JP6130255B2 - Polyester carbonate copolymer - Google Patents

Description

  The present invention relates to a polyester carbonate copolymer having high transparency, high refractive index, low birefringence, and extremely high flow.

  In recent years, resins using bisphenols as raw materials (for example, epoxy resins, polyester resins, polycarbonate resins, polyester carbonate resins, etc.) are widely used as materials with heat resistance, transparency, impact resistance, and high refractive index. Has been. A resin comprising a fluorene derivative such as 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene is promising as a highly transparent and high refractive index material, and is used as an automotive headlamp lens, CD, CD-ROM. It is expected as an optical material such as a pickup lens, a Fresnel lens, an fθ lens for a laser printer, a camera lens, and a projection lens for a rear projection television.

However, in recent years, development of a resin having a higher refractive index has been demanded due to the lighter and thinner products. In general, when the refractive index of an optical material is high, a lens element having the same refractive index can be realized on a surface with a smaller curvature. Therefore, the amount of aberration generated on this surface can be reduced, the number of lenses can be reduced, Decentration sensitivity can be reduced, or the lens thickness can be reduced to reduce the weight.
When an optical resin is used as an optical lens, heat resistance, transparency, low birefringence, and heat and humidity resistance are required in addition to the refractive index. Therefore, there exists a weak point that a use location is limited by the characteristic balance of resin.

  In particular, in recent years, a camera lens having higher imaging performance and lower birefringence has been demanded as the resolution is increased by increasing the number of pixels. In general, as a method of reducing the birefringence, there is a method in which the compositions having positive and negative birefringences having different signs cancel each other's birefringence. For this reason, the composition ratio of materials having birefringence with different signs is very important. Moreover, in order to project a clear image, it is necessary to maintain high transmittance at all wavelengths in the visible light region.

  In recent years, the reduction in size and thickness of optical lenses has been accelerated with the downsizing of electronic devices. For example, camera lenses for mobile phones are extremely small and thin with a diameter of about 5 mm and a thickness of about 0.3 mm, and further miniaturization and thinning are expected to continue in the future. When injection molding such a small thin lens, if the resin has insufficient fluidity, a lens having a desired shape may not be obtained.

Therefore, development of resins having high transparency, high refractive index, and excellent molding fluidity has been performed. For example, a polyester carbonate composed of a fluorene-containing dihydroxy compound and a bisphenol compound has been proposed (Patent Document 1).
Moreover, the polyester carbonate which consists of a fluorene containing dihydroxy compound and aromatic dicarboxylic acid is proposed (patent document 2).
However, there is still room for improvement for use in optical lenses.
That is, a polyester carbonate for an optical lens that satisfies all properties of high transparency, high refractive index, low birefringence, and high molding fluidity in a balanced manner has not yet been achieved.

JP-A-10-101786 International Publication No. 2011-010741

  The present invention is intended to solve the above problems, and provides a polycarbonate copolymer for an optical lens that is highly transparent, has a high refractive index, low birefringence, and satisfies all the properties of high molding fluidity in a well-balanced manner. And an optical lens made of a polyester carbonate copolymer. More specifically, the present invention relates to an optical lens made of a polyester carbonate copolymer excellent in high transparency, heat and humidity resistance, and thermal stability.

  The present inventors have intensively studied to achieve this object. As a result, by copolymerizing a component represented by the following general formula (I) having a spirobifluorene structure and a dicarboxylic acid at a specific composition ratio, it has high refraction, low birefringence and high molding fluidity. The present inventors have found that the polyester carbonate copolymer for optical lenses satisfying all properties in a well-balanced manner has been reached.

That is, the present invention
1. The total of all structural units is 100 mol%, the unit represented by the following formula (I) containing 95 to 5 mol%, and the unit represented by the following formula (II) contains 5 to 95 mol%, the ratio A polyester carbonate copolymer having a viscosity of 0.18 to 0.35 .

（式中のＲ_１〜Ｒ_２は、それぞれ水素原子、フッ素原子、塩素原子、臭素原子、ヨウ素原子、炭素数１〜６のアルキル基、炭素数６〜１２のアリール基、炭素数２〜６のアルケニル基、炭素数１〜６のアルコキシ基又は炭素数７〜１７のアラルキル基を示す。ｎ、ｍは１〜１０の整数である。）

(R _{1 to} R ₂ in the formula are each a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or 2 to 6 carbon atoms. An alkenyl group, an alkoxy group having 1 to 6 carbon atoms or an aralkyl group having 7 to 17 carbon atoms, n and m are integers of 1 to 10.)

（式中のＹは、２，６−ナフタレンジイル基、または１，４−フェニレン基である。）

(Y in the formula is a 2,6-naphthalenediyl group or a 1,4-phenylene group .)

2 . 2. The polyester carbonate copolymer according to 1 above, wherein the structural unit described in the formula (I) has a spirobifluorene structure.
3 . 3. The polyester carbonate copolymer as described in 1 or 2 above, which has a refractive index of 1.650 to 1.675.
4 . 4. The polyester carbonate copolymer according to any one of 1 to 3 , wherein the orientation birefringence is 0 to 1 × 10 ⁻² .
5 . The polyester carbonate copolymer according to any one of 1 to 4 above, wherein the glass transition temperature is 140 to 170 ° C.
6 . The polyester carbonate copolymer according to any one of 1 to 5 above, wherein the phenol content is 1 to 500 ppm.
7 . An optical member comprising the polyester carbonate copolymer according to any one of 1 to 6 above.
8 . An optical lens comprising the polyester carbonate copolymer according to any one of 1 to 6 above.
9 . 9. The optical lens according to 8 , wherein the thickness of the central portion is 0.05 to 3.0 mm and the diameter of the lens portion is 1.0 to 20.0 mm.

  The polyester carbonate copolymer for optical lenses of the present invention has a high refraction, low birefringence and high molding by copolymerizing a diol component having a spirobifluorene structure and a dicarboxylic acid component at a specific composition ratio. Since it has a balance of all the characteristics of fluidity, the industrial effect it produces is exceptional.

<Polyester carbonate copolymer>
Hereafter, each component which comprises the polyester carbonate copolymer for optical lenses of this invention, those compounding ratios, an adjustment method, etc. are demonstrated one by one sequentially.

  The polyester carbonate copolymer of the present invention (hereinafter sometimes abbreviated as copolymer) contains a unit represented by the following formula (I). The content of the unit of the formula (I) is 98 to 1 mol%, preferably 95 to 5 mol%. When it is more than 98 mol%, birefringence occurs, which is not preferable. On the other hand, if it is less than 1 mol%, the glass transition temperature becomes high and handling becomes difficult.

（式中のＲ_１〜Ｒ_２は、それぞれ水素原子、フッ素原子、塩素原子、臭素原子、ヨウ素原子、炭素数１〜６のアルキル基、炭素数６〜１２のアリール基、炭素数２〜６のアルケニル基、炭素数１〜６のアルコキシ基又は炭素数７〜１７のアラルキル基を示す。ｎ、ｍは１〜１０の整数である。）

(R _{1 to} R ₂ in the formula are each a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or 2 to 6 carbon atoms. An alkenyl group, an alkoxy group having 1 to 6 carbon atoms or an aralkyl group having 7 to 17 carbon atoms, n and m are integers of 1 to 10.)

In the structure represented by the general formula (I) in the copolymer of the present invention, R _{1 to} R ₂ are preferably hydrogen atoms.
In the structure represented by the general formula (I) in the copolymer of the present invention, n and m are preferably 1 to 3. When it is 1 or less, the fluidity is poor, and when it is 3 or more, the refractive index is remarkably lowered.

  The copolymer of the present invention contains a unit represented by the following formula (II). The content of the unit of the formula (II) is preferably 2 to 99 mol%, more preferably 5 to 95 mol%. When it is less than 2 mol% or more than 99 mol%, birefringence occurs, which is not preferable.

（式中、Ｒ_３、Ｒ_４は、それぞれ独立に水素原子、炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシル基、炭素数５〜２０のシクロアルキル基、炭素数５〜２０のシクロアルコキシル基、炭素数６〜２０のアリール基または炭素数６〜２０のアリールオキシ基である。Ｙは炭素数２〜８のアルキレン基、炭素数５〜１２のシクロアルキレン基または炭素数６〜２０のアリーレン基である。ｐ、ｑは０〜１０の整数である。）

(In formula, R < ₃ >, R < ₄ > is respectively independently a hydrogen atom, a C1-C20 alkyl group, a C1-C20 alkoxyl group, a C5-C20 cycloalkyl group, and C5-C20. A cycloalkoxyl group, an aryl group having 6 to 20 carbon atoms, or an aryloxy group having 6 to 20 carbon atoms, Y is an alkylene group having 2 to 8 carbon atoms, a cycloalkylene group having 5 to 12 carbon atoms, or 6 carbon atoms. An arylene group of ˜20, p and q are integers of 0-10.)

In the structure represented by the general formula (II) in the copolymer of the present invention, R _{3 to} R ₄ are preferably hydrogen atoms.
In the structure represented by the general formula (II) in the copolymer of the present invention, p and q are preferably 1 to 3. When it is 1 or less, the fluidity is poor, and when it is 3 or more, the refractive index is remarkably lowered.
In the structure represented by the general formula (II) in the copolymer of the present invention, Y is preferably a 2,6-naphthalenediyl group, a 1,4-phenylene group, or a 1,3-phenylene group. .

  The specific viscosity of the copolymer of the present invention is in the range of 0.12 to 0.40, preferably 0.15 to 0.35, and more preferably 0.18 to 0.35. The specific viscosity is measured at 20 ° C. by dissolving 0.7 g of the copolymer in 100 ml of methylene chloride. When the specific viscosity is less than 0.12, the molded product becomes brittle, and when it is higher than 0.40, the melt viscosity and the solution viscosity are increased, the fluidity is lowered, and injection molding such as insufficient filling is caused. In addition, the solubility and stability in a solvent during wet molding are reduced, and precipitation from the solvent makes it impossible to perform wet molding.

  The refractive index of the copolymer of the present invention is preferably in the range of 1.650 to 1.675, more preferably 1.660 to 1.675, and still more preferably 1.665 to 1.675. The refractive index is measured at 25 ° C. and wavelength 589 nm. A refractive index of 1.650 or more is preferable because spherical aberration of the lens can be reduced and the focal length of the lens can be shortened.

The Abbe number (ν) of the copolymer of the present invention is preferably in the range of 18 to 23, more preferably 18 to 22, and still more preferably 19 to 21. The Abbe number is calculated from the refractive index at 25 ° C., wavelengths 486 nm, 589 nm, and 656 nm using the following formula.
v = (nD-1) / (nF-nC)
nD: Refractive index at a wavelength of 589 nm
nF: Refractive index at a wavelength of 656 nm
nC: Refractive index at a wavelength of 486 nm

The orientation birefringence (Δn) of the copolymer of the present invention is preferably in the range of 0 to 10 × 10 ⁻³ , more preferably 0 to 6 × 10 ⁻³ , and still more preferably 0 to 4 × 10 ^−3. . The orientation birefringence (Δn) is measured at a wavelength of 589 nm when a 100 μm-thick cast film obtained from the copolymer is stretched twice at a glass transition temperature (Tg) of the copolymer + 10 ° C.

  The spectral transmittance of the copolymer of the present invention is preferably 80% or more, more preferably 81% or more, and still more preferably 82% or more. The transmittance is measured at a wavelength of 395 nm on a molded plate having a thickness of 0.1 mm. Unless the spectral transmittance is 80% or more, it is not preferable as an optical member.

  The glass transition temperature (Tg) of the copolymer of the present invention is preferably 140 to 170 ° C, more preferably 140 to 165 ° C, and still more preferably 140 to 160 ° C. The glass transition temperature (Tg) is measured at a heating rate of 20 ° C./min. If the Tg is less than 140 ° C., the heat resistance may not be sufficient depending on the use of the optical component formed using the copolymer. On the other hand, if the Tg is higher than 170 ° C., the melt viscosity becomes high, forming a molded body. Handling becomes difficult.

The copolymer of the present invention preferably has a 5% weight loss temperature of 350 ° C. or higher, more preferably 380 ° C. or higher, as an index of thermal stability, measured at a temperature rising rate of 20 ° C./min. . When the 5% weight reduction temperature is lower than 350 ° C., the thermal decomposition during the molding is severe and it becomes difficult to obtain a good molded product, which is not preferable.
The melt viscosity of the copolymer of the present invention at 280 ° C. and a shear rate of 1000 / sec is preferably 30 to 300 Pa · s, more preferably 30 to 250 Pa · s, and still more preferably 50 to 200 Pa · s.

The residual phenol content of the copolymer of the present invention is preferably 1 to 500 ppm, more preferably 1 to 400 ppm, and still more preferably 1 to 300 ppm.
The phenol content can be adjusted by increasing the vacuum, that is, the reaction time at 1.3 kPa or less. When the reaction is not performed at a vacuum degree of 1.3 kPa or less, the phenol content increases. Moreover, when reaction time is too long, the terminal of resin will decompose | disassemble and phenol content will increase.
Further, the phenol content may be adjusted after obtaining the copolymer of the present invention. For example, a method of dissolving the copolymer of the present invention in an organic solvent and washing the organic solvent layer with water, a commonly used uniaxial or biaxial extruder, various kneaders such as kneaders, 133- You may use the method of devolatilizing and removing at the pressure of 13.3 Pa, and the temperature of 200-320 degreeC.

  If the residual phenol content in the copolymer of the present invention is in the range of 1 to 500 ppm, the molding fluidity can be improved without impairing the heat resistance. However, if it exceeds 500 ppm, the thermal stability when melted by heating is poor, and further, mold contamination during resin injection molding becomes severe, which is undesirable because it causes a decrease in wet heat resistance. Furthermore, phenol has a property of coloring when oxidized, and the hue in the copolymer deteriorates. If it is less than 1 ppm, the molding fluidity is inferior. More preferably, it is 300 ppm or less, and still more preferably, 200 ppm or less.

  After leaving for 2000 hours under the conditions of 85 ° C. and 85% RH, which is an index of wet heat resistance in the copolymer of the present invention, the specific viscosity retention is preferably 80% or more, more preferably 85%. As mentioned above, More preferably, it is 90% or more. When the specific viscosity retention is 80% or more, there is no deterioration in hue or strength price of the molded product even when used in a humid heat environment, and there are no restrictions on the use environment of the copolymer. If it is 80% or less, the strength accompanying a decrease in specific viscosity is decreased, cracking and deformation are preferably caused, and the hue is deteriorated.

  The specific viscosity retention after the heat retention test, which is an index of heat resistance in the copolymerization of the present invention, is preferably 70% or more, more preferably 80% or more, and still more preferably 90% or more. A specific viscosity retention of 70% or more is preferred because there is no limitation on the molding of the copolymer, and a thin molded article having a high molding temperature can be molded. Further, the hue of the molded product is preferable without deteriorating. When it is 70% or less, the strength of the molded product is lowered with a decrease in specific viscosity, and cracking and deformation are preferably caused, and the hue of the molded product is also deteriorated. Moreover, the molding conditions at the time of injection molding are limited, which is not preferable.

<Method for producing polyester carbonate copolymer>
The copolymer of the present invention can be produced by reacting a diol component and a carbonate precursor.

(Diol component)
One of the diol components in the copolymer of the present invention is a diol represented by the following formula (III).

（式中、Ｒ_５、Ｒ_６は、それぞれ独立に水素原子、炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシル基、炭素数５〜２０のシクロアルキル基、炭素数５〜２０のシクロアルコキシル基、炭素数６〜２０のアリール基または炭素数６〜２０のアリールオキシ基である。ｒ、ｓは０〜１０の整数である。）

Wherein R ₅ and R ₆ are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxyl group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, or 5 to 20 carbon atoms. A cycloalkoxyl group, an aryl group having 6 to 20 carbon atoms, or an aryloxy group having 6 to 20 carbon atoms. R and s are integers of 0 to 10.)

Content of this diol becomes like this. Preferably it is 99-50 mol%, More preferably, it is 98-60 mol%, More preferably, it is 98-70 mol%.
In the diol represented by the general formula (III) in the copolymer of the present invention, R _{5 to} R ₆ are preferably hydrogen atoms.
In the diol represented by the general formula (III) in the copolymer of the present invention, p and q are preferably 1 to 3.

You may add another diol component to such an extent that the characteristic of this polyester carbonate copolymer is not impaired. Other diols include aliphatic diols such as ethylene glycol, propanediol, butanediol, pentanediol, hexanediol, tricyclo [5.2.1.0 ^2,6 ] decanedimethanol, cyclohexane-1,4-dimethanol , Decalin-2,6-dimethanol, norbornane dimethanol, pentacyclopentadecanedimethanol, cyclopentane-1,3-dimethanol, spiroglycol, 1,4: 3,6-dianhydro-D-sorbitol, 1,4 : 3,6-dianhydro-D-mannitol, alicyclic diol such as 1,4: 3,6-dianhydro-L-iditol, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ) Ethane, bis (4-hydroxyphenyl) ether, bis (4 Hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) ketone, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3-t-butylphenyl) propane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (4-hydroxyphenyl) hexafluoropropane, bis (4-hydroxyphenyl) diphenylmethane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 9 , 9-bis (4-hydroxyphenyl) fluorene, 9,9-bi (4-hydroxy-3-methylphenyl) fluorene, α, ω-bis [2- (p-hydroxyphenyl) ethyl] polydimethylsiloxane, α, ω-bis [3- (o-hydroxyphenyl) propyl] poly Examples thereof include aromatic diols such as dimethylsiloxane, 4,4 ′-[1,3-phenylenebis (1-methylethylidene) droxyphenyl] -1-phenylethane, and bisphenol A.

（Ｗは炭素数２〜８のアルキレン基、炭素数５〜１２のシクロアルキレン基または炭素数６〜２０のアリーレン基、Ｒ_７、Ｒ_８は、単独水素、炭素数１〜３のアルキル基、または、フェニル基） One of the dicarboxylic acid derivatives in the copolymer of the present invention is represented by the following formula (IV).

(W is an alkylene group having 2 to 8 carbon atoms, a cycloalkylene group having 5 to 12 carbon atoms, or an arylene group having 6 to 20 carbon atoms, R ₇ and R ₈ are single hydrogen, an alkyl group having 1 to 3 carbon atoms, Or phenyl group)

In the copolymerization of the present invention, W in the following formula (IV) is preferably 2,6-naphthalenediyl group, 1,4-phenylene group or 1,3-phenylene group.
The content of the carboxylic acid derivative is preferably 50 to 1 mol%, more preferably 40 to 5 mol%.
You may add another dicarboxylic acid component to such an extent that the characteristic of this polyester carbonate copolymer is not impaired. Examples of other dicarboxylic acids used in combination with the dicarboxylic acid include aliphatic dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, methylmalonic acid, ethylmalonic acid, and isophthalic acid. Monocyclic aromatic dicarboxylic acids such as tert-butylisophthalic acid, polycyclic aromatic dicarboxylic acids such as anthracene dicarboxylic acid and phenanthrene dicarboxylic acid, biphenyl dicarboxylic acids such as 2,2′-biphenyldicarboxylic acid, 1,4 -Fatty aliphatic dicarboxylic acids such as cyclodicarboxylic acid and 2,6-decalin dicarboxylic acid. You may use these individually or in combination of 2 or more types. In addition, acid chlorides and esters are used as these derivatives.

(Carbonate precursor)
As carbonate precursors, phosgene, bischloroformate of 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene, diphenyl carbonate, di-p-tolyl carbonate, phenyl-p-tolyl carbonate, di- -Carbonic acid diesters such as -p-chlorophenyl carbonate and dinaphthyl carbonate. Of these, diphenyl carbonate is preferred.

(Production method)
In the reaction of diol and phosgene, the reaction is performed in a non-aqueous system in the presence of an acid binder and a solvent. Examples of the acid binder include pyridine, dimethylaminopyridine, tertiary amine and the like. As the solvent, for example, halogenated hydrocarbons such as methylene chloride and chlorobenzene are used. It is desirable to use a terminal terminator such as phenol or p-tert-butylphenol as the molecular weight regulator. The reaction temperature is usually 0 to 40 ° C., and the reaction time is preferably several minutes to 5 hours.

In the transesterification reaction, a diol, a bisaryl carbonate, and a dicarboxylic acid are mixed in the presence of an inert gas, and the pressure is reduced in the presence of a mixed catalyst comprising an alkali metal compound, an alkaline earth metal compound, a heavy metal compound, or both. The reaction is usually performed at 120 to 350 ° C, preferably 150 to 300 ° C. The degree of vacuum is changed stepwise, and finally the alcohol produced at 133 Pa or less is distilled out of the system. The reaction time is usually about 1 to 4 hours.
As a polymerization catalyst, an alkali metal compound, an alkaline earth metal compound, or a heavy metal compound may be used as a main component, and a nitrogen-containing basic compound may be used as a subsidiary component as necessary.

  Examples of the alkali metal compound include sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium bicarbonate, potassium bicarbonate, lithium bicarbonate, sodium carbonate, potassium carbonate, lithium carbonate, sodium acetate, potassium acetate, lithium acetate, sodium stearate. , Potassium stearate, lithium stearate, sodium salt of bisphenol A, potassium salt, lithium salt, sodium benzoate, potassium benzoate, lithium benzoate and the like. Alkaline earth metal compounds include calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, calcium bicarbonate, barium bicarbonate, magnesium bicarbonate, strontium bicarbonate, calcium carbonate, barium carbonate, magnesium carbonate, strontium carbonate , Calcium acetate, barium acetate, magnesium acetate, strontium acetate, calcium stearate, barium stearate, magnesium stearate, strontium stearate and the like.

  Examples of the nitrogen-containing basic compound include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, trimethylbenzylammonium hydroxide, trimethylamine, triethylamine, dimethylbenzylamine, triphenylamine, dimethylaminopyridine and the like.

  Other transesterification catalysts include zinc, tin, zirconium, lead, titanium, germanium, antimony, osmium, and aluminum salts, such as zinc acetate, zinc benzoate, zinc 2-ethylhexanoate, tin chloride (II ), Tin (IV) chloride, tin (II) acetate, tin (IV) acetate, dibutyltin dilaurate, dibutyltin oxide, dibutyltin dimethoxide, zirconium acetylacetonate, zirconium oxyacetate, zirconium tetrabutoxide, lead (II) acetate, acetic acid Lead (IV) titanium tetrabutoxide (IV) or the like is used.

These catalysts may be used alone or in combination of two or more. The amount of these polymerization catalysts used is a ratio of 10 ⁻⁹ to 10 ⁻³ mol with respect to 1 mol of the diol and the dicarboxylic acid in total. Used. These may be used alone or in combination of two or more. In the transesterification reaction, a diaryl carbonate having an electron-withdrawing substituent may be added at the later stage or after completion of the polycondensation reaction in order to reduce the hydroxy end group. Furthermore, an antioxidant or a heat stabilizer may be added to improve the hue.
These catalysts may be used alone or in combination of two or more, and the amount of these polymerization catalysts used is in a ratio of 10 ⁻⁹ to 10 ⁻³ mol with respect to 1 mol of the total diol component. . Moreover, you may add antioxidant, a heat stabilizer, etc. for a hue improvement.

In the polyester carbonate resin of the present embodiment, the catalyst may be removed or deactivated after the polymerization reaction in order to maintain thermal stability and hydrolysis stability. As for the alkali metal compound or the alkaline earth metal compound, generally, a method of deactivating the catalyst by adding a known acidic substance is preferably carried out. Specific examples of the deactivation include esters such as butyl benzoate, aromatic sulfonic acids such as p-toluenesulfonic acid, butyl p-toluenesulfonate, hexyl p-toluenesulfonate, and the like. Sulfonic acid esters, phosphoric acids such as phosphorous acid, phosphoric acid, phosphonic acid, triphenyl phosphite, monophenyl phosphite, diphenyl phosphite, diethyl phosphite, di-n-propyl phosphite, Phosphorous esters such as di-n-butyl phosphite, di-n-hexyl phosphite, dioctyl phosphite, monooctyl phosphite, triphenyl phosphate, diphenyl phosphate, monophenyl phosphate, phosphoric acid Phosphate esters such as dibutyl, dioctyl phosphate, monooctyl phosphate, diphenylphosphonic acid, dioctylphosphonic acid, dibutylphosphonic acid, etc. Phosphonic acid esters such as phonic acids, diethyl phenylphosphonate, phosphines such as triphenylphosphine and bis (diphenylphosphino) ethane, boric acids such as boric acid and phenylboric acid, tetrabutylphosphonium dodecylbenzenesulfonate, etc. Aromatic sulfonates, stearic acid chloride, benzoyl chloride, organic halides such as p-toluenesulfonic acid chloride, alkylsulfuric acid such as dimethylsulfuric acid, and organic halides such as benzyl chloride are preferably used. These deactivators are used in an amount of 0.01 to 50 times mol, preferably 0.3 to 20 times mol for the amount of catalyst. When the amount is less than 0.01 times the amount of the catalyst, the deactivation effect is insufficient, which is not preferable. Moreover, when it is more than 50 times mole with respect to the amount of catalyst, since heat resistance falls and it becomes easy to color a molded object, it is unpreferable.
After catalyst deactivation, a step of devolatilizing and removing low-boiling compounds in the resin at a pressure of 133 to 13.3 Pa and a temperature of 200 to 320 ° C may be provided.

<Optical lens>
The optical lens of the present invention can be molded by, for example, injection molding, compression molding, injection compression molding, or casting of the copolymer of the present invention.
The optical lens of the present invention may contain various additives in order to impart various characteristics within a range that does not impair the object of the present invention. Additives include mold release agents, heat stabilizers, UV absorbers, bluing agents, antistatic agents, flame retardants, heat ray shielding agents, fluorescent dyes (including fluorescent whitening agents), pigments, light diffusing agents, reinforcing fillers Other resins and elastomers can be blended.
The amount of the ester in the release agent is preferably 90% by weight or more, and more preferably 95% by weight or more when the release agent is 100% by weight.

The release agent content in the optical lens of the present invention is preferably in the range of 0.005 to 2.0 parts by weight, more preferably in the range of 0.01 to 0.6 parts by weight with respect to 100 parts by weight of the copolymer. The range of 0.02 to 0.5 parts by weight is more preferable.
Examples of the heat stabilizer include a phosphorus heat stabilizer, a sulfur heat stabilizer, and a hindered phenol heat stabilizer.
The content of the phosphorus-based heat stabilizer in the copolymer is preferably 0.001 to 0.2 parts by weight with respect to 100 parts by weight of the copolymer.
As for content of the sulfur type heat stabilizer in a copolymer, 0.001-0.2 weight part is preferable with respect to 100 weight part of copolymers.

About a heat stabilizer, a phosphorus stabilizer or a hindered phenol heat stabilizer is preferable. By adding 0.001 to 0.3 parts by weight of a phosphorus stabilizer or a hindered phenol heat stabilizer to 100 parts by weight of the copolymer, heat and moisture resistance is improved. The phosphorus stabilizer and the hindered phenol heat stabilizer can be used in combination.
The content of the ultraviolet absorber is preferably 0.01 to 3.0 parts by weight, more preferably 0.02 to 1.0 parts by weight, even more preferably 100 parts by weight of the copolymer. 0.05 to 0.8 part by weight. If it is the range of this compounding quantity, it is possible to provide sufficient weather resistance to a copolymer molded object according to a use.

Examples of the bluing agent include Macrolex Violet B and Macrolex Blue RR manufactured by Bayer and polysynthremble-RLS manufactured by Clariant. The bluing agent is effective for eliminating the yellow color of the copolymer. In particular, in the case of a copolymer imparted with weather resistance, since a certain amount of UV absorber is blended, there is a reality that the molded body tends to be yellowish depending on the action and color of the UV absorber, especially in sheets and lenses. In order to give a natural transparency, blending of a bluing agent is very effective.
The blending amount of the bluing agent is preferably 0.05 to 1.5 ppm, more preferably 0.1 to 1.2 ppm based on the copolymer.

  In order to add various additives to the polyester carbonate copolymer in the present invention, a known method can be used. For example, a method of mixing each component in a solution state and evaporating the solvent or precipitating in the solvent can be mentioned. From an industrial point of view, a method of kneading each component in a molten state is preferable. For melt kneading, generally used kneading apparatuses such as a single or twin screw extruder and various kneaders can be used. A twin screw extruder is particularly preferred. In melt kneading, the cylinder set temperature of the kneading device is preferably in the range of 200 to 340 ° C, more preferably 250 to 320 ° C. When it is higher than 320 ° C., the polyester carbonate copolymer is decomposed, and coloring and molding defects due to decomposition products increase, which is not preferable. Furthermore, if it is less than 200 degreeC, the viscosity of a polyester carbonate copolymer is high, and various additives cannot be disperse | distributed uniformly. The melt kneading may be performed in a vacuum state. Melting and kneading in a vacuum state is preferable because low molecular weight substances such as residual phenol in the polyester carbonate copolymer are reduced and molding defects can be reduced. The degree of vacuum is preferably a pressure of 13.3 kPa or less, and more preferably 1.3 kPa or less.

At the time of kneading, each component may be mixed uniformly in advance with a device such as a tumbler or a Henschel mixer, or if necessary, a method of omitting the mixing and separately supplying each of the components separately to the kneading device is also used. be able to.
In addition, the optical lens of the present invention is characterized by a small optical distortion. An optical lens made of a general bisphenol A type polyester carbonate resin has a large optical distortion. Although it is not impossible to reduce the value depending on molding conditions, the condition width is very small and molding becomes very difficult. The polyester carbonate copolymer of the present invention has a very small optical strain caused by the orientation of the resin and also has a small molding strain. Therefore, a good optical element can be obtained without setting molding conditions strictly.

When the optical lens of the present invention is manufactured by injection molding, it is preferable to mold it under conditions of a cylinder temperature of 260 to 320 ° C and a mold temperature of 100 to 140 ° C.
The optical lens of the present invention is preferably used in the form of an aspheric lens as necessary. Since an aspheric lens can substantially eliminate spherical aberration with a single lens, there is no need to remove spherical aberration with a combination of a plurality of spherical lenses, thus reducing weight and reducing production costs. It becomes possible. Therefore, the aspherical lens is particularly useful as a camera lens among optical lenses.

  Further, since the copolymer of the present invention has high fluidity, it is particularly useful as a material for an optical lens having a thin, small and complicated shape. As a specific lens size, the thickness of the central portion is 0.05 to 3.0 mm, more preferably 0.05 to 2.0 mm, and still more preferably 0.1 to 2.0 mm. Moreover, a diameter is 1.0 mm-20.0 mm, More preferably, it is 1.0-10.0 mm, More preferably, it is 3.0-10.0 mm. In addition, it is preferably a meniscus lens having a convex surface on one side and a concave surface on the other side.

On the surface of the optical lens of the present invention, a coating layer such as an antireflection layer or a hard coating layer may be provided as necessary. The antireflection layer may be a single layer or a multilayer, and may be organic or inorganic, but is preferably inorganic. Specific examples include oxides or fluorides such as silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, cerium oxide, magnesium oxide, and magnesium fluoride.
Moreover, the optical lens of the present invention may be molded by any method such as mold molding, cutting, polishing, laser processing, electric discharge machining, and edging. Furthermore, mold molding is more preferable.

The following examples further illustrate the present invention.
An evaluation sample was prepared by the following method.

(A) Cast film:
5 g of the obtained polyester carbonate copolymer is dissolved in 50 ml of methylene chloride and cast on a glass petri dish. After sufficiently drying at room temperature, the polyester carbonate copolymer was dried at a temperature of Tg-20 ° C. for 8 hours. A cast film was created.

(B) Lens:
The obtained polyester carbonate copolymer was vacuum-dried at 120 ° C. for 8 hours, and then the thickness was measured using a SE30DU injection molding machine manufactured by Sumitomo Heavy Industries, Ltd. at a molding temperature Tg + 110 ° C. and a mold temperature Tg−10 ° C. A lens having 0.3 mm, a convex curvature radius of 5 mm, a concave curvature radius of 4 mm, and Φ5 mm was injection molded.

(C) Molded Piece As in the case of (b) above, molded pieces having a width of 2.5 cm, a length of 5 cm, and thicknesses of 0.3, 1, 2, and 3 mm, respectively, were injection molded.

Evaluation was based on the following method.
(1) Specific viscosity: The polyester carbonate copolymer pellets obtained after the completion of polymerization were sufficiently dried, and from a solution in which 0.7 g of the pellets were dissolved in 100 ml of methylene chloride, the specific viscosity (η _sp ) Was measured.

(2) Copolymerization ratio: The polyester carbonate copolymer pellet obtained after completion of the polymerization was measured using proton NMR of JNM-AL400 manufactured by JEOL Ltd. It calculated | required from the integral ratio resulting from the peak resulting from ethylene of a spirofluorene derivative of 3.2-4.8 ppm and 8.2-8.0 ppm.

(3) Glass transition point (Tg): The polyester carbonate copolymer pellets were measured by DuPont 910 type DSC at a heating rate of 20 ° C./min.

(4) Spectral transmittance: A 2 mm-thick disk obtained by injection molding was measured using a spectrophotometer U-3310 manufactured by Hitachi, Ltd. Evaluation was performed as follows.
The transmittance at 395 nm is 80% or more:
Transmittance at 395 nm is below 80%: x

(5) Refractive index (nd): A 0.3 mm-thick molded piece obtained by injection molding according to the method of (b) was used for refractive index (wavelength at 25 ° C.) using an ATAGO DR-M2 Abbe refractometer : 589 nm).

(6) Optical distortion: A lens molded by the method of (b) was sandwiched between two polarizing plates, and optical distortion was evaluated by visually observing light leakage from behind by the crossed Nicols method. Evaluation was performed according to the following criteria.
A: There is almost no light leakage.
○: Slight light leakage is observed.
X: Light leakage is remarkable.

(7) Moldability: The lens molded by the method of (b) was checked for filling defects, molding defects, lens brittleness, presence of mold deposits, and the like. Evaluation was classified according to the probability of being defective when 500 sheets were formed, with less than 1% (）), 1 to 5% (◯) 5 to 20% (Δ), and 20% or less (x).

(8) Moisture and heat resistance: After leaving a molded piece having a thickness of 1 mm under conditions of 85 ° C. and 85% RH for 2000 hours, from a solution of 0.7 g of the molded piece dissolved in 100 ml of methylene chloride, the solution at 20 ° C. The specific viscosity (ηsp) was measured, and the specific viscosity retention rate (molecular weight retention rate) after the wet heat test was determined. The specific viscosity retention rate (molecular weight retention rate) was used as an index of moisture and heat resistance.
Δηsp ₁ = (ηsp _1-1 / ηsp _0-1 ) × 100
Δηsp ₁ : specific viscosity retention, ηsp _0-1 : specific viscosity before test, ηsp _1-1 : specific viscosity after test

(9) Thermal stability (heat retention test): After the copolymer was heated and melted at a molding temperature Tg + 110 ° C. for 10 minutes with a SE30DU injection molding machine manufactured by Sumitomo Heavy Industries, Ltd., a mold temperature Tg-10 A molded product having a width of 2.5 cm, a length of 5 cm, and a thickness of 2 mm was formed at a temperature of 5 ° C. From a solution obtained by dissolving 0.7 g of the molded piece in 100 ml of methylene chloride, the specific viscosity (ηsp) of the solution at 20 ° C. was measured to determine the specific viscosity retention rate (molecular weight retention rate). The specific viscosity retention rate (molecular weight retention rate) was used as an index of heat resistance.
Δηsp ₂ = (ηsp _1-2 / ηsp _0-2 ) × 100
Δηsp ₂ : specific viscosity retention, ηsp _0-2 : specific viscosity before test, ηsp1 _-2 : specific viscosity after test

(10) Residual phenol content The diol content in the polyester carbonate copolymer obtained after polymerization was mixed with eluent acetonitrile / 0.2% acetic acid water and acetonitrile in a column of Develosil ODS-7 manufactured by Nomura Chemical. Using the solution, HPLC analysis was performed with a gradient program at a column temperature of 30 ° C. and a detector of 277 nm. Phenol was quantified by preparing a calibration curve using a standard. For measurement, 1.5 g of polyester carbonate copolymer was dissolved in 15 ml of methylene chloride, 135 ml of acetonitrile was added and stirred, concentrated with an evaporator, filtered through a 0.2 μm filter, and 10 μl of this measurement solution was injected. I went.
The measurement limit is 1 ppm.

Example 1
414.7 parts by weight of 2,2′-bis ((hydroxyethoxy) 9,9′-spirobi (9H-fluorene)) (hereinafter sometimes abbreviated as “BESF”), dimethyl naphthalenedicarboxylate (hereinafter “NDCM”) 12.2 parts by weight of diphenyl carbonate (hereinafter may be abbreviated as “DPC”) 213.7 parts by weight, and 5.10 × 10 ⁻² parts by weight of titanium butoxide. It put into the reaction kettle with an apparatus, and heated at 180 degreeC under nitrogen atmosphere normal pressure, and stirred for 20 minutes. Thereafter, the degree of vacuum was adjusted to 20 to 30 kPa over 20 minutes, and the temperature was raised to 260 ° C. at a rate of 60 ° C./hr to conduct a transesterification reaction. Thereafter, while maintaining the temperature at 260 ° C., the pressure was reduced to 0.13 kPa or less over 120 minutes, and the polymerization reaction was performed with stirring for 1 hour under the conditions of 260 ° C. and 0.13 kPa or less.
The polyester carbonate had a molar ratio of BESF to NDCM of 95: 5.
The prepared polymer was vacuum-dried at 120 ° C. for 4 hours, and then bis (2,4-dicumylphenyl) pentaerythritol diphosphite 0.050% and pentaerythritol tetrastearate based on the weight of the resulting resin composition. 0.10% was added and pelletized using a vented φ30 mm single screw extruder. The heat and humidity resistance was good, the specific viscosity retention after the wet heat test was 90%, the heat resistance was also good, the specific viscosity retention after the heat resistance test was 85%, and the residual phenol content was below the measurement limit. The evaluation results are shown in Table 1.

Example 2
Polymerization was carried out in the same manner as in Example 1 except that 327.4 parts by weight of BESF, 61.1 parts by weight of NDCM, and 168.7 parts by weight of DPC were used.
The polyester carbonate had a molar ratio of BESF to NDCM of 75:25.
The prepared polymer was vacuum-dried at 120 ° C. for 4 hours, and then bis (2,4-dicumylphenyl) pentaerythritol diphosphite 0.050% and pentaerythritol tetrastearate based on the weight of the resulting resin composition. 0.10% was added and pelletized using a vented φ30 mm single screw extruder. The heat and humidity resistance was good, the specific viscosity retention after the wet heat test was 90%, the heat resistance was also good, the specific viscosity retention after the heat resistance test was 90%, and the residual phenol content was below the measurement limit. The evaluation results are shown in Table 1.

Example 3
Polymerization was conducted in the same manner as in Example 1 except that BESF 240.1 parts, NDCM 109.9 parts, and DPC 123.7 parts were used.
The polyester carbonate had a BESF to NDCM molar ratio of 45:55.
The prepared polymer was vacuum-dried at 120 ° C. for 4 hours, and then bis (2,4-dicumylphenyl) pentaerythritol diphosphite 0.050% and pentaerythritol tetrastearate based on the weight of the resulting resin composition. 0.10% was added and pelletized using a vented φ30 mm single screw extruder. The heat and humidity resistance was good, the specific viscosity retention after the wet heat test was 95%, the heat resistance was also good, the specific viscosity retention after the heat resistance test was 85%, and the residual phenol content was below the measurement limit. The evaluation results are shown in Table 1.

Example 4
Polymerization was carried out in the same manner as in Example 1 except that 414.7 parts by weight of BESF, 9.8 parts by weight of dimethyl terephthalic acid (hereinafter may be abbreviated as “DMT”), and 213.7 parts by weight of DPC.
The polyester carbonate had a molar ratio of BESF to DMT of 95: 5.
The prepared polymer was vacuum-dried at 120 ° C. for 4 hours, and then bis (2,4-dicumylphenyl) pentaerythritol diphosphite 0.050% and pentaerythritol tetrastearate based on the weight of the resulting resin composition. 0.10% was added and pelletized using a vented φ30 mm single screw extruder. The heat and humidity resistance was good, the specific viscosity retention after the wet heat test was 95%, the heat resistance was good, the specific viscosity retention after the heat resistance test was 90%, and the residual phenol content was below the measurement limit. The evaluation results are shown in Table 1.

Example 5
Polymerization was carried out in the same manner as in Example 1 except that 327.4 parts by weight of BESF, 48.5 parts by weight of DMT, and 168.7 parts by weight of DPC were used.
The polyester carbonate had a molar ratio of BESF to DMT of 95: 5.
The prepared polymer was vacuum-dried at 120 ° C. for 4 hours, and then bis (2,4-dicumylphenyl) pentaerythritol diphosphite 0.050% and pentaerythritol tetrastearate based on the weight of the resulting resin composition. 0.10% was added and pelletized using a vented φ30 mm single screw extruder. The wet heat resistance was good, and the specific viscosity retention after the wet heat test was 85%. Further, the heat resistance was good, the specific viscosity retention after the heat resistance test was 90%, and the residual phenol content was below the measurement limit. The evaluation results are shown in Table 1.

Example 6
Polymerization was conducted in the same manner as in Example 1 except that 240.1 parts by weight of BESF, 87.38 parts by weight of DMT, and 123.7 parts by weight of DPC were used.
The polyester carbonate had a molar ratio of BESF to DMT of 55:45.
The prepared polymer was vacuum-dried at 120 ° C. for 4 hours, and then bis (2,4-dicumylphenyl) pentaerythritol diphosphite 0.050% and pentaerythritol tetrastearate based on the weight of the resulting resin composition. 0.10% was added and pelletized using a vented φ30 mm single screw extruder. The wet heat resistance was good, and the specific viscosity retention after the wet heat test was 80%. Further, the heat resistance was good, the specific viscosity retention after the heat resistance test was 85%, and the residual phenol content was below the measurement limit. The evaluation results are shown in Table 1.

Comparative Example 1
A 20 mL Schlenk type reaction tube was charged with 0.80 part by weight of BESF, 0.39 part by weight of diphenyl carbonate and 0.002 part by weight of 4-dimethylaminopyridine in an argon atmosphere, and the mixture was heated and stirred at 180 ° C. for 30 minutes. Furthermore, the reaction temperature was gradually raised as the pressure in the reaction vessel was reduced stepwise (400 hPa, 200 ° C. for 20 minutes, 20 minutes at 160 hPa, 220 ° C., 20 minutes at 40 hPa, 230 ° C.) Stir for 30 minutes at 1 hPa, 250 ° C. for 30 minutes). The evaluation results are shown in Table 1.

Comparative Example 2
BESF 1.80 parts by weight in a 20 mL Schlenk type reaction tube under argon atmosphere, 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene (hereinafter sometimes abbreviated as “BPEF”) 0.201 parts by weight , DPC (0.981 parts by weight) and 4-dimethylaminopyridine (0.056 parts by weight) were added and polymerized in the same manner as in Comparative Example 1. The evaluation results are shown in Table 1.

Comparative Example 3
A 20 mL Schlenk type reaction tube was charged with 1.50 parts by weight of BESF, 0.502 parts by weight of BPEF, 0.981 parts by weight of DPC, and 0.56 parts by weight of 4-dimethylaminopyridine in an argon atmosphere and polymerized in the same manner as in Comparative Example 1. .
The obtained polycarbonate copolymer had a molar ratio of BESF to BPEF of 75:25. The evaluation results are shown in Table 1.

Comparative Example 4
BPEF 157.86 parts by weight, dimethyl 2,6-naphthalenedicarboxylate (hereinafter sometimes abbreviated as “NDCM”) 9.77 parts by weight, DPC 71.98 parts by weight, sodium hydroxide 8 × 10 ⁻⁶ parts by weight and tetra 3.65 × 10 ⁻³ parts by weight of methylammonium hydroxide was placed in a reaction kettle equipped with a stirrer and a distillation apparatus, heated to 180 ° C. under a nitrogen atmosphere of 760 Torr, and stirred for 20 minutes. Thereafter, the degree of vacuum was adjusted to 20 kPa over 20 minutes, and the temperature was raised to 250 ° C. at a rate of 60 ° C./hr to conduct a transesterification reaction. Thereafter, while maintaining the temperature at 250 ° C., the pressure was reduced to 1 Torr or less over 60 minutes, and the polymerization reaction was carried out for 1 hour under stirring at 250 ° C. and 1 Torr or less.
After completion of the reaction, nitrogen was blown into the reactor to increase the pressure, and then 1.54 × 10 ⁻⁴ parts by weight of tetrabutylphosphonium dodecylbenzenesulfonate was added to deactivate the catalyst. Thereafter, the produced polyester carbonate copolymer was extracted while pelletizing. The polyester carbonate copolymer had a molar ratio of BPEF to NDCM of 90:10.
The prepared polymer was vacuum-dried at 120 ° C. for 4 hours, and then added with 0.050% bis (2,4-dicumylphenyl) pentaerythritol diphosphite and 0.10% pentaerythritol tetrastearate, and vented. Pelletized using a φ30 mm single screw extruder. The evaluation results are shown in Table 1.

  Since the polyester carbonate copolymer obtained in Examples 1 to 6 has an extremely high refractive index and good molding fluidity, the optical distortion of the optical lens obtained by injection molding is small. Furthermore, it has sufficient heat resistance and is excellent as an optical lens. On the other hand, the polymers obtained in Comparative Examples 1, 2, and 3 have a large light leakage and are inferior in performance as an optical lens. In Comparative Examples 2 and 3, the specific viscosity is low, the lens is brittle, and the moldability is poor. Furthermore, the polymer obtained in Comparative Example 4 has a low refractive index and is limited in use.

  The polycarbonate of the present invention has high transparency, high refractive index, low birefringence and high fluidity, and optical lenses such as various cameras such as digital video cameras, telescopes, binoculars, TV projectors, prisms and the like are conventionally expensive. It can be used in fields where high refractive index glass lenses have been used, and is extremely useful.

Claims (9)

The total of all structural units is 100 mol%, the unit represented by the following formula (I) containing 95 to 5 mol%, and the unit represented by the following formula (II) contains 5 to 95 mol%, the ratio A polyester carbonate copolymer having a viscosity of 0.18 to 0.35 .

(R _{1 to} R ₂ in the formula are each a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or 2 to 6 carbon atoms. An alkenyl group, an alkoxy group having 1 to 6 carbon atoms or an aralkyl group having 7 to 17 carbon atoms, n and m are integers of 1 to 10.)

(Y in the formula is a 2,6-naphthalenediyl group or a 1,4-phenylene group .) The polyester carbonate copolymer according to claim 1 , wherein the structural unit represented by the formula (I) has a spirobifluorene structure. Polyester carbonate copolymer according to claim 1 or 2 having a refractive index of 1.650 to 1.675. Polyester carbonate copolymer according to any one of claims 1 to 3 orientation birefringence is 0 to 1 × ^{10 -2.} Glass transition temperature, the polyester carbonate copolymer according to any one of claims 1 to 4, which is 140 to 170 ° C.. The polyester carbonate copolymer according to any one of claims 1 to 5 , wherein the phenol content is 1 to 500 ppm. An optical member comprising the polyester carbonate copolymer according to any one of claims 1 to 6 . An optical lens comprising the polyester carbonate copolymer according to any one of claims 1 to 6 . The optical lens according to claim 8 , wherein the thickness of the central portion is 0.05 to 3.0 mm and the diameter of the lens portion is 1.0 to 20.0 mm.