 ° C., 150 to 200 ° C., 160 in the following steps. It is -190 degreeC, More preferably, it is 165-185 degreeC. In particular, in applications that are expected to be used in a high-temperature environment such as an in-vehicle optical lens, the glass transition temperature is preferably 160 to 180 ° C, more preferably from the viewpoint of achieving both high heat resistance and moldability. Is 165 to 180 ° C, more preferably 168 to 178 ° C, and particularly preferably 170 to 178 ° C. If the glass transition temperature Tg is too low, the resin may be deformed or discolored (or colored) during use. If the Tg is too high, the surface of the molded product (for example, an optical lens) can be formed smoothly. There is a risk of disappearing.

  The weight average molecular weight Mw of the polyester resin can be measured by gel permeation chromatography (GPC) or the like, and can be selected from the range of, for example, about 10,000 to 200,000 in terms of polystyrene. 80000, 25000-60000, 30000-40000. Usually, it is 35000-50000, preferably 40000-45000.

  The refractive index of the polyester resin can be selected from a range of, for example, about 1.63 to 1.7 at a temperature of 20 ° C. and a wavelength of 589 nm, and preferably 1.635 to 1.69, 1.65 in the following steps. 1.68 and 1.66 to 1.678, more preferably 1.665 to 1.675, and particularly 1.67 to 1.673.

  The Abbe number of the polyester resin is, for example, 30 or less, preferably 26 or less, and more preferably 23 or less at a temperature of 20 ° C. The Abbe number of the polyester resin may be selected from a range of, for example, about 17 to 28 at a temperature of 20 ° C., preferably 18 to 24, and more preferably 19 to 21.

The birefringence of the polyester resin may be evaluated by the birefringence (3-fold birefringence) of a stretched film obtained by uniaxially stretching a film formed of polyester alone at a stretch ratio of 3 times. The absolute value of triple birefringence of the stretched film prepared under stretching conditions (glass transition temperature Tg + 10) ° C. and stretching speed of 25 mm / min is, for example, 100 × 10 ^{−4 at} a measurement temperature of 20 ° C. and a wavelength of 600 nm. It can be selected from the following ranges, preferably 50 × 10 ⁻⁴ or less, more preferably 20 × 10 ⁻⁴ or less, further preferably 10 × 10 ⁻⁴ or less, and particularly 3 × 10 ⁻⁴ or less. The absolute value of the triple birefringence may be selected from a range of, for example, about 0.001 × 10 ⁻⁴ to 75 × 10 ^{−4 at} a measurement temperature of 20 ° C. and a wavelength of 600 nm. 005 × 10 ⁻⁴ to 30 × 10 ⁻⁴ , more preferably 0.01 × 10 ⁻⁴ to 15 × 10 ⁻⁴ , still more preferably 0.05 × 10 ^{−4 to} 5 × 10 ⁻⁴ , particularly 0.1 × a ^{10 -4 ~2.5} × ¹⁰ -4.

  In the present specification and claims, the glass transition temperature Tg, the weight average molecular weight Mw, the refractive index, the Abbe number, and the triple birefringence can be measured by the method described in Examples described later.

[Molded body]
Since the molded article of the present invention contains the polyester resin and has excellent heat resistance and optical properties (high refractive index, low birefringence, etc.), it can be used for optical films, optical lenses, optical sheets and the like. It can be used as a member. The shape of the molded body is not particularly limited, and for example, a one-dimensional structure (for example, a linear shape, a thread shape), a two-dimensional structure (for example, a film shape, a sheet shape, a plate shape, etc.), a three-dimensional structure ( Examples thereof include a concave or convex lens shape, a rod shape, and a hollow shape (tubular shape).

  The molded product of the present invention has various additives [for example, fillers or reinforcing materials, colorants (for example, dyes and pigments), conductive agents, flame retardants, plasticizers, lubricants, stabilizers (for example, antioxidants, ultraviolet rays). Absorbents, heat stabilizers, etc.), mold release agents, antistatic agents, dispersants, flow regulators, leveling agents, antifoaming agents, surface modifiers, low stress agents (eg silicone oil, silicone rubber, various types) Plastic powder, various engineering plastic powders, carbon materials, etc.]. These additives may be used alone or in combination of two or more.

  The molded body can be manufactured using, for example, an injection molding method, an injection compression molding method, an extrusion molding method, a transfer molding method, a blow molding method, a pressure molding method, a casting molding method, and the like.

  In particular, since the polyester resin of the present invention is excellent in various optical properties, it is useful for forming a film (particularly an optical film). Therefore, the present invention includes a film (an optical film or an optical sheet) formed of the polyester resin.

  The thickness (average thickness) of such a film can be selected according to the use from the range of about 1 to 1000 μm, for example, 1 to 200 μm, preferably 5 to 150 μm, and more preferably 10 to 120 μm.

  Such a film (optical film) can be produced by forming (or molding) the polyester resin using a conventional film forming method, casting method (solvent casting method), melt extrusion method, calendar method, or the like. .

  The film may be a stretched film. Even if the film of the present invention is a stretched film, low birefringence can be maintained. Such a stretched film may be either a uniaxially stretched film or a biaxially stretched film.

  The stretching ratio is 1.1 to 10 times, preferably 1.2 to 8 times, more preferably 1.5 to 6 times in each direction in uniaxial stretching or biaxial stretching, and usually 1.1 to 2 times. 5 times, preferably 1.2 to 2.3 times, more preferably 1.5 to 2.2 times. In the case of biaxial stretching, it may be equistretching, for example, 1.5 to 5 times in both the longitudinal and transverse directions, and uneven stretching, for example, 1.1 to 4 times in the longitudinal direction and 2 to 6 in the transverse direction. It may be double stretched. In the case of uniaxial stretching, the stretching may be longitudinal stretching, for example, 2.5 to 8 times stretching in the longitudinal direction, or transverse stretching, for example, 1.2 to 5 times stretching in the transverse direction.

  The stretched film has a thickness (average thickness) of, for example, 1 to 150 μm, preferably 3 to 120 μm, and more preferably 5 to 100 μm.

  Such a stretched film can be obtained by subjecting a film after film formation (or an unstretched film) to a stretching treatment. The stretching method is not particularly limited. In the case of uniaxial stretching, either a wet stretching method or a dry stretching method may be used. In the case of biaxial stretching, a tenter method (also called a flat method) may be used. However, a tenter method that is excellent in uniformity of stretch thickness is preferable.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. Evaluation methods and raw materials are shown below.

[Evaluation method]
(Glass transition temperature Tg)
Using a differential scanning calorimeter (“DSC 6220” manufactured by Seiko Instruments Inc.), a sample was put in an aluminum pan, and Tg was measured in the range of 30 to 200 ° C.

(Molecular weight)
Using gel permeation chromatography (“HLC-8120GPC” manufactured by Tosoh Corporation), the sample was dissolved in tetrahydrofuran (THF), and the weight average molecular weight Mw was measured in terms of polystyrene.

(Refractive index)
A polyester resin was press-molded at 200 to 240 ° C. to form a film having a thickness of 200 to 300 μm. This film was cut into a strip of 20 to 30 mm × 10 mm to obtain a test piece. The obtained test piece was measured at a measurement temperature of 20 ° C. and a light source wavelength of 589 nm using a multi-wavelength Abbe refractometer (“DR-M2 / 1410 (circulating constant temperature water bath 60-C3)” manufactured by Atago Co., Ltd.).

(Abbe number)
The test piece used for the measurement of the refractive index was contacted at a measurement temperature of 20 ° C. using a multi-wavelength Abbe refractometer (“DR-M2 / 1410 (Circulation type constant temperature water bath 60-C3)” manufactured by Atago Co., Ltd.). Using diiodomethane as the liquid, the refractive indices nF, nD, and nC at the measurement wavelengths of 486 nm (F line), 589 nm (D line), and 656 nm (C line) were measured and calculated according to the following equations.

    Abbe number = (nD-1) / (nF-nC).

(Birefringence (or triple birefringence))
A polyester resin was press-molded at 160 to 240 ° C. to form a film having a thickness of 100 to 400 μm. This film was cut into a strip of 15 mm × 50 mm, and uniaxially stretched at 25 mm / min so that the stretch ratio was 3 times under a temperature condition of Tg + 10 ° C. to obtain a test piece. About the obtained test piece, retardation is measured by a rotating analyzer method using a retardation film / optical material inspection apparatus ("RETS-100" manufactured by Otsuka Electronics Co., Ltd.) under a measurement temperature of 20 ° C and a measurement wavelength of 600 nm. Was calculated by dividing the absolute value by the thickness of the measurement site.

[material]
(Dicarboxylic acid component)
MBF-DC: bis [9- (2-methoxycarbonylethyl) -fluoren-9-yl] methane (synthesized according to Synthesis Example 1 described later)
DMN: 2,6-naphthalenedicarboxylic acid dimethyl ester DMT: terephthalic acid dimethyl ester FDP-m: 9,9-bis (2-methoxycarbonylethyl) fluorene [9,9-bis (2-carboxyethyl) fluorene (or fluorene -9,9-dipropionic acid) dimethyl ester] and t-butyl acrylate described in Example 1 of JP-A-2005-89422 were changed to methyl acrylate [37.9 g (0.44 mol)]. Except that, synthesized in the same way (diol component)
BPEF: 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene, manufactured by Osaka Gas Chemical Co., Ltd. BOPPEF: 9,9-bis [4- (2-hydroxyethoxy) -3-phenylphenyl] fluorene BNEF manufactured by Osaka Gas Chemical Co., Ltd .: 9,9-bis [6- (2-hydroxyethoxy) -2-naphthyl] fluorene, manufactured by Osaka Gas Chemical Co., Ltd. BINOL-2EO: 2,2′-bis (2 -Hydroxyethoxy) -1,1'-binaphthalene (synthesized according to Synthesis Example 2 described later)
EG: ethylene glycol.

[Synthesis Example 1] Synthesis of MBF-DC Under a nitrogen atmosphere, 470 g (2.83 mol) of fluorene and 1.86 L of N, N-dimethylformamide (DMF) were placed in a 5 L separable flask, and sodium ethoxide 96 at 0 ° C. .6 g (1.42 mol) was added in portions. Next, 33.9 g (1.13 mol) of paraformaldehyde was added, stirred at 10 ° C. or lower for 5 hours, and further stirred at room temperature for 1 hour. To the obtained solution, 1.73 L of 1N hydrochloric acid was added dropwise, the resulting mixture was filtered, and the filtrate was washed with ion-exchanged water. Further, 1.34 L of ion-exchanged water was added, and the mixture was stirred at room temperature for 1 hour and filtered to obtain 902 g of yellow crystals. The crystals were dissolved in 1.8 L of toluene and then dehydrated using a Dean-Stark apparatus. This was left standing overnight and filtered, and then the filtrate was dried under reduced pressure at 80 ° C. to obtain 339 g of bis (fluoren-9-yl) methane (or methylenebisfluorene) in the form of pale yellow crystals.

A 10 L separable flask was charged with 325 g (944 mmol) of methylene bisfluorene, 244 g (2.83 mol) of methyl acrylate and 751 g of methyl isobutyl ketone (MIBK), and the temperature was raised to 60 ° C. While this solution was stirred at 60 ° C., 39.5 g (94.4 mol) of Triton B (registered trademark) [benzyl trimethylammonium hydroxide in 40 wt% methanol solution] was added dropwise over 3 hours. To this solution, 81.3 g (944 mmol) of methyl acrylate was added dropwise and further stirred at 60 ° C. for 1 hour, and then 3000 g of MIBK was added and stirred at room temperature for another 30 minutes. The solution was neutralized by adding an aqueous NaHCO ₃ solution, and then washed with ion-exchanged water. The obtained solution was concentrated, 405 g of ethyl acetate was added, and recrystallization operation was performed to obtain white crystals. The obtained crystals were washed successively with ethyl acetate and methanol to obtain 175 g of MBF-DC in the form of white crystals.

[Synthesis Example 2] Synthesis of BINOL-2EO To a 1 L separable flask, 89 g (0.31 mol) of BINOL, 86 g (0.62 mol) of potassium carbonate, and 295 g of N, N-dimethylformamide (DMF) were charged. After heating to 100 ° C., a solution of 110 g of ethylene carbonate dissolved in 112 g of DMF was gradually added and stirred for 2 hours while maintaining 100 ° C. It was confirmed by HPLC that the conversion rate of BINOL was 99% or more. Distilled water (800 g) and ethyl acetate (900 g) were added to the resulting reaction solution, washed several times with distilled water, concentrated under reduced pressure, and recrystallized with an ethyl acetate / ethanol mixed solvent. The precipitate was filtered and dried to obtain 67 g (yield 58%) of crystals. As a result of analyzing the obtained crystals, the purity by HPLC was 94.8%. According to ¹ H-NMR and mass spectrum, 2,2′-bis (2-hydroxyethoxy) -1,1′- It confirmed that it was binaphthalene (BINOL-2EO).

[Example 1]
DMT 0.5 mol and MBF-DC 0.5 mol as dicarboxylic acid component, BPEF 0.7 mol and EG 2.3 mol as diol component, manganese acetate tetrahydrate 2 × 10 ⁻⁴ mol as transesterification catalyst And 8 × 10 ⁻⁴ mol of calcium acetate monohydrate and gradually heated and melted while stirring. After the temperature was raised to 230 ° C., 14 × 10 ⁻⁴ mol of trimethyl phosphate and 20 × 10 ⁻⁴ mol of germanium oxide And the temperature was raised to 250 ° C., and the pressure was reduced stepwise to 10 kPa. The EG was removed while gradually raising the temperature and reducing the pressure until reaching 270 ° C. and 0.13 kPa or less. After reaching a predetermined stirring torque, the contents were taken out from the reactor to obtain polyester resin pellets.

The obtained pellet was analyzed by ¹ H-NMR. As a result, 50 mol% of the dicarboxylic acid unit introduced into the polyester resin was derived from DMT, 50 mol% was derived from MBF-DC, and 70 of the introduced diol unit. The mol% was derived from BPEF and 30 mol% was derived from EG.

[Example 2]
Polyester resin pellets were obtained in the same manner as in Example 1 except that 0.75 mol of DMT and 0.25 mol of MBF-DC were used as the dicarboxylic acid component, and 0.7 mol of BPEF and 2.3 mol of EG were used as the diol component. It was.

The obtained pellet was analyzed by ¹ H-NMR. As a result, 75 mol% of the dicarboxylic acid unit introduced into the polyester resin was derived from DMT, 25 mol% was derived from MBF-DC, and 70 of the introduced diol unit. The mol% was derived from BPEF and 30 mol% was derived from EG.

[Comparative Example 1]
Polyester resin pellets were obtained in the same manner as in Example 1 except that 1 mol of DMT was used as the dicarboxylic acid component, and 0.7 mol of BPEF and 2.3 mol of EG were used as the diol component.

The obtained pellet was analyzed by ¹ H-NMR. As a result, 100 mol% of the dicarboxylic acid units introduced into the polyester resin were derived from DMT, 70 mol% of the introduced diol units were derived from BPEF, and 30 mol%. Was derived from EG.

[Comparative Example 2]
A polyester resin pellet is obtained in the same manner as in Example 1 except that 0.5 mol of DMT and 0.5 mol of FDP-m are used as the dicarboxylic acid component, and 0.7 mol of BPEF and 2.3 mol of EG are used as the diol component. It was.

The obtained pellet was analyzed by ¹ H-NMR. As a result, 50 mol% of the dicarboxylic acid unit introduced into the polyester resin was derived from DMT, 50 mol% was derived from FDP-m, and 70 of the introduced diol unit. The mol% was derived from BPEF and 30 mol% was derived from EG.

[Example 3]
Polyester resin pellets were obtained in the same manner as in Example 1 except that 0.2 mol of DMN and 0.8 mol of MBF-DC were used as the dicarboxylic acid component, and 0.9 mol and 2.1 mol of EG were used as the diol component. It was.

The obtained pellet was analyzed by ¹ H-NMR. As a result, 20 mol% of the dicarboxylic acid units introduced into the polyester resin were derived from DMN and 80 mol% were derived from MBF-DC. The mol% was derived from BNEF and 10 mol% was derived from EG.

[Example 4]
Example 1 except that DMN 0.2 mol, FDP-m 0.3 mol and MBF-DC 0.5 mol are used as the dicarboxylic acid component, and BNEF 0.9 mol and EG 2.1 mol are used as the diol component. Thus, polyester resin pellets were obtained.

When the obtained pellet was analyzed by ¹ H-NMR, 20 mol% of the dicarboxylic acid unit introduced into the polyester resin was derived from DMN, 30 mol% was derived from FDP-m, and 50 mol% was derived from MBF-DC. Yes, 90 mol% of the introduced diol units were derived from BNEF, and 10 mol% was derived from EG.

[Comparative Example 3]
Polyester resin pellets were obtained in the same manner as in Example 1 except that 0.4 mol of DMN and 0.6 mol of FDP-m were used as the dicarboxylic acid component, and 0.9 mol and 2.1 mol of EG were used as the diol component. It was.

The obtained pellet was analyzed by ¹ H-NMR. As a result, 40 mol% of the dicarboxylic acid unit introduced into the polyester resin was derived from DMN, 60 mol% was derived from FDP-m, and 90 of the introduced diol unit. The mol% was derived from BNEF and 10 mol% was derived from EG.

[Comparative Example 4]
Polyester resin pellets are obtained in the same manner as in Example 1 except that 0.2 mol of DMN and 0.8 mol of FDP-m are used as the dicarboxylic acid component, and 0.9 mol and 2.1 mol of EG are used as the diol component. It was.

The obtained pellet was analyzed by ¹ H-NMR. As a result, 20 mol% of the dicarboxylic acid unit introduced into the polyester resin was derived from DMN, 80 mol% was derived from FDP-m, and 90 of the introduced diol unit. The mol% was derived from BNEF and 10 mol% was derived from EG.

[Example 5]
Polyester resin pellets were obtained in the same manner as in Example 1 except that 0.5 mol of DMN and 0.5 mol of MBF-DC were used as the dicarboxylic acid component, and 0.9 mol of BNEF and 2.1 mol of EG were used as the diol component. It was.

The obtained pellet was analyzed by ¹ H-NMR. As a result, 50 mol% of the dicarboxylic acid unit introduced into the polyester resin was derived from DMN, 50 mol% was derived from MBF-DC, and 90 of the introduced diol unit. The mol% was derived from BNEF and 10 mol% was derived from EG.

[Comparative Example 5]
Polyester resin pellets are obtained in the same manner as in Example 1 except that 0.5 mol of DMN and 0.5 mol of FDP-m are used as the dicarboxylic acid component, and 0.9 mol of BPEF and 2.1 mol of EG are used as the diol component. It was.

The obtained pellet was analyzed by ¹ H-NMR. As a result, 50 mol% of the dicarboxylic acid unit introduced into the polyester resin was derived from DMN, 50 mol% was derived from FDP-m, and 90 of the introduced diol unit. The mol% was derived from BPEF and 10 mol% was derived from EG.

[Example 6]
Polyester resin pellets were obtained in the same manner as in Example 1 except that 0.5 mol of DMN and 0.5 mol of MBF-DC were used as the dicarboxylic acid component, and 0.9 mol of BPEF and 2.1 mol of EG were used as the diol component. It was.

The obtained pellet was analyzed by ¹ H-NMR. As a result, 50 mol% of the dicarboxylic acid unit introduced into the polyester resin was derived from DMN, 50 mol% was derived from MBF-DC, and 90 of the introduced diol unit. The mol% was derived from BPEF and 10 mol% was derived from EG.

[Comparative Example 6]
Polyester resin pellets were obtained in the same manner as in Example 1 except that 0.5 mol of DMN and 0.5 mol of FDP-m were used as the dicarboxylic acid component, and 0.8 mol of BOPPEF and 2.2 mol of EG were used as the diol component. It was.

When the obtained pellet was analyzed by ¹ H-NMR, 50 mol% of the dicarboxylic acid unit introduced into the polyester resin was derived from DMN, 50 mol% was derived from FDP-m, and 80 of the introduced diol unit. The mol% was derived from BOPPEF and 20 mol% was derived from EG.

[Example 7]
Polyester resin pellets were obtained in the same manner as in Example 1 except that 0.5 mol of DMN and 0.5 mol of MBF-DC were used as the dicarboxylic acid component, and 0.8 mol of BOPPEF and 2.2 mol of EG were used as the diol component. It was.

The obtained pellet was analyzed by ¹ H-NMR. As a result, 50 mol% of the dicarboxylic acid unit introduced into the polyester resin was derived from DMN, 50 mol% was derived from MBF-DC, and 80 of the introduced diol unit. The mol% was derived from BOPPEF and 20 mol% was derived from EG.

[Comparative Example 7]
Example 1 except that 0.5 mol DMN and 0.5 mol FDP-m were used as the dicarboxylic acid component, and 0.4 mol BNNEF, 0.4 mol BINOL-2EO and 2.2 mol EG were used as the diol component. Thus, polyester resin pellets were obtained.

The obtained pellet was analyzed by ¹ H-NMR. As a result, 50 mol% of the dicarboxylic acid unit introduced into the polyester resin was derived from DMN, 50 mol% was derived from FDP-m, and 40 of the introduced diol unit. The mol% was derived from BNEF, 40 mol% was derived from BINOL-2EO, and 20 mol% was derived from EG.

[Example 8]
Example 1 except that 0.5 mol DMN and 0.5 mol MBF-DC were used as the dicarboxylic acid component, and 0.4 mol, BNOL-2EO 0.4 mol and EG 2.2 mol were used as the diol component. Thus, polyester resin pellets were obtained.

The obtained pellet was analyzed by ¹ H-NMR. As a result, 50 mol% of the dicarboxylic acid units introduced into the polyester resin were derived from DMN, 50 mol% were derived from MBF-DC, and 40 diol units introduced. The mol% was derived from BNEF, 40 mol% was derived from BINOL-2EO, and 20 mol% was derived from EG.

  Table 1 shows the results obtained in the examples and comparative examples.

  As is clear from Table 1, in the Examples, not only the high refractive index and low birefringence were compatible, but also a relatively high glass transition temperature Tg and a low Abbe number as compared with the Comparative Example.

  In particular, in Example 3, despite having a very high refractive index of 1.67 or more, the absolute value of birefringence, which is a contradictory characteristic, was extremely low. Furthermore, it had high Tg while maintaining moldability, and the balance of all the characteristics was the best.

  The novel polyester resin of the present invention has not only excellent optical properties such as high refractive index, low birefringence, and high transparency, but also high heat resistance. Therefore, the polyester resin (or resin composition thereof) of the present invention includes, for example, paints, inks, adhesives, pressure-sensitive adhesives, resin fillers, antistatic agents, protective films (such as protective films for electronic devices), Electronic materials (charging trays, conductive sheets, carrier transport agents, light emitters, organic photoreceptors, thermal recording materials, hologram recording materials, etc.), electrical / electronic components or equipment (inkjet printers, digital paper, organic semiconductor lasers, dye sensitization) Resin for type solar cell, photochromic material, organic EL element, etc., resin for mechanical parts or equipment (automobile, aerospace material, sensor, sliding member, etc.), optical member (optical film (or optical sheet)), It can be suitably used for optical lenses, optical fibers, optical disks, and the like. In particular, since the polyester resin of the present invention is excellent in optical characteristics, it is useful for constituting (or forming) a molded article (optical member) for optical use.

  Examples of the optical film include a protective film (liquid crystal protective film, etc.), a polarizing film (and a polarizing element and a polarizing plate protective film constituting the protective film), a retardation film, an alignment film (alignment film), and a viewing angle expansion (compensation). Film, diffusion plate (film), prism sheet, light guide plate, brightness enhancement film, near infrared absorption film, reflection film, antireflection (AR) film, antireflection (LR) film, antiglare (AG) film, transparent conductive ( ITO) film, anisotropic conductive film (ACF), electromagnetic wave shielding (EMI) film, film for electrode substrate, film for color filter substrate, barrier film, color filter layer, black matrix layer, adhesive layer or separation between optical films Mold layers, etc., especially device displays (liquid crystal, organic L is useful as an optical film for use in, etc.). Specific examples of the display member (or display) provided with such an optical film include, for example, personal computer monitors, televisions, information terminals (for example, mobile phones such as smartphones, tablet terminals, etc.), and game machines. FPD devices (for example, LCD, PDP, etc.) such as car navigation systems and touch panels.

  Examples of the optical lens include a spectacle lens, a contact lens, a camera lens, a VTR zoom lens, a pickup lens, a Fresnel lens, a solar condenser lens, an objective lens, a rod lens array, and the like. A lens having a low Abbe number [for example, a lens mounted on a small device having a camera function (or a mobile device such as a mobile phone or a digital camera). In particular, since the polyester resin of the present invention has high heat resistance, it can be suitably used even for applications that are assumed to be used in a high-temperature environment (for example, in-vehicle lenses).

Claims (15)

A polyester resin having a dicarboxylic acid unit (A) and a diol unit (B), wherein the dicarboxylic acid unit (A) is represented by the following formula (A1):

(In the formula, A ¹ is the same or different and is a divalent hydrocarbon group which may have a substituent, and A ² is a divalent hydrocarbon group which may have a direct bond or a substituent. R ¹ is the same or different substituent, k is the same or different and represents an integer of 0 to 4.)
The diol unit (B) contains at least a first dicarboxylic acid unit (A1) represented by the following formula (B1):

(Wherein Z is the same or different and arene ring, R ² and R ³ are the same or different substituents, A ³ is the same or different and is a linear or branched alkylene group, m is the same or different and 0 An integer of -4, n is the same or different and is an integer of 0 or more, and p is the same or different and represents an integer of 0 or more.)
The polyester resin which contains at least the 1st diol unit (B1) represented by these. In formula (A1), A ¹ is a linear or branched C _2-4 alkylene group, A ² is a direct bond or a linear or branched C _1-4 alkylene group, and k is an integer of 0 to 2 And
In the formula (B1), Z is a C _6-10 arene ring, R ³ is a C _1-4 alkyl group or a C _6-10 aryl group, A ³ is a linear or branched C _2-4 alkylene group, m The polyester resin according to claim 1, wherein n is an integer of 0 to 2, n is an integer of 0 to 2, and p is an integer of 1 to 10. The ratio of the first dicarboxylic acid unit (A1) is 10 to 100 mol% with respect to the entire dicarboxylic acid unit (A),
The ratio of the first diol unit (B1) is 50 to 100 mol% with respect to the entire diol unit (B),
The ratio of the 1st diol unit (B1) is 0.5-4 mol with respect to 1 mol of 1st dicarboxylic acid units (A1), The polyester resin of Claim 1 or 2. The dicarboxylic acid unit (A) is further represented by the following formula (A2)

(In the formula, Ar represents an arene ring, R ⁴ represents a substituent, and q represents an integer of 0 or more.)
The second dicarboxylic acid unit (A2) represented by the formula (1) is contained at a ratio of first dicarboxylic acid unit (A1) / second dicarboxylic acid unit (A2) (molar ratio) = 99/1 to 10/90. The polyester resin in any one of Claims 1-3. The polyester resin according to claim 4, wherein, in the formula (A2), Ar is a C _6-10 arene ring, R ⁴ is a C _1-4 alkyl group or a C _6-10 aryl group, and q is an integer of 0-4. The dicarboxylic acid unit (A) is further represented by the following formula (A3-1) or (A3-2)

(Wherein R ⁵ is the same or different and is a substituent, r and s are each an integer of 0 to ^4, and A ⁴ and A ⁵ are each a divalent hydrocarbon group which may have a substituent. )
The third dicarboxylic acid unit (A3) represented by the formula (1) is contained at a ratio of the first dicarboxylic acid unit (A1) / the third dicarboxylic acid unit (A3) (molar ratio) = 90/10 to 20/80. The polyester resin in any one of Claims 1-5. It includes at least a formula (A3-1) third of the dicarboxylic acid unit represented by (A3), in formula (A3-1), integer r is 0 to 2, A ⁴ is a linear or branched C The polyester resin according to claim 6, which is a _2-4 alkylene group. The diol unit (B) is further represented by the following formula (B2)

(In the formula, A ⁶ represents a linear or branched alkylene group, and t represents an integer of 1 or more.)
The first diol unit (B1) / second diol unit (B2) (molar ratio) = 99/1 to 50/50 is contained in the second diol unit (B2) represented by formula (1). The polyester resin in any one of -7. In formula (B2), ^{A 6} is a linear or branched _{C 2-4} alkylene group, according to claim 8, wherein the polyester resin t is an integer of 1-3. The diol unit (B) is further represented by the following formula (B3)

(Wherein X is a direct bond or alkylene group, R ⁶ and R ⁷ are the same or different substituents, A ⁷ is the same or different linear or branched alkylene group, u is the same or different and 0 to An integer of 4 is the same or different and v is an integer of 0 to 2, and w is the same or different and represents an integer of 0 or more.)
The first diol unit (B1) / the third diol unit (B3) (molar ratio) = 90/10 to 10/90 is contained in the third diol unit (B3) represented by The polyester resin in any one of -9. In the formula (3), X is a direct bond, R ⁶ and R ⁷ are each a C _1-6 alkyl group or a C _6-12 aryl group, A ⁷ is a linear or branched C _2-6 alkylene group, u The polyester resin according to claim 10, wherein is an integer of 0 to 2, v is 0 or 1, and w is an integer of 0 to 10. A film having a glass transition temperature Tg of 120 to 250 ° C., a temperature of 20 ° C., a refractive index of 1.62 to 1.7 at a wavelength of 589 nm, and a film stretched three times at a temperature 10 ° C. higher than the glass transition temperature. 12. The polyester resin according to claim 1, wherein the absolute value of birefringence is 0.001 × 10 ⁻⁴ to 50 × 10 ⁻⁴ at a temperature of 20 ° C. and a wavelength of 600 nm.   A dicarboxylic acid component (A) containing at least a first dicarboxylic acid component (A1) for forming a first dicarboxylic acid unit (A1) represented by the formula (A1), and represented by the formula (B1) A polyester resin according to any one of claims 1 to 12 is produced by reacting the diol component (B) containing at least the first diol component (B1) for forming the first diol unit (B1). how to.   The molded object containing the polyester resin in any one of Claims 1-12.   The molded article according to claim 14, which is an optical film, an optical sheet, or an optical lens.