JP5616163B2 - Polycarbonate copolymer for optical lens and optical lens using the same - Google Patents

Description

  The present invention relates to an optical lens having a high refractive index and good light resistance against short wavelength light having a wavelength of 350 to 450 nm and having a glass transition temperature suitable for practical use.

  As typical optical resins, polymethacrylate, polycarbonate, polycycloolefin and the like are known. In recent years, it has been used for printing and copying equipment such as optical pickup devices, copiers, printers, etc. used for recording and reading information recording media such as cameras, video cameras, etc., various cameras for imaging, CDs, MOs, DVDs, etc. An optical lens made of an optical resin as described above is used for the optical member.

  Among these, a pickup lens used in an information device that writes and reads information by light is strongly required to have the same characteristics even when the cumulative amount of light irradiation increases. In particular, information equipment using blue laser light capable of realizing a high recording density has been developed, and development of an optical lens for blue laser corresponding to this has been demanded.

  Therefore, an optical lens using an addition polymer of a norbornene monomer hydrogenated with an aromatic ring and an α-olefin is proposed as a material having good resistance to blue laser light having a wavelength of around 400 nm in Patent Document 1. . However, the resin disclosed in Patent Document 1 has a low refractive index of about 1.47 to 1.53 at a wavelength of 405 nm, and when used as an optical lens material for a blue laser, the lens thickness is increased, and reading (writing) is performed. The problem is that the size of the built-in unit becomes large.

  On the other hand, in Patent Document 2, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene (hereinafter referred to as bisphenol BCF) and 4,4 ′-[1,3-phenylene (1-methylethylidene)] bisphenol. An optical member including a repeating structure (hereinafter referred to as bisphenol M) has been proposed. However, although the resin disclosed in Patent Document 2 has a high refractive index of 1.63 or more at a wavelength of 405 nm, it is not resistant to blue laser light having a wavelength of around 400 nm and has a glass transition temperature of 150 ° C. or more. From the viewpoint of moldability when injection molding an optical lens, the problem is that it is too high.

  Therefore, an optical lens having light resistance to light in the vicinity of a wavelength of 400 nm and a high refractive index of, for example, 1.63 or more is required. Further, the resin forming the optical lens has a glass transition temperature of, for example, 120 because of moldability. It is calculated | required that it exists in the range of -145 degreeC.

  By the way, in Patent Document 3, 1,1 ′-(4-hydroxyphenyl) -1-phenylethane (hereinafter referred to as bisphenol AP) and bisphenol M are repeatedly used for the purpose of reducing birefringence when used in an optical disk. Novel copolymeric polycarbonates that are included in the structure have been proposed. However, the material disclosed in Patent Document 3 is only aimed at a low birefringence material, and the light resistance and refractive index with respect to light in the vicinity of a wavelength of 400 nm are unknown. It was completely unclear whether it had such characteristics.

JP 2007-94053 A JP 2004-331688 A JP-A-2-99521

  The present invention solves the above problems and provides an optical lens having a high refractive index, good light resistance to short-wavelength light having a wavelength of 350 to 450 nm, etc., and a glass transition temperature that has no practical problem. There is to do.

  As a result of intensive studies to achieve the above object, the present inventors have found that a polycarbonate copolymer having a specific structure has the above characteristics, and has completed the present invention.

That is, according to the present invention, the following optical lenses are provided.
The repeating unit consists of the following formula (1) and formula (2),
A polycarbonate copolymer having a molar ratio of repeating units represented by the following formulas (1) and (2) of 40/60 to 70/30,
A blue laser pickup having a wavelength of 350 to 450 nm, comprising 0.7 g of the polycarbonate copolymer dissolved in 100 cc of methylene chloride and comprising a polycarbonate copolymer having a specific viscosity of 0.20 to 0.50 measured at 20 ° C. lens.

The polycarbonate copolymer used in the present invention has a high refractive index and excellent light resistance to short wavelength light such as 350 to 450 nm and has an appropriate glass transition temperature. can do.
Therefore, the optical lens of the present invention can be particularly suitably used as an optical lens for equipment using a blue laser, and is extremely useful.

2 is a proton NMR chart of the polycarbonate copolymer of Example 1. FIG.

Hereinafter, the present invention will be described in detail.
The polycarbonate copolymer for optical lenses of the present invention has the formulas (1) and (2).
The repeating molar unit represented by the formula (1) and the formula (2) is 40/60 to 70/30, and is particularly suitable as a lens for short wavelength light such as a blue laser. used.

  The polycarbonate copolymer for optical lenses of the present invention is substantially composed of the repeating units of the above formulas (1) and (2), and may contain a known copolymer component or the like as long as the object of the present invention is not impaired. . From such a viewpoint, it is preferable that 95 mol% or more of the repeating units of the polycarbonate copolymer are the above formulas (1) and (2), and 98 mol% or more is preferably the above formulas (1) and (2). More preferably.

  In the polycarbonate copolymer for optical lenses of the present invention, the molar ratio of the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2) is 40/60 to 70/30, preferably Is 45/55 to 65/35.

  That is, the polycarbonate copolymer for optical lenses of the present invention has a high refractive index by containing the repeating unit represented by the formula (1) and is practical by containing the repeating unit represented by the formula (2). An upper glass transition temperature can be realized. That is, when the molar ratio of the formulas (1) and (2) is 40/60 to 70/30, it is possible to achieve both a high refractive index and a glass transition temperature suitable for an optical lens. Even when a laser beam of around 400 nm is irradiated for a long time, the total light transmittance for light with a wavelength of 350 to 800 nm can be kept high.

Hereinafter, the preferable aspect of the polycarbonate copolymer for optical lenses of this invention is demonstrated.
The optical polycarbonate copolymer of the present invention preferably has a refractive index in the range of 1.630 to 1.650 at 25 ° C. and a wavelength of 405 nm, more preferably 1.633 to 1.645, still more preferably. Is 1.635 to 1.640.

By being in such a range, the thickness of the lens can be made very thin. The polycarbonate copolymer for an optical lens of the present invention has a retention rate after irradiation of the total light transmittance when irradiated with a laser beam having a wavelength of 400 nm (integrated light amount: 520 kJ / cm 3) in a state of a molded plate having a thickness of 2 mm described later. Is preferably 90% or more, and more preferably 93% or more. Such retention after irradiation is expressed by Equation (3).
Retention rate after irradiation of total light transmittance (%) =
(Total light transmittance before irradiation−total light transmittance after irradiation) / total light transmittance before irradiation × 100
... (3)

  When the proportion of the repeating unit represented by the formula (1) is smaller than 40 mol%, the glass transition temperature (Tg) becomes less than 120 ° C., and depending on the use of the optical member formed using the copolymer, This is not preferable because the properties are not sufficient. On the other hand, when the ratio of the repeating unit represented by the formula (1) is larger than 70 mol%, Tg becomes higher than 145 ° C., so that the melt viscosity becomes high and the handling property in forming a molded body is lowered. Therefore, it is not preferable.

  The specific viscosity of the polycarbonate copolymer for optical lenses of the present invention is such that 0.7 g of the polycarbonate copolymer is dissolved in 100 cc of methylene chloride and the specific viscosity measured at 20 ° C. is in the range of 0.20 to 0.50. Preferably, it is 0.22 to 0.45, more preferably 0.25 to 0.40. If the specific viscosity is less than 0.20, the molded product becomes brittle, and if it is higher than 0.50, the melt fluidity is extremely lowered. Therefore, a small and precise shape and dimensional accuracy such as a pickup lens are required. When molding an optical component, molding processability is poor, and problems such as an increase in birefringence of the obtained optical component occur, which is not preferable.

  The polycarbonate copolymer for optical lenses of the present invention preferably has a glass transition temperature (Tg) measured at a temperature rising rate of 20 ° C./min in the range of 120 ° C. to 145 ° C., more preferably 125 to 140. ° C. When the Tg is lower than 120 ° C., the heat resistance is not sufficient depending on the use of the optical lens formed using the copolymer. On the other hand, when Tg is higher than 145 ° C., the melt viscosity becomes high, and the handleability in forming a molded article is lowered. That is, when Tg is in the range of 120 to 145 ° C., both heat resistance and moldability are highly compatible.

  The polycarbonate copolymer for optical lenses of the present invention is produced by a reaction means known per se for producing an ordinary aromatic polycarbonate resin, for example, a method in which a dihydric phenol component is reacted with a carbonate precursor such as phosgene or carbonic acid diester. Is done. Next, basic means for these manufacturing methods will be briefly described.

  As the carbonate precursor, carbonyl halide, carbonate ester, haloformate or the like is used, and specific examples include phosgene, diphenyl carbonate, dihaloformate of dihydric phenol, and the like.

  When producing polycarbonate copolymer by reacting the above dihydric phenol and carbonate precursor by interfacial polymerization method or melting method, use catalyst, terminal terminator, dihydric phenol antioxidant, etc. as necessary May be.

  The reaction by the interfacial polymerization method is usually a reaction between a dihydric phenol and phosgene, and is reacted in the presence of an acid binder and an organic solvent. As the acid binder, for example, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide or an amine compound such as pyridine is used. As the organic solvent, for example, halogenated hydrocarbons such as methylene chloride and chlorobenzene are used. In order to accelerate the reaction, a catalyst such as a tertiary amine such as triethylamine, tetra-n-butylammonium bromide or tetra-n-butylphosphonium bromide, a quaternary ammonium compound or a quaternary phosphonium compound may be used. it can. At that time, the reaction temperature is usually 0 to 40 ° C., the reaction time is preferably about 10 minutes to 5 hours, and the pH during the reaction is preferably maintained at 9 or more.

The reaction by the melting method is usually a transesterification reaction between a dihydric phenol and a carbonate ester. The dihydric phenol and the carbonate ester are mixed with heating in the presence of an inert gas, and the resulting alcohol or phenol is distilled. It is done by the method of making it come out. The reaction temperature varies depending on the boiling point of the alcohol or phenol produced, but is usually in the range of 120 to 350 ° C. In the latter stage of the reaction, the system is evacuated to about 1.3 × 10 ^{3 to} 1.3 × 10 Pa to facilitate the distillation of the alcohol or phenol produced. The reaction time is usually about 1 to 4 hours.

  Examples of the carbonate ester include esters such as an optionally substituted aryl group having 6 to 10 carbon atoms, an aralkyl group, or an alkyl group having 1 to 4 carbon atoms. Specific examples include diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, bis (diphenyl) carbonate, dimethyl carbonate, diethyl carbonate, and dibutyl carbonate. Is preferred.

In addition, a polymerization catalyst can be used to increase the polymerization rate in the melting method. Examples of such a polymerization catalyst include alkali metal compounds such as sodium hydroxide, potassium hydroxide, sodium salt of dihydric phenol, potassium salt, water Alkaline earth metal compounds such as calcium oxide, barium hydroxide and magnesium hydroxide, nitrogen-containing basic compounds such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, trimethylamine and triethylamine, alkali metal and alkaline earth metal alkoxides , Organic acid salts of alkali metals and alkaline earth metals, zinc compounds, boron compounds, aluminum compounds, silicon compounds, germanium compounds, organotin compounds, lead compounds, osmium compounds, antimony compounds, man Down compounds, titanium compounds, usually the esterification reaction, such as zirconium compounds, there can be used a catalyst used in the transesterification reaction. A catalyst may be used independently and may be used in combination of 2 or more types. The amount of these polymerization catalysts used is 1 × 10 ⁻⁸ to 1 × 10 ⁻³ equivalent, preferably 1 × 10 ⁻⁷ to 1 × 10 ⁻³ equivalent, more preferably 1 mol of the raw material dihydric phenol. It is selected in the range of 1 × 10 ^{−6 to} 5 × 10 ⁻⁴ equivalents.

  As the polycarbonate copolymer, monofunctional phenols which are usually used as a terminal terminator can be used in the polymerization reaction. Especially in the case of reactions using phosgene as a carbonate precursor, monofunctional phenols are generally used as end-capping agents for molecular weight control, and the polymers obtained are based on groups based on monofunctional phenols. Since it is blocked by, it is superior in thermal stability compared to other cases.

  Such monofunctional phenols are not particularly limited as long as they are used as a terminal terminator for polycarbonate copolymers, and are generally phenols or lower alkyl-substituted phenols. Specific examples include long chain alkyl-substituted phenols such as phenol, p-tert-butylphenol, p-cumylphenol and isooctylphenol, nonylphenol, decanylphenol, tetradecanylphenol, butyl hydroxybenzoate, octyl hydroxybenzoate, and the like. And long-chain alkyloxyphenols such as hydroxybenzoic acid long-chain alkyl esters, butoxyphenol, octyloxyphenol, heptadecanylphenol and the like. The monofunctional phenols are desirably introduced at the end of at least 1 mol%, preferably at least 4 mol% with respect to the obtained polycarbonate copolymer, and the monofunctional phenols may be used alone or in combination of two or more. May be used.

The polycarbonate copolymer for optical lenses of the present invention is molded into an optical lens by any method such as injection molding, compression molding, and injection compression molding.
Hereinafter, the optical lens of the present invention using the polycarbonate copolymer for optical lenses of the present invention will be described.

Various additives can be used for the polycarbonate copolymer for optical lenses of the present invention in order to impart various characteristics within a range not impairing the object of the present invention. As additives, release agents, heat stabilizers, bluing agents, antistatic agents, flame retardants, fluorescent dyes (including fluorescent whitening agents), pigments, other resins and elastomers can be blended.
Among these, it is a preferable embodiment to contain a phosphorus atom-containing antioxidant or a phenolic antioxidant.

  When the phosphorus atom-containing antioxidant is contained in the optical lens of the present invention, the content is usually 0.01 to 5 parts by weight, preferably 0, per 100 parts by weight of the polycarbonate copolymer. 0.02 to 2 parts by weight, and more preferably 0.05 to 1 part by weight.

  Examples of such phosphorus atom-containing antioxidants include phosphorous acid, phosphoric acid, phosphonous acid, phosphonic acid, and ester derivatives thereof. Specific examples of such compounds include, for example, trimethyl phosphite, triethyl phosphite, tributyl phosphite, trioctyl phosphite, tris (2-ethylhexyl phosphite), trinonyl phosphite, tridecyl phosphite, tris (tridecyl). Phosphite, trioctadecyl phosphite, tristearyl phosphite, tris (2-chloroethyl) phosphite, tris (2,3-dichloropropyl phosphite), tricyclohexyl phosphite, triphenyl phosphite, tricresyl phosphite, Tris (ethylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, tris (nonylphenyl) phosphite, phenyl-didecylphosphite, diphenyl-i Octyl phosphite, diphenyl-2-ethylhexyl phosphite, diphenyl-decyl phosphite, diphenyl-tridecyl phosphite, bis (tridecyl) -pentaerystyryl-diphosphite, distearyl-pentaerystyryl-diphosphite, diphenyl-pentaerythryl -Diphosphite, bis (nonylphenyl) -pentaerystyryl-diphosphite, bis (2,4-di-tert-butylphenyl) -pentaerystyryl-diphosphite, bis (2,6-di-tert-butyl-4-methyl) Phenyl) -pentaerystyryl-diphosphite, tetraphenyl-dipropylene glycol-diphosphite, tetra (tridecyl) -4,4′-isopropylidenediphenyl-diphosphite, tetra ( , 4-Di-tert-butylphenyl) -4,4′-diphenyl phosphite, tetraphenyltetra (tridecyl) pentaerythryl tetraphosphite, trilauryl trithiophosphite, bis (2,4-dicumylphenyl pentaerythritol Phosphorous acids such as diphosphite; phosphoric acids such as trimethyl phosphate, triethyl phosphate, tributyl phosphate, triphenyl phosphate, diphenyl monoorthoxenyl phosphate, dibutyl phosphate, dioctyl phosphate, diisopropyl phosphate; tetrakis (2,4-di- tert-butylphenyl) -4,4-diphenylenephosphonite, etc .; dimethyl benzenephosphonate, diethylbenzenephosphonate, benzenephosphone Illustrative examples include, but are not limited to, phosphonic acids such as diisopropyl acid. Among these phosphorus atom-containing compounds, phosphorous acid derivatives and phosphoric acid ester derivatives are preferable. These phosphorus compounds may be used alone or in combination of two or more.

  When the phenolic antioxidant is contained in the optical lens of the present invention, the content thereof is usually 0.0001 to 2 parts by weight, preferably 0.001 to 100 parts by weight of the polycarbonate copolymer. It is 001-1 weight part, More preferably, it is 0.01-0.5 weight part. Examples of the phenolic antioxidant include octadecyl-3- (3,5-di-tert-butyl-5-methyl-4-hydroxyphenyl) propionate, triethylene glycol-bis [3- (3-tert -Butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], penta Erythritol-tetrakis [3- (3,5-di-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,3,5-trimethyl-2,4,6-tris (3,5-di -Tert-butyl-4-hydroxybenzyl) benzene, N, N-hexamethylenebis (3,5-di-tert-butyl) 4-hydroxy-hydrocinnamide), 3,5-di-tert-butyl-4-hydroxybenzylphosphonate diethyl ester, tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, etc. Although various well-known phenolic antioxidants are illustrated, it is not limited to these. These phenolic antioxidants may be used alone or in combination of two or more.

  Furthermore, in the optical lens of the present invention, it is preferable to add higher fatty acid esters of monohydric or polyhydric alcohol as necessary for the purpose of improving the releasability from the mold at the time of melt molding. . When the higher fatty acid ester is contained in the optical lens of the present invention, the content is usually 0.0001 to 2 parts by weight, preferably 0.001 to 1 part per 100 parts by weight of the polycarbonate copolymer. Parts by weight, more preferably 0.01 to 0.5 parts by weight. Such higher fatty acid esters are more preferably partial or total esters of mono- or polyhydric alcohols having 1 to 20 carbon atoms and saturated fatty acids having 10 to 30 carbon atoms. Specific examples of the higher fatty acid esters include stearic acid monoglyceride, stearic acid monosorbate, behenic acid monoglyceride, pentaerythritol monostearate, pentaerythritol tetrastearate, propylene glycol monostearate, steryl stearate, Examples include, but are not limited to, palmityl palmitate, butyl stearate, methyl laurate, isopropyl palmitate, 2-ethylhexyl stearate, and the like. These higher fatty acid esters may be used alone or in combination of two or more.

  In order to make the optical lens of the present invention contain the additive as described above, any method can be used. Examples of such a method include a method of mixing with a tumbler mill, a V-type blender, a Nauter mixer, a Banbury mixer, a kneading roll, an extruder, and the like.

  The optical lens of the present invention is molded in a molten state by injection molding, injection compression molding, extrusion molding, blow molding, and particularly by various known molding methods such as compression molding and solution casting.

  Since the optical lens of the present invention is highly resistant to short-wavelength light having a wavelength of 350 to 450 nm such as a blue laser, integration of blue laser light such as an optical lens using a blue laser, particularly a pickup lens or a prism lens. It is suitably used for an optical lens with a large irradiation amount.

  As described above, the polycarbonate copolymer for optical lenses of the present invention has a high refractive index, high fluidity, and good light resistance in a balanced manner against short wavelength light having a wavelength of 350 to 450 nm. Therefore, an optical lens using the optical lens is suitable as an optical lens that receives blue laser light irradiation. The wavelength of the blue laser is usually 400 to 410 nm.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to this. The evaluation was performed according to the following method.

(1) Specific viscosity: The polycarbonate copolymer obtained after the completion of polymerization was sufficiently dried, and the specific viscosity (η _sp ) of the solution at 20 ° C. was determined from a solution obtained by dissolving 0.7 g of the polymer in 100 ml of methylene chloride. It was measured.

(2) Copolymerization ratio: 10 mg of a polymer was dissolved in 0.6 ml of deuterated chloroform, and the number of integration was measured 128 times using proton NMR of JNM-AL400 manufactured by JEOL Ltd. The copolymerization ratio was a peak (2.18 ppm) due to the methyl group of 1,1 ′-(4-hydroxyphenyl) -1-phenylethane and 4,4 ′-[1,3-phenylene (1-methylethylidene). It was determined from the integration ratio of the peak (1.62 ppm) attributed to the methyl group of bisphenol.

(3) Glass transition temperature (Tg): About 10 mg of polymer was used, and the temperature was raised under a nitrogen atmosphere (nitrogen flow rate: 40 ml / min) according to JISK7121 using a thermal analysis system DSC-2910 manufactured by TA Instruments. Speed: Measured under the condition of 20 ° C./min.

(4) Refractive index (n _h ): A refractive index of 405 nm at 25 ° C. was measured using a Kalnew refractometer (KPR-2000 manufactured by Kalnew Optical Industry) using a molding plate having a thickness of 2 mm.

(5) Total light transmittance: Measured in a visible light region (380 to 800 nm) with NDH-300A manufactured by Nippon Denshoku Co., Ltd. according to JIS K7361-1, using a 2 mm thick molded plate.

(6) Total light transmittance after irradiation with a high dose and short wavelength laser: The same as that used in (5) above, using a spectral aging tester (XSP type, manufactured by Suga Test Instruments Co., Ltd.). The molded plate was irradiated with 520 kJ / cm ³ as an integrated light amount in a wavelength range of 400 ± 10 nm. The total light transmittance of the molded plate after irradiation was measured.
Retention rate after irradiation of total light transmittance (%) =
(Total light transmittance before irradiation−total light transmittance after irradiation) / total light transmittance before irradiation × 100
... (3)

Example 1
In a flask equipped with a phosgene blowing tube, a thermometer and a stirrer, 18.1 g (0.062 mol) of bisphenol AP, 21.5 g (0.062 mol) of bisphenol M, 262 ml of a 5.5% sodium hydroxide aqueous solution (0. 372 mol) and 128 ml of methylene chloride were charged and dissolved, and the mixture was kept at 20 to 25 ° C. with stirring, and 15.4 g (0.156 mol) of phosgene was required for 60 minutes for blowing phosgenation reaction. After completion of the phosgenation reaction, 0.84 g (0.0056 mol) of p-tert-butylphenol and 17 ml of 25% aqueous sodium hydroxide solution (0.062 mol of sodium hydroxide) were added and stirred, and 0.09 mL (0.00062) of triethylamine was added along the way. Mol) was added and reacted at a temperature of 25 to 35 ° C. for 90 minutes. The separated methylene chloride phase was washed with acid and water until inorganic salts and amines disappeared, and then methylene chloride was removed to obtain a copolymer polycarbonate. This polycarbonate had a molar ratio of bisphenol AP component to bisphenol M component of 50:50, a specific viscosity of 0.28, and a glass transition temperature of 126 ° C.

(Example 2)
The procedure in Example 1 was repeated except that the charged monomer amount was changed to bisphenol AP 14.5 g (0.050 mol) and bisphenol M 25.8 g (0.075 mol). This polycarbonate had a molar ratio of the constituent units of the bisphenol AP component and the bisphenol M component of 40:60, a specific viscosity of 0.29, and a glass transition temperature of 120 ° C.

Example 3
The procedure in Example 1 was repeated except that the amount of monomers charged was changed to 21.7 g (0.075 mol) of bisphenol AP and 17.2 g (0.050 mol) of bisphenol M. This polycarbonate had a molar ratio of bisphenol AP component to bisphenol M component of 60:40, a specific viscosity of 0.29, and a glass transition temperature of 138 ° C.

(Comparative Example 1)
The procedure in Reference Example 1 was repeated except that the amount of monomers charged was changed to 43.4 g (0.038 mol) of bisphenol AP and 30.1 g (0.088 mol) of bisphenol M. This polycarbonate had a molar ratio of the constituent units of the bisphenol AP component and the bisphenol M component of 30:70, a specific viscosity of 0.31, and a glass transition temperature of 115 ° C.

(Comparative Example 2)
The procedure in Example 1 was repeated except that the amount of monomer charged was changed to 29.0 g (0.100 mol) of bisphenol AP and 8.6 g (0.025 mol) of bisphenol M. This polycarbonate had a molar ratio of bisphenol AP component to bisphenol M component of 80:20, a specific viscosity of 0.29, and a glass transition temperature of 150 ° C.

(Comparative Example 3)
The supplementary examination of Unexamined-Japanese-Patent No. 2004-331688 was implemented. In a flask equipped with a phosgene blowing tube, a thermometer, and a stirrer, 13.0 g (0.038 mol) of bisphenol M, 38.3 g (0.101 mol) of bisphenol BCF, 326 ml of a 5.7% aqueous sodium hydroxide solution (0.2 mg of sodium hydroxide). 481 mol) and 107 ml of methylene chloride were charged and dissolved, and the mixture was kept at 20 to 25 ° C. with stirring, and 17.9 g (0.181 mol) of phosgene was required for 60 minutes to perform the blowing phosgenation reaction. After completion of the phosgenation reaction, 1.04 g (0.0069 mol) of p-tert-butylphenol and 3.8 ml of 48% aqueous sodium hydroxide solution (0.069 mol of sodium hydroxide) were added and stirred, and 0.08 mL (0 .00056 mol) was added and reacted at a temperature of 25-35 ° C. for 90 minutes. The separated methylene chloride phase was washed with acid and water until inorganic salts and amines disappeared, and then methylene chloride was removed to obtain a copolymer polycarbonate. This polycarbonate had a molar ratio of bisphenol M component to bisphenol BCF component of 27:73, a specific viscosity of 0.26, and a glass transition temperature of 212 ° C.

(Comparative Example 4)
Polycycloolefin (trade name ZEONEX 340R manufactured by Nippon Zeon Co., Ltd.) was used. The specific viscosity was not measured because it was insoluble in methylene chloride, and the glass transition temperature was 121 ° C.

(Examples 4-6 and Comparative Examples 5-8)
0.050 parts by weight of bis (2,4-dicumylphenyl) pentaerythritol diphosphite and pentaerythritol tetrastearate are added to 100 parts by weight of the polycarbonate copolymers of Examples 1 to 3 and Comparative Examples 1 to 4. After adding 0.10 parts by weight and pelletizing using a φ30 mm single screw extruder with a vent, the polycarbonate copolymer and ZEONEX 340R were vacuum dried at 100 ° C. for 24 hours, and then a 75 ton molding machine manufactured by JSW Co., Ltd. Using (JSW J-75EIII), molded plates having a thickness of 1 mm and 2 mm were formed. The melting temperature at that time is 290 to 310 ° C. for Examples 1 to 3 and Comparative Examples 1 and 2, 340 to 360 ° C. for Comparative Example 3, and 260 to 280 ° C. for Comparative Example 4. Moreover, the total light transmittance was measured using the said shaping | molding board. The results are shown in Table 2.

Table 1 shows the physical properties of the various resins prepared.
The obtained pellets were molded into a lens having a thickness of 0.3 mm, a convex curvature radius of 5 mm, and a diameter of 5 mm using a SE30DU injection molding machine manufactured by Sumitomo Heavy Industries, Ltd. Although irradiated, the optical lenses of Examples 4 to 6 were very good without a decrease in light transmittance.

Bisphenol AP; 1,1 ′-(4-hydroxyphenyl) -1-phenylethanebisphenol M; 4,4 ′-[1,3-phenylene (1-methylethylidene)] bisphenol bisphenol BCF; 9,9-bis ( 4-hydroxy-3-methylphenyl) fluorene

  The optical lens molding material comprising a polycarbonate copolymer having a specific repeating structural unit of the present invention has a high refractive index and light resistance that maintains a high degree of transparency with respect to light having a wavelength of 350 to 450 nm. Because it is excellent and has a glass transition temperature suitable for practical use, this molding material enables high-precision, high-quality optical components (for example, optical plastic lenses for imaging devices such as cameras and VTRs, optical information recording media, etc.) In the field of an optical lens represented by a laser optical system lens such as a pickup lens used in US Pat.

Claims (1)

The repeating unit consists of the following formula (1) and formula (2),
A polycarbonate copolymer having a molar ratio of repeating units represented by the following formulas (1) and (2) of 40/60 to 70/30, wherein 0.7 g of the polycarbonate copolymer is added to 100 cc of methylene chloride It was dissolved in a wavelength blue laser pickup lens of 350~450nm consisting ratio measured at 20 ° C. viscosity from 0.20 to 0.50 der Lupolen polycarbonate copolymer.

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