Dibenzothiophene-substituted aromatic compounds and thermoplastic resins prepared therefrom

Abstract

The present invention relates to the use of a compound of the formula (I) where X1 and X2, independently of each other, are a bond or C1—C5—aIkanediyI; Z1 and Z2, independently of each other, are OH or C(O)ORx, where Rx is selected from the group consisting of hydrogen, C1—C4—alkyl, phenyl and benzyl; one or two of Ra, Rb, Rc and Rd are a dibenzothiophene radical of the formula (II) where # denotes the attachment point to the remainder of the molecule as a monomer for preparing polymers; and to certain compounds of the formula (I) per se. The present invention also relates to a thermoplastic resin comprising a structural unit represented by formula (III) where # represents a connection point to a neighboring structural unit; Z11 is a bridging group —O— or —C(O)—O—, where the carbon atom of the group —C(O)—O— is bound to X1; Z12 is a bridging group —O— or —C(O)—O—, where the carbon atom of the group —C(O)—O— is bound to X2; and X1, X2, Ra, Rb, Rc and Rd are as defined above.

Description

[0001] DESCRIPTION

[0002] Title of Invention: Dibenzothiophene-substituted aromatic compounds and thermoplastic resins prepared therefrom

[0003] The present invention relates to the use of aromatic compounds of the formula (I) as defined below carrying one or two dibenzothiophene radicals and moreover two directly or indirectly bound hydroxyl or carboxy I (ate) groups as monomers for preparing polymers, especially thermoplastic resins, and in particular polycarbonates, polyesters or polyestercarbonates, to polymers, especially thermoplastic resins, and in particular polycarbonates, polyesters or polyestercarbonates, containing such monomers in polymerized (polycondensed) form and to certain aromatic compounds of the formula (I) per se.

[0004] TECHNICAL BACKGROUND

[0005] Optical devices, such as optical lenses made of optical resin instead of op- tical glass, are advantageous in that they can be produced in large numbers by injection molding. Nowadays, optical resins, in particular, transparent polycarbonate resins, are frequently used for producing camera lenses. In this regard, resins with a higher refractive index are highly desirable, as they allow for reducing the size and weight of final products. In general, when using an optical material with a higher refractive index, a lens element of the same refractive power can be achieved with a surface having less cur- vature, so that the amount of aberration generated on this surface can be re- duced. As a result, it is possible to reduce the number of lenses, to reduce the eccentric sensitivity of lenses and / or to reduce the lens thickness to thereby achieve weight reduction.

[0006] WO 2010 / 004877 relates to an organic electroluminescence element containing a plurality of organic layers, and containing independently a compound of the formula (1) in at least one layer of the organic layer. X in formula (1) can be inter alia a phenylene or naphthylene group; these are however not substituted. Moreover, this reference does not disclose polymers containing such com- pounds.

[0007] JP 2019-016809 relates to a method for sublimating and purifying a host mate- rial for organic electroluminescent devices and to a host material purified by said method of sublimation and purification. Among several others, a com- pound of the formula (4-2) is listed as suitable host material, f is 1 to 4, and R8can be a variety of substituents, where however at least one of R8represents a carbazolyl group or a dibenzothiophenyl group of the formula (5) : where X is N or S. Other possible meanings for R8are halogen, alkoxy, cyano, nitro, alkyl, aryl, a heterocyclic group, and a substituent represented by the general formula (5). Hydroxyl- or carboxyl (ate) -containing substituents R8are not mentioned. Nor are such compounds suitable as monomers for preparing polycarbonates or polyesters.

[0008] JP 1997-071642 (JPH09771642) relates to polycarbonate resins useful as electrophotographic photoreceptors and containing a structural unit of the formula (I): where Ar1, Ar3, Ar4, Ar5and Ar6are independently a substituted or unsubstituted arylene group, and Ar2and Ar7are independently a substituted or unsubstituted aryl group. The polycarbonate resin may moreover comprise a constitutional unit represented by the general formula (II): where X can be inter alia a divalent aromatic group. For the case that X has this meaning, 3, 6-di hydroxydibenzothiophene is mentioned among numerous others as suitable diol.

[0009] W0 2022 / 245079 relates to polymer resins, especially polyesters or polycarbonates, comprising repeat units of the following formula: where Ar1 and Ar2 can be inter alia a heteroaryl group, X1 to X4 are O or S, Z1 and Z2 are inter alia an alkylene group, and a and b are an integer from 1 to 10. 2, 5-Di-(dibenzothiophen-2-yl)-benzene-1, 4-diol is used as an intermediate in the synthesis of a certain monomer (monomer 5) used for preparing a polymer resin. 2, 5-Di-(dibenzothiophen-2-yl)-benzene-1, 4-diol itself is however not used as a monomer.

[0010] GN 110790771 relates to compounds based on di th ioindole fluorene units and their use in organic light-emitting diodes. In the multi-step synthesis of such di thio indole fluorenes, dimethyl 2, 5-di (dibenzothiophen-2-yl)benzene- 1, 4— d i carboxy late is mentioned as an intermediate.

[0011] Despite the advances made in the field of optical resins, there is mono oing need for monomers for preparing optical resins, in particular poly- carbonate resins and polyester resins, which monomers result in a high re- fractive index and which are therefore useful for making optical devices, in particular lenses. Apart from that, the monomers should not impair the other optical properties of the optical resins, such as low Abbe’s number, a high degree of transparency and low birefringence. Moreover, the monomers should be easy to prepare. In addition, the resins, in particular polyesters and polycarbonates, obtained from these monomers should have good moisture and heat resistance and they should have a glass transition temperature suitable for injection molding.

[0012] SUMMARY OF THE INVENTION

[0013] These objectives are achieved by monomeric compounds of the formula (I), which are suitable for preparing polymers, to be more precise thermoplastic resins, especially polycarbonates, polyesters and mixed forms thereof (i.e. polyestercarbonates), which are in turn useful for preparing optical devices.

[0014] The present invention relates thus to the use of a compound of the formula (I) where

[0015] X1and X2, independently of each other, are a bond or C1— C5— a I kaned i y I ; Z1and Z2, independently of each other, are OH or C(O)ORx, where

[0016] Rxis selected from the group consisting of hydrogen, C1-C4-alky I, phenyl and benzyl ; one or two of Ra, Rb, Rcand Rdare a dibenzothi ophene radical of the formula (II) : where # denotes the attachment point to the remainder of the molecule; and the other two or three of Ra, Rb, Rcand Rdare each independently selected from the group consisting of hydrogen, halogen, C2-C3-aIkynyI , CN, R, S(O)kR, NHR, NR2, OR and C(O)R; where each R is independently selected from the group consisting of C1-C4-al- ky I , phenyl, benzyl and naphthyl; and k is 0, 1 or 2; or

[0017] Rcand Rdtogether with carbon atoms to which they are bound may also form a fused benzene ring [in this case, as a matter of course, one or both of Raand Rbare a dibenzothiophene radical of the formula (II), and, if only one of Raand Rbis a dibenzothiophene radical of the formula (II), the other is selected from the group consisting of hydrogen, halogen, C2-C3-aIkynyI , CN, R, S (O)kR, NHR, NR2, OR and C (O) R] ; as a monomer, in particular as a monomer for preparing polymers, especially thermoplastic resins, more particularly for preparing thermoplastic resins that are selected from the group consisting of polycarbonates, polyesters and polyestercarbonates, in particular polycarbonates and polyesters.

[0018] The invention relates moreover to a compound (I) per se as defined above, ex- cept for following compounds:

[0019] - dimethyl 2, 5-di (dibenzothiophen- 2-yl) benzene-1, 4-dicarboxyIate; i.e. a com- pound of the fol lowing formula:

[0020] - 2, 5-di (dibenzothiophen-2-yI) benzene-1, 4-diol ; i.e. a compound of the fol- lowing formula:

[0021] Compounds (I) (including those two disclaimed above in context with the com- pounds (I) according to the invention) are suitable monomers for preparing polymers such as polyesters, polycarbonates and mixed forms thereof.

[0022] The invention thus relates also to a polymer, and in particular a thermo- plastic resin, comprising a structural unit derived from compounds (I) and represented by formula (III) where

[0023] # represents a connection point to a neighboring structural unit;

[0024] Z11is a bridging group -O- or -C(O)-O-, where the carbon atom of the group -C(O) -O- is bound to X1;

[0025] Z’zis a bridging group -O- or -C(O) -O-, where the carbon atom of the group -C(O) -O- is bound to X2; and

[0026] X1, X2, Ra, Rb, Rcand Rdare as defined above in context with the use accord- ing to the invention of compounds (I).

[0027] The invention relates also to an optical device made of said thermoplastic resin.

[0028] DETAILED DESCRIPTION OF THE INVENTION

[0029] Definitions

[0030] Depending on the substitution on the central phenyl ring of the compounds of formula (I) (i.e. the phenyl ring carrying radicals Ra, Rb, Rcand Rd), the compounds (I) may have axial chiral ity due to a possibly limited rotation along the bond between a carbon ring atom of said central phenyl ring and one or more of the radicals Ra, Rb, Rcand Rd. Rotation may for example be limited if both of Raand Rbor if both of Rcand Rdare the sterically demanding rad- ical of the formula (II), or, more generally speaking, if the substituent in ortho position to the radical (II) is sterically demanding to such an extent that it hinders rotation along the bond between the central phenyl ring and the radical (II) (as is the case, for example, for a tert-butyl group). More- over, compounds (I) may contain one or more stereogenic centers, for instance if one or more of Ra, Rb, Rcand Rdare R, S (O)kR, NHR, NRZ, OR or O(O) R and R is seo-butyl (the stereogen ic center being the carbon atom in the 2-position of sec-butyl), or if one or both of Z1and Zzare O(O) ORxand R* is sec-butyl, or if one or both of the linking groups X1and X2are non-linear C3- C5- a I - kanediyl with a stereogen io center (e. g. the carbon atom in the 2-position of propane-2, 3-diyI) . In these cases, the compounds of the formula (I) can exist in the form of their pure stereoisomers (pure enantiomers or pure diastere- omers) or in form of mixtures of their stereoisomers, including racemic mix- tures. The present invention relates to both the pure stereoisomer of the compounds of formula (I), e. g. to the pure enantiomers or the pure diastere- omers, and to mixtures of the stereoisomers, including racemic and non-race- mic mixtures of enantiomers and mixtures of diastereomers, provided of course that stereoisomers exist.

[0031] In the present context, the term compound (I), when not defined as a specific stereoisomer or a specific mixture of stereoisomers although axial chirality and / or one or more stereogen ic centers are present, refers to the form of the compound as it is obtained in a non-stereoselective method used for its pro- duction. The term is however also used if it is not necessary or not practi- cable to specify in more detail the stereochemistry of the compound (I).

[0032] In terms of the present invention, halogen denotes fluorine, chlorine, bro- mine or iodine, in particular fluorine, chlorine or bromine.

[0033] C1— C4— A I ky I is a linear or branched saturated aliphatic hydrocarbon radical containing 1, 2, 3 or 4 carbon atoms. Examples are methyl, ethyl, n-propyl, 2— propyl (isopropyl), n-butyl, 2— butyl (1 -methyl propyl ; seo-butyl), (sec-bu- tyl), 2-methy I propyl (isobutyl) or 1, 1 -di methyl ethyl (tert-butyl). C1— C6-Alkyl is a linear or branched saturated aliphatic hydrocarbon radical containing 1 to 6 carbon atoms. Examples are, in addition to those listed for C1— C4— alkyl, n-pentyl, 1 -methyl butyl, 2-methy I butyl, 3-methy I butyl, 2, 2— di methyl propyl, 1- ethy I propyl, 1, 1 -di methyl propyl, 1, 2— di methyl propyl, n-hexyl, 1 -methyl pentyl, 2-methy I penty l , 3-methy I penty l , 4-methy I penty l , 1 , 1 -d i methy I buty l , 1 , 2-d i me- thyl butyl, 1, 3-d i methyl butyl, 2, 2-di methy I buty I, 2, 3-d i methy I buty I, 3, 3-d i me- thy I buty I, 1 -ethyl butyI, 2-ethylbuty I, 1, 1,2-tri methy I propyl, 1,2, 2-tri me- thylpropyl, 1-ethy 1-1 -methy I propyl, or 1 -ethyl -2-methy I propyl.

[0034] C2-C3-A I kyny I is ethynyl, propyn-1-yl or propyn-3-yl (propargyl).

[0035] C1-C5-AI kanediyl, also termed " C1-C5-a I ky I ene ", is a bivalent, saturated, al- iphatic hydrocarbon radical having 1, 2, 3, 4 or 5 carbon atoms. Examples are the methylene group (CH2), linear C1-C5-alkanediy I such as 1, 2-ethanediyl (ethylene; CH2CH2), 1, 3-propanediy I (n-propyl ene; CH2CH2CH2), 1 , 4-butdanediy I (n-butyl ene; CH2CH2CH2CH2) and 1, 5-pentanediyl (n-penty I ene; CH2CH2CH2CH2) , but also branched 2z- C5- a I kaned i y I / a I ky I ene, such as 1 , 1-ethanediy I (-CH(CH3)-, 1- methy 1-1, 2-ethanediyl (propane-2, 3-d iy I) , 1 -methy 1-1, 2-propanediyl, 2-methy I - 1, 2-propanediy I, 2-methy l-1, 3-propanediy I, 1, 3-butanediyl and the like. C1— C4- Alkanediyl, also termed "C1-C4-alky I ene ", is a bivalent, saturated, aliphatic hydrocarbon radical having 1, 2, 3 or 4 carbon atoms. Examples are those listed above for C1— C4-a I kanediyl, except for 1, 5-pentanediyl. C2— C4- Al- kanediyl, also termed " C2— C4-alkylene ", is a bivalent, saturated, aliphatic hydrocarbon radical having 2, 3 or 4 carbon atoms. Examples are those listed above for C1-C4-alkanediyl, except methylene. C5— C6— Cyc IoaI ky I is cyclopentyl or cyclohexyl.

[0036] In terms of the present invention, the term “monocyclic aryl” refers to a monovalent aromatic monocyclic radical, such as in particular phenyl.

[0037] In terms of the present invention, the term “monocyclic hetaryl” refers to a monovalent heteroaromatic monocyclic radical, i.e. a heteroaromatic monocy- cle linked by a single covalent bond to the remainder of the molecule, where the ring member atoms are part of a conjugate π-electron system, where the heteroaromatic monocycle has 5 or 6 ring atoms, which comprise as heterocy- clic ring members 1, 2, 3 or 4 nitrogen atoms or 1 oxygen atom and 0, 1, 2 or 3 nitrogen atoms, or 1 sulphur atom and 0, 1, 2 or 3 nitrogen atoms, where the remaining ring atoms are carbon atoms. Examples include furyl (= furanyl), pyrrolyl (= 1H— pyrrolyl) , thienyl (= th i opheny I ) , imidazolyl (= 1H- imidazolyl), pyrazolyl (= IH-pyrazoly I) , 1, 2, 3-triazolyl, 1, 2, 4-tr iazoly I , tetrazolyl, oxazolyl, thiazolyl, isoxazolyl, isothiazolyl, 1, 2, 3-oxad iazoly I, 1, 2, 4-oxad iazoly I, 1, 2, 5-oxadiazolyl, 1, 3, 4-oxad iazoly I, 1, 2, 3-th i ad iazoly I, 1, 2, 4-th i ad iazoly I, 1, 2, 5— th i ad i azo I y l , 1, 3, 4-thiadiazo1y I, pyridyl (= pyri — dinyl), pyrazinyl, pyridazinyl, pyrimidinyl and triazinyl.

[0038] In terms of the present invention, the term “mono- or polycyclic aryl” re- fers to a monovalent aromatic monocyclic radical as defined herein or to a monovalent aromatic polycyclic radical, i.e. a polycyclic arene linked by a single covalent bond to the remainder of the molecule, where the polycyclic arene is

[0039] (i) an aromatic polycyclic hydrocarbon, i.e. a completely unsaturated polycy- clic hydrocarbon, where each of the carbon atoms is part of a conjugate π- electron system,

[0040] (ii) a polycyclic hydrocarbon which bears at least 1 phenyl ring which is fused to a saturated or unsaturated 4 to 10-membered mono- or bicyclic hydro- carbon ring,

[0041] (iii) a polycyclic hydrocarbon which bears at least 2 phenyl rings which are linked to each other by a covalent bond or which are fused to each other di- rectly and / or which are fused to a saturated or unsaturated 4 to 10-membered mono- or bicyclic hydrocarbon ring.

[0042] Mono- or polycyclic aryl has from 6 to 26, often from 6 to 24 carbon atoms, e. g. 6, 9, 10, 12, 13, 14, 16, 17, 18, 19, 20, 22 or 24 carbon atoms as ring atoms, in particular from 6 to 20 carbon atoms, especially 6, 10, 12, 13, 14, 16, 17 or 18 carbon atoms. Polycyclic aryl typically has 10 to 26 carbon at- oms as ring atoms, in particular from 10 to 20 carbon atoms, especially 10, 12, 13, 14, 16, 17 or 18 carbon atoms.

[0043] In this context, polycyclic aryl bearing 2, 3 or 4 phenyl rings which are l inked to each other via a single bond include e. g. biphenylyl and ter- phenylyl. Polycyclic aryl bearing 2, 3 or 4 phenyl rings which are directly fused to each other include e. g. naphthyl, anthracenyl, phenanthrenyI , pyrenyl, triphenylenyl, chrysenyl and benzo [c] phenanthreny I. Polycyclic ary I bearing 2, 3 or 4 phenyl rings which are fused to a saturated or unsaturated 4- to 10-membered mono- or bicyclic hydrocarbon ring include e. g. 9H- fluo— renyl, biphenylenyl, tetraphenyl eny I , acenaphtheny I (1 , 2— d I hydroacenaph- thylenyl), acenaphthylenyl, 9, 10-dihydroanthracen-1-yl, 1,2, 3, 4- tetrahydrophenanthrenyl , 5, 6, 7, 8-tetrahydrophenanthrenyl, cyclo- pent [fg] acenaphthy I eny I , phenalenyI, fluoranthenyl, benzo [k]fluorantheny I , perylenyl, 9, 10-di hydro-9, 10 [1 ’ , 2’ ]-benzenoanthraceny I , di benzo [a, e] [8]annu- lenyl, 9, 9’ -spi robi [9H-fluoren]yl and spi ro[1H-cyclobuta[de]naphthalene-1 , 9’ - [9H]fluoren]yl.

[0044] Mono- or polycyl ic aryl includes, by way of example phenyl, naphthyl, 9H-flu- orenyl, phenanthryl, anthracenyl, pyrenyl, chrysenyl, benzo[c]phenanthrenyl, acenaphthenyl, acenaphthylenyl, 2, 3-d i hydro-1 H- indeny I, 5, 6, 7, 8-tetrahydro- naphtha I eny I , eye I opent [fg]acenaphthylenyl, 2, 3-d i hydrophenal eny I, 9,1O—dihy— droanthracen-1-yl, 1, 2, 3, 4-tetrahydrophenanthrenyl, 5, 6, 7, 8-tetrahydrophenan- threnyl, f luoranthenyl, benzo [k]fluoranthenyl, biphenyleny I, tri phenyl eny I, tetrapheny I eny 1 , 1 , 2-d i hydroacenaphthy I eny I , di benzo [a, e] [8] annu I eny I , perylenyl, biphenylyl, terphenylyl, naphthylenpheny I, phenanthryl phenyl, an- thracenyl phenyl , pyrenyl phenyl, 9H— f luorenylphenyl, di (naphthyl en) phenyl, naphthy I enb i pheny I , tri (pheny I ) pheny I , tetra (pheny I ) pheny I , pentapheny I (phe- nyl), phenyl naphthyl, bi naphthy I, phenanthryl naphthy I, pyrenylnaphthyl , phe- ny I anthracenyl, biphenyI anthracenyl, naphtha I eny I anthracenyl, phenanthryl an- thracenyl, d i benzo [a, e] [8] annu I eny I, 9, 10-di hydro-9, 10 [1’ ,2’ ]benzoanthra- cenyl, 9,9’ -spi robi-9H-f luorenyl and spiro[1H-cyclobuta[de]naphthalene-1, 9’ - [9H]f I uoren] y I .

[0045] In terms of the present invention, the term “mono- or polycyclic hetaryl” refers to a monovalent heteroaromatic monocyclic radical as defined herein or to a monovalent heteroaromatic polycyclic radical, i.e. a polycyclic hetarene linked by a single covalent bond to the remainder of the molecule, where

[0046] (i) the polycyclic hetarene bears a heteroaromatic monocycle as defined above and at least one, e. g. 1, 2, 3, 4 or 5, further aromatic rings selected from phenyl and heteroaromatic monocycles as defined above, where the aromatic rings of the polycyclic hetarene are linked to each other by a covalent bond and / or fused to each other directly and / or fused to a saturated or unsatu- rated 4 to 10-membered mono- or bicyclic- hydrocarbon ring, or

[0047] (ii) the polycyclic hetarene bears at least one saturated or partially or fully unsaturated 5-, 6-, 7- or 8-membered heterocyclic ring bearing 1, 2 or 3 heteroatoms selected from oxygen, sulphur and nitrogen as ring atoms, such as 2H-pyran, 4H-pyran, thiopyran, 1, 4-dihydropyr idin, 4H-1, 4-oxazin, 4H- 1 , 4- thiazin, 1,4— dioxin, oxepin, th i ep in, dioxin, dithiin, dioxepin, dithiepin, dioxocine, dithiocine and at least one, e. g. 1, 2, 3, 4 or 5, aromatic rings selected from phenyl and heteroaromatic monocycles as defined above, where at least one of the aromatic rings is directly fused to the saturated or par- tially unsaturated 5- to 8-membered heterocyclic ring and where the aromatic rings of the polycyclic hetarene are linked to each other by a covalent bond or fused to each other directly and / or fused to a saturated or unsaturated 4 to 10-membered mono- or bicyclic hydrocarbon ring.

[0048] Mono- or polycyclic hetaryl has from 5 to 26, often from 5 to 24 ring atoms, in particular 5 to 20 ring atoms, which comprise 1, 2, 3 or 4 atoms selected from nitrogen atoms, sulphur atoms and oxygen atoms, where the remainder of the ring atoms are carbon atoms. Polycyclic hetaryl generally has from 9 to 26, often from 9 to 24 ring atoms, in particular 9 to 20 ring atoms, which comprise 1, 2, 3 or 4 atoms selected from nitrogen atoms, sulphur atoms and oxygen atoms, where the remainder of the ring atoms are carbon atoms. Examples of polycyclic hetaryl include, but are not limited to, benzofuryl, benzothienyl, di benzofuranyl (= di benzo [b ,d] furanyl) , di benzothienyl (= d i benzo [b ,d]thienyI) , naphthofuryl, naphthothienyl, furo [3, 2-b] furanyl, f ur o [2, 3-b] furanyl, furo [3, 4-5] furanyl , th i eno [3, 2-b]thienyI , th i eno [2, 3- 5]thienyl, th I eno [3, 4-b] thienyI, oxanthrenyl, thianthrenyl, indolyl (= 1H-in- dolyl), isoindolyl (= 2H-isoindolyl) , carbazolyl, indolizinyl, benzopyra- zolyl, benzimidazolyl, benzoxazoly I, benzothiazolyl, benzo [c,d] indolyl, 1 / 5 benzo[g] indolyl, quino liny I, isoquinol iny I, acridinyl, phenaz iny I, quinazoli- nyl, quinoxal iny I, phenoxazinyl, phenthiazinyl, benzo [b] [ 1 , 5] naphthyr i d i ny I , cinnolinyl, 1, 5— naphthyr i d i ny 1 , 1, 8— naphthyr i d i ny I , phenylpyrrolyl, naph- thylpyrrolyl, di pyridyl, phenyl pyridyl, naphthyl pyridyl, pyri do [4, 3-b] in- dolyl, pyrido[3, 2-b] indolyl, pyri do [3, 2-g] quinol iny I, pyri do [2, 3-b] [1, 8] naph- thyr i di ny I, pyrrolo[3, 2-b]pyr idinyl, pteridinyl, puryl, 9H-xantheny 1 , 9H- thi- oxanthenyl, 2H-chromenyl, 2H-thiochromenyl, phenanthridinyl, phenanthrol inyl, benzo [1, 2-b:4, 3-b' ]difuranyl, benzo [1, 2-b:6, 5-b' ]difuranyl, benzo[1,2- b:5, 4-b ’ ] difuranyl, benzo [1, 2-b:4, 5-b' ]di furanyl, naphthofuranyl, benzo [5] naphtho [1, 2-5 furanyl, benzo [5] naphtho [2, 3-d] furanyl, benzo [b] naph- tho [2, 1-d] furanyl, tri benzo [5, d, f]oxepinyl, di benzo [5,d] thienyl, naph- tho [1, 2-b] thienyl, naphtho [2, 3-b] th i eny I, naphtho [2, 1-b] thienyl, benzo [b] naphtho [1 , 2-d] th i eny I , benzo [b] naphtho [2, 3-d] th i eny I , benzo [b] naph- tho[2, 1—5 th I eny 1 , 6H-dibenzo[5, 5thiopyranyl , 5H, 9H-[1]benzothiopy- rano[5, 4, 3-c, d, e] [2] benzothiopyranyl, 5H, 10H-[1]benzothiopyrano[5, 4, 3- c, d, 5 [2] benzothiopyranyl, benzo [1, 2-5:4, 3-5' Jbisthienyl, benzo [1, 2-b:6, 5- 5' ] bisthienyl, benzo [1, 2-b:5, 4-b' ]bisthienyl, benzo [1, 2-b:4, 5-b' ]bis- thienyl, 1, 4-benzodithi iny I , naphtho [1 , 2-b] [1 , 4] d i th i i ny I , naphtho [2, 3- 5] [1, 4]dithi inyl, thianthrenyl, benzo [a] thianthrenyl, benzo [b] thianthrenyl, di benzo [a, c] thianthrenyl, di benzo [a, h] thianthrenyl, dibenzo[a, i ]thi- anthrenyl, dibenzo[a, j ] thianthrenyl, dibenzo[b, i ] thianthrenyl, 2H-naph- tho [1 , 8-b, c] thienyl, 5H-phenanthro[4, 5-b, c,d] th iopyranyl, 10, 11 -di hydrodi - benzo [b, f ] th i ep i ny 1 , 6, 7-d i hydrod i benzo [b,d] th i ep i ny I , d i benzo [b, f ] th i ep i ny I , di benzo [5, 5 th i ep i ny 1 , 6H-d i benzo

[0055] [1 , 3] d i th i - epinyl, tri benzo [5, d, f ] th i ep iny I, benzothieno[3, 4- a, 5 th i eno [2, 3, 4-

[0049] J, k ] [2] benzoth i ep i ny I , di naphtho [1, 8- bc: 1 ’ , 8’ -f, g ] [1, 5] di th ioc iny I, furo [3, 2- g ] quinolinyl, furo [2, 3- g ] quinol inyl, furo [2, 3-g] quinoxal inyl, benzo[ g ]chrome- nyl, thieno[3, 2-f ] [1] benzothienyl, th i eno [2, 3-f ] [1] benzothienyl, th i eno [3, 2-5 qu i no I i ny I , th i eno [2, 3- g ] qu i no I i ny I , th i eno [2, 3-g] qu i noxa I i ny I , benzo[ g ]thiochromenyl, pyrro I o [3, 2, 1-h, i ] indolyl, benzo [ g ] quinoxal inyl, benzo [f ] quinoxal inyl, and benzo [h] isoquinol inyl.

[0050] In terms of the present invention, the terms “phenylene” , “naphthylene” and “bipheny lylene” refer, as customary in the art, to di radicals of ben- zene, naphthalene and biphenyl, respectively. Accordingly, the terms “phe- nylene” , “naphthylene” and “bipheny lylene” are used herein synonymously with the terms phendiyl, naphthaIendiyI and biphenyldiyl, respectively.

[0051] In terms of the present invention, a “structural unit” is a structural ele- ment which is present repeatedly in the polymer backbone of the thermoplastic resin. Therefore, the terms “structural unit” and “repeating unit” are used synonymously.

[0052] In terms of the present invention, the term “optical device” refers to a device that is transparent for visible light and manipulates light beams, in particular by refraction. Optical devices include, but are not limited to, prisms, lenses, optical films and combinations thereof, especially lenses for cameras and lenses for glasses.

[0053] The remarks made below as to preferred embodiments of the variables (substit- uents) of the compounds of formula (I) and of the structural units of formula (III) are valid on their own as well as preferably in combination with each other.

[0054] The remarks made below concerning preferred embodiments of the variables fur- ther are valid on their own as well as preferably in combination with each other concerning the compounds of formula (I), the structural units of for- mula (III), where applicable, as wel l as concerning the use according to the invention. In case of the compounds (I) according to the invention, however, the above disclaimers apply, whereas in case of the use according to the in- vention or the resin according to the invention, they do not apply.

[0055] In formula (I) and, as far as applicable or transferable, in formula (III), the variables X1, X2, Z1, Z2, Ra, Rb, Rcand Rd, on their own or preferably in any combination preferably have the following meanings:

[0056] In a preferred embodiment, X1and X2, independently of each other, are C1— C5- alkanediyl, especially if Z1and Z2are both OH, and are more preferably meth- ylene or 1, 2-ethylene.

[0057] In another preferred embodiment, X1and X2have the same meaning.

[0058] In a more preferred embodiment, X1and X2have the same meaning and are both

[0059] C1— C5— a I kaned i y I . Even more preferably, X1and X2have the same meaning and are methylene or 1 , 2-ethy I ene. In particular, X1and X2are both methylene.

[0060] In a preferred embodiment, Z1and Z2have the same meaning.

[0061] In another preferred embodiment, Z1and Z2are both OH.

[0062] In a more preferred embodiment, X1and X2have the same meaning and are both methylene or 1, 2-ethylene, and Z1and Z2are both OH. Even more preferably, X1and X2are both methylene and Z1and Z2are both OH.

[0063] In an alternatively preferred embodiment, X1and X2are both a bond.

[0064] In an alternatively preferred embodiment, Z1and Z2are C(O)ORx. Rxis prefer- ably selected from the group consisting of hydrogen and C1— C4— alkyl and is more preferably hydrogen.

[0065] In an alternatively more preferred embodiment, X1and X2are both a bond, and Z1and Z2are O(O) ORx, where Rxis preferably selected from the group consist- ing of hydrogen and C1— C4- alkyl.

[0066] More preference is however given to compounds (I) wherein X1and X2have the same meaning and are both C1— C5-alkanediy I, even more preferably methylene or 1, 2-ethylene and in particular methylene, and Z1and Z2are both OH. In a preferred embodiment, two of the radicals Ra, Rb, Rcand Rdare a di ben- zothiophene radical of the formula (II). Preferably, the two dibenzothiophene radicals (II) are not bound vicinally (i.e. they are not in ortho positon to each other) ; meaning for example that, if Rais a dibenzothiophene radical (II), the second dibenzothiophene radical (II) is preferably Rcor Rd, and not Rb. More preferably, the two dibenzothiophene radicals (II) are in para posi- tion to each other, meaning for example that Raand Rdare a dibenzothiophene radical of the formula (II).

[0067] In a preferred embodiment, those radicals Ra, Rb, Rcand Rdwhich are not a dibenzothiophene radical of the formula (II) are preferably, independently of each other, hydrogen or C1— C4— alkyl , and are more preferably hydrogen. Even more preferably, two of the radicals Ra, Rb, Rcand Rdare a dibenzothiophene radical of the formula (II) and the other two radicals Ra, Rb, Rcand Rdare hydrogen. Particularly preferably, Rais a dibenzothiophene radical (II), Rcor Rdis the second dibenzothiophene radical (II), and the other two radicals Rband Rcor Rdare hydrogen. In particular, Raand Rdare a dibenzothiophene radical of the formula (II), and Rband Rcare hydrogen.

[0068] The dibenzothiophene radical (II) can principally be bound by any of the four carbon atoms of one of the two phenyl rings, i.e. in 1-, 2-, 3- or 4-posi- tion, the numbering of the positions being as follows:

[0069] The dibenzothiophene radical (II) is however preferably bound via its 4-posi- tion and thus preferably a radical of the formula (11.1) where # indicates the attachment point to the remainder of the molecule.

[0070] Thus, in a more preferred embodiment, two of the radicals Ra, Rb, Rcand Rdare a dibenzothiophene radical of the formula (11.1) and the other two radi- cals Ra, Rb, Rcand Rdare hydrogen. Even more preferably, Rais a di benzothio- phene radical (II.1), Rcor Rdis the second dibenzothiophene radical (II.1), and the other two radicals Rband Rcor Rdare hydrogen. In particular, Raand Rdare a dibenzothiophene radical of the formula (11.1), and Rband Rcare hy- drogen.

[0071] In a particular embodiment, X1and X2have the same meaning and are both methylene or 1, 2-ethylene, pref- erably methylene;

[0072] Z1and Z2are both OH; two of the radicals Ra, Rb, Rcand Rdare a dibenzothiophene radical of the formula (II), where the two radicals which are a dibenzothiophene radical of the formula (II) are not vicinally bound; and those radicals Ra, Rb, Rcand Rdwhich are not a dibenzothiophene radical of the formula (II) are hydrogen.

[0073] More particularly,

[0074] X1and X2have the same meaning and are both methylene or 1, 2-ethylene, pref- erably methylene;

[0075] Z1and Z2are both OH; two of the radicals Ra, Rb, Rcand Rdare a dibenzothiophene radical of the formula (II.1), where the two radicals which are a dibenzothiophene radical of the formula (II.1) are not vicinally bound; and those radicals Ra, Rb, Rcand Rdwhich are not a dibenzothiophene radical of the formula (II.1) are hydrogen.

[0076] In an alternatively particular embodiment,

[0077] X1and X2are both a bond;

[0078] Z1and Z2are both C(O)ORx, where Rxis selected from the group consisting of hydrogen and C1— C4- a I ky I ; two of the radicals Ra, Rb, Rcand Rdare a dibenzothiophene radical of the formula (II), preferably (II.1), where the two radicals which are a diben- zothiophene radical of the formula (II) are not vicinally bound; and those radicals Ra, Rb, Rcand Rdwhich are not a dibenzothiophene radical of the formula (II) are hydrogen.

[0079] Specifically, the compound (I) is a compound of the formula (1.1)

[0080] Compounds (I) can be prepared by standard reactions in organic chemistry, such as the Suzuki reaction (also called Suzuki coupling, Suzuki -Miyaura re- action or Suzuki -Miyaura coupling) of suitable precursors of the central phe- nyl moiety and the dibenzothiophene moiety (II), as shown in scheme 1.

[0081] Scheme 1

[0082]

[0083] A1in compounds 1 and I’ is a group -X1-Z1or a precursor thereof, and analo- gously A2in compounds 1 and I’ is a group -X2-Z2or a precursor thereof. LG is a leaving group, such a halogen atom, in particular Br or I, or a sul- fonate [the sulfonate being in particular a fluorinated a Iky I sulfonate or to- sylate, specif ically tr if late (trifluoromethyl sulfonate) or nonaflate (no- nafluorobutyl sulfonate)]. Each R’ has independently one of the meanings of Ra, Rb, Rcand Rdbut for group (II), and G is either also a leaving group LG (if compounds (I) are to be prepared wherein two of the radicals Ra, Rb, Rcand Rdare a group (II)), or has independently one of the meanings of Ra, Rb, Rcand Rdbut for group (II) (if compounds (I) are to be prepared wherein just one of the radicals Ra, Rb, Rcand Rdis group (II)). In compounds I’ , G’ is either a group (II) (if G in compound 1 is LG), or has independently one of the meanings of Ra, Rb, Rcand Rdbut for group (II) (if G in compound 1 is not LG). Instead of the boronic acid 2, a suitable derivative thereof, such as an ester thereof, in particular its C1— C4- alky I ester, can be used (the group being thus — B (O- C1— C4— a I ky I )2instead of — B (OH)2) The Suzuki coupling is generally carried out in the presence of a transition metal catalyst, mostly a Pd or Ni catalyst, more frequently a Pd catalyst, and generally also in the presence of a base. The Pd or Ni catalyst is usually used with a phosphorus ligand, such as tr i -substituted phosphine ligand, such as e. g. tetrak is (tri- phenyl phosphine) pal ladium and tetrakis (tritolylphosphine) palladium. Fre- quently, the palladium catalyst is prepared in situ from a suitable palladium precursor, such as e. g. pal ladium (I I) acetate (Pd(OAc)2, and a suitable phos- phine ligand, like in particular triarylphosphines, such as e. g. tri- phenyl phosphine and tr i to ly I phosphine. Suitable bases can be inorganic or or- ganic. Examples for suitable inorganic bases are alkali metal carbonates, e. g. Li2CO3, Na2CO3, K2CO3or Cs2CO3, alkali metal hydrogen carbonates, e. g.

[0084] LiHCO3, NaHCO3, KHCO3or CsHCO3, alkali metal hydroxides, e. g. Li OH, NaOH or KOH, or phosphates, e. g. Li3PO4, Na3PO4, K3PO4or CS3PO4. Examples for suitable organic bases are open-chained amines, e. g. tr i methyl amine, tr i ethyl amine, tri propyl amine, ethyl di isopropyl amine and the like, basic N-heterocyc les, such as morpholine, pyridine, lutidine, DABCO, DBU or DBN, or alkoxylates, e. g. sodium or potassium methanol ate, ethanol ate, propano I ate, isopropano- late, butanolate or tert-butanol ate. Frequently, an inorganic oxo base, such as the above-listed alkali metal carbonates, is used.

[0085] For a better illustration, scheme 2 shows representatively the synthesis of compounds I' ' wherein Raand Rdare a dibenzothiophene radical (II.1) and Rband Rcare hydrogen.

[0086] Scheme 2

[0087]

[0088] Like in scheme 1, A1in compounds 1’ and 1’ ’ is a group -X1-Z1or a precur- sor thereof, and analogously A2in compounds 1’ and I’ ’ is a group -X2-Z2or a precursor thereof. LG is a leaving group, such a halogen atom, in par- ticular Br or I, or a sulfonate in particular a fluorinated a Iky I sulfonate or tosyl ate, specifically tr if late or nonafl ate.

[0089] It is principally possible to use the Suzuki-reactive groups in the starting compounds inversely, i.e. to start from a boron ic acid (derivative) of the central phenyl moiety (i.e. the phenyl ring substituted by A1and A2carries one or two -B(OH)2groups or a derivative thereof) and a dibenzothiophene carrying the leaving group LG, but especially for preparing compounds (I) with two groups (II), it has proved more convenient to use the starting com- pounds 1, 2, 1’ and 2’ as shown in schemes 1 and 2.

[0090] If one or both of A1and A2in compounds I’ or I’ ’ are a precursor of the desired -X1-Z1or -X2-Z2, these are converted into the desired groups.

[0091] A suitable precursor for the group -CH2-OH as group -X1-Z1or -X2-Z2is for ex- ample a carboxylic acid or carboxylate group -C(O)ORx1, where Rx1is hydrogen or C1— C4— alkyl. If thus for example one or both of A1and A2are a group - C(O)ORx1in compounds I’ or I’ ’ , this can be converted into the desired - CH2-OH group (s) by a reduction reaction, as shown representatively in scheme 3 for compounds I’ (termed for this case I’ ’ ’ ) wherein both of A1and A2are -C (O)ORx1. Useful reduction agents are for example hydride complexes, e. g. lithium aluminum hydride or sodium borohydride, preference being given to lithium aluminum hydride.

[0092] Scheme 3

[0093]

[0094] Another suitable precursor for the group -CH2-OH as group -X1-Z1or -X2-Z2is the formyl group (-CHO) . Thus, in schemes 1 and 2, in compounds 1 and 1’ one or both of A1and A2can be a formyl group. The respective compounds I’ and I’ ’ can be converted into compounds (I) wherein the respective group -X1-Z1and / or -X2-Z2is — CH2— OH by a reduction reaction, as shown representatively in scheme 4 for compounds I’ (termed for this case Iv) wherein both of A1and A2are formyl. Useful reduction agents are here, too, for example hydride com- plexes, e. g. lithium aluminum hydride or sodium borohydride, preference being given in this case to sodium borohydride.

[0095] A suitable precursor for the group -CH2CH2-OH as group - X1- Z1or -X2-Z2is for example a vinyl group -CH=CH2. Thus, in schemes 1 and 2, in compounds 1 and 1’ one or both of A1and A2can be a vinyl group -CH=CH2. The respective com- pounds I’ and 1’ ’ can be converted into compounds (I) wherein the respec- tive group -X’-Z1and / or -X2-Z2is -CH2CH2-OH by subjecting the vinyl group to a hydroboration, using a suitable borane, such as di borane or, preferably, 9— BBN (9-borabicyclo[3.3.1] nonane) , followed by oxidation, generally with H2O2, to the anti-Markovnikov product Ivii, as shown representatively in scheme 5 for compounds I’ (termed for this case Ivi) wherein both of A1and A2are vinyl. The reaction is generally car- ried out in the presence of a base, suitable bases being those listed above. Here, preferably an alkali metal hydroxide is used.

[0096] Scheme 5

[0097]

[0098] Compounds Ivican be obtained from the respective formyl compounds Ivin a Wittig reaction using for example the Wittig reagent (Ph)3P=CH2(Ph = phenyl).

[0099] The formyl group -CHO is also a suitable precursor for the group -CH2CH2CH2-OH or the group -CH2CH2-C (O) ORxas group -X1-Z1or -X2-Z2. Thus, in schemes 1 and 2, in compounds 1 and 1’ one or both of A1and A2can be a formIy group -CHO. The respective compounds I’ and I’ ’ can be converted into compounds (I) wherein the respective group -X1-Z1and / or -X2-Z2is -CH2CH2CH2-OH or the group -CH2CH2-C (O) ORXby reacting the formyl compounds Ivin a Wittig reaction using for example the Wittig reagent (Ph)3P=CH-C (O) ORx, as shown representatively in scheme 6 for compounds I’ (termed for this case Iv) wherein both of A1and A2are formyl. The resulting unsaturated ester 3 can be hydrogenated to the es- ter Iviii, which, if desired can be further converted into the diol Iix, or the unsaturated ester 3 can be reduced to the unsaturated diol 4, which can then be hydrogenated to the diol Iix, Hydrogenation of ester 3 to the ester Iviiior of the diol 4 to the diol Iixis typically effect in the presence of a hydro- genation catalyst, generally a transition metal catalyst, such as Pd. Reduc- tion of the ester Iviiito the diol Iixor of the ester 3 to the diol 4 can be carried out under the conditions mentioned above in context with scheme 3, using for example a hydride complex, e. g. lithium aluminum hydride or sodium borohydride, preference being given to lithium aluminum hydride.

[0100] Scheme 6

[0101]

[0102] The conversion reactions of precursor groups A1and A2to groups -X1-Z1and - X2-Z2shown in schemes 3 to 6 can of course alternatively be applied analo- gously to respectively substituted starting compounds 1. Just by way of exam- ple, a compound 1 wherein A1and A2are -C(O)ORx1can be reduced to a compound 1 wherein A1and A2are -CH2-OH under reaction conditions analogous to those described above in context with scheme 3; or a compound 1 wherein A1and A2are formyl can be reduced to a compound 1 wherein A1and A2are -CH2-OH under reaction conditions analogous to those described above in context with scheme 4; or a compound 1 wherein A1and A2are formyl can be subjected to a Wittig reaction using, for example, the Wittig reagent (Ph)3P=CH2(Ph = phenyl) to afford a compound 1 wherein A1and A2are both vinyl, which can be subjected to a hydroboration / oxidation to afford a compound 1 wherein A1and A2are - CH2CH2-OH under reaction conditions analogous to those described above in con- text with scheme 5; or the compound 1 wherein A1and A2are formyl which can be subjected to a Wittig reaction using for example the Wittig reagent (Ph)3P=CH-C (O) ORxto afford a compound 1 wherein A1and A2are -CH=CH-C (O) ORx, which can be subjected to a hydrogenation to afford a compound 1 wherein A1and A2are -CH2CH2-C (O) ORx, which, if desired can be reduced to afford a com- pound 1 wherein A1and A2are -CH2CH2CH2-OH, or the compound 1 wherein A1and A2are

[0103] — CH=CH— C (O) ORxcan be subjected to a reduction reaction to afford a compound 1 wherein A1and A2are -CH=CH-CH2-OH, which can be hydrogenated to a compound 1 wherein A1and A2are -CH2CH2CH2-OH, under reaction conditions analogous to those described above in context with scheme 6. Thusly obtained compounds 1 can then be reacted with compound 2 in the above-described Suzuki reaction, yielding directly compounds (I) which carry the desired -X1-Z1and -X2-Z2groups. The above schemes show the preparation of compounds (I) wherein the groups - X1— Z1and -X2-Z2have the same meaning. Compounds (I) wherein the groups -X1-Z1and

[0104] —X2-Z2have different meanings can be prepared by using starting compounds 1 already carrying the desired, different groups -X1-Z1and -X2-Z2, or carrying suitable precursor groups for obtaining the respectively desired, different groups - X1- Z1and -X2-Z2. Alternatively, in compounds 1 carrying the same pre- cursor groups A1and A2, these can be subjected selectively to different con- version reactions. Just by way of example, in a compound 1 wherein A1and A2are both formyl, just one formyl group can be subjected selectively to a Wit- tig reaction using the Wittig reagent (Ph)3P=CH-G (O) ORxto be converted into the group -CH=GH-G (O) ORx, which can then be subjected to the hydrogenation and reduction reactions described in context with scheme 6, and the remaining formyl group can then be reduced to a -CH20H group. Thusly, a compound (I) is obtained in which one of the groups -X1-Z1and -X2-Z2is -CH2OH and the other i s

[0105] -CH2CH2CH2-OH or -CH2CH2-C (O) ORx.

[0106] Starting compounds 1 and 2 are either commercially available or can be ob- tained by standard reactions of organic chemistry, such as those depicted above for the conversion of various groups A1and A2.

[0107] The reaction products are usually worked up in a conventional way, e. g. by mixing with water, separating the phases and, where appropriate, purifying the crude products by washing, chromatography or crystallization.

[0108] As stated above, the compounds (I) of the present invention can be obtained in high purity, which means that a product is obtained which does not contain significant amounts of organic impurities different from the compound of for- mula (I), except for volati les. Usually, the purity of compounds of formula (I) is at least 95%, in particular at least 98% and especially at least 99%, based on the non-volatile organic matter, i.e. the product contains at most 5%, in particular at most 2% and especially at most 1% of non-volatile impu- rities different from the compound of formula (I).

[0109] The term "volati les" refers to organic compounds which have a boiling point of less than 200° C at standard pressure (105Pa). Consequently, non-volatile organic matter is understood to mean compounds having a boiling point which exceeds 200° C at standard pressure.

[0110] It is a particular benefit of the invention that the compounds of formula (I), and likewise their solvates, can often be obtained in crystalline form. In the crystalline form the compound of formula (I) may be present in pure form or in the form of a solvate with water or an organic solvent. Therefore, a particular aspect of the invention relates to the compounds of formula (I) which are essentially present in crystal line form. In particular, the inven- tion relates to crystalline forms where the compound of formula (I) is pre- sent without solvent, and to the crystalline solvates of the compounds of formula (I) where the crystals contain a solvent incorporated.

[0111] It is a particular benefit of the invention that the compounds of the formula (I), and likewise their solvates, can often be easily crystallized from con- ventional organic solvents. This allows for an efficient purification of the compounds of formula (I). Suitable organic solvents for crystallizing the compounds of the formula (I) or their solvates include, but are not limited to, aromatic hydrocarbons such as toluene or xylene, al iphatic ketones, in particular ketones having from 3 to 6 carbon atoms, such as acetone, methyl ethyl ketone, methyl isopropyl ketone or diethyl ketone, aliphatic and alicy- clic ethers, such as diethyl ether, dipropyl ether, methyl isobutyl ether, methyl tert-butyl ether, ethyl tert-butyl ether, dioxane or tetrahydrofuran, aliphatic-aromatic ethers, such as anisole, and aliphatic alcohols having 1 to 4 carbon atoms, such as methanol, ethanol or isopropanol, as well as mix- tures thereof.

[0112] Furthermore, impurities, especially color forming impurities and heavy met- als, the latter stemming generally from the Suzuki reaction, that may be pre- sent in a crude preparation of a compound of formula (I) can be removed at any stage of the purification process, e. g. before a filtration step or a crystallization step, by standard procedures, such as treatment with an ad- sorbent, e. g. activated charcoal.

[0113] Alternatively, the compounds of the formula (I), and likewise their solvates, can be obtained in purified form by employing other simple and efficient methods for purifying the raw products of these compounds, such as in partic- ular slurry washing the raw solids obtained directly after the conversion to prepare the compounds of formula (I). Slurry washing is typically conducted at ambient temperature or elevated temperatures of usually about 30 to 90° C, in particular 40 to 80° C. Suitable organic solvents here are in principle the same as those listed above as being suitable for crystallizing the com- pounds of formula (I), such as in particular the mentioned aromatic hydrocar- bons, aliphatic ketones, and aliphatic ethers, e. g. toluene, methyl ethyl ke- tone and methyl tert-butyl ether, or also aliphatic alcohols, such as metha- nol, and alkanes, such as pentane or hexane.

[0114] Accordingly, the compounds of formula (I) used for the preparation of the thermoplastic polymers, in particular the polycarbonates, as defined herein, can be easily prepared and obtained in high yield and high purity. In partic- ular, compounds of formula (I) can be obtained in crystalline form, which al- lows for an efficient purification to the degree required in the preparation of optical resins. In particular, these compounds can be obtained in a purity which provides for high refractive indices and also low haze, which is par- ticularly important for the use in the preparation of optical resins of which the optical device is made of. In conclusion, the compounds of formula (I) are particularly useful as monomers in the preparation of the optical resins.

[0115] In a further aspect, the invention relates to a thermoplastic resin compris- ing a structural unit represented by formula (III)

[0116] where

[0117] # represents a connection point to a neighboring structural unit;

[0118] Z11is a bridging group -O- or - C (O)-O- , where the carbon atom of the group

[0119] — C (O)-O— is bound to X1;

[0120] Z12is a bridging group -O- or -C (O)-O- where the carbon atom of the group -C(O) -O- is bound to X2; and

[0121] X1, X2, Ra, Rb, Rcand Rdare as defined above in context with compounds (I).

[0122] A skilled person will readi ly appreciate that the structural unit (III) com- prised in the thermoplastic resin is derived from the corresponding compound (I). Likewise, the structural unit (III.1.1) shown below is derived from com- pound (1.1).

[0123] A skilled person will also appreciate that the structural units of the for- mula (III) are repeating units within the polymer chains of the thermoplastic resin.

[0124] Preferred meanings of X1, X2, Ra, Rb, Rcand Rdare those described in context with compounds (I), and preferred bridging groups Z11and Z12are those de- rived from preferred meanings of Z1and Z2described in context with compounds (I).

[0125] Thus, in a preferred embodiment, in the structural units (III), X1and X2, in- dependently of each other, are C1— C5— a I kaned i y I , and are more preferably meth- ylene or 1, 2-ethy I ene.

[0126] In another preferred embodiment, X1and X2have the same meaning.

[0127] In a more preferred embodiment, X1and X2have the same meaning and are both C1-C5-alkanediyl . Even more preferably, X1and X2have the same meaning and are methylene or 1 , 2-ethy I ene. In particular, X1and X2are both methylene.

[0128] In a preferred embodiment, Z11and Z12have the same meaning.

[0129] In another preferred embodiment, Z11and Z12are both a bridging group -O-, the structural unit being in this case a structural unit of the formula (III.1) :

[0130] In a more preferred embodiment, X1and X2have the same meaning and are both methylene or 1, 2-ethylene, and Z11and Z12are both a bridging group -O-. Even more preferably, X1and X2are both methylene and Z11and Z12are both a bridg- ing group -O-.

[0131] In an alternatively preferred embodiment, X1and X2are both a bond.

[0132] In an alternatively preferred embodiment, Z11and Z12are both a bridging group -C(O)O-, where the carbon atom of this group is bound to X1and X2, respec- tively.

[0133] In an alternatively more preferred embodiment, X1and X2are both a bond, and Z11and Z12are both a bridging group -C(O)O-, where the carbon atom of this group is bound to X1and X2, respectively.

[0134] More preference is however given to structural units (III) wherein X1and X2have the same meaning and are both C1- C5- a I kaned i y I , even more preferably methylene or 1, 2-ethylene and in particular methylene, Z11and Z12are both a bridging group -O-.

[0135] In a preferred embodiment, two of the radicals Ra, Rb, Rcand Rdare a diben- zothiophene radical of the formula (II). Preferably, the two dibenzothiophene radicals (II) are not bound vicinally; i.e. if Rais a dibenzothiophene radi- cal (II), the second dibenzothiophene radical (II) is Rcor Rd. More prefera- bly, Raand Rdare a dibenzothiophene radical of the formula (II).

[0136] In another preferred embodiment, those radicals Ra, Rb, Rcand Rdwhich are not a dibenzothiophene radical of the formula (II) are preferably, inde- pendently of each other, hydrogen or C1- C4-alky I, and are more preferably hy- drogen. Even more preferably, two of the radicals Ra, Rb, Rcand Rdare a dibenzothiophene radical of the formula (II) and the other two radicals Ra, Rb, Rcand Rdare hydrogen. Particularly preferably, Rais a dibenzothiophene radical (II), Rcor Rdis the second dibenzothiophene radical (II), and the other two radicals Rband Rcor Rdare hydrogen. In particular, Raand Rdare a dibenzothiophene radical of the formula (II), and Rband Rcare hydrogen.

[0137] The dibenzothiophene radical (II) can principally be bound by any of the four carbon atoms of one of the two phenyl rings, i.e. in 1-, 2-, 3- or 4-posi- tion, the numbering of the positions being as follows:

[0138] The dibenzothiophene radical (II) is however preferably bound via its 4— posi- tion and thus preferably a radical of the formula (11.1) where # indicates the attachment point to the remainder of the molecule.

[0139] Thus, in a more preferred embodiment, two of the radicals Ra, Rb, Rcand Rdare a dibenzothiophene radical of the formula (II.1) and the other two radi- cals Ra, Rb, Rcand Rdare hydrogen. Even more preferably, Rais a di benzothio- phene radical (II.1), Rcor Rdis the second dibenzothiophene radical (II.1), and the other two radicals Rband Rcor Rdare hydrogen. In particular, Raand Rdare a dibenzothiophene radical of the formula (II.1), and Rband Rcare hy- drogen.

[0140] In a particular embodiment of structural units (III),

[0141] X1and X2have the same meaning and are both methylene or 1, 2-ethylene;

[0142] Z11and Z12are both a bridging group -O-; two of the radicals Ra, Rb, Rcand Rdare a dibenzothiophene radical of the formula (II), where the two radicals which are a dibenzothiophene radical of the formula (II) are not vicinally bound; and those radicals Ra, Rb, Rcand Rdwhich are not a dibenzothiophene radical of the formula (II) are hydrogen.

[0143] More particularly,

[0144] X1and X2have the same meaning and are both methylene or 1, 2-ethylene, pref- erably methylene;

[0145] Z11and Z12are both a bridging group -O-; two of the radicals Ra, Rb, Rcand Rdare a dibenzothiophene radical of the formula (II.1), where the two radicals which are a dibenzothiophene radical of the formula (II.1) are not vicinally bound; and those radicals Ra, Rb, Rcand Rdwhich are not a dibenzothiophene radical of the formula (II.1) are hydrogen.

[0146] In an alternatively particular embodiment,

[0147] X1and X2are both a bond;

[0148] Z11and Z12are both a bridging group -C(O)O- where the carbon atom of this group is bound to X1and X2, respectively; two of the radicals Ra, Rb, Rcand Rdare a dibenzothiophene radical of the formula (II), preferably (II.1), where the two radicals which are a diben- zothiophene radical of the formula (II) are not vicinally bound; and those radicals Ra, Rb, Rcand Rdwhich are not a dibenzothiophene radical of the formula (II) are hydrogen.

[0149] Specifically, however, the structural unit (III) is a unit of the formula (III.1.1) where # represents the connection point to a neighboring structural unit.

[0150] In addition to the structural units of the formula (III), the thermoplastic resin may have structural units different therefrom. In a preferred embodi- ment, these further structural units are derived from aromatic monomers of the formula (VI) resulting in structural units of the formula (V) :

[0151] HO-Rz-A1-Rz-OH (VI)

[0152] #-O-Rz-A1-Rz-O-# (V) where

[0153] # represents a connection point to a neighboring structural unit;

[0154] A1is a polycyclic radical bearing at least 2 benzene rings, wherein the benzene rings may be connected by A and / or directly fused to each other and / or fused by a non-benzene carbocycle, where A1is unsubstituted or substituted by 1, 2 or 3 radicals Raa, which are selected from the group consisting of halogen, C1-C6- alkyl, C5-C6-cyc I oa I ky I and phenyl;

[0155] A is selected from the group consisting of a single bond, O, O=O, S, SO2, CH2, CH-Ar, CAr2, CH( CH3), C( CH3)2and a radical of the formula (A’) where

[0156] Q represents a single bond, O, NH, O=O, CH2or CH=CH ; R7a, R7b, independently of each other are selected from the group con- sisting of hydrogen, fluorine, CN, R, OR, CHkR3-k, NR2, C(O) R and C (O)NH2, where R is as defined herein and k is 0, 1, 2 or 3; and

[0157] * represents the connection point to a benzene ring;

[0158] Ar is selected from the group consisting of mono- or polycyclic aryl having from 6 to 26 carbon atoms as ring member atoms and mono- or polycyclic hetaryl having a total of 5 to 26 atoms, which are ring members, where 1, 2, 3 or 4 of these ring member atoms of hetaryI are selected from ni- trogen, sulphur and oxygen, while the remainder of these ring member at- oms of hetaryI are carbon atoms, where Ar is unsubstituted or substi- tuted by 1, 2 or 3 radicals Rab, which are selected from the group con- sisting of halogen, phenyl and C1- C4- alkyl ;

[0159] Rzis a single bond, Alk1, O— AIk2— , O— AIk2- [O— AIk2- ]p- or O— AIk3— C (O) — where 0 is bound to A1, and where p is an integer from 1 to 10; Alk1is C1- C4— aIkandiyI ; AIk2is C2- C4- aIkandiyI ; and AIk3is C1- C4- aIkandiyI .

[0160] If Rzin formula (VI) is O- AIk3- C (O) , the esters, in particular the C1- C4—al- ky I esters, of the monomers of formula (VI) may be used instead.

[0161] In the context of formulae (VI) and (V), A1is in particular a polycyclic radical bearing 2 benzene or naphthalene rings, wherein the benzene rings are connected by A. In this context, A is in particular selected from the group consisting of a single bond, CH-Ar, CAr2, and a radical A’.

[0162] In the context of formulae (VI) and (V), Rzis in particular O— AIk2— , where AIk2is in particular linear alkanediyl having 2 to 4 carbon atoms and is es- pecially O-CH2CH2.

[0163] Among the monomers of formula (VI), preference is given to monomers of the general formulae (VI-1) to (VI-6)

[0164] where a and b are 0, 1, 2 or 3, in particular 0 or 1; c and d are 0, 1, 2, 3, 4 or 5, in particular 0 or 1 ; e and f are 0, 1, 2, 3, 4 or 5, in particular 0 or 1 ; and where Rz, Raa, Rab, R7aand R7bare as defined for formula (VI) and where Rzis in particular selected from a single bond, CH2and OCH2CH2.

[0165] Among the monomers of formula (VI), particular preference is given to mono- mers of the general formulae (VI-11) to (VI-20), where Rzand Raaare as de- fined herein and Rzis in particular selected from a single bond, CH2and 0- CH2CH2, and especially is O-CH2CH2:

[0166]

[0167] Examples of compounds of the formulae (VI-11) to (VI-20) are

[0168] 9.9-bis (4-hydroxyphenyI ) fluorene, 9, 9-bis (4-hydroxy-3-methy I pheny I ) fluorene,

[0169] 9.9-bis(4-hydroxy-3-isopropylphenyl)fluorene, 9, 9-bi s (4-hydroxy-3-tert. -bu- tyl pheny I) fluorene, 9, 9-bis (4-hydroxy-3-cyclohexylpheny I) fluorene, 9, 9- bis (4- hydr oxy-3-pheny I pheny I ) fluorene, 9, 9-bis (4- (2-hydroxyethoxy) pheny I ) fluorene also termed BPEF, 9, 9-bis (4- (2-hydroxyethoxy) -3-methylpheny I) fluorene, 9,9- bis (4- (2-hydroxyethoxy) -3- i sopropy I pheny I ) fluorene, 9, 9-bis (4- (2-hydroxyeth- oxy)-3-tert. -butyl pheny I) fluorene, 9, 9-bis (4- (2-hydroxyethoxy) -3-cyc I ohex- y I pheny I ) fluorene, 9, 9-bis (4- (2-hydroxyethoxy) -3-pheny I pheny I ) fluorene a I so termed BPPEF, 9, 9-bis (6-hydroxy-2-naphthy I ) fluorene, 9, 9-bis (6- (2-hydroxyeth- oxy) -2-naphthy I) fluorene, also termed 9, 9- bis (6- (2-hydroxyethoxy) naphthaIene- 2— y I ) fluorene (BNEF), 10, 10-b is (4-hydroxypheny I) anthracen-9-on, 10, 10— bis(4— (2-hydroxyethoxy) pheny I ) anthracen-9-on, 4, 4’ -d i hydroxytetrapheny I methane, 4, 4’ -di -(2-hydroxyethoxy) -tetraphenyl methane, 3, 3’ -di pheny I -4, 4’ -di hydroxy- tetrapheny I methane, d i - (6-hydroxy-2-naphthy I ) -d i pheny I methane, 2, 2’ - [1 , 1' - b inaphthaIene-2, 2’ -diy lb is (oxy)] di ethanol also termed 2, 2’ -bis (2-hydroxyeth- oxy) -1, 1’ -bi naphty I or 2, 2’ -bis (2-hydroxyethoxy) -1,1’ -bi naphthalene (BNE),

[0170] 2, 2’ -bis (1 -hydroxymethoxy) -1 , 1’ -b i naphty 1 , 2, 2’ -bis (3-hydroxypropy I oxy) -1,1’- bi naphty I, 2, 2’ -bis (4-hydroxybutoxy)-1,1’ -bi naphty 1 , 2, 2’ -bi s (2-hydroxyeth- oxy) -6, 6’ -d i pheny I -1 , 1’ -binaphthaIene, 2, 2’ -bis (2-hydroxyethoxy) -6, 6’ - d i (naphthaIene-1 -yI ) -1 , 1’ -binaphthaIene,

[0171] 2, 2’ -bis (2-hydroxymethoxy) -6, 6’ -d i pheny I -1 , 1’ -binaphthaIene, 2, 2’ -bis (2-hy- droxymethoxy) -6, 6’ -d i (naphthaIene-1 -yI ) -1 , 1’ -binaphthaIene, 2, 2’ -bis (2-hy- droxypropoxy)-6, 6’ -di pheny 1-1, 1’ -bi naphthaIene, 2, 2’ -bis (2- hydroxypropoxy) - 6, 6’ - di (naphthaIene-1 -yI )-1, 1’ -bi naphthaIene, 2, 2’ -bis (2-hydroxyethoxy) - 6, 6’ -d i (naphthaIene-2-yI ) -1 , 1’ -binaphthaIene, 2, 2’ -bis (2-hydroxyethoxy) -6,6’- di (9-phenanthry l)-1, 1’ -bi naphthaIene and the like. Among the monomers of the general formula (VI) or of formulae (VI-1) to (VI-6), particular preference is given to the monomers of formulae (VI-1), (VI-2), (VI-3) and (VI-6) with more preference being given to monomers of formulae (VI-1) and (VI-2) and in particular (VI-1). Among the monomers of the formulae (VI-11) to (VI-20), particular preference is given to the monomers of formulae (VI-11), (VI-12), (VI-14), (VI-19) and (V / -20) with more preference being given to monomers of formulae (VI-11), (VI-19) and (VI-20) and in particular to (VI-11). Special preference is given to 2, 2' -bis (2-hydroxyethoxy) -1, 1’ -bi naphtyI (BNE or BHBNA), 2, 2’ -bis (2-hydroxyethoxy) -6, 6’ -d i phenyI -1, 1’ -bi naphty I (DPBHBNA) , 9, 9-bis (4- (2-hydroxyethoxy) pheny I ) fluorene (BPEF) , 9, 9-bis (6- (2-hydroxyeth- oxy) -2-naphthy I) fluorene (BNEF) and 9, 9- bis (4- (2-hydroxyethoxy) -3-phe- nylphenyI) fluorene (BPPEF). More specific preference is given 9, 9— bis (4- (2— hydroxyethoxy) pheny I ) fluorene (BPEF) , 9, 9-bis (6- (2-hydroxyethoxy) -2- naphthyl) fluorene (BNEF) and 9, 9-bis(4-(2-hydroxyethoxy)-3-phenylphenyl)f I uo— rene (BPPEF) , and very specific preference to 9, 9-bis(4-(2-hydroxyethoxy)phe- ny I ) fluorene.

[0172] Accordingly, among the structural units of formula (V) that may be comprised in the thermoplastic resin, preference is given to structural units of the general formulae (V— 1) to (V-6), where a and b are 0, 1, 2 or 3, in particular 0 or 1 ; c and d are 0, 1, 2, 3, 4 or 5, in particular 0 or 1 ; e and f are 0, 1, 2, 3, 4 or 5, in particular 0 or 1 ; and where Rz, Raa, Rab, R7aand R7bare as defined for formula (V) and where Rzis in particular selected from a single bond, CH2and OCH2CH2

[0173] Particular preference is given to structural units of the general formulae (V— 11) to (V-20) , where Rzand Raaare as defined herein and where Rzis in particular selected from a single bond, CH2and O-CH2CH2, and especially is O-CH2CH2:

[0174]

[0175] Among the structural units of the formulae (V-1) to (V-6) , particular prefer- ence is given to the structural units of formulae (V-1), (V-2) and (V-6).

[0176] Among the structural units of the formulae (V— 11) to (V-20), particular pref- erence is given to the structural units of formulae (V— 11) , (V-12), (V-14), (V-19) and (V-20) with more preference being given to structural units of formulae (V-11), (V-19) and (V-20) and in particular to (V— 11) . Special pref- erence is given to structural units derived from 2, 2’-bis(2-hydroxyethoxy)-1,1’ -binaphtyl (BNE or BHBNA) , 2, 2’ -bis(2-hydroxyethoxy)-6, 6' —diphenyl— 1,1’ - binaphtyl (DPBHBNA) and, in particular, 9, 9- bis (4- (2-hydroxyethoxy) phe- nyl) fluorene (BPEF). In a particular preferred group of embodiments, the thermoplastic resin of the present invention comprises at least one structural unit of the formula (III.1) or (III.1.1) and at least one structural unit selected from the group consisting of structural units of the formula (V-11), structural units of the formula (V-19) and structural units of the formula (V-20). In this particular group of embodiments, those thermoplastic resins are preferred, where in the structural units of the formulae (V-11), (V-19) and (V-20) the radicals RZare O-CH2CH2. More particularly, the thermoplastic resin of the present inven- tion comprises at least one structural unit of the formula (III.1.1) and at least one structural unit of the formula (V-11). In this particular embodi- ment, those thermoplastic resins are preferred, where in the structural units of the formula (V-11) the radicals RZare O-CH2CH2.

[0177] In the thermoplastic resins, it is preferred that the total molar ratio of the structural units of the formula (III) is in the range from 1 to 70 mol-%, preferably in the range from 5 to 60 mol-%, further preferably in the range from 8 to 45 mol-%, and even further preferably in the range from 10 to 30 mol-% of the total amount of structural units of the formulae (III) and (V). It is also preferred that the molar ratio of the structural units of the for- mula (V) is from 30 to 99 mol-%, preferably in the range from 40 to 95 mol-%, further preferably in the range from 55 to 92 mol-%, and even further prefer- ably in the range from 70 to 90 mol-%, based on the total molar amount of structural units of the formulae (III) and (V).

[0178] A further embodiment of the present invention relates to thermoplastic resins having only low, almost no or no birefringence. The resins in this context are characterized by having structural units of formula (III), such as in particular formula (III.1) or (III.1.1), wherein the variables have one of the above preferred meanings, and additionally one or more structural units different from the structural units of formula (III) which are preferably se- lected from structural units of the formula (V), in particularly from structural units of formulae (V— 11), (V— 12), (V— 14), (V— 19) and (V-20) and specifically from structural units of the formulae (V— 11), (V— 19) and (V-20). In the thermoplastic resins of this particular preferred embodiment, it is preferred that the total molar ratio of the structural units of the formulae (III), (III.1) or (III.1.1) is in the range from 1 to 70 mol-%, preferably in the range from 5 to 60 mol-%, further preferably in the range from 8 to 45 mol-%, and even further preferably in the range from 10 to 30 mol-% of the total amount of structural units of the formulae (III) and (V).

[0179] The compounds of the formulae (VI), (VI-1), (VI-2), (VI-3), (VI-4), (VI-5), (VI-6), (VI-11), (VI-12), (VI-13), (VI-14), (VI-15), (VI-16), (VI-17), (VI- 18), (VI-19) and (VI-20) are known or can be prepared by analogy to known methods.

[0180] For example, the compounds of the formula (VI-6) can be prepared by various synthesis methods, as disclosed e. g. in JP Publication No. 2014-227387, JP Publication No. 2014-227388, JP Publication No. 2015-168658, and JP Publica- tion No. 2015-187098. For example, 1,1’ -binaphthols may be reacted with eth- ylene glycol monotosylates; alternatively, 1,1’ -bi naphtho Is may be reacted with alkylene oxides, halogenoalkanols, or alkylene carbonates; and alterna- tively, 1,1’ -binaphthols may be reacted with ethylene carbonates. Thereby, the compounds of the formula (VI-6) are obtained where Rz-0H is O— AIk2— or 0- AIk2- [O-AIk2-]p-

[0181] For example, the compounds of the formula (VI-2) can be prepared by various synthesis methods, as disclosed e. g. in JP Patent Publication No. 5442800, and JP Publication No. 2014-028806. Examples include:

[0182] (a) reacting fluorenes with hydroxy naphthalenes in the presence of hydro- chloride gas and mercapto-carboxyI ic acid;

[0183] (b) reacting 9-fluorene with hydroxy naphthalenes in the presence of acid catalyst (and alkyl mercaptan) ;

[0184] (c) reacting fluorenes with hydroxy naphthalenes in the presence of hydro- chloride and thiols (such as, mercapto-carboxyl ic acid) ;

[0185] (d) reacting fluorenes with hydroxy naphthalenes in the presence of sulfuric acid and thiols (such as, mercapto-carboxy I ic acid) and thereafter to crys- tallize the product from a crystallization solvent which consists of hydro- carbons and a polar solvent(s) to form bisnaphthol fluorene; and the like. Thereby, compounds of the formula (VI-2) can be obtained where Rzis a single bond.

[0186] The compounds of formulae (VI), where Rzis O— AIk2— or O— AIk2- [ O—AIk2-]p- can be prepared from compounds of formulae (VI) where Rzis a single bond, by re- action with alkylene oxides or haloalkanols. For example, reacting 9,9— bi s (hydroxynaphthyl)-fluorenes of the formula (VI-2) where Rzis a single bond with alkylene oxides or haloalkanols results in the compounds of the formula (VI-2) where Rzis O— AIk2— or O— AIk2- [O— AIk2- ]p- . For example, 9,9- bis[6-(2-hydroxyethoxy) naphthyl] fluorene can be prepared by reacting 9,9- bis[6-(2-hydroxynaphthyl] fluorene with 2-chloroethanol under alkaline condi- tions.

[0187] The monomers of formula (I) and likewise the co-monomers of formula (VI) used for producing the thermoplastic resin may contain certain impurities result- ing from their preparation. For example, the compounds (I) may contain a halogen atom or a sulfonate group instead of a group (II) (the halogen atom or sulfonate group corresponding to LG in scheme 1 above and being due to in- complete conversion in the Suzuki reaction) ; and e. g. the co-monomers (VI) may contain hydroxy compounds which bear an OH group instead of e. g. a group O— AIk2— OH, or may contain a group O-AIk2- [O-AIk2]p- instead of a group O— AIk2— . The total amount of such impurity compounds is preferably 5000 ppm or lower, more preferably 3000 ppm or lower, more preferably 2000 ppm or lower, and especially preferably 1000 ppm or lower. The total content of the impuri- ties in the monomers used for preparing the thermoplastic resin is preferably 4000 ppm or lower in particular 1500 ppm or lower, and more preferably 1000 ppm or lower. In particular, the total amount of dihydroxy compounds in which a carbon number of at least one of the radicals RZ-OH differs from the formula (VI), is preferably 3000 ppm or lower, more preferably 1500 ppm or lower, still more preferably 1000 ppm or lower, and especially preferably 500 ppm or lower; in the monomer (s) of which the main component is the di hy- droxy compound (s) represented by the formula (VI). The total content of the di hydroxy compounds in which a carbon number of at least one of the radicals RZ-OH differs from the formula (VI) is further preferably 1000 ppm or lower, and more preferably 500 ppm or lower. Likewise, the amount of impurities in the monomers of formula (I) will be in the range given for the monomers of formula (VI).

[0188] Suitable thermoplastic resins for the preparation of optical devices, such as lenses, are in particular polycarbonates, polyestercarbonates and polyesters. Preferred thermoplastic resins for the preparation of optical devices, such as lenses, are in particular polycarbonates.

[0189] Said polycarbonates are structurally characterized by having structural units of the formula (III.1), optionally structural units derived from diol mono- mers which are different from the monomer compound of the formula (I) wherein Z1and Z2are OH, in particular structural units of the formula (V)

[0190] #-O-Rz-A1-Rz-O-# (V), where #, Rzand A1are as defined herein above; and a structural unit of formula (IV— 1) stemming from a carbonate-forming component; where each # represents a connection point to a neighboring structural unit, i.e. to 0 at the connection point of the structural unit of the formula

[0191] (III.1) and, if present, to 0 at the connection point of the structural unit of the formula (V). Thermoplastic resins can be polyestercarbonates and / or polyesters and therefore, a structural unit represented by formulae (V) and (IV-1) or formulae (IV— 2) to (IV— 5) below can be varied so that the thermo- plastic resins include polyestercarbonate units and / or polyester units. Said polyesters are structurally characterized by having at least structural units of the formula (III) and, depending on the nature of the bridging groups Z11and Z12, either structural units derived from dicarboxylic acids (if Z11and Z12are -O-; some examples of suitable units derived from dicar- boxylic acids are depicted in below formulae (IV— 2) to (IV— 5)) or structural units derived from a diol (if Z11and Z12are - C (O) O— ; examples of suitable units derived from diols are the above units of formula (V) and units derived from other diols, such as aliphatic diols, e. g. ethylene glycol, propanediol, butanediol, pentanediol and hexanediol ; alicyclic diols, e. g. tri cy- clo [5.2.1.02, 6] decane dimethanol, eye I ohexane-1, 4-dimethanol, decalin-2, 6— d i — methanol, norbornane dimethanol, pentacyclopentadecane dimethanol, cyclopen- tane-1, 3-dimethanol, spiroglycol, 1 , 4 : 3, 6-dianhydro— D— sorb i to 1 , 1,4:3, 6— di- anhydro— D—mann i to I and 1 , 4 : 3, 6— d i anhydro— L- i d i to I , or aromatic diols differ- ent from diols (VI)). If one of Z11or Z12is -O- and the other is -C(O)O-, no further structural units need to be present, but preferably, units derived from at least one diol, especially from at least one of the above-mentioned diols, and / or at least one unit derived from at least one di carboxylic acid, especially from at least one of the above-mentioned dicarboxylic acid, are present.

[0192] Preferably however, said polyesters are structurally characterized by having at least structural units of the formula (III.1), optionally structural units derived from diol monomers which are different from the monomer compound of the formula (I) wherein Z1and Z2are OH, in particular structural units of the formula (V), and structural units derived from dicarboxylic acids, e. g. of formula (IV— 2) in case of a benzene dicarboxyl ic acid, of formula (IV— 3) in case of a naphthalene carboxylic acid, of formula (IV— 4) in case of oxalic acid and of formula (IV— 5) in case of malonic acid:

[0193] In formula (IV— 2) to (IV— 5) each variable # represents a connection point to a neighboring structural unit, i.e. to 0 of the connection point of the structural unit of the formula (III.1) and, if present, to O of the connec- tion point of the structural unit of the formula (V).

[0194] Said polyestercarbonates are structurally characterized by having structural units of the formula (III), a structural unit of formula (IV— 1) stemming from a carbonate-forming component and, depending on the nature of the bridging groups Z11and Z12, either structural units derived from dicarboxylic acids (if Z11and Z12are -O-; examples of suitable units derived from dicarboxyl ic acids are depicted in above formulae (IV— 2) to (IV— 5)) or structural units derived from a diol (if Z11and Z12are -C(O)O-; examples of suitable units derived from diols are the above units of formula (V) or from the above-men- tioned diols different from diols (VI)). Preferably however, said polyestercarbonates are structurally characterized by having structural units of the formula (III.1), optionally structural units derived from diol monomers which are different from the monomer com- pound of the formula (I) wherein Z1and Z2are OH, in particular structural units of the formula (V), a structural unit of formula (IV— 1) stemming from the carbonate-forming component and structural units derived from di carbox- ylic acid, e. g. of formula (IV— 2) in case of a benzene dicarboxylic acid, of formula (IV— 3) in case of a naphthalene carboxylic acid, of formula (IV— 4) in case of oxal ic acid and of formula (IV— 5) in case of malonic acid.

[0195] A particular group of embodiments relates to thermoplastic copolymer resins, in particular polycarbonates, polyestercarbonates and polyesters, which have both structural units of formula (III), in particular (III.1), and one or more structural units of formula (V), i.e. resins, in particular polycar- bonates, polyestercarbonates and polyesters, which are obtainable by reacting at least one monomer of formula (I), in particular a monomer (I) wherein Z1and Z2are OH, with one or more monomers of formula (VI). In this case the molar ratio of monomers of formula (I) to monomers of formula (VI) and like- wise the molar ratio of the structural units of formula (III), in particular (III.1), to structural units of formula (V) are in the range from 5:95 to 80:20, in particular in the range from 10:90 to 70:30 and especially in the range from 15:85 to 60:40 or in the range from 1:99 to 70:30, in particular in the range from 5:95 to 60:40, more preferably in the range from 8:92 to 45:55 or in the range from 10:90 to 40:60 and especially in the range from 10:90 to 30:70 or in the range from 15:85 to 25:75. Accordingly, the molar ratio of the structural units of the formula (III), in particular (III.1), is usually from 1 to 70 mol-%, in particular from 5 to 60 mol-%, more preferably in the range from 8 to 45 mol-% or in the range from 10 to 40 mol-%, espe- cially in the range from 10 to 30 mol-% or in the range from 15 to 30 mol-%, and specifically in the range from 12 to 25 mol-% or in the range from 15 to 25 mol-%, based on the total molar amount of structural units of the formulae (III.1) and (V). Accordingly, the molar ratio of the structural units of the formula (V) is usually from 30 to 99 mol-% in particular from 40 to 95 mol-%, more preferably in the range from 55 to 92 mol-% or in the range from 60 to 90 mol-%, especially in the range from 70 to 90 mol-% or in the range from 70 to 85 mol-%, and specifically in the range from 75 to 88 mol-% or in the range from 75 to 85 mol-%, based on the total molar amount of structural units of the formulae (III.1) and (V).

[0196] The thermoplastic copolymer resins of the present invention, such as a poly- carbonate resin, may include either one of a random copolymer structure, a block copolymer structure, and an alternating copolymer structure. The ther- moplastic resin according to the present invention does not need to include all of structural units (III) and one or more different structural units (V) in one, same polymer molecule. Namely, the thermoplastic copolymer resin ac- cording to the present invention may be a blend resin as long as the above- described structures are each included in any of a plurality of polymer mole- cules. For example, the thermoplastic resin including all of structural units (III) and structural units (V) described above may be a copolymer including al l of structural units (III) and structural units (V), it may be a mixture of a homopolymer or a copolymer including at least one structural unit (III) and a homopolymer or a copolymer including at least one structural unit (V) or it may be a blend resin of a copolymer including at least one structural unit (III) and a first structural unit (V) and a copolymer including at least one structural unit (III) and at least one other structural unit (V) differ- ent from the first structural unit (V) ; etc.

[0197] Thermoplastic polycarbonates are obtainable by polycondensation of a diol component and a carbonate-forming component. Similarly, thermoplastic polyes- ters are obtainable by polycondensation of a diol component and a dicarbox- ylic acid or an ester-forming derivative thereof or by polycondensation of a compound (I) wherein one of Z1and Z2is -OH and the other is -C(O)ORX. Poly- estercarbonates are obtainable by polycondensation of a diol component, a di- carboxylic acid or an ester-forming derivative thereof and a carbonate-form- ing component.

[0198] The present invention relates also to a method for preparing a resin accord- ing to the invention by subjecting a monomer compound (I) to a polycondensa- tion reaction with a suitable counterpart monomer for obtaining a polycar- bonate, a polyester or a polyestercarbonate. The suitable counterpart depends on the resin to be prepared and the nature of the groups Z1and Z2in the mon- omer (I).

[0199] For instance, for preparing a polycarbonate, a monomer compound (I), wherein Z1and Z2are OH, is subjected to a polycondensation reaction with a car- bonate-forming compound (also termed carbonate precursor), such as a compound LG1— C (=O) — LG1, where each LG1is independently a suitable leaving group, such a halogen atom, OCCI3or a group OR, where R is C1— C4- alkyl , phenyl, chloro- phenyl, tolyl, naphthyl and the like, e. g. phosgene, di phosgene and di ester carbonates such as diethyl carbonate, diphenyl carbonate, di- p- tolyl car- bonate, phenyI— p— tolyl carbonate, di-p-chlorophenyl carbonate and dinaphthyl carbonate.

[0200] For instance, for preparing a polyester, a monomer compound (I), wherein Z1and Z2are OH, is subjected to a polycondensation reaction with dicarboxylic acid or a suitable derivative thereof, such as a dicarboxylic acid halide or a di ester. Suitable dicarboxylic acid (derivatives) are for example compounds (VI 1-2) to (VI 1-5), where X is OH, a halogen atom, especially 01 or Br, or a group OR, where R is C1- C4—alky I, phenyl and the like:

[0201] Further examples for suitable di carboxy lie acid (derivatives) are mentioned below.

[0202] Alternatively, for preparing a polyester, a monomer compound (I), wherein Z1and Z2are - C(O) ORx, is subjected to a polycondensation reaction with a diol. Suitable diols are compounds (VI) as well as the diols mentioned above or be- low which are different from compounds (VI).

[0203] For instance, for preparing a polyestercarbonate, a monomer compound (I), wherein Z1and Z2are OH, is subjected to a polycondensation reaction with a carbonate-forming compound, such as the compound LG1— C (=O) — LG1mentioned above, and a di carboxylic acid or a suitable derivative thereof, such as the di carboxy I io acid (derivatives) mentioned above, or wherein a monomer com- pound (I), wherein Z1and Z2are -C(O)ORX, is subjected to a polycondensation reaction with a carbonate-forming compound, such as the compound LG1-C (=O) -LG1mentioned above, and a diol, such as the diols mentioned above in context with the polyesters.

[0204] Preferably, the method for preparing a polycarbonate comprises subjecting a monomer compound (I), wherein Z1and Z2are OH, to a polycondensation reaction with a carbonate-forming compound, such as the above-mentioned compound LG1- C(=O)-LG1, and optionally with a diol different from said compound (I), pref- erably with a diol (VI) and more preferably with one of the preferred diols (VI), such as (VI-11). In particular, the method for preparing a polycar- bonate comprises subjecting a monomer compound (1.1) to a polycondensation reaction with a carbonate-forming compound, such as the compound LG1-C(=O)- LG1, and optionally with a diol different from said compound (I), preferably with a diol (VI) and more preferably with one of the preferred diols (VI), such as (VI-11). Further details to the method are given below.

[0205] Specifically, thermoplastic resins (polycarbonate resins) can be prepared by the fol lowing methods.

[0206] A method for preparing the thermoplastic resin of the present invention, such as a polycarbonate resin, includes a process of melt polycondensation of a di hydroxy component corresponding to the above-mentioned structural units and a di ester carbonate. According to the present invention the di hydroxy com- pound comprises at least one di hydroxy compound represented by the formula (I) wherein Z1and Z2are OH, in particular by the formula (1.1). In addition to the compound of formula (I), the di hydroxy compound may also comprise one or more di hydroxy compounds represented by the formula (VI), preferably by the formulae (VI-1) to (VI-6), in particular by the formulae (VI-11) to (VI- 20), more particularly by the formulae (VI-11), (VI-12), (VI-14), (VI-19) or (VI-20), especially by the formulae (VI-11), (VI-19) or (VI-20), and very es- pecially by the formula (VI-11).

[0207] As is clear from the above, the polycarbonate resin can be formed by reacting a dihydroxy component with a carbonate precursor such as LG1— C (=O) — LG1, e. g. a diester carbonate, where the di hydroxy component comprises at least one com- pound represented by the formula (I), in particular (1.1), and at least one compound represented by the formulae (VI), (VI-1), (VI-2), (VI-3), (VI-4), (VI-5), (VI-6), (VI-11), (VI-12), (VI-13), (VI-14), (VI-15), (VI-16), (VI- 17), (VI-18), (VI-19) or (VI-20). Specifically, a polycarbonate resin can be formed by a melt polycondensation process in which the compound represented by the formula (I), (I), in particular (1.1), or a combination thereof with at least one compound of the formulae (VI), (VI-1), (VI-2), (VI-3), (VI-4), (VI-5), (VI-6), (VI-11), (VI-12), (VI-13), (VI-14), (VI-15), (VI-16), (VI- 17), (VI-18), (VI-19) or (VI-20) and a carbonate precursor, such as the com- pound LG1- C (=O)-LG1, e. g. a di ester carbonate, are reacted in the presence of a basic compound catalyst, a transesterification catalyst, or a mixed cata- lyst thereof, or in the absence of a catalyst.

[0208] Analogously, a thermoplastic resin (or a polymer) other than a polycarbonate resin, such as polyesters and polyestercarbonates can for example be obtained by melt polycondensation using either the di hydroxy compound represented by the formula (I) wherein Z1and Z2are OH, in particular (1.1), or a combina- tion thereof with at least one compound represented by the formulae (VI), (VI-1), (VI-2), (VI-3), (VI-4), (VI-5), (VI-6), (VI-11), (VI-12), (VI-13), (VI-14), (VI-15), (VI-16), (VI-17), (VI-18), (VI-19) or (VI-20) as a material (or a monomer), and a dicarboxylic acid (derivative), in particular one of the compounds (VI 1-2) to (VI 1-5), or using a dicarboxylic compound (I) wherein Z1and Z2are C(O) ORxand one of the above-mentioned diols, in partic- ular a diol (VI). For obtaining a polyestercarbonate, additionally a car- bonate-forming compound, such as the compound LG1-C(=O)-LG1, is used.

[0209] As mentioned before, the monomers of formula (I) and likewise the co-monomers of formula (VI) used for producing the thermoplastic resin may contain impu- rities resulting from their preparation.

[0210] In particular, the total amount of impurities in the compound of formula (I) is preferably 1000 ppm or lower, more preferably 500 ppm or lower, still more preferably 200 ppm or lower, and especially preferably 100 ppm or lower.

[0211] The polycarbonate resins is preferably obtained by reacting the monomer com- pounds of the formula (I) wherein Z1and Z2are OH or by reacting combination of at least one monomer compound of the formula (I) wherein Z1and Z2are OH, in particular at least one monomer (I) wherein Z1and Z2are OH mentioned herein as preferred, and one or more monomer compounds of the formula (VI), in particular of the formulae (VI-11), (VI-12), (VI-14), (VI-19) or (VI-20), especially of the formulae (VI-11), (VI-19) or (VI-20), and the like, and very especially (VI-11), as dihydroxy components; with carbonate precursors, such as the compound LG1-C (=O)-LG1, e. g. diester carbonates.

[0212] However, in a polymerization process for manufacturing the polycarbonate res- ins, some compounds of the formulae (I) and (VI) may be converted into impu- rities. For instance, in compounds (VI) one of or both of the terminal OH radicals may be replaced with a different radical, such as a vinyl terminal radical represented by -OCH=CH2, and in compounds (I) wherein X1-Z1and / or X2- Zzis C2-C5-aIkyIene-OH, this group may be replaced by an olefinic moiety via water elimination (e. g. in case of -CH2CH2-OH by -CH=CH2) . Because the amount of such impurities is generally small, the prod- ucts of the formed polymers can be used as polycarbonate resins without a pu- rification process.

[0213] The thermoplastic resin of the present invention may also contain minor amounts of impurities, for example, as extra contents of thermoplastic resin composition or a part of the polymer skeleton of the thermoplastic resin. The examples of such impurities include phenols formed by a process for forming the thermoplastic resin (if, for example, di phenyl carbonate is used as car- bonate-forming component), unreacted di ester carbonates and monomers. The to- tal amount of impurities in the thermoplastic resin may be 5000 ppm or lower, or 2000 ppm or lower. The total amount of impurities in the thermoplastic resin is preferably 1000 ppm or lower, more preferably 500 ppm or lower, still more preferably 200 ppm or lower, and especially preferably 100 ppm or I ower.

[0214] The total amount of phenols as impurities in the thermoplastic resin may be 3000 ppm or lower, or 2000 ppm or lower. The total amount of phenols as impurities is preferably 1000 ppm or lower, more preferably 800 ppm or lower, still more preferably 500 ppm or lower, and especially preferably 300 ppm or lower.

[0215] The total amount of di ester carbonates as impurities in the thermoplastic resin is preferably 1000 ppm or lower, more preferably 500 ppm or lower, still more preferably 100 ppm or lower, and especially preferably 50 ppm or lower.

[0216] The total amount of unreacted monomers as impurities in the thermoplastic resin is preferably 3000 ppm or lower, more preferably 2000 ppm or lower, still more preferably 1000 ppm or lower, and especially preferably 500 ppm or lower.

[0217] The lower limit of the total amount of these impurities is not important, but may be 0.1 ppm, or 1.0 ppm.

[0218] The total amount of residual transition metals, such as palladium, (the tran- sition metals stemming generally from the esterification catalyst (if a tran- sition metal-containing catalyst was used at all) and / or from the Suzuki re- action used for preparing monomer (I)) as impurity in the thermoplastic resin is preferably 50 ppm or lower, more preferably 10 ppm or lower. The amount of residual palladium can be reduced by standard procedures like treatment with an adsorbent, e. g. active charcoal.

[0219] Resins having targeted characteristics can be formed by adjusting the amounts of phenols and di ester carbonates. The amounts of phenols, di ester car- bonates, and monomers can be suitably adjusted by arranging the conditions for polycondensation, the working conditions of devices used for polymeriza- tion, or the conditions for extrusion molding after the polycondensation pro- cess.

[0220] The weight-average molecular weight (M„), as determined by GPG (gel permea- tion chromatography), of the thermoplastic resin according to the present in- vention is preferably in the range from 5000 to 100000 Dalton, more prefera- bly 10000 to 80000 Dalton, still more preferably 10000 to 50000 Dalton, 15000 to 55000 Dalton, or 20000 to 60000 Dalton, and in particular in the range from 15000 to 50000 Dalton, 15000 to 55000 Dalton, 20000 to 50000 Dalton, 20000 to 55000 Dalton, 25000 to 55000 Dalton, or 30000 to 50000 Dalton. The GPG measurements may be calibrated by using polystyrene standards. The Mwof a thermoplastic resin of the present invention determined this way may also denoted herein as “polystyrene conversion Mw” , “polystyrene converted Mw” or “Mwdetermined by GPG against a polystyrene standard” . The number-aver- age molecular weight (Mn) of the thermoplastic resin according to the present invention is preferably 3000 to 20000, more preferably 5000 to 15000, and still more preferably 7000 to 14000. The Mnmay be determined analogously to the Mwby GPG measurement calibrated against a polystyrene standard, as de- scribed herein below. The viscosity-average molecular weight (Mv) of the ther- moplastic resin according to the present invention is preferably in the range from 8000 to 20000, more preferably 9000 to 15000, and still more preferably 10000 to 14000.

[0221] The value of the molecular weight distribution (Mw / Mn) of the thermoplastic resin according to the present invention is preferably 1.5 to 9.0, more pref- erably 1.8 to 7.0, and still more preferably 2.0 to 4.0. When a thermoplastic resin has the value of the weight-average molecular weight (Mw) within the above-mentioned suitable range, a molded article made from the thermoplastic resin has high strength. In addition, such a thermo- plastic resin with the suitable Mwvalue is advantageous for molding because of its excel lent fluidity.

[0222] In a particular group of embodiments, the thermoplastic resin of the present invention comprises at least 0.3 % by weight, preferably at least 0.5 % by weight, more preferably at least 0.8 % by weight and in particular at least 1.0 % by weight of low molecular weight compounds having a molecular weight of less than 1000, based on the total weight of the thermoplastic resin.

[0223] The upper l imit of said content of low molecular weight compounds having a Mwof less than 1000 is typically 7.0 % by weight, preferably 5.0 % by weight, more preferably 3.0 % by weight, even more preferably 2.0 % by weight, in particular 1.8 % by weight and specificaI ly 1.7 % by weight. Accordingly, in this particular group of embodiments the content of low molecular weight com- pounds having a molecular weight Mwof less than 1000 in the thermoplastic resin is typically in the range of 0.3 to 7.0 % by weight, preferably in the range of 0.5 to 5.0 % by weight, more preferably 0.8 to 3.0 % by weight, even more preferably in the range of 1.0 to 2.0 % by weight, in particular in the range of 1.0 to 1.8 % by weight and specifically in the range of 1.0 to 1.7 % by weight, based in each case on the total weight of the thermoplastic resin.

[0224] Thermoplastic resins of the present invention comprising low molecular weight compounds with Mw-values of less than 1000 in an amount within the above ranges form molded bodies that have high mechanical strength. Such thermo- plastic resins are in particular not or barely prone to separation or precip- itation of said low molecular weight compounds, also known as bleed-out, in the course of molding processes, such as injection molding. In addition, the thermoplastic resins of the present invention, which contain the low molecu- lar weight compounds in the amounts defined above, have the advantageous properties of high molding speed and reduced energy requirements for molding processes due to their high plasticity.

[0225] The content of the low-molecular-weight compounds in the thermoplastic resin is determined based on the diagram of the GPC analysis described above. In particular, said content is calculated as the ratio of the total area of the peaks of the low-molecular-weight compounds to the total area of all peaks of the diagram obtained by GPC analysis of a thermoplastic resin. Thus, the con- tent of the low molecular weight compounds in the thermoplastic resin (CLWC) is represented by following formula:

[0226] The above-mentioned polycarbonate resin has a high refractive index (nDor nd) and thus is suitable to an optical lens. The values of the refractive index as referred herein are values of a fi lm having a thickness of 0.1 mm may be measured by use of an Abbe refractive index meter by a method of JIS-K— 7142. The refractive index of the polycarbonate resin according to the present in- vention at 23° C at a wavelength of 589 nm is, in case the resin includes the structural unit (III), usually 1.640 or higher, preferably 1.645 or higher, more preferably 1.650 or higher. The thermoplastic resins pf the present in- vention may have a refractive index of 1.660 or higher, or 1.670 or higher; preferably 1.680 or higher or 1.690 or higher; and more preferably 1.6950 or higher or 1.700 or higher.

[0227] For example, the refractive index of the copolycarbonate resin including the structural unit (III.1) and a structural unit (V) according to the present invention is preferably 1.650 to 1.670 or 1.650 to 1.660. The thermoplastic resins pf the present invention may have a refractive index of 1.650 to 1.705, 1.655 to 1.700 or 1.660 to 1.690.

[0228] The Abbe number ( - ) of the polycarbonate resin is preferably 24 or lower, more preferably 23 or lower, and still more preferably 22 or lower, 20 or lower, or 18 or lower. The Abbe number may be calculated by use of the fol lowing equation based on the refractive index at wavelengths of 487 nm, 589 nm and 656 nm at 23° C.

[0229] ■ = (nD- 1) / (nF- nC) nD: refractive index at a wavelength of 589 nm nC: refractive index at a wavelength of 656 nm nF: refractive index at a wavelength of 486 nm

[0230] The glass transition temperature (Tg) of the thermoplastic resin according to the present invention can be 80 to 290° C or 90 to 290° C, preferably 95 to 280° C or 100 to 285° C.more preferably 110 to 275° C or 120 to 280° C.

[0231] The glass transition temperature (Tg) of the polycarbonate resin as an exam- ple of the thermoplastic resin according to the present invention is, in con- sideration of that the polycarbonate is usable for injection molding, prefer- ably 90 to 185° C, more preferably 125 to 175° C, and still more preferably 140 to 165° C. With regard to the molding fluidity and the molding heat re- sistance, the lower limit of Tgis preferably 130° C and more preferably 135° C, and the upper limit of Tgis preferably 185° C and more preferably 175° C. A glass transition temperature (Tg) in the above given ranges pro- vides a significant range of usable temperature and avoids the risk that the melting temperature of the resin may be too high, and thus the resin may be undesirably decomposed or colored. What is more, it al lows for preparing molds having have a high surface accuracy. The values given for the glass transition temperature refer to the values determined by differential scan- ning calorimetry (DSC) using a 10° C / minute heating program according to the protocol of JIS K7121-1987.

[0232] In a preferred embodiment, the absolute value of the orientation birefrin- gence of the thermoplastic resin is preferably in the range of 0 to 1x10-1or 0 to 1x10-2, more preferable in the range of 0 to 5x10-3, even more prefera- ble in the range of 0 to 2x103, in particular in the range of 0 to 1x10-3, and specifically in the range of 0 to 0.4x10-3.

[0233] An optical molded body such as an optical element produced by using a poly- carbonate resin of the present invention has a total light transmittance of preferably 85% or higher, more preferably 87% or higher, and especially pref- erably 88% or higher. A total light transmittance of preferably 85% or higher is as good as that provided by bisphenol A type polycarbonate resin or the Iike. The thermoplastic resin according to the present invention has high moisture and heat resistance. The moisture and heat resistance may be evaluated by performing a "PCT test" (pressure cooker test) on a molded body such as an optical element produced by use of the thermoplastic resin and then measuring the total I ight transmittance of the molded body after the PCT test. In the PCT test, first, an injection molded body having a diameter of 50 mm and a thickness of 3 mm is kept for 20 hours with PC305S III made by HIRAYAMA Cor- poration under the conditions of 120° C, 0.2 MPa, 100%RH for 20 hours. Then, the sample of the injection molded body is removed from the device and the total light transmittance is measured using the SE2000 type spectroscopic parallax measuring instrument made by Nippon Denshoku Industries Co., Ltd in accordance with the method of JIS— K— 7361 — 1.

[0234] The thermoplastic resin according to the present invention has a post-PCT test total light transmittance of 60% or higher, preferably 70% or higher, more preferably 75% or higher, stil l more preferably 80% or higher, and espe- cially preferably 85% or higher. As long as the total light transmittance is 60% or higher, the thermoplastic resin is considered to have a higher mois- ture and heat resistance than that of the conventional thermoplastic resin.

[0235] The thermoplastic resin according to the present invention has a b value, which represents the hue, of preferably 5 or lower. As the b value is smaller, the color is less yellowish, which is good as a hue.

[0236] According to the invention, the diol component, which is used in the prepara- tion of the polycarbonates or polyesters, may additionally comprise one or more diol monomers, which are different from the monomer compound of the for- mula (I) (wherein Z1and Z2are OH), such as one or more monomers of the for- mula (VI).

[0237] Suitable diol monomers, which are different from the monomer compound of the formula (I) ) (wherein Z1and Z2are OH), are those which are conventionally used in the preparation of polycarbonates, e. g. aliphatic diols such as ethylene glycol, propanediol, butanediol, pen- tanediol and hexanediol; alicyclic diols such as tr i eye Io [5.2.1.02, 6] decane dimethanol, cyclohex- ane-1, 4-dimethanol, decal in-2, 6-dimethanol, norbornane dimethanol, penta- cycl opentadecane dimethanol, cyclopentane-1, 3-dimethanol, spiroglycol, 1, 4:3, 6-dianhydro-D-sorbitol, 1, 4:3, 6-dianhydro-D-mannitol and 1,4:3,6— d i anhydro— L— i d i to I are also included in examples of the diol; and aromatic diols, in particular aromatic diols of the formula (VI) such as bis (4-hydroxyphenyI ) methane, 1 , 1 -bis (4-hydroxyphenyI ) ethane, bis (4-hy- droxyphenyI ) ether, bis (4-hydroxyphenyI ) suIfoxide, bis (4-hydroxy- pheny I ) su I f i de, bis (4-hydroxyphenyI ) su I tone, bis (4-hydroxyphenyI ) ketone, 2, 2-bis (4-hydroxyphenyI) propane, 2, 2-b is (4-hydroxy-3-t-buty I phenyl) pro- pane, 2, 2-bis (4-hydroxy-3-methyIphenyl) propane, 1, 1-bi s (4-hydroxy- pheny I) cyclopentane, 1, 1 -bis (4-hydroxyphenyI) cyclohexane, 2, 2—bis(4—hy— droxypheny I) hexaf luoropropane, bis (4-hydroxyphenyI) diphenylmethane, 1, 1- bis (4-hydroxyphenyI )-1 -phenyl ethane, α, ω -bis [2- (p-hy dr oxy- phenyl) ethyljpo I yd i methyl si I oxane, α, ω -bis[3-(o-hydroxyphenyl)pro- pyI ] po I yd i methy I s i I oxane, 4, 4’ - [1 , 3-phenylenebis (1 -methy I ethy I i dene) hy- droxyphenyl]-1 -phenyl ethane, 9, 9-bis (4-hydroxyphenyI) fluorene, 9, 9-bis [4- (2-hydroxyethoxy) -3-methyI phenyI ] fluorene, 9, 9-bis [4- (2-hydroxyethoxy) -3- tert-butyI phenyI ] fluorene, 9, 9-bis [4- (2-hydroxyethoxy) -3- i so- propy I phenyI ] fluorene, 9, 9-bis [4- (2-hydroxyethoxy) -3-cycI ohex- y I pheny l]fluorene, 9, 9-bis (4-hydroxy-3-pheny Ipheny I) fluorene, 9, 9- bis (4- (2-hydr oxy ethy I ) pheny I ) fluorene, 9, 9-bis (4- (2-hydr oxyethyI ) -3-phe- ny I pheny l)fluorene, 9, 9-bis (6-hydroxy-2-naphthy I) fluorene, 9, 9- bis (6- (2- hydroxyethyI ) -2-naphthy I ) fluorene, 10, 10-bis (4-hydroxyphenyI ) anthracen-9- on,

[0238] 10, 10- bis (4- (2-hydroxyethy I ) phenyI ) anthracen-9-on and 2, 2’ - [1 , 1’ -b i naph- tha I ene-2, 2’ -d i y I bis (oxy) ] d i ethano I , also termed 2, 2’ - bis (2-hydroxyeth- oxy) -1 , 1’ -b i naphthy I or 2, 2’ -bis (2-hydroxyethoxy) -1 , 1’ -binaphthaIene (BNE) .

[0239] Preferably, the diol component comprises at least one monomer of the formula (VI) in addition to the monomer of formula (I). In particular, the total amount of monomers of formulae (I) and (VI) contribute to the diol component by at least 90% by weight, based on the total weight of the diol component or by at least 90 mol-%, based on the total molar amount of the diol monomers of the diol component. In particular, the diol component comprises at least one monomer selected from the monomers of formulae (VI-11) to (VI-20) in addition to the monomer of formula (I). More particularly, the diol component com- prises at least one monomer selected from the monomers of formulae (VI-11), (VI-12), (VI-14), (VI-19) and (VI-20) in addition to the monomer of formula (I). Especially, the diol component comprises at least one monomer selected from 2, 2’ -bis (2-hydroxyethoxy) -1 , 1’ -b i naphty 1 , 2, 2’ -bis (2-hydroxyethoxy) - 6, 6’ -di pheny 1-1, 1' -bi naphty I, 9, 9- bis (6- (2-hydroxyethoxy) -2-naphthy I) fluo- rene, 9, 9- bis (4- (2-hydroxyethoxy) pheny I) fluorene and 9, 9-bis (4-(2-hydroxyeth- oxy)-3-phenylphenyl)fluorene and combinations thereof; and more especially 9, 9-bis (4- (2-hydroxyethoxy) -3-pheny I pheny I) fl uor ene, in addition to the mono- mer of formula (I) .

[0240] Frequently, the relative amount of monomer compound of formula (I), based on the total weight of the diol component, is at least 1% by weight, preferably at least 2% or at least 5% by weight, in particular at least 8% by weight or at least 10% by weight and especially at least 12% by weight or at least 15% by weight, preferably in the range of 1 to 90% by weight or in the range of 5 to 90% by weight, in particular in the range of 2 to 80% by weight or in the range of 5 to 80% by weight or in the range of 8 to 80% by weight or in the range 10 to 80% by weight, especially in the range of 5 to 70% by weight or in the range of 8 to 70% by weight or in the range 10 to 70% by weight or in the range of 15 to 70% by weight, more especially in the range of 5 to 30% by weight or in the range of 8 to 30% by weight or in the range 10 to 30% by weight or in the range of 15 to 30% by weight, but may also be as high as

[0241] 100% by weight.

[0242] Frequently, the relative molar amount of monomer compound of formula (I), based on the total molar of the diol component, is at least 1 mol-%, prefera- bly at least 2 mol-% or at least 5 mol-%, in particular at least 8 mol-% or at least 10 mol-% and especially at least 12 mol-% or at least 15 mol-%, preferably in the range of 1 to 80 mol-% or in the range of 2 to 80 mol-% or in the range of 5 to 80 mol-% or in the range of 8 to 80 mol-%, in particular in the range of 2 to 70 mol-% or in the range of 5 to 70 mol-% or in the range of 8 to 70 mol-% or in the range of 10 to 70 mol-%, especially in the range of 5 to 60 mol-% or in the range of 8 to 60 mol-% or in the range of 10 to 60 mol-% or in the range of 12 to 60 mol— % or in the range of 15 to 60 mol-%, more especially in the range of 5 to 30 mol-% or in the range of 8 to 30 mol-% or in the range of 10 to 30 mol-% or in the range of 12 to 30 mol-% or in the range of 15 to 30 mol-%, or in the range of 15 to 25 mol-%, but may also be as high as 100 mol-%.

[0243] Consequently, the relative molar amount of monomer compound of formula (VI), based on the total molar of the diol component, will not exceed 99 mol-% or 98 mol-% or 95 mol-%, in particular not exceed 92 mol-% or 90 mol-% and espe- cially not exceed 88 mol-% or 85 mol-%, and is preferably in the range of 20 to 99 mol-% or in the range of 20 to 98 mol-% or in the range of 20 to 95 mol-% or in the range of 20 to 92 mol-%, in particular in the range of 30 to

[0244] 98 mol-% or in the range of 30 to 95 mol-% or in the range of 30 to 92 mol-% or in the range of 30 to 90 mol-%, especially in the range of 40 to 95 mol-% or in the range of 40 to 92 mol-% or in the range of 40 to 90 mol-% or in the range of 40 to 88 mol-% or in the range of 40 to 85 mol-%, more especially in the range of 70 to 95 mol-% or in the range of 70 to 92 mol-% or in the range of 70 to 90 mol-% or in the range of 70 to 88 mol-% or in the range of 70 to 85 mol-%, or in the range of 75 to 85 mol-%, but may also be as high as 99.9 mo I -%.

[0245] Frequently, the total molar amount of monomers of formula (I) and monomers of formula (VI) is at least 80 mol-%, in particular at least 90 mol-%, espe- cially at least 95 mol-% or up to 100 mol-%, based on the total molar amount of the diol monomers in the diol component.

[0246] Examples of further preferred aromatic dihydroxy compound, which can be used in addition to the monomers of formula (I) and optionally monomers of formula (VI) include, but are not limited to bisphenol A, bisphenol AP, bisphenol AF, bisphenol B, bisphenol BP, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol S, bisphenol P, bisphenol PH, bisphenol TMC, bi- sphenol Z and the I ike.

[0247] In order to adjust the molecular weight and the melt viscosity, the monomers forming the thermoplastic polymer may also include a monofunctional compound, in case of polycarbonates a monofunctional alcohol and in case of polyesters a monofunctional alcohol or a monofunctional carboxylic acid. Suitable mono- alcohols are butanol, hexanol and octanol. Suitable monocarboxyIic acids in- clude e. g. benzoic acid, propionic acid and butyric acid. In order to in- crease the molecular weight and the melt viscosity, the monomers forming the thermoplastic polymer may also include a polyfunctional compound, in case of polycarbonates a polyfunctional alcohol having three or more hydroxyl groups and in case of polyesters a polyfunctional alcohol having three or more hy- droxyl groups or a polyfunctional carboxylic acid having three or more car- boxyl groups. Suitable polyfunctional alcohols are e. g. glycerine, tri me- thylol propane, pentaerythrit and 1, 3, 5-tr i hydroxy pentane. Suitable poly- functional carboxylic acids having three or more carboxyl groups are e. g. tri mellitic acid and pyromel litic acid. The total amount of these compounds, will frequently not exceed 10 mol-%, based on the molar amount of the diol component.

[0248] Suitable carbonate-forming monomers are those which are conventionally used as carbonate-forming monomers in the preparation of polycarbonates, and include, but are not limited to, phosgene, diphosgene and diester carbonates such as diethyl carbonate, diphenyl carbonate, di— p— tolyl carbonate, phenyl- p— tolyl carbonate, di-p-chlorophenyl carbonate and di naphthyl carbonate. Out of these, diphenyl carbonate is particularly preferred. The carbonate forming monomer is frequently used at a ratio of 0.97 to 1.20 mol, and more prefera- bly 0.98 to 1.10 mol, with respect to 1 mol of the dihydroxy compound(s) in tota I .

[0249] Suitable dicarboxylic acids include, but are not limited to aliphatic di carboxy lie acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid; alicycl ic dicarboxylic acids such as tr i eye io [5.2.1.02, 6] decane dicarbox- y I ic acid, eye I ohexane-1, 4-di carboxyl ic acid, decal in-2, 6-dicarboxylic acid, and norbornandicarboxylic acid; and aromatic di carboxylic acids, such as benzene dicarboxylic acids, specifi- cally phthalic acid, isophthal ic acid, 2-methy Iterephthalic acid or ter- ephthalic acid, and naphthalene dicarboxylic acids, specifically naphtha- I ene-1, 3-d i carboxy I ic acid, naphthaIene-1, 4- dicarboxylic acid, naphtha- I ene-1, 5-dicarboxylic acid, naphthaIene-1, 6-dicarboxylic acid, naphtha- I ene-1, 7— dicarboxylic acid, naphthaIene-2, 5- dicarboxylic acid, naphtha- I ene-2, 6- dicarboxylic ac i d, 2- [9- (carboxymethy I ) f I uoren-9-yI ] acet i c acid (formula DC1), 2-[9- (carboxymethyI) f I uoren-9-yI] prop ionic acid (formula DC2), 2,2’ -bis (carboxymethy I oxy) -1, 1’ -bi naphthyl (formula DC3) and naphthaIene-2, 7-d i carboxy lie acid.

[0250] Suitable ester forming derivatives of dicarboxylic acids include, but are not limited to the dialkyl esters, the diphenyl esters and the ditolyl esters.

[0251] In case of polyesters, the ester forming monomer is frequently used at a ra- tio of 0.97 to 1.20 mol, and more preferably 0.98 to 1.10 mol, with respect to 1 mol of the di hydroxy compound (s) in total.

[0252] The polycarbonates of the present invention can be prepared by reacting a diol component comprising a monomer of formula (I) (wherein Z1and Z2are OH) and optionally a further diol monomer such as a monomer of the formula (VI) and a carbonate-forming monomer by analogy to the well-known preparation of polycarbonates as described e. g. in US 9,360,593, US 2016 / 0319069 and US 2017 / 0276837, to which full reference is made.

[0253] The polyesters of the present invention can be prepared by reacting a diol component comprising a monomer of formula (I) (wherein Z1and Z2are OH) and optionally a further diol monomer such as a monomer of the formula (VI) and a dicarboxylic acid or its ester forming derivative by analogy to the well- known preparation of polyesters as described e. g. in US 2017 / 044311 and the references cited therein, to which full reference is made.

[0254] The polyestercarbonates of the present invention can be prepared by reacting a diol component comprising a monomer of formula (I) (wherein Z1and Z2are OH) and optionally a further diol monomer such as a monomer of the formula (VI), a carbonate-forming monomer and a dicarboxyl ic acid or its ester form- ing derivative by analogy to the wel l-known preparation of polyestercar- bonates as described in the art.

[0255] The polycarbonates, polyesters and polyestercarbonates are usually prepared by reacting the monomers of the diol component with the carbonate-forming monomers and / or the ester forming monomers, i.e. the dicarboxylic acids or the ester forming derivatives thereof, in the presence of an esterification catalyst, in particular a transesterification catalyst, in case a carbonate- forming monomer or an ester forming derivative of a polycarboxylic acid is used.

[0256] Suitable transesterification catalysts are basic compounds, which specifi- cally include, but are not limited to, alkaline metal compounds, alkaline earth metal compound, nitrogen-containing compounds, and the like. Likewise, suitable transesterification catalysts are acidic compounds, which specifi- cally include, but are not limited to, Lewis acid compounds of polyvalent metals, including compounds such as zinc, tin, titanium, zirconium, lead, and the like.

[0257] Examples of suitable alkaline metal compound include alkaline metal salts of an organic acid such as acetic acid, stearic acid, benzoic acid, or phe- ny Iphorsphor ic acid, alkaline metal phenolates, alkaline metal oxides, alka- line metal carbonates, alkaline metal borohydr i des, alkaline metal hydrogen carbonates, alkaline metal phosphate, alkaline metal hydrogenphosphate, alka- line metal hydroxides, alkaline metal hydrides, alkaline metal alkoxides, and the like. Specific examples thereof include sodium hydroxide, potassium hy- droxide, cesium hydroxide, lithium hydroxide, sodium hydrogen carbonate, so- dium carbonate, potassium carbonate, cesium carbonate, lithium carbonate, so- dium acetate, potassium acetate, cesium acetate, lithium acetate, sodium stearate, potassium stearate, cesium stearate, lithium stearate, sodium boro- hydr ide, sodium borophenox ide, sodium benzoate, potassium benzoate, cesium benzoate, lithium benzoate, di sodium hydrogen phosphate, di potassium hydrogen phosphate, di lithium hydrogen phosphate, and di sodium phenylphosphate; and also include di sodium salt, di potassium salt, di cesium salt, di I ithium salt of bisphenol A, sodium salt, potassium salt, cesium salt and lithium salt of phenol ; and the I ike. Examples of the alkaline earth metal compound include alkaline earth metal salts of an organic acid such as acetic acid, stearic acid, benzoic acid, or phenylphorsphoric acid, alkaline earth metal phenolates, alkaline earth metal earth oxides, alkaline earth metal carbonates, alkaline metal borohydr ides, alkaline earth metal hydrogen carbonates, alkaline earth metal hydroxides, alkaline earth metal hydrides, alkaline earth metal alkoxides, and the like. Specific examples thereof include magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, magnesium hydrogen carbonate, calcium hydrogen carbonate, strontium hydrogen carbonate, barium hydrogen carbonate, magnesium carbonate, calcium carbonate, strontium carbonate, barium car- bonate, magnesium acetate, calcium acetate, strontium acetate, barium ace- tate, magnesium stearate, calcium stearate, calcium benzoate, magnesium phe- nylphosphate, and the like.

[0258] Examples of the nitrogen-containing compound include quaternary ammoniumhy- droxide, salt thereof, amines, and the like. Specific examples thereof in- clude quaternary ammoniumhydroxides including an alkyl group, an aryl group or the like, such as tetramethyl ammoniumhydroxi de, tetraethyl ammoniumhydrox- ide, tetrapropyl ammoniumhydroxi de, tetrabutyl ammoniumhydroxi de, tr i methyl ben- zylammoniumhydroxide, and the like; tertiary amines such as tri phenyl amine, dimethyl benzyl amine, triphenyl amine, and the like; secondary amines such as di ethyl amine, di butyl amine, and the like; primary amines such as propylamine, butylamine, and the like; imidazoles such as 2-methy I imidazole, 2-pheny I imid- azole, benzoimidazole, and the like; bases or basic salts such as ammonia, tetramethyIammoniumborohydride, tetrabutyIammoniumborohydride, tetrabu- tyl ammoniumtetraphenyl borate, tetraphenyl ammoniumtetraphenyl borate, and the Iike.

[0259] Preferred examples of the transesterification catalyst include salts of poly- valent metals such as zinc, tin, titanium, zirconium, lead, and the like, in particular the chlorides, alkoxy ides, alkanoates, benzoates, acetylacetonates and the like. They may be used independently or in a combination of two or more. Specific examples of such transesterification catalyst include zinc ac- etate, zinc benzoate, zinc 2-ethy I hexanoate, tin (II) chloride, tin (IV) chlo- ride, tin(II) acetate, tin(IV) acetate, dibutyltinlaurate, dibutyltinoxide, dibutyltinmethoxide, zi rconiumacety I acetonate, zirconium oxyacetate, zirconi- umtetrabutoxide, lead(II) acetate, lead(IV) acetate, and the like.

[0260] Preference is also given to using a base, more preferably an inorganic basic salt as transesterification catalyst, in particular an alkaline metal-con- taining base, such as alkaline metal oxides, alkaline metal carbonates, alka- line metal borohydr ides, alkaline metal hydrogen carbonates, alkaline metal phosphate, alkai ine metal hydrogenphosphate, alkaline metal hydroxides or al- kaline metal hydrides. In a specific embodiment, an alkaline metal carbonate or hydrogencarbonate is used.

[0261] The transesterification catalyst are frequently used at a ratio of 10-9to 10-3mo I, preferably 10-7to 10-4moI , with respect to 1 mol of the di hydroxy com- pound (s) in total.

[0262] Frequently, the polycarbonates, polyesters and polyestercarbonates are pre- pared by a melt polycondensation method. In the melt polycondensation, the monomers are reacted in the absence of an additional inert solvent. While the reaction is performed any byproduct formed in the transesterification reac- tion is removed by heating the reaction mixture at ambient pressure or re- duced pressure.

[0263] The melt polycondensation reaction preferably comprises charging the monomers and catalyst into a reactor and subjecting the reaction mixture to conditions where the reaction between the monomers and the formation of the byproduct takes place. It has been found advantageous if the byproduct resides for at least a while in the polycondensation reaction. However, in order to drive the polycondensation reaction to the product side, it is beneficial to remove at least a portion of the formed byproduct during or preferably at the end of the polycondensation reaction. In order to allow the byproduct in the reac- tion mixture, the pressure may be controlled by closing the reactor, or by increasing or decreasing the pressure. The reaction time for this step is 20 minutes or longer and 240 minutes or shorter, preferably 40 minutes or longer and 180 minutes or shorter, and especially preferably 60 minutes or longer and 150 minutes or shorter. In this step, in the case where the byproduct is removed by distillation soon after being generated, the finally obtained thermoplastic resin has a low content of high molecular-weight resin mole- cules. By contrast, in the case where the byproduct is allowed to reside in the reactor for a certain time, the finally obtained thermoplastic resin has a high content of high molecular-weight resin molecules.

[0264] The melt polycondensation reaction may be performed in a continuous system or in a batch system. The reactor usable for the reaction may be of a vertical type including an anchor-type stirring blade, a Maxblend®stirring blade, a helical ribbon-type stirring blade or the like; of a horizontal type includ- ing a paddle blade, a lattice blade, an eye glass-type blade or the like; or an extruder type including a screw. A reactor including a combination of such reactors is preferably usable in consideration of the viscosity of the polymerization product.

[0265] According to the method for producing the thermoplastic resin, such as a pol- ycarbonate resin, after the polymerization reaction is finished, the catalyst may be removed or deactivated in order to maintain the thermal stability and the hydrolysis stability. A preferred method for deactivating the catalyst is the addition of an acidic substance. Specific examples of the acidic sub- stance include esters such as butyl benzoate and the like; aromatic sul- fonates such as p-toluenesulfonic acid and the like; aromatic sulfonic acid esters such as butyl p-toluenesulfonate, hexyl p-toluenesulfonate, and the like; phosphoric acids such as phosphorous acid, phosphoric acid, phosphonic acid, and the like; phosphorous acid esters such as triphenyl phosphite, monophenyl phosphite, diphenyl phosphite, diethyl phosphite, di— n— propyl phosphite, di-n-butyl phosphite, di— n— hexyl phosphite, di octyl phosphite, monooctyl phosphite, and the like; phosphoric acid esters such as triphenyl phosphate, diphenyl phosphate, monophenyl phosphate, di butyl phosphate, di oc- tyl phosphate, monooctyl phosphate, and the like; phosphonic acids such as diphenyl phosphonic acid, dioctyl phosphonic acid, di butyl phosphonic acid, and the like; phosphonic acid esters such as diethyl phenyl phosphonate, and the like; phosphines such as triphenylphosphine, bis (diphe- nylphosphino) ethane, and the like; boric acids such as boric acid, phenyl- boric acid, and the like; aromatic sulfonic acid salts such as tetarabu- ty I phosphonium dodecylbenzensulfonate salt, and the like; organic halides such as chloride stearate, benzoyl chloride, chlor ide p-to I uenesu If onate, and the like; a Iky I sulfonic acids such as di methyl sulfonic acid, and the like; organic hal ides such as benzyl chloride, and the like. These deactivators are frequently used at 0.01 to 50 mol, preferably 0.3 to 20 mol, with respect to the catalyst.

[0266] After the catalyst has been deactivated, there may be a step of removing low boiling point compounds from the polymer by distillation. The distillation is preferably performed at reduced pressure, e. g. at a pressure of 0.1 to 1 mm Hg at a temperature of 200 to 350° C. For this step, a horizontal device in- cluding a stirring blade having a high surface renewal capability such as a paddle blade, a lattice blade, an eye glass-type blade or the like, or a thin film evaporator is preferably used.

[0267] It is desirable that the thermoplastic resin such as a polycarbonate resin has a very small amount of foreign objects. Therefore, the molten product is preferably fi ltered to remove any solids from the melt. The mesh of the fil- ter is preferably 5 pm or less, and more preferably 1 pm or less. It is pre- ferred that the generated polymer is filtrated by a polymer filter. The mesh of the polymer filter is preferably 100 pm or less, and more preferably 30 pm or less. A step of sampling a resin pellet needs to be performed in a low dust environment, needless to say. The dust environment is preferably of class 6 or lower, and more preferably of class 5 or lower.

[0268] The thermoplastic resin may be molded by any conventional molding procedure for producing optical elements. Suitable molding procedures include but are not limited to injection molding, compression molding, casting, roll pro- cessing, extrusion molding, extension and the like.

[0269] Whi le it is possible to mold the thermoplastic resin of the invention as such, it is also possible to mold a resin composition which contains at least one thermoplastic resin of the invention and which further contains at least one additive and / or further resin. Suitable additives include antioxidants, process i ng stabi I i zers, photostabilizers, polymerization metal deactivators, flame retardants, lubricants, antistatic agents, surfactants, antibacterial agents, releasing agents, ultraviolet absorbers, plasticizers, compatibil- izers, and the like. Suitable further resins are e. g. another polycarbonate resin, polyester carbonate resin, polyester resin, polyamide, polyacetal and the like, which does not contain repeating units of the formula (III).

[0270] Examples of the antioxidant include but are not limited to tr iethyleneglycol- bis [3- (3-ter t-buty I -5-methy I -4-hydroxyphenyI ) prop i onate] , 1 , 6-hexaned i o I - bis [3- (3, 5-d i -tert-buty I -4-hydroxyphenyI ) prop i onate] , pentaerythr i to I - tetr ak i s [3- (3, 5-d i -tert-buty I -4-hydroxyphenyI ) prop i onate] , octadecy I -3- (3, 5- d i -tert-buty I -4-hydroxyphenyI ) prop i onate, 3, 9- bis (2, 6-d i -tert-buty I -4- methylphenoxy)-2, 4, 8, 10-tetraoxa-3, 9-d i phosphasp i ro [5.5]undecane, 5, 7—Di — tert-butyI -3- (3, 4-d i methy I pheny I ) benzofur an-2 (3H) -one, 5, 7-D i -tert-buty I -3- (1 , 2d i methy I phenyI ) benzof uran-2 (3H) -one, 1 , 3, 5-tr i methy I -2, 4, 6-tr i s (3, 5-d i - tert-butyI -4-hydroxybenzyI ) benzene, N, N-hexamethy I enebis (3, 5-d i -tert-buty I -4- hydroxy-hydroc i nnam i de, 3, 5-d i -tert-buty I -4-hydroxy-benzy I phosphonate-d i ethy- lester, tr i s (3, 5— di -tert-buty I -4-hydroxybenzyI) i socyanurate, and 3, 9- bis {1,1 — d i methy I -2- [ β - (3-tert-buty I -4-hydroxy-5-methyI phenyI ) prop i ony I oxy] ethy I } - 2, 4, 8, 10-tetraoxaspi ro(5, 5) undecane, and the like. Among these examples, 3,9- bis (2, 6-d i -tert-buty I -4-methy I phenoxy) -2, 4, 8, 10-tetraoxa-3, 9-d i phospha- sp i ro [5.5]undecane, 5, 7— Di -tert-buty I -3- (3, 4-dimethylphenyl)benzofuran-2 (3H) — one, and 5, 7-Di -tert-buty I -3- (1, 2d i methyl pheny I) benzofur an-2 (3H) -one are more preferred. The content of the antioxidant in the thermoplastic resin is pref- erably 0.001 to 0.3 parts by weight with respect to 100 parts by weight of the thermoplastic resin.

[0271] Examples of the processing stabilizer include but are not limited to phospho- rus-based processing stabilizers, sulfur-based processing stabilizers, and the like. Examples of the phosphorus-based processing stabilizer include phosphorous acid, phosphoric acid, phosphonous acid, phosphonic acid, esters thereof, and the like. Specific examples thereof include tri phenyl phosphite, tris (nony I pheny I ) phosph i te, tr i s (2, 4-d i -tert-buty I pheny I ) phosph i te, tris (2, 6- di -tert-buty I phenyl) phosphite, tr i decyl phosphite, tri octyl phosphite, triocta- decy I phosph i te, di decy I monopheny I phosph i te, di octy I monopheny I phosph i te, d i i sopropy I monopheny I phosph i te, monobuty I d i pheny I phosph i te, monodecy I d i phe- ny I phosph i te, monoocty I d i pheny I phosph i te, bis (2, 6-d i -tert-buty I -4- methy I pheny I ) pentaerythr i to I d i phosph i te, 2, 2-methy I enebis (4, 6-d i -tert-bu- ty I pheny I ) octy I phosph i te, bis (nony I pheny I ) pentaerythr i to I d i phosph i te, bis (2, 4-d i cumy I pheny I ) pentaerythr i to I d i phosph i te, bis (2, 4-d i -tert-bu- ty I pheny I ) pentaerythr i to I d i phosph i te, di steary I pentaerythr i to I d i phosph i te, tr i butyl phosphate, tr i ethyl phosphate, tr i methyl phosphate, tr i pheny I phosphate, di pheny I monoorthoxenyl phosphate, di butyl phosphate, di octy I phosphate, di iso- propyl phosphate, dimethyl benzenephosphonate, diethyl benzenephosphonate, di- propyl benzenephosphonate, tetrak i s (2, 4— d i — t— buty I pheny I ) — 4, 4’ - b i phenylened i - phosphon i te, tetrak i s (2, 4-d i -t-buty I pheny I ) -4, 3’ -b i phenylened i phosphon i te, tetrak i s (2, 4-d i -t-buty I pheny I ) -3, 3’ -b i phenylened i phosphon i te, bis (2, 4-d i - tert-buty I pheny I ) -4-pheny I -pheny I phosphon i te, bis (2, 4-d i -tert-buty I pheny I ) -3- pheny I -pheny I phosphonite, and the like. The content of the phosphorus-based processing stabilizer in the thermoplastic resin composition is preferably 0.001 to 0.2 parts by weight with respect to 100 parts by weight of the ther- moplastic resin.

[0272] Examples of the sulfur-based processing stabilizer include but are not lim- ited to pentaerythritol-tetrakis(3-laurylthiopropionate), pentaerythr i to I - tetrak i s (3-myr i sty I th iopropionate) , pentaerythr i to I -tetrak is (3-steary I th io- propionate) , di lauryl -3, 3’ -thiodi propionate, di myristyl -3, 3’ -thiodi propio- nate, di steary I-3, 3’ -thiodi propionate, and the like. The content of the sul- fur-based processing stabilizer in the thermoplastic resin compos iton is preferably 0.001 to 0.2 parts by weight with respect to 100 parts by weight of the thermoplastic resin.

[0273] Preferred releasing agents contain at least 90% by weight of an ester of an alcohol and a fatty acid. Specific examples of the ester of an alcohol and a fatty acid include an ester of a monovalent alcohol and a fatty acid, and a partial ester or a total ester of a polyvalent alcohol and a fatty acid. Pre- ferred examples of the above-described ester of an alcohol and a fatty acid include the esters of a monovalent alcohol having a carbon number of 1 to 20 and a saturated fatty acid having a carbon number of 10 to 30. Preferred ex- amples of partial or total esters of a polyvalent alcohol and a fatty acid include the partial or total ester of a polyvalent alcohol having a carbon number of 2 to 25 and a saturated fatty acid having a carbon number of 10 to 30. Specific examples of the ester of a monovalent alcohol and a fatty acid include stearyl stearate, palmityl palmitate, butyl stearate, methyl laurate, isopropyl palmitate, and the like. Specific examples of the partial or total ester of a polyvalent alcohol and a fatty acid include monoglyceride stea- rate, monoglycer ide stearate, diglycer ide stearate, triglyceride stearate, monosorbitate stearate, monoglyceride behenate, monoglycer ide caprylate, monoglycer ide laurate, pentaerythritol monostearate, pentaerythritol tetrastearate, pentaerythritol tetrapelargonate, propyleneglycol monos- tearate, biphenyl bi phenate, sorb i tan monostearate, 2-ethy I hexyl stearate, to- tal or partial esters of dipentaerythr itol such as di pentaerythritol hexas- tearate and the like, etc. The content of the releasing agent in the resin composition is preferably 0.005 to 2.0 parts by weight, more preferably 0.01 to 0.6 parts by weight, and still more preferably 0.02 to 0.5 parts by weight, with respect to 100 parts by weight of the thermoplastic resin.

[0274] Preferred ultraviolet absorbers are selected from the group consisting of benzotriazole-based ultraviolet absorbers, benzophenone-based ultraviolet ab- sorbers, tri azine-based ultraviolet absorbers, cyclic iminoester-based ultra- violet absorbers, and cyanoacrylate-based ultraviolet absorbers. Namely, the following ultraviolet absorbers may be used independently or in a combination of two or more.

[0275] Examples of benzotr i azole-based ultraviolet absorbers include 2-(2-hydroxy-5- methy I pheny I ) benzotr i azo I e, 2- (2-hydroxy-5-tert-octy I pheny I ) benzotr i azo I e, 2- (2-hydr oxy-3, 5-d i cumy I pheny I ) pheny I benzotr i azo I e, 2- (2-hydroxy-3-tert-buty I - 5-methylphenyl)-5-chlorobenzotriazole, 2, 2’ -methy I eneb is [4- (1, 1, 3, 3-tetra- methy I buty I ) -6- (2N-benzotr i azo I e-2-yI ) pheno I ) ] , 2- (2-hydroxy-3, 5-d i -tert-bu- ty I pheny I ) benzotr i azo I e, 2- (2-hydroxy-3, 5-d i -tert-buty I pheny I ) -5-ch I oroben- zotr i azo I e, 2- (2-hydroxy-3, 5-d i -tert-amy I pheny I ) benzotr i azo I e, 2- (2-hydroxy- 5-tert-octy I pheny I ) benzotri azo I e, 2- (2-hydroxy-5-tert-buty I pheny I ) benzotr i a- zo I e, 2- (2-hydroxy-4-octoxypheny I ) benzotr i azo I e, 2, 2' -methy I enebis (4-cumy I -6- benzotr i azo I epheny I ) , 2, 2’ -p-phenylenebis (1 , 3-benzoxazine-4-one) , 2- [2— hy- droxy— 3— (3, 4, 5, 6-tetrahydrophthal imi demethyl )-5-methy I pheny I] benzotr i azole, and the I ike.

[0276] Examples of benzophenone-based ultraviolet absorbers include 2, 4-d i hy- droxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzo- phenone, 2-hydroxy-4-benzy I oxybenzophenone, 2-hydroxy-4-methoxy-5-su I f oxyben- zophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid hydrate, 2, 2’— di- hydroxy— 4— methoxybenzophenone, 2, 2’ , 4, 4’ -tetrahydroxybenzophenone, 2, 2’ -d i hy- droxy-4, 4’ -d i methoxybenzophenone, 2, 2’ -d i hydroxy-4, 4’ -d i methoxy-5-sod i umsu I - f oxybenzophenone, bis (5-benzoy I -4-hydroxy-2-methoxyphenyI ) methane, 2-hydroxy- 4-n-dodecy I oxybenzophenone, 2-hydroxy-4-methoxy-2’ -carboxybenzophenone, and the like.

[0277] Examples of tr i azine-based ultraviolet absorbers include 2— (4, 6— di phenyl - 1 , 3, 5-tr i az i ne-2-yI ) -5- ( [ (hexy I ) oxy] -pheno 1 , 2- (4, 6-bis (2, 4-d i methy I pheny I ) - 1 , 3, 5— tr i az i ne— 2— y I ) — 5— ( [ (octy I ) oxy] — pheno I , and the like.

[0278] Examples of cycl ic iminoester-based ultraviolet absorbers include 2,2’- bi s (3, 1 -benzoxaz ine-4-one) , 2, 2’ -p-pheny lenebis (3, 1-benzoxazi ne-4-one) , 2,2’ — m-phenylenebis (3, 1 -benzoxazine-4-one) , 2, 2’ - (4, 4' d i phenylene) bis (3, 1 -benzoxa- z i ne-4-one) , 2,2’- (2, 6-naphthaIene) bis (3, 1 -benzoxazine-4-one) , 2, 2’ - (1 , 5- naphthaIene) bis (3, 1 -benzoxazine-4-one) , 2, 2’ - (2-methyI -p-phenylene) bis (3, 1 - benzoxazine-4-one) , 2,2’- (2-n i tro-p-phenylene) bis (3, 1-benzoxazine-4-one) , 2, 2’ -(2-chloro-p-phenylene)bis(3, 1-benzoxazine-4-one), and the like.

[0279] Examples of cyanoacrylate-based ultraviolet absorbers include 1, 3— bis— E(2’ - cyano-3' , 3’ -d i pheny I aery I oy I ) oxy] -2, 2-bis ( ( (2-cyano-3, 3-d i pheny I acry- loyl) oxy) methyI ) propane, 1 , 3-bis- [ (2-cyano-3, 3-d i phenyIaeryIoyI ) oxy] benzene, and the I ike.

[0280] The content of the ultraviolet absorber in the resin composition is prefera- bly 0.01 to 3.0 parts by weight, more preferably 0.02 to 1.0 parts by weight, and still more preferably 0.05 to 0.8 parts by weight, with respect to 100 parts by weight of the thermoplastic resin. The ultraviolet absorber con- tained in such a range of content in accordance with the use may provide a sufficient climate resistance to the thermoplastic resin.

[0281] As mentioned above, the thermoplastic polymer resins, in particular the poly- carbonate resins, comprising repeating units of formula (III) as described herein, provide high transparency and high refractive index to thermoplastic resins, which therefore are suitable for preparing optical devices, where high transparency and high refractive index is required. More precisely, the thermoplastic polycarbonates having structural units of formulae (III) are characterized by having a high refractive index, which is preferably at least 1.640, more preferably at least 1.645, even more preferably at least 1.650.

[0282] The contribution of the monomer of the formula (I) to the refractive index of the thermoplastic resin, in particular a polycarbonate resin, will depend from the refractive index of said monomer and the relative amount of said monomer in the thermoplastic resin. In general, a higher refractive index of the monomer contained in the thermoplastic resin will result in a higher re- fractive index of the resulting thermoplastic resin. Apart from that, the re- fractive index of a thermoplastic resin comprising structural units of the formula (III) can be calculated from the refractive indices of the monomers used for preparing the thermoplastic resin, either from the refractive index of the monomers or ab initio, e. g. by using the computer software ACD / ChemSketch 2012 (Advanced Chemistry Development, Inc.).

[0283] In case of thermoplastic copolymer resins, the refractive index of the ther- moplastic resin, in particular a polycarbonate resin, can be calculated from the refractive indices of the homopolymers of the respective monomers, which form the copolymer resin, by the following so called “Fox equation” '

[0284] 1 / nD= x1 / nD1+ x2 / nD2+ .... xn / nDn, where nDis the refractive index of the copolymer, x1, x2, .... xnare the mass fractions of the monomers 1, 2, .... n in the copolymer and nD1, nD2, .... nDnare the refractive indices of the homopolymers synthesized from only one of the monomers 1, 2, .... n at a time. In case of polycarbonates, x1, x2, .... xnare the mass fractions of the OH monomers 1, 2, .... n, based on the total amount of OH monomer. It is apparent that a higher refractive index of a homopolymer will result in a higher refractive index of the copol- ymer. The refractive indices of the thermoplastic resins can be determined directly or indirectly. For direct determination, the refractive indices no of the thermoplastic resins are measured at a wavelength of 589 nm in accordance with the protocol JIS— K— 7142 using an Abbe refractometer and applying a 0.1 mm film of the thermoplastic resin. In case of the refractive indices of the homopolycarbonates of the compounds of formula (I), the refractive indices can also be determined indirectly. For this, a co-polycarbonate of the re- spective monomer of formula (I) with 9, 9- bis (4- (2-hydroxyethoxy) phenyl) fluo- rene and diphenyl carbonate is prepared according to the protocol of example 1 in column 48 of US 9,360,593 and the refractive indices nDof the co-poly- carbonate is measured at wavelength of 589 nm in accordance with the protocol JIS— K— 7142 using an Abbe refractometer and applying a 0.1 mm film of the co- polycarbonate. From the thus measured refractive indices nD, the refractive index of the homopolycarbonate of the respective monomer can be calculated by applying the Fox equation and the known refractive index of 9, 9— bis (4— (2— hy— droxyethoxy) phenyl) fluorene ( nD(589 nm) = 1.639).

[0285] As mentioned before, compounds of formula (I), which do not bear color-im- parting radicals, such as some of the radicals Ra, Rb, Rc, Rd, can also be ob- tained in a purity which provides for a low yellowness index Y. I., as deter- mined in accordance with ASTM E313, which may also be important for the use in the preparation of optical resins.

[0286] More precisely, the yellowness index Y. I., as determined in accordance with ASTM E313, of the compounds of formula (I) preferably does not exceed 200, more preferably 100, even more preferably 50, in particular 20, more particu- larly 10, even more particularly 5.

[0287] The thermoplastic resin according to the present invention has a high refrac- tive index and a low Abbe number. The thermoplastic resin of the present in- vention can be used for producing a transparent conductive substrate usable for a liquid crystal display, an organic EL display, a solar cell and the like. Also, the thermoplastic resin of the present invention can be used as a structural material for optical parts, such as optical disks, liquid crystal panels, optical cards, optical sheets, optical fibers, connectors, evaporated plastic reflecting mirrors, displays, and the like; or used as optical de- vices suitable for functional material purpose.

[0288] Accordingly, molded articles, such as optical devices, can be formed using the thermoplastic resins of the present invention. The optical devices in- clude optical lenses, and optical films. The specific examples of the optical devices include lenses, films, mirrors, filters, prisms, and so on. These op- tical devices can be formed by arbitrary production process, for example, by injection molding, compression molding, injection compression molding, extru- sion molding, or solution casting.

[0289] Because of an excellent moldability and a high heat resistance, the thermo- plastic resins of the present invention are very suitable for the production of optical lenses which require injection molding. For molding, the thermo- plastic resins of the present invention, such as the polycarbonate resin, can be used with other thermoplastic resins, for example, different polycarbonate resin, polyestercarbonate resin, polyester resin, and other resins, as a mix- ture. In addition, the thermoplastic resins of the present invention can be mixed with additives for forming the optical devices. As the additives for forming the optical devices, those mentioned above can be used. The additives may in- clude antioxidants, processing stabiIizers, photostabilizers, polymerization metal deactivators, flame retardants, lubricants, antistatic agents, surfac- tants, antibacterial agents, releasing agents, ultraviolet absorbers, plasti- cizers, compatibilizers, and the like.

[0290] As is clear from the above, another aspect of the present invention relates to an optical device made of a thermoplastic resin as defined above, where the thermoplastic resin comprises a structural unit represented by the for- mula (III) and optionally of formula (V). As regards to the preferred mean- ings and preferred embodiments of the structural units of the formulae (III) and (V), reference is made to the statements given above.

[0291] An optical device made of an optical resin comprising the repeating units of the formula (III) and optionally repeating units of the formula (V) as de- fined herein are usually optical molded articles such as optical lenses, for example car head lamp lenses, Fresnel lenses, fθ lenses for laser printers, camera lenses, lenses for glasses and projection lenses for rear projection TV’s, CD-ROM pick-up lenses, but also optical disks, optical elements for im- age display media, optical films, film substrates, optical filters or prisms, liquid crystal panels, optical cards, optical sheets, optical fibers, optical connectors, eposition plastic reflective mirrors, and the like. Here particu- lar preference is given to optical lenses and optical films. Optical resins comprising repeating units of the formula (III) and optionally repeating units of the formula (V) are also useful for producing a transparent conduc- tive substrate usable for an optical device suitable as a structural member or a functional member of a transparent conductive substrate for a liquid crystal display, an organic EL display, a solar cell and the like.

[0292] The optical lens produced from the thermoplastic resin according to the pre- sent invention has a high refractive index, a low Abbe number and a low de- gree of birefringence, and is highly moisture and heat resistant. Therefore, the optical lens can be used in the field in which a costly glass lens having a high refractive index is conventionally used, such as for a telescope, bin- oculars, a TV projector and the like. It is preferred that the optical lens is used in the form of an aspherical lens. Merely one aspherical lens may make the spherical aberration substantially zero. Therefore, it is not neces- sary to use a plurality of spherical lenses to remove the spherical aberra- tion. Thereby the weight and the production cost of a device including the spherical aberration is decreased. An aspherical lens is useful especially as a camera lens among various types of optical lenses. The present invention readily provides an aspherical lens having a high refractive index and a low level of birefringence, which is technologically difficult to produce by pro- cessing glass.

[0293] An optical lens of the present invention may be formed, for example, by in- jection molding, compression molding, injection compression molding or cast- ing the resin containing the repeating units of the formula (III) and option- ally repeating units of the formula (V) as defined herein. The optical lens of the present invention is characterized by a small optical distortion. An optical lens comprising a conventional optical resin has a large optical distortion. Although it is not impossible to reduce the value of an optical distortion by molding conditions, the condition widths are very small, thereby making molding extremely difficult. Since the resin having re- peating units of the formula (III) and optionally repeating units of the for- mula (V) as defined herein has an extremely small optical distortion caused by the orientation of the resin and a small molding distortion, an excellent optical element can be obtained without setting molding conditions strictly.

[0294] To manufacture the optical lens of the present invention by injection mold- ing, it is preferred that the lens should be molded at a cylinder temperature of 260° C to 320° C and a mold temperature of 100° C to 140° C.

[0295] The optical lens of the present invention is advantageously used as an as- pherical lens as required. Since spherical aberration can be substantially nullified with a single aspherical lens, spherical aberration does not need to be removed with a combination of spherical lenses, thereby making it pos- sible to reduce the weight and the production cost. Therefore, out of optical lenses, the aspherical lens is particularly useful as a camera lens.

[0296] Since resins having repeating units of the formula (III) and optionally re- peating units of the formula (V) as defined herein have a high moldability, they are particularly useful as the material of an optical lens, which is thin and small in size and has a complex shape. As a lens size, the thickness of the center part of the lens is 0.05 to 3.0 mm, preferably 0.05 to 2.0 mm, more preferably 0.1 to 2.0 mm. The diameter of the lens is 1.0 to 20.0 mm, preferably 1.0 to 10.0 mm, more preferably 3.0 to 10.0 mm. It is preferably a meniscus lens, which is convex on one side and concave on the other side.

[0297] The surface of the optical lens of the present invention may have a coating layer such as an antireflection layer or a hard coat layer as required. The antireflection layer may be a single layer or a multi-layer and composed of an organic material or inorganic material but preferably an inorganic mate- rial. Examples of the inorganic material include oxides and fluorides such as silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, cerium oxide, magnesium oxide and magnesium fluoride.

[0298] The optical lens of the present invention may be formed by an arbitrary method such as metal molding, cutting, polishing, laser machining, discharge machining or edging. Metal molding is preferred.

[0299] An optical film produced by the use of the thermoplastic resin according to the present invention is high in transparency and heat resistance, and there- fore is preferably usable for a liquid crystal substrate film, an optical memory card or the like. In order to avoid foreign objects from being incor- porated into the optical film as much as possible, the molding needs to be performed in a low dust environment, needless to say. The dust environment is preferably of class 6 or lower, and more preferably of class 5 or lower.

[0300] The following examples serve as further illustration of the invention.

[0301] 1. Abbreviations : m. p. : melting point r. t. : room temperature THF: tetrahydrofuran TLC: thin layer chromatography DSC: differential scanning calorimetry

[0302] 2. Preparation of monomers of formula (I)

[0303] 2.1 Analytics relating to monomers of formula (I) :

[0304] 1H-NMR spectra were determined at 23° C using an 80 MHz NMR-spectrometer (Ma- gritek Spinsolve 80). If not stated otherwise the solvent was DMSO-d6.

[0305] IR spectra were recorded by AIR FT-IR, using a Shimadzu FTIR-8400S spectrome- ter (no. of scans: 45, resolution: 4 cm-1; apodization: Happ-Genzel) .

[0306] DSC (differential scanning calorimetry) measurements were performed using a Linseis Chip-DSC 10.

[0307] Unless specified otherwise, melting points of the compounds were determined by Buch i Melting Point B-545.

[0308] UPLC (Ultra Performance Liquid Chromatography) analyses were carried out us- ing the following system and conditions:

[0309] Waters Acquity UPLC H-Class Systems; column: Acquity UPLC BEH C18, 1.7pm, 2.1 x 100 mm; column temperature: 40° C, gradient: acetonitrile / 0.1% HCIO4in water: with acetonitrile at 0 min 60%, at 3.5 min 100%; at 3.6 min 60%; at 5 min 60%; injection volume: 2.0 pl; run time: 6 min; detection at 210 nm.

[0310] The yellowness index YI of the compounds of formula (I) can be determined by analogy with ASTM E313 using the following protocol: 1 g of the compound of formula (I) is dissolved in 19 g of a solvent, e. g. methanol or methylene chloride. The solution is transferred into a 50 mm cuvette and transmission is determined in the range of 300 to 800 nm by a Shimadzu UV-Visible spectro- photometer UV- 1900. The solvent itself, e. g. methanol, is used as a refer- ence. From the spectra the yellowness index can be calculated by using the Software "RGA-software UV2DAT" in accordance with ASTM E308 (Standard prac- tice for computing the colors of objects by using the CIE System) and ASTM E 313 (Standard practice for calculating yellowness and whiteness indices from instrumentally measured color coordinates).

[0311] 2.2 Preparation Examples:

[0312] 2.2.1 Preparation of monomer (1, 1) a) Synthesis of diethyl 2, 5-bis (dibenzo [b ,d] thiophen-4-yI ) benzene-1 , 4— di- carboxylate [B4DBTPDAEt] : To d i ethyl -2, 5-dibromoterephthalate (78.46 g; 206.46 mmol) was added dibenzo [b ,d t]h iophen-4-yI boron ic acid (98.88 g; 433.56 mmol; 2.1 eq.). To this mixture were added anisole (600 mL) and 62.77 g of K2CO3dissolved in 214 g of water. The mixture was stirred at 60-70° C until two dear phases were formed and was purged with argon. To this mixture £ / 7s(o-tolyl)phosphane (2.513 g; 8.26 mmol) and Pd(OCOCH3)2(464 mg; 2.065 mmol) were added under ar- gon atmosphere and the mixture was stirred under reflux unti I the TLC showed a complete conversion. The mixture was cooled to r. t. and precipitated solid was filtered off, washed subsequently with water (50mL) , methanol (3x200mL), and pentane (400mL), and finally dried over night at 60° C. The obtained gray solid was used in the next step without additional purification.

[0313] 1H NMR (80 MHz, DMSO-d6) : δ = 8.58 - 8.25 (m, 4H) , 8.21 - 7.92 (m, 4H) , 7.82 - 7.35 (m, 8H), 3.89 (q, J = 7.1 Hz, 4H), 0.68 (t, J = 7.1 Hz, 6 / 7. b) Synthesis of [2, 5-bis (di benzo [b ,d] thiophen-4-yI ) -1 , 4-phenyIene] dimethanol [B4DBTPDM0; compound (1.1)];

[0314] Lithium aluminium hydride [LiAIH4] (2.57 g; 67,70 mmol; 3 eq.) was dissolved in tetrahydrofuran (800 g; ca. 900 mL) at r.t. and the solution was cooled to 0° C. Then 13.24 g (22.57 mmol) of 2, 5-bis (d i benzo [b ,d] th i ophen-4-yI ) benzene- 1, 4-di carboxy I ate [B4DBTPDAEt] were added as solid in several portions. The reaction mixture was stirred for 1 h at 0° C and then warmed to r.t., and ad- ditionally stirred for 1-2 h at r.t. until the TLC showed a complete conver- sion. The mixture was cautiously quenched with 4.85 g of water in 25 mL of THF at r.t.. Then 4.85 mL of 15% NaOH solution were added, followed by addi- tion of water (9.7 g) under vigorous stirring. The reaction mixture was stirred at r.t. for further 30 min. The obtained aluminium salts were fil- tered off, and the fi lter cake was washed with THF (3x100mL) [warmed to 50- 60ºC]. The organic extracts were combined, and THF was disti lled off to af- ford 9.64 g of the crude title product (yield 83.6%; purity of 98.37%) which was dried in vacuo (20-50 mbar at 60° C). The crude product was recrystal- l ized from THF to obtain the desired product with purity of 99.23%.1H NMR (80 MHz, DMSO-d6): 5 =8.62 - 8.28 (m, 4H) 8.21 - 7.86 (m, 2H) , 7.86 - 7.39 (m, 10H), 5.22 (t, J= 4.7, 2H), 4.46 (d, J= 4.7, Hz, 4H). m. p. (DSC) : 295.5 ° C

[0315] 3. Preparation of polycarbonate resins from monomers of formula (I)

[0316] 3.1 Analytics relating to resins prepared from monomers of formula (I) :

[0317] Refractive index ( nD) :

[0318] Refractive indexes were measured using the test pieces obtained by the gen- eral procedure for preparing homopolycarbonates described in section 3.2 be- low. The measurements were conducted at a temperature of 23° C and at a wave- length of 589 nm using the Rudolph Instruments J257 Automatic refractometer.

[0319] Abbe number (v) :

[0320] Abbe numbers were determined using samples with a thickness of approx. 3 mm, which were the same as those used in the method for measuring the refractive indexes described above. The refractive index values were measured using the Metricon 2010M Prism Coupler at a temperature of 23° C and at wavelengths of 486 nm, 589 nm and 656 nm. The Abbe number was then calculated using the fol- lowing formula: v = (nD- 1 ) / (nF- nC) nD: refractive index at a wavelength of 589 nm nC: refractive index at a wavelength of 656 nm nF: refractive index at a wavelength of 486 nm

[0321] Glass transition temperature (Tg) :

[0322] The glass transition temperature was measured by differential scanning calo- rimetry (DSC) using a 10° C / minute heating program according to JIS K7121- 1987.

[0323] Differential scanning calorimetry device: X-DSG7000 manufactured by Hitachi High-Tech Science Corporation

[0324] Molecular weight

[0325] The values of the weight average molecular weight (Mw) of the resins were measured in accordance with the gel permeation chromatography (GPC) method and calculated by the standard polystyrene conversion approach. The following devices, columns and measurement conditions were used:

[0326] GPC device: HLC-8420GPC (from Tosoh Corporation) ;

[0327] Columns: three TSKgel SuperHM-M (from Tosoh Corporation), one guard column SuperHM-M (from Tosoh Corporation), one TSKgel SuperH-RC (from Tosoh Corporation);

[0328] Detection Device: RI detection

[0329] Standard polystyrene: PstQuick C as standard polystyrene kit (from Tosoh Cor- poration) ;

[0330] Eluent: tetrahydrofuran;

[0331] Flow rate of eluent: 0.6 ml / min;

[0332] Column temperature: 40° C. The number average molecular weight (Mn) values can be calculated using simi- lar methods to those used for measuring the Mwvalues described above. The polystyrene converted weight average molecular weights (Mw) and number aver- age molecular weights (Mn) were calculated using a previously prepared stand- ard curve of polystyrene. Specifically, the standard curve was prepared using a standard polystyrene for which the molecular weight was known ( “PStQuick G” from Tosoh Corporation). Further, a calibration curve was obtained by plotting the elution time and molecular weight value of each of the peaks based on the measured data of the standard polystyrene, and conducting three- dimensional approximation. The values for Mwand Mnwere calculated based on the following calculation formulae:

[0333] In the calculation formulae, “i” represents the “I” th dividing point, “Wi” represents the molecular weight (g) of the polymer at the “i” th di- viding point, “Ni” represents the number of the molecules of the polymer at the “i” th dividing point, and “Mi” represents the molecular mass at the “i” th dividing point. The molecular mass (M) represents the value of the molecular mass of polystyrene at the corresponding elution time in the cali- bration curve.

[0334] Contents of low molecular weight compounds (GLWG)

[0335] The content of low molecular weight compounds (CLWC) represents to the ratio of the combined peak areas of compounds with Mw values below 1000 to the to- tal area of all peaks, where the peak areas are determined according the GPC analysis described above. Therefore, CLWC values can be determined using the following formula:

[0336] The values of the M / ;of the low molecular weight compounds can be determined using the methods described in the above chapter “Molecular weight” .

[0337] Birefringence ( Δn):

[0338] The values of birefringence ( Δn) of resins can for example be measured ac- cording to the following methods: Each resin example to be analyzed is dis- solved in methylene chloride (solvent) to form a solution with the concentra- tion of 10 weight-%. The obtained solution is casted on an SUS plate whose surface has been treated with electroplating and a cast film is made followed by evaporating the solvent at 25 ° C. A square film piece of 50 mm per side having a thickness of 100 μm is cut out from the cast film. The film piece is stretched 1.5-fold below at a temperature 20 ° C higher than the Tgof the resin. Streching can be carried out using the stretching machine SS-70 manu- factured by Shibayama Scientific Go., Ltd. The obtained stretched film is subjected to retardation measurement using the ellipsometer M- 220 manufac- tured by JASGO Corporation. From the retardation / phase difference Re the birefringence values An can be caIcuIated by the f o 11 ow i ng equation

[0339] Δn: orientation birefringence

[0340] Re: phase difference [nm] d: thickness [nm]

[0341] The algebraic sign of the birefringence is represented by the following equa- tion with the use of the refractive index (nII) in the stretching direction of the fi lm and the refractive index in the direction perpendicular to the stretching direction:

[0342] If Δn is positive, it is called positive birefringence, while if Δn is neg- ative, it is called negative birefringence.

[0343] 3.2 Examples for the preparation of homopolycarbonates:

[0344] Example 2'- Homopolycarbonate prepared from B4DBTPDM0 and di phenyl carbonate

[0345] The homopolycarbonate of Example 2 was obtained by reacting B4DBTPDM0, which is the monomer compound of formula (1.1) prepared in Example 1, as diol com- ponent with di phenyl carbonate in analogy to the method for preparing the copolycarbonate of example 3 below (the difference being that that BPEF was omitted). The following Table 1 lists physical properties, namely refractive indices (nD), Abbe numbers (v) and glass trans i st ion temperatures (Tg), of the obtained B4DBTPDM0 homopolycarbonate. For comparative reasons, the table also lists the nD-, ν and Tg-values of a comparative homopolycarbonate prepared analogously from 9, 9-bis (4- (2-hydroxyethoxy) phenyl) fluorine (BPEF) as diol component and diphenylcarbonate. The B4DBTPDM0 homopolycarbonate of Example 2 consists of structural units of the formula (III.1.1) and structural units of the formula (IV— 1) , while the comparative BPEF homopolycarbonate consist of the structural unites derived from the monomer 9, 9-bis(4-(2-hydroxyeth- oxy)phenyl)fluorene and structural units of formula (IV— 1).

[0346] The nD-, ν- and Tg-values of the B4DBTPDM0 homopolycarbonate of Example 2 given in Table 1 were calculated from the respective values of the corre- sponding copolymer derived from the monomer of Example 1 by using the above- mentioned Fox equation. The preparation of this copolymer and its physical data are described in Example 3 below.

[0347] Table 1 : Properties of homopolycarbonates of Example 2 * calculated values

[0348] ** BPEF =

[0349] 3.3 Examples for the preparation of copolycarbonates:

[0350] Example 3: Copolymer prepared from B4DBTPDM0, BPEF and di phenyl carbonate

[0351] As materials, 3.00 kg (5.97 mol) of (2, 5-bis(dibenzo[b,d] thiophen-4-yl)-1, 4- phenyIene) dimethanol (B4DBTPDM0; compound (1.1) as prepared in example 1), 10.47 kg (23.87 mol) of 9, 9- bis [4- (2-hydroxyethoxy) phenyl) fluorene (BPEF), 6.58 kg (30.74 mol) of diphenylcarbonate (DPC) and 12 ml of 2.5 x 10-2mo I / I (3.0 x 10-4mol (10 x 10-6mol to 1 mol of the total amount of the di hydroxy compounds) aqueous solution of sodium hydrogen carbonate were placed into a 50 litre reactor with a stirrer and a distillation device. The reactor was flushed with nitrogen, and the reaction mixture was heated for 1 hour to 205° C and stirred at a pressure of 760 Torr. After the reaction mixture was completely dissolved, the pressure was reduced to 150 Torr in 15 minutes, and then an ester exchange reaction was conducted for 20 minutes at 205° C and 150 Torr. The reaction mixture was then heated to 240° C with a heating ratio of 37.5° C / h, and the reaction conditions of 240° C and 150 Torr were main- tained for 10 minutes. Subsequently, the pressure was reduced to 120 Torr in 10 minutes, and the reaction conditions of 240° C and 120 Torr were main- tained for 70 minutes. After reducing the pressure to 100 Torr in 10 minutes, the reaction conditions of 240° C and 100 Torr were maintained for 10 minutes. The pressure was further reduced to 1 Torr or lower in 40 minutes, and the polymerization reaction was conducted at 240° C and 1 Torr for 10 minutes. After the reaction was completed, the pressure was increased by in- troducing nitrogen into the reactor and the generated polycarbonate resin was pelletized and removed from the reactor. The characteristics of the obtained copolycarbonate resin are summarized in Table 2. For an easier comparison , also the values of the homopolymers of example 2 are listed. The weight aver- age molecular weight ( Mw) of the copolycarbonate resin of Example 3 was 52, 000.

[0352] Table 2: Properties of the copolycarbonate of Example 3, the homopolycar- bonate of example 2 and the comparative homopolycarbonate of example 2

[0353] * calculated values

Claims

CLAIMS 1. The use of a compound of the formula (I)whereX1and X2, independently of each other, are a bond or C1-C5-a I kaned i y I ;Z1and Z2, independently of each other, are OH or C (O)ORX, where Rxis selected from the group consisting of hydrogen, C1-C4- alkyl, phenyl and benzyl ; one or two of Ra, Rb, Rcand Rdare a dibenzothiophene radical of the formula (II) :where # denotes the attachment point to the remainder of the molecule; and the other two or three of Ra, Rb, Rcand Rdare each independently se- lected from the group consisting of hydrogen, halogen, C2- C3- aI - kynyl, CN, R, S (O)kR, NHR, NR2, OR and C (O)R; or Rcand Rdtogether with carbon atoms to which they are bound may also form a fused benzene ring; where each R is independently selected from the group consisting of Ci~ C4- aI kyI , phenyl, benzyl and naphthyl; and k is 0, 1 or 2; as a monomer for producing a thermoplastic resin that is selected from the group consisting of polycarbonates, polyesters and polyestercar- bonates, in particular polycarbonates and polyesters.

2. The use according to claim 1, where X1and X2, independently of each other, are C1-C5- aIkanediyI .

3. The use according to claim 2, where X1and X2are both methylene.

4. The use according to any of the preceding claims, where Z1and Z2are both OH.

5. The use according to claim 1, where X1and X2are both a bond, and Z1and Z2are O(O) ORx, where Rxis preferably selected from the group consisting of hydrogen and C1-C4- alkyl and is more preferably hydrogen.

6. The use according to any of the preceding claims, where two of Ra, Rb, Rcand Rdare a dibenzothiophene radical of the formula (II).

7. The use according to any of the preceding claims, where those radicalsRa, Rb, Rcand Rdwhich are not a dibenzothiophene radical of the formula(I I) are hydrogen.

8. The use according to any of the preceding claims, where Raand Rdare a dibenzothiophene radical of the formula (II), while Rband Rcare hydro- gen.

9. The use according to any of the preceding claims, where the di benzothio- phene radical of the formula (II) is a radical of the formula (II.1)where # indicates the attachment point to the remainder of the molecule.

10. The use according to any of the preceding claims, where the compound of the formula (I) is a compound of the formula (1.1)11. The use according to any one of claims 1 to 10, as a monomer for produc- ing the thermoplastic resin as defined in any one of claims 13 to 21.

12. A compound of the formula (I) as defined in any one of claims 1 to 10, except for following compounds:- dimethyl 2, 5— d I (dibenzothiophen-2-yl)benzene-1, 4-dicarboxyIate; and- 2, 5-d I (d i benzoth i ophen-2-yI ) benzene-1 , 4-dioI .

13. A thermoplastic resin comprising a structural unit represented by for- mula (III)where# represents a connection point to a neighboring structural unit;Z11is a bridging group -O- or -C(O) -O-, where the carbon atom of the group-G (O) -O- is bound to X1;Z12is a bridging group -O- or -C(O) -O-, where the carbon atom of the group -C(O) -O- is bound to X2; andX1, X2, Ra, Rb, Rcand Rdare as defined in any of claims 1 to 10.

14. The thermoplastic resin according to claim 13, where the thermoplastic resin is selected from the group consisting of polycarbonates, polyes- ters and polyestercarbonates, in particular polycarbonates and polyes- ters.

15. The thermoplastic resin according to claim 13 or 14, comprising a struc- tural unit represented by formula (III) where Z11and Z12are both a bridging group -O-; the structural unit being in this case a structural unit of the formula (III.1):

16. The thermoplastic resin according to claim any of claims 13 to 15, where the structural unit of the formula (III) wherein Z11and Z12are both a bridging group -0- is connected to one of the structures represented by formulae (IV-1) to (IV-5)where# represents a connection point to a neighboring structural unit.

17. The thermoplastic resin according to any one of claims 13 to 16, which is selected from copolycarbonate resins, copolyestercarbonate resins and copolyester resins, where the thermoplastic resin, in addition to struc- tural units represented by formula (III), comprises a structural unit of the formula (V),#-O-Rz-A1-Rz-O-#- (V) where# represents a connection point to a neighboring structural unit;A1 is a polycyclic radical bearing at least 2 benzene rings, wherein the benzene rings may be connected by A and / or directly fused to each other and / or fused by a non-benzene carbocycle, where A1 is unsubstituted or substituted by 1, 2 or 3 radicals Raa, which are selected from the group consisting of halogen, C1-C6-alkyl, C5-C6- cycloalkyl and phenyl ;A is selected from the group consisting of a single bond, O, G=O, S, SO2, CH2, CH-Ar, CAr2, CH (CH3) , C (CH3)2and a radical of the formula (A’) whereQ represents a single bond, O, NH, O= O, CH2or CH=CH; R7a, R7b, independently of each other, are selected from the group consisting of hydrogen, fluorine, GN, R, OR, CHkR3-k, NR2, O( O) R and O( O) NH2, where R is as defined in claim 1 and k is O, 1, 2 or 3; and* represents the connection point to a benzene ring;Ar is selected from the group consisting of mono- or polycyclic aryl having from 6 to 26 carbon atoms as ring atoms and mono- or poly- cyclic hetaryl having a total of 5 to 26 atoms, which are ring members, where 1, 2, 3 or 4 of these ring member atoms of hetarylare selected from nitrogen, sulphur and oxygen, while the remain- der of these ring member atoms of hetaryl are carbon atoms, where Ar is unsubstituted or substituted by 1, 2 or 3 radicals Rab, which are selected from the group consisting of halogen, phenyl and C1- C4-aIkyI ; andRzis a single bond, Alk1, O— Alk2— , O- Alk2- [O- Alk2-]p- or O- Alk3- O(O)- where 0 is bound to A1; where p is an integer from 1 to 10; Alk1is C1- C4-aIkandiyI ; Alk2is C2— C4—aIkandiyI ; and Alk3is C1- C4- aIkandiyI .

18. The thermoplastic resin according to claim 17, where the structural unit of the formula V is represented by one of the following formulae V-1 to V-6:where a and b are 0, 1, 2 or 3, in particular 0 or 1 ;c and d are 0, 1, 2, 3, 4 or 5, in particular 0 or 1; e and f are 0, 1, 2, 3, 4 or 5, in particular 0 or 1 ; and where Rz, Raa, Rab, R7aand R7bare as defined for formula (V).

19. The thermoplastic resin according to any one of claims 17 or 18, where the molar ratio of the structural units of the formula (III) is from 1 to 70 mol-%, in particular from 5 to 60 mol-% or 10 to 40 mol-%, based on the total molar amount of structural units of the formulae (III) and (V) and where the molar ratio of the structural units of the formula (V) is from 30 to 99 mol-%, in particular from 40 to 95 mol-% or 60 to 90 mol-%, based on the total molar amount of structural units of the formu- lae (III) and (V).

20. The thermoplastic resin according to any one of claims 13 to 19, which has a refractive index of 1.640 or higher.

21. The thermoplastic resin according to any one of claims 13 to 20, which has an Abbe number of 24 or lower.

22. The thermoplastic resin according to any one of claims 13 to 21 which has a glass transition temperature (Tg) of 90 to 290° C.

23. The thermoplastic resin according to any one of claims 13 to 22 which has a glass transition temperature (Tg) of 90 to 185° C.

24. An optical device made of a thermoplastic resin as defined in any one of claims 13 to 23.

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