Polyester resin, method for producing the same, and use thereof

Abstract

To provide a polyester resin that exhibits an Abbe number in an intermediate region (intermediate Abbe number), and a method for producing the same, and use thereof.SOLUTION: A polyester resin is produced that contains a diol unit (A) and a dicarboxylic acid unit (B) and includes a diol unit (A1) having a pentacycloalkane skeleton and a structural unit having a fluorene skeleton, wherein the diol unit (A1) may be a structural unit represented by formula (1). In the formula, Z1 denotes a pentacycloalkane ring, R1 denotes a substituent, m1 denotes an integer of 0 or more, and A1a and A1b independently denote a direct bond or an alkylene group.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a polyester resin containing a structural unit having a pentacycloalkane skeleton and a structural unit having a fluorene skeleton, as well as a production method and uses thereof. [Background technology]

[0002] Many small or mobile devices such as smartphones and tablet PCs are equipped with optical functions such as cameras in addition to image display functions, and as the performance of these devices improves, the requirements for optical components are increasing. Optical components often use resin materials, which have advantages over optical glass in terms of light weight, impact resistance (flexibility), and moldability (manufacturability), but existing resin materials sometimes cannot adequately meet the increasing requirements.

[0003] For example, imaging lens units installed in devices with camera functions are required to be more compact as devices themselves become thinner and more multifunctional, while also requiring higher resolution as imaging elements have a higher pixel count. To this end, imaging lens units are optically designed with various ingenious lens configurations, shapes, and material selections to achieve compactness, high imaging performance, and the ability to correct various aberrations. Typically, imaging lens units are composed of multiple lenses with different Abbe numbers and refractive indices. For example, they are often composed of a combination of high-Abbe-number and low-Abbe-number lenses. However, the types of resin materials that can be used for optical lenses are limited, limiting the design of highly effective lens units. Therefore, from the perspective of improving functionality and performance, it is important to expand the range of material options to enable greater design freedom and the design of diverse lens units. Therefore, the development of various optical resin materials with different optical properties, such as Abbe numbers, is required. In particular, materials exhibiting an Abbe number in the intermediate range between high and low Abbe numbers (intermediate Abbe numbers) would increase design freedom and enable the optimization of imaging lens units.

[0004] Japanese Patent Laid-Open Publication No. 2007-238856 (Patent Document 1) discloses a polyester resin obtained by reacting a dicarboxylic acid component and a diol component, wherein 85 mol % or more of the dicarboxylic acid component is an aliphatic dicarboxylic acid or an ester-forming derivative thereof, and the diol component contains a specific diol having a tricyclodecane or pentacyclopentadecane skeleton. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-238856 Summary of the Invention [Problem to be solved by the invention]

[0006] In the examples of Patent Document 1, it is described that a polyester resin having high heat resistance and small intrinsic birefringence was prepared by polycondensing polymerization components containing 1,4-cyclohexanedicarboxylic acid as an aliphatic dicarboxylic acid in a proportion of 90 to 100 mol % of the dicarboxylic acid component and tricyclodecane dimethanol or pentacyclopentadecanedimethanol as a diol component. However, Patent Document 1 does not describe anything about the Abbe number.

[0007] Therefore, an object of the present disclosure is to provide a polyester resin exhibiting an Abbe number in the intermediate region (medium Abbe number), as well as a method for producing the same and uses thereof. [Means for solving the problem]

[0008] As a result of intensive research to achieve the above object, the present inventors have found that when a polyester resin is prepared by combining a diol unit having a pentacycloalkane skeleton with a structural unit having a fluorene skeleton, the polyester resin exhibits an Abbe number in the intermediate region, and have completed the present invention (or the present disclosure). That is, the present disclosure may include the following aspects.

[0009] Aspect [1]: A polyester-based resin comprising a diol unit (A) and a dicarboxylic acid unit (B), wherein the diol unit (A) comprises a diol unit (A1) having a pentacycloalkane skeleton, and further comprising a structural unit having a fluorene skeleton.

[0010] Aspect [2]: The polyester resin according to aspect [1], wherein the diol unit (A1) is a structural unit represented by the following formula (1):

[0011] [ka]

[0012] (In the formula, Z 1 represents a pentacycloalkane ring, R 1 represents a substituent, m1 represents an integer of 0 or more, A 1a and A 1b each independently represents a direct bond or an alkylene group.

[0013] Aspect [3]: The polyester resin according to aspect [1] or [2], wherein the diol unit (A) contains a diol unit (A2) represented by the following formula (2) as a constituent unit having a fluorene skeleton:

[0014] [ka]

[0015] (In the formula, R 2 represents a substituent, m2 represents an integer of 0 to 8, Z 2a and Z 2b each independently represents an arene ring, R 3a and R 3b each independently represents a substituent; m3a and m3b each independently represents an integer of 0 or more; A 2a and A2b each independently represents an alkylene group, and n2a and n2b each independently represent an integer of 0 or more.

[0016] Aspect [4]: ​​In the formula (2), Z 2a and Z 2b and independently represent a polycyclic arene ring.

[0017] Aspect [5]: The polyester resin according to aspect [3] or [4], wherein the ratio of the diol units (A1) to the diol units (A2) is the former / latter (molar ratio) = 50 / 50 to 90 / 10.

[0018] Aspect [6]: The polyester resin according to any one of aspects [1] to [5], wherein the diol unit (A) includes a diol unit (A3) represented by the following formula (3):

[0019] [ka]

[0020] (In the formula, A 3 represents an alkylene group, and n3 represents an integer of 1 or more.

[0021] Aspect [7]: The polyester resin according to aspect [6], wherein the ratio of the diol units (A1) to the diol units (A3) is the former / latter (molar ratio) = 50 / 50 to 90 / 10.

[0022] Aspect [8]: The polyester resin according to any one of aspects [1] to [7], wherein the dicarboxylic acid unit (B) includes a dicarboxylic acid unit (B1) that is an alicyclic dicarboxylic acid unit.

[0023] Aspect [9]: The polyester-based resin according to any one of aspects [1] to [8], wherein the dicarboxylic acid unit (B) contains a dicarboxylic acid unit (B2) represented by the following formula (5) as the structural unit having the fluorene skeleton:

[0024] [ka]

[0025] (In the formula, R 5 represents a substituent, m5 represents an integer of 0 to 8, A 5a and A 5b each independently represents an alkylene group.

[0026] Aspect

[10] : In the formula (5), R 5 represents a hydrocarbon group; and m5 represents an integer of 0 to 4.

[0027] Aspect

[11] : The dicarboxylic acid unit (B1) according to aspect [8] is contained, The polyester resin according to aspect [9] or

[10] , wherein the ratio of the dicarboxylic acid units (B1) to the dicarboxylic acid units (B2) (molar ratio) is from 15 / 85 to 80 / 20.

[0028] Aspect

[12] : The diol unit (A) comprises a diol unit (A2) represented by formula (2) according to aspect [3] and a diol unit (A3) represented by formula (3) according to aspect [6]; In the formula (2), Z 2a and Z 2b independently represent a ring-assembled arene ring, The polyester resin according to any one of aspects [1] to

[11] , wherein the dicarboxylic acid unit (B) comprises the dicarboxylic acid unit (B1) according to aspect [8].

[0029] Aspect

[13] : The polyester-based resin according to any one of aspects [1] to

[12] , having an Abbe number νD of 28 to 55.

[0030] Aspect

[14] : The refractive index nD is 1.55 or more, The absolute value of birefringence of the stretched film uniaxially stretched under the conditions of stretching temperature (glass transition temperature Tg + 10) °C, stretching speed 25 mm / min, and stretching ratio 3 times is 55 × 10 at a wavelength of 600 nm.-4 or less (preferably 40 × 10 -4 (below) and The weight average molecular weight Mw is 10,000 to 100,000, The polyester resin according to any one of aspects [1] to

[13] , which has a glass transition temperature Tg of 100 to 180°C.

[0031] Aspect

[15] : A method for producing a polyester resin by polymerizing a diol component (A) containing a diol component (A1) having a pentacycloalkane skeleton and a polymerization component containing a dicarboxylic acid component (B), The method for producing a polyester resin according to any one of aspects [1] to

[14] , wherein the polymerization components further include a polymerization component having a fluorene skeleton.

[0032] Aspect

[16] : A molded article comprising the polyester resin according to any one of aspects [1] to

[14] .

[0033] Aspect

[17] : The molded article according to aspect

[16] , which is an optical element.

[0034] Embodiment

[18] : The molded article according to embodiment

[16] or

[17] , which is an optical lens.

[0035] In addition, the present disclosure may achieve the following secondary objectives (solve secondary problems).

[0036] That is, another object of the present disclosure is to provide a polyester resin that can satisfy a good balance of high refractive index, low birefringence (low absolute value of birefringence), and high heat resistance, as well as a production method and uses thereof.

[0037] Still another object of the present disclosure is to provide a polyester resin that has excellent moldability even when it has a rigid chemical structure containing many ring skeletons, as well as a production method and uses thereof.

[0038] In this specification and claims, the term "Abbe number in the intermediate range (middle Abbe number)" refers to an Abbe number in the range of 28 to 55 when the Abbe number νD measured at a temperature of 20°C is rounded to one decimal place.

[0039] Furthermore, in this specification and claims, the terms "diol unit" and "structural unit derived from a diol component" refer to a unit (or a divalent group) obtained by removing a hydrogen atom from each of the two hydroxyl groups of the corresponding diol, and the term "diol component" (including compounds exemplified as diol components) may be used synonymously with the corresponding "diol unit."

[0040] Similarly, a "dicarboxylic acid unit" and a "structural unit derived from a dicarboxylic acid component" refer to a unit (or a divalent group) obtained by removing OH (hydroxyl group) from each of the two carboxyl groups of the corresponding dicarboxylic acid, and a "dicarboxylic acid component" (including compounds exemplified as dicarboxylic acid components) is sometimes used synonymously with the corresponding "dicarboxylic acid unit."

[0041] The term "dicarboxylic acid component" is used to mean not only dicarboxylic acids but also derivatives that can be used as polymerization components, such as ester-forming derivatives. Examples of ester-forming derivatives of dicarboxylic acids include esters of dicarboxylic acids (dicarboxylic acid esters), acid halides (dicarboxylic acid halides), and acid anhydrides (dicarboxylic acid anhydrides). The esters may be monoesters (half esters) or diesters.

[0042] Examples of the dicarboxylic acid ester include dicarboxylic acid alkyl esters, particularly lower alkyl esters, specifically C esters such as methyl esters, ethyl esters, and t-butyl esters. 1-4 Examples of the dicarboxylic acid halide include acid chloride and acid bromide.

[0043] In this specification and claims, unless otherwise specified, the terms "low birefringence" and "low birefringence" mean that the absolute value of birefringence is small (i.e., close to 0).

[0044] In addition, in this specification and claims, the number of carbon atoms in a substituent is not limited to C1, C6, C 10 For example, an alkyl group with 1 carbon atom is called a "C1 alkyl group," and an aryl group with 6 to 10 carbon atoms is called a "C 6-10 It is sometimes referred to as an "aryl group".

[0045] Furthermore, in this specification and claims, the term "independently" means that a plurality of components are independent components, for example, Z 2a and Z 2b In this case, the arene rings may be the same or different from each other.

[0046] In this specification and claims, the numerical ranges indicated by "X to Y" may include the numerical values ​​X and Y. [Effects of the Invention]

[0047] According to the present disclosure, it is possible to provide a polyester resin exhibiting an Abbe number in the intermediate region (medium Abbe number), as well as a method for producing the same and uses thereof. DETAILED DESCRIPTION OF THE INVENTION

[0048] The present disclosure can also provide a polyester-based resin that can achieve a good balance of high refractive index, low birefringence (low absolute value of birefringence), and high heat resistance, as well as a manufacturing method and uses thereof. The present disclosure can also provide a polyester-based resin that has excellent moldability even when it has a rigid chemical structure containing many ring skeletons (particularly a polycyclic chemical structure such as a pentacycloalkane skeleton or a fluorene skeleton).

[0049] [Polyester resin] The polyester resin of the present disclosure is a polyester resin containing a diol component (A) and a dicarboxylic acid component (B) as polymerization components (monomer components), and includes a diol unit (A) containing a diol unit (A1) having a pentacycloalkane skeleton, and a dicarboxylic acid unit (B), and further includes a structural unit having a fluorene skeleton. The structural unit having a fluorene skeleton may be contained in the diol unit (A) and / or the dicarboxylic acid unit (B). Representative structural units having a fluorene skeleton include the diol unit (A2) and dicarboxylic acid unit (B2) described below.

[0050] The polyester-based resin may be, for example, a polyester resin, a polyester carbonate resin, or the like, and is preferably a polyester resin.

[0051] (Diol unit (A)) The diol unit (A) contains at least a diol unit (A1) having a pentacycloalkane skeleton, and may contain a diol unit (A2) as a structural unit having a fluorene skeleton.

[0052] Diol unit (A1) The diol unit (A1) may be any diol unit having at least a pentacycloalkane skeleton (pentacycloalkane ring). Even when the diol unit (A1) is combined with a structural unit having a fluorene skeleton [such as the diol unit (A2) or dicarboxylic acid unit (B2) described below] to form a polyester resin having a rigid chemical structure containing many ring skeletons, the moldability of the resulting polyester resin is surprisingly likely to be improved, unlike when other polycyclic alicyclic diol units are combined with a structural unit having a fluorene skeleton (for example, Reference Examples 4 to 5 described below).

[0053] The pentacycloalkane ring of the diol unit (A1) may be a five-ring bridged cyclic aliphatic hydrocarbon ring, and the number of carbon atoms constituting the pentacycloalkane ring may be, for example, 14 to 24, preferably 15 to 21, 15 to 18, 15 to 16, and particularly preferably 15. That is, the pentacycloalkane ring is preferably a pentacyclopentadecane ring. Representative pentacycloalkane rings include a dodecahydro-4,9:5,8-dimethano-1H-benzo[f]indene ring represented by the formula on the left below and a dodecahydro-1,4:5,8-dimethano-1H-fluorene ring represented by the formula on the right below.

[0054] [ka]

[0055] Representative examples of the diol unit (A1) include a structural unit represented by the following formula (1).

[0056] [ka]

[0057] (In the formula, Z 1 represents a pentacycloalkane ring, R 1 represents a substituent, m1 represents an integer of 0 or more, A 1a and A 1b each independently represents a direct bond or an alkylene group.

[0058] In the formula (1), Z 1 Examples of the pentacycloalkane ring represented by the formula (I) include the same rings as the pentacycloalkane ring contained in the diol unit (A1), including preferred embodiments such as the number of carbon atoms constituting the ring. 1is a pentacyclopentadecane ring such as a dodecahydro-4,9:5,8-dimethano-1H-benzo[f]indene ring or a dodecahydro-1,4:5,8-dimethano-1H-fluorene ring.

[0059] R 1 The substituent represented by R may be a non-reactive group (or a non-polymerizable group) that is inert to the reaction. 1 Examples of the substituent represented by the formula include a halogen atom, a hydrocarbon group, a group [—OR h ](where R h represents a hydrocarbon group), the group [-SR h ](where R h represents a hydrocarbon group), an acyl group, a nitro group, a cyano group, a substituted amino group (mono- or di-substituted amino group), and the like.

[0060] In this specification and claims, R h The hydrocarbon groups represented by the following formula (I) each represent an independent hydrocarbon group, and may be the same or different from each other.

[0061] Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0062] The hydrocarbon group may be a saturated or unsaturated hydrocarbon group, an aliphatic (including alicyclic) or aromatic hydrocarbon group, and may be a chain (straight or branched) or cyclic hydrocarbon group, or a hydrocarbon group having a structure combining a chain and a cyclic structure. h The number of carbon atoms constituting the hydrocarbon group (or R) is not particularly limited, but may be, for example, about 20 or less, and preferably in the following stepwise order: 1 to 16, 1 to 12, 1 to 10, 1 to 8, 1 to 6, 1 to 4, 1 to 3, 1 to 2. h ) includes, for example, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and the like.

[0063] Examples of the alkyl group (linear or branched alkyl group) include C alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, and t-butyl group. 1-10 alkyl group, preferably C 1-6 alkyl group, more preferably C 1-4 It is an alkyl group.

[0064] Examples of the cycloalkyl group include C cyclopentyl and cyclohexyl groups. 5-10 Cycloalkyl groups are exemplified.

[0065] Examples of the aryl group include C phenyl, alkylphenyl, biphenylyl, and naphthyl groups. 6-12 Examples of the alkylphenyl group include mono- to tri-C alkylphenyl groups such as methylphenyl (or tolyl) and dimethylphenyl (or xylyl). 1-4 Examples include alkyl-phenyl groups.

[0066] Examples of the aralkyl group include C aryl groups such as benzyl and phenethyl groups. 6-10 Aryl-C 1-4 Examples of suitable alkyl groups include:

[0067] The group [-OR h ] and the group [-SR h ], R h The hydrocarbon group represented by R 1 The hydrocarbon groups exemplified above, including preferred embodiments thereof, include alkyl groups, cycloalkyl groups, aryl groups, and aralkyl groups. h ] and the group [-SR h ] includes, for example, groups corresponding to the examples of the hydrocarbon group, and a representative group [—OR h ] includes, for example, an alkoxy group, a cycloalkyloxy group, an aryloxy group, an aralkyloxy group, etc.; a representative group [—SR h ] may be, for example, the hydrocarbon group R hExamples of the thio group include an alkylthio group, a cycloalkylthio group, an arylthio group, and an aralkylthio group.

[0068] Examples of the alkoxy group (linear or branched alkoxy group) include C alkoxy groups such as methoxy group, ethoxy group, propoxy group, n-butoxy group, isobutoxy group, and t-butoxy group. 1-10 Examples of the cycloalkyloxy group include a C alkoxy group such as a cyclohexyloxy group. 5-10 Examples of the aryloxy group include a C aryloxy group such as a phenoxy group. 6-10 Examples of the aralkyloxy group include C aryloxy groups such as benzyloxy groups. 6-10 Aryl-C 1-4 Examples thereof include alkyloxy groups.

[0069] Examples of the alkylthio group include a C alkylthio group such as a methylthio group, an ethylthio group, a propylthio group, an n-butylthio group, and a t-butylthio group. 1-10 Examples of the cycloalkylthio group include a C alkylthio group such as a cyclohexylthio group. 5-10 Examples of the arylthio group include a C thiophenoxy group. 6-10 Examples of the aralkylthio group include a C arylthio group such as a benzylthio group. 6-10 Aryl-C 1-4 Examples include alkylthio groups.

[0070] The acyl group is C 1-12 acyl groups, for example, C such as acetyl group 1-6 Examples include alkyl-carbonyl groups.

[0071] Examples of the mono- or di-substituted amino group include a mono- or di-alkylamino group, a mono- or bis(alkylcarbonyl)amino group, etc. Examples of the mono- or di-alkylamino group include a mono- or di-C group such as a mono- or dimethylamino group. 1-4Examples of the mono- or bis(alkylcarbonyl)amino group include mono- or bis(C alkylamino groups) such as mono- or diacetylamino groups. 1-4 alkyl-carbonyl)amino groups.

[0072] Representative R 1 Examples of the alkyl group include halogen atoms, hydrocarbon groups (such as alkyl groups), and groups [-OR h ] (alkoxy group, etc.), preferably an alkyl group, more preferably a C group such as a methyl group. 1-4 It is an alkyl group.

[0073] R 1 The number of permutations m1 of Z 1 The number of R m1 is preferably 0 or 1, particularly 0. When m1 is 2 or more, the number of R m2 is 2 or more. 1 The types may be the same or different from each other.

[0074] A 1a and A 1b may be either a direct bond (single bond) or an alkylene group (a linear or branched alkylene group), and is preferably an alkylene group. Examples of the alkylene group include C alkylene groups such as methylene, ethylene, trimethylene, and propylene. 1-6 alkylene groups, and preferably C 1-4 Alkylene groups, more preferably C 1-3 Alkylene groups, especially C 1-2 An alkylene group, particularly a methylene group, is preferred. 1a and A 1b The types may be the same or different from each other.

[0075] group [-A 1a O-] and [-A 1b O-]Z 1Of the five rings constituting the pentacycloalkane ring represented by the formula:

[0076] Representative examples of the diol unit (A1) include those represented by the formula (1): Z 1 is C 14-24 represents a pentacycloalkane ring, R 1 is a halogen atom, a hydrocarbon group (such as an alkyl group), or a group [-OR h ] (such as an alkoxy group), m1 represents an integer of 0 to 10, A 1a and A 1b are independently a direct bond or C 1-6 is a diol unit representing an alkylene group;

[0077] Preferably, Z 1 is C 15-18 represents a pentacycloalkane ring, R 1 represents an alkyl group, m1 represents an integer of 0 to 3, A 1a and A 1b are independently a direct bond or C 1-4 is a diol unit representing an alkylene group;

[0078] More preferably, Z 1 is C 15-16 represents a pentacycloalkane ring, R 1 is C 1-4 represents an alkyl group, m1 represents an integer of 0 to 2, A 1a and A 1b are independently a direct bond or C 1-3 is a diol unit representing an alkylene group;

[0079] Particularly preferably, Z 1 is C 15represents a pentacycloalkane ring (pentacyclopentadecane ring), R 1 is C 1-3 represents an alkyl group, m1 represents 0 or 1, A 1a and A 1b is independently C 1-2 It is a diol unit representing an alkylene group.

[0080] Specific examples of the diol unit (A1) include diol units corresponding to pentacyclopentadecanedimethanol, such as dodecahydro-4,9:5,8-dimethano-1H-benzo[f]indenedimethanol and dodecahydro-1,4:5,8-dimethano-1H-fluorenedimethanol.

[0081] The diol unit represented by the formula (1) may be used alone or in combination of two or more kinds. The diol unit (A1) may be used alone or in combination of two or more kinds. The diol component (A1) corresponding to the diol unit (A1) may be an isomer mixture.

[0082] The proportion of the diol units represented by the formula (1) can be selected, for example, from a range of 10 mol% or more, specifically from about 30 to 100 mol%, based on the total diol units (A1), and is preferably 50 mol% or more, 70 mol% or more, 90 mol% or more, and more preferably 100 mol% in the following stepwise manner.

[0083] Diol unit (A2) The diol unit (A) may or may not contain a diol unit (A2) represented by the following formula (2) as a constituent unit having a fluorene skeleton, as necessary. When the diol unit (A2) is combined with the diol unit (A1), it is easy to achieve a medium Abbe number while balancing a high refractive index, low birefringence, and high heat resistance, and it is particularly easy to improve heat resistance while maintaining a balance of the above properties.

[0084] [ka]

[0085] (In the formula, R 2 represents a substituent, m2 represents an integer of 0 to 8, Z 2a and Z 2b each independently represents an arene ring, R 3a and R 3b each independently represents a substituent; m3a and m3b each independently represents an integer of 0 or more; A 2a and A 2b each independently represents an alkylene group, and n2a and n2b each independently represent an integer of 0 or more.

[0086] In the formula (2), R 2 The substituent represented by R may be a non-reactive group (or a non-polymerizable group). 2 Examples of the substituent represented by the formula (1) include R 1 Examples of the groups include the same groups as those exemplified as R 2 Examples of the alkyl group include halogen atoms, hydrocarbon groups, and groups [-OR h ] (alkoxy group, etc.), and the like, are preferably hydrocarbon groups such as alkyl groups and aryl groups, and more preferably alkyl groups. Examples of the alkyl group (linear or branched alkyl group) include C groups such as methyl group, ethyl group, and t-butyl group. 1-6 alkyl groups, and C groups such as methyl groups. 1-4 The alkyl group is preferred. The aryl group is, for example, a C phenyl group. 6-10 Examples include an aryl group.

[0087] R 2 The number of substitutions m2 is, for example, an integer of about 0 to 6, preferably an integer of 0 to 4, an integer of 0 to 2, more preferably 0 or 1, and particularly preferably 0. When m2 is 2 or more, 2 or more R 2 The types of R may be the same or different. In addition, when R is present in both of the two benzene rings forming the fluorene skeleton, 2When R is substituted on one of the benzene rings, 2 The type of R on the other benzene ring 2 The types of R may be the same or different. 2 The substitution position is not particularly limited, and may be, for example, the 2-position, the 3-position, the 2,7-position, etc.

[0088] Z 2a or Z 2b Examples of the arene ring (aromatic hydrocarbon ring) represented by the formula (I) include a monocyclic arene ring such as a benzene ring, a polycyclic arene ring, etc. Examples of the polycyclic arene ring include a fused polycyclic arene ring (fused polycyclic aromatic hydrocarbon ring), a ring-assembled arene ring (ring-assembled aromatic hydrocarbon ring), etc.

[0089] The fused polycyclic arene ring includes, for example, fused bicyclic arene rings, fused tricyclic arene rings, and other fused bicyclic to tetracyclic arene rings. The fused bicyclic arene ring includes, for example, fused bicyclic C rings such as naphthalene rings and indene rings. 9-16 Examples of the fused tricyclic arene ring include fused tricyclic C arene rings such as anthracene rings and phenanthrene rings. 14-20 Preferred fused polycyclic arene rings include fused polycyclic C arene rings such as naphthalene rings. 10-14 It is an arene ring.

[0090] Examples of the ring-assembled arene ring include biarene rings such as biphenyl ring, phenylnaphthalene ring, and binaphthyl ring; and terarene rings such as terphenyl ring (e.g., m-terphenyl ring). Preferred ring-assembled arene rings are bi- or terarene rings (particularly terarene rings), and more preferably C such as biphenyl ring. 12-18 C such as biarene ring and m-terphenyl ring 18-24 Terarene rings, especially m-terphenyl rings and other C 18-22 It is a tellarene ring.

[0091] In this specification and claims, the term "ring assembly arene ring" refers to two or more ring systems (arene ring systems) directly linked by single bonds or double bonds, and the number of bonds directly linking the rings is one less than the number of ring systems. For example, as described above, phenylnaphthalene rings and binaphthyl rings are classified as ring assembly arene rings even though they have a fused polycyclic arene ring skeleton, and are clearly distinguished from "fused polycyclic arene rings" such as naphthalene rings (non-ring assembly arene rings).

[0092] Z 2a ,Z 2b As the arene ring represented by the formula (I), preferably C 6-24 arene rings, and more preferably C rings such as benzene rings, naphthalene rings, biphenyl rings, and terphenyl rings. 6-22 C rings such as arene rings, more preferably naphthalene rings, biphenyl rings, and terphenyl rings 10-22 arene rings, especially C 12-20 C arene rings, especially m-terphenyl rings 18-20 It is an arene ring. Also, Z 2a and / or Z 2b When Z is a polycyclic arene ring (particularly, a ring assembly arene ring such as an m-terphenyl ring), it is preferable because it satisfies a good balance of a medium Abbe number, a high refractive index, and a low birefringence, and can be easily adjusted to have high heat resistance. 2a and Z 2b The types may be the same or different from each other, and are preferably the same from each other.

[0093] In addition, Z bonded to the 9-position of the fluorene ring 2a and Z 2b The substitution position of is not particularly limited, and for example, Z 2a ,Z 2b When Z is a benzene ring, it may be at any position. 2a ,Z 2b When is a naphthalene ring, it is either the 1-position (1-naphthyl) or the 2-position (2-naphthyl), preferably the 2-position, and Z 2a ,Z 2bWhen is a biphenyl ring, it is at the 2-position, 3-position or 4-position, preferably the 3-position, and Z 2a ,Z 2b When is a m-terphenyl ring, it is preferably at the 5'-position.

[0094] R 3a or R 3b The substituent represented by R may be a non-reactive group (or a non-polymerizable group). 3a ,R 3b Examples of the substituent represented by the formula (1) include R 1 The examples of the groups exemplified as R include the same groups as those exemplified as R, including preferred embodiments thereof. 3a ,R 3b Examples of the alkyl group include halogen atoms, hydrocarbon groups, and groups [-OR h ] (such as an alkoxy group), an acyl group, a nitro group, a cyano group, a substituted amino group, and the like, and preferably a hydrocarbon group such as an alkyl group (a linear or branched alkyl group), a cycloalkyl group, an aryl group, or an aralkyl group, or an alkoxy group (a linear or branched alkoxy group) [-OR h and more preferably C such as a methyl group. 1-6 C such as alkyl group and cyclohexyl group 5-8 C such as cycloalkyl group and phenyl group 6-14 C such as aryl group, methoxy group 1-4 Among them, alkyl groups and aryl groups are preferred, and C groups such as methyl groups are particularly preferred. 1-4 C such as alkyl group and phenyl group 6-10 An aryl group is preferred. 3a and R 3b The types of R may be the same or different. 3a ,R 3b is an aryl group, R 3a ,R 3b are Z 2a ,Z 2b may form a ring assembly arene ring together with

[0095] R 3a ,R 3bThe permutation numbers m3a and m3b of Z can be integers greater than or equal to 0. 2a ,Z 2b The number of m3a and m3b can be appropriately selected depending on the type of R, and may be, for example, an integer of about 0 to 6, preferably an integer of 0 to 4, more preferably an integer of 0 to 2, even more preferably 0 or 1, and particularly preferably 0. m3a and m3b may be different from each other, but are preferably the same. When m3a is 2 or more, two or more R 3a may be the same or different from each other; when m3b is 2 or more, two or more R 3b The types may be the same or different from each other.

[0096] R 3a ,R 3b The substitution position of Z is not particularly limited. 2a ,Z 2b In the formula, the bonding position with the 9-position of the fluorene ring and the group [-O-(A 2a O) n2a -],[-O-(A 2b O) n2b -] (i.e., the ether bond [-O-] forming the main chain) may be any position other than the bonding position. For example, Z 2a ,Z 2b may be substituted at the ortho position (the carbon atom adjacent to the bonding position of the ether bond) relative to the ether bond [—O—] in the formula (II).

[0097] A 2a or A 2b Examples of the alkylene group (linear or branched alkylene group) represented by the formula (I) include C alkylene groups such as an ethylene group, a propylene group (1,2-propanediyl group), a trimethylene group, a 1,2-butanediyl group, and a tetramethylene group. 2-6 alkylene groups, and preferably C 2-4 C alkylene group, more preferably ethylene group, propylene group, etc. 2-3 An alkylene group, particularly an ethylene group, is preferred. 2a and A 2b The types may be the same or different from each other, but are preferably the same from each other.

[0098] [-(A 2a O)-] or [-(A 2b The repeat numbers (number of moles added) n2a and n2b of the alkyleneoxy group represented by (O)-) may each be 0 or greater and may be selected from, for example, an integer of about 0 to 15, preferably in the following stepwise order: integers of 0 to 10, integers of 0 to 8, integers of 0 to 6, integers of 0 to 4, integers of 0 to 2, and more preferably 0 or 1. Furthermore, when the repeat numbers n2a and / or n2b are each 1 or greater, polymerization reactivity is easily improved. For example, they may be selected from an integer of about 1 to 15, preferably in the following stepwise order: integers of 1 to 10, integers of 1 to 8, integers of 1 to 6, integers of 1 to 4, integers of 1 to 3, and more preferably 1 or 2, with 1 being particularly preferred. In this specification and claims, the "repeated number (number of moles added)" may be an average value (arithmetic mean value, additive mean value) or an average number of moles added. Therefore, n2a and n2b may each be selected from the range of about 0 to 15, preferably in the following stepwise manner: 0 to 10, 0 to 8, 0 to 6, 0 to 4, 0 to 2, 0 to 1, or may be selected from integers of about 1 to 15, preferably in the following stepwise manner: 1 to 10, 1 to 8, 1 to 6, 1 to 4, 1 to 3, 1 to 2. When n2a and / or n2b are in an appropriate range that is not too large, there is a tendency to easily suppress a decrease in refractive index and heat resistance.

[0099] In addition, n2a and n2b may be the same or different. When n2a is 2 or more, two or more alkyleneoxy groups [-(A 2a The types of alkyleneoxy groups [-(A 2b The types of A)- may be different from each other, but are preferably the same. 2a and A 2b The types may be the same or different from each other, but are preferably the same from each other.

[0100] The group [-O-(A 2a O)n2a -],[-O-(A 2b O) n2b -] (i.e., the ether bond forming the main chain) 2a ,Z 2b The substitution position for Z is not particularly limited. 2a ,Z 2b The group [-O-(A 2a O) n2a -],[-O-(A 2b O) n2b -] Ring Z 2a ,Z 2b The substitution position for Z 2a ,Z 2b When Z is a benzene ring, it is preferably substituted at the 2-, 3- or 4-position of the phenyl group bonded to the 9-position of the fluorene ring, among which the 3- or 4-position, and particularly the 4-position. 2a ,Z 2b When Z is a naphthalene ring, it is often substituted at any one of the 5- to 8-positions of the naphthyl group bonded to the 9-position of the fluorene ring. For example, the 1- or 2-position of the naphthalene ring is substituted with respect to the 9-position of the fluorene ring (substitution in a 1-naphthyl or 2-naphthyl relationship), and it is preferred that Z be substituted with respect to this substitution position in a 1,5- or 2,6-position relationship, particularly in a 2,6-position relationship. 2a ,Z 2b is a ring-assembled arene ring, the group [-O-(A 2a O) n2a -],[-O-(A 2b O) n2b The substitution position of Z - is not particularly limited, and may be, for example, substituted on the arene ring bonded to the 9-position of the fluorene or on the arene ring adjacent to this arene ring. 2a ,Z 2b is a biphenyl ring (or Z 2a ,Z 2b is a benzene ring, m3a and m3b are 1, R 3a ,R 3b is a phenyl group), the 3-position of the biphenyl ring is preferably bonded to the 9-position of the fluorene, and the 6-position of the biphenyl ring is preferably bonded to a group [-O-(A 2a O) n2a-],[-O-(A 2b O) n2b -]; Z 2a ,Z 2b is an m-terphenyl ring (or Z 2a ,Z 2b is a benzene ring, m3a and m3b are 2, and two R 3a ,Two R 3b is a phenyl group), the 5'-position of the m-terphenyl ring is preferably bonded to the 9-position of the fluorene, and the 2'-position of the m-terphenyl ring is preferably bonded to the group [-O-(A 2a O) n2a -],[-O-(A 2b O) n2b -] is preferred.

[0101] Representative examples of the diol unit (A2) include those represented by the formula (2) above, where R 2 is a halogen atom, a hydrocarbon group, or a group [-OR h ], an acyl group, a nitro group, a cyano group, or a substituted amino group; m2 represents an integer of 0 to 2; Z 2a and Z 2b is independently C 6-24 represents a benzene ring or a polycyclic arene ring such as an arene ring, R 3a and R 3b are independently a halogen atom, a hydrocarbon group, a group [-OR h ], an acyl group, a nitro group, a cyano group, or a substituted amino group; m3a and m3b each independently represent an integer of 0 to 2; A 2a and A 2b is independently C 2-6 represents an alkylene group, and n2a and n2b each independently represent an integer of 0 to 10;

[0102] Preferably, R 2 represents a hydrocarbon group, m2 represents an integer of 0 to 2, Z 2a and Z 2b are independently C groups such as benzene ring, naphthalene ring, biphenyl ring, and terphenyl ring. 6-22 represents an arene ring, R 3a and R 3b each independently represents a hydrocarbon group; m3a and m3b each independently represent an integer of 0 to 2; A 2a and A 2b is independently C 2-4 represents an alkylene group, and n2a and n2b each independently represent an integer of 0 to 6;

[0103] More preferably, R 2 is C 1-6 alkyl groups such as alkyl groups or C 6-10 m2 represents an integer of 0 to 2; Z 2a and Z 2b are independently polycyclic arene rings (especially C 10-22 arene ring), R 3a and R 3b is independently C 1-6 alkyl groups such as alkyl groups or C 6-12 m3a and m3b each independently represent an integer of 0 to 2; A 2a and A 2b are independently C groups such as ethylene or propylene groups. 2-3 represents an alkylene group, and n2a and n2b each independently represent an integer of 0 to 2;

[0104] Particularly preferably, R 2 is C 1-4 represents an alkyl group, m2 represents an integer of 0 to 2, Z 2a and Z 2b are independently ring-assembled arene rings (C such as biphenyl rings and terphenyl rings) 12-20 C arene rings, especially m-terphenyl rings 18-20 arene ring), R 3a and R 3b are independently C such as methyl group 1-4m3a and m3b each independently represent an integer of 0 to 2; A 2a and A 2b each independently represents an ethylene group, and n2a and n2b each independently represent 0 or 1.

[0105] Specific examples of the diol component (A2) that forms the diol unit (A2) include 9,9-bis(hydroxyaryl)fluorenes in which n2a and n2b are 0 in the formula (2); and 9,9-bis[hydroxy(poly)alkoxyaryl]fluorenes in which n2a and n2b are 1 or more, for example, about 1 to 10.

[0106] In this specification and claims, unless otherwise specified, the term "(poly)alkoxy" is used to mean both an alkoxy group and a polyalkoxy group.

[0107] Examples of 9,9-bis(hydroxyaryl)fluorenes include 9,9-bis(hydroxyphenyl)fluorene, 9,9-bis(alkyl-hydroxyphenyl)fluorene, 9,9-bis(aryl-hydroxyphenyl)fluorene, and 9,9-bis(hydroxynaphthyl)fluorene.

[0108] Examples of 9,9-bis(hydroxyphenyl)fluorene include 9,9-bis(4-hydroxyphenyl)fluorene.

[0109] Examples of the 9,9-bis(alkyl-hydroxyphenyl)fluorene include 9,9-bis[(mono- or di-)C]fluorene such as 9,9-bis(4-hydroxy-3-methylphenyl)fluorene and 9,9-bis(4-hydroxy-3,5-dimethylphenyl)fluorene. 1-4 alkyl-hydroxyphenyl]fluorene and the like.

[0110] Examples of the 9,9-bis(aryl-hydroxyphenyl)fluorene include 9,9-bis[(mono- or di-)C]fluorene such as 9,9-bis(4-hydroxy-3-phenylphenyl)fluorene and 9,9-bis(4-hydroxy-3,5-diphenylphenyl)fluorene. 6-10 aryl-hydroxyphenyl]fluorene and the like.

[0111] Examples of 9,9-bis(hydroxynaphthyl)fluorene include 9,9-bis(6-hydroxy-2-naphthyl)fluorene and 9,9-bis(5-hydroxy-1-naphthyl)fluorene.

[0112] Examples of 9,9-bis[hydroxy(poly)alkoxyaryl]fluorenes include 9,9-bis[hydroxy(poly)alkoxyphenyl]fluorene, 9,9-bis[alkyl-hydroxy(poly)alkoxyphenyl]fluorene, 9,9-bis[aryl-hydroxy(poly)alkoxyphenyl]fluorene, and 9,9-bis[hydroxy(poly)alkoxynaphthyl]fluorene.

[0113] Examples of the 9,9-bis[hydroxy(poly)alkoxyphenyl]fluorene include 9,9-bis[hydroxy(mono- to deca)C such as 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene and 9,9-bis[4-(2-hydroxypropoxy)phenyl]fluorene. 2-4 alkoxy-phenyl]fluorene and the like.

[0114] Examples of the 9,9-bis[alkyl-hydroxy(poly)alkoxyphenyl]fluorene include 9,9-bis[(mono- or di-)C such as 9,9-bis[4-(2-hydroxyethoxy)-3-methylphenyl]fluorene, 9,9-bis[4-(2-hydroxyethoxy)-3,5-dimethylphenyl]fluorene, and 9,9-bis[4-(2-hydroxypropoxy)-3-methylphenyl]fluorene. 1-4 Alkyl-hydroxy (mono or deca)C 2-4alkoxy-phenyl]fluorene and the like.

[0115] Examples of the 9,9-bis[aryl-hydroxy(poly)alkoxyphenyl]fluorene include 9,9-bis[(mono- or di)C such as 9,9-bis[4-(2-hydroxyethoxy)-3-phenylphenyl]fluorene, 9,9-bis[4-(2-hydroxypropoxy)-3-phenylphenyl]fluorene, and 9,9-bis[4-(2-hydroxyethoxy)-3,5-diphenylphenyl]fluorene. 6-10 Aryl-hydroxy(mono or deca)C 2-4 alkoxy-phenyl]fluorene and the like.

[0116] Examples of the 9,9-bis[hydroxy(poly)alkoxynaphthyl]fluorene include 9,9-bis[hydroxy(mono- to deca)C such as 9,9-bis[6-(2-hydroxyethoxy)-2-naphthyl]fluorene, 9,9-bis[5-(2-hydroxyethoxy)-1-naphthyl]fluorene, and 9,9-bis[6-(2-hydroxypropoxy)-2-naphthyl]fluorene. 2-4 Alkoxy-naphthyl]fluorene and the like.

[0117] These diol units (A2) may be used alone or in combination of two or more.

[0118] Preferred diol units (A2) include structural units derived from 9,9-bis[hydroxy(poly)alkoxyaryl]fluorenes such as 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene, for example, structural units derived from 9,9-bis[hydroxy(poly)alkoxyphenyl]fluorene, 9,9-bis[alkyl-hydroxy(poly)alkoxyphenyl]fluorene, and 9,9-bis[aryl-hydroxy(poly)alkoxyphenyl]fluorene; more preferably, 9,9-bis[(mono or di)C 6-10 Aryl-hydroxy(mono or deca)C 2-4and 9,9-bis[aryl-hydroxy(poly)alkoxyphenyl]fluorene-derived building blocks, such as 9,9-bis[aryl-hydroxy(poly)alkoxyphenyl]fluorene; in particular, 9,9-bis[diC 6-10 Aryl-hydroxy (mono or penta) C 2-3 Alkoxy-phenyl]fluorene-derived building blocks are preferred.

[0119] Diol unit (A3) The diol unit (A) may or may not contain a diol unit (A3) represented by the following formula (3) as necessary. The inclusion of the diol unit (A3) effectively improves polymerizability, mechanical properties, productivity, etc., but when combined with the diol unit (A1), birefringence tends to increase significantly and heat resistance tends to decrease. The polyester resin of the present disclosure appears to effectively reduce birefringence even when it contains the diol unit (A3), likely because it is combined with the diol unit (A1) and a structural unit having a fluorene skeleton.

[0120] [ka]

[0121] (In the formula, A 3 represents an alkylene group, and n3 represents an integer of 1 or more.

[0122] In the formula (3), A 3 Examples of the alkylene group (linear or branched alkylene group) represented by the formula (I) include C alkylene groups such as ethylene group, propylene group, trimethylene group, 1,2-butanediyl group, 1,3-butanediyl group, tetramethylene group, 1,5-pentanediyl group, 1,6-hexanediyl group, 1,8-octanediyl group, and 1,10-decanediyl group. 2-12 alkylene groups, etc., and preferably, 2-10 Alkylene group, C 2-8 Alkylene group, C 2-6 Alkylene group, C2-4 C alkylene groups, more preferably ethylene groups, propylene groups, etc. 2-3 An alkylene group is preferred, with an ethylene group being particularly preferred.

[0123] Alkyleneoxy group [-(A 3 The repeat number n3 of the alkyleneoxy group [(-A)-] may be selected from integers of about 1 to 10, for example, and is preferably an integer of 1 to 4, an integer of 1 to 3, or an integer of 1 to 2 in the following stepwise order, with 1 being particularly preferred. The repeat number n3 may be an average value (arithmetic mean value or additive mean value) and may be selected from a range of about 1 to 10, for example, and is preferably an integer of 1 to 4, an integer of 1 to 3, or an integer of 1 to 2 in the following stepwise order. When n3 is in an appropriate range that is not too large, there is a tendency that a decrease in refractive index and heat resistance can be suppressed. When n3 is 2 or more, two or more alkyleneoxy groups [(-A 3 O-)] may be the same or different from each other.

[0124] Representative examples of the diol unit (A3) include those represented by the formula (3): 3 is C 2-6 represents an alkylene group, and n3 represents an integer of 1 to 10; Preferably, A 3 is C 2-6 represents an alkylene group, and n3 represents an integer of 1 to 4; More preferably, A 3 is C 2-4 represents an alkylene group, and n3 represents an integer of 1 or 2; Particularly preferably, A 3 is C 2-3 represents an alkylene group, and n3 represents 1.

[0125] Specific examples of the diol component (A3) that forms the diol unit (A3) include alkanediols (or alkylene glycols), polyalkanediols (or polyalkylene glycols), and the like.

[0126] Examples of alkylene glycols include those represented by the formula (3) where n3 is 1 and A 3 corresponding to the alkylene group exemplified above, specifically, C 10 alkylene glycols such as ethylene glycol, propylene glycol, trimethylene glycol, 1,2-butanediol, 1,3-butanediol, tetramethylene glycol (or 1,4-butanediol), 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,8-octanediol, and 1,10-decanediol. 2-12 alkylene glycol, etc., and a preferred embodiment is 3 The same applies to

[0127] The polyalkylene glycol may be, for example, a polyalkylene glycol represented by the formula (3) in which n3 is 2 or more, preferably 2 to 10, more preferably 2 to 6, and even more preferably 2 to 4; 3 Polylinear or branched alkylene glycols corresponding to the alkylene groups exemplified above, specifically di- or deca-C alkylene glycols such as diethylene glycol, dipropylene glycol, and triethylene glycol. 2-12 alkylene glycols, and preferably di- to hexa-C 2-6 Alkylene glycol, more preferably di- or tetra-C 2-4 Alkylene glycols are included.

[0128] These diol units (A3) may be contained alone or in combination of two or more. Preferred diol units (A3) are 2-6 alkylene glycols, such as linear or branched alkylene glycols, preferably C 2-4 C alkylene glycol, more preferably ethylene glycol, propylene glycol, etc. 2-3 It is preferred that the alkylene glycol contains units derived from alkylene glycol, particularly ethylene glycol.

[0129] Diol unit (A4) The diol unit (A) may or may not contain a diol unit (A4) that is different from the diol unit (A1), the diol unit (A2), and the diol unit (A3) [that does not belong to the category of the diol units (A1) to (A3)], as necessary.

[0130] Examples of the diol unit (A4) include structural units derived from aromatic diol components (excluding the diol component (A2)), alicyclic diol components (excluding the diol component (A1)), and alkylene oxide (or alkylene carbonate, haloalkanol) adducts of these diol components.

[0131] Examples of aromatic diol components (excluding diol component (A2)) include dihydroxyarenes such as hydroquinone and resorcinol; aromatic aliphatic diols such as benzenedimethanol; bisphenols such as bisphenol A, bisphenol F, bisphenol AD, bisphenol C, bisphenol G, and bisphenol S; and biphenols such as p,p'-biphenol.

[0132] Examples of alicyclic diol components [excluding diol component (A1)] include cycloalkanediols such as cyclohexanediol; bis(hydroxyalkyl)cycloalkanes such as cyclohexanedimethanol; hydrogenated products of the above aromatic diol components such as hydrogenated bisphenol A; and polycyclic (bridged cyclic and / or spirocyclic) diol compounds which may contain a heterocycle such as tricyclodecane dimethanol, isosorbide, and 3,9-bis(2-hydroxy-1,1-dimethylethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane.

[0133] Examples of alkylene oxide (corresponding alkylene carbonate or haloalkanol) adducts of these diol components include C 2-4 C alkylene oxide adducts, preferably ethylene oxide adducts, propylene oxide adducts, etc. 2-3Examples thereof include alkylene oxide adducts, and the number of moles added is not particularly limited.Specific examples include adducts in which about 2 to 10 moles of ethylene oxide are added to 1 mole of bisphenol A.

[0134] These diol units (A4) may be contained alone or in combination of two or more kinds.

[0135] The proportion of the diol units (A4) relative to the total diol units (A) is, for example, 50 mol% or less, preferably 30 mol% or less, and more preferably 10 mol% or less, and may be, for example, about 0.1 to 5 mol%, and it is particularly preferred that the diol units (A4) are substantially free of the diol units (A4).

[0136] The ratio of diol units (A1) to all diol units (A) (also referred to as A1 / A) may be, for example, about 10 to 100 mol%, preferably 30 to 95 mol%, 40 to 90 mol%, and 45 to 85 mol% in the following stepwise manner. A1 / A is also preferably 50 to 99 mol%, 55 to 97 mol% (e.g., 60 to 95 mol%), 65 to 96 mol% (e.g., 70 to 90 mol%), 75 to 95 mol% (e.g., 75 to 85 mol%), 80 to 94 mol%, and 85 to 93 mol%, which may be within the ranges of resins (P1) and (P3) described below. A1 / A is also preferably 20 to 80 mol%, 30 to 70 mol%, 35 to 65 mol%, 40 to 60 mol%, and 45 to 55 mol%, which may be within the range of resin (P2) described below. When the proportion of the diol unit (A1) is in an appropriate range that is not too small, it tends to be easy to adjust the Abbe number to a medium range, and when it is in an appropriate range that is not too large, it tends to be easy to suppress a decrease in the refractive index and, unexpectedly, tends to be easy to improve moldability despite the presence of a polycyclic skeleton.

[0137] The ratio of the total amount of diol units (A1) and diol units (A3) to the total amount of diol units (A) (also referred to as A1,3 / A) may be, for example, about 30 to 100 mol%, preferably 50 mol% or more, 70 mol% or more, 80 mol% or more, 90 mol% or more, and particularly preferably substantially 100 mol%, and these ranges may be the ranges of resins (P1) and (P3) described below. Furthermore, A1,3 / A may also be 50 to 95 mol% (e.g., 60 to 95 mol%), 55 to 90 mol% (e.g., 70 to 90 mol%), 60 to 85 mol% (e.g., 75 to 85 mol%), or 60 to 80 mol% (e.g., 65 to 75 mol%), and these ranges may be the ranges of resin (P2) described below. When the total proportion of the diol units (A1) and (A3) is within a suitable range, it tends to be easy to achieve a good balance between a medium Abbe number and a high refractive index, low birefringence, and / or high heat resistance.When the total proportion of the diol units (A1) and (A3) is within a suitable range, it tends to be easy to achieve a good balance between a medium Abbe number and a high refractive index, low birefringence, and / or high heat resistance.

[0138] The ratio of the total amount of diol units (A1), diol units (A2), and diol units (A3) to the total amount of diol units (A) (also referred to as A1,2,3 / A) may be, for example, about 30 to 100 mol%, preferably 50 mol% or more, 70 mol% or more, 80 mol% or more, 90 mol% or more, and particularly preferably substantially 100 mol%. When the ratio of the total amount of diol units (A1), diol units (A2), and diol units (A3) is in an appropriate range that is not too small, it tends to be easier to achieve a good balance between a medium Abbe number and a high refractive index, low birefringence, and / or high heat resistance.

[0139] The ratio of the diol unit (A1) to the diol unit (A2) (also referred to as A1 / A2) may be selected, for example, from a range of about former / latter (molar ratio) = 30 / 70 to 100 / 0. A1 / A2 is, for example, 50 / 50 to 100 / 0, preferably 70 / 30 to 100 / 0, 80 / 20 to 100 / 0, 90 / 10 to 100 / 0, and particularly preferably substantially 100 / 0, and these ranges may also be the ranges of resins (P1) and (P3) described below. A1 / A2 is preferably 35 / 65 to 90 / 10 (e.g., 50 / 50 to 90 / 10), 40 / 60 to 85 / 15 (e.g., 55 / 45 to 85 / 15), 45 / 55 to 80 / 20 (e.g., 60 / 40 to 80 / 20), 50 / 50 to 75 / 25 (e.g., 65 / 35 to 75 / 25), 55 / 45 to 70 / 30, or 60 / 40 to 65 / 35, and these ranges may also be the ranges for resin (P2) described below. When the proportion of diol units (A1) is in a moderate range that is not too small, it tends to be easy to adjust the Abbe number to a medium level, and when the proportion of diol units (A2) is in a moderate range that is not too small, it tends to be easy to improve the refractive index and maintain or improve heat resistance while suppressing an excessive increase in birefringence (or reducing birefringence).

[0140] The ratio of diol units (A1) to diol units (A3) (also referred to as A1 / A3) may be selected from the range of, for example, the former / latter (molar ratio) = 10 / 90 to 100 / 0, preferably 30 / 70 to 100 / 0, 40 / 60 to 95 / 5, 50 / 50 to 90 / 10, 55 / 45 to 85 / 15, etc. A1 / A3 is also preferably 50 / 50 to 99 / 1, 55 / 45 to 97 / 3 (e.g., 60 / 40 to 95 / 5), 65 / 35 to 96 / 4 (e.g., 70 / 30 to 90 / 10), 75 / 25 to 95 / 5 (e.g., 75 / 25 to 85 / 15), 80 / 20 to 94 / 6, 85 / 15 to 93 / 7, etc. These ranges may also be the ranges of the resin (P1) described below. A1 / A3 is preferably 40 / 60 to 99 / 1 (e.g., 40 / 60 to 85 / 15), 45 / 55 to 95 / 5 (e.g., 50 / 50 to 75 / 25), 50 / 50 to 90 / 10 (e.g., 55 / 45 to 70 / 30), 55 / 45 to 85 / 15, 60 / 40 to 80 / 20, or 65 / 35 to 75 / 25, and these ranges may also be the ranges for resin (P2) described below. When the proportion of diol units (A1) is in an appropriate range that is not too small, there is a tendency to easily suppress an increase in birefringence and a decrease in heat resistance, and when the proportion of diol units (A3) is in an appropriate range that is not too small, there is a tendency to easily improve polymerization reactivity and thereby improve molecular weight, mechanical properties, moldability (productivity), etc.

[0141] The ratio of the diol unit (A2) to the diol unit (A3) (also referred to as A2 / A3) (molar ratio) can be selected from the range of 0 / 100 to 100 / 0, for example, 0 / 100 to 80 / 20, and preferably 0 / 100 to 70 / 30. A2 / A3 is also preferably in the following stepwise ranges: 0 / 100 to 50 / 50, 0 / 100 to 30 / 70, and 0 / 100 to 10 / 90 (particularly 0 / 100), and these ranges may also be those of the resins (P1) and (P3) described below. A2 / A3 is preferably in the following stepwise ranges: 5 / 95 to 99 / 1 (e.g., 10 / 90 to 70 / 30), 15 / 85 to 95 / 5 (e.g., 20 / 80 to 60 / 40), 25 / 75 to 90 / 10 (e.g., 30 / 70 to 50 / 50), 35 / 65 to 85 / 15 (e.g., 35 / 65 to 45 / 55), 40 / 60 to 80 / 20, 45 / 55 to 75 / 25, 50 / 50 to 70 / 30, 55 / 45 to 65 / 35, and these ranges may also be the ranges of the resin (P2) described below. When the proportion of the diol unit (A2) is in an appropriate range that is not too small, there is a tendency that the refractive index is improved and heat resistance is maintained or improved while an excessive increase in birefringence is suppressed (or birefringence is reduced), and when the proportion of the diol unit (A3) is in an appropriate range that is not too small, there is a tendency that the polymerization reactivity is improved and molecular weight, mechanical properties, moldability (productivity), etc. are improved.

[0142] The proportion of the total amount of the diol units (A1) to (A4) may be 100 mol % based on all the diol units (A). The proportion of the diol units (A) [total amount of the diol units (A1) to (A4)] based on all the structural units of the resin (total amount of structural units derived from all the polymerization components constituting the resin) may be, for example, about 10 mol % or more, and preferably 20 to 50 mol %, 30 to 50 mol %, and 40 to 50 mol % in the following stepwise manner.

[0143] The ratio of the diol unit (A) to the dicarboxylic acid unit (B) in the polyester resin is the former / latter (molar ratio) = 1 / 0.8 to 1 / 1.2, preferably 1 / 0.9 to 1 / 1.1, and is preferably approximately equimolar.

[0144] (Dicarboxylic acid unit (B)) Dicarboxylic acid unit (B1) The dicarboxylic acid unit (B) does not necessarily have to contain the dicarboxylic acid unit (B1), which is an alicyclic dicarboxylic acid unit. However, if the dicarboxylic acid unit (B1) is contained, it is preferable in that it exhibits a medium Abbe number while easily achieving a balance between a high refractive index, low birefringence, and high heat resistance.

[0145] The alicyclic dicarboxylic acid unit (B1) may contain at least one aliphatic hydrocarbon ring (alicyclic) skeleton in its chemical structure. The aliphatic hydrocarbon ring may be a non-aromatic ring structure formed by an aliphatic chain, and may be monocyclic or polycyclic, such as a bridged ring or spirocyclic ring, and may or may not contain an unsaturated bond such as a double bond. Examples of such aliphatic hydrocarbon ring include monocyclic aliphatic hydrocarbon rings and bridged cyclic aliphatic hydrocarbon rings.

[0146] Examples of the monocyclic aliphatic hydrocarbon ring include a cycloalkane ring and a cycloalkene ring. Examples of the cycloalkane ring include a C cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, a cyclooctane ring, and the like. 3-20 Examples of the cycloalkene ring include a C cyclopentene ring and a cyclohexene ring. 3-20 Examples include a cycloalkene ring.

[0147] Examples of the bridged cyclic aliphatic hydrocarbon ring include a bridged cyclic cycloalkane ring and a bridged cyclic cycloalkene ring. Examples of the bridged cyclic cycloalkane ring include C cycloalkane rings such as a decalin ring, a norbornane ring, an adamantane ring, a tricyclodecane ring, and a tetracyclododecane ring. 7-20 Examples of the tricyclodecane ring include tricyclo[5.2.1.0] and tetracycloalkane rings. 2,6 ]decane ring, etc. Examples of the tetracyclododecane ring include tetracyclo[4.4.0.1 2,5 .1 7,10]dodecane ring, etc. Examples of the bridged cyclic cycloalkene ring include a C cycloalkene ring such as a norbornene ring, a tricyclodecene ring, and a tetracyclododecene ring. 7-20 Examples include bicycloalkene rings and tetracycloalkene rings.

[0148] The alicyclic dicarboxylic acid unit (B1) may contain these aliphatic hydrocarbon rings alone or in combination of two or more. Among these aliphatic hydrocarbon rings, cycloalkane rings such as cyclohexane ring, bicycloalkane rings such as decalin ring and tricyclodecane ring are preferred, and C 5-10 Cycloalkane rings such as cycloalkane rings, especially C such as cyclohexane rings 5-8 It is a cycloalkane ring.

[0149] The alicyclic dicarboxylic acid unit (B1) may also contain an alkylene group in its chemical structure, such as an alkylene group that bonds (or connects) the aliphatic hydrocarbon ring with a carbonyl group [—C(═O)—] derived from a polymerizable group such as a carboxyl group, or an alkylene group that bonds two or more of the aliphatic hydrocarbon rings together. Examples of such alkylene groups (linear or branched alkylene groups) include C alkylene groups such as methylene, ethylene, trimethylene, propylene, 1,2-butanediyl, and 2-methylpropane-1,3-diyl. 1-8 Preferred alkylene groups include C alkylene groups such as methylene, ethylene, trimethylene, propylene, and 2-methylpropane-1,3-diyl. 1-6 An alkylene group is preferred, and C 1-4 Alkylene groups, more preferably C 1-3 Alkylene groups, especially C such as methylene groups 1-2 It is an alkylene group.

[0150] A preferred alicyclic dicarboxylic acid unit (B1) is represented by the following formula (4).

[0151] [ka]

[0152] (In the formula, Z 3 represents an aliphatic hydrocarbon ring, R 4 represents a substituent, m4 represents an integer of 0 or more, A 4a and A 4b each independently represents a direct bond (or a single bond) or a linear or branched alkylene group.

[0153] In the formula (4), Z 3 Examples of the aliphatic hydrocarbon ring represented by the formula (I) include the monocyclic aliphatic hydrocarbon ring and the bridged cyclic aliphatic hydrocarbon ring. 3 is a cycloalkane ring, a bicycloalkane ring or a tetracycloalkane ring, and more preferably C 5-10 Cycloalkane rings such as cycloalkane rings, especially C such as cyclohexane rings. 5-8 A cycloalkane ring is preferred.

[0154] R 4 The substituent represented by R may be a non-reactive group (or a non-polymerizable group) that is inert to the reaction. 4 Examples of the substituent represented by the formula (1) in the section on diol unit (A1) include R 1 and the like, and preferably a halogen atom, a hydrocarbon group (excluding groups containing an aromatic ring skeleton such as an aryl group or an aralkyl group), a group [—OR h ](where R h represents the hydrocarbon group), and more preferably an aliphatic hydrocarbon group such as a linear or branched alkyl group or a cycloalkyl group, and among these, C 1-4 C such as alkyl group and cyclohexyl group 5-10 It is a cycloalkyl group.

[0155] R 4 The number of permutations m4 of Z 3Depending on the type of R, for example, it is an integer of 0 to 10, preferably an integer of 0 to 6, an integer of 0 to 4, an integer of 0 to 2, more preferably 0 or 1, and particularly preferably 0. When m4 is 2 or more, R 4 The types may be the same or different from each other.

[0156] A 4a or A 4b may be an alkylene group (a linear or branched alkylene group), and examples thereof include the same groups as those exemplified as the alkylene groups that may be contained in the chemical structure of the above-mentioned alicyclic dicarboxylic acid unit (B1), including preferred embodiments thereof.

[0157] A 4a and / or A 4b may be an alkylene group, but represents a direct bond (or a single bond), i.e., Z 3 and the carbonyl group [—C(═O)—] are preferably directly bonded to each other. 4a and A 4b The types may be the same or different from each other, and are preferably the same from each other.

[0158] Z 3 And, A 4a and A 4b (or carbonyl group [—C(═O)—]) is not particularly limited, and Z 3 The furthest position in the 3 When is a cyclohexane ring, it may be at the 1, 4 positions, etc.

[0159] Representative examples of the dicarboxylic acid unit (B1) include those represented by the formula (4): Z 3 represents a monocyclic or bridged cyclic aliphatic hydrocarbon ring, R 4 represents a halogen atom or an aliphatic hydrocarbon group, m4 represents an integer of 0 to 6, A 4a and A 4b are independently a direct bond or C 1-6 Examples of structural units include alkylene groups;

[0160] Preferably Z 3 represents a cycloalkane ring or a bicycloalkane or tetracycloalkane ring, R 4 represents an aliphatic hydrocarbon group, m4 represents an integer of 0 to 4, A 4a and A 4b are independently a direct bond or C 1-4 Examples of structural units include alkylene groups;

[0161] More preferably Z 3 is a cycloalkane ring (especially C 5-10 cycloalkane ring), R 4 is an alkyl group (especially C 1-6 alkyl group) or cycloalkyl group (especially C 5-10 cycloalkyl group), m4 represents an integer of 0 to 2, A 4a and A 4b are independently a direct bond or C 1-4 Alkylene groups (especially those with a direct bond or C 1-3 Examples of structural units include those representing alkylene groups;

[0162] Particularly preferably Z 3 is C 5-8 Cycloalkane rings (especially C rings such as cyclohexane rings) 5-7 cycloalkane ring), R 4 is an alkyl group (especially C 1-4 alkyl group), m4 is 0 or 1, A 4a and A 4b are structural units each independently representing a direct bond.

[0163] Representative alicyclic dicarboxylic acid components that form the structural unit represented by the formula (4) include, for example, cycloalkanedicarboxylic acids, specifically, C 1,4-cyclohexanedicarboxylic acid and the like.5-10 Cycloalkane dicarboxylic acids, etc.; bridged cyclic cycloalkane dicarboxylic acids, specifically, bi- or tricycloalkane dicarboxylic acids such as decalin dicarboxylic acid, norbornane dicarboxylic acid, adamantane dicarboxylic acid, tricyclodecane dicarboxylic acid, etc.; cycloalkene dicarboxylic acids, specifically, C such as cyclohexene dicarboxylic acid, etc. 5-10 Examples thereof include cycloalkene-dicarboxylic acids; bridged cyclic cycloalkene dicarboxylic acids, specifically bi- or tricycloalkene dicarboxylic acids such as norbornene dicarboxylic acid; and ester-forming derivatives thereof.

[0164] The structural unit represented by the formula (4) may be contained alone or in combination of two or more kinds. Among the structural units represented by the formula (4), structural units derived from cycloalkanedicarboxylic acids and bridged cyclic cycloalkanedicarboxylic acids (such as bi- or tricycloalkanedicarboxylic acids) are preferred; and C 5-10 It is a structural unit derived from cycloalkanedicarboxylic acids such as cycloalkane-dicarboxylic acids; in particular, C 5-8 Cycloalkane-dicarboxylic acids (C such as 1,4-cyclohexanedicarboxylic acid) 5-7 Constituent units derived from cycloalkane-dicarboxylic acids, etc. are preferred.

[0165] The alicyclic dicarboxylic acid units (B1) may be contained alone or in combination of two or more kinds.

[0166] The proportion of the alicyclic dicarboxylic acid units represented by the formula (4) may be, for example, 10 mol% or more, specifically, may be selected from the range of about 30 to 100 mol%, based on the total amount of the alicyclic dicarboxylic acid units (B1), and is preferably 50 mol% or more, 70 mol% or more, 90 mol% or more, and more preferably 100 mol%.

[0167] The dicarboxylic acid component derived from the alicyclic dicarboxylic acid unit (B1), such as the structural unit represented by the formula (4), may be an isomer mixture, and may have a trans / cis (molar ratio) selected from 0 / 100 to 100 / 0, specifically about 1 / 99 to 99 / 1, and preferably the following stepwise ratios: 50 / 50 to 100 / 0, 70 / 30 to 100 / 0, 80 / 20 to 100 / 0, and 90 / 10 to 100 / 0.

[0168] Dicarboxylic acid unit (B2) The dicarboxylic acid unit (B) may or may not contain a diol unit (B2) represented by the following formula (5) as a constituent unit having a fluorene skeleton, as necessary. By combining the dicarboxylic acid unit (B2) with the diol unit (A1), it is easy to achieve a medium Abbe number while also achieving a high refractive index, low birefringence, and high heat resistance in a well-balanced manner.

[0169] [ka]

[0170] (In the formula, R 5 represents a substituent, m5 represents an integer of 0 to 8, A 5a and A 5b each independently represents an alkylene group.

[0171] In the formula (5), R 5 The substituent represented by R may be a non-reactive group (or a non-polymerizable group) that is inert to the reaction. 5 Examples of the substituent represented by the formula (1) include R 1 The examples of the groups exemplified as R include the same groups as those exemplified as R, including preferred embodiments thereof. 5 Examples of the alkyl group include halogen atoms, hydrocarbon groups, and groups [-OR h ] (alkoxy group, etc.), and the like, are preferably hydrocarbon groups, more preferably alkyl groups and aryl groups (particularly aryl groups). Examples of the alkyl group (linear or branched alkyl group) include C groups such as methyl group, ethyl group, and t-butyl group.1-6 alkyl groups, and C groups such as methyl groups. 1-4 An alkyl group is preferred. Examples of the aryl group include C aryl groups such as a phenyl group and a naphthyl group (e.g., a 1-naphthyl group, a 2-naphthyl group, etc.). 6-12 aryl groups, and preferably C 6-10 It is preferably an aryl group, more preferably a naphthyl group such as a 2-naphthyl group.

[0172] R 5 The number of substitutions m5 is, for example, an integer of about 0 to 6, preferably an integer of 0 to 4, an integer of 0 to 2, more preferably 0 or 1 or 0 or 2, particularly preferably 0. When m5 is 2 or more, 2 or more R 5 The types of R may be the same or different, and are preferably the same. 5 When R is substituted on one of the benzene rings, 5 The type of R on the other benzene ring 5 The types of R may be the same or different, and are preferably the same. 5 At least one of the C groups is an aryl group (e.g., a phenyl group, a naphthyl group, etc.) 6-10 aryl group, etc.) 5 The substitution position is not particularly limited, and may be, for example, the 2-position or the 2,7-position.

[0173] A 5a or A 5b Examples of the alkylene group (linear or branched alkylene group) represented by the formula (I) include C 1, C 2, C 3, C 4, C 5, C 6, C 7, C 8, C 9, C 10, C 11, C 12, C 13, C 14, C 15, C 16, C 17, C 18, C 19, C 20, C 21, C 22, C 23, C 24, C 25, C 26, C 27, C 28, C 29, C 30, C 31, C 32, C 33, C 28, C 34, C 29, C 35, C 26, C 27, C 28, C 29, C 36, C 29, C 37, C 29, C 38, C 29, C 39, C 1-6 alkylene groups. 5a ,A 5b Examples of C alkyl groups include methylene, ethylene, trimethylene, propylene, and 2-methylpropane-1,3-diyl groups. 1-6 An alkylene group is preferred, and C1-4 It is an alkylene group, and more preferably C 1-3 Alkylene groups, especially C groups such as ethylene and propylene groups. 2-3 An alkylene group is preferred, and an ethylene group is particularly preferred. 5a and A 5b The types may be different from each other, but are preferably the same.

[0174] Representative examples of the dicarboxylic acid unit (B2) include those represented by the formula (5): R 5 represents a hydrocarbon group, a halogen atom, or a cyano group; m5 represents an integer of 0 to 6; A 5a and A 5b is independently C 1-6 Examples include units representing alkylene groups;

[0175] Preferably, R 5 represents a hydrocarbon group such as an alkyl group or an aryl group, m5 represents an integer of 0 to 4, A 5a and A 5b is independently C 1-4 Examples include units representing alkylene groups;

[0176] More preferably, R 5 is C 1-6 Alkyl group, C 6-12 m5 represents an integer of 0 to 2; A 5a and A 5b is independently C 2-4 Examples include units representing alkylene groups;

[0177] Particularly preferably, R 5 is C 1-4 Alkyl group (e.g., methyl group), C 6-10 represents an aryl group (e.g., a phenyl group, a naphthyl group), m5 represents 0 or 1 or 0 or 2 (particularly, 0); A 5a and A5b is independently C 2-3 Examples include units representing alkylene groups.

[0178] Specific examples of the dicarboxylic acid component (B2) forming the dicarboxylic acid unit (B2) include 9,9-bis(carboxyalkyl)fluorenes, more specifically, 9,9-bis(carboxy C)s such as 9,9-bis(2-carboxyethyl)fluorene and 9,9-bis(2-carboxypropyl)fluorene. 2-6 9,9-bis(carboxyalkyl)-arylfluorenes, more specifically, 9,9-bis(carboxyC) such as 9,9-bis(2-carboxyethyl)-2-phenylfluorene, 9,9-bis(2-carboxyethyl)-2-(1-naphthyl)fluorene, 9,9-bis(2-carboxyethyl)-2-(2-naphthyl)fluorene, 9,9-bis(2-carboxypropyl)-2-(2-naphthyl)fluorene, 9,9-bis(2-carboxyethyl)-2,7-di(1-naphthyl)fluorene, and 9,9-bis(2-carboxyethyl)-2,7-di(2-naphthyl)fluorene. 2-6 Alkyl)-(mono or di)C 6-12 arylfluorene, etc.; preferably 9,9-bis(carboxy C 2-4 alkyl)fluorene, or ester-forming derivatives thereof.

[0179] These dicarboxylic acid units (B2) may be used alone or in combination. For example, in the formula (5), R 5 a dicarboxylic acid unit (B2-1) having no aryl group as R 5 At least one aryl group (e.g., a phenyl group, a naphthyl group, etc.) 6-10The ratio of the dicarboxylic acid units (B2-1) to the dicarboxylic acid units (B2-2) may be selected, for example, from the range of former / latter (molar ratio) = 0 / 100 to 100 / 0, preferably in the following stepwise manner: 30 / 70 to 100 / 0, 50 / 50 to 100 / 0, 70 / 30 to 100 / 0, 90 / 10 to 100 / 0 (for example, 90 / 10 to 99 / 1), and more preferably substantially 100 / 0.

[0180] Dicarboxylic acid unit (B3) The dicarboxylic acid unit (B) may or may not contain a dicarboxylic acid unit (B3) which is different from the dicarboxylic acid unit (B1) and the dicarboxylic acid unit (B2) [i.e., does not belong to the category of the dicarboxylic acid units (B1) to (B2)], as necessary.

[0181] Examples of the dicarboxylic acid unit (B3) include structural units derived from aromatic dicarboxylic acid components (excluding the dicarboxylic acid unit (B2)), aliphatic dicarboxylic acid components, and the like.

[0182] Examples of the aromatic dicarboxylic acid component include monocyclic aromatic dicarboxylic acids, polycyclic aromatic dicarboxylic acids, and ester-forming derivatives thereof.

[0183] Examples of monocyclic aromatic dicarboxylic acids include benzene dicarboxylic acids such as phthalic acid, terephthalic acid, and isophthalic acid; alkyl benzene dicarboxylic acids, specifically, C 4-methylisophthalic acid; 1-4 alkyl-benzenedicarboxylic acids and the like.

[0184] Examples of polycyclic aromatic dicarboxylic acids include condensed polycyclic aromatic dicarboxylic acids, specifically condensed polycyclic C dicarboxylic acids such as naphthalenedicarboxylic acid, anthracenedicarboxylic acid, and phenanthrenedicarboxylic acid. 10-14arene-dicarboxylic acids; biaryldicarboxylic acids, specifically biphenyldicarboxylic acids such as 2,2'- or 4,4'-biphenyldicarboxylic acid; diarylalkanedicarboxylic acids, specifically di-C such as 4,4'-diphenylmethanedicarboxylic acid; 6-10 Aryl C 1-6 Alkane-dicarboxylic acids, etc.; diaryl ketone dicarboxylic acids, specifically, di(C) such as 4,4'-diphenyl ketone dicarboxylic acid 6-10 aryl) ketone-dicarboxylic acids; diaryl ether dicarboxylic acids, specifically, di(C) such as 4,4'-diphenyl ether dicarboxylic acid 6-10 aryl) ether-dicarboxylic acids; diarylsulfonedicarboxylic acids, specifically, di(C) such as 4,4'-diphenylsulfonedicarboxylic acid; 6-10 aryl)sulfone-dicarboxylic acid, etc. The naphthalenedicarboxylic acid includes 1,2-, 1,4-, 1,5-, 1,8-, 2,3-, and 2,6-naphthalenedicarboxylic acid, etc.

[0185] Examples of the aliphatic dicarboxylic acid component include alkanedicarboxylic acids (linear or branched alkanedicarboxylic acids), specifically, C alkanedicarboxylic acids such as malonic acid, succinic acid, adipic acid, suberic acid, sebacic acid, and decanedicarboxylic acid. 1-12 Alkane-dicarboxylic acids, etc.; unsaturated aliphatic dicarboxylic acids (linear or branched unsaturated aliphatic dicarboxylic acids), specifically, C such as maleic acid, fumaric acid, and itaconic acid 2-10 Alkene-dicarboxylic acids; and ester-forming derivatives thereof.

[0186] The dicarboxylic acid units (B3) may be contained alone or in combination of two or more kinds.

[0187] The proportion of the dicarboxylic acid units (B3) relative to the total dicarboxylic acid units (B) is, for example, 50 mol% or less, preferably in steps of 30 mol% or less, 20 mol% or less, 15 mol% or less, 10 mol% or less, 5 mol% or less, and 1 mol% or less, and may be, for example, about 0.1 to 3 mol%, and it is particularly preferred that the dicarboxylic acid units (B3) are substantially free of the dicarboxylic acid units (B3).

[0188] The ratio of the total amount of dicarboxylic acid units (B1) and dicarboxylic acid units (B2) to the total amount of dicarboxylic acid units (B) (also referred to as B1,2 / B) may be, for example, about 30 mol% or more, preferably 50 mol% or more, 70 mol% or more, 80 mol% or more, 90 mol% or more, and particularly preferably substantially 100 mol%. When the total amount of dicarboxylic acid units (B1) and dicarboxylic acid units (B2) is in an appropriate range that is not too small, it tends to be easier to achieve a good balance between a medium Abbe number, a high refractive index, low birefringence, and / or high heat resistance.

[0189] The ratio of the dicarboxylic acid units (B1) to the dicarboxylic acid units (B2) (also referred to as B1 / B2) may be, for example, the former / latter (molar ratio) = about 0 / 100 to 100 / 0, and preferably the following stepwise ratios: 20 / 80 to 100 / 0, 30 / 70 to 100 / 0. B1 / B2 is preferably in the following stepwise order: 5 / 95 to 90 / 10 (e.g., 15 / 85 to 80 / 20), 8 / 92 to 75 / 25 (e.g., 20 / 80 to 70 / 30), 10 / 90 to 65 / 35 (e.g., 25 / 75 to 60 / 40), 12 / 88 to 55 / 45 (e.g., 30 / 70 to 50 / 50), 13 / 87 to 50 / 50 (e.g., 35 / 65 to 45 / 55), 14 / 86 to 40 / 60, 15 / 85 to 35 / 65, 16 / 84 to 30 / 70, 17 / 83 to 25 / 75, and these ranges may also be the ranges of the resin (P1) described later. B1 / B2 is preferably in the following stepwise ranges: 50 / 50 to 100 / 0, 70 / 30 to 100 / 0, 80 / 20 to 100 / 0, 90 / 10 to 100 / 0 (particularly 100 / 0), and these ranges may be the ranges of resin (P2) described below. B1 / B2 is also preferably in the following stepwise ranges: 0 / 100 to 50 / 50, 0 / 100 to 30 / 70, 0 / 100 to 20 / 80, 0 / 100 to 10 / 90 (particularly 0 / 100), and these ranges may be the ranges of resin (P3) described below. When the proportion of the dicarboxylic acid unit (B1) is in an appropriate range that is not too small, there is a tendency that the heat resistance can be easily maintained or improved while exhibiting a medium Abbe number (or while preventing the Abbe number from decreasing too much), and when the proportion of the dicarboxylic acid unit (B2) is in an appropriate range that is not too small, there is a tendency that the refractive index can be improved or an excessive increase in birefringence can be prevented (or birefringence can be reduced) while exhibiting a medium Abbe number.

[0190] The total proportion of the dicarboxylic acid units (B1) to (B3) may be 100 mol % based on all the dicarboxylic acid units (B). The proportion of the dicarboxylic acid units (B) [total amount of the dicarboxylic acid units (B1) to (B3)] based on all the structural units of the resin (total amount of structural units derived from all the polymerization components constituting the resin) may be, for example, about 10 mol % or more, and preferably 20 to 50 mol %, 30 to 50 mol %, and 40 to 50 mol % in the following stepwise manner.

[0191] (carbonate unit (C)) The polyester resin may be a polyester carbonate resin containing, in addition to the diol unit (A) and the dicarboxylic acid unit (B), a carbonate unit (C) as required.

[0192] In this specification and claims, the term "carbonate unit" refers to a structural unit derived from a carbonate bond-forming component capable of forming a carbonate bond [-O-C(=O)-O-] upon reaction with a diol component, i.e., a carbonyl group [-C(=O)-]. In other words, a carbonate unit (carbonyl group) can form a carbonate bond together with the terminal oxygen atoms of two adjacently bonded diol units.

[0193] Therefore, the carbonate bond-forming component (C) may be any compound that can form a carbonate bond by reacting with the diol component (A), and typical examples of the carbonate bond-forming component (C) include phosgenes such as phosgene and triphosgene, and carbonate diesters such as diphenyl carbonate.

[0194] These carbonate bond-forming components (C) can be used alone or in combination of two or more. Among these carbonate bond-forming components (C), carbonic acid diesters such as diphenyl carbonate are preferred from the viewpoint of safety.

[0195] The ratio of the total amount of dicarboxylic acid units (B) and carbonate units (C) to the diol units (A) in the resin (molar ratio) is preferably 1 / 0.8 to 1 / 1.2, more preferably 1 / 0.9 to 1 / 1.1, and is preferably approximately equimolar. The ratio of dicarboxylic acid units (B) to carbonate units (C) (also referred to as B / C) (molar ratio) may be selected from the range of about 100 / 0 to 1 / 99, for example, 90 / 10 to 10 / 90, and preferably the following stepwise ratios: 80 / 20 to 20 / 80, 70 / 30 to 30 / 70, and 60 / 40 to 40 / 60.

[0196] (Other structural units (D)) The polyester resin may not contain any other structural unit (D) different from the diol unit (A), the dicarboxylic acid unit (B), and the carbonate unit (C), but may contain such a unit, if necessary, to the extent that the effects of the present disclosure are not impaired.

[0197] Examples of other structural units (D) include structural units derived from a hydroxycarboxylic acid component or lactone component, a polyfunctional polymerization component having three or more polymerizable groups (carboxyl groups and / or hydroxyl groups), a diamine component, an aminocarboxylic acid component or lactam component, a diisocyanate component, etc., and structural units derived from a hydroxycarboxylic acid component or lactone component, a polyfunctional polymerization component having three or more polymerizable groups (carboxyl groups and / or hydroxyl groups), etc. are preferred.

[0198] Examples of the hydroxycarboxylic acid component include aromatic hydroxycarboxylic acids such as hydroxybenzoic acid, aliphatic hydroxycarboxylic acids (hydroxyalkanoic acids) such as lactic acid, 3-hydroxybutyric acid, and 6-hydroxyhexanoic acid, and ester-forming derivatives thereof. Examples of the corresponding lactone component include lactones corresponding to hydroxyalkanoic acids such as ε-caprolactone.

[0199] Examples of polyfunctional polymerization components having three or more polymerizable groups (carboxyl groups and / or hydroxyl groups) include trivalent or higher polycarboxylic acids such as trimellitic acid and pyromellitic acid; trivalent or higher polyhydric alcohols such as glycerin and pentaerythritol; and the like.

[0200] The proportion of such other structural units (D) is, for example, 50 mol% or less, preferably 0 to 30 mol%, 0 to 10 mol% (e.g., 0.01 to 5 mol%), stepwise relative to all structural units [total amount of diol units (A), dicarboxylic acid units (B), carbonate units (C) and other structural units (D)], and it is preferable that other structural units (D) are substantially not contained.

[0201] (Typical resin) Representative polyester resins in the present disclosure include, for example, the following resins (P1) to (P3).

[0202] (P1): The diol unit (A) contains at least the diol unit (A1) and the diol unit (A3), and A resin in which the dicarboxylic acid unit (B) contains at least a dicarboxylic acid unit (B1) and a dicarboxylic acid unit (B2).

[0203] (P2): The diol unit (A) contains at least the diol unit (A1), the diol unit (A2), and the diol unit (A3), and A resin in which the dicarboxylic acid unit (B) contains at least a dicarboxylic acid unit (B1).

[0204] (P3): The diol unit (A) contains at least the diol unit (A1) and the diol unit (A3), and A resin in which the dicarboxylic acid unit (B) contains at least a dicarboxylic acid unit (B2).

[0205] In these resins (P1) to (P3), the preferred embodiments such as the type and proportion of each structural unit are the same as those described above.

[0206] These resins tend to be more likely to achieve a good balance between a medium Abbe number, a high refractive index, low birefringence, and high heat resistance. Among these resins, resin (P1) is preferred because it is easy to adjust the Abbe number to a slightly higher level while achieving the above-mentioned properties in a balanced manner, resin (P2) is preferred because it is easy to further improve heat resistance while achieving the above-mentioned properties in a balanced manner, resin (P3) is preferred because it is easy to adjust the birefringence to a low level while achieving the above-mentioned properties in a balanced manner, and resin (P2) is even more preferred because it has a particularly good balance of each property.

[0207] In the resin (P2), the diol unit (A2) is Z in the formula (2).2a and Z 2b However, if the copolymer contains structural units that are independently polycyclic arene rings (preferably ring-assembled arene rings such as bi- or terarene rings, and more preferably terphenyl rings), it is preferable because the above properties can be well balanced while the heat resistance can be more easily improved.

[0208] [Resin manufacturing method] The method for producing the resin is not particularly limited, except that it is polymerized using polymerization components (monomer components) that include a diol component (A) containing a diol component (A1) having a pentacycloalkane skeleton, a dicarboxylic acid component (B), and further a polymerization component having a fluorene skeleton, and a conventional method can be used depending on the type of polymerization components (or type of resin) contained. For example, the resin can be produced by reacting (polymerizing or polycondensing) a diol component (A) corresponding to the above-mentioned diol unit (A), a dicarboxylic acid component (B) corresponding to the above-mentioned dicarboxylic acid unit (B), and, if necessary, a carbonate bond-forming component (C), etc., and can be prepared by a conventional method, specifically, a melt polymerization method such as a transesterification method or a direct polymerization method, a solution polymerization method, an interfacial polymerization method, etc.

[0209] Depending on the polymerization method, the reaction may be carried out in the presence or absence of a solvent. However, if the solvent remains in the resulting resin, it may corrode the mold during molding. Furthermore, depending on the polymerization method, if by-products such as salts remain, this may cause the resin (or its molded product) to become cloudy, which may result in defects in applications requiring high transparency, such as optical components. Therefore, from the perspective of improving moldability (productivity) and transparency, melt polymerization (or molten polymer) is preferred, as it can effectively prevent the residue or inclusion of solvents, salts, etc.

[0210] The ratio of the dicarboxylic acid component (B) to the diol component (A) is usually, for example, 1 / 1.2 to 1 / 0.8, preferably 1 / 1.1 to 1 / 0.9 (molar ratio), but this range is not necessarily required, and at least one component selected from each dicarboxylic acid component (B) and each diol component (A) may be used in excess of the intended introduction ratio. For example, a diol component (A3) such as ethylene glycol that can be distilled from the reaction system may be used in excess of the ratio (or introduction ratio) that is introduced into the polyester resin.

[0211] When the carbonate bond-forming component (C) is used, the ratio of the total amount of the dicarboxylic acid component (B) and the carbonate bond-forming component (C) to the diol component (A) is, for example, the former / latter (molar ratio) = 1 / 1.2 to 1 / 0.8, preferably 1 / 1.1 to 1 / 0.9. Taking into consideration volatilization and decomposition during the reaction, the carbonate bond-forming component (C) may be used in a slight excess relative to the planned introduction ratio, for example, 0.1 to 5 mol %, preferably 2 to 3 mol % excess of the carbonate bond-forming component (C) relative to the total amount of the dicarboxylic acid units (B) and the carbonate units (C) (total amount planned to be introduced into the resin).

[0212] The polymerization reaction may be carried out in the presence of a catalyst. Conventional esterification catalysts, such as metal catalysts, can be used as the catalyst. Examples of metal catalysts include metal compounds containing alkali metals such as sodium; alkaline earth metals such as magnesium, calcium, and barium; transition metals such as titanium, manganese, and cobalt; metals in Group 12 of the periodic table such as zinc and cadmium; metals in Group 13 of the periodic table such as aluminum; metals in Group 14 of the periodic table such as germanium and lead; and metals in Group 15 of the periodic table such as antimony. Examples of metal compounds include alkoxides; organic acid salts such as acetates and propionates; inorganic acid salts such as borates and carbonates; oxides, and hydrates thereof. Representative metal compounds include germanium compounds such as germanium dioxide, germanium hydroxide, germanium oxalate, germanium tetraethoxide, and germanium-n-butoxide; antimony compounds such as antimony trioxide, antimony acetate, and antimony ethylene glycolate; titanium compounds such as tetra-n-propyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate (or titanium(IV) tetrabutoxide), titanium oxalate, and potassium titanium oxalate; manganese compounds such as manganese acetate tetrahydrate; and calcium compounds such as calcium acetate monohydrate.

[0213] These catalysts can be used alone or in combination of two or more. When using multiple catalysts, each catalyst can be added according to the progress of the reaction. Among these catalysts, manganese acetate tetrahydrate, calcium acetate monohydrate, germanium dioxide, titanium (IV) tetrabutoxide, etc. are preferred. The amount of catalyst used is, for example, 0.01 x 10 per mole of dicarboxylic acid component (B). -4 ~100×10 -4 moles, preferably 0.1 x 10 -4 ~40×10 -4 It is a mole.

[0214] The reaction may be carried out in the presence of a stabilizer such as a heat stabilizer or an antioxidant, if necessary. Heat stabilizers are commonly used, and examples of such stabilizers include phosphorus compounds such as trimethyl phosphate, triethyl phosphate, triphenyl phosphate, dibutyl phosphate (or dibutyl phosphate), phosphorous acid, trimethyl phosphite, and triethyl phosphite. Among these, trimethyl phosphate and dibutyl phosphate are commonly used. The amount of heat stabilizer used is, for example, 0.01 × 10 per mole of the dicarboxylic acid component (B). -4 ~100×10 -4 moles, preferably 0.1 x 10 -4 ~40×10 -4 It is a mole.

[0215] The reaction may be carried out in an atmosphere of an inert gas, such as nitrogen gas, or a rare gas such as helium or argon. Alternatively, the reaction may be carried out under reduced pressure, for example, at a pressure of 1×10 2 ~1×10 4 The reaction can be carried out at a pressure of about 100 Pa. The transesterification reaction can be carried out in an inert gas atmosphere such as nitrogen gas, and the polycondensation reaction can be carried out under reduced pressure. The reaction temperature can be selected depending on the polymerization method. For example, the reaction temperature in the melt polymerization method is about 150 to 320°C, preferably 250 to 310°C, and more preferably 270 to 300°C.

[0216] After the reaction is completed, the produced polyester resin may be separated and purified by a conventional method, for example, a separation and purification means such as washing, extraction, concentration, reprecipitation, centrifugation, filtration, column chromatography, adsorption, or a combination of these means.

[0217] [Resin characteristics and uses] (characteristic) The Abbe number νD of the polyester resin at a temperature of 20°C is, for example, 28 to 55, preferably 28 to 45, 28.5 to 40, and 29 to 38 in the following stepwise ranges. The Abbe number νD is also preferably 30 to 43, 33 to 40, 34 to 39, and 35 to 38 in the following stepwise ranges, and these ranges may be the ranges for resin (P1). The Abbe number νD is also preferably 28 to 37, 28 to 35, 29 to 33, and 29.5 to 31 in the following stepwise ranges, and these ranges may be the ranges for resin (P2). The Abbe number νD is also preferably 28 to 38, 29 to 37, 30 to 36, 31 to 35, and 32 to 34 in the following stepwise ranges, and these ranges may be the ranges for resin (P3).

[0218] The refractive index nD of the polyester resin may be selected from the range of, for example, about 1.54 or more, specifically 1.55 or more, at a temperature of 20°C and a wavelength of 589 nm, and is preferably in the following stepwise order: 1.55 to 1.61, 1.555 to 1.6, 1.56 to 1.595 (for example, 1.56 to 1.59), 1.565 to 1.595 (for example, 1.57 to 1.585), 1.57 to 1.59 (for example, 1.575 to 1.585), and 1.58 to 1.59.

[0219] As will be described later in the Examples section, the birefringence of a polyester resin may be evaluated by measuring the birefringence (3-fold birefringence or birefringence when stretched 3 times) of a stretched film obtained by uniaxially stretching a film formed from the resin alone under predetermined conditions [stretching temperature (glass transition temperature Tg + 10) °C, stretching speed 25 mm / min, stretching ratio 3 times]. The absolute value of the 3-fold birefringence is, for example, 55 × 10 at a measurement temperature of 20 °C and a wavelength of 600 nm. -4 or less (e.g., 0 to 50 × 10 -4 ) range, and when used for applications such as optical lenses, the range is preferably in the following steps: 45×10 -4 Below, 40 x 10 -4 Below, 35 x 10 -4 Below, 30 x 10 -4 Below, 25 x 10 -4 Below, 20 x 10 -4 Below, 15 x 10 -4 Below, 10 x 10-4 Below, 5 x 10 -4 Below, 3 x 10 -4 or less. When the absolute value of the triple birefringence is low, the deterioration of imaging performance can be suppressed even when the film is small, thin, or has a complex shape, and therefore the film can be effectively used as an optical lens. Furthermore, even when the film is thinned by stretching or the like, birefringence or retardation is unlikely to occur in the in-plane direction, and therefore the film can be effectively used as an optical film such as a polarizing plate protective film or a retardation film (for example, a retardation film with a retardation of almost 0). Note that the lower limit of the range of the absolute value of the triple birefringence may be 0 or more, but may be, for example, 0.1 × 10 -4 That's it, 1 x 10 -4 That's it, 10 x 10 -4 The above may also be possible.

[0220] The glass transition temperature Tg of the polyester resin may be, for example, about 80 to 200°C, and preferably the following stepwise range: 100 to 180°C, 110 to 170°C, 120 to 167°C, 125 to 165°C, 130 to 163°C, 135 to 162°C, 140 to 160°C, and 145 to 155°C. If the Tg is in an appropriate range that is not too low, discoloration (or coloring) during production and / or use due to a decrease in heat resistance tends to be easily suppressed, and deformation in a high-temperature environment after molding into a predetermined shape tends to be easily suppressed. If the Tg is in an appropriate range that is not too high, a decrease in moldability or productivity (particularly injection moldability) tends to be easily suppressed.

[0221] The weight-average molecular weight Mw of the polyester resin, calculated in terms of standard polystyrene, may be, for example, about 5,000 to 200,000, and preferably ranges in the following stepwise order: 10,000 to 100,000, 20,000 to 80,000, 30,000 to 70,000, and 35,000 to 65,000. When the weight-average molecular weight Mw is within an appropriate range that is not too low, there is a tendency for deterioration in moldability (productivity) to be easily suppressed, and applications are less likely to be limited.

[0222] In this specification and claims, the Abbe number vD, refractive index nD, triple birefringence, glass transition temperature Tg, and weight average molecular weight Mw can be measured by the methods described in the examples below.

[0223] The polyester resin may be crystalline (crystalline polymer), but is preferably amorphous (amorphous polymer), particularly for use in optical components such as optical lenses.

[0224] (Resin composition and molded article thereof) The resin composition of the present disclosure contains at least the polyester resin of the present disclosure, and may or may not contain other components different from the resin of the present disclosure, as necessary. Examples of other components include other resins different from the resin of the present disclosure, conventional additives, and the like.

[0225] The resin other than the resin of the present disclosure may be a conventional curable resin, but is preferably a thermoplastic resin. Examples of the thermoplastic resin include polyolefin resins (such as linear or cyclic olefin resins); styrene resins (such as polystyrene (PS) or styrene copolymers (including rubber-containing styrene resins (or rubber-grafted styrene copolymers) such as high impact polystyrene (HIPS) and ABS resins)); (meth)acrylic resins (such as homopolymers or copolymers of (meth)acrylic monomers); vinyl acetate resins (including polyvinyl alcohol (PVA) and polyvinyl acetal); vinyl chloride resins (such as homopolymers or copolymers of vinyl chloride and / or vinylidene chloride); fluororesins; polyester resins other than the resin of the present disclosure (such as polyalkylene arylate resins, polyarylate resins, and liquid crystalline polyesters); polycarbonate resins (PC), specifically, bis(2-methyl-2-methyl-1,2-diol). Examples include bisphenol-type polycarbonate resins such as phenol A type; polyamide-type resins (PA) [aliphatic polyamide resins, aromatic polyamide resins (aramid resins)]; polyacetal resins (POM); polyphenylene ether resins (PPE); polyphenylene sulfide resins (PPS); polysulfone-type resins [polysulfone resins (PSF), polyethersulfone (PES)]; polyetherketone-type resins [polyetherketone resins (PEK), polyetheretherketone resins (PEEK), polyetherketoneetherketoneketone (PEKEKK)]; phenoxy resins; polyketone resins; cellulose derivatives (cellulose esters, cellulose ethers, etc.); thermoplastic polyimide resins; polyethernitrile resins; and thermoplastic elastomers (TPE).

[0226] These other resins may be contained alone or in combination. If necessary, the resin of the present disclosure may form a polymer alloy with other resins. The polymer alloy may also contain a compatibilizer.

[0227] The proportion of the polyester-based resin of the present disclosure may be, for example, about 10% by mass or more relative to all resin components in the resin composition (total amount of the polyester-based resin of the present disclosure and other resins), and is preferably 30% by mass or more, 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, and 100% by mass in the following stepwise manner.

[0228] The resin composition may contain various conventional additives, as needed, such as fillers or reinforcing agents, colorants such as dyes and pigments, conductive agents, flame retardants, flame retardant assistants, plasticizers, lubricants, stabilizers, release agents, antistatic agents, dispersants, compatibilizers, flow control agents, leveling agents, antifoaming agents, surface modifiers, stress reducers, and carbon materials. Examples of the stabilizers include antioxidants, ultraviolet absorbers, and heat stabilizers. These additives may be used alone or in combination.

[0229] The total proportion of these additives may be, for example, 50 parts by mass or less, preferably 30 parts by mass or less, 0 to 10 parts by mass, or about 0.1 to 5 parts by mass, stepwise, relative to 100 parts by mass of the resin component in the resin composition.

[0230] The resin composition can be prepared by mixing the polyester resin of the present disclosure and, if necessary, other components by a conventional method such as dry mixing or melt kneading, and the resin composition may be in the form of pellets or the like.

[0231] The present disclosure encompasses a molded article comprising at least the resin of the present disclosure (or the resin composition of the present disclosure). The shape of the molded article is not particularly limited and may be selected depending on the application. For example, the molded article may be in the form of a pellet, a one-dimensional structure such as a linear (fiber or thread) or rod shape, a two-dimensional structure such as a film, sheet, or plate shape, a lens shape such as a block, a concave or convex lens shape, or a three-dimensional structure such as a hollow (tubular or tubular) shape, or a composite or complex shape that combines these shapes. The molded article has a good balance of excellent optical properties and can therefore be effectively used as optical components such as optical films (optical sheets) and optical lenses, particularly optical lenses.

[0232] The molded article can be produced by a conventional molding method, such as injection molding, injection compression molding, extrusion molding, transfer molding, blow molding, compression molding, pressure molding, casting molding, calendering, or foam molding.

[0233] When molding into a lens shape, for example, the molding may be performed by compression molding, injection molding, injection compression molding, transfer molding, pressure molding, or the like.

[0234] When molding into a film, the resin composition can be formed into a film (or molded) by a conventional film-forming method such as a casting method (solvent casting method), a melt extrusion method, or a calendar method.

[0235] The average thickness of the film can be selected from the range of about 1 to 1000 μm depending on the application, and is, for example, 1 to 200 μm, preferably 5 to 150 μm, and more preferably 10 to 120 μm.

[0236] The film may be unstretched or stretched, and even if stretched, it can maintain low birefringence. Such stretched films may be either uniaxially stretched or biaxially stretched.

[0237] The stretching ratio in each direction in uniaxial or biaxial stretching is, for example, 1.1 to 10 times, preferably 1.2 to 8 times, and more preferably 1.5 to 6 times. In the case of biaxial stretching, equal stretching, for example, 1.5 to 5 times stretching in both the longitudinal and transverse directions, or unbalanced stretching, for example, 1.1 to 4 times stretching in the longitudinal direction and 2 to 6 times stretching in the transverse direction, may be used. In the case of uniaxial stretching, 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, may be used.

[0238] The average thickness of the stretched film is, for example, 1 to 150 μm, preferably 3 to 120 μm, and more preferably 5 to 100 μm.

[0239] Such a stretched film can be obtained by stretching a film (or an unstretched film) after film formation. The stretching method is not particularly limited, and in the case of uniaxial stretching, either a wet stretching method or a dry stretching method may be used, and in the case of biaxial stretching, either a tenter method (flat method) or a tube method may be used, although the tenter method, which has excellent uniformity in stretched thickness, is preferred.

[0240] The molded article may also be a composite molded article comprising the resin (or resin composition) of the present disclosure and other constituent members. The proportion of the resin composition of the present disclosure in the molded article is not particularly limited and may be, for example, about 10 to 100 mass %, or about 20 to 80 mass %. [Example]

[0241] The present disclosure will be described in more detail below based on examples, but the present disclosure is not limited to these examples. Details of evaluation items and raw materials are shown below.

[0242] [Evaluation method] (HPLC) The sample was dissolved in acetonitrile and measured using an HPLC (high performance or high performance liquid chromatograph) device "LC-2030" or "LC-2010A HT" manufactured by Shimadzu Corporation and an "ODS-80™" manufactured by Tosoh Corporation as the column, and the HPLC purity [area %] was calculated.

[0243] ( 1 H-NMR) The sample was dissolved in a heavy solvent containing tetramethylsilane as an internal standard, and the NMR spectrum was analyzed using a nuclear magnetic resonance spectrometer (BRUKER "AVANCE III HD"). 1 H-NMR spectrum was measured.

[0244] (molecular weight) The samples were dissolved in chloroform (Examples 1 to 6) or tetrahydrofuran (THF) (Examples 7 to 9, Reference Examples 4 to 6), and the weight average molecular weight Mw in terms of standard polystyrene was determined using gel permeation chromatography ("HLC-8320GPC" manufactured by Tosoh Corporation).

[0245] (glass transition temperature Tg) Measurement was performed using a differential scanning calorimeter ("EXSTAR6000 DSC6220 ASD-2" manufactured by SII NanoTechnology Inc.) in a nitrogen atmosphere at a temperature increase rate of 10°C / min in accordance with JIS K 7121. The Tg value read from the obtained chart as the midpoint glass transition temperature (Tmg) was used.

[0246] (Refractive index nD) The samples were heat-pressed at 200 to 240°C (Examples 1 to 6, Reference Examples 1 to 3) or 140 to 250°C (Examples 7 to 9, Reference Examples 4 to 6) to form films with thicknesses of 200 to 300 μm. These films were cut into strips measuring 20 to 30 mm in length and 10 mm in width to obtain test pieces. The refractive index nD of the obtained test pieces at 589 nm (D line) was measured using a multi-wavelength Abbe refractometer (manufactured by Atago Co., Ltd., "DR-M4 (circulating constant temperature water bath 60-C3)") at a measurement temperature of 20°C and 1-bromonaphthalene as the contact liquid.

[0247] (Abbe number) Using the test piece for which the refractive index nD at 589 nm (D line) was measured, the refractive indices nF and nC were measured in the same manner as for the refractive index nD, except that the measurement wavelengths were changed to 486 nm (F line) and 656 nm (C line). The Abbe number was calculated from the refractive indices nF, nD, and nC at each wavelength using the following formula. (Abbe number) = (nD-1) / (nF-nC)

[0248] (3x birefringence (birefringence when stretched 3x)) The samples were heat-pressed at 200-280°C to form films with thicknesses of 200-600 μm. These films were cut into strips measuring 10 mm long and 50 mm wide and stretched uniaxially (free-end uniaxial stretching) at a temperature of glass transition temperature (Tg) + 10°C at a stretch ratio of 3 at 25 mm / min. The retardation was measured using a phase contrast film and optical material testing device (Otsuka Electronics Co., Ltd., "RETS-100") at a temperature of 20°C and a wavelength of 600 nm by the rotating analyzer method. The birefringence (or triple birefringence) was calculated by dividing the value by the thickness of the measurement site.

[0249] [Polymerization component] (Diol component) Compounds (1a) and (1b): a mixture (isomer mixture) of a compound (DHDBIM) represented by the following formula (1a) and a compound (DHDFM) represented by the following formula (1b) Compound (1a): A compound (DHDBIM) represented by the following formula (1a) BPEF: 9,9-bis[4-(2-hydroxyethoxy)-phenyl]fluorene BDPPEF: 9,9-bis[4-(2-hydroxyethoxy)-3,5-diphenylphenyl]fluorene, synthesized according to Synthesis Example 1 below. EG: Ethylene glycol ISB: Isosorbide SPG: spiroglycol [or 3,9-bis(2-hydroxy-1,1-dimethylethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane] CHDM: 1,4-cyclohexanedimethanol (cis-trans mixture) (Dicarboxylic acid component) FDP-m: 9,9-bis(2-methoxycarbonylethyl)fluorene, synthesized in the same manner as in Example 1 of JP-A-2005-89422, except that methyl acrylate [37.9 g (0.44 mol)] was used instead of t-butyl acrylate. 2-NFDP-m: 2-(2-naphthyl)-9,9-bis(2-methoxycarbonylethyl)fluorene, synthesized according to Synthesis Example 2 below DNFDP-m: 9,9-bis(2-methoxycarbonylethyl)-2,7-di(2-naphthyl)fluorene, synthesized according to Example 1B of WO 2020 / 213470 DMCD: dimethyl cyclohexane-1,4-dicarboxylate (trans / cis (molar ratio) = 98 / 2)

[0250] The structural formula of each resin raw material (polymer component) is shown below.

[0251] [ka]

[0252] [Synthesis Example 1] (BDPPF synthesis)

[0253] [ka]

[0254] A separable flask was charged with 8.1 g (45 mmol) of 9-fluorenone, 33.3 g (135 mmol, 3.0 eq), 90.8 g of toluene, 5.1 g (26.8 mmol) of p-toluenesulfonic acid monohydrate, and 0.5 g (2.5 mmol) of dodecanethiol. The mixture was stirred under reflux conditions (115-127 °C). The end point was the disappearance of the 9-fluorenone peak by HPLC. After cooling to 80 °C, 23 g of dimethylformamide (DMF) and 90 g of toluene were added to dissolve the mixture homogeneously. The resulting solution was washed with ion-exchanged water and drained. This washing procedure was repeated three times. The resulting organic layer was concentrated under reduced pressure and crystallized from methanol and toluene to obtain 9,9-bis(3,5-diphenyl-4-hydroxyphenyl)fluorene (BDPPF) with a purity of 98.9% and a yield of 45.2%.

[0255] (Synthesis of BDPPEF)

[0256] [ka]

[0257] A separable flask was charged with 45.8 g (70 mmol) of BDPPF, 14.8 g (168 mmol) of ethylene carbonate, 4.8 g (35 mmol) of potassium carbonate, and 51.2 g of dimethylformamide, and the mixture was stirred and reacted at 125 to 130°C for 2 hours. 42 g of 24% by mass aqueous sodium hydroxide solution and 105 g of methyl isobutyl ketone (MIBK) were added, and the aqueous layer was removed. The resulting organic layer was then washed with 35 g of ion-exchanged water. This water washing procedure was repeated three times, and the organic layer was concentrated under reduced pressure to remove the solvent. After concentration, the mixture was crystallized from methanol to obtain white crystals of 9,9-bis[4-(2-hydroxyethoxy)-3,5-diphenylphenyl]fluorene (BDPPEF) in a 79% yield and 98.9% purity.

[0258] 1 H NMR (300MHz, CDCl3): δ(ppm)3.1-3.3(8H,m), 7.2-7.5(30H,m), 7.7-7.8(2H,d)

[0259] [Synthesis Example 2] (Synthesis of BrFDP-m)

[0260] [ka]

[0261] A reaction vessel equipped with a stirrer, reflux condenser, and thermometer was charged with 73.5 g (300 mmol) of 2-bromo-9H-fluorene (Tokyo Chemical Industry Co., Ltd.) and 420 g of methyl isobutyl ketone (MIBK) under a nitrogen atmosphere. The mixture was heated to 50 ° C and dissolved. A mixed solvent of 6.3 g of a 40% by weight methanol solution of trimethylbenzylammonium hydroxide (Tokyo Chemical Industry Co., Ltd., "Triton B") and 58 g of MIBK was added dropwise, followed by 56.9 g (660 mmol) of methyl acrylate, and the mixture was stirred at 50 ° C for 2 hours. After completion of the reaction, the mixture was washed twice with water, and the solvent MIBK was removed from the resulting organic layer by vacuum concentration (80 ° C, vacuum). Methanol was then added while maintaining the temperature at 60 ° C to form a homogeneous solution, and the temperature was gradually lowered to precipitate crystals. The obtained white crystals were 9,9-bis(2-methoxycarbonylethyl)-2-bromofluorene (BrFDP-m) represented by the above formula, and the yield was 103 g (yield: 82%, HPLC purity: 99 area %).

[0262] 1 H NMR (300MHz, CDCl3): δ(ppm)1.5-1.6(4H,t), 2.4(4H,m), 3.5(6H,s), 7.3(3H,m), 7.5(2H,d), 7.6(1H,d), 7.7(1H,m)

[0263] (Synthesis of 2-NFDP-m)

[0264] [ka]

[0265] A reaction vessel equipped with a stirrer, reflux condenser, and thermometer was charged with 91.8 g (220 mmol) of the above BrFDP-m, 41.6 g (242 mmol) of 2-naphthylboronic acid, 1013 g of toluene, and 323.2 g of 2 M aqueous sodium carbonate solution (572 mmol in terms of Na2CO3). After stirring, 25 mg (0.11 mmol) of palladium acetate and 58 mg (0.22 mmol) of triphenylphosphine were added. The mixture was heated to 80 °C under a nitrogen atmosphere and stirred for 6 hours. After confirming the disappearance of the raw materials, the aqueous layer was removed. The resulting organic layer was washed three times with 365 mL of ion-exchanged water. After draining, the organic layer was treated with powdered activated carbon (Osaka Gas Chemicals Co., Ltd., "Special Shirasagi") to remove the palladium, and insoluble matter was removed by filtration. The resulting organic layer was concentrated to remove 814 g of toluene, and then 200 g of isopropyl alcohol (IPA) was added. The mixture was cooled to below 10°C with ice water and stirred for 1 hour to precipitate crystals. The precipitated crystals were filtered and dried under reduced pressure to obtain 93 g of 2-NFDP-m as white crystals (yield: 91%, HPLC purity: 99.8% area).

[0266] 1 H-NMR (CDCl3, 300MHz): δ(ppm)1.6-1.7(4H,m), 2.5(4H,m), 3.4(6H,s), 7.4(3H,m), 7.5-7.6(2H,t), 7.7-8.0(8H,m), 8.1(1H,s)

[0267] [Reference example 1] A reaction vessel was charged with DMCD as the dicarboxylic acid component and compounds (1a) and (1b) as the diol components in the proportions shown in Table 1. Titanium (IV) tetrabutoxide [3.7 mg, 11 μmol (157 μmol per 1 mol of dicarboxylic acid component)] was added as a catalyst for the transesterification and polycondensation reactions. The mixture was gradually heated to 220°C under a nitrogen gas atmosphere and stirred to carry out the transesterification reaction. After removing the alcohol component produced by the transesterification reaction, the temperature was gradually raised to 260°C and the pressure was reduced to 130 Pa, and the polycondensation reaction was carried out until the specified stirring torque was reached. After the reaction was completed, the contents were removed from the reactor to obtain a polyester resin.

[0268] [Example 1] A reactor was charged with FDP-m and DMCD as dicarboxylic acid components, compounds (1a) and (1b) as diol components, and EG in the proportions shown in Table 1. Titanium (IV) tetrabutoxide [7.5 mg, 22 μmol (183 μmol per 1 mol of dicarboxylic acid component)] was added as a catalyst for the transesterification and polycondensation reactions. The mixture was gradually heated to 240 °C under a nitrogen gas atmosphere and stirred to carry out the transesterification reaction. After removing the alcohol component produced by the transesterification reaction, dibutyl phosphate [14.3 mg, 68 μmol (567 μmol per 1 mol of dicarboxylic acid component)] was added as a thermal stabilizer. The temperature was gradually raised to 280 °C and the pressure was reduced to 130 Pa. The polycondensation reaction was carried out while removing EG until the specified stirring torque was reached. After the reaction was completed, the contents were removed from the reactor to obtain a polyester resin.

[0269] [Examples 2 to 6 and Reference Examples 2 to 3] A polyester resin was obtained in the same manner as in Example 1, except that the dicarboxylic acid component and the diol component were charged in the ratios shown in Table 1.

[0270] [Table 1]

[0271] The polymer composition ratios [proportions (molar ratios) of constituent units derived from each polymerization component used in the preparation] of each polyester resin obtained in the Examples and Reference Examples and the evaluation results of each physical property value are shown in Table 2 below. 1 The peaks in the H-NMR spectrum overlapped, making it difficult to accurately calculate the polymer composition ratio. However, since there were no highly volatile monomer components other than EG and no sublimation of by-products was confirmed during polymerization, the polymer composition ratio is estimated to be approximately the same as that shown in Table 2 below, based on the polymerization conditions such as the feed ratio and reaction method.

[0272] [Table 2]

[0273] As is clear from the results in Table 2, all of the Examples not only exhibited a medium Abbe number, but also had a high refractive index and low birefringence, and were excellent in heat resistance and moldability, thereby satisfying all properties in a well-balanced manner. Among the Examples, Examples 4 and 6 are preferred in terms of high refractive index or high heat resistance, and Examples 1, 4, and 6 are preferred in terms of low birefringence, with Examples 4 and 6 (especially Example 4) being particularly preferred in that they were able to satisfy all of the medium Abbe number, high refractive index, low birefringence, and heat resistance in an even better balance.

[0274] On the other hand, the Abbe number was high and the refractive index was low in Reference Example 1. Reference Examples 2 and 3 also had low refractive indices, and compared to Reference Example 1, they had high birefringence and low heat resistance (glass transition temperature Tg), probably because they contained units derived from EG.

[0275] [Example 7] The diol components (1a), (1b), and EG, along with the dicarboxylic acid component (FDP-m) were charged to a reactor in the proportions shown in Table 3. Manganese acetate tetrahydrate was added as a catalyst for the transesterification reaction at a ratio of 0.22 mmol per mole of dicarboxylic acid component. The mixture was gradually heated and melted with stirring, and the temperature was raised to 250°C. After that, trimethyl phosphate (0.54 mmol per mole of dicarboxylic acid component) and germanium dioxide (GeO2) (2.60 mmol per mole of dicarboxylic acid component) were added. The temperature was gradually raised to 275°C and the pressure was reduced to 0.13 kPa or less, and the EG was removed while the pressure was reduced. After the predetermined stirring torque was reached, the contents were removed from the reactor, and the polyester resin was obtained.

[0276] [Examples 8 to 9 and Reference Examples 4 to 6] A polyester resin was obtained in the same manner as in Example 7, except that the diol component and the dicarboxylic acid component were charged in the ratios shown in Table 3.

[0277] [Table 3]

[0278] The polymer composition ratios [proportions (molar ratios) of constituent units derived from each polymerization component used in the preparation] of each polyester resin obtained in the Examples and Comparative Examples and the evaluation results of each physical property value are shown in Table 4 below. 1 The peaks in the H-NMR spectrum overlapped, making it difficult to accurately calculate the polymer composition ratio. However, since there were no highly volatile monomer components other than EG and no sublimation of by-products was observed during polymerization, the polymer composition ratio is estimated to be approximately the same as that shown in Table 4 below, based on the polymerization conditions such as the feed ratio and reaction method.

[0279] [Table 4]

[0280] As is clear from the results in Table 4, all of the examples not only exhibited a medium Abbe number, but also had a high refractive index, low birefringence, and excellent heat resistance and moldability, thereby satisfying all of the properties in a well-balanced manner.

[0281] On the other hand, in Reference Examples 4 to 6, which contained diol units having an alicyclic skeleton different from a pentacycloalkane skeleton, the properties could not be balanced and satisfied.

[0282] For example, in Reference Examples 4 to 6, all of them had low Tg and low heat resistance. Moreover, in Reference Example 4, the mechanical properties were low, probably because a high molecular weight product was not obtained, and it was difficult to prepare a test piece. Note that in Reference Example 5, although it was a high molecular weight product, the mechanical properties were low, probably because it contained a spirocyclic skeleton, and it was difficult to prepare a test piece as in Reference Example 4. While it was difficult to prepare test pieces in Reference Examples 4 and 5, which have polycyclic alicyclic skeletons, in the Examples, despite having a pentacycloalkane skeleton with a larger number of rings and a rigid chemical structure, it was unexpectedly possible to prepare predetermined test pieces, and furthermore, the moldability (or mechanical properties) were excellent enough to allow stretching.

[0283] On the other hand, Reference Example 6 having a monocyclic alicyclic skeleton had some moldability, but broke during stretching when measuring the triple birefringence. Furthermore, Reference Example 6 had lower heat resistance (glass transition temperature Tg) than Reference Examples 4 and 5. [Industrial Applicability]

[0284] The polyester resin of the present disclosure may be used in various applications, such as coating agents or coating films, specifically, protective films for paints, inks, electronic devices, liquid crystal components, and the like; adhesives, pressure-sensitive adhesives; resin fillers; electric and electronic materials or electric and electronic components (electrical and electronic devices), specifically, antistatic agents, carrier transport agents, light-emitting bodies, organic photoreceptors, thermosensitive recording materials, photochromic materials, hologram recording materials, charging trays, conductive sheets, optical disks, inkjet printers, digital paper, color filters, organic EL elements, organic semiconductor lasers, dye-sensitized solar cells, sensors, EMI shielding films, and the like; and mechanical materials or mechanical parts (equipment), specifically, automotive materials or parts, aerospace-related materials or parts, sliding members, and the like.

[0285] The polyester resin of the present disclosure can be particularly effectively used as an optical component, such as an optical film (optical sheet) for liquid crystal displays or organic electroluminescence displays, an optical lens for eyeglasses or cameras, a prism, a hologram, or an optical fiber.

[0286] Examples of optical films include polarizing films, polarizing elements and polarizing plate protective films that constitute polarizing films, retardation films, alignment films (alignment films), viewing angle widening (compensation) films, diffuser plates (films), prism sheets, light guide plates, brightness enhancement films, near-infrared absorbing films, reflective films, anti-reflection (AR) films, reflection reducing (LR) films, anti-glare (AG) films, transparent conductive (ITO) films, anisotropic conductive films (ACF), electromagnetic shielding (EMI) films, films for electrode substrates, films for color filter substrates, barrier films, color filter layers, black matrix layers, and adhesive layers or release layers between optical films. These optical films can be effectively used as optical films for displays such as liquid crystal displays (LCDs), organic light-emitting diode displays (OLEDs), plasma displays (PDPs), field emission displays (FEDs), and electronic paper.Specific devices or apparatus (electronic devices such as electronic terminals) include televisions; personal computers (PCs) such as desktop PCs, notebook PCs, and tablet PCs; smartphones, mobile phones; car navigation systems; and devices or apparatus (electronic devices such as electronic terminals) equipped with flat panel displays (FPDs) such as touch panels.

[0287] Examples of optical lenses include eyeglass lenses, contact lenses, camera lenses, VTR zoom lenses, pickup lenses, Fresnel lenses, solar concentrating lenses, objective lenses, and rod lens arrays, and the optical lenses may be particularly suitable for use as optical lenses for cameras, etc. Typical devices or apparatuses in which such optical lenses are mounted include devices with camera functions (particularly small devices or mobile devices) such as smartphones, mobile phones, digital cameras, tablet terminals, and personal computers (PCs); and in-vehicle cameras such as drive recorders and backup cameras (rear cameras).

Claims

1. A polyester-based resin comprising a diol unit (A) and a dicarboxylic acid unit (B), wherein the diol unit (A) comprises a diol unit (A1) having a pentacycloalkane skeleton, and further comprising a structural unit having a fluorene skeleton.

2. The polyester resin according to claim 1, wherein the diol unit (A1) is a structural unit represented by the following formula (1): 【Chemistry 1】 (In the formula, Z １ represents a pentacycloalkane ring, R １ represents a substituent, m1 represents an integer of 0 or more, A １ａ and A １ｂ each independently represents a direct bond or an alkylene group.

3. 3. The polyester resin according to claim 1, wherein the diol unit (A) contains a diol unit (A2) represented by the following formula (2) as the structural unit having a fluorene skeleton: 【Chemistry 2】 (In the formula, R ２ represents a substituent, m2 represents an integer of 0 to 8, Z ２ａ and Z ２ｂ each independently represents an arene ring, R ３ａ and R ３ｂ each independently represents a substituent; m3a and m3b each independently represents an integer of 0 or more; A ２ａ and A ２ｂ each independently represents an alkylene group, and n2a and n2b each independently represent an integer of 0 or more.

4. In the formula (2), Z ２ａ and Z ２ｂ The polyester resin according to claim 3 , wherein each independently represents a polycyclic arene ring.

5. 4. The polyester resin according to claim 3, wherein the ratio of the diol units (A1) to the diol units (A2) (molar ratio) is 50 / 50 to 90 / 10.

6. The polyester resin according to claim 1 or 2, wherein the diol unit (A) includes a diol unit (A3) represented by the following formula (3): 【Transformation 3】 (In the formula, A ３ represents an alkylene group, and n3 represents an integer of 1 or more.

7. 7. The polyester resin according to claim 6, wherein the ratio of the diol units (A1) to the diol units (A3) (molar ratio) is 50 / 50 to 90 / 10.

8. The polyester resin according to claim 1 or 2, wherein the dicarboxylic acid unit (B) includes a dicarboxylic acid unit (B1) that is an alicyclic dicarboxylic acid unit.

9. 3. The polyester resin according to claim 1, wherein the dicarboxylic acid unit (B) contains a dicarboxylic acid unit (B2) represented by the following formula (5) as the structural unit having a fluorene skeleton: 【Chemistry 4】 (In the formula, R ５ represents a substituent, m5 represents an integer of 0 to 8, A ５ａ and A ５ｂ each independently represents an alkylene group.

10. In the formula (5), R ５ The polyester resin according to claim 9, wherein m5 represents an integer of 0 to 4.

11. The dicarboxylic acid unit (B1) according to claim 8 is contained, 10. The polyester resin according to claim 9, wherein the ratio of the dicarboxylic acid units (B1) to the dicarboxylic acid units (B2) (molar ratio) is 15 / 85 to 80 / 20.

12. The diol unit (A) contains a diol unit (A2) represented by formula (2) according to claim 3 and a diol unit (A3) represented by formula (3) according to claim 6, In the formula (2), Z ２ａ and Z ２ｂ independently represent a ring-assembled arene ring, The polyester resin according to claim 1 or 2, wherein the dicarboxylic acid unit (B) comprises the dicarboxylic acid unit (B1) according to claim 8.

13. 3. The polyester resin according to claim 1, wherein the Abbe number νD is 28 to 55.

14. The refractive index nD is 1.55 or more, The absolute value of birefringence of the stretched film uniaxially stretched under the stretching conditions of a stretching temperature (glass transition temperature Tg + 10) ° C., a stretching speed of 25 mm / min, and a stretching ratio of 3 times is 55 × 10 at a wavelength of 600 nm. －４ is as follows: The weight average molecular weight Mw is 10,000 to 100,000, 3. The polyester resin according to claim 1, wherein the glass transition temperature Tg is 100 to 180°C.

15. A method for producing a polyester resin by polymerizing a diol component (A) containing a diol component (A1) having a pentacycloalkane skeleton and a polymerization component containing a dicarboxylic acid component (B), comprising: The method for producing a polyester resin according to claim 1 or 2, wherein the polymerization components further comprise a polymerization component having a fluorene skeleton.

16. A molded article comprising the polyester resin according to claim 1 or 2.

17. The molded article according to claim 16, which is an optical element.

18. The molded article according to claim 16, which is an optical lens.

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