Patent Description:
The present disclosure relates to a polycarbonate composition and an optical product formed therefrom.

Polycarbonates are prepared by condensation-polymerization of an aromatic diol compound such as bisphenol A with a carbonate precursor such as phosgene. The polycarbonates thus prepared have excellent impact strength, dimensional stability, heat resistance and transparency, and are applied to a wide range of fields such as exterior materials of electrical and electronic products, automobile parts, building materials, optical components and clothing materials.

In particular, the range of use of polycarbonate is continuously expanding in the field related to optical components due to its transparency. Spectacles, one of the optical components, are required to control a light transmittance in various wavelength ranges. Recently, as it is known that blue light is harmful to the eyes, the spectacles are required to exhibit sufficiently low light transmittance in the region of <NUM> to <NUM>. However, a light blocking agent added to block blue light makes optical products made from polycarbonate yellowish. Therefore, there is an urgent need for research to provide an optical component that is transparent and can effectively block the blue light.

<CIT> discloses a polycarbonate resin composition and an optical molded product comprising the same.

<CIT> discloses a polycarbonate resin composition comprising a polycarbonate resin; and [[<NUM>-(dimethylamino)phenyl]methylene] propanedioic acid dimethyl ester as a hindered amine UV absorber that selectively absorbs UVA having a wavelength of <NUM> or less.

<CIT> discloses an eyeglass lens comprising a substrate made of an optical material comprising a polymer matrix and at least one <NUM>-(<NUM>-hydroxy-<NUM>-R1-phenyl)benzotriazole, in which R1 is a resonant group, the optical transmittance through a <NUM> thick layer of said optical material being lower than <NUM>% for each light wavelength ranging from <NUM> to <NUM>.

<CIT> discloses a device with at least one filter, in particular for a relieving and preventive eye protection as glasses, sun glasses or pane, wherein the device comprises at least one filter for influencing and filtering UV, blue light and infrared radiation, wherein the at least one filter is characterized by specific limit values defined in their combination.

<CIT> discloses an optical material containing one or more kinds of ultraviolet absorber (a) having a maximum absorption peak within a range of equal to or greater than <NUM> and equal to or less than <NUM>, in which a light transmittance of the optical material having a thickness of <NUM> satisfies the following characteristics (<NUM>) to (<NUM>), (<NUM>) a light transmittance at a wavelength of <NUM> is equal to or less than <NUM>%, (<NUM>) a light transmittance at a wavelength of <NUM> is equal to or less than <NUM>%, and (<NUM>) a light transmittance at a wavelength of <NUM> is equal to or greater than <NUM>%.

In the present disclosure, there is provided a polycarbonate composition.

There is also provided an optical product formed from the polycarbonate composition.

According to an embodiment of the present disclosure, there is provided a polycarbonate composition including a polycarbonate and a light blocking agent,
wherein 5YT420 calculated by the following Equation <NUM> is <NUM> to <NUM>: <MAT> in Equation <NUM>,.

According to another embodiment of the present disclosure, there is provided an optical product formed from the polycarbonate composition.

The polycarbonate composition according to an embodiment of the present disclosure can block blue light without a problem of harmfulness while maintaining various physical properties such as inherent transparency and impact resistance at an excellent level. In particular, the polycarbonate composition has a low yellow index, unlike conventional yellowish blue light blocking products, and thus various colors can be implemented. Accordingly, it is possible to provide optical products with various colors, and it is very suitable for spectacles required to have high transparency and to block blue light that is harmful to the eyes.

Hereinafter, the polycarbonate composition and the optical product formed therefrom according to specific embodiments of the present disclosure will be described.

Conventional blue light blocking products have a yellowish color due to a light blocking agent added to block blue light, so it is difficult to use them for various purposes. In particular, there is a trade-off between a yellow index and a blue light transmittance, and thus the higher the blue light blocking efficiency, the more yellowish the product becomes.

The present inventors have researched about this and developed a polycarbonate composition capable of providing an optical product showing a low transmittance in a blue light region while having a low yellow index, and completed the present invention.

Specifically, in the polycarbonate composition, the blue light transmittance decreases sharply compared to the increase in the yellow index, so that 5YT420 calculated by the above Equation <NUM>, which is an index capable of confirming a balance between the yellow index and the blue light transmittance, may be <NUM> to <NUM>.

The 5YT420 is a value obtained by adding the transmittance at <NUM> to a value <NUM> times the yellow index. Even if the blue light transmittance is at the same level, the 5YT420 appears as a large value when the yellow index increases sharply compared to the decrease in the blue light transmittance, and it appears as a small value when the yellow index does not increase significantly compared to the decrease in the blue light transmittance. Therefore, it can be understood that the lower the value of 5YT420, the better both the yellow index and the blue light transmittance.

The polycarbonate composition according to the embodiment may have 5YT420 calculated by the Equation <NUM> of <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, or <NUM> to <NUM>.

The polycarbonate composition according to the embodiment may have YT410 calculated by the following Equation <NUM> of <NUM> to <NUM>. <MAT> in Equation <NUM>,.

The YT410 is a value obtained by adding the transmittance at <NUM> to the yellow index, and it can be understood that the lower the value, the better both the yellow index and the blue light transmittance, as in 5YT420.

The polycarbonate composition according to the embodiment may have YT410 calculated by the Equation <NUM> of <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, or <NUM> to <NUM>.

The polycarbonate composition according to the embodiment has a small 5YT420 value, which is an index capable of confirming a balance between the yellow index and the blue light transmittance, and thus may exhibit a low blue light transmittance.

Specifically, the polycarbonate composition has a transmittance at <NUM> measured according to ASTM D1003 for a specimen having a thickness of <NUM> formed therefrom of <NUM> to <NUM>%, <NUM> to <NUM>%, <NUM> to <NUM>%, <NUM> to <NUM>%, <NUM> to <NUM>%, <NUM> to <NUM>%, <NUM> to <NUM>%, or <NUM> to <NUM>%, thereby exhibiting a very excellent blue light blocking effect.

Specifically, the polycarbonate composition has a transmittance at <NUM> measured according to ASTM D1003 for a specimen having a thickness of <NUM> formed therefrom of <NUM> to <NUM>%, <NUM> to <NUM>%, <NUM> to <NUM>%, <NUM> to <NUM>%, <NUM> to <NUM>%, <NUM> to <NUM>%, or <NUM> to <NUM>%, thereby exhibiting a very excellent blue light blocking effect.

The polycarbonate composition according to the embodiment has a small 5YT420 value, which is an index capable of confirming a balance between the yellow index and the blue light transmittance, and thus may exhibit a low yellow index.

Specifically, the polycarbonate composition has a very low yellow index measured according to ASTM D1925 for a specimen having a thickness of <NUM> formed therefrom of <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, or <NUM> to <NUM>, thereby exhibiting transparent properties.

In addition, the polycarbonate composition according to the embodiment may achieve a blue light blocking effect while maintaining excellent intrinsic properties of the polycarbonate, thereby exhibiting excellent impact resistance.

Specifically, the polycarbonate composition has an impact strength measured according to ASTM D256 for a specimen having a thickness of <NUM> formed therefrom of <NUM> to <NUM> J/m, <NUM> to <NUM> J/m, <NUM> to <NUM> J/m, <NUM> to <NUM> J/m, <NUM> to <NUM> J/m, <NUM> to <NUM> J/m, <NUM> to <NUM> J/m, or <NUM> to <NUM> J/m, exhibiting very high impact resistance. Accordingly, it is expected that the polycarbonate composition according to the embodiment can exhibit a blue light blocking effect while maintaining the transparency and impact resistance inherent in polycarbonate at an excellent level, thereby overcoming the limitation in application of the conventional blue light blocking products.

The polycarbonate composition according to the above embodiment may have a blue light blocking effect without a problem of harmfulness. Accordingly, an amount of total volatile organic compounds (TVOC) released for <NUM> minutes at <NUM> in a specimen having a thickness of <NUM> formed from the polycarbonate composition may be <NUM> to <NUM> ppm, <NUM> to <NUM> ppm, <NUM> to <NUM> ppm, <NUM> to <NUM> ppm, <NUM> to <NUM> ppm, <NUM> to <NUM> ppm, <NUM> to <NUM> ppm, or <NUM> to <NUM> ppm, indicating very little harmful substances.

The polycarbonate composition according to the embodiment includes a polycarbonate and a light blocking agent, and the light blocking agent includes a compound represented by the following Chemical Formula <NUM> to provide a transparent optical product capable of effectively blocking blue light. <CHM>
in Chemical Formula <NUM>,.

In Chemical Formula <NUM>, when R<NUM> is halogen, it may be F, Cl, Br or I. Specifically, in Chemical Formula <NUM>, R<NUM> may be hydrogen.

In Chemical Formula <NUM>, when at least one of R<NUM> to R<NUM> is halogen, it may be F, Cl, Br, or I, and when at least one of R<NUM> to R<NUM> is a C1 to C5 alkoxy group, it may be a methoxy group, an ethoxy group, a n-propoxy group, an isopropoxy group, a n-butoxy group, an isobutoxy group, a t-butoxy group, a n-pentoxy group, an isopentoxy group, or a neopentoxy group.

Specifically, in Chemical Formula <NUM>, at least one of R<NUM> to R<NUM> may be a C1 to C5 alkoxy group, and the rest may be hydrogen, halogen, a hydroxyl group, a cyano group, or a C1 to C5 alkoxy group. More specifically, in Chemical Formula <NUM>, <NUM> to <NUM> of R<NUM> to R<NUM> may be C1 to C5 alkoxy groups, and the rest may be hydrogen. In this case, the C1 to C5 alkoxy group may be a methoxy group or an ethoxy group, and may preferably be a methoxy group.

The compound represented by the Chemical Formula <NUM> can effectively block blue light even if only a small amount is used compared to the conventional light blocking agent. The light blocking agent is used in an amount of <NUM> to <NUM> wt%, and may be used in an amount of <NUM> to <NUM> wt%, <NUM> to <NUM> wt%, <NUM> to <NUM> wt%, <NUM> to <NUM> wt%, <NUM> to <NUM> wt%, <NUM> to <NUM> wt%, or <NUM> to <NUM> wt% based on a total weight of the polycarbonate and the light blocking agent.

As the light blocking agent, the compound represented by the Chemical Formula <NUM> may be used alone in order to provide a polycarbonate composition which is transparent while effectively absorbing blue light. However, the present disclosure is not limited thereto, and various light blocking agents (light absorbers) known in the art may be additionally included, if necessary.

Meanwhile, the polycarbonate may include a repeating unit represented by the following Chemical Formula <NUM>. <CHM>
in Chemical Formula <NUM>,.

For example, in Chemical Formula <NUM>, R<NUM> to R<NUM> may each independently be hydrogen, a methyl group, a methoxy group, Cl, or Br.

For example, in Chemical Formula <NUM>, Z may be a linear or branched C1 to C10 alkylene group unsubstituted or substituted with phenyl. Specifically, Z may be a methylene group, an ethane-<NUM>,<NUM>-diyl group, a propane-<NUM>,<NUM>-diyl group, a butane-<NUM>,<NUM>-diyl group, a <NUM>-phenylethane-<NUM>,<NUM>-diyl group, or a diphenyl group. In addition, Z may be a cyclohexane-<NUM>,<NUM>-diyl group, O, S, SO, SO<NUM>, or CO.

The repeating unit represented by the Chemical Formula <NUM> may be formed by reacting an aromatic diol compound and a carbonate precursor.

For example, the aromatic diol compound may be at least one selected from the group consisting of bis(<NUM>-hydroxyphenyl)methane, bis(<NUM>-hydroxyphenyl)ether, bis(<NUM>-hydroxyphenyl)sulfone, bis(<NUM>-hydroxyphenyl)sulfoxide, bis(<NUM>-hydroxyphenyl)sulfide, bis(<NUM>-hydroxyphenyl)ketone, <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)ethane, bisphenol A, <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)butane, <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)cyclohexane, <NUM>,<NUM>-bis(<NUM>-hydroxy-<NUM>,<NUM>-dibromophenyl)propane, <NUM>,<NUM>-bis(<NUM>-hydroxy-<NUM>,<NUM>-dichlorophenyl)propane, <NUM>,<NUM>-bis(<NUM>-hydroxy-<NUM>-bromophenyl)propane, <NUM>,<NUM>-bis(<NUM>-hydroxy-<NUM>-chlorophenyl)propane, <NUM>,<NUM>-bis(<NUM>-hydroxy-<NUM>-methylphenyl)propane, <NUM>,<NUM>-bis(<NUM>-hydroxy-<NUM>,<NUM>-dimethylphenyl)propane, <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)-<NUM>-phenylethane, and bis(<NUM>-hydroxyphenyl)diphenylmethane. In addition, the carbonate precursor may be at least one selected from the group consisting of dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, diphenyl carbonate, ditolyl carbonate, bis(chlorophenyl) carbonate, di-m-cresyl carbonate, dinaphthyl carbonate, bis(diphenyl) carbonate, phosgene, triphosgene, diphosgene, bromophosgene and bishaloformate.

The aromatic diol compound and the carbonate precursor may be polymerized by, for example, an interfacial polymerization method to provide a polycarbonate. The interfacial polymerization means that an organic solvent containing a carbonate precursor and an aqueous solution containing an aromatic diol compound are mixed together, and then polymerization occurs at the interface thereof.

In this case, the polymerization reaction is possible at normal pressure and low temperature, and it is easy to control the molecular weight. The interfacial polymerization may be performed in the presence of an acid binder and an organic solvent. In addition, the interfacial polymerization may include, for example, prepolymerization followed by adding a coupling agent and then performing the polymerization again. In this case, a polycarbonate with a high molecular weight may be obtained.

The polymerization is preferably performed at a temperature of <NUM> to <NUM> for <NUM> minutes to <NUM> hours. In addition, it is preferable to maintain the pH of <NUM> or more or <NUM> or more during the reaction.

The solvent that can be used in the polymerization is not particularly limited as long as it is a solvent used in the polymerization of polycarbonate. For example, halogenated hydrocarbon such as methylene chloride or chlorobenzene may be used.

In addition, the polymerization is preferably performed in the presence of an acid binder, and the acid binder may be alkali metal hydroxides such as sodium hydroxide or potassium hydroxide, or amine compounds such as pyridine.

In addition, it is preferable to perform the polymerization in the presence of a molecular weight modifier in order to control the molecular weight of the polycarbonate during the polymerization. The molecular weight modifier may be p-tert-butylphenol, p-cumyl phenol, decyl phenol, dodecyl phenol, tetradecyl phenol, hexadecyl phenol, octadecyl phenol, eicosyl phenol, docosyl phenol, triacontyl phenol or the like. Preferably, the molecular weight modifier may be added before the initiation of polymerization, during the initiation of polymerization, or after the initiation of polymerization.

The polycarbonate may have a melt flow rate (MFR) according to ASTM D1238 of <NUM> to <NUM>/<NUM>. When a polycarbonate having a melt flow rate in the above range is applied to a product with the above-described other components, excellent physical properties can be achieved, and the polycarbonate composition of the embodiment can exhibit excellent processability.

The melt flow rate may be measured under a load of <NUM> at <NUM> according to ASTM D1238.

When the melt flow rate is less than <NUM>/min, processability may decrease, resulting in a problem of productivity degradation, and when the melt flow rate is greater than <NUM>/min, resin flow may be exceeded under the processing conditions, causing surface defects on the molded product. In addition, the melt flow rate may preferably be <NUM> to <NUM>/<NUM>, <NUM> to <NUM>/<NUM>, <NUM> to <NUM>/<NUM>, <NUM> to <NUM>/<NUM>, or <NUM> to <NUM>/<NUM>, and the polycarbonate composition with the above melt flow rate may exhibit more excellent processability and mechanical properties.

In addition, the polycarbonate may have a weight average molecular weight of <NUM>,<NUM>/mol to <NUM>,<NUM>/mol, <NUM>,<NUM>/mol to <NUM>,<NUM>/mol, or <NUM>,<NUM>/mol to <NUM>,<NUM>/mol. For example, the weight average molecular weight of the polycarbonate can be measured by a method of ASTM D5296 using polystyrene as a standard material. As the polycarbonate satisfies the weight average molecular weight range, the polycarbonate composition of the embodiment and an optical product including the polycarbonate may exhibit excellent mechanical properties and optical properties.

The polycarbonate described above is a main component of the polycarbonate composition of the embodiment, and may be included in an amount of <NUM> to <NUM> wt% <NUM> to <NUM> wt%, <NUM> to <NUM> wt%, <NUM> to <NUM> wt% or <NUM> to <NUM> wt% based on the solid content of the total polycarbonate composition. Thereby, the polycarbonate composition of the embodiment may exhibit heat resistance, impact resistance, mechanical strength, and/or transparency inherent in polycarbonate.

The polycarbonate composition may further include various additives known in the art in addition to the above-described light blocking agent. As a non-limiting example, the polycarbonate composition may further include at least one selected from the group consisting of an antioxidant, a heat stabilizer, a light stabilizer, a plasticizer, an antistatic agent, a nucleating agent, a flame retardant, a lubricant, an impact modifier, a fluorescence brightener, an ultraviolet absorber, a pigment, and a dye.

Meanwhile, according to another embodiment of the present disclosure, there is provided an optical product formed from the polycarbonate composition.

The optical product can be applied to various fields related to optical components such as spectacle lenses, light guide plates, and LED lighting.

Since the optical product is made of the polycarbonate composition described above, it has a very low yellow index and thus exhibits high transparency with a very low blue light transmittance, thereby exhibiting excellent blue light blocking effect.

The optical product exhibits a very low yellow index and low transmittance in a blue light region, and is applied to spectacle lenses among the above-described fields to provide transparent spectacles in which blue light is effectively blocked.

A method of providing an optical product from the polycarbonate composition is not particularly limited. As a non-limiting example, the optical product may be prepared by adding an additive commonly used in the technical field to which the present disclosure pertains, if necessary, to the polycarbonate composition and mixing, extruding the mixture into pellets with an extruder, drying the pellets, and then injecting them with an injection molding machine to provide the optical product.

Mixing the polycarbonate composition can be performed by a melt-kneading method, for example, by a method using a ribbon blender, Henschel mixer, Banbury mixer, drum tumbler, single-screw extruder, twin-screw extruder, co-kneader, multi-screw extruder, or the like. The temperature of the melt-kneading may be appropriately adjusted, if necessary.

Next, the melt-kneaded product or pellets may be used as a raw material, and subjected to an injection molding method, an injection compression molding method, an extrusion molding method, a vacuum molding method, a blow molding method, a press molding method, an air pressure molding method, a foaming method, a heat bending molding method, a compression molding method, a calendering molding method, or a rotational molding method.

In the case of using the injection molding method, the polycarbonate composition is placed under high temperature conditions of <NUM> to <NUM>. Since the polycarbonate composition is excellent in heat resistance, it can be applied to the above-described melt-kneading process or injection process with little occurrence of polymer modification or yellowing.

The size, thickness, etc. of the optical product may be appropriately adjusted depending on the purpose of use, and the shape thereof may be flat or curved depending on the purpose of use.

As described above, the optical product according to another exemplary embodiment effectively blocks blue light and exhibits high transparency, so that molded products of various colors can be easily provided.

Hereinafter, the function and effect of the present invention will be described in more detail through specific examples.

A polycarbonate composition was prepared by adding <NUM> wt% of <NUM>-(<NUM>,<NUM>-dimethoxybenzylidene)malononitrile based on a total weight of the polycarbonate composition to bisphenol A-type linear polycarbonate (weight average molecular weight: <NUM>,<NUM>/mol; MFR (<NUM>, <NUM>): <NUM>/<NUM>; manufactured by LG Chemical).

A polycarbonate composition was prepared in the same manner as in Example <NUM>, except that the type and content of the light blocking agent was adjusted as shown in Table <NUM> below.

After preparing specimens from the polycarbonate compositions prepared in Examples and Comparative Examples by the method described below, their physical properties were evaluated, and the results are shown in Table <NUM>.

The polycarbonate composition was supplied to a twin-screw extruder (L/D=<NUM>, Φ=<NUM>, barrel temperature of <NUM>) at <NUM> per hour to prepare pellets, and the pellets were injection-molded to prepare a specimen having width, length, and thickness of <NUM>, <NUM>, and <NUM>, respectively.

The yellow index was measured at room temperature (<NUM>) with UltraScan PRO (manufactured by HunterLab) according to ASTM D1925.

The transmittance at <NUM> and <NUM> were measured with UltraScan PRO (manufactured by HunterLab) according to ASTM D1003.

The impact strength of the <NUM>/<NUM>" specimen (<NUM>/<NUM> inch (<NUM>) thick specimen) was measured according to ASTM D256.

After placing each specimen prepared above in a heating desorption apparatus (JTD-505III manufactured by Japan Analytical Industry), volatile organic compounds released from the specimen at <NUM> for <NUM> minutes were collected, and the amount thereof was measured by GC-MS.

Referring to Comparative Examples <NUM> to <NUM> in which T326 and EV-<NUM> were used together as a light blocking agent, when the content of the light blocking agent was increased to sufficiently lower the blue light transmittance, the yellow index became too high, so that the 5YT420 and the YT410, which are indexes capable of confirming a balance between the yellow index and the blue light transmittance, were very high as <NUM> to <NUM> and <NUM> to <NUM>, respectively. In addition, a significant amount of the light blocking agent was added in Comparative Examples <NUM> to <NUM> to lower the blue light transmittance to a certain level, resulting in very low impact resistance and high TVOC.

In Comparative Example <NUM>, the transmittance at <NUM> was reduced to <NUM>% by using only T326 as a light blocking agent in excess, but the yellow index was very high as <NUM>. Accordingly, YT420 and YT410, which are indexes capable of confirming a balance between the yellow index and the blue light transmittance, were high as <NUM> and <NUM>, respectively, and it was confirmed that impact resistance became very poor and TVOC was rapidly increased.

Referring to Comparative Example <NUM>, only a small amount of EV-<NUM>, a light blocking agent, could give a sufficiently low blue light transmittance, thereby providing a specimen having excellent impact resistance and low TVOC. However, even if only a very small amount of EV-<NUM> was added, the yellow index rapidly increased to provide a strong yellow specimen.

Referring to Comparative Examples <NUM> to <NUM> in which M-T326 was used as a light blocking agent, the degree of increase in the yellow index was large compared to the decrease in the blue light transmittance by the increase in the amount of the light blocking agent. Accordingly, even if the content of the light blocking agent is adjusted to <NUM> wt% to <NUM> wt%, it was confirmed that 5YT420, an index capable of confirming a balance between the yellow index and the blue light transmittance, did not decrease to the level of Examples. In Comparative Examples <NUM> to <NUM>, although there were some points where YT410 was lowered to the level of Examples, the polycarbonate composition of Comparative Example <NUM> with low YT410 of <NUM> had an impact strength of <NUM> J/m and TVOC of <NUM> ppm. Thus, it is difficult to use the composition of Comparative Example <NUM> for applications that must meet a certain level of impact resistance and TVOC, such as spectacle lenses, light guide plates, or LED lighting.

In the case of Comparative Examples <NUM> and <NUM>, even though T329, a light blocking agent, was used in excess compared to Examples, the blue light transmittance was not sufficiently lowered, and 5YT420 and YT410, which are indexes capable of confirming a balance between the yellow index and the blue light transmittance, were high as <NUM> to <NUM> and <NUM> to <NUM>, respectively. In addition, Comparative Example <NUM> had high TVOC, and Comparative Example <NUM> was poor in impact resistance as well as TVOC.

On the other hand, it was confirmed that the specimens formed from the polycarbonate compositions of Examples <NUM> to <NUM> had very low 5YT420 and YT410, which are indexes capable of confirming a balance between the yellow index and the blue light transmittance, of <NUM> to <NUM> and <NUM> to <NUM>, respectively, as well as excellent impact resistance and very low TVOC.

Claim 1:
A polycarbonate composition comprising a polycarbonate and a light blocking agent,
wherein 5YT420 calculated by the following Equation <NUM> is <NUM> to <NUM>: <MAT> in Equation <NUM>,
Y is a yellow index measured according to ASTM D1925 for a specimen having a thickness of <NUM> formed from the polycarbonate composition, and
T420 is a transmittance at <NUM> measured according to ASTM D1003;
the light blocking agent comprises a compound represented by the following Chemical Formula <NUM>:
<CHM>
in Chemical Formula <NUM>,
R<NUM> is hydrogen, halogen, a hydroxyl group or a cyano group, and
R<NUM> to R<NUM> are each independently hydrogen, halogen, a hydroxyl group, a cyano group, or a C1 to C5 alkoxy group, provided that at least one of R<NUM> to R<NUM> is halogen, a hydroxyl group, a cyano group, or a C1 to C5 alkoxy group; and
the light blocking agent is included in an amount of <NUM> to <NUM> wt% based on a total weight of the polycarbonate and the light blocking agent.