Resin and method for preparing the same

Abstract

This application relates to a resin comprising units of chemical formula 1 and chemical formula 2, a method for manufacturing the resin, a resin composition comprising the resin, and a molded article comprising the resin composition.

Description

Technical Field

[0001] This specification relates to resins and methods for their preparation. This specification claims priority to and the benefit of Korean Patent Application Nos. 10-2022-0128853, 10-2022-0128859, and 10-2022-0128861 filed in the Korean Intellectual Property Office on October 7, 2022, and Korean Patent Application No. 10-2022-0159379 filed in the Korean Intellectual Property Office on November 24, 2022, the entire contents of which are incorporated herein by reference. Prior Art

[0002] Optical glass or optical resin is used as an optical material for plastic optical products and optical films, such as various lenses, prisms, optical disc substrates, and optical fibers. While optical glass offers excellent heat resistance, transparency, dimensional stability, and chemical resistance, it suffers from high material costs, poor moldability, and low productivity. Meanwhile, optical materials including optical resins can be mass-produced by injection molding. Polycarbonate resins, polyester resins, polyester-carbonate resins, and the like are used as optical resins. However, optical resins suffer from a disadvantage in that their lack of fluidity reduces their workability. Consequently, their application to injection molding of precision-required objects can be challenging. Injection molding requires increasing the molding temperature, mold temperature, and other factors, but this increases the molding cycle time, leading to increased molding costs and potentially degrading the resin and color during molding. To solve this problem, examples of methods for improving the color fluidity of the resin during molding of optical materials include reducing viscosity, reducing weight average molecular weight, adding low molecular weight oligomers, broadening molecular weight distribution, and the like, but these methods tend to deteriorate the excellent physical properties inherent in the resin, such as heat resistance and impact resistance. Furthermore, optical materials with high refractive indices are generally required to have a transparency equal to or greater than a predetermined level. Due to the transparency of polycarbonate, its use in optical material-related technologies is expected to continue to expand, and there is a demand for optical materials that can effectively prevent yellowing caused by polycarbonate. Therefore, attempts have been made to improve processability and achieve a variety of colors by exhibiting a low yellowness index while maintaining the advantages of the resin. [Citation List] [Patent Document 1] (Patent Document 1) KR 10-2020-0034523 A Summary of the Invention

[0003] [Technical Issues] The exemplary embodiments of this specification have been directed to providing a resin having a novel structure and a method for preparing the same. Another exemplary embodiment of the present specification has been directed to providing a resin composition including a resin having a novel structure and a molded object prepared from the resin composition. [Technical solution] An exemplary embodiment of the present specification provides a resin including a unit of the following Chemical Formula 1 and a unit of the following Chemical Formula 2. In Chemical Formula 1, L is a direct bond; or -L'-C(=O)-, L' is a substituted or unsubstituted aryl group, X1 to X4 are each independently O or S, Z1 and Z2 are each independently a substituted or unsubstituted alkylene group; or a substituted or unsubstituted cycloalkylene group, a and b are each independently an integer from 1 to 10, and when a and b are each 2 or greater, the structures in each bracket are the same as or different from each other, R1 to R4 are each independently hydrogen; substituted or unsubstituted alkyl; substituted or unsubstituted cycloalkyl; substituted or unsubstituted aryl; or substituted or unsubstituted heteroaryl. R1 and R2 are each independently an integer from 0 to 3, and when R1 and R2 are each 2 or greater, two or more of R1 and R2 are the same or different from each other, R3 and R4 are each independently an integer from 0 to 4, and when R3 and R4 are each 2 or greater, two or more of R3 and R4 are the same or different from each other, * Refers to the part connected to the main chain of the resin. In Chemical Formula 2, L1 is a direct bond; or -L1'-C(=O)-, L1' is a substituted or unsubstituted aryl group, L11 is a substituted or unsubstituted alkylene group; a substituted or unsubstituted cycloalkylene group; a divalent fused ring group of an aromatic hydrocarbon ring and an aliphatic hydrocarbon ring, which is substituted or unsubstituted; or a substituted or unsubstituted arylene group, l11 is an integer from 1 to 5, and when l11 is 2 or greater, two or more L11 are the same as or different from each other, X11 to X14 are each independently O or S, Z11 and Z12 are each independently a substituted or unsubstituted alkylene group; or a substituted or unsubstituted cycloalkylene group, c and d are each independently an integer from 0 to 10, and when c and d are each 2 or greater, the structures in each bracket are the same as or different from each other, and *Indicates the portion linked to the main chain of the resin. An exemplary embodiment of this specification provides a method for preparing a resin according to the exemplary embodiment described above, the method comprising: polymerizing a composition for preparing a resin, the composition comprising a compound of the following Chemical Formula 1a; a compound of the following Chemical Formula 2a; and one or more of a polycarbonate precursor and a polyester precursor. In Chemical Formula 1a, X1 to X4 are each independently O or S, Z1 and Z2 are each independently a substituted or unsubstituted alkylene group; or a substituted or unsubstituted cycloalkylene group, a and b are each independently an integer from 1 to 10, and when a and b are each 2 or greater, the structures in each bracket are the same as or different from each other, R1 to R4 are each independently hydrogen; substituted or unsubstituted alkyl; substituted or unsubstituted cycloalkyl; substituted or unsubstituted aryl; or substituted or unsubstituted heteroaryl. R1 and R2 are each independently an integer from 0 to 3, and when R1 and R2 are each 2 or greater, two or more of R1 and R2 are the same or different from each other, R3 and R4 are each independently an integer from 0 to 4, and when R3 and R4 are each 2 or greater, two or more of R3 and R4 are the same or different from each other, In Chemical Formula 2a, L11 is a substituted or unsubstituted alkylene group; a substituted or unsubstituted cycloalkylene group; a divalent fused ring group of an aromatic hydrocarbon ring and an aliphatic hydrocarbon ring, which is substituted or unsubstituted; or a substituted or unsubstituted arylene group, l11 is an integer from 1 to 5, and when l11 is 2 or greater, two or more L11 are the same as or different from each other. X11 to X14 are each independently O or S, Z11 and Z12 are each independently a substituted or unsubstituted alkylene group; or a substituted or unsubstituted cycloalkylene group, and c and d are each independently an integer of 0 to 10, and when c and d are each 2 or greater, the structures in each bracket are the same as or different from each other. Another exemplary embodiment of the present specification provides a resin composition comprising the resin according to the above exemplary embodiment. Yet another exemplary embodiment of the present specification provides a molded article comprising a resin composition comprising the resin according to the above exemplary embodiment. [Beneficial effects] The resin according to the exemplary embodiment of the present specification has a high refractive index and high transparency. An excellent optical lens, optical film, optical thin film, or optical resin having a thin thickness can be obtained by using the resin according to the exemplary embodiment of the present specification. An excellent optical lens, optical film, optical thin film, or optical resin having a high refractive index and a low yellowness index can be obtained by using the resin according to the exemplary embodiment of the present specification. Implementation Method

[0004] This manual will be explained in more detail below. Regarding the resin containing units represented by Chemical Formula 1 according to exemplary embodiments of this specification, the Lorentz-Lorenz formula, which relates molecular structure to refractive index, indicates that the refractive index of a material composed of molecules is increased by increasing the molecular electron density and decreasing the molecular volume. Furthermore, the core structure of Chemical Formula 1 is spiro[fluorene-9,9'-dibenzopyran], and in the case of an electron-rich core structure, the refractive index of the resin can be further improved by increasing the electron density of the structure represented by Chemical Formula 1. The resin can supplement the glass transition temperature (Tg) of the unit represented by Chemical Formula 1 or make the chain behavior of the unit represented by Chemical Formula 1 flexible by including the units represented by Chemical Formula 1 and 2, and has the technical effect of facilitating the injection molding of molded objects. Therefore, the resin according to the exemplary embodiment of the present specification has a high refractive index and high transparency, and an optical lens, optical film, or optical resin using the resin has a thin thickness and can exhibit excellent optical properties. The resin according to the exemplary embodiment of the present specification can be a polycarbonate resin, a polyester resin or a polyester-carbonate resin. Unless otherwise specifically limited in the present specification, the resin includes all three types of resins mentioned above. Throughout the specification of this application, the term "combination thereof" included in a Markush-type expression means a mixture or combination of one or more selected from the group consisting of the constituent elements described in the Markush-type expression, and means including one or more selected from the group consisting of the above constituent elements. In this specification, room temperature is the same as defined in this technology, generally refers to the temperature of laboratories, assay rooms and the like, particularly refers to the temperature used when experiments are conducted without specifying or adjusting the temperature or when samples or materials are left in the room, and in this technology means 15°C to 25°C. In this specification, normal pressure is the same as defined in this technology, and generally means a pressure of about 1 atmosphere, which is the same as normal atmospheric pressure. When a part in the present specification “includes” a constituent element, unless otherwise specifically stated, it does not mean that another constituent element is excluded, but means that another constituent element may be further included. Unless otherwise defined herein, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of exemplary embodiments of the present invention, suitable methods and materials are now described. All publications, patent applications, patents, and other references cited herein are hereby incorporated by reference in their entirety, and in the event of conflict, the present invention (including definitions) controls unless otherwise specified. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting. Examples of substituents in this specification will be described below, but are not limited thereto. In this manual, Refers to the part to be connected. In the present specification, the term "substituted" means that a hydrogen atom bonded to a carbon atom or a nitrogen atom of a compound is changed to another substituent, and the position to be substituted is not limited, as long as the position is the position where the hydrogen atom thereon is substituted, that is, the position where the substituent thereon can be substituted, and when two or more substituents are substituted, the two or more substituents may be the same or different from each other. In the present specification, the term "substituted or unsubstituted" means substituted with one or more substituents selected from the group consisting of deuterium; a halogen group; a hydroxyl group; a cyano group; an alkyl group; a cycloalkyl group; an alkoxy group; an alkenyl group; an aryloxy group; an arylthio group; an alkylthio group; a silyl group; an aryl group; a fused ring group of an aromatic hydrocarbon ring and an aliphatic hydrocarbon ring; and a heteroaryl group, or substituted with a substituent in which two or more substituents among the exemplified substituents are linked together, or having no substituent. In this specification, the fact that two or more substituents are linked means that the hydrogen of any one substituent is linked to another substituent. For example, when two substituents are linked to each other, a phenyl group and a naphthyl group may be linked to each other to form or Furthermore, the case where three substituents are linked to each other includes not only the case where (substituent 1)-(substituent 2)-(substituent 3) are linked to each other continuously, but also the case where (substituent 2) and (substituent 3) are linked to (substituent 1). For example, phenyl, naphthyl, and isopropyl can be linked to each other to form 、 or The above definition also applies to the case where four or more substituents are linked to each other. In the present specification, hydrogen may be hydrogen, deuterium or tritium. In the present specification, a portion in a chemical formula structure that does not indicate a substituent may be substituted with hydrogen, deuterium, or tritium. In the present specification, examples of the halogen group include fluorine, chlorine, bromine or iodine. In the present specification, the alkyl group may be linear or branched, and the number of carbon atoms thereof is not particularly limited, but is preferably 1 to 30. Specific examples thereof include methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tertiary butyl, secondary butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n-pentyl, isopentyl, neopentyl, tertiary pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl, n-heptyl, 1-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, tertiary octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 1-ethyl-propyl, 1,1-dimethyl-propyl, isohexyl, 2-methylpentyl, 4-methylhexyl, 5-methylhexyl and the like, but are not limited thereto. In the present specification, the cycloalkyl group is not particularly limited but preferably has 3 to 30 carbon atoms, and specific examples thereof include cyclopropyl, cyclobutyl, cyclopentyl, 3-methylcyclopentyl, 2,3-dimethylcyclopentyl, cyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 2,3-dimethylcyclohexyl, 3,4,5-trimethylcyclohexyl, 4-tert-butylcyclohexyl, cycloheptyl, cyclooctyl, adamantyl and the like, but are not limited thereto. In this specification, an alkoxy group may be linear, branched, or cyclic. The number of carbon atoms in the alkoxy group is not particularly limited, but is preferably 1 to 30. Specific examples include, but are not limited to, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tertiary butoxy, secondary butoxy, n-pentoxy, neopentoxy, isopentoxy, n-hexyloxy, 3,3-dimethylbutoxy, 2-ethylbutoxy, n-octyloxy, n-nonyloxy, n-decyloxy, benzyloxy, p-methylbenzyloxy, and the like. In the present specification, the alkenyl group may be linear or branched, and the number of carbon atoms thereof is not particularly limited, but is preferably 2 to 30. Specific examples thereof include vinyl, 1-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 3-methyl-1-butenyl, 1,3-butadienyl, allyl, 1-phenylethen-1-yl, 2-phenylethen-1-yl, 2,2-diphenylethen-1-yl, 2-phenyl-2-(naphthalen-1-yl)ethen-1-yl, 2,2-bis(diphenyl-1-yl)ethen-1-yl, stilbenyl, styryl, and the like, but are not limited thereto. In the present specification, the aryl group is not particularly limited, but preferably has 6 to 30 carbon atoms, and the aryl group may be monocyclic or polycyclic. When the aryl group is a monocyclic aryl group, the number of carbon atoms is not particularly limited, but is preferably 6 to 50. Specific examples of the monocyclic aryl group include phenyl, biphenyl, terphenyl, and the like, but are not limited thereto. When the aryl group is a polycyclic aromatic group, the number of carbon atoms is not particularly limited, but is preferably 10 to 50. Specific examples of the polycyclic aromatic group include, but are not limited to, naphthyl, anthracenyl, phenanthrenyl, terphenyl, pyrenyl, phenalene, perylenyl, chrysene, fluorenyl, and the like. In the present specification, the fluorenyl group may be substituted, and adjacent groups may be bonded to each other to form a ring. Examples of the case where the fluorenyl group is substituted include 、 、 、 、 、 、 、 and the like, but not limited thereto. In this specification, "adjacent" groups may refer to a substituent substituted on an atom directly bonded to the atom substituted by the corresponding substituent, a substituent located closest in space to the corresponding substituent, or another substituent substituted on the atom substituted by the corresponding substituent. For example, two substituents substituted at ortho positions in a benzene ring and two substituents substituted on the same carbon in an aliphatic ring can be interpreted as "adjacent" groups to each other. In the present specification, a heteroaryl group includes one or more atoms other than carbon atoms, i.e., one or more heteroatoms. Specifically, the heteroatoms may include one or more atoms selected from the group consisting of O, N, Se, S, and the like. The number of carbon atoms is not particularly limited, but is preferably 2 to 30. The heteroaryl group may be monocyclic or polycyclic. Examples of heteroaryl groups include thienyl, furanyl, pyrrolyl, imidazolyl, thiazolyl, oxazolyl, oxadiazolyl, pyridyl, bipyridyl, pyrimidinyl, triazolyl, triazolyl, acridinyl, pyrimidinyl, quinolinyl, quinazolinyl, quinolinyl, phthalinyl, pyridopyrimidinyl, pyridopyrimidinyl, pyridopyrimidinyl, pyridopyrimidinyl, pyridopyrimidinyl, pyridopyrimidinyl, isoquinolinyl, indolyl, carbazolyl, benzoxazolyl, benzimidazolyl, benzothiazolyl, benzothiophene, dibenzothiophene, benzofuranyl, phenanthridinyl, phenanthrinyl, isoxazolyl, thiadiazolyl, dibenzofuranyl, dibenzosiloleyl, phenanthiophene, phenanthiophene, phenanthiophene, dihydroindenocarbazolyl, spirofluorenexanthene, spirofluorenthioxanthene thiophene, tetrahydronaphthofuranyl, tetrahydrobenzothiophene, tetrahydrobenzofuranyl and the like, but are not limited thereto. In the present specification, a silyl group may be an alkylsilyl group, an arylsilyl group, an alkylarylsilyl group, a heteroarylsilyl group, or the like. The above examples of the alkyl group may apply to the alkyl group in the alkylsilyl group, the above examples of the aryl group may apply to the aryl group in the arylsilyl group, the examples of the alkyl and aryl groups may apply to the alkyl and aryl groups in the alkylsilyl group, and the examples of the heterocyclic group may apply to the heteroaryl group in the heteroarylsilyl group. In the present specification, the hydrocarbon ring group may be an aromatic hydrocarbon ring group, an aliphatic hydrocarbon ring group, or a condensed group of an aromatic hydrocarbon ring and an aliphatic hydrocarbon ring, and may be selected from examples of cycloalkyl groups, aryl groups, and combinations thereof. Examples of the hydrocarbon ring group include phenyl, cyclohexyl, adamantyl, bicyclo[2.2.1]heptyl, bicyclo[2.2.1]octyl, tetrahydronaphthyl, tetrahydroanthracenyl, 1,2,3,4-tetrahydro-1,4-methanonaphthalene, 1,2,3,4-tetrahydro-1,4-ethanonaphthalene, spirocyclopentanefluorenyl, spiroadamantanfluorenyl, spirocyclohexanefluorenyl, and the like, but are not limited thereto. In the present specification, an aryloxy group can be represented by -ORo, and the description of the above aryl group applies to Ro. In the present specification, an arylthio group can be represented by -SRs1, and the description of the above aryl group applies to Rs1. In the present specification, an alkylthio group can be represented by -SRs2, and the description of the above-mentioned alkyl group applies to Rs2. In this specification, an alkylene group refers to a group having two bonding positions in an alkyl group, that is, a divalent group. The above description of the alkyl group is applicable to this alkylene group, except that it is a divalent alkylene group. In this specification, a cycloalkylene group refers to a group having two bonding positions within a cycloalkyl group, that is, a divalent group. The above description of the cycloalkylene group is applicable to this cycloalkylene group, except that it is a divalent cycloalkylene group. In this specification, a divalent fused ring group of an aromatic hydrocarbon ring and an aliphatic hydrocarbon ring refers to a group having two bonding positions in the fused ring group of an aromatic hydrocarbon ring and an aliphatic hydrocarbon ring, that is, a divalent group. The above description of the fused ring group of an aromatic hydrocarbon ring and an aliphatic hydrocarbon ring applies to this group, except that each is a divalent group. In this specification, an arylene group refers to a group having two bonding positions in an aryl group, that is, a divalent group. The above description of the aryl group is applicable to the arylene group, except that it is a divalent group. According to an exemplary embodiment of the present specification, a resin including a unit of the following Chemical Formula 1 and a unit of the following Chemical Formula 2 is provided. In Chemical Formula 1, L is a direct bond; or -L'-C(=O)-, L' is a substituted or unsubstituted aryl group, X1 to X4 are each independently O or S, Z1 and Z2 are each independently a substituted or unsubstituted alkylene group; or a substituted or unsubstituted cycloalkylene group, a and b are each independently an integer from 1 to 10, and when a and b are each 2 or greater, the structures in each bracket are the same as or different from each other, R1 to R4 are each independently hydrogen; substituted or unsubstituted alkyl; substituted or unsubstituted cycloalkyl; substituted or unsubstituted aryl; or substituted or unsubstituted heteroaryl. R1 and R2 are each independently an integer from 0 to 3, and when R1 and R2 are each 2 or greater, two or more of R1 and R2 are the same or different from each other, R3 and R4 are each independently an integer from 0 to 4, and when R3 and R4 are each 2 or greater, two or more of R3 and R4 are the same or different from each other, * Refers to the part connected to the main chain of the resin. In Chemical Formula 2, L1 is a direct bond; or -L1'-C(=O)-, L1' is a substituted or unsubstituted aryl group, L11 is a substituted or unsubstituted alkylene group; a substituted or unsubstituted cycloalkylene group; a divalent fused ring group of an aromatic hydrocarbon ring and an aliphatic hydrocarbon ring, which is substituted or unsubstituted; or a substituted or unsubstituted arylene group, l11 is an integer from 1 to 5, and when l11 is 2 or greater, two or more L11 are the same as or different from each other, X11 to X14 are each independently O or S, Z11 and Z12 are each independently a substituted or unsubstituted alkylene group; or a substituted or unsubstituted cycloalkylene group, c and d are each independently an integer from 0 to 10, and when c and d are each 2 or greater, the structures in each bracket are the same as or different from each other, and *Indicates the portion linked to the main chain of the resin. According to an exemplary embodiment of the present specification, Chemical Formula 1 is represented by the following Chemical Formula 1-1. In Chemical Formula 1-1, The definitions of the substituents are the same as those in Chemical Formula 1. According to an exemplary embodiment of the present specification, Chemical Formula 1 is defined as any one of the following Chemical Formulas 1-2 and 1-3. In chemical formulas 1-2 and 1-3, The definitions of the substituents are the same as those in Chemical Formula 1. According to an exemplary embodiment of this specification, L is a direct bond. According to an exemplary embodiment of the present specification, L is a direct bond, and the resin is a polycarbonate resin. According to an exemplary embodiment of the present specification, L is a direct bond, and the resin is a polyester-carbonate resin. According to an exemplary embodiment of the present specification, L is -L'-C(=O)-. According to an exemplary embodiment of the present specification, L is -L'-C(=O)-, and the resin is a polyester resin. According to an exemplary embodiment of the present specification, L is -L'-C(=O)-, and the resin is a polyester-carbonate resin. According to an exemplary embodiment of the present specification, L' is a monocyclic or polycyclic aryl group having 6 to 30 carbon atoms. According to an exemplary embodiment of the present specification, L' is a monocyclic or polycyclic aryl group having 6 to 20 carbon atoms. According to an exemplary embodiment of the present specification, L' is a phenylene group; or a naphthylene group. According to an exemplary embodiment of the present specification, L' is a phenylene group. According to an exemplary embodiment of the present invention, X1 to X4 are 0. According to an exemplary embodiment of the present invention, X1 to X4 are S. According to an exemplary embodiment of this specification, X1 and X2 are S, and X3 and X4 are O. According to an exemplary embodiment of this specification, X1 and X2 are O, and X3 and X4 are S. According to an exemplary embodiment of this specification, X1 is O. According to an exemplary embodiment of this specification, X2 is O. According to an exemplary embodiment of this specification, X3 is O. According to an exemplary embodiment of this specification, X4 is O. According to an exemplary embodiment of this specification, X1 is S. According to an exemplary embodiment of this specification, X2 is S. According to an exemplary embodiment of this specification, X3 is S. According to an exemplary embodiment of this specification, X4 is S. According to an exemplary embodiment of this specification, a is 1. According to an exemplary embodiment of this specification, b is 1. According to an exemplary embodiment of this specification, a is 2. According to an exemplary embodiment of this specification, b is 2. According to an exemplary embodiment of this specification, a is 3. According to an exemplary embodiment of this specification, b is 3. When a and b are integers of 1 to 10, the resin can have optimized fluidity and processability compared to when a and b are 0. According to exemplary embodiments of the present specification, Z1 and Z2 are the same or different from each other and are each independently a substituted or unsubstituted straight-chain or branched alkylene group having 1 to 30 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic alkylene group having 3 to 30 carbon atoms. According to exemplary embodiments of the present specification, Z1 and Z2 are the same or different from each other and are each independently a substituted or unsubstituted straight-chain or branched alkylene group having 1 to 20 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic alkylene group having 3 to 20 carbon atoms. According to exemplary embodiments of the present specification, Z1 and Z2 are the same or different from each other and are each independently a substituted or unsubstituted straight-chain or branched alkylene group having 1 to 10 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic alkylene group having 3 to 10 carbon atoms. According to an exemplary embodiment of the present specification, Z1 and Z2 are the same as or different from each other, and are each independently a substituted or unsubstituted linear or branched alkylene radical having 1 to 30 carbon atoms. According to an exemplary embodiment of the present specification, Z1 and Z2 are the same as or different from each other, and are each independently a substituted or unsubstituted linear or branched alkylene radical having 1 to 20 carbon atoms. According to an exemplary embodiment of the present specification, Z1 and Z2 are the same as or different from each other, and are each independently a substituted or unsubstituted linear or branched alkylene radical having 1 to 10 carbon atoms. According to exemplary embodiments of the present specification, Z1 and Z2 are the same as or different from each other, and are each independently a substituted or unsubstituted ethylene group. According to exemplary embodiments of the present specification, R1 to R4 are the same as or different from each other and are each independently hydrogen; a substituted or unsubstituted straight-chain or branched alkyl group having 1 to 30 carbon atoms; a substituted or unsubstituted monocyclic or polycyclic cycloalkyl group having 3 to 30 carbon atoms; a substituted or unsubstituted monocyclic or polycyclic aryl group having 6 to 30 carbon atoms; or a monocyclic or polycyclic heteroaryl group having 2 to 30 carbon atoms, which is substituted or unsubstituted and includes one or more of O, S, and N. According to exemplary embodiments of the present specification, R1 to R4 are the same as or different from each other and are each independently hydrogen; a substituted or unsubstituted straight-chain or branched alkyl group having 1 to 20 carbon atoms; a substituted or unsubstituted monocyclic or polycyclic cycloalkyl group having 3 to 20 carbon atoms; a substituted or unsubstituted monocyclic or polycyclic aryl group having 6 to 20 carbon atoms; or a monocyclic or polycyclic heteroaryl group having 2 to 20 carbon atoms, which is substituted or unsubstituted and includes one or more of O, S, and N. According to exemplary embodiments of the present specification, R1 to R4 are the same as or different from each other and are each independently hydrogen; a substituted or unsubstituted straight-chain or branched alkyl group having 1 to 10 carbon atoms; a substituted or unsubstituted monocyclic or polycyclic cycloalkyl group having 3 to 10 carbon atoms; a substituted or unsubstituted monocyclic or polycyclic aryl group having 6 to 10 carbon atoms; or a monocyclic or polycyclic heteroaryl group having 2 to 10 carbon atoms, which is substituted or unsubstituted and includes one or more of O, S, and N. According to an exemplary embodiment of the present specification, R1 to R4 are each independently hydrogen. According to an exemplary embodiment of this specification, L1 is a direct key. According to an exemplary embodiment of the present specification, L1 is a direct bond, and the resin is a polycarbonate resin. According to an exemplary embodiment of the present specification, L1 is a direct bond, and the resin is a polyester-carbonate resin. According to an exemplary embodiment of the present specification, L1 is -L1'-C(=O)-. According to an exemplary embodiment of this specification, L1 is -L1'-C(=O)- , and the resin is polyester resin. According to an exemplary embodiment of this specification, L1 is -L1'-C(=O)- , and the resin is polyester-carbonate resin. According to an exemplary embodiment of the present specification, L1′ is a monocyclic or polycyclic aryl group having 6 to 30 carbon atoms. According to an exemplary embodiment of the present specification, L1′ is a monocyclic or polycyclic aryl group having 6 to 20 carbon atoms. According to an exemplary embodiment of the present specification, L1' is a phenylene group; or a naphthylene group. According to an exemplary embodiment of the present specification, L1′ is a phenylene group. According to exemplary embodiments of the present specification, L11 is a substituted or unsubstituted linear or branched alkylene group having 1 to 30 carbon atoms; a substituted or unsubstituted monocyclic or polycyclic alkylene group having 3 to 30 carbon atoms; a divalent fused ring group of a monocyclic or polycyclic aromatic hydrocarbon ring having 6 to 30 carbon atoms and an aliphatic hydrocarbon ring having 3 to 30 carbon atoms, which is unsubstituted or substituted with a monocyclic or polycyclic aromatic group having 6 to 30 carbon atoms; or a monocyclic or polycyclic aromatic group having 6 to 30 carbon atoms, which is unsubstituted or substituted with a linear or branched alkyl group having 1 to 30 carbon atoms or a monocyclic or polycyclic aromatic group having 6 to 30 carbon atoms. According to exemplary embodiments of the present specification, L11 is a substituted or unsubstituted linear or branched alkylene group having 1 to 20 carbon atoms; a substituted or unsubstituted monocyclic or polycyclic alkylene group having 3 to 20 carbon atoms; a divalent fused ring group of a monocyclic or polycyclic aromatic hydrocarbon ring having 6 to 20 carbon atoms and an aliphatic hydrocarbon ring having 3 to 20 carbon atoms, which is unsubstituted or substituted with a monocyclic or polycyclic aromatic group having 6 to 20 carbon atoms; or a monocyclic or polycyclic aromatic group having 6 to 20 carbon atoms, which is unsubstituted or substituted with a linear or branched alkyl group having 1 to 20 carbon atoms or a monocyclic or polycyclic aromatic group having 6 to 20 carbon atoms. According to an exemplary embodiment of the present specification, L11 is C(CH 3) 2; unsubstituted or methyl-substituted phenylene; biphenylene; a divalent naphthyl group; or a divalent fluorenyl group. According to an exemplary embodiment of the present specification, L11 is a divalent fused ring group of a monocyclic or polycyclic aromatic hydrocarbon ring having 6 to 30 carbon atoms and an aliphatic hydrocarbon ring having 3 to 30 carbon atoms, which is unsubstituted or substituted with a monocyclic or polycyclic aromatic group having 6 to 30 carbon atoms; or a monocyclic or polycyclic aromatic group having 6 to 30 carbon atoms, which is unsubstituted or substituted with a linear or branched alkyl group having 1 to 30 carbon atoms or a monocyclic or polycyclic aromatic group having 6 to 30 carbon atoms. According to an exemplary embodiment of the present specification, L11 is a divalent fused ring group of a monocyclic or polycyclic aromatic hydrocarbon ring having 6 to 20 carbon atoms and an aliphatic hydrocarbon ring having 3 to 20 carbon atoms, which is unsubstituted or substituted with a monocyclic or polycyclic aromatic group having 6 to 20 carbon atoms; or a monocyclic or polycyclic aromatic group having 6 to 20 carbon atoms, which is unsubstituted or substituted with a linear or branched alkyl group having 1 to 20 carbon atoms or a monocyclic or polycyclic aromatic group having 6 to 20 carbon atoms. According to an exemplary embodiment of the present specification, L11 is unsubstituted or methyl-substituted phenylene; biphenylene; fluorenyl substituted with naphthyl; phenylene; binaphthyl; or bisphenol A. According to an exemplary embodiment of this specification, l11 is 1. According to an exemplary embodiment of this specification, l11 is 2, and the two L11s are the same as or different from each other. According to an exemplary embodiment of this specification, l11 is 3, and the three L11s are the same as or different from each other. According to an exemplary embodiment of this specification, l11 is 4, and the four L11s are the same as or different from each other. According to an exemplary embodiment of this specification, l11 is 5, and the five L11s are the same as or different from each other. According to an exemplary embodiment of this specification, X11 is O. According to an exemplary embodiment of this specification, X12 is O. According to an exemplary embodiment of this specification, X13 is O. According to an exemplary embodiment of this specification, X14 is 0. According to an exemplary embodiment of this specification, X11 to X14 are 0. According to an exemplary embodiment of the present specification, Z11 and Z12 are the same as or different from each other, and are each independently a linear or branched alkylene group having 1 to 30 carbon atoms. According to an exemplary embodiment of the present specification, Z11 and Z12 are the same as or different from each other, and are each independently a linear or branched alkylene group having 1 to 20 carbon atoms. According to an exemplary embodiment of the present specification, Z11 and Z12 are the same as or different from each other, and are each independently a linear or branched alkylene radical having 1 to 10 carbon atoms. According to an exemplary embodiment of the present specification, Z11 and Z12 are ethylene groups. According to an exemplary embodiment of this specification, c is 1. According to an exemplary embodiment of this specification, d is 1. According to an exemplary embodiment of this specification, c is 0. According to an exemplary embodiment of this specification, d is 0. According to an exemplary embodiment of the present specification, the resin may have -OH; -SH; -CO 2CH 3; or -OC 6H 5 as the terminal group. According to an exemplary embodiment of the present specification, the unit of Chemical Formula 2 is at least any one of the following Chemical Formulas 2-1 to 2-4. In Chemical Formulas 2-1 to 2-4, X21 to X36 are the same as or different from each other and are each independently O or S, L21 and L22 are the same or different from each other and are each independently a substituted or unsubstituted aryl group; or a substituted or unsubstituted heteroaryl group, Z21 to Z28 are the same as or different from each other and are each independently a substituted or unsubstituted alkylene group; or a substituted or unsubstituted cycloalkylene group, R5 to R10 and R13 to R15 are the same as or different from each other and are each independently hydrogen; a substituted or unsubstituted alkyl group; a substituted or unsubstituted cycloalkyl group; a substituted or unsubstituted aryl group; or a substituted or unsubstituted heteroaryl group, or are bonded with adjacent groups to form a substituted or unsubstituted aromatic hydrocarbon ring group, R11 and R12 are the same as or different from each other and are each independently hydrogen; a substituted or unsubstituted alkyl group; a substituted or unsubstituted cycloalkyl group; a substituted or unsubstituted aryl group; or a substituted or unsubstituted heteroaryl group, or are bonded to each other to form a substituted or unsubstituted hydrocarbon ring group, R101 and R102 are the same as or different from each other and are each independently hydrogen; substituted or unsubstituted alkyl; substituted or unsubstituted cycloalkyl; substituted or unsubstituted aryl; or substituted or unsubstituted heteroaryl. a1 to a4 and b1 to b4 are each an integer from 0 to 10, R5, R6 and R15 are each an integer from 0 to 4, and when R5, R6 and R15 are each 2 or greater, two or more of R5, R6 and R15 are the same as or different from each other, R13 and R14 are each an integer from 0 to 6, and when R13 and R14 are each 2 or greater, two or more of R13 and R14 are the same as or different from each other, R101 and R102 are each an integer from 0 to 2, and when R101 and R102 are each 2 or greater, two or more of R101 and R102 are the same as or different from each other, and *Indicates the portion linked to the main chain of the resin. According to exemplary embodiments of the present specification, Z21 to Z28 are the same as or different from each other and are each independently a substituted or unsubstituted straight-chain or branched alkylene group having 1 to 30 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic alkylene group having 3 to 30 carbon atoms. According to exemplary embodiments of the present specification, Z21 to Z28 are the same as or different from each other and are each independently a substituted or unsubstituted straight-chain or branched alkylene group having 1 to 20 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic alkylene group having 3 to 20 carbon atoms. According to exemplary embodiments of the present specification, Z21 to Z28 are the same as or different from each other and are each independently a substituted or unsubstituted straight-chain or branched alkylene group having 1 to 10 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic alkylene group having 3 to 10 carbon atoms. According to an exemplary embodiment of the present specification, Z21 to Z28 are the same as or different from each other, and are each independently a substituted or unsubstituted linear or branched alkylene group having 1 to 30 carbon atoms. According to an exemplary embodiment of the present specification, Z21 to Z28 are the same as or different from each other, and are each independently a substituted or unsubstituted linear or branched alkylene group having 1 to 20 carbon atoms. According to an exemplary embodiment of the present specification, Z21 to Z28 are the same as or different from each other, and are each independently a substituted or unsubstituted linear or branched alkylene group having 1 to 10 carbon atoms. According to exemplary embodiments of the present specification, Z21 to Z28 are the same as or different from each other, and are each independently a substituted or unsubstituted ethylene group. According to exemplary embodiments of the present specification, R101 and R102 are the same as or different from each other and are each independently hydrogen; a substituted or unsubstituted straight-chain or branched alkyl group having 1 to 30 carbon atoms; a substituted or unsubstituted monocyclic or polycyclic cycloalkyl group having 3 to 30 carbon atoms; a substituted or unsubstituted monocyclic or polycyclic aryl group having 6 to 30 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic heteroaryl group having 2 to 30 carbon atoms, which includes one or more of O, S, and N. According to exemplary embodiments of the present specification, R101 and R102 are the same as or different from each other and are each independently hydrogen; a substituted or unsubstituted straight-chain or branched alkyl group having 1 to 20 carbon atoms; a substituted or unsubstituted monocyclic or polycyclic cycloalkyl group having 3 to 20 carbon atoms; a substituted or unsubstituted monocyclic or polycyclic aryl group having 6 to 20 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic heteroaryl group having 2 to 20 carbon atoms, which includes one or more of O, S, and N. According to exemplary embodiments of the present specification, R101 and R102 are the same as or different from each other and are each independently hydrogen; a substituted or unsubstituted straight-chain or branched alkyl group having 1 to 10 carbon atoms; a substituted or unsubstituted monocyclic or polycyclic cycloalkyl group having 3 to 10 carbon atoms; a substituted or unsubstituted monocyclic or polycyclic aryl group having 6 to 10 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic heteroaryl group having 2 to 10 carbon atoms, which includes one or more of O, S, and N. According to an exemplary embodiment of the present specification, R101 and R102 are each independently hydrogen. According to an exemplary embodiment of the present invention, X21 to X36 are 0. According to an exemplary embodiment of the present invention, X21 to X36 are S. According to an exemplary embodiment of this specification, X21 to X24 are 0. According to an exemplary embodiment of this specification, X25 to X28 are 0. According to an exemplary embodiment of this specification, X29 to X32 are 0. According to an exemplary embodiment of this specification, X33 to X36 are 0. According to an exemplary embodiment of this specification, X21 to X24 are S. According to an exemplary embodiment of this specification, X25 to X28 are S. According to an exemplary embodiment of this specification, X29 to X32 are S. According to an exemplary embodiment of this specification, X33 to X36 are S. According to an exemplary embodiment of the present specification, L21 and L22 are each independently a monocyclic or polycyclic aryl group having 6 to 30 carbon atoms, which is unsubstituted or substituted with a hydroxyl group, a linear or branched alkyl group having 1 to 30 carbon atoms, or a monocyclic or polycyclic aryl group having 6 to 30 carbon atoms. According to an exemplary embodiment of the present specification, L21 and L22 are each independently a monocyclic or polycyclic aryl group having 6 to 20 carbon atoms, which is unsubstituted or substituted with a hydroxyl group, a linear or branched alkyl group having 1 to 20 carbon atoms, or a monocyclic or polycyclic aryl group having 6 to 20 carbon atoms. According to an exemplary embodiment of the present specification, L21 and L22 are each independently a phenylene group which is unsubstituted or substituted with a hydroxyl group, a methyl group, a phenyl group, or a naphthyl group; or a divalent naphthyl group. According to exemplary embodiments of the present specification, R5 to R10 and R13 to R15 are each independently hydrogen; a straight-chain or branched alkyl group having 1 to 30 carbon atoms; a substituted or unsubstituted monocyclic or polycyclic cycloalkyl group having 3 to 30 carbon atoms; a substituted or unsubstituted monocyclic or polycyclic aryl group having 6 to 30 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic heteroaryl group having 2 to 30 carbon atoms, which includes one or more of O, S, and N, or is bonded with an adjacent group to form a monocyclic or polycyclic aromatic hydrocarbon ring having 6 to 30 carbon atoms. According to exemplary embodiments of the present specification, R5 to R10 and R13 to R15 are the same as or different from each other and are each independently hydrogen; a straight-chain or branched alkyl group having 1 to 20 carbon atoms; a substituted or unsubstituted monocyclic or polycyclic cycloalkyl group having 3 to 20 carbon atoms; a substituted or unsubstituted monocyclic or polycyclic aryl group having 6 to 20 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic heteroaryl group having 2 to 20 carbon atoms, which includes one or more of O, S, and N, or is bonded with an adjacent group to form a monocyclic or polycyclic aromatic hydrocarbon ring having 6 to 20 carbon atoms. According to exemplary embodiments of the present specification, R5 to R10 and R13 to R15 are the same as or different from each other and are each independently hydrogen; a substituted or unsubstituted monocyclic or polycyclic aromatic group having 6 to 30 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic heteroaryl group having 2 to 30 carbon atoms, which includes one or more of O, S, and N, or is bonded with an adjacent group to form a monocyclic or polycyclic aromatic hydrocarbon ring having 6 to 30 carbon atoms. According to exemplary embodiments of the present specification, R5 to R10 and R13 to R15 are the same as or different from each other and are each independently hydrogen; a substituted or unsubstituted monocyclic or polycyclic aromatic group having 6 to 20 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic heteroaryl group having 2 to 20 carbon atoms, which includes one or more of O, S, and N, or is bonded with an adjacent group to form a monocyclic or polycyclic aromatic hydrocarbon ring having 6 to 20 carbon atoms. According to exemplary embodiments of the present specification, R5 to R10 and R13 to R15 are the same as or different from each other and are each independently hydrogen; a substituted or unsubstituted monocyclic or polycyclic aromatic group having 6 to 30 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic heteroaryl group having 2 to 30 carbon atoms, which includes one or more of O, S, and N, or is bonded with an adjacent group to form a monocyclic or polycyclic aromatic hydrocarbon ring having 6 to 30 carbon atoms. According to exemplary embodiments of the present specification, R5 to R10 and R13 to R15 are the same as or different from each other and are each independently hydrogen; a substituted or unsubstituted monocyclic or polycyclic aromatic group having 6 to 20 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic heteroaryl group having 2 to 20 carbon atoms, which includes one or more of O, S, and N, or is bonded with an adjacent group to form a monocyclic or polycyclic aromatic hydrocarbon ring having 6 to 20 carbon atoms. According to exemplary embodiments of the present specification, R5 to R10 and R13 to R15 are the same as or different from each other, and are each independently hydrogen; phenyl; or naphthyl, or bonded with an adjacent group to form benzene. According to an exemplary embodiment of the present specification, R5 to R10 and R13 to R15 are the same as or different from each other, and are each independently hydrogen. According to exemplary embodiments of the present specification, R11 and R12 are the same as or different from each other and are each independently hydrogen; a straight-chain or branched alkyl group having 1 to 30 carbon atoms; a monocyclic or polycyclic cycloalkyl group having 6 to 30 carbon atoms; a monocyclic or polycyclic aromatic group having 6 to 30 carbon atoms; or a monocyclic or polycyclic heteroaromatic group having 2 to 30 carbon atoms, or are bonded to each other to form a monocyclic or polycyclic aliphatic hydrocarbon ring having 6 to 30 carbon atoms, which is unsubstituted or substituted with a straight-chain or branched alkyl group having 1 to 30 carbon atoms. According to exemplary embodiments of the present specification, R11 and R12 are the same as or different from each other and are each independently hydrogen; a straight-chain or branched-chain alkyl group having 1 to 20 carbon atoms; a monocyclic or polycyclic cycloalkyl group having 6 to 20 carbon atoms; a monocyclic or polycyclic aryl group having 6 to 20 carbon atoms; or a monocyclic or polycyclic heteroaryl group having 2 to 20 carbon atoms, or are bonded to each other to form a monocyclic or polycyclic aliphatic hydrocarbon ring having 6 to 20 carbon atoms, which is unsubstituted or substituted with a straight-chain or branched-chain alkyl group having 1 to 20 carbon atoms. According to an exemplary embodiment of the present specification, R11 and R12 are the same as or different from each other and are independently hydrogen; methyl; or phenyl, or are bonded to each other to form unsubstituted or methyl-substituted cyclohexane; or cyclododecane. According to exemplary embodiments of the present specification, R11 and R12 are the same as or different from each other, and are each independently hydrogen; methyl; or phenyl. According to an exemplary embodiment of the present specification, R11 and R12 are the same as or different from each other, and are each independently a methyl group. According to an exemplary embodiment of the present specification, the resin is a polycarbonate resin, a polyester resin, or a polyester-carbonate resin, which includes a unit of Chemical Formula 1 and a unit of Chemical Formula 2. According to an exemplary embodiment of the present specification, the resin is a polycarbonate resin, which includes a unit of Chemical Formula 1 and a unit of Chemical Formula 2. According to an exemplary embodiment of the present specification, the resin is a polycarbonate resin, L in Chemical Formula 1 is a direct bond, and L in Chemical Formula 2 is a direct bond. According to an exemplary embodiment of the present specification, the resin is a polycarbonate resin, Chemical Formula 1 is represented by the following Chemical Formula 1-C, and Chemical Formula 2 is represented by the following Chemical Formula 2-C. In chemical formulas 1-C and 2-C, The definitions of the substituents are the same as those in Chemical Formulas 1 and 2. According to an exemplary embodiment of the present specification, the resin is a polycarbonate resin, and Chemical Formula 1 is represented by the following Chemical Formula 1-C-1. In chemical formula 1-C-1, The definitions of the substituents are the same as those in Chemical Formula 1. According to an exemplary embodiment of the present specification, the resin is a polycarbonate resin, and Chemical Formula 1 is any one of the following Chemical Formulas 1-C-2 and 1-C-3. In chemical formulas 1-C-2 and 1-C-3, The definitions of the substituents are the same as those in Chemical Formula 1. According to an exemplary embodiment of the present specification, the resin is a polycarbonate resin, and Chemical Formula 2 is represented by the following Chemical Formula 3-1 or 3-2. In chemical formulas 3-1 and 3-2, l41 and l42 are each independently an integer from 1 to 5, When L41 is 1 or 2, L41 is a substituted or unsubstituted monocyclic aryl group, When L41 is an integer from 3 to 5, L41 is a substituted or unsubstituted polycyclic aromatic group, L42 is a substituted or unsubstituted polycyclic aromatic group, X41 to X44 are each independently O or S, Z41 and Z42 are each independently a substituted or unsubstituted alkylene group; or a substituted or unsubstituted cycloalkylene group, e and f are each independently an integer from 1 to 10, and when e and f are each 2 or greater, the structures in each bracket are the same as or different from each other, and *Indicates the portion linked to the main chain of the resin. The specific descriptions of X41 to X44, Z41 and Z42 are the same as the specific descriptions of X11 to X14, Z11 and Z12 in Chemical Formula 2. The specific descriptions of L41 and L42 are the same as the specific descriptions of L11 in Chemical Formula 2 according to the repeating number L41, as long as they satisfy the above conditions. According to an exemplary embodiment of the present specification, when L41 is 1 or 2, L41 is a substituted or unsubstituted phenylene group. According to an exemplary embodiment of the present specification, when L41 is 1 or 2, L41 is an unsubstituted or methyl-substituted phenylene group. According to an exemplary embodiment of the present specification, when L41 is an integer from 3 to 5, L41 is a substituted or unsubstituted divalent naphthyl group; or a substituted or unsubstituted divalent fluorenyl group. According to an exemplary embodiment of the present specification, when L41 is an integer from 3 to 5, L41 is a divalent naphthyl group; or a divalent fluorenyl group. According to an exemplary embodiment of the present specification, L42 is a substituted or unsubstituted divalent naphthyl group. According to an exemplary embodiment of the present specification, L42 is a divalent naphthyl group. According to an exemplary embodiment of the present specification, the resin is a polycarbonate resin, and when the polycarbonate resin has a thickness of 1 mm or less, the polycarbonate resin has a yellowness index (YI) of 20 or less. Because polycarbonate resins with a low yellowness index (YI) of 20 or less can realize a variety of colors, polycarbonate resins can provide optical products with a variety of colors and are particularly suitable for optical materials requiring high transparency. The yellowness index (YI) according to the exemplary embodiment of the present specification is measured using a polycarbonate resin sample having a thickness of 1 mm in accordance with ASTM D1925. Regarding the test specimens, test specimens having a length, width, and thickness of 50 mm, 50 mm, and 1 mm or less, respectively, were prepared by supplying the polycarbonate composition to a twin-screw extruder (L / D = 36, Φ = 45, barrel temperature 240° C.) at a rate of 55 kg per hour to produce pellets, and then injection molding the pellets on an injection molding machine (manufactured by Hankuk Hydraulic Machine, HMW-016S-15t). According to an exemplary embodiment of the present specification, the resin is a polycarbonate resin, and when the polycarbonate resin has a thickness of 1 mm or less, the polycarbonate resin has a yellowness index (YI) of 0 or more and 20 or less. According to an exemplary embodiment of the present specification, the resin is a polycarbonate resin, and when the polycarbonate resin has a thickness of 1 mm or less, the polycarbonate resin has a yellowness index (YI) of 1 or more to 19 or less, 2 or more to 18 or less, or 3 or more to 17 or less. According to an exemplary embodiment of the present specification, the resin is a polycarbonate resin, and when the polycarbonate resin has a thickness of 1 mm or less, the polycarbonate resin has a yellowness index (YI) of 8 or less. According to an exemplary embodiment of the present specification, the resin is a polycarbonate resin, and when the polycarbonate resin has a thickness of 1 mm or less, the polycarbonate resin has a yellowness index (YI) of 0 or more to 8 or less, or 1 or more to 8 or less. According to exemplary embodiments of the present specification, the polycarbonate resin may have a thickness of 1 mm or less, 0.9 mm or less, 0.8 mm or less, 0.7 mm or less, 0.6 mm or less, or 0.5 mm or less. The polycarbonate resin may have a thickness exceeding 0 mm. When the polycarbonate resin has a thickness of 1 mm or less, in the case where the yellowness index (YI) satisfies the range of 20 or less, the polycarbonate resin can realize various colors due to the low yellowness index, and thus can provide optical products with various colors, and is particularly suitable for optical materials requiring high transparency. When the polycarbonate resin has a thickness of 1 mm or less, in the case where the yellowness index (YI) is in the range exceeding 20, the use of the polycarbonate resin in optical products may be limited because high transparency and various colors cannot be expected. According to an exemplary embodiment of the present specification, the polycarbonate resin has terminal phenoxy groups, and the concentration of the terminal phenoxy groups is 3,000 ppm or higher. Specifically, the concentration of the terminal phenoxy groups is 3,500 ppm to 5,500 ppm, and more specifically, 4,000 ppm to 5,000 ppm. When the concentration of the terminal phenoxy group is 3,000 ppm or more, processability is improved, resulting in excellent injectability. In this specification, the concentration of terminal phenoxy groups can be calculated as follows. First, 0.25 g of pellets are dried and dissolved in 10 ml of dichloromethane. Then, 40 ml of triethylamine is added, and the resulting mixture is allowed to permeate and react with 0.04 g of anthraquinonecarboxylic acid anhydride at room temperature. The reaction product is then washed with water to remove excess anthraquinonecarboxylic acid anhydride. The dichloromethane in the organic layer is removed, and the resulting solid is subjected to GPC analysis using a GPC system (Shodex GPC system-11 manufactured by Showa Denko) equipped with a UV detector (UV wavelength: 325 nm). Peak areas are obtained based on a single-point calibration curve method created using samples with known terminal phenoxy group concentrations, and the phenoxy group concentration is then calculated from the peak areas. According to an exemplary embodiment of the present specification, the content of the terminal phenoxy group is 5 wt % or less based on 100 wt % of the polycarbonate resin. According to an exemplary embodiment of the present specification, the content of the terminal phenoxy group is 0 wt % to 5 wt % based on 100 wt % of the polycarbonate resin. According to exemplary embodiments of this specification, the content of terminal phenoxy groups is 1 to 4 wt%, or 2 to 3 wt%, based on 100 wt% of the polycarbonate resin. When the resin meets this range of terminal phenoxy group content, the processability of the polycarbonate resin is improved, resulting in excellent injectability. According to an exemplary embodiment of the present specification, the resin is a polyester resin including the unit of Chemical Formula 1 and the unit of Chemical Formula 2. According to an exemplary embodiment of the present specification, the resin is a polyester resin, Chemical Formula 1 is represented by the following Chemical Formula 11, and Chemical Formula 2 is represented by the following Chemical Formula 12. In Chemical Formula 11, The definitions of the substituents are the same as those in Chemical Formula 1. In chemical formula 12, The definitions of the substituents are the same as those in Chemical Formula 2. According to an exemplary embodiment of the present specification, the resin is a polyester resin, and Chemical Formula 1 is represented by the following Chemical Formula 11-1. In Chemical Formula 11-1, The definitions of the substituents are the same as those in Chemical Formula 1. According to an exemplary embodiment of the present specification, the resin is a polyester resin, and Chemical Formula 1 is any one of the following Chemical Formulas 11-2 and 11-3. In Chemical Formulas 11-2 and 11-3, the definition of each substituent is the same as that defined in Chemical Formula 1. According to an exemplary embodiment of the present specification, the resin may be a polyester-carbonate resin including a unit of Chemical Formula 1 and a unit of Chemical Formula 2. Compared with a polycarbonate resin, the polyester-carbonate resin is advantageous in terms of heat resistance because the resin including the polyester resin has a rigid chain caused by an arylene group and the relative flexibility is deteriorated due to resonance effect. According to an exemplary embodiment of the present specification, the resin is a polyester-carbonate resin, and the polyester-carbonate resin includes a unit of the following Chemical Formula 21. In Chemical Formula 21, the definitions of L, X1 to X4, Z1, Z2, a, b, R1 to R4, and r1 to r4 are the same as those defined in Chemical Formula 1, L2 is a direct bond; or -L2'-C(=O)-, L2' is a substituted or unsubstituted arylene group, X9 and X10 are each independently O or S, Z5 is a substituted or unsubstituted alkylene group; or a substituted or unsubstituted cycloalkylene group, p is an integer from 0 to 6, and when p is 2 or more, the structures in each bracket are the same or different from each other, r is a real number of 0 ≤ r < 1, as a molar fraction, s is a real number of 0 < s ≤ 1, as a molar fraction, r + s = 1, and * means a part linked to the main chain of the resin. According to an exemplary embodiment of the present specification, the unit of Chemical Formula 21 includes the unit of Chemical Formula 1. According to an exemplary embodiment of the present specification, p is 0. According to an exemplary embodiment of the present specification, p is 1. According to an exemplary embodiment of the present specification, L2 is a direct bond. According to an exemplary embodiment of the present specification, L2 is -L2'-C(=O)-. According to an exemplary embodiment of the present specification, L2′ is a monocyclic or polycyclic aryl group having 6 to 30 carbon atoms. According to an exemplary embodiment of the present specification, L2′ is a monocyclic or polycyclic aryl group having 6 to 20 carbon atoms. According to an exemplary embodiment of the present specification, L2' is a phenylene group; or a naphthylene group. According to an exemplary embodiment of the present specification, L2' is a phenylene group. According to an exemplary embodiment of the present specification, L is a direct bond, and L2 is -L2'-C(=O)-. According to an exemplary embodiment of the present specification, L is -L'-C(=O)-, and L2 is a direct bond. According to an exemplary embodiment of the present specification, Z5 is a substituted or unsubstituted linear or branched alkylene group having 1 to 30 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic alkylene group having 3 to 30 carbon atoms. According to an exemplary embodiment of the present specification, Z5 is a substituted or unsubstituted linear or branched alkylene group having 1 to 20 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic alkylene group having 3 to 20 carbon atoms. According to an exemplary embodiment of the present specification, Z5 is a substituted or unsubstituted straight-chain or branched alkylene group having 1 to 10 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic alkylene group having 3 to 10 carbon atoms. According to an exemplary embodiment of the present specification, Z5 is a substituted or unsubstituted linear or branched alkylene group having 1 to 30 carbon atoms. According to an exemplary embodiment of the present specification, Z5 is a substituted or unsubstituted linear or branched alkylene group having 1 to 20 carbon atoms. According to an exemplary embodiment of the present specification, Z5 is a substituted or unsubstituted linear or branched alkylene group having 1 to 10 carbon atoms. According to an exemplary embodiment of the present specification, Z5 is a substituted or unsubstituted ethylene group. According to an exemplary embodiment of the present invention, X9 and X10 are 0. According to an exemplary embodiment of the present invention, X9 and X10 are S. According to an exemplary embodiment of this specification, X1 to X4, X9 and X10 are 0. According to an exemplary embodiment of this specification, X1 to X4, X9 and X10 are S. According to an exemplary embodiment of this specification, X1 to X4 are S, and X9 and X10 are O. According to an exemplary embodiment of this specification, X1 to X4 are O, and X9 and X10 are S. According to an exemplary embodiment of this specification, X9 is O. According to an exemplary embodiment of this specification, X10 is 0. According to an exemplary embodiment of this specification, X9 is S. According to an exemplary embodiment of this specification, X10 is S. According to an exemplary embodiment of the present specification, r as a molar fraction is 0 to 0.999, and s as a molar fraction is 0.001 to 1, preferably r is 0 to 0.99 and s is 0.01 to 1, and more preferably r is 0 to 0.9 and s is 0.1 to 1. According to an exemplary embodiment of the present specification, r as a molar fraction is 0.001 to 0.999, s as a molar fraction is 0.001 to 0.999, preferably r is 0.01 to 0.99 and s is 0.01 to 0.99, and more preferably r is 0.1 to 0.9 and s is 0.1 to 0.9. When r and s in Chemical Formula 21 are within the above ranges, a polyester-carbonate resin having desired physical properties can be obtained by appropriately adjusting r and s as molar fractions. According to an exemplary embodiment of this specification, Chemical Formula 21 is any one of the following Chemical Formulas 21-A to 21-D. In Chemical Formulas 21-A to 21-D, The definition of each substituent is the same as that in Chemical Formula 21. According to an exemplary embodiment of this specification, Chemical Formula 21 is the following Chemical Formula 21-1. In Chemical Formula 21-1, The definition of each substituent is the same as that in Chemical Formula 21. According to an exemplary embodiment of the present specification, Chemical Formula 21 is any one of the following Chemical Formulas 21-2 and 21-3. In chemical formulas 21-2 and 21-3, The definition of each substituent is the same as that defined in Chemical Formula 21. According to an exemplary embodiment of the present specification, the resin is a polyester-carbonate resin, and the polyester-carbonate resin contains units of the following Chemical Formula 22. In Chemical Formula 22, the definitions of L1, L11, l11, X11 to X14, Z11, Z12, c and d are the same as those defined in Chemical Formula 2, L3 is a direct bond; or -L3'-C(=O)-, L3' is a substituted or unsubstituted arylene group, X15 and X16 are each independently O or S, Z13 is a substituted or unsubstituted alkylene group; or a substituted or unsubstituted cycloalkylene group, p' is an integer from 0 to 6, and when p' is 2 or greater, the structures in each bracket are the same or different from each other, r' as a mole fraction is a real number of 0 ≤ r' < 1, s' as a mole fraction is a real number of 0 < r' ≤ 1, r' + s' = 1, and * means the part linked to the main chain of the resin. According to an exemplary embodiment of the present specification, the unit of Chemical Formula 22 contains the unit of Chemical Formula 2. According to an exemplary embodiment of the present specification, p' is 0. According to an exemplary embodiment of the present specification, p' is 1. According to an exemplary embodiment of the present specification, L3 is a direct bond. According to an exemplary embodiment of the present specification, L3 is -L3'-C(=O)-. According to an exemplary embodiment of the present specification, L3' is a monocyclic or polycyclic arylene group having 6 to 30 carbon atoms. According to an exemplary embodiment of the present specification, L3' is a monocyclic or polycyclic arylene group having 6 to 20 carbon atoms. According to an exemplary embodiment of the present specification, L3' is a monocyclic or polycyclic arylene group having 6 to 10 carbon atoms. According to an exemplary embodiment of the present specification, L3' is a phenylene group; or a naphthylene group. According to an exemplary embodiment of the present specification, L3' is a phenylene group. According to an exemplary embodiment of the present specification, L1 and L3 are direct bonds. According to an exemplary embodiment of the present specification, L1 is -L1'-C(=O)-, and L3 is -L3'-C(=O)-. According to an exemplary embodiment of the present specification, L1 is a direct bond, and L3 is -L3'-C(=O)-. According to an exemplary embodiment of the present specification, L1 is -L1'-C(=O)-, and L3 is a direct bond. According to an exemplary embodiment of the present specification, Z13 is a substituted or unsubstituted linear or branched alkylene group having 1 to 30 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic alkylene group having 3 to 30 carbon atoms. According to an exemplary embodiment of the present specification, Z13 is a substituted or unsubstituted straight-chain or branched alkylene group having 1 to 20 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic alkylene group having 3 to 20 carbon atoms. According to an exemplary embodiment of the present specification, Z13 is a substituted or unsubstituted straight-chain or branched alkylene group having 1 to 10 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic alkylene group having 3 to 10 carbon atoms. According to an exemplary embodiment of the present specification, Z13 is a substituted or unsubstituted linear or branched alkylene group having 1 to 30 carbon atoms. According to an exemplary embodiment of the present specification, Z13 is a substituted or unsubstituted linear or branched alkylene group having 1 to 20 carbon atoms. According to an exemplary embodiment of the present specification, Z13 is a substituted or unsubstituted linear or branched alkylene group having 1 to 10 carbon atoms. According to an exemplary embodiment of the present specification, Z13 is a substituted or unsubstituted ethylene group. According to an exemplary embodiment of the present invention, X15 and X16 are 0. According to an exemplary embodiment of the present invention, X15 and X16 are S. According to an exemplary embodiment of this specification, X11 to X16 are 0. According to an exemplary embodiment of this specification, X11 to X16 are S. According to an exemplary embodiment of this specification, X11 to X14 are S, and X15 and X16 are O. According to an exemplary embodiment of this specification, X11 to X14 are O, and X15 and X16 are S. According to an exemplary embodiment of this specification, X15 is 0. According to an exemplary embodiment of this specification, X16 is 0. According to an exemplary embodiment of this specification, X15 is S. According to an exemplary embodiment of this specification, X16 is S. According to an exemplary embodiment of the present specification, r' as a molar fraction is 0 to 0.999, s' as a molar fraction is 0.001 to 1, preferably r' is 0 to 0.99, s' is 0.01 to 1, and more preferably r' is 0 to 0.9 and s' is 0.1 to 1. According to an exemplary embodiment of the present specification, r' as a molar fraction is 0.001 to 0.999, s' as a molar fraction is 0.001 to 0.999, preferably r' is 0.01 to 0.99 and s' is 0.01 to 0.99, and more preferably r' is 0.1 to 0.9 and s' is 0.1 to 0.9. When r' and s' in Chemical Formula 22 are within the above ranges, a polyester-carbonate resin having desired physical properties can be obtained by appropriately adjusting r' and s' as molar fractions. According to an exemplary embodiment of this specification, Chemical Formula 22 is any one of the following Chemical Formulas 22-A to 22-D. In Chemical Formulas 22-A to 22-D, The definition of each substituent is the same as that in Chemical Formula 22. According to an exemplary embodiment of the present specification, the resin has a weight average molecular weight (Mw) of 5,000 g / mol to 500,000 g / mol. In this specification, the weight-average molecular weight (Mw) of the resin and the oligomer used in preparing the resin can be measured by gel permeation chromatography (GPC) using an Agilent 1200 Series instrument and polystyrene (PS) standards. Specifically, the weight-average molecular weight can be measured using an Agilent 1200 Series instrument using a Polymer Laboratories PLgel MIX-B 300 mm column. In this case, the measurement temperature is 40°C, the solvent used is tetrahydrofuran (THF), and the flow rate is 1 mL / min. Samples of the resin or oligomer are prepared at a concentration of 10 mg / 10 mL and then fed in 10 μL amounts. The weight-average molecular weight (Mw) value is derived using a calibration curve generated using polystyrene standards. In this case, nine types of polystyrene standard products having molecular weights (g / mol) of 2,000 / 10,000 / 30,000 / 70,000 / 200,000 / 700,000 / 2,000,000 / 4,000,000 / 10,000,000 were used. In exemplary embodiments of the present specification, the polycarbonate resin has a weight average molecular weight of 3,000 g / mol to 500,000 g / mol, preferably 5,000 g / mol to 200,000 g / mol, 7,000 g / mol to 150,000 g / mol, or 8,000 g / mol to 100,000 g / mol. More preferably, the polycarbonate resin has a weight average molecular weight of 9,000 g / mol to 90,000 g / mol, 10,000 g / mol to 80,000 g / mol, 12,000 g / mol to 70,000 g / mol, 13,000 g / mol to 60,000 g / mol, or 13,000 g / mol to 50,000 g / mol. According to exemplary embodiments of the present disclosure, the polycarbonate resin has a weight average molecular weight of 5,000 g / mol to 500,000 g / mol, preferably 5,000 g / mol to 200,000 g / mol, 5,000 g / mol to 100,000 g / mol, or 5,000 g / mol to 51,000 g / mol. More preferably, the polycarbonate resin has a weight average molecular weight of 7,000 g / mol to 51,000 g / mol, 8,000 g / mol to 51,000 g / mol, 9,000 g / mol to 51,000 g / mol, 10,000 g / mol to 51,000 g / mol, or 11,000 g / mol to 51,000 g / mol. When the polycarbonate resin falls within the above weight average molecular weight ranges, the polycarbonate resin can have optimal flowability and processability. In exemplary embodiments of the present invention, the polycarbonate resin has a number average molecular weight of 2,000 g / mol to 300,000 g / mol, 3,000 g / mol to 200,000 g / mol, 4,000 g / mol to 150,000 g / mol, 4,500 g / mol to 100,000 g / mol, preferably 5,000 g / mol to 80,000 g / mol, 6,000 g / mol to 50,000 g / mol, 7,000 g / mol to 30,000 g / mol, or 8,000 g / mol to 27,000 g / mol. According to exemplary embodiments of the present invention, the polycarbonate resin has a number average molecular weight of 4,000 g / mol to 100,000 g / mol, 4,000 g / mol to 50,000 g / mol, 4,000 g / mol to 30,000 g / mol, 5,000 g / mol to 30,000 g / mol, and preferably 6,000 g / mol to 30,000 g / mol. When the polycarbonate resin meets the above number average molecular weight ranges, the polycarbonate resin can have optimal flowability and processability. According to exemplary embodiments of the present specification, the polyester resin has a weight average molecular weight of 5,000 g / mol to 500,000 g / mol, preferably 6,000 g / mol to 400,000 g / mol, 7,000 g / mol to 300,000 g / mol, 8,000 g / mol to 200,000 g / mol, or 9,000 g / mol to 100,000 g / mol. More preferably, the polyester resin has a weight average molecular weight of 10,000 g / mol to 90,000 g / mol, 15,000 g / mol to 85,000 g / mol, 20,000 g / mol to 80,000 g / mol, or 25,000 g / mol to 75,000 g / mol. When the polyester resin falls within the above weight average molecular weight ranges, the polyester resin can have optimal flowability and processability. According to exemplary embodiments of the present invention, the polyester resin has a number average molecular weight of 2,000 g / mol to 300,000 g / mol, 4,000 g / mol to 250,000 g / mol, 5,000 g / mol to 210,000 g / mol, 6,000 g / mol to 180,000 g / mol, 7,000 g / mol to 150,000 g / mol, 8,000 g / mol to 120,000 g / mol, 9,000 g / mol to 90,000 g / mol, preferably 10,000 g / mol to 60,000 g / mol, 11,000 g / mol to 50,000 g / mol, or 12,000 g / mol to 45,000 g / mol. According to exemplary embodiments of the present invention, the polyester-carbonate resin has a weight average molecular weight of 5,000 g / mol to 500,000 g / mol, preferably 5,000 g / mol to 300,000 g / mol, 7,000 g / mol to 250,000 g / mol, or 9,000 g / mol to 200,000 g / mol. The polyester-carbonate resin more preferably has a weight average molecular weight of 10,000 g / mol to 150,000 g / mol, 12,000 g / mol to 100,000 g / mol, 13,000 g / mol to 80,000 g / mol, 14,000 g / mol to 60,000 g / mol, or 15,000 g / mol to 55,000 g / mol. When the polyester-carbonate resin meets the above weight average molecular weight range, the polyester-carbonate resin can have optimal fluidity and processability. According to exemplary embodiments of the present invention, the polyester-carbonate resin has a number average molecular weight of 2,000 g / mol to 300,000 g / mol, 3,000 g / mol to 200,000 g / mol, 4,000 g / mol to 100,000 g / mol, 5,000 g / mol to 80,000 g / mol, preferably 6,000 g / mol to 60,000 g / mol, 7,000 g / mol to 40,000 g / mol, or 8,000 g / mol to 30,000 g / mol. According to an exemplary embodiment of the present specification, the resin has a glass transition temperature (Tg) of 90° C. to 200° C. In this specification, the glass transition temperature (Tg) can be measured using differential scanning calorimetry (DSC). Specifically, the glass transition temperature can be measured from a spectrum obtained by heating 5.5 mg to 8.5 mg of a polycarbonate resin sample to 270°C under a nitrogen atmosphere, and then scanning the resin sample while heating the resin sample at a heating rate of 10°C / min during a second heating period after cooling. According to exemplary embodiments of the present disclosure, the polycarbonate resin may have a glass transition temperature (Tg) of 90°C to 200°C. The Tg may preferably be 100°C to 190°C, 120°C to 180°C, 120°C to 170°C, 125°C to 170°C, or 128°C to 160°C. When the polycarbonate resin satisfies this Tg range, its heat resistance and injectability are excellent. Furthermore, when the polycarbonate resin composition is prepared by mixing with a resin having a Tg outside the above range, the Tg can be easily adjusted to achieve the desired physical properties described herein. According to exemplary embodiments of the present specification, the polyester resin may have a glass transition temperature (Tg) of 90°C to 200°C. The glass transition temperature may preferably be 90°C to 190°C, 100°C to 185°C, and 110°C to 180°C. When the polyester resin satisfies this glass transition temperature range, its heat resistance and injectability are excellent. Furthermore, when the polyester resin composition is prepared by mixing with a resin having a glass transition temperature outside the above range, the glass transition temperature can be easily adjusted to achieve the desired physical properties described herein. According to exemplary embodiments of the present specification, the polyester-carbonate resin may have a glass transition temperature (Tg) of 90°C to 200°C. The Tg may preferably be 100°C to 190°C, 110°C to 180°C, 120°C to 170°C, or 130°C to 160°C. When the polyester-carbonate resin satisfies this Tg range, its heat resistance and injectability are excellent. Furthermore, when the polyester-carbonate resin composition is prepared by mixing with a resin having a Tg outside the above range, the Tg can be easily adjusted to achieve the desired physical properties described herein. According to an exemplary embodiment of the present specification, the refractive index of the resin measured at a wavelength of 587 nm is 1.6 to 1.8. In this specification, the refractive index can be determined from a polymerized resin sample, and the resulting value can be obtained based on the wavelength of light using a prism coupler. After the resin sample is brought into close contact with the prism of the prism coupler, light of a specific wavelength is incident on the sample through the prism. The refractive index is then measured by measuring the incident angle at which the light resonates. The Sellmeier coefficient that minimizes the error is then substituted into the Sellmeier equation, and the refractive index at wavelength D (587 nm) can be determined. According to exemplary embodiments of the present disclosure, the polycarbonate resin has a refractive index of 1.5 to 1.75, measured at a wavelength of 587 nm. Preferably, the refractive index is 1.55 to 1.71, or 1.65 to 1.69. When the resin satisfies this refractive index, a thin and lightweight optical lens can be produced when the resin is applied to a molded object, such as an optical lens. According to an exemplary embodiment of the present specification, the refractive index of the polycarbonate resin at 587 nm is 1.6 to 1.8. According to exemplary embodiments of the present disclosure, the refractive index of the polycarbonate resin can be 1.6 to 1.75, or 1.6 to 1.72, preferably 1.61 to 1.69. When the resin satisfies these refractive indices, thin and lightweight optical lenses can be produced when the resin is used to mold an object, such as an optical lens. According to exemplary embodiments of the present disclosure, the polyester resin has a refractive index of 1.50 to 1.75, measured at a wavelength of 587 nm. Preferred refractive indices include 1.55 to 1.73, 1.6 to 1.72, 1.62 to 1.7, and 1.63 to 1.69. When the resin satisfies these refractive indices, thin and lightweight optical lenses can be produced when the resin is used in molded articles, such as optical lenses. According to exemplary embodiments of the present disclosure, the polyester-carbonate resin has a refractive index of 1.50 to 1.75, measured at a wavelength of 587 nm. Preferably, the refractive index is 1.55 to 1.74, 1.60 to 1.73, or 1.61 to 1.69. When the resin satisfies these refractive indices, thin and lightweight optical lenses can be produced when the resin is used in molded articles, such as optical lenses. According to an exemplary embodiment of the present specification, the Abbe's number of the resin measured at wavelengths of 486 nm, 587 nm, and 656 nm is 5 to 45. The Abbe number can be obtained in particular from the following formula, where the refractive indices (n D , n F and n C ) are measured at 20° C. at wavelengths of D (587 nm), F (486 nm) and C (656 nm), respectively. According to exemplary embodiments of the present specification, the polycarbonate resin may have an Abbe number measured and calculated at wavelengths of 486, 587, and 656 nm, ranging from 5 to 45 or from 10 to 25. The Abbe number may preferably be from 14 to 22, from 15 to 24, from 16 to 22, or from 18 to 22. When the polycarbonate resin satisfies the aforementioned Abbe number ranges, it can reduce dispersion and increase sharpness when used in molded articles, such as optical lenses. According to exemplary embodiments of the present specification, the polyester resin may have an Abbe number measured and calculated at wavelengths of 486, 587, and 656 nm, ranging from 5 to 45. Preferably, the Abbe number is 7 to 40, and 9 to 35. More preferably, the Abbe number is 11 to 30, 13 to 28, 15 to 26, or 17 to 25. When the polyester resin satisfies the aforementioned Abbe number ranges, when the polyester resin is used in molded articles (such as optical lenses), it can reduce dispersion and increase clarity. According to exemplary embodiments of the present specification, the polyester-carbonate resin may have an Abbe number measured and calculated at wavelengths of 486, 587, and 656 nm, ranging from 5 to 45. The Abbe number may preferably be from 10 to 29, and more preferably from 14 to 26. When the polyester-carbonate resin satisfies the above Abbe number range, when the polyester-carbonate resin is used in a molded article (such as an optical lens), it can reduce color dispersion and increase clarity. An exemplary embodiment of the present specification provides a method for preparing a resin, the method comprising: polymerizing a composition for preparing the resin, the composition comprising a compound of the following Chemical Formula 1a; a compound of the following Chemical Formula 2a; and one or more of a polycarbonate precursor and a polyester precursor. In Chemical Formula 1a, X1 to X4 are each independently O or S, Z1 and Z2 are each independently a substituted or unsubstituted alkylene group; or a substituted or unsubstituted cycloalkylene group, a and b are each independently an integer from 1 to 10, and when a and b are each 2 or greater, the structures in each bracket are the same as or different from each other, R1 to R4 are each independently hydrogen; substituted or unsubstituted alkyl; substituted or unsubstituted cycloalkyl; substituted or unsubstituted aryl; or substituted or unsubstituted heteroaryl. R1 and R2 are each independently an integer from 0 to 3, and when R1 and R2 are each 2 or greater, two or more of R1 and R2 are the same or different from each other, R3 and R4 are each independently an integer from 0 to 4, and when R3 and R4 are each 2 or greater, two or more of R3 and R4 are the same or different from each other, In Chemical Formula 2a, L11 is a substituted or unsubstituted alkylene group; a substituted or unsubstituted cycloalkylene group; a divalent fused ring group of an aromatic hydrocarbon ring and an aliphatic hydrocarbon ring, which is substituted or unsubstituted; or a substituted or unsubstituted arylene group, l11 is an integer from 1 to 5, and when l11 is 2 or greater, two or more L11 are the same as or different from each other, X11 to X14 are each independently O or S, Z11 and Z12 are each independently a substituted or unsubstituted alkylene group; or a substituted or unsubstituted cycloalkylene group, and c and d are each independently an integer of 0 to 10, and when c and d are each 2 or greater, the structures in each bracket are the same as or different from each other. When the composition includes the compound of Chemical Formula 1a, the composition is easily polymerized and has a refractive index in various ranges or a high refractive index depending on the substituents, and has a wide range of glass transition temperatures. An exemplary embodiment of the present specification provides a method for preparing a polycarbonate resin, the method comprising: polymerizing a composition for preparing a polycarbonate resin, the composition comprising a compound of Chemical Formula 1a; a compound of Chemical Formula 2a; and a polycarbonate precursor. An exemplary embodiment of the present specification provides a method for preparing a polyester resin, the method comprising: polymerizing a composition for preparing a polyester resin, the composition comprising a compound of Chemical Formula 1a; a compound of Chemical Formula 2a; and a polyester precursor. An exemplary embodiment of the present specification provides a method for preparing a polyester-carbonate resin, the method comprising: polymerizing a composition for preparing a polyester-carbonate resin, the composition comprising a compound of Chemical Formula 1a; a compound of Chemical Formula 2a; a polycarbonate precursor; and a polyester precursor. According to an exemplary embodiment of the present specification, the ratio of the compound of Chemical Formula 1a to the compound of Chemical Formula 2a is 0.01 mol% to 99.99 mol%:99.99 mol% to 0.01 mol%. Specifically, the ratio of the compound of Chemical Formula 1a to the compound of Chemical Formula 2a is 0.1 mol% to 99.9 mol%:99.9 mol% to 0.1 mol%, 1 mol% to 99 mol%:99 mol% to 1 mol%, 5 mol% to 95 mol%:95 mol% to 5 mol%, or 10 mol% to 90 mol%:90 mol% to 10 mol%. When the compounds of Chemical Formulas 1a and 2a are included in the aforementioned amounts, the composition readily polymerizes, exhibits a wide range of refractive indices or a high refractive index depending on the substituents, and has a wide range of glass transition temperatures. Furthermore, the glass transition temperature (Tg) and refractive index can be adjusted, and the resin chain behavior can be made flexible, thereby facilitating the injection molding of molded objects. The composition for preparing the resin may further contain a solvent. The solvent may be, for example, diphenyl ether, dimethylacetamide, or methanol, but is not limited thereto, and any solvent applicable to the present technology may be appropriately employed. The solvent may be included in an amount of 5 parts by weight to 60 parts by weight relative to 100 parts by weight of the composition for preparing the resin. The amount of the solvent that may be included is preferably 5 to 50 parts by weight, 7 to 45 parts by weight, or 8 to 40 parts by weight relative to 100 parts by weight of the composition for preparing the resin. According to exemplary embodiments of the present specification, two or more of Chemical Formula 1a may be included. The two or more of Chemical Formula 1a may be the same as or different from each other. According to exemplary embodiments of the present specification, the compound of Chemical Formula 1a may be the following compounds, but is not limited thereto. In an exemplary embodiment of the present specification, the compound of Chemical Formula 2a is the compound of the following Chemical Formulas 2a-1 to 2a-4. In Chemical Formulas 2a-1 to 2a-4, X21 to X36, L21 and L22, Z21 to Z28, R5 to R15, R101, R102, a1 to a4, b1 to b4, r5, r6, r15, r13, r14, R101 and R102 are defined as in Chemical Formulas 2-1 to 2-4. According to exemplary embodiments of the present specification, the compound of Chemical Formula 2a may be any one of the following compounds, but is not limited thereto. According to an exemplary embodiment of the present specification, the compound of Chemical Formula 1a may be included in an amount of 1 to 100 parts by weight or 1 to 99 parts by weight relative to 100 parts by weight of the composition for preparing the resin. The compound of Chemical Formula 1a may be included in an amount of preferably 1 to 60 parts by weight, 1 to 50 parts by weight, 1 to 40 parts by weight, 1 to 30 parts by weight, 1 to 20 parts by weight, or 1 to 10 parts by weight relative to 100 parts by weight of the composition for preparing the resin. According to an exemplary embodiment of the present specification, the compound of Chemical Formula 2a may be included in an amount of 1 to 99 parts by weight relative to 100 parts by weight of the composition for preparing the resin. The compound of Chemical Formula 2a may be included in an amount of preferably 1 to 60 parts by weight, 1 to 50 parts by weight, 1 to 40 parts by weight, 1 to 30 parts by weight, 1 to 20 parts by weight, or 1 to 10 parts by weight relative to 100 parts by weight of the composition for preparing the resin. According to an exemplary embodiment of the present specification, the amount of the polycarbonate precursor that may be included is 1 part by weight to 60 parts by weight relative to 100 parts by weight of the composition for preparing the resin. The polycarbonate precursor may be included in an amount of preferably 1 to 60 parts by weight, 1 to 55 parts by weight, 1 to 50 parts by weight, 1 to 45 parts by weight, or 1 to 40 parts by weight relative to 100 parts by weight of the composition for preparing the resin. According to an exemplary embodiment of the present specification, the polycarbonate precursor is represented by the following chemical formula A. In chemical formula A, Ra1 and Ra2 are each independently a halogen group; a substituted or unsubstituted alkyl group; or a substituted or unsubstituted aryl group, and a1 and a2 are each 0 or 1. According to an exemplary embodiment of the present specification, Ra1 and Ra2 are each independently a halogen group; a substituted or unsubstituted straight-chain or branched alkyl group having 1 to 30 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic aromatic group having 6 to 30 carbon atoms. According to an exemplary embodiment of the present specification, Ra1 and Ra2 are each independently a halogen group; a substituted or unsubstituted linear or branched alkyl group having 1 to 20 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic aromatic group having 6 to 20 carbon atoms. According to an exemplary embodiment of the present specification, Ra1 and Ra2 are each independently a halogen group; a straight-chain or branched alkyl group having 1 to 30 carbon atoms; or a monocyclic or polycyclic aromatic group having 6 to 30 carbon atoms. According to an exemplary embodiment of the present specification, Ra1 and Ra2 are each independently a halogen group; a straight-chain or branched alkyl group having 1 to 20 carbon atoms; or a monocyclic or polycyclic aromatic group having 6 to 20 carbon atoms. According to an exemplary embodiment of the present specification, Ra1 and Ra2 are each independently -Cl; methyl; ethyl; n-propyl; isopropyl; n-butyl; isobutyl; or phenyl. According to an exemplary embodiment of the present specification, Chemical Formula A is any one selected from the following compounds: If necessary, the polycarbonate precursor is used to link additional comonomers. In addition to the compound represented by Chemical Formula A, other specific examples of applicable comonomers include phosgene, triphosgene, diphosgene, bromophosgene, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, ditolyl carbonate, bis(chlorophenyl) carbonate, m-tolyl carbonate, dinaphthyl carbonate, bis(diphenyl) carbonate (bis(diphenyl) carbonate), bishaloformates, or the like. Any one of these or a mixture of two or more thereof may be used. In the exemplary embodiment of the present specification, the polyester precursor may be included in an amount of 1 to 150 parts by weight relative to 100 parts by weight of the composition for preparing the resin. The polyester precursor may be included in an amount of preferably 1 to 140 parts by weight, 1 to 135 parts by weight, 1 to 130 parts by weight, 1 to 125 parts by weight, or 1 to 120 parts by weight relative to 100 parts by weight of the composition for preparing the resin. According to an exemplary embodiment of the present specification, the polyester precursor is represented by the following chemical formula B. In chemical formula B, Rb1 and Rb2 are each independently a halogen group; a hydroxyl group; a substituted or unsubstituted alkyl group; or a substituted or unsubstituted aryl group, Ar1 is a substituted or unsubstituted aryl group, and b1 and b2 are each 0 or 1. According to exemplary embodiments of the present specification, Rb1 and Rb2 are each independently a halogen group; a hydroxyl group; a substituted or unsubstituted straight-chain or branched alkyl group having 1 to 30 carbon atoms; a substituted or unsubstituted monocyclic or polycyclic cycloalkyl group having 6 to 30 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic aryl group having 6 to 30 carbon atoms. According to exemplary embodiments of the present specification, Rb1 and Rb2 are each independently a halogen group; a hydroxyl group; a substituted or unsubstituted straight-chain or branched alkyl group having 1 to 20 carbon atoms; a substituted or unsubstituted monocyclic or polycyclic cycloalkyl group having 6 to 20 carbon atoms; or a substituted or unsubstituted monocyclic or polycyclic aryl group having 6 to 20 carbon atoms. According to an exemplary embodiment of the present specification, Rb1 and Rb2 are each independently a halogen group; a hydroxyl group; a straight-chain or branched alkyl group having 1 to 30 carbon atoms, which is unsubstituted or substituted with a hydroxyl group; a monocyclic or polycyclic cycloalkyl group having 6 to 30 carbon atoms; or a monocyclic or polycyclic aryl group having 6 to 30 carbon atoms. According to exemplary embodiments of the present specification, Rb1 and Rb2 are each independently a halogen group; a hydroxyl group; a straight-chain or branched alkyl group having 1 to 20 carbon atoms, which is unsubstituted or substituted with a hydroxyl group; a monocyclic or polycyclic cycloalkyl group having 6 to 20 carbon atoms; or a monocyclic or polycyclic aromatic group having 6 to 20 carbon atoms. According to an exemplary embodiment of the present specification, Rb1 and Rb2 are each independently -Cl; hydroxyl; methyl; ethyl; n-propyl; n-butyl; isopropyl; isobutyl; hydroxyethyl; or phenyl. According to exemplary embodiments of the present specification, the above definitions of La and Lb may be applied to the definition of Ar1. According to an exemplary embodiment of the present specification, Ar1 is a monocyclic or polycyclic aryl group having 6 to 30 carbon atoms. According to an exemplary embodiment of the present specification, Ar1 is a monocyclic or polycyclic aryl group having 6 to 20 carbon atoms. According to an exemplary embodiment of the present specification, Ar1 is a phenylene group; or a naphthylene group. According to an exemplary embodiment of the present specification, Chemical Formula B is any one selected from the following compounds: According to an exemplary embodiment of the present specification, the unit of the above-mentioned Chemical Formula 1 can be formed by polymerizing the compound of Chemical Formula 1a and the polycarbonate precursor of Chemical Formula A or the polyester precursor of Chemical Formula B, and the unit of the above-mentioned Chemical Formula 2 can be formed by polymerizing the compound of Chemical Formula 2a and the polycarbonate precursor of Chemical Formula A or the polyester precursor of Chemical Formula B. According to an exemplary embodiment of the present specification, the resin is a polycarbonate resin, and preferably the polycarbonate resin is polymerized from the compound of Chemical Formula 1a, the compound of Chemical Formula 2a, and the polycarbonate precursor of Chemical Formula A. The unit of the above Chemical Formula 1-C can be formed by polymerizing the compound of Chemical Formula 1a and the polycarbonate precursor of Chemical Formula A, and the unit of the above Chemical Formula 2-C can be formed by polymerizing the compound of Chemical Formula 2a and the polycarbonate precursor of Chemical Formula A. According to an exemplary embodiment of the present specification, the resin is a polyester resin, and preferably the polyester resin is polymerized from the compound of Chemical Formula 1a, the compound of Chemical Formula 2a, and the polyester precursor of Chemical Formula B. The unit of Chemical Formula 11 can be formed by polymerizing the compound of Chemical Formula 1a and the polyester precursor of Chemical Formula B, and the unit of Chemical Formula 12 can be formed by polymerizing the compound of Chemical Formula 2a and the polyester precursor of Chemical Formula B. According to the exemplary embodiment of this specification, the resin is a polyester-carbonate resin, and preferably the polyester-carbonate resin is polymerized from the compound of Chemical Formula 1a, the compound of Chemical Formula 2a, the polycarbonate precursor of Chemical Formula A, and the polyester precursor of Chemical Formula B. The unit of the above-mentioned Chemical Formula 21 can be formed by polymerizing the compound of Chemical Formula 1a, the polycarbonate precursor of Chemical Formula A, and the polyester precursor of Chemical Formula B, and the unit of the above-mentioned Chemical Formula 22 can be formed by polymerizing the compound of Chemical Formula 2a, the polycarbonate precursor of Chemical Formula A, and the polyester precursor of Chemical Formula B. In the case of polyester resins, the precursor (terephthalate ) has a higher yield than the precursor of polycarbonate resin (carbonate ) has a higher molecular weight and accounts for a larger proportion of the resin weight. Because the precursor reduces the concentration of the diol monomer that achieves a high refractive index, the refractive index of polycarbonate resin is relatively higher than that of polyester resin. Furthermore, polyester resins, due to their structural characteristics, have longer conjugated bond lengths than polycarbonate resins. Due to internal and external hydrogen bonding within the molecules, they generally exhibit a high yellowness index and high heat resistance (such as TG). The compound of Chemical Formula 1a may be used in an amount of 1 to 100 mol parts and 1 to 99 mol parts relative to 100 mol parts of the total monomers constituting the resin including the unit of Chemical Formula 1. The polycarbonate precursor of Chemical Formula A may be used in an amount of 50 to 150 mol parts relative to 100 mol parts of the total monomers of the compound of Chemical Formula 1a constituting the resin. The polyester precursor of Chemical Formula B may be used in an amount of 1 to 150 mol parts relative to 100 mol parts of the total monomers of the compound of Chemical Formula 1a constituting the resin. The compound of Chemical Formula 2a may be used in an amount of 1 to 100 mol parts, and 1 to 99 mol parts relative to 100 mol parts of the total monomers constituting the resin including the unit of Chemical Formula 2. The polycarbonate precursor of Chemical Formula A may be used in an amount of 50 to 150 mol parts relative to 100 mol parts of the total monomers of the compound of Chemical Formula 2a constituting the resin. The polyester precursor of Chemical Formula B may be used in an amount of 1 to 150 parts by mole relative to 100 parts by mole of the total monomers of the compound of Chemical Formula 2a constituting the resin. The resins according to the present specification can be polymerized using methods known in the art. Preferably, the polymerization is carried out by a melt polycondensation method. In the melt polycondensation method, a catalyst may be added as needed. The melt polycondensation can be performed using the resin composition under heating and at normal or reduced pressure, while simultaneously removing byproducts through a transesterification reaction. Materials commonly used in this technology can be used as catalysts. Specifically, in the melt polycondensation method, it is preferred to melt the compound of Chemical Formula 1a, the compound of Chemical Formula 2a, and one or more of a polycarbonate precursor and a polyester precursor in a reaction vessel, and then conduct the reaction while allowing the by-product compounds to remain. To allow the by-product compounds to remain, the reaction apparatus may be shut down, or the pressure may be controlled by reducing or increasing the pressure. The reaction time of this process is 20 minutes or longer to 600 minutes or shorter, preferably 40 minutes or longer to 450 minutes or shorter, and more preferably 60 minutes or longer to 300 minutes or shorter. In this case, when the by-product compounds are distilled off immediately after production, the resulting resin has a low content of high molecular weight materials. However, when the by-product compounds are allowed to remain in the reaction vessel for a specific period of time, a resulting resin having a high content of high molecular weight materials is obtained. The melt polycondensation method can be performed continuously or in batches. The reaction apparatus used for the reaction can be a vertical reactor equipped with an anchor-type impeller, a Maxblend impeller, a spiral ribbon impeller, or the like; a horizontal reactor equipped with paddle blades, lattice blades, spectacle-shaped blades, or the like; or an extruder-type reactor equipped with a screw. Furthermore, considering the viscosity of the polymer, it is desirable to use a reactor that appropriately combines these reactors. In the method for preparing the resin used in this specification, the catalyst may be removed or deactivated to maintain thermal and hydrolytic stability after the polymerization reaction. Catalyst deactivation is preferably performed by adding an acidic material known in the art. As the acidic material, it is preferable to use, for example, the following: esters such as butyl benzoate; aromatic sulfonic acids such as p-toluenesulfonic acid; aromatic sulfonic acid esters such as butyl p-toluenesulfonate and hexyl p-toluenesulfonate; phosphoric acids such as phosphorous acid, phosphoric acid and phosphonic acid; phosphite esters such as triphenyl phosphite, monophenyl phosphite, diphenyl phosphite, diethyl phosphite, di-n-propyl phosphite, di-n-butyl phosphite, di-n-hexyl phosphite, dioctyl phosphite and monooctyl phosphite; phosphate esters such as triphenyl phosphate, diphenyl phosphate , monophenyl phosphate, dibutyl phosphate, dioctyl phosphate and monooctyl phosphate; phosphonic acids such as diphenylphosphonic acid, dioctylphosphonic acid and dibutylphosphonic acid; phosphonate esters such as diethyl phenylphosphonate; phosphines such as triphenylphosphine and bis(diphenylphosphino)ethane; boric acids such as boric acid and phenylboric acid; aromatic sulfonates such as tetrabutylphosphonium dodecylbenzenesulfonate; organic halides such as stearyl chloride, benzyl chloride and p-toluenesulfonyl chloride; alkylsulfuric acid such as dimethylsulfuric acid; organic halides such as chlorotoluene; and the like. The amount of the acidic material that can be used is 0.1 mol to 5 mol, preferably 0.1 mol to 1 mol, relative to 100 mol of the catalyst. When the amount of the acidic material is less than 0.1 mol parts, the deactivation effect becomes insufficient, which is unfavorable. Moreover, when the amount exceeds 5 mol parts, the heat resistance of the resin deteriorates and the molded article is easily colored, which is unfavorable. After catalyst deactivation, the process of devolatilizing and removing low-boiling-point compounds from the resin can be further performed at a pressure of 0.1 mmHg to 1 mmHg and a temperature of 200° C. to 350° C. In this process, a transverse device equipped with stirring blades with excellent surface renewal capabilities (such as paddle blades, mesh blades, and double annular blades) or a thin-film evaporator is preferably used. It is preferable that the resin of the present specification has as little foreign material content as possible, and it is preferable to perform molten raw material filtration, catalyst solution filtration, and the like. The mesh size of the filter used for filtration is preferably 5 μm or smaller, more preferably 1 μm or smaller. Furthermore, the produced resin is preferably filtered using a polymer filter. The mesh size of the polymer filter is preferably 100 μm or smaller, more preferably 30 μm or smaller. Furthermore, the process for obtaining the resin pellets needs to be performed in a low-dust environment, preferably Class 6 or lower, and more preferably Class 5 or lower. Furthermore, in addition to injection molding, examples of a method of molding a molded object including a resin include compression molding, die, roll processing, extrusion molding, stretching, and the like, but are not limited thereto. Another exemplary embodiment of the present specification provides a resin composition comprising the resin according to the above exemplary embodiment. According to an exemplary embodiment of the present specification, the amount of the resin included is 1 part by weight to 80 parts by weight based on 100 parts by weight of the resin composition. According to an exemplary embodiment of the present specification, the resin composition may further include a solvent. The solvent may be, for example, dimethylacetamide or 1,2-dichlorobenzene. The solvent may be included in an amount of 20 parts by weight to 99 parts by weight based on 100 parts by weight of the resin composition. In addition to the compounds of Chemical Formula 1a and Chemical Formula 2a, the resin composition may further include additional monomers. The additional monomers are not particularly limited and can be selected from monomers commonly used in the art of polycarbonate / polyester / polyester-carbonate production, as long as they do not alter the primary physical properties of the resin composition. The amount of the additional monomers that can be used is 1 to 50 mol parts per 100 mol parts of the total monomers constituting the resin containing the units of Chemical Formula 1. In addition to the resin containing the units of Chemical Formula 1 and Chemical Formula 2, the resin composition may further contain one or more additives selected from the group consisting of, for example, antioxidants, plasticizers, antistatic agents, nucleating agents, flame retardants, lubricants, impact modifiers, fluorescent brighteners, UV absorbers, pigments, and dyes, if necessary. The additive may be included in an amount of 1 part by weight to 99 parts by weight based on 100 parts by weight of the resin composition. The types of antioxidants, plasticizers, antistatic agents, nucleating agents, flame retardants, lubricants, impact modifiers, fluorescent brighteners, UV absorbers, pigments or dyes are not particularly limited, and additives suitable for the present technology can be appropriately used. Yet another exemplary embodiment of the present specification provides a molded article comprising the resin composition according to the above exemplary embodiment. According to exemplary embodiments of the present specification, a molded object can be prepared from a resin composition or a cured product thereof. As an example of a method for producing a molded article, it is possible to include thoroughly mixing a resin containing the unit of Chemical Formula 1 and an additive using a mixer, preparing pellets of the resulting mixture by extrusion-molding the mixture using an extruder, drying the pellets, and then ejecting the pellets using an injection molding machine. According to an exemplary embodiment of the present specification, the molded object may be an optical lens. According to an exemplary embodiment of the present specification, the optical lens may have a thickness of 0.1 μm to 30 mm. The optical lens is made of resin, has a thin thickness, a high refractive index and high transparency, and is preferably applicable to cameras. According to an exemplary embodiment of the present specification, the molded article is a light film or optical film. Made of polycarbonate resin, the light film or optical film is thin and has excellent light-collecting and light-diffusing properties. It is preferably used in liquid crystal display backlight modules, flat lenses, meta lenses, and the like. According to an exemplary embodiment of the present specification, the optical film or optical thin film has a thickness of 0.1 nm to 10 mm. In the exemplary embodiment of the present specification, the molded object is an optical resin. The optical resin is made of polycarbonate resin and has low optical loss due to its thin thickness, high refractive index, and low birefringence. The optical resin according to the exemplary embodiment of this specification exhibits low optical loss due to its high refractive index and low birefringence. The optical resin according to the exemplary embodiment of this specification has a glass transition temperature of 90°C to 200°C. Compared to conventional optical materials in the related art, its heat resistance is neither too high nor too low, making it easy to process and exhibiting excellent heat resistance. When the glass transition temperature exceeds 200°C, the melt flow rate increases, making the optical resin difficult to process. However, when the glass transition temperature is below 90°C, the low heat resistance results in poor weather resistance due to the external environment. Therefore, according to the exemplary embodiment of this specification, there are few optical resins that possess suitable thermal properties and achieve a high refractive index. [Example] This description will be illustrated in more detail below through examples. Preparation Example 1. Preparation of polycarbonate resin Preparation Example 1-1. Preparation of Resin 1-1 45.215 g (0.100 mol) of monomer 1-1 and 21.422 g (0.100 mol) of diphenyl carbonate were melted and reacted at 250°C for 5 hours. As the reaction proceeded, phenol was produced as a byproduct. The reduced pressure was adjusted to a maximum of 1 Torr to remove the phenol. After the reaction was completed, resin 1-1 was obtained. This was a polymer molten resin polymerized by blowing nitrogen into the reactor to create an atmospheric pressure atmosphere. Preparation Examples 1-2 to 1-17. Preparation of Resins 1-2 to 1-17 Resins 1-2 to 1-17 were obtained in the same manner as in Preparation Example 1-1, except that the following monomers were used in the molar amounts shown in Table 1 below instead of monomer 1-1 in Preparation Example 1-1. Experimental Example 1. The molecular weight and molecular weight distribution of the polymerized resin samples were confirmed by gel permeation chromatography (GPC), and thermograms were obtained using differential scanning calorimetry (DSC) to study the thermal properties. Molecular weight results by gel permeation chromatography (GPC) were obtained by injecting a solution obtained by dissolving a resin sample at a concentration of 1.0 mg / 1 ml in tetrahydrofuran (THF, stable form, without butylated hydroxytoluene (BHT)) as a solvent, filtering the dissolved resin sample with a syringe filter, and measuring the molecular weight at 40°C. The results are shown in Table 2 below. A Waters RI detector and two Agilent PLgel MIXED-B columns were used. Differential Scanning Calorimetry (DSC) measurements were performed to determine the glass transition temperature (Tg) of the resin. The glass transition temperature (Tg) was obtained from a spectrum obtained by heating 5.5 mg to 8.5 mg of a resin sample to 270°C under a stream of N2, cooling the resin sample, and then scanning the resin sample while heating the resin sample at a heating rate of 10°C / min during the second heating period. The glass transition temperature (Tg) is shown in Table 2 below. Refractive index measurements can be confirmed from polymerized resin samples, and the resulting value can be obtained according to the wavelength of light using a prism-coupler. After placing a resin sample in close contact with the prism of the prism coupler, light of a specific wavelength is incident on the sample through the prism. The refractive index is then measured at the incident angle at which the light resonates. The Szemeier coefficient that minimizes the error is then substituted into the Szemeier equation to determine the refractive index at wavelength D (587 nm). Specifically, the refractive index was measured at a wavelength of 587 nm, and the Abbe number was obtained by the following formula. The refractive indices (n D , n F , and n C ) were measured at wavelengths of D (587 nm), F (486 nm), and C (656 nm), respectively, and are shown in Table 2 below. Abbe number = (n D-1) / (n Fn C) In Table 2, Mn means number average molecular weight, Mw means weight average molecular weight, PDI means polydispersity index, RI means refractive index, Tg means glass transition temperature, and the refractive index is a value measured at a wavelength of 587 nm. According to Table 2, the resins of Examples 1-1 to 1-14 contain units represented by Chemical Formula 1 and Chemical Formula 2 according to exemplary embodiments of the present invention, such that the core structure of Chemical Formula 1 is electron-rich, similar to spiro[fluorene-9,9'-dibenzopyran], and therefore has a high electron density, thereby improving the refractive index of the polycarbonate resin containing this core structure. Furthermore, by including the units represented by Chemical Formula 2, the glass transition temperature (Tg) of the units represented by Chemical Formula 1 can be supplemented, or the chain behavior of the units represented by Chemical Formula 1 can be made flexible, making the resin more suitable for injection molding of molded objects. In contrast, the resin of Comparative Example 1-1 does not include the unit represented by Chemical Formula 2 according to an exemplary embodiment of the present invention, and therefore cannot compensate for the glass transition temperature (Tg) of the unit represented by Chemical Formula 1, nor can it make the chain behavior of the unit represented by Chemical Formula 1 flexible. Therefore, it can be confirmed that the resin is not conducive to the injection molding of molded objects and therefore has a lower refractive index than the resins of Examples 1-1 to 1-14 of the present invention. In order to appropriately apply the resin according to the exemplary embodiment of the present specification to molded objects (such as optical lenses), a high refractive index is preferably required, and it can be confirmed that Examples 1-1 to 1-14 are better optical materials than Comparative Example 1-1 because the refractive index of Comparative Example 1-1 is very low, even though the Abbe number of Comparative Example 1-1 is higher than those of Examples 1-1 to 1-14. Although Comparative Examples 1-2 and 1-3 have refractive indices comparable to those of the examples, homopolymers face the problem of not meeting the physical properties required for easy injection molding. Specifically, homopolymers have a uniform repeating structure and a small free volume due to the good molecular aggregation. This results in high birefringence or poor flowability at high temperatures, making them difficult to extrusion / injection mold. Therefore, in order to prepare a polymer resin that is easily extruded / injected and heat-molded, appropriate physical properties in addition to the refractive index are required. The resin according to exemplary embodiments of the present invention offers advantages that facilitate extrusion / injection and heat molding while also possessing a desired refractive index. Preparation Example 2. Preparation of polyester resin Preparation Example 2-1. Preparation of Resin 2-1 45.251 g (0.100 mol) of monomer 1-1, 9.710 g (0.050 mol) of phthaloyl chloride, and 9.710 g (0.050 mol) of isophthaloyl chloride were melted and reacted at 250°C for 5 hours. Ethylene glycol was produced as a byproduct as the reaction proceeded, and the reduced pressure was adjusted to a maximum of 1 Torr to remove the ethylene glycol. After the reaction was completed, resin 2-1 was obtained. This was a polymer molten resin polymerized by blowing nitrogen into the reactor to create an atmospheric pressure atmosphere. Preparation Examples 2-2 to 2-17. Preparation of Resins 2-2 to 2-17 Resins 2-2 to 2-17 were obtained in the same manner as in Preparation Example 2-1, except that the following monomers were used in the molar amounts shown in Table 3 below instead of monomer 1-1 in Preparation Example 2-1. Experimental Example 2. The molecular weight and molecular weight distribution of the polymerized resin samples were confirmed by gel permeation chromatography (GPC), and thermograms were obtained using differential scanning calorimetry (DSC) to study the thermal properties. Molecular weight results by gel permeation chromatography (GPC) were obtained by injecting a solution obtained by dissolving a resin sample at a concentration of 1.0 mg / 1 ml in tetrahydrofuran (THF, stable form, without butylated hydroxytoluene (BHT)) as a solvent, filtering the dissolved resin sample with a syringe filter, and measuring the molecular weight at 40°C. The results are shown in Table 4 below. A Waters RI detector and two Agilent PLgel MIXED-B columns were used. Differential Scanning Calorimetry (DSC) measurements were performed to determine the glass transition temperature (Tg) of the resin. The glass transition temperature (Tg) was obtained from a spectrum obtained by heating 5.5 mg to 8.5 mg of a resin sample to 270°C under a stream of N2, cooling the resin sample, and then scanning the resin sample while heating the resin sample at a heating rate of 10°C / min during the second heating period. The glass transition temperature (Tg) is shown in Table 4 below. Refractive index measurements can be confirmed from polymerized resin samples, and the resulting value can be obtained according to the wavelength of light using a prism-coupler. After placing a resin sample in close contact with the prism of a prism coupler, light of a specific wavelength is incident on the sample through the prism. The incident angle at which the light resonates is then measured, and the refractive index is measured. The Scheme Meier coefficient that minimizes the error is then substituted into the Scheme Meier equation, and the refractive index at wavelength D (587 nm) is determined. To measure the refractive index and Abbe number of the resin, the resin obtained by polymerization was cut into specific dimensions, and the resin was heated and pressed on a hot plate to flatten the cross section to prepare a sample. The obtained sample was used with a prism coupler to obtain the resulting values ​​according to the wavelength of light, which are shown in Table 4 below. Specifically, the refractive index was measured at a wavelength of 589 nm, and the Abbe number was obtained using the following formula. The refractive indices (n D, n F, and n C) were measured at wavelengths of D (587 nm), F (486 nm), and C (656 nm), respectively. Specifically, the refractive index is measured at a wavelength of 589 nm, and regarding the Abbe number, the Abbe number is obtained by the following formula, where the refractive indices (n D , n F , and n C ) are measured at wavelengths of D (587 nm), F (486 nm), and C (656 nm), respectively. Abbe number = (n D-1) / (n Fn C) In Table 4, Mn means number average molecular weight, Mw means weight average molecular weight, PDI means polydispersity index, RI means refractive index, Tg means glass transition temperature, and the refractive index is a value measured at a wavelength of 587 nm. According to Table 4, Examples 2-1 to 2-16 contain units of Chemical Formula 1 according to an exemplary embodiment of the present invention, and in particular, the core structure of Chemical Formula 1 is electron-rich like spiro[fluorene-9,9'-dibenzopyran] and thus has a high electron density, thereby improving the refractive index of the polyester resin containing the core structure. In addition, since the unit of Chemical Formula 2 is further included in the unit of Chemical Formula 1, the glass transition temperature (Tg) and the refractive index can be adjusted, and the chain behavior of the polyester resin can be made flexible, thereby having a technical effect that is beneficial for injection molding of molded objects. In order to appropriately apply the resin according to the exemplary embodiment of the present invention to molded products (such as optical lenses), a high refractive index is preferably required, and it can be confirmed that Examples 2-1 to 2-16 have very high refractive indices and are therefore excellent optical materials. Although Comparative Example 2-1 has a refractive index comparable to that of the Examples, homopolymers have difficulty satisfying the physical properties required for easy injection molding. Specifically, homopolymers have a uniform repeating structure and a small free volume due to the good molecular aggregation. This results in high birefringence or poor flowability at high temperatures, making them difficult to extrusion / injection. Therefore, in order to prepare a polymer resin that is easily extruded / injected and heat-molded, appropriate physical properties in addition to the refractive index are required. The resin according to an exemplary embodiment of the present invention has the advantage of facilitating extrusion / injection and heat molding while also possessing a desired refractive index. Preparation Example 3. Preparation of polyester-carbonate resin Preparation Example 3-1. Preparation of Resin 3-1 45.251 g (0.100 mol) of monomer 1-1, 14.995 g (0.070 mol) of diphenyl carbonate, and 5.826 g (0.030 mol) of terephthalic chloride were melted at 250°C and reacted for 5 hours. As the reaction proceeded, phenol and hydrochloric acid were produced as byproducts, and the reduced pressure was adjusted to a maximum of 1 Torr to remove the byproducts. After the reaction was completed, resin 3-1 was obtained. This was a polymer molten resin polymerized by blowing nitrogen into the reactor to create an atmospheric pressure atmosphere. Preparation Examples 3-2 to 3-15. Preparation of Resins 3-2 to 3-15 Resins 3-2 to 3-15 were obtained in the same manner as in Preparation Example 3-1, except that the following monomers were used in the molar amounts shown in Table 5 below instead of monomer 1-1 in Preparation Example 3-1. Table 5 shows the molar fractions of each monomer included in resins 3-1 to 3-15. Furthermore, PE precursor (para) refers to the molar fraction of terephthaloyl chloride (which is a polyester precursor), and PE precursor (meta) refers to the molar fraction of isophthaloyl chloride (which is a polyester precursor). Experimental Example 3. The molecular weight and molecular weight distribution of the polymerized resin samples were confirmed by gel permeation chromatography (GPC), and thermograms were obtained using differential scanning calorimetry (DSC) to investigate thermal properties. GPC molecular weight results were obtained by injecting a solution obtained by the following procedure: using tetrahydrofuran (THF, stable form, without butylated hydroxytoluene (BHT)) as the solvent: the resin sample was dissolved in THF at a concentration of 1.0 mg / 1 ml, filtered through a syringe filter, and the molecular weight was measured at 40°C. The results are shown in Table 6 below. A Waters RI detector and two Agilent PLgel MIXED-B columns were used. Differential Scanning Calorimetry (DSC) measurements were performed to determine the glass transition temperature (Tg) of the resin. The glass transition temperature (Tg) was obtained from a spectrum obtained by heating 5.5 mg to 8.5 mg of a resin sample to 270°C under a stream of N2, cooling the resin sample, and then scanning the resin sample while heating the resin sample at a heating rate of 10°C / min during the second heating period. The glass transition temperature (Tg) is shown in Table 6 below. To measure the refractive index and Abbe number of the resin, a prism coupler was used to allow signal light of a specific wavelength to be incident on the resin sample obtained by polymerization. The output light reflected from the bottom of the prism was measured, and the resulting values ​​according to the wavelength of the light were obtained. The values ​​are shown in Table 6 below. Specifically, the refractive index is measured at a wavelength of 587 nm, and regarding the Abbe number, the Abbe number is obtained by the following formula, and the refractive index (n D, n F, and n C) is measured at wavelengths of D (587 nm), F (486 nm), and C (656 nm), respectively. Abbe number = (n D-1) / (n Fn C) In Table 6, Mn means number average molecular weight, Mw means weight average molecular weight, PDI means polydispersity index, RI means refractive index, Tg means glass transition temperature, and the refractive index is a value measured at a wavelength of 587 nm. According to Table 6, Examples 3-1 to 3-14 include the unit of Chemical Formula 1 as the polyester-carbonate resin according to an exemplary embodiment of the present invention. In particular, the core structure of Chemical Formula 1 is electron-rich like spiro[fluorene-9,9'-dibenzopyran] and therefore has a high electron density. It can be confirmed that the refractive index of the polyester-carbonate resin including this core structure is improved. Furthermore, since the unit of Chemical Formula 2 is further included in the unit of Chemical Formula 1, the glass transition temperature (Tg) and the refractive index can be adjusted, and the chain behavior of the polyester-carbonate resin can be made flexible, thereby providing a technical benefit for injection molding of molded objects. Regarding polyester-carbonate resins, polyester-carbonate resins with desired physical properties can be prepared by appropriately adjusting the molar ratio and isomers of polyester precursors and polycarbonate precursors to combine the properties of polyester resins and polycarbonate resins. In order to appropriately apply the resin according to the exemplary embodiment of the present invention to molded products (such as optical lenses), a high refractive index is preferably required, and it can be confirmed that Examples 3-1 to 3-14 have very high refractive indices and are therefore excellent optical materials. Although Comparative Example 3-1 has a refractive index comparable to that of the Examples, the homopolymer has difficulty satisfying the physical properties required for easy injection molding. Specifically, homopolymers have a uniform repeating structure and a small free volume due to the good molecular aggregation. This results in high birefringence or poor flowability at high temperatures, making them difficult to extrusion / injection. Therefore, in order to prepare a polymer resin that is easily extruded / injected and heat-molded, appropriate physical properties in addition to the refractive index are required. The resin according to an exemplary embodiment of the present invention has the advantages of facilitating extrusion / injection and heat molding while also possessing a desired refractive index. Preparation Example 4. Preparation of polycarbonate resin Preparation Example 4-1. Preparation of Resin 4-1 45.053 g (0.100 mol) of monomer 1-1 and 21.422 g (0.100 mol) of diphenyl carbonate were melted at 250°C and reacted for 5 hours. As the reaction proceeded, phenol was produced as a byproduct, and the reduced pressure was adjusted to a maximum of 1 Torr to remove the phenol. After the reaction was completed, Resin 1 was obtained. This was a polymer molten resin polymerized by blowing nitrogen into the reactor to create an atmospheric pressure atmosphere. Preparation Examples 4-2 to 4-4. Preparation of Resins 4-2 to 4-4 Resins 4-2 to 4-4 were obtained in the same manner as in Preparation Example 4-1, except that the following monomers were used in the molar amounts shown in Table 7 below instead of monomer 1-1 in Preparation Example 4-1. Experimental Example 4. The molecular weight and molecular weight distribution of the polymerized resin samples were confirmed by gel permeation chromatography (GPC), and thermograms were obtained using differential scanning calorimetry (DSC) to study the thermal properties. Molecular weight results by gel permeation chromatography (GPC) were obtained by injecting a solution obtained by dissolving a resin sample at a concentration of 1.0 mg / 1 ml in tetrahydrofuran (THF, stabilized with butylated hydroxytoluene (BHT)) as a solvent, filtering the dissolved resin sample with a syringe filter, and measuring the molecular weight at 40°C. The results are shown in Table 8 below. A Waters RI detector and two Agilent PLgel MIXED-B columns were used. Differential Scanning Calorimetry (DSC) measurements were performed to determine the glass transition temperature (Tg) of the resin. The glass transition temperature (Tg) was obtained from a spectrum obtained by heating 5.5 mg to 8.5 mg of a resin sample to 270°C under a stream of N2, cooling the resin sample, and then scanning the resin sample while heating the resin sample at a heating rate of 10°C / min during the second heating period. The glass transition temperature (Tg) is shown in Table 8 below. Refractive index measurements can be confirmed from polymerized resin samples, and the resulting value can be obtained according to the wavelength of light using a prism-coupler. After placing a resin sample in close contact with the prism of the prism coupler, light of a specific wavelength is incident on the sample through the prism. The incident angle at which the light resonates is then measured, and the refractive index is measured. The Scheme Meier coefficient that minimizes the error is obtained and substituted into the Scheme Meier equation, which allows the refractive index at wavelength D (587 nm) to be determined. Specifically, the refractive index is measured at a wavelength of 587 nm and the Abbe number is obtained by the following formula, where the refractive indices (n D , n F , and n C ) are measured at wavelengths of D (587 nm), F (486 nm), and C (656 nm), respectively. Abbe number = (n D-1) / (n Fn C) After preparing samples from the polycarbonate composition prepared in the examples by the following method, the yellowness index of the samples was evaluated and the results are shown in Table 8. 1) Sample preparation Test specimens having a length, width, and thickness of 50 mm, 50 mm, and 1 mm, respectively, were prepared by supplying a polycarbonate composition to a twin-screw extruder (L / D = 36, Φ = 45, barrel temperature 240° C.) at a rate of 55 kg per hour to produce pellets, and then injection-molding the pellets into an injection molding machine (manufactured by Hankuk Hydraulic Machine, HMW-016S-15t). 2) Measurement of Yellowness Index (YI) YI value is based on ASTM D1925 at room temperature (20℃) The image quality was measured using UltraScan PRO (manufactured by HunterLab Inc.). In Table 8, Mn means number average molecular weight, Mw means weight average molecular weight, PDI means polydispersity index, RI means refractive index, Tg means glass transition temperature, the refractive index is a value measured at a wavelength of 587 nm, and the yellowness index is a value measured when the polycarbonate resin has a thickness of 1 mm. According to Table 8, when the polycarbonate resin has a thickness of 1 mm or less, the polycarbonate resins of Examples 4-1 to 4-3 have a yellowness index of 8 or less, can provide optical products with a variety of colors, and are particularly suitable for optical materials requiring high transparency because it is possible to achieve a variety of colors due to the low yellowness index. According to Table 8, the polycarbonate resin according to an exemplary embodiment of the present invention includes the unit of Chemical Formula 1. In particular, the core structure of Chemical Formula 1 is electron-rich like spiro[fluorene-9,9'-dibenzopyran] and thus has a high electron density, so that the refractive index of the polycarbonate resin including the core structure is improved. Furthermore, by including the unit represented by Chemical Formula 2, it is possible to increase the glass transition temperature (Tg) of the unit represented by Chemical Formula 1 or to make the chain behavior of the unit represented by Chemical Formula 1 flexible, thereby facilitating the injection molding of molded objects.

Claims

1. A resin comprising units of the following Chemical Formula 1 and units of the following Chemical Formula 2: In Chemical Formula 1, L is a direct bond; or -L'-C(=O)-, L' is a substituted or unsubstituted aryl group, X1 to X4 are each independently O or S, Z1 and Z2 are each independently a substituted or unsubstituted alkyl group; or a substituted or unsubstituted cycloalkyl group, a and b are each independently an integer from 1 to 10, and when a and b are each 2 or greater, the structures in each bracket are the same or different from each other, R1 to R4 are each independently hydrogen; substituted or unsubstituted alkyl group; substituted or unsubstituted cycloalkyl group; substituted or unsubstituted aryl group; or substituted or unsubstituted heteroaryl group, r1 and r2 are each independently an integer from 0 to 3, and when r1 and r2 are each 2 or greater, two or more of R1 and R2 are the same or different from each other. r3 and r4 are each independent integers from 0 to 4, and when r3 and r4 are each 2 or greater, two or more of R3 and R4 are the same or different from each other. * indicates the portion linked to the main chain of the resin. In formula 2, L1 is a direct bond; or -L1'-C(=O)-, L1' is a substituted or unsubstituted aryl group, L11 is a substituted or unsubstituted alkyl group; a substituted or unsubstituted cycloalkyl group; a divalent fused ring group of an aromatic hydrocarbon ring and an aliphatic hydrocarbon ring, which is substituted or unsubstituted; or a substituted or unsubstituted aryl group. When the resin is a polycarbonate resin, L11 is a naphthyl-substituted genoyl group; or a binatyl group. l11 is an integer from 1 to 5, and when l11 is 2 or greater, two or more L11 are the same or different from each other. X11 to X14 are each independent O or S. Z11 and Z12 are each independently a substituted or unsubstituted alkylene group; or a substituted or unsubstituted cycloalkylene group, c and d are each independently an integer from 0 to 10, and when c and d are each 2 or greater, the structures in parentheses are the same or different from each other, and * indicates the portion linked to the main chain of the resin.

2. The resin of claim 1, wherein the resin is a polycarbonate resin, and the chemical formula 2 is represented by the following chemical formula 3-1 or 3-2: In chemical formulas 3-1 and 3-2, l41 and l42 are each independently an integer from 3 to 5, when l41 is an integer from 3 to 5, L41 is a naphthyl-substituted genoyl; or a binatyl, L42 is a naphthyl-substituted genoyl; or a binatyl, X41 to X44 are each independently O or S, Z41 and Z42 are each independently a substituted or unsubstituted alkylene; or a substituted or unsubstituted cycloalkylene, e and f are each independently an integer from 1 to 10, and when e and f are each 2 or greater, the structures in parentheses are the same or different from each other, and * indicates the portion linked to the main chain of the resin.

3. The resin of claim 1, wherein the resin is a polycarbonate resin, and when the polycarbonate resin has a thickness of 1 mm or less, the resin has a yellow index (YI) of 20 or less.

4. The resin of claim 1, wherein the resin is a polyester resin, wherein chemical formula 1 is represented by the following chemical formula 11, and chemical formula 2 is represented by the following chemical formula 12: In chemical formula 11, the substituents are defined as those defined in chemical formula 1, and in chemical formula 12, the substituents are defined as those defined in chemical formula 2.

5. The resin of claim 1, wherein the resin is a polyester-carbonate resin and the polyester-carbonate resin comprises units of the following chemical formula 21: In chemical formula 21, L, X1 to X4, Z1, Z2, a, b, R1 to R4 and r1 to r4 are defined as in chemical formula 1, L2 is a direct bond; or -L2'-C(=O)-, L2' is a substituted or unsubstituted aryl group, X9 and X10 are each independently O or S, Z5 is a substituted or unsubstituted alkyl group; or a substituted or unsubstituted cycloalkyl group, p is an integer from 0 to 6, and when p is 2 or greater, the structures in each bracket are the same or different from each other, r is a real number of 0 ≤ r < 1 as a molar fraction, s is a real number of 0 < s ≤ 1 as a molar fraction, r + s = 1, and * indicates the portion linked to the main chain of the resin.

6. The resin of claim 1, wherein the chemical formula 1 is the following chemical formula 1-1: In chemical formula 1-1, the definitions of each substituent are the same as those defined in chemical formula 1.

7. The resin of claim 1, wherein Z1 and Z2 are each independently substituted or unsubstituted ethylenyl.

8. The resin as requested in item 1, wherein X1 to X4 are O.

9. The resin of claim 1, wherein the resin has a weight average molecular weight (Mw) of 5,000 g / mol to 500,000 g / mol.

10. The resin of claim 1, wherein the refractive index of the resin is 1.6 to 1.8 as measured at a wavelength of 587 nm.

11. The resin of claim 1, wherein the resin has a glass transition temperature (Tg) of 90°C to 200°C.

12. The resin of claim 1, wherein the Abbe number of the resin measured at wavelengths of 486 nm, 587 nm and 656 nm is 5 to 45.

13. A method for preparing a resin as claimed in any one of claims 1 to 12, the method comprising polymerizing a composition for preparing the resin, the composition comprising a compound of the following chemical formula 1a; a compound of the following chemical formula 2a; and one or more of a polycarbonate precursor and a polyester precursor: In chemical formula 1a, X1 to X4 are each independently O or S; Z1 and Z2 are each independently a substituted or unsubstituted alkyl group; or a substituted or unsubstituted cycloalkyl group; a and b are each independently an integer from 1 to 10, and when a and b are each 2 or greater, the structures in each bracket are the same or different from each other; R1 to R4 are each independently hydrogen; a substituted or unsubstituted alkyl group; a substituted or unsubstituted cycloalkyl group; a substituted or unsubstituted aryl group; or a substituted or unsubstituted heteroaryl group; r1 and r2 are each independently an integer from 0 to 3, and when r1 and r2 are each 2 or greater, two or more of R1 and R2 are the same or different from each other. r3 and r4 are each independent integers from 0 to 4, and when r3 and r4 are each 2 or greater, two or more of R3 and R4 are the same or different from each other. In chemical formula 2a, L11 is a substituted or unsubstituted alkyl group; a substituted or unsubstituted cycloalkyl group; a divalent fused ring group of an aromatic hydrocarbon ring and an aliphatic hydrocarbon ring, which is substituted or unsubstituted; or a substituted or unsubstituted aryl group. When the resin is a polycarbonate resin, L11 is a naphthyl-substituted pyrenyl group; or a binaphthyl group. l11 is an integer from 1 to 5, and when l11 is 2 or greater, two or more L11 are the same or different from each other. X11 to X14 are each independent O or S. Z11 and Z12 are each independently a substituted or unsubstituted alkylene group; or a substituted or unsubstituted cycloalkylene group, and c and d are each independently an integer from 0 to 10, and when c and d are each 2 or greater, the structures in each bracket are the same or different from each other.

14. The method of claim 13, wherein the ratio of the compound of formula 1a to the compound of formula 2a is from 0.01 mol% to 99.99 mol%: 99.99 mol% to 0.01 mol%.

15. The method of claim 13, wherein the polycarbonate precursor is of the following chemical formula A: In chemical formula A, Rb1 and Rb2 are each independently a halogen group; a substituted or unsubstituted alkyl group; or a substituted or unsubstituted aryl group, and a1 and a2 are each 0 or 1.

16. The method of claim 13, wherein the polyester precursor is of the following chemical formula B: In chemical formula B, Ra1 and Ra2 are each independently a halogen group; a hydroxyl group; a substituted or unsubstituted alkyl group; or a substituted or unsubstituted aryl group, Ar1 is a substituted or unsubstituted aryl group, and a1 and a2 are each 0 or 1.

17. A resin composition comprising any one of claims 1 to 12.

18. A molded article comprising a resin composition as claimed in claim 17.